1 #include <petsc/private/dmpleximpl.h> /*I "petscdmplex.h" I*/ 2 #include <parmmg/libparmmg.h> 3 4 PETSC_EXTERN PetscErrorCode DMAdaptMetric_ParMmg_Plex(DM dm, Vec vertexMetric, DMLabel bdLabel, DMLabel rgLabel, DM *dmNew) 5 { 6 MPI_Comm comm, tmpComm; 7 const char *bdName = "_boundary_"; 8 const char *rgName = "_regions_"; 9 DM udm, cdm; 10 DMLabel bdLabelNew, rgLabelNew; 11 const char *bdLabelName, *rgLabelName; 12 IS globalVertexNum; 13 PetscSection coordSection; 14 Vec coordinates; 15 PetscSF sf; 16 const PetscScalar *coords, *met; 17 PetscReal *vertices, *metric, *verticesNew, *verticesNewLoc, gradationFactor; 18 PetscInt *cells, *cellsNew, *cellTags, *cellTagsNew, *verTags, *verTagsNew; 19 PetscInt *bdFaces, *faceTags, *facesNew, *faceTagsNew; 20 PetscInt *corners, *requiredCells, *requiredVer, *ridges, *requiredFaces; 21 PetscInt cStart, cEnd, c, numCells, fStart, fEnd, f, numFaceTags, vStart, vEnd, v, numVertices; 22 PetscInt dim, off, coff, maxConeSize, bdSize, i, j, k, Neq, verbosity, numIter; 23 PetscInt *numVerInterfaces, *ngbRanks, *verNgbRank, *interfaces_lv, *interfaces_gv, *intOffset; 24 PetscInt niranks, nrranks, numNgbRanks, numVerNgbRanksTotal, count, sliceSize, p, r, n, lv, gv; 25 PetscInt *gv_new, *owners, *verticesNewSorted, pStart, pEnd; 26 PetscInt numCellsNew, numVerticesNew, numCornersNew, numFacesNew, numVerticesNewLoc; 27 const PetscInt *gV, *ioffset, *irootloc, *roffset, *rmine, *rremote; 28 PetscBool flg = PETSC_FALSE, noInsert, noSwap, noMove; 29 const PetscMPIInt *iranks, *rranks; 30 PetscMPIInt numProcs, rank; 31 PMMG_pParMesh parmesh = NULL; 32 PetscErrorCode ierr; 33 34 PetscFunctionBegin; 35 ierr = PetscObjectGetComm((PetscObject) dm, &comm);CHKERRQ(ierr); 36 ierr = MPI_Comm_size(comm, &numProcs);CHKERRMPI(ierr); 37 ierr = MPI_Comm_rank(comm, &rank);CHKERRMPI(ierr); 38 ierr = MPI_Comm_dup(comm, &tmpComm);CHKERRMPI(ierr); 39 if (bdLabel) { 40 ierr = PetscObjectGetName((PetscObject) bdLabel, &bdLabelName);CHKERRQ(ierr); 41 ierr = PetscStrcmp(bdLabelName, bdName, &flg);CHKERRQ(ierr); 42 if (flg) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "\"%s\" cannot be used as label for boundary facets", bdLabelName); 43 } 44 if (rgLabel) { 45 ierr = PetscObjectGetName((PetscObject) rgLabel, &rgLabelName);CHKERRQ(ierr); 46 ierr = PetscStrcmp(rgLabelName, rgName, &flg);CHKERRQ(ierr); 47 if (flg) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "\"%s\" cannot be used as label for element tags", rgLabelName); 48 } 49 50 /* Get mesh information */ 51 ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr); 52 if (dim != 3) SETERRQ(comm, PETSC_ERR_ARG_OUTOFRANGE, "ParMmg only works in 3D.\n"); 53 Neq = (dim*(dim+1))/2; 54 ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr); 55 ierr = DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd);CHKERRQ(ierr); 56 ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr); 57 ierr = DMPlexUninterpolate(dm, &udm);CHKERRQ(ierr); 58 ierr = DMPlexGetMaxSizes(udm, &maxConeSize, NULL);CHKERRQ(ierr); 59 numCells = cEnd - cStart; 60 numVertices = vEnd - vStart; 61 62 /* Get cell offsets */ 63 ierr = PetscMalloc1(numCells*maxConeSize, &cells);CHKERRQ(ierr); 64 for (c = 0, coff = 0; c < numCells; ++c) { 65 const PetscInt *cone; 66 PetscInt coneSize, cl; 67 68 ierr = DMPlexGetConeSize(udm, c, &coneSize);CHKERRQ(ierr); 69 ierr = DMPlexGetCone(udm, c, &cone);CHKERRQ(ierr); 70 for (cl = 0; cl < coneSize; ++cl) cells[coff++] = cone[cl] - vStart+1; 71 } 72 73 /* Get vertex coordinate array */ 74 ierr = DMGetCoordinateDM(dm, &cdm);CHKERRQ(ierr); 75 ierr = DMGetLocalSection(cdm, &coordSection);CHKERRQ(ierr); 76 ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr); 77 ierr = VecGetArrayRead(coordinates, &coords);CHKERRQ(ierr); 78 ierr = PetscMalloc2(numVertices*Neq, &metric, dim*numVertices, &vertices);CHKERRQ(ierr); 79 for (v = 0; v < vEnd-vStart; ++v) { 80 ierr = PetscSectionGetOffset(coordSection, v+vStart, &off);CHKERRQ(ierr); 81 for (i = 0; i < dim; ++i) vertices[dim*v+i] = PetscRealPart(coords[off+i]); 82 } 83 ierr = VecRestoreArrayRead(coordinates, &coords);CHKERRQ(ierr); 84 85 /* Get face tags */ 86 if (!bdLabel) { 87 flg = PETSC_TRUE; 88 ierr = DMLabelCreate(PETSC_COMM_SELF, bdName, &bdLabel);CHKERRQ(ierr); 89 ierr = DMPlexMarkBoundaryFaces(dm, 1, bdLabel);CHKERRQ(ierr); 90 } 91 ierr = DMLabelGetBounds(bdLabel, &pStart, &pEnd);CHKERRQ(ierr); 92 for (f = pStart, bdSize = 0, numFaceTags = 0; f < pEnd; ++f) { 93 PetscBool hasPoint; 94 PetscInt *closure = NULL, closureSize, cl; 95 96 ierr = DMLabelHasPoint(bdLabel, f, &hasPoint);CHKERRQ(ierr); 97 if ((!hasPoint) || (f < fStart) || (f >= fEnd)) continue; 98 numFaceTags++; 99 100 ierr = DMPlexGetTransitiveClosure(dm, f, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr); 101 for (cl = 0; cl < closureSize*2; cl += 2) { 102 if ((closure[cl] >= vStart) && (closure[cl] < vEnd)) ++bdSize; 103 } 104 ierr = DMPlexRestoreTransitiveClosure(dm, f, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr); 105 } 106 ierr = PetscMalloc2(bdSize, &bdFaces, numFaceTags, &faceTags);CHKERRQ(ierr); 107 for (f = pStart, bdSize = 0, numFaceTags = 0; f < pEnd; ++f) { 108 PetscBool hasPoint; 109 PetscInt *closure = NULL, closureSize, cl; 110 111 ierr = DMLabelHasPoint(bdLabel, f, &hasPoint);CHKERRQ(ierr); 112 if ((!hasPoint) || (f < fStart) || (f >= fEnd)) continue; 113 114 ierr = DMPlexGetTransitiveClosure(dm, f, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr); 115 for (cl = 0; cl < closureSize*2; cl += 2) { 116 if ((closure[cl] >= vStart) && (closure[cl] < vEnd)) bdFaces[bdSize++] = closure[cl] - vStart+1; 117 } 118 ierr = DMPlexRestoreTransitiveClosure(dm, f, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr); 119 ierr = DMLabelGetValue(bdLabel, f, &faceTags[numFaceTags++]);CHKERRQ(ierr); 120 } 121 122 /* Get cell tags */ 123 ierr = PetscCalloc2(numVertices, &verTags, numCells, &cellTags);CHKERRQ(ierr); 124 if (rgLabel) { 125 for (c = cStart; c < cEnd; ++c) { ierr = DMLabelGetValue(rgLabel, c, &cellTags[c]);CHKERRQ(ierr); } 126 } 127 128 /* Get metric */ 129 ierr = VecViewFromOptions(vertexMetric, NULL, "-adapt_metric_view");CHKERRQ(ierr); 130 ierr = VecGetArrayRead(vertexMetric, &met);CHKERRQ(ierr); 131 for (v = 0; v < (vEnd-vStart); ++v) { 132 for (i = 0, k = 0; i < dim; ++i) { 133 for (j = i; j < dim; ++j) { 134 metric[Neq*v+k] = PetscRealPart(met[dim*dim*v+dim*i+j]); 135 k++; 136 } 137 } 138 } 139 ierr = VecRestoreArrayRead(vertexMetric, &met);CHKERRQ(ierr); 140 141 /* Build ParMMG communicators: the list of vertices between two partitions */ 142 niranks = nrranks = 0; 143 numNgbRanks = 0; 144 if (numProcs > 1) { 145 ierr = DMGetPointSF(dm, &sf);CHKERRQ(ierr); 146 ierr = PetscSFSetUp(sf);CHKERRQ(ierr); 147 ierr = PetscSFGetLeafRanks(sf, &niranks, &iranks, &ioffset, &irootloc);CHKERRQ(ierr); 148 ierr = PetscSFGetRootRanks(sf, &nrranks, &rranks, &roffset, &rmine, &rremote);CHKERRQ(ierr); 149 ierr = PetscCalloc1(numProcs, &numVerInterfaces);CHKERRQ(ierr); 150 151 /* Counting */ 152 for (r = 0; r < niranks; ++r) { 153 for (i=ioffset[r], count=0; i<ioffset[r+1]; ++i) { 154 if (irootloc[i] >= vStart && irootloc[i] < vEnd) count++; 155 } 156 numVerInterfaces[iranks[r]] += count; 157 } 158 for (r = 0; r < nrranks; ++r) { 159 for (i=roffset[r], count=0; i<roffset[r+1]; ++i) { 160 if (rmine[i] >= vStart && rmine[i] < vEnd) count++; 161 } 162 numVerInterfaces[rranks[r]] += count; 163 } 164 for (p = 0; p < numProcs; ++p) { 165 if (numVerInterfaces[p]) numNgbRanks++; 166 } 167 ierr = PetscMalloc2(numNgbRanks, &ngbRanks, numNgbRanks, &verNgbRank);CHKERRQ(ierr); 168 for (p = 0, n = 0; p < numProcs; ++p) { 169 if (numVerInterfaces[p]) { 170 ngbRanks[n] = p; 171 verNgbRank[n] = numVerInterfaces[p]; 172 n++; 173 } 174 } 175 numVerNgbRanksTotal = 0; 176 for (p = 0; p < numNgbRanks; ++p) numVerNgbRanksTotal += verNgbRank[p]; 177 178 /* For each neighbor, fill in interface arrays */ 179 ierr = PetscMalloc3(numVerNgbRanksTotal, &interfaces_lv, numVerNgbRanksTotal, &interfaces_gv, numNgbRanks+1, &intOffset);CHKERRQ(ierr); 180 intOffset[0] = 0; 181 for (p = 0, r = 0, i = 0; p < numNgbRanks; ++p) { 182 intOffset[p+1] = intOffset[p]; 183 if (iranks && iranks[i] == ngbRanks[p]) { 184 185 /* Add the right slice of irootloc at the right place */ 186 sliceSize = ioffset[i+1]-ioffset[i]; 187 for (j = 0, count = 0; j < sliceSize; ++j) { 188 if (ioffset[i]+j >= ioffset[niranks]) SETERRQ(comm, PETSC_ERR_ARG_OUTOFRANGE, "Offset out of range"); 189 v = irootloc[ioffset[i]+j]; 190 if (v >= vStart && v < vEnd) { 191 if (intOffset[p+1]+count >= numVerNgbRanksTotal) SETERRQ(comm, PETSC_ERR_ARG_OUTOFRANGE, "Offset out of range"); 192 interfaces_lv[intOffset[p+1]+count] = v-vStart; 193 count++; 194 } 195 } 196 intOffset[p+1] += count; 197 i++; 198 } 199 if (rranks && rranks[r] == ngbRanks[p]) { 200 201 /* Add the right slice of rmine at the right place */ 202 sliceSize = roffset[r+1]-roffset[r]; 203 for (j = 0, count = 0; j < sliceSize; ++j) { 204 if (roffset[r]+j >= roffset[nrranks]) SETERRQ(comm, PETSC_ERR_ARG_OUTOFRANGE, "Offset out of range"); 205 v = rmine[roffset[r]+j]; 206 if (v >= vStart && v < vEnd) { 207 if (intOffset[p+1]+count >= numVerNgbRanksTotal) SETERRQ(comm, PETSC_ERR_ARG_OUTOFRANGE, "Offset out of range"); 208 interfaces_lv[intOffset[p+1]+count] = v-vStart; 209 count++; 210 } 211 } 212 intOffset[p+1] += count; 213 r++; 214 } 215 if (intOffset[p+1] != intOffset[p] + verNgbRank[p]) SETERRQ(comm, PETSC_ERR_ARG_OUTOFRANGE, "Unequal offsets"); 216 } 217 ierr = DMPlexGetVertexNumbering(udm, &globalVertexNum);CHKERRQ(ierr); 218 ierr = ISGetIndices(globalVertexNum, &gV);CHKERRQ(ierr); 219 for (i = 0; i < numVerNgbRanksTotal; ++i) { 220 v = gV[interfaces_lv[i]]; 221 interfaces_gv[i] = v < 0 ? -v-1 : v; 222 interfaces_lv[i] += 1; 223 interfaces_gv[i] += 1; 224 } 225 ierr = ISRestoreIndices(globalVertexNum, &gV);CHKERRQ(ierr); 226 ierr = PetscFree(numVerInterfaces);CHKERRQ(ierr); 227 } 228 ierr = DMDestroy(&udm);CHKERRQ(ierr); 229 230 /* Send the data to ParMmg and remesh */ 231 ierr = DMPlexMetricNoInsertion(dm, &noInsert);CHKERRQ(ierr); 232 ierr = DMPlexMetricNoSwapping(dm, &noSwap);CHKERRQ(ierr); 233 ierr = DMPlexMetricNoMovement(dm, &noMove);CHKERRQ(ierr); 234 ierr = DMPlexMetricGetVerbosity(dm, &verbosity);CHKERRQ(ierr); 235 ierr = DMPlexMetricGetNumIterations(dm, &numIter);CHKERRQ(ierr); 236 ierr = DMPlexMetricGetGradationFactor(dm, &gradationFactor);CHKERRQ(ierr); 237 ierr = PMMG_Init_parMesh(PMMG_ARG_start, PMMG_ARG_ppParMesh, &parmesh, PMMG_ARG_pMesh, PMMG_ARG_pMet, PMMG_ARG_dim, 3, PMMG_ARG_MPIComm, tmpComm, PMMG_ARG_end); 238 ierr = PMMG_Set_meshSize(parmesh, numVertices, numCells, 0, numFaceTags, 0, 0); 239 ierr = PMMG_Set_iparameter(parmesh, PMMG_IPARAM_APImode, PMMG_APIDISTRIB_nodes); 240 ierr = PMMG_Set_iparameter(parmesh, PMMG_IPARAM_noinsert, noInsert); 241 ierr = PMMG_Set_iparameter(parmesh, PMMG_IPARAM_noswap, noSwap); 242 ierr = PMMG_Set_iparameter(parmesh, PMMG_IPARAM_nomove, noMove); 243 ierr = PMMG_Set_iparameter(parmesh, PMMG_IPARAM_verbose, verbosity); 244 ierr = PMMG_Set_iparameter(parmesh, PMMG_IPARAM_globalNum, 1); 245 ierr = PMMG_Set_iparameter(parmesh, PMMG_IPARAM_niter, numIter); 246 ierr = PMMG_Set_dparameter(parmesh, PMMG_DPARAM_hgrad, gradationFactor); 247 ierr = PMMG_Set_vertices(parmesh, vertices, verTags); 248 ierr = PMMG_Set_tetrahedra(parmesh, cells, cellTags); 249 ierr = PMMG_Set_triangles(parmesh, bdFaces, faceTags); 250 ierr = PMMG_Set_metSize(parmesh, MMG5_Vertex, numVertices, MMG5_Tensor); 251 ierr = PMMG_Set_tensorMets(parmesh, metric); 252 ierr = PMMG_Set_numberOfNodeCommunicators(parmesh, numNgbRanks); 253 for (c = 0; c < numNgbRanks; ++c) { 254 ierr = PMMG_Set_ithNodeCommunicatorSize(parmesh, c, ngbRanks[c], intOffset[c+1]-intOffset[c]); 255 ierr = PMMG_Set_ithNodeCommunicator_nodes(parmesh, c, &interfaces_lv[intOffset[c]], &interfaces_gv[intOffset[c]], 1); 256 } 257 ierr = PMMG_parmmglib_distributed(parmesh); 258 ierr = PetscFree(cells);CHKERRQ(ierr); 259 ierr = PetscFree2(metric, vertices);CHKERRQ(ierr); 260 ierr = PetscFree2(bdFaces, faceTags);CHKERRQ(ierr); 261 ierr = PetscFree2(verTags, cellTags);CHKERRQ(ierr); 262 if (numProcs > 1) { 263 ierr = PetscFree2(ngbRanks, verNgbRank);CHKERRQ(ierr); 264 ierr = PetscFree3(interfaces_lv, interfaces_gv, intOffset);CHKERRQ(ierr); 265 } 266 267 /* Retrieve mesh from Mmg */ 268 numCornersNew = 4; 269 ierr = PMMG_Get_meshSize(parmesh, &numVerticesNew, &numCellsNew, 0, &numFacesNew, 0, 0); 270 ierr = PetscMalloc4(dim*numVerticesNew, &verticesNew, numVerticesNew, &verTagsNew, numVerticesNew, &corners, numVerticesNew, &requiredVer);CHKERRQ(ierr); 271 ierr = PetscMalloc3((dim+1)*numCellsNew, &cellsNew, numCellsNew, &cellTagsNew, numCellsNew, &requiredCells);CHKERRQ(ierr); 272 ierr = PetscMalloc4(dim*numFacesNew, &facesNew, numFacesNew, &faceTagsNew, numFacesNew, &ridges, numFacesNew, &requiredFaces);CHKERRQ(ierr); 273 ierr = PMMG_Get_vertices(parmesh, verticesNew, verTagsNew, corners, requiredVer); 274 ierr = PMMG_Get_tetrahedra(parmesh, cellsNew, cellTagsNew, requiredCells); 275 ierr = PMMG_Get_triangles(parmesh, facesNew, faceTagsNew, requiredFaces); 276 ierr = PetscMalloc2(numVerticesNew, &owners, numVerticesNew, &gv_new); 277 ierr = PMMG_Set_iparameter(parmesh, PMMG_IPARAM_globalNum, 1); 278 ierr = PMMG_Get_verticesGloNum(parmesh, gv_new, owners); 279 for (i = 0; i < dim*numFacesNew; ++i) facesNew[i] -= 1; 280 for (i = 0; i < (dim+1)*numCellsNew; ++i) { 281 cellsNew[i] = gv_new[cellsNew[i]-1]-1; 282 } 283 numVerticesNewLoc = 0; 284 for (i = 0; i < numVerticesNew; ++i) { 285 if (owners[i] == rank) numVerticesNewLoc++; 286 } 287 ierr = PetscMalloc2(numVerticesNewLoc*dim, &verticesNewLoc, numVerticesNew, &verticesNewSorted);CHKERRQ(ierr); 288 for (i = 0, c = 0; i < numVerticesNew; i++) { 289 if (owners[i] == rank) { 290 for (j=0; j<dim; ++j) verticesNewLoc[dim*c+j] = verticesNew[dim*i+j]; 291 c++; 292 } 293 } 294 295 /* Reorder for consistency with DMPlex */ 296 for (i = 0; i < numCellsNew; ++i) { ierr = DMPlexInvertCell(DM_POLYTOPE_TETRAHEDRON, &cellsNew[4*i]);CHKERRQ(ierr); } 297 298 /* Create new plex */ 299 ierr = DMPlexCreateFromCellListParallelPetsc(comm, dim, numCellsNew, numVerticesNewLoc, PETSC_DECIDE, numCornersNew, PETSC_TRUE, cellsNew, dim, verticesNewLoc, NULL, &verticesNewSorted, dmNew);CHKERRQ(ierr); 300 ierr = PMMG_Free_all(PMMG_ARG_start, PMMG_ARG_ppParMesh, &parmesh, PMMG_ARG_end); 301 ierr = PetscFree4(verticesNew, verTagsNew, corners, requiredVer);CHKERRQ(ierr); 302 303 /* Get adapted mesh information */ 304 ierr = DMPlexGetHeightStratum(*dmNew, 0, &cStart, &cEnd);CHKERRQ(ierr); 305 ierr = DMPlexGetHeightStratum(*dmNew, 1, &fStart, &fEnd);CHKERRQ(ierr); 306 ierr = DMPlexGetDepthStratum(*dmNew, 0, &vStart, &vEnd);CHKERRQ(ierr); 307 308 /* Rebuild boundary label */ 309 ierr = DMCreateLabel(*dmNew, flg ? bdName : bdLabelName);CHKERRQ(ierr); 310 ierr = DMGetLabel(*dmNew, flg ? bdName : bdLabelName, &bdLabelNew);CHKERRQ(ierr); 311 for (i = 0; i < numFacesNew; i++) { 312 PetscBool hasTag = PETSC_FALSE; 313 PetscInt numCoveredPoints, numFaces = 0, facePoints[3]; 314 const PetscInt *coveredPoints = NULL; 315 316 for (j = 0; j < dim; ++j) { 317 lv = facesNew[i*dim+j]; 318 gv = gv_new[lv]-1; 319 ierr = PetscFindInt(gv, numVerticesNew, verticesNewSorted, &lv);CHKERRQ(ierr); 320 facePoints[j] = lv+vStart; 321 } 322 ierr = DMPlexGetFullJoin(*dmNew, dim, facePoints, &numCoveredPoints, &coveredPoints);CHKERRQ(ierr); 323 for (j = 0; j < numCoveredPoints; ++j) { 324 if (coveredPoints[j] >= fStart && coveredPoints[j] < fEnd) { 325 numFaces++; 326 f = j; 327 } 328 } 329 if (numFaces != 1) SETERRQ2(comm, PETSC_ERR_ARG_OUTOFRANGE, "%d vertices cannot define more than 1 facet (%d)", dim, numFaces); 330 ierr = DMLabelHasStratum(bdLabel, faceTagsNew[i], &hasTag);CHKERRQ(ierr); 331 if (hasTag) { ierr = DMLabelSetValue(bdLabelNew, coveredPoints[f], faceTagsNew[i]);CHKERRQ(ierr); } 332 ierr = DMPlexRestoreJoin(*dmNew, dim, facePoints, &numCoveredPoints, &coveredPoints);CHKERRQ(ierr); 333 } 334 ierr = PetscFree4(facesNew, faceTagsNew, ridges, requiredFaces);CHKERRQ(ierr); 335 ierr = PetscFree2(owners, gv_new);CHKERRQ(ierr); 336 ierr = PetscFree2(verticesNewLoc, verticesNewSorted);CHKERRQ(ierr); 337 if (flg) { ierr = DMLabelDestroy(&bdLabel);CHKERRQ(ierr); } 338 339 /* Rebuild cell labels */ 340 ierr = DMCreateLabel(*dmNew, rgLabel ? rgLabelName : rgName);CHKERRQ(ierr); 341 ierr = DMGetLabel(*dmNew, rgLabel ? rgLabelName : rgName, &rgLabelNew);CHKERRQ(ierr); 342 for (c = cStart; c < cEnd; ++c) { ierr = DMLabelSetValue(rgLabelNew, c, cellTagsNew[c-cStart]);CHKERRQ(ierr); } 343 ierr = PetscFree3(cellsNew, cellTagsNew, requiredCells);CHKERRQ(ierr); 344 345 PetscFunctionReturn(0); 346 } 347