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; 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 } 204 } 205 if (haveNull && is) { 206 MatNullSpace nullSpace; 207 208 ierr = (*(*subdm)->nullspaceConstructors[nf])(*subdm, nf, &nullSpace);CHKERRQ(ierr); 209 ierr = PetscObjectCompose((PetscObject) *is, "nullspace", (PetscObject) nullSpace);CHKERRQ(ierr); 210 ierr = MatNullSpaceDestroy(&nullSpace);CHKERRQ(ierr); 211 } 212 if (dm->probs) { 213 ierr = DMSetNumFields(*subdm, numFields);CHKERRQ(ierr); 214 for (f = 0; f < numFields; ++f) { 215 PetscObject disc; 216 217 ierr = DMGetField(dm, fields[f], NULL, &disc);CHKERRQ(ierr); 218 ierr = DMSetField(*subdm, f, NULL, disc);CHKERRQ(ierr); 219 } 220 ierr = DMCreateDS(*subdm);CHKERRQ(ierr); 221 if (numFields == 1 && is) { 222 PetscObject disc, space, pmat; 223 224 ierr = DMGetField(*subdm, 0, NULL, &disc);CHKERRQ(ierr); 225 ierr = PetscObjectQuery(disc, "nullspace", &space);CHKERRQ(ierr); 226 if (space) {ierr = PetscObjectCompose((PetscObject) *is, "nullspace", space);CHKERRQ(ierr);} 227 ierr = PetscObjectQuery(disc, "nearnullspace", &space);CHKERRQ(ierr); 228 if (space) {ierr = PetscObjectCompose((PetscObject) *is, "nearnullspace", space);CHKERRQ(ierr);} 229 ierr = PetscObjectQuery(disc, "pmat", &pmat);CHKERRQ(ierr); 230 if (pmat) {ierr = PetscObjectCompose((PetscObject) *is, "pmat", pmat);CHKERRQ(ierr);} 231 } 232 ierr = PetscDSCopyConstants(dm->probs[0].ds, (*subdm)->probs[0].ds);CHKERRQ(ierr); 233 ierr = PetscDSCopyBoundary(dm->probs[0].ds, (*subdm)->probs[0].ds);CHKERRQ(ierr); 234 /* Translate DM fields to DS fields */ 235 if (dm->probs[0].fields) { 236 IS infields, dsfields; 237 const PetscInt *fld, *ofld; 238 PetscInt *fidx; 239 PetscInt onf, nf, f, g; 240 241 ierr = ISCreateGeneral(PETSC_COMM_SELF, numFields, fields, PETSC_USE_POINTER, &infields);CHKERRQ(ierr); 242 ierr = ISIntersect(infields, dm->probs[0].fields, &dsfields);CHKERRQ(ierr); 243 ierr = ISDestroy(&infields);CHKERRQ(ierr); 244 ierr = ISGetLocalSize(dsfields, &nf);CHKERRQ(ierr); 245 if (!nf) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "DS cannot be supported on 0 fields"); 246 ierr = ISGetIndices(dsfields, &fld);CHKERRQ(ierr); 247 ierr = ISGetLocalSize(dm->probs[0].fields, &onf);CHKERRQ(ierr); 248 ierr = ISGetIndices(dm->probs[0].fields, &ofld);CHKERRQ(ierr); 249 ierr = PetscMalloc1(nf, &fidx);CHKERRQ(ierr); 250 for (f = 0, g = 0; f < onf && g < nf; ++f) { 251 if (ofld[f] == fld[g]) fidx[g++] = f; 252 } 253 ierr = ISRestoreIndices(dm->probs[0].fields, &ofld);CHKERRQ(ierr); 254 ierr = ISRestoreIndices(dsfields, &fld);CHKERRQ(ierr); 255 ierr = ISDestroy(&dsfields);CHKERRQ(ierr); 256 ierr = PetscDSSelectEquations(dm->probs[0].ds, nf, fidx, (*subdm)->probs[0].ds);CHKERRQ(ierr); 257 ierr = PetscFree(fidx);CHKERRQ(ierr); 258 } else { 259 ierr = PetscDSSelectEquations(dm->probs[0].ds, numFields, fields, (*subdm)->probs[0].ds);CHKERRQ(ierr); 260 } 261 } 262 if (dm->coarseMesh) { 263 ierr = DMCreateSubDM(dm->coarseMesh, numFields, fields, NULL, &(*subdm)->coarseMesh);CHKERRQ(ierr); 264 } 265 } 266 PetscFunctionReturn(0); 267 } 268 269 /*@C 270 DMCreateSectionSuperDM - Returns an arrays of ISes and DM+Section encapsulating a superproblem defined by the DM+Sections passed in. 271 272 Not collective 273 274 Input Parameter: 275 + dms - The DM objects 276 - len - The number of DMs 277 278 Output Parameters: 279 + is - The global indices for the subproblem, or NULL 280 - superdm - The DM for the superproblem, which must already have be cloned 281 282 Note: This handles all information in the DM class and the PetscSection. This is used as the basis for creating subDMs in specialized classes, 283 such as Plex and Forest. 284 285 Level: intermediate 286 287 .seealso DMCreateSuperDM(), DMGetLocalSection(), DMPlexSetMigrationSF(), DMView() 288 @*/ 289 PetscErrorCode DMCreateSectionSuperDM(DM dms[], PetscInt len, IS **is, DM *superdm) 290 { 291 MPI_Comm comm; 292 PetscSection supersection, *sections, *sectionGlobals; 293 PetscInt *Nfs, Nf = 0, f, supf, nullf = -1, i; 294 PetscBool haveNull = PETSC_FALSE; 295 PetscErrorCode ierr; 296 297 PetscFunctionBegin; 298 ierr = PetscObjectGetComm((PetscObject)dms[0], &comm);CHKERRQ(ierr); 299 /* Pull out local and global sections */ 300 ierr = PetscMalloc3(len, &Nfs, len, §ions, len, §ionGlobals);CHKERRQ(ierr); 301 for (i = 0 ; i < len; ++i) { 302 ierr = DMGetLocalSection(dms[i], §ions[i]);CHKERRQ(ierr); 303 ierr = DMGetGlobalSection(dms[i], §ionGlobals[i]);CHKERRQ(ierr); 304 if (!sections[i]) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Must set default section for DM before splitting fields"); 305 if (!sectionGlobals[i]) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Must set default global section for DM before splitting fields"); 306 ierr = PetscSectionGetNumFields(sections[i], &Nfs[i]);CHKERRQ(ierr); 307 Nf += Nfs[i]; 308 } 309 /* Create the supersection */ 310 ierr = PetscSectionCreateSupersection(sections, len, &supersection);CHKERRQ(ierr); 311 ierr = DMSetLocalSection(*superdm, supersection);CHKERRQ(ierr); 312 /* Create ISes */ 313 if (is) { 314 PetscSection supersectionGlobal; 315 PetscInt bs = -1, startf = 0; 316 317 ierr = PetscMalloc1(len, is);CHKERRQ(ierr); 318 ierr = DMGetGlobalSection(*superdm, &supersectionGlobal);CHKERRQ(ierr); 319 for (i = 0 ; i < len; startf += Nfs[i], ++i) { 320 PetscInt *subIndices; 321 PetscInt subSize, subOff, pStart, pEnd, p, start, end, dummy; 322 323 ierr = PetscSectionGetChart(sectionGlobals[i], &pStart, &pEnd);CHKERRQ(ierr); 324 ierr = PetscSectionGetConstrainedStorageSize(sectionGlobals[i], &subSize);CHKERRQ(ierr); 325 ierr = PetscMalloc1(subSize, &subIndices);CHKERRQ(ierr); 326 for (p = pStart, subOff = 0; p < pEnd; ++p) { 327 PetscInt gdof, gcdof, gtdof, d; 328 329 ierr = PetscSectionGetDof(sectionGlobals[i], p, &gdof);CHKERRQ(ierr); 330 ierr = PetscSectionGetConstraintDof(sections[i], p, &gcdof);CHKERRQ(ierr); 331 gtdof = gdof - gcdof; 332 if (gdof > 0 && gtdof) { 333 if (bs < 0) {bs = gtdof;} 334 else if (bs != gtdof) {bs = 1;} 335 ierr = DMGetGlobalFieldOffset_Private(*superdm, p, startf, &start, &dummy);CHKERRQ(ierr); 336 ierr = DMGetGlobalFieldOffset_Private(*superdm, p, startf+Nfs[i]-1, &dummy, &end);CHKERRQ(ierr); 337 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); 338 for (d = start; d < end; ++d, ++subOff) subIndices[subOff] = d; 339 } 340 } 341 ierr = ISCreateGeneral(comm, subSize, subIndices, PETSC_OWN_POINTER, &(*is)[i]);CHKERRQ(ierr); 342 /* Must have same blocksize on all procs (some might have no points) */ 343 { 344 PetscInt bs = -1, bsLocal[2], bsMinMax[2]; 345 346 bsLocal[0] = bs < 0 ? PETSC_MAX_INT : bs; bsLocal[1] = bs; 347 ierr = PetscGlobalMinMaxInt(comm, bsLocal, bsMinMax);CHKERRQ(ierr); 348 if (bsMinMax[0] != bsMinMax[1]) {bs = 1;} 349 else {bs = bsMinMax[0];} 350 ierr = ISSetBlockSize((*is)[i], bs);CHKERRQ(ierr); 351 } 352 } 353 } 354 /* Preserve discretizations */ 355 if (len && dms[0]->probs) { 356 ierr = DMSetNumFields(*superdm, Nf);CHKERRQ(ierr); 357 for (i = 0, supf = 0; i < len; ++i) { 358 for (f = 0; f < Nfs[i]; ++f, ++supf) { 359 PetscObject disc; 360 361 ierr = DMGetField(dms[i], f, NULL, &disc);CHKERRQ(ierr); 362 ierr = DMSetField(*superdm, supf, NULL, disc);CHKERRQ(ierr); 363 } 364 } 365 ierr = DMCreateDS(*superdm);CHKERRQ(ierr); 366 } 367 /* Preserve nullspaces */ 368 for (i = 0, supf = 0; i < len; ++i) { 369 for (f = 0; f < Nfs[i]; ++f, ++supf) { 370 (*superdm)->nullspaceConstructors[supf] = dms[i]->nullspaceConstructors[f]; 371 if ((*superdm)->nullspaceConstructors[supf]) { 372 haveNull = PETSC_TRUE; 373 nullf = supf; 374 } 375 } 376 } 377 /* Attach nullspace to IS */ 378 if (haveNull && is) { 379 MatNullSpace nullSpace; 380 381 ierr = (*(*superdm)->nullspaceConstructors[nullf])(*superdm, nullf, &nullSpace);CHKERRQ(ierr); 382 ierr = PetscObjectCompose((PetscObject) (*is)[nullf], "nullspace", (PetscObject) nullSpace);CHKERRQ(ierr); 383 ierr = MatNullSpaceDestroy(&nullSpace);CHKERRQ(ierr); 384 } 385 ierr = PetscSectionDestroy(&supersection);CHKERRQ(ierr); 386 ierr = PetscFree3(Nfs, sections, sectionGlobals);CHKERRQ(ierr); 387 PetscFunctionReturn(0); 388 } 389