Actual source code: dacreate.c

      2: #include <petsc/private/dmdaimpl.h>

      4: PetscErrorCode  DMSetFromOptions_DA(PetscOptionItems *PetscOptionsObject,DM da)
      5: {
      7:   DM_DA          *dd    = (DM_DA*)da->data;
      8:   PetscInt       refine = 0,dim = da->dim,maxnlevels = 100,refx[100],refy[100],refz[100],n,i;
      9:   PetscBool      flg;

     14:   if (dd->M < 0) SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_ARG_OUTOFRANGE,"Dimension must be non-negative, call DMSetFromOptions() if you want to change the value at runtime");
     15:   if (dd->N < 0) SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_ARG_OUTOFRANGE,"Dimension must be non-negative, call DMSetFromOptions() if you want to change the value at runtime");
     16:   if (dd->P < 0) SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_ARG_OUTOFRANGE,"Dimension must be non-negative, call DMSetFromOptions() if you want to change the value at runtime");

     18:   PetscOptionsHead(PetscOptionsObject,"DMDA Options");
     19:   PetscOptionsBoundedInt("-da_grid_x","Number of grid points in x direction","DMDASetSizes",dd->M,&dd->M,NULL,1);
     20:   if (dim > 1) {PetscOptionsBoundedInt("-da_grid_y","Number of grid points in y direction","DMDASetSizes",dd->N,&dd->N,NULL,1);}
     21:   if (dim > 2) {PetscOptionsBoundedInt("-da_grid_z","Number of grid points in z direction","DMDASetSizes",dd->P,&dd->P,NULL,1);}

     23:   PetscOptionsBoundedInt("-da_overlap","Decomposition overlap in all directions","DMDASetOverlap",dd->xol,&dd->xol,&flg,0);
     24:   if (flg) {DMDASetOverlap(da,dd->xol,dd->xol,dd->xol);}
     25:   PetscOptionsBoundedInt("-da_overlap_x","Decomposition overlap in x direction","DMDASetOverlap",dd->xol,&dd->xol,NULL,0);
     26:   if (dim > 1) {PetscOptionsBoundedInt("-da_overlap_y","Decomposition overlap in y direction","DMDASetOverlap",dd->yol,&dd->yol,NULL,0);}
     27:   if (dim > 2) {PetscOptionsBoundedInt("-da_overlap_z","Decomposition overlap in z direction","DMDASetOverlap",dd->zol,&dd->zol,NULL,0);}

     29:   PetscOptionsBoundedInt("-da_local_subdomains","","DMDASetNumLocalSubdomains",dd->Nsub,&dd->Nsub,&flg,PETSC_DECIDE);
     30:   if (flg) {DMDASetNumLocalSubDomains(da,dd->Nsub);}

     32:   /* Handle DMDA parallel distribution */
     33:   PetscOptionsBoundedInt("-da_processors_x","Number of processors in x direction","DMDASetNumProcs",dd->m,&dd->m,NULL,PETSC_DECIDE);
     34:   if (dim > 1) {PetscOptionsBoundedInt("-da_processors_y","Number of processors in y direction","DMDASetNumProcs",dd->n,&dd->n,NULL,PETSC_DECIDE);}
     35:   if (dim > 2) {PetscOptionsBoundedInt("-da_processors_z","Number of processors in z direction","DMDASetNumProcs",dd->p,&dd->p,NULL,PETSC_DECIDE);}
     36:   /* Handle DMDA refinement */
     37:   PetscOptionsBoundedInt("-da_refine_x","Refinement ratio in x direction","DMDASetRefinementFactor",dd->refine_x,&dd->refine_x,NULL,1);
     38:   if (dim > 1) {PetscOptionsBoundedInt("-da_refine_y","Refinement ratio in y direction","DMDASetRefinementFactor",dd->refine_y,&dd->refine_y,NULL,1);}
     39:   if (dim > 2) {PetscOptionsBoundedInt("-da_refine_z","Refinement ratio in z direction","DMDASetRefinementFactor",dd->refine_z,&dd->refine_z,NULL,1);}
     40:   dd->coarsen_x = dd->refine_x; dd->coarsen_y = dd->refine_y; dd->coarsen_z = dd->refine_z;

     42:   /* Get refinement factors, defaults taken from the coarse DMDA */
     43:   DMDAGetRefinementFactor(da,&refx[0],&refy[0],&refz[0]);
     44:   for (i=1; i<maxnlevels; i++) {
     45:     refx[i] = refx[0];
     46:     refy[i] = refy[0];
     47:     refz[i] = refz[0];
     48:   }
     49:   n    = maxnlevels;
     50:   PetscOptionsIntArray("-da_refine_hierarchy_x","Refinement factor for each level","None",refx,&n,&flg);
     51:   if (flg) {
     52:     dd->refine_x = refx[0];
     53:     dd->refine_x_hier_n = n;
     54:     PetscMalloc1(n,&dd->refine_x_hier);
     55:     PetscArraycpy(dd->refine_x_hier,refx,n);
     56:   }
     57:   if (dim > 1) {
     58:     n    = maxnlevels;
     59:     PetscOptionsIntArray("-da_refine_hierarchy_y","Refinement factor for each level","None",refy,&n,&flg);
     60:     if (flg) {
     61:       dd->refine_y = refy[0];
     62:       dd->refine_y_hier_n = n;
     63:       PetscMalloc1(n,&dd->refine_y_hier);
     64:       PetscArraycpy(dd->refine_y_hier,refy,n);
     65:     }
     66:   }
     67:   if (dim > 2) {
     68:     n    = maxnlevels;
     69:     PetscOptionsIntArray("-da_refine_hierarchy_z","Refinement factor for each level","None",refz,&n,&flg);
     70:     if (flg) {
     71:       dd->refine_z = refz[0];
     72:       dd->refine_z_hier_n = n;
     73:       PetscMalloc1(n,&dd->refine_z_hier);
     74:       PetscArraycpy(dd->refine_z_hier,refz,n);
     75:     }
     76:   }

     78:   PetscOptionsBoundedInt("-da_refine","Uniformly refine DA one or more times","None",refine,&refine,NULL,0);
     79:   PetscOptionsTail();

     81:   while (refine--) {
     82:     if (dd->bx == DM_BOUNDARY_PERIODIC || dd->interptype == DMDA_Q0) {
     83:       dd->M = dd->refine_x*dd->M;
     84:     } else {
     85:       dd->M = 1 + dd->refine_x*(dd->M - 1);
     86:     }
     87:     if (dd->by == DM_BOUNDARY_PERIODIC || dd->interptype == DMDA_Q0) {
     88:       dd->N = dd->refine_y*dd->N;
     89:     } else {
     90:       dd->N = 1 + dd->refine_y*(dd->N - 1);
     91:     }
     92:     if (dd->bz == DM_BOUNDARY_PERIODIC || dd->interptype == DMDA_Q0) {
     93:       dd->P = dd->refine_z*dd->P;
     94:     } else {
     95:       dd->P = 1 + dd->refine_z*(dd->P - 1);
     96:     }
     97:     da->levelup++;
     98:     if (da->levelup - da->leveldown >= 0) {
     99:       dd->refine_x = refx[da->levelup - da->leveldown];
    100:       dd->refine_y = refy[da->levelup - da->leveldown];
    101:       dd->refine_z = refz[da->levelup - da->leveldown];
    102:     }
    103:     if (da->levelup - da->leveldown >= 1) {
    104:       dd->coarsen_x = refx[da->levelup - da->leveldown - 1];
    105:       dd->coarsen_y = refy[da->levelup - da->leveldown - 1];
    106:       dd->coarsen_z = refz[da->levelup - da->leveldown - 1];
    107:     }
    108:   }
    109:   return(0);
    110: }

    112: extern PetscErrorCode  DMCreateGlobalVector_DA(DM,Vec*);
    113: extern PetscErrorCode  DMCreateLocalVector_DA(DM,Vec*);
    114: extern PetscErrorCode  DMGlobalToLocalBegin_DA(DM,Vec,InsertMode,Vec);
    115: extern PetscErrorCode  DMGlobalToLocalEnd_DA(DM,Vec,InsertMode,Vec);
    116: extern PetscErrorCode  DMLocalToGlobalBegin_DA(DM,Vec,InsertMode,Vec);
    117: extern PetscErrorCode  DMLocalToGlobalEnd_DA(DM,Vec,InsertMode,Vec);
    118: extern PetscErrorCode  DMLocalToLocalBegin_DA(DM,Vec,InsertMode,Vec);
    119: extern PetscErrorCode  DMLocalToLocalEnd_DA(DM,Vec,InsertMode,Vec);
    120: extern PetscErrorCode  DMCreateInterpolation_DA(DM,DM,Mat*,Vec*);
    121: extern PetscErrorCode  DMCreateColoring_DA(DM,ISColoringType,ISColoring*);
    122: extern PetscErrorCode  DMCreateMatrix_DA(DM,Mat*);
    123: extern PetscErrorCode  DMCreateCoordinateDM_DA(DM,DM*);
    124: extern PetscErrorCode  DMRefine_DA(DM,MPI_Comm,DM*);
    125: extern PetscErrorCode  DMCoarsen_DA(DM,MPI_Comm,DM*);
    126: extern PetscErrorCode  DMRefineHierarchy_DA(DM,PetscInt,DM[]);
    127: extern PetscErrorCode  DMCoarsenHierarchy_DA(DM,PetscInt,DM[]);
    128: extern PetscErrorCode  DMCreateInjection_DA(DM,DM,Mat*);
    129: extern PetscErrorCode  DMView_DA(DM,PetscViewer);
    130: extern PetscErrorCode  DMSetUp_DA(DM);
    131: extern PetscErrorCode  DMDestroy_DA(DM);
    132: extern PetscErrorCode  DMCreateDomainDecomposition_DA(DM,PetscInt*,char***,IS**,IS**,DM**);
    133: extern PetscErrorCode  DMCreateDomainDecompositionScatters_DA(DM,PetscInt,DM*,VecScatter**,VecScatter**,VecScatter**);
    134: PETSC_INTERN PetscErrorCode DMGetCompatibility_DA(DM,DM,PetscBool*,PetscBool*);

    136: PetscErrorCode DMLoad_DA(DM da,PetscViewer viewer)
    137: {
    138:   PetscErrorCode   ierr;
    139:   PetscInt         dim,m,n,p,dof,swidth;
    140:   DMDAStencilType  stencil;
    141:   DMBoundaryType   bx,by,bz;
    142:   PetscBool        coors;
    143:   DM               dac;
    144:   Vec              c;

    147:   PetscViewerBinaryRead(viewer,&dim,1,NULL,PETSC_INT);
    148:   PetscViewerBinaryRead(viewer,&m,1,NULL,PETSC_INT);
    149:   PetscViewerBinaryRead(viewer,&n,1,NULL,PETSC_INT);
    150:   PetscViewerBinaryRead(viewer,&p,1,NULL,PETSC_INT);
    151:   PetscViewerBinaryRead(viewer,&dof,1,NULL,PETSC_INT);
    152:   PetscViewerBinaryRead(viewer,&swidth,1,NULL,PETSC_INT);
    153:   PetscViewerBinaryRead(viewer,&bx,1,NULL,PETSC_ENUM);
    154:   PetscViewerBinaryRead(viewer,&by,1,NULL,PETSC_ENUM);
    155:   PetscViewerBinaryRead(viewer,&bz,1,NULL,PETSC_ENUM);
    156:   PetscViewerBinaryRead(viewer,&stencil,1,NULL,PETSC_ENUM);

    158:   DMSetDimension(da, dim);
    159:   DMDASetSizes(da, m,n,p);
    160:   DMDASetBoundaryType(da, bx, by, bz);
    161:   DMDASetDof(da, dof);
    162:   DMDASetStencilType(da, stencil);
    163:   DMDASetStencilWidth(da, swidth);
    164:   DMSetUp(da);
    165:   PetscViewerBinaryRead(viewer,&coors,1,NULL,PETSC_ENUM);
    166:   if (coors) {
    167:     DMGetCoordinateDM(da,&dac);
    168:     DMCreateGlobalVector(dac,&c);
    169:     VecLoad(c,viewer);
    170:     DMSetCoordinates(da,c);
    171:     VecDestroy(&c);
    172:   }
    173:   return(0);
    174: }

    176: PetscErrorCode DMCreateSubDM_DA(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm)
    177: {
    178:   DM_DA         *da = (DM_DA*) dm->data;

    182:   if (subdm) {
    183:     PetscSF sf;
    184:     Vec     coords;
    185:     void   *ctx;
    186:     /* Cannot use DMClone since the dof stuff is mixed in. Ugh
    187:     DMClone(dm, subdm); */
    188:     DMCreate(PetscObjectComm((PetscObject)dm), subdm);
    189:     DMGetPointSF(dm, &sf);
    190:     DMSetPointSF(*subdm, sf);
    191:     DMGetApplicationContext(dm, &ctx);
    192:     DMSetApplicationContext(*subdm, ctx);
    193:     DMGetCoordinatesLocal(dm, &coords);
    194:     if (coords) {
    195:       DMSetCoordinatesLocal(*subdm, coords);
    196:     } else {
    197:       DMGetCoordinates(dm, &coords);
    198:       if (coords) {DMSetCoordinates(*subdm, coords);}
    199:     }

    201:     DMSetType(*subdm, DMDA);
    202:     DMSetDimension(*subdm, dm->dim);
    203:     DMDASetSizes(*subdm, da->M, da->N, da->P);
    204:     DMDASetNumProcs(*subdm, da->m, da->n, da->p);
    205:     DMDASetBoundaryType(*subdm, da->bx, da->by, da->bz);
    206:     DMDASetDof(*subdm, numFields);
    207:     DMDASetStencilType(*subdm, da->stencil_type);
    208:     DMDASetStencilWidth(*subdm, da->s);
    209:     DMDASetOwnershipRanges(*subdm, da->lx, da->ly, da->lz);
    210:   }
    211:   if (is) {
    212:     PetscInt *indices, cnt = 0, dof = da->w, i, j;

    214:     PetscMalloc1(da->Nlocal*numFields/dof, &indices);
    215:     for (i = da->base/dof; i < (da->base+da->Nlocal)/dof; ++i) {
    216:       for (j = 0; j < numFields; ++j) {
    217:         indices[cnt++] = dof*i + fields[j];
    218:       }
    219:     }
    220:     if (cnt != da->Nlocal*numFields/dof) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Count %D does not equal expected value %D", cnt, da->Nlocal*numFields/dof);
    221:     ISCreateGeneral(PetscObjectComm((PetscObject) dm), cnt, indices, PETSC_OWN_POINTER, is);
    222:   }
    223:   return(0);
    224: }

    226: PetscErrorCode DMCreateFieldDecomposition_DA(DM dm, PetscInt *len,char ***namelist, IS **islist, DM **dmlist)
    227: {
    228:   PetscInt       i;
    230:   DM_DA          *dd = (DM_DA*)dm->data;
    231:   PetscInt       dof = dd->w;

    234:   if (len) *len = dof;
    235:   if (islist) {
    236:     Vec      v;
    237:     PetscInt rstart,n;

    239:     DMGetGlobalVector(dm,&v);
    240:     VecGetOwnershipRange(v,&rstart,NULL);
    241:     VecGetLocalSize(v,&n);
    242:     DMRestoreGlobalVector(dm,&v);
    243:     PetscMalloc1(dof,islist);
    244:     for (i=0; i<dof; i++) {
    245:       ISCreateStride(PetscObjectComm((PetscObject)dm),n/dof,rstart+i,dof,&(*islist)[i]);
    246:     }
    247:   }
    248:   if (namelist) {
    249:     PetscMalloc1(dof, namelist);
    250:     if (dd->fieldname) {
    251:       for (i=0; i<dof; i++) {
    252:         PetscStrallocpy(dd->fieldname[i],&(*namelist)[i]);
    253:       }
    254:     } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Currently DMDA must have fieldnames");
    255:   }
    256:   if (dmlist) {
    257:     DM da;

    259:     DMDACreate(PetscObjectComm((PetscObject)dm), &da);
    260:     DMSetDimension(da, dm->dim);
    261:     DMDASetSizes(da, dd->M, dd->N, dd->P);
    262:     DMDASetNumProcs(da, dd->m, dd->n, dd->p);
    263:     DMDASetBoundaryType(da, dd->bx, dd->by, dd->bz);
    264:     DMDASetDof(da, 1);
    265:     DMDASetStencilType(da, dd->stencil_type);
    266:     DMDASetStencilWidth(da, dd->s);
    267:     DMSetUp(da);
    268:     PetscMalloc1(dof,dmlist);
    269:     for (i=0; i<dof-1; i++) {PetscObjectReference((PetscObject)da);}
    270:     for (i=0; i<dof; i++) (*dmlist)[i] = da;
    271:   }
    272:   return(0);
    273: }

    275: PetscErrorCode DMClone_DA(DM dm, DM *newdm)
    276: {
    277:   DM_DA         *da = (DM_DA *) dm->data;

    281:   DMSetType(*newdm, DMDA);
    282:   DMSetDimension(*newdm, dm->dim);
    283:   DMDASetSizes(*newdm, da->M, da->N, da->P);
    284:   DMDASetNumProcs(*newdm, da->m, da->n, da->p);
    285:   DMDASetBoundaryType(*newdm, da->bx, da->by, da->bz);
    286:   DMDASetDof(*newdm, da->w);
    287:   DMDASetStencilType(*newdm, da->stencil_type);
    288:   DMDASetStencilWidth(*newdm, da->s);
    289:   DMDASetOwnershipRanges(*newdm, da->lx, da->ly, da->lz);
    290:   DMSetUp(*newdm);
    291:   return(0);
    292: }

    294: static PetscErrorCode DMHasCreateInjection_DA(DM dm, PetscBool *flg)
    295: {
    296:   DM_DA          *da = (DM_DA *)dm->data;

    301:   *flg = da->interptype == DMDA_Q1 ? PETSC_TRUE : PETSC_FALSE;
    302:   return(0);
    303: }

    305: static PetscErrorCode DMGetDimPoints_DA(DM dm, PetscInt dim, PetscInt *pStart, PetscInt *pEnd)
    306: {

    310:   DMDAGetDepthStratum(dm, dim, pStart, pEnd);
    311:   return(0);
    312: }

    314: static PetscErrorCode DMGetNeighbors_DA(DM dm, PetscInt *nranks, const PetscMPIInt *ranks[])
    315: {
    317:   PetscInt dim;
    318:   DMDAStencilType st;

    321:   DMDAGetNeighbors(dm,ranks);
    322:   DMDAGetInfo(dm,&dim,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,&st);

    324:   switch (dim) {
    325:     case 1:
    326:       *nranks = 3;
    327:       /* if (st == DMDA_STENCIL_STAR) { *nranks = 3; } */
    328:       break;
    329:     case 2:
    330:       *nranks = 9;
    331:       /* if (st == DMDA_STENCIL_STAR) { *nranks = 5; } */
    332:       break;
    333:     case 3:
    334:       *nranks = 27;
    335:       /* if (st == DMDA_STENCIL_STAR) { *nranks = 7; } */
    336:       break;
    337:     default:
    338:       break;
    339:   }
    340:   return(0);
    341: }

    343: /*MC
    344:    DMDA = "da" - A DM object that is used to manage data for a structured grid in 1, 2, or 3 dimensions.
    345:          In the global representation of the vector each process stores a non-overlapping rectangular (or slab in 3d) portion of the grid points.
    346:          In the local representation these rectangular regions (slabs) are extended in all directions by a stencil width.

    348:          The vectors can be thought of as either cell centered or vertex centered on the mesh. But some variables cannot be cell centered and others
    349:          vertex centered; see the documentation for DMSTAG, a similar DM implementation which supports these staggered grids.

    351:   Level: intermediate

    353: .seealso: DMType, DMCOMPOSITE, DMSTAG, DMDACreate(), DMCreate(), DMSetType()
    354: M*/

    356: extern PetscErrorCode DMLocatePoints_DA_Regular(DM,Vec,DMPointLocationType,PetscSF);
    357: PETSC_INTERN PetscErrorCode DMSetUpGLVisViewer_DMDA(PetscObject,PetscViewer);

    359: PETSC_EXTERN PetscErrorCode DMCreate_DA(DM da)
    360: {
    362:   DM_DA          *dd;

    366:   PetscNewLog(da,&dd);
    367:   da->data = dd;

    369:   da->dim        = -1;
    370:   dd->interptype = DMDA_Q1;
    371:   dd->refine_x   = 2;
    372:   dd->refine_y   = 2;
    373:   dd->refine_z   = 2;
    374:   dd->coarsen_x  = 2;
    375:   dd->coarsen_y  = 2;
    376:   dd->coarsen_z  = 2;
    377:   dd->fieldname  = NULL;
    378:   dd->nlocal     = -1;
    379:   dd->Nlocal     = -1;
    380:   dd->M          = -1;
    381:   dd->N          = -1;
    382:   dd->P          = -1;
    383:   dd->m          = -1;
    384:   dd->n          = -1;
    385:   dd->p          = -1;
    386:   dd->w          = -1;
    387:   dd->s          = -1;

    389:   dd->xs = -1; dd->xe = -1; dd->ys = -1; dd->ye = -1; dd->zs = -1; dd->ze = -1;
    390:   dd->Xs = -1; dd->Xe = -1; dd->Ys = -1; dd->Ye = -1; dd->Zs = -1; dd->Ze = -1;

    392:   dd->Nsub            = 1;
    393:   dd->xol             = 0;
    394:   dd->yol             = 0;
    395:   dd->zol             = 0;
    396:   dd->xo              = 0;
    397:   dd->yo              = 0;
    398:   dd->zo              = 0;
    399:   dd->Mo              = -1;
    400:   dd->No              = -1;
    401:   dd->Po              = -1;

    403:   dd->gtol         = NULL;
    404:   dd->ltol         = NULL;
    405:   dd->ao           = NULL;
    406:   PetscStrallocpy(AOBASIC,(char**)&dd->aotype);
    407:   dd->base         = -1;
    408:   dd->bx           = DM_BOUNDARY_NONE;
    409:   dd->by           = DM_BOUNDARY_NONE;
    410:   dd->bz           = DM_BOUNDARY_NONE;
    411:   dd->stencil_type = DMDA_STENCIL_BOX;
    412:   dd->interptype   = DMDA_Q1;
    413:   dd->lx           = NULL;
    414:   dd->ly           = NULL;
    415:   dd->lz           = NULL;

    417:   dd->elementtype = DMDA_ELEMENT_Q1;

    419:   da->ops->globaltolocalbegin          = DMGlobalToLocalBegin_DA;
    420:   da->ops->globaltolocalend            = DMGlobalToLocalEnd_DA;
    421:   da->ops->localtoglobalbegin          = DMLocalToGlobalBegin_DA;
    422:   da->ops->localtoglobalend            = DMLocalToGlobalEnd_DA;
    423:   da->ops->localtolocalbegin           = DMLocalToLocalBegin_DA;
    424:   da->ops->localtolocalend             = DMLocalToLocalEnd_DA;
    425:   da->ops->createglobalvector          = DMCreateGlobalVector_DA;
    426:   da->ops->createlocalvector           = DMCreateLocalVector_DA;
    427:   da->ops->createinterpolation         = DMCreateInterpolation_DA;
    428:   da->ops->getcoloring                 = DMCreateColoring_DA;
    429:   da->ops->creatematrix                = DMCreateMatrix_DA;
    430:   da->ops->refine                      = DMRefine_DA;
    431:   da->ops->coarsen                     = DMCoarsen_DA;
    432:   da->ops->refinehierarchy             = DMRefineHierarchy_DA;
    433:   da->ops->coarsenhierarchy            = DMCoarsenHierarchy_DA;
    434:   da->ops->createinjection             = DMCreateInjection_DA;
    435:   da->ops->hascreateinjection          = DMHasCreateInjection_DA;
    436:   da->ops->destroy                     = DMDestroy_DA;
    437:   da->ops->view                        = NULL;
    438:   da->ops->setfromoptions              = DMSetFromOptions_DA;
    439:   da->ops->setup                       = DMSetUp_DA;
    440:   da->ops->clone                       = DMClone_DA;
    441:   da->ops->load                        = DMLoad_DA;
    442:   da->ops->createcoordinatedm          = DMCreateCoordinateDM_DA;
    443:   da->ops->createsubdm                 = DMCreateSubDM_DA;
    444:   da->ops->createfielddecomposition    = DMCreateFieldDecomposition_DA;
    445:   da->ops->createdomaindecomposition   = DMCreateDomainDecomposition_DA;
    446:   da->ops->createddscatters            = DMCreateDomainDecompositionScatters_DA;
    447:   da->ops->getdimpoints                = DMGetDimPoints_DA;
    448:   da->ops->getneighbors                = DMGetNeighbors_DA;
    449:   da->ops->locatepoints                = DMLocatePoints_DA_Regular;
    450:   da->ops->getcompatibility            = DMGetCompatibility_DA;
    451:   PetscObjectComposeFunction((PetscObject)da,"DMSetUpGLVisViewer_C",DMSetUpGLVisViewer_DMDA);
    452:   return(0);
    453: }

    455: /*@
    456:   DMDACreate - Creates a DMDA object.

    458:   Collective

    460:   Input Parameter:
    461: . comm - The communicator for the DMDA object

    463:   Output Parameter:
    464: . da  - The DMDA object

    466:   Level: advanced

    468:   Developers Note:
    469:   Since there exists DMDACreate1/2/3d() should this routine even exist?

    471: .seealso:  DMDASetSizes(), DMClone(),  DMDACreate1d(), DMDACreate2d(), DMDACreate3d()
    472: @*/
    473: PetscErrorCode  DMDACreate(MPI_Comm comm, DM *da)
    474: {

    479:   DMCreate(comm,da);
    480:   DMSetType(*da,DMDA);
    481:   return(0);
    482: }