1 #include <petsc/private/dmimpl.h> /*I "petscdm.h" I*/ 2 #include <petscds.h> 3 4 PetscErrorCode DMCreateGlobalVector_Section_Private(DM dm,Vec *vec) 5 { 6 PetscSection gSection; 7 PetscInt localSize, bs, blockSize = -1, pStart, pEnd, p; 8 PetscErrorCode ierr; 9 PetscInt in[2],out[2]; 10 11 PetscFunctionBegin; 12 ierr = DMGetGlobalSection(dm, &gSection);CHKERRQ(ierr); 13 ierr = PetscSectionGetChart(gSection, &pStart, &pEnd);CHKERRQ(ierr); 14 for (p = pStart; p < pEnd; ++p) { 15 PetscInt dof, cdof; 16 17 ierr = PetscSectionGetDof(gSection, p, &dof);CHKERRQ(ierr); 18 ierr = PetscSectionGetConstraintDof(gSection, p, &cdof);CHKERRQ(ierr); 19 20 if (dof > 0) { 21 if (blockSize < 0 && dof-cdof > 0) { 22 /* set blockSize */ 23 blockSize = dof-cdof; 24 } else if (dof-cdof != blockSize) { 25 /* non-identical blockSize, set it as 1 */ 26 blockSize = 1; 27 break; 28 } 29 } 30 } 31 32 in[0] = blockSize < 0 ? PETSC_MIN_INT : -blockSize; 33 in[1] = blockSize; 34 ierr = MPIU_Allreduce(in,out,2,MPIU_INT,MPI_MAX,PetscObjectComm((PetscObject)dm));CHKERRQ(ierr); 35 /* -out[0] = min(blockSize), out[1] = max(blockSize) */ 36 if (-out[0] == out[1]) { 37 bs = out[1]; 38 } else bs = 1; 39 40 if (bs < 0) { /* Everyone was empty */ 41 blockSize = 1; 42 bs = 1; 43 } 44 45 ierr = PetscSectionGetConstrainedStorageSize(gSection, &localSize);CHKERRQ(ierr); 46 if (localSize%blockSize) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Mismatch between blocksize %d and local storage size %d", blockSize, localSize); 47 ierr = VecCreate(PetscObjectComm((PetscObject)dm), vec);CHKERRQ(ierr); 48 ierr = VecSetSizes(*vec, localSize, PETSC_DETERMINE);CHKERRQ(ierr); 49 ierr = VecSetBlockSize(*vec, bs);CHKERRQ(ierr); 50 ierr = VecSetType(*vec,dm->vectype);CHKERRQ(ierr); 51 ierr = VecSetDM(*vec, dm);CHKERRQ(ierr); 52 /* ierr = VecSetLocalToGlobalMapping(*vec, dm->ltogmap);CHKERRQ(ierr); */ 53 PetscFunctionReturn(0); 54 } 55 56 PetscErrorCode DMCreateLocalVector_Section_Private(DM dm,Vec *vec) 57 { 58 PetscSection section; 59 PetscInt localSize, blockSize = -1, pStart, pEnd, p; 60 PetscErrorCode ierr; 61 62 PetscFunctionBegin; 63 ierr = DMGetLocalSection(dm, §ion);CHKERRQ(ierr); 64 ierr = PetscSectionGetChart(section, &pStart, &pEnd);CHKERRQ(ierr); 65 for (p = pStart; p < pEnd; ++p) { 66 PetscInt dof; 67 68 ierr = PetscSectionGetDof(section, p, &dof);CHKERRQ(ierr); 69 if ((blockSize < 0) && (dof > 0)) blockSize = dof; 70 if ((dof > 0) && (dof != blockSize)) { 71 blockSize = 1; 72 break; 73 } 74 } 75 ierr = PetscSectionGetStorageSize(section, &localSize);CHKERRQ(ierr); 76 ierr = VecCreate(PETSC_COMM_SELF, vec);CHKERRQ(ierr); 77 ierr = VecSetSizes(*vec, localSize, localSize);CHKERRQ(ierr); 78 ierr = VecSetBlockSize(*vec, blockSize);CHKERRQ(ierr); 79 ierr = VecSetType(*vec,dm->vectype);CHKERRQ(ierr); 80 ierr = VecSetDM(*vec, dm);CHKERRQ(ierr); 81 PetscFunctionReturn(0); 82 } 83 84 /*@C 85 DMCreateSectionSubDM - Returns an IS and subDM+subSection encapsulating a subproblem defined by the fields in a PetscSection in the DM. 86 87 Not collective 88 89 Input Parameters: 90 + dm - The DM object 91 . numFields - The number of fields in this subproblem 92 - fields - The field numbers of the selected fields 93 94 Output Parameters: 95 + is - The global indices for the subproblem 96 - subdm - The DM for the subproblem, which must already have be cloned from dm 97 98 Note: This handles all information in the DM class and the PetscSection. This is used as the basis for creating subDMs in specialized classes, 99 such as Plex and Forest. 100 101 Level: intermediate 102 103 .seealso DMCreateSubDM(), DMGetLocalSection(), DMPlexSetMigrationSF(), DMView() 104 @*/ 105 PetscErrorCode DMCreateSectionSubDM(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm) 106 { 107 PetscSection section, sectionGlobal; 108 PetscInt *subIndices; 109 PetscInt subSize = 0, subOff = 0, Nf, f, pStart, pEnd, p; 110 PetscErrorCode ierr; 111 112 PetscFunctionBegin; 113 if (!numFields) PetscFunctionReturn(0); 114 ierr = DMGetLocalSection(dm, §ion);CHKERRQ(ierr); 115 ierr = DMGetGlobalSection(dm, §ionGlobal);CHKERRQ(ierr); 116 if (!section) SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Must set default section for DM before splitting fields"); 117 if (!sectionGlobal) SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Must set default global section for DM before splitting fields"); 118 ierr = PetscSectionGetNumFields(section, &Nf);CHKERRQ(ierr); 119 if (numFields > Nf) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Number of requested fields %d greater than number of DM fields %d", numFields, Nf); 120 if (is) { 121 PetscInt bs, bsLocal[2], bsMinMax[2]; 122 123 for (f = 0, bs = 0; f < numFields; ++f) { 124 PetscInt Nc; 125 126 ierr = PetscSectionGetFieldComponents(section, fields[f], &Nc);CHKERRQ(ierr); 127 bs += Nc; 128 } 129 ierr = PetscSectionGetChart(sectionGlobal, &pStart, &pEnd);CHKERRQ(ierr); 130 for (p = pStart; p < pEnd; ++p) { 131 PetscInt gdof, pSubSize = 0; 132 133 ierr = PetscSectionGetDof(sectionGlobal, p, &gdof);CHKERRQ(ierr); 134 if (gdof > 0) { 135 for (f = 0; f < numFields; ++f) { 136 PetscInt fdof, fcdof; 137 138 ierr = PetscSectionGetFieldDof(section, p, fields[f], &fdof);CHKERRQ(ierr); 139 ierr = PetscSectionGetFieldConstraintDof(section, p, fields[f], &fcdof);CHKERRQ(ierr); 140 pSubSize += fdof-fcdof; 141 } 142 subSize += pSubSize; 143 if (pSubSize && bs != pSubSize) { 144 /* Layout does not admit a pointwise block size */ 145 bs = 1; 146 } 147 } 148 } 149 /* Must have same blocksize on all procs (some might have no points) */ 150 bsLocal[0] = bs < 0 ? PETSC_MAX_INT : bs; bsLocal[1] = bs; 151 ierr = PetscGlobalMinMaxInt(PetscObjectComm((PetscObject) dm), bsLocal, bsMinMax);CHKERRQ(ierr); 152 if (bsMinMax[0] != bsMinMax[1]) {bs = 1;} 153 else {bs = bsMinMax[0];} 154 ierr = PetscMalloc1(subSize, &subIndices);CHKERRQ(ierr); 155 for (p = pStart; p < pEnd; ++p) { 156 PetscInt gdof, goff; 157 158 ierr = PetscSectionGetDof(sectionGlobal, p, &gdof);CHKERRQ(ierr); 159 if (gdof > 0) { 160 ierr = PetscSectionGetOffset(sectionGlobal, p, &goff);CHKERRQ(ierr); 161 for (f = 0; f < numFields; ++f) { 162 PetscInt fdof, fcdof, fc, f2, poff = 0; 163 164 /* Can get rid of this loop by storing field information in the global section */ 165 for (f2 = 0; f2 < fields[f]; ++f2) { 166 ierr = PetscSectionGetFieldDof(section, p, f2, &fdof);CHKERRQ(ierr); 167 ierr = PetscSectionGetFieldConstraintDof(section, p, f2, &fcdof);CHKERRQ(ierr); 168 poff += fdof-fcdof; 169 } 170 ierr = PetscSectionGetFieldDof(section, p, fields[f], &fdof);CHKERRQ(ierr); 171 ierr = PetscSectionGetFieldConstraintDof(section, p, fields[f], &fcdof);CHKERRQ(ierr); 172 for (fc = 0; fc < fdof-fcdof; ++fc, ++subOff) { 173 subIndices[subOff] = goff+poff+fc; 174 } 175 } 176 } 177 } 178 ierr = ISCreateGeneral(PetscObjectComm((PetscObject)dm), subSize, subIndices, PETSC_OWN_POINTER, is);CHKERRQ(ierr); 179 if (bs > 1) { 180 /* We need to check that the block size does not come from non-contiguous fields */ 181 PetscInt i, j, set = 1; 182 for (i = 0; i < subSize; i += bs) { 183 for (j = 0; j < bs; ++j) { 184 if (subIndices[i+j] != subIndices[i]+j) {set = 0; break;} 185 } 186 } 187 if (set) {ierr = ISSetBlockSize(*is, bs);CHKERRQ(ierr);} 188 } 189 } 190 if (subdm) { 191 PetscSection subsection; 192 PetscBool haveNull = PETSC_FALSE; 193 PetscInt f, nf = 0, of = 0; 194 195 ierr = PetscSectionCreateSubsection(section, numFields, fields, &subsection);CHKERRQ(ierr); 196 ierr = DMSetLocalSection(*subdm, subsection);CHKERRQ(ierr); 197 ierr = PetscSectionDestroy(&subsection);CHKERRQ(ierr); 198 for (f = 0; f < numFields; ++f) { 199 (*subdm)->nullspaceConstructors[f] = dm->nullspaceConstructors[fields[f]]; 200 if ((*subdm)->nullspaceConstructors[f]) { 201 haveNull = PETSC_TRUE; 202 nf = f; 203 of = fields[f]; 204 } 205 } 206 if (dm->probs) { 207 ierr = DMSetNumFields(*subdm, numFields);CHKERRQ(ierr); 208 for (f = 0; f < numFields; ++f) { 209 PetscObject disc; 210 211 ierr = DMGetField(dm, fields[f], NULL, &disc);CHKERRQ(ierr); 212 ierr = DMSetField(*subdm, f, NULL, disc);CHKERRQ(ierr); 213 } 214 ierr = DMCreateDS(*subdm);CHKERRQ(ierr); 215 if (numFields == 1 && is) { 216 PetscObject disc, space, pmat; 217 218 ierr = DMGetField(*subdm, 0, NULL, &disc);CHKERRQ(ierr); 219 ierr = PetscObjectQuery(disc, "nullspace", &space);CHKERRQ(ierr); 220 if (space) {ierr = PetscObjectCompose((PetscObject) *is, "nullspace", space);CHKERRQ(ierr);} 221 ierr = PetscObjectQuery(disc, "nearnullspace", &space);CHKERRQ(ierr); 222 if (space) {ierr = PetscObjectCompose((PetscObject) *is, "nearnullspace", space);CHKERRQ(ierr);} 223 ierr = PetscObjectQuery(disc, "pmat", &pmat);CHKERRQ(ierr); 224 if (pmat) {ierr = PetscObjectCompose((PetscObject) *is, "pmat", pmat);CHKERRQ(ierr);} 225 } 226 /* Check if DSes record their DM fields */ 227 if (dm->probs[0].fields) { 228 PetscInt d, e; 229 230 for (d = 0, e = 0; d < dm->Nds && e < (*subdm)->Nds; ++d) { 231 const PetscInt Nf = dm->probs[d].ds->Nf; 232 const PetscInt *fld; 233 PetscInt f, g; 234 235 ierr = ISGetIndices(dm->probs[d].fields, &fld);CHKERRQ(ierr); 236 for (f = 0; f < Nf; ++f) { 237 for (g = 0; g < numFields; ++g) if (fld[f] == fields[g]) break; 238 if (g < numFields) break; 239 } 240 ierr = ISRestoreIndices(dm->probs[d].fields, &fld);CHKERRQ(ierr); 241 if (f == Nf) continue; 242 ierr = PetscDSCopyConstants(dm->probs[d].ds, (*subdm)->probs[e].ds);CHKERRQ(ierr); 243 ierr = PetscDSCopyBoundary(dm->probs[d].ds, (*subdm)->probs[e].ds);CHKERRQ(ierr); 244 /* Translate DM fields to DS fields */ 245 { 246 IS infields, dsfields; 247 const PetscInt *fld, *ofld; 248 PetscInt *fidx; 249 PetscInt onf, nf, f, g; 250 251 ierr = ISCreateGeneral(PETSC_COMM_SELF, numFields, fields, PETSC_USE_POINTER, &infields);CHKERRQ(ierr); 252 ierr = ISIntersect(infields, dm->probs[d].fields, &dsfields);CHKERRQ(ierr); 253 ierr = ISDestroy(&infields);CHKERRQ(ierr); 254 ierr = ISGetLocalSize(dsfields, &nf);CHKERRQ(ierr); 255 if (!nf) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "DS cannot be supported on 0 fields"); 256 ierr = ISGetIndices(dsfields, &fld);CHKERRQ(ierr); 257 ierr = ISGetLocalSize(dm->probs[d].fields, &onf);CHKERRQ(ierr); 258 ierr = ISGetIndices(dm->probs[d].fields, &ofld);CHKERRQ(ierr); 259 ierr = PetscMalloc1(nf, &fidx);CHKERRQ(ierr); 260 for (f = 0, g = 0; f < onf && g < nf; ++f) { 261 if (ofld[f] == fld[g]) fidx[g++] = f; 262 } 263 ierr = ISRestoreIndices(dm->probs[d].fields, &ofld);CHKERRQ(ierr); 264 ierr = ISRestoreIndices(dsfields, &fld);CHKERRQ(ierr); 265 ierr = ISDestroy(&dsfields);CHKERRQ(ierr); 266 ierr = PetscDSSelectEquations(dm->probs[0].ds, nf, fidx, (*subdm)->probs[0].ds);CHKERRQ(ierr); 267 ierr = PetscFree(fidx);CHKERRQ(ierr); 268 } 269 ++e; 270 } 271 } else { 272 ierr = PetscDSCopyConstants(dm->probs[0].ds, (*subdm)->probs[0].ds);CHKERRQ(ierr); 273 ierr = PetscDSCopyBoundary(dm->probs[0].ds, (*subdm)->probs[0].ds);CHKERRQ(ierr); 274 ierr = PetscDSSelectEquations(dm->probs[0].ds, numFields, fields, (*subdm)->probs[0].ds);CHKERRQ(ierr); 275 } 276 } 277 if (haveNull && is) { 278 MatNullSpace nullSpace; 279 280 ierr = (*(*subdm)->nullspaceConstructors[nf])(*subdm, of, nf, &nullSpace);CHKERRQ(ierr); 281 ierr = PetscObjectCompose((PetscObject) *is, "nullspace", (PetscObject) nullSpace);CHKERRQ(ierr); 282 ierr = MatNullSpaceDestroy(&nullSpace);CHKERRQ(ierr); 283 } 284 if (dm->coarseMesh) { 285 ierr = DMCreateSubDM(dm->coarseMesh, numFields, fields, NULL, &(*subdm)->coarseMesh);CHKERRQ(ierr); 286 } 287 } 288 PetscFunctionReturn(0); 289 } 290 291 /*@C 292 DMCreateSectionSuperDM - Returns an arrays of ISes and DM+Section encapsulating a superproblem defined by the DM+Sections passed in. 293 294 Not collective 295 296 Input Parameter: 297 + dms - The DM objects 298 - len - The number of DMs 299 300 Output Parameters: 301 + is - The global indices for the subproblem, or NULL 302 - superdm - The DM for the superproblem, which must already have be cloned 303 304 Note: This handles all information in the DM class and the PetscSection. This is used as the basis for creating subDMs in specialized classes, 305 such as Plex and Forest. 306 307 Level: intermediate 308 309 .seealso DMCreateSuperDM(), DMGetLocalSection(), DMPlexSetMigrationSF(), DMView() 310 @*/ 311 PetscErrorCode DMCreateSectionSuperDM(DM dms[], PetscInt len, IS **is, DM *superdm) 312 { 313 MPI_Comm comm; 314 PetscSection supersection, *sections, *sectionGlobals; 315 PetscInt *Nfs, Nf = 0, f, supf, oldf = -1, nullf = -1, i; 316 PetscBool haveNull = PETSC_FALSE; 317 PetscErrorCode ierr; 318 319 PetscFunctionBegin; 320 ierr = PetscObjectGetComm((PetscObject)dms[0], &comm);CHKERRQ(ierr); 321 /* Pull out local and global sections */ 322 ierr = PetscMalloc3(len, &Nfs, len, §ions, len, §ionGlobals);CHKERRQ(ierr); 323 for (i = 0 ; i < len; ++i) { 324 ierr = DMGetLocalSection(dms[i], §ions[i]);CHKERRQ(ierr); 325 ierr = DMGetGlobalSection(dms[i], §ionGlobals[i]);CHKERRQ(ierr); 326 if (!sections[i]) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Must set default section for DM before splitting fields"); 327 if (!sectionGlobals[i]) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Must set default global section for DM before splitting fields"); 328 ierr = PetscSectionGetNumFields(sections[i], &Nfs[i]);CHKERRQ(ierr); 329 Nf += Nfs[i]; 330 } 331 /* Create the supersection */ 332 ierr = PetscSectionCreateSupersection(sections, len, &supersection);CHKERRQ(ierr); 333 ierr = DMSetLocalSection(*superdm, supersection);CHKERRQ(ierr); 334 /* Create ISes */ 335 if (is) { 336 PetscSection supersectionGlobal; 337 PetscInt bs = -1, startf = 0; 338 339 ierr = PetscMalloc1(len, is);CHKERRQ(ierr); 340 ierr = DMGetGlobalSection(*superdm, &supersectionGlobal);CHKERRQ(ierr); 341 for (i = 0 ; i < len; startf += Nfs[i], ++i) { 342 PetscInt *subIndices; 343 PetscInt subSize, subOff, pStart, pEnd, p, start, end, dummy; 344 345 ierr = PetscSectionGetChart(sectionGlobals[i], &pStart, &pEnd);CHKERRQ(ierr); 346 ierr = PetscSectionGetConstrainedStorageSize(sectionGlobals[i], &subSize);CHKERRQ(ierr); 347 ierr = PetscMalloc1(subSize, &subIndices);CHKERRQ(ierr); 348 for (p = pStart, subOff = 0; p < pEnd; ++p) { 349 PetscInt gdof, gcdof, gtdof, d; 350 351 ierr = PetscSectionGetDof(sectionGlobals[i], p, &gdof);CHKERRQ(ierr); 352 ierr = PetscSectionGetConstraintDof(sections[i], p, &gcdof);CHKERRQ(ierr); 353 gtdof = gdof - gcdof; 354 if (gdof > 0 && gtdof) { 355 if (bs < 0) {bs = gtdof;} 356 else if (bs != gtdof) {bs = 1;} 357 ierr = DMGetGlobalFieldOffset_Private(*superdm, p, startf, &start, &dummy);CHKERRQ(ierr); 358 ierr = DMGetGlobalFieldOffset_Private(*superdm, p, startf+Nfs[i]-1, &dummy, &end);CHKERRQ(ierr); 359 if (end-start != gtdof) SETERRQ4(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Invalid number of global dofs %D != %D for dm %D on point %D", end-start, gtdof, i, p); 360 for (d = start; d < end; ++d, ++subOff) subIndices[subOff] = d; 361 } 362 } 363 ierr = ISCreateGeneral(comm, subSize, subIndices, PETSC_OWN_POINTER, &(*is)[i]);CHKERRQ(ierr); 364 /* Must have same blocksize on all procs (some might have no points) */ 365 { 366 PetscInt bs = -1, bsLocal[2], bsMinMax[2]; 367 368 bsLocal[0] = bs < 0 ? PETSC_MAX_INT : bs; bsLocal[1] = bs; 369 ierr = PetscGlobalMinMaxInt(comm, bsLocal, bsMinMax);CHKERRQ(ierr); 370 if (bsMinMax[0] != bsMinMax[1]) {bs = 1;} 371 else {bs = bsMinMax[0];} 372 ierr = ISSetBlockSize((*is)[i], bs);CHKERRQ(ierr); 373 } 374 } 375 } 376 /* Preserve discretizations */ 377 if (len && dms[0]->probs) { 378 ierr = DMSetNumFields(*superdm, Nf);CHKERRQ(ierr); 379 for (i = 0, supf = 0; i < len; ++i) { 380 for (f = 0; f < Nfs[i]; ++f, ++supf) { 381 PetscObject disc; 382 383 ierr = DMGetField(dms[i], f, NULL, &disc);CHKERRQ(ierr); 384 ierr = DMSetField(*superdm, supf, NULL, disc);CHKERRQ(ierr); 385 } 386 } 387 ierr = DMCreateDS(*superdm);CHKERRQ(ierr); 388 } 389 /* Preserve nullspaces */ 390 for (i = 0, supf = 0; i < len; ++i) { 391 for (f = 0; f < Nfs[i]; ++f, ++supf) { 392 (*superdm)->nullspaceConstructors[supf] = dms[i]->nullspaceConstructors[f]; 393 if ((*superdm)->nullspaceConstructors[supf]) { 394 haveNull = PETSC_TRUE; 395 nullf = supf; 396 oldf = f; 397 } 398 } 399 } 400 /* Attach nullspace to IS */ 401 if (haveNull && is) { 402 MatNullSpace nullSpace; 403 404 ierr = (*(*superdm)->nullspaceConstructors[nullf])(*superdm, oldf, nullf, &nullSpace);CHKERRQ(ierr); 405 ierr = PetscObjectCompose((PetscObject) (*is)[nullf], "nullspace", (PetscObject) nullSpace);CHKERRQ(ierr); 406 ierr = MatNullSpaceDestroy(&nullSpace);CHKERRQ(ierr); 407 } 408 ierr = PetscSectionDestroy(&supersection);CHKERRQ(ierr); 409 ierr = PetscFree3(Nfs, sections, sectionGlobals);CHKERRQ(ierr); 410 PetscFunctionReturn(0); 411 } 412