Actual source code: dacreate.c

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

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

  9:   PetscFunctionBegin;
 10:   PetscCheck(dd->M >= 0, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "Dimension must be non-negative, call DMSetFromOptions() if you want to change the value at runtime");
 11:   PetscCheck(dd->N >= 0, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "Dimension must be non-negative, call DMSetFromOptions() if you want to change the value at runtime");
 12:   PetscCheck(dd->P >= 0, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "Dimension must be non-negative, call DMSetFromOptions() if you want to change the value at runtime");

 14:   PetscOptionsHeadBegin(PetscOptionsObject, "DMDA Options");
 15:   PetscCall(PetscOptionsBoundedInt("-da_grid_x", "Number of grid points in x direction", "DMDASetSizes", dd->M, &dd->M, NULL, 1));
 16:   if (dim > 1) PetscCall(PetscOptionsBoundedInt("-da_grid_y", "Number of grid points in y direction", "DMDASetSizes", dd->N, &dd->N, NULL, 1));
 17:   if (dim > 2) PetscCall(PetscOptionsBoundedInt("-da_grid_z", "Number of grid points in z direction", "DMDASetSizes", dd->P, &dd->P, NULL, 1));

 19:   PetscCall(PetscOptionsBoundedInt("-da_overlap", "Decomposition overlap in all directions", "DMDASetOverlap", dd->xol, &dd->xol, &flg, 0));
 20:   if (flg) PetscCall(DMDASetOverlap(da, dd->xol, dd->xol, dd->xol));
 21:   PetscCall(PetscOptionsBoundedInt("-da_overlap_x", "Decomposition overlap in x direction", "DMDASetOverlap", dd->xol, &dd->xol, NULL, 0));
 22:   if (dim > 1) PetscCall(PetscOptionsBoundedInt("-da_overlap_y", "Decomposition overlap in y direction", "DMDASetOverlap", dd->yol, &dd->yol, NULL, 0));
 23:   if (dim > 2) PetscCall(PetscOptionsBoundedInt("-da_overlap_z", "Decomposition overlap in z direction", "DMDASetOverlap", dd->zol, &dd->zol, NULL, 0));

 25:   PetscCall(PetscOptionsBoundedInt("-da_local_subdomains", "", "DMDASetNumLocalSubdomains", dd->Nsub, &dd->Nsub, &flg, PETSC_DECIDE));
 26:   if (flg) PetscCall(DMDASetNumLocalSubDomains(da, dd->Nsub));

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

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

 76:   PetscCall(PetscOptionsBoundedInt("-da_refine", "Uniformly refine DA one or more times", "None", refine, &refine, NULL, 0));
 77:   PetscOptionsHeadEnd();

 79:   while (refine--) {
 80:     if (dd->bx == DM_BOUNDARY_PERIODIC || dd->interptype == DMDA_Q0) {
 81:       PetscCall(PetscIntMultError(dd->refine_x, dd->M, &dd->M));
 82:     } else {
 83:       PetscCall(PetscIntMultError(dd->refine_x, dd->M - 1, &dd->M));
 84:       dd->M += 1;
 85:     }
 86:     if (dd->by == DM_BOUNDARY_PERIODIC || dd->interptype == DMDA_Q0) {
 87:       PetscCall(PetscIntMultError(dd->refine_y, dd->N, &dd->N));
 88:     } else {
 89:       PetscCall(PetscIntMultError(dd->refine_y, dd->N - 1, &dd->N));
 90:       dd->N += 1;
 91:     }
 92:     if (dd->bz == DM_BOUNDARY_PERIODIC || dd->interptype == DMDA_Q0) {
 93:       PetscCall(PetscIntMultError(dd->refine_z, dd->P, &dd->P));
 94:     } else {
 95:       PetscCall(PetscIntMultError(dd->refine_z, dd->P - 1, &dd->P));
 96:       dd->P += 1;
 97:     }
 98:     da->levelup++;
 99:     if (da->levelup - da->leveldown >= 0) {
100:       dd->refine_x = refx[da->levelup - da->leveldown];
101:       dd->refine_y = refy[da->levelup - da->leveldown];
102:       dd->refine_z = refz[da->levelup - da->leveldown];
103:     }
104:     if (da->levelup - da->leveldown >= 1) {
105:       dd->coarsen_x = refx[da->levelup - da->leveldown - 1];
106:       dd->coarsen_y = refy[da->levelup - da->leveldown - 1];
107:       dd->coarsen_z = refz[da->levelup - da->leveldown - 1];
108:     }
109:   }
110:   PetscFunctionReturn(PETSC_SUCCESS);
111: }

113: static PetscErrorCode DMLoad_DA(DM da, PetscViewer viewer)
114: {
115:   PetscInt        dim, m, n, p, dof, swidth;
116:   DMDAStencilType stencil;
117:   DMBoundaryType  bx, by, bz;
118:   PetscBool       coors;
119:   DM              dac;
120:   Vec             c;

122:   PetscFunctionBegin;
123:   PetscCall(PetscViewerBinaryRead(viewer, &dim, 1, NULL, PETSC_INT));
124:   PetscCall(PetscViewerBinaryRead(viewer, &m, 1, NULL, PETSC_INT));
125:   PetscCall(PetscViewerBinaryRead(viewer, &n, 1, NULL, PETSC_INT));
126:   PetscCall(PetscViewerBinaryRead(viewer, &p, 1, NULL, PETSC_INT));
127:   PetscCall(PetscViewerBinaryRead(viewer, &dof, 1, NULL, PETSC_INT));
128:   PetscCall(PetscViewerBinaryRead(viewer, &swidth, 1, NULL, PETSC_INT));
129:   PetscCall(PetscViewerBinaryRead(viewer, &bx, 1, NULL, PETSC_ENUM));
130:   PetscCall(PetscViewerBinaryRead(viewer, &by, 1, NULL, PETSC_ENUM));
131:   PetscCall(PetscViewerBinaryRead(viewer, &bz, 1, NULL, PETSC_ENUM));
132:   PetscCall(PetscViewerBinaryRead(viewer, &stencil, 1, NULL, PETSC_ENUM));

134:   PetscCall(DMSetDimension(da, dim));
135:   PetscCall(DMDASetSizes(da, m, n, p));
136:   PetscCall(DMDASetBoundaryType(da, bx, by, bz));
137:   PetscCall(DMDASetDof(da, dof));
138:   PetscCall(DMDASetStencilType(da, stencil));
139:   PetscCall(DMDASetStencilWidth(da, swidth));
140:   PetscCall(DMSetUp(da));
141:   PetscCall(PetscViewerBinaryRead(viewer, &coors, 1, NULL, PETSC_ENUM));
142:   if (coors) {
143:     PetscCall(DMGetCoordinateDM(da, &dac));
144:     PetscCall(DMCreateGlobalVector(dac, &c));
145:     PetscCall(VecLoad(c, viewer));
146:     PetscCall(DMSetCoordinates(da, c));
147:     PetscCall(VecDestroy(&c));
148:   }
149:   PetscFunctionReturn(PETSC_SUCCESS);
150: }

152: static PetscErrorCode DMCreateSubDM_DA(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm)
153: {
154:   DM_DA *da = (DM_DA *)dm->data;

156:   PetscFunctionBegin;
157:   if (subdm) {
158:     PetscSF sf;
159:     Vec     coords;
160:     void   *ctx;
161:     /* Cannot use DMClone since the dof stuff is mixed in. Ugh
162:     PetscCall(DMClone(dm, subdm)); */
163:     PetscCall(DMCreate(PetscObjectComm((PetscObject)dm), subdm));
164:     PetscCall(DMGetPointSF(dm, &sf));
165:     PetscCall(DMSetPointSF(*subdm, sf));
166:     PetscCall(DMGetApplicationContext(dm, &ctx));
167:     PetscCall(DMSetApplicationContext(*subdm, ctx));
168:     PetscCall(DMGetCoordinatesLocal(dm, &coords));
169:     if (coords) {
170:       PetscCall(DMSetCoordinatesLocal(*subdm, coords));
171:     } else {
172:       PetscCall(DMGetCoordinates(dm, &coords));
173:       if (coords) PetscCall(DMSetCoordinates(*subdm, coords));
174:     }

176:     PetscCall(DMSetType(*subdm, DMDA));
177:     PetscCall(DMSetDimension(*subdm, dm->dim));
178:     PetscCall(DMDASetSizes(*subdm, da->M, da->N, da->P));
179:     PetscCall(DMDASetNumProcs(*subdm, da->m, da->n, da->p));
180:     PetscCall(DMDASetBoundaryType(*subdm, da->bx, da->by, da->bz));
181:     PetscCall(DMDASetDof(*subdm, numFields));
182:     PetscCall(DMDASetStencilType(*subdm, da->stencil_type));
183:     PetscCall(DMDASetStencilWidth(*subdm, da->s));
184:     PetscCall(DMDASetOwnershipRanges(*subdm, da->lx, da->ly, da->lz));
185:   }
186:   if (is) {
187:     PetscInt *indices, cnt = 0, dof = da->w, i, j;

189:     PetscCall(PetscMalloc1(da->Nlocal * numFields / dof, &indices));
190:     for (i = da->base / dof; i < (da->base + da->Nlocal) / dof; ++i) {
191:       for (j = 0; j < numFields; ++j) indices[cnt++] = dof * i + fields[j];
192:     }
193:     PetscCheck(cnt == da->Nlocal * numFields / dof, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Count %" PetscInt_FMT " does not equal expected value %" PetscInt_FMT, cnt, da->Nlocal * numFields / dof);
194:     PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)dm), cnt, indices, PETSC_OWN_POINTER, is));
195:   }
196:   PetscFunctionReturn(PETSC_SUCCESS);
197: }

199: static PetscErrorCode DMCreateFieldDecomposition_DA(DM dm, PetscInt *len, char ***namelist, IS **islist, DM **dmlist)
200: {
201:   PetscInt i;
202:   DM_DA   *dd  = (DM_DA *)dm->data;
203:   PetscInt dof = dd->w;

205:   PetscFunctionBegin;
206:   if (len) *len = dof;
207:   if (islist) {
208:     Vec      v;
209:     PetscInt rstart, n;

211:     PetscCall(DMGetGlobalVector(dm, &v));
212:     PetscCall(VecGetOwnershipRange(v, &rstart, NULL));
213:     PetscCall(VecGetLocalSize(v, &n));
214:     PetscCall(DMRestoreGlobalVector(dm, &v));
215:     PetscCall(PetscMalloc1(dof, islist));
216:     for (i = 0; i < dof; i++) PetscCall(ISCreateStride(PetscObjectComm((PetscObject)dm), n / dof, rstart + i, dof, &(*islist)[i]));
217:   }
218:   if (namelist) {
219:     PetscCall(PetscMalloc1(dof, namelist));
220:     if (dd->fieldname) {
221:       for (i = 0; i < dof; i++) PetscCall(PetscStrallocpy(dd->fieldname[i], &(*namelist)[i]));
222:     } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Currently DMDA must have fieldnames");
223:   }
224:   if (dmlist) {
225:     DM da;

227:     PetscCall(DMDACreate(PetscObjectComm((PetscObject)dm), &da));
228:     PetscCall(DMSetDimension(da, dm->dim));
229:     PetscCall(DMDASetSizes(da, dd->M, dd->N, dd->P));
230:     PetscCall(DMDASetNumProcs(da, dd->m, dd->n, dd->p));
231:     PetscCall(DMDASetBoundaryType(da, dd->bx, dd->by, dd->bz));
232:     PetscCall(DMDASetDof(da, 1));
233:     PetscCall(DMDASetStencilType(da, dd->stencil_type));
234:     PetscCall(DMDASetStencilWidth(da, dd->s));
235:     PetscCall(DMSetUp(da));
236:     PetscCall(PetscMalloc1(dof, dmlist));
237:     for (i = 0; i < dof - 1; i++) PetscCall(PetscObjectReference((PetscObject)da));
238:     for (i = 0; i < dof; i++) (*dmlist)[i] = da;
239:   }
240:   PetscFunctionReturn(PETSC_SUCCESS);
241: }

243: static PetscErrorCode DMClone_DA(DM dm, DM *newdm)
244: {
245:   DM_DA *da = (DM_DA *)dm->data;

247:   PetscFunctionBegin;
248:   PetscCall(DMSetType(*newdm, DMDA));
249:   PetscCall(DMSetDimension(*newdm, dm->dim));
250:   PetscCall(DMDASetSizes(*newdm, da->M, da->N, da->P));
251:   PetscCall(DMDASetNumProcs(*newdm, da->m, da->n, da->p));
252:   PetscCall(DMDASetBoundaryType(*newdm, da->bx, da->by, da->bz));
253:   PetscCall(DMDASetDof(*newdm, da->w));
254:   PetscCall(DMDASetStencilType(*newdm, da->stencil_type));
255:   PetscCall(DMDASetStencilWidth(*newdm, da->s));
256:   PetscCall(DMDASetOwnershipRanges(*newdm, da->lx, da->ly, da->lz));
257:   PetscCall(DMSetUp(*newdm));
258:   PetscFunctionReturn(PETSC_SUCCESS);
259: }

261: static PetscErrorCode DMHasCreateInjection_DA(DM dm, PetscBool *flg)
262: {
263:   DM_DA *da = (DM_DA *)dm->data;

265:   PetscFunctionBegin;
267:   PetscAssertPointer(flg, 2);
268:   *flg = da->interptype == DMDA_Q1 ? PETSC_TRUE : PETSC_FALSE;
269:   PetscFunctionReturn(PETSC_SUCCESS);
270: }

272: static PetscErrorCode DMGetDimPoints_DA(DM dm, PetscInt dim, PetscInt *pStart, PetscInt *pEnd)
273: {
274:   PetscFunctionBegin;
275:   PetscCall(DMDAGetDepthStratum(dm, dim, pStart, pEnd));
276:   PetscFunctionReturn(PETSC_SUCCESS);
277: }

279: static PetscErrorCode DMGetNeighbors_DA(DM dm, PetscInt *nranks, const PetscMPIInt *ranks[])
280: {
281:   PetscInt        dim;
282:   DMDAStencilType st;

284:   PetscFunctionBegin;
285:   PetscCall(DMDAGetNeighbors(dm, ranks));
286:   PetscCall(DMDAGetInfo(dm, &dim, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, &st));

288:   switch (dim) {
289:   case 1:
290:     *nranks = 3;
291:     /* if (st == DMDA_STENCIL_STAR) *nranks = 3; */
292:     break;
293:   case 2:
294:     *nranks = 9;
295:     /* if (st == DMDA_STENCIL_STAR) *nranks = 5; */
296:     break;
297:   case 3:
298:     *nranks = 27;
299:     /* if (st == DMDA_STENCIL_STAR) *nranks = 7; */
300:     break;
301:   default:
302:     break;
303:   }
304:   PetscFunctionReturn(PETSC_SUCCESS);
305: }

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

312:          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
313:          vertex centered; see the documentation for `DMSTAG`, a similar `DM` implementation which supports more general staggered grids.

315:   Level: intermediate

317: .seealso: [](sec_struct), `DMType`, `DMCOMPOSITE`, `DMSTAG`, `DMDACreate()`, `DMCreate()`, `DMSetType()`, `DMDASetStencilWidth()`, `DMDASetStencilType()`,
318:           `DMDAStencilType`
319: M*/

321: PETSC_EXTERN PetscErrorCode DMCreate_DA(DM da)
322: {
323:   DM_DA *dd;

325:   PetscFunctionBegin;
326:   PetscAssertPointer(da, 1);
327:   PetscCall(PetscNew(&dd));
328:   da->data = dd;

330:   da->dim        = -1;
331:   dd->interptype = DMDA_Q1;
332:   dd->refine_x   = 2;
333:   dd->refine_y   = 2;
334:   dd->refine_z   = 2;
335:   dd->coarsen_x  = 2;
336:   dd->coarsen_y  = 2;
337:   dd->coarsen_z  = 2;
338:   dd->fieldname  = NULL;
339:   dd->nlocal     = -1;
340:   dd->Nlocal     = -1;
341:   dd->M          = -1;
342:   dd->N          = -1;
343:   dd->P          = -1;
344:   dd->m          = -1;
345:   dd->n          = -1;
346:   dd->p          = -1;
347:   dd->w          = -1;
348:   dd->s          = -1;

350:   dd->xs = -1;
351:   dd->xe = -1;
352:   dd->ys = -1;
353:   dd->ye = -1;
354:   dd->zs = -1;
355:   dd->ze = -1;
356:   dd->Xs = -1;
357:   dd->Xe = -1;
358:   dd->Ys = -1;
359:   dd->Ye = -1;
360:   dd->Zs = -1;
361:   dd->Ze = -1;

363:   dd->Nsub = 1;
364:   dd->xol  = 0;
365:   dd->yol  = 0;
366:   dd->zol  = 0;
367:   dd->xo   = 0;
368:   dd->yo   = 0;
369:   dd->zo   = 0;
370:   dd->Mo   = -1;
371:   dd->No   = -1;
372:   dd->Po   = -1;

374:   dd->gtol = NULL;
375:   dd->ltol = NULL;
376:   dd->ao   = NULL;
377:   PetscCall(PetscStrallocpy(AOBASIC, (char **)&dd->aotype));
378:   dd->base         = -1;
379:   dd->bx           = DM_BOUNDARY_NONE;
380:   dd->by           = DM_BOUNDARY_NONE;
381:   dd->bz           = DM_BOUNDARY_NONE;
382:   dd->stencil_type = DMDA_STENCIL_BOX;
383:   dd->interptype   = DMDA_Q1;
384:   dd->lx           = NULL;
385:   dd->ly           = NULL;
386:   dd->lz           = NULL;

388:   dd->elementtype = DMDA_ELEMENT_Q1;

390:   da->ops->globaltolocalbegin        = DMGlobalToLocalBegin_DA;
391:   da->ops->globaltolocalend          = DMGlobalToLocalEnd_DA;
392:   da->ops->localtoglobalbegin        = DMLocalToGlobalBegin_DA;
393:   da->ops->localtoglobalend          = DMLocalToGlobalEnd_DA;
394:   da->ops->localtolocalbegin         = DMLocalToLocalBegin_DA;
395:   da->ops->localtolocalend           = DMLocalToLocalEnd_DA;
396:   da->ops->createglobalvector        = DMCreateGlobalVector_DA;
397:   da->ops->createlocalvector         = DMCreateLocalVector_DA;
398:   da->ops->createinterpolation       = DMCreateInterpolation_DA;
399:   da->ops->getcoloring               = DMCreateColoring_DA;
400:   da->ops->creatematrix              = DMCreateMatrix_DA;
401:   da->ops->refine                    = DMRefine_DA;
402:   da->ops->coarsen                   = DMCoarsen_DA;
403:   da->ops->refinehierarchy           = DMRefineHierarchy_DA;
404:   da->ops->coarsenhierarchy          = DMCoarsenHierarchy_DA;
405:   da->ops->createinjection           = DMCreateInjection_DA;
406:   da->ops->hascreateinjection        = DMHasCreateInjection_DA;
407:   da->ops->destroy                   = DMDestroy_DA;
408:   da->ops->view                      = NULL;
409:   da->ops->setfromoptions            = DMSetFromOptions_DA;
410:   da->ops->setup                     = DMSetUp_DA;
411:   da->ops->clone                     = DMClone_DA;
412:   da->ops->load                      = DMLoad_DA;
413:   da->ops->createcoordinatedm        = DMCreateCoordinateDM_DA;
414:   da->ops->createsubdm               = DMCreateSubDM_DA;
415:   da->ops->createfielddecomposition  = DMCreateFieldDecomposition_DA;
416:   da->ops->createdomaindecomposition = DMCreateDomainDecomposition_DA;
417:   da->ops->createddscatters          = DMCreateDomainDecompositionScatters_DA;
418:   da->ops->getdimpoints              = DMGetDimPoints_DA;
419:   da->ops->getneighbors              = DMGetNeighbors_DA;
420:   da->ops->locatepoints              = DMLocatePoints_DA_Regular;
421:   da->ops->getcompatibility          = DMGetCompatibility_DA;
422:   PetscCall(PetscObjectComposeFunction((PetscObject)da, "DMSetUpGLVisViewer_C", DMSetUpGLVisViewer_DMDA));
423:   PetscFunctionReturn(PETSC_SUCCESS);
424: }

426: /*@
427:   DMDACreate - Creates a `DMDA` object for managing structured grids.

429:   Collective

431:   Input Parameter:
432: . comm - The communicator for the `DMDA` object

434:   Output Parameter:
435: . da - The DMDA object

437:   Level: advanced

439:   Developer Note:
440:   Since there exists DMDACreate1/2/3d() should this routine even exist?

442: .seealso: [](sec_struct), `DMDASetSizes()`, `DMClone()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`
443: @*/
444: PetscErrorCode DMDACreate(MPI_Comm comm, DM *da)
445: {
446:   PetscFunctionBegin;
447:   PetscAssertPointer(da, 2);
448:   PetscCall(DMCreate(comm, da));
449:   PetscCall(DMSetType(*da, DMDA));
450:   PetscFunctionReturn(PETSC_SUCCESS);
451: }