Actual source code: dmimpl.h
petsc-3.12.4 2020-02-04
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      3: #if !defined(_DMIMPL_H)
      4: #define _DMIMPL_H

      6:  #include <petscdm.h>
      7:  #include <petsc/private/petscimpl.h>
      8:  #include <petsc/private/petscdsimpl.h>
      9:  #include <petsc/private/sectionimpl.h>

     11: PETSC_EXTERN PetscBool DMRegisterAllCalled;
     12: PETSC_EXTERN PetscErrorCode DMRegisterAll(void);
     13: typedef PetscErrorCode (*NullSpaceFunc)(DM dm, PetscInt field, MatNullSpace *nullSpace);

     15: typedef struct _DMOps *DMOps;
     16: struct _DMOps {
     17:   PetscErrorCode (*view)(DM,PetscViewer);
     18:   PetscErrorCode (*load)(DM,PetscViewer);
     19:   PetscErrorCode (*clone)(DM,DM*);
     20:   PetscErrorCode (*setfromoptions)(PetscOptionItems*,DM);
     21:   PetscErrorCode (*setup)(DM);
     22:   PetscErrorCode (*createlocalsection)(DM);
     23:   PetscErrorCode (*createdefaultconstraints)(DM);
     24:   PetscErrorCode (*createglobalvector)(DM,Vec*);
     25:   PetscErrorCode (*createlocalvector)(DM,Vec*);
     26:   PetscErrorCode (*getlocaltoglobalmapping)(DM);
     27:   PetscErrorCode (*createfieldis)(DM,PetscInt*,char***,IS**);
     28:   PetscErrorCode (*createcoordinatedm)(DM,DM*);
     29:   PetscErrorCode (*createcoordinatefield)(DM,DMField*);

     31:   PetscErrorCode (*getcoloring)(DM,ISColoringType,ISColoring*);
     32:   PetscErrorCode (*creatematrix)(DM, Mat*);
     33:   PetscErrorCode (*createinterpolation)(DM,DM,Mat*,Vec*);
     34:   PetscErrorCode (*createrestriction)(DM,DM,Mat*);
     35:   PetscErrorCode (*createmassmatrix)(DM,DM,Mat*);
     36:   PetscErrorCode (*hascreateinjection)(DM,PetscBool*);
     37:   PetscErrorCode (*createinjection)(DM,DM,Mat*);

     39:   PetscErrorCode (*refine)(DM,MPI_Comm,DM*);
     40:   PetscErrorCode (*coarsen)(DM,MPI_Comm,DM*);
     41:   PetscErrorCode (*refinehierarchy)(DM,PetscInt,DM*);
     42:   PetscErrorCode (*coarsenhierarchy)(DM,PetscInt,DM*);
     43:   PetscErrorCode (*adaptlabel)(DM,DMLabel,DM*);
     44:   PetscErrorCode (*adaptmetric)(DM,Vec,DMLabel,DM*);

     46:   PetscErrorCode (*globaltolocalbegin)(DM,Vec,InsertMode,Vec);
     47:   PetscErrorCode (*globaltolocalend)(DM,Vec,InsertMode,Vec);
     48:   PetscErrorCode (*localtoglobalbegin)(DM,Vec,InsertMode,Vec);
     49:   PetscErrorCode (*localtoglobalend)(DM,Vec,InsertMode,Vec);
     50:   PetscErrorCode (*localtolocalbegin)(DM,Vec,InsertMode,Vec);
     51:   PetscErrorCode (*localtolocalend)(DM,Vec,InsertMode,Vec);

     53:   PetscErrorCode (*destroy)(DM);

     55:   PetscErrorCode (*computevariablebounds)(DM,Vec,Vec);

     57:   PetscErrorCode (*createsubdm)(DM,PetscInt,const PetscInt*,IS*,DM*);
     58:   PetscErrorCode (*createsuperdm)(DM*,PetscInt,IS**,DM*);
     59:   PetscErrorCode (*createfielddecomposition)(DM,PetscInt*,char***,IS**,DM**);
     60:   PetscErrorCode (*createdomaindecomposition)(DM,PetscInt*,char***,IS**,IS**,DM**);
     61:   PetscErrorCode (*createddscatters)(DM,PetscInt,DM*,VecScatter**,VecScatter**,VecScatter**);

     63:   PetscErrorCode (*getdimpoints)(DM,PetscInt,PetscInt*,PetscInt*);
     64:   PetscErrorCode (*locatepoints)(DM,Vec,DMPointLocationType,PetscSF);
     65:   PetscErrorCode (*getneighbors)(DM,PetscInt*,const PetscMPIInt**);
     66:   PetscErrorCode (*getboundingbox)(DM,PetscReal*,PetscReal*);
     67:   PetscErrorCode (*getlocalboundingbox)(DM,PetscReal*,PetscReal*);
     68:   PetscErrorCode (*locatepointssubdomain)(DM,Vec,PetscMPIInt**);

     70:   PetscErrorCode (*projectfunctionlocal)(DM,PetscReal,PetscErrorCode(**)(PetscInt,PetscReal,const PetscReal[],PetscInt,PetscScalar *,void *),void **,InsertMode,Vec);
     71:   PetscErrorCode (*projectfunctionlabellocal)(DM,PetscReal,DMLabel,PetscInt,const PetscInt[],PetscInt,const PetscInt[],PetscErrorCode(**)(PetscInt,PetscReal,const PetscReal[],PetscInt,PetscScalar *,void *),void **,InsertMode,Vec);
     72:   PetscErrorCode (*projectfieldlocal)(DM,PetscReal,Vec,void(**)(PetscInt,PetscInt,PetscInt,const PetscInt[],const PetscInt[],const PetscScalar[],const PetscScalar[],const PetscScalar[],const PetscInt[],const PetscInt[],const PetscScalar[],const PetscScalar[],const PetscScalar[],PetscReal,const PetscReal[],PetscInt,const PetscScalar[],PetscScalar[]),InsertMode,Vec);
     73:   PetscErrorCode (*projectfieldlabellocal)(DM,PetscReal,DMLabel,PetscInt,const PetscInt[],PetscInt,const PetscInt[],Vec,void(**)(PetscInt,PetscInt,PetscInt,const PetscInt[],const PetscInt[],const PetscScalar[],const PetscScalar[],const PetscScalar[],const PetscInt[],const PetscInt[],const PetscScalar[],const PetscScalar[],const PetscScalar[],PetscReal,const PetscReal[],PetscInt,const PetscScalar[],PetscScalar[]),InsertMode,Vec);
     74:   PetscErrorCode (*computel2diff)(DM,PetscReal,PetscErrorCode(**)(PetscInt, PetscReal,const PetscReal [], PetscInt, PetscScalar *, void *), void **, Vec, PetscReal *);
     75:   PetscErrorCode (*computel2gradientdiff)(DM,PetscReal,PetscErrorCode(**)(PetscInt,PetscReal,const PetscReal [],const PetscReal[],PetscInt, PetscScalar *,void *),void **,Vec,const PetscReal[],PetscReal *);
     76:   PetscErrorCode (*computel2fielddiff)(DM,PetscReal,PetscErrorCode(**)(PetscInt, PetscReal,const PetscReal [], PetscInt, PetscScalar *, void *), void **, Vec, PetscReal *);

     78:   PetscErrorCode (*getcompatibility)(DM,DM,PetscBool*,PetscBool*);
     79: };

     81: PETSC_EXTERN PetscErrorCode DMLocalizeCoordinate_Internal(DM, PetscInt, const PetscScalar[], const PetscScalar[], PetscScalar[]);
     82: PETSC_EXTERN PetscErrorCode DMLocalizeCoordinateReal_Internal(DM, PetscInt, const PetscReal[], const PetscReal[], PetscReal[]);
     83: PETSC_EXTERN PetscErrorCode DMLocalizeAddCoordinate_Internal(DM, PetscInt, const PetscScalar[], const PetscScalar[], PetscScalar[]);

     85: typedef struct _DMCoarsenHookLink *DMCoarsenHookLink;
     86: struct _DMCoarsenHookLink {
     87:   PetscErrorCode (*coarsenhook)(DM,DM,void*);              /* Run once, when coarse DM is created */
     88:   PetscErrorCode (*restricthook)(DM,Mat,Vec,Mat,DM,void*); /* Run each time a new problem is restricted to a coarse grid */
     89:   void *ctx;
     90:   DMCoarsenHookLink next;
     91: };

     93: typedef struct _DMRefineHookLink *DMRefineHookLink;
     94: struct _DMRefineHookLink {
     95:   PetscErrorCode (*refinehook)(DM,DM,void*);     /* Run once, when a fine DM is created */
     96:   PetscErrorCode (*interphook)(DM,Mat,DM,void*); /* Run each time a new problem is interpolated to a fine grid */
     97:   void *ctx;
     98:   DMRefineHookLink next;
     99: };

    101: typedef struct _DMSubDomainHookLink *DMSubDomainHookLink;
    102: struct _DMSubDomainHookLink {
    103:   PetscErrorCode (*ddhook)(DM,DM,void*);
    104:   PetscErrorCode (*restricthook)(DM,VecScatter,VecScatter,DM,void*);
    105:   void *ctx;
    106:   DMSubDomainHookLink next;
    107: };

    109: typedef struct _DMGlobalToLocalHookLink *DMGlobalToLocalHookLink;
    110: struct _DMGlobalToLocalHookLink {
    111:   PetscErrorCode (*beginhook)(DM,Vec,InsertMode,Vec,void*);
    112:   PetscErrorCode (*endhook)(DM,Vec,InsertMode,Vec,void*);
    113:   void *ctx;
    114:   DMGlobalToLocalHookLink next;
    115: };

    117: typedef struct _DMLocalToGlobalHookLink *DMLocalToGlobalHookLink;
    118: struct _DMLocalToGlobalHookLink {
    119:   PetscErrorCode (*beginhook)(DM,Vec,InsertMode,Vec,void*);
    120:   PetscErrorCode (*endhook)(DM,Vec,InsertMode,Vec,void*);
    121:   void *ctx;
    122:   DMLocalToGlobalHookLink next;
    123: };

    125: typedef enum {DMVEC_STATUS_IN,DMVEC_STATUS_OUT} DMVecStatus;
    126: typedef struct _DMNamedVecLink *DMNamedVecLink;
    127: struct _DMNamedVecLink {
    128:   Vec X;
    129:   char *name;
    130:   DMVecStatus status;
    131:   DMNamedVecLink next;
    132: };

    134: typedef struct _DMWorkLink *DMWorkLink;
    135: struct _DMWorkLink {
    136:   size_t     bytes;
    137:   void       *mem;
    138:   DMWorkLink next;
    139: };

    141: #define DM_MAX_WORK_VECTORS 100 /* work vectors available to users  via DMGetGlobalVector(), DMGetLocalVector() */

    143: struct _n_DMLabelLink {
    144:   DMLabel              label;
    145:   PetscBool            output;
    146:   struct _n_DMLabelLink *next;
    147: };
    148: typedef struct _n_DMLabelLink *DMLabelLink;

    150: struct _n_DMLabelLinkList {
    151:   PetscInt refct;
    152:   DMLabelLink next;
    153: };
    154: typedef struct _n_DMLabelLinkList *DMLabelLinkList;

    156: typedef struct _n_Boundary *DMBoundary;

    158: struct _n_Boundary {
    159:   DSBoundary  dsboundary;
    160:   DMLabel     label;
    161:   DMBoundary  next;
    162: };

    164: typedef struct _n_Field {
    165:   PetscObject disc;         /* Field discretization, or a PetscContainer with the field name */
    166:   DMLabel     label;        /* Label defining the domain of definition of the field */
    167:   PetscBool   adjacency[2]; /* Flags for defining variable influence (adjacency) for each field [use cone() or support() first, use the transitive closure] */
    168: } RegionField;

    170: typedef struct _n_Space {
    171:   PetscDS ds;     /* Approximation space in this domain */
    172:   DMLabel label;  /* Label defining the domain of definition of the discretization */
    173:   IS      fields; /* Map from DS field numbers to original field numbers in the DM */
    174: } DMSpace;

    176: PETSC_INTERN PetscErrorCode DMDestroyLabelLinkList_Internal(DM);

    178: struct _p_DM {
    179:   PETSCHEADER(struct _DMOps);
    180:   Vec                     localin[DM_MAX_WORK_VECTORS],localout[DM_MAX_WORK_VECTORS];
    181:   Vec                     globalin[DM_MAX_WORK_VECTORS],globalout[DM_MAX_WORK_VECTORS];
    182:   DMNamedVecLink          namedglobal;
    183:   DMNamedVecLink          namedlocal;
    184:   DMWorkLink              workin,workout;
    185:   DMLabelLinkList         labels;            /* Linked list of labels */
    186:   DMLabel                 depthLabel;        /* Optimized access to depth label */
    187:   void                    *ctx;    /* a user context */
    188:   PetscErrorCode          (*ctxdestroy)(void**);
    189:   Vec                     x;       /* location at which the functions/Jacobian are computed */
    190:   ISColoringType          coloringtype;
    191:   MatFDColoring           fd;
    192:   VecType                 vectype;  /* type of vector created with DMCreateLocalVector() and DMCreateGlobalVector() */
    193:   MatType                 mattype;  /* type of matrix created with DMCreateMatrix() */
    194:   PetscInt                bs;
    195:   ISLocalToGlobalMapping  ltogmap;
    196:   PetscBool               prealloc_only; /* Flag indicating the DMCreateMatrix() should only preallocate, not fill the matrix */
    197:   PetscBool               structure_only; /* Flag indicating the DMCreateMatrix() create matrix structure without values */
    198:   PetscInt                levelup,leveldown;  /* if the DM has been obtained by refining (or coarsening) this indicates how many times that process has been used to generate this DM */
    199:   PetscBool               setupcalled;        /* Indicates that the DM has been set up, methods that modify a DM such that a fresh setup is required should reset this flag */
    200:   PetscBool               setfromoptionscalled;
    201:   void                    *data;
    202:   /* Hierarchy / Submeshes */
    203:   DM                      coarseMesh;
    204:   DM                      fineMesh;
    205:   DMCoarsenHookLink       coarsenhook; /* For transfering auxiliary problem data to coarser grids */
    206:   DMRefineHookLink        refinehook;
    207:   DMSubDomainHookLink     subdomainhook;
    208:   DMGlobalToLocalHookLink gtolhook;
    209:   DMLocalToGlobalHookLink ltoghook;
    210:   /* Topology */
    211:   PetscInt                dim;                  /* The topological dimension */
    212:   /* Flexible communication */
    213:   PetscSF                 sfMigration;          /* SF for point distribution created during distribution */
    214:   PetscSF                 sf;                   /* SF for parallel point overlap */
    215:   PetscSF                 sectionSF;            /* SF for parallel dof overlap using section */
    216:   PetscSF                 sfNatural;            /* SF mapping to the "natural" ordering */
    217:   PetscBool               useNatural;           /* Create the natural SF */
    218:   /* Allows a non-standard data layout */
    219:   PetscBool               adjacency[2];         /* [use cone() or support() first, use the transitive closure] */
    220:   PetscSection            localSection;         /* Layout for local vectors */
    221:   PetscSection            globalSection;        /* Layout for global vectors */
    222:   PetscLayout             map;
    223:   /* Constraints */
    224:   PetscSection            defaultConstraintSection;
    225:   Mat                     defaultConstraintMat;
    226:   /* Basis transformation */
    227:   DM                      transformDM;          /* Layout for basis transformation */
    228:   Vec                     transform;            /* Basis transformation matrices */
    229:   void                   *transformCtx;         /* Basis transformation context */
    230:   PetscErrorCode        (*transformSetUp)(DM, void *);
    231:   PetscErrorCode        (*transformDestroy)(DM, void *);
    232:   PetscErrorCode        (*transformGetMatrix)(DM, const PetscReal[], PetscBool, const PetscScalar **, void *);
    233:   /* Coordinates */
    234:   PetscInt                dimEmbed;             /* The dimension of the embedding space */
    235:   DM                      coordinateDM;         /* Layout for coordinates */
    236:   Vec                     coordinates;          /* Coordinate values in global vector */
    237:   Vec                     coordinatesLocal;     /* Coordinate values in local  vector */
    238:   PetscBool               periodic;             /* Is the DM periodic? */
    239:   DMField                 coordinateField;      /* Coordinates as an abstract field */
    240:   PetscReal              *L, *maxCell;          /* Size of periodic box and max cell size for determining periodicity */
    241:   DMBoundaryType         *bdtype;               /* Indicates type of topological boundary */
    242:   /* Null spaces -- of course I should make this have a variable number of fields */
    243:   /*   I now believe this might not be the right way: see below */
    244:   NullSpaceFunc           nullspaceConstructors[10];
    245:   NullSpaceFunc           nearnullspaceConstructors[10];
    246:   /* Fields are represented by objects */
    247:   PetscInt                Nf;                   /* Number of fields defined on the total domain */
    248:   RegionField            *fields;               /* Array of discretization fields with regions of validity */
    249:   DMBoundary              boundary;             /* List of boundary conditions */
    250:   PetscInt                Nds;                  /* Number of discrete systems defined on the total domain */
    251:   DMSpace                *probs;                /* Array of discrete systems */
    252:   /* Output structures */
    253:   DM                      dmBC;                 /* The DM with boundary conditions in the global DM */
    254:   PetscInt                outputSequenceNum;    /* The current sequence number for output */
    255:   PetscReal               outputSequenceVal;    /* The current sequence value for output */

    257:   PetscObject             dmksp,dmsnes,dmts;
    258: };

    260: PETSC_EXTERN PetscLogEvent DM_Convert;
    261: PETSC_EXTERN PetscLogEvent DM_GlobalToLocal;
    262: PETSC_EXTERN PetscLogEvent DM_LocalToGlobal;
    263: PETSC_EXTERN PetscLogEvent DM_LocatePoints;
    264: PETSC_EXTERN PetscLogEvent DM_Coarsen;
    265: PETSC_EXTERN PetscLogEvent DM_Refine;
    266: PETSC_EXTERN PetscLogEvent DM_CreateInterpolation;
    267: PETSC_EXTERN PetscLogEvent DM_CreateRestriction;
    268: PETSC_EXTERN PetscLogEvent DM_CreateInjection;
    269: PETSC_EXTERN PetscLogEvent DM_CreateMatrix;

    271: PETSC_EXTERN PetscErrorCode DMCreateGlobalVector_Section_Private(DM,Vec*);
    272: PETSC_EXTERN PetscErrorCode DMCreateLocalVector_Section_Private(DM,Vec*);

    274: PETSC_EXTERN PetscErrorCode DMView_GLVis(DM,PetscViewer,PetscErrorCode(*)(DM,PetscViewer));

    276: /*

    278:           Composite Vectors

    280:       Single global representation
    281:       Individual global representations
    282:       Single local representation
    283:       Individual local representations

    285:       Subsets of individual as a single????? Do we handle this by having DMComposite inside composite??????

    287:        DM da_u, da_v, da_p

    289:        DM dm_velocities

    291:        DM dm

    293:        DMDACreate(,&da_u);
    294:        DMDACreate(,&da_v);
    295:        DMCompositeCreate(,&dm_velocities);
    296:        DMCompositeAddDM(dm_velocities,(DM)du);
    297:        DMCompositeAddDM(dm_velocities,(DM)dv);

    299:        DMDACreate(,&da_p);
    300:        DMCompositeCreate(,&dm_velocities);
    301:        DMCompositeAddDM(dm,(DM)dm_velocities);
    302:        DMCompositeAddDM(dm,(DM)dm_p);

    305:     Access parts of composite vectors (Composite only)
    306:     ---------------------------------
    307:       DMCompositeGetAccess  - access the global vector as subvectors and array (for redundant arrays)
    308:       ADD for local vector -

    310:     Element access
    311:     --------------
    312:       From global vectors
    313:          -DAVecGetArray   - for DMDA
    314:          -VecGetArray - for DMSliced
    315:          ADD for DMComposite???  maybe

    317:       From individual vector
    318:           -DAVecGetArray - for DMDA
    319:           -VecGetArray -for sliced
    320:          ADD for DMComposite??? maybe

    322:       From single local vector
    323:           ADD         * single local vector as arrays?

    325:    Communication
    326:    -------------
    327:       DMGlobalToLocal - global vector to single local vector

    329:       DMCompositeScatter/Gather - direct to individual local vectors and arrays   CHANGE name closer to GlobalToLocal?

    331:    Obtaining vectors
    332:    -----------------
    333:       DMCreateGlobal/Local
    334:       DMGetGlobal/Local
    335:       DMCompositeGetLocalVectors   - gives individual local work vectors and arrays

    338: ?????   individual global vectors   ????

    340: */

    342: #if defined(PETSC_HAVE_HDF5)
    343: PETSC_EXTERN PetscErrorCode DMSequenceLoad_HDF5_Internal(DM, const char *, PetscInt, PetscScalar *, PetscViewer);
    344: #endif

    346: PETSC_STATIC_INLINE PetscErrorCode DMGetLocalOffset_Private(DM dm, PetscInt point, PetscInt *start, PetscInt *end)
    347: {
    349: #if defined(PETSC_USE_DEBUG)
    350:   {
    351:     PetscInt       dof;
    353:     *start = *end = 0; /* Silence overzealous compiler warning */
    354:     if (!dm->localSection) SETERRQ(PetscObjectComm((PetscObject) dm), PETSC_ERR_ARG_WRONG, "DM must have a local section, see DMSetLocalSection()");
    355:     PetscSectionGetOffset(dm->localSection, point, start);
    356:     PetscSectionGetDof(dm->localSection, point, &dof);
    357:     *end = *start + dof;
    358:   }
    359: #else
    360:   {
    361:     const PetscSection s = dm->localSection;
    362:     *start = s->atlasOff[point - s->pStart];
    363:     *end   = *start + s->atlasDof[point - s->pStart];
    364:   }
    365: #endif
    366:   return(0);
    367: }

    369: PETSC_STATIC_INLINE PetscErrorCode DMGetLocalFieldOffset_Private(DM dm, PetscInt point, PetscInt field, PetscInt *start, PetscInt *end)
    370: {
    372: #if defined(PETSC_USE_DEBUG)
    373:   {
    374:     PetscInt       dof;
    376:     *start = *end = 0; /* Silence overzealous compiler warning */
    377:     if (!dm->localSection) SETERRQ(PetscObjectComm((PetscObject) dm), PETSC_ERR_ARG_WRONG, "DM must have a local section, see DMSetLocalSection()");
    378:     PetscSectionGetFieldOffset(dm->localSection, point, field, start);
    379:     PetscSectionGetFieldDof(dm->localSection, point, field, &dof);
    380:     *end = *start + dof;
    381:   }
    382: #else
    383:   {
    384:     const PetscSection s = dm->localSection->field[field];
    385:     *start = s->atlasOff[point - s->pStart];
    386:     *end   = *start + s->atlasDof[point - s->pStart];
    387:   }
    388: #endif
    389:   return(0);
    390: }

    392: PETSC_STATIC_INLINE PetscErrorCode DMGetGlobalOffset_Private(DM dm, PetscInt point, PetscInt *start, PetscInt *end)
    393: {
    395: #if defined(PETSC_USE_DEBUG)
    396:   {
    398:     PetscInt       dof,cdof;
    399:     *start = *end = 0; /* Silence overzealous compiler warning */
    400:     if (!dm->localSection) SETERRQ(PetscObjectComm((PetscObject) dm), PETSC_ERR_ARG_WRONG, "DM must have a local section, see DMSetLocalSection()");
    401:     if (!dm->globalSection) SETERRQ(PetscObjectComm((PetscObject) dm), PETSC_ERR_ARG_WRONG, "DM must have a global section. It will be created automatically by DMGetGlobalSection()");
    402:     PetscSectionGetOffset(dm->globalSection, point, start);
    403:     PetscSectionGetDof(dm->globalSection, point, &dof);
    404:     PetscSectionGetConstraintDof(dm->globalSection, point, &cdof);
    405:     *end = *start + dof - cdof + (dof < 0 ? 1 : 0);
    406:   }
    407: #else
    408:   {
    409:     const PetscSection s    = dm->globalSection;
    410:     const PetscInt     dof  = s->atlasDof[point - s->pStart];
    411:     const PetscInt     cdof = s->bc ? s->bc->atlasDof[point - s->bc->pStart] : 0;
    412:     *start = s->atlasOff[point - s->pStart];
    413:     *end   = *start + dof - cdof + (dof < 0 ? 1 : 0);
    414:   }
    415: #endif
    416:   return(0);
    417: }

    419: PETSC_STATIC_INLINE PetscErrorCode DMGetGlobalFieldOffset_Private(DM dm, PetscInt point, PetscInt field, PetscInt *start, PetscInt *end)
    420: {
    422: #if defined(PETSC_USE_DEBUG)
    423:   {
    424:     PetscInt       loff, lfoff, fdof, fcdof, ffcdof, f;
    426:     *start = *end = 0; /* Silence overzealous compiler warning */
    427:     if (!dm->localSection) SETERRQ(PetscObjectComm((PetscObject) dm), PETSC_ERR_ARG_WRONG, "DM must have a local section, see DMSetLocalSection()");
    428:     if (!dm->globalSection) SETERRQ(PetscObjectComm((PetscObject) dm), PETSC_ERR_ARG_WRONG, "DM must have a global section. It will be crated automatically by DMGetGlobalSection()");
    429:     PetscSectionGetOffset(dm->globalSection, point, start);
    430:     PetscSectionGetOffset(dm->localSection, point, &loff);
    431:     PetscSectionGetFieldOffset(dm->localSection, point, field, &lfoff);
    432:     PetscSectionGetFieldDof(dm->localSection, point, field, &fdof);
    433:     PetscSectionGetFieldConstraintDof(dm->localSection, point, field, &fcdof);
    434:     *start = *start < 0 ? *start - (lfoff-loff) : *start + lfoff-loff;
    435:     for (f = 0; f < field; ++f) {
    436:       PetscSectionGetFieldConstraintDof(dm->localSection, point, f, &ffcdof);
    437:       *start = *start < 0 ? *start + ffcdof : *start - ffcdof;
    438:     }
    439:     *end   = *start < 0 ? *start - (fdof-fcdof) : *start + fdof-fcdof;
    440:   }
    441: #else
    442:   {
    443:     const PetscSection s     = dm->localSection;
    444:     const PetscSection fs    = dm->localSection->field[field];
    445:     const PetscSection gs    = dm->globalSection;
    446:     const PetscInt     loff  = s->atlasOff[point - s->pStart];
    447:     const PetscInt     goff  = gs->atlasOff[point - s->pStart];
    448:     const PetscInt     lfoff = fs->atlasOff[point - s->pStart];
    449:     const PetscInt     fdof  = fs->atlasDof[point - s->pStart];
    450:     const PetscInt     fcdof = fs->bc ? fs->bc->atlasDof[point - fs->bc->pStart] : 0;
    451:     PetscInt           ffcdof = 0, f;

    453:     for (f = 0; f < field; ++f) {
    454:       const PetscSection ffs = dm->localSection->field[f];
    455:       ffcdof += ffs->bc ? ffs->bc->atlasDof[point - ffs->bc->pStart] : 0;
    456:     }
    457:     *start = goff + (goff < 0 ? loff-lfoff + ffcdof : lfoff-loff - ffcdof);
    458:     *end   = *start < 0 ? *start - (fdof-fcdof) : *start + fdof-fcdof;
    459:   }
    460: #endif
    461:   return(0);
    462: }

    464: PETSC_EXTERN PetscErrorCode DMGetBasisTransformDM_Internal(DM, DM *);
    465: PETSC_EXTERN PetscErrorCode DMGetBasisTransformVec_Internal(DM, Vec *);
    466: PETSC_INTERN PetscErrorCode DMConstructBasisTransform_Internal(DM);

    468: PETSC_INTERN PetscErrorCode DMGetLocalBoundingIndices_DMDA(DM, PetscReal[], PetscReal[]);

    470: #endif