xref: /petsc/src/dm/impls/plex/plexsubmesh.c (revision 0e49e2e2047f92bda7ad4610208cb8d0b76ad438)
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 = VecSetFromOptions(newCoordinates);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   PetscMPIInt        numProcs;
253   PetscErrorCode     ierr;
254 
255   PetscFunctionBegin;
256   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
257   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
258   for (d = 0; d <= depth; ++d) {
259     totShift += depthShift[d];
260     ierr      = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
261   }
262   /* Step 9: Convert pointSF */
263   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)dm), &numProcs);CHKERRQ(ierr);
264   ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
265   ierr = DMGetPointSF(dmNew, &sfPointNew);CHKERRQ(ierr);
266   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
267   ierr = PetscSFGetGraph(sfPoint, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
268   if (numRoots >= 0) {
269     ierr = PetscMalloc2(numRoots,PetscInt,&newLocation,pEnd-pStart,PetscInt,&newRemoteLocation);CHKERRQ(ierr);
270     for (l=0; l<numRoots; l++) newLocation[l] = DMPlexShiftPoint_Internal(l, depth, depthEnd, depthShift);
271     ierr = PetscSFBcastBegin(sfPoint, MPIU_INT, newLocation, newRemoteLocation);CHKERRQ(ierr);
272     ierr = PetscSFBcastEnd(sfPoint, MPIU_INT, newLocation, newRemoteLocation);CHKERRQ(ierr);
273     ierr = PetscMalloc(numLeaves * sizeof(PetscInt),    &glocalPoints);CHKERRQ(ierr);
274     ierr = PetscMalloc(numLeaves * sizeof(PetscSFNode), &gremotePoints);CHKERRQ(ierr);
275     for (l = 0; l < numLeaves; ++l) {
276       glocalPoints[l]        = DMPlexShiftPoint_Internal(localPoints[l], depth, depthEnd, depthShift);
277       gremotePoints[l].rank  = remotePoints[l].rank;
278       gremotePoints[l].index = newRemoteLocation[localPoints[l]];
279     }
280     ierr = PetscFree2(newLocation,newRemoteLocation);CHKERRQ(ierr);
281     ierr = PetscSFSetGraph(sfPointNew, numRoots + totShift, numLeaves, glocalPoints, PETSC_OWN_POINTER, gremotePoints, PETSC_OWN_POINTER);CHKERRQ(ierr);
282   }
283   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
284   PetscFunctionReturn(0);
285 }
286 
287 #undef __FUNCT__
288 #define __FUNCT__ "DMPlexShiftLabels_Internal"
289 static PetscErrorCode DMPlexShiftLabels_Internal(DM dm, PetscInt depthShift[], DM dmNew)
290 {
291   PetscSF            sfPoint;
292   DMLabel            vtkLabel, ghostLabel;
293   PetscInt          *depthEnd;
294   const PetscSFNode *leafRemote;
295   const PetscInt    *leafLocal;
296   PetscInt           depth = 0, d, numLeaves, numLabels, l, cStart, cEnd, c, fStart, fEnd, f;
297   PetscMPIInt        rank;
298   PetscErrorCode     ierr;
299 
300   PetscFunctionBegin;
301   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
302   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
303   for (d = 0; d <= depth; ++d) {
304     ierr = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
305   }
306   /* Step 10: Convert labels */
307   ierr = DMPlexGetNumLabels(dm, &numLabels);CHKERRQ(ierr);
308   for (l = 0; l < numLabels; ++l) {
309     DMLabel         label, newlabel;
310     const char     *lname;
311     PetscBool       isDepth;
312     IS              valueIS;
313     const PetscInt *values;
314     PetscInt        numValues, val;
315 
316     ierr = DMPlexGetLabelName(dm, l, &lname);CHKERRQ(ierr);
317     ierr = PetscStrcmp(lname, "depth", &isDepth);CHKERRQ(ierr);
318     if (isDepth) continue;
319     ierr = DMPlexCreateLabel(dmNew, lname);CHKERRQ(ierr);
320     ierr = DMPlexGetLabel(dm, lname, &label);CHKERRQ(ierr);
321     ierr = DMPlexGetLabel(dmNew, lname, &newlabel);CHKERRQ(ierr);
322     ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
323     ierr = ISGetLocalSize(valueIS, &numValues);CHKERRQ(ierr);
324     ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
325     for (val = 0; val < numValues; ++val) {
326       IS              pointIS;
327       const PetscInt *points;
328       PetscInt        numPoints, p;
329 
330       ierr = DMLabelGetStratumIS(label, values[val], &pointIS);CHKERRQ(ierr);
331       ierr = ISGetLocalSize(pointIS, &numPoints);CHKERRQ(ierr);
332       ierr = ISGetIndices(pointIS, &points);CHKERRQ(ierr);
333       for (p = 0; p < numPoints; ++p) {
334         const PetscInt newpoint = DMPlexShiftPoint_Internal(points[p], depth, depthEnd, depthShift);
335 
336         ierr = DMLabelSetValue(newlabel, newpoint, values[val]);CHKERRQ(ierr);
337       }
338       ierr = ISRestoreIndices(pointIS, &points);CHKERRQ(ierr);
339       ierr = ISDestroy(&pointIS);CHKERRQ(ierr);
340     }
341     ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
342     ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
343   }
344   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
345   /* Step 11: Make label for output (vtk) and to mark ghost points (ghost) */
346   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank);CHKERRQ(ierr);
347   ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
348   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
349   ierr = PetscSFGetGraph(sfPoint, NULL, &numLeaves, &leafLocal, &leafRemote);CHKERRQ(ierr);
350   ierr = DMPlexCreateLabel(dmNew, "vtk");CHKERRQ(ierr);
351   ierr = DMPlexCreateLabel(dmNew, "ghost");CHKERRQ(ierr);
352   ierr = DMPlexGetLabel(dmNew, "vtk", &vtkLabel);CHKERRQ(ierr);
353   ierr = DMPlexGetLabel(dmNew, "ghost", &ghostLabel);CHKERRQ(ierr);
354   for (l = 0, c = cStart; l < numLeaves && c < cEnd; ++l, ++c) {
355     for (; c < leafLocal[l] && c < cEnd; ++c) {
356       ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
357     }
358     if (leafLocal[l] >= cEnd) break;
359     if (leafRemote[l].rank == rank) {
360       ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
361     } else {
362       ierr = DMLabelSetValue(ghostLabel, c, 2);CHKERRQ(ierr);
363     }
364   }
365   for (; c < cEnd; ++c) {
366     ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
367   }
368   if (0) {
369     ierr = PetscViewerASCIISynchronizedAllow(PETSC_VIEWER_STDOUT_WORLD, PETSC_TRUE);CHKERRQ(ierr);
370     ierr = DMLabelView(vtkLabel, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
371     ierr = PetscViewerFlush(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
372   }
373   ierr = DMPlexGetHeightStratum(dmNew, 1, &fStart, &fEnd);CHKERRQ(ierr);
374   for (f = fStart; f < fEnd; ++f) {
375     PetscInt numCells;
376 
377     ierr = DMPlexGetSupportSize(dmNew, f, &numCells);CHKERRQ(ierr);
378     if (numCells < 2) {
379       ierr = DMLabelSetValue(ghostLabel, f, 1);CHKERRQ(ierr);
380     } else {
381       const PetscInt *cells = NULL;
382       PetscInt        vA, vB;
383 
384       ierr = DMPlexGetSupport(dmNew, f, &cells);CHKERRQ(ierr);
385       ierr = DMLabelGetValue(vtkLabel, cells[0], &vA);CHKERRQ(ierr);
386       ierr = DMLabelGetValue(vtkLabel, cells[1], &vB);CHKERRQ(ierr);
387       if (!vA && !vB) {ierr = DMLabelSetValue(ghostLabel, f, 1);CHKERRQ(ierr);}
388     }
389   }
390   if (0) {
391     ierr = PetscViewerASCIISynchronizedAllow(PETSC_VIEWER_STDOUT_WORLD, PETSC_TRUE);CHKERRQ(ierr);
392     ierr = DMLabelView(ghostLabel, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
393     ierr = PetscViewerFlush(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
394   }
395   PetscFunctionReturn(0);
396 }
397 
398 #undef __FUNCT__
399 #define __FUNCT__ "DMPlexConstructGhostCells_Internal"
400 static PetscErrorCode DMPlexConstructGhostCells_Internal(DM dm, DMLabel label, PetscInt *numGhostCells, DM gdm)
401 {
402   IS              valueIS;
403   const PetscInt *values;
404   PetscInt       *depthShift;
405   PetscInt        depth = 0, numFS, fs, ghostCell, cEnd, c;
406   PetscErrorCode  ierr;
407 
408   PetscFunctionBegin;
409   /* Count ghost cells */
410   ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
411   ierr = ISGetLocalSize(valueIS, &numFS);CHKERRQ(ierr);
412   ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
413 
414   *numGhostCells = 0;
415   for (fs = 0; fs < numFS; ++fs) {
416     PetscInt numBdFaces;
417 
418     ierr = DMLabelGetStratumSize(label, values[fs], &numBdFaces);CHKERRQ(ierr);
419 
420     *numGhostCells += numBdFaces;
421   }
422   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
423   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthShift);CHKERRQ(ierr);
424   ierr = PetscMemzero(depthShift, (depth+1) * sizeof(PetscInt));CHKERRQ(ierr);
425   if (depth >= 0) depthShift[depth] = *numGhostCells;
426   ierr = DMPlexShiftSizes_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
427   /* Step 3: Set cone/support sizes for new points */
428   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
429   for (c = cEnd; c < cEnd + *numGhostCells; ++c) {
430     ierr = DMPlexSetConeSize(gdm, c, 1);CHKERRQ(ierr);
431   }
432   for (fs = 0; fs < numFS; ++fs) {
433     IS              faceIS;
434     const PetscInt *faces;
435     PetscInt        numFaces, f;
436 
437     ierr = DMLabelGetStratumIS(label, values[fs], &faceIS);CHKERRQ(ierr);
438     ierr = ISGetLocalSize(faceIS, &numFaces);CHKERRQ(ierr);
439     ierr = ISGetIndices(faceIS, &faces);CHKERRQ(ierr);
440     for (f = 0; f < numFaces; ++f) {
441       PetscInt size;
442 
443       ierr = DMPlexGetSupportSize(dm, faces[f], &size);CHKERRQ(ierr);
444       if (size != 1) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "DM has boundary face %d with %d support cells", faces[f], size);
445       ierr = DMPlexSetSupportSize(gdm, faces[f] + *numGhostCells, 2);CHKERRQ(ierr);
446     }
447     ierr = ISRestoreIndices(faceIS, &faces);CHKERRQ(ierr);
448     ierr = ISDestroy(&faceIS);CHKERRQ(ierr);
449   }
450   /* Step 4: Setup ghosted DM */
451   ierr = DMSetUp(gdm);CHKERRQ(ierr);
452   ierr = DMPlexShiftPoints_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
453   /* Step 6: Set cones and supports for new points */
454   ghostCell = cEnd;
455   for (fs = 0; fs < numFS; ++fs) {
456     IS              faceIS;
457     const PetscInt *faces;
458     PetscInt        numFaces, f;
459 
460     ierr = DMLabelGetStratumIS(label, values[fs], &faceIS);CHKERRQ(ierr);
461     ierr = ISGetLocalSize(faceIS, &numFaces);CHKERRQ(ierr);
462     ierr = ISGetIndices(faceIS, &faces);CHKERRQ(ierr);
463     for (f = 0; f < numFaces; ++f, ++ghostCell) {
464       PetscInt newFace = faces[f] + *numGhostCells;
465 
466       ierr = DMPlexSetCone(gdm, ghostCell, &newFace);CHKERRQ(ierr);
467       ierr = DMPlexInsertSupport(gdm, newFace, 1, ghostCell);CHKERRQ(ierr);
468     }
469     ierr = ISRestoreIndices(faceIS, &faces);CHKERRQ(ierr);
470     ierr = ISDestroy(&faceIS);CHKERRQ(ierr);
471   }
472   ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
473   ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
474   /* Step 7: Stratify */
475   ierr = DMPlexStratify(gdm);CHKERRQ(ierr);
476   ierr = DMPlexShiftCoordinates_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
477   ierr = DMPlexShiftSF_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
478   ierr = DMPlexShiftLabels_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
479   ierr = PetscFree(depthShift);CHKERRQ(ierr);
480   PetscFunctionReturn(0);
481 }
482 
483 #undef __FUNCT__
484 #define __FUNCT__ "DMPlexConstructGhostCells"
485 /*@C
486   DMPlexConstructGhostCells - Construct ghost cells which connect to every boundary face
487 
488   Collective on dm
489 
490   Input Parameters:
491 + dm - The original DM
492 - labelName - The label specifying the boundary faces, or "Face Sets" if this is NULL
493 
494   Output Parameters:
495 + numGhostCells - The number of ghost cells added to the DM
496 - dmGhosted - The new DM
497 
498   Note: If no label exists of that name, one will be created marking all boundary faces
499 
500   Level: developer
501 
502 .seealso: DMCreate()
503 */
504 PetscErrorCode DMPlexConstructGhostCells(DM dm, const char labelName[], PetscInt *numGhostCells, DM *dmGhosted)
505 {
506   DM             gdm;
507   DMLabel        label;
508   const char    *name = labelName ? labelName : "Face Sets";
509   PetscInt       dim;
510   PetscErrorCode ierr;
511 
512   PetscFunctionBegin;
513   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
514   PetscValidPointer(numGhostCells, 3);
515   PetscValidPointer(dmGhosted, 4);
516   ierr = DMCreate(PetscObjectComm((PetscObject)dm), &gdm);CHKERRQ(ierr);
517   ierr = DMSetType(gdm, DMPLEX);CHKERRQ(ierr);
518   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
519   ierr = DMPlexSetDimension(gdm, dim);CHKERRQ(ierr);
520   ierr = DMPlexGetLabel(dm, name, &label);CHKERRQ(ierr);
521   if (!label) {
522     /* Get label for boundary faces */
523     ierr = DMPlexCreateLabel(dm, name);CHKERRQ(ierr);
524     ierr = DMPlexGetLabel(dm, name, &label);CHKERRQ(ierr);
525     ierr = DMPlexMarkBoundaryFaces(dm, label);CHKERRQ(ierr);
526   }
527   ierr = DMPlexConstructGhostCells_Internal(dm, label, numGhostCells, gdm);CHKERRQ(ierr);
528   ierr = DMSetFromOptions(gdm);CHKERRQ(ierr);
529   *dmGhosted = gdm;
530   PetscFunctionReturn(0);
531 }
532 
533 #undef __FUNCT__
534 #define __FUNCT__ "DMPlexConstructCohesiveCells_Internal"
535 static PetscErrorCode DMPlexConstructCohesiveCells_Internal(DM dm, DMLabel label, DM sdm)
536 {
537   MPI_Comm        comm;
538   IS              valueIS, *pointIS;
539   const PetscInt *values, **splitPoints;
540   PetscSection    coordSection;
541   Vec             coordinates;
542   PetscScalar    *coords;
543   PetscInt       *depthShift, *depthOffset, *pMaxNew, *numSplitPoints, *coneNew, *coneONew, *supportNew;
544   PetscInt        shift = 100, depth = 0, dep, dim, d, numSP = 0, sp, maxConeSize, maxSupportSize, numLabels, pEnd, p, v;
545   PetscErrorCode  ierr;
546 
547   PetscFunctionBegin;
548   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
549   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
550   /* Count split points and add cohesive cells */
551   if (label) {
552     ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
553     ierr = ISGetLocalSize(valueIS, &numSP);CHKERRQ(ierr);
554     ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
555   }
556   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
557   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
558   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);
559   ierr = PetscMalloc3(depth+1,IS,&pointIS,depth+1,PetscInt,&numSplitPoints,depth+1,const PetscInt*,&splitPoints);CHKERRQ(ierr);
560   ierr = PetscMemzero(depthShift, (depth+1) * sizeof(PetscInt));CHKERRQ(ierr);
561   for (d = 0; d <= depth; ++d) {
562     ierr              = DMPlexGetDepthStratum(dm, d, NULL, &pMaxNew[d]);CHKERRQ(ierr);
563     numSplitPoints[d] = 0;
564     splitPoints[d]    = NULL;
565     pointIS[d]        = NULL;
566   }
567   for (sp = 0; sp < numSP; ++sp) {
568     const PetscInt dep = values[sp];
569 
570     if ((dep < 0) || (dep > depth)) continue;
571     ierr = DMLabelGetStratumSize(label, dep, &depthShift[dep]);CHKERRQ(ierr);
572     ierr = DMLabelGetStratumIS(label, dep, &pointIS[dep]);CHKERRQ(ierr);
573     if (pointIS[dep]) {
574       ierr = ISGetLocalSize(pointIS[dep], &numSplitPoints[dep]);CHKERRQ(ierr);
575       ierr = ISGetIndices(pointIS[dep], &splitPoints[dep]);CHKERRQ(ierr);
576     }
577   }
578   if (depth >= 0) {
579     /* Calculate number of additional points */
580     depthShift[depth] = depthShift[depth-1]; /* There is a cohesive cell for every split face   */
581     depthShift[1]    += depthShift[0];       /* There is a cohesive edge for every split vertex */
582     /* Calculate hybrid bound for each dimension */
583     pMaxNew[0] += depthShift[depth];
584     if (depth > 1) pMaxNew[dim-1] += depthShift[depth] + depthShift[0];
585     if (depth > 2) pMaxNew[1]     += depthShift[depth] + depthShift[0] + depthShift[dim-1];
586 
587     /* Calculate point offset for each dimension */
588     depthOffset[depth] = 0;
589     depthOffset[0]     = depthOffset[depth] + depthShift[depth];
590     if (depth > 1) depthOffset[dim-1] = depthOffset[0]     + depthShift[0];
591     if (depth > 2) depthOffset[1]     = depthOffset[dim-1] + depthShift[dim-1];
592   }
593   ierr = DMPlexShiftSizes_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
594   /* Step 3: Set cone/support sizes for new points */
595   for (dep = 0; dep <= depth; ++dep) {
596     for (p = 0; p < numSplitPoints[dep]; ++p) {
597       const PetscInt  oldp   = splitPoints[dep][p];
598       const PetscInt  newp   = depthOffset[dep] + oldp;
599       const PetscInt  splitp = pMaxNew[dep] + p;
600       const PetscInt *support;
601       PetscInt        coneSize, supportSize, q, e;
602 
603       ierr = DMPlexGetConeSize(dm, oldp, &coneSize);CHKERRQ(ierr);
604       ierr = DMPlexSetConeSize(sdm, splitp, coneSize);CHKERRQ(ierr);
605       ierr = DMPlexGetSupportSize(dm, oldp, &supportSize);CHKERRQ(ierr);
606       ierr = DMPlexSetSupportSize(sdm, splitp, supportSize);CHKERRQ(ierr);
607       if (dep == depth-1) {
608         const PetscInt ccell = pMaxNew[depth] + p;
609         /* Add cohesive cells, they are prisms */
610         ierr = DMPlexSetConeSize(sdm, ccell, 2 + coneSize);CHKERRQ(ierr);
611       } else if (dep == 0) {
612         const PetscInt cedge = pMaxNew[1] + (depthShift[1] - depthShift[0]) + p;
613 
614         ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
615         /* Split old vertex: Edges in old split faces and new cohesive edge */
616         for (e = 0, q = 0; e < supportSize; ++e) {
617           PetscInt val;
618 
619           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
620           if ((val == 1) || (val == (shift + 1))) ++q;
621         }
622         ierr = DMPlexSetSupportSize(sdm, newp, q+1);CHKERRQ(ierr);
623         /* Split new vertex: Edges in new split faces and new cohesive edge */
624         for (e = 0, q = 0; e < supportSize; ++e) {
625           PetscInt val;
626 
627           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
628           if ((val == 1) || (val == -(shift + 1))) ++q;
629         }
630         ierr = DMPlexSetSupportSize(sdm, splitp, q+1);CHKERRQ(ierr);
631         /* Add cohesive edges */
632         ierr = DMPlexSetConeSize(sdm, cedge, 2);CHKERRQ(ierr);
633         /* Punt for now on support, you loop over closure, extract faces, check which ones are in the label */
634       } else if (dep == dim-2) {
635         ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
636         /* Split old edge: Faces in positive side cells and old split faces */
637         for (e = 0, q = 0; e < supportSize; ++e) {
638           PetscInt val;
639 
640           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
641           if ((val == dim-1) || (val == (shift + dim-1))) ++q;
642         }
643         ierr = DMPlexSetSupportSize(sdm, newp, q);CHKERRQ(ierr);
644         /* Split new edge: Faces in negative side cells and new split faces */
645         for (e = 0, q = 0; e < supportSize; ++e) {
646           PetscInt val;
647 
648           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
649           if ((val == dim-1) || (val == -(shift + dim-1))) ++q;
650         }
651         ierr = DMPlexSetSupportSize(sdm, splitp, q);CHKERRQ(ierr);
652       }
653     }
654   }
655   /* Step 4: Setup split DM */
656   ierr = DMSetUp(sdm);CHKERRQ(ierr);
657   ierr = DMPlexShiftPoints_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
658   /* Step 6: Set cones and supports for new points */
659   for (dep = 0; dep <= depth; ++dep) {
660     for (p = 0; p < numSplitPoints[dep]; ++p) {
661       const PetscInt  oldp   = splitPoints[dep][p];
662       const PetscInt  newp   = depthOffset[dep] + oldp;
663       const PetscInt  splitp = pMaxNew[dep] + p;
664       const PetscInt *cone, *support, *ornt;
665       PetscInt        coneSize, supportSize, q, v, e, s;
666 
667       ierr = DMPlexGetConeSize(dm, oldp, &coneSize);CHKERRQ(ierr);
668       ierr = DMPlexGetCone(dm, oldp, &cone);CHKERRQ(ierr);
669       ierr = DMPlexGetConeOrientation(dm, oldp, &ornt);CHKERRQ(ierr);
670       ierr = DMPlexGetSupportSize(dm, oldp, &supportSize);CHKERRQ(ierr);
671       ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
672       if (dep == depth-1) {
673         const PetscInt  ccell = pMaxNew[depth] + p;
674         const PetscInt *supportF;
675 
676         /* Split face:       copy in old face to new face to start */
677         ierr = DMPlexGetSupport(sdm, newp,  &supportF);CHKERRQ(ierr);
678         ierr = DMPlexSetSupport(sdm, splitp, supportF);CHKERRQ(ierr);
679         /* Split old face:   old vertices/edges in cone so no change */
680         /* Split new face:   new vertices/edges in cone */
681         for (q = 0; q < coneSize; ++q) {
682           ierr = PetscFindInt(cone[q], numSplitPoints[dim-2], splitPoints[dim-2], &v);CHKERRQ(ierr);
683 
684           coneNew[2+q] = pMaxNew[dim-2] + v;
685         }
686         ierr = DMPlexSetCone(sdm, splitp, &coneNew[2]);CHKERRQ(ierr);
687         ierr = DMPlexSetConeOrientation(sdm, splitp, ornt);CHKERRQ(ierr);
688         /* Cohesive cell:    Old and new split face, then new cohesive edges */
689         coneNew[0] = newp;   coneONew[0] = -coneSize; /* We know it has to be negative to be on the negative side */
690         coneNew[1] = splitp; coneONew[1] = coneONew[0];
691         for (q = 0; q < coneSize; ++q) {
692           coneNew[2+q]  = (pMaxNew[1] - pMaxNew[dim-2]) + (depthShift[1] - depthShift[0]) + coneNew[2+q];
693           coneONew[2+q] = 0;
694         }
695         ierr = DMPlexSetCone(sdm, ccell, coneNew);CHKERRQ(ierr);
696         ierr = DMPlexSetConeOrientation(sdm, ccell, coneONew);CHKERRQ(ierr);
697 
698         for (s = 0; s < supportSize; ++s) {
699           PetscInt val;
700 
701           ierr = DMLabelGetValue(label, support[s], &val);CHKERRQ(ierr);
702           if (val < 0) {
703             /* Split old face:   Replace negative side cell with cohesive cell */
704             ierr = DMPlexInsertSupport(sdm, newp, s, ccell);CHKERRQ(ierr);
705           } else {
706             /* Split new face:   Replace positive side cell with cohesive cell */
707             ierr = DMPlexInsertSupport(sdm, splitp, s, ccell);CHKERRQ(ierr);
708           }
709         }
710       } else if (dep == 0) {
711         const PetscInt cedge = pMaxNew[1] + (depthShift[1] - depthShift[0]) + p;
712 
713         /* Split old vertex: Edges in old split faces and new cohesive edge */
714         for (e = 0, q = 0; e < supportSize; ++e) {
715           PetscInt val;
716 
717           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
718           if ((val == 1) || (val == (shift + 1))) {
719             supportNew[q++] = depthOffset[1] + support[e];
720           }
721         }
722         supportNew[q] = cedge;
723 
724         ierr = DMPlexSetSupport(sdm, newp, supportNew);CHKERRQ(ierr);
725         /* Split new vertex: Edges in new split faces and new cohesive edge */
726         for (e = 0, q = 0; e < supportSize; ++e) {
727           PetscInt val, edge;
728 
729           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
730           if (val == 1) {
731             ierr = PetscFindInt(support[e], numSplitPoints[1], splitPoints[1], &edge);CHKERRQ(ierr);
732             if (edge < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Edge %d is not a split edge", support[e]);
733             supportNew[q++] = pMaxNew[1] + edge;
734           } else if (val == -(shift + 1)) {
735             supportNew[q++] = depthOffset[1] + support[e];
736           }
737         }
738         supportNew[q] = cedge;
739         ierr          = DMPlexSetSupport(sdm, splitp, supportNew);CHKERRQ(ierr);
740         /* Cohesive edge:    Old and new split vertex, punting on support */
741         coneNew[0] = newp;
742         coneNew[1] = splitp;
743         ierr       = DMPlexSetCone(sdm, cedge, coneNew);CHKERRQ(ierr);
744       } else if (dep == dim-2) {
745         /* Split old edge:   old vertices in cone so no change */
746         /* Split new edge:   new vertices in cone */
747         for (q = 0; q < coneSize; ++q) {
748           ierr = PetscFindInt(cone[q], numSplitPoints[dim-3], splitPoints[dim-3], &v);CHKERRQ(ierr);
749 
750           coneNew[q] = pMaxNew[dim-3] + v;
751         }
752         ierr = DMPlexSetCone(sdm, splitp, coneNew);CHKERRQ(ierr);
753         /* Split old edge: Faces in positive side cells and old split faces */
754         for (e = 0, q = 0; e < supportSize; ++e) {
755           PetscInt val;
756 
757           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
758           if ((val == dim-1) || (val == (shift + dim-1))) {
759             supportNew[q++] = depthOffset[dim-1] + support[e];
760           }
761         }
762         ierr = DMPlexSetSupport(sdm, newp, supportNew);CHKERRQ(ierr);
763         /* Split new edge: Faces in negative side cells and new split faces */
764         for (e = 0, q = 0; e < supportSize; ++e) {
765           PetscInt val, face;
766 
767           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
768           if (val == dim-1) {
769             ierr = PetscFindInt(support[e], numSplitPoints[dim-1], splitPoints[dim-1], &face);CHKERRQ(ierr);
770             if (face < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Face %d is not a split face", support[e]);
771             supportNew[q++] = pMaxNew[dim-1] + face;
772           } else if (val == -(shift + dim-1)) {
773             supportNew[q++] = depthOffset[dim-1] + support[e];
774           }
775         }
776         ierr = DMPlexSetSupport(sdm, splitp, supportNew);CHKERRQ(ierr);
777       }
778     }
779   }
780   /* Step 6b: Replace split points in negative side cones */
781   for (sp = 0; sp < numSP; ++sp) {
782     PetscInt        dep = values[sp];
783     IS              pIS;
784     PetscInt        numPoints;
785     const PetscInt *points;
786 
787     if (dep >= 0) continue;
788     ierr = DMLabelGetStratumIS(label, dep, &pIS);CHKERRQ(ierr);
789     if (!pIS) continue;
790     dep  = -dep - shift;
791     ierr = ISGetLocalSize(pIS, &numPoints);CHKERRQ(ierr);
792     ierr = ISGetIndices(pIS, &points);CHKERRQ(ierr);
793     for (p = 0; p < numPoints; ++p) {
794       const PetscInt  oldp = points[p];
795       const PetscInt  newp = depthOffset[dep] + oldp;
796       const PetscInt *cone;
797       PetscInt        coneSize, c;
798       PetscBool       replaced = PETSC_FALSE;
799 
800       /* Negative edge: replace split vertex */
801       /* Negative cell: replace split face */
802       ierr = DMPlexGetConeSize(sdm, newp, &coneSize);CHKERRQ(ierr);
803       ierr = DMPlexGetCone(sdm, newp, &cone);CHKERRQ(ierr);
804       for (c = 0; c < coneSize; ++c) {
805         const PetscInt coldp = cone[c] - depthOffset[dep-1];
806         PetscInt       csplitp, cp, val;
807 
808         ierr = DMLabelGetValue(label, coldp, &val);CHKERRQ(ierr);
809         if (val == dep-1) {
810           ierr = PetscFindInt(coldp, numSplitPoints[dep-1], splitPoints[dep-1], &cp);CHKERRQ(ierr);
811           if (cp < 0) SETERRQ2(comm, PETSC_ERR_ARG_WRONG, "Point %d is not a split point of dimension %d", oldp, dep-1);
812           csplitp  = pMaxNew[dep-1] + cp;
813           ierr     = DMPlexInsertCone(sdm, newp, c, csplitp);CHKERRQ(ierr);
814           replaced = PETSC_TRUE;
815         }
816       }
817       if (!replaced) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "The cone of point %d does not contain split points", oldp);
818     }
819     ierr = ISRestoreIndices(pIS, &points);CHKERRQ(ierr);
820     ierr = ISDestroy(&pIS);CHKERRQ(ierr);
821   }
822   /* Step 7: Stratify */
823   ierr = DMPlexStratify(sdm);CHKERRQ(ierr);
824   /* Step 8: Coordinates */
825   ierr = DMPlexShiftCoordinates_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
826   ierr = DMPlexGetCoordinateSection(sdm, &coordSection);CHKERRQ(ierr);
827   ierr = DMGetCoordinatesLocal(sdm, &coordinates);CHKERRQ(ierr);
828   ierr = VecGetArray(coordinates, &coords);CHKERRQ(ierr);
829   for (v = 0; v < (numSplitPoints ? numSplitPoints[0] : 0); ++v) {
830     const PetscInt newp   = depthOffset[0] + splitPoints[0][v];
831     const PetscInt splitp = pMaxNew[0] + v;
832     PetscInt       dof, off, soff, d;
833 
834     ierr = PetscSectionGetDof(coordSection, newp, &dof);CHKERRQ(ierr);
835     ierr = PetscSectionGetOffset(coordSection, newp, &off);CHKERRQ(ierr);
836     ierr = PetscSectionGetOffset(coordSection, splitp, &soff);CHKERRQ(ierr);
837     for (d = 0; d < dof; ++d) coords[soff+d] = coords[off+d];
838   }
839   ierr = VecRestoreArray(coordinates, &coords);CHKERRQ(ierr);
840   /* Step 9: SF, if I can figure this out we can split the mesh in parallel */
841   ierr = DMPlexShiftSF_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
842   /* Step 10: Labels */
843   ierr = DMPlexShiftLabels_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
844   ierr = DMPlexGetNumLabels(sdm, &numLabels);CHKERRQ(ierr);
845   for (dep = 0; dep <= depth; ++dep) {
846     for (p = 0; p < numSplitPoints[dep]; ++p) {
847       const PetscInt newp   = depthOffset[dep] + splitPoints[dep][p];
848       const PetscInt splitp = pMaxNew[dep] + p;
849       PetscInt       l;
850 
851       for (l = 0; l < numLabels; ++l) {
852         DMLabel     mlabel;
853         const char *lname;
854         PetscInt    val;
855 
856         ierr = DMPlexGetLabelName(sdm, l, &lname);CHKERRQ(ierr);
857         ierr = DMPlexGetLabel(sdm, lname, &mlabel);CHKERRQ(ierr);
858         ierr = DMLabelGetValue(mlabel, newp, &val);CHKERRQ(ierr);
859         if (val >= 0) {
860           ierr = DMLabelSetValue(mlabel, splitp, val);CHKERRQ(ierr);
861           if (dep == 0) {
862             const PetscInt cedge = pMaxNew[1] + (depthShift[1] - depthShift[0]) + p;
863             ierr = DMLabelSetValue(mlabel, cedge, val);CHKERRQ(ierr);
864           }
865         }
866       }
867     }
868   }
869   for (sp = 0; sp < numSP; ++sp) {
870     const PetscInt dep = values[sp];
871 
872     if ((dep < 0) || (dep > depth)) continue;
873     if (pointIS[dep]) {ierr = ISRestoreIndices(pointIS[dep], &splitPoints[dep]);CHKERRQ(ierr);}
874     ierr = ISDestroy(&pointIS[dep]);CHKERRQ(ierr);
875   }
876   if (label) {
877     ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
878     ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
879   }
880   ierr = DMPlexGetChart(sdm, NULL, &pEnd);CHKERRQ(ierr);
881   if (depth > 0) pMaxNew[0] += depthShift[0];        /* Account for shadow vertices */
882   if (depth > 1) pMaxNew[1]  = pEnd - depthShift[0]; /* There is a hybrid edge for every shadow vertex */
883   if (depth > 2) pMaxNew[2]  = -1;                   /* There are no hybrid faces */
884   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);
885   ierr = PetscFree6(depthShift, depthOffset, pMaxNew, coneNew, coneONew, supportNew);CHKERRQ(ierr);
886   ierr = PetscFree3(pointIS, numSplitPoints, splitPoints);CHKERRQ(ierr);
887   PetscFunctionReturn(0);
888 }
889 
890 #undef __FUNCT__
891 #define __FUNCT__ "DMPlexConstructCohesiveCells"
892 /*@C
893   DMPlexConstructCohesiveCells - Construct cohesive cells which split the face along an internal interface
894 
895   Collective on dm
896 
897   Input Parameters:
898 + dm - The original DM
899 - labelName - The label specifying the boundary faces (this could be auto-generated)
900 
901   Output Parameters:
902 - dmSplit - The new DM
903 
904   Level: developer
905 
906 .seealso: DMCreate(), DMPlexLabelCohesiveComplete()
907 @*/
908 PetscErrorCode DMPlexConstructCohesiveCells(DM dm, DMLabel label, DM *dmSplit)
909 {
910   DM             sdm;
911   PetscInt       dim;
912   PetscErrorCode ierr;
913 
914   PetscFunctionBegin;
915   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
916   PetscValidPointer(dmSplit, 4);
917   ierr = DMCreate(PetscObjectComm((PetscObject)dm), &sdm);CHKERRQ(ierr);
918   ierr = DMSetType(sdm, DMPLEX);CHKERRQ(ierr);
919   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
920   ierr = DMPlexSetDimension(sdm, dim);CHKERRQ(ierr);
921   switch (dim) {
922   case 2:
923   case 3:
924     ierr = DMPlexConstructCohesiveCells_Internal(dm, label, sdm);CHKERRQ(ierr);
925     break;
926   default:
927     SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot construct cohesive cells for dimension %d", dim);
928   }
929   *dmSplit = sdm;
930   PetscFunctionReturn(0);
931 }
932 
933 #undef __FUNCT__
934 #define __FUNCT__ "DMPlexLabelCohesiveComplete"
935 /*@
936   DMPlexLabelCohesiveComplete - Starting with a label marking vertices on an internal surface, we add all other mesh pieces
937   to complete the surface
938 
939   Input Parameters:
940 + dm - The DM
941 - label - A DMLabel marking the surface vertices
942 
943   Output Parameter:
944 . label - A DMLabel marking all surface points
945 
946   Level: developer
947 
948 .seealso: DMPlexConstructCohesiveCells(), DMPlexLabelComplete()
949 @*/
950 PetscErrorCode DMPlexLabelCohesiveComplete(DM dm, DMLabel label)
951 {
952   IS              dimIS;
953   const PetscInt *points;
954   PetscInt        shift = 100, dim, dep, cStart, cEnd, numPoints, p, val;
955   PetscErrorCode  ierr;
956 
957   PetscFunctionBegin;
958   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
959   /* Cell orientation for face gives the side of the fault */
960   ierr = DMLabelGetStratumIS(label, dim-1, &dimIS);CHKERRQ(ierr);
961   if (!dimIS) PetscFunctionReturn(0);
962   ierr = ISGetLocalSize(dimIS, &numPoints);CHKERRQ(ierr);
963   ierr = ISGetIndices(dimIS, &points);CHKERRQ(ierr);
964   for (p = 0; p < numPoints; ++p) {
965     const PetscInt *support;
966     PetscInt        supportSize, s;
967 
968     ierr = DMPlexGetSupportSize(dm, points[p], &supportSize);CHKERRQ(ierr);
969     if (supportSize != 2) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Split face %d has %d != 2 supports", points[p], supportSize);
970     ierr = DMPlexGetSupport(dm, points[p], &support);CHKERRQ(ierr);
971     for (s = 0; s < supportSize; ++s) {
972       const PetscInt *cone, *ornt;
973       PetscInt        coneSize, c;
974       PetscBool       pos = PETSC_TRUE;
975 
976       ierr = DMPlexGetConeSize(dm, support[s], &coneSize);CHKERRQ(ierr);
977       ierr = DMPlexGetCone(dm, support[s], &cone);CHKERRQ(ierr);
978       ierr = DMPlexGetConeOrientation(dm, support[s], &ornt);CHKERRQ(ierr);
979       for (c = 0; c < coneSize; ++c) {
980         if (cone[c] == points[p]) {
981           if (ornt[c] >= 0) {
982             ierr = DMLabelSetValue(label, support[s],   shift+dim);CHKERRQ(ierr);
983           } else {
984             ierr = DMLabelSetValue(label, support[s], -(shift+dim));CHKERRQ(ierr);
985             pos  = PETSC_FALSE;
986           }
987           break;
988         }
989       }
990       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]);
991       /* Put faces touching the fault in the label */
992       for (c = 0; c < coneSize; ++c) {
993         const PetscInt point = cone[c];
994 
995         ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
996         if (val == -1) {
997           PetscInt *closure = NULL;
998           PetscInt  closureSize, cl;
999 
1000           ierr = DMPlexGetTransitiveClosure(dm, point, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1001           for (cl = 0; cl < closureSize*2; cl += 2) {
1002             const PetscInt clp = closure[cl];
1003 
1004             ierr = DMLabelGetValue(label, clp, &val);CHKERRQ(ierr);
1005             if ((val >= 0) && (val < dim-1)) {
1006               ierr = DMLabelSetValue(label, point, pos == PETSC_TRUE ? shift+dim-1 : -(shift+dim-1));CHKERRQ(ierr);
1007               break;
1008             }
1009           }
1010           ierr = DMPlexRestoreTransitiveClosure(dm, point, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1011         }
1012       }
1013     }
1014   }
1015   ierr = ISRestoreIndices(dimIS, &points);CHKERRQ(ierr);
1016   ierr = ISDestroy(&dimIS);CHKERRQ(ierr);
1017   /* Search for other cells/faces/edges connected to the fault by a vertex */
1018   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
1019   ierr = DMLabelGetStratumIS(label, 0, &dimIS);CHKERRQ(ierr);
1020   if (!dimIS) PetscFunctionReturn(0);
1021   ierr = ISGetLocalSize(dimIS, &numPoints);CHKERRQ(ierr);
1022   ierr = ISGetIndices(dimIS, &points);CHKERRQ(ierr);
1023   for (p = 0; p < numPoints; ++p) {
1024     PetscInt *star = NULL;
1025     PetscInt  starSize, s;
1026     PetscInt  again = 1;  /* 0: Finished 1: Keep iterating after a change 2: No change */
1027 
1028     /* First mark cells connected to the fault */
1029     ierr = DMPlexGetTransitiveClosure(dm, points[p], PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1030     while (again) {
1031       if (again > 1) SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Could not classify all cells connected to the fault");
1032       again = 0;
1033       for (s = 0; s < starSize*2; s += 2) {
1034         const PetscInt  point = star[s];
1035         const PetscInt *cone;
1036         PetscInt        coneSize, c;
1037 
1038         if ((point < cStart) || (point >= cEnd)) continue;
1039         ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
1040         if (val != -1) continue;
1041         again = 2;
1042         ierr  = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
1043         ierr  = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
1044         for (c = 0; c < coneSize; ++c) {
1045           ierr = DMLabelGetValue(label, cone[c], &val);CHKERRQ(ierr);
1046           if (val != -1) {
1047             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);
1048             if (val > 0) {
1049               ierr = DMLabelSetValue(label, point,   shift+dim);CHKERRQ(ierr);
1050             } else {
1051               ierr = DMLabelSetValue(label, point, -(shift+dim));CHKERRQ(ierr);
1052             }
1053             again = 1;
1054             break;
1055           }
1056         }
1057       }
1058     }
1059     /* Classify the rest by cell membership */
1060     for (s = 0; s < starSize*2; s += 2) {
1061       const PetscInt point = star[s];
1062 
1063       ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
1064       if (val == -1) {
1065         PetscInt  *sstar = NULL;
1066         PetscInt   sstarSize, ss;
1067         PetscBool  marked = PETSC_FALSE;
1068 
1069         ierr = DMPlexGetTransitiveClosure(dm, point, PETSC_FALSE, &sstarSize, &sstar);CHKERRQ(ierr);
1070         for (ss = 0; ss < sstarSize*2; ss += 2) {
1071           const PetscInt spoint = sstar[ss];
1072 
1073           if ((spoint < cStart) || (spoint >= cEnd)) continue;
1074           ierr = DMLabelGetValue(label, spoint, &val);CHKERRQ(ierr);
1075           if (val == -1) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Cell %d in star of %d does not have a valid label", spoint, point);
1076           ierr = DMPlexGetLabelValue(dm, "depth", point, &dep);CHKERRQ(ierr);
1077           if (val > 0) {
1078             ierr = DMLabelSetValue(label, point,   shift+dep);CHKERRQ(ierr);
1079           } else {
1080             ierr = DMLabelSetValue(label, point, -(shift+dep));CHKERRQ(ierr);
1081           }
1082           marked = PETSC_TRUE;
1083           break;
1084         }
1085         ierr = DMPlexRestoreTransitiveClosure(dm, point, PETSC_FALSE, &sstarSize, &sstar);CHKERRQ(ierr);
1086         if (!marked) SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Point %d could not be classified", point);
1087       }
1088     }
1089     ierr = DMPlexRestoreTransitiveClosure(dm, points[p], PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1090   }
1091   ierr = ISRestoreIndices(dimIS, &points);CHKERRQ(ierr);
1092   ierr = ISDestroy(&dimIS);CHKERRQ(ierr);
1093   PetscFunctionReturn(0);
1094 }
1095 
1096 #undef __FUNCT__
1097 #define __FUNCT__ "DMPlexMarkSubmesh_Uninterpolated"
1098 /* Here we need the explicit assumption that:
1099 
1100      For any marked cell, the marked vertices constitute a single face
1101 */
1102 static PetscErrorCode DMPlexMarkSubmesh_Uninterpolated(DM dm, DMLabel vertexLabel, PetscInt value, DMLabel subpointMap, PetscInt *numFaces, PetscInt *nFV, DM subdm)
1103 {
1104   IS               subvertexIS;
1105   const PetscInt  *subvertices;
1106   PetscInt        *pStart, *pEnd, *pMax, pSize;
1107   PetscInt         depth, dim, d, numSubVerticesInitial = 0, v;
1108   PetscErrorCode   ierr;
1109 
1110   PetscFunctionBegin;
1111   *numFaces = 0;
1112   *nFV      = 0;
1113   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
1114   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1115   pSize = PetscMax(depth, dim) + 1;
1116   ierr = PetscMalloc3(pSize,PetscInt,&pStart,pSize,PetscInt,&pEnd,pSize,PetscInt,&pMax);CHKERRQ(ierr);
1117   ierr = DMPlexGetHybridBounds(dm, &pMax[depth], depth>1 ? &pMax[depth-1] : NULL, depth > 2 ? &pMax[1] : NULL, &pMax[0]);CHKERRQ(ierr);
1118   for (d = 0; d <= depth; ++d) {
1119     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1120     if (pMax[d] >= 0) pEnd[d] = PetscMin(pEnd[d], pMax[d]);
1121   }
1122   /* Loop over initial vertices and mark all faces in the collective star() */
1123   ierr = DMLabelGetStratumIS(vertexLabel, value, &subvertexIS);CHKERRQ(ierr);
1124   if (subvertexIS) {
1125     ierr = ISGetSize(subvertexIS, &numSubVerticesInitial);CHKERRQ(ierr);
1126     ierr = ISGetIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1127   }
1128   for (v = 0; v < numSubVerticesInitial; ++v) {
1129     const PetscInt vertex = subvertices[v];
1130     PetscInt      *star   = NULL;
1131     PetscInt       starSize, s, numCells = 0, c;
1132 
1133     ierr = DMPlexGetTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1134     for (s = 0; s < starSize*2; s += 2) {
1135       const PetscInt point = star[s];
1136       if ((point >= pStart[depth]) && (point < pEnd[depth])) star[numCells++] = point;
1137     }
1138     for (c = 0; c < numCells; ++c) {
1139       const PetscInt cell    = star[c];
1140       PetscInt      *closure = NULL;
1141       PetscInt       closureSize, cl;
1142       PetscInt       cellLoc, numCorners = 0, faceSize = 0;
1143 
1144       ierr = DMLabelGetValue(subpointMap, cell, &cellLoc);CHKERRQ(ierr);
1145       if (cellLoc == 2) continue;
1146       if (cellLoc >= 0) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Cell %d has dimension %d in the surface label", cell, cellLoc);
1147       ierr = DMPlexGetTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1148       for (cl = 0; cl < closureSize*2; cl += 2) {
1149         const PetscInt point = closure[cl];
1150         PetscInt       vertexLoc;
1151 
1152         if ((point >= pStart[0]) && (point < pEnd[0])) {
1153           ++numCorners;
1154           ierr = DMLabelGetValue(vertexLabel, point, &vertexLoc);CHKERRQ(ierr);
1155           if (vertexLoc == value) closure[faceSize++] = point;
1156         }
1157       }
1158       if (!(*nFV)) {ierr = DMPlexGetNumFaceVertices(dm, dim, numCorners, nFV);CHKERRQ(ierr);}
1159       if (faceSize > *nFV) SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Invalid submesh: Too many vertices %d of an element on the surface", faceSize);
1160       if (faceSize == *nFV) {
1161         const PetscInt *cells = NULL;
1162         PetscInt        numCells, nc;
1163 
1164         ++(*numFaces);
1165         for (cl = 0; cl < faceSize; ++cl) {
1166           ierr = DMLabelSetValue(subpointMap, closure[cl], 0);CHKERRQ(ierr);
1167         }
1168         ierr = DMPlexGetJoin(dm, faceSize, closure, &numCells, &cells);CHKERRQ(ierr);
1169         for (nc = 0; nc < numCells; ++nc) {
1170           ierr = DMLabelSetValue(subpointMap, cells[nc], 2);CHKERRQ(ierr);
1171         }
1172         ierr = DMPlexRestoreJoin(dm, faceSize, closure, &numCells, &cells);CHKERRQ(ierr);
1173       }
1174       ierr = DMPlexRestoreTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1175     }
1176     ierr = DMPlexRestoreTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1177   }
1178   if (subvertexIS) {
1179     ierr = ISRestoreIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1180   }
1181   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
1182   ierr = PetscFree3(pStart,pEnd,pMax);CHKERRQ(ierr);
1183   PetscFunctionReturn(0);
1184 }
1185 
1186 #undef __FUNCT__
1187 #define __FUNCT__ "DMPlexMarkSubmesh_Interpolated"
1188 static PetscErrorCode DMPlexMarkSubmesh_Interpolated(DM dm, DMLabel vertexLabel, PetscInt value, DMLabel subpointMap, DM subdm)
1189 {
1190   IS               subvertexIS;
1191   const PetscInt  *subvertices;
1192   PetscInt        *pStart, *pEnd, *pMax;
1193   PetscInt         dim, d, numSubVerticesInitial = 0, v;
1194   PetscErrorCode   ierr;
1195 
1196   PetscFunctionBegin;
1197   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1198   ierr = PetscMalloc3(dim+1,PetscInt,&pStart,dim+1,PetscInt,&pEnd,dim+1,PetscInt,&pMax);CHKERRQ(ierr);
1199   ierr = DMPlexGetHybridBounds(dm, &pMax[dim], dim>1 ? &pMax[dim-1] : NULL, dim > 2 ? &pMax[1] : NULL, &pMax[0]);CHKERRQ(ierr);
1200   for (d = 0; d <= dim; ++d) {
1201     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1202     if (pMax[d] >= 0) pEnd[d] = PetscMin(pEnd[d], pMax[d]);
1203   }
1204   /* Loop over initial vertices and mark all faces in the collective star() */
1205   ierr = DMLabelGetStratumIS(vertexLabel, value, &subvertexIS);CHKERRQ(ierr);
1206   if (subvertexIS) {
1207     ierr = ISGetSize(subvertexIS, &numSubVerticesInitial);CHKERRQ(ierr);
1208     ierr = ISGetIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1209   }
1210   for (v = 0; v < numSubVerticesInitial; ++v) {
1211     const PetscInt vertex = subvertices[v];
1212     PetscInt      *star   = NULL;
1213     PetscInt       starSize, s, numFaces = 0, f;
1214 
1215     ierr = DMPlexGetTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1216     for (s = 0; s < starSize*2; s += 2) {
1217       const PetscInt point = star[s];
1218       if ((point >= pStart[dim-1]) && (point < pEnd[dim-1])) star[numFaces++] = point;
1219     }
1220     for (f = 0; f < numFaces; ++f) {
1221       const PetscInt face    = star[f];
1222       PetscInt      *closure = NULL;
1223       PetscInt       closureSize, c;
1224       PetscInt       faceLoc;
1225 
1226       ierr = DMLabelGetValue(subpointMap, face, &faceLoc);CHKERRQ(ierr);
1227       if (faceLoc == dim-1) continue;
1228       if (faceLoc >= 0) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Face %d has dimension %d in the surface label", face, faceLoc);
1229       ierr = DMPlexGetTransitiveClosure(dm, face, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1230       for (c = 0; c < closureSize*2; c += 2) {
1231         const PetscInt point = closure[c];
1232         PetscInt       vertexLoc;
1233 
1234         if ((point >= pStart[0]) && (point < pEnd[0])) {
1235           ierr = DMLabelGetValue(vertexLabel, point, &vertexLoc);CHKERRQ(ierr);
1236           if (vertexLoc != value) break;
1237         }
1238       }
1239       if (c == closureSize*2) {
1240         const PetscInt *support;
1241         PetscInt        supportSize, s;
1242 
1243         for (c = 0; c < closureSize*2; c += 2) {
1244           const PetscInt point = closure[c];
1245 
1246           for (d = 0; d < dim; ++d) {
1247             if ((point >= pStart[d]) && (point < pEnd[d])) {
1248               ierr = DMLabelSetValue(subpointMap, point, d);CHKERRQ(ierr);
1249               break;
1250             }
1251           }
1252         }
1253         ierr = DMPlexGetSupportSize(dm, face, &supportSize);CHKERRQ(ierr);
1254         ierr = DMPlexGetSupport(dm, face, &support);CHKERRQ(ierr);
1255         for (s = 0; s < supportSize; ++s) {
1256           ierr = DMLabelSetValue(subpointMap, support[s], dim);CHKERRQ(ierr);
1257         }
1258       }
1259       ierr = DMPlexRestoreTransitiveClosure(dm, face, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1260     }
1261     ierr = DMPlexRestoreTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1262   }
1263   if (subvertexIS) {
1264     ierr = ISRestoreIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1265   }
1266   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
1267   ierr = PetscFree3(pStart,pEnd,pMax);CHKERRQ(ierr);
1268   PetscFunctionReturn(0);
1269 }
1270 
1271 #undef __FUNCT__
1272 #define __FUNCT__ "DMPlexMarkCohesiveSubmesh_Uninterpolated"
1273 static PetscErrorCode DMPlexMarkCohesiveSubmesh_Uninterpolated(DM dm, PetscBool hasLagrange, DMLabel subpointMap, PetscInt *numFaces, PetscInt *nFV, PetscInt *subCells[], DM subdm)
1274 {
1275   const PetscInt *cone;
1276   PetscInt        dim, cMax, cEnd, c, p, coneSize;
1277   PetscErrorCode  ierr;
1278 
1279   PetscFunctionBegin;
1280   *numFaces = 0;
1281   *nFV = 0;
1282   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1283   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
1284   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
1285   if (cMax < 0) PetscFunctionReturn(0);
1286   ierr = DMPlexGetConeSize(dm, cMax, &coneSize);CHKERRQ(ierr);
1287   *numFaces = cEnd - cMax;
1288   *nFV      = hasLagrange ? coneSize/3 : coneSize/2;
1289   ierr = PetscMalloc(*numFaces *2 * sizeof(PetscInt), subCells);CHKERRQ(ierr);
1290   for (c = cMax; c < cEnd; ++c) {
1291     const PetscInt *cells;
1292     PetscInt        numCells;
1293 
1294     ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
1295     for (p = 0; p < *nFV; ++p) {
1296       ierr = DMLabelSetValue(subpointMap, cone[p], 0);CHKERRQ(ierr);
1297     }
1298     /* Negative face */
1299     ierr = DMPlexGetJoin(dm, *nFV, cone, &numCells, &cells);CHKERRQ(ierr);
1300     if (numCells != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
1301     for (p = 0; p < numCells; ++p) {
1302       ierr = DMLabelSetValue(subpointMap, cells[p], 2);CHKERRQ(ierr);
1303       (*subCells)[(c-cMax)*2+p] = cells[p];
1304     }
1305     ierr = DMPlexRestoreJoin(dm, *nFV, cone, &numCells, &cells);CHKERRQ(ierr);
1306     /* Positive face is not included */
1307   }
1308   PetscFunctionReturn(0);
1309 }
1310 
1311 #undef __FUNCT__
1312 #define __FUNCT__ "DMPlexMarkCohesiveSubmesh_Interpolated"
1313 static PetscErrorCode DMPlexMarkCohesiveSubmesh_Interpolated(DM dm, PetscBool hasLagrange, DMLabel subpointMap, DM subdm)
1314 {
1315   PetscInt      *pStart, *pEnd;
1316   PetscInt       dim, cMax, cEnd, c, d;
1317   PetscErrorCode ierr;
1318 
1319   PetscFunctionBegin;
1320   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1321   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
1322   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
1323   if (cMax < 0) PetscFunctionReturn(0);
1324   ierr = PetscMalloc2(dim+1,PetscInt,&pStart,dim+1,PetscInt,&pEnd);CHKERRQ(ierr);
1325   for (d = 0; d <= dim; ++d) {
1326     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1327   }
1328   for (c = cMax; c < cEnd; ++c) {
1329     const PetscInt *cone;
1330     PetscInt       *closure = NULL;
1331     PetscInt        coneSize, closureSize, cl;
1332 
1333     ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
1334     if (hasLagrange) {
1335       if (coneSize != 3) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
1336     } else {
1337       if (coneSize != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
1338     }
1339     /* Negative face */
1340     ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
1341     ierr = DMPlexGetTransitiveClosure(dm, cone[0], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1342     for (cl = 0; cl < closureSize*2; cl += 2) {
1343       const PetscInt point = closure[cl];
1344 
1345       for (d = 0; d <= dim; ++d) {
1346         if ((point >= pStart[d]) && (point < pEnd[d])) {
1347           ierr = DMLabelSetValue(subpointMap, point, d);CHKERRQ(ierr);
1348           break;
1349         }
1350       }
1351     }
1352     ierr = DMPlexRestoreTransitiveClosure(dm, cone[0], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1353     /* Cells -- positive face is not included */
1354     for (cl = 0; cl < 1; ++cl) {
1355       const PetscInt *support;
1356       PetscInt        supportSize, s;
1357 
1358       ierr = DMPlexGetSupportSize(dm, cone[cl], &supportSize);CHKERRQ(ierr);
1359       if (supportSize != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive faces should separate two cells");
1360       ierr = DMPlexGetSupport(dm, cone[cl], &support);CHKERRQ(ierr);
1361       for (s = 0; s < supportSize; ++s) {
1362         ierr = DMLabelSetValue(subpointMap, support[s], dim);CHKERRQ(ierr);
1363       }
1364     }
1365   }
1366   ierr = PetscFree2(pStart, pEnd);CHKERRQ(ierr);
1367   PetscFunctionReturn(0);
1368 }
1369 
1370 #undef __FUNCT__
1371 #define __FUNCT__ "DMPlexGetFaceOrientation"
1372 PetscErrorCode DMPlexGetFaceOrientation(DM dm, PetscInt cell, PetscInt numCorners, PetscInt indices[], PetscInt oppositeVertex, PetscInt origVertices[], PetscInt faceVertices[], PetscBool *posOriented)
1373 {
1374   MPI_Comm       comm;
1375   PetscBool      posOrient = PETSC_FALSE;
1376   const PetscInt debug     = 0;
1377   PetscInt       cellDim, faceSize, f;
1378   PetscErrorCode ierr;
1379 
1380   PetscFunctionBegin;
1381   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1382   ierr = DMPlexGetDimension(dm, &cellDim);CHKERRQ(ierr);
1383   if (debug) {PetscPrintf(comm, "cellDim: %d numCorners: %d\n", cellDim, numCorners);CHKERRQ(ierr);}
1384 
1385   if (cellDim == numCorners-1) {
1386     /* Simplices */
1387     faceSize  = numCorners-1;
1388     posOrient = !(oppositeVertex%2) ? PETSC_TRUE : PETSC_FALSE;
1389   } else if (cellDim == 1 && numCorners == 3) {
1390     /* Quadratic line */
1391     faceSize  = 1;
1392     posOrient = PETSC_TRUE;
1393   } else if (cellDim == 2 && numCorners == 4) {
1394     /* Quads */
1395     faceSize = 2;
1396     if ((indices[1] > indices[0]) && (indices[1] - indices[0] == 1)) {
1397       posOrient = PETSC_TRUE;
1398     } else if ((indices[0] == 3) && (indices[1] == 0)) {
1399       posOrient = PETSC_TRUE;
1400     } else {
1401       if (((indices[0] > indices[1]) && (indices[0] - indices[1] == 1)) || ((indices[0] == 0) && (indices[1] == 3))) {
1402         posOrient = PETSC_FALSE;
1403       } else SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid quad crossedge");
1404     }
1405   } else if (cellDim == 2 && numCorners == 6) {
1406     /* Quadratic triangle (I hate this) */
1407     /* Edges are determined by the first 2 vertices (corners of edges) */
1408     const PetscInt faceSizeTri = 3;
1409     PetscInt       sortedIndices[3], i, iFace;
1410     PetscBool      found                    = PETSC_FALSE;
1411     PetscInt       faceVerticesTriSorted[9] = {
1412       0, 3,  4, /* bottom */
1413       1, 4,  5, /* right */
1414       2, 3,  5, /* left */
1415     };
1416     PetscInt       faceVerticesTri[9] = {
1417       0, 3,  4, /* bottom */
1418       1, 4,  5, /* right */
1419       2, 5,  3, /* left */
1420     };
1421 
1422     faceSize = faceSizeTri;
1423     for (i = 0; i < faceSizeTri; ++i) sortedIndices[i] = indices[i];
1424     ierr = PetscSortInt(faceSizeTri, sortedIndices);CHKERRQ(ierr);
1425     for (iFace = 0; iFace < 3; ++iFace) {
1426       const PetscInt ii = iFace*faceSizeTri;
1427       PetscInt       fVertex, cVertex;
1428 
1429       if ((sortedIndices[0] == faceVerticesTriSorted[ii+0]) &&
1430           (sortedIndices[1] == faceVerticesTriSorted[ii+1])) {
1431         for (fVertex = 0; fVertex < faceSizeTri; ++fVertex) {
1432           for (cVertex = 0; cVertex < faceSizeTri; ++cVertex) {
1433             if (indices[cVertex] == faceVerticesTri[ii+fVertex]) {
1434               faceVertices[fVertex] = origVertices[cVertex];
1435               break;
1436             }
1437           }
1438         }
1439         found = PETSC_TRUE;
1440         break;
1441       }
1442     }
1443     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid tri crossface");
1444     if (posOriented) *posOriented = PETSC_TRUE;
1445     PetscFunctionReturn(0);
1446   } else if (cellDim == 2 && numCorners == 9) {
1447     /* Quadratic quad (I hate this) */
1448     /* Edges are determined by the first 2 vertices (corners of edges) */
1449     const PetscInt faceSizeQuad = 3;
1450     PetscInt       sortedIndices[3], i, iFace;
1451     PetscBool      found                      = PETSC_FALSE;
1452     PetscInt       faceVerticesQuadSorted[12] = {
1453       0, 1,  4, /* bottom */
1454       1, 2,  5, /* right */
1455       2, 3,  6, /* top */
1456       0, 3,  7, /* left */
1457     };
1458     PetscInt       faceVerticesQuad[12] = {
1459       0, 1,  4, /* bottom */
1460       1, 2,  5, /* right */
1461       2, 3,  6, /* top */
1462       3, 0,  7, /* left */
1463     };
1464 
1465     faceSize = faceSizeQuad;
1466     for (i = 0; i < faceSizeQuad; ++i) sortedIndices[i] = indices[i];
1467     ierr = PetscSortInt(faceSizeQuad, sortedIndices);CHKERRQ(ierr);
1468     for (iFace = 0; iFace < 4; ++iFace) {
1469       const PetscInt ii = iFace*faceSizeQuad;
1470       PetscInt       fVertex, cVertex;
1471 
1472       if ((sortedIndices[0] == faceVerticesQuadSorted[ii+0]) &&
1473           (sortedIndices[1] == faceVerticesQuadSorted[ii+1])) {
1474         for (fVertex = 0; fVertex < faceSizeQuad; ++fVertex) {
1475           for (cVertex = 0; cVertex < faceSizeQuad; ++cVertex) {
1476             if (indices[cVertex] == faceVerticesQuad[ii+fVertex]) {
1477               faceVertices[fVertex] = origVertices[cVertex];
1478               break;
1479             }
1480           }
1481         }
1482         found = PETSC_TRUE;
1483         break;
1484       }
1485     }
1486     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid quad crossface");
1487     if (posOriented) *posOriented = PETSC_TRUE;
1488     PetscFunctionReturn(0);
1489   } else if (cellDim == 3 && numCorners == 8) {
1490     /* Hexes
1491        A hex is two oriented quads with the normal of the first
1492        pointing up at the second.
1493 
1494           7---6
1495          /|  /|
1496         4---5 |
1497         | 3-|-2
1498         |/  |/
1499         0---1
1500 
1501         Faces are determined by the first 4 vertices (corners of faces) */
1502     const PetscInt faceSizeHex = 4;
1503     PetscInt       sortedIndices[4], i, iFace;
1504     PetscBool      found                     = PETSC_FALSE;
1505     PetscInt       faceVerticesHexSorted[24] = {
1506       0, 1, 2, 3,  /* bottom */
1507       4, 5, 6, 7,  /* top */
1508       0, 1, 4, 5,  /* front */
1509       1, 2, 5, 6,  /* right */
1510       2, 3, 6, 7,  /* back */
1511       0, 3, 4, 7,  /* left */
1512     };
1513     PetscInt       faceVerticesHex[24] = {
1514       3, 2, 1, 0,  /* bottom */
1515       4, 5, 6, 7,  /* top */
1516       0, 1, 5, 4,  /* front */
1517       1, 2, 6, 5,  /* right */
1518       2, 3, 7, 6,  /* back */
1519       3, 0, 4, 7,  /* left */
1520     };
1521 
1522     faceSize = faceSizeHex;
1523     for (i = 0; i < faceSizeHex; ++i) sortedIndices[i] = indices[i];
1524     ierr = PetscSortInt(faceSizeHex, sortedIndices);CHKERRQ(ierr);
1525     for (iFace = 0; iFace < 6; ++iFace) {
1526       const PetscInt ii = iFace*faceSizeHex;
1527       PetscInt       fVertex, cVertex;
1528 
1529       if ((sortedIndices[0] == faceVerticesHexSorted[ii+0]) &&
1530           (sortedIndices[1] == faceVerticesHexSorted[ii+1]) &&
1531           (sortedIndices[2] == faceVerticesHexSorted[ii+2]) &&
1532           (sortedIndices[3] == faceVerticesHexSorted[ii+3])) {
1533         for (fVertex = 0; fVertex < faceSizeHex; ++fVertex) {
1534           for (cVertex = 0; cVertex < faceSizeHex; ++cVertex) {
1535             if (indices[cVertex] == faceVerticesHex[ii+fVertex]) {
1536               faceVertices[fVertex] = origVertices[cVertex];
1537               break;
1538             }
1539           }
1540         }
1541         found = PETSC_TRUE;
1542         break;
1543       }
1544     }
1545     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid hex crossface");
1546     if (posOriented) *posOriented = PETSC_TRUE;
1547     PetscFunctionReturn(0);
1548   } else if (cellDim == 3 && numCorners == 10) {
1549     /* Quadratic tet */
1550     /* Faces are determined by the first 3 vertices (corners of faces) */
1551     const PetscInt faceSizeTet = 6;
1552     PetscInt       sortedIndices[6], i, iFace;
1553     PetscBool      found                     = PETSC_FALSE;
1554     PetscInt       faceVerticesTetSorted[24] = {
1555       0, 1, 2,  6, 7, 8, /* bottom */
1556       0, 3, 4,  6, 7, 9,  /* front */
1557       1, 4, 5,  7, 8, 9,  /* right */
1558       2, 3, 5,  6, 8, 9,  /* left */
1559     };
1560     PetscInt       faceVerticesTet[24] = {
1561       0, 1, 2,  6, 7, 8, /* bottom */
1562       0, 4, 3,  6, 7, 9,  /* front */
1563       1, 5, 4,  7, 8, 9,  /* right */
1564       2, 3, 5,  8, 6, 9,  /* left */
1565     };
1566 
1567     faceSize = faceSizeTet;
1568     for (i = 0; i < faceSizeTet; ++i) sortedIndices[i] = indices[i];
1569     ierr = PetscSortInt(faceSizeTet, sortedIndices);CHKERRQ(ierr);
1570     for (iFace=0; iFace < 4; ++iFace) {
1571       const PetscInt ii = iFace*faceSizeTet;
1572       PetscInt       fVertex, cVertex;
1573 
1574       if ((sortedIndices[0] == faceVerticesTetSorted[ii+0]) &&
1575           (sortedIndices[1] == faceVerticesTetSorted[ii+1]) &&
1576           (sortedIndices[2] == faceVerticesTetSorted[ii+2]) &&
1577           (sortedIndices[3] == faceVerticesTetSorted[ii+3])) {
1578         for (fVertex = 0; fVertex < faceSizeTet; ++fVertex) {
1579           for (cVertex = 0; cVertex < faceSizeTet; ++cVertex) {
1580             if (indices[cVertex] == faceVerticesTet[ii+fVertex]) {
1581               faceVertices[fVertex] = origVertices[cVertex];
1582               break;
1583             }
1584           }
1585         }
1586         found = PETSC_TRUE;
1587         break;
1588       }
1589     }
1590     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid tet crossface");
1591     if (posOriented) *posOriented = PETSC_TRUE;
1592     PetscFunctionReturn(0);
1593   } else if (cellDim == 3 && numCorners == 27) {
1594     /* Quadratic hexes (I hate this)
1595        A hex is two oriented quads with the normal of the first
1596        pointing up at the second.
1597 
1598          7---6
1599         /|  /|
1600        4---5 |
1601        | 3-|-2
1602        |/  |/
1603        0---1
1604 
1605        Faces are determined by the first 4 vertices (corners of faces) */
1606     const PetscInt faceSizeQuadHex = 9;
1607     PetscInt       sortedIndices[9], i, iFace;
1608     PetscBool      found                         = PETSC_FALSE;
1609     PetscInt       faceVerticesQuadHexSorted[54] = {
1610       0, 1, 2, 3,  8, 9, 10, 11,  24, /* bottom */
1611       4, 5, 6, 7,  12, 13, 14, 15,  25, /* top */
1612       0, 1, 4, 5,  8, 12, 16, 17,  22, /* front */
1613       1, 2, 5, 6,  9, 13, 17, 18,  21, /* right */
1614       2, 3, 6, 7,  10, 14, 18, 19,  23, /* back */
1615       0, 3, 4, 7,  11, 15, 16, 19,  20, /* left */
1616     };
1617     PetscInt       faceVerticesQuadHex[54] = {
1618       3, 2, 1, 0,  10, 9, 8, 11,  24, /* bottom */
1619       4, 5, 6, 7,  12, 13, 14, 15,  25, /* top */
1620       0, 1, 5, 4,  8, 17, 12, 16,  22, /* front */
1621       1, 2, 6, 5,  9, 18, 13, 17,  21, /* right */
1622       2, 3, 7, 6,  10, 19, 14, 18,  23, /* back */
1623       3, 0, 4, 7,  11, 16, 15, 19,  20 /* left */
1624     };
1625 
1626     faceSize = faceSizeQuadHex;
1627     for (i = 0; i < faceSizeQuadHex; ++i) sortedIndices[i] = indices[i];
1628     ierr = PetscSortInt(faceSizeQuadHex, sortedIndices);CHKERRQ(ierr);
1629     for (iFace = 0; iFace < 6; ++iFace) {
1630       const PetscInt ii = iFace*faceSizeQuadHex;
1631       PetscInt       fVertex, cVertex;
1632 
1633       if ((sortedIndices[0] == faceVerticesQuadHexSorted[ii+0]) &&
1634           (sortedIndices[1] == faceVerticesQuadHexSorted[ii+1]) &&
1635           (sortedIndices[2] == faceVerticesQuadHexSorted[ii+2]) &&
1636           (sortedIndices[3] == faceVerticesQuadHexSorted[ii+3])) {
1637         for (fVertex = 0; fVertex < faceSizeQuadHex; ++fVertex) {
1638           for (cVertex = 0; cVertex < faceSizeQuadHex; ++cVertex) {
1639             if (indices[cVertex] == faceVerticesQuadHex[ii+fVertex]) {
1640               faceVertices[fVertex] = origVertices[cVertex];
1641               break;
1642             }
1643           }
1644         }
1645         found = PETSC_TRUE;
1646         break;
1647       }
1648     }
1649     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid hex crossface");
1650     if (posOriented) *posOriented = PETSC_TRUE;
1651     PetscFunctionReturn(0);
1652   } else SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Unknown cell type for faceOrientation().");
1653   if (!posOrient) {
1654     if (debug) {ierr = PetscPrintf(comm, "  Reversing initial face orientation\n");CHKERRQ(ierr);}
1655     for (f = 0; f < faceSize; ++f) faceVertices[f] = origVertices[faceSize-1 - f];
1656   } else {
1657     if (debug) {ierr = PetscPrintf(comm, "  Keeping initial face orientation\n");CHKERRQ(ierr);}
1658     for (f = 0; f < faceSize; ++f) faceVertices[f] = origVertices[f];
1659   }
1660   if (posOriented) *posOriented = posOrient;
1661   PetscFunctionReturn(0);
1662 }
1663 
1664 #undef __FUNCT__
1665 #define __FUNCT__ "DMPlexGetOrientedFace"
1666 /*
1667     Given a cell and a face, as a set of vertices,
1668       return the oriented face, as a set of vertices, in faceVertices
1669     The orientation is such that the face normal points out of the cell
1670 */
1671 PetscErrorCode DMPlexGetOrientedFace(DM dm, PetscInt cell, PetscInt faceSize, const PetscInt face[], PetscInt numCorners, PetscInt indices[], PetscInt origVertices[], PetscInt faceVertices[], PetscBool *posOriented)
1672 {
1673   const PetscInt *cone = NULL;
1674   PetscInt        coneSize, v, f, v2;
1675   PetscInt        oppositeVertex = -1;
1676   PetscErrorCode  ierr;
1677 
1678   PetscFunctionBegin;
1679   ierr = DMPlexGetConeSize(dm, cell, &coneSize);CHKERRQ(ierr);
1680   ierr = DMPlexGetCone(dm, cell, &cone);CHKERRQ(ierr);
1681   for (v = 0, v2 = 0; v < coneSize; ++v) {
1682     PetscBool found = PETSC_FALSE;
1683 
1684     for (f = 0; f < faceSize; ++f) {
1685       if (face[f] == cone[v]) {
1686         found = PETSC_TRUE; break;
1687       }
1688     }
1689     if (found) {
1690       indices[v2]      = v;
1691       origVertices[v2] = cone[v];
1692       ++v2;
1693     } else {
1694       oppositeVertex = v;
1695     }
1696   }
1697   ierr = DMPlexGetFaceOrientation(dm, cell, numCorners, indices, oppositeVertex, origVertices, faceVertices, posOriented);CHKERRQ(ierr);
1698   PetscFunctionReturn(0);
1699 }
1700 
1701 #undef __FUNCT__
1702 #define __FUNCT__ "DMPlexInsertFace_Internal"
1703 /*
1704   DMPlexInsertFace_Internal - Puts a face into the mesh
1705 
1706   Not collective
1707 
1708   Input Parameters:
1709   + dm              - The DMPlex
1710   . numFaceVertex   - The number of vertices in the face
1711   . faceVertices    - The vertices in the face for dm
1712   . subfaceVertices - The vertices in the face for subdm
1713   . numCorners      - The number of vertices in the cell
1714   . cell            - A cell in dm containing the face
1715   . subcell         - A cell in subdm containing the face
1716   . firstFace       - First face in the mesh
1717   - newFacePoint    - Next face in the mesh
1718 
1719   Output Parameters:
1720   . newFacePoint - Contains next face point number on input, updated on output
1721 
1722   Level: developer
1723 */
1724 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)
1725 {
1726   MPI_Comm        comm;
1727   DM_Plex        *submesh = (DM_Plex*) subdm->data;
1728   const PetscInt *faces;
1729   PetscInt        numFaces, coneSize;
1730   PetscErrorCode  ierr;
1731 
1732   PetscFunctionBegin;
1733   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1734   ierr = DMPlexGetConeSize(subdm, subcell, &coneSize);CHKERRQ(ierr);
1735   if (coneSize != 1) SETERRQ2(comm, PETSC_ERR_ARG_OUTOFRANGE, "Cone size of cell %d is %d != 1", cell, coneSize);
1736 #if 0
1737   /* Cannot use this because support() has not been constructed yet */
1738   ierr = DMPlexGetJoin(subdm, numFaceVertices, subfaceVertices, &numFaces, &faces);CHKERRQ(ierr);
1739 #else
1740   {
1741     PetscInt f;
1742 
1743     numFaces = 0;
1744     ierr     = DMGetWorkArray(subdm, 1, PETSC_INT, (void **) &faces);CHKERRQ(ierr);
1745     for (f = firstFace; f < *newFacePoint; ++f) {
1746       PetscInt dof, off, d;
1747 
1748       ierr = PetscSectionGetDof(submesh->coneSection, f, &dof);CHKERRQ(ierr);
1749       ierr = PetscSectionGetOffset(submesh->coneSection, f, &off);CHKERRQ(ierr);
1750       /* Yes, I know this is quadratic, but I expect the sizes to be <5 */
1751       for (d = 0; d < dof; ++d) {
1752         const PetscInt p = submesh->cones[off+d];
1753         PetscInt       v;
1754 
1755         for (v = 0; v < numFaceVertices; ++v) {
1756           if (subfaceVertices[v] == p) break;
1757         }
1758         if (v == numFaceVertices) break;
1759       }
1760       if (d == dof) {
1761         numFaces               = 1;
1762         ((PetscInt*) faces)[0] = f;
1763       }
1764     }
1765   }
1766 #endif
1767   if (numFaces > 1) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Vertex set had %d faces, not one", numFaces);
1768   else if (numFaces == 1) {
1769     /* Add the other cell neighbor for this face */
1770     ierr = DMPlexSetCone(subdm, subcell, faces);CHKERRQ(ierr);
1771   } else {
1772     PetscInt *indices, *origVertices, *orientedVertices, *orientedSubVertices, v, ov;
1773     PetscBool posOriented;
1774 
1775     ierr                = DMGetWorkArray(subdm, 4*numFaceVertices * sizeof(PetscInt), PETSC_INT, &orientedVertices);CHKERRQ(ierr);
1776     origVertices        = &orientedVertices[numFaceVertices];
1777     indices             = &orientedVertices[numFaceVertices*2];
1778     orientedSubVertices = &orientedVertices[numFaceVertices*3];
1779     ierr                = DMPlexGetOrientedFace(dm, cell, numFaceVertices, faceVertices, numCorners, indices, origVertices, orientedVertices, &posOriented);CHKERRQ(ierr);
1780     /* TODO: I know that routine should return a permutation, not the indices */
1781     for (v = 0; v < numFaceVertices; ++v) {
1782       const PetscInt vertex = faceVertices[v], subvertex = subfaceVertices[v];
1783       for (ov = 0; ov < numFaceVertices; ++ov) {
1784         if (orientedVertices[ov] == vertex) {
1785           orientedSubVertices[ov] = subvertex;
1786           break;
1787         }
1788       }
1789       if (ov == numFaceVertices) SETERRQ1(comm, PETSC_ERR_PLIB, "Could not find face vertex %d in orientated set", vertex);
1790     }
1791     ierr = DMPlexSetCone(subdm, *newFacePoint, orientedSubVertices);CHKERRQ(ierr);
1792     ierr = DMPlexSetCone(subdm, subcell, newFacePoint);CHKERRQ(ierr);
1793     ierr = DMRestoreWorkArray(subdm, 4*numFaceVertices * sizeof(PetscInt), PETSC_INT, &orientedVertices);CHKERRQ(ierr);
1794     ++(*newFacePoint);
1795   }
1796 #if 0
1797   ierr = DMPlexRestoreJoin(subdm, numFaceVertices, subfaceVertices, &numFaces, &faces);CHKERRQ(ierr);
1798 #else
1799   ierr = DMRestoreWorkArray(subdm, 1, PETSC_INT, (void **) &faces);CHKERRQ(ierr);
1800 #endif
1801   PetscFunctionReturn(0);
1802 }
1803 
1804 #undef __FUNCT__
1805 #define __FUNCT__ "DMPlexCreateSubmesh_Uninterpolated"
1806 static PetscErrorCode DMPlexCreateSubmesh_Uninterpolated(DM dm, const char vertexLabelName[], PetscInt value, DM subdm)
1807 {
1808   MPI_Comm        comm;
1809   DMLabel         vertexLabel, subpointMap;
1810   IS              subvertexIS,  subcellIS;
1811   const PetscInt *subVertices, *subCells;
1812   PetscInt        numSubVertices, firstSubVertex, numSubCells;
1813   PetscInt       *subface, maxConeSize, numSubFaces, firstSubFace, newFacePoint, nFV;
1814   PetscInt        vStart, vEnd, c, f;
1815   PetscErrorCode  ierr;
1816 
1817   PetscFunctionBegin;
1818   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1819   /* Create subpointMap which marks the submesh */
1820   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
1821   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
1822   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
1823   ierr = DMPlexGetLabel(dm, vertexLabelName, &vertexLabel);CHKERRQ(ierr);
1824   ierr = DMPlexMarkSubmesh_Uninterpolated(dm, vertexLabel, value, subpointMap, &numSubFaces, &nFV, subdm);CHKERRQ(ierr);
1825   /* Setup chart */
1826   ierr = DMLabelGetStratumSize(subpointMap, 0, &numSubVertices);CHKERRQ(ierr);
1827   ierr = DMLabelGetStratumSize(subpointMap, 2, &numSubCells);CHKERRQ(ierr);
1828   ierr = DMPlexSetChart(subdm, 0, numSubCells+numSubFaces+numSubVertices);CHKERRQ(ierr);
1829   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
1830   /* Set cone sizes */
1831   firstSubVertex = numSubCells;
1832   firstSubFace   = numSubCells+numSubVertices;
1833   newFacePoint   = firstSubFace;
1834   ierr = DMLabelGetStratumIS(subpointMap, 0, &subvertexIS);CHKERRQ(ierr);
1835   if (subvertexIS) {ierr = ISGetIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
1836   ierr = DMLabelGetStratumIS(subpointMap, 2, &subcellIS);CHKERRQ(ierr);
1837   if (subcellIS) {ierr = ISGetIndices(subcellIS, &subCells);CHKERRQ(ierr);}
1838   for (c = 0; c < numSubCells; ++c) {
1839     ierr = DMPlexSetConeSize(subdm, c, 1);CHKERRQ(ierr);
1840   }
1841   for (f = firstSubFace; f < firstSubFace+numSubFaces; ++f) {
1842     ierr = DMPlexSetConeSize(subdm, f, nFV);CHKERRQ(ierr);
1843   }
1844   ierr = DMSetUp(subdm);CHKERRQ(ierr);
1845   /* Create face cones */
1846   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
1847   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
1848   ierr = DMGetWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
1849   for (c = 0; c < numSubCells; ++c) {
1850     const PetscInt cell    = subCells[c];
1851     const PetscInt subcell = c;
1852     PetscInt      *closure = NULL;
1853     PetscInt       closureSize, cl, numCorners = 0, faceSize = 0;
1854 
1855     ierr = DMPlexGetTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1856     for (cl = 0; cl < closureSize*2; cl += 2) {
1857       const PetscInt point = closure[cl];
1858       PetscInt       subVertex;
1859 
1860       if ((point >= vStart) && (point < vEnd)) {
1861         ++numCorners;
1862         ierr = PetscFindInt(point, numSubVertices, subVertices, &subVertex);CHKERRQ(ierr);
1863         if (subVertex >= 0) {
1864           closure[faceSize] = point;
1865           subface[faceSize] = firstSubVertex+subVertex;
1866           ++faceSize;
1867         }
1868       }
1869     }
1870     if (faceSize > nFV) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Invalid submesh: Too many vertices %d of an element on the surface", faceSize);
1871     if (faceSize == nFV) {
1872       ierr = DMPlexInsertFace_Internal(dm, subdm, faceSize, closure, subface, numCorners, cell, subcell, firstSubFace, &newFacePoint);CHKERRQ(ierr);
1873     }
1874     ierr = DMPlexRestoreTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1875   }
1876   ierr = DMRestoreWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
1877   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
1878   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
1879   /* Build coordinates */
1880   {
1881     PetscSection coordSection, subCoordSection;
1882     Vec          coordinates, subCoordinates;
1883     PetscScalar *coords, *subCoords;
1884     PetscInt     numComp, coordSize, v;
1885 
1886     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
1887     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
1888     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
1889     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
1890     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
1891     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
1892     ierr = PetscSectionSetChart(subCoordSection, firstSubVertex, firstSubVertex+numSubVertices);CHKERRQ(ierr);
1893     for (v = 0; v < numSubVertices; ++v) {
1894       const PetscInt vertex    = subVertices[v];
1895       const PetscInt subvertex = firstSubVertex+v;
1896       PetscInt       dof;
1897 
1898       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
1899       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
1900       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
1901     }
1902     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
1903     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
1904     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
1905     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
1906     ierr = VecSetFromOptions(subCoordinates);CHKERRQ(ierr);
1907     if (coordSize) {
1908       ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
1909       ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
1910       for (v = 0; v < numSubVertices; ++v) {
1911         const PetscInt vertex    = subVertices[v];
1912         const PetscInt subvertex = firstSubVertex+v;
1913         PetscInt       dof, off, sdof, soff, d;
1914 
1915         ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
1916         ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
1917         ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
1918         ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
1919         if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
1920         for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
1921       }
1922       ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
1923       ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
1924     }
1925     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
1926     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
1927   }
1928   /* Cleanup */
1929   if (subvertexIS) {ierr = ISRestoreIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
1930   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
1931   if (subcellIS) {ierr = ISRestoreIndices(subcellIS, &subCells);CHKERRQ(ierr);}
1932   ierr = ISDestroy(&subcellIS);CHKERRQ(ierr);
1933   PetscFunctionReturn(0);
1934 }
1935 
1936 #undef __FUNCT__
1937 #define __FUNCT__ "DMPlexCreateSubmesh_Interpolated"
1938 static PetscErrorCode DMPlexCreateSubmesh_Interpolated(DM dm, const char vertexLabelName[], PetscInt value, DM subdm)
1939 {
1940   MPI_Comm         comm;
1941   DMLabel          subpointMap, vertexLabel;
1942   IS              *subpointIS;
1943   const PetscInt **subpoints;
1944   PetscInt        *numSubPoints, *firstSubPoint, *coneNew;
1945   PetscInt         totSubPoints = 0, maxConeSize, dim, p, d, v;
1946   PetscErrorCode   ierr;
1947 
1948   PetscFunctionBegin;
1949   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1950   /* Create subpointMap which marks the submesh */
1951   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
1952   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
1953   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
1954   ierr = DMPlexGetLabel(dm, vertexLabelName, &vertexLabel);CHKERRQ(ierr);
1955   ierr = DMPlexMarkSubmesh_Interpolated(dm, vertexLabel, value, subpointMap, subdm);CHKERRQ(ierr);
1956   /* Setup chart */
1957   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1958   ierr = PetscMalloc4(dim+1,PetscInt,&numSubPoints,dim+1,PetscInt,&firstSubPoint,dim+1,IS,&subpointIS,dim+1,const PetscInt *,&subpoints);CHKERRQ(ierr);
1959   for (d = 0; d <= dim; ++d) {
1960     ierr = DMLabelGetStratumSize(subpointMap, d, &numSubPoints[d]);CHKERRQ(ierr);
1961     totSubPoints += numSubPoints[d];
1962   }
1963   ierr = DMPlexSetChart(subdm, 0, totSubPoints);CHKERRQ(ierr);
1964   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
1965   /* Set cone sizes */
1966   firstSubPoint[dim] = 0;
1967   firstSubPoint[0]   = firstSubPoint[dim] + numSubPoints[dim];
1968   if (dim > 1) {firstSubPoint[dim-1] = firstSubPoint[0]     + numSubPoints[0];}
1969   if (dim > 2) {firstSubPoint[dim-2] = firstSubPoint[dim-1] + numSubPoints[dim-1];}
1970   for (d = 0; d <= dim; ++d) {
1971     ierr = DMLabelGetStratumIS(subpointMap, d, &subpointIS[d]);CHKERRQ(ierr);
1972     ierr = ISGetIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
1973   }
1974   for (d = 0; d <= dim; ++d) {
1975     for (p = 0; p < numSubPoints[d]; ++p) {
1976       const PetscInt  point    = subpoints[d][p];
1977       const PetscInt  subpoint = firstSubPoint[d] + p;
1978       const PetscInt *cone;
1979       PetscInt        coneSize, coneSizeNew, c, val;
1980 
1981       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
1982       ierr = DMPlexSetConeSize(subdm, subpoint, coneSize);CHKERRQ(ierr);
1983       if (d == dim) {
1984         ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
1985         for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
1986           ierr = DMLabelGetValue(subpointMap, cone[c], &val);CHKERRQ(ierr);
1987           if (val >= 0) coneSizeNew++;
1988         }
1989         ierr = DMPlexSetConeSize(subdm, subpoint, coneSizeNew);CHKERRQ(ierr);
1990       }
1991     }
1992   }
1993   ierr = DMSetUp(subdm);CHKERRQ(ierr);
1994   /* Set cones */
1995   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
1996   ierr = PetscMalloc(maxConeSize * sizeof(PetscInt), &coneNew);CHKERRQ(ierr);
1997   for (d = 0; d <= dim; ++d) {
1998     for (p = 0; p < numSubPoints[d]; ++p) {
1999       const PetscInt  point    = subpoints[d][p];
2000       const PetscInt  subpoint = firstSubPoint[d] + p;
2001       const PetscInt *cone, *ornt;
2002       PetscInt        coneSize, subconeSize, coneSizeNew, c, subc;
2003 
2004       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2005       ierr = DMPlexGetConeSize(subdm, subpoint, &subconeSize);CHKERRQ(ierr);
2006       ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2007       ierr = DMPlexGetConeOrientation(dm, point, &ornt);CHKERRQ(ierr);
2008       for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2009         ierr = PetscFindInt(cone[c], numSubPoints[d-1], subpoints[d-1], &subc);CHKERRQ(ierr);
2010         if (subc >= 0) coneNew[coneSizeNew++] = firstSubPoint[d-1] + subc;
2011       }
2012       if (coneSizeNew != subconeSize) SETERRQ2(comm, PETSC_ERR_PLIB, "Number of cone points located %d does not match subcone size %d", coneSizeNew, subconeSize);
2013       ierr = DMPlexSetCone(subdm, subpoint, coneNew);CHKERRQ(ierr);
2014       ierr = DMPlexSetConeOrientation(subdm, subpoint, ornt);CHKERRQ(ierr);
2015     }
2016   }
2017   ierr = PetscFree(coneNew);CHKERRQ(ierr);
2018   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2019   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2020   /* Build coordinates */
2021   {
2022     PetscSection coordSection, subCoordSection;
2023     Vec          coordinates, subCoordinates;
2024     PetscScalar *coords, *subCoords;
2025     PetscInt     numComp, coordSize;
2026 
2027     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2028     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2029     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2030     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2031     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2032     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2033     ierr = PetscSectionSetChart(subCoordSection, firstSubPoint[0], firstSubPoint[0]+numSubPoints[0]);CHKERRQ(ierr);
2034     for (v = 0; v < numSubPoints[0]; ++v) {
2035       const PetscInt vertex    = subpoints[0][v];
2036       const PetscInt subvertex = firstSubPoint[0]+v;
2037       PetscInt       dof;
2038 
2039       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2040       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2041       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2042     }
2043     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2044     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2045     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2046     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2047     ierr = VecSetFromOptions(subCoordinates);CHKERRQ(ierr);
2048     ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2049     ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2050     for (v = 0; v < numSubPoints[0]; ++v) {
2051       const PetscInt vertex    = subpoints[0][v];
2052       const PetscInt subvertex = firstSubPoint[0]+v;
2053       PetscInt dof, off, sdof, soff, d;
2054 
2055       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2056       ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2057       ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2058       ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2059       if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2060       for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2061     }
2062     ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2063     ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2064     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2065     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2066   }
2067   /* Cleanup */
2068   for (d = 0; d <= dim; ++d) {
2069     ierr = ISRestoreIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2070     ierr = ISDestroy(&subpointIS[d]);CHKERRQ(ierr);
2071   }
2072   ierr = PetscFree4(numSubPoints,firstSubPoint,subpointIS,subpoints);CHKERRQ(ierr);
2073   PetscFunctionReturn(0);
2074 }
2075 
2076 #undef __FUNCT__
2077 #define __FUNCT__ "DMPlexCreateSubmesh"
2078 /*@C
2079   DMPlexCreateSubmesh - Extract a hypersurface from the mesh using vertices defined by a label
2080 
2081   Input Parameters:
2082 + dm           - The original mesh
2083 . vertexLabel  - The DMLabel marking vertices contained in the surface
2084 - value        - The label value to use
2085 
2086   Output Parameter:
2087 . subdm - The surface mesh
2088 
2089   Note: This function produces a DMLabel mapping original points in the submesh to their depth. This can be obtained using DMPlexGetSubpointMap().
2090 
2091   Level: developer
2092 
2093 .seealso: DMPlexGetSubpointMap(), DMPlexGetLabel(), DMLabelSetValue()
2094 @*/
2095 PetscErrorCode DMPlexCreateSubmesh(DM dm, const char vertexLabel[], PetscInt value, DM *subdm)
2096 {
2097   PetscInt       dim, depth;
2098   PetscErrorCode ierr;
2099 
2100   PetscFunctionBegin;
2101   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2102   PetscValidCharPointer(vertexLabel, 2);
2103   PetscValidPointer(subdm, 3);
2104   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2105   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2106   ierr = DMCreate(PetscObjectComm((PetscObject)dm), subdm);CHKERRQ(ierr);
2107   ierr = DMSetType(*subdm, DMPLEX);CHKERRQ(ierr);
2108   ierr = DMPlexSetDimension(*subdm, dim-1);CHKERRQ(ierr);
2109   if (depth == dim) {
2110     ierr = DMPlexCreateSubmesh_Interpolated(dm, vertexLabel, value, *subdm);CHKERRQ(ierr);
2111   } else {
2112     ierr = DMPlexCreateSubmesh_Uninterpolated(dm, vertexLabel, value, *subdm);CHKERRQ(ierr);
2113   }
2114   PetscFunctionReturn(0);
2115 }
2116 
2117 #undef __FUNCT__
2118 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh_Uninterpolated"
2119 static PetscErrorCode DMPlexCreateCohesiveSubmesh_Uninterpolated(DM dm, PetscBool hasLagrange, DM subdm)
2120 {
2121   MPI_Comm        comm;
2122   DMLabel         subpointMap;
2123   IS              subvertexIS;
2124   const PetscInt *subVertices;
2125   PetscInt        numSubVertices, firstSubVertex, numSubCells, *subCells;
2126   PetscInt       *subface, maxConeSize, numSubFaces, firstSubFace, newFacePoint, nFV;
2127   PetscInt        cMax, c, f;
2128   PetscErrorCode  ierr;
2129 
2130   PetscFunctionBegin;
2131   ierr = PetscObjectGetComm((PetscObject)dm, &comm);CHKERRQ(ierr);
2132   /* Create subpointMap which marks the submesh */
2133   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2134   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2135   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2136   ierr = DMPlexMarkCohesiveSubmesh_Uninterpolated(dm, hasLagrange, subpointMap, &numSubFaces, &nFV, &subCells, subdm);CHKERRQ(ierr);
2137   /* Setup chart */
2138   ierr = DMLabelGetStratumSize(subpointMap, 0, &numSubVertices);CHKERRQ(ierr);
2139   ierr = DMLabelGetStratumSize(subpointMap, 2, &numSubCells);CHKERRQ(ierr);
2140   ierr = DMPlexSetChart(subdm, 0, numSubCells+numSubFaces+numSubVertices);CHKERRQ(ierr);
2141   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2142   /* Set cone sizes */
2143   firstSubVertex = numSubCells;
2144   firstSubFace   = numSubCells+numSubVertices;
2145   newFacePoint   = firstSubFace;
2146   ierr = DMLabelGetStratumIS(subpointMap, 0, &subvertexIS);CHKERRQ(ierr);
2147   if (subvertexIS) {ierr = ISGetIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2148   for (c = 0; c < numSubCells; ++c) {
2149     ierr = DMPlexSetConeSize(subdm, c, 1);CHKERRQ(ierr);
2150   }
2151   for (f = firstSubFace; f < firstSubFace+numSubFaces; ++f) {
2152     ierr = DMPlexSetConeSize(subdm, f, nFV);CHKERRQ(ierr);
2153   }
2154   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2155   /* Create face cones */
2156   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2157   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
2158   ierr = DMGetWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2159   for (c = 0; c < numSubCells; ++c) {
2160     const PetscInt  cell    = subCells[c];
2161     const PetscInt  subcell = c;
2162     const PetscInt *cone, *cells;
2163     PetscInt        numCells, subVertex, p, v;
2164 
2165     if (cell < cMax) continue;
2166     ierr = DMPlexGetCone(dm, cell, &cone);CHKERRQ(ierr);
2167     for (v = 0; v < nFV; ++v) {
2168       ierr = PetscFindInt(cone[v], numSubVertices, subVertices, &subVertex);CHKERRQ(ierr);
2169       subface[v] = firstSubVertex+subVertex;
2170     }
2171     ierr = DMPlexSetCone(subdm, newFacePoint, subface);CHKERRQ(ierr);
2172     ierr = DMPlexSetCone(subdm, subcell, &newFacePoint);CHKERRQ(ierr);
2173     ierr = DMPlexGetJoin(dm, nFV, cone, &numCells, &cells);CHKERRQ(ierr);
2174     if (numCells != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
2175     for (p = 0; p < numCells; ++p) {
2176       PetscInt negsubcell;
2177 
2178       if (cells[p] >= cMax) continue;
2179       /* I know this is a crap search */
2180       for (negsubcell = 0; negsubcell < numSubCells; ++negsubcell) {
2181         if (subCells[negsubcell] == cells[p]) break;
2182       }
2183       if (negsubcell == numSubCells) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find negative face neighbor for cohesive cell %d", cell);
2184       ierr = DMPlexSetCone(subdm, negsubcell, &newFacePoint);CHKERRQ(ierr);
2185     }
2186     ierr = DMPlexRestoreJoin(dm, nFV, cone, &numCells, &cells);CHKERRQ(ierr);
2187     ++newFacePoint;
2188   }
2189   ierr = DMRestoreWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2190   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2191   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2192   /* Build coordinates */
2193   {
2194     PetscSection coordSection, subCoordSection;
2195     Vec          coordinates, subCoordinates;
2196     PetscScalar *coords, *subCoords;
2197     PetscInt     numComp, coordSize, v;
2198 
2199     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2200     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2201     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2202     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2203     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2204     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2205     ierr = PetscSectionSetChart(subCoordSection, firstSubVertex, firstSubVertex+numSubVertices);CHKERRQ(ierr);
2206     for (v = 0; v < numSubVertices; ++v) {
2207       const PetscInt vertex    = subVertices[v];
2208       const PetscInt subvertex = firstSubVertex+v;
2209       PetscInt       dof;
2210 
2211       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2212       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2213       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2214     }
2215     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2216     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2217     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2218     if (coordSize) {
2219       ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2220       ierr = VecSetFromOptions(subCoordinates);CHKERRQ(ierr);
2221       ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2222       ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2223       for (v = 0; v < numSubVertices; ++v) {
2224         const PetscInt vertex    = subVertices[v];
2225         const PetscInt subvertex = firstSubVertex+v;
2226         PetscInt       dof, off, sdof, soff, d;
2227 
2228         ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2229         ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2230         ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2231         ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2232         if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2233         for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2234       }
2235       ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2236       ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2237     }
2238     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2239     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2240   }
2241   /* Cleanup */
2242   if (subvertexIS) {ierr = ISRestoreIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2243   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
2244   ierr = PetscFree(subCells);CHKERRQ(ierr);
2245   PetscFunctionReturn(0);
2246 }
2247 
2248 #undef __FUNCT__
2249 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh_Interpolated"
2250 static PetscErrorCode DMPlexCreateCohesiveSubmesh_Interpolated(DM dm, PetscBool hasLagrange, DM subdm)
2251 {
2252   MPI_Comm         comm;
2253   DMLabel          subpointMap;
2254   IS              *subpointIS;
2255   const PetscInt **subpoints;
2256   PetscInt        *numSubPoints, *firstSubPoint, *coneNew;
2257   PetscInt         totSubPoints = 0, maxConeSize, dim, p, d, v;
2258   PetscErrorCode   ierr;
2259 
2260   PetscFunctionBegin;
2261   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2262   /* Create subpointMap which marks the submesh */
2263   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2264   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2265   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2266   ierr = DMPlexMarkCohesiveSubmesh_Interpolated(dm, hasLagrange, subpointMap, subdm);CHKERRQ(ierr);
2267   /* Setup chart */
2268   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2269   ierr = PetscMalloc4(dim+1,PetscInt,&numSubPoints,dim+1,PetscInt,&firstSubPoint,dim+1,IS,&subpointIS,dim+1,const PetscInt *,&subpoints);CHKERRQ(ierr);
2270   for (d = 0; d <= dim; ++d) {
2271     ierr = DMLabelGetStratumSize(subpointMap, d, &numSubPoints[d]);CHKERRQ(ierr);
2272     totSubPoints += numSubPoints[d];
2273   }
2274   ierr = DMPlexSetChart(subdm, 0, totSubPoints);CHKERRQ(ierr);
2275   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2276   /* Set cone sizes */
2277   firstSubPoint[dim] = 0;
2278   firstSubPoint[0]   = firstSubPoint[dim] + numSubPoints[dim];
2279   if (dim > 1) {firstSubPoint[dim-1] = firstSubPoint[0]     + numSubPoints[0];}
2280   if (dim > 2) {firstSubPoint[dim-2] = firstSubPoint[dim-1] + numSubPoints[dim-1];}
2281   for (d = 0; d <= dim; ++d) {
2282     ierr = DMLabelGetStratumIS(subpointMap, d, &subpointIS[d]);CHKERRQ(ierr);
2283     ierr = ISGetIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2284   }
2285   for (d = 0; d <= dim; ++d) {
2286     for (p = 0; p < numSubPoints[d]; ++p) {
2287       const PetscInt  point    = subpoints[d][p];
2288       const PetscInt  subpoint = firstSubPoint[d] + p;
2289       const PetscInt *cone;
2290       PetscInt        coneSize, coneSizeNew, c, val;
2291 
2292       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2293       ierr = DMPlexSetConeSize(subdm, subpoint, coneSize);CHKERRQ(ierr);
2294       if (d == dim) {
2295         ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2296         for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2297           ierr = DMLabelGetValue(subpointMap, cone[c], &val);CHKERRQ(ierr);
2298           if (val >= 0) coneSizeNew++;
2299         }
2300         ierr = DMPlexSetConeSize(subdm, subpoint, coneSizeNew);CHKERRQ(ierr);
2301       }
2302     }
2303   }
2304   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2305   /* Set cones */
2306   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2307   ierr = PetscMalloc(maxConeSize * sizeof(PetscInt), &coneNew);CHKERRQ(ierr);
2308   for (d = 0; d <= dim; ++d) {
2309     for (p = 0; p < numSubPoints[d]; ++p) {
2310       const PetscInt  point    = subpoints[d][p];
2311       const PetscInt  subpoint = firstSubPoint[d] + p;
2312       const PetscInt *cone;
2313       PetscInt        coneSize, subconeSize, coneSizeNew, c, subc;
2314 
2315       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2316       ierr = DMPlexGetConeSize(subdm, subpoint, &subconeSize);CHKERRQ(ierr);
2317       ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2318       for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2319         ierr = PetscFindInt(cone[c], numSubPoints[d-1], subpoints[d-1], &subc);CHKERRQ(ierr);
2320         if (subc >= 0) coneNew[coneSizeNew++] = firstSubPoint[d-1] + subc;
2321       }
2322       if (coneSizeNew != subconeSize) SETERRQ2(comm, PETSC_ERR_PLIB, "Number of cone points located %d does not match subcone size %d", coneSizeNew, subconeSize);
2323       ierr = DMPlexSetCone(subdm, subpoint, coneNew);CHKERRQ(ierr);
2324     }
2325   }
2326   ierr = PetscFree(coneNew);CHKERRQ(ierr);
2327   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2328   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2329   /* Build coordinates */
2330   {
2331     PetscSection coordSection, subCoordSection;
2332     Vec          coordinates, subCoordinates;
2333     PetscScalar *coords, *subCoords;
2334     PetscInt     numComp, coordSize;
2335 
2336     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2337     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2338     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2339     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2340     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2341     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2342     ierr = PetscSectionSetChart(subCoordSection, firstSubPoint[0], firstSubPoint[0]+numSubPoints[0]);CHKERRQ(ierr);
2343     for (v = 0; v < numSubPoints[0]; ++v) {
2344       const PetscInt vertex    = subpoints[0][v];
2345       const PetscInt subvertex = firstSubPoint[0]+v;
2346       PetscInt       dof;
2347 
2348       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2349       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2350       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2351     }
2352     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2353     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2354     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2355     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2356     ierr = VecSetFromOptions(subCoordinates);CHKERRQ(ierr);
2357     ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2358     ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2359     for (v = 0; v < numSubPoints[0]; ++v) {
2360       const PetscInt vertex    = subpoints[0][v];
2361       const PetscInt subvertex = firstSubPoint[0]+v;
2362       PetscInt dof, off, sdof, soff, d;
2363 
2364       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2365       ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2366       ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2367       ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2368       if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2369       for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2370     }
2371     ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2372     ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2373     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2374     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2375   }
2376   /* Cleanup */
2377   for (d = 0; d <= dim; ++d) {
2378     ierr = ISRestoreIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2379     ierr = ISDestroy(&subpointIS[d]);CHKERRQ(ierr);
2380   }
2381   ierr = PetscFree4(numSubPoints,firstSubPoint,subpointIS,subpoints);CHKERRQ(ierr);
2382   PetscFunctionReturn(0);
2383 }
2384 
2385 #undef __FUNCT__
2386 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh"
2387 /*
2388   DMPlexCreateCohesiveSubmesh - Extract from a mesh with cohesive cells the hypersurface defined by one face of the cells.
2389 
2390   Input Parameters:
2391 + dm          - The original mesh
2392 - hasLagrange - The mesh has Lagrange unknowns in the cohesive cells
2393 
2394   Output Parameter:
2395 . subdm - The surface mesh
2396 
2397   Note: This function produces a DMLabel mapping original points in the submesh to their depth. This can be obtained using DMPlexGetSubpointMap().
2398 
2399   Level: developer
2400 
2401 .seealso: DMPlexGetSubpointMap(), DMPlexCreateSubmesh()
2402 */
2403 PetscErrorCode DMPlexCreateCohesiveSubmesh(DM dm, PetscBool hasLagrange, DM *subdm)
2404 {
2405   PetscInt       dim, depth;
2406   PetscErrorCode ierr;
2407 
2408   PetscFunctionBegin;
2409   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2410   PetscValidPointer(subdm, 3);
2411   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2412   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2413   ierr = DMCreate(PetscObjectComm((PetscObject)dm), subdm);CHKERRQ(ierr);
2414   ierr = DMSetType(*subdm, DMPLEX);CHKERRQ(ierr);
2415   ierr = DMPlexSetDimension(*subdm, dim-1);CHKERRQ(ierr);
2416   if (depth == dim) {
2417     ierr = DMPlexCreateCohesiveSubmesh_Interpolated(dm, hasLagrange, *subdm);CHKERRQ(ierr);
2418   } else {
2419     ierr = DMPlexCreateCohesiveSubmesh_Uninterpolated(dm, hasLagrange, *subdm);CHKERRQ(ierr);
2420   }
2421   PetscFunctionReturn(0);
2422 }
2423 
2424 #undef __FUNCT__
2425 #define __FUNCT__ "DMPlexGetSubpointMap"
2426 /*@
2427   DMPlexGetSubpointMap - Returns a DMLabel with point dimension as values
2428 
2429   Input Parameter:
2430 . dm - The submesh DM
2431 
2432   Output Parameter:
2433 . subpointMap - The DMLabel of all the points from the original mesh in this submesh, or NULL if this is not a submesh
2434 
2435   Level: developer
2436 
2437 .seealso: DMPlexCreateSubmesh(), DMPlexCreateSubpointIS()
2438 @*/
2439 PetscErrorCode DMPlexGetSubpointMap(DM dm, DMLabel *subpointMap)
2440 {
2441   DM_Plex *mesh = (DM_Plex*) dm->data;
2442 
2443   PetscFunctionBegin;
2444   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2445   PetscValidPointer(subpointMap, 2);
2446   *subpointMap = mesh->subpointMap;
2447   PetscFunctionReturn(0);
2448 }
2449 
2450 #undef __FUNCT__
2451 #define __FUNCT__ "DMPlexSetSubpointMap"
2452 /* Note: Should normally not be called by the user, since it is set in DMPlexCreateSubmesh() */
2453 PetscErrorCode DMPlexSetSubpointMap(DM dm, DMLabel subpointMap)
2454 {
2455   DM_Plex       *mesh = (DM_Plex *) dm->data;
2456   DMLabel        tmp;
2457   PetscErrorCode ierr;
2458 
2459   PetscFunctionBegin;
2460   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2461   tmp  = mesh->subpointMap;
2462   mesh->subpointMap = subpointMap;
2463   ++mesh->subpointMap->refct;
2464   ierr = DMLabelDestroy(&tmp);CHKERRQ(ierr);
2465   PetscFunctionReturn(0);
2466 }
2467 
2468 #undef __FUNCT__
2469 #define __FUNCT__ "DMPlexCreateSubpointIS"
2470 /*@
2471   DMPlexCreateSubpointIS - Creates an IS covering the entire subdm chart with the original points as data
2472 
2473   Input Parameter:
2474 . dm - The submesh DM
2475 
2476   Output Parameter:
2477 . subpointIS - The IS of all the points from the original mesh in this submesh, or NULL if this is not a submesh
2478 
2479   Note: This is IS is guaranteed to be sorted by the construction of the submesh
2480 
2481   Level: developer
2482 
2483 .seealso: DMPlexCreateSubmesh(), DMPlexGetSubpointMap()
2484 @*/
2485 PetscErrorCode DMPlexCreateSubpointIS(DM dm, IS *subpointIS)
2486 {
2487   MPI_Comm        comm;
2488   DMLabel         subpointMap;
2489   IS              is;
2490   const PetscInt *opoints;
2491   PetscInt       *points, *depths;
2492   PetscInt        depth, depStart, depEnd, d, pStart, pEnd, p, n, off;
2493   PetscErrorCode  ierr;
2494 
2495   PetscFunctionBegin;
2496   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2497   PetscValidPointer(subpointIS, 2);
2498   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2499   *subpointIS = NULL;
2500   ierr = DMPlexGetSubpointMap(dm, &subpointMap);CHKERRQ(ierr);
2501   if (subpointMap) {
2502     ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2503     ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
2504     if (pStart) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Submeshes must start the point numbering at 0, not %d", pStart);
2505     ierr = DMGetWorkArray(dm, depth+1, PETSC_INT, &depths);CHKERRQ(ierr);
2506     depths[0] = depth;
2507     depths[1] = 0;
2508     for(d = 2; d <= depth; ++d) {depths[d] = depth+1 - d;}
2509     ierr = PetscMalloc(pEnd * sizeof(PetscInt), &points);CHKERRQ(ierr);
2510     for(d = 0, off = 0; d <= depth; ++d) {
2511       const PetscInt dep = depths[d];
2512 
2513       ierr = DMPlexGetDepthStratum(dm, dep, &depStart, &depEnd);CHKERRQ(ierr);
2514       ierr = DMLabelGetStratumSize(subpointMap, dep, &n);CHKERRQ(ierr);
2515       if (((d < 2) && (depth > 1)) || (d == 1)) { /* Only check vertices and cells for now since the map is broken for others */
2516         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);
2517       } else {
2518         if (!n) {
2519           if (d == 0) {
2520             /* Missing cells */
2521             for(p = 0; p < depEnd-depStart; ++p, ++off) points[off] = -1;
2522           } else {
2523             /* Missing faces */
2524             for(p = 0; p < depEnd-depStart; ++p, ++off) points[off] = PETSC_MAX_INT;
2525           }
2526         }
2527       }
2528       if (n) {
2529         ierr = DMLabelGetStratumIS(subpointMap, dep, &is);CHKERRQ(ierr);
2530         ierr = ISGetIndices(is, &opoints);CHKERRQ(ierr);
2531         for(p = 0; p < n; ++p, ++off) points[off] = opoints[p];
2532         ierr = ISRestoreIndices(is, &opoints);CHKERRQ(ierr);
2533         ierr = ISDestroy(&is);CHKERRQ(ierr);
2534       }
2535     }
2536     ierr = DMRestoreWorkArray(dm, depth+1, PETSC_INT, &depths);CHKERRQ(ierr);
2537     if (off != pEnd) SETERRQ2(comm, PETSC_ERR_ARG_WRONG, "The number of mapped submesh points %d should be %d", off, pEnd);
2538     ierr = ISCreateGeneral(comm, pEnd, points, PETSC_OWN_POINTER, subpointIS);CHKERRQ(ierr);
2539   }
2540   PetscFunctionReturn(0);
2541 }
2542