Actual source code: dm.c

      1: #include <petscvec.h>
      2: #include <petsc/private/dmimpl.h>
      3: #include <petsc/private/dmlabelimpl.h>
      4: #include <petsc/private/petscdsimpl.h>
      5: #include <petscdmplex.h>
      6: #include <petscdmceed.h>
      7: #include <petscdmfield.h>
      8: #include <petscsf.h>
      9: #include <petscds.h>

     11: #ifdef PETSC_HAVE_LIBCEED
     12: #include <petscfeceed.h>
     13: #endif

     15: PetscClassId DM_CLASSID;
     16: PetscClassId DMLABEL_CLASSID;
     17: PetscLogEvent DM_Convert, DM_GlobalToLocal, DM_LocalToGlobal, DM_LocalToLocal, DM_LocatePoints, DM_Coarsen, DM_Refine, DM_CreateInterpolation, DM_CreateRestriction, DM_CreateInjection, DM_CreateMatrix, DM_CreateMassMatrix, DM_Load, DM_View, DM_AdaptInterpolator, DM_ProjectFunction;

     19: const char *const DMBoundaryTypes[]          = {"NONE", "GHOSTED", "MIRROR", "PERIODIC", "TWIST", "DMBoundaryType", "DM_BOUNDARY_", NULL};
     20: const char *const DMBoundaryConditionTypes[] = {"INVALID", "ESSENTIAL", "NATURAL", "INVALID", "LOWER_BOUND", "ESSENTIAL_FIELD", "NATURAL_FIELD", "INVALID", "UPPER_BOUND", "ESSENTIAL_BD_FIELD", "NATURAL_RIEMANN", "DMBoundaryConditionType",
     21:                                                 "DM_BC_",  NULL};
     22: const char *const DMBlockingTypes[]          = {"TOPOLOGICAL_POINT", "FIELD_NODE", "DMBlockingType", "DM_BLOCKING_", NULL};
     23: const char *const DMPolytopeTypes[] =
     24:   {"vertex",  "segment",      "tensor_segment", "triangle", "quadrilateral",  "tensor_quad",  "tetrahedron", "hexahedron", "triangular_prism", "tensor_triangular_prism", "tensor_quadrilateral_prism", "pyramid", "FV_ghost_cell", "interior_ghost_cell",
     25:    "unknown", "unknown_cell", "unknown_face",   "invalid",  "DMPolytopeType", "DM_POLYTOPE_", NULL};
     26: const char *const DMCopyLabelsModes[] = {"replace", "keep", "fail", "DMCopyLabelsMode", "DM_COPY_LABELS_", NULL};

     28: /*@
     29:   DMCreate - Creates an empty `DM` object. `DM`s are the abstract objects in PETSc that mediate between meshes and discretizations and the
     30:   algebraic solvers, time integrators, and optimization algorithms in PETSc.

     32:   Collective

     34:   Input Parameter:
     35: . comm - The communicator for the `DM` object

     37:   Output Parameter:
     38: . dm - The `DM` object

     40:   Level: beginner

     42:   Notes:
     43:   See `DMType` for a brief summary of available `DM`.

     45:   The type must then be set with `DMSetType()`. If you never call `DMSetType()` it will generate an
     46:   error when you try to use the `dm`.

     48:   `DM` is an orphan initialism or orphan acronym, the letters have no meaning and never did.

     50: .seealso: [](ch_dmbase), `DM`, `DMSetType()`, `DMType`, `DMDACreate()`, `DMDA`, `DMSLICED`, `DMCOMPOSITE`, `DMPLEX`, `DMMOAB`, `DMNETWORK`
     51: @*/
     52: PetscErrorCode DMCreate(MPI_Comm comm, DM *dm)
     53: {
     54:   DM      v;
     55:   PetscDS ds;

     57:   PetscFunctionBegin;
     58:   PetscAssertPointer(dm, 2);

     60:   PetscCall(DMInitializePackage());
     61:   PetscCall(PetscHeaderCreate(v, DM_CLASSID, "DM", "Distribution Manager", "DM", comm, DMDestroy, DMView));
     62:   ((PetscObject)v)->non_cyclic_references = &DMCountNonCyclicReferences;
     63:   v->setupcalled                          = PETSC_FALSE;
     64:   v->setfromoptionscalled                 = PETSC_FALSE;
     65:   v->ltogmap                              = NULL;
     66:   v->bind_below                           = 0;
     67:   v->bs                                   = 1;
     68:   v->coloringtype                         = IS_COLORING_GLOBAL;
     69:   PetscCall(PetscSFCreate(comm, &v->sf));
     70:   PetscCall(PetscSFCreate(comm, &v->sectionSF));
     71:   v->labels                    = NULL;
     72:   v->adjacency[0]              = PETSC_FALSE;
     73:   v->adjacency[1]              = PETSC_TRUE;
     74:   v->depthLabel                = NULL;
     75:   v->celltypeLabel             = NULL;
     76:   v->localSection              = NULL;
     77:   v->globalSection             = NULL;
     78:   v->defaultConstraint.section = NULL;
     79:   v->defaultConstraint.mat     = NULL;
     80:   v->defaultConstraint.bias    = NULL;
     81:   v->coordinates[0].dim        = PETSC_DEFAULT;
     82:   v->coordinates[1].dim        = PETSC_DEFAULT;
     83:   v->sparseLocalize            = PETSC_TRUE;
     84:   v->dim                       = PETSC_DETERMINE;
     85:   PetscCall(PetscDSCreate(PETSC_COMM_SELF, &ds));
     86:   PetscCall(DMSetRegionDS(v, NULL, NULL, ds, NULL));
     87:   PetscCall(PetscDSDestroy(&ds));
     88:   PetscCall(PetscHMapAuxCreate(&v->auxData));
     89:   v->dmBC              = NULL;
     90:   v->coarseMesh        = NULL;
     91:   v->outputSequenceNum = -1;
     92:   v->outputSequenceVal = 0.0;
     93:   PetscCall(DMSetVecType(v, VECSTANDARD));
     94:   PetscCall(DMSetMatType(v, MATAIJ));

     96:   *dm = v;
     97:   PetscFunctionReturn(PETSC_SUCCESS);
     98: }

    100: /*@
    101:   DMClone - Creates a `DM` object with the same topology as the original.

    103:   Collective

    105:   Input Parameter:
    106: . dm - The original `DM` object

    108:   Output Parameter:
    109: . newdm - The new `DM` object

    111:   Level: beginner

    113:   Notes:
    114:   For some `DM` implementations this is a shallow clone, the result of which may share (reference counted) information with its parent. For example,
    115:   `DMClone()` applied to a `DMPLEX` object will result in a new `DMPLEX` that shares the topology with the original `DMPLEX`. It does not
    116:   share the `PetscSection` of the original `DM`.

    118:   The clone is considered set up if the original has been set up.

    120:   Use `DMConvert()` for a general way to create new `DM` from a given `DM`

    122: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMCreate()`, `DMSetType()`, `DMSetLocalSection()`, `DMSetGlobalSection()`, `DMPLEX`, `DMConvert()`
    123: @*/
    124: PetscErrorCode DMClone(DM dm, DM *newdm)
    125: {
    126:   PetscSF              sf;
    127:   Vec                  coords;
    128:   void                *ctx;
    129:   MatOrderingType      otype;
    130:   DMReorderDefaultFlag flg;
    131:   PetscInt             dim, cdim, i;

    133:   PetscFunctionBegin;
    135:   PetscAssertPointer(newdm, 2);
    136:   PetscCall(DMCreate(PetscObjectComm((PetscObject)dm), newdm));
    137:   PetscCall(DMCopyLabels(dm, *newdm, PETSC_COPY_VALUES, PETSC_TRUE, DM_COPY_LABELS_FAIL));
    138:   (*newdm)->leveldown     = dm->leveldown;
    139:   (*newdm)->levelup       = dm->levelup;
    140:   (*newdm)->prealloc_only = dm->prealloc_only;
    141:   (*newdm)->prealloc_skip = dm->prealloc_skip;
    142:   PetscCall(PetscFree((*newdm)->vectype));
    143:   PetscCall(PetscStrallocpy(dm->vectype, (char **)&(*newdm)->vectype));
    144:   PetscCall(PetscFree((*newdm)->mattype));
    145:   PetscCall(PetscStrallocpy(dm->mattype, (char **)&(*newdm)->mattype));
    146:   PetscCall(DMGetDimension(dm, &dim));
    147:   PetscCall(DMSetDimension(*newdm, dim));
    148:   PetscTryTypeMethod(dm, clone, newdm);
    149:   (*newdm)->setupcalled = dm->setupcalled;
    150:   PetscCall(DMGetPointSF(dm, &sf));
    151:   PetscCall(DMSetPointSF(*newdm, sf));
    152:   PetscCall(DMGetApplicationContext(dm, &ctx));
    153:   PetscCall(DMSetApplicationContext(*newdm, ctx));
    154:   PetscCall(DMReorderSectionGetDefault(dm, &flg));
    155:   PetscCall(DMReorderSectionSetDefault(*newdm, flg));
    156:   PetscCall(DMReorderSectionGetType(dm, &otype));
    157:   PetscCall(DMReorderSectionSetType(*newdm, otype));
    158:   for (i = 0; i < 2; ++i) {
    159:     if (dm->coordinates[i].dm) {
    160:       DM           ncdm;
    161:       PetscSection cs;
    162:       PetscInt     pEnd = -1, pEndMax = -1;

    164:       PetscCall(DMGetLocalSection(dm->coordinates[i].dm, &cs));
    165:       if (cs) PetscCall(PetscSectionGetChart(cs, NULL, &pEnd));
    166:       PetscCallMPI(MPIU_Allreduce(&pEnd, &pEndMax, 1, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)dm)));
    167:       if (pEndMax >= 0) {
    168:         PetscCall(DMClone(dm->coordinates[i].dm, &ncdm));
    169:         PetscCall(DMCopyDisc(dm->coordinates[i].dm, ncdm));
    170:         PetscCall(DMSetLocalSection(ncdm, cs));
    171:         if (dm->coordinates[i].dm->periodic.setup) {
    172:           ncdm->periodic.setup = dm->coordinates[i].dm->periodic.setup;
    173:           PetscCall(ncdm->periodic.setup(ncdm));
    174:         }
    175:         if (i) PetscCall(DMSetCellCoordinateDM(*newdm, ncdm));
    176:         else PetscCall(DMSetCoordinateDM(*newdm, ncdm));
    177:         PetscCall(DMDestroy(&ncdm));
    178:       }
    179:     }
    180:   }
    181:   PetscCall(DMGetCoordinateDim(dm, &cdim));
    182:   PetscCall(DMSetCoordinateDim(*newdm, cdim));
    183:   PetscCall(DMGetCoordinatesLocal(dm, &coords));
    184:   if (coords) {
    185:     PetscCall(DMSetCoordinatesLocal(*newdm, coords));
    186:   } else {
    187:     PetscCall(DMGetCoordinates(dm, &coords));
    188:     if (coords) PetscCall(DMSetCoordinates(*newdm, coords));
    189:   }
    190:   PetscCall(DMGetCellCoordinatesLocal(dm, &coords));
    191:   if (coords) {
    192:     PetscCall(DMSetCellCoordinatesLocal(*newdm, coords));
    193:   } else {
    194:     PetscCall(DMGetCellCoordinates(dm, &coords));
    195:     if (coords) PetscCall(DMSetCellCoordinates(*newdm, coords));
    196:   }
    197:   {
    198:     const PetscReal *maxCell, *Lstart, *L;

    200:     PetscCall(DMGetPeriodicity(dm, &maxCell, &Lstart, &L));
    201:     PetscCall(DMSetPeriodicity(*newdm, maxCell, Lstart, L));
    202:   }
    203:   {
    204:     PetscBool useCone, useClosure;

    206:     PetscCall(DMGetAdjacency(dm, PETSC_DEFAULT, &useCone, &useClosure));
    207:     PetscCall(DMSetAdjacency(*newdm, PETSC_DEFAULT, useCone, useClosure));
    208:   }
    209:   PetscFunctionReturn(PETSC_SUCCESS);
    210: }

    212: /*@
    213:   DMSetVecType - Sets the type of vector to be created with `DMCreateLocalVector()` and `DMCreateGlobalVector()`

    215:   Logically Collective

    217:   Input Parameters:
    218: + dm    - initial distributed array
    219: - ctype - the vector type, for example `VECSTANDARD`, `VECCUDA`, or `VECVIENNACL`

    221:   Options Database Key:
    222: . -dm_vec_type ctype - the type of vector to create

    224:   Level: intermediate

    226: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMDestroy()`, `DMDAInterpolationType`, `VecType`, `DMGetVecType()`, `DMSetMatType()`, `DMGetMatType()`,
    227:           `VECSTANDARD`, `VECCUDA`, `VECVIENNACL`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`
    228: @*/
    229: PetscErrorCode DMSetVecType(DM dm, VecType ctype)
    230: {
    231:   char *tmp;

    233:   PetscFunctionBegin;
    235:   PetscAssertPointer(ctype, 2);
    236:   tmp = (char *)dm->vectype;
    237:   PetscCall(PetscStrallocpy(ctype, (char **)&dm->vectype));
    238:   PetscCall(PetscFree(tmp));
    239:   PetscFunctionReturn(PETSC_SUCCESS);
    240: }

    242: /*@
    243:   DMGetVecType - Gets the type of vector created with `DMCreateLocalVector()` and `DMCreateGlobalVector()`

    245:   Logically Collective

    247:   Input Parameter:
    248: . da - initial distributed array

    250:   Output Parameter:
    251: . ctype - the vector type

    253:   Level: intermediate

    255: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMDestroy()`, `DMDAInterpolationType`, `VecType`, `DMSetMatType()`, `DMGetMatType()`, `DMSetVecType()`
    256: @*/
    257: PetscErrorCode DMGetVecType(DM da, VecType *ctype)
    258: {
    259:   PetscFunctionBegin;
    261:   *ctype = da->vectype;
    262:   PetscFunctionReturn(PETSC_SUCCESS);
    263: }

    265: /*@
    266:   VecGetDM - Gets the `DM` defining the data layout of the vector

    268:   Not Collective

    270:   Input Parameter:
    271: . v - The `Vec`

    273:   Output Parameter:
    274: . dm - The `DM`

    276:   Level: intermediate

    278:   Note:
    279:   A `Vec` may not have a `DM` associated with it.

    281: .seealso: [](ch_dmbase), `DM`, `VecSetDM()`, `DMGetLocalVector()`, `DMGetGlobalVector()`, `DMSetVecType()`
    282: @*/
    283: PetscErrorCode VecGetDM(Vec v, DM *dm)
    284: {
    285:   PetscFunctionBegin;
    287:   PetscAssertPointer(dm, 2);
    288:   PetscCall(PetscObjectQuery((PetscObject)v, "__PETSc_dm", (PetscObject *)dm));
    289:   PetscFunctionReturn(PETSC_SUCCESS);
    290: }

    292: /*@
    293:   VecSetDM - Sets the `DM` defining the data layout of the vector.

    295:   Not Collective

    297:   Input Parameters:
    298: + v  - The `Vec`
    299: - dm - The `DM`

    301:   Level: developer

    303:   Notes:
    304:   This is rarely used, generally one uses `DMGetLocalVector()` or  `DMGetGlobalVector()` to create a vector associated with a given `DM`

    306:   This is NOT the same as `DMCreateGlobalVector()` since it does not change the view methods or perform other customization, but merely sets the `DM` member.

    308: .seealso: [](ch_dmbase), `DM`, `VecGetDM()`, `DMGetLocalVector()`, `DMGetGlobalVector()`, `DMSetVecType()`
    309: @*/
    310: PetscErrorCode VecSetDM(Vec v, DM dm)
    311: {
    312:   PetscFunctionBegin;
    315:   PetscCall(PetscObjectCompose((PetscObject)v, "__PETSc_dm", (PetscObject)dm));
    316:   PetscFunctionReturn(PETSC_SUCCESS);
    317: }

    319: /*@
    320:   DMSetISColoringType - Sets the type of coloring, `IS_COLORING_GLOBAL` or `IS_COLORING_LOCAL` that is created by the `DM`

    322:   Logically Collective

    324:   Input Parameters:
    325: + dm    - the `DM` context
    326: - ctype - the matrix type

    328:   Options Database Key:
    329: . -dm_is_coloring_type - global or local

    331:   Level: intermediate

    333: .seealso: [](ch_dmbase), `DM`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `MatType`, `DMGetMatType()`,
    334:           `DMGetISColoringType()`, `ISColoringType`, `IS_COLORING_GLOBAL`, `IS_COLORING_LOCAL`
    335: @*/
    336: PetscErrorCode DMSetISColoringType(DM dm, ISColoringType ctype)
    337: {
    338:   PetscFunctionBegin;
    340:   dm->coloringtype = ctype;
    341:   PetscFunctionReturn(PETSC_SUCCESS);
    342: }

    344: /*@
    345:   DMGetISColoringType - Gets the type of coloring, `IS_COLORING_GLOBAL` or `IS_COLORING_LOCAL` that is created by the `DM`

    347:   Logically Collective

    349:   Input Parameter:
    350: . dm - the `DM` context

    352:   Output Parameter:
    353: . ctype - the matrix type

    355:   Options Database Key:
    356: . -dm_is_coloring_type - global or local

    358:   Level: intermediate

    360: .seealso: [](ch_dmbase), `DM`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `MatType`, `DMGetMatType()`,
    361:           `ISColoringType`, `IS_COLORING_GLOBAL`, `IS_COLORING_LOCAL`
    362: @*/
    363: PetscErrorCode DMGetISColoringType(DM dm, ISColoringType *ctype)
    364: {
    365:   PetscFunctionBegin;
    367:   *ctype = dm->coloringtype;
    368:   PetscFunctionReturn(PETSC_SUCCESS);
    369: }

    371: /*@
    372:   DMSetMatType - Sets the type of matrix created with `DMCreateMatrix()`

    374:   Logically Collective

    376:   Input Parameters:
    377: + dm    - the `DM` context
    378: - ctype - the matrix type, for example `MATMPIAIJ`

    380:   Options Database Key:
    381: . -dm_mat_type ctype - the type of the matrix to create, for example mpiaij

    383:   Level: intermediate

    385: .seealso: [](ch_dmbase), `DM`, `MatType`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `DMGetMatType()`, `DMCreateGlobalVector()`, `DMCreateLocalVector()`
    386: @*/
    387: PetscErrorCode DMSetMatType(DM dm, MatType ctype)
    388: {
    389:   char *tmp;

    391:   PetscFunctionBegin;
    393:   PetscAssertPointer(ctype, 2);
    394:   tmp = (char *)dm->mattype;
    395:   PetscCall(PetscStrallocpy(ctype, (char **)&dm->mattype));
    396:   PetscCall(PetscFree(tmp));
    397:   PetscFunctionReturn(PETSC_SUCCESS);
    398: }

    400: /*@
    401:   DMGetMatType - Gets the type of matrix that would be created with `DMCreateMatrix()`

    403:   Logically Collective

    405:   Input Parameter:
    406: . dm - the `DM` context

    408:   Output Parameter:
    409: . ctype - the matrix type

    411:   Level: intermediate

    413: .seealso: [](ch_dmbase), `DM`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `MatType`, `DMSetMatType()`
    414: @*/
    415: PetscErrorCode DMGetMatType(DM dm, MatType *ctype)
    416: {
    417:   PetscFunctionBegin;
    419:   *ctype = dm->mattype;
    420:   PetscFunctionReturn(PETSC_SUCCESS);
    421: }

    423: /*@
    424:   MatGetDM - Gets the `DM` defining the data layout of the matrix

    426:   Not Collective

    428:   Input Parameter:
    429: . A - The `Mat`

    431:   Output Parameter:
    432: . dm - The `DM`

    434:   Level: intermediate

    436:   Note:
    437:   A matrix may not have a `DM` associated with it

    439:   Developer Note:
    440:   Since the `Mat` class doesn't know about the `DM` class the `DM` object is associated with the `Mat` through a `PetscObjectCompose()` operation

    442: .seealso: [](ch_dmbase), `DM`, `MatSetDM()`, `DMCreateMatrix()`, `DMSetMatType()`
    443: @*/
    444: PetscErrorCode MatGetDM(Mat A, DM *dm)
    445: {
    446:   PetscFunctionBegin;
    448:   PetscAssertPointer(dm, 2);
    449:   PetscCall(PetscObjectQuery((PetscObject)A, "__PETSc_dm", (PetscObject *)dm));
    450:   PetscFunctionReturn(PETSC_SUCCESS);
    451: }

    453: /*@
    454:   MatSetDM - Sets the `DM` defining the data layout of the matrix

    456:   Not Collective

    458:   Input Parameters:
    459: + A  - The `Mat`
    460: - dm - The `DM`

    462:   Level: developer

    464:   Note:
    465:   This is rarely used in practice, rather `DMCreateMatrix()` is used to create a matrix associated with a particular `DM`

    467:   Developer Note:
    468:   Since the `Mat` class doesn't know about the `DM` class the `DM` object is associated with
    469:   the `Mat` through a `PetscObjectCompose()` operation

    471: .seealso: [](ch_dmbase), `DM`, `MatGetDM()`, `DMCreateMatrix()`, `DMSetMatType()`
    472: @*/
    473: PetscErrorCode MatSetDM(Mat A, DM dm)
    474: {
    475:   PetscFunctionBegin;
    478:   PetscCall(PetscObjectCompose((PetscObject)A, "__PETSc_dm", (PetscObject)dm));
    479:   PetscFunctionReturn(PETSC_SUCCESS);
    480: }

    482: /*@
    483:   DMSetOptionsPrefix - Sets the prefix prepended to all option names when searching through the options database

    485:   Logically Collective

    487:   Input Parameters:
    488: + dm     - the `DM` context
    489: - prefix - the prefix to prepend

    491:   Level: advanced

    493:   Note:
    494:   A hyphen (-) must NOT be given at the beginning of the prefix name.
    495:   The first character of all runtime options is AUTOMATICALLY the hyphen.

    497: .seealso: [](ch_dmbase), `DM`, `PetscObjectSetOptionsPrefix()`, `DMSetFromOptions()`
    498: @*/
    499: PetscErrorCode DMSetOptionsPrefix(DM dm, const char prefix[])
    500: {
    501:   PetscFunctionBegin;
    503:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)dm, prefix));
    504:   if (dm->sf) PetscCall(PetscObjectSetOptionsPrefix((PetscObject)dm->sf, prefix));
    505:   if (dm->sectionSF) PetscCall(PetscObjectSetOptionsPrefix((PetscObject)dm->sectionSF, prefix));
    506:   PetscFunctionReturn(PETSC_SUCCESS);
    507: }

    509: /*@
    510:   DMAppendOptionsPrefix - Appends an additional string to an already existing prefix used for searching for
    511:   `DM` options in the options database.

    513:   Logically Collective

    515:   Input Parameters:
    516: + dm     - the `DM` context
    517: - prefix - the string to append to the current prefix

    519:   Level: advanced

    521:   Note:
    522:   If the `DM` does not currently have an options prefix then this value is used alone as the prefix as if `DMSetOptionsPrefix()` had been called.
    523:   A hyphen (-) must NOT be given at the beginning of the prefix name.
    524:   The first character of all runtime options is AUTOMATICALLY the hyphen.

    526: .seealso: [](ch_dmbase), `DM`, `DMSetOptionsPrefix()`, `DMGetOptionsPrefix()`, `PetscObjectAppendOptionsPrefix()`, `DMSetFromOptions()`
    527: @*/
    528: PetscErrorCode DMAppendOptionsPrefix(DM dm, const char prefix[])
    529: {
    530:   PetscFunctionBegin;
    532:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)dm, prefix));
    533:   PetscFunctionReturn(PETSC_SUCCESS);
    534: }

    536: /*@
    537:   DMGetOptionsPrefix - Gets the prefix used for searching for all
    538:   DM options in the options database.

    540:   Not Collective

    542:   Input Parameter:
    543: . dm - the `DM` context

    545:   Output Parameter:
    546: . prefix - pointer to the prefix string used is returned

    548:   Level: advanced

    550: .seealso: [](ch_dmbase), `DM`, `DMSetOptionsPrefix()`, `DMAppendOptionsPrefix()`, `DMSetFromOptions()`
    551: @*/
    552: PetscErrorCode DMGetOptionsPrefix(DM dm, const char *prefix[])
    553: {
    554:   PetscFunctionBegin;
    556:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)dm, prefix));
    557:   PetscFunctionReturn(PETSC_SUCCESS);
    558: }

    560: static PetscErrorCode DMCountNonCyclicReferences_Internal(DM dm, PetscBool recurseCoarse, PetscBool recurseFine, PetscInt *ncrefct)
    561: {
    562:   PetscInt refct = ((PetscObject)dm)->refct;

    564:   PetscFunctionBegin;
    565:   *ncrefct = 0;
    566:   if (dm->coarseMesh && dm->coarseMesh->fineMesh == dm) {
    567:     refct--;
    568:     if (recurseCoarse) {
    569:       PetscInt coarseCount;

    571:       PetscCall(DMCountNonCyclicReferences_Internal(dm->coarseMesh, PETSC_TRUE, PETSC_FALSE, &coarseCount));
    572:       refct += coarseCount;
    573:     }
    574:   }
    575:   if (dm->fineMesh && dm->fineMesh->coarseMesh == dm) {
    576:     refct--;
    577:     if (recurseFine) {
    578:       PetscInt fineCount;

    580:       PetscCall(DMCountNonCyclicReferences_Internal(dm->fineMesh, PETSC_FALSE, PETSC_TRUE, &fineCount));
    581:       refct += fineCount;
    582:     }
    583:   }
    584:   *ncrefct = refct;
    585:   PetscFunctionReturn(PETSC_SUCCESS);
    586: }

    588: /* Generic wrapper for DMCountNonCyclicReferences_Internal() */
    589: PetscErrorCode DMCountNonCyclicReferences(PetscObject dm, PetscInt *ncrefct)
    590: {
    591:   PetscFunctionBegin;
    592:   PetscCall(DMCountNonCyclicReferences_Internal((DM)dm, PETSC_TRUE, PETSC_TRUE, ncrefct));
    593:   PetscFunctionReturn(PETSC_SUCCESS);
    594: }

    596: PetscErrorCode DMDestroyLabelLinkList_Internal(DM dm)
    597: {
    598:   DMLabelLink next = dm->labels;

    600:   PetscFunctionBegin;
    601:   /* destroy the labels */
    602:   while (next) {
    603:     DMLabelLink tmp = next->next;

    605:     if (next->label == dm->depthLabel) dm->depthLabel = NULL;
    606:     if (next->label == dm->celltypeLabel) dm->celltypeLabel = NULL;
    607:     PetscCall(DMLabelDestroy(&next->label));
    608:     PetscCall(PetscFree(next));
    609:     next = tmp;
    610:   }
    611:   dm->labels = NULL;
    612:   PetscFunctionReturn(PETSC_SUCCESS);
    613: }

    615: static PetscErrorCode DMDestroyCoordinates_Private(DMCoordinates *c)
    616: {
    617:   PetscFunctionBegin;
    618:   c->dim = PETSC_DEFAULT;
    619:   PetscCall(DMDestroy(&c->dm));
    620:   PetscCall(VecDestroy(&c->x));
    621:   PetscCall(VecDestroy(&c->xl));
    622:   PetscCall(DMFieldDestroy(&c->field));
    623:   PetscFunctionReturn(PETSC_SUCCESS);
    624: }

    626: /*@
    627:   DMDestroy - Destroys a `DM`.

    629:   Collective

    631:   Input Parameter:
    632: . dm - the `DM` object to destroy

    634:   Level: developer

    636: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMType`, `DMSetType()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`
    637: @*/
    638: PetscErrorCode DMDestroy(DM *dm)
    639: {
    640:   PetscInt cnt;

    642:   PetscFunctionBegin;
    643:   if (!*dm) PetscFunctionReturn(PETSC_SUCCESS);

    646:   /* count all non-cyclic references in the doubly-linked list of coarse<->fine meshes */
    647:   PetscCall(DMCountNonCyclicReferences_Internal(*dm, PETSC_TRUE, PETSC_TRUE, &cnt));
    648:   --((PetscObject)*dm)->refct;
    649:   if (--cnt > 0) {
    650:     *dm = NULL;
    651:     PetscFunctionReturn(PETSC_SUCCESS);
    652:   }
    653:   if (((PetscObject)*dm)->refct < 0) PetscFunctionReturn(PETSC_SUCCESS);
    654:   ((PetscObject)*dm)->refct = 0;

    656:   PetscCall(DMClearGlobalVectors(*dm));
    657:   PetscCall(DMClearLocalVectors(*dm));
    658:   PetscCall(DMClearNamedGlobalVectors(*dm));
    659:   PetscCall(DMClearNamedLocalVectors(*dm));

    661:   /* Destroy the list of hooks */
    662:   {
    663:     DMCoarsenHookLink link, next;
    664:     for (link = (*dm)->coarsenhook; link; link = next) {
    665:       next = link->next;
    666:       PetscCall(PetscFree(link));
    667:     }
    668:     (*dm)->coarsenhook = NULL;
    669:   }
    670:   {
    671:     DMRefineHookLink link, next;
    672:     for (link = (*dm)->refinehook; link; link = next) {
    673:       next = link->next;
    674:       PetscCall(PetscFree(link));
    675:     }
    676:     (*dm)->refinehook = NULL;
    677:   }
    678:   {
    679:     DMSubDomainHookLink link, next;
    680:     for (link = (*dm)->subdomainhook; link; link = next) {
    681:       next = link->next;
    682:       PetscCall(PetscFree(link));
    683:     }
    684:     (*dm)->subdomainhook = NULL;
    685:   }
    686:   {
    687:     DMGlobalToLocalHookLink link, next;
    688:     for (link = (*dm)->gtolhook; link; link = next) {
    689:       next = link->next;
    690:       PetscCall(PetscFree(link));
    691:     }
    692:     (*dm)->gtolhook = NULL;
    693:   }
    694:   {
    695:     DMLocalToGlobalHookLink link, next;
    696:     for (link = (*dm)->ltoghook; link; link = next) {
    697:       next = link->next;
    698:       PetscCall(PetscFree(link));
    699:     }
    700:     (*dm)->ltoghook = NULL;
    701:   }
    702:   /* Destroy the work arrays */
    703:   {
    704:     DMWorkLink link, next;
    705:     PetscCheck(!(*dm)->workout, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Work array still checked out %p %p", (void *)(*dm)->workout, (*dm)->workout->mem);
    706:     for (link = (*dm)->workin; link; link = next) {
    707:       next = link->next;
    708:       PetscCall(PetscFree(link->mem));
    709:       PetscCall(PetscFree(link));
    710:     }
    711:     (*dm)->workin = NULL;
    712:   }
    713:   /* destroy the labels */
    714:   PetscCall(DMDestroyLabelLinkList_Internal(*dm));
    715:   /* destroy the fields */
    716:   PetscCall(DMClearFields(*dm));
    717:   /* destroy the boundaries */
    718:   {
    719:     DMBoundary next = (*dm)->boundary;
    720:     while (next) {
    721:       DMBoundary b = next;

    723:       next = b->next;
    724:       PetscCall(PetscFree(b));
    725:     }
    726:   }

    728:   PetscCall(PetscObjectDestroy(&(*dm)->dmksp));
    729:   PetscCall(PetscObjectDestroy(&(*dm)->dmsnes));
    730:   PetscCall(PetscObjectDestroy(&(*dm)->dmts));

    732:   if ((*dm)->ctx && (*dm)->ctxdestroy) PetscCall((*(*dm)->ctxdestroy)(&(*dm)->ctx));
    733:   PetscCall(MatFDColoringDestroy(&(*dm)->fd));
    734:   PetscCall(ISLocalToGlobalMappingDestroy(&(*dm)->ltogmap));
    735:   PetscCall(PetscFree((*dm)->vectype));
    736:   PetscCall(PetscFree((*dm)->mattype));

    738:   PetscCall(PetscSectionDestroy(&(*dm)->localSection));
    739:   PetscCall(PetscSectionDestroy(&(*dm)->globalSection));
    740:   PetscCall(PetscFree((*dm)->reorderSectionType));
    741:   PetscCall(PetscLayoutDestroy(&(*dm)->map));
    742:   PetscCall(PetscSectionDestroy(&(*dm)->defaultConstraint.section));
    743:   PetscCall(MatDestroy(&(*dm)->defaultConstraint.mat));
    744:   PetscCall(PetscSFDestroy(&(*dm)->sf));
    745:   PetscCall(PetscSFDestroy(&(*dm)->sectionSF));
    746:   if ((*dm)->sfNatural) PetscCall(PetscSFDestroy(&(*dm)->sfNatural));
    747:   PetscCall(PetscObjectDereference((PetscObject)(*dm)->sfMigration));
    748:   PetscCall(DMClearAuxiliaryVec(*dm));
    749:   PetscCall(PetscHMapAuxDestroy(&(*dm)->auxData));
    750:   if ((*dm)->coarseMesh && (*dm)->coarseMesh->fineMesh == *dm) PetscCall(DMSetFineDM((*dm)->coarseMesh, NULL));

    752:   PetscCall(DMDestroy(&(*dm)->coarseMesh));
    753:   if ((*dm)->fineMesh && (*dm)->fineMesh->coarseMesh == *dm) PetscCall(DMSetCoarseDM((*dm)->fineMesh, NULL));
    754:   PetscCall(DMDestroy(&(*dm)->fineMesh));
    755:   PetscCall(PetscFree((*dm)->Lstart));
    756:   PetscCall(PetscFree((*dm)->L));
    757:   PetscCall(PetscFree((*dm)->maxCell));
    758:   PetscCall(PetscFree2((*dm)->nullspaceConstructors, (*dm)->nearnullspaceConstructors));
    759:   PetscCall(DMDestroyCoordinates_Private(&(*dm)->coordinates[0]));
    760:   PetscCall(DMDestroyCoordinates_Private(&(*dm)->coordinates[1]));
    761:   if ((*dm)->transformDestroy) PetscCall((*(*dm)->transformDestroy)(*dm, (*dm)->transformCtx));
    762:   PetscCall(DMDestroy(&(*dm)->transformDM));
    763:   PetscCall(VecDestroy(&(*dm)->transform));
    764:   for (PetscInt i = 0; i < (*dm)->periodic.num_affines; i++) {
    765:     PetscCall(VecScatterDestroy(&(*dm)->periodic.affine_to_local[i]));
    766:     PetscCall(VecDestroy(&(*dm)->periodic.affine[i]));
    767:   }
    768:   if ((*dm)->periodic.num_affines > 0) PetscCall(PetscFree2((*dm)->periodic.affine_to_local, (*dm)->periodic.affine));

    770:   PetscCall(DMClearDS(*dm));
    771:   PetscCall(DMDestroy(&(*dm)->dmBC));
    772:   /* if memory was published with SAWs then destroy it */
    773:   PetscCall(PetscObjectSAWsViewOff((PetscObject)*dm));

    775:   PetscTryTypeMethod(*dm, destroy);
    776:   PetscCall(DMMonitorCancel(*dm));
    777:   PetscCall(DMCeedDestroy(&(*dm)->dmceed));
    778: #ifdef PETSC_HAVE_LIBCEED
    779:   PetscCallCEED(CeedElemRestrictionDestroy(&(*dm)->ceedERestrict));
    780:   PetscCallCEED(CeedDestroy(&(*dm)->ceed));
    781: #endif
    782:   /* We do not destroy (*dm)->data here so that we can reference count backend objects */
    783:   PetscCall(PetscHeaderDestroy(dm));
    784:   PetscFunctionReturn(PETSC_SUCCESS);
    785: }

    787: /*@
    788:   DMSetUp - sets up the data structures inside a `DM` object

    790:   Collective

    792:   Input Parameter:
    793: . dm - the `DM` object to setup

    795:   Level: intermediate

    797:   Note:
    798:   This is usually called after various parameter setting operations and `DMSetFromOptions()` are called on the `DM`

    800: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMSetType()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`
    801: @*/
    802: PetscErrorCode DMSetUp(DM dm)
    803: {
    804:   PetscFunctionBegin;
    806:   if (dm->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
    807:   PetscTryTypeMethod(dm, setup);
    808:   dm->setupcalled = PETSC_TRUE;
    809:   PetscFunctionReturn(PETSC_SUCCESS);
    810: }

    812: /*@
    813:   DMSetFromOptions - sets parameters in a `DM` from the options database

    815:   Collective

    817:   Input Parameter:
    818: . dm - the `DM` object to set options for

    820:   Options Database Keys:
    821: + -dm_preallocate_only                               - Only preallocate the matrix for `DMCreateMatrix()` and `DMCreateMassMatrix()`, but do not fill it with zeros
    822: . -dm_vec_type <type>                                - type of vector to create inside `DM`
    823: . -dm_mat_type <type>                                - type of matrix to create inside `DM`
    824: . -dm_is_coloring_type                               - <global or local>
    825: . -dm_bind_below <n>                                 - bind (force execution on CPU) for `Vec` and `Mat` objects with local size (number of vector entries or matrix rows) below n; currently only supported for `DMDA`
    826: . -dm_plex_option_phases <ph0_, ph1_, ...>           - List of prefixes for option processing phases
    827: . -dm_plex_filename <str>                            - File containing a mesh
    828: . -dm_plex_boundary_filename <str>                   - File containing a mesh boundary
    829: . -dm_plex_name <str>                                - Name of the mesh in the file
    830: . -dm_plex_shape <shape>                             - The domain shape, such as `BOX`, `SPHERE`, etc.
    831: . -dm_plex_cell <ct>                                 - Cell shape
    832: . -dm_plex_reference_cell_domain <bool>              - Use a reference cell domain
    833: . -dm_plex_dim <dim>                                 - Set the topological dimension
    834: . -dm_plex_simplex <bool>                            - `PETSC_TRUE` for simplex elements, `PETSC_FALSE` for tensor elements
    835: . -dm_plex_interpolate <bool>                        - `PETSC_TRUE` turns on topological interpolation (creating edges and faces)
    836: . -dm_plex_orient <bool>                             - `PETSC_TRUE` turns on topological orientation (flipping edges and faces)
    837: . -dm_plex_scale <sc>                                - Scale factor for mesh coordinates
    838: . -dm_coord_remap <bool>                             - Map coordinates using a function
    839: . -dm_plex_coordinate_dim <dim>                      - Change the coordinate dimension of a mesh (usually given with cdm_ prefix)
    840: . -dm_coord_map <mapname>                            - Select a builtin coordinate map
    841: . -dm_coord_map_params <p0,p1,p2,...>                - Set coordinate mapping parameters
    842: . -dm_plex_box_faces <m,n,p>                         - Number of faces along each dimension
    843: . -dm_plex_box_lower <x,y,z>                         - Specify lower-left-bottom coordinates for the box
    844: . -dm_plex_box_upper <x,y,z>                         - Specify upper-right-top coordinates for the box
    845: . -dm_plex_box_bd <bx,by,bz>                         - Specify the `DMBoundaryType` for each direction
    846: . -dm_plex_sphere_radius <r>                         - The sphere radius
    847: . -dm_plex_ball_radius <r>                           - Radius of the ball
    848: . -dm_plex_cylinder_bd <bz>                          - Boundary type in the z direction
    849: . -dm_plex_cylinder_num_wedges <n>                   - Number of wedges around the cylinder
    850: . -dm_plex_reorder <order>                           - Reorder the mesh using the specified algorithm
    851: . -dm_refine_pre <n>                                 - The number of refinements before distribution
    852: . -dm_refine_uniform_pre <bool>                      - Flag for uniform refinement before distribution
    853: . -dm_refine_volume_limit_pre <v>                    - The maximum cell volume after refinement before distribution
    854: . -dm_refine <n>                                     - The number of refinements after distribution
    855: . -dm_extrude <l>                                    - Activate extrusion and specify the number of layers to extrude
    856: . -dm_plex_save_transform <bool>                     - Save the `DMPlexTransform` that produced this mesh
    857: . -dm_plex_transform_extrude_thickness <t>           - The total thickness of extruded layers
    858: . -dm_plex_transform_extrude_use_tensor <bool>       - Use tensor cells when extruding
    859: . -dm_plex_transform_extrude_symmetric <bool>        - Extrude layers symmetrically about the surface
    860: . -dm_plex_transform_extrude_normal <n0,...,nd>      - Specify the extrusion direction
    861: . -dm_plex_transform_extrude_thicknesses <t0,...,tl> - Specify thickness of each layer
    862: . -dm_plex_create_fv_ghost_cells                     - Flag to create finite volume ghost cells on the boundary
    863: . -dm_plex_fv_ghost_cells_label <name>               - Label name for ghost cells boundary
    864: . -dm_distribute <bool>                              - Flag to redistribute a mesh among processes
    865: . -dm_distribute_overlap <n>                         - The size of the overlap halo
    866: . -dm_plex_adj_cone <bool>                           - Set adjacency direction
    867: . -dm_plex_adj_closure <bool>                        - Set adjacency size
    868: . -dm_plex_use_ceed <bool>                           - Use LibCEED as the FEM backend
    869: . -dm_plex_check_symmetry                            - Check that the adjacency information in the mesh is symmetric - `DMPlexCheckSymmetry()`
    870: . -dm_plex_check_skeleton                            - Check that each cell has the correct number of vertices (only for homogeneous simplex or tensor meshes) - `DMPlexCheckSkeleton()`
    871: . -dm_plex_check_faces                               - Check that the faces of each cell give a vertex order this is consistent with what we expect from the cell type - `DMPlexCheckFaces()`
    872: . -dm_plex_check_geometry                            - Check that cells have positive volume - `DMPlexCheckGeometry()`
    873: . -dm_plex_check_pointsf                             - Check some necessary conditions for `PointSF` - `DMPlexCheckPointSF()`
    874: . -dm_plex_check_interface_cones                     - Check points on inter-partition interfaces have conforming order of cone points - `DMPlexCheckInterfaceCones()`
    875: - -dm_plex_check_all                                 - Perform all the checks above

    877:   Level: intermediate

    879:   Note:
    880:   For some `DMType` such as `DMDA` this cannot be called after `DMSetUp()` has been called.

    882: .seealso: [](ch_dmbase), `DM`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`,
    883:          `DMPlexCheckSymmetry()`, `DMPlexCheckSkeleton()`, `DMPlexCheckFaces()`, `DMPlexCheckGeometry()`, `DMPlexCheckPointSF()`, `DMPlexCheckInterfaceCones()`,
    884:          `DMSetOptionsPrefix()`, `DMType`, `DMPLEX`, `DMDA`, `DMSetUp()`
    885: @*/
    886: PetscErrorCode DMSetFromOptions(DM dm)
    887: {
    888:   char      typeName[256];
    889:   PetscBool flg;

    891:   PetscFunctionBegin;
    893:   dm->setfromoptionscalled = PETSC_TRUE;
    894:   if (dm->sf) PetscCall(PetscSFSetFromOptions(dm->sf));
    895:   if (dm->sectionSF) PetscCall(PetscSFSetFromOptions(dm->sectionSF));
    896:   if (dm->coordinates[0].dm) PetscCall(DMSetFromOptions(dm->coordinates[0].dm));
    897:   PetscObjectOptionsBegin((PetscObject)dm);
    898:   PetscCall(PetscOptionsBool("-dm_preallocate_only", "only preallocate matrix, but do not set column indices", "DMSetMatrixPreallocateOnly", dm->prealloc_only, &dm->prealloc_only, NULL));
    899:   PetscCall(PetscOptionsFList("-dm_vec_type", "Vector type used for created vectors", "DMSetVecType", VecList, dm->vectype, typeName, 256, &flg));
    900:   if (flg) PetscCall(DMSetVecType(dm, typeName));
    901:   PetscCall(PetscOptionsFList("-dm_mat_type", "Matrix type used for created matrices", "DMSetMatType", MatList, dm->mattype ? dm->mattype : typeName, typeName, sizeof(typeName), &flg));
    902:   if (flg) PetscCall(DMSetMatType(dm, typeName));
    903:   PetscCall(PetscOptionsEnum("-dm_blocking_type", "Topological point or field node blocking", "DMSetBlockingType", DMBlockingTypes, (PetscEnum)dm->blocking_type, (PetscEnum *)&dm->blocking_type, NULL));
    904:   PetscCall(PetscOptionsEnum("-dm_is_coloring_type", "Global or local coloring of Jacobian", "DMSetISColoringType", ISColoringTypes, (PetscEnum)dm->coloringtype, (PetscEnum *)&dm->coloringtype, NULL));
    905:   PetscCall(PetscOptionsInt("-dm_bind_below", "Set the size threshold (in entries) below which the Vec is bound to the CPU", "VecBindToCPU", dm->bind_below, &dm->bind_below, &flg));
    906:   PetscCall(PetscOptionsBool("-dm_ignore_perm_output", "Ignore the local section permutation on output", "DMGetOutputDM", dm->ignorePermOutput, &dm->ignorePermOutput, NULL));
    907:   PetscTryTypeMethod(dm, setfromoptions, PetscOptionsObject);
    908:   /* process any options handlers added with PetscObjectAddOptionsHandler() */
    909:   PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)dm, PetscOptionsObject));
    910:   PetscOptionsEnd();
    911:   PetscFunctionReturn(PETSC_SUCCESS);
    912: }

    914: /*@
    915:   DMViewFromOptions - View a `DM` in a particular way based on a request in the options database

    917:   Collective

    919:   Input Parameters:
    920: + dm   - the `DM` object
    921: . obj  - optional object that provides the prefix for the options database (if `NULL` then the prefix in `obj` is used)
    922: - name - option string that is used to activate viewing

    924:   Level: intermediate

    926:   Note:
    927:   See `PetscObjectViewFromOptions()` for a list of values that can be provided in the options database to determine how the `DM` is viewed

    929: .seealso: [](ch_dmbase), `DM`, `DMView()`, `PetscObjectViewFromOptions()`, `DMCreate()`
    930: @*/
    931: PetscErrorCode DMViewFromOptions(DM dm, PeOp PetscObject obj, const char name[])
    932: {
    933:   PetscFunctionBegin;
    935:   PetscCall(PetscObjectViewFromOptions((PetscObject)dm, obj, name));
    936:   PetscFunctionReturn(PETSC_SUCCESS);
    937: }

    939: /*@
    940:   DMView - Views a `DM`. Depending on the `PetscViewer` and its `PetscViewerFormat` it may print some ASCII information about the `DM` to the screen or a file or
    941:   save the `DM` in a binary file to be loaded later or create a visualization of the `DM`

    943:   Collective

    945:   Input Parameters:
    946: + dm - the `DM` object to view
    947: - v  - the viewer

    949:   Options Database Keys:
    950: + -view_pyvista_warp <f>                 - Warps the mesh by the active scalar with factor f
    951: . -view_pyvista_clip <xl,xu,yl,yu,zl,zu> - Defines the clipping box
    952: . -dm_view_draw_line_color <int>         - Specify the X-window color for cell borders
    953: . -dm_view_draw_cell_color <int>         - Specify the X-window color for cells
    954: - -dm_view_draw_affine <bool>            - Flag to ignore high-order edges

    956:   Level: beginner

    958:   Notes:

    960:   `PetscViewer` = `PETSCVIEWERHDF5` i.e. HDF5 format can be used with `PETSC_VIEWER_HDF5_PETSC` as the `PetscViewerFormat` to save multiple `DMPLEX`
    961:   meshes in a single HDF5 file. This in turn requires one to name the `DMPLEX` object with `PetscObjectSetName()`
    962:   before saving it with `DMView()` and before loading it with `DMLoad()` for identification of the mesh object.

    964:   `PetscViewer` = `PETSCVIEWEREXODUSII` i.e. ExodusII format assumes that element blocks (mapped to "Cell sets" labels)
    965:   consists of sequentially numbered cells.

    967:   If `dm` has been distributed, only the part of the `DM` on MPI rank 0 (including "ghost" cells and vertices) will be written.

    969:   Only TRI, TET, QUAD, and HEX cells are supported in ExodusII.

    971:   `DMPLEX` only represents geometry while most post-processing software expect that a mesh also provides information on the discretization space. This function assumes that the file represents Lagrange finite elements of order 1 or 2.
    972:   The order of the mesh shall be set using `PetscViewerExodusIISetOrder()`

    974:   Variable names can be set and queried using `PetscViewerExodusII[Set/Get][Nodal/Zonal]VariableNames[s]`.

    976: .seealso: [](ch_dmbase), `DM`, `PetscViewer`, `PetscViewerFormat`, `PetscViewerSetFormat()`, `DMDestroy()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMLoad()`, `PetscObjectSetName()`
    977: @*/
    978: PetscErrorCode DMView(DM dm, PetscViewer v)
    979: {
    980:   PetscBool         isbinary;
    981:   PetscMPIInt       size;
    982:   PetscViewerFormat format;

    984:   PetscFunctionBegin;
    986:   if (!v) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)dm), &v));
    988:   /* Ideally, we would like to have this test on.
    989:      However, it currently breaks socket viz via GLVis.
    990:      During DMView(parallel_mesh,glvis_viewer), each
    991:      process opens a sequential ASCII socket to visualize
    992:      the local mesh, and PetscObjectView(dm,local_socket)
    993:      is internally called inside VecView_GLVis, incurring
    994:      in an error here */
    995:   /* PetscCheckSameComm(dm,1,v,2); */
    996:   PetscCall(PetscViewerCheckWritable(v));

    998:   PetscCall(PetscLogEventBegin(DM_View, v, 0, 0, 0));
    999:   PetscCall(PetscViewerGetFormat(v, &format));
    1000:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size));
    1001:   if (size == 1 && format == PETSC_VIEWER_LOAD_BALANCE) PetscFunctionReturn(PETSC_SUCCESS);
    1002:   PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)dm, v));
    1003:   PetscCall(PetscObjectTypeCompare((PetscObject)v, PETSCVIEWERBINARY, &isbinary));
    1004:   if (isbinary) {
    1005:     PetscInt classid = DM_FILE_CLASSID;
    1006:     char     type[256];

    1008:     PetscCall(PetscViewerBinaryWrite(v, &classid, 1, PETSC_INT));
    1009:     PetscCall(PetscStrncpy(type, ((PetscObject)dm)->type_name, sizeof(type)));
    1010:     PetscCall(PetscViewerBinaryWrite(v, type, 256, PETSC_CHAR));
    1011:   }
    1012:   PetscTryTypeMethod(dm, view, v);
    1013:   PetscCall(PetscLogEventEnd(DM_View, v, 0, 0, 0));
    1014:   PetscFunctionReturn(PETSC_SUCCESS);
    1015: }

    1017: /*@
    1018:   DMCreateGlobalVector - Creates a global vector from a `DM` object. A global vector is a parallel vector that has no duplicate values shared between MPI ranks,
    1019:   that is it has no ghost locations.

    1021:   Collective

    1023:   Input Parameter:
    1024: . dm - the `DM` object

    1026:   Output Parameter:
    1027: . vec - the global vector

    1029:   Level: beginner

    1031: .seealso: [](ch_dmbase), `DM`, `Vec`, `DMCreateLocalVector()`, `DMGetGlobalVector()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`,
    1032:          `DMGlobalToLocalBegin()`, `DMGlobalToLocalEnd()`
    1033: @*/
    1034: PetscErrorCode DMCreateGlobalVector(DM dm, Vec *vec)
    1035: {
    1036:   PetscFunctionBegin;
    1038:   PetscAssertPointer(vec, 2);
    1039:   PetscUseTypeMethod(dm, createglobalvector, vec);
    1040:   if (PetscDefined(USE_DEBUG)) {
    1041:     DM vdm;

    1043:     PetscCall(VecGetDM(*vec, &vdm));
    1044:     PetscCheck(vdm, PETSC_COMM_SELF, PETSC_ERR_PLIB, "DM type '%s' did not attach the DM to the vector", ((PetscObject)dm)->type_name);
    1045:   }
    1046:   PetscFunctionReturn(PETSC_SUCCESS);
    1047: }

    1049: /*@
    1050:   DMCreateLocalVector - Creates a local vector from a `DM` object.

    1052:   Not Collective

    1054:   Input Parameter:
    1055: . dm - the `DM` object

    1057:   Output Parameter:
    1058: . vec - the local vector

    1060:   Level: beginner

    1062:   Note:
    1063:   A local vector usually has ghost locations that contain values that are owned by different MPI ranks. A global vector has no ghost locations.

    1065: .seealso: [](ch_dmbase), `DM`, `Vec`, `DMCreateGlobalVector()`, `DMGetLocalVector()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`
    1066:          `DMGlobalToLocalBegin()`, `DMGlobalToLocalEnd()`
    1067: @*/
    1068: PetscErrorCode DMCreateLocalVector(DM dm, Vec *vec)
    1069: {
    1070:   PetscFunctionBegin;
    1072:   PetscAssertPointer(vec, 2);
    1073:   PetscUseTypeMethod(dm, createlocalvector, vec);
    1074:   if (PetscDefined(USE_DEBUG)) {
    1075:     DM vdm;

    1077:     PetscCall(VecGetDM(*vec, &vdm));
    1078:     PetscCheck(vdm, PETSC_COMM_SELF, PETSC_ERR_LIB, "DM type '%s' did not attach the DM to the vector", ((PetscObject)dm)->type_name);
    1079:   }
    1080:   PetscFunctionReturn(PETSC_SUCCESS);
    1081: }

    1083: /*@
    1084:   DMGetLocalToGlobalMapping - Accesses the local-to-global mapping in a `DM`.

    1086:   Collective

    1088:   Input Parameter:
    1089: . dm - the `DM` that provides the mapping

    1091:   Output Parameter:
    1092: . ltog - the mapping

    1094:   Level: advanced

    1096:   Notes:
    1097:   The global to local mapping allows one to set values into the global vector or matrix using `VecSetValuesLocal()` and `MatSetValuesLocal()`

    1099:   Vectors obtained with  `DMCreateGlobalVector()` and matrices obtained with `DMCreateMatrix()` already contain the global mapping so you do
    1100:   need to use this function with those objects.

    1102:   This mapping can then be used by `VecSetLocalToGlobalMapping()` or `MatSetLocalToGlobalMapping()`.

    1104: .seealso: [](ch_dmbase), `DM`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`, `VecSetLocalToGlobalMapping()`, `MatSetLocalToGlobalMapping()`,
    1105:           `DMCreateMatrix()`
    1106: @*/
    1107: PetscErrorCode DMGetLocalToGlobalMapping(DM dm, ISLocalToGlobalMapping *ltog)
    1108: {
    1109:   PetscInt bs = -1, bsLocal[2], bsMinMax[2];

    1111:   PetscFunctionBegin;
    1113:   PetscAssertPointer(ltog, 2);
    1114:   if (!dm->ltogmap) {
    1115:     PetscSection section, sectionGlobal;

    1117:     PetscCall(DMGetLocalSection(dm, &section));
    1118:     if (section) {
    1119:       const PetscInt *cdofs;
    1120:       PetscInt       *ltog;
    1121:       PetscInt        pStart, pEnd, n, p, k, l;

    1123:       PetscCall(DMGetGlobalSection(dm, &sectionGlobal));
    1124:       PetscCall(PetscSectionGetChart(section, &pStart, &pEnd));
    1125:       PetscCall(PetscSectionGetStorageSize(section, &n));
    1126:       PetscCall(PetscMalloc1(n, &ltog)); /* We want the local+overlap size */
    1127:       for (p = pStart, l = 0; p < pEnd; ++p) {
    1128:         PetscInt bdof, cdof, dof, off, c, cind;

    1130:         /* Should probably use constrained dofs */
    1131:         PetscCall(PetscSectionGetDof(section, p, &dof));
    1132:         PetscCall(PetscSectionGetConstraintDof(section, p, &cdof));
    1133:         PetscCall(PetscSectionGetConstraintIndices(section, p, &cdofs));
    1134:         PetscCall(PetscSectionGetOffset(sectionGlobal, p, &off));
    1135:         /* If you have dofs, and constraints, and they are unequal, we set the blocksize to 1 */
    1136:         bdof = cdof && (dof - cdof) ? 1 : dof;
    1137:         if (dof) bs = bs < 0 ? bdof : PetscGCD(bs, bdof);

    1139:         for (c = 0, cind = 0; c < dof; ++c, ++l) {
    1140:           if (cind < cdof && c == cdofs[cind]) {
    1141:             ltog[l] = off < 0 ? off - c : -(off + c + 1);
    1142:             cind++;
    1143:           } else {
    1144:             ltog[l] = (off < 0 ? -(off + 1) : off) + c - cind;
    1145:           }
    1146:         }
    1147:       }
    1148:       /* Must have same blocksize on all procs (some might have no points) */
    1149:       bsLocal[0] = bs < 0 ? PETSC_INT_MAX : bs;
    1150:       bsLocal[1] = bs;
    1151:       PetscCall(PetscGlobalMinMaxInt(PetscObjectComm((PetscObject)dm), bsLocal, bsMinMax));
    1152:       if (bsMinMax[0] != bsMinMax[1]) {
    1153:         bs = 1;
    1154:       } else {
    1155:         bs = bsMinMax[0];
    1156:       }
    1157:       bs = bs < 0 ? 1 : bs;
    1158:       /* Must reduce indices by blocksize */
    1159:       if (bs > 1) {
    1160:         for (l = 0, k = 0; l < n; l += bs, ++k) {
    1161:           // Integer division of negative values truncates toward zero(!), not toward negative infinity
    1162:           ltog[k] = ltog[l] >= 0 ? ltog[l] / bs : -(-(ltog[l] + 1) / bs + 1);
    1163:         }
    1164:         n /= bs;
    1165:       }
    1166:       PetscCall(ISLocalToGlobalMappingCreate(PetscObjectComm((PetscObject)dm), bs, n, ltog, PETSC_OWN_POINTER, &dm->ltogmap));
    1167:     } else PetscUseTypeMethod(dm, getlocaltoglobalmapping);
    1168:   }
    1169:   *ltog = dm->ltogmap;
    1170:   PetscFunctionReturn(PETSC_SUCCESS);
    1171: }

    1173: /*@
    1174:   DMGetBlockSize - Gets the inherent block size associated with a `DM`

    1176:   Not Collective

    1178:   Input Parameter:
    1179: . dm - the `DM` with block structure

    1181:   Output Parameter:
    1182: . bs - the block size, 1 implies no exploitable block structure

    1184:   Level: intermediate

    1186:   Notes:
    1187:   This might be the number of degrees of freedom at each grid point for a structured grid.

    1189:   Complex `DM` that represent multiphysics or staggered grids or mixed-methods do not generally have a single inherent block size, but
    1190:   rather different locations in the vectors may have a different block size.

    1192: .seealso: [](ch_dmbase), `DM`, `ISCreateBlock()`, `VecSetBlockSize()`, `MatSetBlockSize()`, `DMGetLocalToGlobalMapping()`
    1193: @*/
    1194: PetscErrorCode DMGetBlockSize(DM dm, PetscInt *bs)
    1195: {
    1196:   PetscFunctionBegin;
    1198:   PetscAssertPointer(bs, 2);
    1199:   PetscCheck(dm->bs >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "DM does not have enough information to provide a block size yet");
    1200:   *bs = dm->bs;
    1201:   PetscFunctionReturn(PETSC_SUCCESS);
    1202: }

    1204: /*@
    1205:   DMCreateInterpolation - Gets the interpolation matrix between two `DM` objects. The resulting matrix map degrees of freedom in the vector obtained by
    1206:   `DMCreateGlobalVector()` on the coarse `DM` to similar vectors on the fine grid `DM`.

    1208:   Collective

    1210:   Input Parameters:
    1211: + dmc - the `DM` object
    1212: - dmf - the second, finer `DM` object

    1214:   Output Parameters:
    1215: + mat - the interpolation
    1216: - vec - the scaling (optional, pass `NULL` if not needed), see `DMCreateInterpolationScale()`

    1218:   Level: developer

    1220:   Notes:
    1221:   For `DMDA` objects this only works for "uniform refinement", that is the refined mesh was obtained `DMRefine()` or the coarse mesh was obtained by
    1222:   DMCoarsen(). The coordinates set into the `DMDA` are completely ignored in computing the interpolation.

    1224:   For `DMDA` objects you can use this interpolation (more precisely the interpolation from the `DMGetCoordinateDM()`) to interpolate the mesh coordinate
    1225:   vectors EXCEPT in the periodic case where it does not make sense since the coordinate vectors are not periodic.

    1227: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolationScale()`
    1228: @*/
    1229: PetscErrorCode DMCreateInterpolation(DM dmc, DM dmf, Mat *mat, Vec *vec)
    1230: {
    1231:   PetscFunctionBegin;
    1234:   PetscAssertPointer(mat, 3);
    1235:   PetscCall(PetscLogEventBegin(DM_CreateInterpolation, dmc, dmf, 0, 0));
    1236:   PetscUseTypeMethod(dmc, createinterpolation, dmf, mat, vec);
    1237:   PetscCall(PetscLogEventEnd(DM_CreateInterpolation, dmc, dmf, 0, 0));
    1238:   PetscFunctionReturn(PETSC_SUCCESS);
    1239: }

    1241: /*@
    1242:   DMCreateInterpolationScale - Forms L = 1/(R*1) where 1 is the vector of all ones, and R is
    1243:   the transpose of the interpolation between the `DM`.

    1245:   Input Parameters:
    1246: + dac - `DM` that defines a coarse mesh
    1247: . daf - `DM` that defines a fine mesh
    1248: - mat - the restriction (or interpolation operator) from fine to coarse

    1250:   Output Parameter:
    1251: . scale - the scaled vector

    1253:   Level: advanced

    1255:   Note:
    1256:   xcoarse = diag(L)*R*xfine preserves scale and is thus suitable for state (versus residual)
    1257:   restriction. In other words xcoarse is the coarse representation of xfine.

    1259:   Developer Note:
    1260:   If the fine-scale `DMDA` has the -dm_bind_below option set to true, then `DMCreateInterpolationScale()` calls `MatSetBindingPropagates()`
    1261:   on the restriction/interpolation operator to set the bindingpropagates flag to true.

    1263: .seealso: [](ch_dmbase), `DM`, `MatRestrict()`, `MatInterpolate()`, `DMCreateInterpolation()`, `DMCreateRestriction()`, `DMCreateGlobalVector()`
    1264: @*/
    1265: PetscErrorCode DMCreateInterpolationScale(DM dac, DM daf, Mat mat, Vec *scale)
    1266: {
    1267:   Vec         fine;
    1268:   PetscScalar one = 1.0;
    1269: #if defined(PETSC_HAVE_CUDA)
    1270:   PetscBool bindingpropagates, isbound;
    1271: #endif

    1273:   PetscFunctionBegin;
    1274:   PetscCall(DMCreateGlobalVector(daf, &fine));
    1275:   PetscCall(DMCreateGlobalVector(dac, scale));
    1276:   PetscCall(VecSet(fine, one));
    1277: #if defined(PETSC_HAVE_CUDA)
    1278:   /* If the 'fine' Vec is bound to the CPU, it makes sense to bind 'mat' as well.
    1279:    * Note that we only do this for the CUDA case, right now, but if we add support for MatMultTranspose() via ViennaCL,
    1280:    * we'll need to do it for that case, too.*/
    1281:   PetscCall(VecGetBindingPropagates(fine, &bindingpropagates));
    1282:   if (bindingpropagates) {
    1283:     PetscCall(MatSetBindingPropagates(mat, PETSC_TRUE));
    1284:     PetscCall(VecBoundToCPU(fine, &isbound));
    1285:     PetscCall(MatBindToCPU(mat, isbound));
    1286:   }
    1287: #endif
    1288:   PetscCall(MatRestrict(mat, fine, *scale));
    1289:   PetscCall(VecDestroy(&fine));
    1290:   PetscCall(VecReciprocal(*scale));
    1291:   PetscFunctionReturn(PETSC_SUCCESS);
    1292: }

    1294: /*@
    1295:   DMCreateRestriction - Gets restriction matrix between two `DM` objects. The resulting matrix map degrees of freedom in the vector obtained by
    1296:   `DMCreateGlobalVector()` on the fine `DM` to similar vectors on the coarse grid `DM`.

    1298:   Collective

    1300:   Input Parameters:
    1301: + dmc - the `DM` object
    1302: - dmf - the second, finer `DM` object

    1304:   Output Parameter:
    1305: . mat - the restriction

    1307:   Level: developer

    1309:   Note:
    1310:   This only works for `DMSTAG`. For many situations either the transpose of the operator obtained with `DMCreateInterpolation()` or that
    1311:   matrix multiplied by the vector obtained with `DMCreateInterpolationScale()` provides the desired object.

    1313: .seealso: [](ch_dmbase), `DM`, `DMRestrict()`, `DMInterpolate()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateInterpolation()`
    1314: @*/
    1315: PetscErrorCode DMCreateRestriction(DM dmc, DM dmf, Mat *mat)
    1316: {
    1317:   PetscFunctionBegin;
    1320:   PetscAssertPointer(mat, 3);
    1321:   PetscCall(PetscLogEventBegin(DM_CreateRestriction, dmc, dmf, 0, 0));
    1322:   PetscUseTypeMethod(dmc, createrestriction, dmf, mat);
    1323:   PetscCall(PetscLogEventEnd(DM_CreateRestriction, dmc, dmf, 0, 0));
    1324:   PetscFunctionReturn(PETSC_SUCCESS);
    1325: }

    1327: /*@
    1328:   DMCreateInjection - Gets injection matrix between two `DM` objects.

    1330:   Collective

    1332:   Input Parameters:
    1333: + dac - the `DM` object
    1334: - daf - the second, finer `DM` object

    1336:   Output Parameter:
    1337: . mat - the injection

    1339:   Level: developer

    1341:   Notes:
    1342:   This is an operator that applied to a vector obtained with `DMCreateGlobalVector()` on the
    1343:   fine grid maps the values to a vector on the vector on the coarse `DM` by simply selecting
    1344:   the values on the coarse grid points. This compares to the operator obtained by
    1345:   `DMCreateRestriction()` or the transpose of the operator obtained by
    1346:   `DMCreateInterpolation()` that uses a "local weighted average" of the values around the
    1347:   coarse grid point as the coarse grid value.

    1349:   For `DMDA` objects this only works for "uniform refinement", that is the refined mesh was obtained `DMRefine()` or the coarse mesh was obtained by
    1350:   `DMCoarsen()`. The coordinates set into the `DMDA` are completely ignored in computing the injection.

    1352: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMCreateInterpolation()`,
    1353:           `DMCreateRestriction()`, `MatRestrict()`, `MatInterpolate()`
    1354: @*/
    1355: PetscErrorCode DMCreateInjection(DM dac, DM daf, Mat *mat)
    1356: {
    1357:   PetscFunctionBegin;
    1360:   PetscAssertPointer(mat, 3);
    1361:   PetscCall(PetscLogEventBegin(DM_CreateInjection, dac, daf, 0, 0));
    1362:   PetscUseTypeMethod(dac, createinjection, daf, mat);
    1363:   PetscCall(PetscLogEventEnd(DM_CreateInjection, dac, daf, 0, 0));
    1364:   PetscFunctionReturn(PETSC_SUCCESS);
    1365: }

    1367: /*@
    1368:   DMCreateMassMatrix - Gets the mass matrix between two `DM` objects, M_ij = \int \phi_i \psi_j where the \phi are Galerkin basis functions for a
    1369:   a Galerkin finite element model on the `DM`

    1371:   Collective

    1373:   Input Parameters:
    1374: + dmc - the target `DM` object
    1375: - dmf - the source `DM` object, can be `NULL`

    1377:   Output Parameter:
    1378: . mat - the mass matrix

    1380:   Level: developer

    1382:   Notes:
    1383:   For `DMPLEX` the finite element model for the `DM` must have been already provided.

    1385:   if `dmc` is `dmf` or `NULL`, then x^t M x is an approximation to the L2 norm of the vector x which is obtained by `DMCreateGlobalVector()`

    1387: .seealso: [](ch_dmbase), `DM`, `DMCreateMassMatrixLumped()`, `DMCreateMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolation()`, `DMCreateInjection()`
    1388: @*/
    1389: PetscErrorCode DMCreateMassMatrix(DM dmc, DM dmf, Mat *mat)
    1390: {
    1391:   PetscFunctionBegin;
    1393:   if (!dmf) dmf = dmc;
    1395:   PetscAssertPointer(mat, 3);
    1396:   PetscCall(PetscLogEventBegin(DM_CreateMassMatrix, dmc, dmf, 0, 0));
    1397:   PetscUseTypeMethod(dmc, createmassmatrix, dmf, mat);
    1398:   PetscCall(PetscLogEventEnd(DM_CreateMassMatrix, dmc, dmf, 0, 0));
    1399:   PetscFunctionReturn(PETSC_SUCCESS);
    1400: }

    1402: /*@
    1403:   DMCreateMassMatrixLumped - Gets the lumped mass matrix for a given `DM`

    1405:   Collective

    1407:   Input Parameter:
    1408: . dm - the `DM` object

    1410:   Output Parameters:
    1411: + llm - the local lumped mass matrix, which is a diagonal matrix, represented as a vector
    1412: - lm  - the global lumped mass matrix, which is a diagonal matrix, represented as a vector

    1414:   Level: developer

    1416:   Note:
    1417:   See `DMCreateMassMatrix()` for how to create the non-lumped version of the mass matrix.

    1419: .seealso: [](ch_dmbase), `DM`, `DMCreateMassMatrix()`, `DMCreateMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolation()`, `DMCreateInjection()`
    1420: @*/
    1421: PetscErrorCode DMCreateMassMatrixLumped(DM dm, Vec *llm, Vec *lm)
    1422: {
    1423:   PetscFunctionBegin;
    1425:   if (llm) PetscAssertPointer(llm, 2);
    1426:   if (lm) PetscAssertPointer(lm, 3);
    1427:   if (llm || lm) PetscUseTypeMethod(dm, createmassmatrixlumped, llm, lm);
    1428:   PetscFunctionReturn(PETSC_SUCCESS);
    1429: }

    1431: /*@
    1432:   DMCreateGradientMatrix - Gets the gradient matrix between two `DM` objects, M_(ic)j = \int \partial_c \phi_i \psi_j where the \phi are Galerkin basis functions for a Galerkin finite element model on the `DM`

    1434:   Collective

    1436:   Input Parameters:
    1437: + dmc - the target `DM` object
    1438: - dmf - the source `DM` object, can be `NULL`

    1440:   Output Parameter:
    1441: . mat - the gradient matrix

    1443:   Level: developer

    1445:   Notes:
    1446:   For `DMPLEX` the finite element model for the `DM` must have been already provided.

    1448: .seealso: [](ch_dmbase), `DM`, `DMCreateMassMatrix()`, `DMCreateMassMatrixLumped()`, `DMCreateMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolation()`, `DMCreateInjection()`
    1449: @*/
    1450: PetscErrorCode DMCreateGradientMatrix(DM dmc, DM dmf, Mat *mat)
    1451: {
    1452:   PetscFunctionBegin;
    1454:   if (!dmf) dmf = dmc;
    1456:   PetscAssertPointer(mat, 3);
    1457:   PetscUseTypeMethod(dmc, creategradientmatrix, dmf, mat);
    1458:   PetscFunctionReturn(PETSC_SUCCESS);
    1459: }

    1461: /*@
    1462:   DMCreateColoring - Gets coloring of a graph associated with the `DM`. Often the graph represents the operator matrix associated with the discretization
    1463:   of a PDE on the `DM`.

    1465:   Collective

    1467:   Input Parameters:
    1468: + dm    - the `DM` object
    1469: - ctype - `IS_COLORING_LOCAL` or `IS_COLORING_GLOBAL`

    1471:   Output Parameter:
    1472: . coloring - the coloring

    1474:   Level: developer

    1476:   Notes:
    1477:   Coloring of matrices can also be computed directly from the sparse matrix nonzero structure via the `MatColoring` object or from the mesh from which the
    1478:   matrix comes from (what this function provides). In general using the mesh produces a more optimal coloring (fewer colors).

    1480:   This produces a coloring with the distance of 2, see `MatSetColoringDistance()` which can be used for efficiently computing Jacobians with `MatFDColoringCreate()`
    1481:   For `DMDA` in three dimensions with periodic boundary conditions the number of grid points in each dimension must be divisible by 2*stencil_width + 1,
    1482:   otherwise an error will be generated.

    1484: .seealso: [](ch_dmbase), `DM`, `ISColoring`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatType()`, `MatColoring`, `MatFDColoringCreate()`
    1485: @*/
    1486: PetscErrorCode DMCreateColoring(DM dm, ISColoringType ctype, ISColoring *coloring)
    1487: {
    1488:   PetscFunctionBegin;
    1490:   PetscAssertPointer(coloring, 3);
    1491:   PetscUseTypeMethod(dm, getcoloring, ctype, coloring);
    1492:   PetscFunctionReturn(PETSC_SUCCESS);
    1493: }

    1495: /*@
    1496:   DMCreateMatrix - Gets an empty matrix for a `DM` that is most commonly used to store the Jacobian of a discrete PDE operator.

    1498:   Collective

    1500:   Input Parameter:
    1501: . dm - the `DM` object

    1503:   Output Parameter:
    1504: . mat - the empty Jacobian

    1506:   Options Database Key:
    1507: . -dm_preallocate_only - Only preallocate the matrix for `DMCreateMatrix()` and `DMCreateMassMatrix()`, but do not fill it with zeros

    1509:   Level: beginner

    1511:   Notes:
    1512:   This properly preallocates the number of nonzeros in the sparse matrix so you
    1513:   do not need to do it yourself.

    1515:   By default it also sets the nonzero structure and puts in the zero entries. To prevent setting
    1516:   the nonzero pattern call `DMSetMatrixPreallocateOnly()`

    1518:   For `DMDA`, when you call `MatView()` on this matrix it is displayed using the global natural ordering, NOT in the ordering used
    1519:   internally by PETSc.

    1521:   For `DMDA`, in general it is easiest to use `MatSetValuesStencil()` or `MatSetValuesLocal()` to put values into the matrix because
    1522:   `MatSetValues()` requires the indices for the global numbering for the `DMDA` which is complic`ated to compute

    1524: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMSetMatType()`, `DMCreateMassMatrix()`
    1525: @*/
    1526: PetscErrorCode DMCreateMatrix(DM dm, Mat *mat)
    1527: {
    1528:   PetscFunctionBegin;
    1530:   PetscAssertPointer(mat, 2);
    1531:   PetscCall(MatInitializePackage());
    1532:   PetscCall(PetscLogEventBegin(DM_CreateMatrix, 0, 0, 0, 0));
    1533:   PetscUseTypeMethod(dm, creatematrix, mat);
    1534:   if (PetscDefined(USE_DEBUG)) {
    1535:     DM mdm;

    1537:     PetscCall(MatGetDM(*mat, &mdm));
    1538:     PetscCheck(mdm, PETSC_COMM_SELF, PETSC_ERR_PLIB, "DM type '%s' did not attach the DM to the matrix", ((PetscObject)dm)->type_name);
    1539:   }
    1540:   /* Handle nullspace and near nullspace */
    1541:   if (dm->Nf) {
    1542:     MatNullSpace nullSpace;
    1543:     PetscInt     Nf, f;

    1545:     PetscCall(DMGetNumFields(dm, &Nf));
    1546:     for (f = 0; f < Nf; ++f) {
    1547:       if (dm->nullspaceConstructors && dm->nullspaceConstructors[f]) {
    1548:         PetscCall((*dm->nullspaceConstructors[f])(dm, f, f, &nullSpace));
    1549:         PetscCall(MatSetNullSpace(*mat, nullSpace));
    1550:         PetscCall(MatNullSpaceDestroy(&nullSpace));
    1551:         break;
    1552:       }
    1553:     }
    1554:     for (f = 0; f < Nf; ++f) {
    1555:       if (dm->nearnullspaceConstructors && dm->nearnullspaceConstructors[f]) {
    1556:         PetscCall((*dm->nearnullspaceConstructors[f])(dm, f, f, &nullSpace));
    1557:         PetscCall(MatSetNearNullSpace(*mat, nullSpace));
    1558:         PetscCall(MatNullSpaceDestroy(&nullSpace));
    1559:       }
    1560:     }
    1561:   }
    1562:   PetscCall(PetscLogEventEnd(DM_CreateMatrix, 0, 0, 0, 0));
    1563:   PetscFunctionReturn(PETSC_SUCCESS);
    1564: }

    1566: /*@
    1567:   DMSetMatrixPreallocateSkip - When `DMCreateMatrix()` is called the matrix sizes and
    1568:   `ISLocalToGlobalMapping` will be properly set, but the data structures to store values in the
    1569:   matrices will not be preallocated.

    1571:   Logically Collective

    1573:   Input Parameters:
    1574: + dm   - the `DM`
    1575: - skip - `PETSC_TRUE` to skip preallocation

    1577:   Level: developer

    1579:   Note:
    1580:   This is most useful to reduce initialization costs when `MatSetPreallocationCOO()` and
    1581:   `MatSetValuesCOO()` will be used.

    1583: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `DMSetMatrixStructureOnly()`, `DMSetMatrixPreallocateOnly()`
    1584: @*/
    1585: PetscErrorCode DMSetMatrixPreallocateSkip(DM dm, PetscBool skip)
    1586: {
    1587:   PetscFunctionBegin;
    1589:   dm->prealloc_skip = skip;
    1590:   PetscFunctionReturn(PETSC_SUCCESS);
    1591: }

    1593: /*@
    1594:   DMSetMatrixPreallocateOnly - When `DMCreateMatrix()` is called the matrix will be properly
    1595:   preallocated but the nonzero structure and zero values will not be set.

    1597:   Logically Collective

    1599:   Input Parameters:
    1600: + dm   - the `DM`
    1601: - only - `PETSC_TRUE` if only want preallocation

    1603:   Options Database Key:
    1604: . -dm_preallocate_only - Only preallocate the matrix for `DMCreateMatrix()`, `DMCreateMassMatrix()`, but do not fill it with zeros

    1606:   Level: developer

    1608: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixStructureOnly()`, `DMSetMatrixPreallocateSkip()`
    1609: @*/
    1610: PetscErrorCode DMSetMatrixPreallocateOnly(DM dm, PetscBool only)
    1611: {
    1612:   PetscFunctionBegin;
    1614:   dm->prealloc_only = only;
    1615:   PetscFunctionReturn(PETSC_SUCCESS);
    1616: }

    1618: /*@
    1619:   DMSetMatrixStructureOnly - When `DMCreateMatrix()` is called, the matrix nonzero structure will be created
    1620:   but the array for numerical values will not be allocated.

    1622:   Logically Collective

    1624:   Input Parameters:
    1625: + dm   - the `DM`
    1626: - only - `PETSC_TRUE` if you only want matrix nonzero structure

    1628:   Level: developer

    1630: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `DMSetMatrixPreallocateOnly()`, `DMSetMatrixPreallocateSkip()`
    1631: @*/
    1632: PetscErrorCode DMSetMatrixStructureOnly(DM dm, PetscBool only)
    1633: {
    1634:   PetscFunctionBegin;
    1636:   dm->structure_only = only;
    1637:   PetscFunctionReturn(PETSC_SUCCESS);
    1638: }

    1640: /*@
    1641:   DMSetBlockingType - set the blocking granularity to be used for variable block size `DMCreateMatrix()` is called

    1643:   Logically Collective

    1645:   Input Parameters:
    1646: + dm    - the `DM`
    1647: - btype - block by topological point or field node

    1649:   Options Database Key:
    1650: . -dm_blocking_type [topological_point, field_node] - use topological point blocking or field node blocking

    1652:   Level: advanced

    1654: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `MatSetVariableBlockSizes()`
    1655: @*/
    1656: PetscErrorCode DMSetBlockingType(DM dm, DMBlockingType btype)
    1657: {
    1658:   PetscFunctionBegin;
    1660:   dm->blocking_type = btype;
    1661:   PetscFunctionReturn(PETSC_SUCCESS);
    1662: }

    1664: /*@
    1665:   DMGetBlockingType - get the blocking granularity to be used for variable block size `DMCreateMatrix()` is called

    1667:   Not Collective

    1669:   Input Parameter:
    1670: . dm - the `DM`

    1672:   Output Parameter:
    1673: . btype - block by topological point or field node

    1675:   Level: advanced

    1677: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `MatSetVariableBlockSizes()`
    1678: @*/
    1679: PetscErrorCode DMGetBlockingType(DM dm, DMBlockingType *btype)
    1680: {
    1681:   PetscFunctionBegin;
    1683:   PetscAssertPointer(btype, 2);
    1684:   *btype = dm->blocking_type;
    1685:   PetscFunctionReturn(PETSC_SUCCESS);
    1686: }

    1688: /*@C
    1689:   DMGetWorkArray - Gets a work array guaranteed to be at least the input size, restore with `DMRestoreWorkArray()`

    1691:   Not Collective

    1693:   Input Parameters:
    1694: + dm    - the `DM` object
    1695: . count - The minimum size
    1696: - dtype - MPI data type, often `MPIU_REAL`, `MPIU_SCALAR`, or `MPIU_INT`)

    1698:   Output Parameter:
    1699: . mem - the work array

    1701:   Level: developer

    1703:   Notes:
    1704:   A `DM` may stash the array between instantiations so using this routine may be more efficient than calling `PetscMalloc()`

    1706:   The array may contain nonzero values

    1708: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMCreate()`, `DMRestoreWorkArray()`, `PetscMalloc()`
    1709: @*/
    1710: PetscErrorCode DMGetWorkArray(DM dm, PetscInt count, MPI_Datatype dtype, void *mem)
    1711: {
    1712:   DMWorkLink  link;
    1713:   PetscMPIInt dsize;

    1715:   PetscFunctionBegin;
    1717:   PetscAssertPointer(mem, 4);
    1718:   if (!count) {
    1719:     *(void **)mem = NULL;
    1720:     PetscFunctionReturn(PETSC_SUCCESS);
    1721:   }
    1722:   if (dm->workin) {
    1723:     link       = dm->workin;
    1724:     dm->workin = dm->workin->next;
    1725:   } else {
    1726:     PetscCall(PetscNew(&link));
    1727:   }
    1728:   /* Avoid MPI_Type_size for most used datatypes
    1729:      Get size directly */
    1730:   if (dtype == MPIU_INT) dsize = sizeof(PetscInt);
    1731:   else if (dtype == MPIU_REAL) dsize = sizeof(PetscReal);
    1732: #if defined(PETSC_USE_64BIT_INDICES)
    1733:   else if (dtype == MPI_INT) dsize = sizeof(int);
    1734: #endif
    1735: #if defined(PETSC_USE_COMPLEX)
    1736:   else if (dtype == MPIU_SCALAR) dsize = sizeof(PetscScalar);
    1737: #endif
    1738:   else PetscCallMPI(MPI_Type_size(dtype, &dsize));

    1740:   if (((size_t)dsize * count) > link->bytes) {
    1741:     PetscCall(PetscFree(link->mem));
    1742:     PetscCall(PetscMalloc(dsize * count, &link->mem));
    1743:     link->bytes = dsize * count;
    1744:   }
    1745:   link->next    = dm->workout;
    1746:   dm->workout   = link;
    1747:   *(void **)mem = link->mem;
    1748:   PetscFunctionReturn(PETSC_SUCCESS);
    1749: }

    1751: /*@C
    1752:   DMRestoreWorkArray - Restores a work array obtained with `DMCreateWorkArray()`

    1754:   Not Collective

    1756:   Input Parameters:
    1757: + dm    - the `DM` object
    1758: . count - The minimum size
    1759: - dtype - MPI data type, often `MPIU_REAL`, `MPIU_SCALAR`, `MPIU_INT`

    1761:   Output Parameter:
    1762: . mem - the work array

    1764:   Level: developer

    1766:   Developer Note:
    1767:   count and dtype are ignored, they are only needed for `DMGetWorkArray()`

    1769: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMCreate()`, `DMGetWorkArray()`
    1770: @*/
    1771: PetscErrorCode DMRestoreWorkArray(DM dm, PetscInt count, MPI_Datatype dtype, void *mem)
    1772: {
    1773:   DMWorkLink *p, link;

    1775:   PetscFunctionBegin;
    1776:   PetscAssertPointer(mem, 4);
    1777:   (void)count;
    1778:   (void)dtype;
    1779:   if (!*(void **)mem) PetscFunctionReturn(PETSC_SUCCESS);
    1780:   for (p = &dm->workout; (link = *p); p = &link->next) {
    1781:     if (link->mem == *(void **)mem) {
    1782:       *p            = link->next;
    1783:       link->next    = dm->workin;
    1784:       dm->workin    = link;
    1785:       *(void **)mem = NULL;
    1786:       PetscFunctionReturn(PETSC_SUCCESS);
    1787:     }
    1788:   }
    1789:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Array was not checked out");
    1790: }

    1792: /*@C
    1793:   DMSetNullSpaceConstructor - Provide a callback function which constructs the nullspace for a given field, defined with `DMAddField()`, when function spaces
    1794:   are joined or split, such as in `DMCreateSubDM()`

    1796:   Logically Collective; No Fortran Support

    1798:   Input Parameters:
    1799: + dm     - The `DM`
    1800: . field  - The field number for the nullspace
    1801: - nullsp - A callback to create the nullspace

    1803:   Calling sequence of `nullsp`:
    1804: + dm        - The present `DM`
    1805: . origField - The field number given above, in the original `DM`
    1806: . field     - The field number in dm
    1807: - nullSpace - The nullspace for the given field

    1809:   Level: intermediate

    1811: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetNullSpaceConstructor()`, `DMSetNearNullSpaceConstructor()`, `DMGetNearNullSpaceConstructor()`, `DMCreateSubDM()`, `DMCreateSuperDM()`
    1812: @*/
    1813: PetscErrorCode DMSetNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (*nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1814: {
    1815:   PetscFunctionBegin;
    1817:   PetscCheck(field < dm->Nf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= %" PetscInt_FMT " fields", field, dm->Nf);
    1818:   PetscCheck(dm->nullspaceConstructors, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Must call DMCreateDS() to setup nullspaces");
    1819:   dm->nullspaceConstructors[field] = nullsp;
    1820:   PetscFunctionReturn(PETSC_SUCCESS);
    1821: }

    1823: /*@C
    1824:   DMGetNullSpaceConstructor - Return the callback function which constructs the nullspace for a given field, defined with `DMAddField()`

    1826:   Not Collective; No Fortran Support

    1828:   Input Parameters:
    1829: + dm    - The `DM`
    1830: - field - The field number for the nullspace

    1832:   Output Parameter:
    1833: . nullsp - A callback to create the nullspace

    1835:   Calling sequence of `nullsp`:
    1836: + dm        - The present DM
    1837: . origField - The field number given above, in the original DM
    1838: . field     - The field number in dm
    1839: - nullSpace - The nullspace for the given field

    1841:   Level: intermediate

    1843: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`, `DMSetNullSpaceConstructor()`, `DMSetNearNullSpaceConstructor()`, `DMGetNearNullSpaceConstructor()`, `DMCreateSubDM()`, `DMCreateSuperDM()`
    1844: @*/
    1845: PetscErrorCode DMGetNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (**nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1846: {
    1847:   PetscFunctionBegin;
    1849:   PetscAssertPointer(nullsp, 3);
    1850:   PetscCheck(field < dm->Nf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= %" PetscInt_FMT " fields", field, dm->Nf);
    1851:   PetscCheck(dm->nullspaceConstructors, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Must call DMCreateDS() to setup nullspaces");
    1852:   *nullsp = dm->nullspaceConstructors[field];
    1853:   PetscFunctionReturn(PETSC_SUCCESS);
    1854: }

    1856: /*@C
    1857:   DMSetNearNullSpaceConstructor - Provide a callback function which constructs the near-nullspace for a given field, defined with `DMAddField()`

    1859:   Logically Collective; No Fortran Support

    1861:   Input Parameters:
    1862: + dm     - The `DM`
    1863: . field  - The field number for the nullspace
    1864: - nullsp - A callback to create the near-nullspace

    1866:   Calling sequence of `nullsp`:
    1867: + dm        - The present `DM`
    1868: . origField - The field number given above, in the original `DM`
    1869: . field     - The field number in dm
    1870: - nullSpace - The nullspace for the given field

    1872:   Level: intermediate

    1874: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetNearNullSpaceConstructor()`, `DMSetNullSpaceConstructor()`, `DMGetNullSpaceConstructor()`, `DMCreateSubDM()`, `DMCreateSuperDM()`,
    1875:           `MatNullSpace`
    1876: @*/
    1877: PetscErrorCode DMSetNearNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (*nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1878: {
    1879:   PetscFunctionBegin;
    1881:   PetscCheck(field < dm->Nf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= %" PetscInt_FMT " fields", field, dm->Nf);
    1882:   PetscCheck(dm->nearnullspaceConstructors, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Must call DMCreateDS() to setup nullspaces");
    1883:   dm->nearnullspaceConstructors[field] = nullsp;
    1884:   PetscFunctionReturn(PETSC_SUCCESS);
    1885: }

    1887: /*@C
    1888:   DMGetNearNullSpaceConstructor - Return the callback function which constructs the near-nullspace for a given field, defined with `DMAddField()`

    1890:   Not Collective; No Fortran Support

    1892:   Input Parameters:
    1893: + dm    - The `DM`
    1894: - field - The field number for the nullspace

    1896:   Output Parameter:
    1897: . nullsp - A callback to create the near-nullspace

    1899:   Calling sequence of `nullsp`:
    1900: + dm        - The present `DM`
    1901: . origField - The field number given above, in the original `DM`
    1902: . field     - The field number in dm
    1903: - nullSpace - The nullspace for the given field

    1905:   Level: intermediate

    1907: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`, `DMSetNearNullSpaceConstructor()`, `DMSetNullSpaceConstructor()`, `DMGetNullSpaceConstructor()`, `DMCreateSubDM()`,
    1908:           `MatNullSpace`, `DMCreateSuperDM()`
    1909: @*/
    1910: PetscErrorCode DMGetNearNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (**nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1911: {
    1912:   PetscFunctionBegin;
    1914:   PetscAssertPointer(nullsp, 3);
    1915:   PetscCheck(field < dm->Nf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= %" PetscInt_FMT " fields", field, dm->Nf);
    1916:   PetscCheck(dm->nearnullspaceConstructors, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Must call DMCreateDS() to setup nullspaces");
    1917:   *nullsp = dm->nearnullspaceConstructors[field];
    1918:   PetscFunctionReturn(PETSC_SUCCESS);
    1919: }

    1921: /*@C
    1922:   DMCreateFieldIS - Creates a set of `IS` objects with the global indices of dofs for each field defined with `DMAddField()`

    1924:   Not Collective; No Fortran Support

    1926:   Input Parameter:
    1927: . dm - the `DM` object

    1929:   Output Parameters:
    1930: + numFields  - The number of fields (or `NULL` if not requested)
    1931: . fieldNames - The name of each field (or `NULL` if not requested)
    1932: - fields     - The global indices for each field (or `NULL` if not requested)

    1934:   Level: intermediate

    1936:   Note:
    1937:   The user is responsible for freeing all requested arrays. In particular, every entry of `fieldNames` should be freed with
    1938:   `PetscFree()`, every entry of `fields` should be destroyed with `ISDestroy()`, and both arrays should be freed with
    1939:   `PetscFree()`.

    1941:   Developer Note:
    1942:   It is not clear why both this function and `DMCreateFieldDecomposition()` exist. Having two seems redundant and confusing. This function should
    1943:   likely be removed.

    1945: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`,
    1946:           `DMCreateFieldDecomposition()`
    1947: @*/
    1948: PetscErrorCode DMCreateFieldIS(DM dm, PetscInt *numFields, char ***fieldNames, IS *fields[])
    1949: {
    1950:   PetscSection section, sectionGlobal;

    1952:   PetscFunctionBegin;
    1954:   if (numFields) {
    1955:     PetscAssertPointer(numFields, 2);
    1956:     *numFields = 0;
    1957:   }
    1958:   if (fieldNames) {
    1959:     PetscAssertPointer(fieldNames, 3);
    1960:     *fieldNames = NULL;
    1961:   }
    1962:   if (fields) {
    1963:     PetscAssertPointer(fields, 4);
    1964:     *fields = NULL;
    1965:   }
    1966:   PetscCall(DMGetLocalSection(dm, &section));
    1967:   if (section) {
    1968:     PetscInt *fieldSizes, *fieldNc, **fieldIndices;
    1969:     PetscInt  nF, f, pStart, pEnd, p;

    1971:     PetscCall(DMGetGlobalSection(dm, &sectionGlobal));
    1972:     PetscCall(PetscSectionGetNumFields(section, &nF));
    1973:     PetscCall(PetscMalloc3(nF, &fieldSizes, nF, &fieldNc, nF, &fieldIndices));
    1974:     PetscCall(PetscSectionGetChart(sectionGlobal, &pStart, &pEnd));
    1975:     for (f = 0; f < nF; ++f) {
    1976:       fieldSizes[f] = 0;
    1977:       PetscCall(PetscSectionGetFieldComponents(section, f, &fieldNc[f]));
    1978:     }
    1979:     for (p = pStart; p < pEnd; ++p) {
    1980:       PetscInt gdof;

    1982:       PetscCall(PetscSectionGetDof(sectionGlobal, p, &gdof));
    1983:       if (gdof > 0) {
    1984:         for (f = 0; f < nF; ++f) {
    1985:           PetscInt fdof, fcdof, fpdof;

    1987:           PetscCall(PetscSectionGetFieldDof(section, p, f, &fdof));
    1988:           PetscCall(PetscSectionGetFieldConstraintDof(section, p, f, &fcdof));
    1989:           fpdof = fdof - fcdof;
    1990:           if (fpdof && fpdof != fieldNc[f]) {
    1991:             /* Layout does not admit a pointwise block size */
    1992:             fieldNc[f] = 1;
    1993:           }
    1994:           fieldSizes[f] += fpdof;
    1995:         }
    1996:       }
    1997:     }
    1998:     for (f = 0; f < nF; ++f) {
    1999:       PetscCall(PetscMalloc1(fieldSizes[f], &fieldIndices[f]));
    2000:       fieldSizes[f] = 0;
    2001:     }
    2002:     for (p = pStart; p < pEnd; ++p) {
    2003:       PetscInt gdof, goff;

    2005:       PetscCall(PetscSectionGetDof(sectionGlobal, p, &gdof));
    2006:       if (gdof > 0) {
    2007:         PetscCall(PetscSectionGetOffset(sectionGlobal, p, &goff));
    2008:         for (f = 0; f < nF; ++f) {
    2009:           PetscInt fdof, fcdof, fc;

    2011:           PetscCall(PetscSectionGetFieldDof(section, p, f, &fdof));
    2012:           PetscCall(PetscSectionGetFieldConstraintDof(section, p, f, &fcdof));
    2013:           for (fc = 0; fc < fdof - fcdof; ++fc, ++fieldSizes[f]) fieldIndices[f][fieldSizes[f]] = goff++;
    2014:         }
    2015:       }
    2016:     }
    2017:     if (numFields) *numFields = nF;
    2018:     if (fieldNames) {
    2019:       PetscCall(PetscMalloc1(nF, fieldNames));
    2020:       for (f = 0; f < nF; ++f) {
    2021:         const char *fieldName;

    2023:         PetscCall(PetscSectionGetFieldName(section, f, &fieldName));
    2024:         PetscCall(PetscStrallocpy(fieldName, &(*fieldNames)[f]));
    2025:       }
    2026:     }
    2027:     if (fields) {
    2028:       PetscCall(PetscMalloc1(nF, fields));
    2029:       for (f = 0; f < nF; ++f) {
    2030:         PetscInt bs, in[2], out[2];

    2032:         PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)dm), fieldSizes[f], fieldIndices[f], PETSC_OWN_POINTER, &(*fields)[f]));
    2033:         in[0] = -fieldNc[f];
    2034:         in[1] = fieldNc[f];
    2035:         PetscCallMPI(MPIU_Allreduce(in, out, 2, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)dm)));
    2036:         bs = (-out[0] == out[1]) ? out[1] : 1;
    2037:         PetscCall(ISSetBlockSize((*fields)[f], bs));
    2038:       }
    2039:     }
    2040:     PetscCall(PetscFree3(fieldSizes, fieldNc, fieldIndices));
    2041:   } else PetscTryTypeMethod(dm, createfieldis, numFields, fieldNames, fields);
    2042:   PetscFunctionReturn(PETSC_SUCCESS);
    2043: }

    2045: /*@C
    2046:   DMCreateFieldDecomposition - Returns a list of `IS` objects defining a decomposition of a problem into subproblems
    2047:   corresponding to different fields.

    2049:   Not Collective; No Fortran Support

    2051:   Input Parameter:
    2052: . dm - the `DM` object

    2054:   Output Parameters:
    2055: + len      - The number of fields (or `NULL` if not requested)
    2056: . namelist - The name for each field (or `NULL` if not requested)
    2057: . islist   - The global indices for each field (or `NULL` if not requested)
    2058: - dmlist   - The `DM`s for each field subproblem (or `NULL`, if not requested; if `NULL` is returned, no `DM`s are defined)

    2060:   Level: intermediate

    2062:   Notes:
    2063:   Each `IS` contains the global indices of the dofs of the corresponding field, defined by
    2064:   `DMAddField()`. The optional list of `DM`s define the `DM` for each subproblem.

    2066:   The same as `DMCreateFieldIS()` but also returns a `DM` for each field.

    2068:   The user is responsible for freeing all requested arrays. In particular, every entry of `namelist` should be freed with
    2069:   `PetscFree()`, every entry of `islist` should be destroyed with `ISDestroy()`, every entry of `dmlist` should be destroyed with `DMDestroy()`,
    2070:   and all of the arrays should be freed with `PetscFree()`.

    2072:   Fortran Notes:
    2073:   Use the declarations
    2074: .vb
    2075:   character(80), pointer :: namelist(:)
    2076:   IS, pointer :: islist(:)
    2077:   DM, pointer :: dmlist(:)
    2078: .ve

    2080:   `namelist` must be provided, `islist` may be `PETSC_NULL_IS_POINTER` and `dmlist` may be `PETSC_NULL_DM_POINTER`

    2082:   Use `DMDestroyFieldDecomposition()` to free the returned objects

    2084:   Developer Notes:
    2085:   It is not clear why this function and `DMCreateFieldIS()` exist. Having two seems redundant and confusing.

    2087:   Unlike  `DMRefine()`, `DMCoarsen()`, and `DMCreateDomainDecomposition()` this provides no mechanism to provide hooks that are called after the
    2088:   decomposition is computed.

    2090: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMCreateFieldIS()`, `DMCreateSubDM()`, `DMCreateDomainDecomposition()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`
    2091: @*/
    2092: PetscErrorCode DMCreateFieldDecomposition(DM dm, PetscInt *len, char ***namelist, IS *islist[], DM *dmlist[])
    2093: {
    2094:   PetscFunctionBegin;
    2096:   if (len) {
    2097:     PetscAssertPointer(len, 2);
    2098:     *len = 0;
    2099:   }
    2100:   if (namelist) {
    2101:     PetscAssertPointer(namelist, 3);
    2102:     *namelist = NULL;
    2103:   }
    2104:   if (islist) {
    2105:     PetscAssertPointer(islist, 4);
    2106:     *islist = NULL;
    2107:   }
    2108:   if (dmlist) {
    2109:     PetscAssertPointer(dmlist, 5);
    2110:     *dmlist = NULL;
    2111:   }
    2112:   /*
    2113:    Is it a good idea to apply the following check across all impls?
    2114:    Perhaps some impls can have a well-defined decomposition before DMSetUp?
    2115:    This, however, follows the general principle that accessors are not well-behaved until the object is set up.
    2116:    */
    2117:   PetscCheck(dm->setupcalled, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Decomposition defined only after DMSetUp");
    2118:   if (!dm->ops->createfielddecomposition) {
    2119:     PetscSection section;
    2120:     PetscInt     numFields, f;

    2122:     PetscCall(DMGetLocalSection(dm, &section));
    2123:     if (section) PetscCall(PetscSectionGetNumFields(section, &numFields));
    2124:     if (section && numFields && dm->ops->createsubdm) {
    2125:       if (len) *len = numFields;
    2126:       if (namelist) PetscCall(PetscMalloc1(numFields, namelist));
    2127:       if (islist) PetscCall(PetscMalloc1(numFields, islist));
    2128:       if (dmlist) PetscCall(PetscMalloc1(numFields, dmlist));
    2129:       for (f = 0; f < numFields; ++f) {
    2130:         const char *fieldName;

    2132:         PetscCall(DMCreateSubDM(dm, 1, &f, islist ? &(*islist)[f] : NULL, dmlist ? &(*dmlist)[f] : NULL));
    2133:         if (namelist) {
    2134:           PetscCall(PetscSectionGetFieldName(section, f, &fieldName));
    2135:           PetscCall(PetscStrallocpy(fieldName, &(*namelist)[f]));
    2136:         }
    2137:       }
    2138:     } else {
    2139:       PetscCall(DMCreateFieldIS(dm, len, namelist, islist));
    2140:       /* By default there are no DMs associated with subproblems. */
    2141:       if (dmlist) *dmlist = NULL;
    2142:     }
    2143:   } else PetscUseTypeMethod(dm, createfielddecomposition, len, namelist, islist, dmlist);
    2144:   PetscFunctionReturn(PETSC_SUCCESS);
    2145: }

    2147: /*@
    2148:   DMCreateSubDM - Returns an `IS` and `DM` encapsulating a subproblem defined by the fields passed in.
    2149:   The fields are defined by `DMCreateFieldIS()`.

    2151:   Not collective

    2153:   Input Parameters:
    2154: + dm        - The `DM` object
    2155: . numFields - The number of fields to select
    2156: - fields    - The field numbers of the selected fields

    2158:   Output Parameters:
    2159: + is    - The global indices for all the degrees of freedom in the new sub `DM`, use `NULL` if not needed
    2160: - subdm - The `DM` for the subproblem, use `NULL` if not needed

    2162:   Level: intermediate

    2164:   Note:
    2165:   You need to call `DMPlexSetMigrationSF()` on the original `DM` if you want the Global-To-Natural map to be automatically constructed

    2167: .seealso: [](ch_dmbase), `DM`, `DMCreateFieldIS()`, `DMCreateFieldDecomposition()`, `DMAddField()`, `DMCreateSuperDM()`, `IS`, `VecISCopy()`, `DMPlexSetMigrationSF()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`
    2168: @*/
    2169: PetscErrorCode DMCreateSubDM(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm)
    2170: {
    2171:   PetscFunctionBegin;
    2173:   PetscAssertPointer(fields, 3);
    2174:   if (is) PetscAssertPointer(is, 4);
    2175:   if (subdm) PetscAssertPointer(subdm, 5);
    2176:   PetscUseTypeMethod(dm, createsubdm, numFields, fields, is, subdm);
    2177:   PetscFunctionReturn(PETSC_SUCCESS);
    2178: }

    2180: /*@C
    2181:   DMCreateSuperDM - Returns an arrays of `IS` and a single `DM` encapsulating a superproblem defined by multiple `DM`s passed in.

    2183:   Not collective

    2185:   Input Parameters:
    2186: + dms - The `DM` objects
    2187: - n   - The number of `DM`s

    2189:   Output Parameters:
    2190: + is      - The global indices for each of subproblem within the super `DM`, or `NULL`, its length is `n`
    2191: - superdm - The `DM` for the superproblem

    2193:   Level: intermediate

    2195:   Note:
    2196:   You need to call `DMPlexSetMigrationSF()` on the original `DM` if you want the Global-To-Natural map to be automatically constructed

    2198: .seealso: [](ch_dmbase), `DM`, `DMCreateSubDM()`, `DMPlexSetMigrationSF()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMCreateFieldIS()`, `DMCreateDomainDecomposition()`
    2199: @*/
    2200: PetscErrorCode DMCreateSuperDM(DM dms[], PetscInt n, IS *is[], DM *superdm)
    2201: {
    2202:   PetscInt i;

    2204:   PetscFunctionBegin;
    2205:   PetscAssertPointer(dms, 1);
    2207:   if (is) PetscAssertPointer(is, 3);
    2208:   PetscAssertPointer(superdm, 4);
    2209:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of DMs must be nonnegative: %" PetscInt_FMT, n);
    2210:   if (n) {
    2211:     DM dm = dms[0];
    2212:     PetscCheck(dm->ops->createsuperdm, PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "No method createsuperdm for DM of type %s", ((PetscObject)dm)->type_name);
    2213:     PetscCall((*dm->ops->createsuperdm)(dms, n, is, superdm));
    2214:   }
    2215:   PetscFunctionReturn(PETSC_SUCCESS);
    2216: }

    2218: /*@C
    2219:   DMCreateDomainDecomposition - Returns lists of `IS` objects defining a decomposition of a
    2220:   problem into subproblems corresponding to restrictions to pairs of nested subdomains.

    2222:   Not Collective

    2224:   Input Parameter:
    2225: . dm - the `DM` object

    2227:   Output Parameters:
    2228: + n           - The number of subproblems in the domain decomposition (or `NULL` if not requested), also the length of the four arrays below
    2229: . namelist    - The name for each subdomain (or `NULL` if not requested)
    2230: . innerislist - The global indices for each inner subdomain (or `NULL`, if not requested)
    2231: . outerislist - The global indices for each outer subdomain (or `NULL`, if not requested)
    2232: - dmlist      - The `DM`s for each subdomain subproblem (or `NULL`, if not requested; if `NULL` is returned, no `DM`s are defined)

    2234:   Level: intermediate

    2236:   Notes:
    2237:   Each `IS` contains the global indices of the dofs of the corresponding subdomains with in the
    2238:   dofs of the original `DM`. The inner subdomains conceptually define a nonoverlapping
    2239:   covering, while outer subdomains can overlap.

    2241:   The optional list of `DM`s define a `DM` for each subproblem.

    2243:   The user is responsible for freeing all requested arrays. In particular, every entry of `namelist` should be freed with
    2244:   `PetscFree()`, every entry of `innerislist` and `outerislist` should be destroyed with `ISDestroy()`, every entry of `dmlist` should be destroyed with `DMDestroy()`,
    2245:   and all of the arrays should be freed with `PetscFree()`.

    2247:   Developer Notes:
    2248:   The `dmlist` is for the inner subdomains or the outer subdomains or all subdomains?

    2250:   The names are inconsistent, the hooks use `DMSubDomainHook` which is nothing like `DMCreateDomainDecomposition()` while `DMRefineHook` is used for `DMRefine()`.

    2252: .seealso: [](ch_dmbase), `DM`, `DMCreateFieldDecomposition()`, `DMDestroy()`, `DMCreateDomainDecompositionScatters()`, `DMView()`, `DMCreateInterpolation()`,
    2253:           `DMSubDomainHookAdd()`, `DMSubDomainHookRemove()`,`DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`
    2254: @*/
    2255: PetscErrorCode DMCreateDomainDecomposition(DM dm, PetscInt *n, char ***namelist, IS *innerislist[], IS *outerislist[], DM *dmlist[])
    2256: {
    2257:   DMSubDomainHookLink link;
    2258:   PetscInt            i, l;

    2260:   PetscFunctionBegin;
    2262:   if (n) {
    2263:     PetscAssertPointer(n, 2);
    2264:     *n = 0;
    2265:   }
    2266:   if (namelist) {
    2267:     PetscAssertPointer(namelist, 3);
    2268:     *namelist = NULL;
    2269:   }
    2270:   if (innerislist) {
    2271:     PetscAssertPointer(innerislist, 4);
    2272:     *innerislist = NULL;
    2273:   }
    2274:   if (outerislist) {
    2275:     PetscAssertPointer(outerislist, 5);
    2276:     *outerislist = NULL;
    2277:   }
    2278:   if (dmlist) {
    2279:     PetscAssertPointer(dmlist, 6);
    2280:     *dmlist = NULL;
    2281:   }
    2282:   /*
    2283:    Is it a good idea to apply the following check across all impls?
    2284:    Perhaps some impls can have a well-defined decomposition before DMSetUp?
    2285:    This, however, follows the general principle that accessors are not well-behaved until the object is set up.
    2286:    */
    2287:   PetscCheck(dm->setupcalled, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Decomposition defined only after DMSetUp");
    2288:   if (dm->ops->createdomaindecomposition) {
    2289:     PetscUseTypeMethod(dm, createdomaindecomposition, &l, namelist, innerislist, outerislist, dmlist);
    2290:     /* copy subdomain hooks and context over to the subdomain DMs */
    2291:     if (dmlist && *dmlist) {
    2292:       for (i = 0; i < l; i++) {
    2293:         for (link = dm->subdomainhook; link; link = link->next) {
    2294:           if (link->ddhook) PetscCall((*link->ddhook)(dm, (*dmlist)[i], link->ctx));
    2295:         }
    2296:         if (dm->ctx) (*dmlist)[i]->ctx = dm->ctx;
    2297:       }
    2298:     }
    2299:     if (n) *n = l;
    2300:   }
    2301:   PetscFunctionReturn(PETSC_SUCCESS);
    2302: }

    2304: /*@C
    2305:   DMCreateDomainDecompositionScatters - Returns scatters to the subdomain vectors from the global vector for subdomains created with
    2306:   `DMCreateDomainDecomposition()`

    2308:   Not Collective

    2310:   Input Parameters:
    2311: + dm     - the `DM` object
    2312: . n      - the number of subdomains
    2313: - subdms - the local subdomains

    2315:   Output Parameters:
    2316: + iscat - scatter from global vector to nonoverlapping global vector entries on subdomain
    2317: . oscat - scatter from global vector to overlapping global vector entries on subdomain
    2318: - gscat - scatter from global vector to local vector on subdomain (fills in ghosts)

    2320:   Level: developer

    2322:   Note:
    2323:   This is an alternative to the iis and ois arguments in `DMCreateDomainDecomposition()` that allow for the solution
    2324:   of general nonlinear problems with overlapping subdomain methods.  While merely having index sets that enable subsets
    2325:   of the residual equations to be created is fine for linear problems, nonlinear problems require local assembly of
    2326:   solution and residual data.

    2328:   Developer Note:
    2329:   Can the subdms input be anything or are they exactly the `DM` obtained from
    2330:   `DMCreateDomainDecomposition()`?

    2332: .seealso: [](ch_dmbase), `DM`, `DMCreateDomainDecomposition()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMCreateFieldIS()`
    2333: @*/
    2334: PetscErrorCode DMCreateDomainDecompositionScatters(DM dm, PetscInt n, DM *subdms, VecScatter *iscat[], VecScatter *oscat[], VecScatter *gscat[])
    2335: {
    2336:   PetscFunctionBegin;
    2338:   PetscAssertPointer(subdms, 3);
    2339:   PetscUseTypeMethod(dm, createddscatters, n, subdms, iscat, oscat, gscat);
    2340:   PetscFunctionReturn(PETSC_SUCCESS);
    2341: }

    2343: /*@
    2344:   DMRefine - Refines a `DM` object using a standard nonadaptive refinement of the underlying mesh

    2346:   Collective

    2348:   Input Parameters:
    2349: + dm   - the `DM` object
    2350: - comm - the communicator to contain the new `DM` object (or `MPI_COMM_NULL`)

    2352:   Output Parameter:
    2353: . dmf - the refined `DM`, or `NULL`

    2355:   Options Database Key:
    2356: . -dm_plex_cell_refiner <strategy> - chooses the refinement strategy, e.g. regular, tohex

    2358:   Level: developer

    2360:   Note:
    2361:   If no refinement was done, the return value is `NULL`

    2363: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateDomainDecomposition()`,
    2364:           `DMRefineHookAdd()`, `DMRefineHookRemove()`
    2365: @*/
    2366: PetscErrorCode DMRefine(DM dm, MPI_Comm comm, DM *dmf)
    2367: {
    2368:   DMRefineHookLink link;

    2370:   PetscFunctionBegin;
    2372:   PetscCall(PetscLogEventBegin(DM_Refine, dm, 0, 0, 0));
    2373:   PetscUseTypeMethod(dm, refine, comm, dmf);
    2374:   if (*dmf) {
    2375:     (*dmf)->ops->creatematrix = dm->ops->creatematrix;

    2377:     PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)dm, (PetscObject)*dmf));

    2379:     (*dmf)->ctx       = dm->ctx;
    2380:     (*dmf)->leveldown = dm->leveldown;
    2381:     (*dmf)->levelup   = dm->levelup + 1;

    2383:     PetscCall(DMSetMatType(*dmf, dm->mattype));
    2384:     for (link = dm->refinehook; link; link = link->next) {
    2385:       if (link->refinehook) PetscCall((*link->refinehook)(dm, *dmf, link->ctx));
    2386:     }
    2387:   }
    2388:   PetscCall(PetscLogEventEnd(DM_Refine, dm, 0, 0, 0));
    2389:   PetscFunctionReturn(PETSC_SUCCESS);
    2390: }

    2392: /*@C
    2393:   DMRefineHookAdd - adds a callback to be run when interpolating a nonlinear problem to a finer grid

    2395:   Logically Collective; No Fortran Support

    2397:   Input Parameters:
    2398: + coarse     - `DM` on which to run a hook when interpolating to a finer level
    2399: . refinehook - function to run when setting up the finer level
    2400: . interphook - function to run to update data on finer levels (once per `SNESSolve()`)
    2401: - ctx        - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    2403:   Calling sequence of `refinehook`:
    2404: + coarse - coarse level `DM`
    2405: . fine   - fine level `DM` to interpolate problem to
    2406: - ctx    - optional user-defined function context

    2408:   Calling sequence of `interphook`:
    2409: + coarse - coarse level `DM`
    2410: . interp - matrix interpolating a coarse-level solution to the finer grid
    2411: . fine   - fine level `DM` to update
    2412: - ctx    - optional user-defined function context

    2414:   Level: advanced

    2416:   Notes:
    2417:   This function is only needed if auxiliary data that is attached to the `DM`s via, for example, `PetscObjectCompose()`, needs to be
    2418:   passed to fine grids while grid sequencing.

    2420:   The actual interpolation is done when `DMInterpolate()` is called.

    2422:   If this function is called multiple times, the hooks will be run in the order they are added.

    2424: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `DMInterpolate()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2425: @*/
    2426: PetscErrorCode DMRefineHookAdd(DM coarse, PetscErrorCode (*refinehook)(DM coarse, DM fine, void *ctx), PetscErrorCode (*interphook)(DM coarse, Mat interp, DM fine, void *ctx), void *ctx)
    2427: {
    2428:   DMRefineHookLink link, *p;

    2430:   PetscFunctionBegin;
    2432:   for (p = &coarse->refinehook; *p; p = &(*p)->next) { /* Scan to the end of the current list of hooks */
    2433:     if ((*p)->refinehook == refinehook && (*p)->interphook == interphook && (*p)->ctx == ctx) PetscFunctionReturn(PETSC_SUCCESS);
    2434:   }
    2435:   PetscCall(PetscNew(&link));
    2436:   link->refinehook = refinehook;
    2437:   link->interphook = interphook;
    2438:   link->ctx        = ctx;
    2439:   link->next       = NULL;
    2440:   *p               = link;
    2441:   PetscFunctionReturn(PETSC_SUCCESS);
    2442: }

    2444: /*@C
    2445:   DMRefineHookRemove - remove a callback from the list of hooks, that have been set with `DMRefineHookAdd()`, to be run when interpolating
    2446:   a nonlinear problem to a finer grid

    2448:   Logically Collective; No Fortran Support

    2450:   Input Parameters:
    2451: + coarse     - the `DM` on which to run a hook when restricting to a coarser level
    2452: . refinehook - function to run when setting up a finer level
    2453: . interphook - function to run to update data on finer levels
    2454: - ctx        - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    2456:   Level: advanced

    2458:   Note:
    2459:   This function does nothing if the hook is not in the list.

    2461: .seealso: [](ch_dmbase), `DM`, `DMRefineHookAdd()`, `DMCoarsenHookRemove()`, `DMInterpolate()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2462: @*/
    2463: PetscErrorCode DMRefineHookRemove(DM coarse, PetscErrorCode (*refinehook)(DM, DM, void *), PetscErrorCode (*interphook)(DM, Mat, DM, void *), void *ctx)
    2464: {
    2465:   DMRefineHookLink link, *p;

    2467:   PetscFunctionBegin;
    2469:   for (p = &coarse->refinehook; *p; p = &(*p)->next) { /* Search the list of current hooks */
    2470:     if ((*p)->refinehook == refinehook && (*p)->interphook == interphook && (*p)->ctx == ctx) {
    2471:       link = *p;
    2472:       *p   = link->next;
    2473:       PetscCall(PetscFree(link));
    2474:       break;
    2475:     }
    2476:   }
    2477:   PetscFunctionReturn(PETSC_SUCCESS);
    2478: }

    2480: /*@
    2481:   DMInterpolate - interpolates user-defined problem data attached to a `DM` to a finer `DM` by running hooks registered by `DMRefineHookAdd()`

    2483:   Collective if any hooks are

    2485:   Input Parameters:
    2486: + coarse - coarser `DM` to use as a base
    2487: . interp - interpolation matrix, apply using `MatInterpolate()`
    2488: - fine   - finer `DM` to update

    2490:   Level: developer

    2492:   Developer Note:
    2493:   This routine is called `DMInterpolate()` while the hook is called `DMRefineHookAdd()`. It would be better to have an
    2494:   an API with consistent terminology.

    2496: .seealso: [](ch_dmbase), `DM`, `DMRefineHookAdd()`, `MatInterpolate()`
    2497: @*/
    2498: PetscErrorCode DMInterpolate(DM coarse, Mat interp, DM fine)
    2499: {
    2500:   DMRefineHookLink link;

    2502:   PetscFunctionBegin;
    2503:   for (link = fine->refinehook; link; link = link->next) {
    2504:     if (link->interphook) PetscCall((*link->interphook)(coarse, interp, fine, link->ctx));
    2505:   }
    2506:   PetscFunctionReturn(PETSC_SUCCESS);
    2507: }

    2509: /*@
    2510:   DMInterpolateSolution - Interpolates a solution from a coarse mesh to a fine mesh.

    2512:   Collective

    2514:   Input Parameters:
    2515: + coarse    - coarse `DM`
    2516: . fine      - fine `DM`
    2517: . interp    - (optional) the matrix computed by `DMCreateInterpolation()`.  Implementations may not need this, but if it
    2518:             is available it can avoid some recomputation.  If it is provided, `MatInterpolate()` will be used if
    2519:             the coarse `DM` does not have a specialized implementation.
    2520: - coarseSol - solution on the coarse mesh

    2522:   Output Parameter:
    2523: . fineSol - the interpolation of coarseSol to the fine mesh

    2525:   Level: developer

    2527:   Note:
    2528:   This function exists because the interpolation of a solution vector between meshes is not always a linear
    2529:   map.  For example, if a boundary value problem has an inhomogeneous Dirichlet boundary condition that is compressed
    2530:   out of the solution vector.  Or if interpolation is inherently a nonlinear operation, such as a method using
    2531:   slope-limiting reconstruction.

    2533:   Developer Note:
    2534:   This doesn't just interpolate "solutions" so its API name is questionable.

    2536: .seealso: [](ch_dmbase), `DM`, `DMInterpolate()`, `DMCreateInterpolation()`
    2537: @*/
    2538: PetscErrorCode DMInterpolateSolution(DM coarse, DM fine, Mat interp, Vec coarseSol, Vec fineSol)
    2539: {
    2540:   PetscErrorCode (*interpsol)(DM, DM, Mat, Vec, Vec) = NULL;

    2542:   PetscFunctionBegin;

    2548:   PetscCall(PetscObjectQueryFunction((PetscObject)coarse, "DMInterpolateSolution_C", &interpsol));
    2549:   if (interpsol) {
    2550:     PetscCall((*interpsol)(coarse, fine, interp, coarseSol, fineSol));
    2551:   } else if (interp) {
    2552:     PetscCall(MatInterpolate(interp, coarseSol, fineSol));
    2553:   } else SETERRQ(PetscObjectComm((PetscObject)coarse), PETSC_ERR_SUP, "DM %s does not implement DMInterpolateSolution()", ((PetscObject)coarse)->type_name);
    2554:   PetscFunctionReturn(PETSC_SUCCESS);
    2555: }

    2557: /*@
    2558:   DMGetRefineLevel - Gets the number of refinements that have generated this `DM` from some initial `DM`.

    2560:   Not Collective

    2562:   Input Parameter:
    2563: . dm - the `DM` object

    2565:   Output Parameter:
    2566: . level - number of refinements

    2568:   Level: developer

    2570:   Note:
    2571:   This can be used, by example, to set the number of coarser levels associated with this `DM` for a multigrid solver.

    2573: .seealso: [](ch_dmbase), `DM`, `DMRefine()`, `DMCoarsen()`, `DMGetCoarsenLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    2574: @*/
    2575: PetscErrorCode DMGetRefineLevel(DM dm, PetscInt *level)
    2576: {
    2577:   PetscFunctionBegin;
    2579:   *level = dm->levelup;
    2580:   PetscFunctionReturn(PETSC_SUCCESS);
    2581: }

    2583: /*@
    2584:   DMSetRefineLevel - Sets the number of refinements that have generated this `DM`.

    2586:   Not Collective

    2588:   Input Parameters:
    2589: + dm    - the `DM` object
    2590: - level - number of refinements

    2592:   Level: advanced

    2594:   Notes:
    2595:   This value is used by `PCMG` to determine how many multigrid levels to use

    2597:   The values are usually set automatically by the process that is causing the refinements of an initial `DM` by calling this routine.

    2599: .seealso: [](ch_dmbase), `DM`, `DMGetRefineLevel()`, `DMCoarsen()`, `DMGetCoarsenLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    2600: @*/
    2601: PetscErrorCode DMSetRefineLevel(DM dm, PetscInt level)
    2602: {
    2603:   PetscFunctionBegin;
    2605:   dm->levelup = level;
    2606:   PetscFunctionReturn(PETSC_SUCCESS);
    2607: }

    2609: /*@
    2610:   DMExtrude - Extrude a `DM` object from a surface

    2612:   Collective

    2614:   Input Parameters:
    2615: + dm     - the `DM` object
    2616: - layers - the number of extruded cell layers

    2618:   Output Parameter:
    2619: . dme - the extruded `DM`, or `NULL`

    2621:   Level: developer

    2623:   Note:
    2624:   If no extrusion was done, the return value is `NULL`

    2626: .seealso: [](ch_dmbase), `DM`, `DMRefine()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`
    2627: @*/
    2628: PetscErrorCode DMExtrude(DM dm, PetscInt layers, DM *dme)
    2629: {
    2630:   PetscFunctionBegin;
    2632:   PetscUseTypeMethod(dm, extrude, layers, dme);
    2633:   if (*dme) {
    2634:     (*dme)->ops->creatematrix = dm->ops->creatematrix;
    2635:     PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)dm, (PetscObject)*dme));
    2636:     (*dme)->ctx = dm->ctx;
    2637:     PetscCall(DMSetMatType(*dme, dm->mattype));
    2638:   }
    2639:   PetscFunctionReturn(PETSC_SUCCESS);
    2640: }

    2642: PetscErrorCode DMGetBasisTransformDM_Internal(DM dm, DM *tdm)
    2643: {
    2644:   PetscFunctionBegin;
    2646:   PetscAssertPointer(tdm, 2);
    2647:   *tdm = dm->transformDM;
    2648:   PetscFunctionReturn(PETSC_SUCCESS);
    2649: }

    2651: PetscErrorCode DMGetBasisTransformVec_Internal(DM dm, Vec *tv)
    2652: {
    2653:   PetscFunctionBegin;
    2655:   PetscAssertPointer(tv, 2);
    2656:   *tv = dm->transform;
    2657:   PetscFunctionReturn(PETSC_SUCCESS);
    2658: }

    2660: /*@
    2661:   DMHasBasisTransform - Whether the `DM` employs a basis transformation from functions in global vectors to functions in local vectors

    2663:   Input Parameter:
    2664: . dm - The `DM`

    2666:   Output Parameter:
    2667: . flg - `PETSC_TRUE` if a basis transformation should be done

    2669:   Level: developer

    2671: .seealso: [](ch_dmbase), `DM`, `DMPlexGlobalToLocalBasis()`, `DMPlexLocalToGlobalBasis()`, `DMPlexCreateBasisRotation()`
    2672: @*/
    2673: PetscErrorCode DMHasBasisTransform(DM dm, PetscBool *flg)
    2674: {
    2675:   Vec tv;

    2677:   PetscFunctionBegin;
    2679:   PetscAssertPointer(flg, 2);
    2680:   PetscCall(DMGetBasisTransformVec_Internal(dm, &tv));
    2681:   *flg = tv ? PETSC_TRUE : PETSC_FALSE;
    2682:   PetscFunctionReturn(PETSC_SUCCESS);
    2683: }

    2685: PetscErrorCode DMConstructBasisTransform_Internal(DM dm)
    2686: {
    2687:   PetscSection s, ts;
    2688:   PetscScalar *ta;
    2689:   PetscInt     cdim, pStart, pEnd, p, Nf, f, Nc, dof;

    2691:   PetscFunctionBegin;
    2692:   PetscCall(DMGetCoordinateDim(dm, &cdim));
    2693:   PetscCall(DMGetLocalSection(dm, &s));
    2694:   PetscCall(PetscSectionGetChart(s, &pStart, &pEnd));
    2695:   PetscCall(PetscSectionGetNumFields(s, &Nf));
    2696:   PetscCall(DMClone(dm, &dm->transformDM));
    2697:   PetscCall(DMGetLocalSection(dm->transformDM, &ts));
    2698:   PetscCall(PetscSectionSetNumFields(ts, Nf));
    2699:   PetscCall(PetscSectionSetChart(ts, pStart, pEnd));
    2700:   for (f = 0; f < Nf; ++f) {
    2701:     PetscCall(PetscSectionGetFieldComponents(s, f, &Nc));
    2702:     /* We could start to label fields by their transformation properties */
    2703:     if (Nc != cdim) continue;
    2704:     for (p = pStart; p < pEnd; ++p) {
    2705:       PetscCall(PetscSectionGetFieldDof(s, p, f, &dof));
    2706:       if (!dof) continue;
    2707:       PetscCall(PetscSectionSetFieldDof(ts, p, f, PetscSqr(cdim)));
    2708:       PetscCall(PetscSectionAddDof(ts, p, PetscSqr(cdim)));
    2709:     }
    2710:   }
    2711:   PetscCall(PetscSectionSetUp(ts));
    2712:   PetscCall(DMCreateLocalVector(dm->transformDM, &dm->transform));
    2713:   PetscCall(VecGetArray(dm->transform, &ta));
    2714:   for (p = pStart; p < pEnd; ++p) {
    2715:     for (f = 0; f < Nf; ++f) {
    2716:       PetscCall(PetscSectionGetFieldDof(ts, p, f, &dof));
    2717:       if (dof) {
    2718:         PetscReal          x[3] = {0.0, 0.0, 0.0};
    2719:         PetscScalar       *tva;
    2720:         const PetscScalar *A;

    2722:         /* TODO Get quadrature point for this dual basis vector for coordinate */
    2723:         PetscCall((*dm->transformGetMatrix)(dm, x, PETSC_TRUE, &A, dm->transformCtx));
    2724:         PetscCall(DMPlexPointLocalFieldRef(dm->transformDM, p, f, ta, (void *)&tva));
    2725:         PetscCall(PetscArraycpy(tva, A, PetscSqr(cdim)));
    2726:       }
    2727:     }
    2728:   }
    2729:   PetscCall(VecRestoreArray(dm->transform, &ta));
    2730:   PetscFunctionReturn(PETSC_SUCCESS);
    2731: }

    2733: PetscErrorCode DMCopyTransform(DM dm, DM newdm)
    2734: {
    2735:   PetscFunctionBegin;
    2738:   newdm->transformCtx       = dm->transformCtx;
    2739:   newdm->transformSetUp     = dm->transformSetUp;
    2740:   newdm->transformDestroy   = NULL;
    2741:   newdm->transformGetMatrix = dm->transformGetMatrix;
    2742:   if (newdm->transformSetUp) PetscCall(DMConstructBasisTransform_Internal(newdm));
    2743:   PetscFunctionReturn(PETSC_SUCCESS);
    2744: }

    2746: /*@C
    2747:   DMGlobalToLocalHookAdd - adds a callback to be run when `DMGlobalToLocal()` is called

    2749:   Logically Collective

    2751:   Input Parameters:
    2752: + dm        - the `DM`
    2753: . beginhook - function to run at the beginning of `DMGlobalToLocalBegin()`
    2754: . endhook   - function to run after `DMGlobalToLocalEnd()` has completed
    2755: - ctx       - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    2757:   Calling sequence of `beginhook`:
    2758: + dm   - global `DM`
    2759: . g    - global vector
    2760: . mode - mode
    2761: . l    - local vector
    2762: - ctx  - optional user-defined function context

    2764:   Calling sequence of `endhook`:
    2765: + dm   - global `DM`
    2766: . g    - global vector
    2767: . mode - mode
    2768: . l    - local vector
    2769: - ctx  - optional user-defined function context

    2771:   Level: advanced

    2773:   Note:
    2774:   The hook may be used to provide, for example, values that represent boundary conditions in the local vectors that do not exist on the global vector.

    2776: .seealso: [](ch_dmbase), `DM`, `DMGlobalToLocal()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2777: @*/
    2778: PetscErrorCode DMGlobalToLocalHookAdd(DM dm, PetscErrorCode (*beginhook)(DM dm, Vec g, InsertMode mode, Vec l, void *ctx), PetscErrorCode (*endhook)(DM dm, Vec g, InsertMode mode, Vec l, void *ctx), void *ctx)
    2779: {
    2780:   DMGlobalToLocalHookLink link, *p;

    2782:   PetscFunctionBegin;
    2784:   for (p = &dm->gtolhook; *p; p = &(*p)->next) { } /* Scan to the end of the current list of hooks */
    2785:   PetscCall(PetscNew(&link));
    2786:   link->beginhook = beginhook;
    2787:   link->endhook   = endhook;
    2788:   link->ctx       = ctx;
    2789:   link->next      = NULL;
    2790:   *p              = link;
    2791:   PetscFunctionReturn(PETSC_SUCCESS);
    2792: }

    2794: static PetscErrorCode DMGlobalToLocalHook_Constraints(DM dm, Vec g, InsertMode mode, Vec l, void *ctx)
    2795: {
    2796:   Mat          cMat;
    2797:   Vec          cVec, cBias;
    2798:   PetscSection section, cSec;
    2799:   PetscInt     pStart, pEnd, p, dof;

    2801:   PetscFunctionBegin;
    2802:   (void)g;
    2803:   (void)ctx;
    2805:   PetscCall(DMGetDefaultConstraints(dm, &cSec, &cMat, &cBias));
    2806:   if (cMat && (mode == INSERT_VALUES || mode == INSERT_ALL_VALUES || mode == INSERT_BC_VALUES)) {
    2807:     PetscInt nRows;

    2809:     PetscCall(MatGetSize(cMat, &nRows, NULL));
    2810:     if (nRows <= 0) PetscFunctionReturn(PETSC_SUCCESS);
    2811:     PetscCall(DMGetLocalSection(dm, &section));
    2812:     PetscCall(MatCreateVecs(cMat, NULL, &cVec));
    2813:     PetscCall(MatMult(cMat, l, cVec));
    2814:     if (cBias) PetscCall(VecAXPY(cVec, 1., cBias));
    2815:     PetscCall(PetscSectionGetChart(cSec, &pStart, &pEnd));
    2816:     for (p = pStart; p < pEnd; p++) {
    2817:       PetscCall(PetscSectionGetDof(cSec, p, &dof));
    2818:       if (dof) {
    2819:         PetscScalar *vals;
    2820:         PetscCall(VecGetValuesSection(cVec, cSec, p, &vals));
    2821:         PetscCall(VecSetValuesSection(l, section, p, vals, INSERT_ALL_VALUES));
    2822:       }
    2823:     }
    2824:     PetscCall(VecDestroy(&cVec));
    2825:   }
    2826:   PetscFunctionReturn(PETSC_SUCCESS);
    2827: }

    2829: /*@
    2830:   DMGlobalToLocal - update local vectors from global vector

    2832:   Neighbor-wise Collective

    2834:   Input Parameters:
    2835: + dm   - the `DM` object
    2836: . g    - the global vector
    2837: . mode - `INSERT_VALUES` or `ADD_VALUES`
    2838: - l    - the local vector

    2840:   Level: beginner

    2842:   Notes:
    2843:   The communication involved in this update can be overlapped with computation by instead using
    2844:   `DMGlobalToLocalBegin()` and `DMGlobalToLocalEnd()`.

    2846:   `DMGlobalToLocalHookAdd()` may be used to provide additional operations that are performed during the update process.

    2848: .seealso: [](ch_dmbase), `DM`, `DMGlobalToLocalHookAdd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`,
    2849:           `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`,
    2850:           `DMGlobalToLocalBegin()` `DMGlobalToLocalEnd()`
    2851: @*/
    2852: PetscErrorCode DMGlobalToLocal(DM dm, Vec g, InsertMode mode, Vec l)
    2853: {
    2854:   PetscFunctionBegin;
    2855:   PetscCall(DMGlobalToLocalBegin(dm, g, mode, l));
    2856:   PetscCall(DMGlobalToLocalEnd(dm, g, mode, l));
    2857:   PetscFunctionReturn(PETSC_SUCCESS);
    2858: }

    2860: /*@
    2861:   DMGlobalToLocalBegin - Begins updating local vectors from global vector

    2863:   Neighbor-wise Collective

    2865:   Input Parameters:
    2866: + dm   - the `DM` object
    2867: . g    - the global vector
    2868: . mode - `INSERT_VALUES` or `ADD_VALUES`
    2869: - l    - the local vector

    2871:   Level: intermediate

    2873:   Notes:
    2874:   The operation is completed with `DMGlobalToLocalEnd()`

    2876:   One can perform local computations between the `DMGlobalToLocalBegin()` and  `DMGlobalToLocalEnd()` to overlap communication and computation

    2878:   `DMGlobalToLocal()` is a short form of  `DMGlobalToLocalBegin()` and  `DMGlobalToLocalEnd()`

    2880:   `DMGlobalToLocalHookAdd()` may be used to provide additional operations that are performed during the update process.

    2882: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`
    2883: @*/
    2884: PetscErrorCode DMGlobalToLocalBegin(DM dm, Vec g, InsertMode mode, Vec l)
    2885: {
    2886:   PetscSF                 sf;
    2887:   DMGlobalToLocalHookLink link;

    2889:   PetscFunctionBegin;
    2891:   for (link = dm->gtolhook; link; link = link->next) {
    2892:     if (link->beginhook) PetscCall((*link->beginhook)(dm, g, mode, l, link->ctx));
    2893:   }
    2894:   PetscCall(DMGetSectionSF(dm, &sf));
    2895:   if (sf) {
    2896:     const PetscScalar *gArray;
    2897:     PetscScalar       *lArray;
    2898:     PetscMemType       lmtype, gmtype;

    2900:     PetscCheck(mode != ADD_VALUES, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", (int)mode);
    2901:     PetscCall(VecGetArrayAndMemType(l, &lArray, &lmtype));
    2902:     PetscCall(VecGetArrayReadAndMemType(g, &gArray, &gmtype));
    2903:     PetscCall(PetscSFBcastWithMemTypeBegin(sf, MPIU_SCALAR, gmtype, gArray, lmtype, lArray, MPI_REPLACE));
    2904:     PetscCall(VecRestoreArrayAndMemType(l, &lArray));
    2905:     PetscCall(VecRestoreArrayReadAndMemType(g, &gArray));
    2906:   } else {
    2907:     PetscUseTypeMethod(dm, globaltolocalbegin, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    2908:   }
    2909:   PetscFunctionReturn(PETSC_SUCCESS);
    2910: }

    2912: /*@
    2913:   DMGlobalToLocalEnd - Ends updating local vectors from global vector

    2915:   Neighbor-wise Collective

    2917:   Input Parameters:
    2918: + dm   - the `DM` object
    2919: . g    - the global vector
    2920: . mode - `INSERT_VALUES` or `ADD_VALUES`
    2921: - l    - the local vector

    2923:   Level: intermediate

    2925:   Note:
    2926:   See `DMGlobalToLocalBegin()` for details.

    2928: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMLocalToGlobalBegin()`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`
    2929: @*/
    2930: PetscErrorCode DMGlobalToLocalEnd(DM dm, Vec g, InsertMode mode, Vec l)
    2931: {
    2932:   PetscSF                 sf;
    2933:   const PetscScalar      *gArray;
    2934:   PetscScalar            *lArray;
    2935:   PetscBool               transform;
    2936:   DMGlobalToLocalHookLink link;
    2937:   PetscMemType            lmtype, gmtype;

    2939:   PetscFunctionBegin;
    2941:   PetscCall(DMGetSectionSF(dm, &sf));
    2942:   PetscCall(DMHasBasisTransform(dm, &transform));
    2943:   if (sf) {
    2944:     PetscCheck(mode != ADD_VALUES, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", (int)mode);

    2946:     PetscCall(VecGetArrayAndMemType(l, &lArray, &lmtype));
    2947:     PetscCall(VecGetArrayReadAndMemType(g, &gArray, &gmtype));
    2948:     PetscCall(PetscSFBcastEnd(sf, MPIU_SCALAR, gArray, lArray, MPI_REPLACE));
    2949:     PetscCall(VecRestoreArrayAndMemType(l, &lArray));
    2950:     PetscCall(VecRestoreArrayReadAndMemType(g, &gArray));
    2951:     if (transform) PetscCall(DMPlexGlobalToLocalBasis(dm, l));
    2952:   } else {
    2953:     PetscUseTypeMethod(dm, globaltolocalend, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    2954:   }
    2955:   PetscCall(DMGlobalToLocalHook_Constraints(dm, g, mode, l, NULL));
    2956:   for (link = dm->gtolhook; link; link = link->next) {
    2957:     if (link->endhook) PetscCall((*link->endhook)(dm, g, mode, l, link->ctx));
    2958:   }
    2959:   PetscFunctionReturn(PETSC_SUCCESS);
    2960: }

    2962: /*@C
    2963:   DMLocalToGlobalHookAdd - adds a callback to be run when a local to global is called

    2965:   Logically Collective

    2967:   Input Parameters:
    2968: + dm        - the `DM`
    2969: . beginhook - function to run at the beginning of `DMLocalToGlobalBegin()`
    2970: . endhook   - function to run after `DMLocalToGlobalEnd()` has completed
    2971: - ctx       - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    2973:   Calling sequence of `beginhook`:
    2974: + global - global `DM`
    2975: . l      - local vector
    2976: . mode   - mode
    2977: . g      - global vector
    2978: - ctx    - optional user-defined function context

    2980:   Calling sequence of `endhook`:
    2981: + global - global `DM`
    2982: . l      - local vector
    2983: . mode   - mode
    2984: . g      - global vector
    2985: - ctx    - optional user-defined function context

    2987:   Level: advanced

    2989: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobal()`, `DMRefineHookAdd()`, `DMGlobalToLocalHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2990: @*/
    2991: PetscErrorCode DMLocalToGlobalHookAdd(DM dm, PetscErrorCode (*beginhook)(DM global, Vec l, InsertMode mode, Vec g, void *ctx), PetscErrorCode (*endhook)(DM global, Vec l, InsertMode mode, Vec g, void *ctx), void *ctx)
    2992: {
    2993:   DMLocalToGlobalHookLink link, *p;

    2995:   PetscFunctionBegin;
    2997:   for (p = &dm->ltoghook; *p; p = &(*p)->next) { } /* Scan to the end of the current list of hooks */
    2998:   PetscCall(PetscNew(&link));
    2999:   link->beginhook = beginhook;
    3000:   link->endhook   = endhook;
    3001:   link->ctx       = ctx;
    3002:   link->next      = NULL;
    3003:   *p              = link;
    3004:   PetscFunctionReturn(PETSC_SUCCESS);
    3005: }

    3007: static PetscErrorCode DMLocalToGlobalHook_Constraints(DM dm, Vec l, InsertMode mode, Vec g, void *ctx)
    3008: {
    3009:   PetscFunctionBegin;
    3010:   (void)g;
    3011:   (void)ctx;
    3013:   if (mode == ADD_VALUES || mode == ADD_ALL_VALUES || mode == ADD_BC_VALUES) {
    3014:     Mat          cMat;
    3015:     Vec          cVec;
    3016:     PetscInt     nRows;
    3017:     PetscSection section, cSec;
    3018:     PetscInt     pStart, pEnd, p, dof;

    3020:     PetscCall(DMGetDefaultConstraints(dm, &cSec, &cMat, NULL));
    3021:     if (!cMat) PetscFunctionReturn(PETSC_SUCCESS);

    3023:     PetscCall(MatGetSize(cMat, &nRows, NULL));
    3024:     if (nRows <= 0) PetscFunctionReturn(PETSC_SUCCESS);
    3025:     PetscCall(DMGetLocalSection(dm, &section));
    3026:     PetscCall(MatCreateVecs(cMat, NULL, &cVec));
    3027:     PetscCall(PetscSectionGetChart(cSec, &pStart, &pEnd));
    3028:     for (p = pStart; p < pEnd; p++) {
    3029:       PetscCall(PetscSectionGetDof(cSec, p, &dof));
    3030:       if (dof) {
    3031:         PetscInt     d;
    3032:         PetscScalar *vals;
    3033:         PetscCall(VecGetValuesSection(l, section, p, &vals));
    3034:         PetscCall(VecSetValuesSection(cVec, cSec, p, vals, mode));
    3035:         /* for this to be the true transpose, we have to zero the values that
    3036:          * we just extracted */
    3037:         for (d = 0; d < dof; d++) vals[d] = 0.;
    3038:       }
    3039:     }
    3040:     PetscCall(MatMultTransposeAdd(cMat, cVec, l, l));
    3041:     PetscCall(VecDestroy(&cVec));
    3042:   }
    3043:   PetscFunctionReturn(PETSC_SUCCESS);
    3044: }
    3045: /*@
    3046:   DMLocalToGlobal - updates global vectors from local vectors

    3048:   Neighbor-wise Collective

    3050:   Input Parameters:
    3051: + dm   - the `DM` object
    3052: . l    - the local vector
    3053: . mode - if `INSERT_VALUES` then no parallel communication is used, if `ADD_VALUES` then all ghost points from the same base point accumulate into that base point.
    3054: - g    - the global vector

    3056:   Level: beginner

    3058:   Notes:
    3059:   The communication involved in this update can be overlapped with computation by using
    3060:   `DMLocalToGlobalBegin()` and `DMLocalToGlobalEnd()`.

    3062:   In the `ADD_VALUES` case you normally would zero the receiving vector before beginning this operation.

    3064:   `INSERT_VALUES` is not supported for `DMDA`; in that case simply compute the values directly into a global vector instead of a local one.

    3066:   Use `DMLocalToGlobalHookAdd()` to add additional operations that are performed on the data during the update process

    3068: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobalBegin()`, `DMLocalToGlobalEnd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMGlobalToLocalEnd()`, `DMGlobalToLocalBegin()`, `DMLocalToGlobalHookAdd()`, `DMGlobaToLocallHookAdd()`
    3069: @*/
    3070: PetscErrorCode DMLocalToGlobal(DM dm, Vec l, InsertMode mode, Vec g)
    3071: {
    3072:   PetscFunctionBegin;
    3073:   PetscCall(DMLocalToGlobalBegin(dm, l, mode, g));
    3074:   PetscCall(DMLocalToGlobalEnd(dm, l, mode, g));
    3075:   PetscFunctionReturn(PETSC_SUCCESS);
    3076: }

    3078: /*@
    3079:   DMLocalToGlobalBegin - begins updating global vectors from local vectors

    3081:   Neighbor-wise Collective

    3083:   Input Parameters:
    3084: + dm   - the `DM` object
    3085: . l    - the local vector
    3086: . mode - if `INSERT_VALUES` then no parallel communication is used, if `ADD_VALUES` then all ghost points from the same base point accumulate into that base point.
    3087: - g    - the global vector

    3089:   Level: intermediate

    3091:   Notes:
    3092:   In the `ADD_VALUES` case you normally would zero the receiving vector before beginning this operation.

    3094:   `INSERT_VALUES is` not supported for `DMDA`, in that case simply compute the values directly into a global vector instead of a local one.

    3096:   Use `DMLocalToGlobalEnd()` to complete the communication process.

    3098:   `DMLocalToGlobal()` is a short form of  `DMLocalToGlobalBegin()` and  `DMLocalToGlobalEnd()`

    3100:   `DMLocalToGlobalHookAdd()` may be used to provide additional operations that are performed during the update process.

    3102: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMGlobalToLocalEnd()`, `DMGlobalToLocalBegin()`
    3103: @*/
    3104: PetscErrorCode DMLocalToGlobalBegin(DM dm, Vec l, InsertMode mode, Vec g)
    3105: {
    3106:   PetscSF                 sf;
    3107:   PetscSection            s, gs;
    3108:   DMLocalToGlobalHookLink link;
    3109:   Vec                     tmpl;
    3110:   const PetscScalar      *lArray;
    3111:   PetscScalar            *gArray;
    3112:   PetscBool               isInsert, transform, l_inplace = PETSC_FALSE, g_inplace = PETSC_FALSE;
    3113:   PetscMemType            lmtype = PETSC_MEMTYPE_HOST, gmtype = PETSC_MEMTYPE_HOST;

    3115:   PetscFunctionBegin;
    3117:   for (link = dm->ltoghook; link; link = link->next) {
    3118:     if (link->beginhook) PetscCall((*link->beginhook)(dm, l, mode, g, link->ctx));
    3119:   }
    3120:   PetscCall(DMLocalToGlobalHook_Constraints(dm, l, mode, g, NULL));
    3121:   PetscCall(DMGetSectionSF(dm, &sf));
    3122:   PetscCall(DMGetLocalSection(dm, &s));
    3123:   switch (mode) {
    3124:   case INSERT_VALUES:
    3125:   case INSERT_ALL_VALUES:
    3126:   case INSERT_BC_VALUES:
    3127:     isInsert = PETSC_TRUE;
    3128:     break;
    3129:   case ADD_VALUES:
    3130:   case ADD_ALL_VALUES:
    3131:   case ADD_BC_VALUES:
    3132:     isInsert = PETSC_FALSE;
    3133:     break;
    3134:   default:
    3135:     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", mode);
    3136:   }
    3137:   if ((sf && !isInsert) || (s && isInsert)) {
    3138:     PetscCall(DMHasBasisTransform(dm, &transform));
    3139:     if (transform) {
    3140:       PetscCall(DMGetNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3141:       PetscCall(VecCopy(l, tmpl));
    3142:       PetscCall(DMPlexLocalToGlobalBasis(dm, tmpl));
    3143:       PetscCall(VecGetArrayRead(tmpl, &lArray));
    3144:     } else if (isInsert) {
    3145:       PetscCall(VecGetArrayRead(l, &lArray));
    3146:     } else {
    3147:       PetscCall(VecGetArrayReadAndMemType(l, &lArray, &lmtype));
    3148:       l_inplace = PETSC_TRUE;
    3149:     }
    3150:     if (s && isInsert) {
    3151:       PetscCall(VecGetArray(g, &gArray));
    3152:     } else {
    3153:       PetscCall(VecGetArrayAndMemType(g, &gArray, &gmtype));
    3154:       g_inplace = PETSC_TRUE;
    3155:     }
    3156:     if (sf && !isInsert) {
    3157:       PetscCall(PetscSFReduceWithMemTypeBegin(sf, MPIU_SCALAR, lmtype, lArray, gmtype, gArray, MPIU_SUM));
    3158:     } else if (s && isInsert) {
    3159:       PetscInt gStart, pStart, pEnd, p;

    3161:       PetscCall(DMGetGlobalSection(dm, &gs));
    3162:       PetscCall(PetscSectionGetChart(s, &pStart, &pEnd));
    3163:       PetscCall(VecGetOwnershipRange(g, &gStart, NULL));
    3164:       for (p = pStart; p < pEnd; ++p) {
    3165:         PetscInt dof, gdof, cdof, gcdof, off, goff, d, e;

    3167:         PetscCall(PetscSectionGetDof(s, p, &dof));
    3168:         PetscCall(PetscSectionGetDof(gs, p, &gdof));
    3169:         PetscCall(PetscSectionGetConstraintDof(s, p, &cdof));
    3170:         PetscCall(PetscSectionGetConstraintDof(gs, p, &gcdof));
    3171:         PetscCall(PetscSectionGetOffset(s, p, &off));
    3172:         PetscCall(PetscSectionGetOffset(gs, p, &goff));
    3173:         /* Ignore off-process data and points with no global data */
    3174:         if (!gdof || goff < 0) continue;
    3175:         PetscCheck(dof == gdof, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Inconsistent sizes, p: %" PetscInt_FMT " dof: %" PetscInt_FMT " gdof: %" PetscInt_FMT " cdof: %" PetscInt_FMT " gcdof: %" PetscInt_FMT, p, dof, gdof, cdof, gcdof);
    3176:         /* If no constraints are enforced in the global vector */
    3177:         if (!gcdof) {
    3178:           for (d = 0; d < dof; ++d) gArray[goff - gStart + d] = lArray[off + d];
    3179:           /* If constraints are enforced in the global vector */
    3180:         } else if (cdof == gcdof) {
    3181:           const PetscInt *cdofs;
    3182:           PetscInt        cind = 0;

    3184:           PetscCall(PetscSectionGetConstraintIndices(s, p, &cdofs));
    3185:           for (d = 0, e = 0; d < dof; ++d) {
    3186:             if ((cind < cdof) && (d == cdofs[cind])) {
    3187:               ++cind;
    3188:               continue;
    3189:             }
    3190:             gArray[goff - gStart + e++] = lArray[off + d];
    3191:           }
    3192:         } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Inconsistent sizes, p: %" PetscInt_FMT " dof: %" PetscInt_FMT " gdof: %" PetscInt_FMT " cdof: %" PetscInt_FMT " gcdof: %" PetscInt_FMT, p, dof, gdof, cdof, gcdof);
    3193:       }
    3194:     }
    3195:     if (g_inplace) {
    3196:       PetscCall(VecRestoreArrayAndMemType(g, &gArray));
    3197:     } else {
    3198:       PetscCall(VecRestoreArray(g, &gArray));
    3199:     }
    3200:     if (transform) {
    3201:       PetscCall(VecRestoreArrayRead(tmpl, &lArray));
    3202:       PetscCall(DMRestoreNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3203:     } else if (l_inplace) {
    3204:       PetscCall(VecRestoreArrayReadAndMemType(l, &lArray));
    3205:     } else {
    3206:       PetscCall(VecRestoreArrayRead(l, &lArray));
    3207:     }
    3208:   } else {
    3209:     PetscUseTypeMethod(dm, localtoglobalbegin, l, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), g);
    3210:   }
    3211:   PetscFunctionReturn(PETSC_SUCCESS);
    3212: }

    3214: /*@
    3215:   DMLocalToGlobalEnd - updates global vectors from local vectors

    3217:   Neighbor-wise Collective

    3219:   Input Parameters:
    3220: + dm   - the `DM` object
    3221: . l    - the local vector
    3222: . mode - `INSERT_VALUES` or `ADD_VALUES`
    3223: - g    - the global vector

    3225:   Level: intermediate

    3227:   Note:
    3228:   See `DMLocalToGlobalBegin()` for full details

    3230: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobalBegin()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocalEnd()`
    3231: @*/
    3232: PetscErrorCode DMLocalToGlobalEnd(DM dm, Vec l, InsertMode mode, Vec g)
    3233: {
    3234:   PetscSF                 sf;
    3235:   PetscSection            s;
    3236:   DMLocalToGlobalHookLink link;
    3237:   PetscBool               isInsert, transform;

    3239:   PetscFunctionBegin;
    3241:   PetscCall(DMGetSectionSF(dm, &sf));
    3242:   PetscCall(DMGetLocalSection(dm, &s));
    3243:   switch (mode) {
    3244:   case INSERT_VALUES:
    3245:   case INSERT_ALL_VALUES:
    3246:     isInsert = PETSC_TRUE;
    3247:     break;
    3248:   case ADD_VALUES:
    3249:   case ADD_ALL_VALUES:
    3250:     isInsert = PETSC_FALSE;
    3251:     break;
    3252:   default:
    3253:     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", mode);
    3254:   }
    3255:   if (sf && !isInsert) {
    3256:     const PetscScalar *lArray;
    3257:     PetscScalar       *gArray;
    3258:     Vec                tmpl;

    3260:     PetscCall(DMHasBasisTransform(dm, &transform));
    3261:     if (transform) {
    3262:       PetscCall(DMGetNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3263:       PetscCall(VecGetArrayRead(tmpl, &lArray));
    3264:     } else {
    3265:       PetscCall(VecGetArrayReadAndMemType(l, &lArray, NULL));
    3266:     }
    3267:     PetscCall(VecGetArrayAndMemType(g, &gArray, NULL));
    3268:     PetscCall(PetscSFReduceEnd(sf, MPIU_SCALAR, lArray, gArray, MPIU_SUM));
    3269:     if (transform) {
    3270:       PetscCall(VecRestoreArrayRead(tmpl, &lArray));
    3271:       PetscCall(DMRestoreNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3272:     } else {
    3273:       PetscCall(VecRestoreArrayReadAndMemType(l, &lArray));
    3274:     }
    3275:     PetscCall(VecRestoreArrayAndMemType(g, &gArray));
    3276:   } else if (s && isInsert) {
    3277:   } else {
    3278:     PetscUseTypeMethod(dm, localtoglobalend, l, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), g);
    3279:   }
    3280:   for (link = dm->ltoghook; link; link = link->next) {
    3281:     if (link->endhook) PetscCall((*link->endhook)(dm, g, mode, l, link->ctx));
    3282:   }
    3283:   PetscFunctionReturn(PETSC_SUCCESS);
    3284: }

    3286: /*@
    3287:   DMLocalToLocalBegin - Begins the process of mapping values from a local vector (that include
    3288:   ghost points that contain irrelevant values) to another local vector where the ghost points
    3289:   in the second are set correctly from values on other MPI ranks.

    3291:   Neighbor-wise Collective

    3293:   Input Parameters:
    3294: + dm   - the `DM` object
    3295: . g    - the original local vector
    3296: - mode - one of `INSERT_VALUES` or `ADD_VALUES`

    3298:   Output Parameter:
    3299: . l - the local vector with correct ghost values

    3301:   Level: intermediate

    3303:   Note:
    3304:   Must be followed by `DMLocalToLocalEnd()`.

    3306: .seealso: [](ch_dmbase), `DM`, `DMLocalToLocalEnd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`
    3307: @*/
    3308: PetscErrorCode DMLocalToLocalBegin(DM dm, Vec g, InsertMode mode, Vec l)
    3309: {
    3310:   PetscFunctionBegin;
    3314:   PetscUseTypeMethod(dm, localtolocalbegin, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    3315:   PetscFunctionReturn(PETSC_SUCCESS);
    3316: }

    3318: /*@
    3319:   DMLocalToLocalEnd - Maps from a local vector to another local vector where the ghost
    3320:   points in the second are set correctly. Must be preceded by `DMLocalToLocalBegin()`.

    3322:   Neighbor-wise Collective

    3324:   Input Parameters:
    3325: + dm   - the `DM` object
    3326: . g    - the original local vector
    3327: - mode - one of `INSERT_VALUES` or `ADD_VALUES`

    3329:   Output Parameter:
    3330: . l - the local vector with correct ghost values

    3332:   Level: intermediate

    3334: .seealso: [](ch_dmbase), `DM`, `DMLocalToLocalBegin()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`
    3335: @*/
    3336: PetscErrorCode DMLocalToLocalEnd(DM dm, Vec g, InsertMode mode, Vec l)
    3337: {
    3338:   PetscFunctionBegin;
    3342:   PetscUseTypeMethod(dm, localtolocalend, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    3343:   PetscFunctionReturn(PETSC_SUCCESS);
    3344: }

    3346: /*@
    3347:   DMCoarsen - Coarsens a `DM` object using a standard, non-adaptive coarsening of the underlying mesh

    3349:   Collective

    3351:   Input Parameters:
    3352: + dm   - the `DM` object
    3353: - comm - the communicator to contain the new `DM` object (or `MPI_COMM_NULL`)

    3355:   Output Parameter:
    3356: . dmc - the coarsened `DM`

    3358:   Level: developer

    3360: .seealso: [](ch_dmbase), `DM`, `DMRefine()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateDomainDecomposition()`,
    3361:           `DMCoarsenHookAdd()`, `DMCoarsenHookRemove()`
    3362: @*/
    3363: PetscErrorCode DMCoarsen(DM dm, MPI_Comm comm, DM *dmc)
    3364: {
    3365:   DMCoarsenHookLink link;

    3367:   PetscFunctionBegin;
    3369:   PetscCall(PetscLogEventBegin(DM_Coarsen, dm, 0, 0, 0));
    3370:   PetscUseTypeMethod(dm, coarsen, comm, dmc);
    3371:   if (*dmc) {
    3372:     (*dmc)->bind_below = dm->bind_below; /* Propagate this from parent DM; otherwise -dm_bind_below will be useless for multigrid cases. */
    3373:     PetscCall(DMSetCoarseDM(dm, *dmc));
    3374:     (*dmc)->ops->creatematrix = dm->ops->creatematrix;
    3375:     PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)dm, (PetscObject)*dmc));
    3376:     (*dmc)->ctx       = dm->ctx;
    3377:     (*dmc)->levelup   = dm->levelup;
    3378:     (*dmc)->leveldown = dm->leveldown + 1;
    3379:     PetscCall(DMSetMatType(*dmc, dm->mattype));
    3380:     for (link = dm->coarsenhook; link; link = link->next) {
    3381:       if (link->coarsenhook) PetscCall((*link->coarsenhook)(dm, *dmc, link->ctx));
    3382:     }
    3383:   }
    3384:   PetscCall(PetscLogEventEnd(DM_Coarsen, dm, 0, 0, 0));
    3385:   PetscCheck(*dmc, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "NULL coarse mesh produced");
    3386:   PetscFunctionReturn(PETSC_SUCCESS);
    3387: }

    3389: /*@C
    3390:   DMCoarsenHookAdd - adds a callback to be run when restricting a nonlinear problem to the coarse grid

    3392:   Logically Collective; No Fortran Support

    3394:   Input Parameters:
    3395: + fine         - `DM` on which to run a hook when restricting to a coarser level
    3396: . coarsenhook  - function to run when setting up a coarser level
    3397: . restricthook - function to run to update data on coarser levels (called once per `SNESSolve()`)
    3398: - ctx          - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    3400:   Calling sequence of `coarsenhook`:
    3401: + fine   - fine level `DM`
    3402: . coarse - coarse level `DM` to restrict problem to
    3403: - ctx    - optional user-defined function context

    3405:   Calling sequence of `restricthook`:
    3406: + fine      - fine level `DM`
    3407: . mrestrict - matrix restricting a fine-level solution to the coarse grid, usually the transpose of the interpolation
    3408: . rscale    - scaling vector for restriction
    3409: . inject    - matrix restricting by injection
    3410: . coarse    - coarse level DM to update
    3411: - ctx       - optional user-defined function context

    3413:   Level: advanced

    3415:   Notes:
    3416:   This function is only needed if auxiliary data, attached to the `DM` with `PetscObjectCompose()`, needs to be set up or passed from the fine `DM` to the coarse `DM`.

    3418:   If this function is called multiple times, the hooks will be run in the order they are added.

    3420:   In order to compose with nonlinear preconditioning without duplicating storage, the hook should be implemented to
    3421:   extract the finest level information from its context (instead of from the `SNES`).

    3423:   The hooks are automatically called by `DMRestrict()`

    3425: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookRemove()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    3426: @*/
    3427: PetscErrorCode DMCoarsenHookAdd(DM fine, PetscErrorCode (*coarsenhook)(DM fine, DM coarse, void *ctx), PetscErrorCode (*restricthook)(DM fine, Mat mrestrict, Vec rscale, Mat inject, DM coarse, void *ctx), void *ctx)
    3428: {
    3429:   DMCoarsenHookLink link, *p;

    3431:   PetscFunctionBegin;
    3433:   for (p = &fine->coarsenhook; *p; p = &(*p)->next) { /* Scan to the end of the current list of hooks */
    3434:     if ((*p)->coarsenhook == coarsenhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) PetscFunctionReturn(PETSC_SUCCESS);
    3435:   }
    3436:   PetscCall(PetscNew(&link));
    3437:   link->coarsenhook  = coarsenhook;
    3438:   link->restricthook = restricthook;
    3439:   link->ctx          = ctx;
    3440:   link->next         = NULL;
    3441:   *p                 = link;
    3442:   PetscFunctionReturn(PETSC_SUCCESS);
    3443: }

    3445: /*@C
    3446:   DMCoarsenHookRemove - remove a callback set with `DMCoarsenHookAdd()`

    3448:   Logically Collective; No Fortran Support

    3450:   Input Parameters:
    3451: + fine         - `DM` on which to run a hook when restricting to a coarser level
    3452: . coarsenhook  - function to run when setting up a coarser level
    3453: . restricthook - function to run to update data on coarser levels
    3454: - ctx          - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    3456:   Level: advanced

    3458:   Notes:
    3459:   This function does nothing if the `coarsenhook` is not in the list.

    3461:   See `DMCoarsenHookAdd()` for the calling sequence of `coarsenhook` and `restricthook`

    3463: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    3464: @*/
    3465: PetscErrorCode DMCoarsenHookRemove(DM fine, PetscErrorCode (*coarsenhook)(DM, DM, void *), PetscErrorCode (*restricthook)(DM, Mat, Vec, Mat, DM, void *), void *ctx)
    3466: {
    3467:   DMCoarsenHookLink link, *p;

    3469:   PetscFunctionBegin;
    3471:   for (p = &fine->coarsenhook; *p; p = &(*p)->next) { /* Search the list of current hooks */
    3472:     if ((*p)->coarsenhook == coarsenhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) {
    3473:       link = *p;
    3474:       *p   = link->next;
    3475:       PetscCall(PetscFree(link));
    3476:       break;
    3477:     }
    3478:   }
    3479:   PetscFunctionReturn(PETSC_SUCCESS);
    3480: }

    3482: /*@
    3483:   DMRestrict - restricts user-defined problem data to a coarser `DM` by running hooks registered by `DMCoarsenHookAdd()`

    3485:   Collective if any hooks are

    3487:   Input Parameters:
    3488: + fine    - finer `DM` from which the data is obtained
    3489: . restrct - restriction matrix, apply using `MatRestrict()`, usually the transpose of the interpolation
    3490: . rscale  - scaling vector for restriction
    3491: . inject  - injection matrix, also use `MatRestrict()`
    3492: - coarse  - coarser `DM` to update

    3494:   Level: developer

    3496:   Developer Note:
    3497:   Though this routine is called `DMRestrict()` the hooks are added with `DMCoarsenHookAdd()`, a consistent terminology would be better

    3499: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `MatRestrict()`, `DMInterpolate()`, `DMRefineHookAdd()`
    3500: @*/
    3501: PetscErrorCode DMRestrict(DM fine, Mat restrct, Vec rscale, Mat inject, DM coarse)
    3502: {
    3503:   DMCoarsenHookLink link;

    3505:   PetscFunctionBegin;
    3506:   for (link = fine->coarsenhook; link; link = link->next) {
    3507:     if (link->restricthook) PetscCall((*link->restricthook)(fine, restrct, rscale, inject, coarse, link->ctx));
    3508:   }
    3509:   PetscFunctionReturn(PETSC_SUCCESS);
    3510: }

    3512: /*@C
    3513:   DMSubDomainHookAdd - adds a callback to be run when restricting a problem to subdomain `DM`s with `DMCreateDomainDecomposition()`

    3515:   Logically Collective; No Fortran Support

    3517:   Input Parameters:
    3518: + global       - global `DM`
    3519: . ddhook       - function to run to pass data to the decomposition `DM` upon its creation
    3520: . restricthook - function to run to update data on block solve (at the beginning of the block solve)
    3521: - ctx          - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    3523:   Calling sequence of `ddhook`:
    3524: + global - global `DM`
    3525: . block  - subdomain `DM`
    3526: - ctx    - optional user-defined function context

    3528:   Calling sequence of `restricthook`:
    3529: + global - global `DM`
    3530: . out    - scatter to the outer (with ghost and overlap points) sub vector
    3531: . in     - scatter to sub vector values only owned locally
    3532: . block  - subdomain `DM`
    3533: - ctx    - optional user-defined function context

    3535:   Level: advanced

    3537:   Notes:
    3538:   This function can be used if auxiliary data needs to be set up on subdomain `DM`s.

    3540:   If this function is called multiple times, the hooks will be run in the order they are added.

    3542:   In order to compose with nonlinear preconditioning without duplicating storage, the hook should be implemented to
    3543:   extract the global information from its context (instead of from the `SNES`).

    3545:   Developer Note:
    3546:   It is unclear what "block solve" means within the definition of `restricthook`

    3548: .seealso: [](ch_dmbase), `DM`, `DMSubDomainHookRemove()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`, `DMCreateDomainDecomposition()`
    3549: @*/
    3550: PetscErrorCode DMSubDomainHookAdd(DM global, PetscErrorCode (*ddhook)(DM global, DM block, void *ctx), PetscErrorCode (*restricthook)(DM global, VecScatter out, VecScatter in, DM block, void *ctx), void *ctx)
    3551: {
    3552:   DMSubDomainHookLink link, *p;

    3554:   PetscFunctionBegin;
    3556:   for (p = &global->subdomainhook; *p; p = &(*p)->next) { /* Scan to the end of the current list of hooks */
    3557:     if ((*p)->ddhook == ddhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) PetscFunctionReturn(PETSC_SUCCESS);
    3558:   }
    3559:   PetscCall(PetscNew(&link));
    3560:   link->restricthook = restricthook;
    3561:   link->ddhook       = ddhook;
    3562:   link->ctx          = ctx;
    3563:   link->next         = NULL;
    3564:   *p                 = link;
    3565:   PetscFunctionReturn(PETSC_SUCCESS);
    3566: }

    3568: /*@C
    3569:   DMSubDomainHookRemove - remove a callback from the list to be run when restricting a problem to subdomain `DM`s with `DMCreateDomainDecomposition()`

    3571:   Logically Collective; No Fortran Support

    3573:   Input Parameters:
    3574: + global       - global `DM`
    3575: . ddhook       - function to run to pass data to the decomposition `DM` upon its creation
    3576: . restricthook - function to run to update data on block solve (at the beginning of the block solve)
    3577: - ctx          - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    3579:   Level: advanced

    3581:   Note:
    3582:   See `DMSubDomainHookAdd()` for the calling sequences of `ddhook` and `restricthook`

    3584: .seealso: [](ch_dmbase), `DM`, `DMSubDomainHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`,
    3585:           `DMCreateDomainDecomposition()`
    3586: @*/
    3587: PetscErrorCode DMSubDomainHookRemove(DM global, PetscErrorCode (*ddhook)(DM, DM, void *), PetscErrorCode (*restricthook)(DM, VecScatter, VecScatter, DM, void *), void *ctx)
    3588: {
    3589:   DMSubDomainHookLink link, *p;

    3591:   PetscFunctionBegin;
    3593:   for (p = &global->subdomainhook; *p; p = &(*p)->next) { /* Search the list of current hooks */
    3594:     if ((*p)->ddhook == ddhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) {
    3595:       link = *p;
    3596:       *p   = link->next;
    3597:       PetscCall(PetscFree(link));
    3598:       break;
    3599:     }
    3600:   }
    3601:   PetscFunctionReturn(PETSC_SUCCESS);
    3602: }

    3604: /*@
    3605:   DMSubDomainRestrict - restricts user-defined problem data to a subdomain `DM` by running hooks registered by `DMSubDomainHookAdd()`

    3607:   Collective if any hooks are

    3609:   Input Parameters:
    3610: + global   - The global `DM` to use as a base
    3611: . oscatter - The scatter from domain global vector filling subdomain global vector with overlap
    3612: . gscatter - The scatter from domain global vector filling subdomain local vector with ghosts
    3613: - subdm    - The subdomain `DM` to update

    3615:   Level: developer

    3617: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `MatRestrict()`, `DMCreateDomainDecomposition()`
    3618: @*/
    3619: PetscErrorCode DMSubDomainRestrict(DM global, VecScatter oscatter, VecScatter gscatter, DM subdm)
    3620: {
    3621:   DMSubDomainHookLink link;

    3623:   PetscFunctionBegin;
    3624:   for (link = global->subdomainhook; link; link = link->next) {
    3625:     if (link->restricthook) PetscCall((*link->restricthook)(global, oscatter, gscatter, subdm, link->ctx));
    3626:   }
    3627:   PetscFunctionReturn(PETSC_SUCCESS);
    3628: }

    3630: /*@
    3631:   DMGetCoarsenLevel - Gets the number of coarsenings that have generated this `DM`.

    3633:   Not Collective

    3635:   Input Parameter:
    3636: . dm - the `DM` object

    3638:   Output Parameter:
    3639: . level - number of coarsenings

    3641:   Level: developer

    3643: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMSetCoarsenLevel()`, `DMGetRefineLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3644: @*/
    3645: PetscErrorCode DMGetCoarsenLevel(DM dm, PetscInt *level)
    3646: {
    3647:   PetscFunctionBegin;
    3649:   PetscAssertPointer(level, 2);
    3650:   *level = dm->leveldown;
    3651:   PetscFunctionReturn(PETSC_SUCCESS);
    3652: }

    3654: /*@
    3655:   DMSetCoarsenLevel - Sets the number of coarsenings that have generated this `DM`.

    3657:   Collective

    3659:   Input Parameters:
    3660: + dm    - the `DM` object
    3661: - level - number of coarsenings

    3663:   Level: developer

    3665:   Note:
    3666:   This is rarely used directly, the information is automatically set when a `DM` is created with `DMCoarsen()`

    3668: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMGetCoarsenLevel()`, `DMGetRefineLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3669: @*/
    3670: PetscErrorCode DMSetCoarsenLevel(DM dm, PetscInt level)
    3671: {
    3672:   PetscFunctionBegin;
    3674:   dm->leveldown = level;
    3675:   PetscFunctionReturn(PETSC_SUCCESS);
    3676: }

    3678: /*@
    3679:   DMRefineHierarchy - Refines a `DM` object, all levels at once

    3681:   Collective

    3683:   Input Parameters:
    3684: + dm      - the `DM` object
    3685: - nlevels - the number of levels of refinement

    3687:   Output Parameter:
    3688: . dmf - the refined `DM` hierarchy

    3690:   Level: developer

    3692: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMCoarsenHierarchy()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3693: @*/
    3694: PetscErrorCode DMRefineHierarchy(DM dm, PetscInt nlevels, DM dmf[])
    3695: {
    3696:   PetscFunctionBegin;
    3698:   PetscCheck(nlevels >= 0, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "nlevels cannot be negative");
    3699:   if (nlevels == 0) PetscFunctionReturn(PETSC_SUCCESS);
    3700:   PetscAssertPointer(dmf, 3);
    3701:   if (dm->ops->refine && !dm->ops->refinehierarchy) {
    3702:     PetscInt i;

    3704:     PetscCall(DMRefine(dm, PetscObjectComm((PetscObject)dm), &dmf[0]));
    3705:     for (i = 1; i < nlevels; i++) PetscCall(DMRefine(dmf[i - 1], PetscObjectComm((PetscObject)dm), &dmf[i]));
    3706:   } else PetscUseTypeMethod(dm, refinehierarchy, nlevels, dmf);
    3707:   PetscFunctionReturn(PETSC_SUCCESS);
    3708: }

    3710: /*@
    3711:   DMCoarsenHierarchy - Coarsens a `DM` object, all levels at once

    3713:   Collective

    3715:   Input Parameters:
    3716: + dm      - the `DM` object
    3717: - nlevels - the number of levels of coarsening

    3719:   Output Parameter:
    3720: . dmc - the coarsened `DM` hierarchy

    3722:   Level: developer

    3724: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMRefineHierarchy()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3725: @*/
    3726: PetscErrorCode DMCoarsenHierarchy(DM dm, PetscInt nlevels, DM dmc[])
    3727: {
    3728:   PetscFunctionBegin;
    3730:   PetscCheck(nlevels >= 0, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "nlevels cannot be negative");
    3731:   if (nlevels == 0) PetscFunctionReturn(PETSC_SUCCESS);
    3732:   PetscAssertPointer(dmc, 3);
    3733:   if (dm->ops->coarsen && !dm->ops->coarsenhierarchy) {
    3734:     PetscInt i;

    3736:     PetscCall(DMCoarsen(dm, PetscObjectComm((PetscObject)dm), &dmc[0]));
    3737:     for (i = 1; i < nlevels; i++) PetscCall(DMCoarsen(dmc[i - 1], PetscObjectComm((PetscObject)dm), &dmc[i]));
    3738:   } else PetscUseTypeMethod(dm, coarsenhierarchy, nlevels, dmc);
    3739:   PetscFunctionReturn(PETSC_SUCCESS);
    3740: }

    3742: /*@C
    3743:   DMSetApplicationContextDestroy - Sets a user function that will be called to destroy the application context when the `DM` is destroyed

    3745:   Logically Collective if the function is collective

    3747:   Input Parameters:
    3748: + dm      - the `DM` object
    3749: - destroy - the destroy function, see `PetscCtxDestroyFn` for the calling sequence

    3751:   Level: intermediate

    3753: .seealso: [](ch_dmbase), `DM`, `DMSetApplicationContext()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`,
    3754:           `DMGetApplicationContext()`, `PetscCtxDestroyFn`
    3755: @*/
    3756: PetscErrorCode DMSetApplicationContextDestroy(DM dm, PetscCtxDestroyFn *destroy)
    3757: {
    3758:   PetscFunctionBegin;
    3760:   dm->ctxdestroy = destroy;
    3761:   PetscFunctionReturn(PETSC_SUCCESS);
    3762: }

    3764: /*@
    3765:   DMSetApplicationContext - Set a user context into a `DM` object

    3767:   Not Collective

    3769:   Input Parameters:
    3770: + dm  - the `DM` object
    3771: - ctx - the user context

    3773:   Level: intermediate

    3775:   Note:
    3776:   A user context is a way to pass problem specific information that is accessible whenever the `DM` is available
    3777:   In a multilevel solver, the user context is shared by all the `DM` in the hierarchy; it is thus not advisable
    3778:   to store objects that represent discretized quantities inside the context.

    3780:   Fortran Note:
    3781:   This only works when `ctx` is a Fortran derived type (it cannot be a `PetscObject`), we recommend writing a Fortran interface definition for this
    3782:   function that tells the Fortran compiler the derived data type that is passed in as the `ctx` argument. See `DMGetApplicationContext()` for
    3783:   an example.

    3785: .seealso: [](ch_dmbase), `DM`, `DMGetApplicationContext()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`
    3786: @*/
    3787: PetscErrorCode DMSetApplicationContext(DM dm, void *ctx)
    3788: {
    3789:   PetscFunctionBegin;
    3791:   dm->ctx = ctx;
    3792:   PetscFunctionReturn(PETSC_SUCCESS);
    3793: }

    3795: /*@
    3796:   DMGetApplicationContext - Gets a user context from a `DM` object provided with `DMSetApplicationContext()`

    3798:   Not Collective

    3800:   Input Parameter:
    3801: . dm - the `DM` object

    3803:   Output Parameter:
    3804: . ctx - a pointer to the user context

    3806:   Level: intermediate

    3808:   Note:
    3809:   A user context is a way to pass problem specific information that is accessible whenever the `DM` is available

    3811:   Fortran Notes:
    3812:   This only works when the context is a Fortran derived type (it cannot be a `PetscObject`) and you **must** write a Fortran interface definition for this
    3813:   function that tells the Fortran compiler the derived data type that is returned as the `ctx` argument. For example,
    3814: .vb
    3815:   Interface DMGetApplicationContext
    3816:     Subroutine DMGetApplicationContext(dm,ctx,ierr)
    3817:   #include <petsc/finclude/petscdm.h>
    3818:       use petscdm
    3819:       DM dm
    3820:       type(tUsertype), pointer :: ctx
    3821:       PetscErrorCode ierr
    3822:     End Subroutine
    3823:   End Interface DMGetApplicationContext
    3824: .ve

    3826:   The prototype for `ctx` must be
    3827: .vb
    3828:   type(tUsertype), pointer :: ctx
    3829: .ve

    3831: .seealso: [](ch_dmbase), `DM`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`
    3832: @*/
    3833: PetscErrorCode DMGetApplicationContext(DM dm, PeCtx ctx)
    3834: {
    3835:   PetscFunctionBegin;
    3837:   *(void **)ctx = dm->ctx;
    3838:   PetscFunctionReturn(PETSC_SUCCESS);
    3839: }

    3841: /*@C
    3842:   DMSetVariableBounds - sets a function to compute the lower and upper bound vectors for `SNESVI`.

    3844:   Logically Collective

    3846:   Input Parameters:
    3847: + dm - the DM object
    3848: - f  - the function that computes variable bounds used by `SNESVI` (use `NULL` to cancel a previous function that was set)

    3850:   Level: intermediate

    3852:   Developer Note:
    3853:   Should be called `DMSetComputeVIBounds()` or something similar

    3855: .seealso: [](ch_dmbase), `DM`, `DMComputeVariableBounds()`, `DMHasVariableBounds()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMGetApplicationContext()`,
    3856:          `DMSetJacobian()`
    3857: @*/
    3858: PetscErrorCode DMSetVariableBounds(DM dm, PetscErrorCode (*f)(DM, Vec, Vec))
    3859: {
    3860:   PetscFunctionBegin;
    3862:   dm->ops->computevariablebounds = f;
    3863:   PetscFunctionReturn(PETSC_SUCCESS);
    3864: }

    3866: /*@
    3867:   DMHasVariableBounds - does the `DM` object have a variable bounds function?

    3869:   Not Collective

    3871:   Input Parameter:
    3872: . dm - the `DM` object to destroy

    3874:   Output Parameter:
    3875: . flg - `PETSC_TRUE` if the variable bounds function exists

    3877:   Level: developer

    3879: .seealso: [](ch_dmbase), `DM`, `DMComputeVariableBounds()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMGetApplicationContext()`
    3880: @*/
    3881: PetscErrorCode DMHasVariableBounds(DM dm, PetscBool *flg)
    3882: {
    3883:   PetscFunctionBegin;
    3885:   PetscAssertPointer(flg, 2);
    3886:   *flg = (dm->ops->computevariablebounds) ? PETSC_TRUE : PETSC_FALSE;
    3887:   PetscFunctionReturn(PETSC_SUCCESS);
    3888: }

    3890: /*@
    3891:   DMComputeVariableBounds - compute variable bounds used by `SNESVI`.

    3893:   Logically Collective

    3895:   Input Parameter:
    3896: . dm - the `DM` object

    3898:   Output Parameters:
    3899: + xl - lower bound
    3900: - xu - upper bound

    3902:   Level: advanced

    3904:   Note:
    3905:   This is generally not called by users. It calls the function provided by the user with DMSetVariableBounds()

    3907: .seealso: [](ch_dmbase), `DM`, `DMHasVariableBounds()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMGetApplicationContext()`
    3908: @*/
    3909: PetscErrorCode DMComputeVariableBounds(DM dm, Vec xl, Vec xu)
    3910: {
    3911:   PetscFunctionBegin;
    3915:   PetscUseTypeMethod(dm, computevariablebounds, xl, xu);
    3916:   PetscFunctionReturn(PETSC_SUCCESS);
    3917: }

    3919: /*@
    3920:   DMHasColoring - does the `DM` object have a method of providing a coloring?

    3922:   Not Collective

    3924:   Input Parameter:
    3925: . dm - the DM object

    3927:   Output Parameter:
    3928: . flg - `PETSC_TRUE` if the `DM` has facilities for `DMCreateColoring()`.

    3930:   Level: developer

    3932: .seealso: [](ch_dmbase), `DM`, `DMCreateColoring()`
    3933: @*/
    3934: PetscErrorCode DMHasColoring(DM dm, PetscBool *flg)
    3935: {
    3936:   PetscFunctionBegin;
    3938:   PetscAssertPointer(flg, 2);
    3939:   *flg = (dm->ops->getcoloring) ? PETSC_TRUE : PETSC_FALSE;
    3940:   PetscFunctionReturn(PETSC_SUCCESS);
    3941: }

    3943: /*@
    3944:   DMHasCreateRestriction - does the `DM` object have a method of providing a restriction?

    3946:   Not Collective

    3948:   Input Parameter:
    3949: . dm - the `DM` object

    3951:   Output Parameter:
    3952: . flg - `PETSC_TRUE` if the `DM` has facilities for `DMCreateRestriction()`.

    3954:   Level: developer

    3956: .seealso: [](ch_dmbase), `DM`, `DMCreateRestriction()`, `DMHasCreateInterpolation()`, `DMHasCreateInjection()`
    3957: @*/
    3958: PetscErrorCode DMHasCreateRestriction(DM dm, PetscBool *flg)
    3959: {
    3960:   PetscFunctionBegin;
    3962:   PetscAssertPointer(flg, 2);
    3963:   *flg = (dm->ops->createrestriction) ? PETSC_TRUE : PETSC_FALSE;
    3964:   PetscFunctionReturn(PETSC_SUCCESS);
    3965: }

    3967: /*@
    3968:   DMHasCreateInjection - does the `DM` object have a method of providing an injection?

    3970:   Not Collective

    3972:   Input Parameter:
    3973: . dm - the `DM` object

    3975:   Output Parameter:
    3976: . flg - `PETSC_TRUE` if the `DM` has facilities for `DMCreateInjection()`.

    3978:   Level: developer

    3980: .seealso: [](ch_dmbase), `DM`, `DMCreateInjection()`, `DMHasCreateRestriction()`, `DMHasCreateInterpolation()`
    3981: @*/
    3982: PetscErrorCode DMHasCreateInjection(DM dm, PetscBool *flg)
    3983: {
    3984:   PetscFunctionBegin;
    3986:   PetscAssertPointer(flg, 2);
    3987:   if (dm->ops->hascreateinjection) PetscUseTypeMethod(dm, hascreateinjection, flg);
    3988:   else *flg = (dm->ops->createinjection) ? PETSC_TRUE : PETSC_FALSE;
    3989:   PetscFunctionReturn(PETSC_SUCCESS);
    3990: }

    3992: PetscFunctionList DMList              = NULL;
    3993: PetscBool         DMRegisterAllCalled = PETSC_FALSE;

    3995: /*@
    3996:   DMSetType - Builds a `DM`, for a particular `DM` implementation.

    3998:   Collective

    4000:   Input Parameters:
    4001: + dm     - The `DM` object
    4002: - method - The name of the `DMType`, for example `DMDA`, `DMPLEX`

    4004:   Options Database Key:
    4005: . -dm_type <type> - Sets the `DM` type; use -help for a list of available types

    4007:   Level: intermediate

    4009:   Note:
    4010:   Of the `DM` is constructed by directly calling a function to construct a particular `DM`, for example, `DMDACreate2d()` or `DMPlexCreateBoxMesh()`

    4012: .seealso: [](ch_dmbase), `DM`, `DMType`, `DMDA`, `DMPLEX`, `DMGetType()`, `DMCreate()`, `DMDACreate2d()`
    4013: @*/
    4014: PetscErrorCode DMSetType(DM dm, DMType method)
    4015: {
    4016:   PetscErrorCode (*r)(DM);
    4017:   PetscBool match;

    4019:   PetscFunctionBegin;
    4021:   PetscCall(PetscObjectTypeCompare((PetscObject)dm, method, &match));
    4022:   if (match) PetscFunctionReturn(PETSC_SUCCESS);

    4024:   PetscCall(DMRegisterAll());
    4025:   PetscCall(PetscFunctionListFind(DMList, method, &r));
    4026:   PetscCheck(r, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown DM type: %s", method);

    4028:   PetscTryTypeMethod(dm, destroy);
    4029:   PetscCall(PetscMemzero(dm->ops, sizeof(*dm->ops)));
    4030:   PetscCall(PetscObjectChangeTypeName((PetscObject)dm, method));
    4031:   PetscCall((*r)(dm));
    4032:   PetscFunctionReturn(PETSC_SUCCESS);
    4033: }

    4035: /*@
    4036:   DMGetType - Gets the `DM` type name (as a string) from the `DM`.

    4038:   Not Collective

    4040:   Input Parameter:
    4041: . dm - The `DM`

    4043:   Output Parameter:
    4044: . type - The `DMType` name

    4046:   Level: intermediate

    4048: .seealso: [](ch_dmbase), `DM`, `DMType`, `DMDA`, `DMPLEX`, `DMSetType()`, `DMCreate()`
    4049: @*/
    4050: PetscErrorCode DMGetType(DM dm, DMType *type)
    4051: {
    4052:   PetscFunctionBegin;
    4054:   PetscAssertPointer(type, 2);
    4055:   PetscCall(DMRegisterAll());
    4056:   *type = ((PetscObject)dm)->type_name;
    4057:   PetscFunctionReturn(PETSC_SUCCESS);
    4058: }

    4060: /*@
    4061:   DMConvert - Converts a `DM` to another `DM`, either of the same or different type.

    4063:   Collective

    4065:   Input Parameters:
    4066: + dm      - the `DM`
    4067: - newtype - new `DM` type (use "same" for the same type)

    4069:   Output Parameter:
    4070: . M - pointer to new `DM`

    4072:   Level: intermediate

    4074:   Note:
    4075:   Cannot be used to convert a sequential `DM` to a parallel or a parallel to sequential,
    4076:   the MPI communicator of the generated `DM` is always the same as the communicator
    4077:   of the input `DM`.

    4079: .seealso: [](ch_dmbase), `DM`, `DMSetType()`, `DMCreate()`, `DMClone()`
    4080: @*/
    4081: PetscErrorCode DMConvert(DM dm, DMType newtype, DM *M)
    4082: {
    4083:   DM        B;
    4084:   char      convname[256];
    4085:   PetscBool sametype /*, issame */;

    4087:   PetscFunctionBegin;
    4090:   PetscAssertPointer(M, 3);
    4091:   PetscCall(PetscObjectTypeCompare((PetscObject)dm, newtype, &sametype));
    4092:   /* PetscCall(PetscStrcmp(newtype, "same", &issame)); */
    4093:   if (sametype) {
    4094:     *M = dm;
    4095:     PetscCall(PetscObjectReference((PetscObject)dm));
    4096:     PetscFunctionReturn(PETSC_SUCCESS);
    4097:   } else {
    4098:     PetscErrorCode (*conv)(DM, DMType, DM *) = NULL;

    4100:     /*
    4101:        Order of precedence:
    4102:        1) See if a specialized converter is known to the current DM.
    4103:        2) See if a specialized converter is known to the desired DM class.
    4104:        3) See if a good general converter is registered for the desired class
    4105:        4) See if a good general converter is known for the current matrix.
    4106:        5) Use a really basic converter.
    4107:     */

    4109:     /* 1) See if a specialized converter is known to the current DM and the desired class */
    4110:     PetscCall(PetscStrncpy(convname, "DMConvert_", sizeof(convname)));
    4111:     PetscCall(PetscStrlcat(convname, ((PetscObject)dm)->type_name, sizeof(convname)));
    4112:     PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
    4113:     PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
    4114:     PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
    4115:     PetscCall(PetscObjectQueryFunction((PetscObject)dm, convname, &conv));
    4116:     if (conv) goto foundconv;

    4118:     /* 2)  See if a specialized converter is known to the desired DM class. */
    4119:     PetscCall(DMCreate(PetscObjectComm((PetscObject)dm), &B));
    4120:     PetscCall(DMSetType(B, newtype));
    4121:     PetscCall(PetscStrncpy(convname, "DMConvert_", sizeof(convname)));
    4122:     PetscCall(PetscStrlcat(convname, ((PetscObject)dm)->type_name, sizeof(convname)));
    4123:     PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
    4124:     PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
    4125:     PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
    4126:     PetscCall(PetscObjectQueryFunction((PetscObject)B, convname, &conv));
    4127:     if (conv) {
    4128:       PetscCall(DMDestroy(&B));
    4129:       goto foundconv;
    4130:     }

    4132: #if 0
    4133:     /* 3) See if a good general converter is registered for the desired class */
    4134:     conv = B->ops->convertfrom;
    4135:     PetscCall(DMDestroy(&B));
    4136:     if (conv) goto foundconv;

    4138:     /* 4) See if a good general converter is known for the current matrix */
    4139:     if (dm->ops->convert) conv = dm->ops->convert;
    4140:     if (conv) goto foundconv;
    4141: #endif

    4143:     /* 5) Use a really basic converter. */
    4144:     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "No conversion possible between DM types %s and %s", ((PetscObject)dm)->type_name, newtype);

    4146:   foundconv:
    4147:     PetscCall(PetscLogEventBegin(DM_Convert, dm, 0, 0, 0));
    4148:     PetscCall((*conv)(dm, newtype, M));
    4149:     /* Things that are independent of DM type: We should consult DMClone() here */
    4150:     {
    4151:       const PetscReal *maxCell, *Lstart, *L;

    4153:       PetscCall(DMGetPeriodicity(dm, &maxCell, &Lstart, &L));
    4154:       PetscCall(DMSetPeriodicity(*M, maxCell, Lstart, L));
    4155:       (*M)->prealloc_only = dm->prealloc_only;
    4156:       PetscCall(PetscFree((*M)->vectype));
    4157:       PetscCall(PetscStrallocpy(dm->vectype, (char **)&(*M)->vectype));
    4158:       PetscCall(PetscFree((*M)->mattype));
    4159:       PetscCall(PetscStrallocpy(dm->mattype, (char **)&(*M)->mattype));
    4160:     }
    4161:     PetscCall(PetscLogEventEnd(DM_Convert, dm, 0, 0, 0));
    4162:   }
    4163:   PetscCall(PetscObjectStateIncrease((PetscObject)*M));
    4164:   PetscFunctionReturn(PETSC_SUCCESS);
    4165: }

    4167: /*@C
    4168:   DMRegister -  Adds a new `DM` type implementation

    4170:   Not Collective, No Fortran Support

    4172:   Input Parameters:
    4173: + sname    - The name of a new user-defined creation routine
    4174: - function - The creation routine itself

    4176:   Level: advanced

    4178:   Note:
    4179:   `DMRegister()` may be called multiple times to add several user-defined `DM`s

    4181:   Example Usage:
    4182: .vb
    4183:     DMRegister("my_da", MyDMCreate);
    4184: .ve

    4186:   Then, your `DM` type can be chosen with the procedural interface via
    4187: .vb
    4188:     DMCreate(MPI_Comm, DM *);
    4189:     DMSetType(DM,"my_da");
    4190: .ve
    4191:   or at runtime via the option
    4192: .vb
    4193:     -da_type my_da
    4194: .ve

    4196: .seealso: [](ch_dmbase), `DM`, `DMType`, `DMSetType()`, `DMRegisterAll()`, `DMRegisterDestroy()`
    4197: @*/
    4198: PetscErrorCode DMRegister(const char sname[], PetscErrorCode (*function)(DM))
    4199: {
    4200:   PetscFunctionBegin;
    4201:   PetscCall(DMInitializePackage());
    4202:   PetscCall(PetscFunctionListAdd(&DMList, sname, function));
    4203:   PetscFunctionReturn(PETSC_SUCCESS);
    4204: }

    4206: /*@
    4207:   DMLoad - Loads a DM that has been stored in binary  with `DMView()`.

    4209:   Collective

    4211:   Input Parameters:
    4212: + newdm  - the newly loaded `DM`, this needs to have been created with `DMCreate()` or
    4213:            some related function before a call to `DMLoad()`.
    4214: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()` or
    4215:            `PETSCVIEWERHDF5` file viewer, obtained from `PetscViewerHDF5Open()`

    4217:   Level: intermediate

    4219:   Notes:
    4220:   The type is determined by the data in the file, any type set into the DM before this call is ignored.

    4222:   Using `PETSCVIEWERHDF5` type with `PETSC_VIEWER_HDF5_PETSC` format, one can save multiple `DMPLEX`
    4223:   meshes in a single HDF5 file. This in turn requires one to name the `DMPLEX` object with `PetscObjectSetName()`
    4224:   before saving it with `DMView()` and before loading it with `DMLoad()` for identification of the mesh object.

    4226: .seealso: [](ch_dmbase), `DM`, `PetscViewerBinaryOpen()`, `DMView()`, `MatLoad()`, `VecLoad()`
    4227: @*/
    4228: PetscErrorCode DMLoad(DM newdm, PetscViewer viewer)
    4229: {
    4230:   PetscBool isbinary, ishdf5;

    4232:   PetscFunctionBegin;
    4235:   PetscCall(PetscViewerCheckReadable(viewer));
    4236:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
    4237:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
    4238:   PetscCall(PetscLogEventBegin(DM_Load, viewer, 0, 0, 0));
    4239:   if (isbinary) {
    4240:     PetscInt classid;
    4241:     char     type[256];

    4243:     PetscCall(PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT));
    4244:     PetscCheck(classid == DM_FILE_CLASSID, PetscObjectComm((PetscObject)newdm), PETSC_ERR_ARG_WRONG, "Not DM next in file, classid found %" PetscInt_FMT, classid);
    4245:     PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
    4246:     PetscCall(DMSetType(newdm, type));
    4247:     PetscTryTypeMethod(newdm, load, viewer);
    4248:   } else if (ishdf5) {
    4249:     PetscTryTypeMethod(newdm, load, viewer);
    4250:   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen() or PetscViewerHDF5Open()");
    4251:   PetscCall(PetscLogEventEnd(DM_Load, viewer, 0, 0, 0));
    4252:   PetscFunctionReturn(PETSC_SUCCESS);
    4253: }

    4255: /* FEM Support */

    4257: PetscErrorCode DMPrintCellIndices(PetscInt c, const char name[], PetscInt len, const PetscInt x[])
    4258: {
    4259:   PetscInt f;

    4261:   PetscFunctionBegin;
    4262:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4263:   for (f = 0; f < len; ++f) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  | %" PetscInt_FMT " |\n", x[f]));
    4264:   PetscFunctionReturn(PETSC_SUCCESS);
    4265: }

    4267: PetscErrorCode DMPrintCellVector(PetscInt c, const char name[], PetscInt len, const PetscScalar x[])
    4268: {
    4269:   PetscInt f;

    4271:   PetscFunctionBegin;
    4272:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4273:   for (f = 0; f < len; ++f) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  | %g |\n", (double)PetscRealPart(x[f])));
    4274:   PetscFunctionReturn(PETSC_SUCCESS);
    4275: }

    4277: PetscErrorCode DMPrintCellVectorReal(PetscInt c, const char name[], PetscInt len, const PetscReal x[])
    4278: {
    4279:   PetscInt f;

    4281:   PetscFunctionBegin;
    4282:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4283:   for (f = 0; f < len; ++f) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  | %g |\n", (double)x[f]));
    4284:   PetscFunctionReturn(PETSC_SUCCESS);
    4285: }

    4287: PetscErrorCode DMPrintCellMatrix(PetscInt c, const char name[], PetscInt rows, PetscInt cols, const PetscScalar A[])
    4288: {
    4289:   PetscInt f, g;

    4291:   PetscFunctionBegin;
    4292:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4293:   for (f = 0; f < rows; ++f) {
    4294:     PetscCall(PetscPrintf(PETSC_COMM_SELF, "  |"));
    4295:     for (g = 0; g < cols; ++g) PetscCall(PetscPrintf(PETSC_COMM_SELF, " % 9.5g", (double)PetscRealPart(A[f * cols + g])));
    4296:     PetscCall(PetscPrintf(PETSC_COMM_SELF, " |\n"));
    4297:   }
    4298:   PetscFunctionReturn(PETSC_SUCCESS);
    4299: }

    4301: PetscErrorCode DMPrintLocalVec(DM dm, const char name[], PetscReal tol, Vec X)
    4302: {
    4303:   PetscInt           localSize, bs;
    4304:   PetscMPIInt        size;
    4305:   Vec                x, xglob;
    4306:   const PetscScalar *xarray;

    4308:   PetscFunctionBegin;
    4309:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size));
    4310:   PetscCall(VecDuplicate(X, &x));
    4311:   PetscCall(VecCopy(X, x));
    4312:   PetscCall(VecFilter(x, tol));
    4313:   PetscCall(PetscPrintf(PetscObjectComm((PetscObject)dm), "%s:\n", name));
    4314:   if (size > 1) {
    4315:     PetscCall(VecGetLocalSize(x, &localSize));
    4316:     PetscCall(VecGetArrayRead(x, &xarray));
    4317:     PetscCall(VecGetBlockSize(x, &bs));
    4318:     PetscCall(VecCreateMPIWithArray(PetscObjectComm((PetscObject)dm), bs, localSize, PETSC_DETERMINE, xarray, &xglob));
    4319:   } else {
    4320:     xglob = x;
    4321:   }
    4322:   PetscCall(VecView(xglob, PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)dm))));
    4323:   if (size > 1) {
    4324:     PetscCall(VecDestroy(&xglob));
    4325:     PetscCall(VecRestoreArrayRead(x, &xarray));
    4326:   }
    4327:   PetscCall(VecDestroy(&x));
    4328:   PetscFunctionReturn(PETSC_SUCCESS);
    4329: }

    4331: /*@
    4332:   DMGetLocalSection - Get the `PetscSection` encoding the local data layout for the `DM`.

    4334:   Input Parameter:
    4335: . dm - The `DM`

    4337:   Output Parameter:
    4338: . section - The `PetscSection`

    4340:   Options Database Key:
    4341: . -dm_petscsection_view - View the section created by the `DM`

    4343:   Level: intermediate

    4345:   Note:
    4346:   This gets a borrowed reference, so the user should not destroy this `PetscSection`.

    4348: .seealso: [](ch_dmbase), `DM`, `DMSetLocalSection()`, `DMGetGlobalSection()`
    4349: @*/
    4350: PetscErrorCode DMGetLocalSection(DM dm, PetscSection *section)
    4351: {
    4352:   PetscFunctionBegin;
    4354:   PetscAssertPointer(section, 2);
    4355:   if (!dm->localSection && dm->ops->createlocalsection) {
    4356:     PetscInt d;

    4358:     if (dm->setfromoptionscalled) {
    4359:       PetscObject       obj = (PetscObject)dm;
    4360:       PetscViewer       viewer;
    4361:       PetscViewerFormat format;
    4362:       PetscBool         flg;

    4364:       PetscCall(PetscOptionsCreateViewer(PetscObjectComm(obj), obj->options, obj->prefix, "-dm_petscds_view", &viewer, &format, &flg));
    4365:       if (flg) PetscCall(PetscViewerPushFormat(viewer, format));
    4366:       for (d = 0; d < dm->Nds; ++d) {
    4367:         PetscCall(PetscDSSetFromOptions(dm->probs[d].ds));
    4368:         if (flg) PetscCall(PetscDSView(dm->probs[d].ds, viewer));
    4369:       }
    4370:       if (flg) {
    4371:         PetscCall(PetscViewerFlush(viewer));
    4372:         PetscCall(PetscViewerPopFormat(viewer));
    4373:         PetscCall(PetscViewerDestroy(&viewer));
    4374:       }
    4375:     }
    4376:     PetscUseTypeMethod(dm, createlocalsection);
    4377:     if (dm->localSection) PetscCall(PetscObjectViewFromOptions((PetscObject)dm->localSection, NULL, "-dm_petscsection_view"));
    4378:   }
    4379:   *section = dm->localSection;
    4380:   PetscFunctionReturn(PETSC_SUCCESS);
    4381: }

    4383: /*@
    4384:   DMSetLocalSection - Set the `PetscSection` encoding the local data layout for the `DM`.

    4386:   Input Parameters:
    4387: + dm      - The `DM`
    4388: - section - The `PetscSection`

    4390:   Level: intermediate

    4392:   Note:
    4393:   Any existing Section will be destroyed

    4395: .seealso: [](ch_dmbase), `DM`, `PetscSection`, `DMGetLocalSection()`, `DMSetGlobalSection()`
    4396: @*/
    4397: PetscErrorCode DMSetLocalSection(DM dm, PetscSection section)
    4398: {
    4399:   PetscInt numFields = 0;
    4400:   PetscInt f;

    4402:   PetscFunctionBegin;
    4405:   PetscCall(PetscObjectReference((PetscObject)section));
    4406:   PetscCall(PetscSectionDestroy(&dm->localSection));
    4407:   dm->localSection = section;
    4408:   if (section) PetscCall(PetscSectionGetNumFields(dm->localSection, &numFields));
    4409:   if (numFields) {
    4410:     PetscCall(DMSetNumFields(dm, numFields));
    4411:     for (f = 0; f < numFields; ++f) {
    4412:       PetscObject disc;
    4413:       const char *name;

    4415:       PetscCall(PetscSectionGetFieldName(dm->localSection, f, &name));
    4416:       PetscCall(DMGetField(dm, f, NULL, &disc));
    4417:       PetscCall(PetscObjectSetName(disc, name));
    4418:     }
    4419:   }
    4420:   /* The global section and the SectionSF will be rebuilt
    4421:      in the next call to DMGetGlobalSection() and DMGetSectionSF(). */
    4422:   PetscCall(PetscSectionDestroy(&dm->globalSection));
    4423:   PetscCall(PetscSFDestroy(&dm->sectionSF));
    4424:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &dm->sectionSF));

    4426:   /* Clear scratch vectors */
    4427:   PetscCall(DMClearGlobalVectors(dm));
    4428:   PetscCall(DMClearLocalVectors(dm));
    4429:   PetscCall(DMClearNamedGlobalVectors(dm));
    4430:   PetscCall(DMClearNamedLocalVectors(dm));
    4431:   PetscFunctionReturn(PETSC_SUCCESS);
    4432: }

    4434: /*@C
    4435:   DMCreateSectionPermutation - Create a permutation of the `PetscSection` chart and optionally a block structure.

    4437:   Input Parameter:
    4438: . dm - The `DM`

    4440:   Output Parameters:
    4441: + perm        - A permutation of the mesh points in the chart
    4442: - blockStarts - A high bit is set for the point that begins every block, or `NULL` for default blocking

    4444:   Level: developer

    4446: .seealso: [](ch_dmbase), `DM`, `PetscSection`, `DMGetLocalSection()`, `DMGetGlobalSection()`
    4447: @*/
    4448: PetscErrorCode DMCreateSectionPermutation(DM dm, IS *perm, PetscBT *blockStarts)
    4449: {
    4450:   PetscFunctionBegin;
    4451:   *perm        = NULL;
    4452:   *blockStarts = NULL;
    4453:   PetscTryTypeMethod(dm, createsectionpermutation, perm, blockStarts);
    4454:   PetscFunctionReturn(PETSC_SUCCESS);
    4455: }

    4457: /*@
    4458:   DMGetDefaultConstraints - Get the `PetscSection` and `Mat` that specify the local constraint interpolation. See `DMSetDefaultConstraints()` for a description of the purpose of constraint interpolation.

    4460:   not Collective

    4462:   Input Parameter:
    4463: . dm - The `DM`

    4465:   Output Parameters:
    4466: + section - The `PetscSection` describing the range of the constraint matrix: relates rows of the constraint matrix to dofs of the default section.  Returns `NULL` if there are no local constraints.
    4467: . mat     - The `Mat` that interpolates local constraints: its width should be the layout size of the default section.  Returns `NULL` if there are no local constraints.
    4468: - bias    - Vector containing bias to be added to constrained dofs

    4470:   Level: advanced

    4472:   Note:
    4473:   This gets borrowed references, so the user should not destroy the `PetscSection`, `Mat`, or `Vec`.

    4475: .seealso: [](ch_dmbase), `DM`, `DMSetDefaultConstraints()`
    4476: @*/
    4477: PetscErrorCode DMGetDefaultConstraints(DM dm, PetscSection *section, Mat *mat, Vec *bias)
    4478: {
    4479:   PetscFunctionBegin;
    4481:   if (!dm->defaultConstraint.section && !dm->defaultConstraint.mat && dm->ops->createdefaultconstraints) PetscUseTypeMethod(dm, createdefaultconstraints);
    4482:   if (section) *section = dm->defaultConstraint.section;
    4483:   if (mat) *mat = dm->defaultConstraint.mat;
    4484:   if (bias) *bias = dm->defaultConstraint.bias;
    4485:   PetscFunctionReturn(PETSC_SUCCESS);
    4486: }

    4488: /*@
    4489:   DMSetDefaultConstraints - Set the `PetscSection` and `Mat` that specify the local constraint interpolation.

    4491:   Collective

    4493:   Input Parameters:
    4494: + dm      - The `DM`
    4495: . section - The `PetscSection` describing the range of the constraint matrix: relates rows of the constraint matrix to dofs of the default section.  Must have a local communicator (`PETSC_COMM_SELF` or derivative).
    4496: . mat     - The `Mat` that interpolates local constraints: its width should be the layout size of the default section:  `NULL` indicates no constraints.  Must have a local communicator (`PETSC_COMM_SELF` or derivative).
    4497: - bias    - A bias vector to be added to constrained values in the local vector.  `NULL` indicates no bias.  Must have a local communicator (`PETSC_COMM_SELF` or derivative).

    4499:   Level: advanced

    4501:   Notes:
    4502:   If a constraint matrix is specified, then it is applied during `DMGlobalToLocalEnd()` when mode is `INSERT_VALUES`, `INSERT_BC_VALUES`, or `INSERT_ALL_VALUES`.  Without a constraint matrix, the local vector l returned by `DMGlobalToLocalEnd()` contains values that have been scattered from a global vector without modification; with a constraint matrix A, l is modified by computing c = A * l + bias, l[s[i]] = c[i], where the scatter s is defined by the `PetscSection` returned by `DMGetDefaultConstraints()`.

    4504:   If a constraint matrix is specified, then its adjoint is applied during `DMLocalToGlobalBegin()` when mode is `ADD_VALUES`, `ADD_BC_VALUES`, or `ADD_ALL_VALUES`.  Without a constraint matrix, the local vector l is accumulated into a global vector without modification; with a constraint matrix A, l is first modified by computing c[i] = l[s[i]], l[s[i]] = 0, l = l + A'*c, which is the adjoint of the operation described above.  Any bias, if specified, is ignored when accumulating.

    4506:   This increments the references of the `PetscSection`, `Mat`, and `Vec`, so they user can destroy them.

    4508: .seealso: [](ch_dmbase), `DM`, `DMGetDefaultConstraints()`
    4509: @*/
    4510: PetscErrorCode DMSetDefaultConstraints(DM dm, PetscSection section, Mat mat, Vec bias)
    4511: {
    4512:   PetscMPIInt result;

    4514:   PetscFunctionBegin;
    4516:   if (section) {
    4518:     PetscCallMPI(MPI_Comm_compare(PETSC_COMM_SELF, PetscObjectComm((PetscObject)section), &result));
    4519:     PetscCheck(result == MPI_CONGRUENT || result == MPI_IDENT, PETSC_COMM_SELF, PETSC_ERR_ARG_NOTSAMECOMM, "constraint section must have local communicator");
    4520:   }
    4521:   if (mat) {
    4523:     PetscCallMPI(MPI_Comm_compare(PETSC_COMM_SELF, PetscObjectComm((PetscObject)mat), &result));
    4524:     PetscCheck(result == MPI_CONGRUENT || result == MPI_IDENT, PETSC_COMM_SELF, PETSC_ERR_ARG_NOTSAMECOMM, "constraint matrix must have local communicator");
    4525:   }
    4526:   if (bias) {
    4528:     PetscCallMPI(MPI_Comm_compare(PETSC_COMM_SELF, PetscObjectComm((PetscObject)bias), &result));
    4529:     PetscCheck(result == MPI_CONGRUENT || result == MPI_IDENT, PETSC_COMM_SELF, PETSC_ERR_ARG_NOTSAMECOMM, "constraint bias must have local communicator");
    4530:   }
    4531:   PetscCall(PetscObjectReference((PetscObject)section));
    4532:   PetscCall(PetscSectionDestroy(&dm->defaultConstraint.section));
    4533:   dm->defaultConstraint.section = section;
    4534:   PetscCall(PetscObjectReference((PetscObject)mat));
    4535:   PetscCall(MatDestroy(&dm->defaultConstraint.mat));
    4536:   dm->defaultConstraint.mat = mat;
    4537:   PetscCall(PetscObjectReference((PetscObject)bias));
    4538:   PetscCall(VecDestroy(&dm->defaultConstraint.bias));
    4539:   dm->defaultConstraint.bias = bias;
    4540:   PetscFunctionReturn(PETSC_SUCCESS);
    4541: }

    4543: #if defined(PETSC_USE_DEBUG)
    4544: /*
    4545:   DMDefaultSectionCheckConsistency - Check the consistentcy of the global and local sections. Generates and error if they are not consistent.

    4547:   Input Parameters:
    4548: + dm - The `DM`
    4549: . localSection - `PetscSection` describing the local data layout
    4550: - globalSection - `PetscSection` describing the global data layout

    4552:   Level: intermediate

    4554: .seealso: [](ch_dmbase), `DM`, `DMGetSectionSF()`, `DMSetSectionSF()`
    4555: */
    4556: static PetscErrorCode DMDefaultSectionCheckConsistency_Internal(DM dm, PetscSection localSection, PetscSection globalSection)
    4557: {
    4558:   MPI_Comm        comm;
    4559:   PetscLayout     layout;
    4560:   const PetscInt *ranges;
    4561:   PetscInt        pStart, pEnd, p, nroots;
    4562:   PetscMPIInt     size, rank;
    4563:   PetscBool       valid = PETSC_TRUE, gvalid;

    4565:   PetscFunctionBegin;
    4566:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
    4568:   PetscCallMPI(MPI_Comm_size(comm, &size));
    4569:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    4570:   PetscCall(PetscSectionGetChart(globalSection, &pStart, &pEnd));
    4571:   PetscCall(PetscSectionGetConstrainedStorageSize(globalSection, &nroots));
    4572:   PetscCall(PetscLayoutCreate(comm, &layout));
    4573:   PetscCall(PetscLayoutSetBlockSize(layout, 1));
    4574:   PetscCall(PetscLayoutSetLocalSize(layout, nroots));
    4575:   PetscCall(PetscLayoutSetUp(layout));
    4576:   PetscCall(PetscLayoutGetRanges(layout, &ranges));
    4577:   for (p = pStart; p < pEnd; ++p) {
    4578:     PetscInt dof, cdof, off, gdof, gcdof, goff, gsize, d;

    4580:     PetscCall(PetscSectionGetDof(localSection, p, &dof));
    4581:     PetscCall(PetscSectionGetOffset(localSection, p, &off));
    4582:     PetscCall(PetscSectionGetConstraintDof(localSection, p, &cdof));
    4583:     PetscCall(PetscSectionGetDof(globalSection, p, &gdof));
    4584:     PetscCall(PetscSectionGetConstraintDof(globalSection, p, &gcdof));
    4585:     PetscCall(PetscSectionGetOffset(globalSection, p, &goff));
    4586:     if (!gdof) continue; /* Censored point */
    4587:     if ((gdof < 0 ? -(gdof + 1) : gdof) != dof) {
    4588:       PetscCall(PetscSynchronizedPrintf(comm, "[%d]Global dof %" PetscInt_FMT " for point %" PetscInt_FMT " not equal to local dof %" PetscInt_FMT "\n", rank, gdof, p, dof));
    4589:       valid = PETSC_FALSE;
    4590:     }
    4591:     if (gcdof && (gcdof != cdof)) {
    4592:       PetscCall(PetscSynchronizedPrintf(comm, "[%d]Global constraints %" PetscInt_FMT " for point %" PetscInt_FMT " not equal to local constraints %" PetscInt_FMT "\n", rank, gcdof, p, cdof));
    4593:       valid = PETSC_FALSE;
    4594:     }
    4595:     if (gdof < 0) {
    4596:       gsize = gdof < 0 ? -(gdof + 1) - gcdof : gdof - gcdof;
    4597:       for (d = 0; d < gsize; ++d) {
    4598:         PetscInt offset = -(goff + 1) + d, r;

    4600:         PetscCall(PetscFindInt(offset, size + 1, ranges, &r));
    4601:         if (r < 0) r = -(r + 2);
    4602:         if ((r < 0) || (r >= size)) {
    4603:           PetscCall(PetscSynchronizedPrintf(comm, "[%d]Point %" PetscInt_FMT " mapped to invalid process %" PetscInt_FMT " (%" PetscInt_FMT ", %" PetscInt_FMT ")\n", rank, p, r, gdof, goff));
    4604:           valid = PETSC_FALSE;
    4605:           break;
    4606:         }
    4607:       }
    4608:     }
    4609:   }
    4610:   PetscCall(PetscLayoutDestroy(&layout));
    4611:   PetscCall(PetscSynchronizedFlush(comm, NULL));
    4612:   PetscCallMPI(MPIU_Allreduce(&valid, &gvalid, 1, MPI_C_BOOL, MPI_LAND, comm));
    4613:   if (!gvalid) {
    4614:     PetscCall(DMView(dm, NULL));
    4615:     SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Inconsistent local and global sections");
    4616:   }
    4617:   PetscFunctionReturn(PETSC_SUCCESS);
    4618: }
    4619: #endif

    4621: PetscErrorCode DMGetIsoperiodicPointSF_Internal(DM dm, PetscSF *sf)
    4622: {
    4623:   PetscErrorCode (*f)(DM, PetscSF *);

    4625:   PetscFunctionBegin;
    4627:   PetscAssertPointer(sf, 2);
    4628:   PetscCall(PetscObjectQueryFunction((PetscObject)dm, "DMGetIsoperiodicPointSF_C", &f));
    4629:   if (f) PetscCall(f(dm, sf));
    4630:   else *sf = dm->sf;
    4631:   PetscFunctionReturn(PETSC_SUCCESS);
    4632: }

    4634: /*@
    4635:   DMGetGlobalSection - Get the `PetscSection` encoding the global data layout for the `DM`.

    4637:   Collective

    4639:   Input Parameter:
    4640: . dm - The `DM`

    4642:   Output Parameter:
    4643: . section - The `PetscSection`

    4645:   Level: intermediate

    4647:   Note:
    4648:   This gets a borrowed reference, so the user should not destroy this `PetscSection`.

    4650: .seealso: [](ch_dmbase), `DM`, `DMSetLocalSection()`, `DMGetLocalSection()`
    4651: @*/
    4652: PetscErrorCode DMGetGlobalSection(DM dm, PetscSection *section)
    4653: {
    4654:   PetscFunctionBegin;
    4656:   PetscAssertPointer(section, 2);
    4657:   if (!dm->globalSection) {
    4658:     PetscSection s;
    4659:     PetscSF      sf;

    4661:     PetscCall(DMGetLocalSection(dm, &s));
    4662:     PetscCheck(s, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "DM must have a default PetscSection in order to create a global PetscSection");
    4663:     PetscCheck(dm->sf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "DM must have a point PetscSF in order to create a global PetscSection");
    4664:     PetscCall(DMGetIsoperiodicPointSF_Internal(dm, &sf));
    4665:     PetscCall(PetscSectionCreateGlobalSection(s, sf, PETSC_TRUE, PETSC_FALSE, PETSC_FALSE, &dm->globalSection));
    4666:     PetscCall(PetscLayoutDestroy(&dm->map));
    4667:     PetscCall(PetscSectionGetValueLayout(PetscObjectComm((PetscObject)dm), dm->globalSection, &dm->map));
    4668:     PetscCall(PetscSectionViewFromOptions(dm->globalSection, NULL, "-global_section_view"));
    4669:   }
    4670:   *section = dm->globalSection;
    4671:   PetscFunctionReturn(PETSC_SUCCESS);
    4672: }

    4674: /*@
    4675:   DMSetGlobalSection - Set the `PetscSection` encoding the global data layout for the `DM`.

    4677:   Input Parameters:
    4678: + dm      - The `DM`
    4679: - section - The PetscSection, or `NULL`

    4681:   Level: intermediate

    4683:   Note:
    4684:   Any existing `PetscSection` will be destroyed

    4686: .seealso: [](ch_dmbase), `DM`, `DMGetGlobalSection()`, `DMSetLocalSection()`
    4687: @*/
    4688: PetscErrorCode DMSetGlobalSection(DM dm, PetscSection section)
    4689: {
    4690:   PetscFunctionBegin;
    4693:   PetscCall(PetscObjectReference((PetscObject)section));
    4694:   PetscCall(PetscSectionDestroy(&dm->globalSection));
    4695:   dm->globalSection = section;
    4696: #if defined(PETSC_USE_DEBUG)
    4697:   if (section) PetscCall(DMDefaultSectionCheckConsistency_Internal(dm, dm->localSection, section));
    4698: #endif
    4699:   /* Clear global scratch vectors and sectionSF */
    4700:   PetscCall(PetscSFDestroy(&dm->sectionSF));
    4701:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &dm->sectionSF));
    4702:   PetscCall(DMClearGlobalVectors(dm));
    4703:   PetscCall(DMClearNamedGlobalVectors(dm));
    4704:   PetscFunctionReturn(PETSC_SUCCESS);
    4705: }

    4707: /*@
    4708:   DMGetSectionSF - Get the `PetscSF` encoding the parallel dof overlap for the `DM`. If it has not been set,
    4709:   it is created from the default `PetscSection` layouts in the `DM`.

    4711:   Input Parameter:
    4712: . dm - The `DM`

    4714:   Output Parameter:
    4715: . sf - The `PetscSF`

    4717:   Level: intermediate

    4719:   Note:
    4720:   This gets a borrowed reference, so the user should not destroy this `PetscSF`.

    4722: .seealso: [](ch_dmbase), `DM`, `DMSetSectionSF()`, `DMCreateSectionSF()`
    4723: @*/
    4724: PetscErrorCode DMGetSectionSF(DM dm, PetscSF *sf)
    4725: {
    4726:   PetscInt nroots;

    4728:   PetscFunctionBegin;
    4730:   PetscAssertPointer(sf, 2);
    4731:   if (!dm->sectionSF) PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &dm->sectionSF));
    4732:   PetscCall(PetscSFGetGraph(dm->sectionSF, &nroots, NULL, NULL, NULL));
    4733:   if (nroots < 0) {
    4734:     PetscSection section, gSection;

    4736:     PetscCall(DMGetLocalSection(dm, &section));
    4737:     if (section) {
    4738:       PetscCall(DMGetGlobalSection(dm, &gSection));
    4739:       PetscCall(DMCreateSectionSF(dm, section, gSection));
    4740:     } else {
    4741:       *sf = NULL;
    4742:       PetscFunctionReturn(PETSC_SUCCESS);
    4743:     }
    4744:   }
    4745:   *sf = dm->sectionSF;
    4746:   PetscFunctionReturn(PETSC_SUCCESS);
    4747: }

    4749: /*@
    4750:   DMSetSectionSF - Set the `PetscSF` encoding the parallel dof overlap for the `DM`

    4752:   Input Parameters:
    4753: + dm - The `DM`
    4754: - sf - The `PetscSF`

    4756:   Level: intermediate

    4758:   Note:
    4759:   Any previous `PetscSF` is destroyed

    4761: .seealso: [](ch_dmbase), `DM`, `DMGetSectionSF()`, `DMCreateSectionSF()`
    4762: @*/
    4763: PetscErrorCode DMSetSectionSF(DM dm, PetscSF sf)
    4764: {
    4765:   PetscFunctionBegin;
    4768:   PetscCall(PetscObjectReference((PetscObject)sf));
    4769:   PetscCall(PetscSFDestroy(&dm->sectionSF));
    4770:   dm->sectionSF = sf;
    4771:   PetscFunctionReturn(PETSC_SUCCESS);
    4772: }

    4774: /*@
    4775:   DMCreateSectionSF - Create the `PetscSF` encoding the parallel dof overlap for the `DM` based upon the `PetscSection`s
    4776:   describing the data layout.

    4778:   Input Parameters:
    4779: + dm            - The `DM`
    4780: . localSection  - `PetscSection` describing the local data layout
    4781: - globalSection - `PetscSection` describing the global data layout

    4783:   Level: developer

    4785:   Note:
    4786:   One usually uses `DMGetSectionSF()` to obtain the `PetscSF`

    4788:   Developer Note:
    4789:   Since this routine has for arguments the two sections from the `DM` and puts the resulting `PetscSF`
    4790:   directly into the `DM`, perhaps this function should not take the local and global sections as
    4791:   input and should just obtain them from the `DM`? Plus PETSc creation functions return the thing
    4792:   they create, this returns nothing

    4794: .seealso: [](ch_dmbase), `DM`, `DMGetSectionSF()`, `DMSetSectionSF()`, `DMGetLocalSection()`, `DMGetGlobalSection()`
    4795: @*/
    4796: PetscErrorCode DMCreateSectionSF(DM dm, PetscSection localSection, PetscSection globalSection)
    4797: {
    4798:   PetscFunctionBegin;
    4800:   PetscCall(PetscSFSetGraphSection(dm->sectionSF, localSection, globalSection));
    4801:   PetscFunctionReturn(PETSC_SUCCESS);
    4802: }

    4804: /*@
    4805:   DMGetPointSF - Get the `PetscSF` encoding the parallel section point overlap for the `DM`.

    4807:   Not collective but the resulting `PetscSF` is collective

    4809:   Input Parameter:
    4810: . dm - The `DM`

    4812:   Output Parameter:
    4813: . sf - The `PetscSF`

    4815:   Level: intermediate

    4817:   Note:
    4818:   This gets a borrowed reference, so the user should not destroy this `PetscSF`.

    4820: .seealso: [](ch_dmbase), `DM`, `DMSetPointSF()`, `DMGetSectionSF()`, `DMSetSectionSF()`, `DMCreateSectionSF()`
    4821: @*/
    4822: PetscErrorCode DMGetPointSF(DM dm, PetscSF *sf)
    4823: {
    4824:   PetscFunctionBegin;
    4826:   PetscAssertPointer(sf, 2);
    4827:   *sf = dm->sf;
    4828:   PetscFunctionReturn(PETSC_SUCCESS);
    4829: }

    4831: /*@
    4832:   DMSetPointSF - Set the `PetscSF` encoding the parallel section point overlap for the `DM`.

    4834:   Collective

    4836:   Input Parameters:
    4837: + dm - The `DM`
    4838: - sf - The `PetscSF`

    4840:   Level: intermediate

    4842: .seealso: [](ch_dmbase), `DM`, `DMGetPointSF()`, `DMGetSectionSF()`, `DMSetSectionSF()`, `DMCreateSectionSF()`
    4843: @*/
    4844: PetscErrorCode DMSetPointSF(DM dm, PetscSF sf)
    4845: {
    4846:   PetscFunctionBegin;
    4849:   PetscCall(PetscObjectReference((PetscObject)sf));
    4850:   PetscCall(PetscSFDestroy(&dm->sf));
    4851:   dm->sf = sf;
    4852:   PetscFunctionReturn(PETSC_SUCCESS);
    4853: }

    4855: /*@
    4856:   DMGetNaturalSF - Get the `PetscSF` encoding the map back to the original mesh ordering

    4858:   Input Parameter:
    4859: . dm - The `DM`

    4861:   Output Parameter:
    4862: . sf - The `PetscSF`

    4864:   Level: intermediate

    4866:   Note:
    4867:   This gets a borrowed reference, so the user should not destroy this `PetscSF`.

    4869: .seealso: [](ch_dmbase), `DM`, `DMSetNaturalSF()`, `DMSetUseNatural()`, `DMGetUseNatural()`, `DMPlexCreateGlobalToNaturalSF()`, `DMPlexDistribute()`
    4870: @*/
    4871: PetscErrorCode DMGetNaturalSF(DM dm, PetscSF *sf)
    4872: {
    4873:   PetscFunctionBegin;
    4875:   PetscAssertPointer(sf, 2);
    4876:   *sf = dm->sfNatural;
    4877:   PetscFunctionReturn(PETSC_SUCCESS);
    4878: }

    4880: /*@
    4881:   DMSetNaturalSF - Set the PetscSF encoding the map back to the original mesh ordering

    4883:   Input Parameters:
    4884: + dm - The DM
    4885: - sf - The PetscSF

    4887:   Level: intermediate

    4889: .seealso: [](ch_dmbase), `DM`, `DMGetNaturalSF()`, `DMSetUseNatural()`, `DMGetUseNatural()`, `DMPlexCreateGlobalToNaturalSF()`, `DMPlexDistribute()`
    4890: @*/
    4891: PetscErrorCode DMSetNaturalSF(DM dm, PetscSF sf)
    4892: {
    4893:   PetscFunctionBegin;
    4896:   PetscCall(PetscObjectReference((PetscObject)sf));
    4897:   PetscCall(PetscSFDestroy(&dm->sfNatural));
    4898:   dm->sfNatural = sf;
    4899:   PetscFunctionReturn(PETSC_SUCCESS);
    4900: }

    4902: static PetscErrorCode DMSetDefaultAdjacency_Private(DM dm, PetscInt f, PetscObject disc)
    4903: {
    4904:   PetscClassId id;

    4906:   PetscFunctionBegin;
    4907:   PetscCall(PetscObjectGetClassId(disc, &id));
    4908:   if (id == PETSCFE_CLASSID) {
    4909:     PetscCall(DMSetAdjacency(dm, f, PETSC_FALSE, PETSC_TRUE));
    4910:   } else if (id == PETSCFV_CLASSID) {
    4911:     PetscCall(DMSetAdjacency(dm, f, PETSC_TRUE, PETSC_FALSE));
    4912:   } else {
    4913:     PetscCall(DMSetAdjacency(dm, f, PETSC_FALSE, PETSC_TRUE));
    4914:   }
    4915:   PetscFunctionReturn(PETSC_SUCCESS);
    4916: }

    4918: static PetscErrorCode DMFieldEnlarge_Static(DM dm, PetscInt NfNew)
    4919: {
    4920:   RegionField *tmpr;
    4921:   PetscInt     Nf = dm->Nf, f;

    4923:   PetscFunctionBegin;
    4924:   if (Nf >= NfNew) PetscFunctionReturn(PETSC_SUCCESS);
    4925:   PetscCall(PetscMalloc1(NfNew, &tmpr));
    4926:   for (f = 0; f < Nf; ++f) tmpr[f] = dm->fields[f];
    4927:   for (f = Nf; f < NfNew; ++f) {
    4928:     tmpr[f].disc        = NULL;
    4929:     tmpr[f].label       = NULL;
    4930:     tmpr[f].avoidTensor = PETSC_FALSE;
    4931:   }
    4932:   PetscCall(PetscFree(dm->fields));
    4933:   dm->Nf     = NfNew;
    4934:   dm->fields = tmpr;
    4935:   PetscFunctionReturn(PETSC_SUCCESS);
    4936: }

    4938: /*@
    4939:   DMClearFields - Remove all fields from the `DM`

    4941:   Logically Collective

    4943:   Input Parameter:
    4944: . dm - The `DM`

    4946:   Level: intermediate

    4948: .seealso: [](ch_dmbase), `DM`, `DMGetNumFields()`, `DMSetNumFields()`, `DMSetField()`
    4949: @*/
    4950: PetscErrorCode DMClearFields(DM dm)
    4951: {
    4952:   PetscInt f;

    4954:   PetscFunctionBegin;
    4956:   if (!dm->fields) PetscFunctionReturn(PETSC_SUCCESS); // DMDA does not use fields field in DM
    4957:   for (f = 0; f < dm->Nf; ++f) {
    4958:     PetscCall(PetscObjectDestroy(&dm->fields[f].disc));
    4959:     PetscCall(DMLabelDestroy(&dm->fields[f].label));
    4960:   }
    4961:   PetscCall(PetscFree(dm->fields));
    4962:   dm->fields = NULL;
    4963:   dm->Nf     = 0;
    4964:   PetscFunctionReturn(PETSC_SUCCESS);
    4965: }

    4967: /*@
    4968:   DMGetNumFields - Get the number of fields in the `DM`

    4970:   Not Collective

    4972:   Input Parameter:
    4973: . dm - The `DM`

    4975:   Output Parameter:
    4976: . numFields - The number of fields

    4978:   Level: intermediate

    4980: .seealso: [](ch_dmbase), `DM`, `DMSetNumFields()`, `DMSetField()`
    4981: @*/
    4982: PetscErrorCode DMGetNumFields(DM dm, PetscInt *numFields)
    4983: {
    4984:   PetscFunctionBegin;
    4986:   PetscAssertPointer(numFields, 2);
    4987:   *numFields = dm->Nf;
    4988:   PetscFunctionReturn(PETSC_SUCCESS);
    4989: }

    4991: /*@
    4992:   DMSetNumFields - Set the number of fields in the `DM`

    4994:   Logically Collective

    4996:   Input Parameters:
    4997: + dm        - The `DM`
    4998: - numFields - The number of fields

    5000:   Level: intermediate

    5002: .seealso: [](ch_dmbase), `DM`, `DMGetNumFields()`, `DMSetField()`
    5003: @*/
    5004: PetscErrorCode DMSetNumFields(DM dm, PetscInt numFields)
    5005: {
    5006:   PetscInt Nf, f;

    5008:   PetscFunctionBegin;
    5010:   PetscCall(DMGetNumFields(dm, &Nf));
    5011:   for (f = Nf; f < numFields; ++f) {
    5012:     PetscContainer obj;

    5014:     PetscCall(PetscContainerCreate(PetscObjectComm((PetscObject)dm), &obj));
    5015:     PetscCall(DMAddField(dm, NULL, (PetscObject)obj));
    5016:     PetscCall(PetscContainerDestroy(&obj));
    5017:   }
    5018:   PetscFunctionReturn(PETSC_SUCCESS);
    5019: }

    5021: /*@
    5022:   DMGetField - Return the `DMLabel` and discretization object for a given `DM` field

    5024:   Not Collective

    5026:   Input Parameters:
    5027: + dm - The `DM`
    5028: - f  - The field number

    5030:   Output Parameters:
    5031: + label - The label indicating the support of the field, or `NULL` for the entire mesh (pass in `NULL` if not needed)
    5032: - disc  - The discretization object (pass in `NULL` if not needed)

    5034:   Level: intermediate

    5036: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMSetField()`
    5037: @*/
    5038: PetscErrorCode DMGetField(DM dm, PetscInt f, DMLabel *label, PetscObject *disc)
    5039: {
    5040:   PetscFunctionBegin;
    5042:   PetscAssertPointer(disc, 4);
    5043:   PetscCheck((f >= 0) && (f < dm->Nf), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", f, dm->Nf);
    5044:   if (!dm->fields) {
    5045:     if (label) *label = NULL;
    5046:     if (disc) *disc = NULL;
    5047:   } else { // some DM such as DMDA do not have dm->fields
    5048:     if (label) *label = dm->fields[f].label;
    5049:     if (disc) *disc = dm->fields[f].disc;
    5050:   }
    5051:   PetscFunctionReturn(PETSC_SUCCESS);
    5052: }

    5054: /* Does not clear the DS */
    5055: PetscErrorCode DMSetField_Internal(DM dm, PetscInt f, DMLabel label, PetscObject disc)
    5056: {
    5057:   PetscFunctionBegin;
    5058:   PetscCall(DMFieldEnlarge_Static(dm, f + 1));
    5059:   PetscCall(DMLabelDestroy(&dm->fields[f].label));
    5060:   PetscCall(PetscObjectDestroy(&dm->fields[f].disc));
    5061:   dm->fields[f].label = label;
    5062:   dm->fields[f].disc  = disc;
    5063:   PetscCall(PetscObjectReference((PetscObject)label));
    5064:   PetscCall(PetscObjectReference(disc));
    5065:   PetscFunctionReturn(PETSC_SUCCESS);
    5066: }

    5068: /*@
    5069:   DMSetField - Set the discretization object for a given `DM` field. Usually one would call `DMAddField()` which automatically handles
    5070:   the field numbering.

    5072:   Logically Collective

    5074:   Input Parameters:
    5075: + dm    - The `DM`
    5076: . f     - The field number
    5077: . label - The label indicating the support of the field, or `NULL` for the entire mesh
    5078: - disc  - The discretization object

    5080:   Level: intermediate

    5082: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`
    5083: @*/
    5084: PetscErrorCode DMSetField(DM dm, PetscInt f, DMLabel label, PetscObject disc)
    5085: {
    5086:   PetscFunctionBegin;
    5090:   PetscCheck(f >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be non-negative", f);
    5091:   PetscCall(DMSetField_Internal(dm, f, label, disc));
    5092:   PetscCall(DMSetDefaultAdjacency_Private(dm, f, disc));
    5093:   PetscCall(DMClearDS(dm));
    5094:   PetscFunctionReturn(PETSC_SUCCESS);
    5095: }

    5097: /*@
    5098:   DMAddField - Add a field to a `DM` object. A field is a function space defined by of a set of discretization points (geometric entities)
    5099:   and a discretization object that defines the function space associated with those points.

    5101:   Logically Collective

    5103:   Input Parameters:
    5104: + dm    - The `DM`
    5105: . label - The label indicating the support of the field, or `NULL` for the entire mesh
    5106: - disc  - The discretization object

    5108:   Level: intermediate

    5110:   Notes:
    5111:   The label already exists or will be added to the `DM` with `DMSetLabel()`.

    5113:   For example, a piecewise continuous pressure field can be defined by coefficients at the cell centers of a mesh and piecewise constant functions
    5114:   within each cell. Thus a specific function in the space is defined by the combination of a `Vec` containing the coefficients, a `DM` defining the
    5115:   geometry entities, a `DMLabel` indicating a subset of those geometric entities, and a discretization object, such as a `PetscFE`.

    5117:   Fortran Note:
    5118:   Use the argument `PetscObjectCast(disc)` as the second argument

    5120: .seealso: [](ch_dmbase), `DM`, `DMSetLabel()`, `DMSetField()`, `DMGetField()`, `PetscFE`
    5121: @*/
    5122: PetscErrorCode DMAddField(DM dm, DMLabel label, PetscObject disc)
    5123: {
    5124:   PetscInt Nf = dm->Nf;

    5126:   PetscFunctionBegin;
    5130:   PetscCall(DMFieldEnlarge_Static(dm, Nf + 1));
    5131:   dm->fields[Nf].label = label;
    5132:   dm->fields[Nf].disc  = disc;
    5133:   PetscCall(PetscObjectReference((PetscObject)label));
    5134:   PetscCall(PetscObjectReference(disc));
    5135:   PetscCall(DMSetDefaultAdjacency_Private(dm, Nf, disc));
    5136:   PetscCall(DMClearDS(dm));
    5137:   PetscFunctionReturn(PETSC_SUCCESS);
    5138: }

    5140: /*@
    5141:   DMSetFieldAvoidTensor - Set flag to avoid defining the field on tensor cells

    5143:   Logically Collective

    5145:   Input Parameters:
    5146: + dm          - The `DM`
    5147: . f           - The field index
    5148: - avoidTensor - `PETSC_TRUE` to skip defining the field on tensor cells

    5150:   Level: intermediate

    5152: .seealso: [](ch_dmbase), `DM`, `DMGetFieldAvoidTensor()`, `DMSetField()`, `DMGetField()`
    5153: @*/
    5154: PetscErrorCode DMSetFieldAvoidTensor(DM dm, PetscInt f, PetscBool avoidTensor)
    5155: {
    5156:   PetscFunctionBegin;
    5157:   PetscCheck((f >= 0) && (f < dm->Nf), PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Field %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", f, dm->Nf);
    5158:   dm->fields[f].avoidTensor = avoidTensor;
    5159:   PetscFunctionReturn(PETSC_SUCCESS);
    5160: }

    5162: /*@
    5163:   DMGetFieldAvoidTensor - Get flag to avoid defining the field on tensor cells

    5165:   Not Collective

    5167:   Input Parameters:
    5168: + dm - The `DM`
    5169: - f  - The field index

    5171:   Output Parameter:
    5172: . avoidTensor - The flag to avoid defining the field on tensor cells

    5174:   Level: intermediate

    5176: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMSetField()`, `DMGetField()`, `DMSetFieldAvoidTensor()`
    5177: @*/
    5178: PetscErrorCode DMGetFieldAvoidTensor(DM dm, PetscInt f, PetscBool *avoidTensor)
    5179: {
    5180:   PetscFunctionBegin;
    5181:   PetscCheck((f >= 0) && (f < dm->Nf), PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Field %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", f, dm->Nf);
    5182:   *avoidTensor = dm->fields[f].avoidTensor;
    5183:   PetscFunctionReturn(PETSC_SUCCESS);
    5184: }

    5186: /*@
    5187:   DMCopyFields - Copy the discretizations for the `DM` into another `DM`

    5189:   Collective

    5191:   Input Parameters:
    5192: + dm        - The `DM`
    5193: . minDegree - Minimum degree for a discretization, or `PETSC_DETERMINE` for no limit
    5194: - maxDegree - Maximum degree for a discretization, or `PETSC_DETERMINE` for no limit

    5196:   Output Parameter:
    5197: . newdm - The `DM`

    5199:   Level: advanced

    5201: .seealso: [](ch_dmbase), `DM`, `DMGetField()`, `DMSetField()`, `DMAddField()`, `DMCopyDS()`, `DMGetDS()`, `DMGetCellDS()`
    5202: @*/
    5203: PetscErrorCode DMCopyFields(DM dm, PetscInt minDegree, PetscInt maxDegree, DM newdm)
    5204: {
    5205:   PetscInt Nf, f;

    5207:   PetscFunctionBegin;
    5208:   if (dm == newdm) PetscFunctionReturn(PETSC_SUCCESS);
    5209:   PetscCall(DMGetNumFields(dm, &Nf));
    5210:   PetscCall(DMClearFields(newdm));
    5211:   for (f = 0; f < Nf; ++f) {
    5212:     DMLabel      label;
    5213:     PetscObject  field;
    5214:     PetscClassId id;
    5215:     PetscBool    useCone, useClosure;

    5217:     PetscCall(DMGetField(dm, f, &label, &field));
    5218:     PetscCall(PetscObjectGetClassId(field, &id));
    5219:     if (id == PETSCFE_CLASSID) {
    5220:       PetscFE newfe;

    5222:       PetscCall(PetscFELimitDegree((PetscFE)field, minDegree, maxDegree, &newfe));
    5223:       PetscCall(DMSetField(newdm, f, label, (PetscObject)newfe));
    5224:       PetscCall(PetscFEDestroy(&newfe));
    5225:     } else {
    5226:       PetscCall(DMSetField(newdm, f, label, field));
    5227:     }
    5228:     PetscCall(DMGetAdjacency(dm, f, &useCone, &useClosure));
    5229:     PetscCall(DMSetAdjacency(newdm, f, useCone, useClosure));
    5230:   }
    5231:   // Create nullspace constructor slots
    5232:   if (dm->nullspaceConstructors) {
    5233:     PetscCall(PetscFree2(newdm->nullspaceConstructors, newdm->nearnullspaceConstructors));
    5234:     PetscCall(PetscCalloc2(Nf, &newdm->nullspaceConstructors, Nf, &newdm->nearnullspaceConstructors));
    5235:   }
    5236:   PetscFunctionReturn(PETSC_SUCCESS);
    5237: }

    5239: /*@
    5240:   DMGetAdjacency - Returns the flags for determining variable influence

    5242:   Not Collective

    5244:   Input Parameters:
    5245: + dm - The `DM` object
    5246: - f  - The field number, or `PETSC_DEFAULT` for the default adjacency

    5248:   Output Parameters:
    5249: + useCone    - Flag for variable influence starting with the cone operation
    5250: - useClosure - Flag for variable influence using transitive closure

    5252:   Level: developer

    5254:   Notes:
    5255: .vb
    5256:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5257:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5258:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5259: .ve
    5260:   Further explanation can be found in the User's Manual Section on the Influence of Variables on One Another.

    5262: .seealso: [](ch_dmbase), `DM`, `DMSetAdjacency()`, `DMGetField()`, `DMSetField()`
    5263: @*/
    5264: PetscErrorCode DMGetAdjacency(DM dm, PetscInt f, PetscBool *useCone, PetscBool *useClosure)
    5265: {
    5266:   PetscFunctionBegin;
    5268:   if (useCone) PetscAssertPointer(useCone, 3);
    5269:   if (useClosure) PetscAssertPointer(useClosure, 4);
    5270:   if (f < 0) {
    5271:     if (useCone) *useCone = dm->adjacency[0];
    5272:     if (useClosure) *useClosure = dm->adjacency[1];
    5273:   } else {
    5274:     PetscInt Nf;

    5276:     PetscCall(DMGetNumFields(dm, &Nf));
    5277:     PetscCheck(f < Nf, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", f, Nf);
    5278:     if (useCone) *useCone = dm->fields[f].adjacency[0];
    5279:     if (useClosure) *useClosure = dm->fields[f].adjacency[1];
    5280:   }
    5281:   PetscFunctionReturn(PETSC_SUCCESS);
    5282: }

    5284: /*@
    5285:   DMSetAdjacency - Set the flags for determining variable influence

    5287:   Not Collective

    5289:   Input Parameters:
    5290: + dm         - The `DM` object
    5291: . f          - The field number
    5292: . useCone    - Flag for variable influence starting with the cone operation
    5293: - useClosure - Flag for variable influence using transitive closure

    5295:   Level: developer

    5297:   Notes:
    5298: .vb
    5299:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5300:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5301:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5302: .ve
    5303:   Further explanation can be found in the User's Manual Section on the Influence of Variables on One Another.

    5305: .seealso: [](ch_dmbase), `DM`, `DMGetAdjacency()`, `DMGetField()`, `DMSetField()`
    5306: @*/
    5307: PetscErrorCode DMSetAdjacency(DM dm, PetscInt f, PetscBool useCone, PetscBool useClosure)
    5308: {
    5309:   PetscFunctionBegin;
    5311:   if (f < 0) {
    5312:     dm->adjacency[0] = useCone;
    5313:     dm->adjacency[1] = useClosure;
    5314:   } else {
    5315:     PetscInt Nf;

    5317:     PetscCall(DMGetNumFields(dm, &Nf));
    5318:     PetscCheck(f < Nf, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", f, Nf);
    5319:     dm->fields[f].adjacency[0] = useCone;
    5320:     dm->fields[f].adjacency[1] = useClosure;
    5321:   }
    5322:   PetscFunctionReturn(PETSC_SUCCESS);
    5323: }

    5325: /*@
    5326:   DMGetBasicAdjacency - Returns the flags for determining variable influence, using either the default or field 0 if it is defined

    5328:   Not collective

    5330:   Input Parameter:
    5331: . dm - The `DM` object

    5333:   Output Parameters:
    5334: + useCone    - Flag for variable influence starting with the cone operation
    5335: - useClosure - Flag for variable influence using transitive closure

    5337:   Level: developer

    5339:   Notes:
    5340: .vb
    5341:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5342:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5343:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5344: .ve

    5346: .seealso: [](ch_dmbase), `DM`, `DMSetBasicAdjacency()`, `DMGetField()`, `DMSetField()`
    5347: @*/
    5348: PetscErrorCode DMGetBasicAdjacency(DM dm, PetscBool *useCone, PetscBool *useClosure)
    5349: {
    5350:   PetscInt Nf;

    5352:   PetscFunctionBegin;
    5354:   if (useCone) PetscAssertPointer(useCone, 2);
    5355:   if (useClosure) PetscAssertPointer(useClosure, 3);
    5356:   PetscCall(DMGetNumFields(dm, &Nf));
    5357:   if (!Nf) {
    5358:     PetscCall(DMGetAdjacency(dm, PETSC_DEFAULT, useCone, useClosure));
    5359:   } else {
    5360:     PetscCall(DMGetAdjacency(dm, 0, useCone, useClosure));
    5361:   }
    5362:   PetscFunctionReturn(PETSC_SUCCESS);
    5363: }

    5365: /*@
    5366:   DMSetBasicAdjacency - Set the flags for determining variable influence, using either the default or field 0 if it is defined

    5368:   Not Collective

    5370:   Input Parameters:
    5371: + dm         - The `DM` object
    5372: . useCone    - Flag for variable influence starting with the cone operation
    5373: - useClosure - Flag for variable influence using transitive closure

    5375:   Level: developer

    5377:   Notes:
    5378: .vb
    5379:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5380:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5381:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5382: .ve

    5384: .seealso: [](ch_dmbase), `DM`, `DMGetBasicAdjacency()`, `DMGetField()`, `DMSetField()`
    5385: @*/
    5386: PetscErrorCode DMSetBasicAdjacency(DM dm, PetscBool useCone, PetscBool useClosure)
    5387: {
    5388:   PetscInt Nf;

    5390:   PetscFunctionBegin;
    5392:   PetscCall(DMGetNumFields(dm, &Nf));
    5393:   if (!Nf) {
    5394:     PetscCall(DMSetAdjacency(dm, PETSC_DEFAULT, useCone, useClosure));
    5395:   } else {
    5396:     PetscCall(DMSetAdjacency(dm, 0, useCone, useClosure));
    5397:   }
    5398:   PetscFunctionReturn(PETSC_SUCCESS);
    5399: }

    5401: PetscErrorCode DMCompleteBCLabels_Internal(DM dm)
    5402: {
    5403:   DM           plex;
    5404:   DMLabel     *labels, *glabels;
    5405:   const char **names;
    5406:   char        *sendNames, *recvNames;
    5407:   PetscInt     Nds, s, maxLabels = 0, maxLen = 0, gmaxLen, Nl = 0, gNl, l, gl, m;
    5408:   size_t       len;
    5409:   MPI_Comm     comm;
    5410:   PetscMPIInt  rank, size, p, *counts, *displs;

    5412:   PetscFunctionBegin;
    5413:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
    5414:   PetscCallMPI(MPI_Comm_size(comm, &size));
    5415:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    5416:   PetscCall(DMGetNumDS(dm, &Nds));
    5417:   for (s = 0; s < Nds; ++s) {
    5418:     PetscDS  dsBC;
    5419:     PetscInt numBd;

    5421:     PetscCall(DMGetRegionNumDS(dm, s, NULL, NULL, &dsBC, NULL));
    5422:     PetscCall(PetscDSGetNumBoundary(dsBC, &numBd));
    5423:     maxLabels += numBd;
    5424:   }
    5425:   PetscCall(PetscCalloc1(maxLabels, &labels));
    5426:   /* Get list of labels to be completed */
    5427:   for (s = 0; s < Nds; ++s) {
    5428:     PetscDS  dsBC;
    5429:     PetscInt numBd, bd;

    5431:     PetscCall(DMGetRegionNumDS(dm, s, NULL, NULL, &dsBC, NULL));
    5432:     PetscCall(PetscDSGetNumBoundary(dsBC, &numBd));
    5433:     for (bd = 0; bd < numBd; ++bd) {
    5434:       DMLabel      label;
    5435:       PetscInt     field;
    5436:       PetscObject  obj;
    5437:       PetscClassId id;

    5439:       PetscCall(PetscDSGetBoundary(dsBC, bd, NULL, NULL, NULL, &label, NULL, NULL, &field, NULL, NULL, NULL, NULL, NULL));
    5440:       PetscCall(DMGetField(dm, field, NULL, &obj));
    5441:       PetscCall(PetscObjectGetClassId(obj, &id));
    5442:       if (id != PETSCFE_CLASSID || !label) continue;
    5443:       for (l = 0; l < Nl; ++l)
    5444:         if (labels[l] == label) break;
    5445:       if (l == Nl) labels[Nl++] = label;
    5446:     }
    5447:   }
    5448:   /* Get label names */
    5449:   PetscCall(PetscMalloc1(Nl, &names));
    5450:   for (l = 0; l < Nl; ++l) PetscCall(PetscObjectGetName((PetscObject)labels[l], &names[l]));
    5451:   for (l = 0; l < Nl; ++l) {
    5452:     PetscCall(PetscStrlen(names[l], &len));
    5453:     maxLen = PetscMax(maxLen, (PetscInt)len + 2);
    5454:   }
    5455:   PetscCall(PetscFree(labels));
    5456:   PetscCallMPI(MPIU_Allreduce(&maxLen, &gmaxLen, 1, MPIU_INT, MPI_MAX, comm));
    5457:   PetscCall(PetscCalloc1(Nl * gmaxLen, &sendNames));
    5458:   for (l = 0; l < Nl; ++l) PetscCall(PetscStrncpy(&sendNames[gmaxLen * l], names[l], gmaxLen));
    5459:   PetscCall(PetscFree(names));
    5460:   /* Put all names on all processes */
    5461:   PetscCall(PetscCalloc2(size, &counts, size + 1, &displs));
    5462:   PetscCallMPI(MPI_Allgather(&Nl, 1, MPI_INT, counts, 1, MPI_INT, comm));
    5463:   for (p = 0; p < size; ++p) displs[p + 1] = displs[p] + counts[p];
    5464:   gNl = displs[size];
    5465:   for (p = 0; p < size; ++p) {
    5466:     counts[p] *= gmaxLen;
    5467:     displs[p] *= gmaxLen;
    5468:   }
    5469:   PetscCall(PetscCalloc2(gNl * gmaxLen, &recvNames, gNl, &glabels));
    5470:   PetscCallMPI(MPI_Allgatherv(sendNames, counts[rank], MPI_CHAR, recvNames, counts, displs, MPI_CHAR, comm));
    5471:   PetscCall(PetscFree2(counts, displs));
    5472:   PetscCall(PetscFree(sendNames));
    5473:   for (l = 0, gl = 0; l < gNl; ++l) {
    5474:     PetscCall(DMGetLabel(dm, &recvNames[l * gmaxLen], &glabels[gl]));
    5475:     PetscCheck(glabels[gl], PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Label %s missing on rank %d", &recvNames[l * gmaxLen], rank);
    5476:     for (m = 0; m < gl; ++m)
    5477:       if (glabels[m] == glabels[gl]) goto next_label;
    5478:     PetscCall(DMConvert(dm, DMPLEX, &plex));
    5479:     PetscCall(DMPlexLabelComplete(plex, glabels[gl]));
    5480:     PetscCall(DMDestroy(&plex));
    5481:     ++gl;
    5482:   next_label:
    5483:     continue;
    5484:   }
    5485:   PetscCall(PetscFree2(recvNames, glabels));
    5486:   PetscFunctionReturn(PETSC_SUCCESS);
    5487: }

    5489: static PetscErrorCode DMDSEnlarge_Static(DM dm, PetscInt NdsNew)
    5490: {
    5491:   DMSpace *tmpd;
    5492:   PetscInt Nds = dm->Nds, s;

    5494:   PetscFunctionBegin;
    5495:   if (Nds >= NdsNew) PetscFunctionReturn(PETSC_SUCCESS);
    5496:   PetscCall(PetscMalloc1(NdsNew, &tmpd));
    5497:   for (s = 0; s < Nds; ++s) tmpd[s] = dm->probs[s];
    5498:   for (s = Nds; s < NdsNew; ++s) {
    5499:     tmpd[s].ds     = NULL;
    5500:     tmpd[s].label  = NULL;
    5501:     tmpd[s].fields = NULL;
    5502:   }
    5503:   PetscCall(PetscFree(dm->probs));
    5504:   dm->Nds   = NdsNew;
    5505:   dm->probs = tmpd;
    5506:   PetscFunctionReturn(PETSC_SUCCESS);
    5507: }

    5509: /*@
    5510:   DMGetNumDS - Get the number of discrete systems in the `DM`

    5512:   Not Collective

    5514:   Input Parameter:
    5515: . dm - The `DM`

    5517:   Output Parameter:
    5518: . Nds - The number of `PetscDS` objects

    5520:   Level: intermediate

    5522: .seealso: [](ch_dmbase), `DM`, `DMGetDS()`, `DMGetCellDS()`
    5523: @*/
    5524: PetscErrorCode DMGetNumDS(DM dm, PetscInt *Nds)
    5525: {
    5526:   PetscFunctionBegin;
    5528:   PetscAssertPointer(Nds, 2);
    5529:   *Nds = dm->Nds;
    5530:   PetscFunctionReturn(PETSC_SUCCESS);
    5531: }

    5533: /*@
    5534:   DMClearDS - Remove all discrete systems from the `DM`

    5536:   Logically Collective

    5538:   Input Parameter:
    5539: . dm - The `DM`

    5541:   Level: intermediate

    5543: .seealso: [](ch_dmbase), `DM`, `DMGetNumDS()`, `DMGetDS()`, `DMSetField()`
    5544: @*/
    5545: PetscErrorCode DMClearDS(DM dm)
    5546: {
    5547:   PetscInt s;

    5549:   PetscFunctionBegin;
    5551:   for (s = 0; s < dm->Nds; ++s) {
    5552:     PetscCall(PetscDSDestroy(&dm->probs[s].ds));
    5553:     PetscCall(PetscDSDestroy(&dm->probs[s].dsIn));
    5554:     PetscCall(DMLabelDestroy(&dm->probs[s].label));
    5555:     PetscCall(ISDestroy(&dm->probs[s].fields));
    5556:   }
    5557:   PetscCall(PetscFree(dm->probs));
    5558:   dm->probs = NULL;
    5559:   dm->Nds   = 0;
    5560:   PetscFunctionReturn(PETSC_SUCCESS);
    5561: }

    5563: /*@
    5564:   DMGetDS - Get the default `PetscDS`

    5566:   Not Collective

    5568:   Input Parameter:
    5569: . dm - The `DM`

    5571:   Output Parameter:
    5572: . ds - The default `PetscDS`

    5574:   Level: intermediate

    5576:   Note:
    5577:   The `ds` is owned by the `dm` and should not be destroyed directly.

    5579: .seealso: [](ch_dmbase), `DM`, `DMGetCellDS()`, `DMGetRegionDS()`
    5580: @*/
    5581: PetscErrorCode DMGetDS(DM dm, PetscDS *ds)
    5582: {
    5583:   PetscFunctionBeginHot;
    5585:   PetscAssertPointer(ds, 2);
    5586:   PetscCheck(dm->Nds > 0, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Need to call DMCreateDS() before calling DMGetDS()");
    5587:   *ds = dm->probs[0].ds;
    5588:   PetscFunctionReturn(PETSC_SUCCESS);
    5589: }

    5591: /*@
    5592:   DMGetCellDS - Get the `PetscDS` defined on a given cell

    5594:   Not Collective

    5596:   Input Parameters:
    5597: + dm    - The `DM`
    5598: - point - Cell for the `PetscDS`

    5600:   Output Parameters:
    5601: + ds   - The `PetscDS` defined on the given cell
    5602: - dsIn - The `PetscDS` for input on the given cell, or `NULL` if the same ds

    5604:   Level: developer

    5606: .seealso: [](ch_dmbase), `DM`, `DMGetDS()`, `DMSetRegionDS()`
    5607: @*/
    5608: PetscErrorCode DMGetCellDS(DM dm, PetscInt point, PetscDS *ds, PetscDS *dsIn)
    5609: {
    5610:   PetscDS  dsDef = NULL;
    5611:   PetscInt s;

    5613:   PetscFunctionBeginHot;
    5615:   if (ds) PetscAssertPointer(ds, 3);
    5616:   if (dsIn) PetscAssertPointer(dsIn, 4);
    5617:   PetscCheck(point >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Mesh point cannot be negative: %" PetscInt_FMT, point);
    5618:   if (ds) *ds = NULL;
    5619:   if (dsIn) *dsIn = NULL;
    5620:   for (s = 0; s < dm->Nds; ++s) {
    5621:     PetscInt val;

    5623:     if (!dm->probs[s].label) {
    5624:       dsDef = dm->probs[s].ds;
    5625:     } else {
    5626:       PetscCall(DMLabelGetValue(dm->probs[s].label, point, &val));
    5627:       if (val >= 0) {
    5628:         if (ds) *ds = dm->probs[s].ds;
    5629:         if (dsIn) *dsIn = dm->probs[s].dsIn;
    5630:         break;
    5631:       }
    5632:     }
    5633:   }
    5634:   if (ds && !*ds) *ds = dsDef;
    5635:   PetscFunctionReturn(PETSC_SUCCESS);
    5636: }

    5638: /*@
    5639:   DMGetRegionDS - Get the `PetscDS` for a given mesh region, defined by a `DMLabel`

    5641:   Not Collective

    5643:   Input Parameters:
    5644: + dm    - The `DM`
    5645: - label - The `DMLabel` defining the mesh region, or `NULL` for the entire mesh

    5647:   Output Parameters:
    5648: + fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL`
    5649: . ds     - The `PetscDS` defined on the given region, or `NULL`
    5650: - dsIn   - The `PetscDS` for input in the given region, or `NULL`

    5652:   Level: advanced

    5654:   Note:
    5655:   If a non-`NULL` label is given, but there is no `PetscDS` on that specific label,
    5656:   the `PetscDS` for the full domain (if present) is returned. Returns with
    5657:   fields = `NULL` and ds = `NULL` if there is no `PetscDS` for the full domain.

    5659: .seealso: [](ch_dmbase), `DM`, `DMGetRegionNumDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5660: @*/
    5661: PetscErrorCode DMGetRegionDS(DM dm, DMLabel label, IS *fields, PetscDS *ds, PetscDS *dsIn)
    5662: {
    5663:   PetscInt Nds = dm->Nds, s;

    5665:   PetscFunctionBegin;
    5668:   if (fields) {
    5669:     PetscAssertPointer(fields, 3);
    5670:     *fields = NULL;
    5671:   }
    5672:   if (ds) {
    5673:     PetscAssertPointer(ds, 4);
    5674:     *ds = NULL;
    5675:   }
    5676:   if (dsIn) {
    5677:     PetscAssertPointer(dsIn, 5);
    5678:     *dsIn = NULL;
    5679:   }
    5680:   for (s = 0; s < Nds; ++s) {
    5681:     if (dm->probs[s].label == label || !dm->probs[s].label) {
    5682:       if (fields) *fields = dm->probs[s].fields;
    5683:       if (ds) *ds = dm->probs[s].ds;
    5684:       if (dsIn) *dsIn = dm->probs[s].dsIn;
    5685:       if (dm->probs[s].label) PetscFunctionReturn(PETSC_SUCCESS);
    5686:     }
    5687:   }
    5688:   PetscFunctionReturn(PETSC_SUCCESS);
    5689: }

    5691: /*@
    5692:   DMSetRegionDS - Set the `PetscDS` for a given mesh region, defined by a `DMLabel`

    5694:   Collective

    5696:   Input Parameters:
    5697: + dm     - The `DM`
    5698: . label  - The `DMLabel` defining the mesh region, or `NULL` for the entire mesh
    5699: . fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL` for all fields
    5700: . ds     - The `PetscDS` defined on the given region
    5701: - dsIn   - The `PetscDS` for input on the given cell, or `NULL` if it is the same `PetscDS`

    5703:   Level: advanced

    5705:   Note:
    5706:   If the label has a `PetscDS` defined, it will be replaced. Otherwise, it will be added to the `DM`. If the `PetscDS` is replaced,
    5707:   the fields argument is ignored.

    5709: .seealso: [](ch_dmbase), `DM`, `DMGetRegionDS()`, `DMSetRegionNumDS()`, `DMGetDS()`, `DMGetCellDS()`
    5710: @*/
    5711: PetscErrorCode DMSetRegionDS(DM dm, DMLabel label, IS fields, PetscDS ds, PetscDS dsIn)
    5712: {
    5713:   PetscInt Nds = dm->Nds, s;

    5715:   PetscFunctionBegin;
    5721:   for (s = 0; s < Nds; ++s) {
    5722:     if (dm->probs[s].label == label) {
    5723:       PetscCall(PetscDSDestroy(&dm->probs[s].ds));
    5724:       PetscCall(PetscDSDestroy(&dm->probs[s].dsIn));
    5725:       dm->probs[s].ds   = ds;
    5726:       dm->probs[s].dsIn = dsIn;
    5727:       PetscFunctionReturn(PETSC_SUCCESS);
    5728:     }
    5729:   }
    5730:   PetscCall(DMDSEnlarge_Static(dm, Nds + 1));
    5731:   PetscCall(PetscObjectReference((PetscObject)label));
    5732:   PetscCall(PetscObjectReference((PetscObject)fields));
    5733:   PetscCall(PetscObjectReference((PetscObject)ds));
    5734:   PetscCall(PetscObjectReference((PetscObject)dsIn));
    5735:   if (!label) {
    5736:     /* Put the NULL label at the front, so it is returned as the default */
    5737:     for (s = Nds - 1; s >= 0; --s) dm->probs[s + 1] = dm->probs[s];
    5738:     Nds = 0;
    5739:   }
    5740:   dm->probs[Nds].label  = label;
    5741:   dm->probs[Nds].fields = fields;
    5742:   dm->probs[Nds].ds     = ds;
    5743:   dm->probs[Nds].dsIn   = dsIn;
    5744:   PetscFunctionReturn(PETSC_SUCCESS);
    5745: }

    5747: /*@
    5748:   DMGetRegionNumDS - Get the `PetscDS` for a given mesh region, defined by the region number

    5750:   Not Collective

    5752:   Input Parameters:
    5753: + dm  - The `DM`
    5754: - num - The region number, in [0, Nds)

    5756:   Output Parameters:
    5757: + label  - The region label, or `NULL`
    5758: . fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL`
    5759: . ds     - The `PetscDS` defined on the given region, or `NULL`
    5760: - dsIn   - The `PetscDS` for input in the given region, or `NULL`

    5762:   Level: advanced

    5764: .seealso: [](ch_dmbase), `DM`, `DMGetRegionDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5765: @*/
    5766: PetscErrorCode DMGetRegionNumDS(DM dm, PetscInt num, DMLabel *label, IS *fields, PetscDS *ds, PetscDS *dsIn)
    5767: {
    5768:   PetscInt Nds;

    5770:   PetscFunctionBegin;
    5772:   PetscCall(DMGetNumDS(dm, &Nds));
    5773:   PetscCheck((num >= 0) && (num < Nds), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Region number %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", num, Nds);
    5774:   if (label) {
    5775:     PetscAssertPointer(label, 3);
    5776:     *label = dm->probs[num].label;
    5777:   }
    5778:   if (fields) {
    5779:     PetscAssertPointer(fields, 4);
    5780:     *fields = dm->probs[num].fields;
    5781:   }
    5782:   if (ds) {
    5783:     PetscAssertPointer(ds, 5);
    5784:     *ds = dm->probs[num].ds;
    5785:   }
    5786:   if (dsIn) {
    5787:     PetscAssertPointer(dsIn, 6);
    5788:     *dsIn = dm->probs[num].dsIn;
    5789:   }
    5790:   PetscFunctionReturn(PETSC_SUCCESS);
    5791: }

    5793: /*@
    5794:   DMSetRegionNumDS - Set the `PetscDS` for a given mesh region, defined by the region number

    5796:   Not Collective

    5798:   Input Parameters:
    5799: + dm     - The `DM`
    5800: . num    - The region number, in [0, Nds)
    5801: . label  - The region label, or `NULL`
    5802: . fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL` to prevent setting
    5803: . ds     - The `PetscDS` defined on the given region, or `NULL` to prevent setting
    5804: - dsIn   - The `PetscDS` for input on the given cell, or `NULL` if it is the same `PetscDS`

    5806:   Level: advanced

    5808: .seealso: [](ch_dmbase), `DM`, `DMGetRegionDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5809: @*/
    5810: PetscErrorCode DMSetRegionNumDS(DM dm, PetscInt num, DMLabel label, IS fields, PetscDS ds, PetscDS dsIn)
    5811: {
    5812:   PetscInt Nds;

    5814:   PetscFunctionBegin;
    5817:   PetscCall(DMGetNumDS(dm, &Nds));
    5818:   PetscCheck((num >= 0) && (num < Nds), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Region number %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", num, Nds);
    5819:   PetscCall(PetscObjectReference((PetscObject)label));
    5820:   PetscCall(DMLabelDestroy(&dm->probs[num].label));
    5821:   dm->probs[num].label = label;
    5822:   if (fields) {
    5824:     PetscCall(PetscObjectReference((PetscObject)fields));
    5825:     PetscCall(ISDestroy(&dm->probs[num].fields));
    5826:     dm->probs[num].fields = fields;
    5827:   }
    5828:   if (ds) {
    5830:     PetscCall(PetscObjectReference((PetscObject)ds));
    5831:     PetscCall(PetscDSDestroy(&dm->probs[num].ds));
    5832:     dm->probs[num].ds = ds;
    5833:   }
    5834:   if (dsIn) {
    5836:     PetscCall(PetscObjectReference((PetscObject)dsIn));
    5837:     PetscCall(PetscDSDestroy(&dm->probs[num].dsIn));
    5838:     dm->probs[num].dsIn = dsIn;
    5839:   }
    5840:   PetscFunctionReturn(PETSC_SUCCESS);
    5841: }

    5843: /*@
    5844:   DMFindRegionNum - Find the region number for a given `PetscDS`, or -1 if it is not found.

    5846:   Not Collective

    5848:   Input Parameters:
    5849: + dm - The `DM`
    5850: - ds - The `PetscDS` defined on the given region

    5852:   Output Parameter:
    5853: . num - The region number, in [0, Nds), or -1 if not found

    5855:   Level: advanced

    5857: .seealso: [](ch_dmbase), `DM`, `DMGetRegionNumDS()`, `DMGetRegionDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5858: @*/
    5859: PetscErrorCode DMFindRegionNum(DM dm, PetscDS ds, PetscInt *num)
    5860: {
    5861:   PetscInt Nds, n;

    5863:   PetscFunctionBegin;
    5866:   PetscAssertPointer(num, 3);
    5867:   PetscCall(DMGetNumDS(dm, &Nds));
    5868:   for (n = 0; n < Nds; ++n)
    5869:     if (ds == dm->probs[n].ds) break;
    5870:   if (n >= Nds) *num = -1;
    5871:   else *num = n;
    5872:   PetscFunctionReturn(PETSC_SUCCESS);
    5873: }

    5875: /*@
    5876:   DMCreateFEDefault - Create a `PetscFE` based on the celltype for the mesh

    5878:   Not Collective

    5880:   Input Parameters:
    5881: + dm     - The `DM`
    5882: . Nc     - The number of components for the field
    5883: . prefix - The options prefix for the output `PetscFE`, or `NULL`
    5884: - qorder - The quadrature order or `PETSC_DETERMINE` to use `PetscSpace` polynomial degree

    5886:   Output Parameter:
    5887: . fem - The `PetscFE`

    5889:   Level: intermediate

    5891:   Note:
    5892:   This is a convenience method that just calls `PetscFECreateByCell()` underneath.

    5894: .seealso: [](ch_dmbase), `DM`, `PetscFECreateByCell()`, `DMAddField()`, `DMCreateDS()`, `DMGetCellDS()`, `DMGetRegionDS()`
    5895: @*/
    5896: PetscErrorCode DMCreateFEDefault(DM dm, PetscInt Nc, const char prefix[], PetscInt qorder, PetscFE *fem)
    5897: {
    5898:   DMPolytopeType ct;
    5899:   PetscInt       dim, cStart;

    5901:   PetscFunctionBegin;
    5904:   if (prefix) PetscAssertPointer(prefix, 3);
    5906:   PetscAssertPointer(fem, 5);
    5907:   PetscCall(DMGetDimension(dm, &dim));
    5908:   PetscCall(DMPlexGetHeightStratum(dm, 0, &cStart, NULL));
    5909:   PetscCall(DMPlexGetCellType(dm, cStart, &ct));
    5910:   PetscCall(PetscFECreateByCell(PETSC_COMM_SELF, dim, Nc, ct, prefix, qorder, fem));
    5911:   PetscFunctionReturn(PETSC_SUCCESS);
    5912: }

    5914: /*@
    5915:   DMCreateDS - Create the discrete systems for the `DM` based upon the fields added to the `DM`

    5917:   Collective

    5919:   Input Parameter:
    5920: . dm - The `DM`

    5922:   Options Database Key:
    5923: . -dm_petscds_view - View all the `PetscDS` objects in this `DM`

    5925:   Level: intermediate

    5927:   Developer Note:
    5928:   The name of this function is wrong. Create functions always return the created object as one of the arguments.

    5930: .seealso: [](ch_dmbase), `DM`, `DMSetField`, `DMAddField()`, `DMGetDS()`, `DMGetCellDS()`, `DMGetRegionDS()`, `DMSetRegionDS()`
    5931: @*/
    5932: PetscErrorCode DMCreateDS(DM dm)
    5933: {
    5934:   MPI_Comm  comm;
    5935:   PetscDS   dsDef;
    5936:   DMLabel  *labelSet;
    5937:   PetscInt  dE, Nf = dm->Nf, f, s, Nl, l, Ndef, k;
    5938:   PetscBool doSetup = PETSC_TRUE, flg;

    5940:   PetscFunctionBegin;
    5942:   if (!dm->fields) PetscFunctionReturn(PETSC_SUCCESS);
    5943:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
    5944:   PetscCall(DMGetCoordinateDim(dm, &dE));
    5945:   // Create nullspace constructor slots
    5946:   PetscCall(PetscFree2(dm->nullspaceConstructors, dm->nearnullspaceConstructors));
    5947:   PetscCall(PetscCalloc2(Nf, &dm->nullspaceConstructors, Nf, &dm->nearnullspaceConstructors));
    5948:   /* Determine how many regions we have */
    5949:   PetscCall(PetscMalloc1(Nf, &labelSet));
    5950:   Nl   = 0;
    5951:   Ndef = 0;
    5952:   for (f = 0; f < Nf; ++f) {
    5953:     DMLabel  label = dm->fields[f].label;
    5954:     PetscInt l;

    5956: #ifdef PETSC_HAVE_LIBCEED
    5957:     /* Move CEED context to discretizations */
    5958:     {
    5959:       PetscClassId id;

    5961:       PetscCall(PetscObjectGetClassId(dm->fields[f].disc, &id));
    5962:       if (id == PETSCFE_CLASSID) {
    5963:         Ceed ceed;

    5965:         PetscCall(DMGetCeed(dm, &ceed));
    5966:         PetscCall(PetscFESetCeed((PetscFE)dm->fields[f].disc, ceed));
    5967:       }
    5968:     }
    5969: #endif
    5970:     if (!label) {
    5971:       ++Ndef;
    5972:       continue;
    5973:     }
    5974:     for (l = 0; l < Nl; ++l)
    5975:       if (label == labelSet[l]) break;
    5976:     if (l < Nl) continue;
    5977:     labelSet[Nl++] = label;
    5978:   }
    5979:   /* Create default DS if there are no labels to intersect with */
    5980:   PetscCall(DMGetRegionDS(dm, NULL, NULL, &dsDef, NULL));
    5981:   if (!dsDef && Ndef && !Nl) {
    5982:     IS        fields;
    5983:     PetscInt *fld, nf;

    5985:     for (f = 0, nf = 0; f < Nf; ++f)
    5986:       if (!dm->fields[f].label) ++nf;
    5987:     PetscCheck(nf, comm, PETSC_ERR_PLIB, "All fields have labels, but we are trying to create a default DS");
    5988:     PetscCall(PetscMalloc1(nf, &fld));
    5989:     for (f = 0, nf = 0; f < Nf; ++f)
    5990:       if (!dm->fields[f].label) fld[nf++] = f;
    5991:     PetscCall(ISCreate(PETSC_COMM_SELF, &fields));
    5992:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)fields, "dm_fields_"));
    5993:     PetscCall(ISSetType(fields, ISGENERAL));
    5994:     PetscCall(ISGeneralSetIndices(fields, nf, fld, PETSC_OWN_POINTER));

    5996:     PetscCall(PetscDSCreate(PETSC_COMM_SELF, &dsDef));
    5997:     PetscCall(DMSetRegionDS(dm, NULL, fields, dsDef, NULL));
    5998:     PetscCall(PetscDSDestroy(&dsDef));
    5999:     PetscCall(ISDestroy(&fields));
    6000:   }
    6001:   PetscCall(DMGetRegionDS(dm, NULL, NULL, &dsDef, NULL));
    6002:   if (dsDef) PetscCall(PetscDSSetCoordinateDimension(dsDef, dE));
    6003:   /* Intersect labels with default fields */
    6004:   if (Ndef && Nl) {
    6005:     DM              plex;
    6006:     DMLabel         cellLabel;
    6007:     IS              fieldIS, allcellIS, defcellIS = NULL;
    6008:     PetscInt       *fields;
    6009:     const PetscInt *cells;
    6010:     PetscInt        depth, nf = 0, n, c;

    6012:     PetscCall(DMConvert(dm, DMPLEX, &plex));
    6013:     PetscCall(DMPlexGetDepth(plex, &depth));
    6014:     PetscCall(DMGetStratumIS(plex, "dim", depth, &allcellIS));
    6015:     if (!allcellIS) PetscCall(DMGetStratumIS(plex, "depth", depth, &allcellIS));
    6016:     /* TODO This looks like it only works for one label */
    6017:     for (l = 0; l < Nl; ++l) {
    6018:       DMLabel label = labelSet[l];
    6019:       IS      pointIS;

    6021:       PetscCall(ISDestroy(&defcellIS));
    6022:       PetscCall(DMLabelGetStratumIS(label, 1, &pointIS));
    6023:       PetscCall(ISDifference(allcellIS, pointIS, &defcellIS));
    6024:       PetscCall(ISDestroy(&pointIS));
    6025:     }
    6026:     PetscCall(ISDestroy(&allcellIS));

    6028:     PetscCall(DMLabelCreate(PETSC_COMM_SELF, "defaultCells", &cellLabel));
    6029:     PetscCall(ISGetLocalSize(defcellIS, &n));
    6030:     PetscCall(ISGetIndices(defcellIS, &cells));
    6031:     for (c = 0; c < n; ++c) PetscCall(DMLabelSetValue(cellLabel, cells[c], 1));
    6032:     PetscCall(ISRestoreIndices(defcellIS, &cells));
    6033:     PetscCall(ISDestroy(&defcellIS));
    6034:     PetscCall(DMPlexLabelComplete(plex, cellLabel));

    6036:     PetscCall(PetscMalloc1(Ndef, &fields));
    6037:     for (f = 0; f < Nf; ++f)
    6038:       if (!dm->fields[f].label) fields[nf++] = f;
    6039:     PetscCall(ISCreate(PETSC_COMM_SELF, &fieldIS));
    6040:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)fieldIS, "dm_fields_"));
    6041:     PetscCall(ISSetType(fieldIS, ISGENERAL));
    6042:     PetscCall(ISGeneralSetIndices(fieldIS, nf, fields, PETSC_OWN_POINTER));

    6044:     PetscCall(PetscDSCreate(PETSC_COMM_SELF, &dsDef));
    6045:     PetscCall(DMSetRegionDS(dm, cellLabel, fieldIS, dsDef, NULL));
    6046:     PetscCall(PetscDSSetCoordinateDimension(dsDef, dE));
    6047:     PetscCall(DMLabelDestroy(&cellLabel));
    6048:     PetscCall(PetscDSDestroy(&dsDef));
    6049:     PetscCall(ISDestroy(&fieldIS));
    6050:     PetscCall(DMDestroy(&plex));
    6051:   }
    6052:   /* Create label DSes
    6053:      - WE ONLY SUPPORT IDENTICAL OR DISJOINT LABELS
    6054:   */
    6055:   /* TODO Should check that labels are disjoint */
    6056:   for (l = 0; l < Nl; ++l) {
    6057:     DMLabel   label = labelSet[l];
    6058:     PetscDS   ds, dsIn = NULL;
    6059:     IS        fields;
    6060:     PetscInt *fld, nf;

    6062:     PetscCall(PetscDSCreate(PETSC_COMM_SELF, &ds));
    6063:     for (f = 0, nf = 0; f < Nf; ++f)
    6064:       if (label == dm->fields[f].label || !dm->fields[f].label) ++nf;
    6065:     PetscCall(PetscMalloc1(nf, &fld));
    6066:     for (f = 0, nf = 0; f < Nf; ++f)
    6067:       if (label == dm->fields[f].label || !dm->fields[f].label) fld[nf++] = f;
    6068:     PetscCall(ISCreate(PETSC_COMM_SELF, &fields));
    6069:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)fields, "dm_fields_"));
    6070:     PetscCall(ISSetType(fields, ISGENERAL));
    6071:     PetscCall(ISGeneralSetIndices(fields, nf, fld, PETSC_OWN_POINTER));
    6072:     PetscCall(PetscDSSetCoordinateDimension(ds, dE));
    6073:     {
    6074:       DMPolytopeType ct;
    6075:       PetscInt       lStart, lEnd;
    6076:       PetscBool      isCohesiveLocal = PETSC_FALSE, isCohesive;

    6078:       PetscCall(DMLabelGetBounds(label, &lStart, &lEnd));
    6079:       if (lStart >= 0) {
    6080:         PetscCall(DMPlexGetCellType(dm, lStart, &ct));
    6081:         switch (ct) {
    6082:         case DM_POLYTOPE_POINT_PRISM_TENSOR:
    6083:         case DM_POLYTOPE_SEG_PRISM_TENSOR:
    6084:         case DM_POLYTOPE_TRI_PRISM_TENSOR:
    6085:         case DM_POLYTOPE_QUAD_PRISM_TENSOR:
    6086:           isCohesiveLocal = PETSC_TRUE;
    6087:           break;
    6088:         default:
    6089:           break;
    6090:         }
    6091:       }
    6092:       PetscCallMPI(MPIU_Allreduce(&isCohesiveLocal, &isCohesive, 1, MPI_C_BOOL, MPI_LOR, comm));
    6093:       if (isCohesive) {
    6094:         PetscCall(PetscDSCreate(PETSC_COMM_SELF, &dsIn));
    6095:         PetscCall(PetscDSSetCoordinateDimension(dsIn, dE));
    6096:       }
    6097:       for (f = 0, nf = 0; f < Nf; ++f) {
    6098:         if (label == dm->fields[f].label || !dm->fields[f].label) {
    6099:           if (label == dm->fields[f].label) {
    6100:             PetscCall(PetscDSSetDiscretization(ds, nf, NULL));
    6101:             PetscCall(PetscDSSetCohesive(ds, nf, isCohesive));
    6102:             if (dsIn) {
    6103:               PetscCall(PetscDSSetDiscretization(dsIn, nf, NULL));
    6104:               PetscCall(PetscDSSetCohesive(dsIn, nf, isCohesive));
    6105:             }
    6106:           }
    6107:           ++nf;
    6108:         }
    6109:       }
    6110:     }
    6111:     PetscCall(DMSetRegionDS(dm, label, fields, ds, dsIn));
    6112:     PetscCall(ISDestroy(&fields));
    6113:     PetscCall(PetscDSDestroy(&ds));
    6114:     PetscCall(PetscDSDestroy(&dsIn));
    6115:   }
    6116:   PetscCall(PetscFree(labelSet));
    6117:   /* Set fields in DSes */
    6118:   for (s = 0; s < dm->Nds; ++s) {
    6119:     PetscDS         ds     = dm->probs[s].ds;
    6120:     PetscDS         dsIn   = dm->probs[s].dsIn;
    6121:     IS              fields = dm->probs[s].fields;
    6122:     const PetscInt *fld;
    6123:     PetscInt        nf, dsnf;
    6124:     PetscBool       isCohesive;

    6126:     PetscCall(PetscDSGetNumFields(ds, &dsnf));
    6127:     PetscCall(PetscDSIsCohesive(ds, &isCohesive));
    6128:     PetscCall(ISGetLocalSize(fields, &nf));
    6129:     PetscCall(ISGetIndices(fields, &fld));
    6130:     for (f = 0; f < nf; ++f) {
    6131:       PetscObject  disc = dm->fields[fld[f]].disc;
    6132:       PetscBool    isCohesiveField;
    6133:       PetscClassId id;

    6135:       /* Handle DS with no fields */
    6136:       if (dsnf) PetscCall(PetscDSGetCohesive(ds, f, &isCohesiveField));
    6137:       /* If this is a cohesive cell, then regular fields need the lower dimensional discretization */
    6138:       if (isCohesive) {
    6139:         if (!isCohesiveField) {
    6140:           PetscObject bdDisc;

    6142:           PetscCall(PetscFEGetHeightSubspace((PetscFE)disc, 1, (PetscFE *)&bdDisc));
    6143:           PetscCall(PetscDSSetDiscretization(ds, f, bdDisc));
    6144:           PetscCall(PetscDSSetDiscretization(dsIn, f, disc));
    6145:         } else {
    6146:           PetscCall(PetscDSSetDiscretization(ds, f, disc));
    6147:           PetscCall(PetscDSSetDiscretization(dsIn, f, disc));
    6148:         }
    6149:       } else {
    6150:         PetscCall(PetscDSSetDiscretization(ds, f, disc));
    6151:       }
    6152:       /* We allow people to have placeholder fields and construct the Section by hand */
    6153:       PetscCall(PetscObjectGetClassId(disc, &id));
    6154:       if ((id != PETSCFE_CLASSID) && (id != PETSCFV_CLASSID)) doSetup = PETSC_FALSE;
    6155:     }
    6156:     PetscCall(ISRestoreIndices(fields, &fld));
    6157:   }
    6158:   /* Allow k-jet tabulation */
    6159:   PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)dm)->prefix, "-dm_ds_jet_degree", &k, &flg));
    6160:   if (flg) {
    6161:     for (s = 0; s < dm->Nds; ++s) {
    6162:       PetscDS  ds   = dm->probs[s].ds;
    6163:       PetscDS  dsIn = dm->probs[s].dsIn;
    6164:       PetscInt Nf, f;

    6166:       PetscCall(PetscDSGetNumFields(ds, &Nf));
    6167:       for (f = 0; f < Nf; ++f) {
    6168:         PetscCall(PetscDSSetJetDegree(ds, f, k));
    6169:         if (dsIn) PetscCall(PetscDSSetJetDegree(dsIn, f, k));
    6170:       }
    6171:     }
    6172:   }
    6173:   /* Setup DSes */
    6174:   if (doSetup) {
    6175:     for (s = 0; s < dm->Nds; ++s) {
    6176:       if (dm->setfromoptionscalled) {
    6177:         PetscCall(PetscDSSetFromOptions(dm->probs[s].ds));
    6178:         if (dm->probs[s].dsIn) PetscCall(PetscDSSetFromOptions(dm->probs[s].dsIn));
    6179:       }
    6180:       PetscCall(PetscDSSetUp(dm->probs[s].ds));
    6181:       if (dm->probs[s].dsIn) PetscCall(PetscDSSetUp(dm->probs[s].dsIn));
    6182:     }
    6183:   }
    6184:   PetscFunctionReturn(PETSC_SUCCESS);
    6185: }

    6187: /*@
    6188:   DMUseTensorOrder - Use a tensor product closure ordering for the default section

    6190:   Input Parameters:
    6191: + dm     - The DM
    6192: - tensor - Flag for tensor order

    6194:   Level: developer

    6196: .seealso: `DMPlexSetClosurePermutationTensor()`, `PetscSectionResetClosurePermutation()`
    6197: @*/
    6198: PetscErrorCode DMUseTensorOrder(DM dm, PetscBool tensor)
    6199: {
    6200:   PetscInt  Nf;
    6201:   PetscBool reorder = PETSC_TRUE, isPlex;

    6203:   PetscFunctionBegin;
    6204:   PetscCall(PetscObjectTypeCompare((PetscObject)dm, DMPLEX, &isPlex));
    6205:   PetscCall(DMGetNumFields(dm, &Nf));
    6206:   for (PetscInt f = 0; f < Nf; ++f) {
    6207:     PetscObject  obj;
    6208:     PetscClassId id;

    6210:     PetscCall(DMGetField(dm, f, NULL, &obj));
    6211:     PetscCall(PetscObjectGetClassId(obj, &id));
    6212:     if (id == PETSCFE_CLASSID) {
    6213:       PetscSpace sp;
    6214:       PetscBool  tensor;

    6216:       PetscCall(PetscFEGetBasisSpace((PetscFE)obj, &sp));
    6217:       PetscCall(PetscSpacePolynomialGetTensor(sp, &tensor));
    6218:       reorder = reorder && tensor ? PETSC_TRUE : PETSC_FALSE;
    6219:     } else reorder = PETSC_FALSE;
    6220:   }
    6221:   if (tensor) {
    6222:     if (reorder && isPlex) PetscCall(DMPlexSetClosurePermutationTensor(dm, PETSC_DETERMINE, NULL));
    6223:   } else {
    6224:     PetscSection s;

    6226:     PetscCall(DMGetLocalSection(dm, &s));
    6227:     if (s) PetscCall(PetscSectionResetClosurePermutation(s));
    6228:   }
    6229:   PetscFunctionReturn(PETSC_SUCCESS);
    6230: }

    6232: /*@
    6233:   DMComputeExactSolution - Compute the exact solution for a given `DM`, using the `PetscDS` information.

    6235:   Collective

    6237:   Input Parameters:
    6238: + dm   - The `DM`
    6239: - time - The time

    6241:   Output Parameters:
    6242: + u   - The vector will be filled with exact solution values, or `NULL`
    6243: - u_t - The vector will be filled with the time derivative of exact solution values, or `NULL`

    6245:   Level: developer

    6247:   Note:
    6248:   The user must call `PetscDSSetExactSolution()` before using this routine

    6250: .seealso: [](ch_dmbase), `DM`, `PetscDSSetExactSolution()`
    6251: @*/
    6252: PetscErrorCode DMComputeExactSolution(DM dm, PetscReal time, Vec u, Vec u_t)
    6253: {
    6254:   PetscErrorCode (**exacts)(PetscInt, PetscReal, const PetscReal x[], PetscInt, PetscScalar *u, void *ctx);
    6255:   void   **ectxs;
    6256:   Vec      locu, locu_t;
    6257:   PetscInt Nf, Nds, s;

    6259:   PetscFunctionBegin;
    6261:   if (u) {
    6263:     PetscCall(DMGetLocalVector(dm, &locu));
    6264:     PetscCall(VecSet(locu, 0.));
    6265:   }
    6266:   if (u_t) {
    6268:     PetscCall(DMGetLocalVector(dm, &locu_t));
    6269:     PetscCall(VecSet(locu_t, 0.));
    6270:   }
    6271:   PetscCall(DMGetNumFields(dm, &Nf));
    6272:   PetscCall(PetscMalloc2(Nf, &exacts, Nf, &ectxs));
    6273:   PetscCall(DMGetNumDS(dm, &Nds));
    6274:   for (s = 0; s < Nds; ++s) {
    6275:     PetscDS         ds;
    6276:     DMLabel         label;
    6277:     IS              fieldIS;
    6278:     const PetscInt *fields, id = 1;
    6279:     PetscInt        dsNf, f;

    6281:     PetscCall(DMGetRegionNumDS(dm, s, &label, &fieldIS, &ds, NULL));
    6282:     PetscCall(PetscDSGetNumFields(ds, &dsNf));
    6283:     PetscCall(ISGetIndices(fieldIS, &fields));
    6284:     PetscCall(PetscArrayzero(exacts, Nf));
    6285:     PetscCall(PetscArrayzero(ectxs, Nf));
    6286:     if (u) {
    6287:       for (f = 0; f < dsNf; ++f) PetscCall(PetscDSGetExactSolution(ds, fields[f], &exacts[fields[f]], &ectxs[fields[f]]));
    6288:       if (label) PetscCall(DMProjectFunctionLabelLocal(dm, time, label, 1, &id, 0, NULL, exacts, ectxs, INSERT_ALL_VALUES, locu));
    6289:       else PetscCall(DMProjectFunctionLocal(dm, time, exacts, ectxs, INSERT_ALL_VALUES, locu));
    6290:     }
    6291:     if (u_t) {
    6292:       PetscCall(PetscArrayzero(exacts, Nf));
    6293:       PetscCall(PetscArrayzero(ectxs, Nf));
    6294:       for (f = 0; f < dsNf; ++f) PetscCall(PetscDSGetExactSolutionTimeDerivative(ds, fields[f], &exacts[fields[f]], &ectxs[fields[f]]));
    6295:       if (label) PetscCall(DMProjectFunctionLabelLocal(dm, time, label, 1, &id, 0, NULL, exacts, ectxs, INSERT_ALL_VALUES, locu_t));
    6296:       else PetscCall(DMProjectFunctionLocal(dm, time, exacts, ectxs, INSERT_ALL_VALUES, locu_t));
    6297:     }
    6298:     PetscCall(ISRestoreIndices(fieldIS, &fields));
    6299:   }
    6300:   if (u) {
    6301:     PetscCall(PetscObjectSetName((PetscObject)u, "Exact Solution"));
    6302:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)u, "exact_"));
    6303:   }
    6304:   if (u_t) {
    6305:     PetscCall(PetscObjectSetName((PetscObject)u, "Exact Solution Time Derivative"));
    6306:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)u_t, "exact_t_"));
    6307:   }
    6308:   PetscCall(PetscFree2(exacts, ectxs));
    6309:   if (u) {
    6310:     PetscCall(DMLocalToGlobalBegin(dm, locu, INSERT_ALL_VALUES, u));
    6311:     PetscCall(DMLocalToGlobalEnd(dm, locu, INSERT_ALL_VALUES, u));
    6312:     PetscCall(DMRestoreLocalVector(dm, &locu));
    6313:   }
    6314:   if (u_t) {
    6315:     PetscCall(DMLocalToGlobalBegin(dm, locu_t, INSERT_ALL_VALUES, u_t));
    6316:     PetscCall(DMLocalToGlobalEnd(dm, locu_t, INSERT_ALL_VALUES, u_t));
    6317:     PetscCall(DMRestoreLocalVector(dm, &locu_t));
    6318:   }
    6319:   PetscFunctionReturn(PETSC_SUCCESS);
    6320: }

    6322: static PetscErrorCode DMTransferDS_Internal(DM dm, DMLabel label, IS fields, PetscInt minDegree, PetscInt maxDegree, PetscDS ds, PetscDS dsIn)
    6323: {
    6324:   PetscDS dsNew, dsInNew = NULL;

    6326:   PetscFunctionBegin;
    6327:   PetscCall(PetscDSCreate(PetscObjectComm((PetscObject)ds), &dsNew));
    6328:   PetscCall(PetscDSCopy(ds, minDegree, maxDegree, dm, dsNew));
    6329:   if (dsIn) {
    6330:     PetscCall(PetscDSCreate(PetscObjectComm((PetscObject)dsIn), &dsInNew));
    6331:     PetscCall(PetscDSCopy(dsIn, minDegree, maxDegree, dm, dsInNew));
    6332:   }
    6333:   PetscCall(DMSetRegionDS(dm, label, fields, dsNew, dsInNew));
    6334:   PetscCall(PetscDSDestroy(&dsNew));
    6335:   PetscCall(PetscDSDestroy(&dsInNew));
    6336:   PetscFunctionReturn(PETSC_SUCCESS);
    6337: }

    6339: /*@
    6340:   DMCopyDS - Copy the discrete systems for the `DM` into another `DM`

    6342:   Collective

    6344:   Input Parameters:
    6345: + dm        - The `DM`
    6346: . minDegree - Minimum degree for a discretization, or `PETSC_DETERMINE` for no limit
    6347: - maxDegree - Maximum degree for a discretization, or `PETSC_DETERMINE` for no limit

    6349:   Output Parameter:
    6350: . newdm - The `DM`

    6352:   Level: advanced

    6354: .seealso: [](ch_dmbase), `DM`, `DMCopyFields()`, `DMAddField()`, `DMGetDS()`, `DMGetCellDS()`, `DMGetRegionDS()`, `DMSetRegionDS()`
    6355: @*/
    6356: PetscErrorCode DMCopyDS(DM dm, PetscInt minDegree, PetscInt maxDegree, DM newdm)
    6357: {
    6358:   PetscInt Nds, s;

    6360:   PetscFunctionBegin;
    6361:   if (dm == newdm) PetscFunctionReturn(PETSC_SUCCESS);
    6362:   PetscCall(DMGetNumDS(dm, &Nds));
    6363:   PetscCall(DMClearDS(newdm));
    6364:   for (s = 0; s < Nds; ++s) {
    6365:     DMLabel  label;
    6366:     IS       fields;
    6367:     PetscDS  ds, dsIn, newds;
    6368:     PetscInt Nbd, bd;

    6370:     PetscCall(DMGetRegionNumDS(dm, s, &label, &fields, &ds, &dsIn));
    6371:     /* TODO: We need to change all keys from labels in the old DM to labels in the new DM */
    6372:     PetscCall(DMTransferDS_Internal(newdm, label, fields, minDegree, maxDegree, ds, dsIn));
    6373:     /* Complete new labels in the new DS */
    6374:     PetscCall(DMGetRegionDS(newdm, label, NULL, &newds, NULL));
    6375:     PetscCall(PetscDSGetNumBoundary(newds, &Nbd));
    6376:     for (bd = 0; bd < Nbd; ++bd) {
    6377:       PetscWeakForm wf;
    6378:       DMLabel       label;
    6379:       PetscInt      field;

    6381:       PetscCall(PetscDSGetBoundary(newds, bd, &wf, NULL, NULL, &label, NULL, NULL, &field, NULL, NULL, NULL, NULL, NULL));
    6382:       PetscCall(PetscWeakFormReplaceLabel(wf, label));
    6383:     }
    6384:   }
    6385:   PetscCall(DMCompleteBCLabels_Internal(newdm));
    6386:   PetscFunctionReturn(PETSC_SUCCESS);
    6387: }

    6389: /*@
    6390:   DMCopyDisc - Copy the fields and discrete systems for the `DM` into another `DM`

    6392:   Collective

    6394:   Input Parameter:
    6395: . dm - The `DM`

    6397:   Output Parameter:
    6398: . newdm - The `DM`

    6400:   Level: advanced

    6402:   Developer Note:
    6403:   Really ugly name, nothing in PETSc is called a `Disc` plus it is an ugly abbreviation

    6405: .seealso: [](ch_dmbase), `DM`, `DMCopyFields()`, `DMCopyDS()`
    6406: @*/
    6407: PetscErrorCode DMCopyDisc(DM dm, DM newdm)
    6408: {
    6409:   PetscFunctionBegin;
    6410:   PetscCall(DMCopyFields(dm, PETSC_DETERMINE, PETSC_DETERMINE, newdm));
    6411:   PetscCall(DMCopyDS(dm, PETSC_DETERMINE, PETSC_DETERMINE, newdm));
    6412:   PetscFunctionReturn(PETSC_SUCCESS);
    6413: }

    6415: /*@
    6416:   DMGetDimension - Return the topological dimension of the `DM`

    6418:   Not Collective

    6420:   Input Parameter:
    6421: . dm - The `DM`

    6423:   Output Parameter:
    6424: . dim - The topological dimension

    6426:   Level: beginner

    6428: .seealso: [](ch_dmbase), `DM`, `DMSetDimension()`, `DMCreate()`
    6429: @*/
    6430: PetscErrorCode DMGetDimension(DM dm, PetscInt *dim)
    6431: {
    6432:   PetscFunctionBegin;
    6434:   PetscAssertPointer(dim, 2);
    6435:   *dim = dm->dim;
    6436:   PetscFunctionReturn(PETSC_SUCCESS);
    6437: }

    6439: /*@
    6440:   DMSetDimension - Set the topological dimension of the `DM`

    6442:   Collective

    6444:   Input Parameters:
    6445: + dm  - The `DM`
    6446: - dim - The topological dimension

    6448:   Level: beginner

    6450: .seealso: [](ch_dmbase), `DM`, `DMGetDimension()`, `DMCreate()`
    6451: @*/
    6452: PetscErrorCode DMSetDimension(DM dm, PetscInt dim)
    6453: {
    6454:   PetscDS  ds;
    6455:   PetscInt Nds, n;

    6457:   PetscFunctionBegin;
    6460:   dm->dim = dim;
    6461:   if (dm->dim >= 0) {
    6462:     PetscCall(DMGetNumDS(dm, &Nds));
    6463:     for (n = 0; n < Nds; ++n) {
    6464:       PetscCall(DMGetRegionNumDS(dm, n, NULL, NULL, &ds, NULL));
    6465:       if (ds->dimEmbed < 0) PetscCall(PetscDSSetCoordinateDimension(ds, dim));
    6466:     }
    6467:   }
    6468:   PetscFunctionReturn(PETSC_SUCCESS);
    6469: }

    6471: /*@
    6472:   DMGetDimPoints - Get the half-open interval for all points of a given dimension

    6474:   Collective

    6476:   Input Parameters:
    6477: + dm  - the `DM`
    6478: - dim - the dimension

    6480:   Output Parameters:
    6481: + pStart - The first point of the given dimension
    6482: - pEnd   - The first point following points of the given dimension

    6484:   Level: intermediate

    6486:   Note:
    6487:   The points are vertices in the Hasse diagram encoding the topology. This is explained in
    6488:   https://arxiv.org/abs/0908.4427. If no points exist of this dimension in the storage scheme,
    6489:   then the interval is empty.

    6491: .seealso: [](ch_dmbase), `DM`, `DMPLEX`, `DMPlexGetDepthStratum()`, `DMPlexGetHeightStratum()`
    6492: @*/
    6493: PetscErrorCode DMGetDimPoints(DM dm, PetscInt dim, PetscInt *pStart, PetscInt *pEnd)
    6494: {
    6495:   PetscInt d;

    6497:   PetscFunctionBegin;
    6499:   PetscCall(DMGetDimension(dm, &d));
    6500:   PetscCheck((dim >= 0) && (dim <= d), PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid dimension %" PetscInt_FMT, dim);
    6501:   PetscUseTypeMethod(dm, getdimpoints, dim, pStart, pEnd);
    6502:   PetscFunctionReturn(PETSC_SUCCESS);
    6503: }

    6505: /*@
    6506:   DMGetOutputDM - Retrieve the `DM` associated with the layout for output

    6508:   Collective

    6510:   Input Parameter:
    6511: . dm - The original `DM`

    6513:   Output Parameter:
    6514: . odm - The `DM` which provides the layout for output

    6516:   Level: intermediate

    6518:   Note:
    6519:   In some situations the vector obtained with `DMCreateGlobalVector()` excludes points for degrees of freedom that are associated with fixed (Dirichelet) boundary
    6520:   conditions since the algebraic solver does not solve for those variables. The output `DM` includes these excluded points and its global vector contains the
    6521:   locations for those dof so that they can be output to a file or other viewer along with the unconstrained dof.

    6523: .seealso: [](ch_dmbase), `DM`, `VecView()`, `DMGetGlobalSection()`, `DMCreateGlobalVector()`, `PetscSectionHasConstraints()`, `DMSetGlobalSection()`
    6524: @*/
    6525: PetscErrorCode DMGetOutputDM(DM dm, DM *odm)
    6526: {
    6527:   PetscSection section;
    6528:   IS           perm;
    6529:   PetscBool    hasConstraints, newDM, gnewDM;
    6530:   PetscInt     num_face_sfs = 0;

    6532:   PetscFunctionBegin;
    6534:   PetscAssertPointer(odm, 2);
    6535:   PetscCall(DMGetLocalSection(dm, &section));
    6536:   PetscCall(PetscSectionHasConstraints(section, &hasConstraints));
    6537:   PetscCall(PetscSectionGetPermutation(section, &perm));
    6538:   PetscCall(DMPlexGetIsoperiodicFaceSF(dm, &num_face_sfs, NULL));
    6539:   newDM = hasConstraints || perm || (num_face_sfs > 0) ? PETSC_TRUE : PETSC_FALSE;
    6540:   PetscCallMPI(MPIU_Allreduce(&newDM, &gnewDM, 1, MPI_C_BOOL, MPI_LOR, PetscObjectComm((PetscObject)dm)));
    6541:   if (!gnewDM) {
    6542:     *odm = dm;
    6543:     PetscFunctionReturn(PETSC_SUCCESS);
    6544:   }
    6545:   if (!dm->dmBC) {
    6546:     PetscSection newSection, gsection;
    6547:     PetscSF      sf, sfNatural;
    6548:     PetscBool    usePerm = dm->ignorePermOutput ? PETSC_FALSE : PETSC_TRUE;

    6550:     PetscCall(DMClone(dm, &dm->dmBC));
    6551:     PetscCall(DMCopyDisc(dm, dm->dmBC));
    6552:     PetscCall(PetscSectionClone(section, &newSection));
    6553:     PetscCall(DMSetLocalSection(dm->dmBC, newSection));
    6554:     PetscCall(PetscSectionDestroy(&newSection));
    6555:     PetscCall(DMGetNaturalSF(dm, &sfNatural));
    6556:     PetscCall(DMSetNaturalSF(dm->dmBC, sfNatural));
    6557:     PetscCall(DMGetPointSF(dm->dmBC, &sf));
    6558:     PetscCall(PetscSectionCreateGlobalSection(section, sf, usePerm, PETSC_TRUE, PETSC_FALSE, &gsection));
    6559:     PetscCall(DMSetGlobalSection(dm->dmBC, gsection));
    6560:     PetscCall(PetscSectionDestroy(&gsection));
    6561:   }
    6562:   *odm = dm->dmBC;
    6563:   PetscFunctionReturn(PETSC_SUCCESS);
    6564: }

    6566: /*@
    6567:   DMGetOutputSequenceNumber - Retrieve the sequence number/value for output

    6569:   Input Parameter:
    6570: . dm - The original `DM`

    6572:   Output Parameters:
    6573: + num - The output sequence number
    6574: - val - The output sequence value

    6576:   Level: intermediate

    6578:   Note:
    6579:   This is intended for output that should appear in sequence, for instance
    6580:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6582:   Developer Note:
    6583:   The `DM` serves as a convenient place to store the current iteration value. The iteration is not
    6584:   not directly related to the `DM`.

    6586: .seealso: [](ch_dmbase), `DM`, `VecView()`
    6587: @*/
    6588: PetscErrorCode DMGetOutputSequenceNumber(DM dm, PetscInt *num, PetscReal *val)
    6589: {
    6590:   PetscFunctionBegin;
    6592:   if (num) {
    6593:     PetscAssertPointer(num, 2);
    6594:     *num = dm->outputSequenceNum;
    6595:   }
    6596:   if (val) {
    6597:     PetscAssertPointer(val, 3);
    6598:     *val = dm->outputSequenceVal;
    6599:   }
    6600:   PetscFunctionReturn(PETSC_SUCCESS);
    6601: }

    6603: /*@
    6604:   DMSetOutputSequenceNumber - Set the sequence number/value for output

    6606:   Input Parameters:
    6607: + dm  - The original `DM`
    6608: . num - The output sequence number
    6609: - val - The output sequence value

    6611:   Level: intermediate

    6613:   Note:
    6614:   This is intended for output that should appear in sequence, for instance
    6615:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6617: .seealso: [](ch_dmbase), `DM`, `VecView()`
    6618: @*/
    6619: PetscErrorCode DMSetOutputSequenceNumber(DM dm, PetscInt num, PetscReal val)
    6620: {
    6621:   PetscFunctionBegin;
    6623:   dm->outputSequenceNum = num;
    6624:   dm->outputSequenceVal = val;
    6625:   PetscFunctionReturn(PETSC_SUCCESS);
    6626: }

    6628: /*@
    6629:   DMOutputSequenceLoad - Retrieve the sequence value from a `PetscViewer`

    6631:   Input Parameters:
    6632: + dm     - The original `DM`
    6633: . viewer - The `PetscViewer` to get it from
    6634: . name   - The sequence name
    6635: - num    - The output sequence number

    6637:   Output Parameter:
    6638: . val - The output sequence value

    6640:   Level: intermediate

    6642:   Note:
    6643:   This is intended for output that should appear in sequence, for instance
    6644:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6646:   Developer Note:
    6647:   It is unclear at the user API level why a `DM` is needed as input

    6649: .seealso: [](ch_dmbase), `DM`, `DMGetOutputSequenceNumber()`, `DMSetOutputSequenceNumber()`, `VecView()`
    6650: @*/
    6651: PetscErrorCode DMOutputSequenceLoad(DM dm, PetscViewer viewer, const char name[], PetscInt num, PetscReal *val)
    6652: {
    6653:   PetscBool ishdf5;

    6655:   PetscFunctionBegin;
    6658:   PetscAssertPointer(name, 3);
    6659:   PetscAssertPointer(val, 5);
    6660:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
    6661:   PetscCheck(ishdf5, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerHDF5Open()");
    6662: #if defined(PETSC_HAVE_HDF5)
    6663:   PetscScalar value;

    6665:   PetscCall(DMSequenceLoad_HDF5_Internal(dm, name, num, &value, viewer));
    6666:   *val = PetscRealPart(value);
    6667: #endif
    6668:   PetscFunctionReturn(PETSC_SUCCESS);
    6669: }

    6671: /*@
    6672:   DMGetOutputSequenceLength - Retrieve the number of sequence values from a `PetscViewer`

    6674:   Input Parameters:
    6675: + dm     - The original `DM`
    6676: . viewer - The `PetscViewer` to get it from
    6677: - name   - The sequence name

    6679:   Output Parameter:
    6680: . len - The length of the output sequence

    6682:   Level: intermediate

    6684:   Note:
    6685:   This is intended for output that should appear in sequence, for instance
    6686:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6688:   Developer Note:
    6689:   It is unclear at the user API level why a `DM` is needed as input

    6691: .seealso: [](ch_dmbase), `DM`, `DMGetOutputSequenceNumber()`, `DMSetOutputSequenceNumber()`, `VecView()`
    6692: @*/
    6693: PetscErrorCode DMGetOutputSequenceLength(DM dm, PetscViewer viewer, const char name[], PetscInt *len)
    6694: {
    6695:   PetscBool ishdf5;

    6697:   PetscFunctionBegin;
    6700:   PetscAssertPointer(name, 3);
    6701:   PetscAssertPointer(len, 4);
    6702:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
    6703:   PetscCheck(ishdf5, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerHDF5Open()");
    6704: #if defined(PETSC_HAVE_HDF5)
    6705:   PetscCall(DMSequenceGetLength_HDF5_Internal(dm, name, len, viewer));
    6706: #endif
    6707:   PetscFunctionReturn(PETSC_SUCCESS);
    6708: }

    6710: /*@
    6711:   DMGetUseNatural - Get the flag for creating a mapping to the natural order when a `DM` is (re)distributed in parallel

    6713:   Not Collective

    6715:   Input Parameter:
    6716: . dm - The `DM`

    6718:   Output Parameter:
    6719: . useNatural - `PETSC_TRUE` to build the mapping to a natural order during distribution

    6721:   Level: beginner

    6723: .seealso: [](ch_dmbase), `DM`, `DMSetUseNatural()`, `DMCreate()`
    6724: @*/
    6725: PetscErrorCode DMGetUseNatural(DM dm, PetscBool *useNatural)
    6726: {
    6727:   PetscFunctionBegin;
    6729:   PetscAssertPointer(useNatural, 2);
    6730:   *useNatural = dm->useNatural;
    6731:   PetscFunctionReturn(PETSC_SUCCESS);
    6732: }

    6734: /*@
    6735:   DMSetUseNatural - Set the flag for creating a mapping to the natural order when a `DM` is (re)distributed in parallel

    6737:   Collective

    6739:   Input Parameters:
    6740: + dm         - The `DM`
    6741: - useNatural - `PETSC_TRUE` to build the mapping to a natural order during distribution

    6743:   Level: beginner

    6745:   Note:
    6746:   This also causes the map to be build after `DMCreateSubDM()` and `DMCreateSuperDM()`

    6748: .seealso: [](ch_dmbase), `DM`, `DMGetUseNatural()`, `DMCreate()`, `DMPlexDistribute()`, `DMCreateSubDM()`, `DMCreateSuperDM()`
    6749: @*/
    6750: PetscErrorCode DMSetUseNatural(DM dm, PetscBool useNatural)
    6751: {
    6752:   PetscFunctionBegin;
    6755:   dm->useNatural = useNatural;
    6756:   PetscFunctionReturn(PETSC_SUCCESS);
    6757: }

    6759: /*@
    6760:   DMCreateLabel - Create a label of the given name if it does not already exist in the `DM`

    6762:   Not Collective

    6764:   Input Parameters:
    6765: + dm   - The `DM` object
    6766: - name - The label name

    6768:   Level: intermediate

    6770: .seealso: [](ch_dmbase), `DM`, `DMLabelCreate()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6771: @*/
    6772: PetscErrorCode DMCreateLabel(DM dm, const char name[])
    6773: {
    6774:   PetscBool flg;
    6775:   DMLabel   label;

    6777:   PetscFunctionBegin;
    6779:   PetscAssertPointer(name, 2);
    6780:   PetscCall(DMHasLabel(dm, name, &flg));
    6781:   if (!flg) {
    6782:     PetscCall(DMLabelCreate(PETSC_COMM_SELF, name, &label));
    6783:     PetscCall(DMAddLabel(dm, label));
    6784:     PetscCall(DMLabelDestroy(&label));
    6785:   }
    6786:   PetscFunctionReturn(PETSC_SUCCESS);
    6787: }

    6789: /*@
    6790:   DMCreateLabelAtIndex - Create a label of the given name at the given index. If it already exists in the `DM`, move it to this index.

    6792:   Not Collective

    6794:   Input Parameters:
    6795: + dm   - The `DM` object
    6796: . l    - The index for the label
    6797: - name - The label name

    6799:   Level: intermediate

    6801: .seealso: [](ch_dmbase), `DM`, `DMCreateLabel()`, `DMLabelCreate()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6802: @*/
    6803: PetscErrorCode DMCreateLabelAtIndex(DM dm, PetscInt l, const char name[])
    6804: {
    6805:   DMLabelLink orig, prev = NULL;
    6806:   DMLabel     label;
    6807:   PetscInt    Nl, m;
    6808:   PetscBool   flg, match;
    6809:   const char *lname;

    6811:   PetscFunctionBegin;
    6813:   PetscAssertPointer(name, 3);
    6814:   PetscCall(DMHasLabel(dm, name, &flg));
    6815:   if (!flg) {
    6816:     PetscCall(DMLabelCreate(PETSC_COMM_SELF, name, &label));
    6817:     PetscCall(DMAddLabel(dm, label));
    6818:     PetscCall(DMLabelDestroy(&label));
    6819:   }
    6820:   PetscCall(DMGetNumLabels(dm, &Nl));
    6821:   PetscCheck(l < Nl, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label index %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", l, Nl);
    6822:   for (m = 0, orig = dm->labels; m < Nl; ++m, prev = orig, orig = orig->next) {
    6823:     PetscCall(PetscObjectGetName((PetscObject)orig->label, &lname));
    6824:     PetscCall(PetscStrcmp(name, lname, &match));
    6825:     if (match) break;
    6826:   }
    6827:   if (m == l) PetscFunctionReturn(PETSC_SUCCESS);
    6828:   if (!m) dm->labels = orig->next;
    6829:   else prev->next = orig->next;
    6830:   if (!l) {
    6831:     orig->next = dm->labels;
    6832:     dm->labels = orig;
    6833:   } else {
    6834:     for (m = 0, prev = dm->labels; m < l - 1; ++m, prev = prev->next);
    6835:     orig->next = prev->next;
    6836:     prev->next = orig;
    6837:   }
    6838:   PetscFunctionReturn(PETSC_SUCCESS);
    6839: }

    6841: /*@
    6842:   DMGetLabelValue - Get the value in a `DMLabel` for the given point, with -1 as the default

    6844:   Not Collective

    6846:   Input Parameters:
    6847: + dm    - The `DM` object
    6848: . name  - The label name
    6849: - point - The mesh point

    6851:   Output Parameter:
    6852: . value - The label value for this point, or -1 if the point is not in the label

    6854:   Level: beginner

    6856: .seealso: [](ch_dmbase), `DM`, `DMLabelGetValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6857: @*/
    6858: PetscErrorCode DMGetLabelValue(DM dm, const char name[], PetscInt point, PetscInt *value)
    6859: {
    6860:   DMLabel label;

    6862:   PetscFunctionBegin;
    6864:   PetscAssertPointer(name, 2);
    6865:   PetscCall(DMGetLabel(dm, name, &label));
    6866:   PetscCheck(label, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "No label named %s was found", name);
    6867:   PetscCall(DMLabelGetValue(label, point, value));
    6868:   PetscFunctionReturn(PETSC_SUCCESS);
    6869: }

    6871: /*@
    6872:   DMSetLabelValue - Add a point to a `DMLabel` with given value

    6874:   Not Collective

    6876:   Input Parameters:
    6877: + dm    - The `DM` object
    6878: . name  - The label name
    6879: . point - The mesh point
    6880: - value - The label value for this point

    6882:   Output Parameter:

    6884:   Level: beginner

    6886: .seealso: [](ch_dmbase), `DM`, `DMLabelSetValue()`, `DMGetStratumIS()`, `DMClearLabelValue()`
    6887: @*/
    6888: PetscErrorCode DMSetLabelValue(DM dm, const char name[], PetscInt point, PetscInt value)
    6889: {
    6890:   DMLabel label;

    6892:   PetscFunctionBegin;
    6894:   PetscAssertPointer(name, 2);
    6895:   PetscCall(DMGetLabel(dm, name, &label));
    6896:   if (!label) {
    6897:     PetscCall(DMCreateLabel(dm, name));
    6898:     PetscCall(DMGetLabel(dm, name, &label));
    6899:   }
    6900:   PetscCall(DMLabelSetValue(label, point, value));
    6901:   PetscFunctionReturn(PETSC_SUCCESS);
    6902: }

    6904: /*@
    6905:   DMClearLabelValue - Remove a point from a `DMLabel` with given value

    6907:   Not Collective

    6909:   Input Parameters:
    6910: + dm    - The `DM` object
    6911: . name  - The label name
    6912: . point - The mesh point
    6913: - value - The label value for this point

    6915:   Level: beginner

    6917: .seealso: [](ch_dmbase), `DM`, `DMLabelClearValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6918: @*/
    6919: PetscErrorCode DMClearLabelValue(DM dm, const char name[], PetscInt point, PetscInt value)
    6920: {
    6921:   DMLabel label;

    6923:   PetscFunctionBegin;
    6925:   PetscAssertPointer(name, 2);
    6926:   PetscCall(DMGetLabel(dm, name, &label));
    6927:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    6928:   PetscCall(DMLabelClearValue(label, point, value));
    6929:   PetscFunctionReturn(PETSC_SUCCESS);
    6930: }

    6932: /*@
    6933:   DMGetLabelSize - Get the value of `DMLabelGetNumValues()` of a `DMLabel` in the `DM`

    6935:   Not Collective

    6937:   Input Parameters:
    6938: + dm   - The `DM` object
    6939: - name - The label name

    6941:   Output Parameter:
    6942: . size - The number of different integer ids, or 0 if the label does not exist

    6944:   Level: beginner

    6946:   Developer Note:
    6947:   This should be renamed to something like `DMGetLabelNumValues()` or removed.

    6949: .seealso: [](ch_dmbase), `DM`, `DMLabelGetNumValues()`, `DMSetLabelValue()`, `DMGetLabel()`
    6950: @*/
    6951: PetscErrorCode DMGetLabelSize(DM dm, const char name[], PetscInt *size)
    6952: {
    6953:   DMLabel label;

    6955:   PetscFunctionBegin;
    6957:   PetscAssertPointer(name, 2);
    6958:   PetscAssertPointer(size, 3);
    6959:   PetscCall(DMGetLabel(dm, name, &label));
    6960:   *size = 0;
    6961:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    6962:   PetscCall(DMLabelGetNumValues(label, size));
    6963:   PetscFunctionReturn(PETSC_SUCCESS);
    6964: }

    6966: /*@
    6967:   DMGetLabelIdIS - Get the `DMLabelGetValueIS()` from a `DMLabel` in the `DM`

    6969:   Not Collective

    6971:   Input Parameters:
    6972: + dm   - The `DM` object
    6973: - name - The label name

    6975:   Output Parameter:
    6976: . ids - The integer ids, or `NULL` if the label does not exist

    6978:   Level: beginner

    6980: .seealso: [](ch_dmbase), `DM`, `DMLabelGetValueIS()`, `DMGetLabelSize()`
    6981: @*/
    6982: PetscErrorCode DMGetLabelIdIS(DM dm, const char name[], IS *ids)
    6983: {
    6984:   DMLabel label;

    6986:   PetscFunctionBegin;
    6988:   PetscAssertPointer(name, 2);
    6989:   PetscAssertPointer(ids, 3);
    6990:   PetscCall(DMGetLabel(dm, name, &label));
    6991:   *ids = NULL;
    6992:   if (label) {
    6993:     PetscCall(DMLabelGetValueIS(label, ids));
    6994:   } else {
    6995:     /* returning an empty IS */
    6996:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, 0, NULL, PETSC_USE_POINTER, ids));
    6997:   }
    6998:   PetscFunctionReturn(PETSC_SUCCESS);
    6999: }

    7001: /*@
    7002:   DMGetStratumSize - Get the number of points in a label stratum

    7004:   Not Collective

    7006:   Input Parameters:
    7007: + dm    - The `DM` object
    7008: . name  - The label name of the stratum
    7009: - value - The stratum value

    7011:   Output Parameter:
    7012: . size - The number of points, also called the stratum size

    7014:   Level: beginner

    7016: .seealso: [](ch_dmbase), `DM`, `DMLabelGetStratumSize()`, `DMGetLabelSize()`, `DMGetLabelIds()`
    7017: @*/
    7018: PetscErrorCode DMGetStratumSize(DM dm, const char name[], PetscInt value, PetscInt *size)
    7019: {
    7020:   DMLabel label;

    7022:   PetscFunctionBegin;
    7024:   PetscAssertPointer(name, 2);
    7025:   PetscAssertPointer(size, 4);
    7026:   PetscCall(DMGetLabel(dm, name, &label));
    7027:   *size = 0;
    7028:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7029:   PetscCall(DMLabelGetStratumSize(label, value, size));
    7030:   PetscFunctionReturn(PETSC_SUCCESS);
    7031: }

    7033: /*@
    7034:   DMGetStratumIS - Get the points in a label stratum

    7036:   Not Collective

    7038:   Input Parameters:
    7039: + dm    - The `DM` object
    7040: . name  - The label name
    7041: - value - The stratum value

    7043:   Output Parameter:
    7044: . points - The stratum points, or `NULL` if the label does not exist or does not have that value

    7046:   Level: beginner

    7048: .seealso: [](ch_dmbase), `DM`, `DMLabelGetStratumIS()`, `DMGetStratumSize()`
    7049: @*/
    7050: PetscErrorCode DMGetStratumIS(DM dm, const char name[], PetscInt value, IS *points)
    7051: {
    7052:   DMLabel label;

    7054:   PetscFunctionBegin;
    7056:   PetscAssertPointer(name, 2);
    7057:   PetscAssertPointer(points, 4);
    7058:   PetscCall(DMGetLabel(dm, name, &label));
    7059:   *points = NULL;
    7060:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7061:   PetscCall(DMLabelGetStratumIS(label, value, points));
    7062:   PetscFunctionReturn(PETSC_SUCCESS);
    7063: }

    7065: /*@
    7066:   DMSetStratumIS - Set the points in a label stratum

    7068:   Not Collective

    7070:   Input Parameters:
    7071: + dm     - The `DM` object
    7072: . name   - The label name
    7073: . value  - The stratum value
    7074: - points - The stratum points

    7076:   Level: beginner

    7078: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMClearLabelStratum()`, `DMLabelClearStratum()`, `DMLabelSetStratumIS()`, `DMGetStratumSize()`
    7079: @*/
    7080: PetscErrorCode DMSetStratumIS(DM dm, const char name[], PetscInt value, IS points)
    7081: {
    7082:   DMLabel label;

    7084:   PetscFunctionBegin;
    7086:   PetscAssertPointer(name, 2);
    7088:   PetscCall(DMGetLabel(dm, name, &label));
    7089:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7090:   PetscCall(DMLabelSetStratumIS(label, value, points));
    7091:   PetscFunctionReturn(PETSC_SUCCESS);
    7092: }

    7094: /*@
    7095:   DMClearLabelStratum - Remove all points from a stratum from a `DMLabel`

    7097:   Not Collective

    7099:   Input Parameters:
    7100: + dm    - The `DM` object
    7101: . name  - The label name
    7102: - value - The label value for this point

    7104:   Output Parameter:

    7106:   Level: beginner

    7108: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMLabelClearStratum()`, `DMSetLabelValue()`, `DMGetStratumIS()`, `DMClearLabelValue()`
    7109: @*/
    7110: PetscErrorCode DMClearLabelStratum(DM dm, const char name[], PetscInt value)
    7111: {
    7112:   DMLabel label;

    7114:   PetscFunctionBegin;
    7116:   PetscAssertPointer(name, 2);
    7117:   PetscCall(DMGetLabel(dm, name, &label));
    7118:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7119:   PetscCall(DMLabelClearStratum(label, value));
    7120:   PetscFunctionReturn(PETSC_SUCCESS);
    7121: }

    7123: /*@
    7124:   DMGetNumLabels - Return the number of labels defined by on the `DM`

    7126:   Not Collective

    7128:   Input Parameter:
    7129: . dm - The `DM` object

    7131:   Output Parameter:
    7132: . numLabels - the number of Labels

    7134:   Level: intermediate

    7136: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetLabelByNum()`, `DMGetLabelName()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7137: @*/
    7138: PetscErrorCode DMGetNumLabels(DM dm, PetscInt *numLabels)
    7139: {
    7140:   DMLabelLink next = dm->labels;
    7141:   PetscInt    n    = 0;

    7143:   PetscFunctionBegin;
    7145:   PetscAssertPointer(numLabels, 2);
    7146:   while (next) {
    7147:     ++n;
    7148:     next = next->next;
    7149:   }
    7150:   *numLabels = n;
    7151:   PetscFunctionReturn(PETSC_SUCCESS);
    7152: }

    7154: /*@
    7155:   DMGetLabelName - Return the name of nth label

    7157:   Not Collective

    7159:   Input Parameters:
    7160: + dm - The `DM` object
    7161: - n  - the label number

    7163:   Output Parameter:
    7164: . name - the label name

    7166:   Level: intermediate

    7168:   Developer Note:
    7169:   Some of the functions that appropriate on labels using their number have the suffix ByNum, others do not.

    7171: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetLabelByNum()`, `DMGetLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7172: @*/
    7173: PetscErrorCode DMGetLabelName(DM dm, PetscInt n, const char *name[])
    7174: {
    7175:   DMLabelLink next = dm->labels;
    7176:   PetscInt    l    = 0;

    7178:   PetscFunctionBegin;
    7180:   PetscAssertPointer(name, 3);
    7181:   while (next) {
    7182:     if (l == n) {
    7183:       PetscCall(PetscObjectGetName((PetscObject)next->label, name));
    7184:       PetscFunctionReturn(PETSC_SUCCESS);
    7185:     }
    7186:     ++l;
    7187:     next = next->next;
    7188:   }
    7189:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label %" PetscInt_FMT " does not exist in this DM", n);
    7190: }

    7192: /*@
    7193:   DMHasLabel - Determine whether the `DM` has a label of a given name

    7195:   Not Collective

    7197:   Input Parameters:
    7198: + dm   - The `DM` object
    7199: - name - The label name

    7201:   Output Parameter:
    7202: . hasLabel - `PETSC_TRUE` if the label is present

    7204:   Level: intermediate

    7206: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetLabel()`, `DMGetLabelByNum()`, `DMCreateLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7207: @*/
    7208: PetscErrorCode DMHasLabel(DM dm, const char name[], PetscBool *hasLabel)
    7209: {
    7210:   DMLabelLink next = dm->labels;
    7211:   const char *lname;

    7213:   PetscFunctionBegin;
    7215:   PetscAssertPointer(name, 2);
    7216:   PetscAssertPointer(hasLabel, 3);
    7217:   *hasLabel = PETSC_FALSE;
    7218:   while (next) {
    7219:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7220:     PetscCall(PetscStrcmp(name, lname, hasLabel));
    7221:     if (*hasLabel) break;
    7222:     next = next->next;
    7223:   }
    7224:   PetscFunctionReturn(PETSC_SUCCESS);
    7225: }

    7227: // PetscClangLinter pragma ignore: -fdoc-section-header-unknown
    7228: /*@
    7229:   DMGetLabel - Return the label of a given name, or `NULL`, from a `DM`

    7231:   Not Collective

    7233:   Input Parameters:
    7234: + dm   - The `DM` object
    7235: - name - The label name

    7237:   Output Parameter:
    7238: . label - The `DMLabel`, or `NULL` if the label is absent

    7240:   Default labels in a `DMPLEX`:
    7241: + "depth"       - Holds the depth (co-dimension) of each mesh point
    7242: . "celltype"    - Holds the topological type of each cell
    7243: . "ghost"       - If the DM is distributed with overlap, this marks the cells and faces in the overlap
    7244: . "Cell Sets"   - Mirrors the cell sets defined by GMsh and ExodusII
    7245: . "Face Sets"   - Mirrors the face sets defined by GMsh and ExodusII
    7246: - "Vertex Sets" - Mirrors the vertex sets defined by GMsh

    7248:   Level: intermediate

    7250: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMHasLabel()`, `DMGetLabelByNum()`, `DMAddLabel()`, `DMCreateLabel()`, `DMPlexGetDepthLabel()`, `DMPlexGetCellType()`
    7251: @*/
    7252: PetscErrorCode DMGetLabel(DM dm, const char name[], DMLabel *label)
    7253: {
    7254:   DMLabelLink next = dm->labels;
    7255:   PetscBool   hasLabel;
    7256:   const char *lname;

    7258:   PetscFunctionBegin;
    7260:   PetscAssertPointer(name, 2);
    7261:   PetscAssertPointer(label, 3);
    7262:   *label = NULL;
    7263:   while (next) {
    7264:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7265:     PetscCall(PetscStrcmp(name, lname, &hasLabel));
    7266:     if (hasLabel) {
    7267:       *label = next->label;
    7268:       break;
    7269:     }
    7270:     next = next->next;
    7271:   }
    7272:   PetscFunctionReturn(PETSC_SUCCESS);
    7273: }

    7275: /*@
    7276:   DMGetLabelByNum - Return the nth label on a `DM`

    7278:   Not Collective

    7280:   Input Parameters:
    7281: + dm - The `DM` object
    7282: - n  - the label number

    7284:   Output Parameter:
    7285: . label - the label

    7287:   Level: intermediate

    7289: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMAddLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7290: @*/
    7291: PetscErrorCode DMGetLabelByNum(DM dm, PetscInt n, DMLabel *label)
    7292: {
    7293:   DMLabelLink next = dm->labels;
    7294:   PetscInt    l    = 0;

    7296:   PetscFunctionBegin;
    7298:   PetscAssertPointer(label, 3);
    7299:   while (next) {
    7300:     if (l == n) {
    7301:       *label = next->label;
    7302:       PetscFunctionReturn(PETSC_SUCCESS);
    7303:     }
    7304:     ++l;
    7305:     next = next->next;
    7306:   }
    7307:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label %" PetscInt_FMT " does not exist in this DM", n);
    7308: }

    7310: /*@
    7311:   DMAddLabel - Add the label to this `DM`

    7313:   Not Collective

    7315:   Input Parameters:
    7316: + dm    - The `DM` object
    7317: - label - The `DMLabel`

    7319:   Level: developer

    7321: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7322: @*/
    7323: PetscErrorCode DMAddLabel(DM dm, DMLabel label)
    7324: {
    7325:   DMLabelLink l, *p, tmpLabel;
    7326:   PetscBool   hasLabel;
    7327:   const char *lname;
    7328:   PetscBool   flg;

    7330:   PetscFunctionBegin;
    7332:   PetscCall(PetscObjectGetName((PetscObject)label, &lname));
    7333:   PetscCall(DMHasLabel(dm, lname, &hasLabel));
    7334:   PetscCheck(!hasLabel, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label %s already exists in this DM", lname);
    7335:   PetscCall(PetscCalloc1(1, &tmpLabel));
    7336:   tmpLabel->label  = label;
    7337:   tmpLabel->output = PETSC_TRUE;
    7338:   for (p = &dm->labels; (l = *p); p = &l->next) { }
    7339:   *p = tmpLabel;
    7340:   PetscCall(PetscObjectReference((PetscObject)label));
    7341:   PetscCall(PetscStrcmp(lname, "depth", &flg));
    7342:   if (flg) dm->depthLabel = label;
    7343:   PetscCall(PetscStrcmp(lname, "celltype", &flg));
    7344:   if (flg) dm->celltypeLabel = label;
    7345:   PetscFunctionReturn(PETSC_SUCCESS);
    7346: }

    7348: // PetscClangLinter pragma ignore: -fdoc-section-header-unknown
    7349: /*@
    7350:   DMSetLabel - Replaces the label of a given name, or ignores it if the name is not present

    7352:   Not Collective

    7354:   Input Parameters:
    7355: + dm    - The `DM` object
    7356: - label - The `DMLabel`, having the same name, to substitute

    7358:   Default labels in a `DMPLEX`:
    7359: + "depth"       - Holds the depth (co-dimension) of each mesh point
    7360: . "celltype"    - Holds the topological type of each cell
    7361: . "ghost"       - If the DM is distributed with overlap, this marks the cells and faces in the overlap
    7362: . "Cell Sets"   - Mirrors the cell sets defined by GMsh and ExodusII
    7363: . "Face Sets"   - Mirrors the face sets defined by GMsh and ExodusII
    7364: - "Vertex Sets" - Mirrors the vertex sets defined by GMsh

    7366:   Level: intermediate

    7368: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMPlexGetDepthLabel()`, `DMPlexGetCellType()`
    7369: @*/
    7370: PetscErrorCode DMSetLabel(DM dm, DMLabel label)
    7371: {
    7372:   DMLabelLink next = dm->labels;
    7373:   PetscBool   hasLabel, flg;
    7374:   const char *name, *lname;

    7376:   PetscFunctionBegin;
    7379:   PetscCall(PetscObjectGetName((PetscObject)label, &name));
    7380:   while (next) {
    7381:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7382:     PetscCall(PetscStrcmp(name, lname, &hasLabel));
    7383:     if (hasLabel) {
    7384:       PetscCall(PetscObjectReference((PetscObject)label));
    7385:       PetscCall(PetscStrcmp(lname, "depth", &flg));
    7386:       if (flg) dm->depthLabel = label;
    7387:       PetscCall(PetscStrcmp(lname, "celltype", &flg));
    7388:       if (flg) dm->celltypeLabel = label;
    7389:       PetscCall(DMLabelDestroy(&next->label));
    7390:       next->label = label;
    7391:       break;
    7392:     }
    7393:     next = next->next;
    7394:   }
    7395:   PetscFunctionReturn(PETSC_SUCCESS);
    7396: }

    7398: /*@
    7399:   DMRemoveLabel - Remove the label given by name from this `DM`

    7401:   Not Collective

    7403:   Input Parameters:
    7404: + dm   - The `DM` object
    7405: - name - The label name

    7407:   Output Parameter:
    7408: . label - The `DMLabel`, or `NULL` if the label is absent. Pass in `NULL` to call `DMLabelDestroy()` on the label, otherwise the
    7409:           caller is responsible for calling `DMLabelDestroy()`.

    7411:   Level: developer

    7413: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMLabelDestroy()`, `DMRemoveLabelBySelf()`
    7414: @*/
    7415: PetscErrorCode DMRemoveLabel(DM dm, const char name[], DMLabel *label)
    7416: {
    7417:   DMLabelLink link, *pnext;
    7418:   PetscBool   hasLabel;
    7419:   const char *lname;

    7421:   PetscFunctionBegin;
    7423:   PetscAssertPointer(name, 2);
    7424:   if (label) {
    7425:     PetscAssertPointer(label, 3);
    7426:     *label = NULL;
    7427:   }
    7428:   for (pnext = &dm->labels; (link = *pnext); pnext = &link->next) {
    7429:     PetscCall(PetscObjectGetName((PetscObject)link->label, &lname));
    7430:     PetscCall(PetscStrcmp(name, lname, &hasLabel));
    7431:     if (hasLabel) {
    7432:       *pnext = link->next; /* Remove from list */
    7433:       PetscCall(PetscStrcmp(name, "depth", &hasLabel));
    7434:       if (hasLabel) dm->depthLabel = NULL;
    7435:       PetscCall(PetscStrcmp(name, "celltype", &hasLabel));
    7436:       if (hasLabel) dm->celltypeLabel = NULL;
    7437:       if (label) *label = link->label;
    7438:       else PetscCall(DMLabelDestroy(&link->label));
    7439:       PetscCall(PetscFree(link));
    7440:       break;
    7441:     }
    7442:   }
    7443:   PetscFunctionReturn(PETSC_SUCCESS);
    7444: }

    7446: /*@
    7447:   DMRemoveLabelBySelf - Remove the label from this `DM`

    7449:   Not Collective

    7451:   Input Parameters:
    7452: + dm           - The `DM` object
    7453: . label        - The `DMLabel` to be removed from the `DM`
    7454: - failNotFound - Should it fail if the label is not found in the `DM`?

    7456:   Level: developer

    7458:   Note:
    7459:   Only exactly the same instance is removed if found, name match is ignored.
    7460:   If the `DM` has an exclusive reference to the label, the label gets destroyed and
    7461:   *label nullified.

    7463: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabel()` `DMGetLabelValue()`, `DMSetLabelValue()`, `DMLabelDestroy()`, `DMRemoveLabel()`
    7464: @*/
    7465: PetscErrorCode DMRemoveLabelBySelf(DM dm, DMLabel *label, PetscBool failNotFound)
    7466: {
    7467:   DMLabelLink link, *pnext;
    7468:   PetscBool   hasLabel = PETSC_FALSE;

    7470:   PetscFunctionBegin;
    7472:   PetscAssertPointer(label, 2);
    7473:   if (!*label && !failNotFound) PetscFunctionReturn(PETSC_SUCCESS);
    7476:   for (pnext = &dm->labels; (link = *pnext); pnext = &link->next) {
    7477:     if (*label == link->label) {
    7478:       hasLabel = PETSC_TRUE;
    7479:       *pnext   = link->next; /* Remove from list */
    7480:       if (*label == dm->depthLabel) dm->depthLabel = NULL;
    7481:       if (*label == dm->celltypeLabel) dm->celltypeLabel = NULL;
    7482:       if (((PetscObject)link->label)->refct < 2) *label = NULL; /* nullify if exclusive reference */
    7483:       PetscCall(DMLabelDestroy(&link->label));
    7484:       PetscCall(PetscFree(link));
    7485:       break;
    7486:     }
    7487:   }
    7488:   PetscCheck(hasLabel || !failNotFound, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Given label not found in DM");
    7489:   PetscFunctionReturn(PETSC_SUCCESS);
    7490: }

    7492: /*@
    7493:   DMGetLabelOutput - Get the output flag for a given label

    7495:   Not Collective

    7497:   Input Parameters:
    7498: + dm   - The `DM` object
    7499: - name - The label name

    7501:   Output Parameter:
    7502: . output - The flag for output

    7504:   Level: developer

    7506: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMSetLabelOutput()`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7507: @*/
    7508: PetscErrorCode DMGetLabelOutput(DM dm, const char name[], PetscBool *output)
    7509: {
    7510:   DMLabelLink next = dm->labels;
    7511:   const char *lname;

    7513:   PetscFunctionBegin;
    7515:   PetscAssertPointer(name, 2);
    7516:   PetscAssertPointer(output, 3);
    7517:   while (next) {
    7518:     PetscBool flg;

    7520:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7521:     PetscCall(PetscStrcmp(name, lname, &flg));
    7522:     if (flg) {
    7523:       *output = next->output;
    7524:       PetscFunctionReturn(PETSC_SUCCESS);
    7525:     }
    7526:     next = next->next;
    7527:   }
    7528:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "No label named %s was present in this dm", name);
    7529: }

    7531: /*@
    7532:   DMSetLabelOutput - Set if a given label should be saved to a `PetscViewer` in calls to `DMView()`

    7534:   Not Collective

    7536:   Input Parameters:
    7537: + dm     - The `DM` object
    7538: . name   - The label name
    7539: - output - `PETSC_TRUE` to save the label to the viewer

    7541:   Level: developer

    7543: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetOutputFlag()`, `DMGetLabelOutput()`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7544: @*/
    7545: PetscErrorCode DMSetLabelOutput(DM dm, const char name[], PetscBool output)
    7546: {
    7547:   DMLabelLink next = dm->labels;
    7548:   const char *lname;

    7550:   PetscFunctionBegin;
    7552:   PetscAssertPointer(name, 2);
    7553:   while (next) {
    7554:     PetscBool flg;

    7556:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7557:     PetscCall(PetscStrcmp(name, lname, &flg));
    7558:     if (flg) {
    7559:       next->output = output;
    7560:       PetscFunctionReturn(PETSC_SUCCESS);
    7561:     }
    7562:     next = next->next;
    7563:   }
    7564:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "No label named %s was present in this dm", name);
    7565: }

    7567: /*@
    7568:   DMCopyLabels - Copy labels from one `DM` mesh to another `DM` with a superset of the points

    7570:   Collective

    7572:   Input Parameters:
    7573: + dmA   - The `DM` object with initial labels
    7574: . dmB   - The `DM` object to which labels are copied
    7575: . mode  - Copy labels by pointers (`PETSC_OWN_POINTER`) or duplicate them (`PETSC_COPY_VALUES`)
    7576: . all   - Copy all labels including "depth", "dim", and "celltype" (`PETSC_TRUE`) which are otherwise ignored (`PETSC_FALSE`)
    7577: - emode - How to behave when a `DMLabel` in the source and destination `DM`s with the same name is encountered (see `DMCopyLabelsMode`)

    7579:   Level: intermediate

    7581:   Note:
    7582:   This is typically used when interpolating or otherwise adding to a mesh, or testing.

    7584: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMAddLabel()`, `DMCopyLabelsMode`
    7585: @*/
    7586: PetscErrorCode DMCopyLabels(DM dmA, DM dmB, PetscCopyMode mode, PetscBool all, DMCopyLabelsMode emode)
    7587: {
    7588:   DMLabel     label, labelNew, labelOld;
    7589:   const char *name;
    7590:   PetscBool   flg;
    7591:   DMLabelLink link;

    7593:   PetscFunctionBegin;
    7598:   PetscCheck(mode != PETSC_USE_POINTER, PetscObjectComm((PetscObject)dmA), PETSC_ERR_SUP, "PETSC_USE_POINTER not supported for objects");
    7599:   if (dmA == dmB) PetscFunctionReturn(PETSC_SUCCESS);
    7600:   for (link = dmA->labels; link; link = link->next) {
    7601:     label = link->label;
    7602:     PetscCall(PetscObjectGetName((PetscObject)label, &name));
    7603:     if (!all) {
    7604:       PetscCall(PetscStrcmp(name, "depth", &flg));
    7605:       if (flg) continue;
    7606:       PetscCall(PetscStrcmp(name, "dim", &flg));
    7607:       if (flg) continue;
    7608:       PetscCall(PetscStrcmp(name, "celltype", &flg));
    7609:       if (flg) continue;
    7610:     }
    7611:     PetscCall(DMGetLabel(dmB, name, &labelOld));
    7612:     if (labelOld) {
    7613:       switch (emode) {
    7614:       case DM_COPY_LABELS_KEEP:
    7615:         continue;
    7616:       case DM_COPY_LABELS_REPLACE:
    7617:         PetscCall(DMRemoveLabelBySelf(dmB, &labelOld, PETSC_TRUE));
    7618:         break;
    7619:       case DM_COPY_LABELS_FAIL:
    7620:         SETERRQ(PetscObjectComm((PetscObject)dmA), PETSC_ERR_ARG_OUTOFRANGE, "Label %s already exists in destination DM", name);
    7621:       default:
    7622:         SETERRQ(PetscObjectComm((PetscObject)dmA), PETSC_ERR_ARG_OUTOFRANGE, "Unhandled DMCopyLabelsMode %d", (int)emode);
    7623:       }
    7624:     }
    7625:     if (mode == PETSC_COPY_VALUES) {
    7626:       PetscCall(DMLabelDuplicate(label, &labelNew));
    7627:     } else {
    7628:       labelNew = label;
    7629:     }
    7630:     PetscCall(DMAddLabel(dmB, labelNew));
    7631:     if (mode == PETSC_COPY_VALUES) PetscCall(DMLabelDestroy(&labelNew));
    7632:   }
    7633:   PetscFunctionReturn(PETSC_SUCCESS);
    7634: }

    7636: /*@C
    7637:   DMCompareLabels - Compare labels between two `DM` objects

    7639:   Collective; No Fortran Support

    7641:   Input Parameters:
    7642: + dm0 - First `DM` object
    7643: - dm1 - Second `DM` object

    7645:   Output Parameters:
    7646: + equal   - (Optional) Flag whether labels of `dm0` and `dm1` are the same
    7647: - message - (Optional) Message describing the difference, or `NULL` if there is no difference

    7649:   Level: intermediate

    7651:   Notes:
    7652:   The output flag equal will be the same on all processes.

    7654:   If equal is passed as `NULL` and difference is found, an error is thrown on all processes.

    7656:   Make sure to pass equal is `NULL` on all processes or none of them.

    7658:   The output message is set independently on each rank.

    7660:   message must be freed with `PetscFree()`

    7662:   If message is passed as `NULL` and a difference is found, the difference description is printed to `stderr` in synchronized manner.

    7664:   Make sure to pass message as `NULL` on all processes or no processes.

    7666:   Labels are matched by name. If the number of labels and their names are equal,
    7667:   `DMLabelCompare()` is used to compare each pair of labels with the same name.

    7669:   Developer Note:
    7670:   Cannot automatically generate the Fortran stub because `message` must be freed with `PetscFree()`

    7672: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMAddLabel()`, `DMCopyLabelsMode`, `DMLabelCompare()`
    7673: @*/
    7674: PetscErrorCode DMCompareLabels(DM dm0, DM dm1, PetscBool *equal, char *message[]) PeNS
    7675: {
    7676:   PetscInt    n, i;
    7677:   char        msg[PETSC_MAX_PATH_LEN] = "";
    7678:   PetscBool   eq;
    7679:   MPI_Comm    comm;
    7680:   PetscMPIInt rank;

    7682:   PetscFunctionBegin;
    7685:   PetscCheckSameComm(dm0, 1, dm1, 2);
    7686:   if (equal) PetscAssertPointer(equal, 3);
    7687:   if (message) PetscAssertPointer(message, 4);
    7688:   PetscCall(PetscObjectGetComm((PetscObject)dm0, &comm));
    7689:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    7690:   {
    7691:     PetscInt n1;

    7693:     PetscCall(DMGetNumLabels(dm0, &n));
    7694:     PetscCall(DMGetNumLabels(dm1, &n1));
    7695:     eq = (PetscBool)(n == n1);
    7696:     if (!eq) PetscCall(PetscSNPrintf(msg, sizeof(msg), "Number of labels in dm0 = %" PetscInt_FMT " != %" PetscInt_FMT " = Number of labels in dm1", n, n1));
    7697:     PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &eq, 1, MPI_C_BOOL, MPI_LAND, comm));
    7698:     if (!eq) goto finish;
    7699:   }
    7700:   for (i = 0; i < n; i++) {
    7701:     DMLabel     l0, l1;
    7702:     const char *name;
    7703:     char       *msgInner;

    7705:     /* Ignore label order */
    7706:     PetscCall(DMGetLabelByNum(dm0, i, &l0));
    7707:     PetscCall(PetscObjectGetName((PetscObject)l0, &name));
    7708:     PetscCall(DMGetLabel(dm1, name, &l1));
    7709:     if (!l1) {
    7710:       PetscCall(PetscSNPrintf(msg, sizeof(msg), "Label \"%s\" (#%" PetscInt_FMT " in dm0) not found in dm1", name, i));
    7711:       eq = PETSC_FALSE;
    7712:       break;
    7713:     }
    7714:     PetscCall(DMLabelCompare(comm, l0, l1, &eq, &msgInner));
    7715:     PetscCall(PetscStrncpy(msg, msgInner, sizeof(msg)));
    7716:     PetscCall(PetscFree(msgInner));
    7717:     if (!eq) break;
    7718:   }
    7719:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &eq, 1, MPI_C_BOOL, MPI_LAND, comm));
    7720: finish:
    7721:   /* If message output arg not set, print to stderr */
    7722:   if (message) {
    7723:     *message = NULL;
    7724:     if (msg[0]) PetscCall(PetscStrallocpy(msg, message));
    7725:   } else {
    7726:     if (msg[0]) PetscCall(PetscSynchronizedFPrintf(comm, PETSC_STDERR, "[%d] %s\n", rank, msg));
    7727:     PetscCall(PetscSynchronizedFlush(comm, PETSC_STDERR));
    7728:   }
    7729:   /* If same output arg not ser and labels are not equal, throw error */
    7730:   if (equal) *equal = eq;
    7731:   else PetscCheck(eq, comm, PETSC_ERR_ARG_INCOMP, "DMLabels are not the same in dm0 and dm1");
    7732:   PetscFunctionReturn(PETSC_SUCCESS);
    7733: }

    7735: PetscErrorCode DMSetLabelValue_Fast(DM dm, DMLabel *label, const char name[], PetscInt point, PetscInt value)
    7736: {
    7737:   PetscFunctionBegin;
    7738:   PetscAssertPointer(label, 2);
    7739:   if (!*label) {
    7740:     PetscCall(DMCreateLabel(dm, name));
    7741:     PetscCall(DMGetLabel(dm, name, label));
    7742:   }
    7743:   PetscCall(DMLabelSetValue(*label, point, value));
    7744:   PetscFunctionReturn(PETSC_SUCCESS);
    7745: }

    7747: /*
    7748:   Many mesh programs, such as Triangle and TetGen, allow only a single label for each mesh point. Therefore, we would
    7749:   like to encode all label IDs using a single, universal label. We can do this by assigning an integer to every
    7750:   (label, id) pair in the DM.

    7752:   However, a mesh point can have multiple labels, so we must separate all these values. We will assign a bit range to
    7753:   each label.
    7754: */
    7755: PetscErrorCode DMUniversalLabelCreate(DM dm, DMUniversalLabel *universal)
    7756: {
    7757:   DMUniversalLabel ul;
    7758:   PetscBool       *active;
    7759:   PetscInt         pStart, pEnd, p, Nl, l, m;

    7761:   PetscFunctionBegin;
    7762:   PetscCall(PetscMalloc1(1, &ul));
    7763:   PetscCall(DMLabelCreate(PETSC_COMM_SELF, "universal", &ul->label));
    7764:   PetscCall(DMGetNumLabels(dm, &Nl));
    7765:   PetscCall(PetscCalloc1(Nl, &active));
    7766:   ul->Nl = 0;
    7767:   for (l = 0; l < Nl; ++l) {
    7768:     PetscBool   isdepth, iscelltype;
    7769:     const char *name;

    7771:     PetscCall(DMGetLabelName(dm, l, &name));
    7772:     PetscCall(PetscStrncmp(name, "depth", 6, &isdepth));
    7773:     PetscCall(PetscStrncmp(name, "celltype", 9, &iscelltype));
    7774:     active[l] = !(isdepth || iscelltype) ? PETSC_TRUE : PETSC_FALSE;
    7775:     if (active[l]) ++ul->Nl;
    7776:   }
    7777:   PetscCall(PetscCalloc5(ul->Nl, &ul->names, ul->Nl, &ul->indices, ul->Nl + 1, &ul->offsets, ul->Nl + 1, &ul->bits, ul->Nl, &ul->masks));
    7778:   ul->Nv = 0;
    7779:   for (l = 0, m = 0; l < Nl; ++l) {
    7780:     DMLabel     label;
    7781:     PetscInt    nv;
    7782:     const char *name;

    7784:     if (!active[l]) continue;
    7785:     PetscCall(DMGetLabelName(dm, l, &name));
    7786:     PetscCall(DMGetLabelByNum(dm, l, &label));
    7787:     PetscCall(DMLabelGetNumValues(label, &nv));
    7788:     PetscCall(PetscStrallocpy(name, &ul->names[m]));
    7789:     ul->indices[m] = l;
    7790:     ul->Nv += nv;
    7791:     ul->offsets[m + 1] = nv;
    7792:     ul->bits[m + 1]    = PetscCeilReal(PetscLog2Real(nv + 1));
    7793:     ++m;
    7794:   }
    7795:   for (l = 1; l <= ul->Nl; ++l) {
    7796:     ul->offsets[l] = ul->offsets[l - 1] + ul->offsets[l];
    7797:     ul->bits[l]    = ul->bits[l - 1] + ul->bits[l];
    7798:   }
    7799:   for (l = 0; l < ul->Nl; ++l) {
    7800:     PetscInt b;

    7802:     ul->masks[l] = 0;
    7803:     for (b = ul->bits[l]; b < ul->bits[l + 1]; ++b) ul->masks[l] |= 1 << b;
    7804:   }
    7805:   PetscCall(PetscMalloc1(ul->Nv, &ul->values));
    7806:   for (l = 0, m = 0; l < Nl; ++l) {
    7807:     DMLabel         label;
    7808:     IS              valueIS;
    7809:     const PetscInt *varr;
    7810:     PetscInt        nv, v;

    7812:     if (!active[l]) continue;
    7813:     PetscCall(DMGetLabelByNum(dm, l, &label));
    7814:     PetscCall(DMLabelGetNumValues(label, &nv));
    7815:     PetscCall(DMLabelGetValueIS(label, &valueIS));
    7816:     PetscCall(ISGetIndices(valueIS, &varr));
    7817:     for (v = 0; v < nv; ++v) ul->values[ul->offsets[m] + v] = varr[v];
    7818:     PetscCall(ISRestoreIndices(valueIS, &varr));
    7819:     PetscCall(ISDestroy(&valueIS));
    7820:     PetscCall(PetscSortInt(nv, &ul->values[ul->offsets[m]]));
    7821:     ++m;
    7822:   }
    7823:   PetscCall(DMPlexGetChart(dm, &pStart, &pEnd));
    7824:   for (p = pStart; p < pEnd; ++p) {
    7825:     PetscInt  uval   = 0;
    7826:     PetscBool marked = PETSC_FALSE;

    7828:     for (l = 0, m = 0; l < Nl; ++l) {
    7829:       DMLabel  label;
    7830:       PetscInt val, defval, loc, nv;

    7832:       if (!active[l]) continue;
    7833:       PetscCall(DMGetLabelByNum(dm, l, &label));
    7834:       PetscCall(DMLabelGetValue(label, p, &val));
    7835:       PetscCall(DMLabelGetDefaultValue(label, &defval));
    7836:       if (val == defval) {
    7837:         ++m;
    7838:         continue;
    7839:       }
    7840:       nv     = ul->offsets[m + 1] - ul->offsets[m];
    7841:       marked = PETSC_TRUE;
    7842:       PetscCall(PetscFindInt(val, nv, &ul->values[ul->offsets[m]], &loc));
    7843:       PetscCheck(loc >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Label value %" PetscInt_FMT " not found in compression array", val);
    7844:       uval += (loc + 1) << ul->bits[m];
    7845:       ++m;
    7846:     }
    7847:     if (marked) PetscCall(DMLabelSetValue(ul->label, p, uval));
    7848:   }
    7849:   PetscCall(PetscFree(active));
    7850:   *universal = ul;
    7851:   PetscFunctionReturn(PETSC_SUCCESS);
    7852: }

    7854: PetscErrorCode DMUniversalLabelDestroy(DMUniversalLabel *universal)
    7855: {
    7856:   PetscInt l;

    7858:   PetscFunctionBegin;
    7859:   for (l = 0; l < (*universal)->Nl; ++l) PetscCall(PetscFree((*universal)->names[l]));
    7860:   PetscCall(DMLabelDestroy(&(*universal)->label));
    7861:   PetscCall(PetscFree5((*universal)->names, (*universal)->indices, (*universal)->offsets, (*universal)->bits, (*universal)->masks));
    7862:   PetscCall(PetscFree((*universal)->values));
    7863:   PetscCall(PetscFree(*universal));
    7864:   *universal = NULL;
    7865:   PetscFunctionReturn(PETSC_SUCCESS);
    7866: }

    7868: PetscErrorCode DMUniversalLabelGetLabel(DMUniversalLabel ul, DMLabel *ulabel)
    7869: {
    7870:   PetscFunctionBegin;
    7871:   PetscAssertPointer(ulabel, 2);
    7872:   *ulabel = ul->label;
    7873:   PetscFunctionReturn(PETSC_SUCCESS);
    7874: }

    7876: PetscErrorCode DMUniversalLabelCreateLabels(DMUniversalLabel ul, PetscBool preserveOrder, DM dm)
    7877: {
    7878:   PetscInt Nl = ul->Nl, l;

    7880:   PetscFunctionBegin;
    7882:   for (l = 0; l < Nl; ++l) {
    7883:     if (preserveOrder) PetscCall(DMCreateLabelAtIndex(dm, ul->indices[l], ul->names[l]));
    7884:     else PetscCall(DMCreateLabel(dm, ul->names[l]));
    7885:   }
    7886:   if (preserveOrder) {
    7887:     for (l = 0; l < ul->Nl; ++l) {
    7888:       const char *name;
    7889:       PetscBool   match;

    7891:       PetscCall(DMGetLabelName(dm, ul->indices[l], &name));
    7892:       PetscCall(PetscStrcmp(name, ul->names[l], &match));
    7893:       PetscCheck(match, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Label %" PetscInt_FMT " name %s does not match new name %s", l, name, ul->names[l]);
    7894:     }
    7895:   }
    7896:   PetscFunctionReturn(PETSC_SUCCESS);
    7897: }

    7899: PetscErrorCode DMUniversalLabelSetLabelValue(DMUniversalLabel ul, DM dm, PetscBool useIndex, PetscInt p, PetscInt value)
    7900: {
    7901:   PetscInt l;

    7903:   PetscFunctionBegin;
    7904:   for (l = 0; l < ul->Nl; ++l) {
    7905:     DMLabel  label;
    7906:     PetscInt lval = (value & ul->masks[l]) >> ul->bits[l];

    7908:     if (lval) {
    7909:       if (useIndex) PetscCall(DMGetLabelByNum(dm, ul->indices[l], &label));
    7910:       else PetscCall(DMGetLabel(dm, ul->names[l], &label));
    7911:       PetscCall(DMLabelSetValue(label, p, ul->values[ul->offsets[l] + lval - 1]));
    7912:     }
    7913:   }
    7914:   PetscFunctionReturn(PETSC_SUCCESS);
    7915: }

    7917: /*@
    7918:   DMGetCoarseDM - Get the coarse `DM`from which this `DM` was obtained by refinement

    7920:   Not Collective

    7922:   Input Parameter:
    7923: . dm - The `DM` object

    7925:   Output Parameter:
    7926: . cdm - The coarse `DM`

    7928:   Level: intermediate

    7930: .seealso: [](ch_dmbase), `DM`, `DMSetCoarseDM()`, `DMCoarsen()`
    7931: @*/
    7932: PetscErrorCode DMGetCoarseDM(DM dm, DM *cdm)
    7933: {
    7934:   PetscFunctionBegin;
    7936:   PetscAssertPointer(cdm, 2);
    7937:   *cdm = dm->coarseMesh;
    7938:   PetscFunctionReturn(PETSC_SUCCESS);
    7939: }

    7941: /*@
    7942:   DMSetCoarseDM - Set the coarse `DM` from which this `DM` was obtained by refinement

    7944:   Input Parameters:
    7945: + dm  - The `DM` object
    7946: - cdm - The coarse `DM`

    7948:   Level: intermediate

    7950:   Note:
    7951:   Normally this is set automatically by `DMRefine()`

    7953: .seealso: [](ch_dmbase), `DM`, `DMGetCoarseDM()`, `DMCoarsen()`, `DMSetRefine()`, `DMSetFineDM()`
    7954: @*/
    7955: PetscErrorCode DMSetCoarseDM(DM dm, DM cdm)
    7956: {
    7957:   PetscFunctionBegin;
    7960:   if (dm == cdm) cdm = NULL;
    7961:   PetscCall(PetscObjectReference((PetscObject)cdm));
    7962:   PetscCall(DMDestroy(&dm->coarseMesh));
    7963:   dm->coarseMesh = cdm;
    7964:   PetscFunctionReturn(PETSC_SUCCESS);
    7965: }

    7967: /*@
    7968:   DMGetFineDM - Get the fine mesh from which this `DM` was obtained by coarsening

    7970:   Input Parameter:
    7971: . dm - The `DM` object

    7973:   Output Parameter:
    7974: . fdm - The fine `DM`

    7976:   Level: intermediate

    7978: .seealso: [](ch_dmbase), `DM`, `DMSetFineDM()`, `DMCoarsen()`, `DMRefine()`
    7979: @*/
    7980: PetscErrorCode DMGetFineDM(DM dm, DM *fdm)
    7981: {
    7982:   PetscFunctionBegin;
    7984:   PetscAssertPointer(fdm, 2);
    7985:   *fdm = dm->fineMesh;
    7986:   PetscFunctionReturn(PETSC_SUCCESS);
    7987: }

    7989: /*@
    7990:   DMSetFineDM - Set the fine mesh from which this was obtained by coarsening

    7992:   Input Parameters:
    7993: + dm  - The `DM` object
    7994: - fdm - The fine `DM`

    7996:   Level: developer

    7998:   Note:
    7999:   Normally this is set automatically by `DMCoarsen()`

    8001: .seealso: [](ch_dmbase), `DM`, `DMGetFineDM()`, `DMCoarsen()`, `DMRefine()`
    8002: @*/
    8003: PetscErrorCode DMSetFineDM(DM dm, DM fdm)
    8004: {
    8005:   PetscFunctionBegin;
    8008:   if (dm == fdm) fdm = NULL;
    8009:   PetscCall(PetscObjectReference((PetscObject)fdm));
    8010:   PetscCall(DMDestroy(&dm->fineMesh));
    8011:   dm->fineMesh = fdm;
    8012:   PetscFunctionReturn(PETSC_SUCCESS);
    8013: }

    8015: /*@C
    8016:   DMAddBoundary - Add a boundary condition, for a single field, to a model represented by a `DM`

    8018:   Collective

    8020:   Input Parameters:
    8021: + dm       - The `DM`, with a `PetscDS` that matches the problem being constrained
    8022: . type     - The type of condition, e.g. `DM_BC_ESSENTIAL_ANALYTIC`, `DM_BC_ESSENTIAL_FIELD` (Dirichlet), or `DM_BC_NATURAL` (Neumann)
    8023: . name     - The BC name
    8024: . label    - The label defining constrained points
    8025: . Nv       - The number of `DMLabel` values for constrained points
    8026: . values   - An array of values for constrained points
    8027: . field    - The field to constrain
    8028: . Nc       - The number of constrained field components (0 will constrain all components)
    8029: . comps    - An array of constrained component numbers
    8030: . bcFunc   - A pointwise function giving boundary values
    8031: . bcFunc_t - A pointwise function giving the time derivative of the boundary values, or `NULL`
    8032: - ctx      - An optional user context for bcFunc

    8034:   Output Parameter:
    8035: . bd - (Optional) Boundary number

    8037:   Options Database Keys:
    8038: + -bc_<boundary name> <num>      - Overrides the boundary ids
    8039: - -bc_<boundary name>_comp <num> - Overrides the boundary components

    8041:   Level: intermediate

    8043:   Notes:
    8044:   If the `DM` is of type `DMPLEX` and the field is of type `PetscFE`, then this function completes the label using `DMPlexLabelComplete()`.

    8046:   Both bcFunc and bcFunc_t will depend on the boundary condition type. If the type if `DM_BC_ESSENTIAL`, then the calling sequence is\:
    8047: .vb
    8048:  void bcFunc(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar bcval[])
    8049: .ve

    8051:   If the type is `DM_BC_ESSENTIAL_FIELD` or other _FIELD value, then the calling sequence is\:

    8053: .vb
    8054:   void bcFunc(PetscInt dim, PetscInt Nf, PetscInt NfAux,
    8055:               const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
    8056:               const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
    8057:               PetscReal time, const PetscReal x[], PetscScalar bcval[])
    8058: .ve
    8059: + dim - the spatial dimension
    8060: . Nf - the number of fields
    8061: . uOff - the offset into u[] and u_t[] for each field
    8062: . uOff_x - the offset into u_x[] for each field
    8063: . u - each field evaluated at the current point
    8064: . u_t - the time derivative of each field evaluated at the current point
    8065: . u_x - the gradient of each field evaluated at the current point
    8066: . aOff - the offset into a[] and a_t[] for each auxiliary field
    8067: . aOff_x - the offset into a_x[] for each auxiliary field
    8068: . a - each auxiliary field evaluated at the current point
    8069: . a_t - the time derivative of each auxiliary field evaluated at the current point
    8070: . a_x - the gradient of auxiliary each field evaluated at the current point
    8071: . t - current time
    8072: . x - coordinates of the current point
    8073: . numConstants - number of constant parameters
    8074: . constants - constant parameters
    8075: - bcval - output values at the current point

    8077: .seealso: [](ch_dmbase), `DM`, `DSGetBoundary()`, `PetscDSAddBoundary()`
    8078: @*/
    8079: PetscErrorCode DMAddBoundary(DM dm, DMBoundaryConditionType type, const char name[], DMLabel label, PetscInt Nv, const PetscInt values[], PetscInt field, PetscInt Nc, const PetscInt comps[], PetscVoidFn *bcFunc, PetscVoidFn *bcFunc_t, void *ctx, PetscInt *bd)
    8080: {
    8081:   PetscDS ds;

    8083:   PetscFunctionBegin;
    8090:   PetscCheck(!dm->localSection, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Cannot add boundary to DM after creating local section");
    8091:   PetscCall(DMGetDS(dm, &ds));
    8092:   /* Complete label */
    8093:   if (label) {
    8094:     PetscObject  obj;
    8095:     PetscClassId id;

    8097:     PetscCall(DMGetField(dm, field, NULL, &obj));
    8098:     PetscCall(PetscObjectGetClassId(obj, &id));
    8099:     if (id == PETSCFE_CLASSID) {
    8100:       DM plex;

    8102:       PetscCall(DMConvert(dm, DMPLEX, &plex));
    8103:       if (plex) PetscCall(DMPlexLabelComplete(plex, label));
    8104:       PetscCall(DMDestroy(&plex));
    8105:     }
    8106:   }
    8107:   PetscCall(PetscDSAddBoundary(ds, type, name, label, Nv, values, field, Nc, comps, bcFunc, bcFunc_t, ctx, bd));
    8108:   PetscFunctionReturn(PETSC_SUCCESS);
    8109: }

    8111: /* TODO Remove this since now the structures are the same */
    8112: static PetscErrorCode DMPopulateBoundary(DM dm)
    8113: {
    8114:   PetscDS     ds;
    8115:   DMBoundary *lastnext;
    8116:   DSBoundary  dsbound;

    8118:   PetscFunctionBegin;
    8119:   PetscCall(DMGetDS(dm, &ds));
    8120:   dsbound = ds->boundary;
    8121:   if (dm->boundary) {
    8122:     DMBoundary next = dm->boundary;

    8124:     /* quick check to see if the PetscDS has changed */
    8125:     if (next->dsboundary == dsbound) PetscFunctionReturn(PETSC_SUCCESS);
    8126:     /* the PetscDS has changed: tear down and rebuild */
    8127:     while (next) {
    8128:       DMBoundary b = next;

    8130:       next = b->next;
    8131:       PetscCall(PetscFree(b));
    8132:     }
    8133:     dm->boundary = NULL;
    8134:   }

    8136:   lastnext = &dm->boundary;
    8137:   while (dsbound) {
    8138:     DMBoundary dmbound;

    8140:     PetscCall(PetscNew(&dmbound));
    8141:     dmbound->dsboundary = dsbound;
    8142:     dmbound->label      = dsbound->label;
    8143:     /* push on the back instead of the front so that it is in the same order as in the PetscDS */
    8144:     *lastnext = dmbound;
    8145:     lastnext  = &dmbound->next;
    8146:     dsbound   = dsbound->next;
    8147:   }
    8148:   PetscFunctionReturn(PETSC_SUCCESS);
    8149: }

    8151: /* TODO: missing manual page */
    8152: PetscErrorCode DMIsBoundaryPoint(DM dm, PetscInt point, PetscBool *isBd)
    8153: {
    8154:   DMBoundary b;

    8156:   PetscFunctionBegin;
    8158:   PetscAssertPointer(isBd, 3);
    8159:   *isBd = PETSC_FALSE;
    8160:   PetscCall(DMPopulateBoundary(dm));
    8161:   b = dm->boundary;
    8162:   while (b && !*isBd) {
    8163:     DMLabel    label = b->label;
    8164:     DSBoundary dsb   = b->dsboundary;
    8165:     PetscInt   i;

    8167:     if (label) {
    8168:       for (i = 0; i < dsb->Nv && !*isBd; ++i) PetscCall(DMLabelStratumHasPoint(label, dsb->values[i], point, isBd));
    8169:     }
    8170:     b = b->next;
    8171:   }
    8172:   PetscFunctionReturn(PETSC_SUCCESS);
    8173: }

    8175: /*@
    8176:   DMHasBound - Determine whether a bound condition was specified

    8178:   Logically collective

    8180:   Input Parameter:
    8181: . dm - The `DM`, with a `PetscDS` that matches the problem being constrained

    8183:   Output Parameter:
    8184: . hasBound - Flag indicating if a bound condition was specified

    8186:   Level: intermediate

    8188: .seealso: [](ch_dmbase), `DM`, `DSAddBoundary()`, `PetscDSAddBoundary()`
    8189: @*/
    8190: PetscErrorCode DMHasBound(DM dm, PetscBool *hasBound)
    8191: {
    8192:   PetscDS  ds;
    8193:   PetscInt Nf, numBd;

    8195:   PetscFunctionBegin;
    8196:   *hasBound = PETSC_FALSE;
    8197:   PetscCall(DMGetDS(dm, &ds));
    8198:   PetscCall(PetscDSGetNumFields(ds, &Nf));
    8199:   for (PetscInt f = 0; f < Nf; ++f) {
    8200:     PetscSimplePointFn *lfunc, *ufunc;

    8202:     PetscCall(PetscDSGetLowerBound(ds, f, &lfunc, NULL));
    8203:     PetscCall(PetscDSGetUpperBound(ds, f, &ufunc, NULL));
    8204:     if (lfunc || ufunc) *hasBound = PETSC_TRUE;
    8205:   }

    8207:   PetscCall(PetscDSGetNumBoundary(ds, &numBd));
    8208:   PetscCall(PetscDSUpdateBoundaryLabels(ds, dm));
    8209:   for (PetscInt b = 0; b < numBd; ++b) {
    8210:     PetscWeakForm           wf;
    8211:     DMBoundaryConditionType type;
    8212:     const char             *name;
    8213:     DMLabel                 label;
    8214:     PetscInt                numids;
    8215:     const PetscInt         *ids;
    8216:     PetscInt                field, Nc;
    8217:     const PetscInt         *comps;
    8218:     PetscVoidFn            *bvfunc;
    8219:     void                   *ctx;

    8221:     PetscCall(PetscDSGetBoundary(ds, b, &wf, &type, &name, &label, &numids, &ids, &field, &Nc, &comps, &bvfunc, NULL, &ctx));
    8222:     if (type == DM_BC_LOWER_BOUND || type == DM_BC_UPPER_BOUND) *hasBound = PETSC_TRUE;
    8223:   }
    8224:   PetscFunctionReturn(PETSC_SUCCESS);
    8225: }

    8227: /*@C
    8228:   DMProjectFunction - This projects the given function into the function space provided by a `DM`, putting the coefficients in a global vector.

    8230:   Collective

    8232:   Input Parameters:
    8233: + dm    - The `DM`
    8234: . time  - The time
    8235: . funcs - The coordinate functions to evaluate, one per field
    8236: . ctxs  - Optional array of contexts to pass to each coordinate function.  ctxs itself may be null.
    8237: - mode  - The insertion mode for values

    8239:   Output Parameter:
    8240: . X - vector

    8242:   Calling sequence of `funcs`:
    8243: + dim  - The spatial dimension
    8244: . time - The time at which to sample
    8245: . x    - The coordinates
    8246: . Nc   - The number of components
    8247: . u    - The output field values
    8248: - ctx  - optional user-defined function context

    8250:   Level: developer

    8252:   Developer Notes:
    8253:   This API is specific to only particular usage of `DM`

    8255:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8257: .seealso: [](ch_dmbase), `DM`, `DMProjectFunctionLocal()`, `DMProjectFunctionLabel()`, `DMComputeL2Diff()`
    8258: @*/
    8259: PetscErrorCode DMProjectFunction(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx), void **ctxs, InsertMode mode, Vec X)
    8260: {
    8261:   Vec localX;

    8263:   PetscFunctionBegin;
    8265:   PetscCall(PetscLogEventBegin(DM_ProjectFunction, dm, X, 0, 0));
    8266:   PetscCall(DMGetLocalVector(dm, &localX));
    8267:   PetscCall(VecSet(localX, 0.));
    8268:   PetscCall(DMProjectFunctionLocal(dm, time, funcs, ctxs, mode, localX));
    8269:   PetscCall(DMLocalToGlobalBegin(dm, localX, mode, X));
    8270:   PetscCall(DMLocalToGlobalEnd(dm, localX, mode, X));
    8271:   PetscCall(DMRestoreLocalVector(dm, &localX));
    8272:   PetscCall(PetscLogEventEnd(DM_ProjectFunction, dm, X, 0, 0));
    8273:   PetscFunctionReturn(PETSC_SUCCESS);
    8274: }

    8276: /*@C
    8277:   DMProjectFunctionLocal - This projects the given function into the function space provided by a `DM`, putting the coefficients in a local vector.

    8279:   Not Collective

    8281:   Input Parameters:
    8282: + dm    - The `DM`
    8283: . time  - The time
    8284: . funcs - The coordinate functions to evaluate, one per field
    8285: . ctxs  - Optional array of contexts to pass to each coordinate function.  ctxs itself may be null.
    8286: - mode  - The insertion mode for values

    8288:   Output Parameter:
    8289: . localX - vector

    8291:   Calling sequence of `funcs`:
    8292: + dim  - The spatial dimension
    8293: . time - The current timestep
    8294: . x    - The coordinates
    8295: . Nc   - The number of components
    8296: . u    - The output field values
    8297: - ctx  - optional user-defined function context

    8299:   Level: developer

    8301:   Developer Notes:
    8302:   This API is specific to only particular usage of `DM`

    8304:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8306: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMProjectFunctionLabel()`, `DMComputeL2Diff()`
    8307: @*/
    8308: PetscErrorCode DMProjectFunctionLocal(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx), void **ctxs, InsertMode mode, Vec localX)
    8309: {
    8310:   PetscFunctionBegin;
    8313:   PetscUseTypeMethod(dm, projectfunctionlocal, time, funcs, ctxs, mode, localX);
    8314:   PetscFunctionReturn(PETSC_SUCCESS);
    8315: }

    8317: /*@C
    8318:   DMProjectFunctionLabel - This projects the given function into the function space provided by the `DM`, putting the coefficients in a global vector, setting values only for points in the given label.

    8320:   Collective

    8322:   Input Parameters:
    8323: + dm     - The `DM`
    8324: . time   - The time
    8325: . numIds - The number of ids
    8326: . ids    - The ids
    8327: . Nc     - The number of components
    8328: . comps  - The components
    8329: . label  - The `DMLabel` selecting the portion of the mesh for projection
    8330: . funcs  - The coordinate functions to evaluate, one per field
    8331: . ctxs   - Optional array of contexts to pass to each coordinate function.  ctxs may be null.
    8332: - mode   - The insertion mode for values

    8334:   Output Parameter:
    8335: . X - vector

    8337:   Calling sequence of `funcs`:
    8338: + dim  - The spatial dimension
    8339: . time - The current timestep
    8340: . x    - The coordinates
    8341: . Nc   - The number of components
    8342: . u    - The output field values
    8343: - ctx  - optional user-defined function context

    8345:   Level: developer

    8347:   Developer Notes:
    8348:   This API is specific to only particular usage of `DM`

    8350:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8352: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMProjectFunctionLocal()`, `DMProjectFunctionLabelLocal()`, `DMComputeL2Diff()`
    8353: @*/
    8354: PetscErrorCode DMProjectFunctionLabel(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx), void **ctxs, InsertMode mode, Vec X)
    8355: {
    8356:   Vec localX;

    8358:   PetscFunctionBegin;
    8360:   PetscCall(DMGetLocalVector(dm, &localX));
    8361:   PetscCall(VecSet(localX, 0.));
    8362:   PetscCall(DMProjectFunctionLabelLocal(dm, time, label, numIds, ids, Nc, comps, funcs, ctxs, mode, localX));
    8363:   PetscCall(DMLocalToGlobalBegin(dm, localX, mode, X));
    8364:   PetscCall(DMLocalToGlobalEnd(dm, localX, mode, X));
    8365:   PetscCall(DMRestoreLocalVector(dm, &localX));
    8366:   PetscFunctionReturn(PETSC_SUCCESS);
    8367: }

    8369: /*@C
    8370:   DMProjectFunctionLabelLocal - This projects the given function into the function space provided by the `DM`, putting the coefficients in a local vector, setting values only for points in the given label.

    8372:   Not Collective

    8374:   Input Parameters:
    8375: + dm     - The `DM`
    8376: . time   - The time
    8377: . label  - The `DMLabel` selecting the portion of the mesh for projection
    8378: . numIds - The number of ids
    8379: . ids    - The ids
    8380: . Nc     - The number of components
    8381: . comps  - The components
    8382: . funcs  - The coordinate functions to evaluate, one per field
    8383: . ctxs   - Optional array of contexts to pass to each coordinate function.  ctxs itself may be null.
    8384: - mode   - The insertion mode for values

    8386:   Output Parameter:
    8387: . localX - vector

    8389:   Calling sequence of `funcs`:
    8390: + dim  - The spatial dimension
    8391: . time - The current time
    8392: . x    - The coordinates
    8393: . Nc   - The number of components
    8394: . u    - The output field values
    8395: - ctx  - optional user-defined function context

    8397:   Level: developer

    8399:   Developer Notes:
    8400:   This API is specific to only particular usage of `DM`

    8402:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8404: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMProjectFunctionLocal()`, `DMProjectFunctionLabel()`, `DMComputeL2Diff()`
    8405: @*/
    8406: PetscErrorCode DMProjectFunctionLabelLocal(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx), void **ctxs, InsertMode mode, Vec localX)
    8407: {
    8408:   PetscFunctionBegin;
    8411:   PetscUseTypeMethod(dm, projectfunctionlabellocal, time, label, numIds, ids, Nc, comps, funcs, ctxs, mode, localX);
    8412:   PetscFunctionReturn(PETSC_SUCCESS);
    8413: }

    8415: /*@C
    8416:   DMProjectFieldLocal - This projects the given function of the input fields into the function space provided by the `DM`, putting the coefficients in a local vector.

    8418:   Not Collective

    8420:   Input Parameters:
    8421: + dm     - The `DM`
    8422: . time   - The time
    8423: . localU - The input field vector; may be `NULL` if projection is defined purely by coordinates
    8424: . funcs  - The functions to evaluate, one per field
    8425: - mode   - The insertion mode for values

    8427:   Output Parameter:
    8428: . localX - The output vector

    8430:   Calling sequence of `funcs`:
    8431: + dim          - The spatial dimension
    8432: . Nf           - The number of input fields
    8433: . NfAux        - The number of input auxiliary fields
    8434: . uOff         - The offset of each field in u[]
    8435: . uOff_x       - The offset of each field in u_x[]
    8436: . u            - The field values at this point in space
    8437: . u_t          - The field time derivative at this point in space (or `NULL`)
    8438: . u_x          - The field derivatives at this point in space
    8439: . aOff         - The offset of each auxiliary field in u[]
    8440: . aOff_x       - The offset of each auxiliary field in u_x[]
    8441: . a            - The auxiliary field values at this point in space
    8442: . a_t          - The auxiliary field time derivative at this point in space (or `NULL`)
    8443: . a_x          - The auxiliary field derivatives at this point in space
    8444: . t            - The current time
    8445: . x            - The coordinates of this point
    8446: . numConstants - The number of constants
    8447: . constants    - The value of each constant
    8448: - f            - The value of the function at this point in space

    8450:   Level: intermediate

    8452:   Note:
    8453:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8454:   The input `DM`, attached to U, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8455:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8456:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8458:   Developer Notes:
    8459:   This API is specific to only particular usage of `DM`

    8461:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8463: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabelLocal()`,
    8464: `DMProjectFunction()`, `DMComputeL2Diff()`
    8465: @*/
    8466: PetscErrorCode DMProjectFieldLocal(DM dm, PetscReal time, Vec localU, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec localX)
    8467: {
    8468:   PetscFunctionBegin;
    8472:   PetscUseTypeMethod(dm, projectfieldlocal, time, localU, funcs, mode, localX);
    8473:   PetscFunctionReturn(PETSC_SUCCESS);
    8474: }

    8476: /*@C
    8477:   DMProjectFieldLabelLocal - This projects the given function of the input fields into the function space provided, putting the coefficients in a local vector, calculating only over the portion of the domain specified by the label.

    8479:   Not Collective

    8481:   Input Parameters:
    8482: + dm     - The `DM`
    8483: . time   - The time
    8484: . label  - The `DMLabel` marking the portion of the domain to output
    8485: . numIds - The number of label ids to use
    8486: . ids    - The label ids to use for marking
    8487: . Nc     - The number of components to set in the output, or `PETSC_DETERMINE` for all components
    8488: . comps  - The components to set in the output, or `NULL` for all components
    8489: . localU - The input field vector
    8490: . funcs  - The functions to evaluate, one per field
    8491: - mode   - The insertion mode for values

    8493:   Output Parameter:
    8494: . localX - The output vector

    8496:   Calling sequence of `funcs`:
    8497: + dim          - The spatial dimension
    8498: . Nf           - The number of input fields
    8499: . NfAux        - The number of input auxiliary fields
    8500: . uOff         - The offset of each field in u[]
    8501: . uOff_x       - The offset of each field in u_x[]
    8502: . u            - The field values at this point in space
    8503: . u_t          - The field time derivative at this point in space (or `NULL`)
    8504: . u_x          - The field derivatives at this point in space
    8505: . aOff         - The offset of each auxiliary field in u[]
    8506: . aOff_x       - The offset of each auxiliary field in u_x[]
    8507: . a            - The auxiliary field values at this point in space
    8508: . a_t          - The auxiliary field time derivative at this point in space (or `NULL`)
    8509: . a_x          - The auxiliary field derivatives at this point in space
    8510: . t            - The current time
    8511: . x            - The coordinates of this point
    8512: . numConstants - The number of constants
    8513: . constants    - The value of each constant
    8514: - f            - The value of the function at this point in space

    8516:   Level: intermediate

    8518:   Note:
    8519:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8520:   The input `DM`, attached to localU, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8521:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8522:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8524:   Developer Notes:
    8525:   This API is specific to only particular usage of `DM`

    8527:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8529: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabel()`, `DMProjectFunction()`, `DMComputeL2Diff()`
    8530: @*/
    8531: PetscErrorCode DMProjectFieldLabelLocal(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], Vec localU, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec localX)
    8532: {
    8533:   PetscFunctionBegin;
    8537:   PetscUseTypeMethod(dm, projectfieldlabellocal, time, label, numIds, ids, Nc, comps, localU, funcs, mode, localX);
    8538:   PetscFunctionReturn(PETSC_SUCCESS);
    8539: }

    8541: /*@C
    8542:   DMProjectFieldLabel - This projects the given function of the input fields into the function space provided, putting the coefficients in a global vector, calculating only over the portion of the domain specified by the label.

    8544:   Not Collective

    8546:   Input Parameters:
    8547: + dm     - The `DM`
    8548: . time   - The time
    8549: . label  - The `DMLabel` marking the portion of the domain to output
    8550: . numIds - The number of label ids to use
    8551: . ids    - The label ids to use for marking
    8552: . Nc     - The number of components to set in the output, or `PETSC_DETERMINE` for all components
    8553: . comps  - The components to set in the output, or `NULL` for all components
    8554: . U      - The input field vector
    8555: . funcs  - The functions to evaluate, one per field
    8556: - mode   - The insertion mode for values

    8558:   Output Parameter:
    8559: . X - The output vector

    8561:   Calling sequence of `funcs`:
    8562: + dim          - The spatial dimension
    8563: . Nf           - The number of input fields
    8564: . NfAux        - The number of input auxiliary fields
    8565: . uOff         - The offset of each field in u[]
    8566: . uOff_x       - The offset of each field in u_x[]
    8567: . u            - The field values at this point in space
    8568: . u_t          - The field time derivative at this point in space (or `NULL`)
    8569: . u_x          - The field derivatives at this point in space
    8570: . aOff         - The offset of each auxiliary field in u[]
    8571: . aOff_x       - The offset of each auxiliary field in u_x[]
    8572: . a            - The auxiliary field values at this point in space
    8573: . a_t          - The auxiliary field time derivative at this point in space (or `NULL`)
    8574: . a_x          - The auxiliary field derivatives at this point in space
    8575: . t            - The current time
    8576: . x            - The coordinates of this point
    8577: . numConstants - The number of constants
    8578: . constants    - The value of each constant
    8579: - f            - The value of the function at this point in space

    8581:   Level: intermediate

    8583:   Note:
    8584:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8585:   The input `DM`, attached to U, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8586:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8587:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8589:   Developer Notes:
    8590:   This API is specific to only particular usage of `DM`

    8592:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8594: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabelLocal()`, `DMProjectFunction()`, `DMComputeL2Diff()`
    8595: @*/
    8596: PetscErrorCode DMProjectFieldLabel(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], Vec U, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec X)
    8597: {
    8598:   DM  dmIn;
    8599:   Vec localU, localX;

    8601:   PetscFunctionBegin;
    8603:   PetscCall(VecGetDM(U, &dmIn));
    8604:   PetscCall(DMGetLocalVector(dmIn, &localU));
    8605:   PetscCall(DMGetLocalVector(dm, &localX));
    8606:   PetscCall(VecSet(localX, 0.));
    8607:   PetscCall(DMGlobalToLocalBegin(dmIn, U, mode, localU));
    8608:   PetscCall(DMGlobalToLocalEnd(dmIn, U, mode, localU));
    8609:   PetscCall(DMProjectFieldLabelLocal(dm, time, label, numIds, ids, Nc, comps, localU, funcs, mode, localX));
    8610:   PetscCall(DMLocalToGlobalBegin(dm, localX, mode, X));
    8611:   PetscCall(DMLocalToGlobalEnd(dm, localX, mode, X));
    8612:   PetscCall(DMRestoreLocalVector(dm, &localX));
    8613:   PetscCall(DMRestoreLocalVector(dmIn, &localU));
    8614:   PetscFunctionReturn(PETSC_SUCCESS);
    8615: }

    8617: /*@C
    8618:   DMProjectBdFieldLabelLocal - This projects the given function of the input fields into the function space provided, putting the coefficients in a local vector, calculating only over the portion of the domain boundary specified by the label.

    8620:   Not Collective

    8622:   Input Parameters:
    8623: + dm     - The `DM`
    8624: . time   - The time
    8625: . label  - The `DMLabel` marking the portion of the domain boundary to output
    8626: . numIds - The number of label ids to use
    8627: . ids    - The label ids to use for marking
    8628: . Nc     - The number of components to set in the output, or `PETSC_DETERMINE` for all components
    8629: . comps  - The components to set in the output, or `NULL` for all components
    8630: . localU - The input field vector
    8631: . funcs  - The functions to evaluate, one per field
    8632: - mode   - The insertion mode for values

    8634:   Output Parameter:
    8635: . localX - The output vector

    8637:   Calling sequence of `funcs`:
    8638: + dim          - The spatial dimension
    8639: . Nf           - The number of input fields
    8640: . NfAux        - The number of input auxiliary fields
    8641: . uOff         - The offset of each field in u[]
    8642: . uOff_x       - The offset of each field in u_x[]
    8643: . u            - The field values at this point in space
    8644: . u_t          - The field time derivative at this point in space (or `NULL`)
    8645: . u_x          - The field derivatives at this point in space
    8646: . aOff         - The offset of each auxiliary field in u[]
    8647: . aOff_x       - The offset of each auxiliary field in u_x[]
    8648: . a            - The auxiliary field values at this point in space
    8649: . a_t          - The auxiliary field time derivative at this point in space (or `NULL`)
    8650: . a_x          - The auxiliary field derivatives at this point in space
    8651: . t            - The current time
    8652: . x            - The coordinates of this point
    8653: . n            - The face normal
    8654: . numConstants - The number of constants
    8655: . constants    - The value of each constant
    8656: - f            - The value of the function at this point in space

    8658:   Level: intermediate

    8660:   Note:
    8661:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8662:   The input `DM`, attached to U, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8663:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8664:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8666:   Developer Notes:
    8667:   This API is specific to only particular usage of `DM`

    8669:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8671: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabelLocal()`, `DMProjectFunction()`, `DMComputeL2Diff()`
    8672: @*/
    8673: PetscErrorCode DMProjectBdFieldLabelLocal(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], Vec localU, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], const PetscReal n[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec localX)
    8674: {
    8675:   PetscFunctionBegin;
    8679:   PetscUseTypeMethod(dm, projectbdfieldlabellocal, time, label, numIds, ids, Nc, comps, localU, funcs, mode, localX);
    8680:   PetscFunctionReturn(PETSC_SUCCESS);
    8681: }

    8683: /*@C
    8684:   DMComputeL2Diff - This function computes the L_2 difference between a function u and an FEM interpolant solution u_h.

    8686:   Collective

    8688:   Input Parameters:
    8689: + dm    - The `DM`
    8690: . time  - The time
    8691: . funcs - The functions to evaluate for each field component
    8692: . ctxs  - Optional array of contexts to pass to each function, or `NULL`.
    8693: - X     - The coefficient vector u_h, a global vector

    8695:   Output Parameter:
    8696: . diff - The diff ||u - u_h||_2

    8698:   Level: developer

    8700:   Developer Notes:
    8701:   This API is specific to only particular usage of `DM`

    8703:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8705: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMComputeL2FieldDiff()`, `DMComputeL2GradientDiff()`
    8706: @*/
    8707: PetscErrorCode DMComputeL2Diff(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar *, void *), void **ctxs, Vec X, PetscReal *diff)
    8708: {
    8709:   PetscFunctionBegin;
    8712:   PetscUseTypeMethod(dm, computel2diff, time, funcs, ctxs, X, diff);
    8713:   PetscFunctionReturn(PETSC_SUCCESS);
    8714: }

    8716: /*@C
    8717:   DMComputeL2GradientDiff - This function computes the L_2 difference between the gradient of a function u and an FEM interpolant solution grad u_h.

    8719:   Collective

    8721:   Input Parameters:
    8722: + dm    - The `DM`
    8723: . time  - The time
    8724: . funcs - The gradient functions to evaluate for each field component
    8725: . ctxs  - Optional array of contexts to pass to each function, or `NULL`.
    8726: . X     - The coefficient vector u_h, a global vector
    8727: - n     - The vector to project along

    8729:   Output Parameter:
    8730: . diff - The diff ||(grad u - grad u_h) . n||_2

    8732:   Level: developer

    8734:   Developer Notes:
    8735:   This API is specific to only particular usage of `DM`

    8737:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8739: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMComputeL2Diff()`, `DMComputeL2FieldDiff()`
    8740: @*/
    8741: PetscErrorCode DMComputeL2GradientDiff(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], const PetscReal[], PetscInt, PetscScalar *, void *), void **ctxs, Vec X, const PetscReal n[], PetscReal *diff)
    8742: {
    8743:   PetscFunctionBegin;
    8746:   PetscUseTypeMethod(dm, computel2gradientdiff, time, funcs, ctxs, X, n, diff);
    8747:   PetscFunctionReturn(PETSC_SUCCESS);
    8748: }

    8750: /*@C
    8751:   DMComputeL2FieldDiff - This function computes the L_2 difference between a function u and an FEM interpolant solution u_h, separated into field components.

    8753:   Collective

    8755:   Input Parameters:
    8756: + dm    - The `DM`
    8757: . time  - The time
    8758: . funcs - The functions to evaluate for each field component
    8759: . ctxs  - Optional array of contexts to pass to each function, or `NULL`.
    8760: - X     - The coefficient vector u_h, a global vector

    8762:   Output Parameter:
    8763: . diff - The array of differences, ||u^f - u^f_h||_2

    8765:   Level: developer

    8767:   Developer Notes:
    8768:   This API is specific to only particular usage of `DM`

    8770:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8772: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMComputeL2GradientDiff()`
    8773: @*/
    8774: PetscErrorCode DMComputeL2FieldDiff(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar *, void *), void **ctxs, Vec X, PetscReal diff[])
    8775: {
    8776:   PetscFunctionBegin;
    8779:   PetscUseTypeMethod(dm, computel2fielddiff, time, funcs, ctxs, X, diff);
    8780:   PetscFunctionReturn(PETSC_SUCCESS);
    8781: }

    8783: /*@C
    8784:   DMGetNeighbors - Gets an array containing the MPI ranks of all the processes neighbors

    8786:   Not Collective

    8788:   Input Parameter:
    8789: . dm - The `DM`

    8791:   Output Parameters:
    8792: + nranks - the number of neighbours
    8793: - ranks  - the neighbors ranks

    8795:   Level: beginner

    8797:   Note:
    8798:   Do not free the array, it is freed when the `DM` is destroyed.

    8800: .seealso: [](ch_dmbase), `DM`, `DMDAGetNeighbors()`, `PetscSFGetRootRanks()`
    8801: @*/
    8802: PetscErrorCode DMGetNeighbors(DM dm, PetscInt *nranks, const PetscMPIInt *ranks[])
    8803: {
    8804:   PetscFunctionBegin;
    8806:   PetscUseTypeMethod(dm, getneighbors, nranks, ranks);
    8807:   PetscFunctionReturn(PETSC_SUCCESS);
    8808: }

    8810: #include <petsc/private/matimpl.h>

    8812: /*
    8813:     Converts the input vector to a ghosted vector and then calls the standard coloring code.
    8814:     This must be a different function because it requires DM which is not defined in the Mat library
    8815: */
    8816: static PetscErrorCode MatFDColoringApply_AIJDM(Mat J, MatFDColoring coloring, Vec x1, void *sctx)
    8817: {
    8818:   PetscFunctionBegin;
    8819:   if (coloring->ctype == IS_COLORING_LOCAL) {
    8820:     Vec x1local;
    8821:     DM  dm;
    8822:     PetscCall(MatGetDM(J, &dm));
    8823:     PetscCheck(dm, PetscObjectComm((PetscObject)J), PETSC_ERR_ARG_INCOMP, "IS_COLORING_LOCAL requires a DM");
    8824:     PetscCall(DMGetLocalVector(dm, &x1local));
    8825:     PetscCall(DMGlobalToLocalBegin(dm, x1, INSERT_VALUES, x1local));
    8826:     PetscCall(DMGlobalToLocalEnd(dm, x1, INSERT_VALUES, x1local));
    8827:     x1 = x1local;
    8828:   }
    8829:   PetscCall(MatFDColoringApply_AIJ(J, coloring, x1, sctx));
    8830:   if (coloring->ctype == IS_COLORING_LOCAL) {
    8831:     DM dm;
    8832:     PetscCall(MatGetDM(J, &dm));
    8833:     PetscCall(DMRestoreLocalVector(dm, &x1));
    8834:   }
    8835:   PetscFunctionReturn(PETSC_SUCCESS);
    8836: }

    8838: /*@
    8839:   MatFDColoringUseDM - allows a `MatFDColoring` object to use the `DM` associated with the matrix to compute a `IS_COLORING_LOCAL` coloring

    8841:   Input Parameters:
    8842: + coloring   - The matrix to get the `DM` from
    8843: - fdcoloring - the `MatFDColoring` object

    8845:   Level: advanced

    8847:   Developer Note:
    8848:   This routine exists because the PETSc `Mat` library does not know about the `DM` objects

    8850: .seealso: [](ch_dmbase), `DM`, `MatFDColoring`, `MatFDColoringCreate()`, `ISColoringType`
    8851: @*/
    8852: PetscErrorCode MatFDColoringUseDM(Mat coloring, MatFDColoring fdcoloring)
    8853: {
    8854:   PetscFunctionBegin;
    8855:   coloring->ops->fdcoloringapply = MatFDColoringApply_AIJDM;
    8856:   PetscFunctionReturn(PETSC_SUCCESS);
    8857: }

    8859: /*@
    8860:   DMGetCompatibility - determine if two `DM`s are compatible

    8862:   Collective

    8864:   Input Parameters:
    8865: + dm1 - the first `DM`
    8866: - dm2 - the second `DM`

    8868:   Output Parameters:
    8869: + compatible - whether or not the two `DM`s are compatible
    8870: - set        - whether or not the compatible value was actually determined and set

    8872:   Level: advanced

    8874:   Notes:
    8875:   Two `DM`s are deemed compatible if they represent the same parallel decomposition
    8876:   of the same topology. This implies that the section (field data) on one
    8877:   "makes sense" with respect to the topology and parallel decomposition of the other.
    8878:   Loosely speaking, compatible `DM`s represent the same domain and parallel
    8879:   decomposition, but hold different data.

    8881:   Typically, one would confirm compatibility if intending to simultaneously iterate
    8882:   over a pair of vectors obtained from different `DM`s.

    8884:   For example, two `DMDA` objects are compatible if they have the same local
    8885:   and global sizes and the same stencil width. They can have different numbers
    8886:   of degrees of freedom per node. Thus, one could use the node numbering from
    8887:   either `DM` in bounds for a loop over vectors derived from either `DM`.

    8889:   Consider the operation of summing data living on a 2-dof `DMDA` to data living
    8890:   on a 1-dof `DMDA`, which should be compatible, as in the following snippet.
    8891: .vb
    8892:   ...
    8893:   PetscCall(DMGetCompatibility(da1,da2,&compatible,&set));
    8894:   if (set && compatible)  {
    8895:     PetscCall(DMDAVecGetArrayDOF(da1,vec1,&arr1));
    8896:     PetscCall(DMDAVecGetArrayDOF(da2,vec2,&arr2));
    8897:     PetscCall(DMDAGetCorners(da1,&x,&y,NULL,&m,&n,NULL));
    8898:     for (j=y; j<y+n; ++j) {
    8899:       for (i=x; i<x+m, ++i) {
    8900:         arr1[j][i][0] = arr2[j][i][0] + arr2[j][i][1];
    8901:       }
    8902:     }
    8903:     PetscCall(DMDAVecRestoreArrayDOF(da1,vec1,&arr1));
    8904:     PetscCall(DMDAVecRestoreArrayDOF(da2,vec2,&arr2));
    8905:   } else {
    8906:     SETERRQ(PetscObjectComm((PetscObject)da1,PETSC_ERR_ARG_INCOMP,"DMDA objects incompatible");
    8907:   }
    8908:   ...
    8909: .ve

    8911:   Checking compatibility might be expensive for a given implementation of `DM`,
    8912:   or might be impossible to unambiguously confirm or deny. For this reason,
    8913:   this function may decline to determine compatibility, and hence users should
    8914:   always check the "set" output parameter.

    8916:   A `DM` is always compatible with itself.

    8918:   In the current implementation, `DM`s which live on "unequal" communicators
    8919:   (MPI_UNEQUAL in the terminology of MPI_Comm_compare()) are always deemed
    8920:   incompatible.

    8922:   This function is labeled "Collective," as information about all subdomains
    8923:   is required on each rank. However, in `DM` implementations which store all this
    8924:   information locally, this function may be merely "Logically Collective".

    8926:   Developer Note:
    8927:   Compatibility is assumed to be a symmetric concept; `DM` A is compatible with `DM` B
    8928:   iff B is compatible with A. Thus, this function checks the implementations
    8929:   of both dm and dmc (if they are of different types), attempting to determine
    8930:   compatibility. It is left to `DM` implementers to ensure that symmetry is
    8931:   preserved. The simplest way to do this is, when implementing type-specific
    8932:   logic for this function, is to check for existing logic in the implementation
    8933:   of other `DM` types and let *set = PETSC_FALSE if found.

    8935: .seealso: [](ch_dmbase), `DM`, `DMDACreateCompatibleDMDA()`, `DMStagCreateCompatibleDMStag()`
    8936: @*/
    8937: PetscErrorCode DMGetCompatibility(DM dm1, DM dm2, PetscBool *compatible, PetscBool *set)
    8938: {
    8939:   PetscMPIInt compareResult;
    8940:   DMType      type, type2;
    8941:   PetscBool   sameType;

    8943:   PetscFunctionBegin;

    8947:   /* Declare a DM compatible with itself */
    8948:   if (dm1 == dm2) {
    8949:     *set        = PETSC_TRUE;
    8950:     *compatible = PETSC_TRUE;
    8951:     PetscFunctionReturn(PETSC_SUCCESS);
    8952:   }

    8954:   /* Declare a DM incompatible with a DM that lives on an "unequal"
    8955:      communicator. Note that this does not preclude compatibility with
    8956:      DMs living on "congruent" or "similar" communicators, but this must be
    8957:      determined by the implementation-specific logic */
    8958:   PetscCallMPI(MPI_Comm_compare(PetscObjectComm((PetscObject)dm1), PetscObjectComm((PetscObject)dm2), &compareResult));
    8959:   if (compareResult == MPI_UNEQUAL) {
    8960:     *set        = PETSC_TRUE;
    8961:     *compatible = PETSC_FALSE;
    8962:     PetscFunctionReturn(PETSC_SUCCESS);
    8963:   }

    8965:   /* Pass to the implementation-specific routine, if one exists. */
    8966:   if (dm1->ops->getcompatibility) {
    8967:     PetscUseTypeMethod(dm1, getcompatibility, dm2, compatible, set);
    8968:     if (*set) PetscFunctionReturn(PETSC_SUCCESS);
    8969:   }

    8971:   /* If dm1 and dm2 are of different types, then attempt to check compatibility
    8972:      with an implementation of this function from dm2 */
    8973:   PetscCall(DMGetType(dm1, &type));
    8974:   PetscCall(DMGetType(dm2, &type2));
    8975:   PetscCall(PetscStrcmp(type, type2, &sameType));
    8976:   if (!sameType && dm2->ops->getcompatibility) {
    8977:     PetscUseTypeMethod(dm2, getcompatibility, dm1, compatible, set); /* Note argument order */
    8978:   } else {
    8979:     *set = PETSC_FALSE;
    8980:   }
    8981:   PetscFunctionReturn(PETSC_SUCCESS);
    8982: }

    8984: /*@C
    8985:   DMMonitorSet - Sets an additional monitor function that is to be used after a solve to monitor discretization performance.

    8987:   Logically Collective

    8989:   Input Parameters:
    8990: + dm             - the `DM`
    8991: . f              - the monitor function
    8992: . mctx           - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
    8993: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence

    8995:   Options Database Key:
    8996: . -dm_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `DMMonitorSet()`, but
    8997:                        does not cancel those set via the options database.

    8999:   Level: intermediate

    9001:   Note:
    9002:   Several different monitoring routines may be set by calling
    9003:   `DMMonitorSet()` multiple times or with `DMMonitorSetFromOptions()`; all will be called in the
    9004:   order in which they were set.

    9006:   Fortran Note:
    9007:   Only a single monitor function can be set for each `DM` object

    9009:   Developer Note:
    9010:   This API has a generic name but seems specific to a very particular aspect of the use of `DM`

    9012: .seealso: [](ch_dmbase), `DM`, `DMMonitorCancel()`, `DMMonitorSetFromOptions()`, `DMMonitor()`, `PetscCtxDestroyFn`
    9013: @*/
    9014: PetscErrorCode DMMonitorSet(DM dm, PetscErrorCode (*f)(DM, void *), void *mctx, PetscCtxDestroyFn *monitordestroy)
    9015: {
    9016:   PetscFunctionBegin;
    9018:   for (PetscInt m = 0; m < dm->numbermonitors; ++m) {
    9019:     PetscBool identical;

    9021:     PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))(PetscVoidFn *)f, mctx, monitordestroy, (PetscErrorCode (*)(void))(PetscVoidFn *)dm->monitor[m], dm->monitorcontext[m], dm->monitordestroy[m], &identical));
    9022:     if (identical) PetscFunctionReturn(PETSC_SUCCESS);
    9023:   }
    9024:   PetscCheck(dm->numbermonitors < MAXDMMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
    9025:   dm->monitor[dm->numbermonitors]          = f;
    9026:   dm->monitordestroy[dm->numbermonitors]   = monitordestroy;
    9027:   dm->monitorcontext[dm->numbermonitors++] = mctx;
    9028:   PetscFunctionReturn(PETSC_SUCCESS);
    9029: }

    9031: /*@
    9032:   DMMonitorCancel - Clears all the monitor functions for a `DM` object.

    9034:   Logically Collective

    9036:   Input Parameter:
    9037: . dm - the DM

    9039:   Options Database Key:
    9040: . -dm_monitor_cancel - cancels all monitors that have been hardwired
    9041:   into a code by calls to `DMonitorSet()`, but does not cancel those
    9042:   set via the options database

    9044:   Level: intermediate

    9046:   Note:
    9047:   There is no way to clear one specific monitor from a `DM` object.

    9049: .seealso: [](ch_dmbase), `DM`, `DMMonitorSet()`, `DMMonitorSetFromOptions()`, `DMMonitor()`
    9050: @*/
    9051: PetscErrorCode DMMonitorCancel(DM dm)
    9052: {
    9053:   PetscInt m;

    9055:   PetscFunctionBegin;
    9057:   for (m = 0; m < dm->numbermonitors; ++m) {
    9058:     if (dm->monitordestroy[m]) PetscCall((*dm->monitordestroy[m])(&dm->monitorcontext[m]));
    9059:   }
    9060:   dm->numbermonitors = 0;
    9061:   PetscFunctionReturn(PETSC_SUCCESS);
    9062: }

    9064: /*@C
    9065:   DMMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user

    9067:   Collective

    9069:   Input Parameters:
    9070: + dm           - `DM` object you wish to monitor
    9071: . name         - the monitor type one is seeking
    9072: . help         - message indicating what monitoring is done
    9073: . manual       - manual page for the monitor
    9074: . monitor      - the monitor function, this must use a `PetscViewerFormat` as its context
    9075: - monitorsetup - a function that is called once ONLY if the user selected this monitor that may set additional features of the `DM` or `PetscViewer` objects

    9077:   Output Parameter:
    9078: . flg - Flag set if the monitor was created

    9080:   Level: developer

    9082: .seealso: [](ch_dmbase), `DM`, `PetscOptionsCreateViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
    9083:           `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`
    9084:           `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
    9085:           `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
    9086:           `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
    9087:           `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
    9088:           `PetscOptionsFList()`, `PetscOptionsEList()`, `DMMonitor()`, `DMMonitorSet()`
    9089: @*/
    9090: PetscErrorCode DMMonitorSetFromOptions(DM dm, const char name[], const char help[], const char manual[], PetscErrorCode (*monitor)(DM, void *), PetscErrorCode (*monitorsetup)(DM, PetscViewerAndFormat *), PetscBool *flg)
    9091: {
    9092:   PetscViewer       viewer;
    9093:   PetscViewerFormat format;

    9095:   PetscFunctionBegin;
    9097:   PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)dm), ((PetscObject)dm)->options, ((PetscObject)dm)->prefix, name, &viewer, &format, flg));
    9098:   if (*flg) {
    9099:     PetscViewerAndFormat *vf;

    9101:     PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
    9102:     PetscCall(PetscViewerDestroy(&viewer));
    9103:     if (monitorsetup) PetscCall((*monitorsetup)(dm, vf));
    9104:     PetscCall(DMMonitorSet(dm, monitor, vf, (PetscCtxDestroyFn *)PetscViewerAndFormatDestroy));
    9105:   }
    9106:   PetscFunctionReturn(PETSC_SUCCESS);
    9107: }

    9109: /*@
    9110:   DMMonitor - runs the user provided monitor routines, if they exist

    9112:   Collective

    9114:   Input Parameter:
    9115: . dm - The `DM`

    9117:   Level: developer

    9119:   Developer Note:
    9120:   Note should indicate when during the life of the `DM` the monitor is run. It appears to be
    9121:   related to the discretization process seems rather specialized since some `DM` have no
    9122:   concept of discretization.

    9124: .seealso: [](ch_dmbase), `DM`, `DMMonitorSet()`, `DMMonitorSetFromOptions()`
    9125: @*/
    9126: PetscErrorCode DMMonitor(DM dm)
    9127: {
    9128:   PetscInt m;

    9130:   PetscFunctionBegin;
    9131:   if (!dm) PetscFunctionReturn(PETSC_SUCCESS);
    9133:   for (m = 0; m < dm->numbermonitors; ++m) PetscCall((*dm->monitor[m])(dm, dm->monitorcontext[m]));
    9134:   PetscFunctionReturn(PETSC_SUCCESS);
    9135: }

    9137: /*@
    9138:   DMComputeError - Computes the error assuming the user has provided the exact solution functions

    9140:   Collective

    9142:   Input Parameters:
    9143: + dm  - The `DM`
    9144: - sol - The solution vector

    9146:   Input/Output Parameter:
    9147: . errors - An array of length Nf, the number of fields, or `NULL` for no output; on output
    9148:            contains the error in each field

    9150:   Output Parameter:
    9151: . errorVec - A vector to hold the cellwise error (may be `NULL`)

    9153:   Level: developer

    9155:   Note:
    9156:   The exact solutions come from the `PetscDS` object, and the time comes from `DMGetOutputSequenceNumber()`.

    9158: .seealso: [](ch_dmbase), `DM`, `DMMonitorSet()`, `DMGetRegionNumDS()`, `PetscDSGetExactSolution()`, `DMGetOutputSequenceNumber()`
    9159: @*/
    9160: PetscErrorCode DMComputeError(DM dm, Vec sol, PetscReal errors[], Vec *errorVec)
    9161: {
    9162:   PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
    9163:   void    **ctxs;
    9164:   PetscReal time;
    9165:   PetscInt  Nf, f, Nds, s;

    9167:   PetscFunctionBegin;
    9168:   PetscCall(DMGetNumFields(dm, &Nf));
    9169:   PetscCall(PetscCalloc2(Nf, &exactSol, Nf, &ctxs));
    9170:   PetscCall(DMGetNumDS(dm, &Nds));
    9171:   for (s = 0; s < Nds; ++s) {
    9172:     PetscDS         ds;
    9173:     DMLabel         label;
    9174:     IS              fieldIS;
    9175:     const PetscInt *fields;
    9176:     PetscInt        dsNf;

    9178:     PetscCall(DMGetRegionNumDS(dm, s, &label, &fieldIS, &ds, NULL));
    9179:     PetscCall(PetscDSGetNumFields(ds, &dsNf));
    9180:     if (fieldIS) PetscCall(ISGetIndices(fieldIS, &fields));
    9181:     for (f = 0; f < dsNf; ++f) {
    9182:       const PetscInt field = fields[f];
    9183:       PetscCall(PetscDSGetExactSolution(ds, field, &exactSol[field], &ctxs[field]));
    9184:     }
    9185:     if (fieldIS) PetscCall(ISRestoreIndices(fieldIS, &fields));
    9186:   }
    9187:   for (f = 0; f < Nf; ++f) PetscCheck(exactSol[f], PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "DS must contain exact solution functions in order to calculate error, missing for field %" PetscInt_FMT, f);
    9188:   PetscCall(DMGetOutputSequenceNumber(dm, NULL, &time));
    9189:   if (errors) PetscCall(DMComputeL2FieldDiff(dm, time, exactSol, ctxs, sol, errors));
    9190:   if (errorVec) {
    9191:     DM             edm;
    9192:     DMPolytopeType ct;
    9193:     PetscBool      simplex;
    9194:     PetscInt       dim, cStart, Nf;

    9196:     PetscCall(DMClone(dm, &edm));
    9197:     PetscCall(DMGetDimension(edm, &dim));
    9198:     PetscCall(DMPlexGetHeightStratum(dm, 0, &cStart, NULL));
    9199:     PetscCall(DMPlexGetCellType(dm, cStart, &ct));
    9200:     simplex = DMPolytopeTypeGetNumVertices(ct) == DMPolytopeTypeGetDim(ct) + 1 ? PETSC_TRUE : PETSC_FALSE;
    9201:     PetscCall(DMGetNumFields(dm, &Nf));
    9202:     for (f = 0; f < Nf; ++f) {
    9203:       PetscFE         fe, efe;
    9204:       PetscQuadrature q;
    9205:       const char     *name;

    9207:       PetscCall(DMGetField(dm, f, NULL, (PetscObject *)&fe));
    9208:       PetscCall(PetscFECreateLagrange(PETSC_COMM_SELF, dim, Nf, simplex, 0, PETSC_DETERMINE, &efe));
    9209:       PetscCall(PetscObjectGetName((PetscObject)fe, &name));
    9210:       PetscCall(PetscObjectSetName((PetscObject)efe, name));
    9211:       PetscCall(PetscFEGetQuadrature(fe, &q));
    9212:       PetscCall(PetscFESetQuadrature(efe, q));
    9213:       PetscCall(DMSetField(edm, f, NULL, (PetscObject)efe));
    9214:       PetscCall(PetscFEDestroy(&efe));
    9215:     }
    9216:     PetscCall(DMCreateDS(edm));

    9218:     PetscCall(DMCreateGlobalVector(edm, errorVec));
    9219:     PetscCall(PetscObjectSetName((PetscObject)*errorVec, "Error"));
    9220:     PetscCall(DMPlexComputeL2DiffVec(dm, time, exactSol, ctxs, sol, *errorVec));
    9221:     PetscCall(DMDestroy(&edm));
    9222:   }
    9223:   PetscCall(PetscFree2(exactSol, ctxs));
    9224:   PetscFunctionReturn(PETSC_SUCCESS);
    9225: }

    9227: /*@
    9228:   DMGetNumAuxiliaryVec - Get the number of auxiliary vectors associated with this `DM`

    9230:   Not Collective

    9232:   Input Parameter:
    9233: . dm - The `DM`

    9235:   Output Parameter:
    9236: . numAux - The number of auxiliary data vectors

    9238:   Level: advanced

    9240: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMSetAuxiliaryVec()`, `DMGetAuxiliaryLabels()`, `DMGetAuxiliaryVec()`
    9241: @*/
    9242: PetscErrorCode DMGetNumAuxiliaryVec(DM dm, PetscInt *numAux)
    9243: {
    9244:   PetscFunctionBegin;
    9246:   PetscCall(PetscHMapAuxGetSize(dm->auxData, numAux));
    9247:   PetscFunctionReturn(PETSC_SUCCESS);
    9248: }

    9250: /*@
    9251:   DMGetAuxiliaryVec - Get the auxiliary vector for region specified by the given label and value, and equation part

    9253:   Not Collective

    9255:   Input Parameters:
    9256: + dm    - The `DM`
    9257: . label - The `DMLabel`
    9258: . value - The label value indicating the region
    9259: - part  - The equation part, or 0 if unused

    9261:   Output Parameter:
    9262: . aux - The `Vec` holding auxiliary field data

    9264:   Level: advanced

    9266:   Note:
    9267:   If no auxiliary vector is found for this (label, value), (`NULL`, 0, 0) is checked as well.

    9269: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMSetAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryLabels()`
    9270: @*/
    9271: PetscErrorCode DMGetAuxiliaryVec(DM dm, DMLabel label, PetscInt value, PetscInt part, Vec *aux)
    9272: {
    9273:   PetscHashAuxKey key, wild = {NULL, 0, 0};
    9274:   PetscBool       has;

    9276:   PetscFunctionBegin;
    9279:   key.label = label;
    9280:   key.value = value;
    9281:   key.part  = part;
    9282:   PetscCall(PetscHMapAuxHas(dm->auxData, key, &has));
    9283:   if (has) PetscCall(PetscHMapAuxGet(dm->auxData, key, aux));
    9284:   else PetscCall(PetscHMapAuxGet(dm->auxData, wild, aux));
    9285:   PetscFunctionReturn(PETSC_SUCCESS);
    9286: }

    9288: /*@
    9289:   DMSetAuxiliaryVec - Set an auxiliary vector for region specified by the given label and value, and equation part

    9291:   Not Collective because auxiliary vectors are not parallel

    9293:   Input Parameters:
    9294: + dm    - The `DM`
    9295: . label - The `DMLabel`
    9296: . value - The label value indicating the region
    9297: . part  - The equation part, or 0 if unused
    9298: - aux   - The `Vec` holding auxiliary field data

    9300:   Level: advanced

    9302: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMGetAuxiliaryLabels()`, `DMCopyAuxiliaryVec()`
    9303: @*/
    9304: PetscErrorCode DMSetAuxiliaryVec(DM dm, DMLabel label, PetscInt value, PetscInt part, Vec aux)
    9305: {
    9306:   Vec             old;
    9307:   PetscHashAuxKey key;

    9309:   PetscFunctionBegin;
    9312:   key.label = label;
    9313:   key.value = value;
    9314:   key.part  = part;
    9315:   PetscCall(PetscHMapAuxGet(dm->auxData, key, &old));
    9316:   PetscCall(PetscObjectReference((PetscObject)aux));
    9317:   if (!aux) PetscCall(PetscHMapAuxDel(dm->auxData, key));
    9318:   else PetscCall(PetscHMapAuxSet(dm->auxData, key, aux));
    9319:   PetscCall(VecDestroy(&old));
    9320:   PetscFunctionReturn(PETSC_SUCCESS);
    9321: }

    9323: /*@
    9324:   DMGetAuxiliaryLabels - Get the labels, values, and parts for all auxiliary vectors in this `DM`

    9326:   Not Collective

    9328:   Input Parameter:
    9329: . dm - The `DM`

    9331:   Output Parameters:
    9332: + labels - The `DMLabel`s for each `Vec`
    9333: . values - The label values for each `Vec`
    9334: - parts  - The equation parts for each `Vec`

    9336:   Level: advanced

    9338:   Note:
    9339:   The arrays passed in must be at least as large as `DMGetNumAuxiliaryVec()`.

    9341: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMSetAuxiliaryVec()`, `DMCopyAuxiliaryVec()`
    9342: @*/
    9343: PetscErrorCode DMGetAuxiliaryLabels(DM dm, DMLabel labels[], PetscInt values[], PetscInt parts[])
    9344: {
    9345:   PetscHashAuxKey *keys;
    9346:   PetscInt         n, i, off = 0;

    9348:   PetscFunctionBegin;
    9350:   PetscAssertPointer(labels, 2);
    9351:   PetscAssertPointer(values, 3);
    9352:   PetscAssertPointer(parts, 4);
    9353:   PetscCall(DMGetNumAuxiliaryVec(dm, &n));
    9354:   PetscCall(PetscMalloc1(n, &keys));
    9355:   PetscCall(PetscHMapAuxGetKeys(dm->auxData, &off, keys));
    9356:   for (i = 0; i < n; ++i) {
    9357:     labels[i] = keys[i].label;
    9358:     values[i] = keys[i].value;
    9359:     parts[i]  = keys[i].part;
    9360:   }
    9361:   PetscCall(PetscFree(keys));
    9362:   PetscFunctionReturn(PETSC_SUCCESS);
    9363: }

    9365: /*@
    9366:   DMCopyAuxiliaryVec - Copy the auxiliary vector data on a `DM` to a new `DM`

    9368:   Not Collective

    9370:   Input Parameter:
    9371: . dm - The `DM`

    9373:   Output Parameter:
    9374: . dmNew - The new `DM`, now with the same auxiliary data

    9376:   Level: advanced

    9378:   Note:
    9379:   This is a shallow copy of the auxiliary vectors

    9381: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMSetAuxiliaryVec()`
    9382: @*/
    9383: PetscErrorCode DMCopyAuxiliaryVec(DM dm, DM dmNew)
    9384: {
    9385:   PetscFunctionBegin;
    9388:   if (dm == dmNew) PetscFunctionReturn(PETSC_SUCCESS);
    9389:   PetscCall(DMClearAuxiliaryVec(dmNew));

    9391:   PetscCall(PetscHMapAuxDestroy(&dmNew->auxData));
    9392:   PetscCall(PetscHMapAuxDuplicate(dm->auxData, &dmNew->auxData));
    9393:   {
    9394:     Vec     *auxData;
    9395:     PetscInt n, i, off = 0;

    9397:     PetscCall(PetscHMapAuxGetSize(dmNew->auxData, &n));
    9398:     PetscCall(PetscMalloc1(n, &auxData));
    9399:     PetscCall(PetscHMapAuxGetVals(dmNew->auxData, &off, auxData));
    9400:     for (i = 0; i < n; ++i) PetscCall(PetscObjectReference((PetscObject)auxData[i]));
    9401:     PetscCall(PetscFree(auxData));
    9402:   }
    9403:   PetscFunctionReturn(PETSC_SUCCESS);
    9404: }

    9406: /*@
    9407:   DMClearAuxiliaryVec - Destroys the auxiliary vector information and creates a new empty one

    9409:   Not Collective

    9411:   Input Parameter:
    9412: . dm - The `DM`

    9414:   Level: advanced

    9416: .seealso: [](ch_dmbase), `DM`, `DMCopyAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMSetAuxiliaryVec()`
    9417: @*/
    9418: PetscErrorCode DMClearAuxiliaryVec(DM dm)
    9419: {
    9420:   Vec     *auxData;
    9421:   PetscInt n, i, off = 0;

    9423:   PetscFunctionBegin;
    9424:   PetscCall(PetscHMapAuxGetSize(dm->auxData, &n));
    9425:   PetscCall(PetscMalloc1(n, &auxData));
    9426:   PetscCall(PetscHMapAuxGetVals(dm->auxData, &off, auxData));
    9427:   for (i = 0; i < n; ++i) PetscCall(VecDestroy(&auxData[i]));
    9428:   PetscCall(PetscFree(auxData));
    9429:   PetscCall(PetscHMapAuxDestroy(&dm->auxData));
    9430:   PetscCall(PetscHMapAuxCreate(&dm->auxData));
    9431:   PetscFunctionReturn(PETSC_SUCCESS);
    9432: }

    9434: /*@
    9435:   DMPolytopeMatchOrientation - Determine an orientation (transformation) that takes the source face arrangement to the target face arrangement

    9437:   Not Collective

    9439:   Input Parameters:
    9440: + ct         - The `DMPolytopeType`
    9441: . sourceCone - The source arrangement of faces
    9442: - targetCone - The target arrangement of faces

    9444:   Output Parameters:
    9445: + ornt  - The orientation (transformation) which will take the source arrangement to the target arrangement
    9446: - found - Flag indicating that a suitable orientation was found

    9448:   Level: advanced

    9450:   Note:
    9451:   An arrangement is a face order combined with an orientation for each face

    9453:   Each orientation (transformation) is labeled with an integer from negative `DMPolytopeTypeGetNumArrangements(ct)`/2 to `DMPolytopeTypeGetNumArrangements(ct)`/2
    9454:   that labels each arrangement (face ordering plus orientation for each face).

    9456:   See `DMPolytopeMatchVertexOrientation()` to find a new vertex orientation that takes the source vertex arrangement to the target vertex arrangement

    9458: .seealso: [](ch_dmbase), `DM`, `DMPolytopeGetOrientation()`, `DMPolytopeMatchVertexOrientation()`, `DMPolytopeGetVertexOrientation()`
    9459: @*/
    9460: PetscErrorCode DMPolytopeMatchOrientation(DMPolytopeType ct, const PetscInt sourceCone[], const PetscInt targetCone[], PetscInt *ornt, PetscBool *found)
    9461: {
    9462:   const PetscInt cS = DMPolytopeTypeGetConeSize(ct);
    9463:   const PetscInt nO = DMPolytopeTypeGetNumArrangements(ct) / 2;
    9464:   PetscInt       o, c;

    9466:   PetscFunctionBegin;
    9467:   if (!nO) {
    9468:     *ornt  = 0;
    9469:     *found = PETSC_TRUE;
    9470:     PetscFunctionReturn(PETSC_SUCCESS);
    9471:   }
    9472:   for (o = -nO; o < nO; ++o) {
    9473:     const PetscInt *arr = DMPolytopeTypeGetArrangement(ct, o);

    9475:     for (c = 0; c < cS; ++c)
    9476:       if (sourceCone[arr[c * 2]] != targetCone[c]) break;
    9477:     if (c == cS) {
    9478:       *ornt = o;
    9479:       break;
    9480:     }
    9481:   }
    9482:   *found = o == nO ? PETSC_FALSE : PETSC_TRUE;
    9483:   PetscFunctionReturn(PETSC_SUCCESS);
    9484: }

    9486: /*@
    9487:   DMPolytopeGetOrientation - Determine an orientation (transformation) that takes the source face arrangement to the target face arrangement

    9489:   Not Collective

    9491:   Input Parameters:
    9492: + ct         - The `DMPolytopeType`
    9493: . sourceCone - The source arrangement of faces
    9494: - targetCone - The target arrangement of faces

    9496:   Output Parameter:
    9497: . ornt - The orientation (transformation) which will take the source arrangement to the target arrangement

    9499:   Level: advanced

    9501:   Note:
    9502:   This function is the same as `DMPolytopeMatchOrientation()` except it will generate an error if no suitable orientation can be found.

    9504:   Developer Note:
    9505:   It is unclear why this function needs to exist since one can simply call `DMPolytopeMatchOrientation()` and error if none is found

    9507: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMPolytopeMatchOrientation()`, `DMPolytopeGetVertexOrientation()`, `DMPolytopeMatchVertexOrientation()`
    9508: @*/
    9509: PetscErrorCode DMPolytopeGetOrientation(DMPolytopeType ct, const PetscInt sourceCone[], const PetscInt targetCone[], PetscInt *ornt)
    9510: {
    9511:   PetscBool found;

    9513:   PetscFunctionBegin;
    9514:   PetscCall(DMPolytopeMatchOrientation(ct, sourceCone, targetCone, ornt, &found));
    9515:   PetscCheck(found, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find orientation for %s", DMPolytopeTypes[ct]);
    9516:   PetscFunctionReturn(PETSC_SUCCESS);
    9517: }

    9519: /*@
    9520:   DMPolytopeMatchVertexOrientation - Determine an orientation (transformation) that takes the source vertex arrangement to the target vertex arrangement

    9522:   Not Collective

    9524:   Input Parameters:
    9525: + ct         - The `DMPolytopeType`
    9526: . sourceVert - The source arrangement of vertices
    9527: - targetVert - The target arrangement of vertices

    9529:   Output Parameters:
    9530: + ornt  - The orientation (transformation) which will take the source arrangement to the target arrangement
    9531: - found - Flag indicating that a suitable orientation was found

    9533:   Level: advanced

    9535:   Notes:
    9536:   An arrangement is a vertex order

    9538:   Each orientation (transformation) is labeled with an integer from negative `DMPolytopeTypeGetNumArrangements(ct)`/2 to `DMPolytopeTypeGetNumArrangements(ct)`/2
    9539:   that labels each arrangement (vertex ordering).

    9541:   See `DMPolytopeMatchOrientation()` to find a new face orientation that takes the source face arrangement to the target face arrangement

    9543: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMPolytopeGetOrientation()`, `DMPolytopeMatchOrientation()`, `DMPolytopeTypeGetNumVertices()`, `DMPolytopeTypeGetVertexArrangement()`
    9544: @*/
    9545: PetscErrorCode DMPolytopeMatchVertexOrientation(DMPolytopeType ct, const PetscInt sourceVert[], const PetscInt targetVert[], PetscInt *ornt, PetscBool *found)
    9546: {
    9547:   const PetscInt cS = DMPolytopeTypeGetNumVertices(ct);
    9548:   const PetscInt nO = DMPolytopeTypeGetNumArrangements(ct) / 2;
    9549:   PetscInt       o, c;

    9551:   PetscFunctionBegin;
    9552:   if (!nO) {
    9553:     *ornt  = 0;
    9554:     *found = PETSC_TRUE;
    9555:     PetscFunctionReturn(PETSC_SUCCESS);
    9556:   }
    9557:   for (o = -nO; o < nO; ++o) {
    9558:     const PetscInt *arr = DMPolytopeTypeGetVertexArrangement(ct, o);

    9560:     for (c = 0; c < cS; ++c)
    9561:       if (sourceVert[arr[c]] != targetVert[c]) break;
    9562:     if (c == cS) {
    9563:       *ornt = o;
    9564:       break;
    9565:     }
    9566:   }
    9567:   *found = o == nO ? PETSC_FALSE : PETSC_TRUE;
    9568:   PetscFunctionReturn(PETSC_SUCCESS);
    9569: }

    9571: /*@
    9572:   DMPolytopeGetVertexOrientation - Determine an orientation (transformation) that takes the source vertex arrangement to the target vertex arrangement

    9574:   Not Collective

    9576:   Input Parameters:
    9577: + ct         - The `DMPolytopeType`
    9578: . sourceCone - The source arrangement of vertices
    9579: - targetCone - The target arrangement of vertices

    9581:   Output Parameter:
    9582: . ornt - The orientation (transformation) which will take the source arrangement to the target arrangement

    9584:   Level: advanced

    9586:   Note:
    9587:   This function is the same as `DMPolytopeMatchVertexOrientation()` except it errors if not orientation is possible.

    9589:   Developer Note:
    9590:   It is unclear why this function needs to exist since one can simply call `DMPolytopeMatchVertexOrientation()` and error if none is found

    9592: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMPolytopeMatchVertexOrientation()`, `DMPolytopeGetOrientation()`
    9593: @*/
    9594: PetscErrorCode DMPolytopeGetVertexOrientation(DMPolytopeType ct, const PetscInt sourceCone[], const PetscInt targetCone[], PetscInt *ornt)
    9595: {
    9596:   PetscBool found;

    9598:   PetscFunctionBegin;
    9599:   PetscCall(DMPolytopeMatchVertexOrientation(ct, sourceCone, targetCone, ornt, &found));
    9600:   PetscCheck(found, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find orientation for %s", DMPolytopeTypes[ct]);
    9601:   PetscFunctionReturn(PETSC_SUCCESS);
    9602: }

    9604: /*@
    9605:   DMPolytopeInCellTest - Check whether a point lies inside the reference cell of given type

    9607:   Not Collective

    9609:   Input Parameters:
    9610: + ct    - The `DMPolytopeType`
    9611: - point - Coordinates of the point

    9613:   Output Parameter:
    9614: . inside - Flag indicating whether the point is inside the reference cell of given type

    9616:   Level: advanced

    9618: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMLocatePoints()`
    9619: @*/
    9620: PetscErrorCode DMPolytopeInCellTest(DMPolytopeType ct, const PetscReal point[], PetscBool *inside)
    9621: {
    9622:   PetscReal sum = 0.0;
    9623:   PetscInt  d;

    9625:   PetscFunctionBegin;
    9626:   *inside = PETSC_TRUE;
    9627:   switch (ct) {
    9628:   case DM_POLYTOPE_TRIANGLE:
    9629:   case DM_POLYTOPE_TETRAHEDRON:
    9630:     for (d = 0; d < DMPolytopeTypeGetDim(ct); ++d) {
    9631:       if (point[d] < -1.0) {
    9632:         *inside = PETSC_FALSE;
    9633:         break;
    9634:       }
    9635:       sum += point[d];
    9636:     }
    9637:     if (sum > PETSC_SMALL) {
    9638:       *inside = PETSC_FALSE;
    9639:       break;
    9640:     }
    9641:     break;
    9642:   case DM_POLYTOPE_QUADRILATERAL:
    9643:   case DM_POLYTOPE_HEXAHEDRON:
    9644:     for (d = 0; d < DMPolytopeTypeGetDim(ct); ++d)
    9645:       if (PetscAbsReal(point[d]) > 1. + PETSC_SMALL) {
    9646:         *inside = PETSC_FALSE;
    9647:         break;
    9648:       }
    9649:     break;
    9650:   default:
    9651:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unsupported polytope type %s", DMPolytopeTypes[ct]);
    9652:   }
    9653:   PetscFunctionReturn(PETSC_SUCCESS);
    9654: }

    9656: /*@
    9657:   DMReorderSectionSetDefault - Set flag indicating whether the local section should be reordered by default

    9659:   Logically collective

    9661:   Input Parameters:
    9662: + dm      - The DM
    9663: - reorder - Flag for reordering

    9665:   Level: intermediate

    9667: .seealso: `DMReorderSectionGetDefault()`
    9668: @*/
    9669: PetscErrorCode DMReorderSectionSetDefault(DM dm, DMReorderDefaultFlag reorder)
    9670: {
    9671:   PetscFunctionBegin;
    9673:   PetscTryMethod(dm, "DMReorderSectionSetDefault_C", (DM, DMReorderDefaultFlag), (dm, reorder));
    9674:   PetscFunctionReturn(PETSC_SUCCESS);
    9675: }

    9677: /*@
    9678:   DMReorderSectionGetDefault - Get flag indicating whether the local section should be reordered by default

    9680:   Not collective

    9682:   Input Parameter:
    9683: . dm - The DM

    9685:   Output Parameter:
    9686: . reorder - Flag for reordering

    9688:   Level: intermediate

    9690: .seealso: `DMReorderSetDefault()`
    9691: @*/
    9692: PetscErrorCode DMReorderSectionGetDefault(DM dm, DMReorderDefaultFlag *reorder)
    9693: {
    9694:   PetscFunctionBegin;
    9696:   PetscAssertPointer(reorder, 2);
    9697:   *reorder = DM_REORDER_DEFAULT_NOTSET;
    9698:   PetscTryMethod(dm, "DMReorderSectionGetDefault_C", (DM, DMReorderDefaultFlag *), (dm, reorder));
    9699:   PetscFunctionReturn(PETSC_SUCCESS);
    9700: }

    9702: /*@
    9703:   DMReorderSectionSetType - Set the type of local section reordering

    9705:   Logically collective

    9707:   Input Parameters:
    9708: + dm      - The DM
    9709: - reorder - The reordering method

    9711:   Level: intermediate

    9713: .seealso: `DMReorderSectionGetType()`, `DMReorderSectionSetDefault()`
    9714: @*/
    9715: PetscErrorCode DMReorderSectionSetType(DM dm, MatOrderingType reorder)
    9716: {
    9717:   PetscFunctionBegin;
    9719:   PetscTryMethod(dm, "DMReorderSectionSetType_C", (DM, MatOrderingType), (dm, reorder));
    9720:   PetscFunctionReturn(PETSC_SUCCESS);
    9721: }

    9723: /*@
    9724:   DMReorderSectionGetType - Get the reordering type for the local section

    9726:   Not collective

    9728:   Input Parameter:
    9729: . dm - The DM

    9731:   Output Parameter:
    9732: . reorder - The reordering method

    9734:   Level: intermediate

    9736: .seealso: `DMReorderSetDefault()`, `DMReorderSectionGetDefault()`
    9737: @*/
    9738: PetscErrorCode DMReorderSectionGetType(DM dm, MatOrderingType *reorder)
    9739: {
    9740:   PetscFunctionBegin;
    9742:   PetscAssertPointer(reorder, 2);
    9743:   *reorder = NULL;
    9744:   PetscTryMethod(dm, "DMReorderSectionGetType_C", (DM, MatOrderingType *), (dm, reorder));
    9745:   PetscFunctionReturn(PETSC_SUCCESS);
    9746: }