xref: /petsc/src/dm/impls/plex/plexsubmesh.c (revision 9a3563707ca709e52e4d1a78cda51041c8321de1)
1 #include <petsc-private/dmpleximpl.h>   /*I      "petscdmplex.h"   I*/
2 #include <petscsf.h>
3 
4 #undef __FUNCT__
5 #define __FUNCT__ "DMPlexMarkBoundaryFaces"
6 /*@
7   DMPlexMarkBoundaryFaces - Mark all faces on the boundary
8 
9   Not Collective
10 
11   Input Parameter:
12 . dm - The original DM
13 
14   Output Parameter:
15 . label - The DMLabel marking boundary faces with value 1
16 
17   Level: developer
18 
19 .seealso: DMLabelCreate(), DMPlexCreateLabel()
20 @*/
21 PetscErrorCode DMPlexMarkBoundaryFaces(DM dm, DMLabel label)
22 {
23   PetscInt       fStart, fEnd, f;
24   PetscErrorCode ierr;
25 
26   PetscFunctionBegin;
27   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
28   ierr = DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd);CHKERRQ(ierr);
29   for (f = fStart; f < fEnd; ++f) {
30     PetscInt supportSize;
31 
32     ierr = DMPlexGetSupportSize(dm, f, &supportSize);CHKERRQ(ierr);
33     if (supportSize == 1) {
34       ierr = DMLabelSetValue(label, f, 1);CHKERRQ(ierr);
35     }
36   }
37   PetscFunctionReturn(0);
38 }
39 
40 #undef __FUNCT__
41 #define __FUNCT__ "DMPlexLabelComplete"
42 /*@
43   DMPlexLabelComplete - Starting with a label marking points on a surface, we add the transitive closure to the surface
44 
45   Input Parameters:
46 + dm - The DM
47 - label - A DMLabel marking the surface points
48 
49   Output Parameter:
50 . label - A DMLabel marking all surface points in the transitive closure
51 
52   Level: developer
53 
54 .seealso: DMPlexLabelCohesiveComplete()
55 @*/
56 PetscErrorCode DMPlexLabelComplete(DM dm, DMLabel label)
57 {
58   IS              valueIS;
59   const PetscInt *values;
60   PetscInt        numValues, v;
61   PetscErrorCode  ierr;
62 
63   PetscFunctionBegin;
64   ierr = DMLabelGetNumValues(label, &numValues);CHKERRQ(ierr);
65   ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
66   ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
67   for (v = 0; v < numValues; ++v) {
68     IS              pointIS;
69     const PetscInt *points;
70     PetscInt        numPoints, p;
71 
72     ierr = DMLabelGetStratumSize(label, values[v], &numPoints);CHKERRQ(ierr);
73     ierr = DMLabelGetStratumIS(label, values[v], &pointIS);CHKERRQ(ierr);
74     ierr = ISGetIndices(pointIS, &points);CHKERRQ(ierr);
75     for (p = 0; p < numPoints; ++p) {
76       PetscInt *closure = NULL;
77       PetscInt  closureSize, c;
78 
79       ierr = DMPlexGetTransitiveClosure(dm, points[p], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
80       for (c = 0; c < closureSize*2; c += 2) {
81         ierr = DMLabelSetValue(label, closure[c], values[v]);CHKERRQ(ierr);
82       }
83       ierr = DMPlexRestoreTransitiveClosure(dm, points[p], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
84     }
85     ierr = ISRestoreIndices(pointIS, &points);CHKERRQ(ierr);
86     ierr = ISDestroy(&pointIS);CHKERRQ(ierr);
87   }
88   ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
89   ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
90   PetscFunctionReturn(0);
91 }
92 
93 #undef __FUNCT__
94 #define __FUNCT__ "DMPlexShiftPoint_Internal"
95 PETSC_STATIC_INLINE PetscInt DMPlexShiftPoint_Internal(PetscInt p, PetscInt depth, PetscInt depthEnd[], PetscInt depthShift[])
96 {
97   if (depth < 0) return p;
98   /* Cells    */ if (p < depthEnd[depth])   return p;
99   /* Vertices */ if (p < depthEnd[0])       return p + depthShift[depth];
100   /* Faces    */ if (p < depthEnd[depth-1]) return p + depthShift[depth] + depthShift[0];
101   /* Edges    */                            return p + depthShift[depth] + depthShift[0] + depthShift[depth-1];
102 }
103 
104 #undef __FUNCT__
105 #define __FUNCT__ "DMPlexShiftSizes_Internal"
106 static PetscErrorCode DMPlexShiftSizes_Internal(DM dm, PetscInt depthShift[], DM dmNew)
107 {
108   PetscInt      *depthEnd;
109   PetscInt       depth = 0, d, pStart, pEnd, p;
110   PetscErrorCode ierr;
111 
112   PetscFunctionBegin;
113   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
114   if (depth < 0) PetscFunctionReturn(0);
115   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
116   /* Step 1: Expand chart */
117   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
118   for (d = 0; d <= depth; ++d) {
119     pEnd += depthShift[d];
120     ierr  = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
121   }
122   ierr = DMPlexSetChart(dmNew, pStart, pEnd);CHKERRQ(ierr);
123   /* Step 2: Set cone and support sizes */
124   for (d = 0; d <= depth; ++d) {
125     ierr = DMPlexGetDepthStratum(dm, d, &pStart, &pEnd);CHKERRQ(ierr);
126     for (p = pStart; p < pEnd; ++p) {
127       PetscInt newp = DMPlexShiftPoint_Internal(p, depth, depthEnd, depthShift);
128       PetscInt size;
129 
130       ierr = DMPlexGetConeSize(dm, p, &size);CHKERRQ(ierr);
131       ierr = DMPlexSetConeSize(dmNew, newp, size);CHKERRQ(ierr);
132       ierr = DMPlexGetSupportSize(dm, p, &size);CHKERRQ(ierr);
133       ierr = DMPlexSetSupportSize(dmNew, newp, size);CHKERRQ(ierr);
134     }
135   }
136   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
137   PetscFunctionReturn(0);
138 }
139 
140 #undef __FUNCT__
141 #define __FUNCT__ "DMPlexShiftPoints_Internal"
142 static PetscErrorCode DMPlexShiftPoints_Internal(DM dm, PetscInt depthShift[], DM dmNew)
143 {
144   PetscInt      *depthEnd, *newpoints;
145   PetscInt       depth = 0, d, maxConeSize, maxSupportSize, pStart, pEnd, p;
146   PetscErrorCode ierr;
147 
148   PetscFunctionBegin;
149   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
150   if (depth < 0) PetscFunctionReturn(0);
151   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
152   ierr = PetscMalloc2(depth+1,PetscInt,&depthEnd,PetscMax(maxConeSize, maxSupportSize),PetscInt,&newpoints);CHKERRQ(ierr);
153   for (d = 0; d <= depth; ++d) {
154     ierr = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
155   }
156   /* Step 5: Set cones and supports */
157   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
158   for (p = pStart; p < pEnd; ++p) {
159     const PetscInt *points = NULL, *orientations = NULL;
160     PetscInt        size, i, newp = DMPlexShiftPoint_Internal(p, depth, depthEnd, depthShift);
161 
162     ierr = DMPlexGetConeSize(dm, p, &size);CHKERRQ(ierr);
163     ierr = DMPlexGetCone(dm, p, &points);CHKERRQ(ierr);
164     ierr = DMPlexGetConeOrientation(dm, p, &orientations);CHKERRQ(ierr);
165     for (i = 0; i < size; ++i) {
166       newpoints[i] = DMPlexShiftPoint_Internal(points[i], depth, depthEnd, depthShift);
167     }
168     ierr = DMPlexSetCone(dmNew, newp, newpoints);CHKERRQ(ierr);
169     ierr = DMPlexSetConeOrientation(dmNew, newp, orientations);CHKERRQ(ierr);
170     ierr = DMPlexGetSupportSize(dm, p, &size);CHKERRQ(ierr);
171     ierr = DMPlexGetSupport(dm, p, &points);CHKERRQ(ierr);
172     for (i = 0; i < size; ++i) {
173       newpoints[i] = DMPlexShiftPoint_Internal(points[i], depth, depthEnd, depthShift);
174     }
175     ierr = DMPlexSetSupport(dmNew, newp, newpoints);CHKERRQ(ierr);
176   }
177   ierr = PetscFree2(depthEnd,newpoints);CHKERRQ(ierr);
178   PetscFunctionReturn(0);
179 }
180 
181 #undef __FUNCT__
182 #define __FUNCT__ "DMPlexShiftCoordinates_Internal"
183 static PetscErrorCode DMPlexShiftCoordinates_Internal(DM dm, PetscInt depthShift[], DM dmNew)
184 {
185   PetscSection   coordSection, newCoordSection;
186   Vec            coordinates, newCoordinates;
187   PetscScalar   *coords, *newCoords;
188   PetscInt      *depthEnd, coordSize;
189   PetscInt       dim, depth = 0, d, vStart, vEnd, vStartNew, vEndNew, v;
190   PetscErrorCode ierr;
191 
192   PetscFunctionBegin;
193   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
194   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
195   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
196   for (d = 0; d <= depth; ++d) {
197     ierr = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
198   }
199   /* Step 8: Convert coordinates */
200   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
201   ierr = DMPlexGetDepthStratum(dmNew, 0, &vStartNew, &vEndNew);CHKERRQ(ierr);
202   ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
203   ierr = PetscSectionCreate(PetscObjectComm((PetscObject)dm), &newCoordSection);CHKERRQ(ierr);
204   ierr = PetscSectionSetNumFields(newCoordSection, 1);CHKERRQ(ierr);
205   ierr = PetscSectionSetFieldComponents(newCoordSection, 0, dim);CHKERRQ(ierr);
206   ierr = PetscSectionSetChart(newCoordSection, vStartNew, vEndNew);CHKERRQ(ierr);
207   for (v = vStartNew; v < vEndNew; ++v) {
208     ierr = PetscSectionSetDof(newCoordSection, v, dim);CHKERRQ(ierr);
209     ierr = PetscSectionSetFieldDof(newCoordSection, v, 0, dim);CHKERRQ(ierr);
210   }
211   ierr = PetscSectionSetUp(newCoordSection);CHKERRQ(ierr);
212   ierr = DMPlexSetCoordinateSection(dmNew, newCoordSection);CHKERRQ(ierr);
213   ierr = PetscSectionGetStorageSize(newCoordSection, &coordSize);CHKERRQ(ierr);
214   ierr = VecCreate(PetscObjectComm((PetscObject)dm), &newCoordinates);CHKERRQ(ierr);
215   ierr = PetscObjectSetName((PetscObject) newCoordinates, "coordinates");CHKERRQ(ierr);
216   ierr = VecSetSizes(newCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
217   ierr = VecSetFromOptions(newCoordinates);CHKERRQ(ierr);
218   ierr = DMSetCoordinatesLocal(dmNew, newCoordinates);CHKERRQ(ierr);
219   ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
220   ierr = VecGetArray(coordinates, &coords);CHKERRQ(ierr);
221   ierr = VecGetArray(newCoordinates, &newCoords);CHKERRQ(ierr);
222   for (v = vStart; v < vEnd; ++v) {
223     PetscInt dof, off, noff, d;
224 
225     ierr = PetscSectionGetDof(coordSection, v, &dof);CHKERRQ(ierr);
226     ierr = PetscSectionGetOffset(coordSection, v, &off);CHKERRQ(ierr);
227     ierr = PetscSectionGetOffset(newCoordSection, DMPlexShiftPoint_Internal(v, depth, depthEnd, depthShift), &noff);CHKERRQ(ierr);
228     for (d = 0; d < dof; ++d) {
229       newCoords[noff+d] = coords[off+d];
230     }
231   }
232   ierr = VecRestoreArray(coordinates, &coords);CHKERRQ(ierr);
233   ierr = VecRestoreArray(newCoordinates, &newCoords);CHKERRQ(ierr);
234   ierr = VecDestroy(&newCoordinates);CHKERRQ(ierr);
235   ierr = PetscSectionDestroy(&newCoordSection);CHKERRQ(ierr);
236   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
237   PetscFunctionReturn(0);
238 }
239 
240 #undef __FUNCT__
241 #define __FUNCT__ "DMPlexShiftSF_Internal"
242 static PetscErrorCode DMPlexShiftSF_Internal(DM dm, PetscInt depthShift[], DM dmNew)
243 {
244   PetscInt          *depthEnd;
245   PetscInt           depth = 0, d;
246   PetscSF            sfPoint, sfPointNew;
247   const PetscSFNode *remotePoints;
248   PetscSFNode       *gremotePoints;
249   const PetscInt    *localPoints;
250   PetscInt          *glocalPoints, *newLocation, *newRemoteLocation;
251   PetscInt           numRoots, numLeaves, l, pStart, pEnd, totShift = 0;
252   PetscMPIInt        numProcs;
253   PetscErrorCode     ierr;
254 
255   PetscFunctionBegin;
256   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
257   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
258   for (d = 0; d <= depth; ++d) {
259     totShift += depthShift[d];
260     ierr      = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
261   }
262   /* Step 9: Convert pointSF */
263   ierr = MPI_Comm_size(PetscObjectComm((PetscObject)dm), &numProcs);CHKERRQ(ierr);
264   ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
265   ierr = DMGetPointSF(dmNew, &sfPointNew);CHKERRQ(ierr);
266   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
267   ierr = PetscSFGetGraph(sfPoint, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
268   if (numRoots >= 0) {
269     ierr = PetscMalloc2(numRoots,PetscInt,&newLocation,pEnd-pStart,PetscInt,&newRemoteLocation);CHKERRQ(ierr);
270     for (l=0; l<numRoots; l++) newLocation[l] = DMPlexShiftPoint_Internal(l, depth, depthEnd, depthShift);
271     ierr = PetscSFBcastBegin(sfPoint, MPIU_INT, newLocation, newRemoteLocation);CHKERRQ(ierr);
272     ierr = PetscSFBcastEnd(sfPoint, MPIU_INT, newLocation, newRemoteLocation);CHKERRQ(ierr);
273     ierr = PetscMalloc(numLeaves * sizeof(PetscInt),    &glocalPoints);CHKERRQ(ierr);
274     ierr = PetscMalloc(numLeaves * sizeof(PetscSFNode), &gremotePoints);CHKERRQ(ierr);
275     for (l = 0; l < numLeaves; ++l) {
276       glocalPoints[l]        = DMPlexShiftPoint_Internal(localPoints[l], depth, depthEnd, depthShift);
277       gremotePoints[l].rank  = remotePoints[l].rank;
278       gremotePoints[l].index = newRemoteLocation[localPoints[l]];
279     }
280     ierr = PetscFree2(newLocation,newRemoteLocation);CHKERRQ(ierr);
281     ierr = PetscSFSetGraph(sfPointNew, numRoots + totShift, numLeaves, glocalPoints, PETSC_OWN_POINTER, gremotePoints, PETSC_OWN_POINTER);CHKERRQ(ierr);
282   }
283   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
284   PetscFunctionReturn(0);
285 }
286 
287 #undef __FUNCT__
288 #define __FUNCT__ "DMPlexShiftLabels_Internal"
289 static PetscErrorCode DMPlexShiftLabels_Internal(DM dm, PetscInt depthShift[], DM dmNew)
290 {
291   PetscSF            sfPoint;
292   DMLabel            vtkLabel, ghostLabel;
293   PetscInt          *depthEnd;
294   const PetscSFNode *leafRemote;
295   const PetscInt    *leafLocal;
296   PetscInt           depth = 0, d, numLeaves, numLabels, l, cStart, cEnd, c, fStart, fEnd, f;
297   PetscMPIInt        rank;
298   PetscErrorCode     ierr;
299 
300   PetscFunctionBegin;
301   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
302   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthEnd);CHKERRQ(ierr);
303   for (d = 0; d <= depth; ++d) {
304     ierr = DMPlexGetDepthStratum(dm, d, NULL, &depthEnd[d]);CHKERRQ(ierr);
305   }
306   /* Step 10: Convert labels */
307   ierr = DMPlexGetNumLabels(dm, &numLabels);CHKERRQ(ierr);
308   for (l = 0; l < numLabels; ++l) {
309     DMLabel         label, newlabel;
310     const char     *lname;
311     PetscBool       isDepth;
312     IS              valueIS;
313     const PetscInt *values;
314     PetscInt        numValues, val;
315 
316     ierr = DMPlexGetLabelName(dm, l, &lname);CHKERRQ(ierr);
317     ierr = PetscStrcmp(lname, "depth", &isDepth);CHKERRQ(ierr);
318     if (isDepth) continue;
319     ierr = DMPlexCreateLabel(dmNew, lname);CHKERRQ(ierr);
320     ierr = DMPlexGetLabel(dm, lname, &label);CHKERRQ(ierr);
321     ierr = DMPlexGetLabel(dmNew, lname, &newlabel);CHKERRQ(ierr);
322     ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
323     ierr = ISGetLocalSize(valueIS, &numValues);CHKERRQ(ierr);
324     ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
325     for (val = 0; val < numValues; ++val) {
326       IS              pointIS;
327       const PetscInt *points;
328       PetscInt        numPoints, p;
329 
330       ierr = DMLabelGetStratumIS(label, values[val], &pointIS);CHKERRQ(ierr);
331       ierr = ISGetLocalSize(pointIS, &numPoints);CHKERRQ(ierr);
332       ierr = ISGetIndices(pointIS, &points);CHKERRQ(ierr);
333       for (p = 0; p < numPoints; ++p) {
334         const PetscInt newpoint = DMPlexShiftPoint_Internal(points[p], depth, depthEnd, depthShift);
335 
336         ierr = DMLabelSetValue(newlabel, newpoint, values[val]);CHKERRQ(ierr);
337       }
338       ierr = ISRestoreIndices(pointIS, &points);CHKERRQ(ierr);
339       ierr = ISDestroy(&pointIS);CHKERRQ(ierr);
340     }
341     ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
342     ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
343   }
344   ierr = PetscFree(depthEnd);CHKERRQ(ierr);
345   /* Step 11: Make label for output (vtk) and to mark ghost points (ghost) */
346   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank);CHKERRQ(ierr);
347   ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
348   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
349   ierr = PetscSFGetGraph(sfPoint, NULL, &numLeaves, &leafLocal, &leafRemote);CHKERRQ(ierr);
350   ierr = DMPlexCreateLabel(dmNew, "vtk");CHKERRQ(ierr);
351   ierr = DMPlexCreateLabel(dmNew, "ghost");CHKERRQ(ierr);
352   ierr = DMPlexGetLabel(dmNew, "vtk", &vtkLabel);CHKERRQ(ierr);
353   ierr = DMPlexGetLabel(dmNew, "ghost", &ghostLabel);CHKERRQ(ierr);
354   for (l = 0, c = cStart; l < numLeaves && c < cEnd; ++l, ++c) {
355     for (; c < leafLocal[l] && c < cEnd; ++c) {
356       ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
357     }
358     if (leafLocal[l] >= cEnd) break;
359     if (leafRemote[l].rank == rank) {
360       ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
361     } else {
362       ierr = DMLabelSetValue(ghostLabel, c, 2);CHKERRQ(ierr);
363     }
364   }
365   for (; c < cEnd; ++c) {
366     ierr = DMLabelSetValue(vtkLabel, c, 1);CHKERRQ(ierr);
367   }
368   if (0) {
369     ierr = PetscViewerASCIISynchronizedAllow(PETSC_VIEWER_STDOUT_WORLD, PETSC_TRUE);CHKERRQ(ierr);
370     ierr = DMLabelView(vtkLabel, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
371     ierr = PetscViewerFlush(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
372   }
373   ierr = DMPlexGetHeightStratum(dmNew, 1, &fStart, &fEnd);CHKERRQ(ierr);
374   for (f = fStart; f < fEnd; ++f) {
375     PetscInt numCells;
376 
377     ierr = DMPlexGetSupportSize(dmNew, f, &numCells);CHKERRQ(ierr);
378     if (numCells < 2) {
379       ierr = DMLabelSetValue(ghostLabel, f, 1);CHKERRQ(ierr);
380     } else {
381       const PetscInt *cells = NULL;
382       PetscInt        vA, vB;
383 
384       ierr = DMPlexGetSupport(dmNew, f, &cells);CHKERRQ(ierr);
385       ierr = DMLabelGetValue(vtkLabel, cells[0], &vA);CHKERRQ(ierr);
386       ierr = DMLabelGetValue(vtkLabel, cells[1], &vB);CHKERRQ(ierr);
387       if (!vA && !vB) {ierr = DMLabelSetValue(ghostLabel, f, 1);CHKERRQ(ierr);}
388     }
389   }
390   if (0) {
391     ierr = PetscViewerASCIISynchronizedAllow(PETSC_VIEWER_STDOUT_WORLD, PETSC_TRUE);CHKERRQ(ierr);
392     ierr = DMLabelView(ghostLabel, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
393     ierr = PetscViewerFlush(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
394   }
395   PetscFunctionReturn(0);
396 }
397 
398 #undef __FUNCT__
399 #define __FUNCT__ "DMPlexConstructGhostCells_Internal"
400 static PetscErrorCode DMPlexConstructGhostCells_Internal(DM dm, DMLabel label, PetscInt *numGhostCells, DM gdm)
401 {
402   IS              valueIS;
403   const PetscInt *values;
404   PetscInt       *depthShift;
405   PetscInt        depth = 0, numFS, fs, ghostCell, cEnd, c;
406   PetscErrorCode  ierr;
407 
408   PetscFunctionBegin;
409   /* Count ghost cells */
410   ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
411   ierr = ISGetLocalSize(valueIS, &numFS);CHKERRQ(ierr);
412   ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
413 
414   *numGhostCells = 0;
415   for (fs = 0; fs < numFS; ++fs) {
416     PetscInt numBdFaces;
417 
418     ierr = DMLabelGetStratumSize(label, values[fs], &numBdFaces);CHKERRQ(ierr);
419 
420     *numGhostCells += numBdFaces;
421   }
422   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
423   ierr = PetscMalloc((depth+1) * sizeof(PetscInt), &depthShift);CHKERRQ(ierr);
424   ierr = PetscMemzero(depthShift, (depth+1) * sizeof(PetscInt));CHKERRQ(ierr);
425   if (depth >= 0) depthShift[depth] = *numGhostCells;
426   ierr = DMPlexShiftSizes_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
427   /* Step 3: Set cone/support sizes for new points */
428   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
429   for (c = cEnd; c < cEnd + *numGhostCells; ++c) {
430     ierr = DMPlexSetConeSize(gdm, c, 1);CHKERRQ(ierr);
431   }
432   for (fs = 0; fs < numFS; ++fs) {
433     IS              faceIS;
434     const PetscInt *faces;
435     PetscInt        numFaces, f;
436 
437     ierr = DMLabelGetStratumIS(label, values[fs], &faceIS);CHKERRQ(ierr);
438     ierr = ISGetLocalSize(faceIS, &numFaces);CHKERRQ(ierr);
439     ierr = ISGetIndices(faceIS, &faces);CHKERRQ(ierr);
440     for (f = 0; f < numFaces; ++f) {
441       PetscInt size;
442 
443       ierr = DMPlexGetSupportSize(dm, faces[f], &size);CHKERRQ(ierr);
444       if (size != 1) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "DM has boundary face %d with %d support cells", faces[f], size);
445       ierr = DMPlexSetSupportSize(gdm, faces[f] + *numGhostCells, 2);CHKERRQ(ierr);
446     }
447     ierr = ISRestoreIndices(faceIS, &faces);CHKERRQ(ierr);
448     ierr = ISDestroy(&faceIS);CHKERRQ(ierr);
449   }
450   /* Step 4: Setup ghosted DM */
451   ierr = DMSetUp(gdm);CHKERRQ(ierr);
452   ierr = DMPlexShiftPoints_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
453   /* Step 6: Set cones and supports for new points */
454   ghostCell = cEnd;
455   for (fs = 0; fs < numFS; ++fs) {
456     IS              faceIS;
457     const PetscInt *faces;
458     PetscInt        numFaces, f;
459 
460     ierr = DMLabelGetStratumIS(label, values[fs], &faceIS);CHKERRQ(ierr);
461     ierr = ISGetLocalSize(faceIS, &numFaces);CHKERRQ(ierr);
462     ierr = ISGetIndices(faceIS, &faces);CHKERRQ(ierr);
463     for (f = 0; f < numFaces; ++f, ++ghostCell) {
464       PetscInt newFace = faces[f] + *numGhostCells;
465 
466       ierr = DMPlexSetCone(gdm, ghostCell, &newFace);CHKERRQ(ierr);
467       ierr = DMPlexInsertSupport(gdm, newFace, 1, ghostCell);CHKERRQ(ierr);
468     }
469     ierr = ISRestoreIndices(faceIS, &faces);CHKERRQ(ierr);
470     ierr = ISDestroy(&faceIS);CHKERRQ(ierr);
471   }
472   ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
473   ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
474   /* Step 7: Stratify */
475   ierr = DMPlexStratify(gdm);CHKERRQ(ierr);
476   ierr = DMPlexShiftCoordinates_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
477   ierr = DMPlexShiftSF_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
478   ierr = DMPlexShiftLabels_Internal(dm, depthShift, gdm);CHKERRQ(ierr);
479   ierr = PetscFree(depthShift);CHKERRQ(ierr);
480   PetscFunctionReturn(0);
481 }
482 
483 #undef __FUNCT__
484 #define __FUNCT__ "DMPlexConstructGhostCells"
485 /*@C
486   DMPlexConstructGhostCells - Construct ghost cells which connect to every boundary face
487 
488   Collective on dm
489 
490   Input Parameters:
491 + dm - The original DM
492 - labelName - The label specifying the boundary faces, or "Face Sets" if this is NULL
493 
494   Output Parameters:
495 + numGhostCells - The number of ghost cells added to the DM
496 - dmGhosted - The new DM
497 
498   Note: If no label exists of that name, one will be created marking all boundary faces
499 
500   Level: developer
501 
502 .seealso: DMCreate()
503 */
504 PetscErrorCode DMPlexConstructGhostCells(DM dm, const char labelName[], PetscInt *numGhostCells, DM *dmGhosted)
505 {
506   DM             gdm;
507   DMLabel        label;
508   const char    *name = labelName ? labelName : "Face Sets";
509   PetscInt       dim;
510   PetscErrorCode ierr;
511 
512   PetscFunctionBegin;
513   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
514   PetscValidPointer(numGhostCells, 3);
515   PetscValidPointer(dmGhosted, 4);
516   ierr = DMCreate(PetscObjectComm((PetscObject)dm), &gdm);CHKERRQ(ierr);
517   ierr = DMSetType(gdm, DMPLEX);CHKERRQ(ierr);
518   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
519   ierr = DMPlexSetDimension(gdm, dim);CHKERRQ(ierr);
520   ierr = DMPlexGetLabel(dm, name, &label);CHKERRQ(ierr);
521   if (!label) {
522     /* Get label for boundary faces */
523     ierr = DMPlexCreateLabel(dm, name);CHKERRQ(ierr);
524     ierr = DMPlexGetLabel(dm, name, &label);CHKERRQ(ierr);
525     ierr = DMPlexMarkBoundaryFaces(dm, label);CHKERRQ(ierr);
526   }
527   ierr = DMPlexConstructGhostCells_Internal(dm, label, numGhostCells, gdm);CHKERRQ(ierr);
528   ierr = DMSetFromOptions(gdm);CHKERRQ(ierr);
529   *dmGhosted = gdm;
530   PetscFunctionReturn(0);
531 }
532 
533 #undef __FUNCT__
534 #define __FUNCT__ "DMPlexConstructCohesiveCells_Internal"
535 static PetscErrorCode DMPlexConstructCohesiveCells_Internal(DM dm, DMLabel label, DM sdm)
536 {
537   MPI_Comm        comm;
538   IS              valueIS, *pointIS;
539   const PetscInt *values, **splitPoints;
540   PetscSection    coordSection;
541   Vec             coordinates;
542   PetscScalar    *coords;
543   PetscInt       *depthShift, *depthOffset, *pMaxNew, *numSplitPoints, *coneNew, *supportNew;
544   PetscInt        shift = 100, depth = 0, dep, dim, d, numSP = 0, sp, maxConeSize, maxSupportSize, numLabels, p, v;
545   PetscErrorCode  ierr;
546 
547   PetscFunctionBegin;
548   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
549   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
550   /* Count split points and add cohesive cells */
551   if (label) {
552     ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
553     ierr = ISGetLocalSize(valueIS, &numSP);CHKERRQ(ierr);
554     ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
555   }
556   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
557   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
558   ierr = PetscMalloc5(depth+1,PetscInt,&depthShift,depth+1,PetscInt,&depthOffset,depth+1,PetscInt,&pMaxNew,maxConeSize*3,PetscInt,&coneNew,maxSupportSize,PetscInt,&supportNew);CHKERRQ(ierr);
559   ierr = PetscMalloc3(depth+1,IS,&pointIS,depth+1,PetscInt,&numSplitPoints,depth+1,const PetscInt*,&splitPoints);CHKERRQ(ierr);
560   ierr = PetscMemzero(depthShift, (depth+1) * sizeof(PetscInt));CHKERRQ(ierr);
561   for (d = 0; d <= depth; ++d) {
562     ierr              = DMPlexGetDepthStratum(dm, d, NULL, &pMaxNew[d]);CHKERRQ(ierr);
563     numSplitPoints[d] = 0;
564     splitPoints[d]    = NULL;
565     pointIS[d]        = NULL;
566   }
567   for (sp = 0; sp < numSP; ++sp) {
568     const PetscInt dep = values[sp];
569 
570     if ((dep < 0) || (dep > depth)) continue;
571     ierr = DMLabelGetStratumSize(label, dep, &depthShift[dep]);CHKERRQ(ierr);
572     ierr = DMLabelGetStratumIS(label, dep, &pointIS[dep]);CHKERRQ(ierr);
573     if (pointIS[dep]) {
574       ierr = ISGetLocalSize(pointIS[dep], &numSplitPoints[dep]);CHKERRQ(ierr);
575       ierr = ISGetIndices(pointIS[dep], &splitPoints[dep]);CHKERRQ(ierr);
576     }
577   }
578   if (depth >= 0) {
579     /* Calculate number of additional points */
580     depthShift[depth] = depthShift[depth-1]; /* There is a cohesive cell for every split face   */
581     depthShift[1]    += depthShift[0];       /* There is a cohesive edge for every split vertex */
582     /* Calculate hybrid bound for each dimension */
583     pMaxNew[0] += depthShift[depth];
584     if (depth > 1) pMaxNew[dim-1] += depthShift[depth] + depthShift[0];
585     if (depth > 2) pMaxNew[1]     += depthShift[depth] + depthShift[0] + depthShift[dim-1];
586 
587     /* Calculate point offset for each dimension */
588     depthOffset[depth] = 0;
589     depthOffset[0]     = depthOffset[depth] + depthShift[depth];
590     if (depth > 1) depthOffset[dim-1] = depthOffset[0]     + depthShift[0];
591     if (depth > 2) depthOffset[1]     = depthOffset[dim-1] + depthShift[dim-1];
592   }
593   ierr = DMPlexShiftSizes_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
594   /* Step 3: Set cone/support sizes for new points */
595   for (dep = 0; dep <= depth; ++dep) {
596     for (p = 0; p < numSplitPoints[dep]; ++p) {
597       const PetscInt  oldp   = splitPoints[dep][p];
598       const PetscInt  newp   = depthOffset[dep] + oldp;
599       const PetscInt  splitp = pMaxNew[dep] + p;
600       const PetscInt *support;
601       PetscInt        coneSize, supportSize, q, e;
602 
603       ierr = DMPlexGetConeSize(dm, oldp, &coneSize);CHKERRQ(ierr);
604       ierr = DMPlexSetConeSize(sdm, splitp, coneSize);CHKERRQ(ierr);
605       ierr = DMPlexGetSupportSize(dm, oldp, &supportSize);CHKERRQ(ierr);
606       ierr = DMPlexSetSupportSize(sdm, splitp, supportSize);CHKERRQ(ierr);
607       if (dep == depth-1) {
608         const PetscInt ccell = pMaxNew[depth] + p;
609         /* Add cohesive cells, they are prisms */
610         ierr = DMPlexSetConeSize(sdm, ccell, 2 + coneSize);CHKERRQ(ierr);
611       } else if (dep == 0) {
612         const PetscInt cedge = pMaxNew[1] + (depthShift[1] - depthShift[0]) + p;
613 
614         ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
615         /* Split old vertex: Edges in old split faces and new cohesive edge */
616         for (e = 0, q = 0; e < supportSize; ++e) {
617           PetscInt val;
618 
619           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
620           if ((val == 1) || (val == (shift + 1))) ++q;
621         }
622         ierr = DMPlexSetSupportSize(sdm, newp, q+1);CHKERRQ(ierr);
623         /* Split new vertex: Edges in new split faces and new cohesive edge */
624         for (e = 0, q = 0; e < supportSize; ++e) {
625           PetscInt val;
626 
627           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
628           if ((val == 1) || (val == -(shift + 1))) ++q;
629         }
630         ierr = DMPlexSetSupportSize(sdm, splitp, q+1);CHKERRQ(ierr);
631         /* Add cohesive edges */
632         ierr = DMPlexSetConeSize(sdm, cedge, 2);CHKERRQ(ierr);
633         /* Punt for now on support, you loop over closure, extract faces, check which ones are in the label */
634       } else if (dep == dim-2) {
635         ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
636         /* Split old edge: Faces in positive side cells and old split faces */
637         for (e = 0, q = 0; e < supportSize; ++e) {
638           PetscInt val;
639 
640           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
641           if ((val == dim-1) || (val == (shift + dim-1))) ++q;
642         }
643         ierr = DMPlexSetSupportSize(sdm, newp, q);CHKERRQ(ierr);
644         /* Split new edge: Faces in negative side cells and new split faces */
645         for (e = 0, q = 0; e < supportSize; ++e) {
646           PetscInt val;
647 
648           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
649           if ((val == dim-1) || (val == -(shift + dim-1))) ++q;
650         }
651         ierr = DMPlexSetSupportSize(sdm, splitp, q);CHKERRQ(ierr);
652       }
653     }
654   }
655   /* Step 4: Setup split DM */
656   ierr = DMSetUp(sdm);CHKERRQ(ierr);
657   ierr = DMPlexShiftPoints_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
658   /* Step 6: Set cones and supports for new points */
659   for (dep = 0; dep <= depth; ++dep) {
660     for (p = 0; p < numSplitPoints[dep]; ++p) {
661       const PetscInt  oldp   = splitPoints[dep][p];
662       const PetscInt  newp   = depthOffset[dep] + oldp;
663       const PetscInt  splitp = pMaxNew[dep] + p;
664       const PetscInt *cone, *support, *ornt;
665       PetscInt        coneSize, supportSize, q, v, e, s;
666 
667       ierr = DMPlexGetConeSize(dm, oldp, &coneSize);CHKERRQ(ierr);
668       ierr = DMPlexGetCone(dm, oldp, &cone);CHKERRQ(ierr);
669       ierr = DMPlexGetConeOrientation(dm, oldp, &ornt);CHKERRQ(ierr);
670       ierr = DMPlexGetSupportSize(dm, oldp, &supportSize);CHKERRQ(ierr);
671       ierr = DMPlexGetSupport(dm, oldp, &support);CHKERRQ(ierr);
672       if (dep == depth-1) {
673         const PetscInt  ccell = pMaxNew[depth] + p;
674         const PetscInt *supportF;
675 
676         /* Split face:       copy in old face to new face to start */
677         ierr = DMPlexGetSupport(sdm, newp,  &supportF);CHKERRQ(ierr);
678         ierr = DMPlexSetSupport(sdm, splitp, supportF);CHKERRQ(ierr);
679         /* Split old face:   old vertices/edges in cone so no change */
680         /* Split new face:   new vertices/edges in cone */
681         for (q = 0; q < coneSize; ++q) {
682           ierr = PetscFindInt(cone[q], numSplitPoints[dim-2], splitPoints[dim-2], &v);CHKERRQ(ierr);
683 
684           coneNew[2+q] = pMaxNew[dim-2] + v;
685         }
686         ierr = DMPlexSetCone(sdm, splitp, &coneNew[2]);CHKERRQ(ierr);
687         ierr = DMPlexSetConeOrientation(sdm, splitp, ornt);CHKERRQ(ierr);
688         /* Cohesive cell:    Old and new split face, then new cohesive edges */
689         coneNew[0] = newp;
690         coneNew[1] = splitp;
691         for (q = 0; q < coneSize; ++q) {
692           coneNew[2+q] = (pMaxNew[1] - pMaxNew[dim-2]) + (depthShift[1] - depthShift[0]) + coneNew[2+q];
693         }
694         ierr = DMPlexSetCone(sdm, ccell, coneNew);CHKERRQ(ierr);
695 
696 
697         for (s = 0; s < supportSize; ++s) {
698           PetscInt val;
699 
700           ierr = DMLabelGetValue(label, support[s], &val);CHKERRQ(ierr);
701           if (val < 0) {
702             /* Split old face:   Replace negative side cell with cohesive cell */
703             ierr = DMPlexInsertSupport(sdm, newp, s, ccell);CHKERRQ(ierr);
704           } else {
705             /* Split new face:   Replace positive side cell with cohesive cell */
706             ierr = DMPlexInsertSupport(sdm, splitp, s, ccell);CHKERRQ(ierr);
707           }
708         }
709       } else if (dep == 0) {
710         const PetscInt cedge = pMaxNew[1] + (depthShift[1] - depthShift[0]) + p;
711 
712         /* Split old vertex: Edges in old split faces and new cohesive edge */
713         for (e = 0, q = 0; e < supportSize; ++e) {
714           PetscInt val;
715 
716           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
717           if ((val == 1) || (val == (shift + 1))) {
718             supportNew[q++] = depthOffset[1] + support[e];
719           }
720         }
721         supportNew[q] = cedge;
722 
723         ierr = DMPlexSetSupport(sdm, newp, supportNew);CHKERRQ(ierr);
724         /* Split new vertex: Edges in new split faces and new cohesive edge */
725         for (e = 0, q = 0; e < supportSize; ++e) {
726           PetscInt val, edge;
727 
728           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
729           if (val == 1) {
730             ierr = PetscFindInt(support[e], numSplitPoints[1], splitPoints[1], &edge);CHKERRQ(ierr);
731             if (edge < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Edge %d is not a split edge", support[e]);
732             supportNew[q++] = pMaxNew[1] + edge;
733           } else if (val == -(shift + 1)) {
734             supportNew[q++] = depthOffset[1] + support[e];
735           }
736         }
737         supportNew[q] = cedge;
738         ierr          = DMPlexSetSupport(sdm, splitp, supportNew);CHKERRQ(ierr);
739         /* Cohesive edge:    Old and new split vertex, punting on support */
740         coneNew[0] = newp;
741         coneNew[1] = splitp;
742         ierr       = DMPlexSetCone(sdm, cedge, coneNew);CHKERRQ(ierr);
743       } else if (dep == dim-2) {
744         /* Split old edge:   old vertices in cone so no change */
745         /* Split new edge:   new vertices in cone */
746         for (q = 0; q < coneSize; ++q) {
747           ierr = PetscFindInt(cone[q], numSplitPoints[dim-3], splitPoints[dim-3], &v);CHKERRQ(ierr);
748 
749           coneNew[q] = pMaxNew[dim-3] + v;
750         }
751         ierr = DMPlexSetCone(sdm, splitp, coneNew);CHKERRQ(ierr);
752         /* Split old edge: Faces in positive side cells and old split faces */
753         for (e = 0, q = 0; e < supportSize; ++e) {
754           PetscInt val;
755 
756           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
757           if ((val == dim-1) || (val == (shift + dim-1))) {
758             supportNew[q++] = depthOffset[dim-1] + support[e];
759           }
760         }
761         ierr = DMPlexSetSupport(sdm, newp, supportNew);CHKERRQ(ierr);
762         /* Split new edge: Faces in negative side cells and new split faces */
763         for (e = 0, q = 0; e < supportSize; ++e) {
764           PetscInt val, face;
765 
766           ierr = DMLabelGetValue(label, support[e], &val);CHKERRQ(ierr);
767           if (val == dim-1) {
768             ierr = PetscFindInt(support[e], numSplitPoints[dim-1], splitPoints[dim-1], &face);CHKERRQ(ierr);
769             if (face < 0) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Face %d is not a split face", support[e]);
770             supportNew[q++] = pMaxNew[dim-1] + face;
771           } else if (val == -(shift + dim-1)) {
772             supportNew[q++] = depthOffset[dim-1] + support[e];
773           }
774         }
775         ierr = DMPlexSetSupport(sdm, splitp, supportNew);CHKERRQ(ierr);
776       }
777     }
778   }
779   /* Step 6b: Replace split points in negative side cones */
780   for (sp = 0; sp < numSP; ++sp) {
781     PetscInt        dep = values[sp];
782     IS              pIS;
783     PetscInt        numPoints;
784     const PetscInt *points;
785 
786     if (dep >= 0) continue;
787     ierr = DMLabelGetStratumIS(label, dep, &pIS);CHKERRQ(ierr);
788     if (!pIS) continue;
789     dep  = -dep - shift;
790     ierr = ISGetLocalSize(pIS, &numPoints);CHKERRQ(ierr);
791     ierr = ISGetIndices(pIS, &points);CHKERRQ(ierr);
792     for (p = 0; p < numPoints; ++p) {
793       const PetscInt  oldp = points[p];
794       const PetscInt  newp = depthOffset[dep] + oldp;
795       const PetscInt *cone;
796       PetscInt        coneSize, c;
797       PetscBool       replaced = PETSC_FALSE;
798 
799       /* Negative edge: replace split vertex */
800       /* Negative cell: replace split face */
801       ierr = DMPlexGetConeSize(sdm, newp, &coneSize);CHKERRQ(ierr);
802       ierr = DMPlexGetCone(sdm, newp, &cone);CHKERRQ(ierr);
803       for (c = 0; c < coneSize; ++c) {
804         const PetscInt coldp = cone[c] - depthOffset[dep-1];
805         PetscInt       csplitp, cp, val;
806 
807         ierr = DMLabelGetValue(label, coldp, &val);CHKERRQ(ierr);
808         if (val == dep-1) {
809           ierr = PetscFindInt(coldp, numSplitPoints[dep-1], splitPoints[dep-1], &cp);CHKERRQ(ierr);
810           if (cp < 0) SETERRQ2(comm, PETSC_ERR_ARG_WRONG, "Point %d is not a split point of dimension %d", oldp, dep-1);
811           csplitp  = pMaxNew[dep-1] + cp;
812           ierr     = DMPlexInsertCone(sdm, newp, c, csplitp);CHKERRQ(ierr);
813           replaced = PETSC_TRUE;
814         }
815       }
816       if (!replaced) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "The cone of point %d does not contain split points", oldp);
817     }
818     ierr = ISRestoreIndices(pIS, &points);CHKERRQ(ierr);
819     ierr = ISDestroy(&pIS);CHKERRQ(ierr);
820   }
821   /* Step 7: Stratify */
822   ierr = DMPlexStratify(sdm);CHKERRQ(ierr);
823   /* Step 8: Coordinates */
824   ierr = DMPlexShiftCoordinates_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
825   ierr = DMPlexGetCoordinateSection(sdm, &coordSection);CHKERRQ(ierr);
826   ierr = DMGetCoordinatesLocal(sdm, &coordinates);CHKERRQ(ierr);
827   ierr = VecGetArray(coordinates, &coords);CHKERRQ(ierr);
828   for (v = 0; v < (numSplitPoints ? numSplitPoints[0] : 0); ++v) {
829     const PetscInt newp   = depthOffset[0] + splitPoints[0][v];
830     const PetscInt splitp = pMaxNew[0] + v;
831     PetscInt       dof, off, soff, d;
832 
833     ierr = PetscSectionGetDof(coordSection, newp, &dof);CHKERRQ(ierr);
834     ierr = PetscSectionGetOffset(coordSection, newp, &off);CHKERRQ(ierr);
835     ierr = PetscSectionGetOffset(coordSection, splitp, &soff);CHKERRQ(ierr);
836     for (d = 0; d < dof; ++d) coords[soff+d] = coords[off+d];
837   }
838   ierr = VecRestoreArray(coordinates, &coords);CHKERRQ(ierr);
839   /* Step 9: SF, if I can figure this out we can split the mesh in parallel */
840   ierr = DMPlexShiftSF_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
841   /* Step 10: Labels */
842   ierr = DMPlexShiftLabels_Internal(dm, depthShift, sdm);CHKERRQ(ierr);
843   ierr = DMPlexGetNumLabels(sdm, &numLabels);CHKERRQ(ierr);
844   for (dep = 0; dep <= depth; ++dep) {
845     for (p = 0; p < numSplitPoints[dep]; ++p) {
846       const PetscInt newp   = depthOffset[dep] + splitPoints[dep][p];
847       const PetscInt splitp = pMaxNew[dep] + p;
848       PetscInt       l;
849 
850       for (l = 0; l < numLabels; ++l) {
851         DMLabel     mlabel;
852         const char *lname;
853         PetscInt    val;
854         PetscBool   isDepth;
855 
856         ierr = DMPlexGetLabelName(sdm, l, &lname);CHKERRQ(ierr);
857         ierr = PetscStrcmp(lname, "depth", &isDepth);CHKERRQ(ierr);
858         if (isDepth) continue;
859         ierr = DMPlexGetLabel(sdm, lname, &mlabel);CHKERRQ(ierr);
860         ierr = DMLabelGetValue(mlabel, newp, &val);CHKERRQ(ierr);
861         if (val >= 0) {
862           ierr = DMLabelSetValue(mlabel, splitp, val);CHKERRQ(ierr);
863 #if 0
864           /* Do not put cohesive edges into the label */
865           if (dep == 0) {
866             const PetscInt cedge = pMaxNew[1] + (depthShift[1] - depthShift[0]) + p;
867             ierr = DMLabelSetValue(mlabel, cedge, val);CHKERRQ(ierr);
868           }
869 #endif
870         }
871       }
872     }
873   }
874   for (sp = 0; sp < numSP; ++sp) {
875     const PetscInt dep = values[sp];
876 
877     if ((dep < 0) || (dep > depth)) continue;
878     if (pointIS[dep]) {ierr = ISRestoreIndices(pointIS[dep], &splitPoints[dep]);CHKERRQ(ierr);}
879     ierr = ISDestroy(&pointIS[dep]);CHKERRQ(ierr);
880   }
881   if (label) {
882     ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
883     ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
884   }
885   ierr = PetscFree5(depthShift, depthOffset, pMaxNew, coneNew, supportNew);CHKERRQ(ierr);
886   ierr = PetscFree3(pointIS, numSplitPoints, splitPoints);CHKERRQ(ierr);
887   PetscFunctionReturn(0);
888 }
889 
890 #undef __FUNCT__
891 #define __FUNCT__ "DMPlexConstructCohesiveCells"
892 /*@C
893   DMPlexConstructCohesiveCells - Construct cohesive cells which split the face along an internal interface
894 
895   Collective on dm
896 
897   Input Parameters:
898 + dm - The original DM
899 - labelName - The label specifying the boundary faces (this could be auto-generated)
900 
901   Output Parameters:
902 - dmSplit - The new DM
903 
904   Level: developer
905 
906 .seealso: DMCreate(), DMPlexLabelCohesiveComplete()
907 @*/
908 PetscErrorCode DMPlexConstructCohesiveCells(DM dm, DMLabel label, DM *dmSplit)
909 {
910   DM             sdm;
911   PetscInt       dim;
912   PetscErrorCode ierr;
913 
914   PetscFunctionBegin;
915   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
916   PetscValidPointer(dmSplit, 4);
917   ierr = DMCreate(PetscObjectComm((PetscObject)dm), &sdm);CHKERRQ(ierr);
918   ierr = DMSetType(sdm, DMPLEX);CHKERRQ(ierr);
919   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
920   ierr = DMPlexSetDimension(sdm, dim);CHKERRQ(ierr);
921   switch (dim) {
922   case 2:
923   case 3:
924     ierr = DMPlexConstructCohesiveCells_Internal(dm, label, sdm);CHKERRQ(ierr);
925     break;
926   default:
927     SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot construct cohesive cells for dimension %d", dim);
928   }
929   *dmSplit = sdm;
930   PetscFunctionReturn(0);
931 }
932 
933 #undef __FUNCT__
934 #define __FUNCT__ "DMPlexLabelCohesiveComplete"
935 /*@
936   DMPlexLabelCohesiveComplete - Starting with a label marking vertices on an internal surface, we add all other mesh pieces
937   to complete the surface
938 
939   Input Parameters:
940 + dm - The DM
941 - label - A DMLabel marking the surface vertices
942 
943   Output Parameter:
944 . label - A DMLabel marking all surface points
945 
946   Level: developer
947 
948 .seealso: DMPlexConstructCohesiveCells(), DMPlexLabelComplete()
949 @*/
950 PetscErrorCode DMPlexLabelCohesiveComplete(DM dm, DMLabel label)
951 {
952   IS              dimIS;
953   const PetscInt *points;
954   PetscInt        shift = 100, dim, dep, cStart, cEnd, numPoints, p, val;
955   PetscErrorCode  ierr;
956 
957   PetscFunctionBegin;
958   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
959   /* Cell orientation for face gives the side of the fault */
960   ierr = DMLabelGetStratumIS(label, dim-1, &dimIS);CHKERRQ(ierr);
961   if (!dimIS) PetscFunctionReturn(0);
962   ierr = ISGetLocalSize(dimIS, &numPoints);CHKERRQ(ierr);
963   ierr = ISGetIndices(dimIS, &points);CHKERRQ(ierr);
964   for (p = 0; p < numPoints; ++p) {
965     const PetscInt *support;
966     PetscInt        supportSize, s;
967 
968     ierr = DMPlexGetSupportSize(dm, points[p], &supportSize);CHKERRQ(ierr);
969     if (supportSize != 2) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Split face %d has %d != 2 supports", points[p], supportSize);
970     ierr = DMPlexGetSupport(dm, points[p], &support);CHKERRQ(ierr);
971     for (s = 0; s < supportSize; ++s) {
972       const PetscInt *cone, *ornt;
973       PetscInt        coneSize, c;
974       PetscBool       pos = PETSC_TRUE;
975 
976       ierr = DMPlexGetConeSize(dm, support[s], &coneSize);CHKERRQ(ierr);
977       ierr = DMPlexGetCone(dm, support[s], &cone);CHKERRQ(ierr);
978       ierr = DMPlexGetConeOrientation(dm, support[s], &ornt);CHKERRQ(ierr);
979       for (c = 0; c < coneSize; ++c) {
980         if (cone[c] == points[p]) {
981           if (ornt[c] >= 0) {
982             ierr = DMLabelSetValue(label, support[s],   shift+dim);CHKERRQ(ierr);
983           } else {
984             ierr = DMLabelSetValue(label, support[s], -(shift+dim));CHKERRQ(ierr);
985             pos  = PETSC_FALSE;
986           }
987           break;
988         }
989       }
990       if (c == coneSize) SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Cell split face %d support does not have it in the cone", points[p]);
991       /* Put faces touching the fault in the label */
992       for (c = 0; c < coneSize; ++c) {
993         const PetscInt point = cone[c];
994 
995         ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
996         if (val == -1) {
997           PetscInt *closure = NULL;
998           PetscInt  closureSize, cl;
999 
1000           ierr = DMPlexGetTransitiveClosure(dm, point, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1001           for (cl = 0; cl < closureSize*2; cl += 2) {
1002             const PetscInt clp = closure[cl];
1003 
1004             ierr = DMLabelGetValue(label, clp, &val);CHKERRQ(ierr);
1005             if ((val >= 0) && (val < dim-1)) {
1006               ierr = DMLabelSetValue(label, point, pos == PETSC_TRUE ? shift+dim-1 : -(shift+dim-1));CHKERRQ(ierr);
1007               break;
1008             }
1009           }
1010           ierr = DMPlexRestoreTransitiveClosure(dm, point, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1011         }
1012       }
1013     }
1014   }
1015   ierr = ISRestoreIndices(dimIS, &points);CHKERRQ(ierr);
1016   ierr = ISDestroy(&dimIS);CHKERRQ(ierr);
1017   /* Search for other cells/faces/edges connected to the fault by a vertex */
1018   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
1019   ierr = DMLabelGetStratumIS(label, 0, &dimIS);CHKERRQ(ierr);
1020   if (!dimIS) PetscFunctionReturn(0);
1021   ierr = ISGetLocalSize(dimIS, &numPoints);CHKERRQ(ierr);
1022   ierr = ISGetIndices(dimIS, &points);CHKERRQ(ierr);
1023   for (p = 0; p < numPoints; ++p) {
1024     PetscInt *star = NULL;
1025     PetscInt  starSize, s;
1026     PetscInt  again = 1;  /* 0: Finished 1: Keep iterating after a change 2: No change */
1027 
1028     /* First mark cells connected to the fault */
1029     ierr = DMPlexGetTransitiveClosure(dm, points[p], PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1030     while (again) {
1031       if (again > 1) SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Could not classify all cells connected to the fault");
1032       again = 0;
1033       for (s = 0; s < starSize*2; s += 2) {
1034         const PetscInt  point = star[s];
1035         const PetscInt *cone;
1036         PetscInt        coneSize, c;
1037 
1038         if ((point < cStart) || (point >= cEnd)) continue;
1039         ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
1040         if (val != -1) continue;
1041         again = 2;
1042         ierr  = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
1043         ierr  = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
1044         for (c = 0; c < coneSize; ++c) {
1045           ierr = DMLabelGetValue(label, cone[c], &val);CHKERRQ(ierr);
1046           if (val != -1) {
1047             if (abs(val) < shift) SETERRQ3(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Face %d on cell %d has an invalid label %d", cone[c], point, val);
1048             if (val > 0) {
1049               ierr = DMLabelSetValue(label, point,   shift+dim);CHKERRQ(ierr);
1050             } else {
1051               ierr = DMLabelSetValue(label, point, -(shift+dim));CHKERRQ(ierr);
1052             }
1053             again = 1;
1054             break;
1055           }
1056         }
1057       }
1058     }
1059     /* Classify the rest by cell membership */
1060     for (s = 0; s < starSize*2; s += 2) {
1061       const PetscInt point = star[s];
1062 
1063       ierr = DMLabelGetValue(label, point, &val);CHKERRQ(ierr);
1064       if (val == -1) {
1065         PetscInt  *sstar = NULL;
1066         PetscInt   sstarSize, ss;
1067         PetscBool  marked = PETSC_FALSE;
1068 
1069         ierr = DMPlexGetTransitiveClosure(dm, point, PETSC_FALSE, &sstarSize, &sstar);CHKERRQ(ierr);
1070         for (ss = 0; ss < sstarSize*2; ss += 2) {
1071           const PetscInt spoint = sstar[ss];
1072 
1073           if ((spoint < cStart) || (spoint >= cEnd)) continue;
1074           ierr = DMLabelGetValue(label, spoint, &val);CHKERRQ(ierr);
1075           if (val == -1) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Cell %d in star of %d does not have a valid label", spoint, point);
1076           ierr = DMPlexGetLabelValue(dm, "depth", point, &dep);CHKERRQ(ierr);
1077           if (val > 0) {
1078             ierr = DMLabelSetValue(label, point,   shift+dep);CHKERRQ(ierr);
1079           } else {
1080             ierr = DMLabelSetValue(label, point, -(shift+dep));CHKERRQ(ierr);
1081           }
1082           marked = PETSC_TRUE;
1083           break;
1084         }
1085         ierr = DMPlexRestoreTransitiveClosure(dm, point, PETSC_FALSE, &sstarSize, &sstar);CHKERRQ(ierr);
1086         if (!marked) SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Point %d could not be classified", point);
1087       }
1088     }
1089     ierr = DMPlexRestoreTransitiveClosure(dm, points[p], PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1090   }
1091   ierr = ISRestoreIndices(dimIS, &points);CHKERRQ(ierr);
1092   ierr = ISDestroy(&dimIS);CHKERRQ(ierr);
1093   PetscFunctionReturn(0);
1094 }
1095 
1096 #undef __FUNCT__
1097 #define __FUNCT__ "DMPlexMarkSubmesh_Uninterpolated"
1098 /* Here we need the explicit assumption that:
1099 
1100      For any marked cell, the marked vertices constitute a single face
1101 */
1102 static PetscErrorCode DMPlexMarkSubmesh_Uninterpolated(DM dm, DMLabel vertexLabel, PetscInt value, DMLabel subpointMap, PetscInt *numFaces, PetscInt *nFV, DM subdm)
1103 {
1104   IS               subvertexIS;
1105   const PetscInt  *subvertices;
1106   PetscInt        *pStart, *pEnd, *pMax, pSize;
1107   PetscInt         depth, dim, d, numSubVerticesInitial = 0, v;
1108   PetscErrorCode   ierr;
1109 
1110   PetscFunctionBegin;
1111   *numFaces = 0;
1112   *nFV      = 0;
1113   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
1114   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1115   pSize = PetscMax(depth, dim) + 1;
1116   ierr = PetscMalloc3(pSize,PetscInt,&pStart,pSize,PetscInt,&pEnd,pSize,PetscInt,&pMax);CHKERRQ(ierr);
1117   ierr = DMPlexGetHybridBounds(dm, &pMax[depth], depth>1 ? &pMax[depth-1] : NULL, depth > 2 ? &pMax[1] : NULL, &pMax[0]);CHKERRQ(ierr);
1118   for (d = 0; d <= depth; ++d) {
1119     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1120     if (pMax[d] >= 0) pEnd[d] = PetscMin(pEnd[d], pMax[d]);
1121   }
1122   /* Loop over initial vertices and mark all faces in the collective star() */
1123   ierr = DMLabelGetStratumIS(vertexLabel, value, &subvertexIS);CHKERRQ(ierr);
1124   if (subvertexIS) {
1125     ierr = ISGetSize(subvertexIS, &numSubVerticesInitial);CHKERRQ(ierr);
1126     ierr = ISGetIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1127   }
1128   for (v = 0; v < numSubVerticesInitial; ++v) {
1129     const PetscInt vertex = subvertices[v];
1130     PetscInt      *star   = NULL;
1131     PetscInt       starSize, s, numCells = 0, c;
1132 
1133     ierr = DMPlexGetTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1134     for (s = 0; s < starSize*2; s += 2) {
1135       const PetscInt point = star[s];
1136       if ((point >= pStart[depth]) && (point < pEnd[depth])) star[numCells++] = point;
1137     }
1138     for (c = 0; c < numCells; ++c) {
1139       const PetscInt cell    = star[c];
1140       PetscInt      *closure = NULL;
1141       PetscInt       closureSize, cl;
1142       PetscInt       cellLoc, numCorners = 0, faceSize = 0;
1143 
1144       ierr = DMLabelGetValue(subpointMap, cell, &cellLoc);CHKERRQ(ierr);
1145       if (cellLoc == 2) continue;
1146       if (cellLoc >= 0) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Cell %d has dimension %d in the surface label", cell, cellLoc);
1147       ierr = DMPlexGetTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1148       for (cl = 0; cl < closureSize*2; cl += 2) {
1149         const PetscInt point = closure[cl];
1150         PetscInt       vertexLoc;
1151 
1152         if ((point >= pStart[0]) && (point < pEnd[0])) {
1153           ++numCorners;
1154           ierr = DMLabelGetValue(vertexLabel, point, &vertexLoc);CHKERRQ(ierr);
1155           if (vertexLoc == value) closure[faceSize++] = point;
1156         }
1157       }
1158       if (!(*nFV)) {ierr = DMPlexGetNumFaceVertices(dm, dim, numCorners, nFV);CHKERRQ(ierr);}
1159       if (faceSize > *nFV) SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Invalid submesh: Too many vertices %d of an element on the surface", faceSize);
1160       if (faceSize == *nFV) {
1161         const PetscInt *cells = NULL;
1162         PetscInt        numCells, nc;
1163 
1164         ++(*numFaces);
1165         for (cl = 0; cl < faceSize; ++cl) {
1166           ierr = DMLabelSetValue(subpointMap, closure[cl], 0);CHKERRQ(ierr);
1167         }
1168         ierr = DMPlexGetJoin(dm, faceSize, closure, &numCells, &cells);CHKERRQ(ierr);
1169         for (nc = 0; nc < numCells; ++nc) {
1170           ierr = DMLabelSetValue(subpointMap, cells[nc], 2);CHKERRQ(ierr);
1171         }
1172         ierr = DMPlexRestoreJoin(dm, faceSize, closure, &numCells, &cells);CHKERRQ(ierr);
1173       }
1174       ierr = DMPlexRestoreTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1175     }
1176     ierr = DMPlexRestoreTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1177   }
1178   if (subvertexIS) {
1179     ierr = ISRestoreIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1180   }
1181   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
1182   ierr = PetscFree3(pStart,pEnd,pMax);CHKERRQ(ierr);
1183   PetscFunctionReturn(0);
1184 }
1185 
1186 #undef __FUNCT__
1187 #define __FUNCT__ "DMPlexMarkSubmesh_Interpolated"
1188 static PetscErrorCode DMPlexMarkSubmesh_Interpolated(DM dm, DMLabel vertexLabel, PetscInt value, DMLabel subpointMap, DM subdm)
1189 {
1190   IS               subvertexIS;
1191   const PetscInt  *subvertices;
1192   PetscInt        *pStart, *pEnd, *pMax;
1193   PetscInt         dim, d, numSubVerticesInitial = 0, v;
1194   PetscErrorCode   ierr;
1195 
1196   PetscFunctionBegin;
1197   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1198   ierr = PetscMalloc3(dim+1,PetscInt,&pStart,dim+1,PetscInt,&pEnd,dim+1,PetscInt,&pMax);CHKERRQ(ierr);
1199   ierr = DMPlexGetHybridBounds(dm, &pMax[dim], dim>1 ? &pMax[dim-1] : NULL, dim > 2 ? &pMax[1] : NULL, &pMax[0]);CHKERRQ(ierr);
1200   for (d = 0; d <= dim; ++d) {
1201     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1202     if (pMax[d] >= 0) pEnd[d] = PetscMin(pEnd[d], pMax[d]);
1203   }
1204   /* Loop over initial vertices and mark all faces in the collective star() */
1205   ierr = DMLabelGetStratumIS(vertexLabel, value, &subvertexIS);CHKERRQ(ierr);
1206   if (subvertexIS) {
1207     ierr = ISGetSize(subvertexIS, &numSubVerticesInitial);CHKERRQ(ierr);
1208     ierr = ISGetIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1209   }
1210   for (v = 0; v < numSubVerticesInitial; ++v) {
1211     const PetscInt vertex = subvertices[v];
1212     PetscInt      *star   = NULL;
1213     PetscInt       starSize, s, numFaces = 0, f;
1214 
1215     ierr = DMPlexGetTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1216     for (s = 0; s < starSize*2; s += 2) {
1217       const PetscInt point = star[s];
1218       if ((point >= pStart[dim-1]) && (point < pEnd[dim-1])) star[numFaces++] = point;
1219     }
1220     for (f = 0; f < numFaces; ++f) {
1221       const PetscInt face    = star[f];
1222       PetscInt      *closure = NULL;
1223       PetscInt       closureSize, c;
1224       PetscInt       faceLoc;
1225 
1226       ierr = DMLabelGetValue(subpointMap, face, &faceLoc);CHKERRQ(ierr);
1227       if (faceLoc == dim-1) continue;
1228       if (faceLoc >= 0) SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Face %d has dimension %d in the surface label", face, faceLoc);
1229       ierr = DMPlexGetTransitiveClosure(dm, face, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1230       for (c = 0; c < closureSize*2; c += 2) {
1231         const PetscInt point = closure[c];
1232         PetscInt       vertexLoc;
1233 
1234         if ((point >= pStart[0]) && (point < pEnd[0])) {
1235           ierr = DMLabelGetValue(vertexLabel, point, &vertexLoc);CHKERRQ(ierr);
1236           if (vertexLoc != value) break;
1237         }
1238       }
1239       if (c == closureSize*2) {
1240         const PetscInt *support;
1241         PetscInt        supportSize, s;
1242 
1243         for (c = 0; c < closureSize*2; c += 2) {
1244           const PetscInt point = closure[c];
1245 
1246           for (d = 0; d < dim; ++d) {
1247             if ((point >= pStart[d]) && (point < pEnd[d])) {
1248               ierr = DMLabelSetValue(subpointMap, point, d);CHKERRQ(ierr);
1249               break;
1250             }
1251           }
1252         }
1253         ierr = DMPlexGetSupportSize(dm, face, &supportSize);CHKERRQ(ierr);
1254         ierr = DMPlexGetSupport(dm, face, &support);CHKERRQ(ierr);
1255         for (s = 0; s < supportSize; ++s) {
1256           ierr = DMLabelSetValue(subpointMap, support[s], dim);CHKERRQ(ierr);
1257         }
1258       }
1259       ierr = DMPlexRestoreTransitiveClosure(dm, face, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1260     }
1261     ierr = DMPlexRestoreTransitiveClosure(dm, vertex, PETSC_FALSE, &starSize, &star);CHKERRQ(ierr);
1262   }
1263   if (subvertexIS) {
1264     ierr = ISRestoreIndices(subvertexIS, &subvertices);CHKERRQ(ierr);
1265   }
1266   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
1267   ierr = PetscFree3(pStart,pEnd,pMax);CHKERRQ(ierr);
1268   PetscFunctionReturn(0);
1269 }
1270 
1271 #undef __FUNCT__
1272 #define __FUNCT__ "DMPlexMarkCohesiveSubmesh_Uninterpolated"
1273 static PetscErrorCode DMPlexMarkCohesiveSubmesh_Uninterpolated(DM dm, PetscBool hasLagrange, const char labelname[], PetscInt value, DMLabel subpointMap, PetscInt *numFaces, PetscInt *nFV, PetscInt *subCells[], DM subdm)
1274 {
1275   DMLabel         label = NULL;
1276   const PetscInt *cone;
1277   PetscInt        dim, cMax, cEnd, c, p, coneSize;
1278   PetscErrorCode  ierr;
1279 
1280   PetscFunctionBegin;
1281   if (labelname) {ierr = DMPlexGetLabel(dm, labelname, &label);CHKERRQ(ierr);}
1282   *numFaces = 0;
1283   *nFV = 0;
1284   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1285   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
1286   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
1287   if (cMax < 0) PetscFunctionReturn(0);
1288   if (label) {
1289     for (c = cMax; c < cEnd; ++c) {
1290       PetscInt val;
1291 
1292       ierr = DMLabelGetValue(label, c, &val);CHKERRQ(ierr);
1293       if (val == value) {
1294         ++(*numFaces);
1295         ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
1296       }
1297     }
1298   } else {
1299     *numFaces = cEnd - cMax;
1300     ierr = DMPlexGetConeSize(dm, cMax, &coneSize);CHKERRQ(ierr);
1301   }
1302   *nFV = hasLagrange ? coneSize/3 : coneSize/2;
1303   ierr = PetscMalloc(*numFaces *2 * sizeof(PetscInt), subCells);CHKERRQ(ierr);
1304   for (c = cMax; c < cEnd; ++c) {
1305     const PetscInt *cells;
1306     PetscInt        numCells;
1307 
1308     if (label) {
1309       PetscInt val;
1310 
1311       ierr = DMLabelGetValue(label, c, &val);CHKERRQ(ierr);
1312       if (val != value) continue;
1313     }
1314     ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
1315     for (p = 0; p < *nFV; ++p) {
1316       ierr = DMLabelSetValue(subpointMap, cone[p], 0);CHKERRQ(ierr);
1317     }
1318     /* Negative face */
1319     ierr = DMPlexGetJoin(dm, *nFV, cone, &numCells, &cells);CHKERRQ(ierr);
1320     if (numCells != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
1321     for (p = 0; p < numCells; ++p) {
1322       ierr = DMLabelSetValue(subpointMap, cells[p], 2);CHKERRQ(ierr);
1323       (*subCells)[(c-cMax)*2+p] = cells[p];
1324     }
1325     ierr = DMPlexRestoreJoin(dm, *nFV, cone, &numCells, &cells);CHKERRQ(ierr);
1326     /* Positive face is not included */
1327   }
1328   PetscFunctionReturn(0);
1329 }
1330 
1331 #undef __FUNCT__
1332 #define __FUNCT__ "DMPlexMarkCohesiveSubmesh_Interpolated"
1333 static PetscErrorCode DMPlexMarkCohesiveSubmesh_Interpolated(DM dm, PetscBool hasLagrange, const char labelname[], PetscInt value, DMLabel subpointMap, DM subdm)
1334 {
1335   DMLabel        label = NULL;
1336   PetscInt      *pStart, *pEnd;
1337   PetscInt       dim, cMax, cEnd, c, d;
1338   PetscErrorCode ierr;
1339 
1340   PetscFunctionBegin;
1341   if (labelname) {ierr = DMPlexGetLabel(dm, labelname, &label);CHKERRQ(ierr);}
1342   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1343   ierr = DMPlexGetHeightStratum(dm, 0, NULL, &cEnd);CHKERRQ(ierr);
1344   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
1345   if (cMax < 0) PetscFunctionReturn(0);
1346   ierr = PetscMalloc2(dim+1,PetscInt,&pStart,dim+1,PetscInt,&pEnd);CHKERRQ(ierr);
1347   for (d = 0; d <= dim; ++d) {
1348     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
1349   }
1350   for (c = cMax; c < cEnd; ++c) {
1351     const PetscInt *cone;
1352     PetscInt       *closure = NULL;
1353     PetscInt        coneSize, closureSize, cl;
1354 
1355     if (label) {
1356       PetscInt val;
1357 
1358       ierr = DMLabelGetValue(label, c, &val);CHKERRQ(ierr);
1359       if (val != value) continue;
1360     }
1361     ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
1362     if (hasLagrange) {
1363       if (coneSize != 3) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
1364     } else {
1365       if (coneSize != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
1366     }
1367     /* Negative face */
1368     ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
1369     ierr = DMPlexGetTransitiveClosure(dm, cone[0], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1370     for (cl = 0; cl < closureSize*2; cl += 2) {
1371       const PetscInt point = closure[cl];
1372 
1373       for (d = 0; d <= dim; ++d) {
1374         if ((point >= pStart[d]) && (point < pEnd[d])) {
1375           ierr = DMLabelSetValue(subpointMap, point, d);CHKERRQ(ierr);
1376           break;
1377         }
1378       }
1379     }
1380     ierr = DMPlexRestoreTransitiveClosure(dm, cone[0], PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1381     /* Cells -- positive face is not included */
1382     for (cl = 0; cl < 1; ++cl) {
1383       const PetscInt *support;
1384       PetscInt        supportSize, s;
1385 
1386       ierr = DMPlexGetSupportSize(dm, cone[cl], &supportSize);CHKERRQ(ierr);
1387       if (supportSize != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive faces should separate two cells");
1388       ierr = DMPlexGetSupport(dm, cone[cl], &support);CHKERRQ(ierr);
1389       for (s = 0; s < supportSize; ++s) {
1390         ierr = DMLabelSetValue(subpointMap, support[s], dim);CHKERRQ(ierr);
1391       }
1392     }
1393   }
1394   ierr = PetscFree2(pStart, pEnd);CHKERRQ(ierr);
1395   PetscFunctionReturn(0);
1396 }
1397 
1398 #undef __FUNCT__
1399 #define __FUNCT__ "DMPlexGetFaceOrientation"
1400 PetscErrorCode DMPlexGetFaceOrientation(DM dm, PetscInt cell, PetscInt numCorners, PetscInt indices[], PetscInt oppositeVertex, PetscInt origVertices[], PetscInt faceVertices[], PetscBool *posOriented)
1401 {
1402   MPI_Comm       comm;
1403   PetscBool      posOrient = PETSC_FALSE;
1404   const PetscInt debug     = 0;
1405   PetscInt       cellDim, faceSize, f;
1406   PetscErrorCode ierr;
1407 
1408   PetscFunctionBegin;
1409   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1410   ierr = DMPlexGetDimension(dm, &cellDim);CHKERRQ(ierr);
1411   if (debug) {PetscPrintf(comm, "cellDim: %d numCorners: %d\n", cellDim, numCorners);CHKERRQ(ierr);}
1412 
1413   if (cellDim == numCorners-1) {
1414     /* Simplices */
1415     faceSize  = numCorners-1;
1416     posOrient = !(oppositeVertex%2) ? PETSC_TRUE : PETSC_FALSE;
1417   } else if (cellDim == 1 && numCorners == 3) {
1418     /* Quadratic line */
1419     faceSize  = 1;
1420     posOrient = PETSC_TRUE;
1421   } else if (cellDim == 2 && numCorners == 4) {
1422     /* Quads */
1423     faceSize = 2;
1424     if ((indices[1] > indices[0]) && (indices[1] - indices[0] == 1)) {
1425       posOrient = PETSC_TRUE;
1426     } else if ((indices[0] == 3) && (indices[1] == 0)) {
1427       posOrient = PETSC_TRUE;
1428     } else {
1429       if (((indices[0] > indices[1]) && (indices[0] - indices[1] == 1)) || ((indices[0] == 0) && (indices[1] == 3))) {
1430         posOrient = PETSC_FALSE;
1431       } else SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid quad crossedge");
1432     }
1433   } else if (cellDim == 2 && numCorners == 6) {
1434     /* Quadratic triangle (I hate this) */
1435     /* Edges are determined by the first 2 vertices (corners of edges) */
1436     const PetscInt faceSizeTri = 3;
1437     PetscInt       sortedIndices[3], i, iFace;
1438     PetscBool      found                    = PETSC_FALSE;
1439     PetscInt       faceVerticesTriSorted[9] = {
1440       0, 3,  4, /* bottom */
1441       1, 4,  5, /* right */
1442       2, 3,  5, /* left */
1443     };
1444     PetscInt       faceVerticesTri[9] = {
1445       0, 3,  4, /* bottom */
1446       1, 4,  5, /* right */
1447       2, 5,  3, /* left */
1448     };
1449 
1450     faceSize = faceSizeTri;
1451     for (i = 0; i < faceSizeTri; ++i) sortedIndices[i] = indices[i];
1452     ierr = PetscSortInt(faceSizeTri, sortedIndices);CHKERRQ(ierr);
1453     for (iFace = 0; iFace < 3; ++iFace) {
1454       const PetscInt ii = iFace*faceSizeTri;
1455       PetscInt       fVertex, cVertex;
1456 
1457       if ((sortedIndices[0] == faceVerticesTriSorted[ii+0]) &&
1458           (sortedIndices[1] == faceVerticesTriSorted[ii+1])) {
1459         for (fVertex = 0; fVertex < faceSizeTri; ++fVertex) {
1460           for (cVertex = 0; cVertex < faceSizeTri; ++cVertex) {
1461             if (indices[cVertex] == faceVerticesTri[ii+fVertex]) {
1462               faceVertices[fVertex] = origVertices[cVertex];
1463               break;
1464             }
1465           }
1466         }
1467         found = PETSC_TRUE;
1468         break;
1469       }
1470     }
1471     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid tri crossface");
1472     if (posOriented) *posOriented = PETSC_TRUE;
1473     PetscFunctionReturn(0);
1474   } else if (cellDim == 2 && numCorners == 9) {
1475     /* Quadratic quad (I hate this) */
1476     /* Edges are determined by the first 2 vertices (corners of edges) */
1477     const PetscInt faceSizeQuad = 3;
1478     PetscInt       sortedIndices[3], i, iFace;
1479     PetscBool      found                      = PETSC_FALSE;
1480     PetscInt       faceVerticesQuadSorted[12] = {
1481       0, 1,  4, /* bottom */
1482       1, 2,  5, /* right */
1483       2, 3,  6, /* top */
1484       0, 3,  7, /* left */
1485     };
1486     PetscInt       faceVerticesQuad[12] = {
1487       0, 1,  4, /* bottom */
1488       1, 2,  5, /* right */
1489       2, 3,  6, /* top */
1490       3, 0,  7, /* left */
1491     };
1492 
1493     faceSize = faceSizeQuad;
1494     for (i = 0; i < faceSizeQuad; ++i) sortedIndices[i] = indices[i];
1495     ierr = PetscSortInt(faceSizeQuad, sortedIndices);CHKERRQ(ierr);
1496     for (iFace = 0; iFace < 4; ++iFace) {
1497       const PetscInt ii = iFace*faceSizeQuad;
1498       PetscInt       fVertex, cVertex;
1499 
1500       if ((sortedIndices[0] == faceVerticesQuadSorted[ii+0]) &&
1501           (sortedIndices[1] == faceVerticesQuadSorted[ii+1])) {
1502         for (fVertex = 0; fVertex < faceSizeQuad; ++fVertex) {
1503           for (cVertex = 0; cVertex < faceSizeQuad; ++cVertex) {
1504             if (indices[cVertex] == faceVerticesQuad[ii+fVertex]) {
1505               faceVertices[fVertex] = origVertices[cVertex];
1506               break;
1507             }
1508           }
1509         }
1510         found = PETSC_TRUE;
1511         break;
1512       }
1513     }
1514     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid quad crossface");
1515     if (posOriented) *posOriented = PETSC_TRUE;
1516     PetscFunctionReturn(0);
1517   } else if (cellDim == 3 && numCorners == 8) {
1518     /* Hexes
1519        A hex is two oriented quads with the normal of the first
1520        pointing up at the second.
1521 
1522           7---6
1523          /|  /|
1524         4---5 |
1525         | 3-|-2
1526         |/  |/
1527         0---1
1528 
1529         Faces are determined by the first 4 vertices (corners of faces) */
1530     const PetscInt faceSizeHex = 4;
1531     PetscInt       sortedIndices[4], i, iFace;
1532     PetscBool      found                     = PETSC_FALSE;
1533     PetscInt       faceVerticesHexSorted[24] = {
1534       0, 1, 2, 3,  /* bottom */
1535       4, 5, 6, 7,  /* top */
1536       0, 1, 4, 5,  /* front */
1537       1, 2, 5, 6,  /* right */
1538       2, 3, 6, 7,  /* back */
1539       0, 3, 4, 7,  /* left */
1540     };
1541     PetscInt       faceVerticesHex[24] = {
1542       3, 2, 1, 0,  /* bottom */
1543       4, 5, 6, 7,  /* top */
1544       0, 1, 5, 4,  /* front */
1545       1, 2, 6, 5,  /* right */
1546       2, 3, 7, 6,  /* back */
1547       3, 0, 4, 7,  /* left */
1548     };
1549 
1550     faceSize = faceSizeHex;
1551     for (i = 0; i < faceSizeHex; ++i) sortedIndices[i] = indices[i];
1552     ierr = PetscSortInt(faceSizeHex, sortedIndices);CHKERRQ(ierr);
1553     for (iFace = 0; iFace < 6; ++iFace) {
1554       const PetscInt ii = iFace*faceSizeHex;
1555       PetscInt       fVertex, cVertex;
1556 
1557       if ((sortedIndices[0] == faceVerticesHexSorted[ii+0]) &&
1558           (sortedIndices[1] == faceVerticesHexSorted[ii+1]) &&
1559           (sortedIndices[2] == faceVerticesHexSorted[ii+2]) &&
1560           (sortedIndices[3] == faceVerticesHexSorted[ii+3])) {
1561         for (fVertex = 0; fVertex < faceSizeHex; ++fVertex) {
1562           for (cVertex = 0; cVertex < faceSizeHex; ++cVertex) {
1563             if (indices[cVertex] == faceVerticesHex[ii+fVertex]) {
1564               faceVertices[fVertex] = origVertices[cVertex];
1565               break;
1566             }
1567           }
1568         }
1569         found = PETSC_TRUE;
1570         break;
1571       }
1572     }
1573     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid hex crossface");
1574     if (posOriented) *posOriented = PETSC_TRUE;
1575     PetscFunctionReturn(0);
1576   } else if (cellDim == 3 && numCorners == 10) {
1577     /* Quadratic tet */
1578     /* Faces are determined by the first 3 vertices (corners of faces) */
1579     const PetscInt faceSizeTet = 6;
1580     PetscInt       sortedIndices[6], i, iFace;
1581     PetscBool      found                     = PETSC_FALSE;
1582     PetscInt       faceVerticesTetSorted[24] = {
1583       0, 1, 2,  6, 7, 8, /* bottom */
1584       0, 3, 4,  6, 7, 9,  /* front */
1585       1, 4, 5,  7, 8, 9,  /* right */
1586       2, 3, 5,  6, 8, 9,  /* left */
1587     };
1588     PetscInt       faceVerticesTet[24] = {
1589       0, 1, 2,  6, 7, 8, /* bottom */
1590       0, 4, 3,  6, 7, 9,  /* front */
1591       1, 5, 4,  7, 8, 9,  /* right */
1592       2, 3, 5,  8, 6, 9,  /* left */
1593     };
1594 
1595     faceSize = faceSizeTet;
1596     for (i = 0; i < faceSizeTet; ++i) sortedIndices[i] = indices[i];
1597     ierr = PetscSortInt(faceSizeTet, sortedIndices);CHKERRQ(ierr);
1598     for (iFace=0; iFace < 4; ++iFace) {
1599       const PetscInt ii = iFace*faceSizeTet;
1600       PetscInt       fVertex, cVertex;
1601 
1602       if ((sortedIndices[0] == faceVerticesTetSorted[ii+0]) &&
1603           (sortedIndices[1] == faceVerticesTetSorted[ii+1]) &&
1604           (sortedIndices[2] == faceVerticesTetSorted[ii+2]) &&
1605           (sortedIndices[3] == faceVerticesTetSorted[ii+3])) {
1606         for (fVertex = 0; fVertex < faceSizeTet; ++fVertex) {
1607           for (cVertex = 0; cVertex < faceSizeTet; ++cVertex) {
1608             if (indices[cVertex] == faceVerticesTet[ii+fVertex]) {
1609               faceVertices[fVertex] = origVertices[cVertex];
1610               break;
1611             }
1612           }
1613         }
1614         found = PETSC_TRUE;
1615         break;
1616       }
1617     }
1618     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid tet crossface");
1619     if (posOriented) *posOriented = PETSC_TRUE;
1620     PetscFunctionReturn(0);
1621   } else if (cellDim == 3 && numCorners == 27) {
1622     /* Quadratic hexes (I hate this)
1623        A hex is two oriented quads with the normal of the first
1624        pointing up at the second.
1625 
1626          7---6
1627         /|  /|
1628        4---5 |
1629        | 3-|-2
1630        |/  |/
1631        0---1
1632 
1633        Faces are determined by the first 4 vertices (corners of faces) */
1634     const PetscInt faceSizeQuadHex = 9;
1635     PetscInt       sortedIndices[9], i, iFace;
1636     PetscBool      found                         = PETSC_FALSE;
1637     PetscInt       faceVerticesQuadHexSorted[54] = {
1638       0, 1, 2, 3,  8, 9, 10, 11,  24, /* bottom */
1639       4, 5, 6, 7,  12, 13, 14, 15,  25, /* top */
1640       0, 1, 4, 5,  8, 12, 16, 17,  22, /* front */
1641       1, 2, 5, 6,  9, 13, 17, 18,  21, /* right */
1642       2, 3, 6, 7,  10, 14, 18, 19,  23, /* back */
1643       0, 3, 4, 7,  11, 15, 16, 19,  20, /* left */
1644     };
1645     PetscInt       faceVerticesQuadHex[54] = {
1646       3, 2, 1, 0,  10, 9, 8, 11,  24, /* bottom */
1647       4, 5, 6, 7,  12, 13, 14, 15,  25, /* top */
1648       0, 1, 5, 4,  8, 17, 12, 16,  22, /* front */
1649       1, 2, 6, 5,  9, 18, 13, 17,  21, /* right */
1650       2, 3, 7, 6,  10, 19, 14, 18,  23, /* back */
1651       3, 0, 4, 7,  11, 16, 15, 19,  20 /* left */
1652     };
1653 
1654     faceSize = faceSizeQuadHex;
1655     for (i = 0; i < faceSizeQuadHex; ++i) sortedIndices[i] = indices[i];
1656     ierr = PetscSortInt(faceSizeQuadHex, sortedIndices);CHKERRQ(ierr);
1657     for (iFace = 0; iFace < 6; ++iFace) {
1658       const PetscInt ii = iFace*faceSizeQuadHex;
1659       PetscInt       fVertex, cVertex;
1660 
1661       if ((sortedIndices[0] == faceVerticesQuadHexSorted[ii+0]) &&
1662           (sortedIndices[1] == faceVerticesQuadHexSorted[ii+1]) &&
1663           (sortedIndices[2] == faceVerticesQuadHexSorted[ii+2]) &&
1664           (sortedIndices[3] == faceVerticesQuadHexSorted[ii+3])) {
1665         for (fVertex = 0; fVertex < faceSizeQuadHex; ++fVertex) {
1666           for (cVertex = 0; cVertex < faceSizeQuadHex; ++cVertex) {
1667             if (indices[cVertex] == faceVerticesQuadHex[ii+fVertex]) {
1668               faceVertices[fVertex] = origVertices[cVertex];
1669               break;
1670             }
1671           }
1672         }
1673         found = PETSC_TRUE;
1674         break;
1675       }
1676     }
1677     if (!found) SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Invalid hex crossface");
1678     if (posOriented) *posOriented = PETSC_TRUE;
1679     PetscFunctionReturn(0);
1680   } else SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Unknown cell type for faceOrientation().");
1681   if (!posOrient) {
1682     if (debug) {ierr = PetscPrintf(comm, "  Reversing initial face orientation\n");CHKERRQ(ierr);}
1683     for (f = 0; f < faceSize; ++f) faceVertices[f] = origVertices[faceSize-1 - f];
1684   } else {
1685     if (debug) {ierr = PetscPrintf(comm, "  Keeping initial face orientation\n");CHKERRQ(ierr);}
1686     for (f = 0; f < faceSize; ++f) faceVertices[f] = origVertices[f];
1687   }
1688   if (posOriented) *posOriented = posOrient;
1689   PetscFunctionReturn(0);
1690 }
1691 
1692 #undef __FUNCT__
1693 #define __FUNCT__ "DMPlexGetOrientedFace"
1694 /*
1695     Given a cell and a face, as a set of vertices,
1696       return the oriented face, as a set of vertices, in faceVertices
1697     The orientation is such that the face normal points out of the cell
1698 */
1699 PetscErrorCode DMPlexGetOrientedFace(DM dm, PetscInt cell, PetscInt faceSize, const PetscInt face[], PetscInt numCorners, PetscInt indices[], PetscInt origVertices[], PetscInt faceVertices[], PetscBool *posOriented)
1700 {
1701   const PetscInt *cone = NULL;
1702   PetscInt        coneSize, v, f, v2;
1703   PetscInt        oppositeVertex = -1;
1704   PetscErrorCode  ierr;
1705 
1706   PetscFunctionBegin;
1707   ierr = DMPlexGetConeSize(dm, cell, &coneSize);CHKERRQ(ierr);
1708   ierr = DMPlexGetCone(dm, cell, &cone);CHKERRQ(ierr);
1709   for (v = 0, v2 = 0; v < coneSize; ++v) {
1710     PetscBool found = PETSC_FALSE;
1711 
1712     for (f = 0; f < faceSize; ++f) {
1713       if (face[f] == cone[v]) {
1714         found = PETSC_TRUE; break;
1715       }
1716     }
1717     if (found) {
1718       indices[v2]      = v;
1719       origVertices[v2] = cone[v];
1720       ++v2;
1721     } else {
1722       oppositeVertex = v;
1723     }
1724   }
1725   ierr = DMPlexGetFaceOrientation(dm, cell, numCorners, indices, oppositeVertex, origVertices, faceVertices, posOriented);CHKERRQ(ierr);
1726   PetscFunctionReturn(0);
1727 }
1728 
1729 #undef __FUNCT__
1730 #define __FUNCT__ "DMPlexInsertFace_Internal"
1731 /*
1732   DMPlexInsertFace_Internal - Puts a face into the mesh
1733 
1734   Not collective
1735 
1736   Input Parameters:
1737   + dm              - The DMPlex
1738   . numFaceVertex   - The number of vertices in the face
1739   . faceVertices    - The vertices in the face for dm
1740   . subfaceVertices - The vertices in the face for subdm
1741   . numCorners      - The number of vertices in the cell
1742   . cell            - A cell in dm containing the face
1743   . subcell         - A cell in subdm containing the face
1744   . firstFace       - First face in the mesh
1745   - newFacePoint    - Next face in the mesh
1746 
1747   Output Parameters:
1748   . newFacePoint - Contains next face point number on input, updated on output
1749 
1750   Level: developer
1751 */
1752 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)
1753 {
1754   MPI_Comm        comm;
1755   DM_Plex        *submesh = (DM_Plex*) subdm->data;
1756   const PetscInt *faces;
1757   PetscInt        numFaces, coneSize;
1758   PetscErrorCode  ierr;
1759 
1760   PetscFunctionBegin;
1761   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1762   ierr = DMPlexGetConeSize(subdm, subcell, &coneSize);CHKERRQ(ierr);
1763   if (coneSize != 1) SETERRQ2(comm, PETSC_ERR_ARG_OUTOFRANGE, "Cone size of cell %d is %d != 1", cell, coneSize);
1764 #if 0
1765   /* Cannot use this because support() has not been constructed yet */
1766   ierr = DMPlexGetJoin(subdm, numFaceVertices, subfaceVertices, &numFaces, &faces);CHKERRQ(ierr);
1767 #else
1768   {
1769     PetscInt f;
1770 
1771     numFaces = 0;
1772     ierr     = DMGetWorkArray(subdm, 1, PETSC_INT, (void **) &faces);CHKERRQ(ierr);
1773     for (f = firstFace; f < *newFacePoint; ++f) {
1774       PetscInt dof, off, d;
1775 
1776       ierr = PetscSectionGetDof(submesh->coneSection, f, &dof);CHKERRQ(ierr);
1777       ierr = PetscSectionGetOffset(submesh->coneSection, f, &off);CHKERRQ(ierr);
1778       /* Yes, I know this is quadratic, but I expect the sizes to be <5 */
1779       for (d = 0; d < dof; ++d) {
1780         const PetscInt p = submesh->cones[off+d];
1781         PetscInt       v;
1782 
1783         for (v = 0; v < numFaceVertices; ++v) {
1784           if (subfaceVertices[v] == p) break;
1785         }
1786         if (v == numFaceVertices) break;
1787       }
1788       if (d == dof) {
1789         numFaces               = 1;
1790         ((PetscInt*) faces)[0] = f;
1791       }
1792     }
1793   }
1794 #endif
1795   if (numFaces > 1) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Vertex set had %d faces, not one", numFaces);
1796   else if (numFaces == 1) {
1797     /* Add the other cell neighbor for this face */
1798     ierr = DMPlexSetCone(subdm, subcell, faces);CHKERRQ(ierr);
1799   } else {
1800     PetscInt *indices, *origVertices, *orientedVertices, *orientedSubVertices, v, ov;
1801     PetscBool posOriented;
1802 
1803     ierr                = DMGetWorkArray(subdm, 4*numFaceVertices * sizeof(PetscInt), PETSC_INT, &orientedVertices);CHKERRQ(ierr);
1804     origVertices        = &orientedVertices[numFaceVertices];
1805     indices             = &orientedVertices[numFaceVertices*2];
1806     orientedSubVertices = &orientedVertices[numFaceVertices*3];
1807     ierr                = DMPlexGetOrientedFace(dm, cell, numFaceVertices, faceVertices, numCorners, indices, origVertices, orientedVertices, &posOriented);CHKERRQ(ierr);
1808     /* TODO: I know that routine should return a permutation, not the indices */
1809     for (v = 0; v < numFaceVertices; ++v) {
1810       const PetscInt vertex = faceVertices[v], subvertex = subfaceVertices[v];
1811       for (ov = 0; ov < numFaceVertices; ++ov) {
1812         if (orientedVertices[ov] == vertex) {
1813           orientedSubVertices[ov] = subvertex;
1814           break;
1815         }
1816       }
1817       if (ov == numFaceVertices) SETERRQ1(comm, PETSC_ERR_PLIB, "Could not find face vertex %d in orientated set", vertex);
1818     }
1819     ierr = DMPlexSetCone(subdm, *newFacePoint, orientedSubVertices);CHKERRQ(ierr);
1820     ierr = DMPlexSetCone(subdm, subcell, newFacePoint);CHKERRQ(ierr);
1821     ierr = DMRestoreWorkArray(subdm, 4*numFaceVertices * sizeof(PetscInt), PETSC_INT, &orientedVertices);CHKERRQ(ierr);
1822     ++(*newFacePoint);
1823   }
1824 #if 0
1825   ierr = DMPlexRestoreJoin(subdm, numFaceVertices, subfaceVertices, &numFaces, &faces);CHKERRQ(ierr);
1826 #else
1827   ierr = DMRestoreWorkArray(subdm, 1, PETSC_INT, (void **) &faces);CHKERRQ(ierr);
1828 #endif
1829   PetscFunctionReturn(0);
1830 }
1831 
1832 #undef __FUNCT__
1833 #define __FUNCT__ "DMPlexCreateSubmesh_Uninterpolated"
1834 static PetscErrorCode DMPlexCreateSubmesh_Uninterpolated(DM dm, const char vertexLabelName[], PetscInt value, DM subdm)
1835 {
1836   MPI_Comm        comm;
1837   DMLabel         vertexLabel, subpointMap;
1838   IS              subvertexIS,  subcellIS;
1839   const PetscInt *subVertices, *subCells;
1840   PetscInt        numSubVertices, firstSubVertex, numSubCells;
1841   PetscInt       *subface, maxConeSize, numSubFaces, firstSubFace, newFacePoint, nFV;
1842   PetscInt        vStart, vEnd, c, f;
1843   PetscErrorCode  ierr;
1844 
1845   PetscFunctionBegin;
1846   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1847   /* Create subpointMap which marks the submesh */
1848   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
1849   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
1850   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
1851   ierr = DMPlexGetLabel(dm, vertexLabelName, &vertexLabel);CHKERRQ(ierr);
1852   ierr = DMPlexMarkSubmesh_Uninterpolated(dm, vertexLabel, value, subpointMap, &numSubFaces, &nFV, subdm);CHKERRQ(ierr);
1853   /* Setup chart */
1854   ierr = DMLabelGetStratumSize(subpointMap, 0, &numSubVertices);CHKERRQ(ierr);
1855   ierr = DMLabelGetStratumSize(subpointMap, 2, &numSubCells);CHKERRQ(ierr);
1856   ierr = DMPlexSetChart(subdm, 0, numSubCells+numSubFaces+numSubVertices);CHKERRQ(ierr);
1857   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
1858   /* Set cone sizes */
1859   firstSubVertex = numSubCells;
1860   firstSubFace   = numSubCells+numSubVertices;
1861   newFacePoint   = firstSubFace;
1862   ierr = DMLabelGetStratumIS(subpointMap, 0, &subvertexIS);CHKERRQ(ierr);
1863   if (subvertexIS) {ierr = ISGetIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
1864   ierr = DMLabelGetStratumIS(subpointMap, 2, &subcellIS);CHKERRQ(ierr);
1865   if (subcellIS) {ierr = ISGetIndices(subcellIS, &subCells);CHKERRQ(ierr);}
1866   for (c = 0; c < numSubCells; ++c) {
1867     ierr = DMPlexSetConeSize(subdm, c, 1);CHKERRQ(ierr);
1868   }
1869   for (f = firstSubFace; f < firstSubFace+numSubFaces; ++f) {
1870     ierr = DMPlexSetConeSize(subdm, f, nFV);CHKERRQ(ierr);
1871   }
1872   ierr = DMSetUp(subdm);CHKERRQ(ierr);
1873   /* Create face cones */
1874   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
1875   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
1876   ierr = DMGetWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
1877   for (c = 0; c < numSubCells; ++c) {
1878     const PetscInt cell    = subCells[c];
1879     const PetscInt subcell = c;
1880     PetscInt      *closure = NULL;
1881     PetscInt       closureSize, cl, numCorners = 0, faceSize = 0;
1882 
1883     ierr = DMPlexGetTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1884     for (cl = 0; cl < closureSize*2; cl += 2) {
1885       const PetscInt point = closure[cl];
1886       PetscInt       subVertex;
1887 
1888       if ((point >= vStart) && (point < vEnd)) {
1889         ++numCorners;
1890         ierr = PetscFindInt(point, numSubVertices, subVertices, &subVertex);CHKERRQ(ierr);
1891         if (subVertex >= 0) {
1892           closure[faceSize] = point;
1893           subface[faceSize] = firstSubVertex+subVertex;
1894           ++faceSize;
1895         }
1896       }
1897     }
1898     if (faceSize > nFV) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Invalid submesh: Too many vertices %d of an element on the surface", faceSize);
1899     if (faceSize == nFV) {
1900       ierr = DMPlexInsertFace_Internal(dm, subdm, faceSize, closure, subface, numCorners, cell, subcell, firstSubFace, &newFacePoint);CHKERRQ(ierr);
1901     }
1902     ierr = DMPlexRestoreTransitiveClosure(dm, cell, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1903   }
1904   ierr = DMRestoreWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
1905   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
1906   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
1907   /* Build coordinates */
1908   {
1909     PetscSection coordSection, subCoordSection;
1910     Vec          coordinates, subCoordinates;
1911     PetscScalar *coords, *subCoords;
1912     PetscInt     numComp, coordSize, v;
1913 
1914     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
1915     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
1916     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
1917     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
1918     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
1919     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
1920     ierr = PetscSectionSetChart(subCoordSection, firstSubVertex, firstSubVertex+numSubVertices);CHKERRQ(ierr);
1921     for (v = 0; v < numSubVertices; ++v) {
1922       const PetscInt vertex    = subVertices[v];
1923       const PetscInt subvertex = firstSubVertex+v;
1924       PetscInt       dof;
1925 
1926       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
1927       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
1928       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
1929     }
1930     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
1931     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
1932     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
1933     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
1934     ierr = VecSetFromOptions(subCoordinates);CHKERRQ(ierr);
1935     if (coordSize) {
1936       ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
1937       ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
1938       for (v = 0; v < numSubVertices; ++v) {
1939         const PetscInt vertex    = subVertices[v];
1940         const PetscInt subvertex = firstSubVertex+v;
1941         PetscInt       dof, off, sdof, soff, d;
1942 
1943         ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
1944         ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
1945         ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
1946         ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
1947         if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
1948         for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
1949       }
1950       ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
1951       ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
1952     }
1953     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
1954     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
1955   }
1956   /* Cleanup */
1957   if (subvertexIS) {ierr = ISRestoreIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
1958   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
1959   if (subcellIS) {ierr = ISRestoreIndices(subcellIS, &subCells);CHKERRQ(ierr);}
1960   ierr = ISDestroy(&subcellIS);CHKERRQ(ierr);
1961   PetscFunctionReturn(0);
1962 }
1963 
1964 #undef __FUNCT__
1965 #define __FUNCT__ "DMPlexCreateSubmesh_Interpolated"
1966 static PetscErrorCode DMPlexCreateSubmesh_Interpolated(DM dm, const char vertexLabelName[], PetscInt value, DM subdm)
1967 {
1968   MPI_Comm         comm;
1969   DMLabel          subpointMap, vertexLabel;
1970   IS              *subpointIS;
1971   const PetscInt **subpoints;
1972   PetscInt        *numSubPoints, *firstSubPoint, *coneNew;
1973   PetscInt         totSubPoints = 0, maxConeSize, dim, p, d, v;
1974   PetscErrorCode   ierr;
1975 
1976   PetscFunctionBegin;
1977   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
1978   /* Create subpointMap which marks the submesh */
1979   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
1980   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
1981   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
1982   ierr = DMPlexGetLabel(dm, vertexLabelName, &vertexLabel);CHKERRQ(ierr);
1983   ierr = DMPlexMarkSubmesh_Interpolated(dm, vertexLabel, value, subpointMap, subdm);CHKERRQ(ierr);
1984   /* Setup chart */
1985   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
1986   ierr = PetscMalloc4(dim+1,PetscInt,&numSubPoints,dim+1,PetscInt,&firstSubPoint,dim+1,IS,&subpointIS,dim+1,const PetscInt *,&subpoints);CHKERRQ(ierr);
1987   for (d = 0; d <= dim; ++d) {
1988     ierr = DMLabelGetStratumSize(subpointMap, d, &numSubPoints[d]);CHKERRQ(ierr);
1989     totSubPoints += numSubPoints[d];
1990   }
1991   ierr = DMPlexSetChart(subdm, 0, totSubPoints);CHKERRQ(ierr);
1992   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
1993   /* Set cone sizes */
1994   firstSubPoint[dim] = 0;
1995   firstSubPoint[0]   = firstSubPoint[dim] + numSubPoints[dim];
1996   if (dim > 1) {firstSubPoint[dim-1] = firstSubPoint[0]     + numSubPoints[0];}
1997   if (dim > 2) {firstSubPoint[dim-2] = firstSubPoint[dim-1] + numSubPoints[dim-1];}
1998   for (d = 0; d <= dim; ++d) {
1999     ierr = DMLabelGetStratumIS(subpointMap, d, &subpointIS[d]);CHKERRQ(ierr);
2000     ierr = ISGetIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2001   }
2002   for (d = 0; d <= dim; ++d) {
2003     for (p = 0; p < numSubPoints[d]; ++p) {
2004       const PetscInt  point    = subpoints[d][p];
2005       const PetscInt  subpoint = firstSubPoint[d] + p;
2006       const PetscInt *cone;
2007       PetscInt        coneSize, coneSizeNew, c, val;
2008 
2009       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2010       ierr = DMPlexSetConeSize(subdm, subpoint, coneSize);CHKERRQ(ierr);
2011       if (d == dim) {
2012         ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2013         for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2014           ierr = DMLabelGetValue(subpointMap, cone[c], &val);CHKERRQ(ierr);
2015           if (val >= 0) coneSizeNew++;
2016         }
2017         ierr = DMPlexSetConeSize(subdm, subpoint, coneSizeNew);CHKERRQ(ierr);
2018       }
2019     }
2020   }
2021   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2022   /* Set cones */
2023   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2024   ierr = PetscMalloc(maxConeSize * sizeof(PetscInt), &coneNew);CHKERRQ(ierr);
2025   for (d = 0; d <= dim; ++d) {
2026     for (p = 0; p < numSubPoints[d]; ++p) {
2027       const PetscInt  point    = subpoints[d][p];
2028       const PetscInt  subpoint = firstSubPoint[d] + p;
2029       const PetscInt *cone;
2030       PetscInt        coneSize, subconeSize, coneSizeNew, c, subc;
2031 
2032       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2033       ierr = DMPlexGetConeSize(subdm, subpoint, &subconeSize);CHKERRQ(ierr);
2034       ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2035       for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2036         ierr = PetscFindInt(cone[c], numSubPoints[d-1], subpoints[d-1], &subc);CHKERRQ(ierr);
2037         if (subc >= 0) coneNew[coneSizeNew++] = firstSubPoint[d-1] + subc;
2038       }
2039       if (coneSizeNew != subconeSize) SETERRQ2(comm, PETSC_ERR_PLIB, "Number of cone points located %d does not match subcone size %d", coneSizeNew, subconeSize);
2040       ierr = DMPlexSetCone(subdm, subpoint, coneNew);CHKERRQ(ierr);
2041     }
2042   }
2043   ierr = PetscFree(coneNew);CHKERRQ(ierr);
2044   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2045   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2046   /* Build coordinates */
2047   {
2048     PetscSection coordSection, subCoordSection;
2049     Vec          coordinates, subCoordinates;
2050     PetscScalar *coords, *subCoords;
2051     PetscInt     numComp, coordSize;
2052 
2053     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2054     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2055     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2056     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2057     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2058     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2059     ierr = PetscSectionSetChart(subCoordSection, firstSubPoint[0], firstSubPoint[0]+numSubPoints[0]);CHKERRQ(ierr);
2060     for (v = 0; v < numSubPoints[0]; ++v) {
2061       const PetscInt vertex    = subpoints[0][v];
2062       const PetscInt subvertex = firstSubPoint[0]+v;
2063       PetscInt       dof;
2064 
2065       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2066       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2067       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2068     }
2069     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2070     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2071     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2072     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2073     ierr = VecSetFromOptions(subCoordinates);CHKERRQ(ierr);
2074     ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2075     ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2076     for (v = 0; v < numSubPoints[0]; ++v) {
2077       const PetscInt vertex    = subpoints[0][v];
2078       const PetscInt subvertex = firstSubPoint[0]+v;
2079       PetscInt dof, off, sdof, soff, d;
2080 
2081       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2082       ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2083       ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2084       ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2085       if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2086       for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2087     }
2088     ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2089     ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2090     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2091     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2092   }
2093   /* Cleanup */
2094   for (d = 0; d <= dim; ++d) {
2095     ierr = ISRestoreIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2096     ierr = ISDestroy(&subpointIS[d]);CHKERRQ(ierr);
2097   }
2098   ierr = PetscFree4(numSubPoints,firstSubPoint,subpointIS,subpoints);CHKERRQ(ierr);
2099   PetscFunctionReturn(0);
2100 }
2101 
2102 #undef __FUNCT__
2103 #define __FUNCT__ "DMPlexCreateSubmesh"
2104 /*@C
2105   DMPlexCreateSubmesh - Extract a hypersurface from the mesh using vertices defined by a label
2106 
2107   Input Parameters:
2108 + dm           - The original mesh
2109 . vertexLabel  - The DMLabel marking vertices contained in the surface
2110 - value        - The label value to use
2111 
2112   Output Parameter:
2113 . subdm - The surface mesh
2114 
2115   Note: This function produces a DMLabel mapping original points in the submesh to their depth. This can be obtained using DMPlexGetSubpointMap().
2116 
2117   Level: developer
2118 
2119 .seealso: DMPlexGetSubpointMap(), DMPlexGetLabel(), DMLabelSetValue()
2120 @*/
2121 PetscErrorCode DMPlexCreateSubmesh(DM dm, const char vertexLabel[], PetscInt value, DM *subdm)
2122 {
2123   PetscInt       dim, depth;
2124   PetscErrorCode ierr;
2125 
2126   PetscFunctionBegin;
2127   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2128   PetscValidCharPointer(vertexLabel, 2);
2129   PetscValidPointer(subdm, 3);
2130   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2131   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2132   ierr = DMCreate(PetscObjectComm((PetscObject)dm), subdm);CHKERRQ(ierr);
2133   ierr = DMSetType(*subdm, DMPLEX);CHKERRQ(ierr);
2134   ierr = DMPlexSetDimension(*subdm, dim-1);CHKERRQ(ierr);
2135   if (depth == dim) {
2136     ierr = DMPlexCreateSubmesh_Interpolated(dm, vertexLabel, value, *subdm);CHKERRQ(ierr);
2137   } else {
2138     ierr = DMPlexCreateSubmesh_Uninterpolated(dm, vertexLabel, value, *subdm);CHKERRQ(ierr);
2139   }
2140   PetscFunctionReturn(0);
2141 }
2142 
2143 #undef __FUNCT__
2144 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh_Uninterpolated"
2145 static PetscErrorCode DMPlexCreateCohesiveSubmesh_Uninterpolated(DM dm, PetscBool hasLagrange, const char label[], PetscInt value, DM subdm)
2146 {
2147   MPI_Comm        comm;
2148   DMLabel         subpointMap;
2149   IS              subvertexIS;
2150   const PetscInt *subVertices;
2151   PetscInt        numSubVertices, firstSubVertex, numSubCells, *subCells;
2152   PetscInt       *subface, maxConeSize, numSubFaces, firstSubFace, newFacePoint, nFV;
2153   PetscInt        cMax, c, f;
2154   PetscErrorCode  ierr;
2155 
2156   PetscFunctionBegin;
2157   ierr = PetscObjectGetComm((PetscObject)dm, &comm);CHKERRQ(ierr);
2158   /* Create subpointMap which marks the submesh */
2159   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2160   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2161   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2162   ierr = DMPlexMarkCohesiveSubmesh_Uninterpolated(dm, hasLagrange, label, value, subpointMap, &numSubFaces, &nFV, &subCells, subdm);CHKERRQ(ierr);
2163   /* Setup chart */
2164   ierr = DMLabelGetStratumSize(subpointMap, 0, &numSubVertices);CHKERRQ(ierr);
2165   ierr = DMLabelGetStratumSize(subpointMap, 2, &numSubCells);CHKERRQ(ierr);
2166   ierr = DMPlexSetChart(subdm, 0, numSubCells+numSubFaces+numSubVertices);CHKERRQ(ierr);
2167   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2168   /* Set cone sizes */
2169   firstSubVertex = numSubCells;
2170   firstSubFace   = numSubCells+numSubVertices;
2171   newFacePoint   = firstSubFace;
2172   ierr = DMLabelGetStratumIS(subpointMap, 0, &subvertexIS);CHKERRQ(ierr);
2173   if (subvertexIS) {ierr = ISGetIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2174   for (c = 0; c < numSubCells; ++c) {
2175     ierr = DMPlexSetConeSize(subdm, c, 1);CHKERRQ(ierr);
2176   }
2177   for (f = firstSubFace; f < firstSubFace+numSubFaces; ++f) {
2178     ierr = DMPlexSetConeSize(subdm, f, nFV);CHKERRQ(ierr);
2179   }
2180   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2181   /* Create face cones */
2182   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2183   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
2184   ierr = DMGetWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2185   for (c = 0; c < numSubCells; ++c) {
2186     const PetscInt  cell    = subCells[c];
2187     const PetscInt  subcell = c;
2188     const PetscInt *cone, *cells;
2189     PetscInt        numCells, subVertex, p, v;
2190 
2191     if (cell < cMax) continue;
2192     ierr = DMPlexGetCone(dm, cell, &cone);CHKERRQ(ierr);
2193     for (v = 0; v < nFV; ++v) {
2194       ierr = PetscFindInt(cone[v], numSubVertices, subVertices, &subVertex);CHKERRQ(ierr);
2195       subface[v] = firstSubVertex+subVertex;
2196     }
2197     ierr = DMPlexSetCone(subdm, newFacePoint, subface);CHKERRQ(ierr);
2198     ierr = DMPlexSetCone(subdm, subcell, &newFacePoint);CHKERRQ(ierr);
2199     ierr = DMPlexGetJoin(dm, nFV, cone, &numCells, &cells);CHKERRQ(ierr);
2200     if (numCells != 2) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cohesive cells should separate two cells");
2201     for (p = 0; p < numCells; ++p) {
2202       PetscInt negsubcell;
2203 
2204       if (cells[p] >= cMax) continue;
2205       /* I know this is a crap search */
2206       for (negsubcell = 0; negsubcell < numSubCells; ++negsubcell) {
2207         if (subCells[negsubcell] == cells[p]) break;
2208       }
2209       if (negsubcell == numSubCells) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find negative face neighbor for cohesive cell %d", cell);
2210       ierr = DMPlexSetCone(subdm, negsubcell, &newFacePoint);CHKERRQ(ierr);
2211     }
2212     ierr = DMPlexRestoreJoin(dm, nFV, cone, &numCells, &cells);CHKERRQ(ierr);
2213     ++newFacePoint;
2214   }
2215   ierr = DMRestoreWorkArray(subdm, maxConeSize, PETSC_INT, (void**) &subface);CHKERRQ(ierr);
2216   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2217   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2218   /* Build coordinates */
2219   {
2220     PetscSection coordSection, subCoordSection;
2221     Vec          coordinates, subCoordinates;
2222     PetscScalar *coords, *subCoords;
2223     PetscInt     numComp, coordSize, v;
2224 
2225     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2226     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2227     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2228     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2229     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2230     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2231     ierr = PetscSectionSetChart(subCoordSection, firstSubVertex, firstSubVertex+numSubVertices);CHKERRQ(ierr);
2232     for (v = 0; v < numSubVertices; ++v) {
2233       const PetscInt vertex    = subVertices[v];
2234       const PetscInt subvertex = firstSubVertex+v;
2235       PetscInt       dof;
2236 
2237       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2238       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2239       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2240     }
2241     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2242     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2243     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2244     if (coordSize) {
2245       ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2246       ierr = VecSetFromOptions(subCoordinates);CHKERRQ(ierr);
2247       ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2248       ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2249       for (v = 0; v < numSubVertices; ++v) {
2250         const PetscInt vertex    = subVertices[v];
2251         const PetscInt subvertex = firstSubVertex+v;
2252         PetscInt       dof, off, sdof, soff, d;
2253 
2254         ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2255         ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2256         ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2257         ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2258         if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2259         for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2260       }
2261       ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2262       ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2263     }
2264     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2265     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2266   }
2267   /* Cleanup */
2268   if (subvertexIS) {ierr = ISRestoreIndices(subvertexIS, &subVertices);CHKERRQ(ierr);}
2269   ierr = ISDestroy(&subvertexIS);CHKERRQ(ierr);
2270   ierr = PetscFree(subCells);CHKERRQ(ierr);
2271   PetscFunctionReturn(0);
2272 }
2273 
2274 #undef __FUNCT__
2275 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh_Interpolated"
2276 static PetscErrorCode DMPlexCreateCohesiveSubmesh_Interpolated(DM dm, PetscBool hasLagrange, const char label[], PetscInt value, DM subdm)
2277 {
2278   MPI_Comm         comm;
2279   DMLabel          subpointMap;
2280   IS              *subpointIS;
2281   const PetscInt **subpoints;
2282   PetscInt        *numSubPoints, *firstSubPoint, *coneNew;
2283   PetscInt         totSubPoints = 0, maxConeSize, dim, p, d, v;
2284   PetscErrorCode   ierr;
2285 
2286   PetscFunctionBegin;
2287   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2288   /* Create subpointMap which marks the submesh */
2289   ierr = DMLabelCreate("subpoint_map", &subpointMap);CHKERRQ(ierr);
2290   ierr = DMPlexSetSubpointMap(subdm, subpointMap);CHKERRQ(ierr);
2291   ierr = DMLabelDestroy(&subpointMap);CHKERRQ(ierr);
2292   ierr = DMPlexMarkCohesiveSubmesh_Interpolated(dm, hasLagrange, label, value, subpointMap, subdm);CHKERRQ(ierr);
2293   /* Setup chart */
2294   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2295   ierr = PetscMalloc4(dim+1,PetscInt,&numSubPoints,dim+1,PetscInt,&firstSubPoint,dim+1,IS,&subpointIS,dim+1,const PetscInt *,&subpoints);CHKERRQ(ierr);
2296   for (d = 0; d <= dim; ++d) {
2297     ierr = DMLabelGetStratumSize(subpointMap, d, &numSubPoints[d]);CHKERRQ(ierr);
2298     totSubPoints += numSubPoints[d];
2299   }
2300   ierr = DMPlexSetChart(subdm, 0, totSubPoints);CHKERRQ(ierr);
2301   ierr = DMPlexSetVTKCellHeight(subdm, 1);CHKERRQ(ierr);
2302   /* Set cone sizes */
2303   firstSubPoint[dim] = 0;
2304   firstSubPoint[0]   = firstSubPoint[dim] + numSubPoints[dim];
2305   if (dim > 1) {firstSubPoint[dim-1] = firstSubPoint[0]     + numSubPoints[0];}
2306   if (dim > 2) {firstSubPoint[dim-2] = firstSubPoint[dim-1] + numSubPoints[dim-1];}
2307   for (d = 0; d <= dim; ++d) {
2308     ierr = DMLabelGetStratumIS(subpointMap, d, &subpointIS[d]);CHKERRQ(ierr);
2309     ierr = ISGetIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2310   }
2311   for (d = 0; d <= dim; ++d) {
2312     for (p = 0; p < numSubPoints[d]; ++p) {
2313       const PetscInt  point    = subpoints[d][p];
2314       const PetscInt  subpoint = firstSubPoint[d] + p;
2315       const PetscInt *cone;
2316       PetscInt        coneSize, coneSizeNew, c, val;
2317 
2318       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2319       ierr = DMPlexSetConeSize(subdm, subpoint, coneSize);CHKERRQ(ierr);
2320       if (d == dim) {
2321         ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2322         for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2323           ierr = DMLabelGetValue(subpointMap, cone[c], &val);CHKERRQ(ierr);
2324           if (val >= 0) coneSizeNew++;
2325         }
2326         ierr = DMPlexSetConeSize(subdm, subpoint, coneSizeNew);CHKERRQ(ierr);
2327       }
2328     }
2329   }
2330   ierr = DMSetUp(subdm);CHKERRQ(ierr);
2331   /* Set cones */
2332   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, NULL);CHKERRQ(ierr);
2333   ierr = PetscMalloc(maxConeSize * sizeof(PetscInt), &coneNew);CHKERRQ(ierr);
2334   for (d = 0; d <= dim; ++d) {
2335     for (p = 0; p < numSubPoints[d]; ++p) {
2336       const PetscInt  point    = subpoints[d][p];
2337       const PetscInt  subpoint = firstSubPoint[d] + p;
2338       const PetscInt *cone;
2339       PetscInt        coneSize, subconeSize, coneSizeNew, c, subc;
2340 
2341       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
2342       ierr = DMPlexGetConeSize(subdm, subpoint, &subconeSize);CHKERRQ(ierr);
2343       ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
2344       for (c = 0, coneSizeNew = 0; c < coneSize; ++c) {
2345         ierr = PetscFindInt(cone[c], numSubPoints[d-1], subpoints[d-1], &subc);CHKERRQ(ierr);
2346         if (subc >= 0) coneNew[coneSizeNew++] = firstSubPoint[d-1] + subc;
2347       }
2348       if (coneSizeNew != subconeSize) SETERRQ2(comm, PETSC_ERR_PLIB, "Number of cone points located %d does not match subcone size %d", coneSizeNew, subconeSize);
2349       ierr = DMPlexSetCone(subdm, subpoint, coneNew);CHKERRQ(ierr);
2350     }
2351   }
2352   ierr = PetscFree(coneNew);CHKERRQ(ierr);
2353   ierr = DMPlexSymmetrize(subdm);CHKERRQ(ierr);
2354   ierr = DMPlexStratify(subdm);CHKERRQ(ierr);
2355   /* Build coordinates */
2356   {
2357     PetscSection coordSection, subCoordSection;
2358     Vec          coordinates, subCoordinates;
2359     PetscScalar *coords, *subCoords;
2360     PetscInt     numComp, coordSize;
2361 
2362     ierr = DMPlexGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
2363     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
2364     ierr = DMPlexGetCoordinateSection(subdm, &subCoordSection);CHKERRQ(ierr);
2365     ierr = PetscSectionSetNumFields(subCoordSection, 1);CHKERRQ(ierr);
2366     ierr = PetscSectionGetFieldComponents(coordSection, 0, &numComp);CHKERRQ(ierr);
2367     ierr = PetscSectionSetFieldComponents(subCoordSection, 0, numComp);CHKERRQ(ierr);
2368     ierr = PetscSectionSetChart(subCoordSection, firstSubPoint[0], firstSubPoint[0]+numSubPoints[0]);CHKERRQ(ierr);
2369     for (v = 0; v < numSubPoints[0]; ++v) {
2370       const PetscInt vertex    = subpoints[0][v];
2371       const PetscInt subvertex = firstSubPoint[0]+v;
2372       PetscInt       dof;
2373 
2374       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2375       ierr = PetscSectionSetDof(subCoordSection, subvertex, dof);CHKERRQ(ierr);
2376       ierr = PetscSectionSetFieldDof(subCoordSection, subvertex, 0, dof);CHKERRQ(ierr);
2377     }
2378     ierr = PetscSectionSetUp(subCoordSection);CHKERRQ(ierr);
2379     ierr = PetscSectionGetStorageSize(subCoordSection, &coordSize);CHKERRQ(ierr);
2380     ierr = VecCreate(comm, &subCoordinates);CHKERRQ(ierr);
2381     ierr = VecSetSizes(subCoordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
2382     ierr = VecSetFromOptions(subCoordinates);CHKERRQ(ierr);
2383     ierr = VecGetArray(coordinates,    &coords);CHKERRQ(ierr);
2384     ierr = VecGetArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2385     for (v = 0; v < numSubPoints[0]; ++v) {
2386       const PetscInt vertex    = subpoints[0][v];
2387       const PetscInt subvertex = firstSubPoint[0]+v;
2388       PetscInt dof, off, sdof, soff, d;
2389 
2390       ierr = PetscSectionGetDof(coordSection, vertex, &dof);CHKERRQ(ierr);
2391       ierr = PetscSectionGetOffset(coordSection, vertex, &off);CHKERRQ(ierr);
2392       ierr = PetscSectionGetDof(subCoordSection, subvertex, &sdof);CHKERRQ(ierr);
2393       ierr = PetscSectionGetOffset(subCoordSection, subvertex, &soff);CHKERRQ(ierr);
2394       if (dof != sdof) SETERRQ4(comm, PETSC_ERR_PLIB, "Coordinate dimension %d on subvertex %d, vertex %d should be %d", sdof, subvertex, vertex, dof);
2395       for (d = 0; d < dof; ++d) subCoords[soff+d] = coords[off+d];
2396     }
2397     ierr = VecRestoreArray(coordinates,    &coords);CHKERRQ(ierr);
2398     ierr = VecRestoreArray(subCoordinates, &subCoords);CHKERRQ(ierr);
2399     ierr = DMSetCoordinatesLocal(subdm, subCoordinates);CHKERRQ(ierr);
2400     ierr = VecDestroy(&subCoordinates);CHKERRQ(ierr);
2401   }
2402   /* Cleanup */
2403   for (d = 0; d <= dim; ++d) {
2404     ierr = ISRestoreIndices(subpointIS[d], &subpoints[d]);CHKERRQ(ierr);
2405     ierr = ISDestroy(&subpointIS[d]);CHKERRQ(ierr);
2406   }
2407   ierr = PetscFree4(numSubPoints,firstSubPoint,subpointIS,subpoints);CHKERRQ(ierr);
2408   PetscFunctionReturn(0);
2409 }
2410 
2411 #undef __FUNCT__
2412 #define __FUNCT__ "DMPlexCreateCohesiveSubmesh"
2413 /*
2414   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.
2415 
2416   Input Parameters:
2417 + dm          - The original mesh
2418 . hasLagrange - The mesh has Lagrange unknowns in the cohesive cells
2419 . label       - A label name, or PETSC_NULL
2420 - value  - A label value
2421 
2422   Output Parameter:
2423 . subdm - The surface mesh
2424 
2425   Note: This function produces a DMLabel mapping original points in the submesh to their depth. This can be obtained using DMPlexGetSubpointMap().
2426 
2427   Level: developer
2428 
2429 .seealso: DMPlexGetSubpointMap(), DMPlexCreateSubmesh()
2430 */
2431 PetscErrorCode DMPlexCreateCohesiveSubmesh(DM dm, PetscBool hasLagrange, const char label[], PetscInt value, DM *subdm)
2432 {
2433   PetscInt       dim, depth;
2434   PetscErrorCode ierr;
2435 
2436   PetscFunctionBegin;
2437   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2438   PetscValidPointer(subdm, 5);
2439   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
2440   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2441   ierr = DMCreate(PetscObjectComm((PetscObject)dm), subdm);CHKERRQ(ierr);
2442   ierr = DMSetType(*subdm, DMPLEX);CHKERRQ(ierr);
2443   ierr = DMPlexSetDimension(*subdm, dim-1);CHKERRQ(ierr);
2444   if (depth == dim) {
2445     ierr = DMPlexCreateCohesiveSubmesh_Interpolated(dm, hasLagrange, label, value, *subdm);CHKERRQ(ierr);
2446   } else {
2447     ierr = DMPlexCreateCohesiveSubmesh_Uninterpolated(dm, hasLagrange, label, value, *subdm);CHKERRQ(ierr);
2448   }
2449   PetscFunctionReturn(0);
2450 }
2451 
2452 #undef __FUNCT__
2453 #define __FUNCT__ "DMPlexGetSubpointMap"
2454 /*@
2455   DMPlexGetSubpointMap - Returns a DMLabel with point dimension as values
2456 
2457   Input Parameter:
2458 . dm - The submesh DM
2459 
2460   Output Parameter:
2461 . subpointMap - The DMLabel of all the points from the original mesh in this submesh, or NULL if this is not a submesh
2462 
2463   Level: developer
2464 
2465 .seealso: DMPlexCreateSubmesh(), DMPlexCreateSubpointIS()
2466 @*/
2467 PetscErrorCode DMPlexGetSubpointMap(DM dm, DMLabel *subpointMap)
2468 {
2469   DM_Plex *mesh = (DM_Plex*) dm->data;
2470 
2471   PetscFunctionBegin;
2472   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2473   PetscValidPointer(subpointMap, 2);
2474   *subpointMap = mesh->subpointMap;
2475   PetscFunctionReturn(0);
2476 }
2477 
2478 #undef __FUNCT__
2479 #define __FUNCT__ "DMPlexSetSubpointMap"
2480 /* Note: Should normally not be called by the user, since it is set in DMPlexCreateSubmesh() */
2481 PetscErrorCode DMPlexSetSubpointMap(DM dm, DMLabel subpointMap)
2482 {
2483   DM_Plex       *mesh = (DM_Plex *) dm->data;
2484   DMLabel        tmp;
2485   PetscErrorCode ierr;
2486 
2487   PetscFunctionBegin;
2488   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2489   tmp  = mesh->subpointMap;
2490   mesh->subpointMap = subpointMap;
2491   ++mesh->subpointMap->refct;
2492   ierr = DMLabelDestroy(&tmp);CHKERRQ(ierr);
2493   PetscFunctionReturn(0);
2494 }
2495 
2496 #undef __FUNCT__
2497 #define __FUNCT__ "DMPlexCreateSubpointIS"
2498 /*@
2499   DMPlexCreateSubpointIS - Creates an IS covering the entire subdm chart with the original points as data
2500 
2501   Input Parameter:
2502 . dm - The submesh DM
2503 
2504   Output Parameter:
2505 . subpointIS - The IS of all the points from the original mesh in this submesh, or NULL if this is not a submesh
2506 
2507   Note: This is IS is guaranteed to be sorted by the construction of the submesh
2508 
2509   Level: developer
2510 
2511 .seealso: DMPlexCreateSubmesh(), DMPlexGetSubpointMap()
2512 @*/
2513 PetscErrorCode DMPlexCreateSubpointIS(DM dm, IS *subpointIS)
2514 {
2515   MPI_Comm        comm;
2516   DMLabel         subpointMap;
2517   IS              is;
2518   const PetscInt *opoints;
2519   PetscInt       *points, *depths;
2520   PetscInt        depth, depStart, depEnd, d, pStart, pEnd, p, n, off;
2521   PetscErrorCode  ierr;
2522 
2523   PetscFunctionBegin;
2524   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
2525   PetscValidPointer(subpointIS, 2);
2526   ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
2527   *subpointIS = NULL;
2528   ierr = DMPlexGetSubpointMap(dm, &subpointMap);CHKERRQ(ierr);
2529   if (subpointMap) {
2530     ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
2531     ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
2532     if (pStart) SETERRQ1(comm, PETSC_ERR_ARG_WRONG, "Submeshes must start the point numbering at 0, not %d", pStart);
2533     ierr = DMGetWorkArray(dm, depth+1, PETSC_INT, &depths);CHKERRQ(ierr);
2534     depths[0] = depth;
2535     depths[1] = 0;
2536     for(d = 2; d <= depth; ++d) {depths[d] = depth+1 - d;}
2537     ierr = PetscMalloc(pEnd * sizeof(PetscInt), &points);CHKERRQ(ierr);
2538     for(d = 0, off = 0; d <= depth; ++d) {
2539       const PetscInt dep = depths[d];
2540 
2541       ierr = DMPlexGetDepthStratum(dm, dep, &depStart, &depEnd);CHKERRQ(ierr);
2542       ierr = DMLabelGetStratumSize(subpointMap, dep, &n);CHKERRQ(ierr);
2543       if (((d < 2) && (depth > 1)) || (d == 1)) { /* Only check vertices and cells for now since the map is broken for others */
2544         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);
2545       } else {
2546         if (!n) {
2547           if (d == 0) {
2548             /* Missing cells */
2549             for(p = 0; p < depEnd-depStart; ++p, ++off) points[off] = -1;
2550           } else {
2551             /* Missing faces */
2552             for(p = 0; p < depEnd-depStart; ++p, ++off) points[off] = PETSC_MAX_INT;
2553           }
2554         }
2555       }
2556       if (n) {
2557         ierr = DMLabelGetStratumIS(subpointMap, dep, &is);CHKERRQ(ierr);
2558         ierr = ISGetIndices(is, &opoints);CHKERRQ(ierr);
2559         for(p = 0; p < n; ++p, ++off) points[off] = opoints[p];
2560         ierr = ISRestoreIndices(is, &opoints);CHKERRQ(ierr);
2561         ierr = ISDestroy(&is);CHKERRQ(ierr);
2562       }
2563     }
2564     ierr = DMRestoreWorkArray(dm, depth+1, PETSC_INT, &depths);CHKERRQ(ierr);
2565     if (off != pEnd) SETERRQ2(comm, PETSC_ERR_ARG_WRONG, "The number of mapped submesh points %d should be %d", off, pEnd);
2566     ierr = ISCreateGeneral(comm, pEnd, points, PETSC_OWN_POINTER, subpointIS);CHKERRQ(ierr);
2567   }
2568   PetscFunctionReturn(0);
2569 }
2570