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