xref: /petsc/src/dm/impls/plex/plexsection.c (revision 63f3c55c12ae2f190c391f6df6c540efe018a44a)
1 #include <petsc/private/dmpleximpl.h>   /*I      "petscdmplex.h"   I*/
2 
3 /* Set the number of dof on each point and separate by fields */
4 static PetscErrorCode DMPlexCreateSectionFields(DM dm, const PetscInt numComp[], PetscSection *section)
5 {
6   DMLabel        depthLabel;
7   PetscInt       depth, Nf, f, pStart, pEnd;
8   PetscBool     *isFE;
9   PetscErrorCode ierr;
10 
11   PetscFunctionBegin;
12   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
13   ierr = DMPlexGetDepthLabel(dm,&depthLabel);CHKERRQ(ierr);
14   ierr = DMGetNumFields(dm, &Nf);CHKERRQ(ierr);
15   ierr = PetscCalloc1(Nf, &isFE);CHKERRQ(ierr);
16   for (f = 0; f < Nf; ++f) {
17     PetscObject  obj;
18     PetscClassId id;
19 
20     ierr = DMGetField(dm, f, NULL, &obj);CHKERRQ(ierr);
21     ierr = PetscObjectGetClassId(obj, &id);CHKERRQ(ierr);
22     if (id == PETSCFE_CLASSID)      {isFE[f] = PETSC_TRUE;}
23     else if (id == PETSCFV_CLASSID) {isFE[f] = PETSC_FALSE;}
24   }
25 
26   ierr = PetscSectionCreate(PetscObjectComm((PetscObject)dm), section);CHKERRQ(ierr);
27   if (Nf > 0) {
28     ierr = PetscSectionSetNumFields(*section, Nf);CHKERRQ(ierr);
29     if (numComp) {
30       for (f = 0; f < Nf; ++f) {
31         ierr = PetscSectionSetFieldComponents(*section, f, numComp[f]);CHKERRQ(ierr);
32         if (isFE[f]) {
33           PetscFE           fe;
34           PetscDualSpace    dspace;
35           const PetscInt    ***perms;
36           const PetscScalar ***flips;
37           const PetscInt    *numDof;
38 
39           ierr = DMGetField(dm,f,NULL,(PetscObject *) &fe);CHKERRQ(ierr);
40           ierr = PetscFEGetDualSpace(fe,&dspace);CHKERRQ(ierr);
41           ierr = PetscDualSpaceGetSymmetries(dspace,&perms,&flips);CHKERRQ(ierr);
42           ierr = PetscDualSpaceGetNumDof(dspace,&numDof);CHKERRQ(ierr);
43           if (perms || flips) {
44             DM              K;
45             PetscInt        h;
46             PetscSectionSym sym;
47 
48             ierr = PetscDualSpaceGetDM(dspace,&K);CHKERRQ(ierr);
49             ierr = PetscSectionSymCreateLabel(PetscObjectComm((PetscObject)*section),depthLabel,&sym);CHKERRQ(ierr);
50             for (h = 0; h <= depth; h++) {
51               PetscDualSpace    hspace;
52               PetscInt          kStart, kEnd;
53               PetscInt          kConeSize;
54               const PetscInt    **perms0 = NULL;
55               const PetscScalar **flips0 = NULL;
56 
57               ierr = PetscDualSpaceGetHeightSubspace(dspace,h,&hspace);CHKERRQ(ierr);
58               ierr = DMPlexGetHeightStratum(K,h,&kStart,&kEnd);CHKERRQ(ierr);
59               if (!hspace) continue;
60               ierr = PetscDualSpaceGetSymmetries(hspace,&perms,&flips);CHKERRQ(ierr);
61               if (perms) perms0 = perms[0];
62               if (flips) flips0 = flips[0];
63               if (!(perms0 || flips0)) continue;
64               ierr = DMPlexGetConeSize(K,kStart,&kConeSize);CHKERRQ(ierr);
65               ierr = PetscSectionSymLabelSetStratum(sym,depth - h,numDof[depth - h],-kConeSize,kConeSize,PETSC_USE_POINTER,perms0 ? &perms0[-kConeSize] : NULL,flips0 ? &flips0[-kConeSize] : NULL);CHKERRQ(ierr);
66             }
67             ierr = PetscSectionSetFieldSym(*section,f,sym);CHKERRQ(ierr);
68             ierr = PetscSectionSymDestroy(&sym);CHKERRQ(ierr);
69           }
70         }
71       }
72     }
73   }
74   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
75   ierr = PetscSectionSetChart(*section, pStart, pEnd);CHKERRQ(ierr);
76   ierr = PetscFree(isFE);CHKERRQ(ierr);
77   PetscFunctionReturn(0);
78 }
79 
80 /* Set the number of dof on each point and separate by fields */
81 static PetscErrorCode DMPlexCreateSectionDof(DM dm, DMLabel label[],const PetscInt numDof[], PetscSection section)
82 {
83   DMLabel        depthLabel;
84   PetscInt      *pMax;
85   PetscInt       depth, cellHeight, pStart = 0, pEnd = 0;
86   PetscInt       Nf, f, dim, d, dep, p;
87   PetscBool     *isFE;
88   PetscErrorCode ierr;
89 
90   PetscFunctionBegin;
91   ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr);
92   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
93   ierr = DMPlexGetDepthLabel(dm,&depthLabel);CHKERRQ(ierr);
94   ierr = DMGetNumFields(dm, &Nf);CHKERRQ(ierr);
95   ierr = PetscMalloc1(Nf, &isFE);CHKERRQ(ierr);
96   for (f = 0; f < Nf; ++f) {
97     PetscObject  obj;
98     PetscClassId id;
99 
100     ierr = DMGetField(dm, f, NULL, &obj);CHKERRQ(ierr);
101     ierr = PetscObjectGetClassId(obj, &id);CHKERRQ(ierr);
102     /* User is allowed to put a "placeholder" field in (c.f. DMCreateDS) */
103     isFE[f] = id == PETSCFE_CLASSID ? PETSC_TRUE : PETSC_FALSE;
104   }
105 
106   ierr = PetscMalloc1(depth+1, &pMax);CHKERRQ(ierr);
107   ierr = DMPlexGetHybridBounds(dm, depth >= 0 ? &pMax[depth] : NULL, depth>1 ? &pMax[depth-1] : NULL, depth>2 ? &pMax[1] : NULL, &pMax[0]);CHKERRQ(ierr);
108   ierr = DMPlexGetVTKCellHeight(dm, &cellHeight);CHKERRQ(ierr);
109   for (f = 0; f < Nf; ++f) {
110     if (label && label[f]) {
111       IS              pointIS;
112       const PetscInt *points;
113       PetscInt        n;
114 
115       ierr = DMLabelGetStratumIS(label[f], 1, &pointIS);CHKERRQ(ierr);
116       if (!pointIS) continue;
117       ierr = ISGetLocalSize(pointIS, &n);CHKERRQ(ierr);
118       ierr = ISGetIndices(pointIS, &points);CHKERRQ(ierr);
119       for (p = 0; p < n; ++p) {
120         const PetscInt point = points[p];
121         PetscInt       dof, d;
122 
123         ierr = DMLabelGetValue(depthLabel, point, &d);CHKERRQ(ierr);
124         ierr = DMPlexGetDepthStratum(dm, d, NULL, &pEnd);CHKERRQ(ierr);
125         /* If this is a hybrid point, use dof for one dimension lower */
126         if ((point >= pMax[d]) && (point < pEnd)) --d;
127         dof  = d < 0 ? 0 : numDof[f*(dim+1)+d];
128         ierr = PetscSectionSetFieldDof(section, point, f, dof);CHKERRQ(ierr);
129         ierr = PetscSectionAddDof(section, point, dof);CHKERRQ(ierr);
130       }
131       ierr = ISRestoreIndices(pointIS, &points);CHKERRQ(ierr);
132       ierr = ISDestroy(&pointIS);CHKERRQ(ierr);
133     } else {
134       for (dep = 0; dep <= depth - cellHeight; ++dep) {
135         /* Cases: dim > depth (cell-vertex mesh), dim == depth (fully interpolated), dim < depth (interpolated submesh) */
136         d    = dim <= depth ? dep : (!dep ? 0 : dim);
137         ierr = DMPlexGetDepthStratum(dm, dep, &pStart, &pEnd);CHKERRQ(ierr);
138         pMax[dep] = pMax[dep] < 0 ? pEnd : pMax[dep];
139         for (p = pStart; p < pEnd; ++p) {
140           const PetscInt dof = numDof[f*(dim+1)+d];
141 
142           if (isFE[f] && p >= pMax[dep]) continue;
143           ierr = PetscSectionSetFieldDof(section, p, f, dof);CHKERRQ(ierr);
144           ierr = PetscSectionAddDof(section, p, dof);CHKERRQ(ierr);
145         }
146       }
147     }
148   }
149   ierr = PetscFree(pMax);CHKERRQ(ierr);
150   ierr = PetscFree(isFE);CHKERRQ(ierr);
151   PetscFunctionReturn(0);
152 }
153 
154 /* Set the number of dof on each point and separate by fields
155    If bcComps is NULL or the IS is NULL, constrain every dof on the point
156 */
157 static PetscErrorCode DMPlexCreateSectionBCDof(DM dm, PetscInt numBC, const PetscInt bcField[], const IS bcComps[], const IS bcPoints[], PetscSection section)
158 {
159   PetscInt       Nf;
160   PetscInt       bc;
161   PetscSection   aSec;
162   PetscErrorCode ierr;
163 
164   PetscFunctionBegin;
165   ierr = PetscSectionGetNumFields(section, &Nf);CHKERRQ(ierr);
166   for (bc = 0; bc < numBC; ++bc) {
167     PetscInt        field = 0;
168     const PetscInt *comp;
169     const PetscInt *idx;
170     PetscInt        Nc = -1, n, i;
171 
172     if (Nf) field = bcField[bc];
173     if (bcComps && bcComps[bc]) {ierr = ISGetLocalSize(bcComps[bc], &Nc);CHKERRQ(ierr);}
174     if (bcComps && bcComps[bc]) {ierr = ISGetIndices(bcComps[bc], &comp);CHKERRQ(ierr);}
175     ierr = ISGetLocalSize(bcPoints[bc], &n);CHKERRQ(ierr);
176     ierr = ISGetIndices(bcPoints[bc], &idx);CHKERRQ(ierr);
177     for (i = 0; i < n; ++i) {
178       const PetscInt p = idx[i];
179       PetscInt       numConst;
180 
181       if (Nf) {
182         ierr = PetscSectionGetFieldDof(section, p, field, &numConst);CHKERRQ(ierr);
183       } else {
184         ierr = PetscSectionGetDof(section, p, &numConst);CHKERRQ(ierr);
185       }
186       /* If Nc < 0, constrain every dof on the point */
187       /* TODO: Matt, this only works if there is one node on the point.  We need to handle numDofs > NumComponents */
188       if (Nc > 0) numConst = PetscMin(numConst, Nc);
189       if (Nf) {ierr = PetscSectionAddFieldConstraintDof(section, p, field, numConst);CHKERRQ(ierr);}
190       ierr = PetscSectionAddConstraintDof(section, p, numConst);CHKERRQ(ierr);
191     }
192     ierr = ISRestoreIndices(bcPoints[bc], &idx);CHKERRQ(ierr);
193     if (bcComps && bcComps[bc]) {ierr = ISRestoreIndices(bcComps[bc], &comp);CHKERRQ(ierr);}
194   }
195   ierr = DMPlexGetAnchors(dm, &aSec, NULL);CHKERRQ(ierr);
196   if (aSec) {
197     PetscInt aStart, aEnd, a;
198 
199     ierr = PetscSectionGetChart(aSec, &aStart, &aEnd);CHKERRQ(ierr);
200     for (a = aStart; a < aEnd; a++) {
201       PetscInt dof, f;
202 
203       ierr = PetscSectionGetDof(aSec, a, &dof);CHKERRQ(ierr);
204       if (dof) {
205         /* if there are point-to-point constraints, then all dofs are constrained */
206         ierr = PetscSectionGetDof(section, a, &dof);CHKERRQ(ierr);
207         ierr = PetscSectionSetConstraintDof(section, a, dof);CHKERRQ(ierr);
208         for (f = 0; f < Nf; f++) {
209           ierr = PetscSectionGetFieldDof(section, a, f, &dof);CHKERRQ(ierr);
210           ierr = PetscSectionSetFieldConstraintDof(section, a, f, dof);CHKERRQ(ierr);
211         }
212       }
213     }
214   }
215   PetscFunctionReturn(0);
216 }
217 
218 /* Set the constrained field indices on each point
219    If bcComps is NULL or the IS is NULL, constrain every dof on the point
220 */
221 static PetscErrorCode DMPlexCreateSectionBCIndicesField(DM dm, PetscInt numBC,const PetscInt bcField[], const IS bcComps[], const IS bcPoints[], PetscSection section)
222 {
223   PetscSection   aSec;
224   PetscInt      *indices;
225   PetscInt       Nf, cdof, maxDof = 0, pStart, pEnd, p, bc, f, d;
226   PetscErrorCode ierr;
227 
228   PetscFunctionBegin;
229   ierr = PetscSectionGetNumFields(section, &Nf);CHKERRQ(ierr);
230   if (!Nf) PetscFunctionReturn(0);
231   /* Initialize all field indices to -1 */
232   ierr = PetscSectionGetChart(section, &pStart, &pEnd);CHKERRQ(ierr);
233   for (p = pStart; p < pEnd; ++p) {ierr = PetscSectionGetConstraintDof(section, p, &cdof);CHKERRQ(ierr); maxDof = PetscMax(maxDof, cdof);}
234   ierr = PetscMalloc1(maxDof, &indices);CHKERRQ(ierr);
235   for (d = 0; d < maxDof; ++d) indices[d] = -1;
236   for (p = pStart; p < pEnd; ++p) for (f = 0; f < Nf; ++f) {ierr = PetscSectionSetFieldConstraintIndices(section, p, f, indices);CHKERRQ(ierr);}
237   /* Handle BC constraints */
238   for (bc = 0; bc < numBC; ++bc) {
239     const PetscInt  field = bcField[bc];
240     const PetscInt *comp, *idx;
241     PetscInt        Nc = -1, n, i;
242 
243     if (bcComps && bcComps[bc]) {ierr = ISGetLocalSize(bcComps[bc], &Nc);CHKERRQ(ierr);}
244     if (bcComps && bcComps[bc]) {ierr = ISGetIndices(bcComps[bc], &comp);CHKERRQ(ierr);}
245     ierr = ISGetLocalSize(bcPoints[bc], &n);CHKERRQ(ierr);
246     ierr = ISGetIndices(bcPoints[bc], &idx);CHKERRQ(ierr);
247     for (i = 0; i < n; ++i) {
248       const PetscInt  p = idx[i];
249       const PetscInt *find;
250       PetscInt        fdof, fcdof, c;
251 
252       ierr = PetscSectionGetFieldDof(section, p, field, &fdof);CHKERRQ(ierr);
253       if (!fdof) continue;
254       if (Nc < 0) {
255         for (d = 0; d < fdof; ++d) indices[d] = d;
256         fcdof = fdof;
257       } else {
258         ierr = PetscSectionGetFieldConstraintDof(section, p, field, &fcdof);CHKERRQ(ierr);
259         ierr = PetscSectionGetFieldConstraintIndices(section, p, field, &find);CHKERRQ(ierr);
260         for (d = 0; d < fcdof; ++d) {if (find[d] < 0) break; indices[d] = find[d];}
261         for (c = 0; c < Nc; ++c) indices[d++] = comp[c];
262         ierr = PetscSortRemoveDupsInt(&d, indices);CHKERRQ(ierr);
263         for (c = d; c < fcdof; ++c) indices[c] = -1;
264         fcdof = d;
265       }
266       ierr = PetscSectionSetFieldConstraintDof(section, p, field, fcdof);CHKERRQ(ierr);
267       ierr = PetscSectionSetFieldConstraintIndices(section, p, field, indices);CHKERRQ(ierr);
268     }
269     if (bcComps && bcComps[bc]) {ierr = ISRestoreIndices(bcComps[bc], &comp);CHKERRQ(ierr);}
270     ierr = ISRestoreIndices(bcPoints[bc], &idx);CHKERRQ(ierr);
271   }
272   /* Handle anchors */
273   ierr = DMPlexGetAnchors(dm, &aSec, NULL);CHKERRQ(ierr);
274   if (aSec) {
275     PetscInt aStart, aEnd, a;
276 
277     for (d = 0; d < maxDof; ++d) indices[d] = d;
278     ierr = PetscSectionGetChart(aSec, &aStart, &aEnd);CHKERRQ(ierr);
279     for (a = aStart; a < aEnd; a++) {
280       PetscInt dof, f;
281 
282       ierr = PetscSectionGetDof(aSec, a, &dof);CHKERRQ(ierr);
283       if (dof) {
284         /* if there are point-to-point constraints, then all dofs are constrained */
285         for (f = 0; f < Nf; f++) {
286           ierr = PetscSectionSetFieldConstraintIndices(section, a, f, indices);CHKERRQ(ierr);
287         }
288       }
289     }
290   }
291   ierr = PetscFree(indices);CHKERRQ(ierr);
292   PetscFunctionReturn(0);
293 }
294 
295 /* Set the constrained indices on each point */
296 static PetscErrorCode DMPlexCreateSectionBCIndices(DM dm, PetscSection section)
297 {
298   PetscInt      *indices;
299   PetscInt       Nf, maxDof, pStart, pEnd, p, f, d;
300   PetscErrorCode ierr;
301 
302   PetscFunctionBegin;
303   ierr = PetscSectionGetNumFields(section, &Nf);CHKERRQ(ierr);
304   ierr = PetscSectionGetMaxDof(section, &maxDof);CHKERRQ(ierr);
305   ierr = PetscSectionGetChart(section, &pStart, &pEnd);CHKERRQ(ierr);
306   ierr = PetscMalloc1(maxDof, &indices);CHKERRQ(ierr);
307   for (d = 0; d < maxDof; ++d) indices[d] = -1;
308   for (p = pStart; p < pEnd; ++p) {
309     PetscInt cdof, d;
310 
311     ierr = PetscSectionGetConstraintDof(section, p, &cdof);CHKERRQ(ierr);
312     if (cdof) {
313       if (Nf) {
314         PetscInt numConst = 0, foff = 0;
315 
316         for (f = 0; f < Nf; ++f) {
317           const PetscInt *find;
318           PetscInt        fcdof, fdof;
319 
320           ierr = PetscSectionGetFieldDof(section, p, f, &fdof);CHKERRQ(ierr);
321           ierr = PetscSectionGetFieldConstraintDof(section, p, f, &fcdof);CHKERRQ(ierr);
322           /* Change constraint numbering from field component to local dof number */
323           ierr = PetscSectionGetFieldConstraintIndices(section, p, f, &find);CHKERRQ(ierr);
324           for (d = 0; d < fcdof; ++d) indices[numConst+d] = find[d] + foff;
325           numConst += fcdof;
326           foff     += fdof;
327         }
328         if (cdof != numConst) {ierr = PetscSectionSetConstraintDof(section, p, numConst);CHKERRQ(ierr);}
329       } else {
330         for (d = 0; d < cdof; ++d) indices[d] = d;
331       }
332       ierr = PetscSectionSetConstraintIndices(section, p, indices);CHKERRQ(ierr);
333     }
334   }
335   ierr = PetscFree(indices);CHKERRQ(ierr);
336   PetscFunctionReturn(0);
337 }
338 
339 /*@C
340   DMPlexCreateSection - Create a PetscSection based upon the dof layout specification provided.
341 
342   Not Collective
343 
344   Input Parameters:
345 + dm        - The DMPlex object
346 . numComp   - An array of size numFields that holds the number of components for each field
347 . numDof    - An array of size numFields*(dim+1) which holds the number of dof for each field on a mesh piece of dimension d
348 . label     - The label indicating the mesh support of each field, or NULL for the whole mesh
349 . numBC     - The number of boundary conditions
350 . bcField   - An array of size numBC giving the field number for each boundry condition
351 . bcComps   - [Optional] An array of size numBC giving an IS holding the field components to which each boundary condition applies
352 . bcPoints  - An array of size numBC giving an IS holding the Plex points to which each boundary condition applies
353 - perm      - Optional permutation of the chart, or NULL
354 
355   Output Parameter:
356 . section - The PetscSection object
357 
358   Notes:
359     numDof[f*(dim+1)+d] gives the number of dof for field f on points of dimension d. For instance, numDof[1] is the
360   number of dof for field 0 on each edge.
361 
362   The chart permutation is the same one set using PetscSectionSetPermutation()
363 
364   Level: developer
365 
366   Fortran Notes:
367   A Fortran 90 version is available as DMPlexCreateSectionF90()
368 
369   TODO: How is this related to DMCreateLocalSection()
370 
371 .seealso: DMPlexCreate(), PetscSectionCreate(), PetscSectionSetPermutation()
372 @*/
373 PetscErrorCode DMPlexCreateSection(DM dm, DMLabel label[], const PetscInt numComp[],const PetscInt numDof[], PetscInt numBC, const PetscInt bcField[], const IS bcComps[], const IS bcPoints[], IS perm, PetscSection *section)
374 {
375   PetscSection   aSec;
376   PetscErrorCode ierr;
377 
378   PetscFunctionBegin;
379   ierr = DMPlexCreateSectionFields(dm, numComp, section);CHKERRQ(ierr);
380   ierr = DMPlexCreateSectionDof(dm, label, numDof, *section);CHKERRQ(ierr);
381   ierr = DMPlexCreateSectionBCDof(dm, numBC, bcField, bcComps, bcPoints, *section);CHKERRQ(ierr);
382   if (perm) {ierr = PetscSectionSetPermutation(*section, perm);CHKERRQ(ierr);}
383   ierr = PetscSectionSetFromOptions(*section);CHKERRQ(ierr);
384   ierr = PetscSectionSetUp(*section);CHKERRQ(ierr);
385   ierr = DMPlexGetAnchors(dm,&aSec,NULL);CHKERRQ(ierr);
386   if (numBC || aSec) {
387     ierr = DMPlexCreateSectionBCIndicesField(dm, numBC, bcField, bcComps, bcPoints, *section);CHKERRQ(ierr);
388     ierr = DMPlexCreateSectionBCIndices(dm, *section);CHKERRQ(ierr);
389   }
390   ierr = PetscSectionViewFromOptions(*section,NULL,"-section_view");CHKERRQ(ierr);
391   PetscFunctionReturn(0);
392 }
393 
394 PetscErrorCode DMCreateLocalSection_Plex(DM dm)
395 {
396   PetscDS        probBC;
397   PetscSection   section;
398   DMLabel       *labels;
399   IS            *bcPoints, *bcComps;
400   PetscBool     *isFE;
401   PetscInt      *bcFields, *numComp, *numDof;
402   PetscInt       depth, dim, numBd, numBC = 0, Nf, bd, bc = 0, f;
403   PetscInt       cStart, cEnd, cEndInterior;
404   PetscErrorCode ierr;
405 
406   PetscFunctionBegin;
407   ierr = DMGetNumFields(dm, &Nf);CHKERRQ(ierr);
408   /* FE and FV boundary conditions are handled slightly differently */
409   ierr = PetscMalloc1(Nf, &isFE);CHKERRQ(ierr);
410   for (f = 0; f < Nf; ++f) {
411     PetscObject  obj;
412     PetscClassId id;
413 
414     ierr = DMGetField(dm, f, NULL, &obj);CHKERRQ(ierr);
415     ierr = PetscObjectGetClassId(obj, &id);CHKERRQ(ierr);
416     if (id == PETSCFE_CLASSID)      {isFE[f] = PETSC_TRUE;}
417     else if (id == PETSCFV_CLASSID) {isFE[f] = PETSC_FALSE;}
418     else SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Unknown discretization type for field %D", f);
419   }
420   /* Allocate boundary point storage for FEM boundaries */
421   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
422   ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr);
423   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
424   ierr = DMPlexGetHybridBounds(dm, &cEndInterior, NULL, NULL, NULL);CHKERRQ(ierr);
425   ierr = DMGetDS(dm, &probBC);CHKERRQ(ierr);
426   ierr = PetscDSGetNumBoundary(probBC, &numBd);CHKERRQ(ierr);
427   if (!Nf && numBd) SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "number of fields is zero and number of boundary conditions is nonzero (this should never happen)");
428   for (bd = 0; bd < numBd; ++bd) {
429     PetscInt                field;
430     DMBoundaryConditionType type;
431     const char             *labelName;
432     DMLabel                 label;
433 
434     ierr = PetscDSGetBoundary(probBC, bd, &type, NULL, &labelName, &field, NULL, NULL, NULL, NULL, NULL, NULL);CHKERRQ(ierr);
435     ierr = DMGetLabel(dm,labelName,&label);CHKERRQ(ierr);
436     if (label && isFE[field] && (type & DM_BC_ESSENTIAL)) ++numBC;
437   }
438   /* Add ghost cell boundaries for FVM */
439   for (f = 0; f < Nf; ++f) if (!isFE[f] && cEndInterior >= 0) ++numBC;
440   ierr = PetscCalloc3(numBC,&bcFields,numBC,&bcPoints,numBC,&bcComps);CHKERRQ(ierr);
441   /* Constrain ghost cells for FV */
442   for (f = 0; f < Nf; ++f) {
443     PetscInt *newidx, c;
444 
445     if (isFE[f] || cEndInterior < 0) continue;
446     ierr = PetscMalloc1(cEnd-cEndInterior,&newidx);CHKERRQ(ierr);
447     for (c = cEndInterior; c < cEnd; ++c) newidx[c-cEndInterior] = c;
448     bcFields[bc] = f;
449     ierr = ISCreateGeneral(PetscObjectComm((PetscObject) dm), cEnd-cEndInterior, newidx, PETSC_OWN_POINTER, &bcPoints[bc++]);CHKERRQ(ierr);
450   }
451   /* Handle FEM Dirichlet boundaries */
452   for (bd = 0; bd < numBd; ++bd) {
453     const char             *bdLabel;
454     DMLabel                 label;
455     const PetscInt         *comps;
456     const PetscInt         *values;
457     PetscInt                bd2, field, numComps, numValues;
458     DMBoundaryConditionType type;
459     PetscBool               duplicate = PETSC_FALSE;
460 
461     ierr = PetscDSGetBoundary(probBC, bd, &type, NULL, &bdLabel, &field, &numComps, &comps, NULL, &numValues, &values, NULL);CHKERRQ(ierr);
462     ierr = DMGetLabel(dm, bdLabel, &label);CHKERRQ(ierr);
463     if (!isFE[field] || !label) continue;
464     /* Only want to modify label once */
465     for (bd2 = 0; bd2 < bd; ++bd2) {
466       const char *bdname;
467       ierr = PetscDSGetBoundary(probBC, bd2, NULL, NULL, &bdname, NULL, NULL, NULL, NULL, NULL, NULL, NULL);CHKERRQ(ierr);
468       ierr = PetscStrcmp(bdname, bdLabel, &duplicate);CHKERRQ(ierr);
469       if (duplicate) break;
470     }
471     if (!duplicate && (isFE[field])) {
472       /* don't complete cells, which are just present to give orientation to the boundary */
473       ierr = DMPlexLabelComplete(dm, label);CHKERRQ(ierr);
474     }
475     /* Filter out cells, if you actually want to constrain cells you need to do things by hand right now */
476     if (type & DM_BC_ESSENTIAL) {
477       PetscInt       *newidx;
478       PetscInt        n, newn = 0, p, v;
479 
480       bcFields[bc] = field;
481       if (numComps) {ierr = ISCreateGeneral(PetscObjectComm((PetscObject) dm), numComps, comps, PETSC_COPY_VALUES, &bcComps[bc]);CHKERRQ(ierr);}
482       for (v = 0; v < numValues; ++v) {
483         IS              tmp;
484         const PetscInt *idx;
485 
486         ierr = DMGetStratumIS(dm, bdLabel, values[v], &tmp);CHKERRQ(ierr);
487         if (!tmp) continue;
488         ierr = ISGetLocalSize(tmp, &n);CHKERRQ(ierr);
489         ierr = ISGetIndices(tmp, &idx);CHKERRQ(ierr);
490         if (isFE[field]) {
491           for (p = 0; p < n; ++p) if ((idx[p] < cStart) || (idx[p] >= cEnd)) ++newn;
492         } else {
493           for (p = 0; p < n; ++p) if ((idx[p] >= cStart) || (idx[p] < cEnd)) ++newn;
494         }
495         ierr = ISRestoreIndices(tmp, &idx);CHKERRQ(ierr);
496         ierr = ISDestroy(&tmp);CHKERRQ(ierr);
497       }
498       ierr = PetscMalloc1(newn,&newidx);CHKERRQ(ierr);
499       newn = 0;
500       for (v = 0; v < numValues; ++v) {
501         IS              tmp;
502         const PetscInt *idx;
503 
504         ierr = DMGetStratumIS(dm, bdLabel, values[v], &tmp);CHKERRQ(ierr);
505         if (!tmp) continue;
506         ierr = ISGetLocalSize(tmp, &n);CHKERRQ(ierr);
507         ierr = ISGetIndices(tmp, &idx);CHKERRQ(ierr);
508         if (isFE[field]) {
509           for (p = 0; p < n; ++p) if ((idx[p] < cStart) || (idx[p] >= cEnd)) newidx[newn++] = idx[p];
510         } else {
511           for (p = 0; p < n; ++p) if ((idx[p] >= cStart) || (idx[p] < cEnd)) newidx[newn++] = idx[p];
512         }
513         ierr = ISRestoreIndices(tmp, &idx);CHKERRQ(ierr);
514         ierr = ISDestroy(&tmp);CHKERRQ(ierr);
515       }
516       ierr = ISCreateGeneral(PetscObjectComm((PetscObject) dm), newn, newidx, PETSC_OWN_POINTER, &bcPoints[bc++]);CHKERRQ(ierr);
517     }
518   }
519   /* Handle discretization */
520   ierr = PetscCalloc3(Nf,&labels,Nf,&numComp,Nf*(dim+1),&numDof);CHKERRQ(ierr);
521   for (f = 0; f < Nf; ++f) {
522     labels[f] = dm->fields[f].label;
523     if (isFE[f]) {
524       PetscFE         fe = (PetscFE) dm->fields[f].disc;
525       const PetscInt *numFieldDof;
526       PetscInt        fedim, d;
527 
528       ierr = PetscFEGetNumComponents(fe, &numComp[f]);CHKERRQ(ierr);
529       ierr = PetscFEGetNumDof(fe, &numFieldDof);CHKERRQ(ierr);
530       ierr = PetscFEGetSpatialDimension(fe, &fedim);CHKERRQ(ierr);
531       for (d = 0; d < PetscMin(dim, fedim)+1; ++d) numDof[f*(dim+1)+d] = numFieldDof[d];
532     } else {
533       PetscFV fv = (PetscFV) dm->fields[f].disc;
534 
535       ierr = PetscFVGetNumComponents(fv, &numComp[f]);CHKERRQ(ierr);
536       numDof[f*(dim+1)+dim] = numComp[f];
537     }
538   }
539   for (f = 0; f < Nf; ++f) {
540     PetscInt d;
541     for (d = 1; d < dim; ++d) {
542       if ((numDof[f*(dim+1)+d] > 0) && (depth < dim)) SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Mesh must be interpolated when unknowns are specified on edges or faces.");
543     }
544   }
545   ierr = DMPlexCreateSection(dm, labels, numComp, numDof, numBC, bcFields, bcComps, bcPoints, NULL, &section);CHKERRQ(ierr);
546   for (f = 0; f < Nf; ++f) {
547     PetscFE     fe;
548     const char *name;
549 
550     if (isFE[f]) {
551       ierr = DMGetField(dm, f, NULL, (PetscObject *) &fe);CHKERRQ(ierr);
552       ierr = PetscObjectGetName((PetscObject) fe, &name);CHKERRQ(ierr);
553       ierr = PetscSectionSetFieldName(section, f, name);CHKERRQ(ierr);
554     }
555   }
556   ierr = DMSetLocalSection(dm, section);CHKERRQ(ierr);
557   ierr = PetscSectionDestroy(&section);CHKERRQ(ierr);
558   for (bc = 0; bc < numBC; ++bc) {ierr = ISDestroy(&bcPoints[bc]);CHKERRQ(ierr);ierr = ISDestroy(&bcComps[bc]);CHKERRQ(ierr);}
559   ierr = PetscFree3(bcFields,bcPoints,bcComps);CHKERRQ(ierr);
560   ierr = PetscFree3(labels,numComp,numDof);CHKERRQ(ierr);
561   ierr = PetscFree(isFE);CHKERRQ(ierr);
562   PetscFunctionReturn(0);
563 }
564