xref: /petsc/src/dm/impls/plex/plexsubmesh.c (revision d0fa310fbf6f1106c4a755013bbae91f82fb3541)
1 #include <petsc-private/dmpleximpl.h>   /*I      "petscdmplex.h"   I*/
2 #include <petscsf.h>
3 
4 #undef __FUNCT__
5 #define __FUNCT__ "DMPlexMarkBoundaryFaces"
6 /*@
7   DMPlexMarkBoundaryFaces - Mark all faces on the boundary
8 
9   Not Collective
10 
11   Input Parameter:
12 . dm - The original DM
13 
14   Output Parameter:
15 . label - The DMLabel marking boundary faces with value 1
16 
17   Level: developer
18 
19 .seealso: DMLabelCreate(), DMPlexCreateLabel()
20 @*/
21 PetscErrorCode DMPlexMarkBoundaryFaces(DM dm, DMLabel label)
22 {
23   PetscInt       fStart, fEnd, f;
24   PetscErrorCode ierr;
25 
26   PetscFunctionBegin;
27   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
28   ierr = DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd);CHKERRQ(ierr);
29   for (f = fStart; f < fEnd; ++f) {
30     PetscInt supportSize;
31 
32     ierr = DMPlexGetSupportSize(dm, f, &supportSize);CHKERRQ(ierr);
33     if (supportSize == 1) {
34       ierr = DMLabelSetValue(label, f, 1);CHKERRQ(ierr);
35     }
36   }
37   PetscFunctionReturn(0);
38 }
39 
40 #undef __FUNCT__
41 #define __FUNCT__ "DMPlexLabelComplete"
42 /*@
43   DMPlexLabelComplete - Starting with a label marking points on a surface, we add the transitive closure to the surface
44 
45   Input Parameters:
46 + dm - The DM
47 - label - A DMLabel marking the surface points
48 
49   Output Parameter:
50 . label - A DMLabel marking all surface points in the transitive closure
51 
52   Level: developer
53 
54 .seealso: DMPlexLabelCohesiveComplete()
55 @*/
56 PetscErrorCode DMPlexLabelComplete(DM dm, DMLabel label)
57 {
58   IS              valueIS;
59   const PetscInt *values;
60   PetscInt        numValues, v;
61   PetscErrorCode  ierr;
62 
63   PetscFunctionBegin;
64   ierr = DMLabelGetNumValues(label, &numValues);CHKERRQ(ierr);
65   ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
66   ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
67   for (v = 0; v < numValues; ++v) {
68     IS              pointIS;
69     const PetscInt *points;
70     PetscInt        numPoints, p;
71 
72     ierr = DMLabelGetStratumSize(label, values[v], &numPoints);CHKERRQ(ierr);
73     ierr = DMLabelGetStratumIS(label, values[v], &pointIS);CHKERRQ(ierr);
74     ierr = ISGetIndices(pointIS, &points);CHKERRQ(ierr);
75     for (p = 0; p < numPoints; ++p) {
76       PetscInt *closure = NULL;
77       PetscInt  closureSize, c;
78 
79       ierr = DMPlexGetTransitiveClosure(dm, points[p], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
80       for (c = 0; c < closureSize*2; c += 2) {
81         ierr = DMLabelSetValue(label, closure[c], values[v]);CHKERRQ(ierr);
82       }
83       ierr = DMPlexRestoreTransitiveClosure(dm, points[p], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
84     }
85     ierr = ISRestoreIndices(pointIS, &points);CHKERRQ(ierr);
86     ierr = ISDestroy(&pointIS);CHKERRQ(ierr);
87   }
88   ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
89   ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
90   PetscFunctionReturn(0);
91 }
92 
93 #undef __FUNCT__
94 #define __FUNCT__ "DMPlexShiftPoint_Internal"
95 PETSC_STATIC_INLINE PetscInt DMPlexShiftPoint_Internal(PetscInt p, PetscInt depth, PetscInt depthEnd[], PetscInt depthShift[])
96 {
97   if (depth < 0) return p;
98   /* Cells    */ if (p < depthEnd[depth])   return p;
99   /* Vertices */ if (p < depthEnd[0])       return p + depthShift[depth];
100   /* Faces    */ if (p < depthEnd[depth-1]) return p + depthShift[depth] + depthShift[0];
101   /* Edges    */                            return p + depthShift[depth] + depthShift[0] + depthShift[depth-1];
102 }
103 
104 #undef __FUNCT__
105 #define __FUNCT__ "DMPlexShiftSizes_Internal"
106 static PetscErrorCode DMPlexShiftSizes_Internal(DM dm, PetscInt depthShift[], DM dmNew)
107 {
108   PetscInt      *depthEnd;
109   PetscInt       depth = 0, d, pStart, pEnd, p;
110   PetscErrorCode ierr;
111 
112   PetscFunctionBegin;
113   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
114   if (depth < 0) PetscFunctionReturn(0);
115   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
116   /* Step 1: Expand chart */
117   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
118   for (d = 0; d <= depth; ++d) {
119     pEnd += depthShift[d];
120     ierr  = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
121   }
122   ierr = DMPlexSetChart(dmNew, pStart, pEnd);CHKERRQ(ierr);
123   /* Step 2: Set cone and support sizes */
124   for (d = 0; d <= depth; ++d) {
125     ierr = DMPlexGetDepthStratum(dm, d, &pStart, &pEnd);CHKERRQ(ierr);
126     for (p = pStart; p < pEnd; ++p) {
127       PetscInt newp = DMPlexShiftPoint_Internal(p, depth, depthEnd, depthShift);
128       PetscInt size;
129 
130       ierr = DMPlexGetConeSize(dm, p, &size);CHKERRQ(ierr);
131       ierr = DMPlexSetConeSize(dmNew, newp, size);CHKERRQ(ierr);
132       ierr = DMPlexGetSupportSize(dm, p, &size);CHKERRQ(ierr);
133       ierr = DMPlexSetSupportSize(dmNew, newp, size);CHKERRQ(ierr);
134     }
135   }
136   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
137   PetscFunctionReturn(0);
138 }
139 
140 #undef __FUNCT__
141 #define __FUNCT__ "DMPlexShiftPoints_Internal"
142 static PetscErrorCode DMPlexShiftPoints_Internal(DM dm, PetscInt depthShift[], DM dmNew)
143 {
144   PetscInt      *depthEnd, *newpoints;
145   PetscInt       depth = 0, d, maxConeSize, maxSupportSize, pStart, pEnd, p;
146   PetscErrorCode ierr;
147 
148   PetscFunctionBegin;
149   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
150   if (depth < 0) PetscFunctionReturn(0);
151   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
152   ierr = PetscMalloc2(depth+1,PetscInt,&depthEnd,PetscMax(maxConeSize, maxSupportSize),PetscInt,&newpoints);CHKERRQ(ierr);
153   for (d = 0; d <= depth; ++d) {
154     ierr = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
155   }
156   /* Step 5: Set cones and supports */
157   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
158   for (p = pStart; p < pEnd; ++p) {
159     const PetscInt *points = NULL, *orientations = NULL;
160     PetscInt        size, i, newp = DMPlexShiftPoint_Internal(p, depth, depthEnd, depthShift);
161 
162     ierr = DMPlexGetConeSize(dm, p, &size);CHKERRQ(ierr);
163     ierr = DMPlexGetCone(dm, p, &points);CHKERRQ(ierr);
164     ierr = DMPlexGetConeOrientation(dm, p, &orientations);CHKERRQ(ierr);
165     for (i = 0; i < size; ++i) {
166       newpoints[i] = DMPlexShiftPoint_Internal(points[i], depth, depthEnd, depthShift);
167     }
168     ierr = DMPlexSetCone(dmNew, newp, newpoints);CHKERRQ(ierr);
169     ierr = DMPlexSetConeOrientation(dmNew, newp, orientations);CHKERRQ(ierr);
170     ierr = DMPlexGetSupportSize(dm, p, &size);CHKERRQ(ierr);
171     ierr = DMPlexGetSupport(dm, p, &points);CHKERRQ(ierr);
172     for (i = 0; i < size; ++i) {
173       newpoints[i] = DMPlexShiftPoint_Internal(points[i], depth, depthEnd, depthShift);
174     }
175     ierr = DMPlexSetSupport(dmNew, newp, newpoints);CHKERRQ(ierr);
176   }
177   ierr = PetscFree2(depthEnd,newpoints);CHKERRQ(ierr);
178   PetscFunctionReturn(0);
179 }
180 
181 #undef __FUNCT__
182 #define __FUNCT__ "DMPlexShiftCoordinates_Internal"
183 static PetscErrorCode DMPlexShiftCoordinates_Internal(DM dm, PetscInt depthShift[], DM dmNew)
184 {
185   PetscSection   coordSection, newCoordSection;
186   Vec            coordinates, newCoordinates;
187   PetscScalar   *coords, *newCoords;
188   PetscInt      *depthEnd, coordSize;
189   PetscInt       dim, depth = 0, d, vStart, vEnd, vStartNew, vEndNew, v;
190   PetscErrorCode ierr;
191 
192   PetscFunctionBegin;
193   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
194   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
195   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
196   for (d = 0; d <= depth; ++d) {
197     ierr = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
198   }
199   /* Step 8: Convert coordinates */
200   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
201   ierr = DMPlexGetDepthStratum(dmNew, 0, &vStartNew, &vEndNew);CHKERRQ(ierr);
202   ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
203   ierr = PetscSectionCreate(PetscObjectComm((PetscObject)dm), &newCoordSection);CHKERRQ(ierr);
204   ierr = PetscSectionSetNumFields(newCoordSection, 1);CHKERRQ(ierr);
205   ierr = PetscSectionSetFieldComponents(newCoordSection, 0, dim);CHKERRQ(ierr);
206   ierr = PetscSectionSetChart(newCoordSection, vStartNew, vEndNew);CHKERRQ(ierr);
207   for (v = vStartNew; v < vEndNew; ++v) {
208     ierr = PetscSectionSetDof(newCoordSection, v, dim);CHKERRQ(ierr);
209     ierr = PetscSectionSetFieldDof(newCoordSection, v, 0, dim);CHKERRQ(ierr);
210   }
211   ierr = PetscSectionSetUp(newCoordSection);CHKERRQ(ierr);
212   ierr = DMPlexSetCoordinateSection(dmNew, newCoordSection);CHKERRQ(ierr);
213   ierr = PetscSectionGetStorageSize(newCoordSection, &coordSize);CHKERRQ(ierr);
214   ierr = VecCreate(PetscObjectComm((PetscObject)dm), &newCoordinates);CHKERRQ(ierr);
215   ierr = PetscObjectSetName((PetscObject) newCoordinates, "coordinates");CHKERRQ(ierr);
216   ierr = VecSetSizes(newCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
217   ierr = VecSetType(newCoordinates,dm->vectype);CHKERRQ(ierr);
218   ierr = DMSetCoordinatesLocal(dmNew, newCoordinates);CHKERRQ(ierr);
219   ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
220   ierr = VecGetArray(coordinates, &coords);CHKERRQ(ierr);
221   ierr = VecGetArray(newCoordinates, &newCoords);CHKERRQ(ierr);
222   for (v = vStart; v < vEnd; ++v) {
223     PetscInt dof, off, noff, d;
224 
225     ierr = PetscSectionGetDof(coordSection, v, &dof);CHKERRQ(ierr);
226     ierr = PetscSectionGetOffset(coordSection, v, &off);CHKERRQ(ierr);
227     ierr = PetscSectionGetOffset(newCoordSection, DMPlexShiftPoint_Internal(v, depth, depthEnd, depthShift), &noff);CHKERRQ(ierr);
228     for (d = 0; d < dof; ++d) {
229       newCoords[noff+d] = coords[off+d];
230     }
231   }
232   ierr = VecRestoreArray(coordinates, &coords);CHKERRQ(ierr);
233   ierr = VecRestoreArray(newCoordinates, &newCoords);CHKERRQ(ierr);
234   ierr = VecDestroy(&newCoordinates);CHKERRQ(ierr);
235   ierr = PetscSectionDestroy(&newCoordSection);CHKERRQ(ierr);
236   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
237   PetscFunctionReturn(0);
238 }
239 
240 #undef __FUNCT__
241 #define __FUNCT__ "DMPlexShiftSF_Internal"
242 static PetscErrorCode DMPlexShiftSF_Internal(DM dm, PetscInt depthShift[], DM dmNew)
243 {
244   PetscInt          *depthEnd;
245   PetscInt           depth = 0, d;
246   PetscSF            sfPoint, sfPointNew;
247   const PetscSFNode *remotePoints;
248   PetscSFNode       *gremotePoints;
249   const PetscInt    *localPoints;
250   PetscInt          *glocalPoints, *newLocation, *newRemoteLocation;
251   PetscInt           numRoots, numLeaves, l, pStart, pEnd, totShift = 0;
252   PetscErrorCode     ierr;
253 
254   PetscFunctionBegin;
255   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
256   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
257   for (d = 0; d <= depth; ++d) {
258     totShift += depthShift[d];
259     ierr      = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
260   }
261   /* Step 9: Convert pointSF */
262   ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
263   ierr = DMGetPointSF(dmNew, &sfPointNew);CHKERRQ(ierr);
264   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
265   ierr = PetscSFGetGraph(sfPoint, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
266   if (numRoots >= 0) {
267     ierr = PetscMalloc2(numRoots,PetscInt,&newLocation,pEnd-pStart,PetscInt,&newRemoteLocation);CHKERRQ(ierr);
268     for (l=0; l<numRoots; l++) newLocation[l] = DMPlexShiftPoint_Internal(l, depth, depthEnd, depthShift);
269     ierr = PetscSFBcastBegin(sfPoint, MPIU_INT, newLocation, newRemoteLocation);CHKERRQ(ierr);
270     ierr = PetscSFBcastEnd(sfPoint, MPIU_INT, newLocation, newRemoteLocation);CHKERRQ(ierr);
271     ierr = PetscMalloc(numLeaves * sizeof(PetscInt),    &glocalPoints);CHKERRQ(ierr);
272     ierr = PetscMalloc(numLeaves * sizeof(PetscSFNode), &gremotePoints);CHKERRQ(ierr);
273     for (l = 0; l < numLeaves; ++l) {
274       glocalPoints[l]        = DMPlexShiftPoint_Internal(localPoints[l], depth, depthEnd, depthShift);
275       gremotePoints[l].rank  = remotePoints[l].rank;
276       gremotePoints[l].index = newRemoteLocation[localPoints[l]];
277     }
278     ierr = PetscFree2(newLocation,newRemoteLocation);CHKERRQ(ierr);
279     ierr = PetscSFSetGraph(sfPointNew, numRoots + totShift, numLeaves, glocalPoints, PETSC_OWN_POINTER, gremotePoints, PETSC_OWN_POINTER);CHKERRQ(ierr);
280   }
281   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
282   PetscFunctionReturn(0);
283 }
284 
285 #undef __FUNCT__
286 #define __FUNCT__ "DMPlexShiftLabels_Internal"
287 static PetscErrorCode DMPlexShiftLabels_Internal(DM dm, PetscInt depthShift[], DM dmNew)
288 {
289   PetscSF            sfPoint;
290   DMLabel            vtkLabel, ghostLabel;
291   PetscInt          *depthEnd;
292   const PetscSFNode *leafRemote;
293   const PetscInt    *leafLocal;
294   PetscInt           depth = 0, d, numLeaves, numLabels, l, cStart, cEnd, c, fStart, fEnd, f;
295   PetscMPIInt        rank;
296   PetscErrorCode     ierr;
297 
298   PetscFunctionBegin;
299   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
300   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
301   for (d = 0; d <= depth; ++d) {
302     ierr = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
303   }
304   /* Step 10: Convert labels */
305   ierr = DMPlexGetNumLabels(dm, &numLabels);CHKERRQ(ierr);
306   for (l = 0; l < numLabels; ++l) {
307     DMLabel         label, newlabel;
308     const char     *lname;
309     PetscBool       isDepth;
310     IS              valueIS;
311     const PetscInt *values;
312     PetscInt        numValues, val;
313 
314     ierr = DMPlexGetLabelName(dm, l, &lname);CHKERRQ(ierr);
315     ierr = PetscStrcmp(lname, "depth", &isDepth);CHKERRQ(ierr);
316     if (isDepth) continue;
317     ierr = DMPlexCreateLabel(dmNew, lname);CHKERRQ(ierr);
318     ierr = DMPlexGetLabel(dm, lname, &label);CHKERRQ(ierr);
319     ierr = DMPlexGetLabel(dmNew, lname, &newlabel);CHKERRQ(ierr);
320     ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
321     ierr = ISGetLocalSize(valueIS, &numValues);CHKERRQ(ierr);
322     ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
323     for (val = 0; val < numValues; ++val) {
324       IS              pointIS;
325       const PetscInt *points;
326       PetscInt        numPoints, p;
327 
328       ierr = DMLabelGetStratumIS(label, values[val], &pointIS);CHKERRQ(ierr);
329       ierr = ISGetLocalSize(pointIS, &numPoints);CHKERRQ(ierr);
330       ierr = ISGetIndices(pointIS, &points);CHKERRQ(ierr);
331       for (p = 0; p < numPoints; ++p) {
332         const PetscInt newpoint = DMPlexShiftPoint_Internal(points[p], depth, depthEnd, depthShift);
333 
334         ierr = DMLabelSetValue(newlabel, newpoint, values[val]);CHKERRQ(ierr);
335       }
336       ierr = ISRestoreIndices(pointIS, &points);CHKERRQ(ierr);
337       ierr = ISDestroy(&pointIS);CHKERRQ(ierr);
338     }
339     ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
340     ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
341   }
342   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
343   /* Step 11: Make label for output (vtk) and to mark ghost points (ghost) */
344   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank);CHKERRQ(ierr);
345   ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
346   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
347   ierr = PetscSFGetGraph(sfPoint, NULL, &numLeaves, &leafLocal, &leafRemote);CHKERRQ(ierr);
348   ierr = DMPlexCreateLabel(dmNew, "vtk");CHKERRQ(ierr);
349   ierr = DMPlexCreateLabel(dmNew, "ghost");CHKERRQ(ierr);
350   ierr = DMPlexGetLabel(dmNew, "vtk", &vtkLabel);CHKERRQ(ierr);
351   ierr = DMPlexGetLabel(dmNew, "ghost", &ghostLabel);CHKERRQ(ierr);
352   for (l = 0, c = cStart; l < numLeaves && c < cEnd; ++l, ++c) {
353     for (; c < leafLocal[l] && c < cEnd; ++c) {
354       ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
355     }
356     if (leafLocal[l] >= cEnd) break;
357     if (leafRemote[l].rank == rank) {
358       ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
359     } else {
360       ierr = DMLabelSetValue(ghostLabel, c, 2);CHKERRQ(ierr);
361     }
362   }
363   for (; c < cEnd; ++c) {
364     ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
365   }
366   if (0) {
367     ierr = PetscViewerASCIISynchronizedAllow(PETSC_VIEWER_STDOUT_WORLD, PETSC_TRUE);CHKERRQ(ierr);
368     ierr = DMLabelView(vtkLabel, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
369     ierr = PetscViewerFlush(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
370   }
371   ierr = DMPlexGetHeightStratum(dmNew, 1, &fStart, &fEnd);CHKERRQ(ierr);
372   for (f = fStart; f < fEnd; ++f) {
373     PetscInt numCells;
374 
375     ierr = DMPlexGetSupportSize(dmNew, f, &numCells);CHKERRQ(ierr);
376     if (numCells < 2) {
377       ierr = DMLabelSetValue(ghostLabel, f, 1);CHKERRQ(ierr);
378     } else {
379       const PetscInt *cells = NULL;
380       PetscInt        vA, vB;
381 
382       ierr = DMPlexGetSupport(dmNew, f, &cells);CHKERRQ(ierr);
383       ierr = DMLabelGetValue(vtkLabel, cells[0], &vA);CHKERRQ(ierr);
384       ierr = DMLabelGetValue(vtkLabel, cells[1], &vB);CHKERRQ(ierr);
385       if (!vA && !vB) {ierr = DMLabelSetValue(ghostLabel, f, 1);CHKERRQ(ierr);}
386     }
387   }
388   if (0) {
389     ierr = PetscViewerASCIISynchronizedAllow(PETSC_VIEWER_STDOUT_WORLD, PETSC_TRUE);CHKERRQ(ierr);
390     ierr = DMLabelView(ghostLabel, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
391     ierr = PetscViewerFlush(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
392   }
393   PetscFunctionReturn(0);
394 }
395 
396 #undef __FUNCT__
397 #define __FUNCT__ "DMPlexConstructGhostCells_Internal"
398 static PetscErrorCode DMPlexConstructGhostCells_Internal(DM dm, DMLabel label, PetscInt *numGhostCells, DM gdm)
399 {
400   IS              valueIS;
401   const PetscInt *values;
402   PetscInt       *depthShift;
403   PetscInt        depth = 0, numFS, fs, ghostCell, cEnd, c;
404   PetscErrorCode  ierr;
405 
406   PetscFunctionBegin;
407   /* Count ghost cells */
408   ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
409   ierr = ISGetLocalSize(valueIS, &numFS);CHKERRQ(ierr);
410   ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
411 
412   *numGhostCells = 0;
413   for (fs = 0; fs < numFS; ++fs) {
414     PetscInt numBdFaces;
415 
416     ierr = DMLabelGetStratumSize(label, values[fs], &numBdFaces);CHKERRQ(ierr);
417 
418     *numGhostCells += numBdFaces;
419   }
420   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
421   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthShift);CHKERRQ(ierr);
422   ierr = PetscMemzero(depthShift, (depth+1) * sizeof(PetscInt));CHKERRQ(ierr);
423   if (depth >= 0) depthShift[depth] = *numGhostCells;
424   ierr = DMPlexShiftSizes_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
425   /* Step 3: Set cone/support sizes for new points */
426   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
427   for (c = cEnd; c < cEnd + *numGhostCells; ++c) {
428     ierr = DMPlexSetConeSize(gdm, c, 1);CHKERRQ(ierr);
429   }
430   for (fs = 0; fs < numFS; ++fs) {
431     IS              faceIS;
432     const PetscInt *faces;
433     PetscInt        numFaces, f;
434 
435     ierr = DMLabelGetStratumIS(label, values[fs], &faceIS);CHKERRQ(ierr);
436     ierr = ISGetLocalSize(faceIS, &numFaces);CHKERRQ(ierr);
437     ierr = ISGetIndices(faceIS, &faces);CHKERRQ(ierr);
438     for (f = 0; f < numFaces; ++f) {
439       PetscInt size;
440 
441       ierr = DMPlexGetSupportSize(dm, faces[f], &size);CHKERRQ(ierr);
442       if (size != 1) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "DM has boundary face %d with %d support cells", faces[f], size);
443       ierr = DMPlexSetSupportSize(gdm, faces[f] + *numGhostCells, 2);CHKERRQ(ierr);
444     }
445     ierr = ISRestoreIndices(faceIS, &faces);CHKERRQ(ierr);
446     ierr = ISDestroy(&faceIS);CHKERRQ(ierr);
447   }
448   /* Step 4: Setup ghosted DM */
449   ierr = DMSetUp(gdm);CHKERRQ(ierr);
450   ierr = DMPlexShiftPoints_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
451   /* Step 6: Set cones and supports for new points */
452   ghostCell = cEnd;
453   for (fs = 0; fs < numFS; ++fs) {
454     IS              faceIS;
455     const PetscInt *faces;
456     PetscInt        numFaces, f;
457 
458     ierr = DMLabelGetStratumIS(label, values[fs], &faceIS);CHKERRQ(ierr);
459     ierr = ISGetLocalSize(faceIS, &numFaces);CHKERRQ(ierr);
460     ierr = ISGetIndices(faceIS, &faces);CHKERRQ(ierr);
461     for (f = 0; f < numFaces; ++f, ++ghostCell) {
462       PetscInt newFace = faces[f] + *numGhostCells;
463 
464       ierr = DMPlexSetCone(gdm, ghostCell, &newFace);CHKERRQ(ierr);
465       ierr = DMPlexInsertSupport(gdm, newFace, 1, ghostCell);CHKERRQ(ierr);
466     }
467     ierr = ISRestoreIndices(faceIS, &faces);CHKERRQ(ierr);
468     ierr = ISDestroy(&faceIS);CHKERRQ(ierr);
469   }
470   ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
471   ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
472   /* Step 7: Stratify */
473   ierr = DMPlexStratify(gdm);CHKERRQ(ierr);
474   ierr = DMPlexShiftCoordinates_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
475   ierr = DMPlexShiftSF_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
476   ierr = DMPlexShiftLabels_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
477   ierr = PetscFree(depthShift);CHKERRQ(ierr);
478   PetscFunctionReturn(0);
479 }
480 
481 #undef __FUNCT__
482 #define __FUNCT__ "DMPlexConstructGhostCells"
483 /*@C
484   DMPlexConstructGhostCells - Construct ghost cells which connect to every boundary face
485 
486   Collective on dm
487 
488   Input Parameters:
489 + dm - The original DM
490 - labelName - The label specifying the boundary faces, or "Face Sets" if this is NULL
491 
492   Output Parameters:
493 + numGhostCells - The number of ghost cells added to the DM
494 - dmGhosted - The new DM
495 
496   Note: If no label exists of that name, one will be created marking all boundary faces
497 
498   Level: developer
499 
500 .seealso: DMCreate()
501 */
502 PetscErrorCode DMPlexConstructGhostCells(DM dm, const char labelName[], PetscInt *numGhostCells, DM *dmGhosted)
503 {
504   DM             gdm;
505   DMLabel        label;
506   const char    *name = labelName ? labelName : "Face Sets";
507   PetscInt       dim;
508   PetscErrorCode ierr;
509 
510   PetscFunctionBegin;
511   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
512   PetscValidPointer(numGhostCells, 3);
513   PetscValidPointer(dmGhosted, 4);
514   ierr = DMCreate(PetscObjectComm((PetscObject)dm), &gdm);CHKERRQ(ierr);
515   ierr = DMSetType(gdm, DMPLEX);CHKERRQ(ierr);
516   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
517   ierr = DMPlexSetDimension(gdm, dim);CHKERRQ(ierr);
518   ierr = DMPlexGetLabel(dm, name, &label);CHKERRQ(ierr);
519   if (!label) {
520     /* Get label for boundary faces */
521     ierr = DMPlexCreateLabel(dm, name);CHKERRQ(ierr);
522     ierr = DMPlexGetLabel(dm, name, &label);CHKERRQ(ierr);
523     ierr = DMPlexMarkBoundaryFaces(dm, label);CHKERRQ(ierr);
524   }
525   ierr = DMPlexConstructGhostCells_Internal(dm, label, numGhostCells, gdm);CHKERRQ(ierr);
526   ierr = DMSetFromOptions(gdm);CHKERRQ(ierr);
527   *dmGhosted = gdm;
528   PetscFunctionReturn(0);
529 }
530 
531 #undef __FUNCT__
532 #define __FUNCT__ "DMPlexConstructCohesiveCells_Internal"
533 /*
534   We are adding two kinds of points here:
535     Replicated: Copies of points which exist in the mesh, such as vertices identified across a fault
536     Hybrid:     Entirely new points, such as cohesive cells
537 */
538 static PetscErrorCode DMPlexConstructCohesiveCells_Internal(DM dm, DMLabel label, DM sdm)
539 {
540   MPI_Comm         comm;
541   IS               valueIS;
542   PetscInt         numSP = 0;       /* The number of depths for which we have replicated points */
543   const PetscInt  *values;          /* List of depths for which we have replicated points */
544   IS              *pointIS;
545   PetscInt        *numSplitPoints;  /* The number of replicated points at each depth */
546   PetscInt        *numHybridPoints; /* The number of hybrid points at each depth */
547   const PetscInt **splitPoints;     /* Replicated points for each depth */
548   PetscSection     coordSection;
549   Vec              coordinates;
550   PetscScalar     *coords;
551   PetscInt         depths[4];       /* Depths in the order that plex points are numbered */
552   PetscInt        *depthShift;      /* Number of replicated+hybrid points at each depth */
553   PetscInt        *depthOffset;     /* Prefix sums of depthShift */
554   PetscInt        *pMaxNew;         /* The first replicated point at each depth in the new mesh, hybrids come after this */
555   PetscInt        *coneNew, *coneONew, *supportNew;
556   PetscInt         shift = 100, depth = 0, dep, dim, d, sp, maxConeSize, maxSupportSize, numLabels, vStart, vEnd, pEnd, p, v;
557   PetscErrorCode   ierr;
558 
559   PetscFunctionBegin;
560   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
561   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
562   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
563   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
564   depths[0] = depth;
565   depths[1] = 0;
566   depths[2] = depth-1;
567   depths[3] = 1;
568   /* Count split points and add cohesive cells */
569   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
570   ierr = PetscMalloc6(depth+1,PetscInt,&depthShift,depth+1,PetscInt,&depthOffset,depth+1,PetscInt,&pMaxNew,maxConeSize*3,PetscInt,&coneNew,maxConeSize*3,PetscInt,&coneONew,maxSupportSize,PetscInt,&supportNew);CHKERRQ(ierr);
571   ierr = PetscMalloc4(depth+1,IS,&pointIS,depth+1,PetscInt,&numSplitPoints,depth+1,PetscInt,&numHybridPoints,depth+1,const PetscInt*,&splitPoints);CHKERRQ(ierr);
572   ierr = PetscMemzero(depthShift,  (depth+1) * sizeof(PetscInt));CHKERRQ(ierr);
573   ierr = PetscMemzero(depthOffset, (depth+1) * sizeof(PetscInt));CHKERRQ(ierr);
574   for (d = 0; d <= depth; ++d) {
575     ierr               = DMPlexGetDepthStratum(dm, d, NULL, &pMaxNew[d]);CHKERRQ(ierr);
576     numSplitPoints[d]  = 0;
577     numHybridPoints[d] = 0;
578     splitPoints[d]     = NULL;
579     pointIS[d]         = NULL;
580   }
581   if (label) {
582     ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
583     ierr = ISGetLocalSize(valueIS, &numSP);CHKERRQ(ierr);
584     ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
585   }
586   for (sp = 0; sp < numSP; ++sp) {
587     const PetscInt dep = values[sp];
588 
589     if ((dep < 0) || (dep > depth)) continue;
590     ierr = DMLabelGetStratumIS(label, dep, &pointIS[dep]);CHKERRQ(ierr);
591     if (pointIS[dep]) {
592       ierr = ISGetLocalSize(pointIS[dep], &numSplitPoints[dep]);CHKERRQ(ierr);
593       ierr = ISGetIndices(pointIS[dep], &splitPoints[dep]);CHKERRQ(ierr);
594     }
595   }
596   /* Calculate number of hybrid points */
597   for (d = 1; d <= depth; ++d) numHybridPoints[d]     = numSplitPoints[d-1]; /* There is a hybrid cell/face/edge for every split face/edge/vertex   */
598   for (d = 0; d <= depth; ++d) depthShift[d]          = numSplitPoints[d] + numHybridPoints[d];
599   for (d = 1; d <= depth; ++d) depthOffset[depths[d]] = depthOffset[depths[d-1]] + depthShift[depths[d-1]];
600   for (d = 0; d <= depth; ++d) pMaxNew[d]            += depthOffset[d];
601   ierr = DMPlexShiftSizes_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
602   /* Step 3: Set cone/support sizes for new points */
603   for (dep = 0; dep <= depth; ++dep) {
604     for (p = 0; p < numSplitPoints[dep]; ++p) {
605       const PetscInt  oldp   = splitPoints[dep][p];
606       const PetscInt  newp   = oldp + depthOffset[dep];
607       const PetscInt  splitp = p    + pMaxNew[dep];
608       const PetscInt *support;
609       PetscInt        coneSize, supportSize, qf, qn, qp, e;
610 
611       ierr = DMPlexGetConeSize(dm, oldp, &coneSize);CHKERRQ(ierr);
612       ierr = DMPlexSetConeSize(sdm, splitp, coneSize);CHKERRQ(ierr);
613       ierr = DMPlexGetSupportSize(dm, oldp, &supportSize);CHKERRQ(ierr);
614       ierr = DMPlexSetSupportSize(sdm, splitp, supportSize);CHKERRQ(ierr);
615       if (dep == depth-1) {
616         const PetscInt hybcell = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
617 
618         /* Add cohesive cells, they are prisms */
619         ierr = DMPlexSetConeSize(sdm, hybcell, 2 + coneSize);CHKERRQ(ierr);
620       } else if (dep == 0) {
621         const PetscInt hybedge = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
622 
623         ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
624         for (e = 0, qn = 0, qp = 0, qf = 0; e < supportSize; ++e) {
625           PetscInt val;
626 
627           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
628           if (val == 1) ++qf;
629           if ((val == 1) || (val ==  (shift + 1))) ++qn;
630           if ((val == 1) || (val == -(shift + 1))) ++qp;
631         }
632         /* Split old vertex: Edges into original vertex and new cohesive edge */
633         ierr = DMPlexSetSupportSize(sdm, newp, qn+1);CHKERRQ(ierr);
634         /* Split new vertex: Edges into split vertex and new cohesive edge */
635         ierr = DMPlexSetSupportSize(sdm, splitp, qp+1);CHKERRQ(ierr);
636         /* Add hybrid edge */
637         ierr = DMPlexSetConeSize(sdm, hybedge, 2);CHKERRQ(ierr);
638         ierr = DMPlexSetSupportSize(sdm, hybedge, qf);CHKERRQ(ierr);
639       } else if (dep == dim-2) {
640         const PetscInt hybface = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
641 
642         ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
643         for (e = 0, qn = 0, qp = 0, qf = 0; e < supportSize; ++e) {
644           PetscInt val;
645 
646           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
647           if (val == dim-1) ++qf;
648           if ((val == dim-1) || (val ==  (shift + dim-1))) ++qn;
649           if ((val == dim-1) || (val == -(shift + dim-1))) ++qp;
650         }
651         /* Split old edge: Faces into original edge and cohesive face (positive side?) */
652         ierr = DMPlexSetSupportSize(sdm, newp, qn+1);CHKERRQ(ierr);
653         /* Split new edge: Faces into split edge and cohesive face (negative side?) */
654         ierr = DMPlexSetSupportSize(sdm, splitp, qp+1);CHKERRQ(ierr);
655         /* Add hybrid face */
656         ierr = DMPlexSetConeSize(sdm, hybface, 4);CHKERRQ(ierr);
657         ierr = DMPlexSetSupportSize(sdm, hybface, qf);CHKERRQ(ierr);
658       }
659     }
660   }
661   /* Step 4: Setup split DM */
662   ierr = DMSetUp(sdm);CHKERRQ(ierr);
663   ierr = DMPlexShiftPoints_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
664   /* Step 6: Set cones and supports for new points */
665   for (dep = 0; dep <= depth; ++dep) {
666     for (p = 0; p < numSplitPoints[dep]; ++p) {
667       const PetscInt  oldp   = splitPoints[dep][p];
668       const PetscInt  newp   = oldp + depthOffset[dep];
669       const PetscInt  splitp = p    + pMaxNew[dep];
670       const PetscInt *cone, *support, *ornt;
671       PetscInt        coneSize, supportSize, q, qf, qn, qp, v, e, s;
672 
673       ierr = DMPlexGetConeSize(dm, oldp, &coneSize);CHKERRQ(ierr);
674       ierr = DMPlexGetCone(dm, oldp, &cone);CHKERRQ(ierr);
675       ierr = DMPlexGetConeOrientation(dm, oldp, &ornt);CHKERRQ(ierr);
676       ierr = DMPlexGetSupportSize(dm, oldp, &supportSize);CHKERRQ(ierr);
677       ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
678       if (dep == depth-1) {
679         const PetscInt  hybcell = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
680         const PetscInt *supportF;
681 
682         /* Split face:       copy in old face to new face to start */
683         ierr = DMPlexGetSupport(sdm, newp,  &supportF);CHKERRQ(ierr);
684         ierr = DMPlexSetSupport(sdm, splitp, supportF);CHKERRQ(ierr);
685         /* Split old face:   old vertices/edges in cone so no change */
686         /* Split new face:   new vertices/edges in cone */
687         for (q = 0; q < coneSize; ++q) {
688           ierr = PetscFindInt(cone[q], numSplitPoints[dep-1], splitPoints[dep-1], &v);CHKERRQ(ierr);
689 
690           coneNew[2+q] = v + pMaxNew[dep-1];
691         }
692         ierr = DMPlexSetCone(sdm, splitp, &coneNew[2]);CHKERRQ(ierr);
693         ierr = DMPlexSetConeOrientation(sdm, splitp, ornt);CHKERRQ(ierr);
694         /* Face support */
695         for (s = 0; s < supportSize; ++s) {
696           PetscInt val;
697 
698           ierr = DMLabelGetValue(label, support[s], &val);CHKERRQ(ierr);
699           if (val < 0) {
700             /* Split old face:   Replace negative side cell with cohesive cell */
701              ierr = DMPlexInsertSupport(sdm, newp, s, hybcell);CHKERRQ(ierr);
702           } else {
703             /* Split new face:   Replace positive side cell with cohesive cell */
704             ierr = DMPlexInsertSupport(sdm, splitp, s, hybcell);CHKERRQ(ierr);
705             /* Get orientation for cohesive face */
706             {
707               const PetscInt *ncone, *nconeO;
708               PetscInt        nconeSize, nc;
709 
710               ierr = DMPlexGetConeSize(dm, support[s], &nconeSize);CHKERRQ(ierr);
711               ierr = DMPlexGetCone(dm, support[s], &ncone);CHKERRQ(ierr);
712               ierr = DMPlexGetConeOrientation(dm, support[s], &nconeO);CHKERRQ(ierr);
713               for (nc = 0; nc < nconeSize; ++nc) {
714                 if (ncone[nc] == oldp) {
715                   coneONew[0] = nconeO[nc];
716                   break;
717                 }
718               }
719               if (nc >= nconeSize) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not locate face %d in neighboring cell %d", oldp, support[s]);
720             }
721           }
722         }
723         /* Cohesive cell:    Old and new split face, then new cohesive faces */
724         coneNew[0]  = newp;   /* Extracted negative side orientation above */
725         coneNew[1]  = splitp;
726         coneONew[1] = coneONew[0];
727         for (q = 0; q < coneSize; ++q) {
728           coneNew[2+q] += (pMaxNew[dep] - pMaxNew[dep-1]) + numSplitPoints[dep];
729           coneONew[2+q] = 0;
730         }
731         ierr = DMPlexSetCone(sdm, hybcell, coneNew);CHKERRQ(ierr);
732         ierr = DMPlexSetConeOrientation(sdm, hybcell, coneONew);CHKERRQ(ierr);
733       } else if (dep == 0) {
734         const PetscInt hybedge = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
735 
736         /* Split old vertex: Edges in old split faces and new cohesive edge */
737         for (e = 0, qn = 0; e < supportSize; ++e) {
738           PetscInt val;
739 
740           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
741           if ((val == 1) || (val == (shift + 1))) {
742             supportNew[qn++] = support[e] + depthOffset[dep+1];
743           }
744         }
745         supportNew[qn] = hybedge;
746         ierr = DMPlexSetSupport(sdm, newp, supportNew);CHKERRQ(ierr);
747         /* Split new vertex: Edges in new split faces and new cohesive edge */
748         for (e = 0, qp = 0; e < supportSize; ++e) {
749           PetscInt val, edge;
750 
751           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
752           if (val == 1) {
753             ierr = PetscFindInt(support[e], numSplitPoints[dep+1], splitPoints[dep+1], &edge);CHKERRQ(ierr);
754             if (edge < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Edge %d is not a split edge", support[e]);
755             supportNew[qp++] = edge + pMaxNew[dep+1];
756           } else if (val == -(shift + 1)) {
757             supportNew[qp++] = support[e] + depthOffset[dep+1];
758           }
759         }
760         supportNew[qp] = hybedge;
761         ierr = DMPlexSetSupport(sdm, splitp, supportNew);CHKERRQ(ierr);
762         /* Hybrid edge:    Old and new split vertex */
763         coneNew[0] = newp;
764         coneNew[1] = splitp;
765         ierr = DMPlexSetCone(sdm, hybedge, coneNew);CHKERRQ(ierr);
766         for (e = 0, qf = 0; e < supportSize; ++e) {
767           PetscInt val, edge;
768 
769           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
770           if (val == 1) {
771             ierr = PetscFindInt(support[e], numSplitPoints[dep+1], splitPoints[dep+1], &edge);CHKERRQ(ierr);
772             if (edge < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Edge %d is not a split edge", support[e]);
773             supportNew[qf++] = edge + pMaxNew[dep+2] + numSplitPoints[dep+2];
774           }
775         }
776         ierr = DMPlexSetSupport(sdm, hybedge, supportNew);CHKERRQ(ierr);
777       } else if (dep == dim-2) {
778         const PetscInt hybface = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
779 
780         /* Split old edge:   old vertices in cone so no change */
781         /* Split new edge:   new vertices in cone */
782         for (q = 0; q < coneSize; ++q) {
783           ierr = PetscFindInt(cone[q], numSplitPoints[dep-1], splitPoints[dep-1], &v);CHKERRQ(ierr);
784 
785           coneNew[q] = v + pMaxNew[dep-1];
786         }
787         ierr = DMPlexSetCone(sdm, splitp, coneNew);CHKERRQ(ierr);
788         /* Split old edge: Faces in positive side cells and old split faces */
789         for (e = 0, q = 0; e < supportSize; ++e) {
790           PetscInt val;
791 
792           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
793           if (val == dim-1) {
794             supportNew[q++] = support[e] + depthOffset[dep+1];
795           } else if (val == (shift + dim-1)) {
796             supportNew[q++] = support[e] + depthOffset[dep+1];
797           }
798         }
799         supportNew[q++] = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
800         ierr = DMPlexSetSupport(sdm, newp, supportNew);CHKERRQ(ierr);
801         /* Split new edge: Faces in negative side cells and new split faces */
802         for (e = 0, q = 0; e < supportSize; ++e) {
803           PetscInt val, face;
804 
805           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
806           if (val == dim-1) {
807             ierr = PetscFindInt(support[e], numSplitPoints[dep+1], splitPoints[dep+1], &face);CHKERRQ(ierr);
808             if (face < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Face %d is not a split face", support[e]);
809             supportNew[q++] = face + pMaxNew[dep+1];
810           } else if (val == -(shift + dim-1)) {
811             supportNew[q++] = support[e] + depthOffset[dep+1];
812           }
813         }
814         supportNew[q++] = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
815         ierr = DMPlexSetSupport(sdm, splitp, supportNew);CHKERRQ(ierr);
816         /* Hybrid face */
817         coneNew[0] = newp;
818         coneNew[1] = splitp;
819         for (v = 0; v < coneSize; ++v) {
820           PetscInt vertex;
821           ierr = PetscFindInt(cone[v], numSplitPoints[dep-1], splitPoints[dep-1], &vertex);CHKERRQ(ierr);
822           if (vertex < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Vertex %d is not a split vertex", support[e]);
823           coneNew[2+v] = vertex + pMaxNew[dep] + numSplitPoints[dep];
824         }
825         ierr = DMPlexSetCone(sdm, hybface, coneNew);CHKERRQ(ierr);
826         for (e = 0, qf = 0; e < supportSize; ++e) {
827           PetscInt val, face;
828 
829           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
830           if (val == dim-1) {
831             ierr = PetscFindInt(support[e], numSplitPoints[dep+1], splitPoints[dep+1], &face);CHKERRQ(ierr);
832             if (face < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Face %d is not a split face", support[e]);
833             supportNew[qf++] = face + pMaxNew[dep+2] + numSplitPoints[dep+2];
834           }
835         }
836         ierr = DMPlexSetSupport(sdm, hybface, supportNew);CHKERRQ(ierr);
837       }
838     }
839   }
840   /* Step 6b: Replace split points in negative side cones */
841   for (sp = 0; sp < numSP; ++sp) {
842     PetscInt        dep = values[sp];
843     IS              pIS;
844     PetscInt        numPoints;
845     const PetscInt *points;
846 
847     if (dep >= 0) continue;
848     ierr = DMLabelGetStratumIS(label, dep, &pIS);CHKERRQ(ierr);
849     if (!pIS) continue;
850     dep  = -dep - shift;
851     ierr = ISGetLocalSize(pIS, &numPoints);CHKERRQ(ierr);
852     ierr = ISGetIndices(pIS, &points);CHKERRQ(ierr);
853     for (p = 0; p < numPoints; ++p) {
854       const PetscInt  oldp = points[p];
855       const PetscInt  newp = depthOffset[dep] + oldp;
856       const PetscInt *cone;
857       PetscInt        coneSize, c;
858       /* PetscBool       replaced = PETSC_FALSE; */
859 
860       /* Negative edge: replace split vertex */
861       /* Negative cell: replace split face */
862       ierr = DMPlexGetConeSize(sdm, newp, &coneSize);CHKERRQ(ierr);
863       ierr = DMPlexGetCone(sdm, newp, &cone);CHKERRQ(ierr);
864       for (c = 0; c < coneSize; ++c) {
865         const PetscInt coldp = cone[c] - depthOffset[dep-1];
866         PetscInt       csplitp, cp, val;
867 
868         ierr = DMLabelGetValue(label, coldp, &val);CHKERRQ(ierr);
869         if (val == dep-1) {
870           ierr = PetscFindInt(coldp, numSplitPoints[dep-1], splitPoints[dep-1], &cp);CHKERRQ(ierr);
871           if (cp < 0) SETERRQ2(comm, PETSC_ERR_ARG_WRONG, "Point %d is not a split point of dimension %d", oldp, dep-1);
872           csplitp  = pMaxNew[dep-1] + cp;
873           ierr     = DMPlexInsertCone(sdm, newp, c, csplitp);CHKERRQ(ierr);
874           /* replaced = PETSC_TRUE; */
875         }
876       }
877       /* Cells with only a vertex or edge on the submesh have no replacement */
878       /* if (!replaced) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "The cone of point %d does not contain split points", oldp); */
879     }
880     ierr = ISRestoreIndices(pIS, &points);CHKERRQ(ierr);
881     ierr = ISDestroy(&pIS);CHKERRQ(ierr);
882   }
883   /* Step 7: Stratify */
884   ierr = DMPlexStratify(sdm);CHKERRQ(ierr);
885   /* Step 8: Coordinates */
886   ierr = DMPlexShiftCoordinates_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
887   ierr = DMPlexGetCoordinateSection(sdm, &coordSection);CHKERRQ(ierr);
888   ierr = DMGetCoordinatesLocal(sdm, &coordinates);CHKERRQ(ierr);
889   ierr = VecGetArray(coordinates, &coords);CHKERRQ(ierr);
890   for (v = 0; v < (numSplitPoints ? numSplitPoints[0] : 0); ++v) {
891     const PetscInt newp   = depthOffset[0] + splitPoints[0][v];
892     const PetscInt splitp = pMaxNew[0] + v;
893     PetscInt       dof, off, soff, d;
894 
895     ierr = PetscSectionGetDof(coordSection, newp, &dof);CHKERRQ(ierr);
896     ierr = PetscSectionGetOffset(coordSection, newp, &off);CHKERRQ(ierr);
897     ierr = PetscSectionGetOffset(coordSection, splitp, &soff);CHKERRQ(ierr);
898     for (d = 0; d < dof; ++d) coords[soff+d] = coords[off+d];
899   }
900   ierr = VecRestoreArray(coordinates, &coords);CHKERRQ(ierr);
901   /* Step 9: SF, if I can figure this out we can split the mesh in parallel */
902   ierr = DMPlexShiftSF_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
903   /* Step 10: Labels */
904   ierr = DMPlexShiftLabels_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
905   ierr = DMPlexGetNumLabels(sdm, &numLabels);CHKERRQ(ierr);
906   for (dep = 0; dep <= depth; ++dep) {
907     for (p = 0; p < numSplitPoints[dep]; ++p) {
908       const PetscInt newp   = depthOffset[dep] + splitPoints[dep][p];
909       const PetscInt splitp = pMaxNew[dep] + p;
910       PetscInt       l;
911 
912       for (l = 0; l < numLabels; ++l) {
913         DMLabel     mlabel;
914         const char *lname;
915         PetscInt    val;
916         PetscBool   isDepth;
917 
918         ierr = DMPlexGetLabelName(sdm, l, &lname);CHKERRQ(ierr);
919         ierr = PetscStrcmp(lname, "depth", &isDepth);CHKERRQ(ierr);
920         if (isDepth) continue;
921         ierr = DMPlexGetLabel(sdm, lname, &mlabel);CHKERRQ(ierr);
922         ierr = DMLabelGetValue(mlabel, newp, &val);CHKERRQ(ierr);
923         if (val >= 0) {
924           ierr = DMLabelSetValue(mlabel, splitp, val);CHKERRQ(ierr);
925 #if 0
926           /* Do not put cohesive edges into the label */
927           if (dep == 0) {
928             const PetscInt cedge = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
929             ierr = DMLabelSetValue(mlabel, cedge, val);CHKERRQ(ierr);
930           } else if (dep == dim-2) {
931             const PetscInt cface = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
932             ierr = DMLabelSetValue(mlabel, cface, val);CHKERRQ(ierr);
933           }
934           /* Do not put cohesive faces into the label */
935 #endif
936         }
937       }
938     }
939   }
940   for (sp = 0; sp < numSP; ++sp) {
941     const PetscInt dep = values[sp];
942 
943     if ((dep < 0) || (dep > depth)) continue;
944     if (pointIS[dep]) {ierr = ISRestoreIndices(pointIS[dep], &splitPoints[dep]);CHKERRQ(ierr);}
945     ierr = ISDestroy(&pointIS[dep]);CHKERRQ(ierr);
946   }
947   if (label) {
948     ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
949     ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
950   }
951   for (d = 0; d <= depth; ++d) {
952     ierr = DMPlexGetDepthStratum(sdm, d, NULL, &pEnd);CHKERRQ(ierr);
953     pMaxNew[d] = pEnd - numHybridPoints[d];
954   }
955   ierr = DMPlexSetHybridBounds(sdm, depth >= 0 ? pMaxNew[depth] : PETSC_DETERMINE, depth>1 ? pMaxNew[depth-1] : PETSC_DETERMINE, depth>2 ? pMaxNew[1] : PETSC_DETERMINE, depth >= 0 ? pMaxNew[0] : PETSC_DETERMINE);CHKERRQ(ierr);
956   ierr = PetscFree6(depthShift, depthOffset, pMaxNew, coneNew, coneONew, supportNew);CHKERRQ(ierr);
957   ierr = PetscFree4(pointIS, numSplitPoints, numHybridPoints, splitPoints);CHKERRQ(ierr);
958   PetscFunctionReturn(0);
959 }
960 
961 #undef __FUNCT__
962 #define __FUNCT__ "DMPlexConstructCohesiveCells"
963 /*@C
964   DMPlexConstructCohesiveCells - Construct cohesive cells which split the face along an internal interface
965 
966   Collective on dm
967 
968   Input Parameters:
969 + dm - The original DM
970 - label - The label specifying the boundary faces (this could be auto-generated)
971 
972   Output Parameters:
973 - dmSplit - The new DM
974 
975   Level: developer
976 
977 .seealso: DMCreate(), DMPlexLabelCohesiveComplete()
978 @*/
979 PetscErrorCode DMPlexConstructCohesiveCells(DM dm, DMLabel label, DM *dmSplit)
980 {
981   DM             sdm;
982   PetscInt       dim;
983   PetscErrorCode ierr;
984 
985   PetscFunctionBegin;
986   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
987   PetscValidPointer(dmSplit, 3);
988   ierr = DMCreate(PetscObjectComm((PetscObject)dm), &sdm);CHKERRQ(ierr);
989   ierr = DMSetType(sdm, DMPLEX);CHKERRQ(ierr);
990   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
991   ierr = DMPlexSetDimension(sdm, dim);CHKERRQ(ierr);
992   switch (dim) {
993   case 2:
994   case 3:
995     ierr = DMPlexConstructCohesiveCells_Internal(dm, label, sdm);CHKERRQ(ierr);
996     break;
997   default:
998     SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot construct cohesive cells for dimension %d", dim);
999   }
1000   *dmSplit = sdm;
1001   PetscFunctionReturn(0);
1002 }
1003 
1004 #undef __FUNCT__
1005 #define __FUNCT__ "DMPlexLabelCohesiveComplete"
1006 /*@
1007   DMPlexLabelCohesiveComplete - Starting with a label marking vertices on an internal surface, we add all other mesh pieces
1008   to complete the surface
1009 
1010   Input Parameters:
1011 + dm - The DM
1012 . label - A DMLabel marking the surface vertices
1013 . flip  - Flag to flip the submesh normal and replace points on the other side
1014 - subdm - The subDM associated with the label, or NULL
1015 
1016   Output Parameter:
1017 . label - A DMLabel marking all surface points
1018 
1019   Level: developer
1020 
1021 .seealso: DMPlexConstructCohesiveCells(), DMPlexLabelComplete()
1022 @*/
1023 PetscErrorCode DMPlexLabelCohesiveComplete(DM dm, DMLabel label, PetscBool flip, DM subdm)
1024 {
1025   DMLabel         depthLabel;
1026   IS              dimIS, subpointIS;
1027   const PetscInt *points, *subpoints;
1028   const PetscInt  rev   = flip ? -1 : 1;
1029   PetscInt        shift = 100, dim, dep, cStart, cEnd, numPoints, numSubpoints, p, val;
1030   PetscErrorCode  ierr;
1031 
1032   PetscFunctionBegin;
1033   ierr = DMPlexGetDepthLabel(dm, &depthLabel);CHKERRQ(ierr);
1034   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1035   if (subdm) {
1036     ierr = DMPlexCreateSubpointIS(subdm, &subpointIS);CHKERRQ(ierr);
1037     if (subpointIS) {
1038       ierr = ISGetLocalSize(subpointIS, &numSubpoints);CHKERRQ(ierr);
1039       ierr = ISGetIndices(subpointIS, &subpoints);CHKERRQ(ierr);
1040     }
1041   }
1042   /* Cell orientation for face gives the side of the fault */
1043   ierr = DMLabelGetStratumIS(label, dim-1, &dimIS);CHKERRQ(ierr);
1044   if (!dimIS) PetscFunctionReturn(0);
1045   ierr = ISGetLocalSize(dimIS, &numPoints);CHKERRQ(ierr);
1046   ierr = ISGetIndices(dimIS, &points);CHKERRQ(ierr);
1047   for (p = 0; p < numPoints; ++p) {
1048     const PetscInt *support;
1049     PetscInt        supportSize, s;
1050 
1051     ierr = DMPlexGetSupportSize(dm, points[p], &supportSize);CHKERRQ(ierr);
1052     if (supportSize != 2) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Split face %d has %d != 2 supports", points[p], supportSize);
1053     ierr = DMPlexGetSupport(dm, points[p], &support);CHKERRQ(ierr);
1054     for (s = 0; s < supportSize; ++s) {
1055       const PetscInt *cone, *ornt;
1056       PetscInt        coneSize, c;
1057       PetscBool       pos = PETSC_TRUE;
1058 
1059       ierr = DMPlexGetConeSize(dm, support[s], &coneSize);CHKERRQ(ierr);
1060       ierr = DMPlexGetCone(dm, support[s], &cone);CHKERRQ(ierr);
1061       ierr = DMPlexGetConeOrientation(dm, support[s], &ornt);CHKERRQ(ierr);
1062       for (c = 0; c < coneSize; ++c) {
1063         if (cone[c] == points[p]) {
1064           PetscInt o = ornt[c];
1065 
1066           if (subdm) {
1067             const PetscInt *subcone, *subornt;
1068             PetscInt        subpoint, subface, subconeSize, sc;
1069 
1070             ierr = PetscFindInt(support[s], numSubpoints, subpoints, &subpoint);CHKERRQ(ierr);
1071             ierr = PetscFindInt(points[p],  numSubpoints, subpoints, &subface);CHKERRQ(ierr);
1072             ierr = DMPlexGetConeSize(subdm, subpoint, &subconeSize);CHKERRQ(ierr);
1073             ierr = DMPlexGetCone(subdm, subpoint, &subcone);CHKERRQ(ierr);
1074             ierr = DMPlexGetConeOrientation(subdm, subpoint, &subornt);CHKERRQ(ierr);
1075             for (sc = 0; sc < subconeSize; ++sc) {
1076               if (subcone[sc] == subface) {
1077                 o = subornt[0];
1078                 break;
1079               }
1080             }
1081             if (sc >= subconeSize) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find point %d in cone for subpoint %d", points[p], subpoint);
1082           }
1083           if (o >= 0) {
1084             ierr = DMLabelSetValue(label, support[s],  rev*(shift+dim));CHKERRQ(ierr);
1085             pos  = rev > 0 ? PETSC_TRUE : PETSC_FALSE;
1086           } else {
1087             ierr = DMLabelSetValue(label, support[s], -rev*(shift+dim));CHKERRQ(ierr);
1088             pos  = rev > 0 ? PETSC_FALSE : PETSC_TRUE;
1089           }
1090           break;
1091         }
1092       }
1093       if (c == coneSize) SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Cell split face %d support does not have it in the cone", points[p]);
1094       /* Put faces touching the fault in the label */
1095       for (c = 0; c < coneSize; ++c) {
1096         const PetscInt point = cone[c];
1097 
1098         ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
1099         if (val == -1) {
1100           PetscInt *closure = NULL;
1101           PetscInt  closureSize, cl;
1102 
1103           ierr = DMPlexGetTransitiveClosure(dm, point, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1104           for (cl = 0; cl < closureSize*2; cl += 2) {
1105             const PetscInt clp = closure[cl];
1106 
1107             ierr = DMLabelGetValue(label, clp, &val);CHKERRQ(ierr);
1108             if ((val >= 0) && (val < dim-1)) {
1109               ierr = DMLabelSetValue(label, point, pos == PETSC_TRUE ? shift+dim-1 : -(shift+dim-1));CHKERRQ(ierr);
1110               break;
1111             }
1112           }
1113           ierr = DMPlexRestoreTransitiveClosure(dm, point, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1114         }
1115       }
1116     }
1117   }
1118   if (subdm) {
1119     if (subpointIS) {ierr = ISRestoreIndices(subpointIS, &subpoints);CHKERRQ(ierr);}
1120     ierr = ISDestroy(&subpointIS);CHKERRQ(ierr);
1121   }
1122   ierr = ISRestoreIndices(dimIS, &points);CHKERRQ(ierr);
1123   ierr = ISDestroy(&dimIS);CHKERRQ(ierr);
1124   /* Search for other cells/faces/edges connected to the fault by a vertex */
1125   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
1126   ierr = DMLabelGetStratumIS(label, 0, &dimIS);CHKERRQ(ierr);
1127   if (!dimIS) PetscFunctionReturn(0);
1128   ierr = ISGetLocalSize(dimIS, &numPoints);CHKERRQ(ierr);
1129   ierr = ISGetIndices(dimIS, &points);CHKERRQ(ierr);
1130   for (p = 0; p < numPoints; ++p) {
1131     PetscInt *star = NULL;
1132     PetscInt  starSize, s;
1133     PetscInt  again = 1;  /* 0: Finished 1: Keep iterating after a change 2: No change */
1134 
1135     /* First mark cells connected to the fault */
1136     ierr = DMPlexGetTransitiveClosure(dm, points[p], PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1137     while (again) {
1138       if (again > 1) SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Could not classify all cells connected to the fault");
1139       again = 0;
1140       for (s = 0; s < starSize*2; s += 2) {
1141         const PetscInt  point = star[s];
1142         const PetscInt *cone;
1143         PetscInt        coneSize, c;
1144 
1145         if ((point < cStart) || (point >= cEnd)) continue;
1146         ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
1147         if (val != -1) continue;
1148         again = 2;
1149         ierr  = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
1150         ierr  = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
1151         for (c = 0; c < coneSize; ++c) {
1152           ierr = DMLabelGetValue(label, cone[c], &val);CHKERRQ(ierr);
1153           if (val != -1) {
1154             if (abs(val) < shift) SETERRQ3(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Face %d on cell %d has an invalid label %d", cone[c], point, val);
1155             if (val > 0) {
1156               ierr = DMLabelSetValue(label, point,   shift+dim);CHKERRQ(ierr);
1157             } else {
1158               ierr = DMLabelSetValue(label, point, -(shift+dim));CHKERRQ(ierr);
1159             }
1160             again = 1;
1161             break;
1162           }
1163         }
1164       }
1165     }
1166     /* Classify the rest by cell membership */
1167     for (s = 0; s < starSize*2; s += 2) {
1168       const PetscInt point = star[s];
1169 
1170       ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
1171       if (val == -1) {
1172         PetscInt  *sstar = NULL;
1173         PetscInt   sstarSize, ss;
1174         PetscBool  marked = PETSC_FALSE;
1175 
1176         ierr = DMPlexGetTransitiveClosure(dm, point, PETSC_FALSE, &sstarSize, &sstar);CHKERRQ(ierr);
1177         for (ss = 0; ss < sstarSize*2; ss += 2) {
1178           const PetscInt spoint = sstar[ss];
1179 
1180           if ((spoint < cStart) || (spoint >= cEnd)) continue;
1181           ierr = DMLabelGetValue(label, spoint, &val);CHKERRQ(ierr);
1182           if (val == -1) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Cell %d in star of %d does not have a valid label", spoint, point);
1183           ierr = DMLabelGetValue(depthLabel, point, &dep);CHKERRQ(ierr);
1184           if (val > 0) {
1185             ierr = DMLabelSetValue(label, point,   shift+dep);CHKERRQ(ierr);
1186           } else {
1187             ierr = DMLabelSetValue(label, point, -(shift+dep));CHKERRQ(ierr);
1188           }
1189           marked = PETSC_TRUE;
1190           break;
1191         }
1192         ierr = DMPlexRestoreTransitiveClosure(dm, point, PETSC_FALSE, &sstarSize, &sstar);CHKERRQ(ierr);
1193         if (!marked) SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Point %d could not be classified", point);
1194       }
1195     }
1196     ierr = DMPlexRestoreTransitiveClosure(dm, points[p], PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1197   }
1198   ierr = ISRestoreIndices(dimIS, &points);CHKERRQ(ierr);
1199   ierr = ISDestroy(&dimIS);CHKERRQ(ierr);
1200   PetscFunctionReturn(0);
1201 }
1202 
1203 #undef __FUNCT__
1204 #define __FUNCT__ "DMPlexCreateHybridMesh"
1205 /*@C
1206   DMPlexCreateHybridMesh - Create a mesh with hybrid cells along an internal interface
1207 
1208   Collective on dm
1209 
1210   Input Parameters:
1211 + dm - The original DM
1212 - labelName - The label specifying the interface vertices
1213 
1214   Output Parameters:
1215 + hybridLabel - The label fully marking the interface
1216 - dmHybrid - The new DM
1217 
1218   Level: developer
1219 
1220 .seealso: DMPlexConstructCohesiveCells(), DMPlexLabelCohesiveComplete(), DMCreate()
1221 @*/
1222 PetscErrorCode DMPlexCreateHybridMesh(DM dm, DMLabel label, DMLabel *hybridLabel, DM *dmHybrid)
1223 {
1224   DM             idm;
1225   DMLabel        subpointMap, hlabel;
1226   PetscInt       dim;
1227   PetscErrorCode ierr;
1228 
1229   PetscFunctionBegin;
1230   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
1231   if (hybridLabel) PetscValidPointer(hybridLabel, 3);
1232   PetscValidPointer(dmHybrid, 4);
1233   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1234   ierr = DMPlexCreateSubmesh(dm, label, 1, &idm);CHKERRQ(ierr);
1235   ierr = DMPlexOrient(idm);CHKERRQ(ierr);
1236   ierr = DMPlexGetSubpointMap(idm, &subpointMap);CHKERRQ(ierr);
1237   ierr = DMLabelDuplicate(subpointMap, &hlabel);CHKERRQ(ierr);
1238   ierr = DMLabelClearStratum(hlabel, dim);CHKERRQ(ierr);
1239   ierr = DMPlexLabelCohesiveComplete(dm, hlabel, PETSC_FALSE, idm);CHKERRQ(ierr);
1240   ierr = DMDestroy(&idm);CHKERRQ(ierr);
1241   ierr = DMPlexConstructCohesiveCells(dm, hlabel, dmHybrid);CHKERRQ(ierr);
1242   if (hybridLabel) *hybridLabel = hlabel;
1243   else             {ierr = DMLabelDestroy(&hlabel);CHKERRQ(ierr);}
1244   PetscFunctionReturn(0);
1245 }
1246 
1247 #undef __FUNCT__
1248 #define __FUNCT__ "DMPlexMarkSubmesh_Uninterpolated"
1249 /* Here we need the explicit assumption that:
1250 
1251      For any marked cell, the marked vertices constitute a single face
1252 */
1253 static PetscErrorCode DMPlexMarkSubmesh_Uninterpolated(DM dm, DMLabel vertexLabel, PetscInt value, DMLabel subpointMap, PetscInt *numFaces, PetscInt *nFV, DM subdm)
1254 {
1255   IS               subvertexIS = NULL;
1256   const PetscInt  *subvertices;
1257   PetscInt        *pStart, *pEnd, *pMax, pSize;
1258   PetscInt         depth, dim, d, numSubVerticesInitial = 0, v;
1259   PetscErrorCode   ierr;
1260 
1261   PetscFunctionBegin;
1262   *numFaces = 0;
1263   *nFV      = 0;
1264   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
1265   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1266   pSize = PetscMax(depth, dim) + 1;
1267   ierr = PetscMalloc3(pSize,PetscInt,&pStart,pSize,PetscInt,&pEnd,pSize,PetscInt,&pMax);CHKERRQ(ierr);
1268   ierr = DMPlexGetHybridBounds(dm, depth >= 0 ? &pMax[depth] : NULL, depth>1 ? &pMax[depth-1] : NULL, depth>2 ? &pMax[1] : NULL, &pMax[0]);CHKERRQ(ierr);
1269   for (d = 0; d <= depth; ++d) {
1270     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1271     if (pMax[d] >= 0) pEnd[d] = PetscMin(pEnd[d], pMax[d]);
1272   }
1273   /* Loop over initial vertices and mark all faces in the collective star() */
1274   if (vertexLabel) {ierr = DMLabelGetStratumIS(vertexLabel, value, &subvertexIS);CHKERRQ(ierr);}
1275   if (subvertexIS) {
1276     ierr = ISGetSize(subvertexIS, &numSubVerticesInitial);CHKERRQ(ierr);
1277     ierr = ISGetIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1278   }
1279   for (v = 0; v < numSubVerticesInitial; ++v) {
1280     const PetscInt vertex = subvertices[v];
1281     PetscInt      *star   = NULL;
1282     PetscInt       starSize, s, numCells = 0, c;
1283 
1284     ierr = DMPlexGetTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1285     for (s = 0; s < starSize*2; s += 2) {
1286       const PetscInt point = star[s];
1287       if ((point >= pStart[depth]) && (point < pEnd[depth])) star[numCells++] = point;
1288     }
1289     for (c = 0; c < numCells; ++c) {
1290       const PetscInt cell    = star[c];
1291       PetscInt      *closure = NULL;
1292       PetscInt       closureSize, cl;
1293       PetscInt       cellLoc, numCorners = 0, faceSize = 0;
1294 
1295       ierr = DMLabelGetValue(subpointMap, cell, &cellLoc);CHKERRQ(ierr);
1296       if (cellLoc == 2) continue;
1297       if (cellLoc >= 0) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Cell %d has dimension %d in the surface label", cell, cellLoc);
1298       ierr = DMPlexGetTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1299       for (cl = 0; cl < closureSize*2; cl += 2) {
1300         const PetscInt point = closure[cl];
1301         PetscInt       vertexLoc;
1302 
1303         if ((point >= pStart[0]) && (point < pEnd[0])) {
1304           ++numCorners;
1305           ierr = DMLabelGetValue(vertexLabel, point, &vertexLoc);CHKERRQ(ierr);
1306           if (vertexLoc == value) closure[faceSize++] = point;
1307         }
1308       }
1309       if (!(*nFV)) {ierr = DMPlexGetNumFaceVertices(dm, dim, numCorners, nFV);CHKERRQ(ierr);}
1310       if (faceSize > *nFV) SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Invalid submesh: Too many vertices %d of an element on the surface", faceSize);
1311       if (faceSize == *nFV) {
1312         const PetscInt *cells = NULL;
1313         PetscInt        numCells, nc;
1314 
1315         ++(*numFaces);
1316         for (cl = 0; cl < faceSize; ++cl) {
1317           ierr = DMLabelSetValue(subpointMap, closure[cl], 0);CHKERRQ(ierr);
1318         }
1319         ierr = DMPlexGetJoin(dm, faceSize, closure, &numCells, &cells);CHKERRQ(ierr);
1320         for (nc = 0; nc < numCells; ++nc) {
1321           ierr = DMLabelSetValue(subpointMap, cells[nc], 2);CHKERRQ(ierr);
1322         }
1323         ierr = DMPlexRestoreJoin(dm, faceSize, closure, &numCells, &cells);CHKERRQ(ierr);
1324       }
1325       ierr = DMPlexRestoreTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1326     }
1327     ierr = DMPlexRestoreTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1328   }
1329   if (subvertexIS) {
1330     ierr = ISRestoreIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1331   }
1332   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
1333   ierr = PetscFree3(pStart,pEnd,pMax);CHKERRQ(ierr);
1334   PetscFunctionReturn(0);
1335 }
1336 
1337 #undef __FUNCT__
1338 #define __FUNCT__ "DMPlexMarkSubmesh_Interpolated"
1339 static PetscErrorCode DMPlexMarkSubmesh_Interpolated(DM dm, DMLabel vertexLabel, PetscInt value, DMLabel subpointMap, DM subdm)
1340 {
1341   IS               subvertexIS;
1342   const PetscInt  *subvertices;
1343   PetscInt        *pStart, *pEnd, *pMax;
1344   PetscInt         dim, d, numSubVerticesInitial = 0, v;
1345   PetscErrorCode   ierr;
1346 
1347   PetscFunctionBegin;
1348   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1349   ierr = PetscMalloc3(dim+1,PetscInt,&pStart,dim+1,PetscInt,&pEnd,dim+1,PetscInt,&pMax);CHKERRQ(ierr);
1350   ierr = DMPlexGetHybridBounds(dm, &pMax[dim], dim>1 ? &pMax[dim-1] : NULL, dim > 2 ? &pMax[1] : NULL, &pMax[0]);CHKERRQ(ierr);
1351   for (d = 0; d <= dim; ++d) {
1352     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1353     if (pMax[d] >= 0) pEnd[d] = PetscMin(pEnd[d], pMax[d]);
1354   }
1355   /* Loop over initial vertices and mark all faces in the collective star() */
1356   ierr = DMLabelGetStratumIS(vertexLabel, value, &subvertexIS);CHKERRQ(ierr);
1357   if (subvertexIS) {
1358     ierr = ISGetSize(subvertexIS, &numSubVerticesInitial);CHKERRQ(ierr);
1359     ierr = ISGetIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1360   }
1361   for (v = 0; v < numSubVerticesInitial; ++v) {
1362     const PetscInt vertex = subvertices[v];
1363     PetscInt      *star   = NULL;
1364     PetscInt       starSize, s, numFaces = 0, f;
1365 
1366     ierr = DMPlexGetTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1367     for (s = 0; s < starSize*2; s += 2) {
1368       const PetscInt point = star[s];
1369       if ((point >= pStart[dim-1]) && (point < pEnd[dim-1])) star[numFaces++] = point;
1370     }
1371     for (f = 0; f < numFaces; ++f) {
1372       const PetscInt face    = star[f];
1373       PetscInt      *closure = NULL;
1374       PetscInt       closureSize, c;
1375       PetscInt       faceLoc;
1376 
1377       ierr = DMLabelGetValue(subpointMap, face, &faceLoc);CHKERRQ(ierr);
1378       if (faceLoc == dim-1) continue;
1379       if (faceLoc >= 0) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Face %d has dimension %d in the surface label", face, faceLoc);
1380       ierr = DMPlexGetTransitiveClosure(dm, face, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1381       for (c = 0; c < closureSize*2; c += 2) {
1382         const PetscInt point = closure[c];
1383         PetscInt       vertexLoc;
1384 
1385         if ((point >= pStart[0]) && (point < pEnd[0])) {
1386           ierr = DMLabelGetValue(vertexLabel, point, &vertexLoc);CHKERRQ(ierr);
1387           if (vertexLoc != value) break;
1388         }
1389       }
1390       if (c == closureSize*2) {
1391         const PetscInt *support;
1392         PetscInt        supportSize, s;
1393 
1394         for (c = 0; c < closureSize*2; c += 2) {
1395           const PetscInt point = closure[c];
1396 
1397           for (d = 0; d < dim; ++d) {
1398             if ((point >= pStart[d]) && (point < pEnd[d])) {
1399               ierr = DMLabelSetValue(subpointMap, point, d);CHKERRQ(ierr);
1400               break;
1401             }
1402           }
1403         }
1404         ierr = DMPlexGetSupportSize(dm, face, &supportSize);CHKERRQ(ierr);
1405         ierr = DMPlexGetSupport(dm, face, &support);CHKERRQ(ierr);
1406         for (s = 0; s < supportSize; ++s) {
1407           ierr = DMLabelSetValue(subpointMap, support[s], dim);CHKERRQ(ierr);
1408         }
1409       }
1410       ierr = DMPlexRestoreTransitiveClosure(dm, face, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1411     }
1412     ierr = DMPlexRestoreTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1413   }
1414   if (subvertexIS) {
1415     ierr = ISRestoreIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1416   }
1417   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
1418   ierr = PetscFree3(pStart,pEnd,pMax);CHKERRQ(ierr);
1419   PetscFunctionReturn(0);
1420 }
1421 
1422 #undef __FUNCT__
1423 #define __FUNCT__ "DMPlexMarkCohesiveSubmesh_Uninterpolated"
1424 static PetscErrorCode DMPlexMarkCohesiveSubmesh_Uninterpolated(DM dm, PetscBool hasLagrange, const char labelname[], PetscInt value, DMLabel subpointMap, PetscInt *numFaces, PetscInt *nFV, PetscInt *subCells[], DM subdm)
1425 {
1426   DMLabel         label = NULL;
1427   const PetscInt *cone;
1428   PetscInt        dim, cMax, cEnd, c, subc = 0, p, coneSize;
1429   PetscErrorCode  ierr;
1430 
1431   PetscFunctionBegin;
1432   *numFaces = 0;
1433   *nFV = 0;
1434   if (labelname) {ierr = DMPlexGetLabel(dm, labelname, &label);CHKERRQ(ierr);}
1435   *subCells = NULL;
1436   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1437   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
1438   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
1439   if (cMax < 0) PetscFunctionReturn(0);
1440   if (label) {
1441     for (c = cMax; c < cEnd; ++c) {
1442       PetscInt val;
1443 
1444       ierr = DMLabelGetValue(label, c, &val);CHKERRQ(ierr);
1445       if (val == value) {
1446         ++(*numFaces);
1447         ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
1448       }
1449     }
1450   } else {
1451     *numFaces = cEnd - cMax;
1452     ierr = DMPlexGetConeSize(dm, cMax, &coneSize);CHKERRQ(ierr);
1453   }
1454   *nFV = hasLagrange ? coneSize/3 : coneSize/2;
1455   ierr = PetscMalloc(*numFaces *2 * sizeof(PetscInt), subCells);CHKERRQ(ierr);
1456   for (c = cMax; c < cEnd; ++c) {
1457     const PetscInt *cells;
1458     PetscInt        numCells;
1459 
1460     if (label) {
1461       PetscInt val;
1462 
1463       ierr = DMLabelGetValue(label, c, &val);CHKERRQ(ierr);
1464       if (val != value) continue;
1465     }
1466     ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
1467     for (p = 0; p < *nFV; ++p) {
1468       ierr = DMLabelSetValue(subpointMap, cone[p], 0);CHKERRQ(ierr);
1469     }
1470     /* Negative face */
1471     ierr = DMPlexGetJoin(dm, *nFV, cone, &numCells, &cells);CHKERRQ(ierr);
1472     /* Not true in parallel
1473     if (numCells != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells"); */
1474     for (p = 0; p < numCells; ++p) {
1475       ierr = DMLabelSetValue(subpointMap, cells[p], 2);CHKERRQ(ierr);
1476       (*subCells)[subc++] = cells[p];
1477     }
1478     ierr = DMPlexRestoreJoin(dm, *nFV, cone, &numCells, &cells);CHKERRQ(ierr);
1479     /* Positive face is not included */
1480   }
1481   PetscFunctionReturn(0);
1482 }
1483 
1484 #undef __FUNCT__
1485 #define __FUNCT__ "DMPlexMarkCohesiveSubmesh_Interpolated"
1486 static PetscErrorCode DMPlexMarkCohesiveSubmesh_Interpolated(DM dm, PetscBool hasLagrange, const char labelname[], PetscInt value, DMLabel subpointMap, DM subdm)
1487 {
1488   DMLabel        label = NULL;
1489   PetscInt      *pStart, *pEnd;
1490   PetscInt       dim, cMax, cEnd, c, d;
1491   PetscErrorCode ierr;
1492 
1493   PetscFunctionBegin;
1494   if (labelname) {ierr = DMPlexGetLabel(dm, labelname, &label);CHKERRQ(ierr);}
1495   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1496   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
1497   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
1498   if (cMax < 0) PetscFunctionReturn(0);
1499   ierr = PetscMalloc2(dim+1,PetscInt,&pStart,dim+1,PetscInt,&pEnd);CHKERRQ(ierr);
1500   for (d = 0; d <= dim; ++d) {
1501     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1502   }
1503   for (c = cMax; c < cEnd; ++c) {
1504     const PetscInt *cone;
1505     PetscInt       *closure = NULL;
1506     PetscInt        coneSize, closureSize, cl;
1507 
1508     if (label) {
1509       PetscInt val;
1510 
1511       ierr = DMLabelGetValue(label, c, &val);CHKERRQ(ierr);
1512       if (val != value) continue;
1513     }
1514     ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
1515     if (hasLagrange) {
1516       if (coneSize != 3) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
1517     } else {
1518       if (coneSize != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
1519     }
1520     /* Negative face */
1521     ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
1522     ierr = DMPlexGetTransitiveClosure(dm, cone[0], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1523     for (cl = 0; cl < closureSize*2; cl += 2) {
1524       const PetscInt point = closure[cl];
1525 
1526       for (d = 0; d <= dim; ++d) {
1527         if ((point >= pStart[d]) && (point < pEnd[d])) {
1528           ierr = DMLabelSetValue(subpointMap, point, d);CHKERRQ(ierr);
1529           break;
1530         }
1531       }
1532     }
1533     ierr = DMPlexRestoreTransitiveClosure(dm, cone[0], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1534     /* Cells -- positive face is not included */
1535     for (cl = 0; cl < 1; ++cl) {
1536       const PetscInt *support;
1537       PetscInt        supportSize, s;
1538 
1539       ierr = DMPlexGetSupportSize(dm, cone[cl], &supportSize);CHKERRQ(ierr);
1540       if (supportSize != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive faces should separate two cells");
1541       ierr = DMPlexGetSupport(dm, cone[cl], &support);CHKERRQ(ierr);
1542       for (s = 0; s < supportSize; ++s) {
1543         ierr = DMLabelSetValue(subpointMap, support[s], dim);CHKERRQ(ierr);
1544       }
1545     }
1546   }
1547   ierr = PetscFree2(pStart, pEnd);CHKERRQ(ierr);
1548   PetscFunctionReturn(0);
1549 }
1550 
1551 #undef __FUNCT__
1552 #define __FUNCT__ "DMPlexGetFaceOrientation"
1553 PetscErrorCode DMPlexGetFaceOrientation(DM dm, PetscInt cell, PetscInt numCorners, PetscInt indices[], PetscInt oppositeVertex, PetscInt origVertices[], PetscInt faceVertices[], PetscBool *posOriented)
1554 {
1555   MPI_Comm       comm;
1556   PetscBool      posOrient = PETSC_FALSE;
1557   const PetscInt debug     = 0;
1558   PetscInt       cellDim, faceSize, f;
1559   PetscErrorCode ierr;
1560 
1561   PetscFunctionBegin;
1562   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1563   ierr = DMPlexGetDimension(dm, &cellDim);CHKERRQ(ierr);
1564   if (debug) {PetscPrintf(comm, "cellDim: %d numCorners: %d\n", cellDim, numCorners);CHKERRQ(ierr);}
1565 
1566   if (cellDim == 1 && numCorners == 2) {
1567     /* Triangle */
1568     faceSize  = numCorners-1;
1569     posOrient = !(oppositeVertex%2) ? PETSC_TRUE : PETSC_FALSE;
1570   } else if (cellDim == 2 && numCorners == 3) {
1571     /* Triangle */
1572     faceSize  = numCorners-1;
1573     posOrient = !(oppositeVertex%2) ? PETSC_TRUE : PETSC_FALSE;
1574   } else if (cellDim == 3 && numCorners == 4) {
1575     /* Tetrahedron */
1576     faceSize  = numCorners-1;
1577     posOrient = (oppositeVertex%2) ? PETSC_TRUE : PETSC_FALSE;
1578   } else if (cellDim == 1 && numCorners == 3) {
1579     /* Quadratic line */
1580     faceSize  = 1;
1581     posOrient = PETSC_TRUE;
1582   } else if (cellDim == 2 && numCorners == 4) {
1583     /* Quads */
1584     faceSize = 2;
1585     if ((indices[1] > indices[0]) && (indices[1] - indices[0] == 1)) {
1586       posOrient = PETSC_TRUE;
1587     } else if ((indices[0] == 3) && (indices[1] == 0)) {
1588       posOrient = PETSC_TRUE;
1589     } else {
1590       if (((indices[0] > indices[1]) && (indices[0] - indices[1] == 1)) || ((indices[0] == 0) && (indices[1] == 3))) {
1591         posOrient = PETSC_FALSE;
1592       } else SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid quad crossedge");
1593     }
1594   } else if (cellDim == 2 && numCorners == 6) {
1595     /* Quadratic triangle (I hate this) */
1596     /* Edges are determined by the first 2 vertices (corners of edges) */
1597     const PetscInt faceSizeTri = 3;
1598     PetscInt       sortedIndices[3], i, iFace;
1599     PetscBool      found                    = PETSC_FALSE;
1600     PetscInt       faceVerticesTriSorted[9] = {
1601       0, 3,  4, /* bottom */
1602       1, 4,  5, /* right */
1603       2, 3,  5, /* left */
1604     };
1605     PetscInt       faceVerticesTri[9] = {
1606       0, 3,  4, /* bottom */
1607       1, 4,  5, /* right */
1608       2, 5,  3, /* left */
1609     };
1610 
1611     faceSize = faceSizeTri;
1612     for (i = 0; i < faceSizeTri; ++i) sortedIndices[i] = indices[i];
1613     ierr = PetscSortInt(faceSizeTri, sortedIndices);CHKERRQ(ierr);
1614     for (iFace = 0; iFace < 3; ++iFace) {
1615       const PetscInt ii = iFace*faceSizeTri;
1616       PetscInt       fVertex, cVertex;
1617 
1618       if ((sortedIndices[0] == faceVerticesTriSorted[ii+0]) &&
1619           (sortedIndices[1] == faceVerticesTriSorted[ii+1])) {
1620         for (fVertex = 0; fVertex < faceSizeTri; ++fVertex) {
1621           for (cVertex = 0; cVertex < faceSizeTri; ++cVertex) {
1622             if (indices[cVertex] == faceVerticesTri[ii+fVertex]) {
1623               faceVertices[fVertex] = origVertices[cVertex];
1624               break;
1625             }
1626           }
1627         }
1628         found = PETSC_TRUE;
1629         break;
1630       }
1631     }
1632     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid tri crossface");
1633     if (posOriented) *posOriented = PETSC_TRUE;
1634     PetscFunctionReturn(0);
1635   } else if (cellDim == 2 && numCorners == 9) {
1636     /* Quadratic quad (I hate this) */
1637     /* Edges are determined by the first 2 vertices (corners of edges) */
1638     const PetscInt faceSizeQuad = 3;
1639     PetscInt       sortedIndices[3], i, iFace;
1640     PetscBool      found                      = PETSC_FALSE;
1641     PetscInt       faceVerticesQuadSorted[12] = {
1642       0, 1,  4, /* bottom */
1643       1, 2,  5, /* right */
1644       2, 3,  6, /* top */
1645       0, 3,  7, /* left */
1646     };
1647     PetscInt       faceVerticesQuad[12] = {
1648       0, 1,  4, /* bottom */
1649       1, 2,  5, /* right */
1650       2, 3,  6, /* top */
1651       3, 0,  7, /* left */
1652     };
1653 
1654     faceSize = faceSizeQuad;
1655     for (i = 0; i < faceSizeQuad; ++i) sortedIndices[i] = indices[i];
1656     ierr = PetscSortInt(faceSizeQuad, sortedIndices);CHKERRQ(ierr);
1657     for (iFace = 0; iFace < 4; ++iFace) {
1658       const PetscInt ii = iFace*faceSizeQuad;
1659       PetscInt       fVertex, cVertex;
1660 
1661       if ((sortedIndices[0] == faceVerticesQuadSorted[ii+0]) &&
1662           (sortedIndices[1] == faceVerticesQuadSorted[ii+1])) {
1663         for (fVertex = 0; fVertex < faceSizeQuad; ++fVertex) {
1664           for (cVertex = 0; cVertex < faceSizeQuad; ++cVertex) {
1665             if (indices[cVertex] == faceVerticesQuad[ii+fVertex]) {
1666               faceVertices[fVertex] = origVertices[cVertex];
1667               break;
1668             }
1669           }
1670         }
1671         found = PETSC_TRUE;
1672         break;
1673       }
1674     }
1675     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid quad crossface");
1676     if (posOriented) *posOriented = PETSC_TRUE;
1677     PetscFunctionReturn(0);
1678   } else if (cellDim == 3 && numCorners == 8) {
1679     /* Hexes
1680        A hex is two oriented quads with the normal of the first
1681        pointing up at the second.
1682 
1683           7---6
1684          /|  /|
1685         4---5 |
1686         | 1-|-2
1687         |/  |/
1688         0---3
1689 
1690         Faces are determined by the first 4 vertices (corners of faces) */
1691     const PetscInt faceSizeHex = 4;
1692     PetscInt       sortedIndices[4], i, iFace;
1693     PetscBool      found                     = PETSC_FALSE;
1694     PetscInt       faceVerticesHexSorted[24] = {
1695       0, 1, 2, 3,  /* bottom */
1696       4, 5, 6, 7,  /* top */
1697       0, 3, 4, 5,  /* front */
1698       2, 3, 5, 6,  /* right */
1699       1, 2, 6, 7,  /* back */
1700       0, 1, 4, 7,  /* left */
1701     };
1702     PetscInt       faceVerticesHex[24] = {
1703       1, 2, 3, 0,  /* bottom */
1704       4, 5, 6, 7,  /* top */
1705       0, 3, 5, 4,  /* front */
1706       3, 2, 6, 5,  /* right */
1707       2, 1, 7, 6,  /* back */
1708       1, 0, 4, 7,  /* left */
1709     };
1710 
1711     faceSize = faceSizeHex;
1712     for (i = 0; i < faceSizeHex; ++i) sortedIndices[i] = indices[i];
1713     ierr = PetscSortInt(faceSizeHex, sortedIndices);CHKERRQ(ierr);
1714     for (iFace = 0; iFace < 6; ++iFace) {
1715       const PetscInt ii = iFace*faceSizeHex;
1716       PetscInt       fVertex, cVertex;
1717 
1718       if ((sortedIndices[0] == faceVerticesHexSorted[ii+0]) &&
1719           (sortedIndices[1] == faceVerticesHexSorted[ii+1]) &&
1720           (sortedIndices[2] == faceVerticesHexSorted[ii+2]) &&
1721           (sortedIndices[3] == faceVerticesHexSorted[ii+3])) {
1722         for (fVertex = 0; fVertex < faceSizeHex; ++fVertex) {
1723           for (cVertex = 0; cVertex < faceSizeHex; ++cVertex) {
1724             if (indices[cVertex] == faceVerticesHex[ii+fVertex]) {
1725               faceVertices[fVertex] = origVertices[cVertex];
1726               break;
1727             }
1728           }
1729         }
1730         found = PETSC_TRUE;
1731         break;
1732       }
1733     }
1734     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid hex crossface");
1735     if (posOriented) *posOriented = PETSC_TRUE;
1736     PetscFunctionReturn(0);
1737   } else if (cellDim == 3 && numCorners == 10) {
1738     /* Quadratic tet */
1739     /* Faces are determined by the first 3 vertices (corners of faces) */
1740     const PetscInt faceSizeTet = 6;
1741     PetscInt       sortedIndices[6], i, iFace;
1742     PetscBool      found                     = PETSC_FALSE;
1743     PetscInt       faceVerticesTetSorted[24] = {
1744       0, 1, 2,  6, 7, 8, /* bottom */
1745       0, 3, 4,  6, 7, 9,  /* front */
1746       1, 4, 5,  7, 8, 9,  /* right */
1747       2, 3, 5,  6, 8, 9,  /* left */
1748     };
1749     PetscInt       faceVerticesTet[24] = {
1750       0, 1, 2,  6, 7, 8, /* bottom */
1751       0, 4, 3,  6, 7, 9,  /* front */
1752       1, 5, 4,  7, 8, 9,  /* right */
1753       2, 3, 5,  8, 6, 9,  /* left */
1754     };
1755 
1756     faceSize = faceSizeTet;
1757     for (i = 0; i < faceSizeTet; ++i) sortedIndices[i] = indices[i];
1758     ierr = PetscSortInt(faceSizeTet, sortedIndices);CHKERRQ(ierr);
1759     for (iFace=0; iFace < 4; ++iFace) {
1760       const PetscInt ii = iFace*faceSizeTet;
1761       PetscInt       fVertex, cVertex;
1762 
1763       if ((sortedIndices[0] == faceVerticesTetSorted[ii+0]) &&
1764           (sortedIndices[1] == faceVerticesTetSorted[ii+1]) &&
1765           (sortedIndices[2] == faceVerticesTetSorted[ii+2]) &&
1766           (sortedIndices[3] == faceVerticesTetSorted[ii+3])) {
1767         for (fVertex = 0; fVertex < faceSizeTet; ++fVertex) {
1768           for (cVertex = 0; cVertex < faceSizeTet; ++cVertex) {
1769             if (indices[cVertex] == faceVerticesTet[ii+fVertex]) {
1770               faceVertices[fVertex] = origVertices[cVertex];
1771               break;
1772             }
1773           }
1774         }
1775         found = PETSC_TRUE;
1776         break;
1777       }
1778     }
1779     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid tet crossface");
1780     if (posOriented) *posOriented = PETSC_TRUE;
1781     PetscFunctionReturn(0);
1782   } else if (cellDim == 3 && numCorners == 27) {
1783     /* Quadratic hexes (I hate this)
1784        A hex is two oriented quads with the normal of the first
1785        pointing up at the second.
1786 
1787          7---6
1788         /|  /|
1789        4---5 |
1790        | 3-|-2
1791        |/  |/
1792        0---1
1793 
1794        Faces are determined by the first 4 vertices (corners of faces) */
1795     const PetscInt faceSizeQuadHex = 9;
1796     PetscInt       sortedIndices[9], i, iFace;
1797     PetscBool      found                         = PETSC_FALSE;
1798     PetscInt       faceVerticesQuadHexSorted[54] = {
1799       0, 1, 2, 3,  8, 9, 10, 11,  24, /* bottom */
1800       4, 5, 6, 7,  12, 13, 14, 15,  25, /* top */
1801       0, 1, 4, 5,  8, 12, 16, 17,  22, /* front */
1802       1, 2, 5, 6,  9, 13, 17, 18,  21, /* right */
1803       2, 3, 6, 7,  10, 14, 18, 19,  23, /* back */
1804       0, 3, 4, 7,  11, 15, 16, 19,  20, /* left */
1805     };
1806     PetscInt       faceVerticesQuadHex[54] = {
1807       3, 2, 1, 0,  10, 9, 8, 11,  24, /* bottom */
1808       4, 5, 6, 7,  12, 13, 14, 15,  25, /* top */
1809       0, 1, 5, 4,  8, 17, 12, 16,  22, /* front */
1810       1, 2, 6, 5,  9, 18, 13, 17,  21, /* right */
1811       2, 3, 7, 6,  10, 19, 14, 18,  23, /* back */
1812       3, 0, 4, 7,  11, 16, 15, 19,  20 /* left */
1813     };
1814 
1815     faceSize = faceSizeQuadHex;
1816     for (i = 0; i < faceSizeQuadHex; ++i) sortedIndices[i] = indices[i];
1817     ierr = PetscSortInt(faceSizeQuadHex, sortedIndices);CHKERRQ(ierr);
1818     for (iFace = 0; iFace < 6; ++iFace) {
1819       const PetscInt ii = iFace*faceSizeQuadHex;
1820       PetscInt       fVertex, cVertex;
1821 
1822       if ((sortedIndices[0] == faceVerticesQuadHexSorted[ii+0]) &&
1823           (sortedIndices[1] == faceVerticesQuadHexSorted[ii+1]) &&
1824           (sortedIndices[2] == faceVerticesQuadHexSorted[ii+2]) &&
1825           (sortedIndices[3] == faceVerticesQuadHexSorted[ii+3])) {
1826         for (fVertex = 0; fVertex < faceSizeQuadHex; ++fVertex) {
1827           for (cVertex = 0; cVertex < faceSizeQuadHex; ++cVertex) {
1828             if (indices[cVertex] == faceVerticesQuadHex[ii+fVertex]) {
1829               faceVertices[fVertex] = origVertices[cVertex];
1830               break;
1831             }
1832           }
1833         }
1834         found = PETSC_TRUE;
1835         break;
1836       }
1837     }
1838     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid hex crossface");
1839     if (posOriented) *posOriented = PETSC_TRUE;
1840     PetscFunctionReturn(0);
1841   } else SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Unknown cell type for faceOrientation().");
1842   if (!posOrient) {
1843     if (debug) {ierr = PetscPrintf(comm, "  Reversing initial face orientation\n");CHKERRQ(ierr);}
1844     for (f = 0; f < faceSize; ++f) faceVertices[f] = origVertices[faceSize-1 - f];
1845   } else {
1846     if (debug) {ierr = PetscPrintf(comm, "  Keeping initial face orientation\n");CHKERRQ(ierr);}
1847     for (f = 0; f < faceSize; ++f) faceVertices[f] = origVertices[f];
1848   }
1849   if (posOriented) *posOriented = posOrient;
1850   PetscFunctionReturn(0);
1851 }
1852 
1853 #undef __FUNCT__
1854 #define __FUNCT__ "DMPlexGetOrientedFace"
1855 /*
1856     Given a cell and a face, as a set of vertices,
1857       return the oriented face, as a set of vertices, in faceVertices
1858     The orientation is such that the face normal points out of the cell
1859 */
1860 PetscErrorCode DMPlexGetOrientedFace(DM dm, PetscInt cell, PetscInt faceSize, const PetscInt face[], PetscInt numCorners, PetscInt indices[], PetscInt origVertices[], PetscInt faceVertices[], PetscBool *posOriented)
1861 {
1862   const PetscInt *cone = NULL;
1863   PetscInt        coneSize, v, f, v2;
1864   PetscInt        oppositeVertex = -1;
1865   PetscErrorCode  ierr;
1866 
1867   PetscFunctionBegin;
1868   ierr = DMPlexGetConeSize(dm, cell, &coneSize);CHKERRQ(ierr);
1869   ierr = DMPlexGetCone(dm, cell, &cone);CHKERRQ(ierr);
1870   for (v = 0, v2 = 0; v < coneSize; ++v) {
1871     PetscBool found = PETSC_FALSE;
1872 
1873     for (f = 0; f < faceSize; ++f) {
1874       if (face[f] == cone[v]) {
1875         found = PETSC_TRUE; break;
1876       }
1877     }
1878     if (found) {
1879       indices[v2]      = v;
1880       origVertices[v2] = cone[v];
1881       ++v2;
1882     } else {
1883       oppositeVertex = v;
1884     }
1885   }
1886   ierr = DMPlexGetFaceOrientation(dm, cell, numCorners, indices, oppositeVertex, origVertices, faceVertices, posOriented);CHKERRQ(ierr);
1887   PetscFunctionReturn(0);
1888 }
1889 
1890 #undef __FUNCT__
1891 #define __FUNCT__ "DMPlexInsertFace_Internal"
1892 /*
1893   DMPlexInsertFace_Internal - Puts a face into the mesh
1894 
1895   Not collective
1896 
1897   Input Parameters:
1898   + dm              - The DMPlex
1899   . numFaceVertex   - The number of vertices in the face
1900   . faceVertices    - The vertices in the face for dm
1901   . subfaceVertices - The vertices in the face for subdm
1902   . numCorners      - The number of vertices in the cell
1903   . cell            - A cell in dm containing the face
1904   . subcell         - A cell in subdm containing the face
1905   . firstFace       - First face in the mesh
1906   - newFacePoint    - Next face in the mesh
1907 
1908   Output Parameters:
1909   . newFacePoint - Contains next face point number on input, updated on output
1910 
1911   Level: developer
1912 */
1913 static PetscErrorCode DMPlexInsertFace_Internal(DM dm, DM subdm, PetscInt numFaceVertices, const PetscInt faceVertices[], const PetscInt subfaceVertices[], PetscInt numCorners, PetscInt cell, PetscInt subcell, PetscInt firstFace, PetscInt *newFacePoint)
1914 {
1915   MPI_Comm        comm;
1916   DM_Plex        *submesh = (DM_Plex*) subdm->data;
1917   const PetscInt *faces;
1918   PetscInt        numFaces, coneSize;
1919   PetscErrorCode  ierr;
1920 
1921   PetscFunctionBegin;
1922   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1923   ierr = DMPlexGetConeSize(subdm, subcell, &coneSize);CHKERRQ(ierr);
1924   if (coneSize != 1) SETERRQ2(comm, PETSC_ERR_ARG_OUTOFRANGE, "Cone size of cell %d is %d != 1", cell, coneSize);
1925 #if 0
1926   /* Cannot use this because support() has not been constructed yet */
1927   ierr = DMPlexGetJoin(subdm, numFaceVertices, subfaceVertices, &numFaces, &faces);CHKERRQ(ierr);
1928 #else
1929   {
1930     PetscInt f;
1931 
1932     numFaces = 0;
1933     ierr     = DMGetWorkArray(subdm, 1, PETSC_INT, (void **) &faces);CHKERRQ(ierr);
1934     for (f = firstFace; f < *newFacePoint; ++f) {
1935       PetscInt dof, off, d;
1936 
1937       ierr = PetscSectionGetDof(submesh->coneSection, f, &dof);CHKERRQ(ierr);
1938       ierr = PetscSectionGetOffset(submesh->coneSection, f, &off);CHKERRQ(ierr);
1939       /* Yes, I know this is quadratic, but I expect the sizes to be <5 */
1940       for (d = 0; d < dof; ++d) {
1941         const PetscInt p = submesh->cones[off+d];
1942         PetscInt       v;
1943 
1944         for (v = 0; v < numFaceVertices; ++v) {
1945           if (subfaceVertices[v] == p) break;
1946         }
1947         if (v == numFaceVertices) break;
1948       }
1949       if (d == dof) {
1950         numFaces               = 1;
1951         ((PetscInt*) faces)[0] = f;
1952       }
1953     }
1954   }
1955 #endif
1956   if (numFaces > 1) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Vertex set had %d faces, not one", numFaces);
1957   else if (numFaces == 1) {
1958     /* Add the other cell neighbor for this face */
1959     ierr = DMPlexSetCone(subdm, subcell, faces);CHKERRQ(ierr);
1960   } else {
1961     PetscInt *indices, *origVertices, *orientedVertices, *orientedSubVertices, v, ov;
1962     PetscBool posOriented;
1963 
1964     ierr                = DMGetWorkArray(subdm, 4*numFaceVertices * sizeof(PetscInt), PETSC_INT, &orientedVertices);CHKERRQ(ierr);
1965     origVertices        = &orientedVertices[numFaceVertices];
1966     indices             = &orientedVertices[numFaceVertices*2];
1967     orientedSubVertices = &orientedVertices[numFaceVertices*3];
1968     ierr                = DMPlexGetOrientedFace(dm, cell, numFaceVertices, faceVertices, numCorners, indices, origVertices, orientedVertices, &posOriented);CHKERRQ(ierr);
1969     /* TODO: I know that routine should return a permutation, not the indices */
1970     for (v = 0; v < numFaceVertices; ++v) {
1971       const PetscInt vertex = faceVertices[v], subvertex = subfaceVertices[v];
1972       for (ov = 0; ov < numFaceVertices; ++ov) {
1973         if (orientedVertices[ov] == vertex) {
1974           orientedSubVertices[ov] = subvertex;
1975           break;
1976         }
1977       }
1978       if (ov == numFaceVertices) SETERRQ1(comm, PETSC_ERR_PLIB, "Could not find face vertex %d in orientated set", vertex);
1979     }
1980     ierr = DMPlexSetCone(subdm, *newFacePoint, orientedSubVertices);CHKERRQ(ierr);
1981     ierr = DMPlexSetCone(subdm, subcell, newFacePoint);CHKERRQ(ierr);
1982     ierr = DMRestoreWorkArray(subdm, 4*numFaceVertices * sizeof(PetscInt), PETSC_INT, &orientedVertices);CHKERRQ(ierr);
1983     ++(*newFacePoint);
1984   }
1985 #if 0
1986   ierr = DMPlexRestoreJoin(subdm, numFaceVertices, subfaceVertices, &numFaces, &faces);CHKERRQ(ierr);
1987 #else
1988   ierr = DMRestoreWorkArray(subdm, 1, PETSC_INT, (void **) &faces);CHKERRQ(ierr);
1989 #endif
1990   PetscFunctionReturn(0);
1991 }
1992 
1993 #undef __FUNCT__
1994 #define __FUNCT__ "DMPlexCreateSubmesh_Uninterpolated"
1995 static PetscErrorCode DMPlexCreateSubmesh_Uninterpolated(DM dm, DMLabel vertexLabel, PetscInt value, DM subdm)
1996 {
1997   MPI_Comm        comm;
1998   DMLabel         subpointMap;
1999   IS              subvertexIS,  subcellIS;
2000   const PetscInt *subVertices, *subCells;
2001   PetscInt        numSubVertices, firstSubVertex, numSubCells;
2002   PetscInt       *subface, maxConeSize, numSubFaces = 0, firstSubFace, newFacePoint, nFV = 0;
2003   PetscInt        vStart, vEnd, c, f;
2004   PetscErrorCode  ierr;
2005 
2006   PetscFunctionBegin;
2007   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2008   /* Create subpointMap which marks the submesh */
2009   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2010   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2011   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2012   if (vertexLabel) {ierr = DMPlexMarkSubmesh_Uninterpolated(dm, vertexLabel, value, subpointMap, &numSubFaces, &nFV, subdm);CHKERRQ(ierr);}
2013   /* Setup chart */
2014   ierr = DMLabelGetStratumSize(subpointMap, 0, &numSubVertices);CHKERRQ(ierr);
2015   ierr = DMLabelGetStratumSize(subpointMap, 2, &numSubCells);CHKERRQ(ierr);
2016   ierr = DMPlexSetChart(subdm, 0, numSubCells+numSubFaces+numSubVertices);CHKERRQ(ierr);
2017   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2018   /* Set cone sizes */
2019   firstSubVertex = numSubCells;
2020   firstSubFace   = numSubCells+numSubVertices;
2021   newFacePoint   = firstSubFace;
2022   ierr = DMLabelGetStratumIS(subpointMap, 0, &subvertexIS);CHKERRQ(ierr);
2023   if (subvertexIS) {ierr = ISGetIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2024   ierr = DMLabelGetStratumIS(subpointMap, 2, &subcellIS);CHKERRQ(ierr);
2025   if (subcellIS) {ierr = ISGetIndices(subcellIS, &subCells);CHKERRQ(ierr);}
2026   for (c = 0; c < numSubCells; ++c) {
2027     ierr = DMPlexSetConeSize(subdm, c, 1);CHKERRQ(ierr);
2028   }
2029   for (f = firstSubFace; f < firstSubFace+numSubFaces; ++f) {
2030     ierr = DMPlexSetConeSize(subdm, f, nFV);CHKERRQ(ierr);
2031   }
2032   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2033   /* Create face cones */
2034   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
2035   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2036   ierr = DMGetWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2037   for (c = 0; c < numSubCells; ++c) {
2038     const PetscInt cell    = subCells[c];
2039     const PetscInt subcell = c;
2040     PetscInt      *closure = NULL;
2041     PetscInt       closureSize, cl, numCorners = 0, faceSize = 0;
2042 
2043     ierr = DMPlexGetTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
2044     for (cl = 0; cl < closureSize*2; cl += 2) {
2045       const PetscInt point = closure[cl];
2046       PetscInt       subVertex;
2047 
2048       if ((point >= vStart) && (point < vEnd)) {
2049         ++numCorners;
2050         ierr = PetscFindInt(point, numSubVertices, subVertices, &subVertex);CHKERRQ(ierr);
2051         if (subVertex >= 0) {
2052           closure[faceSize] = point;
2053           subface[faceSize] = firstSubVertex+subVertex;
2054           ++faceSize;
2055         }
2056       }
2057     }
2058     if (faceSize > nFV) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Invalid submesh: Too many vertices %d of an element on the surface", faceSize);
2059     if (faceSize == nFV) {
2060       ierr = DMPlexInsertFace_Internal(dm, subdm, faceSize, closure, subface, numCorners, cell, subcell, firstSubFace, &newFacePoint);CHKERRQ(ierr);
2061     }
2062     ierr = DMPlexRestoreTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
2063   }
2064   ierr = DMRestoreWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2065   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2066   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2067   /* Build coordinates */
2068   {
2069     PetscSection coordSection, subCoordSection;
2070     Vec          coordinates, subCoordinates;
2071     PetscScalar *coords, *subCoords;
2072     PetscInt     numComp, coordSize, v;
2073 
2074     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2075     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2076     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2077     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2078     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2079     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2080     ierr = PetscSectionSetChart(subCoordSection, firstSubVertex, firstSubVertex+numSubVertices);CHKERRQ(ierr);
2081     for (v = 0; v < numSubVertices; ++v) {
2082       const PetscInt vertex    = subVertices[v];
2083       const PetscInt subvertex = firstSubVertex+v;
2084       PetscInt       dof;
2085 
2086       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2087       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2088       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2089     }
2090     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2091     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2092     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2093     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2094     ierr = VecSetType(subCoordinates,dm->vectype);CHKERRQ(ierr);
2095     if (coordSize) {
2096       ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2097       ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2098       for (v = 0; v < numSubVertices; ++v) {
2099         const PetscInt vertex    = subVertices[v];
2100         const PetscInt subvertex = firstSubVertex+v;
2101         PetscInt       dof, off, sdof, soff, d;
2102 
2103         ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2104         ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2105         ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2106         ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2107         if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2108         for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2109       }
2110       ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2111       ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2112     }
2113     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2114     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2115   }
2116   /* Cleanup */
2117   if (subvertexIS) {ierr = ISRestoreIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2118   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
2119   if (subcellIS) {ierr = ISRestoreIndices(subcellIS, &subCells);CHKERRQ(ierr);}
2120   ierr = ISDestroy(&subcellIS);CHKERRQ(ierr);
2121   PetscFunctionReturn(0);
2122 }
2123 
2124 #undef __FUNCT__
2125 #define __FUNCT__ "DMPlexCreateSubmesh_Interpolated"
2126 static PetscErrorCode DMPlexCreateSubmesh_Interpolated(DM dm, DMLabel vertexLabel, PetscInt value, DM subdm)
2127 {
2128   MPI_Comm         comm;
2129   DMLabel          subpointMap;
2130   IS              *subpointIS;
2131   const PetscInt **subpoints;
2132   PetscInt        *numSubPoints, *firstSubPoint, *coneNew, *coneONew;
2133   PetscInt         totSubPoints = 0, maxConeSize, dim, p, d, v;
2134   PetscErrorCode   ierr;
2135 
2136   PetscFunctionBegin;
2137   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2138   /* Create subpointMap which marks the submesh */
2139   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2140   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2141   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2142   if (vertexLabel) {ierr = DMPlexMarkSubmesh_Interpolated(dm, vertexLabel, value, subpointMap, subdm);CHKERRQ(ierr);}
2143   /* Setup chart */
2144   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2145   ierr = PetscMalloc4(dim+1,PetscInt,&numSubPoints,dim+1,PetscInt,&firstSubPoint,dim+1,IS,&subpointIS,dim+1,const PetscInt *,&subpoints);CHKERRQ(ierr);
2146   for (d = 0; d <= dim; ++d) {
2147     ierr = DMLabelGetStratumSize(subpointMap, d, &numSubPoints[d]);CHKERRQ(ierr);
2148     totSubPoints += numSubPoints[d];
2149   }
2150   ierr = DMPlexSetChart(subdm, 0, totSubPoints);CHKERRQ(ierr);
2151   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2152   /* Set cone sizes */
2153   firstSubPoint[dim] = 0;
2154   firstSubPoint[0]   = firstSubPoint[dim] + numSubPoints[dim];
2155   if (dim > 1) {firstSubPoint[dim-1] = firstSubPoint[0]     + numSubPoints[0];}
2156   if (dim > 2) {firstSubPoint[dim-2] = firstSubPoint[dim-1] + numSubPoints[dim-1];}
2157   for (d = 0; d <= dim; ++d) {
2158     ierr = DMLabelGetStratumIS(subpointMap, d, &subpointIS[d]);CHKERRQ(ierr);
2159     ierr = ISGetIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2160   }
2161   for (d = 0; d <= dim; ++d) {
2162     for (p = 0; p < numSubPoints[d]; ++p) {
2163       const PetscInt  point    = subpoints[d][p];
2164       const PetscInt  subpoint = firstSubPoint[d] + p;
2165       const PetscInt *cone;
2166       PetscInt        coneSize, coneSizeNew, c, val;
2167 
2168       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2169       ierr = DMPlexSetConeSize(subdm, subpoint, coneSize);CHKERRQ(ierr);
2170       if (d == dim) {
2171         ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2172         for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2173           ierr = DMLabelGetValue(subpointMap, cone[c], &val);CHKERRQ(ierr);
2174           if (val >= 0) coneSizeNew++;
2175         }
2176         ierr = DMPlexSetConeSize(subdm, subpoint, coneSizeNew);CHKERRQ(ierr);
2177       }
2178     }
2179   }
2180   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2181   /* Set cones */
2182   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2183   ierr = PetscMalloc2(maxConeSize,PetscInt,&coneNew,maxConeSize,PetscInt,&coneONew);CHKERRQ(ierr);
2184   for (d = 0; d <= dim; ++d) {
2185     for (p = 0; p < numSubPoints[d]; ++p) {
2186       const PetscInt  point    = subpoints[d][p];
2187       const PetscInt  subpoint = firstSubPoint[d] + p;
2188       const PetscInt *cone, *ornt;
2189       PetscInt        coneSize, subconeSize, coneSizeNew, c, subc;
2190 
2191       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2192       ierr = DMPlexGetConeSize(subdm, subpoint, &subconeSize);CHKERRQ(ierr);
2193       ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2194       ierr = DMPlexGetConeOrientation(dm, point, &ornt);CHKERRQ(ierr);
2195       for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2196         ierr = PetscFindInt(cone[c], numSubPoints[d-1], subpoints[d-1], &subc);CHKERRQ(ierr);
2197         if (subc >= 0) {
2198           coneNew[coneSizeNew]  = firstSubPoint[d-1] + subc;
2199           coneONew[coneSizeNew] = ornt[c];
2200           ++coneSizeNew;
2201         }
2202       }
2203       if (coneSizeNew != subconeSize) SETERRQ2(comm, PETSC_ERR_PLIB, "Number of cone points located %d does not match subcone size %d", coneSizeNew, subconeSize);
2204       ierr = DMPlexSetCone(subdm, subpoint, coneNew);CHKERRQ(ierr);
2205       ierr = DMPlexSetConeOrientation(subdm, subpoint, coneONew);CHKERRQ(ierr);
2206     }
2207   }
2208   ierr = PetscFree2(coneNew,coneONew);CHKERRQ(ierr);
2209   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2210   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2211   /* Build coordinates */
2212   {
2213     PetscSection coordSection, subCoordSection;
2214     Vec          coordinates, subCoordinates;
2215     PetscScalar *coords, *subCoords;
2216     PetscInt     numComp, coordSize;
2217 
2218     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2219     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2220     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2221     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2222     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2223     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2224     ierr = PetscSectionSetChart(subCoordSection, firstSubPoint[0], firstSubPoint[0]+numSubPoints[0]);CHKERRQ(ierr);
2225     for (v = 0; v < numSubPoints[0]; ++v) {
2226       const PetscInt vertex    = subpoints[0][v];
2227       const PetscInt subvertex = firstSubPoint[0]+v;
2228       PetscInt       dof;
2229 
2230       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2231       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2232       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2233     }
2234     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2235     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2236     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2237     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2238     ierr = VecSetType(subCoordinates,dm->vectype);CHKERRQ(ierr);
2239     ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2240     ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2241     for (v = 0; v < numSubPoints[0]; ++v) {
2242       const PetscInt vertex    = subpoints[0][v];
2243       const PetscInt subvertex = firstSubPoint[0]+v;
2244       PetscInt dof, off, sdof, soff, d;
2245 
2246       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2247       ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2248       ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2249       ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2250       if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2251       for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2252     }
2253     ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2254     ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2255     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2256     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2257   }
2258   /* Cleanup */
2259   for (d = 0; d <= dim; ++d) {
2260     ierr = ISRestoreIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2261     ierr = ISDestroy(&subpointIS[d]);CHKERRQ(ierr);
2262   }
2263   ierr = PetscFree4(numSubPoints,firstSubPoint,subpointIS,subpoints);CHKERRQ(ierr);
2264   PetscFunctionReturn(0);
2265 }
2266 
2267 #undef __FUNCT__
2268 #define __FUNCT__ "DMPlexCreateSubmesh"
2269 /*@
2270   DMPlexCreateSubmesh - Extract a hypersurface from the mesh using vertices defined by a label
2271 
2272   Input Parameters:
2273 + dm           - The original mesh
2274 . vertexLabel  - The DMLabel marking vertices contained in the surface
2275 - value        - The label value to use
2276 
2277   Output Parameter:
2278 . subdm - The surface mesh
2279 
2280   Note: This function produces a DMLabel mapping original points in the submesh to their depth. This can be obtained using DMPlexGetSubpointMap().
2281 
2282   Level: developer
2283 
2284 .seealso: DMPlexGetSubpointMap(), DMPlexGetLabel(), DMLabelSetValue()
2285 @*/
2286 PetscErrorCode DMPlexCreateSubmesh(DM dm, DMLabel vertexLabel, PetscInt value, DM *subdm)
2287 {
2288   PetscInt       dim, depth;
2289   PetscErrorCode ierr;
2290 
2291   PetscFunctionBegin;
2292   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2293   PetscValidPointer(subdm, 3);
2294   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2295   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2296   ierr = DMCreate(PetscObjectComm((PetscObject)dm), subdm);CHKERRQ(ierr);
2297   ierr = DMSetType(*subdm, DMPLEX);CHKERRQ(ierr);
2298   ierr = DMPlexSetDimension(*subdm, dim-1);CHKERRQ(ierr);
2299   if (depth == dim) {
2300     ierr = DMPlexCreateSubmesh_Interpolated(dm, vertexLabel, value, *subdm);CHKERRQ(ierr);
2301   } else {
2302     ierr = DMPlexCreateSubmesh_Uninterpolated(dm, vertexLabel, value, *subdm);CHKERRQ(ierr);
2303   }
2304   PetscFunctionReturn(0);
2305 }
2306 
2307 #undef __FUNCT__
2308 #define __FUNCT__ "DMPlexFilterPoint_Internal"
2309 PETSC_STATIC_INLINE PetscInt DMPlexFilterPoint_Internal(PetscInt point, PetscInt firstSubPoint, PetscInt numSubPoints, const PetscInt subPoints[])
2310 {
2311   PetscInt       subPoint;
2312   PetscErrorCode ierr;
2313 
2314   ierr = PetscFindInt(point, numSubPoints, subPoints, &subPoint); if (ierr < 0) return ierr;
2315   return subPoint < 0 ? subPoint : firstSubPoint+subPoint;
2316 }
2317 
2318 #undef __FUNCT__
2319 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh_Uninterpolated"
2320 static PetscErrorCode DMPlexCreateCohesiveSubmesh_Uninterpolated(DM dm, PetscBool hasLagrange, const char label[], PetscInt value, DM subdm)
2321 {
2322   MPI_Comm        comm;
2323   DMLabel         subpointMap;
2324   IS              subvertexIS;
2325   const PetscInt *subVertices;
2326   PetscInt        numSubVertices, firstSubVertex, numSubCells, *subCells = NULL;
2327   PetscInt       *subface, maxConeSize, numSubFaces, firstSubFace, newFacePoint, nFV;
2328   PetscInt        cMax, c, f;
2329   PetscErrorCode  ierr;
2330 
2331   PetscFunctionBegin;
2332   ierr = PetscObjectGetComm((PetscObject)dm, &comm);CHKERRQ(ierr);
2333   /* Create subpointMap which marks the submesh */
2334   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2335   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2336   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2337   ierr = DMPlexMarkCohesiveSubmesh_Uninterpolated(dm, hasLagrange, label, value, subpointMap, &numSubFaces, &nFV, &subCells, subdm);CHKERRQ(ierr);
2338   /* Setup chart */
2339   ierr = DMLabelGetStratumSize(subpointMap, 0, &numSubVertices);CHKERRQ(ierr);
2340   ierr = DMLabelGetStratumSize(subpointMap, 2, &numSubCells);CHKERRQ(ierr);
2341   ierr = DMPlexSetChart(subdm, 0, numSubCells+numSubFaces+numSubVertices);CHKERRQ(ierr);
2342   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2343   /* Set cone sizes */
2344   firstSubVertex = numSubCells;
2345   firstSubFace   = numSubCells+numSubVertices;
2346   newFacePoint   = firstSubFace;
2347   ierr = DMLabelGetStratumIS(subpointMap, 0, &subvertexIS);CHKERRQ(ierr);
2348   if (subvertexIS) {ierr = ISGetIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2349   for (c = 0; c < numSubCells; ++c) {
2350     ierr = DMPlexSetConeSize(subdm, c, 1);CHKERRQ(ierr);
2351   }
2352   for (f = firstSubFace; f < firstSubFace+numSubFaces; ++f) {
2353     ierr = DMPlexSetConeSize(subdm, f, nFV);CHKERRQ(ierr);
2354   }
2355   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2356   /* Create face cones */
2357   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2358   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
2359   ierr = DMGetWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2360   for (c = 0; c < numSubCells; ++c) {
2361     const PetscInt  cell    = subCells[c];
2362     const PetscInt  subcell = c;
2363     const PetscInt *cone, *cells;
2364     PetscInt        numCells, subVertex, p, v;
2365 
2366     if (cell < cMax) continue;
2367     ierr = DMPlexGetCone(dm, cell, &cone);CHKERRQ(ierr);
2368     for (v = 0; v < nFV; ++v) {
2369       ierr = PetscFindInt(cone[v], numSubVertices, subVertices, &subVertex);CHKERRQ(ierr);
2370       subface[v] = firstSubVertex+subVertex;
2371     }
2372     ierr = DMPlexSetCone(subdm, newFacePoint, subface);CHKERRQ(ierr);
2373     ierr = DMPlexSetCone(subdm, subcell, &newFacePoint);CHKERRQ(ierr);
2374     ierr = DMPlexGetJoin(dm, nFV, cone, &numCells, &cells);CHKERRQ(ierr);
2375     /* Not true in parallel
2376     if (numCells != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells"); */
2377     for (p = 0; p < numCells; ++p) {
2378       PetscInt negsubcell;
2379 
2380       if (cells[p] >= cMax) continue;
2381       /* I know this is a crap search */
2382       for (negsubcell = 0; negsubcell < numSubCells; ++negsubcell) {
2383         if (subCells[negsubcell] == cells[p]) break;
2384       }
2385       if (negsubcell == numSubCells) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find negative face neighbor for cohesive cell %d", cell);
2386       ierr = DMPlexSetCone(subdm, negsubcell, &newFacePoint);CHKERRQ(ierr);
2387     }
2388     ierr = DMPlexRestoreJoin(dm, nFV, cone, &numCells, &cells);CHKERRQ(ierr);
2389     ++newFacePoint;
2390   }
2391   ierr = DMRestoreWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2392   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2393   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2394   /* Build coordinates */
2395   {
2396     PetscSection coordSection, subCoordSection;
2397     Vec          coordinates, subCoordinates;
2398     PetscScalar *coords, *subCoords;
2399     PetscInt     numComp, coordSize, v;
2400 
2401     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2402     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2403     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2404     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2405     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2406     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2407     ierr = PetscSectionSetChart(subCoordSection, firstSubVertex, firstSubVertex+numSubVertices);CHKERRQ(ierr);
2408     for (v = 0; v < numSubVertices; ++v) {
2409       const PetscInt vertex    = subVertices[v];
2410       const PetscInt subvertex = firstSubVertex+v;
2411       PetscInt       dof;
2412 
2413       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2414       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2415       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2416     }
2417     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2418     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2419     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2420     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2421     ierr = VecSetType(subCoordinates,dm->vectype);CHKERRQ(ierr);
2422     ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2423     ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2424     for (v = 0; v < numSubVertices; ++v) {
2425       const PetscInt vertex    = subVertices[v];
2426       const PetscInt subvertex = firstSubVertex+v;
2427       PetscInt       dof, off, sdof, soff, d;
2428 
2429       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2430       ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2431       ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2432       ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2433       if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2434       for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2435     }
2436     ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2437     ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2438     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2439     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2440   }
2441   /* Build SF */
2442   CHKMEMQ;
2443   {
2444     PetscSF            sfPoint, sfPointSub;
2445     const PetscSFNode *remotePoints;
2446     PetscSFNode       *sremotePoints, *newLocalPoints, *newOwners;
2447     const PetscInt    *localPoints;
2448     PetscInt          *slocalPoints;
2449     PetscInt           numRoots, numLeaves, numSubRoots = numSubCells+numSubFaces+numSubVertices, numSubLeaves = 0, l, sl, ll, pStart, pEnd, p, vStart, vEnd;
2450     PetscMPIInt        rank;
2451 
2452     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject) dm), &rank);CHKERRQ(ierr);
2453     ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
2454     ierr = DMGetPointSF(subdm, &sfPointSub);CHKERRQ(ierr);
2455     ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
2456     ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
2457     ierr = PetscSFGetGraph(sfPoint, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
2458     if (numRoots >= 0) {
2459       /* Only vertices should be shared */
2460       ierr = PetscMalloc2(pEnd-pStart,PetscSFNode,&newLocalPoints,numRoots,PetscSFNode,&newOwners);CHKERRQ(ierr);
2461       for (p = 0; p < pEnd-pStart; ++p) {
2462         newLocalPoints[p].rank  = -2;
2463         newLocalPoints[p].index = -2;
2464       }
2465       /* Set subleaves */
2466       for (l = 0; l < numLeaves; ++l) {
2467         const PetscInt point    = localPoints[l];
2468         const PetscInt subPoint = DMPlexFilterPoint_Internal(point, firstSubVertex, numSubVertices, subVertices);
2469 
2470         if ((point < vStart) && (point >= vEnd)) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Should not be mapping anything but vertices, %d", point);
2471         if (subPoint < 0) continue;
2472         newLocalPoints[point-pStart].rank  = rank;
2473         newLocalPoints[point-pStart].index = subPoint;
2474         ++numSubLeaves;
2475       }
2476       /* Must put in owned subpoints */
2477       for (p = pStart; p < pEnd; ++p) {
2478         const PetscInt subPoint = DMPlexFilterPoint_Internal(p, firstSubVertex, numSubVertices, subVertices);
2479 
2480         if (subPoint < 0) {
2481           newOwners[p-pStart].rank  = -3;
2482           newOwners[p-pStart].index = -3;
2483         } else {
2484           newOwners[p-pStart].rank  = rank;
2485           newOwners[p-pStart].index = subPoint;
2486         }
2487       }
2488       ierr = PetscSFReduceBegin(sfPoint, MPIU_2INT, newLocalPoints, newOwners, MPI_MAXLOC);CHKERRQ(ierr);
2489       ierr = PetscSFReduceEnd(sfPoint, MPIU_2INT, newLocalPoints, newOwners, MPI_MAXLOC);CHKERRQ(ierr);
2490       ierr = PetscSFBcastBegin(sfPoint, MPIU_2INT, newOwners, newLocalPoints);CHKERRQ(ierr);
2491       ierr = PetscSFBcastEnd(sfPoint, MPIU_2INT, newOwners, newLocalPoints);CHKERRQ(ierr);
2492       ierr = PetscMalloc(numSubLeaves * sizeof(PetscInt),    &slocalPoints);CHKERRQ(ierr);
2493       ierr = PetscMalloc(numSubLeaves * sizeof(PetscSFNode), &sremotePoints);CHKERRQ(ierr);
2494       for (l = 0, sl = 0, ll = 0; l < numLeaves; ++l) {
2495         const PetscInt point    = localPoints[l];
2496         const PetscInt subPoint = DMPlexFilterPoint_Internal(point, firstSubVertex, numSubVertices, subVertices);
2497 
2498         if (subPoint < 0) continue;
2499         if (newLocalPoints[point].rank == rank) {++ll; continue;}
2500         slocalPoints[sl]        = subPoint;
2501         sremotePoints[sl].rank  = newLocalPoints[point].rank;
2502         sremotePoints[sl].index = newLocalPoints[point].index;
2503         if (sremotePoints[sl].rank  < 0) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid remote rank for local point %d", point);
2504         if (sremotePoints[sl].index < 0) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid remote subpoint for local point %d", point);
2505         ++sl;
2506       }
2507       ierr = PetscFree2(newLocalPoints,newOwners);CHKERRQ(ierr);
2508       if (sl + ll != numSubLeaves) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Mismatch in number of subleaves %d + %d != %d", sl, ll, numSubLeaves);
2509       ierr = PetscSFSetGraph(sfPointSub, numSubRoots, sl, slocalPoints, PETSC_OWN_POINTER, sremotePoints, PETSC_OWN_POINTER);CHKERRQ(ierr);
2510     }
2511   }
2512   CHKMEMQ;
2513   /* Cleanup */
2514   if (subvertexIS) {ierr = ISRestoreIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2515   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
2516   ierr = PetscFree(subCells);CHKERRQ(ierr);
2517   PetscFunctionReturn(0);
2518 }
2519 
2520 #undef __FUNCT__
2521 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh_Interpolated"
2522 static PetscErrorCode DMPlexCreateCohesiveSubmesh_Interpolated(DM dm, PetscBool hasLagrange, const char label[], PetscInt value, DM subdm)
2523 {
2524   MPI_Comm         comm;
2525   DMLabel          subpointMap;
2526   IS              *subpointIS;
2527   const PetscInt **subpoints;
2528   PetscInt        *numSubPoints, *firstSubPoint, *coneNew;
2529   PetscInt         totSubPoints = 0, maxConeSize, dim, p, d, v;
2530   PetscErrorCode   ierr;
2531 
2532   PetscFunctionBegin;
2533   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2534   /* Create subpointMap which marks the submesh */
2535   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2536   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2537   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2538   ierr = DMPlexMarkCohesiveSubmesh_Interpolated(dm, hasLagrange, label, value, subpointMap, subdm);CHKERRQ(ierr);
2539   /* Setup chart */
2540   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2541   ierr = PetscMalloc4(dim+1,PetscInt,&numSubPoints,dim+1,PetscInt,&firstSubPoint,dim+1,IS,&subpointIS,dim+1,const PetscInt *,&subpoints);CHKERRQ(ierr);
2542   for (d = 0; d <= dim; ++d) {
2543     ierr = DMLabelGetStratumSize(subpointMap, d, &numSubPoints[d]);CHKERRQ(ierr);
2544     totSubPoints += numSubPoints[d];
2545   }
2546   ierr = DMPlexSetChart(subdm, 0, totSubPoints);CHKERRQ(ierr);
2547   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2548   /* Set cone sizes */
2549   firstSubPoint[dim] = 0;
2550   firstSubPoint[0]   = firstSubPoint[dim] + numSubPoints[dim];
2551   if (dim > 1) {firstSubPoint[dim-1] = firstSubPoint[0]     + numSubPoints[0];}
2552   if (dim > 2) {firstSubPoint[dim-2] = firstSubPoint[dim-1] + numSubPoints[dim-1];}
2553   for (d = 0; d <= dim; ++d) {
2554     ierr = DMLabelGetStratumIS(subpointMap, d, &subpointIS[d]);CHKERRQ(ierr);
2555     ierr = ISGetIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2556   }
2557   for (d = 0; d <= dim; ++d) {
2558     for (p = 0; p < numSubPoints[d]; ++p) {
2559       const PetscInt  point    = subpoints[d][p];
2560       const PetscInt  subpoint = firstSubPoint[d] + p;
2561       const PetscInt *cone;
2562       PetscInt        coneSize, coneSizeNew, c, val;
2563 
2564       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2565       ierr = DMPlexSetConeSize(subdm, subpoint, coneSize);CHKERRQ(ierr);
2566       if (d == dim) {
2567         ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2568         for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2569           ierr = DMLabelGetValue(subpointMap, cone[c], &val);CHKERRQ(ierr);
2570           if (val >= 0) coneSizeNew++;
2571         }
2572         ierr = DMPlexSetConeSize(subdm, subpoint, coneSizeNew);CHKERRQ(ierr);
2573       }
2574     }
2575   }
2576   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2577   /* Set cones */
2578   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2579   ierr = PetscMalloc(maxConeSize * sizeof(PetscInt), &coneNew);CHKERRQ(ierr);
2580   for (d = 0; d <= dim; ++d) {
2581     for (p = 0; p < numSubPoints[d]; ++p) {
2582       const PetscInt  point    = subpoints[d][p];
2583       const PetscInt  subpoint = firstSubPoint[d] + p;
2584       const PetscInt *cone;
2585       PetscInt        coneSize, subconeSize, coneSizeNew, c, subc;
2586 
2587       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2588       ierr = DMPlexGetConeSize(subdm, subpoint, &subconeSize);CHKERRQ(ierr);
2589       ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2590       for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2591         ierr = PetscFindInt(cone[c], numSubPoints[d-1], subpoints[d-1], &subc);CHKERRQ(ierr);
2592         if (subc >= 0) coneNew[coneSizeNew++] = firstSubPoint[d-1] + subc;
2593       }
2594       if (coneSizeNew != subconeSize) SETERRQ2(comm, PETSC_ERR_PLIB, "Number of cone points located %d does not match subcone size %d", coneSizeNew, subconeSize);
2595       ierr = DMPlexSetCone(subdm, subpoint, coneNew);CHKERRQ(ierr);
2596     }
2597   }
2598   ierr = PetscFree(coneNew);CHKERRQ(ierr);
2599   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2600   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2601   /* Build coordinates */
2602   {
2603     PetscSection coordSection, subCoordSection;
2604     Vec          coordinates, subCoordinates;
2605     PetscScalar *coords, *subCoords;
2606     PetscInt     numComp, coordSize;
2607 
2608     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2609     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2610     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2611     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2612     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2613     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2614     ierr = PetscSectionSetChart(subCoordSection, firstSubPoint[0], firstSubPoint[0]+numSubPoints[0]);CHKERRQ(ierr);
2615     for (v = 0; v < numSubPoints[0]; ++v) {
2616       const PetscInt vertex    = subpoints[0][v];
2617       const PetscInt subvertex = firstSubPoint[0]+v;
2618       PetscInt       dof;
2619 
2620       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2621       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2622       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2623     }
2624     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2625     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2626     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2627     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2628     ierr = VecSetType(subCoordinates,dm->vectype);CHKERRQ(ierr);
2629     ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2630     ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2631     for (v = 0; v < numSubPoints[0]; ++v) {
2632       const PetscInt vertex    = subpoints[0][v];
2633       const PetscInt subvertex = firstSubPoint[0]+v;
2634       PetscInt dof, off, sdof, soff, d;
2635 
2636       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2637       ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2638       ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2639       ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2640       if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2641       for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2642     }
2643     ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2644     ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2645     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2646     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2647   }
2648   /* Cleanup */
2649   for (d = 0; d <= dim; ++d) {
2650     ierr = ISRestoreIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2651     ierr = ISDestroy(&subpointIS[d]);CHKERRQ(ierr);
2652   }
2653   ierr = PetscFree4(numSubPoints,firstSubPoint,subpointIS,subpoints);CHKERRQ(ierr);
2654   PetscFunctionReturn(0);
2655 }
2656 
2657 #undef __FUNCT__
2658 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh"
2659 /*
2660   DMPlexCreateCohesiveSubmesh - Extract from a mesh with cohesive cells the hypersurface defined by one face of the cells. Optionally, a Label an be given to restrict the cells.
2661 
2662   Input Parameters:
2663 + dm          - The original mesh
2664 . hasLagrange - The mesh has Lagrange unknowns in the cohesive cells
2665 . label       - A label name, or PETSC_NULL
2666 - value  - A label value
2667 
2668   Output Parameter:
2669 . subdm - The surface mesh
2670 
2671   Note: This function produces a DMLabel mapping original points in the submesh to their depth. This can be obtained using DMPlexGetSubpointMap().
2672 
2673   Level: developer
2674 
2675 .seealso: DMPlexGetSubpointMap(), DMPlexCreateSubmesh()
2676 */
2677 PetscErrorCode DMPlexCreateCohesiveSubmesh(DM dm, PetscBool hasLagrange, const char label[], PetscInt value, DM *subdm)
2678 {
2679   PetscInt       dim, depth;
2680   PetscErrorCode ierr;
2681 
2682   PetscFunctionBegin;
2683   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2684   PetscValidPointer(subdm, 5);
2685   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2686   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2687   ierr = DMCreate(PetscObjectComm((PetscObject)dm), subdm);CHKERRQ(ierr);
2688   ierr = DMSetType(*subdm, DMPLEX);CHKERRQ(ierr);
2689   ierr = DMPlexSetDimension(*subdm, dim-1);CHKERRQ(ierr);
2690   if (depth == dim) {
2691     ierr = DMPlexCreateCohesiveSubmesh_Interpolated(dm, hasLagrange, label, value, *subdm);CHKERRQ(ierr);
2692   } else {
2693     ierr = DMPlexCreateCohesiveSubmesh_Uninterpolated(dm, hasLagrange, label, value, *subdm);CHKERRQ(ierr);
2694   }
2695   PetscFunctionReturn(0);
2696 }
2697 
2698 #undef __FUNCT__
2699 #define __FUNCT__ "DMPlexGetSubpointMap"
2700 /*@
2701   DMPlexGetSubpointMap - Returns a DMLabel with point dimension as values
2702 
2703   Input Parameter:
2704 . dm - The submesh DM
2705 
2706   Output Parameter:
2707 . subpointMap - The DMLabel of all the points from the original mesh in this submesh, or NULL if this is not a submesh
2708 
2709   Level: developer
2710 
2711 .seealso: DMPlexCreateSubmesh(), DMPlexCreateSubpointIS()
2712 @*/
2713 PetscErrorCode DMPlexGetSubpointMap(DM dm, DMLabel *subpointMap)
2714 {
2715   DM_Plex *mesh = (DM_Plex*) dm->data;
2716 
2717   PetscFunctionBegin;
2718   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2719   PetscValidPointer(subpointMap, 2);
2720   *subpointMap = mesh->subpointMap;
2721   PetscFunctionReturn(0);
2722 }
2723 
2724 #undef __FUNCT__
2725 #define __FUNCT__ "DMPlexSetSubpointMap"
2726 /* Note: Should normally not be called by the user, since it is set in DMPlexCreateSubmesh() */
2727 PetscErrorCode DMPlexSetSubpointMap(DM dm, DMLabel subpointMap)
2728 {
2729   DM_Plex       *mesh = (DM_Plex *) dm->data;
2730   DMLabel        tmp;
2731   PetscErrorCode ierr;
2732 
2733   PetscFunctionBegin;
2734   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2735   tmp  = mesh->subpointMap;
2736   mesh->subpointMap = subpointMap;
2737   ++mesh->subpointMap->refct;
2738   ierr = DMLabelDestroy(&tmp);CHKERRQ(ierr);
2739   PetscFunctionReturn(0);
2740 }
2741 
2742 #undef __FUNCT__
2743 #define __FUNCT__ "DMPlexCreateSubpointIS"
2744 /*@
2745   DMPlexCreateSubpointIS - Creates an IS covering the entire subdm chart with the original points as data
2746 
2747   Input Parameter:
2748 . dm - The submesh DM
2749 
2750   Output Parameter:
2751 . subpointIS - The IS of all the points from the original mesh in this submesh, or NULL if this is not a submesh
2752 
2753   Note: This is IS is guaranteed to be sorted by the construction of the submesh
2754 
2755   Level: developer
2756 
2757 .seealso: DMPlexCreateSubmesh(), DMPlexGetSubpointMap()
2758 @*/
2759 PetscErrorCode DMPlexCreateSubpointIS(DM dm, IS *subpointIS)
2760 {
2761   MPI_Comm        comm;
2762   DMLabel         subpointMap;
2763   IS              is;
2764   const PetscInt *opoints;
2765   PetscInt       *points, *depths;
2766   PetscInt        depth, depStart, depEnd, d, pStart, pEnd, p, n, off;
2767   PetscErrorCode  ierr;
2768 
2769   PetscFunctionBegin;
2770   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2771   PetscValidPointer(subpointIS, 2);
2772   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2773   *subpointIS = NULL;
2774   ierr = DMPlexGetSubpointMap(dm, &subpointMap);CHKERRQ(ierr);
2775   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2776   if (subpointMap && depth >= 0) {
2777     ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
2778     if (pStart) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Submeshes must start the point numbering at 0, not %d", pStart);
2779     ierr = DMGetWorkArray(dm, depth+1, PETSC_INT, &depths);CHKERRQ(ierr);
2780     depths[0] = depth;
2781     depths[1] = 0;
2782     for(d = 2; d <= depth; ++d) {depths[d] = depth+1 - d;}
2783     ierr = PetscMalloc(pEnd * sizeof(PetscInt), &points);CHKERRQ(ierr);
2784     for(d = 0, off = 0; d <= depth; ++d) {
2785       const PetscInt dep = depths[d];
2786 
2787       ierr = DMPlexGetDepthStratum(dm, dep, &depStart, &depEnd);CHKERRQ(ierr);
2788       ierr = DMLabelGetStratumSize(subpointMap, dep, &n);CHKERRQ(ierr);
2789       if (((d < 2) && (depth > 1)) || (d == 1)) { /* Only check vertices and cells for now since the map is broken for others */
2790         if (n != depEnd-depStart) SETERRQ3(comm, PETSC_ERR_ARG_WRONG, "The number of mapped submesh points %d at depth %d should be %d", n, dep, depEnd-depStart);
2791       } else {
2792         if (!n) {
2793           if (d == 0) {
2794             /* Missing cells */
2795             for(p = 0; p < depEnd-depStart; ++p, ++off) points[off] = -1;
2796           } else {
2797             /* Missing faces */
2798             for(p = 0; p < depEnd-depStart; ++p, ++off) points[off] = PETSC_MAX_INT;
2799           }
2800         }
2801       }
2802       if (n) {
2803         ierr = DMLabelGetStratumIS(subpointMap, dep, &is);CHKERRQ(ierr);
2804         ierr = ISGetIndices(is, &opoints);CHKERRQ(ierr);
2805         for(p = 0; p < n; ++p, ++off) points[off] = opoints[p];
2806         ierr = ISRestoreIndices(is, &opoints);CHKERRQ(ierr);
2807         ierr = ISDestroy(&is);CHKERRQ(ierr);
2808       }
2809     }
2810     ierr = DMRestoreWorkArray(dm, depth+1, PETSC_INT, &depths);CHKERRQ(ierr);
2811     if (off != pEnd) SETERRQ2(comm, PETSC_ERR_ARG_WRONG, "The number of mapped submesh points %d should be %d", off, pEnd);
2812     ierr = ISCreateGeneral(PETSC_COMM_SELF, pEnd, points, PETSC_OWN_POINTER, subpointIS);CHKERRQ(ierr);
2813   }
2814   PetscFunctionReturn(0);
2815 }
2816