xref: /petsc/src/dm/impls/plex/plexsubmesh.c (revision da748e8f40e7c337d041e723c479cfc616d6641e)
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, maxConeSizeNew, maxSupportSizeNew, 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 = DMPlexGetMaxSizes(dmNew, &maxConeSizeNew, &maxSupportSizeNew);CHKERRQ(ierr);
153   ierr = PetscMalloc2(depth+1,PetscInt,&depthEnd,PetscMax(PetscMax(maxConeSize, maxSupportSize), PetscMax(maxConeSizeNew, maxSupportSizeNew)),PetscInt,&newpoints);CHKERRQ(ierr);
154   for (d = 0; d <= depth; ++d) {
155     ierr = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
156   }
157   /* Step 5: Set cones and supports */
158   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
159   for (p = pStart; p < pEnd; ++p) {
160     const PetscInt *points = NULL, *orientations = NULL;
161     PetscInt        size,sizeNew, i, newp = DMPlexShiftPoint_Internal(p, depth, depthEnd, depthShift);
162 
163     ierr = DMPlexGetConeSize(dm, p, &size);CHKERRQ(ierr);
164     ierr = DMPlexGetCone(dm, p, &points);CHKERRQ(ierr);
165     ierr = DMPlexGetConeOrientation(dm, p, &orientations);CHKERRQ(ierr);
166     for (i = 0; i < size; ++i) {
167       newpoints[i] = DMPlexShiftPoint_Internal(points[i], depth, depthEnd, depthShift);
168     }
169     ierr = DMPlexSetCone(dmNew, newp, newpoints);CHKERRQ(ierr);
170     ierr = DMPlexSetConeOrientation(dmNew, newp, orientations);CHKERRQ(ierr);
171     ierr = DMPlexGetSupportSize(dm, p, &size);CHKERRQ(ierr);
172     ierr = DMPlexGetSupportSize(dmNew, newp, &sizeNew);CHKERRQ(ierr);
173     ierr = DMPlexGetSupport(dm, p, &points);CHKERRQ(ierr);
174     for (i = 0; i < size; ++i) {
175       newpoints[i] = DMPlexShiftPoint_Internal(points[i], depth, depthEnd, depthShift);
176     }
177     for (i = size; i < sizeNew; ++i) newpoints[i] = 0;
178     ierr = DMPlexSetSupport(dmNew, newp, newpoints);CHKERRQ(ierr);
179   }
180   ierr = PetscFree2(depthEnd,newpoints);CHKERRQ(ierr);
181   PetscFunctionReturn(0);
182 }
183 
184 #undef __FUNCT__
185 #define __FUNCT__ "DMPlexShiftCoordinates_Internal"
186 static PetscErrorCode DMPlexShiftCoordinates_Internal(DM dm, PetscInt depthShift[], DM dmNew)
187 {
188   PetscSection   coordSection, newCoordSection;
189   Vec            coordinates, newCoordinates;
190   PetscScalar   *coords, *newCoords;
191   PetscInt      *depthEnd, coordSize;
192   PetscInt       dim, depth = 0, d, vStart, vEnd, vStartNew, vEndNew, v;
193   PetscErrorCode ierr;
194 
195   PetscFunctionBegin;
196   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
197   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
198   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
199   for (d = 0; d <= depth; ++d) {
200     ierr = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
201   }
202   /* Step 8: Convert coordinates */
203   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
204   ierr = DMPlexGetDepthStratum(dmNew, 0, &vStartNew, &vEndNew);CHKERRQ(ierr);
205   ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
206   ierr = PetscSectionCreate(PetscObjectComm((PetscObject)dm), &newCoordSection);CHKERRQ(ierr);
207   ierr = PetscSectionSetNumFields(newCoordSection, 1);CHKERRQ(ierr);
208   ierr = PetscSectionSetFieldComponents(newCoordSection, 0, dim);CHKERRQ(ierr);
209   ierr = PetscSectionSetChart(newCoordSection, vStartNew, vEndNew);CHKERRQ(ierr);
210   for (v = vStartNew; v < vEndNew; ++v) {
211     ierr = PetscSectionSetDof(newCoordSection, v, dim);CHKERRQ(ierr);
212     ierr = PetscSectionSetFieldDof(newCoordSection, v, 0, dim);CHKERRQ(ierr);
213   }
214   ierr = PetscSectionSetUp(newCoordSection);CHKERRQ(ierr);
215   ierr = DMPlexSetCoordinateSection(dmNew, newCoordSection);CHKERRQ(ierr);
216   ierr = PetscSectionGetStorageSize(newCoordSection, &coordSize);CHKERRQ(ierr);
217   ierr = VecCreate(PetscObjectComm((PetscObject)dm), &newCoordinates);CHKERRQ(ierr);
218   ierr = PetscObjectSetName((PetscObject) newCoordinates, "coordinates");CHKERRQ(ierr);
219   ierr = VecSetSizes(newCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
220   ierr = VecSetType(newCoordinates,VECSTANDARD);CHKERRQ(ierr);
221   ierr = DMSetCoordinatesLocal(dmNew, newCoordinates);CHKERRQ(ierr);
222   ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
223   ierr = VecGetArray(coordinates, &coords);CHKERRQ(ierr);
224   ierr = VecGetArray(newCoordinates, &newCoords);CHKERRQ(ierr);
225   for (v = vStart; v < vEnd; ++v) {
226     PetscInt dof, off, noff, d;
227 
228     ierr = PetscSectionGetDof(coordSection, v, &dof);CHKERRQ(ierr);
229     ierr = PetscSectionGetOffset(coordSection, v, &off);CHKERRQ(ierr);
230     ierr = PetscSectionGetOffset(newCoordSection, DMPlexShiftPoint_Internal(v, depth, depthEnd, depthShift), &noff);CHKERRQ(ierr);
231     for (d = 0; d < dof; ++d) {
232       newCoords[noff+d] = coords[off+d];
233     }
234   }
235   ierr = VecRestoreArray(coordinates, &coords);CHKERRQ(ierr);
236   ierr = VecRestoreArray(newCoordinates, &newCoords);CHKERRQ(ierr);
237   ierr = VecDestroy(&newCoordinates);CHKERRQ(ierr);
238   ierr = PetscSectionDestroy(&newCoordSection);CHKERRQ(ierr);
239   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
240   PetscFunctionReturn(0);
241 }
242 
243 #undef __FUNCT__
244 #define __FUNCT__ "DMPlexShiftSF_Internal"
245 static PetscErrorCode DMPlexShiftSF_Internal(DM dm, PetscInt depthShift[], DM dmNew)
246 {
247   PetscInt          *depthEnd;
248   PetscInt           depth = 0, d;
249   PetscSF            sfPoint, sfPointNew;
250   const PetscSFNode *remotePoints;
251   PetscSFNode       *gremotePoints;
252   const PetscInt    *localPoints;
253   PetscInt          *glocalPoints, *newLocation, *newRemoteLocation;
254   PetscInt           numRoots, numLeaves, l, pStart, pEnd, totShift = 0;
255   PetscErrorCode     ierr;
256 
257   PetscFunctionBegin;
258   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
259   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
260   for (d = 0; d <= depth; ++d) {
261     totShift += depthShift[d];
262     ierr      = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
263   }
264   /* Step 9: Convert pointSF */
265   ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
266   ierr = DMGetPointSF(dmNew, &sfPointNew);CHKERRQ(ierr);
267   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
268   ierr = PetscSFGetGraph(sfPoint, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
269   if (numRoots >= 0) {
270     ierr = PetscMalloc2(numRoots,PetscInt,&newLocation,pEnd-pStart,PetscInt,&newRemoteLocation);CHKERRQ(ierr);
271     for (l=0; l<numRoots; l++) newLocation[l] = DMPlexShiftPoint_Internal(l, depth, depthEnd, depthShift);
272     ierr = PetscSFBcastBegin(sfPoint, MPIU_INT, newLocation, newRemoteLocation);CHKERRQ(ierr);
273     ierr = PetscSFBcastEnd(sfPoint, MPIU_INT, newLocation, newRemoteLocation);CHKERRQ(ierr);
274     ierr = PetscMalloc(numLeaves * sizeof(PetscInt),    &glocalPoints);CHKERRQ(ierr);
275     ierr = PetscMalloc(numLeaves * sizeof(PetscSFNode), &gremotePoints);CHKERRQ(ierr);
276     for (l = 0; l < numLeaves; ++l) {
277       glocalPoints[l]        = DMPlexShiftPoint_Internal(localPoints[l], depth, depthEnd, depthShift);
278       gremotePoints[l].rank  = remotePoints[l].rank;
279       gremotePoints[l].index = newRemoteLocation[localPoints[l]];
280     }
281     ierr = PetscFree2(newLocation,newRemoteLocation);CHKERRQ(ierr);
282     ierr = PetscSFSetGraph(sfPointNew, numRoots + totShift, numLeaves, glocalPoints, PETSC_OWN_POINTER, gremotePoints, PETSC_OWN_POINTER);CHKERRQ(ierr);
283   }
284   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
285   PetscFunctionReturn(0);
286 }
287 
288 #undef __FUNCT__
289 #define __FUNCT__ "DMPlexShiftLabels_Internal"
290 static PetscErrorCode DMPlexShiftLabels_Internal(DM dm, PetscInt depthShift[], DM dmNew)
291 {
292   PetscSF            sfPoint;
293   DMLabel            vtkLabel, ghostLabel;
294   PetscInt          *depthEnd;
295   const PetscSFNode *leafRemote;
296   const PetscInt    *leafLocal;
297   PetscInt           depth = 0, d, numLeaves, numLabels, l, cStart, cEnd, c, fStart, fEnd, f;
298   PetscMPIInt        rank;
299   PetscErrorCode     ierr;
300 
301   PetscFunctionBegin;
302   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
303   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
304   for (d = 0; d <= depth; ++d) {
305     ierr = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
306   }
307   /* Step 10: Convert labels */
308   ierr = DMPlexGetNumLabels(dm, &numLabels);CHKERRQ(ierr);
309   for (l = 0; l < numLabels; ++l) {
310     DMLabel         label, newlabel;
311     const char     *lname;
312     PetscBool       isDepth;
313     IS              valueIS;
314     const PetscInt *values;
315     PetscInt        numValues, val;
316 
317     ierr = DMPlexGetLabelName(dm, l, &lname);CHKERRQ(ierr);
318     ierr = PetscStrcmp(lname, "depth", &isDepth);CHKERRQ(ierr);
319     if (isDepth) continue;
320     ierr = DMPlexCreateLabel(dmNew, lname);CHKERRQ(ierr);
321     ierr = DMPlexGetLabel(dm, lname, &label);CHKERRQ(ierr);
322     ierr = DMPlexGetLabel(dmNew, lname, &newlabel);CHKERRQ(ierr);
323     ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
324     ierr = ISGetLocalSize(valueIS, &numValues);CHKERRQ(ierr);
325     ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
326     for (val = 0; val < numValues; ++val) {
327       IS              pointIS;
328       const PetscInt *points;
329       PetscInt        numPoints, p;
330 
331       ierr = DMLabelGetStratumIS(label, values[val], &pointIS);CHKERRQ(ierr);
332       ierr = ISGetLocalSize(pointIS, &numPoints);CHKERRQ(ierr);
333       ierr = ISGetIndices(pointIS, &points);CHKERRQ(ierr);
334       for (p = 0; p < numPoints; ++p) {
335         const PetscInt newpoint = DMPlexShiftPoint_Internal(points[p], depth, depthEnd, depthShift);
336 
337         ierr = DMLabelSetValue(newlabel, newpoint, values[val]);CHKERRQ(ierr);
338       }
339       ierr = ISRestoreIndices(pointIS, &points);CHKERRQ(ierr);
340       ierr = ISDestroy(&pointIS);CHKERRQ(ierr);
341     }
342     ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
343     ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
344   }
345   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
346   /* Step 11: Make label for output (vtk) and to mark ghost points (ghost) */
347   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank);CHKERRQ(ierr);
348   ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
349   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
350   ierr = PetscSFGetGraph(sfPoint, NULL, &numLeaves, &leafLocal, &leafRemote);CHKERRQ(ierr);
351   ierr = DMPlexCreateLabel(dmNew, "vtk");CHKERRQ(ierr);
352   ierr = DMPlexCreateLabel(dmNew, "ghost");CHKERRQ(ierr);
353   ierr = DMPlexGetLabel(dmNew, "vtk", &vtkLabel);CHKERRQ(ierr);
354   ierr = DMPlexGetLabel(dmNew, "ghost", &ghostLabel);CHKERRQ(ierr);
355   for (l = 0, c = cStart; l < numLeaves && c < cEnd; ++l, ++c) {
356     for (; c < leafLocal[l] && c < cEnd; ++c) {
357       ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
358     }
359     if (leafLocal[l] >= cEnd) break;
360     if (leafRemote[l].rank == rank) {
361       ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
362     } else {
363       ierr = DMLabelSetValue(ghostLabel, c, 2);CHKERRQ(ierr);
364     }
365   }
366   for (; c < cEnd; ++c) {
367     ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
368   }
369   if (0) {
370     ierr = PetscViewerASCIISynchronizedAllow(PETSC_VIEWER_STDOUT_WORLD, PETSC_TRUE);CHKERRQ(ierr);
371     ierr = DMLabelView(vtkLabel, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
372     ierr = PetscViewerFlush(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
373   }
374   ierr = DMPlexGetHeightStratum(dmNew, 1, &fStart, &fEnd);CHKERRQ(ierr);
375   for (f = fStart; f < fEnd; ++f) {
376     PetscInt numCells;
377 
378     ierr = DMPlexGetSupportSize(dmNew, f, &numCells);CHKERRQ(ierr);
379     if (numCells < 2) {
380       ierr = DMLabelSetValue(ghostLabel, f, 1);CHKERRQ(ierr);
381     } else {
382       const PetscInt *cells = NULL;
383       PetscInt        vA, vB;
384 
385       ierr = DMPlexGetSupport(dmNew, f, &cells);CHKERRQ(ierr);
386       ierr = DMLabelGetValue(vtkLabel, cells[0], &vA);CHKERRQ(ierr);
387       ierr = DMLabelGetValue(vtkLabel, cells[1], &vB);CHKERRQ(ierr);
388       if (!vA && !vB) {ierr = DMLabelSetValue(ghostLabel, f, 1);CHKERRQ(ierr);}
389     }
390   }
391   if (0) {
392     ierr = PetscViewerASCIISynchronizedAllow(PETSC_VIEWER_STDOUT_WORLD, PETSC_TRUE);CHKERRQ(ierr);
393     ierr = DMLabelView(ghostLabel, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
394     ierr = PetscViewerFlush(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
395   }
396   PetscFunctionReturn(0);
397 }
398 
399 #undef __FUNCT__
400 #define __FUNCT__ "DMPlexConstructGhostCells_Internal"
401 static PetscErrorCode DMPlexConstructGhostCells_Internal(DM dm, DMLabel label, PetscInt *numGhostCells, DM gdm)
402 {
403   IS              valueIS;
404   const PetscInt *values;
405   PetscInt       *depthShift;
406   PetscInt        depth = 0, numFS, fs, fStart, fEnd, ghostCell, cEnd, c;
407   PetscErrorCode  ierr;
408 
409   PetscFunctionBegin;
410   ierr = DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd);CHKERRQ(ierr);
411   /* Count ghost cells */
412   ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
413   ierr = ISGetLocalSize(valueIS, &numFS);CHKERRQ(ierr);
414   ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
415   *numGhostCells = 0;
416   for (fs = 0; fs < numFS; ++fs) {
417     IS              faceIS;
418     const PetscInt *faces;
419     PetscInt        numFaces, f, numBdFaces = 0;
420 
421     ierr = DMLabelGetStratumIS(label, values[fs], &faceIS);CHKERRQ(ierr);
422     ierr = ISGetLocalSize(faceIS, &numFaces);CHKERRQ(ierr);
423     ierr = ISGetIndices(faceIS, &faces);CHKERRQ(ierr);
424     for (f = 0; f < numFaces; ++f) {
425       if ((faces[f] >= fStart) && (faces[f] < fEnd)) ++numBdFaces;
426     }
427     *numGhostCells += numBdFaces;
428     ierr = ISDestroy(&faceIS);CHKERRQ(ierr);
429   }
430   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
431   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthShift);CHKERRQ(ierr);
432   ierr = PetscMemzero(depthShift, (depth+1) * sizeof(PetscInt));CHKERRQ(ierr);
433   if (depth >= 0) depthShift[depth] = *numGhostCells;
434   ierr = DMPlexShiftSizes_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
435   /* Step 3: Set cone/support sizes for new points */
436   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
437   for (c = cEnd; c < cEnd + *numGhostCells; ++c) {
438     ierr = DMPlexSetConeSize(gdm, c, 1);CHKERRQ(ierr);
439   }
440   for (fs = 0; fs < numFS; ++fs) {
441     IS              faceIS;
442     const PetscInt *faces;
443     PetscInt        numFaces, f;
444 
445     ierr = DMLabelGetStratumIS(label, values[fs], &faceIS);CHKERRQ(ierr);
446     ierr = ISGetLocalSize(faceIS, &numFaces);CHKERRQ(ierr);
447     ierr = ISGetIndices(faceIS, &faces);CHKERRQ(ierr);
448     for (f = 0; f < numFaces; ++f) {
449       PetscInt size;
450 
451       if ((faces[f] < fStart) || (faces[f] >= fEnd)) continue;
452       ierr = DMPlexGetSupportSize(dm, faces[f], &size);CHKERRQ(ierr);
453       if (size != 1) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "DM has boundary face %d with %d support cells", faces[f], size);
454       ierr = DMPlexSetSupportSize(gdm, faces[f] + *numGhostCells, 2);CHKERRQ(ierr);
455     }
456     ierr = ISRestoreIndices(faceIS, &faces);CHKERRQ(ierr);
457     ierr = ISDestroy(&faceIS);CHKERRQ(ierr);
458   }
459   /* Step 4: Setup ghosted DM */
460   ierr = DMSetUp(gdm);CHKERRQ(ierr);
461   ierr = DMPlexShiftPoints_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
462   /* Step 6: Set cones and supports for new points */
463   ghostCell = cEnd;
464   for (fs = 0; fs < numFS; ++fs) {
465     IS              faceIS;
466     const PetscInt *faces;
467     PetscInt        numFaces, f;
468 
469     ierr = DMLabelGetStratumIS(label, values[fs], &faceIS);CHKERRQ(ierr);
470     ierr = ISGetLocalSize(faceIS, &numFaces);CHKERRQ(ierr);
471     ierr = ISGetIndices(faceIS, &faces);CHKERRQ(ierr);
472     for (f = 0; f < numFaces; ++f) {
473       PetscInt newFace = faces[f] + *numGhostCells;
474 
475       if ((faces[f] < fStart) || (faces[f] >= fEnd)) continue;
476       ierr = DMPlexSetCone(gdm, ghostCell, &newFace);CHKERRQ(ierr);
477       ierr = DMPlexInsertSupport(gdm, newFace, 1, ghostCell);CHKERRQ(ierr);
478       ++ghostCell;
479     }
480     ierr = ISRestoreIndices(faceIS, &faces);CHKERRQ(ierr);
481     ierr = ISDestroy(&faceIS);CHKERRQ(ierr);
482   }
483   ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
484   ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
485   /* Step 7: Stratify */
486   ierr = DMPlexStratify(gdm);CHKERRQ(ierr);
487   ierr = DMPlexShiftCoordinates_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
488   ierr = DMPlexShiftSF_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
489   ierr = DMPlexShiftLabels_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
490   ierr = PetscFree(depthShift);CHKERRQ(ierr);
491   PetscFunctionReturn(0);
492 }
493 
494 #undef __FUNCT__
495 #define __FUNCT__ "DMPlexConstructGhostCells"
496 /*@C
497   DMPlexConstructGhostCells - Construct ghost cells which connect to every boundary face
498 
499   Collective on dm
500 
501   Input Parameters:
502 + dm - The original DM
503 - labelName - The label specifying the boundary faces, or "Face Sets" if this is NULL
504 
505   Output Parameters:
506 + numGhostCells - The number of ghost cells added to the DM
507 - dmGhosted - The new DM
508 
509   Note: If no label exists of that name, one will be created marking all boundary faces
510 
511   Level: developer
512 
513 .seealso: DMCreate()
514 @*/
515 PetscErrorCode DMPlexConstructGhostCells(DM dm, const char labelName[], PetscInt *numGhostCells, DM *dmGhosted)
516 {
517   DM             gdm;
518   DMLabel        label;
519   const char    *name = labelName ? labelName : "Face Sets";
520   PetscInt       dim;
521   PetscErrorCode ierr;
522 
523   PetscFunctionBegin;
524   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
525   PetscValidPointer(numGhostCells, 3);
526   PetscValidPointer(dmGhosted, 4);
527   ierr = DMCreate(PetscObjectComm((PetscObject)dm), &gdm);CHKERRQ(ierr);
528   ierr = DMSetType(gdm, DMPLEX);CHKERRQ(ierr);
529   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
530   ierr = DMPlexSetDimension(gdm, dim);CHKERRQ(ierr);
531   ierr = DMPlexGetLabel(dm, name, &label);CHKERRQ(ierr);
532   if (!label) {
533     /* Get label for boundary faces */
534     ierr = DMPlexCreateLabel(dm, name);CHKERRQ(ierr);
535     ierr = DMPlexGetLabel(dm, name, &label);CHKERRQ(ierr);
536     ierr = DMPlexMarkBoundaryFaces(dm, label);CHKERRQ(ierr);
537   }
538   ierr = DMPlexConstructGhostCells_Internal(dm, label, numGhostCells, gdm);CHKERRQ(ierr);
539   ierr = DMSetFromOptions(gdm);CHKERRQ(ierr);
540   *dmGhosted = gdm;
541   PetscFunctionReturn(0);
542 }
543 
544 #undef __FUNCT__
545 #define __FUNCT__ "DMPlexConstructCohesiveCells_Internal"
546 /*
547   We are adding two kinds of points here:
548     Replicated: Copies of points which exist in the mesh, such as vertices identified across a fault
549     Hybrid:     Entirely new points, such as cohesive cells
550 */
551 static PetscErrorCode DMPlexConstructCohesiveCells_Internal(DM dm, DMLabel label, DM sdm)
552 {
553   MPI_Comm         comm;
554   IS               valueIS;
555   PetscInt         numSP = 0;       /* The number of depths for which we have replicated points */
556   const PetscInt  *values;          /* List of depths for which we have replicated points */
557   IS              *splitIS;
558   IS              *unsplitIS;
559   PetscInt        *numSplitPoints;   /* The number of replicated points at each depth */
560   PetscInt        *numUnsplitPoints; /* The number of non-replicated points at each depth which still give rise to hybrid points */
561   PetscInt        *numHybridPoints;  /* The number of hybrid points at each depth */
562   const PetscInt **splitPoints;      /* Replicated points for each depth */
563   const PetscInt **unsplitPoints;    /* Non-replicated points for each depth */
564   PetscSection     coordSection;
565   Vec              coordinates;
566   PetscScalar     *coords;
567   PetscInt         depths[4];       /* Depths in the order that plex points are numbered */
568   PetscInt        *depthShift;      /* Number of replicated+hybrid points at each depth */
569   PetscInt        *depthOffset;     /* Prefix sums of depthShift */
570   PetscInt        *pMaxNew;         /* The first replicated point at each depth in the new mesh, hybrids come after this */
571   PetscInt        *coneNew, *coneONew, *supportNew;
572   PetscInt         shift = 100, shift2 = 200, depth = 0, dep, dim, d, sp, maxConeSize, maxSupportSize, maxConeSizeNew, maxSupportSizeNew, numLabels, vStart, vEnd, pEnd, p, v;
573   PetscErrorCode   ierr;
574 
575   PetscFunctionBegin;
576   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
577   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
578   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
579   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
580   depths[0] = depth;
581   depths[1] = 0;
582   depths[2] = depth-1;
583   depths[3] = 1;
584   /* Count split points and add cohesive cells */
585   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
586   ierr = PetscMalloc3(depth+1,PetscInt,&depthShift,depth+1,PetscInt,&depthOffset,depth+1,PetscInt,&pMaxNew);CHKERRQ(ierr);
587   ierr = PetscMalloc7(depth+1,IS,&splitIS,depth+1,IS,&unsplitIS,depth+1,PetscInt,&numSplitPoints,depth+1,PetscInt,&numUnsplitPoints,depth+1,PetscInt,&numHybridPoints,depth+1,const PetscInt*,&splitPoints,depth+1,const PetscInt*,&unsplitPoints);CHKERRQ(ierr);
588   ierr = PetscMemzero(depthShift,  (depth+1) * sizeof(PetscInt));CHKERRQ(ierr);
589   ierr = PetscMemzero(depthOffset, (depth+1) * sizeof(PetscInt));CHKERRQ(ierr);
590   for (d = 0; d <= depth; ++d) {
591     ierr                = DMPlexGetDepthStratum(dm, d, NULL, &pMaxNew[d]);CHKERRQ(ierr);
592     numSplitPoints[d]   = 0;
593     numUnsplitPoints[d] = 0;
594     numHybridPoints[d]  = 0;
595     splitPoints[d]      = NULL;
596     unsplitPoints[d]    = NULL;
597     splitIS[d]          = NULL;
598     unsplitIS[d]        = NULL;
599   }
600   if (label) {
601     ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
602     ierr = ISGetLocalSize(valueIS, &numSP);CHKERRQ(ierr);
603     ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
604   }
605   for (sp = 0; sp < numSP; ++sp) {
606     const PetscInt dep = values[sp];
607 
608     if ((dep < 0) || (dep > depth)) continue;
609     ierr = DMLabelGetStratumIS(label, dep, &splitIS[dep]);CHKERRQ(ierr);
610     if (splitIS[dep]) {
611       ierr = ISGetLocalSize(splitIS[dep], &numSplitPoints[dep]);CHKERRQ(ierr);
612       ierr = ISGetIndices(splitIS[dep], &splitPoints[dep]);CHKERRQ(ierr);
613     }
614     ierr = DMLabelGetStratumIS(label, shift2+dep, &unsplitIS[dep]);CHKERRQ(ierr);
615     if (unsplitIS[dep]) {
616       ierr = ISGetLocalSize(unsplitIS[dep], &numUnsplitPoints[dep]);CHKERRQ(ierr);
617       ierr = ISGetIndices(unsplitIS[dep], &unsplitPoints[dep]);CHKERRQ(ierr);
618     }
619   }
620   /* Calculate number of hybrid points */
621   for (d = 1; d <= depth; ++d) numHybridPoints[d]     = numSplitPoints[d-1] + numUnsplitPoints[d-1]; /* There is a hybrid cell/face/edge for every split face/edge/vertex   */
622   for (d = 0; d <= depth; ++d) depthShift[d]          = numSplitPoints[d] + numHybridPoints[d];
623   for (d = 1; d <= depth; ++d) depthOffset[depths[d]] = depthOffset[depths[d-1]] + depthShift[depths[d-1]];
624   for (d = 0; d <= depth; ++d) pMaxNew[d]            += depthOffset[d];
625   ierr = DMPlexShiftSizes_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
626   /* Step 3: Set cone/support sizes for new points */
627   for (dep = 0; dep <= depth; ++dep) {
628     for (p = 0; p < numSplitPoints[dep]; ++p) {
629       const PetscInt  oldp   = splitPoints[dep][p];
630       const PetscInt  newp   = oldp + depthOffset[dep];
631       const PetscInt  splitp = p    + pMaxNew[dep];
632       const PetscInt *support;
633       PetscInt        coneSize, supportSize, qf, qn, qp, e;
634 
635       ierr = DMPlexGetConeSize(dm, oldp, &coneSize);CHKERRQ(ierr);
636       ierr = DMPlexSetConeSize(sdm, splitp, coneSize);CHKERRQ(ierr);
637       ierr = DMPlexGetSupportSize(dm, oldp, &supportSize);CHKERRQ(ierr);
638       ierr = DMPlexSetSupportSize(sdm, splitp, supportSize);CHKERRQ(ierr);
639       if (dep == depth-1) {
640         const PetscInt hybcell = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
641 
642         /* Add cohesive cells, they are prisms */
643         ierr = DMPlexSetConeSize(sdm, hybcell, 2 + coneSize);CHKERRQ(ierr);
644       } else if (dep == 0) {
645         const PetscInt hybedge = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
646 
647         ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
648         for (e = 0, qn = 0, qp = 0, qf = 0; e < supportSize; ++e) {
649           PetscInt val;
650 
651           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
652           if (val == 1) ++qf;
653           if ((val == 1) || (val ==  (shift + 1))) ++qn;
654           if ((val == 1) || (val == -(shift + 1))) ++qp;
655         }
656         /* Split old vertex: Edges into original vertex and new cohesive edge */
657         ierr = DMPlexSetSupportSize(sdm, newp, qn+1);CHKERRQ(ierr);
658         /* Split new vertex: Edges into split vertex and new cohesive edge */
659         ierr = DMPlexSetSupportSize(sdm, splitp, qp+1);CHKERRQ(ierr);
660         /* Add hybrid edge */
661         ierr = DMPlexSetConeSize(sdm, hybedge, 2);CHKERRQ(ierr);
662         ierr = DMPlexSetSupportSize(sdm, hybedge, qf);CHKERRQ(ierr);
663       } else if (dep == dim-2) {
664         const PetscInt hybface = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
665 
666         ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
667         for (e = 0, qn = 0, qp = 0, qf = 0; e < supportSize; ++e) {
668           PetscInt val;
669 
670           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
671           if (val == dim-1) ++qf;
672           if ((val == dim-1) || (val ==  (shift + dim-1))) ++qn;
673           if ((val == dim-1) || (val == -(shift + dim-1))) ++qp;
674         }
675         /* Split old edge: Faces into original edge and cohesive face (positive side?) */
676         ierr = DMPlexSetSupportSize(sdm, newp, qn+1);CHKERRQ(ierr);
677         /* Split new edge: Faces into split edge and cohesive face (negative side?) */
678         ierr = DMPlexSetSupportSize(sdm, splitp, qp+1);CHKERRQ(ierr);
679         /* Add hybrid face */
680         ierr = DMPlexSetConeSize(sdm, hybface, 4);CHKERRQ(ierr);
681         ierr = DMPlexSetSupportSize(sdm, hybface, qf);CHKERRQ(ierr);
682       }
683     }
684   }
685   for (dep = 0; dep <= depth; ++dep) {
686     for (p = 0; p < numUnsplitPoints[dep]; ++p) {
687       const PetscInt  oldp   = unsplitPoints[dep][p];
688       const PetscInt  newp   = oldp + depthOffset[dep];
689       const PetscInt *support;
690       PetscInt        coneSize, supportSize, qf, qn, qp, e;
691 
692       ierr = DMPlexGetConeSize(dm, oldp, &coneSize);CHKERRQ(ierr);
693       ierr = DMPlexGetSupportSize(dm, oldp, &supportSize);CHKERRQ(ierr);
694       if (dep == 0) {
695         const PetscInt hybedge = p + pMaxNew[dep+1] + numSplitPoints[dep+1] + numSplitPoints[dep];
696 
697         /* Unsplit vertex: Edges into original vertex, split edge, and new cohesive edge twice */
698         ierr = DMPlexSetSupportSize(sdm, newp, supportSize+3);CHKERRQ(ierr);
699         /* Add hybrid edge */
700         ierr = DMPlexSetConeSize(sdm, hybedge, 2);CHKERRQ(ierr);
701         ierr = DMPlexSetSupportSize(sdm, hybedge, 1);CHKERRQ(ierr);
702       } else if (dep == dim-2) {
703         const PetscInt hybface = p + pMaxNew[dep+1] + numSplitPoints[dep+1] + numSplitPoints[dep];
704 
705         ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
706         for (e = 0, qn = 0, qp = 0, qf = 0; e < supportSize; ++e) {
707           PetscInt val;
708 
709           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
710           if (val == dim-1) ++qf;
711           if ((val == dim-1) || (val ==  (shift + dim-1))) ++qn;
712           if ((val == dim-1) || (val == -(shift + dim-1))) ++qp;
713         }
714         /* Unsplit edge: Faces into original edge, split face, and cohesive face twice */
715         ierr = DMPlexSetSupportSize(sdm, newp, supportSize+3);CHKERRQ(ierr);
716         /* Add hybrid face */
717         ierr = DMPlexSetConeSize(sdm, hybface, 4);CHKERRQ(ierr);
718         ierr = DMPlexSetSupportSize(sdm, hybface, 1);CHKERRQ(ierr);
719       }
720     }
721   }
722   /* Step 4: Setup split DM */
723   ierr = DMSetUp(sdm);CHKERRQ(ierr);
724   ierr = DMPlexShiftPoints_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
725   ierr = DMPlexGetMaxSizes(sdm, &maxConeSizeNew, &maxSupportSizeNew);CHKERRQ(ierr);
726   ierr = PetscMalloc3(PetscMax(maxConeSize, maxConeSizeNew)*3,PetscInt,&coneNew,PetscMax(maxConeSize, maxConeSizeNew)*3,PetscInt,&coneONew,PetscMax(maxSupportSize, maxSupportSizeNew),PetscInt,&supportNew);CHKERRQ(ierr);
727   /* Step 6: Set cones and supports for new points */
728   for (dep = 0; dep <= depth; ++dep) {
729     for (p = 0; p < numSplitPoints[dep]; ++p) {
730       const PetscInt  oldp   = splitPoints[dep][p];
731       const PetscInt  newp   = oldp + depthOffset[dep];
732       const PetscInt  splitp = p    + pMaxNew[dep];
733       const PetscInt *cone, *support, *ornt;
734       PetscInt        coneSize, supportSize, q, qf, qn, qp, v, e, s;
735 
736       ierr = DMPlexGetConeSize(dm, oldp, &coneSize);CHKERRQ(ierr);
737       ierr = DMPlexGetCone(dm, oldp, &cone);CHKERRQ(ierr);
738       ierr = DMPlexGetConeOrientation(dm, oldp, &ornt);CHKERRQ(ierr);
739       ierr = DMPlexGetSupportSize(dm, oldp, &supportSize);CHKERRQ(ierr);
740       ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
741       if (dep == depth-1) {
742         const PetscInt  hybcell = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
743         const PetscInt *supportF;
744 
745         /* Split face:       copy in old face to new face to start */
746         ierr = DMPlexGetSupport(sdm, newp,  &supportF);CHKERRQ(ierr);
747         ierr = DMPlexSetSupport(sdm, splitp, supportF);CHKERRQ(ierr);
748         /* Split old face:   old vertices/edges in cone so no change */
749         /* Split new face:   new vertices/edges in cone */
750         for (q = 0; q < coneSize; ++q) {
751           ierr = PetscFindInt(cone[q], numSplitPoints[dep-1], splitPoints[dep-1], &v);CHKERRQ(ierr);
752           if (v < 0) {
753             ierr = PetscFindInt(cone[q], numUnsplitPoints[dep-1], unsplitPoints[dep-1], &v);CHKERRQ(ierr);
754             if (v < 0) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not locate point %d in split or unsplit points of depth %d", cone[q], dep-1);
755             coneNew[2+q] = cone[q] + depthOffset[dep-1];
756           } else {
757             coneNew[2+q] = v + pMaxNew[dep-1];
758           }
759         }
760         ierr = DMPlexSetCone(sdm, splitp, &coneNew[2]);CHKERRQ(ierr);
761         ierr = DMPlexSetConeOrientation(sdm, splitp, ornt);CHKERRQ(ierr);
762         /* Face support */
763         for (s = 0; s < supportSize; ++s) {
764           PetscInt val;
765 
766           ierr = DMLabelGetValue(label, support[s], &val);CHKERRQ(ierr);
767           if (val < 0) {
768             /* Split old face:   Replace negative side cell with cohesive cell */
769              ierr = DMPlexInsertSupport(sdm, newp, s, hybcell);CHKERRQ(ierr);
770           } else {
771             /* Split new face:   Replace positive side cell with cohesive cell */
772             ierr = DMPlexInsertSupport(sdm, splitp, s, hybcell);CHKERRQ(ierr);
773             /* Get orientation for cohesive face */
774             {
775               const PetscInt *ncone, *nconeO;
776               PetscInt        nconeSize, nc;
777 
778               ierr = DMPlexGetConeSize(dm, support[s], &nconeSize);CHKERRQ(ierr);
779               ierr = DMPlexGetCone(dm, support[s], &ncone);CHKERRQ(ierr);
780               ierr = DMPlexGetConeOrientation(dm, support[s], &nconeO);CHKERRQ(ierr);
781               for (nc = 0; nc < nconeSize; ++nc) {
782                 if (ncone[nc] == oldp) {
783                   coneONew[0] = nconeO[nc];
784                   break;
785                 }
786               }
787               if (nc >= nconeSize) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not locate face %d in neighboring cell %d", oldp, support[s]);
788             }
789           }
790         }
791         /* Cohesive cell:    Old and new split face, then new cohesive faces */
792         coneNew[0]  = newp;   /* Extracted negative side orientation above */
793         coneNew[1]  = splitp;
794         coneONew[1] = coneONew[0];
795         for (q = 0; q < coneSize; ++q) {
796           ierr = PetscFindInt(cone[q], numSplitPoints[dep-1], splitPoints[dep-1], &v);CHKERRQ(ierr);
797           if (v < 0) {
798             ierr = PetscFindInt(cone[q], numUnsplitPoints[dep-1], unsplitPoints[dep-1], &v);CHKERRQ(ierr);
799             coneNew[2+q]  = v + pMaxNew[dep] + numSplitPoints[dep] + numSplitPoints[dep-1];
800             coneONew[2+q] = 0;
801           } else {
802             coneNew[2+q]  = v + pMaxNew[dep] + numSplitPoints[dep];
803           }
804           coneONew[2+q] = 0;
805         }
806         ierr = DMPlexSetCone(sdm, hybcell, coneNew);CHKERRQ(ierr);
807         ierr = DMPlexSetConeOrientation(sdm, hybcell, coneONew);CHKERRQ(ierr);
808       } else if (dep == 0) {
809         const PetscInt hybedge = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
810 
811         /* Split old vertex: Edges in old split faces and new cohesive edge */
812         for (e = 0, qn = 0; e < supportSize; ++e) {
813           PetscInt val;
814 
815           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
816           if ((val == 1) || (val == (shift + 1))) {
817             supportNew[qn++] = support[e] + depthOffset[dep+1];
818           }
819         }
820         supportNew[qn] = hybedge;
821         ierr = DMPlexSetSupport(sdm, newp, supportNew);CHKERRQ(ierr);
822         /* Split new vertex: Edges in new split faces and new cohesive edge */
823         for (e = 0, qp = 0; e < supportSize; ++e) {
824           PetscInt val, edge;
825 
826           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
827           if (val == 1) {
828             ierr = PetscFindInt(support[e], numSplitPoints[dep+1], splitPoints[dep+1], &edge);CHKERRQ(ierr);
829             if (edge < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Edge %d is not a split edge", support[e]);
830             supportNew[qp++] = edge + pMaxNew[dep+1];
831           } else if (val == -(shift + 1)) {
832             supportNew[qp++] = support[e] + depthOffset[dep+1];
833           }
834         }
835         supportNew[qp] = hybedge;
836         ierr = DMPlexSetSupport(sdm, splitp, supportNew);CHKERRQ(ierr);
837         /* Hybrid edge:    Old and new split vertex */
838         coneNew[0] = newp;
839         coneNew[1] = splitp;
840         ierr = DMPlexSetCone(sdm, hybedge, coneNew);CHKERRQ(ierr);
841         for (e = 0, qf = 0; e < supportSize; ++e) {
842           PetscInt val, edge;
843 
844           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
845           if (val == 1) {
846             ierr = PetscFindInt(support[e], numSplitPoints[dep+1], splitPoints[dep+1], &edge);CHKERRQ(ierr);
847             if (edge < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Edge %d is not a split edge", support[e]);
848             supportNew[qf++] = edge + pMaxNew[dep+2] + numSplitPoints[dep+2];
849           }
850         }
851         ierr = DMPlexSetSupport(sdm, hybedge, supportNew);CHKERRQ(ierr);
852       } else if (dep == dim-2) {
853         const PetscInt hybface = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
854 
855         /* Split old edge:   old vertices in cone so no change */
856         /* Split new edge:   new vertices in cone */
857         for (q = 0; q < coneSize; ++q) {
858           ierr = PetscFindInt(cone[q], numSplitPoints[dep-1], splitPoints[dep-1], &v);CHKERRQ(ierr);
859 
860           coneNew[q] = v + pMaxNew[dep-1];
861         }
862         ierr = DMPlexSetCone(sdm, splitp, coneNew);CHKERRQ(ierr);
863         /* Split old edge: Faces in positive side cells and old split faces */
864         for (e = 0, q = 0; e < supportSize; ++e) {
865           PetscInt val;
866 
867           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
868           if (val == dim-1) {
869             supportNew[q++] = support[e] + depthOffset[dep+1];
870           } else if (val == (shift + dim-1)) {
871             supportNew[q++] = support[e] + depthOffset[dep+1];
872           }
873         }
874         supportNew[q++] = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
875         ierr = DMPlexSetSupport(sdm, newp, supportNew);CHKERRQ(ierr);
876         /* Split new edge: Faces in negative side cells and new split faces */
877         for (e = 0, q = 0; e < supportSize; ++e) {
878           PetscInt val, face;
879 
880           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
881           if (val == dim-1) {
882             ierr = PetscFindInt(support[e], numSplitPoints[dep+1], splitPoints[dep+1], &face);CHKERRQ(ierr);
883             if (face < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Face %d is not a split face", support[e]);
884             supportNew[q++] = face + pMaxNew[dep+1];
885           } else if (val == -(shift + dim-1)) {
886             supportNew[q++] = support[e] + depthOffset[dep+1];
887           }
888         }
889         supportNew[q++] = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
890         ierr = DMPlexSetSupport(sdm, splitp, supportNew);CHKERRQ(ierr);
891         /* Hybrid face */
892         coneNew[0] = newp;
893         coneNew[1] = splitp;
894         for (v = 0; v < coneSize; ++v) {
895           PetscInt vertex;
896           ierr = PetscFindInt(cone[v], numSplitPoints[dep-1], splitPoints[dep-1], &vertex);CHKERRQ(ierr);
897           if (vertex < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Vertex %d is not a split vertex", support[e]);
898           coneNew[2+v] = vertex + pMaxNew[dep] + numSplitPoints[dep];
899         }
900         ierr = DMPlexSetCone(sdm, hybface, coneNew);CHKERRQ(ierr);
901         for (e = 0, qf = 0; e < supportSize; ++e) {
902           PetscInt val, face;
903 
904           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
905           if (val == dim-1) {
906             ierr = PetscFindInt(support[e], numSplitPoints[dep+1], splitPoints[dep+1], &face);CHKERRQ(ierr);
907             if (face < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Face %d is not a split face", support[e]);
908             supportNew[qf++] = face + pMaxNew[dep+2] + numSplitPoints[dep+2];
909           }
910         }
911         ierr = DMPlexSetSupport(sdm, hybface, supportNew);CHKERRQ(ierr);
912       }
913     }
914   }
915   for (dep = 0; dep <= depth; ++dep) {
916     for (p = 0; p < numUnsplitPoints[dep]; ++p) {
917       const PetscInt  oldp   = unsplitPoints[dep][p];
918       const PetscInt  newp   = oldp + depthOffset[dep];
919       const PetscInt *cone, *support, *ornt;
920       PetscInt        coneSize, supportSize, supportSizeNew, q, qf, e, s;
921 
922       ierr = DMPlexGetConeSize(dm, oldp, &coneSize);CHKERRQ(ierr);
923       ierr = DMPlexGetCone(dm, oldp, &cone);CHKERRQ(ierr);
924       ierr = DMPlexGetConeOrientation(dm, oldp, &ornt);CHKERRQ(ierr);
925       ierr = DMPlexGetSupportSize(dm, oldp, &supportSize);CHKERRQ(ierr);
926       ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
927       if (dep == 0) {
928         const PetscInt hybedge = p + pMaxNew[dep+1] + numSplitPoints[dep+1] + numSplitPoints[dep];
929 
930         /* Unsplit vertex */
931         ierr = DMPlexGetSupportSize(sdm, newp, &supportSizeNew);CHKERRQ(ierr);
932         for (s = 0, q = 0; s < supportSize; ++s) {
933           supportNew[q++] = support[s] + depthOffset[dep+1];
934           ierr = PetscFindInt(support[s], numSplitPoints[dep+1], splitPoints[dep+1], &e);CHKERRQ(ierr);
935           if (e >= 0) {
936             supportNew[q++] = e + pMaxNew[dep+1];
937           }
938         }
939         supportNew[q++] = hybedge;
940         supportNew[q++] = hybedge;
941         if (q != supportSizeNew) SETERRQ3(comm, PETSC_ERR_ARG_WRONG, "Support size %d != %d for vertex %d", q, supportSizeNew, newp);
942         ierr = DMPlexSetSupport(sdm, newp, supportNew);CHKERRQ(ierr);
943         /* Hybrid edge */
944         coneNew[0] = newp;
945         coneNew[1] = newp;
946         ierr = DMPlexSetCone(sdm, hybedge, coneNew);CHKERRQ(ierr);
947         for (e = 0, qf = 0; e < supportSize; ++e) {
948           PetscInt val, edge;
949 
950           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
951           if (val == 1) {
952             ierr = PetscFindInt(support[e], numSplitPoints[dep+1], splitPoints[dep+1], &edge);CHKERRQ(ierr);
953             if (edge < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Edge %d is not a split edge", support[e]);
954             supportNew[qf++] = edge + pMaxNew[dep+2] + numSplitPoints[dep+2];
955           }
956         }
957         ierr = DMPlexSetSupport(sdm, hybedge, supportNew);CHKERRQ(ierr);
958       }
959     }
960   }
961   /* Step 6b: Replace split points in negative side cones */
962   for (sp = 0; sp < numSP; ++sp) {
963     PetscInt        dep = values[sp];
964     IS              pIS;
965     PetscInt        numPoints;
966     const PetscInt *points;
967 
968     if (dep >= 0) continue;
969     ierr = DMLabelGetStratumIS(label, dep, &pIS);CHKERRQ(ierr);
970     if (!pIS) continue;
971     dep  = -dep - shift;
972     ierr = ISGetLocalSize(pIS, &numPoints);CHKERRQ(ierr);
973     ierr = ISGetIndices(pIS, &points);CHKERRQ(ierr);
974     for (p = 0; p < numPoints; ++p) {
975       const PetscInt  oldp = points[p];
976       const PetscInt  newp = depthOffset[dep] + oldp;
977       const PetscInt *cone;
978       PetscInt        coneSize, c;
979       /* PetscBool       replaced = PETSC_FALSE; */
980 
981       /* Negative edge: replace split vertex */
982       /* Negative cell: replace split face */
983       ierr = DMPlexGetConeSize(sdm, newp, &coneSize);CHKERRQ(ierr);
984       ierr = DMPlexGetCone(sdm, newp, &cone);CHKERRQ(ierr);
985       for (c = 0; c < coneSize; ++c) {
986         const PetscInt coldp = cone[c] - depthOffset[dep-1];
987         PetscInt       csplitp, cp, val;
988 
989         ierr = DMLabelGetValue(label, coldp, &val);CHKERRQ(ierr);
990         if (val == dep-1) {
991           ierr = PetscFindInt(coldp, numSplitPoints[dep-1], splitPoints[dep-1], &cp);CHKERRQ(ierr);
992           if (cp < 0) SETERRQ2(comm, PETSC_ERR_ARG_WRONG, "Point %d is not a split point of dimension %d", oldp, dep-1);
993           csplitp  = pMaxNew[dep-1] + cp;
994           ierr     = DMPlexInsertCone(sdm, newp, c, csplitp);CHKERRQ(ierr);
995           /* replaced = PETSC_TRUE; */
996         }
997       }
998       /* Cells with only a vertex or edge on the submesh have no replacement */
999       /* if (!replaced) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "The cone of point %d does not contain split points", oldp); */
1000     }
1001     ierr = ISRestoreIndices(pIS, &points);CHKERRQ(ierr);
1002     ierr = ISDestroy(&pIS);CHKERRQ(ierr);
1003   }
1004   /* Step 7: Stratify */
1005   ierr = DMPlexStratify(sdm);CHKERRQ(ierr);
1006   /* Step 8: Coordinates */
1007   ierr = DMPlexShiftCoordinates_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
1008   ierr = DMPlexGetCoordinateSection(sdm, &coordSection);CHKERRQ(ierr);
1009   ierr = DMGetCoordinatesLocal(sdm, &coordinates);CHKERRQ(ierr);
1010   ierr = VecGetArray(coordinates, &coords);CHKERRQ(ierr);
1011   for (v = 0; v < (numSplitPoints ? numSplitPoints[0] : 0); ++v) {
1012     const PetscInt newp   = depthOffset[0] + splitPoints[0][v];
1013     const PetscInt splitp = pMaxNew[0] + v;
1014     PetscInt       dof, off, soff, d;
1015 
1016     ierr = PetscSectionGetDof(coordSection, newp, &dof);CHKERRQ(ierr);
1017     ierr = PetscSectionGetOffset(coordSection, newp, &off);CHKERRQ(ierr);
1018     ierr = PetscSectionGetOffset(coordSection, splitp, &soff);CHKERRQ(ierr);
1019     for (d = 0; d < dof; ++d) coords[soff+d] = coords[off+d];
1020   }
1021   ierr = VecRestoreArray(coordinates, &coords);CHKERRQ(ierr);
1022   /* Step 9: SF, if I can figure this out we can split the mesh in parallel */
1023   ierr = DMPlexShiftSF_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
1024   /* Step 10: Labels */
1025   ierr = DMPlexShiftLabels_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
1026   ierr = DMPlexGetNumLabels(sdm, &numLabels);CHKERRQ(ierr);
1027   for (dep = 0; dep <= depth; ++dep) {
1028     for (p = 0; p < numSplitPoints[dep]; ++p) {
1029       const PetscInt newp   = depthOffset[dep] + splitPoints[dep][p];
1030       const PetscInt splitp = pMaxNew[dep] + p;
1031       PetscInt       l;
1032 
1033       for (l = 0; l < numLabels; ++l) {
1034         DMLabel     mlabel;
1035         const char *lname;
1036         PetscInt    val;
1037         PetscBool   isDepth;
1038 
1039         ierr = DMPlexGetLabelName(sdm, l, &lname);CHKERRQ(ierr);
1040         ierr = PetscStrcmp(lname, "depth", &isDepth);CHKERRQ(ierr);
1041         if (isDepth) continue;
1042         ierr = DMPlexGetLabel(sdm, lname, &mlabel);CHKERRQ(ierr);
1043         ierr = DMLabelGetValue(mlabel, newp, &val);CHKERRQ(ierr);
1044         if (val >= 0) {
1045           ierr = DMLabelSetValue(mlabel, splitp, val);CHKERRQ(ierr);
1046 #if 0
1047           /* Do not put cohesive edges into the label */
1048           if (dep == 0) {
1049             const PetscInt cedge = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
1050             ierr = DMLabelSetValue(mlabel, cedge, val);CHKERRQ(ierr);
1051           } else if (dep == dim-2) {
1052             const PetscInt cface = p + pMaxNew[dep+1] + numSplitPoints[dep+1];
1053             ierr = DMLabelSetValue(mlabel, cface, val);CHKERRQ(ierr);
1054           }
1055           /* Do not put cohesive faces into the label */
1056 #endif
1057         }
1058       }
1059     }
1060   }
1061   for (sp = 0; sp < numSP; ++sp) {
1062     const PetscInt dep = values[sp];
1063 
1064     if ((dep < 0) || (dep > depth)) continue;
1065     if (splitIS[dep]) {ierr = ISRestoreIndices(splitIS[dep], &splitPoints[dep]);CHKERRQ(ierr);}
1066     ierr = ISDestroy(&splitIS[dep]);CHKERRQ(ierr);
1067     if (unsplitIS[dep]) {ierr = ISRestoreIndices(unsplitIS[dep], &unsplitPoints[dep]);CHKERRQ(ierr);}
1068     ierr = ISDestroy(&unsplitIS[dep]);CHKERRQ(ierr);
1069   }
1070   if (label) {
1071     ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
1072     ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
1073   }
1074   for (d = 0; d <= depth; ++d) {
1075     ierr = DMPlexGetDepthStratum(sdm, d, NULL, &pEnd);CHKERRQ(ierr);
1076     pMaxNew[d] = pEnd - numHybridPoints[d];
1077   }
1078   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);
1079   ierr = PetscFree3(depthShift, depthOffset, pMaxNew);CHKERRQ(ierr);
1080   ierr = PetscFree3(coneNew, coneONew, supportNew);CHKERRQ(ierr);
1081   ierr = PetscFree7(splitIS, unsplitIS, numSplitPoints, numUnsplitPoints, numHybridPoints, splitPoints, unsplitPoints);CHKERRQ(ierr);
1082   PetscFunctionReturn(0);
1083 }
1084 
1085 #undef __FUNCT__
1086 #define __FUNCT__ "DMPlexConstructCohesiveCells"
1087 /*@C
1088   DMPlexConstructCohesiveCells - Construct cohesive cells which split the face along an internal interface
1089 
1090   Collective on dm
1091 
1092   Input Parameters:
1093 + dm - The original DM
1094 - label - The label specifying the boundary faces (this could be auto-generated)
1095 
1096   Output Parameters:
1097 - dmSplit - The new DM
1098 
1099   Level: developer
1100 
1101 .seealso: DMCreate(), DMPlexLabelCohesiveComplete()
1102 @*/
1103 PetscErrorCode DMPlexConstructCohesiveCells(DM dm, DMLabel label, DM *dmSplit)
1104 {
1105   DM             sdm;
1106   PetscInt       dim;
1107   PetscErrorCode ierr;
1108 
1109   PetscFunctionBegin;
1110   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
1111   PetscValidPointer(dmSplit, 3);
1112   ierr = DMCreate(PetscObjectComm((PetscObject)dm), &sdm);CHKERRQ(ierr);
1113   ierr = DMSetType(sdm, DMPLEX);CHKERRQ(ierr);
1114   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1115   ierr = DMPlexSetDimension(sdm, dim);CHKERRQ(ierr);
1116   switch (dim) {
1117   case 2:
1118   case 3:
1119     ierr = DMPlexConstructCohesiveCells_Internal(dm, label, sdm);CHKERRQ(ierr);
1120     break;
1121   default:
1122     SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot construct cohesive cells for dimension %d", dim);
1123   }
1124   *dmSplit = sdm;
1125   PetscFunctionReturn(0);
1126 }
1127 
1128 #undef __FUNCT__
1129 #define __FUNCT__ "DMPlexLabelCohesiveComplete"
1130 /*@
1131   DMPlexLabelCohesiveComplete - Starting with a label marking vertices on an internal surface, we add all other mesh pieces
1132   to complete the surface
1133 
1134   Input Parameters:
1135 + dm - The DM
1136 . label - A DMLabel marking the surface vertices
1137 . flip  - Flag to flip the submesh normal and replace points on the other side
1138 - subdm - The subDM associated with the label, or NULL
1139 
1140   Output Parameter:
1141 . label - A DMLabel marking all surface points
1142 
1143   Level: developer
1144 
1145 .seealso: DMPlexConstructCohesiveCells(), DMPlexLabelComplete()
1146 @*/
1147 PetscErrorCode DMPlexLabelCohesiveComplete(DM dm, DMLabel label, PetscBool flip, DM subdm)
1148 {
1149   DMLabel         depthLabel;
1150   IS              dimIS, subpointIS, facePosIS, faceNegIS;
1151   const PetscInt *points, *subpoints;
1152   const PetscInt  rev   = flip ? -1 : 1;
1153   PetscInt        shift = 100, shift2 = 200, dim, dep, cStart, cEnd, numPoints, numSubpoints, p, val;
1154   PetscErrorCode  ierr;
1155 
1156   PetscFunctionBegin;
1157   ierr = DMPlexGetDepthLabel(dm, &depthLabel);CHKERRQ(ierr);
1158   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1159   if (subdm) {
1160     ierr = DMPlexCreateSubpointIS(subdm, &subpointIS);CHKERRQ(ierr);
1161     if (subpointIS) {
1162       ierr = ISGetLocalSize(subpointIS, &numSubpoints);CHKERRQ(ierr);
1163       ierr = ISGetIndices(subpointIS, &subpoints);CHKERRQ(ierr);
1164     }
1165   }
1166   /* Mark cell on the fault, and its faces which touch the fault: cell orientation for face gives the side of the fault */
1167   ierr = DMLabelGetStratumIS(label, dim-1, &dimIS);CHKERRQ(ierr);
1168   if (!dimIS) PetscFunctionReturn(0);
1169   ierr = ISGetLocalSize(dimIS, &numPoints);CHKERRQ(ierr);
1170   ierr = ISGetIndices(dimIS, &points);CHKERRQ(ierr);
1171   for (p = 0; p < numPoints; ++p) { /* Loop over fault faces */
1172     const PetscInt *support;
1173     PetscInt        supportSize, s;
1174 
1175     ierr = DMPlexGetSupportSize(dm, points[p], &supportSize);CHKERRQ(ierr);
1176     if (supportSize != 2) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Split face %d has %d != 2 supports", points[p], supportSize);
1177     ierr = DMPlexGetSupport(dm, points[p], &support);CHKERRQ(ierr);
1178     for (s = 0; s < supportSize; ++s) {
1179       const PetscInt *cone, *ornt;
1180       PetscInt        coneSize, c;
1181       PetscBool       pos = PETSC_TRUE;
1182 
1183       ierr = DMPlexGetConeSize(dm, support[s], &coneSize);CHKERRQ(ierr);
1184       ierr = DMPlexGetCone(dm, support[s], &cone);CHKERRQ(ierr);
1185       ierr = DMPlexGetConeOrientation(dm, support[s], &ornt);CHKERRQ(ierr);
1186       for (c = 0; c < coneSize; ++c) {
1187         if (cone[c] == points[p]) {
1188           PetscInt o = ornt[c];
1189 
1190           if (subdm) {
1191             const PetscInt *subcone, *subornt;
1192             PetscInt        subpoint, subface, subconeSize, sc;
1193 
1194             ierr = PetscFindInt(support[s], numSubpoints, subpoints, &subpoint);CHKERRQ(ierr);
1195             ierr = PetscFindInt(points[p],  numSubpoints, subpoints, &subface);CHKERRQ(ierr);
1196             ierr = DMPlexGetConeSize(subdm, subpoint, &subconeSize);CHKERRQ(ierr);
1197             ierr = DMPlexGetCone(subdm, subpoint, &subcone);CHKERRQ(ierr);
1198             ierr = DMPlexGetConeOrientation(subdm, subpoint, &subornt);CHKERRQ(ierr);
1199             for (sc = 0; sc < subconeSize; ++sc) {
1200               if (subcone[sc] == subface) {
1201                 o = subornt[0];
1202                 break;
1203               }
1204             }
1205             if (sc >= subconeSize) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find point %d in cone for subpoint %d", points[p], subpoint);
1206           }
1207           if (o >= 0) {
1208             ierr = DMLabelSetValue(label, support[s],  rev*(shift+dim));CHKERRQ(ierr);
1209             pos  = rev > 0 ? PETSC_TRUE : PETSC_FALSE;
1210           } else {
1211             ierr = DMLabelSetValue(label, support[s], -rev*(shift+dim));CHKERRQ(ierr);
1212             pos  = rev > 0 ? PETSC_FALSE : PETSC_TRUE;
1213           }
1214           break;
1215         }
1216       }
1217       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]);
1218       /* Put faces touching the fault in the label */
1219       for (c = 0; c < coneSize; ++c) {
1220         const PetscInt point = cone[c];
1221 
1222         ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
1223         if (val == -1) {
1224           PetscInt *closure = NULL;
1225           PetscInt  closureSize, cl;
1226 
1227           ierr = DMPlexGetTransitiveClosure(dm, point, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1228           for (cl = 0; cl < closureSize*2; cl += 2) {
1229             const PetscInt clp = closure[cl];
1230 
1231             ierr = DMLabelGetValue(label, clp, &val);CHKERRQ(ierr);
1232             if ((val >= 0) && (val < dim-1)) {
1233               ierr = DMLabelSetValue(label, point, pos == PETSC_TRUE ? shift+dim-1 : -(shift+dim-1));CHKERRQ(ierr);
1234               break;
1235             }
1236           }
1237           ierr = DMPlexRestoreTransitiveClosure(dm, point, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1238         }
1239       }
1240     }
1241   }
1242   if (subdm) {
1243     if (subpointIS) {ierr = ISRestoreIndices(subpointIS, &subpoints);CHKERRQ(ierr);}
1244     ierr = ISDestroy(&subpointIS);CHKERRQ(ierr);
1245   }
1246   ierr = ISRestoreIndices(dimIS, &points);CHKERRQ(ierr);
1247   ierr = ISDestroy(&dimIS);CHKERRQ(ierr);
1248   /* Search for other cells/faces/edges connected to the fault by a vertex */
1249   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
1250   ierr = DMLabelGetStratumIS(label, 0, &dimIS);CHKERRQ(ierr);
1251   if (!dimIS) PetscFunctionReturn(0);
1252   ierr = ISGetLocalSize(dimIS, &numPoints);CHKERRQ(ierr);
1253   ierr = ISGetIndices(dimIS, &points);CHKERRQ(ierr);
1254   for (p = 0; p < numPoints; ++p) { /* Loop over fault vertices */
1255     PetscInt *star = NULL;
1256     PetscInt  starSize, s;
1257     PetscInt  again = 1;  /* 0: Finished 1: Keep iterating after a change 2: No change */
1258 
1259     /* All points connected to the fault are inside a cell, so at the top level we will only check cells */
1260     ierr = DMPlexGetTransitiveClosure(dm, points[p], PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1261     while (again) {
1262       if (again > 1) SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Could not classify all cells connected to the fault");
1263       again = 0;
1264       for (s = 0; s < starSize*2; s += 2) {
1265         const PetscInt  point = star[s];
1266         const PetscInt *cone;
1267         PetscInt        coneSize, c;
1268 
1269         if ((point < cStart) || (point >= cEnd)) continue;
1270         ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
1271         if (val != -1) continue;
1272         again = again == 1 ? 1 : 2;
1273         ierr  = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
1274         ierr  = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
1275         for (c = 0; c < coneSize; ++c) {
1276           ierr = DMLabelGetValue(label, cone[c], &val);CHKERRQ(ierr);
1277           if (val != -1) {
1278             const PetscInt *ccone;
1279             PetscInt        cconeSize, cc, side;
1280 
1281             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);
1282             if (val > 0) side =  1;
1283             else         side = -1;
1284             ierr = DMLabelSetValue(label, point, side*(shift+dim));CHKERRQ(ierr);
1285             /* Mark cell faces which touch the fault */
1286             ierr = DMPlexGetConeSize(dm, point, &cconeSize);CHKERRQ(ierr);
1287             ierr = DMPlexGetCone(dm, point, &ccone);CHKERRQ(ierr);
1288             for (cc = 0; cc < cconeSize; ++cc) {
1289               PetscInt *closure = NULL;
1290               PetscInt  closureSize, cl;
1291 
1292               ierr = DMLabelGetValue(label, ccone[cc], &val);CHKERRQ(ierr);
1293               if (val != -1) continue;
1294               ierr = DMPlexGetTransitiveClosure(dm, ccone[cc], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1295               for (cl = 0; cl < closureSize*2; cl += 2) {
1296                 const PetscInt clp = closure[cl];
1297 
1298                 ierr = DMLabelGetValue(label, clp, &val);CHKERRQ(ierr);
1299                 if (val == -1) continue;
1300                 ierr = DMLabelSetValue(label, ccone[cc], side*(shift+dim-1));CHKERRQ(ierr);
1301                 break;
1302               }
1303               ierr = DMPlexRestoreTransitiveClosure(dm, ccone[cc], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1304             }
1305             again = 1;
1306             break;
1307           }
1308         }
1309       }
1310     }
1311     /* Classify the rest by cell membership */
1312     for (s = 0; s < starSize*2; s += 2) {
1313       const PetscInt point = star[s];
1314 
1315       ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
1316       if (val == -1) {
1317         PetscInt  *sstar = NULL;
1318         PetscInt   sstarSize, ss;
1319         PetscBool  marked = PETSC_FALSE;
1320 
1321         ierr = DMPlexGetTransitiveClosure(dm, point, PETSC_FALSE, &sstarSize, &sstar);CHKERRQ(ierr);
1322         for (ss = 0; ss < sstarSize*2; ss += 2) {
1323           const PetscInt spoint = sstar[ss];
1324 
1325           if ((spoint < cStart) || (spoint >= cEnd)) continue;
1326           ierr = DMLabelGetValue(label, spoint, &val);CHKERRQ(ierr);
1327           if (val == -1) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Cell %d in star of %d does not have a valid label", spoint, point);
1328           ierr = DMLabelGetValue(depthLabel, point, &dep);CHKERRQ(ierr);
1329           if (val > 0) {
1330             ierr = DMLabelSetValue(label, point,   shift+dep);CHKERRQ(ierr);
1331           } else {
1332             ierr = DMLabelSetValue(label, point, -(shift+dep));CHKERRQ(ierr);
1333           }
1334           marked = PETSC_TRUE;
1335           break;
1336         }
1337         ierr = DMPlexRestoreTransitiveClosure(dm, point, PETSC_FALSE, &sstarSize, &sstar);CHKERRQ(ierr);
1338         if (!marked) SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Point %d could not be classified", point);
1339       }
1340     }
1341     ierr = DMPlexRestoreTransitiveClosure(dm, points[p], PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1342   }
1343   ierr = ISRestoreIndices(dimIS, &points);CHKERRQ(ierr);
1344   ierr = ISDestroy(&dimIS);CHKERRQ(ierr);
1345   /* If any faces touching the fault divide cells on either side, split them */
1346   ierr = DMLabelGetStratumIS(label,   shift+dim-1,  &facePosIS);CHKERRQ(ierr);
1347   ierr = DMLabelGetStratumIS(label, -(shift+dim-1), &faceNegIS);CHKERRQ(ierr);
1348   ierr = ISExpand(facePosIS, faceNegIS, &dimIS);CHKERRQ(ierr);
1349   ierr = ISDestroy(&facePosIS);CHKERRQ(ierr);
1350   ierr = ISDestroy(&faceNegIS);CHKERRQ(ierr);
1351   ierr = ISGetLocalSize(dimIS, &numPoints);CHKERRQ(ierr);
1352   ierr = ISGetIndices(dimIS, &points);CHKERRQ(ierr);
1353   for (p = 0; p < numPoints; ++p) {
1354     const PetscInt  point = points[p];
1355     const PetscInt *support;
1356     PetscInt        supportSize, valA, valB;
1357 
1358     ierr = DMPlexGetSupportSize(dm, point, &supportSize);CHKERRQ(ierr);
1359     if (supportSize != 2) continue;
1360     ierr = DMPlexGetSupport(dm, point, &support);CHKERRQ(ierr);
1361     ierr = DMLabelGetValue(label, support[0], &valA);CHKERRQ(ierr);
1362     ierr = DMLabelGetValue(label, support[1], &valB);CHKERRQ(ierr);
1363     if ((valA == -1) || (valB == -1)) continue;
1364     if (valA*valB > 0) continue;
1365     /* Split the face */
1366     ierr = DMLabelGetValue(label, point, &valA);CHKERRQ(ierr);
1367     ierr = DMLabelClearValue(label, point, valA);CHKERRQ(ierr);
1368     ierr = DMLabelSetValue(label, point, dim-1);CHKERRQ(ierr);
1369     /* Label its closure as unsplit */
1370     {
1371       PetscInt *closure = NULL;
1372       PetscInt  closureSize, cl;
1373 
1374       ierr = DMPlexGetTransitiveClosure(dm, point, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1375       for (cl = 0; cl < closureSize*2; cl += 2) {
1376         ierr = DMLabelGetValue(label, closure[cl], &valA);CHKERRQ(ierr);
1377         if (valA != -1) continue;
1378         ierr = DMLabelGetValue(depthLabel, closure[cl], &dep);CHKERRQ(ierr);
1379         ierr = DMLabelSetValue(label, closure[cl], shift2+dep);CHKERRQ(ierr);
1380       }
1381       ierr = DMPlexRestoreTransitiveClosure(dm, point, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1382     }
1383   }
1384   ierr = ISRestoreIndices(dimIS, &points);CHKERRQ(ierr);
1385   ierr = ISDestroy(&dimIS);CHKERRQ(ierr);
1386   PetscFunctionReturn(0);
1387 }
1388 
1389 #undef __FUNCT__
1390 #define __FUNCT__ "DMPlexCreateHybridMesh"
1391 /*@C
1392   DMPlexCreateHybridMesh - Create a mesh with hybrid cells along an internal interface
1393 
1394   Collective on dm
1395 
1396   Input Parameters:
1397 + dm - The original DM
1398 - labelName - The label specifying the interface vertices
1399 
1400   Output Parameters:
1401 + hybridLabel - The label fully marking the interface
1402 - dmHybrid - The new DM
1403 
1404   Level: developer
1405 
1406 .seealso: DMPlexConstructCohesiveCells(), DMPlexLabelCohesiveComplete(), DMCreate()
1407 @*/
1408 PetscErrorCode DMPlexCreateHybridMesh(DM dm, DMLabel label, DMLabel *hybridLabel, DM *dmHybrid)
1409 {
1410   DM             idm;
1411   DMLabel        subpointMap, hlabel;
1412   PetscInt       dim;
1413   PetscErrorCode ierr;
1414 
1415   PetscFunctionBegin;
1416   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
1417   if (hybridLabel) PetscValidPointer(hybridLabel, 3);
1418   PetscValidPointer(dmHybrid, 4);
1419   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1420   ierr = DMPlexCreateSubmesh(dm, label, 1, &idm);CHKERRQ(ierr);
1421   ierr = DMPlexOrient(idm);CHKERRQ(ierr);
1422   ierr = DMPlexGetSubpointMap(idm, &subpointMap);CHKERRQ(ierr);
1423   ierr = DMLabelDuplicate(subpointMap, &hlabel);CHKERRQ(ierr);
1424   ierr = DMLabelClearStratum(hlabel, dim);CHKERRQ(ierr);
1425   ierr = DMPlexLabelCohesiveComplete(dm, hlabel, PETSC_FALSE, idm);CHKERRQ(ierr);
1426   ierr = DMDestroy(&idm);CHKERRQ(ierr);
1427   ierr = DMPlexConstructCohesiveCells(dm, hlabel, dmHybrid);CHKERRQ(ierr);
1428   if (hybridLabel) *hybridLabel = hlabel;
1429   else             {ierr = DMLabelDestroy(&hlabel);CHKERRQ(ierr);}
1430   PetscFunctionReturn(0);
1431 }
1432 
1433 #undef __FUNCT__
1434 #define __FUNCT__ "DMPlexMarkSubmesh_Uninterpolated"
1435 /* Here we need the explicit assumption that:
1436 
1437      For any marked cell, the marked vertices constitute a single face
1438 */
1439 static PetscErrorCode DMPlexMarkSubmesh_Uninterpolated(DM dm, DMLabel vertexLabel, PetscInt value, DMLabel subpointMap, PetscInt *numFaces, PetscInt *nFV, DM subdm)
1440 {
1441   IS               subvertexIS = NULL;
1442   const PetscInt  *subvertices;
1443   PetscInt        *pStart, *pEnd, *pMax, pSize;
1444   PetscInt         depth, dim, d, numSubVerticesInitial = 0, v;
1445   PetscErrorCode   ierr;
1446 
1447   PetscFunctionBegin;
1448   *numFaces = 0;
1449   *nFV      = 0;
1450   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
1451   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1452   pSize = PetscMax(depth, dim) + 1;
1453   ierr = PetscMalloc3(pSize,PetscInt,&pStart,pSize,PetscInt,&pEnd,pSize,PetscInt,&pMax);CHKERRQ(ierr);
1454   ierr = DMPlexGetHybridBounds(dm, depth >= 0 ? &pMax[depth] : NULL, depth>1 ? &pMax[depth-1] : NULL, depth>2 ? &pMax[1] : NULL, &pMax[0]);CHKERRQ(ierr);
1455   for (d = 0; d <= depth; ++d) {
1456     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1457     if (pMax[d] >= 0) pEnd[d] = PetscMin(pEnd[d], pMax[d]);
1458   }
1459   /* Loop over initial vertices and mark all faces in the collective star() */
1460   if (vertexLabel) {ierr = DMLabelGetStratumIS(vertexLabel, value, &subvertexIS);CHKERRQ(ierr);}
1461   if (subvertexIS) {
1462     ierr = ISGetSize(subvertexIS, &numSubVerticesInitial);CHKERRQ(ierr);
1463     ierr = ISGetIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1464   }
1465   for (v = 0; v < numSubVerticesInitial; ++v) {
1466     const PetscInt vertex = subvertices[v];
1467     PetscInt      *star   = NULL;
1468     PetscInt       starSize, s, numCells = 0, c;
1469 
1470     ierr = DMPlexGetTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1471     for (s = 0; s < starSize*2; s += 2) {
1472       const PetscInt point = star[s];
1473       if ((point >= pStart[depth]) && (point < pEnd[depth])) star[numCells++] = point;
1474     }
1475     for (c = 0; c < numCells; ++c) {
1476       const PetscInt cell    = star[c];
1477       PetscInt      *closure = NULL;
1478       PetscInt       closureSize, cl;
1479       PetscInt       cellLoc, numCorners = 0, faceSize = 0;
1480 
1481       ierr = DMLabelGetValue(subpointMap, cell, &cellLoc);CHKERRQ(ierr);
1482       if (cellLoc == 2) continue;
1483       if (cellLoc >= 0) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Cell %d has dimension %d in the surface label", cell, cellLoc);
1484       ierr = DMPlexGetTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1485       for (cl = 0; cl < closureSize*2; cl += 2) {
1486         const PetscInt point = closure[cl];
1487         PetscInt       vertexLoc;
1488 
1489         if ((point >= pStart[0]) && (point < pEnd[0])) {
1490           ++numCorners;
1491           ierr = DMLabelGetValue(vertexLabel, point, &vertexLoc);CHKERRQ(ierr);
1492           if (vertexLoc == value) closure[faceSize++] = point;
1493         }
1494       }
1495       if (!(*nFV)) {ierr = DMPlexGetNumFaceVertices(dm, dim, numCorners, nFV);CHKERRQ(ierr);}
1496       if (faceSize > *nFV) SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Invalid submesh: Too many vertices %d of an element on the surface", faceSize);
1497       if (faceSize == *nFV) {
1498         const PetscInt *cells = NULL;
1499         PetscInt        numCells, nc;
1500 
1501         ++(*numFaces);
1502         for (cl = 0; cl < faceSize; ++cl) {
1503           ierr = DMLabelSetValue(subpointMap, closure[cl], 0);CHKERRQ(ierr);
1504         }
1505         ierr = DMPlexGetJoin(dm, faceSize, closure, &numCells, &cells);CHKERRQ(ierr);
1506         for (nc = 0; nc < numCells; ++nc) {
1507           ierr = DMLabelSetValue(subpointMap, cells[nc], 2);CHKERRQ(ierr);
1508         }
1509         ierr = DMPlexRestoreJoin(dm, faceSize, closure, &numCells, &cells);CHKERRQ(ierr);
1510       }
1511       ierr = DMPlexRestoreTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1512     }
1513     ierr = DMPlexRestoreTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1514   }
1515   if (subvertexIS) {
1516     ierr = ISRestoreIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1517   }
1518   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
1519   ierr = PetscFree3(pStart,pEnd,pMax);CHKERRQ(ierr);
1520   PetscFunctionReturn(0);
1521 }
1522 
1523 #undef __FUNCT__
1524 #define __FUNCT__ "DMPlexMarkSubmesh_Interpolated"
1525 static PetscErrorCode DMPlexMarkSubmesh_Interpolated(DM dm, DMLabel vertexLabel, PetscInt value, DMLabel subpointMap, DM subdm)
1526 {
1527   IS               subvertexIS;
1528   const PetscInt  *subvertices;
1529   PetscInt        *pStart, *pEnd, *pMax;
1530   PetscInt         dim, d, numSubVerticesInitial = 0, v;
1531   PetscErrorCode   ierr;
1532 
1533   PetscFunctionBegin;
1534   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1535   ierr = PetscMalloc3(dim+1,PetscInt,&pStart,dim+1,PetscInt,&pEnd,dim+1,PetscInt,&pMax);CHKERRQ(ierr);
1536   ierr = DMPlexGetHybridBounds(dm, &pMax[dim], dim>1 ? &pMax[dim-1] : NULL, dim > 2 ? &pMax[1] : NULL, &pMax[0]);CHKERRQ(ierr);
1537   for (d = 0; d <= dim; ++d) {
1538     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1539     if (pMax[d] >= 0) pEnd[d] = PetscMin(pEnd[d], pMax[d]);
1540   }
1541   /* Loop over initial vertices and mark all faces in the collective star() */
1542   ierr = DMLabelGetStratumIS(vertexLabel, value, &subvertexIS);CHKERRQ(ierr);
1543   if (subvertexIS) {
1544     ierr = ISGetSize(subvertexIS, &numSubVerticesInitial);CHKERRQ(ierr);
1545     ierr = ISGetIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1546   }
1547   for (v = 0; v < numSubVerticesInitial; ++v) {
1548     const PetscInt vertex = subvertices[v];
1549     PetscInt      *star   = NULL;
1550     PetscInt       starSize, s, numFaces = 0, f;
1551 
1552     ierr = DMPlexGetTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1553     for (s = 0; s < starSize*2; s += 2) {
1554       const PetscInt point = star[s];
1555       if ((point >= pStart[dim-1]) && (point < pEnd[dim-1])) star[numFaces++] = point;
1556     }
1557     for (f = 0; f < numFaces; ++f) {
1558       const PetscInt face    = star[f];
1559       PetscInt      *closure = NULL;
1560       PetscInt       closureSize, c;
1561       PetscInt       faceLoc;
1562 
1563       ierr = DMLabelGetValue(subpointMap, face, &faceLoc);CHKERRQ(ierr);
1564       if (faceLoc == dim-1) continue;
1565       if (faceLoc >= 0) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Face %d has dimension %d in the surface label", face, faceLoc);
1566       ierr = DMPlexGetTransitiveClosure(dm, face, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1567       for (c = 0; c < closureSize*2; c += 2) {
1568         const PetscInt point = closure[c];
1569         PetscInt       vertexLoc;
1570 
1571         if ((point >= pStart[0]) && (point < pEnd[0])) {
1572           ierr = DMLabelGetValue(vertexLabel, point, &vertexLoc);CHKERRQ(ierr);
1573           if (vertexLoc != value) break;
1574         }
1575       }
1576       if (c == closureSize*2) {
1577         const PetscInt *support;
1578         PetscInt        supportSize, s;
1579 
1580         for (c = 0; c < closureSize*2; c += 2) {
1581           const PetscInt point = closure[c];
1582 
1583           for (d = 0; d < dim; ++d) {
1584             if ((point >= pStart[d]) && (point < pEnd[d])) {
1585               ierr = DMLabelSetValue(subpointMap, point, d);CHKERRQ(ierr);
1586               break;
1587             }
1588           }
1589         }
1590         ierr = DMPlexGetSupportSize(dm, face, &supportSize);CHKERRQ(ierr);
1591         ierr = DMPlexGetSupport(dm, face, &support);CHKERRQ(ierr);
1592         for (s = 0; s < supportSize; ++s) {
1593           ierr = DMLabelSetValue(subpointMap, support[s], dim);CHKERRQ(ierr);
1594         }
1595       }
1596       ierr = DMPlexRestoreTransitiveClosure(dm, face, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1597     }
1598     ierr = DMPlexRestoreTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1599   }
1600   if (subvertexIS) {
1601     ierr = ISRestoreIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1602   }
1603   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
1604   ierr = PetscFree3(pStart,pEnd,pMax);CHKERRQ(ierr);
1605   PetscFunctionReturn(0);
1606 }
1607 
1608 #undef __FUNCT__
1609 #define __FUNCT__ "DMPlexMarkCohesiveSubmesh_Uninterpolated"
1610 static PetscErrorCode DMPlexMarkCohesiveSubmesh_Uninterpolated(DM dm, PetscBool hasLagrange, const char labelname[], PetscInt value, DMLabel subpointMap, PetscInt *numFaces, PetscInt *nFV, PetscInt *subCells[], DM subdm)
1611 {
1612   DMLabel         label = NULL;
1613   const PetscInt *cone;
1614   PetscInt        dim, cMax, cEnd, c, subc = 0, p, coneSize;
1615   PetscErrorCode  ierr;
1616 
1617   PetscFunctionBegin;
1618   *numFaces = 0;
1619   *nFV = 0;
1620   if (labelname) {ierr = DMPlexGetLabel(dm, labelname, &label);CHKERRQ(ierr);}
1621   *subCells = NULL;
1622   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1623   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
1624   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
1625   if (cMax < 0) PetscFunctionReturn(0);
1626   if (label) {
1627     for (c = cMax; c < cEnd; ++c) {
1628       PetscInt val;
1629 
1630       ierr = DMLabelGetValue(label, c, &val);CHKERRQ(ierr);
1631       if (val == value) {
1632         ++(*numFaces);
1633         ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
1634       }
1635     }
1636   } else {
1637     *numFaces = cEnd - cMax;
1638     ierr = DMPlexGetConeSize(dm, cMax, &coneSize);CHKERRQ(ierr);
1639   }
1640   *nFV = hasLagrange ? coneSize/3 : coneSize/2;
1641   ierr = PetscMalloc(*numFaces *2 * sizeof(PetscInt), subCells);CHKERRQ(ierr);
1642   for (c = cMax; c < cEnd; ++c) {
1643     const PetscInt *cells;
1644     PetscInt        numCells;
1645 
1646     if (label) {
1647       PetscInt val;
1648 
1649       ierr = DMLabelGetValue(label, c, &val);CHKERRQ(ierr);
1650       if (val != value) continue;
1651     }
1652     ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
1653     for (p = 0; p < *nFV; ++p) {
1654       ierr = DMLabelSetValue(subpointMap, cone[p], 0);CHKERRQ(ierr);
1655     }
1656     /* Negative face */
1657     ierr = DMPlexGetJoin(dm, *nFV, cone, &numCells, &cells);CHKERRQ(ierr);
1658     /* Not true in parallel
1659     if (numCells != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells"); */
1660     for (p = 0; p < numCells; ++p) {
1661       ierr = DMLabelSetValue(subpointMap, cells[p], 2);CHKERRQ(ierr);
1662       (*subCells)[subc++] = cells[p];
1663     }
1664     ierr = DMPlexRestoreJoin(dm, *nFV, cone, &numCells, &cells);CHKERRQ(ierr);
1665     /* Positive face is not included */
1666   }
1667   PetscFunctionReturn(0);
1668 }
1669 
1670 #undef __FUNCT__
1671 #define __FUNCT__ "DMPlexMarkCohesiveSubmesh_Interpolated"
1672 static PetscErrorCode DMPlexMarkCohesiveSubmesh_Interpolated(DM dm, const char labelname[], PetscInt value, DMLabel subpointMap, DM subdm)
1673 {
1674   DMLabel        label = NULL;
1675   PetscInt      *pStart, *pEnd;
1676   PetscInt       dim, cMax, cEnd, c, d;
1677   PetscErrorCode ierr;
1678 
1679   PetscFunctionBegin;
1680   if (labelname) {ierr = DMPlexGetLabel(dm, labelname, &label);CHKERRQ(ierr);}
1681   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1682   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
1683   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
1684   if (cMax < 0) PetscFunctionReturn(0);
1685   ierr = PetscMalloc2(dim+1,PetscInt,&pStart,dim+1,PetscInt,&pEnd);CHKERRQ(ierr);
1686   for (d = 0; d <= dim; ++d) {ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);}
1687   for (c = cMax; c < cEnd; ++c) {
1688     const PetscInt *cone;
1689     PetscInt       *closure = NULL;
1690     PetscInt        fconeSize, coneSize, closureSize, cl, val;
1691 
1692     if (label) {
1693       ierr = DMLabelGetValue(label, c, &val);CHKERRQ(ierr);
1694       if (val != value) continue;
1695     }
1696     ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
1697     ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
1698     ierr = DMPlexGetConeSize(dm, cone[0], &fconeSize);CHKERRQ(ierr);
1699     if (coneSize != (fconeSize ? fconeSize : 1) + 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
1700     /* Negative face */
1701     ierr = DMPlexGetTransitiveClosure(dm, cone[0], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1702     for (cl = 0; cl < closureSize*2; cl += 2) {
1703       const PetscInt point = closure[cl];
1704 
1705       for (d = 0; d <= dim; ++d) {
1706         if ((point >= pStart[d]) && (point < pEnd[d])) {
1707           ierr = DMLabelSetValue(subpointMap, point, d);CHKERRQ(ierr);
1708           break;
1709         }
1710       }
1711     }
1712     ierr = DMPlexRestoreTransitiveClosure(dm, cone[0], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1713     /* Cells -- positive face is not included */
1714     for (cl = 0; cl < 1; ++cl) {
1715       const PetscInt *support;
1716       PetscInt        supportSize, s;
1717 
1718       ierr = DMPlexGetSupportSize(dm, cone[cl], &supportSize);CHKERRQ(ierr);
1719       if (supportSize != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive faces should separate two cells");
1720       ierr = DMPlexGetSupport(dm, cone[cl], &support);CHKERRQ(ierr);
1721       for (s = 0; s < supportSize; ++s) {
1722         ierr = DMLabelSetValue(subpointMap, support[s], dim);CHKERRQ(ierr);
1723       }
1724     }
1725   }
1726   ierr = PetscFree2(pStart, pEnd);CHKERRQ(ierr);
1727   PetscFunctionReturn(0);
1728 }
1729 
1730 #undef __FUNCT__
1731 #define __FUNCT__ "DMPlexGetFaceOrientation"
1732 PetscErrorCode DMPlexGetFaceOrientation(DM dm, PetscInt cell, PetscInt numCorners, PetscInt indices[], PetscInt oppositeVertex, PetscInt origVertices[], PetscInt faceVertices[], PetscBool *posOriented)
1733 {
1734   MPI_Comm       comm;
1735   PetscBool      posOrient = PETSC_FALSE;
1736   const PetscInt debug     = 0;
1737   PetscInt       cellDim, faceSize, f;
1738   PetscErrorCode ierr;
1739 
1740   PetscFunctionBegin;
1741   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1742   ierr = DMPlexGetDimension(dm, &cellDim);CHKERRQ(ierr);
1743   if (debug) {PetscPrintf(comm, "cellDim: %d numCorners: %d\n", cellDim, numCorners);CHKERRQ(ierr);}
1744 
1745   if (cellDim == 1 && numCorners == 2) {
1746     /* Triangle */
1747     faceSize  = numCorners-1;
1748     posOrient = !(oppositeVertex%2) ? PETSC_TRUE : PETSC_FALSE;
1749   } else if (cellDim == 2 && numCorners == 3) {
1750     /* Triangle */
1751     faceSize  = numCorners-1;
1752     posOrient = !(oppositeVertex%2) ? PETSC_TRUE : PETSC_FALSE;
1753   } else if (cellDim == 3 && numCorners == 4) {
1754     /* Tetrahedron */
1755     faceSize  = numCorners-1;
1756     posOrient = (oppositeVertex%2) ? PETSC_TRUE : PETSC_FALSE;
1757   } else if (cellDim == 1 && numCorners == 3) {
1758     /* Quadratic line */
1759     faceSize  = 1;
1760     posOrient = PETSC_TRUE;
1761   } else if (cellDim == 2 && numCorners == 4) {
1762     /* Quads */
1763     faceSize = 2;
1764     if ((indices[1] > indices[0]) && (indices[1] - indices[0] == 1)) {
1765       posOrient = PETSC_TRUE;
1766     } else if ((indices[0] == 3) && (indices[1] == 0)) {
1767       posOrient = PETSC_TRUE;
1768     } else {
1769       if (((indices[0] > indices[1]) && (indices[0] - indices[1] == 1)) || ((indices[0] == 0) && (indices[1] == 3))) {
1770         posOrient = PETSC_FALSE;
1771       } else SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid quad crossedge");
1772     }
1773   } else if (cellDim == 2 && numCorners == 6) {
1774     /* Quadratic triangle (I hate this) */
1775     /* Edges are determined by the first 2 vertices (corners of edges) */
1776     const PetscInt faceSizeTri = 3;
1777     PetscInt       sortedIndices[3], i, iFace;
1778     PetscBool      found                    = PETSC_FALSE;
1779     PetscInt       faceVerticesTriSorted[9] = {
1780       0, 3,  4, /* bottom */
1781       1, 4,  5, /* right */
1782       2, 3,  5, /* left */
1783     };
1784     PetscInt       faceVerticesTri[9] = {
1785       0, 3,  4, /* bottom */
1786       1, 4,  5, /* right */
1787       2, 5,  3, /* left */
1788     };
1789 
1790     faceSize = faceSizeTri;
1791     for (i = 0; i < faceSizeTri; ++i) sortedIndices[i] = indices[i];
1792     ierr = PetscSortInt(faceSizeTri, sortedIndices);CHKERRQ(ierr);
1793     for (iFace = 0; iFace < 3; ++iFace) {
1794       const PetscInt ii = iFace*faceSizeTri;
1795       PetscInt       fVertex, cVertex;
1796 
1797       if ((sortedIndices[0] == faceVerticesTriSorted[ii+0]) &&
1798           (sortedIndices[1] == faceVerticesTriSorted[ii+1])) {
1799         for (fVertex = 0; fVertex < faceSizeTri; ++fVertex) {
1800           for (cVertex = 0; cVertex < faceSizeTri; ++cVertex) {
1801             if (indices[cVertex] == faceVerticesTri[ii+fVertex]) {
1802               faceVertices[fVertex] = origVertices[cVertex];
1803               break;
1804             }
1805           }
1806         }
1807         found = PETSC_TRUE;
1808         break;
1809       }
1810     }
1811     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid tri crossface");
1812     if (posOriented) *posOriented = PETSC_TRUE;
1813     PetscFunctionReturn(0);
1814   } else if (cellDim == 2 && numCorners == 9) {
1815     /* Quadratic quad (I hate this) */
1816     /* Edges are determined by the first 2 vertices (corners of edges) */
1817     const PetscInt faceSizeQuad = 3;
1818     PetscInt       sortedIndices[3], i, iFace;
1819     PetscBool      found                      = PETSC_FALSE;
1820     PetscInt       faceVerticesQuadSorted[12] = {
1821       0, 1,  4, /* bottom */
1822       1, 2,  5, /* right */
1823       2, 3,  6, /* top */
1824       0, 3,  7, /* left */
1825     };
1826     PetscInt       faceVerticesQuad[12] = {
1827       0, 1,  4, /* bottom */
1828       1, 2,  5, /* right */
1829       2, 3,  6, /* top */
1830       3, 0,  7, /* left */
1831     };
1832 
1833     faceSize = faceSizeQuad;
1834     for (i = 0; i < faceSizeQuad; ++i) sortedIndices[i] = indices[i];
1835     ierr = PetscSortInt(faceSizeQuad, sortedIndices);CHKERRQ(ierr);
1836     for (iFace = 0; iFace < 4; ++iFace) {
1837       const PetscInt ii = iFace*faceSizeQuad;
1838       PetscInt       fVertex, cVertex;
1839 
1840       if ((sortedIndices[0] == faceVerticesQuadSorted[ii+0]) &&
1841           (sortedIndices[1] == faceVerticesQuadSorted[ii+1])) {
1842         for (fVertex = 0; fVertex < faceSizeQuad; ++fVertex) {
1843           for (cVertex = 0; cVertex < faceSizeQuad; ++cVertex) {
1844             if (indices[cVertex] == faceVerticesQuad[ii+fVertex]) {
1845               faceVertices[fVertex] = origVertices[cVertex];
1846               break;
1847             }
1848           }
1849         }
1850         found = PETSC_TRUE;
1851         break;
1852       }
1853     }
1854     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid quad crossface");
1855     if (posOriented) *posOriented = PETSC_TRUE;
1856     PetscFunctionReturn(0);
1857   } else if (cellDim == 3 && numCorners == 8) {
1858     /* Hexes
1859        A hex is two oriented quads with the normal of the first
1860        pointing up at the second.
1861 
1862           7---6
1863          /|  /|
1864         4---5 |
1865         | 1-|-2
1866         |/  |/
1867         0---3
1868 
1869         Faces are determined by the first 4 vertices (corners of faces) */
1870     const PetscInt faceSizeHex = 4;
1871     PetscInt       sortedIndices[4], i, iFace;
1872     PetscBool      found                     = PETSC_FALSE;
1873     PetscInt       faceVerticesHexSorted[24] = {
1874       0, 1, 2, 3,  /* bottom */
1875       4, 5, 6, 7,  /* top */
1876       0, 3, 4, 5,  /* front */
1877       2, 3, 5, 6,  /* right */
1878       1, 2, 6, 7,  /* back */
1879       0, 1, 4, 7,  /* left */
1880     };
1881     PetscInt       faceVerticesHex[24] = {
1882       1, 2, 3, 0,  /* bottom */
1883       4, 5, 6, 7,  /* top */
1884       0, 3, 5, 4,  /* front */
1885       3, 2, 6, 5,  /* right */
1886       2, 1, 7, 6,  /* back */
1887       1, 0, 4, 7,  /* left */
1888     };
1889 
1890     faceSize = faceSizeHex;
1891     for (i = 0; i < faceSizeHex; ++i) sortedIndices[i] = indices[i];
1892     ierr = PetscSortInt(faceSizeHex, sortedIndices);CHKERRQ(ierr);
1893     for (iFace = 0; iFace < 6; ++iFace) {
1894       const PetscInt ii = iFace*faceSizeHex;
1895       PetscInt       fVertex, cVertex;
1896 
1897       if ((sortedIndices[0] == faceVerticesHexSorted[ii+0]) &&
1898           (sortedIndices[1] == faceVerticesHexSorted[ii+1]) &&
1899           (sortedIndices[2] == faceVerticesHexSorted[ii+2]) &&
1900           (sortedIndices[3] == faceVerticesHexSorted[ii+3])) {
1901         for (fVertex = 0; fVertex < faceSizeHex; ++fVertex) {
1902           for (cVertex = 0; cVertex < faceSizeHex; ++cVertex) {
1903             if (indices[cVertex] == faceVerticesHex[ii+fVertex]) {
1904               faceVertices[fVertex] = origVertices[cVertex];
1905               break;
1906             }
1907           }
1908         }
1909         found = PETSC_TRUE;
1910         break;
1911       }
1912     }
1913     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid hex crossface");
1914     if (posOriented) *posOriented = PETSC_TRUE;
1915     PetscFunctionReturn(0);
1916   } else if (cellDim == 3 && numCorners == 10) {
1917     /* Quadratic tet */
1918     /* Faces are determined by the first 3 vertices (corners of faces) */
1919     const PetscInt faceSizeTet = 6;
1920     PetscInt       sortedIndices[6], i, iFace;
1921     PetscBool      found                     = PETSC_FALSE;
1922     PetscInt       faceVerticesTetSorted[24] = {
1923       0, 1, 2,  6, 7, 8, /* bottom */
1924       0, 3, 4,  6, 7, 9,  /* front */
1925       1, 4, 5,  7, 8, 9,  /* right */
1926       2, 3, 5,  6, 8, 9,  /* left */
1927     };
1928     PetscInt       faceVerticesTet[24] = {
1929       0, 1, 2,  6, 7, 8, /* bottom */
1930       0, 4, 3,  6, 7, 9,  /* front */
1931       1, 5, 4,  7, 8, 9,  /* right */
1932       2, 3, 5,  8, 6, 9,  /* left */
1933     };
1934 
1935     faceSize = faceSizeTet;
1936     for (i = 0; i < faceSizeTet; ++i) sortedIndices[i] = indices[i];
1937     ierr = PetscSortInt(faceSizeTet, sortedIndices);CHKERRQ(ierr);
1938     for (iFace=0; iFace < 4; ++iFace) {
1939       const PetscInt ii = iFace*faceSizeTet;
1940       PetscInt       fVertex, cVertex;
1941 
1942       if ((sortedIndices[0] == faceVerticesTetSorted[ii+0]) &&
1943           (sortedIndices[1] == faceVerticesTetSorted[ii+1]) &&
1944           (sortedIndices[2] == faceVerticesTetSorted[ii+2]) &&
1945           (sortedIndices[3] == faceVerticesTetSorted[ii+3])) {
1946         for (fVertex = 0; fVertex < faceSizeTet; ++fVertex) {
1947           for (cVertex = 0; cVertex < faceSizeTet; ++cVertex) {
1948             if (indices[cVertex] == faceVerticesTet[ii+fVertex]) {
1949               faceVertices[fVertex] = origVertices[cVertex];
1950               break;
1951             }
1952           }
1953         }
1954         found = PETSC_TRUE;
1955         break;
1956       }
1957     }
1958     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid tet crossface");
1959     if (posOriented) *posOriented = PETSC_TRUE;
1960     PetscFunctionReturn(0);
1961   } else if (cellDim == 3 && numCorners == 27) {
1962     /* Quadratic hexes (I hate this)
1963        A hex is two oriented quads with the normal of the first
1964        pointing up at the second.
1965 
1966          7---6
1967         /|  /|
1968        4---5 |
1969        | 3-|-2
1970        |/  |/
1971        0---1
1972 
1973        Faces are determined by the first 4 vertices (corners of faces) */
1974     const PetscInt faceSizeQuadHex = 9;
1975     PetscInt       sortedIndices[9], i, iFace;
1976     PetscBool      found                         = PETSC_FALSE;
1977     PetscInt       faceVerticesQuadHexSorted[54] = {
1978       0, 1, 2, 3,  8, 9, 10, 11,  24, /* bottom */
1979       4, 5, 6, 7,  12, 13, 14, 15,  25, /* top */
1980       0, 1, 4, 5,  8, 12, 16, 17,  22, /* front */
1981       1, 2, 5, 6,  9, 13, 17, 18,  21, /* right */
1982       2, 3, 6, 7,  10, 14, 18, 19,  23, /* back */
1983       0, 3, 4, 7,  11, 15, 16, 19,  20, /* left */
1984     };
1985     PetscInt       faceVerticesQuadHex[54] = {
1986       3, 2, 1, 0,  10, 9, 8, 11,  24, /* bottom */
1987       4, 5, 6, 7,  12, 13, 14, 15,  25, /* top */
1988       0, 1, 5, 4,  8, 17, 12, 16,  22, /* front */
1989       1, 2, 6, 5,  9, 18, 13, 17,  21, /* right */
1990       2, 3, 7, 6,  10, 19, 14, 18,  23, /* back */
1991       3, 0, 4, 7,  11, 16, 15, 19,  20 /* left */
1992     };
1993 
1994     faceSize = faceSizeQuadHex;
1995     for (i = 0; i < faceSizeQuadHex; ++i) sortedIndices[i] = indices[i];
1996     ierr = PetscSortInt(faceSizeQuadHex, sortedIndices);CHKERRQ(ierr);
1997     for (iFace = 0; iFace < 6; ++iFace) {
1998       const PetscInt ii = iFace*faceSizeQuadHex;
1999       PetscInt       fVertex, cVertex;
2000 
2001       if ((sortedIndices[0] == faceVerticesQuadHexSorted[ii+0]) &&
2002           (sortedIndices[1] == faceVerticesQuadHexSorted[ii+1]) &&
2003           (sortedIndices[2] == faceVerticesQuadHexSorted[ii+2]) &&
2004           (sortedIndices[3] == faceVerticesQuadHexSorted[ii+3])) {
2005         for (fVertex = 0; fVertex < faceSizeQuadHex; ++fVertex) {
2006           for (cVertex = 0; cVertex < faceSizeQuadHex; ++cVertex) {
2007             if (indices[cVertex] == faceVerticesQuadHex[ii+fVertex]) {
2008               faceVertices[fVertex] = origVertices[cVertex];
2009               break;
2010             }
2011           }
2012         }
2013         found = PETSC_TRUE;
2014         break;
2015       }
2016     }
2017     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid hex crossface");
2018     if (posOriented) *posOriented = PETSC_TRUE;
2019     PetscFunctionReturn(0);
2020   } else SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Unknown cell type for faceOrientation().");
2021   if (!posOrient) {
2022     if (debug) {ierr = PetscPrintf(comm, "  Reversing initial face orientation\n");CHKERRQ(ierr);}
2023     for (f = 0; f < faceSize; ++f) faceVertices[f] = origVertices[faceSize-1 - f];
2024   } else {
2025     if (debug) {ierr = PetscPrintf(comm, "  Keeping initial face orientation\n");CHKERRQ(ierr);}
2026     for (f = 0; f < faceSize; ++f) faceVertices[f] = origVertices[f];
2027   }
2028   if (posOriented) *posOriented = posOrient;
2029   PetscFunctionReturn(0);
2030 }
2031 
2032 #undef __FUNCT__
2033 #define __FUNCT__ "DMPlexGetOrientedFace"
2034 /*
2035     Given a cell and a face, as a set of vertices,
2036       return the oriented face, as a set of vertices, in faceVertices
2037     The orientation is such that the face normal points out of the cell
2038 */
2039 PetscErrorCode DMPlexGetOrientedFace(DM dm, PetscInt cell, PetscInt faceSize, const PetscInt face[], PetscInt numCorners, PetscInt indices[], PetscInt origVertices[], PetscInt faceVertices[], PetscBool *posOriented)
2040 {
2041   const PetscInt *cone = NULL;
2042   PetscInt        coneSize, v, f, v2;
2043   PetscInt        oppositeVertex = -1;
2044   PetscErrorCode  ierr;
2045 
2046   PetscFunctionBegin;
2047   ierr = DMPlexGetConeSize(dm, cell, &coneSize);CHKERRQ(ierr);
2048   ierr = DMPlexGetCone(dm, cell, &cone);CHKERRQ(ierr);
2049   for (v = 0, v2 = 0; v < coneSize; ++v) {
2050     PetscBool found = PETSC_FALSE;
2051 
2052     for (f = 0; f < faceSize; ++f) {
2053       if (face[f] == cone[v]) {
2054         found = PETSC_TRUE; break;
2055       }
2056     }
2057     if (found) {
2058       indices[v2]      = v;
2059       origVertices[v2] = cone[v];
2060       ++v2;
2061     } else {
2062       oppositeVertex = v;
2063     }
2064   }
2065   ierr = DMPlexGetFaceOrientation(dm, cell, numCorners, indices, oppositeVertex, origVertices, faceVertices, posOriented);CHKERRQ(ierr);
2066   PetscFunctionReturn(0);
2067 }
2068 
2069 #undef __FUNCT__
2070 #define __FUNCT__ "DMPlexInsertFace_Internal"
2071 /*
2072   DMPlexInsertFace_Internal - Puts a face into the mesh
2073 
2074   Not collective
2075 
2076   Input Parameters:
2077   + dm              - The DMPlex
2078   . numFaceVertex   - The number of vertices in the face
2079   . faceVertices    - The vertices in the face for dm
2080   . subfaceVertices - The vertices in the face for subdm
2081   . numCorners      - The number of vertices in the cell
2082   . cell            - A cell in dm containing the face
2083   . subcell         - A cell in subdm containing the face
2084   . firstFace       - First face in the mesh
2085   - newFacePoint    - Next face in the mesh
2086 
2087   Output Parameters:
2088   . newFacePoint - Contains next face point number on input, updated on output
2089 
2090   Level: developer
2091 */
2092 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)
2093 {
2094   MPI_Comm        comm;
2095   DM_Plex        *submesh = (DM_Plex*) subdm->data;
2096   const PetscInt *faces;
2097   PetscInt        numFaces, coneSize;
2098   PetscErrorCode  ierr;
2099 
2100   PetscFunctionBegin;
2101   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2102   ierr = DMPlexGetConeSize(subdm, subcell, &coneSize);CHKERRQ(ierr);
2103   if (coneSize != 1) SETERRQ2(comm, PETSC_ERR_ARG_OUTOFRANGE, "Cone size of cell %d is %d != 1", cell, coneSize);
2104 #if 0
2105   /* Cannot use this because support() has not been constructed yet */
2106   ierr = DMPlexGetJoin(subdm, numFaceVertices, subfaceVertices, &numFaces, &faces);CHKERRQ(ierr);
2107 #else
2108   {
2109     PetscInt f;
2110 
2111     numFaces = 0;
2112     ierr     = DMGetWorkArray(subdm, 1, PETSC_INT, (void **) &faces);CHKERRQ(ierr);
2113     for (f = firstFace; f < *newFacePoint; ++f) {
2114       PetscInt dof, off, d;
2115 
2116       ierr = PetscSectionGetDof(submesh->coneSection, f, &dof);CHKERRQ(ierr);
2117       ierr = PetscSectionGetOffset(submesh->coneSection, f, &off);CHKERRQ(ierr);
2118       /* Yes, I know this is quadratic, but I expect the sizes to be <5 */
2119       for (d = 0; d < dof; ++d) {
2120         const PetscInt p = submesh->cones[off+d];
2121         PetscInt       v;
2122 
2123         for (v = 0; v < numFaceVertices; ++v) {
2124           if (subfaceVertices[v] == p) break;
2125         }
2126         if (v == numFaceVertices) break;
2127       }
2128       if (d == dof) {
2129         numFaces               = 1;
2130         ((PetscInt*) faces)[0] = f;
2131       }
2132     }
2133   }
2134 #endif
2135   if (numFaces > 1) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Vertex set had %d faces, not one", numFaces);
2136   else if (numFaces == 1) {
2137     /* Add the other cell neighbor for this face */
2138     ierr = DMPlexSetCone(subdm, subcell, faces);CHKERRQ(ierr);
2139   } else {
2140     PetscInt *indices, *origVertices, *orientedVertices, *orientedSubVertices, v, ov;
2141     PetscBool posOriented;
2142 
2143     ierr                = DMGetWorkArray(subdm, 4*numFaceVertices * sizeof(PetscInt), PETSC_INT, &orientedVertices);CHKERRQ(ierr);
2144     origVertices        = &orientedVertices[numFaceVertices];
2145     indices             = &orientedVertices[numFaceVertices*2];
2146     orientedSubVertices = &orientedVertices[numFaceVertices*3];
2147     ierr                = DMPlexGetOrientedFace(dm, cell, numFaceVertices, faceVertices, numCorners, indices, origVertices, orientedVertices, &posOriented);CHKERRQ(ierr);
2148     /* TODO: I know that routine should return a permutation, not the indices */
2149     for (v = 0; v < numFaceVertices; ++v) {
2150       const PetscInt vertex = faceVertices[v], subvertex = subfaceVertices[v];
2151       for (ov = 0; ov < numFaceVertices; ++ov) {
2152         if (orientedVertices[ov] == vertex) {
2153           orientedSubVertices[ov] = subvertex;
2154           break;
2155         }
2156       }
2157       if (ov == numFaceVertices) SETERRQ1(comm, PETSC_ERR_PLIB, "Could not find face vertex %d in orientated set", vertex);
2158     }
2159     ierr = DMPlexSetCone(subdm, *newFacePoint, orientedSubVertices);CHKERRQ(ierr);
2160     ierr = DMPlexSetCone(subdm, subcell, newFacePoint);CHKERRQ(ierr);
2161     ierr = DMRestoreWorkArray(subdm, 4*numFaceVertices * sizeof(PetscInt), PETSC_INT, &orientedVertices);CHKERRQ(ierr);
2162     ++(*newFacePoint);
2163   }
2164 #if 0
2165   ierr = DMPlexRestoreJoin(subdm, numFaceVertices, subfaceVertices, &numFaces, &faces);CHKERRQ(ierr);
2166 #else
2167   ierr = DMRestoreWorkArray(subdm, 1, PETSC_INT, (void **) &faces);CHKERRQ(ierr);
2168 #endif
2169   PetscFunctionReturn(0);
2170 }
2171 
2172 #undef __FUNCT__
2173 #define __FUNCT__ "DMPlexCreateSubmesh_Uninterpolated"
2174 static PetscErrorCode DMPlexCreateSubmesh_Uninterpolated(DM dm, DMLabel vertexLabel, PetscInt value, DM subdm)
2175 {
2176   MPI_Comm        comm;
2177   DMLabel         subpointMap;
2178   IS              subvertexIS,  subcellIS;
2179   const PetscInt *subVertices, *subCells;
2180   PetscInt        numSubVertices, firstSubVertex, numSubCells;
2181   PetscInt       *subface, maxConeSize, numSubFaces = 0, firstSubFace, newFacePoint, nFV = 0;
2182   PetscInt        vStart, vEnd, c, f;
2183   PetscErrorCode  ierr;
2184 
2185   PetscFunctionBegin;
2186   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2187   /* Create subpointMap which marks the submesh */
2188   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2189   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2190   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2191   if (vertexLabel) {ierr = DMPlexMarkSubmesh_Uninterpolated(dm, vertexLabel, value, subpointMap, &numSubFaces, &nFV, subdm);CHKERRQ(ierr);}
2192   /* Setup chart */
2193   ierr = DMLabelGetStratumSize(subpointMap, 0, &numSubVertices);CHKERRQ(ierr);
2194   ierr = DMLabelGetStratumSize(subpointMap, 2, &numSubCells);CHKERRQ(ierr);
2195   ierr = DMPlexSetChart(subdm, 0, numSubCells+numSubFaces+numSubVertices);CHKERRQ(ierr);
2196   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2197   /* Set cone sizes */
2198   firstSubVertex = numSubCells;
2199   firstSubFace   = numSubCells+numSubVertices;
2200   newFacePoint   = firstSubFace;
2201   ierr = DMLabelGetStratumIS(subpointMap, 0, &subvertexIS);CHKERRQ(ierr);
2202   if (subvertexIS) {ierr = ISGetIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2203   ierr = DMLabelGetStratumIS(subpointMap, 2, &subcellIS);CHKERRQ(ierr);
2204   if (subcellIS) {ierr = ISGetIndices(subcellIS, &subCells);CHKERRQ(ierr);}
2205   for (c = 0; c < numSubCells; ++c) {
2206     ierr = DMPlexSetConeSize(subdm, c, 1);CHKERRQ(ierr);
2207   }
2208   for (f = firstSubFace; f < firstSubFace+numSubFaces; ++f) {
2209     ierr = DMPlexSetConeSize(subdm, f, nFV);CHKERRQ(ierr);
2210   }
2211   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2212   /* Create face cones */
2213   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
2214   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2215   ierr = DMGetWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2216   for (c = 0; c < numSubCells; ++c) {
2217     const PetscInt cell    = subCells[c];
2218     const PetscInt subcell = c;
2219     PetscInt      *closure = NULL;
2220     PetscInt       closureSize, cl, numCorners = 0, faceSize = 0;
2221 
2222     ierr = DMPlexGetTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
2223     for (cl = 0; cl < closureSize*2; cl += 2) {
2224       const PetscInt point = closure[cl];
2225       PetscInt       subVertex;
2226 
2227       if ((point >= vStart) && (point < vEnd)) {
2228         ++numCorners;
2229         ierr = PetscFindInt(point, numSubVertices, subVertices, &subVertex);CHKERRQ(ierr);
2230         if (subVertex >= 0) {
2231           closure[faceSize] = point;
2232           subface[faceSize] = firstSubVertex+subVertex;
2233           ++faceSize;
2234         }
2235       }
2236     }
2237     if (faceSize > nFV) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Invalid submesh: Too many vertices %d of an element on the surface", faceSize);
2238     if (faceSize == nFV) {
2239       ierr = DMPlexInsertFace_Internal(dm, subdm, faceSize, closure, subface, numCorners, cell, subcell, firstSubFace, &newFacePoint);CHKERRQ(ierr);
2240     }
2241     ierr = DMPlexRestoreTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
2242   }
2243   ierr = DMRestoreWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2244   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2245   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2246   /* Build coordinates */
2247   {
2248     PetscSection coordSection, subCoordSection;
2249     Vec          coordinates, subCoordinates;
2250     PetscScalar *coords, *subCoords;
2251     PetscInt     numComp, coordSize, v;
2252 
2253     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2254     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2255     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2256     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2257     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2258     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2259     ierr = PetscSectionSetChart(subCoordSection, firstSubVertex, firstSubVertex+numSubVertices);CHKERRQ(ierr);
2260     for (v = 0; v < numSubVertices; ++v) {
2261       const PetscInt vertex    = subVertices[v];
2262       const PetscInt subvertex = firstSubVertex+v;
2263       PetscInt       dof;
2264 
2265       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2266       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2267       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2268     }
2269     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2270     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2271     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2272     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2273     ierr = VecSetType(subCoordinates,VECSTANDARD);CHKERRQ(ierr);
2274     if (coordSize) {
2275       ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2276       ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2277       for (v = 0; v < numSubVertices; ++v) {
2278         const PetscInt vertex    = subVertices[v];
2279         const PetscInt subvertex = firstSubVertex+v;
2280         PetscInt       dof, off, sdof, soff, d;
2281 
2282         ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2283         ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2284         ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2285         ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2286         if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2287         for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2288       }
2289       ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2290       ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2291     }
2292     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2293     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2294   }
2295   /* Cleanup */
2296   if (subvertexIS) {ierr = ISRestoreIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2297   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
2298   if (subcellIS) {ierr = ISRestoreIndices(subcellIS, &subCells);CHKERRQ(ierr);}
2299   ierr = ISDestroy(&subcellIS);CHKERRQ(ierr);
2300   PetscFunctionReturn(0);
2301 }
2302 
2303 #undef __FUNCT__
2304 #define __FUNCT__ "DMPlexCreateSubmesh_Interpolated"
2305 static PetscErrorCode DMPlexCreateSubmesh_Interpolated(DM dm, DMLabel vertexLabel, PetscInt value, DM subdm)
2306 {
2307   MPI_Comm         comm;
2308   DMLabel          subpointMap;
2309   IS              *subpointIS;
2310   const PetscInt **subpoints;
2311   PetscInt        *numSubPoints, *firstSubPoint, *coneNew, *coneONew;
2312   PetscInt         totSubPoints = 0, maxConeSize, dim, p, d, v;
2313   PetscErrorCode   ierr;
2314 
2315   PetscFunctionBegin;
2316   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2317   /* Create subpointMap which marks the submesh */
2318   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2319   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2320   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2321   if (vertexLabel) {ierr = DMPlexMarkSubmesh_Interpolated(dm, vertexLabel, value, subpointMap, subdm);CHKERRQ(ierr);}
2322   /* Setup chart */
2323   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2324   ierr = PetscMalloc4(dim+1,PetscInt,&numSubPoints,dim+1,PetscInt,&firstSubPoint,dim+1,IS,&subpointIS,dim+1,const PetscInt *,&subpoints);CHKERRQ(ierr);
2325   for (d = 0; d <= dim; ++d) {
2326     ierr = DMLabelGetStratumSize(subpointMap, d, &numSubPoints[d]);CHKERRQ(ierr);
2327     totSubPoints += numSubPoints[d];
2328   }
2329   ierr = DMPlexSetChart(subdm, 0, totSubPoints);CHKERRQ(ierr);
2330   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2331   /* Set cone sizes */
2332   firstSubPoint[dim] = 0;
2333   firstSubPoint[0]   = firstSubPoint[dim] + numSubPoints[dim];
2334   if (dim > 1) {firstSubPoint[dim-1] = firstSubPoint[0]     + numSubPoints[0];}
2335   if (dim > 2) {firstSubPoint[dim-2] = firstSubPoint[dim-1] + numSubPoints[dim-1];}
2336   for (d = 0; d <= dim; ++d) {
2337     ierr = DMLabelGetStratumIS(subpointMap, d, &subpointIS[d]);CHKERRQ(ierr);
2338     ierr = ISGetIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2339   }
2340   for (d = 0; d <= dim; ++d) {
2341     for (p = 0; p < numSubPoints[d]; ++p) {
2342       const PetscInt  point    = subpoints[d][p];
2343       const PetscInt  subpoint = firstSubPoint[d] + p;
2344       const PetscInt *cone;
2345       PetscInt        coneSize, coneSizeNew, c, val;
2346 
2347       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2348       ierr = DMPlexSetConeSize(subdm, subpoint, coneSize);CHKERRQ(ierr);
2349       if (d == dim) {
2350         ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2351         for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2352           ierr = DMLabelGetValue(subpointMap, cone[c], &val);CHKERRQ(ierr);
2353           if (val >= 0) coneSizeNew++;
2354         }
2355         ierr = DMPlexSetConeSize(subdm, subpoint, coneSizeNew);CHKERRQ(ierr);
2356       }
2357     }
2358   }
2359   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2360   /* Set cones */
2361   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2362   ierr = PetscMalloc2(maxConeSize,PetscInt,&coneNew,maxConeSize,PetscInt,&coneONew);CHKERRQ(ierr);
2363   for (d = 0; d <= dim; ++d) {
2364     for (p = 0; p < numSubPoints[d]; ++p) {
2365       const PetscInt  point    = subpoints[d][p];
2366       const PetscInt  subpoint = firstSubPoint[d] + p;
2367       const PetscInt *cone, *ornt;
2368       PetscInt        coneSize, subconeSize, coneSizeNew, c, subc;
2369 
2370       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2371       ierr = DMPlexGetConeSize(subdm, subpoint, &subconeSize);CHKERRQ(ierr);
2372       ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2373       ierr = DMPlexGetConeOrientation(dm, point, &ornt);CHKERRQ(ierr);
2374       for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2375         ierr = PetscFindInt(cone[c], numSubPoints[d-1], subpoints[d-1], &subc);CHKERRQ(ierr);
2376         if (subc >= 0) {
2377           coneNew[coneSizeNew]  = firstSubPoint[d-1] + subc;
2378           coneONew[coneSizeNew] = ornt[c];
2379           ++coneSizeNew;
2380         }
2381       }
2382       if (coneSizeNew != subconeSize) SETERRQ2(comm, PETSC_ERR_PLIB, "Number of cone points located %d does not match subcone size %d", coneSizeNew, subconeSize);
2383       ierr = DMPlexSetCone(subdm, subpoint, coneNew);CHKERRQ(ierr);
2384       ierr = DMPlexSetConeOrientation(subdm, subpoint, coneONew);CHKERRQ(ierr);
2385     }
2386   }
2387   ierr = PetscFree2(coneNew,coneONew);CHKERRQ(ierr);
2388   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2389   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2390   /* Build coordinates */
2391   {
2392     PetscSection coordSection, subCoordSection;
2393     Vec          coordinates, subCoordinates;
2394     PetscScalar *coords, *subCoords;
2395     PetscInt     numComp, coordSize;
2396 
2397     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2398     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2399     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2400     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2401     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2402     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2403     ierr = PetscSectionSetChart(subCoordSection, firstSubPoint[0], firstSubPoint[0]+numSubPoints[0]);CHKERRQ(ierr);
2404     for (v = 0; v < numSubPoints[0]; ++v) {
2405       const PetscInt vertex    = subpoints[0][v];
2406       const PetscInt subvertex = firstSubPoint[0]+v;
2407       PetscInt       dof;
2408 
2409       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2410       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2411       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2412     }
2413     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2414     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2415     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2416     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2417     ierr = VecSetType(subCoordinates,VECSTANDARD);CHKERRQ(ierr);
2418     ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2419     ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2420     for (v = 0; v < numSubPoints[0]; ++v) {
2421       const PetscInt vertex    = subpoints[0][v];
2422       const PetscInt subvertex = firstSubPoint[0]+v;
2423       PetscInt dof, off, sdof, soff, d;
2424 
2425       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2426       ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2427       ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2428       ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2429       if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2430       for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2431     }
2432     ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2433     ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2434     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2435     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2436   }
2437   /* Cleanup */
2438   for (d = 0; d <= dim; ++d) {
2439     ierr = ISRestoreIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2440     ierr = ISDestroy(&subpointIS[d]);CHKERRQ(ierr);
2441   }
2442   ierr = PetscFree4(numSubPoints,firstSubPoint,subpointIS,subpoints);CHKERRQ(ierr);
2443   PetscFunctionReturn(0);
2444 }
2445 
2446 #undef __FUNCT__
2447 #define __FUNCT__ "DMPlexCreateSubmesh"
2448 /*@
2449   DMPlexCreateSubmesh - Extract a hypersurface from the mesh using vertices defined by a label
2450 
2451   Input Parameters:
2452 + dm           - The original mesh
2453 . vertexLabel  - The DMLabel marking vertices contained in the surface
2454 - value        - The label value to use
2455 
2456   Output Parameter:
2457 . subdm - The surface mesh
2458 
2459   Note: This function produces a DMLabel mapping original points in the submesh to their depth. This can be obtained using DMPlexGetSubpointMap().
2460 
2461   Level: developer
2462 
2463 .seealso: DMPlexGetSubpointMap(), DMPlexGetLabel(), DMLabelSetValue()
2464 @*/
2465 PetscErrorCode DMPlexCreateSubmesh(DM dm, DMLabel vertexLabel, PetscInt value, DM *subdm)
2466 {
2467   PetscInt       dim, depth;
2468   PetscErrorCode ierr;
2469 
2470   PetscFunctionBegin;
2471   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2472   PetscValidPointer(subdm, 3);
2473   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2474   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2475   ierr = DMCreate(PetscObjectComm((PetscObject)dm), subdm);CHKERRQ(ierr);
2476   ierr = DMSetType(*subdm, DMPLEX);CHKERRQ(ierr);
2477   ierr = DMPlexSetDimension(*subdm, dim-1);CHKERRQ(ierr);
2478   if (depth == dim) {
2479     ierr = DMPlexCreateSubmesh_Interpolated(dm, vertexLabel, value, *subdm);CHKERRQ(ierr);
2480   } else {
2481     ierr = DMPlexCreateSubmesh_Uninterpolated(dm, vertexLabel, value, *subdm);CHKERRQ(ierr);
2482   }
2483   PetscFunctionReturn(0);
2484 }
2485 
2486 #undef __FUNCT__
2487 #define __FUNCT__ "DMPlexFilterPoint_Internal"
2488 PETSC_STATIC_INLINE PetscInt DMPlexFilterPoint_Internal(PetscInt point, PetscInt firstSubPoint, PetscInt numSubPoints, const PetscInt subPoints[])
2489 {
2490   PetscInt       subPoint;
2491   PetscErrorCode ierr;
2492 
2493   ierr = PetscFindInt(point, numSubPoints, subPoints, &subPoint); if (ierr < 0) return ierr;
2494   return subPoint < 0 ? subPoint : firstSubPoint+subPoint;
2495 }
2496 
2497 #undef __FUNCT__
2498 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh_Uninterpolated"
2499 static PetscErrorCode DMPlexCreateCohesiveSubmesh_Uninterpolated(DM dm, PetscBool hasLagrange, const char label[], PetscInt value, DM subdm)
2500 {
2501   MPI_Comm        comm;
2502   DMLabel         subpointMap;
2503   IS              subvertexIS;
2504   const PetscInt *subVertices;
2505   PetscInt        numSubVertices, firstSubVertex, numSubCells, *subCells = NULL;
2506   PetscInt       *subface, maxConeSize, numSubFaces, firstSubFace, newFacePoint, nFV;
2507   PetscInt        cMax, c, f;
2508   PetscErrorCode  ierr;
2509 
2510   PetscFunctionBegin;
2511   ierr = PetscObjectGetComm((PetscObject)dm, &comm);CHKERRQ(ierr);
2512   /* Create subpointMap which marks the submesh */
2513   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2514   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2515   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2516   ierr = DMPlexMarkCohesiveSubmesh_Uninterpolated(dm, hasLagrange, label, value, subpointMap, &numSubFaces, &nFV, &subCells, subdm);CHKERRQ(ierr);
2517   /* Setup chart */
2518   ierr = DMLabelGetStratumSize(subpointMap, 0, &numSubVertices);CHKERRQ(ierr);
2519   ierr = DMLabelGetStratumSize(subpointMap, 2, &numSubCells);CHKERRQ(ierr);
2520   ierr = DMPlexSetChart(subdm, 0, numSubCells+numSubFaces+numSubVertices);CHKERRQ(ierr);
2521   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2522   /* Set cone sizes */
2523   firstSubVertex = numSubCells;
2524   firstSubFace   = numSubCells+numSubVertices;
2525   newFacePoint   = firstSubFace;
2526   ierr = DMLabelGetStratumIS(subpointMap, 0, &subvertexIS);CHKERRQ(ierr);
2527   if (subvertexIS) {ierr = ISGetIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2528   for (c = 0; c < numSubCells; ++c) {
2529     ierr = DMPlexSetConeSize(subdm, c, 1);CHKERRQ(ierr);
2530   }
2531   for (f = firstSubFace; f < firstSubFace+numSubFaces; ++f) {
2532     ierr = DMPlexSetConeSize(subdm, f, nFV);CHKERRQ(ierr);
2533   }
2534   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2535   /* Create face cones */
2536   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2537   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
2538   ierr = DMGetWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2539   for (c = 0; c < numSubCells; ++c) {
2540     const PetscInt  cell    = subCells[c];
2541     const PetscInt  subcell = c;
2542     const PetscInt *cone, *cells;
2543     PetscInt        numCells, subVertex, p, v;
2544 
2545     if (cell < cMax) continue;
2546     ierr = DMPlexGetCone(dm, cell, &cone);CHKERRQ(ierr);
2547     for (v = 0; v < nFV; ++v) {
2548       ierr = PetscFindInt(cone[v], numSubVertices, subVertices, &subVertex);CHKERRQ(ierr);
2549       subface[v] = firstSubVertex+subVertex;
2550     }
2551     ierr = DMPlexSetCone(subdm, newFacePoint, subface);CHKERRQ(ierr);
2552     ierr = DMPlexSetCone(subdm, subcell, &newFacePoint);CHKERRQ(ierr);
2553     ierr = DMPlexGetJoin(dm, nFV, cone, &numCells, &cells);CHKERRQ(ierr);
2554     /* Not true in parallel
2555     if (numCells != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells"); */
2556     for (p = 0; p < numCells; ++p) {
2557       PetscInt negsubcell;
2558 
2559       if (cells[p] >= cMax) continue;
2560       /* I know this is a crap search */
2561       for (negsubcell = 0; negsubcell < numSubCells; ++negsubcell) {
2562         if (subCells[negsubcell] == cells[p]) break;
2563       }
2564       if (negsubcell == numSubCells) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find negative face neighbor for cohesive cell %d", cell);
2565       ierr = DMPlexSetCone(subdm, negsubcell, &newFacePoint);CHKERRQ(ierr);
2566     }
2567     ierr = DMPlexRestoreJoin(dm, nFV, cone, &numCells, &cells);CHKERRQ(ierr);
2568     ++newFacePoint;
2569   }
2570   ierr = DMRestoreWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2571   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2572   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2573   /* Build coordinates */
2574   {
2575     PetscSection coordSection, subCoordSection;
2576     Vec          coordinates, subCoordinates;
2577     PetscScalar *coords, *subCoords;
2578     PetscInt     numComp, coordSize, v;
2579 
2580     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2581     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2582     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2583     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2584     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2585     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2586     ierr = PetscSectionSetChart(subCoordSection, firstSubVertex, firstSubVertex+numSubVertices);CHKERRQ(ierr);
2587     for (v = 0; v < numSubVertices; ++v) {
2588       const PetscInt vertex    = subVertices[v];
2589       const PetscInt subvertex = firstSubVertex+v;
2590       PetscInt       dof;
2591 
2592       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2593       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2594       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2595     }
2596     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2597     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2598     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2599     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2600     ierr = VecSetType(subCoordinates,VECSTANDARD);CHKERRQ(ierr);
2601     ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2602     ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2603     for (v = 0; v < numSubVertices; ++v) {
2604       const PetscInt vertex    = subVertices[v];
2605       const PetscInt subvertex = firstSubVertex+v;
2606       PetscInt       dof, off, sdof, soff, d;
2607 
2608       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2609       ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2610       ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2611       ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2612       if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2613       for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2614     }
2615     ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2616     ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2617     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2618     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2619   }
2620   /* Build SF */
2621   CHKMEMQ;
2622   {
2623     PetscSF            sfPoint, sfPointSub;
2624     const PetscSFNode *remotePoints;
2625     PetscSFNode       *sremotePoints, *newLocalPoints, *newOwners;
2626     const PetscInt    *localPoints;
2627     PetscInt          *slocalPoints;
2628     PetscInt           numRoots, numLeaves, numSubRoots = numSubCells+numSubFaces+numSubVertices, numSubLeaves = 0, l, sl, ll, pStart, pEnd, p, vStart, vEnd;
2629     PetscMPIInt        rank;
2630 
2631     ierr = MPI_Comm_rank(PetscObjectComm((PetscObject) dm), &rank);CHKERRQ(ierr);
2632     ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
2633     ierr = DMGetPointSF(subdm, &sfPointSub);CHKERRQ(ierr);
2634     ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
2635     ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
2636     ierr = PetscSFGetGraph(sfPoint, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
2637     if (numRoots >= 0) {
2638       /* Only vertices should be shared */
2639       ierr = PetscMalloc2(pEnd-pStart,PetscSFNode,&newLocalPoints,numRoots,PetscSFNode,&newOwners);CHKERRQ(ierr);
2640       for (p = 0; p < pEnd-pStart; ++p) {
2641         newLocalPoints[p].rank  = -2;
2642         newLocalPoints[p].index = -2;
2643       }
2644       /* Set subleaves */
2645       for (l = 0; l < numLeaves; ++l) {
2646         const PetscInt point    = localPoints[l];
2647         const PetscInt subPoint = DMPlexFilterPoint_Internal(point, firstSubVertex, numSubVertices, subVertices);
2648 
2649         if ((point < vStart) && (point >= vEnd)) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Should not be mapping anything but vertices, %d", point);
2650         if (subPoint < 0) continue;
2651         newLocalPoints[point-pStart].rank  = rank;
2652         newLocalPoints[point-pStart].index = subPoint;
2653         ++numSubLeaves;
2654       }
2655       /* Must put in owned subpoints */
2656       for (p = pStart; p < pEnd; ++p) {
2657         const PetscInt subPoint = DMPlexFilterPoint_Internal(p, firstSubVertex, numSubVertices, subVertices);
2658 
2659         if (subPoint < 0) {
2660           newOwners[p-pStart].rank  = -3;
2661           newOwners[p-pStart].index = -3;
2662         } else {
2663           newOwners[p-pStart].rank  = rank;
2664           newOwners[p-pStart].index = subPoint;
2665         }
2666       }
2667       ierr = PetscSFReduceBegin(sfPoint, MPIU_2INT, newLocalPoints, newOwners, MPI_MAXLOC);CHKERRQ(ierr);
2668       ierr = PetscSFReduceEnd(sfPoint, MPIU_2INT, newLocalPoints, newOwners, MPI_MAXLOC);CHKERRQ(ierr);
2669       ierr = PetscSFBcastBegin(sfPoint, MPIU_2INT, newOwners, newLocalPoints);CHKERRQ(ierr);
2670       ierr = PetscSFBcastEnd(sfPoint, MPIU_2INT, newOwners, newLocalPoints);CHKERRQ(ierr);
2671       ierr = PetscMalloc(numSubLeaves * sizeof(PetscInt),    &slocalPoints);CHKERRQ(ierr);
2672       ierr = PetscMalloc(numSubLeaves * sizeof(PetscSFNode), &sremotePoints);CHKERRQ(ierr);
2673       for (l = 0, sl = 0, ll = 0; l < numLeaves; ++l) {
2674         const PetscInt point    = localPoints[l];
2675         const PetscInt subPoint = DMPlexFilterPoint_Internal(point, firstSubVertex, numSubVertices, subVertices);
2676 
2677         if (subPoint < 0) continue;
2678         if (newLocalPoints[point].rank == rank) {++ll; continue;}
2679         slocalPoints[sl]        = subPoint;
2680         sremotePoints[sl].rank  = newLocalPoints[point].rank;
2681         sremotePoints[sl].index = newLocalPoints[point].index;
2682         if (sremotePoints[sl].rank  < 0) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid remote rank for local point %d", point);
2683         if (sremotePoints[sl].index < 0) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid remote subpoint for local point %d", point);
2684         ++sl;
2685       }
2686       ierr = PetscFree2(newLocalPoints,newOwners);CHKERRQ(ierr);
2687       if (sl + ll != numSubLeaves) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Mismatch in number of subleaves %d + %d != %d", sl, ll, numSubLeaves);
2688       ierr = PetscSFSetGraph(sfPointSub, numSubRoots, sl, slocalPoints, PETSC_OWN_POINTER, sremotePoints, PETSC_OWN_POINTER);CHKERRQ(ierr);
2689     }
2690   }
2691   CHKMEMQ;
2692   /* Cleanup */
2693   if (subvertexIS) {ierr = ISRestoreIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2694   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
2695   ierr = PetscFree(subCells);CHKERRQ(ierr);
2696   PetscFunctionReturn(0);
2697 }
2698 
2699 #undef __FUNCT__
2700 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh_Interpolated"
2701 static PetscErrorCode DMPlexCreateCohesiveSubmesh_Interpolated(DM dm, const char label[], PetscInt value, DM subdm)
2702 {
2703   MPI_Comm         comm;
2704   DMLabel          subpointMap;
2705   IS              *subpointIS;
2706   const PetscInt **subpoints;
2707   PetscInt        *numSubPoints, *firstSubPoint, *coneNew, *orntNew;
2708   PetscInt         totSubPoints = 0, maxConeSize, dim, p, d, v;
2709   PetscErrorCode   ierr;
2710 
2711   PetscFunctionBegin;
2712   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2713   /* Create subpointMap which marks the submesh */
2714   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2715   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2716   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2717   ierr = DMPlexMarkCohesiveSubmesh_Interpolated(dm, label, value, subpointMap, subdm);CHKERRQ(ierr);
2718   /* Setup chart */
2719   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2720   ierr = PetscMalloc4(dim+1,PetscInt,&numSubPoints,dim+1,PetscInt,&firstSubPoint,dim+1,IS,&subpointIS,dim+1,const PetscInt *,&subpoints);CHKERRQ(ierr);
2721   for (d = 0; d <= dim; ++d) {
2722     ierr = DMLabelGetStratumSize(subpointMap, d, &numSubPoints[d]);CHKERRQ(ierr);
2723     totSubPoints += numSubPoints[d];
2724   }
2725   ierr = DMPlexSetChart(subdm, 0, totSubPoints);CHKERRQ(ierr);
2726   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2727   /* Set cone sizes */
2728   firstSubPoint[dim] = 0;
2729   firstSubPoint[0]   = firstSubPoint[dim] + numSubPoints[dim];
2730   if (dim > 1) {firstSubPoint[dim-1] = firstSubPoint[0]     + numSubPoints[0];}
2731   if (dim > 2) {firstSubPoint[dim-2] = firstSubPoint[dim-1] + numSubPoints[dim-1];}
2732   for (d = 0; d <= dim; ++d) {
2733     ierr = DMLabelGetStratumIS(subpointMap, d, &subpointIS[d]);CHKERRQ(ierr);
2734     ierr = ISGetIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2735   }
2736   for (d = 0; d <= dim; ++d) {
2737     for (p = 0; p < numSubPoints[d]; ++p) {
2738       const PetscInt  point    = subpoints[d][p];
2739       const PetscInt  subpoint = firstSubPoint[d] + p;
2740       const PetscInt *cone;
2741       PetscInt        coneSize, coneSizeNew, c, val;
2742 
2743       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2744       ierr = DMPlexSetConeSize(subdm, subpoint, coneSize);CHKERRQ(ierr);
2745       if (d == dim) {
2746         ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2747         for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2748           ierr = DMLabelGetValue(subpointMap, cone[c], &val);CHKERRQ(ierr);
2749           if (val >= 0) coneSizeNew++;
2750         }
2751         ierr = DMPlexSetConeSize(subdm, subpoint, coneSizeNew);CHKERRQ(ierr);
2752       }
2753     }
2754   }
2755   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2756   /* Set cones */
2757   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2758   ierr = PetscMalloc2(maxConeSize,PetscInt,&coneNew,maxConeSize,PetscInt,&orntNew);CHKERRQ(ierr);
2759   for (d = 0; d <= dim; ++d) {
2760     for (p = 0; p < numSubPoints[d]; ++p) {
2761       const PetscInt  point    = subpoints[d][p];
2762       const PetscInt  subpoint = firstSubPoint[d] + p;
2763       const PetscInt *cone, *ornt;
2764       PetscInt        coneSize, subconeSize, coneSizeNew, c, subc;
2765 
2766       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2767       ierr = DMPlexGetConeSize(subdm, subpoint, &subconeSize);CHKERRQ(ierr);
2768       ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2769       ierr = DMPlexGetConeOrientation(dm, point, &ornt);CHKERRQ(ierr);
2770       for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2771         ierr = PetscFindInt(cone[c], numSubPoints[d-1], subpoints[d-1], &subc);CHKERRQ(ierr);
2772         if (subc >= 0) {
2773           coneNew[coneSizeNew]   = firstSubPoint[d-1] + subc;
2774           orntNew[coneSizeNew++] = ornt[c];
2775         }
2776       }
2777       if (coneSizeNew != subconeSize) SETERRQ2(comm, PETSC_ERR_PLIB, "Number of cone points located %d does not match subcone size %d", coneSizeNew, subconeSize);
2778       ierr = DMPlexSetCone(subdm, subpoint, coneNew);CHKERRQ(ierr);
2779       ierr = DMPlexSetConeOrientation(subdm, subpoint, orntNew);CHKERRQ(ierr);
2780     }
2781   }
2782   ierr = PetscFree2(coneNew,orntNew);CHKERRQ(ierr);
2783   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2784   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2785   /* Build coordinates */
2786   {
2787     PetscSection coordSection, subCoordSection;
2788     Vec          coordinates, subCoordinates;
2789     PetscScalar *coords, *subCoords;
2790     PetscInt     numComp, coordSize;
2791 
2792     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2793     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2794     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2795     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2796     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2797     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2798     ierr = PetscSectionSetChart(subCoordSection, firstSubPoint[0], firstSubPoint[0]+numSubPoints[0]);CHKERRQ(ierr);
2799     for (v = 0; v < numSubPoints[0]; ++v) {
2800       const PetscInt vertex    = subpoints[0][v];
2801       const PetscInt subvertex = firstSubPoint[0]+v;
2802       PetscInt       dof;
2803 
2804       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2805       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2806       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2807     }
2808     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2809     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2810     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2811     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2812     ierr = VecSetType(subCoordinates,VECSTANDARD);CHKERRQ(ierr);
2813     ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2814     ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2815     for (v = 0; v < numSubPoints[0]; ++v) {
2816       const PetscInt vertex    = subpoints[0][v];
2817       const PetscInt subvertex = firstSubPoint[0]+v;
2818       PetscInt dof, off, sdof, soff, d;
2819 
2820       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2821       ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2822       ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2823       ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2824       if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2825       for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2826     }
2827     ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2828     ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2829     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2830     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2831   }
2832   /* Cleanup */
2833   for (d = 0; d <= dim; ++d) {
2834     ierr = ISRestoreIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2835     ierr = ISDestroy(&subpointIS[d]);CHKERRQ(ierr);
2836   }
2837   ierr = PetscFree4(numSubPoints,firstSubPoint,subpointIS,subpoints);CHKERRQ(ierr);
2838   PetscFunctionReturn(0);
2839 }
2840 
2841 #undef __FUNCT__
2842 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh"
2843 /*
2844   DMPlexCreateCohesiveSubmesh - Extract from a mesh with cohesive cells the hypersurface defined by one face of the cells. Optionally, a Label an be given to restrict the cells.
2845 
2846   Input Parameters:
2847 + dm          - The original mesh
2848 . hasLagrange - The mesh has Lagrange unknowns in the cohesive cells
2849 . label       - A label name, or PETSC_NULL
2850 - value  - A label value
2851 
2852   Output Parameter:
2853 . subdm - The surface mesh
2854 
2855   Note: This function produces a DMLabel mapping original points in the submesh to their depth. This can be obtained using DMPlexGetSubpointMap().
2856 
2857   Level: developer
2858 
2859 .seealso: DMPlexGetSubpointMap(), DMPlexCreateSubmesh()
2860 */
2861 PetscErrorCode DMPlexCreateCohesiveSubmesh(DM dm, PetscBool hasLagrange, const char label[], PetscInt value, DM *subdm)
2862 {
2863   PetscInt       dim, depth;
2864   PetscErrorCode ierr;
2865 
2866   PetscFunctionBegin;
2867   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2868   PetscValidPointer(subdm, 5);
2869   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2870   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2871   ierr = DMCreate(PetscObjectComm((PetscObject)dm), subdm);CHKERRQ(ierr);
2872   ierr = DMSetType(*subdm, DMPLEX);CHKERRQ(ierr);
2873   ierr = DMPlexSetDimension(*subdm, dim-1);CHKERRQ(ierr);
2874   if (depth == dim) {
2875     ierr = DMPlexCreateCohesiveSubmesh_Interpolated(dm, label, value, *subdm);CHKERRQ(ierr);
2876   } else {
2877     ierr = DMPlexCreateCohesiveSubmesh_Uninterpolated(dm, hasLagrange, label, value, *subdm);CHKERRQ(ierr);
2878   }
2879   PetscFunctionReturn(0);
2880 }
2881 
2882 #undef __FUNCT__
2883 #define __FUNCT__ "DMPlexGetSubpointMap"
2884 /*@
2885   DMPlexGetSubpointMap - Returns a DMLabel with point dimension as values
2886 
2887   Input Parameter:
2888 . dm - The submesh DM
2889 
2890   Output Parameter:
2891 . subpointMap - The DMLabel of all the points from the original mesh in this submesh, or NULL if this is not a submesh
2892 
2893   Level: developer
2894 
2895 .seealso: DMPlexCreateSubmesh(), DMPlexCreateSubpointIS()
2896 @*/
2897 PetscErrorCode DMPlexGetSubpointMap(DM dm, DMLabel *subpointMap)
2898 {
2899   DM_Plex *mesh = (DM_Plex*) dm->data;
2900 
2901   PetscFunctionBegin;
2902   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2903   PetscValidPointer(subpointMap, 2);
2904   *subpointMap = mesh->subpointMap;
2905   PetscFunctionReturn(0);
2906 }
2907 
2908 #undef __FUNCT__
2909 #define __FUNCT__ "DMPlexSetSubpointMap"
2910 /* Note: Should normally not be called by the user, since it is set in DMPlexCreateSubmesh() */
2911 PetscErrorCode DMPlexSetSubpointMap(DM dm, DMLabel subpointMap)
2912 {
2913   DM_Plex       *mesh = (DM_Plex *) dm->data;
2914   DMLabel        tmp;
2915   PetscErrorCode ierr;
2916 
2917   PetscFunctionBegin;
2918   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2919   tmp  = mesh->subpointMap;
2920   mesh->subpointMap = subpointMap;
2921   ++mesh->subpointMap->refct;
2922   ierr = DMLabelDestroy(&tmp);CHKERRQ(ierr);
2923   PetscFunctionReturn(0);
2924 }
2925 
2926 #undef __FUNCT__
2927 #define __FUNCT__ "DMPlexCreateSubpointIS"
2928 /*@
2929   DMPlexCreateSubpointIS - Creates an IS covering the entire subdm chart with the original points as data
2930 
2931   Input Parameter:
2932 . dm - The submesh DM
2933 
2934   Output Parameter:
2935 . subpointIS - The IS of all the points from the original mesh in this submesh, or NULL if this is not a submesh
2936 
2937   Note: This is IS is guaranteed to be sorted by the construction of the submesh
2938 
2939   Level: developer
2940 
2941 .seealso: DMPlexCreateSubmesh(), DMPlexGetSubpointMap()
2942 @*/
2943 PetscErrorCode DMPlexCreateSubpointIS(DM dm, IS *subpointIS)
2944 {
2945   MPI_Comm        comm;
2946   DMLabel         subpointMap;
2947   IS              is;
2948   const PetscInt *opoints;
2949   PetscInt       *points, *depths;
2950   PetscInt        depth, depStart, depEnd, d, pStart, pEnd, p, n, off;
2951   PetscErrorCode  ierr;
2952 
2953   PetscFunctionBegin;
2954   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2955   PetscValidPointer(subpointIS, 2);
2956   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2957   *subpointIS = NULL;
2958   ierr = DMPlexGetSubpointMap(dm, &subpointMap);CHKERRQ(ierr);
2959   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2960   if (subpointMap && depth >= 0) {
2961     ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
2962     if (pStart) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Submeshes must start the point numbering at 0, not %d", pStart);
2963     ierr = DMGetWorkArray(dm, depth+1, PETSC_INT, &depths);CHKERRQ(ierr);
2964     depths[0] = depth;
2965     depths[1] = 0;
2966     for(d = 2; d <= depth; ++d) {depths[d] = depth+1 - d;}
2967     ierr = PetscMalloc(pEnd * sizeof(PetscInt), &points);CHKERRQ(ierr);
2968     for(d = 0, off = 0; d <= depth; ++d) {
2969       const PetscInt dep = depths[d];
2970 
2971       ierr = DMPlexGetDepthStratum(dm, dep, &depStart, &depEnd);CHKERRQ(ierr);
2972       ierr = DMLabelGetStratumSize(subpointMap, dep, &n);CHKERRQ(ierr);
2973       if (((d < 2) && (depth > 1)) || (d == 1)) { /* Only check vertices and cells for now since the map is broken for others */
2974         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);
2975       } else {
2976         if (!n) {
2977           if (d == 0) {
2978             /* Missing cells */
2979             for(p = 0; p < depEnd-depStart; ++p, ++off) points[off] = -1;
2980           } else {
2981             /* Missing faces */
2982             for(p = 0; p < depEnd-depStart; ++p, ++off) points[off] = PETSC_MAX_INT;
2983           }
2984         }
2985       }
2986       if (n) {
2987         ierr = DMLabelGetStratumIS(subpointMap, dep, &is);CHKERRQ(ierr);
2988         ierr = ISGetIndices(is, &opoints);CHKERRQ(ierr);
2989         for(p = 0; p < n; ++p, ++off) points[off] = opoints[p];
2990         ierr = ISRestoreIndices(is, &opoints);CHKERRQ(ierr);
2991         ierr = ISDestroy(&is);CHKERRQ(ierr);
2992       }
2993     }
2994     ierr = DMRestoreWorkArray(dm, depth+1, PETSC_INT, &depths);CHKERRQ(ierr);
2995     if (off != pEnd) SETERRQ2(comm, PETSC_ERR_ARG_WRONG, "The number of mapped submesh points %d should be %d", off, pEnd);
2996     ierr = ISCreateGeneral(PETSC_COMM_SELF, pEnd, points, PETSC_OWN_POINTER, subpointIS);CHKERRQ(ierr);
2997   }
2998   PetscFunctionReturn(0);
2999 }
3000