xref: /petsc/src/dm/impls/plex/plexinterpolate.c (revision 6dc21c250422d0f29984dbbfd0625e44819bf3b1)
1 #include <petsc/private/dmpleximpl.h>   /*I      "petscdmplex.h"   I*/
2 #include <petsc/private/hashmapi.h>
3 #include <petsc/private/hashmapij.h>
4 
5 /* HashIJKL */
6 
7 #include <petsc/private/hashmap.h>
8 
9 typedef struct _PetscHashIJKLKey { PetscInt i, j, k, l; } PetscHashIJKLKey;
10 
11 #define PetscHashIJKLKeyHash(key) \
12   PetscHashCombine(PetscHashCombine(PetscHashInt((key).i),PetscHashInt((key).j)), \
13                    PetscHashCombine(PetscHashInt((key).k),PetscHashInt((key).l)))
14 
15 #define PetscHashIJKLKeyEqual(k1,k2) \
16   (((k1).i==(k2).i) ? ((k1).j==(k2).j) ? ((k1).k==(k2).k) ? ((k1).l==(k2).l) : 0 : 0 : 0)
17 
18 PETSC_HASH_MAP(HashIJKL, PetscHashIJKLKey, PetscInt, PetscHashIJKLKeyHash, PetscHashIJKLKeyEqual, -1)
19 
20 
21 /*
22   DMPlexGetFaces_Internal - Gets groups of vertices that correspond to faces for the given cell
23   This assumes that the mesh is not interpolated from the depth of point p to the vertices
24 */
25 PetscErrorCode DMPlexGetFaces_Internal(DM dm, PetscInt dim, PetscInt p, PetscInt *numFaces, PetscInt *faceSize, const PetscInt *faces[])
26 {
27   const PetscInt *cone = NULL;
28   PetscInt        coneSize;
29   PetscErrorCode  ierr;
30 
31   PetscFunctionBegin;
32   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
33   ierr = DMPlexGetConeSize(dm, p, &coneSize);CHKERRQ(ierr);
34   ierr = DMPlexGetCone(dm, p, &cone);CHKERRQ(ierr);
35   ierr = DMPlexGetRawFaces_Internal(dm, dim, coneSize, cone, numFaces, faceSize, faces);CHKERRQ(ierr);
36   PetscFunctionReturn(0);
37 }
38 
39 /*
40   DMPlexRestoreFaces_Internal - Restores the array
41 */
42 PetscErrorCode DMPlexRestoreFaces_Internal(DM dm, PetscInt dim, PetscInt p, PetscInt *numFaces, PetscInt *faceSize, const PetscInt *faces[])
43 {
44   PetscErrorCode  ierr;
45 
46   PetscFunctionBegin;
47   if (faces) { ierr = DMRestoreWorkArray(dm, 0, MPIU_INT, (void *) faces);CHKERRQ(ierr); }
48   PetscFunctionReturn(0);
49 }
50 
51 /*
52   DMPlexGetRawFaces_Internal - Gets groups of vertices that correspond to faces for the given cone
53 */
54 PetscErrorCode DMPlexGetRawFaces_Internal(DM dm, PetscInt dim, PetscInt coneSize, const PetscInt cone[], PetscInt *numFaces, PetscInt *faceSize, const PetscInt *faces[])
55 {
56   PetscInt       *facesTmp;
57   PetscInt        maxConeSize, maxSupportSize;
58   PetscErrorCode  ierr;
59 
60   PetscFunctionBegin;
61   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
62   if (faces && coneSize) PetscValidIntPointer(cone,4);
63   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
64   if (faces) {ierr = DMGetWorkArray(dm, PetscSqr(PetscMax(maxConeSize, maxSupportSize)), MPIU_INT, &facesTmp);CHKERRQ(ierr);}
65   switch (dim) {
66   case 1:
67     switch (coneSize) {
68     case 2:
69       if (faces) {
70         facesTmp[0] = cone[0]; facesTmp[1] = cone[1];
71         *faces = facesTmp;
72       }
73       if (numFaces) *numFaces = 2;
74       if (faceSize) *faceSize = 1;
75       break;
76     default:
77       SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Cone size %D not supported for dimension %D", coneSize, dim);
78     }
79     break;
80   case 2:
81     switch (coneSize) {
82     case 3:
83       if (faces) {
84         facesTmp[0] = cone[0]; facesTmp[1] = cone[1];
85         facesTmp[2] = cone[1]; facesTmp[3] = cone[2];
86         facesTmp[4] = cone[2]; facesTmp[5] = cone[0];
87         *faces = facesTmp;
88       }
89       if (numFaces) *numFaces = 3;
90       if (faceSize) *faceSize = 2;
91       break;
92     case 4:
93       /* Vertices follow right hand rule */
94       if (faces) {
95         facesTmp[0] = cone[0]; facesTmp[1] = cone[1];
96         facesTmp[2] = cone[1]; facesTmp[3] = cone[2];
97         facesTmp[4] = cone[2]; facesTmp[5] = cone[3];
98         facesTmp[6] = cone[3]; facesTmp[7] = cone[0];
99         *faces = facesTmp;
100       }
101       if (numFaces) *numFaces = 4;
102       if (faceSize) *faceSize = 2;
103       break;
104     default:
105       SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Cone size %D not supported for dimension %D", coneSize, dim);
106     }
107     break;
108   case 3:
109     switch (coneSize) {
110     case 3:
111       if (faces) {
112         facesTmp[0] = cone[0]; facesTmp[1] = cone[1];
113         facesTmp[2] = cone[1]; facesTmp[3] = cone[2];
114         facesTmp[4] = cone[2]; facesTmp[5] = cone[0];
115         *faces = facesTmp;
116       }
117       if (numFaces) *numFaces = 3;
118       if (faceSize) *faceSize = 2;
119       break;
120     case 4:
121       /* Vertices of first face follow right hand rule and normal points away from last vertex */
122       if (faces) {
123         facesTmp[0] = cone[0]; facesTmp[1]  = cone[1]; facesTmp[2]  = cone[2];
124         facesTmp[3] = cone[0]; facesTmp[4]  = cone[3]; facesTmp[5]  = cone[1];
125         facesTmp[6] = cone[0]; facesTmp[7]  = cone[2]; facesTmp[8]  = cone[3];
126         facesTmp[9] = cone[2]; facesTmp[10] = cone[1]; facesTmp[11] = cone[3];
127         *faces = facesTmp;
128       }
129       if (numFaces) *numFaces = 4;
130       if (faceSize) *faceSize = 3;
131       break;
132     case 8:
133       /*  7--------6
134          /|       /|
135         / |      / |
136        4--------5  |
137        |  |     |  |
138        |  |     |  |
139        |  1--------2
140        | /      | /
141        |/       |/
142        0--------3
143        */
144       if (faces) {
145         facesTmp[0]  = cone[0]; facesTmp[1]  = cone[1]; facesTmp[2]  = cone[2]; facesTmp[3]  = cone[3]; /* Bottom */
146         facesTmp[4]  = cone[4]; facesTmp[5]  = cone[5]; facesTmp[6]  = cone[6]; facesTmp[7]  = cone[7]; /* Top */
147         facesTmp[8]  = cone[0]; facesTmp[9]  = cone[3]; facesTmp[10] = cone[5]; facesTmp[11] = cone[4]; /* Front */
148         facesTmp[12] = cone[2]; facesTmp[13] = cone[1]; facesTmp[14] = cone[7]; facesTmp[15] = cone[6]; /* Back */
149         facesTmp[16] = cone[3]; facesTmp[17] = cone[2]; facesTmp[18] = cone[6]; facesTmp[19] = cone[5]; /* Right */
150         facesTmp[20] = cone[0]; facesTmp[21] = cone[4]; facesTmp[22] = cone[7]; facesTmp[23] = cone[1]; /* Left */
151         *faces = facesTmp;
152       }
153       if (numFaces) *numFaces = 6;
154       if (faceSize) *faceSize = 4;
155       break;
156     default:
157       SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Cone size %D not supported for dimension %D", coneSize, dim);
158     }
159     break;
160   default:
161     SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Dimension %D not supported", dim);
162   }
163   PetscFunctionReturn(0);
164 }
165 
166 /*
167   DMPlexGetRawFacesHybrid_Internal - Gets groups of vertices that correspond to faces for the given cone using hybrid ordering (prisms)
168 */
169 static PetscErrorCode DMPlexGetRawFacesHybrid_Internal(DM dm, PetscInt dim, PetscInt coneSize, const PetscInt cone[], PetscInt *numFaces, PetscInt *numFacesNotH, PetscInt *faceSize, const PetscInt *faces[])
170 {
171   PetscInt       *facesTmp;
172   PetscInt        maxConeSize, maxSupportSize;
173   PetscErrorCode  ierr;
174 
175   PetscFunctionBegin;
176   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
177   if (faces && coneSize) PetscValidIntPointer(cone,4);
178   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
179   if (faces) {ierr = DMGetWorkArray(dm, PetscSqr(PetscMax(maxConeSize, maxSupportSize)), MPIU_INT, &facesTmp);CHKERRQ(ierr);}
180   switch (dim) {
181   case 1:
182     switch (coneSize) {
183     case 2:
184       if (faces) {
185         facesTmp[0] = cone[0]; facesTmp[1] = cone[1];
186         *faces = facesTmp;
187       }
188       if (numFaces)     *numFaces = 2;
189       if (numFacesNotH) *numFacesNotH = 2;
190       if (faceSize)     *faceSize = 1;
191       break;
192     default:
193       SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Cone size %D not supported for dimension %D", coneSize, dim);
194     }
195     break;
196   case 2:
197     switch (coneSize) {
198     case 4:
199       if (faces) {
200         facesTmp[0] = cone[0]; facesTmp[1] = cone[1];
201         facesTmp[2] = cone[2]; facesTmp[3] = cone[3];
202         facesTmp[4] = cone[0]; facesTmp[5] = cone[2];
203         facesTmp[6] = cone[1]; facesTmp[7] = cone[3];
204         *faces = facesTmp;
205       }
206       if (numFaces)     *numFaces = 4;
207       if (numFacesNotH) *numFacesNotH = 2;
208       if (faceSize)     *faceSize = 2;
209       break;
210     default:
211       SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Cone size %D not supported for dimension %D", coneSize, dim);
212     }
213     break;
214   case 3:
215     switch (coneSize) {
216     case 6: /* triangular prism */
217       if (faces) {
218         facesTmp[0]  = cone[0]; facesTmp[1]  = cone[1]; facesTmp[2]  = cone[2]; facesTmp[3]  = -1;      /* Bottom */
219         facesTmp[4]  = cone[3]; facesTmp[5]  = cone[4]; facesTmp[6]  = cone[5]; facesTmp[7]  = -1;      /* Top */
220         facesTmp[8]  = cone[0]; facesTmp[9]  = cone[1]; facesTmp[10] = cone[3]; facesTmp[11] = cone[4]; /* Back left */
221         facesTmp[12] = cone[1]; facesTmp[13] = cone[2]; facesTmp[14] = cone[4]; facesTmp[15] = cone[5]; /* Back right */
222         facesTmp[16] = cone[2]; facesTmp[17] = cone[0]; facesTmp[18] = cone[5]; facesTmp[19] = cone[3]; /* Front */
223         *faces = facesTmp;
224       }
225       if (numFaces)     *numFaces = 5;
226       if (numFacesNotH) *numFacesNotH = 2;
227       if (faceSize)     *faceSize = -4;
228       break;
229     default:
230       SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Cone size %D not supported for dimension %D", coneSize, dim);
231     }
232     break;
233   default:
234     SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Dimension %D not supported", dim);
235   }
236   PetscFunctionReturn(0);
237 }
238 
239 static PetscErrorCode DMPlexRestoreRawFacesHybrid_Internal(DM dm, PetscInt dim, PetscInt coneSize, const PetscInt cone[], PetscInt *numFaces, PetscInt *numFacesNotH, PetscInt *faceSize, const PetscInt *faces[])
240 {
241   PetscErrorCode  ierr;
242 
243   PetscFunctionBegin;
244   if (faces) { ierr = DMRestoreWorkArray(dm, 0, MPIU_INT, (void *) faces);CHKERRQ(ierr); }
245   PetscFunctionReturn(0);
246 }
247 
248 static PetscErrorCode DMPlexGetFacesHybrid_Internal(DM dm, PetscInt dim, PetscInt p, PetscInt *numFaces, PetscInt *numFacesNotH, PetscInt *faceSize, const PetscInt *faces[])
249 {
250   const PetscInt *cone = NULL;
251   PetscInt        coneSize;
252   PetscErrorCode  ierr;
253 
254   PetscFunctionBegin;
255   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
256   ierr = DMPlexGetConeSize(dm, p, &coneSize);CHKERRQ(ierr);
257   ierr = DMPlexGetCone(dm, p, &cone);CHKERRQ(ierr);
258   ierr = DMPlexGetRawFacesHybrid_Internal(dm, dim, coneSize, cone, numFaces, numFacesNotH, faceSize, faces);CHKERRQ(ierr);
259   PetscFunctionReturn(0);
260 }
261 
262 /* This interpolates faces for cells at some stratum */
263 static PetscErrorCode DMPlexInterpolateFaces_Internal(DM dm, PetscInt cellDepth, DM idm)
264 {
265   DMLabel        subpointMap;
266   PetscHashIJKL  faceTable;
267   PetscInt      *pStart, *pEnd;
268   PetscInt       cellDim, depth, faceDepth = cellDepth, numPoints = 0, faceSizeAll = 0, face, c, d;
269   PetscInt       coneSizeH = 0, faceSizeAllH = 0, numCellFacesH = 0, faceH, pMax = -1, dim, outerloop;
270   PetscInt       cMax, fMax, eMax, vMax;
271   PetscErrorCode ierr;
272 
273   PetscFunctionBegin;
274   ierr = DMGetDimension(dm, &cellDim);CHKERRQ(ierr);
275   /* HACK: I need a better way to determine face dimension, or an alternative to GetFaces() */
276   ierr = DMPlexGetSubpointMap(dm, &subpointMap);CHKERRQ(ierr);
277   if (subpointMap) ++cellDim;
278   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
279   ++depth;
280   ++cellDepth;
281   cellDim -= depth - cellDepth;
282   ierr = PetscMalloc2(depth+1,&pStart,depth+1,&pEnd);CHKERRQ(ierr);
283   for (d = depth-1; d >= faceDepth; --d) {
284     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d+1], &pEnd[d+1]);CHKERRQ(ierr);
285   }
286   ierr = DMPlexGetDepthStratum(dm, -1, NULL, &pStart[faceDepth]);CHKERRQ(ierr);
287   pEnd[faceDepth] = pStart[faceDepth];
288   for (d = faceDepth-1; d >= 0; --d) {
289     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
290   }
291   cMax = fMax = eMax = vMax = PETSC_DETERMINE;
292   ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr);
293   if (cellDim == dim) {
294     ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
295     pMax = cMax;
296   } else if (cellDim == dim -1) {
297     ierr = DMPlexGetHybridBounds(dm, &cMax, &fMax, NULL, NULL);CHKERRQ(ierr);
298     pMax = fMax;
299   }
300   pMax = pMax < 0 ? pEnd[cellDepth] : pMax;
301   if (pMax < pEnd[cellDepth]) {
302     const PetscInt *cellFaces, *cone;
303     PetscInt        numCellFacesT, faceSize, cf;
304 
305     ierr = DMPlexGetConeSize(dm, pMax, &coneSizeH);CHKERRQ(ierr);
306     ierr = DMPlexGetCone(dm, pMax, &cone);CHKERRQ(ierr);
307     ierr = DMPlexGetRawFacesHybrid_Internal(dm, cellDim, coneSizeH, cone, &numCellFacesH, &numCellFacesT, &faceSize, &cellFaces);CHKERRQ(ierr);
308     if (faceSize < 0) {
309       PetscInt *sizes, minv, maxv;
310 
311       /* count vertices of hybrid and non-hybrid faces */
312       ierr = PetscCalloc1(numCellFacesH, &sizes);CHKERRQ(ierr);
313       for (cf = 0; cf < numCellFacesT; ++cf) { /* These are the non-hybrid faces */
314         const PetscInt *cellFace = &cellFaces[-cf*faceSize];
315         PetscInt       f;
316 
317         for (f = 0; f < -faceSize; ++f) sizes[cf] += (cellFace[f] >= 0 ? 1 : 0);
318       }
319       ierr = PetscSortInt(numCellFacesT, sizes);CHKERRQ(ierr);
320       minv = sizes[0];
321       maxv = sizes[PetscMax(numCellFacesT-1, 0)];
322       if (minv != maxv) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_SUP, "Different number of vertices for non-hybrid face %D != %D", minv, maxv);
323       faceSizeAll = minv;
324       ierr = PetscMemzero(sizes, numCellFacesH*sizeof(PetscInt));CHKERRQ(ierr);
325       for (cf = numCellFacesT; cf < numCellFacesH; ++cf) { /* These are the hybrid faces */
326         const PetscInt *cellFace = &cellFaces[-cf*faceSize];
327         PetscInt       f;
328 
329         for (f = 0; f < -faceSize; ++f) sizes[cf-numCellFacesT] += (cellFace[f] >= 0 ? 1 : 0);
330       }
331       ierr = PetscSortInt(numCellFacesH - numCellFacesT, sizes);CHKERRQ(ierr);
332       minv = sizes[0];
333       maxv = sizes[PetscMax(numCellFacesH - numCellFacesT-1, 0)];
334       ierr = PetscFree(sizes);CHKERRQ(ierr);
335       if (minv != maxv) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_SUP, "Different number of vertices for hybrid face %D != %D", minv, maxv);
336       faceSizeAllH = minv;
337     } else { /* the size of the faces in hybrid cells is the same */
338       faceSizeAll = faceSizeAllH = faceSize;
339     }
340     ierr = DMPlexRestoreRawFacesHybrid_Internal(dm, cellDim, coneSizeH, cone, &numCellFacesH, &numCellFacesT, &faceSize, &cellFaces);CHKERRQ(ierr);
341   } else if (pEnd[cellDepth] > pStart[cellDepth]) {
342     ierr = DMPlexGetFaces_Internal(dm, cellDim, pStart[cellDepth], NULL, &faceSizeAll, NULL);CHKERRQ(ierr);
343   }
344   if (faceSizeAll > 4) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Do not support interpolation of meshes with faces of %D vertices", faceSizeAll);
345 
346   /* With hybrid grids, we first iterate on hybrid cells and start numbering the non-hybrid grids
347      Then, faces for non-hybrid cells are numbered.
348      This is to guarantee consistent orientations (all 0) of all the points in the cone of the hybrid cells */
349   ierr = PetscHashIJKLCreate(&faceTable);CHKERRQ(ierr);
350   for (outerloop = 0, face = pStart[faceDepth]; outerloop < 2; outerloop++) {
351     PetscInt start, end;
352 
353     start = outerloop == 0 ? pMax : pStart[cellDepth];
354     end = outerloop == 0 ? pEnd[cellDepth] : pMax;
355     for (c = start; c < end; ++c) {
356       const PetscInt *cellFaces;
357       PetscInt        numCellFaces, faceSize, faceSizeInc, cf;
358 
359       if (c < pMax) {
360         ierr = DMPlexGetFaces_Internal(dm, cellDim, c, &numCellFaces, &faceSize, &cellFaces);CHKERRQ(ierr);
361         if (faceSize != faceSizeAll) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Inconsistent face for cell %D of size %D != %D", c, faceSize, faceSizeAll);
362       } else { /* Hybrid cell */
363         const PetscInt *cone;
364         PetscInt        numCellFacesN, coneSize;
365 
366         ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
367         if (coneSize != coneSizeH) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unexpected hybrid coneSize %D != %D", coneSize, coneSizeH);
368         ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
369         ierr = DMPlexGetRawFacesHybrid_Internal(dm, cellDim, coneSize, cone, &numCellFaces, &numCellFacesN, &faceSize, &cellFaces);CHKERRQ(ierr);
370         if (numCellFaces != numCellFacesH) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unexpected numCellFaces %D != %D for hybrid cell %D", numCellFaces, numCellFacesH, c);
371         faceSize = PetscMax(faceSize, -faceSize);
372         if (faceSize > 4) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Do not support interpolation of meshes with faces of %D vertices", faceSize);
373         numCellFaces = numCellFacesN; /* process only non-hybrid faces */
374       }
375       faceSizeInc = faceSize;
376       for (cf = 0; cf < numCellFaces; ++cf) {
377         const PetscInt   *cellFace = &cellFaces[cf*faceSizeInc];
378         PetscInt          faceSizeH = faceSize;
379         PetscHashIJKLKey  key;
380         PetscHashIter     iter;
381         PetscBool         missing;
382 
383         if (faceSizeInc == 2) {
384           key.i = PetscMin(cellFace[0], cellFace[1]);
385           key.j = PetscMax(cellFace[0], cellFace[1]);
386           key.k = PETSC_MAX_INT;
387           key.l = PETSC_MAX_INT;
388         } else {
389           key.i = cellFace[0];
390           key.j = cellFace[1];
391           key.k = cellFace[2];
392           key.l = faceSize > 3 ? (cellFace[3] < 0 ? faceSizeH = 3, PETSC_MAX_INT : cellFace[3]) : PETSC_MAX_INT;
393           ierr  = PetscSortInt(faceSize, (PetscInt *) &key);CHKERRQ(ierr);
394         }
395         /* this check is redundant for non-hybrid meshes */
396         if (faceSizeH != faceSizeAll) SETERRQ4(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unexpected number of vertices for face %D of point %D -> %D != %D", cf, c, faceSizeH, faceSizeAll);
397         ierr = PetscHashIJKLPut(faceTable, key, &iter, &missing);CHKERRQ(ierr);
398         if (missing) {ierr = PetscHashIJKLIterSet(faceTable, iter, face++);CHKERRQ(ierr);}
399       }
400       if (c < pMax) {
401         ierr = DMPlexRestoreFaces_Internal(dm, cellDim, c, &numCellFaces, &faceSize, &cellFaces);CHKERRQ(ierr);
402       } else {
403         ierr = DMPlexRestoreRawFacesHybrid_Internal(dm, cellDim, coneSizeH, NULL, NULL, NULL, NULL, &cellFaces);CHKERRQ(ierr);
404       }
405     }
406   }
407   pEnd[faceDepth] = face;
408 
409   /* Second pass for hybrid meshes: number hybrid faces */
410   for (c = pMax; c < pEnd[cellDepth]; ++c) {
411     const PetscInt *cellFaces, *cone;
412     PetscInt        numCellFaces, numCellFacesN, faceSize, cf, coneSize;
413 
414     ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
415     ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
416     ierr = DMPlexGetRawFacesHybrid_Internal(dm, cellDim, coneSize, cone, &numCellFaces, &numCellFacesN, &faceSize, &cellFaces);CHKERRQ(ierr);
417     if (numCellFaces != numCellFacesH) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unexpected hybrid numCellFaces %D != %D", numCellFaces, numCellFacesH);
418     faceSize = PetscMax(faceSize, -faceSize);
419     for (cf = numCellFacesN; cf < numCellFaces; ++cf) { /* These are the hybrid faces */
420       const PetscInt   *cellFace = &cellFaces[cf*faceSize];
421       PetscHashIJKLKey  key;
422       PetscHashIter     iter;
423       PetscBool         missing;
424       PetscInt          faceSizeH = faceSize;
425 
426       if (faceSize == 2) {
427         key.i = PetscMin(cellFace[0], cellFace[1]);
428         key.j = PetscMax(cellFace[0], cellFace[1]);
429         key.k = PETSC_MAX_INT;
430         key.l = PETSC_MAX_INT;
431       } else {
432         key.i = cellFace[0];
433         key.j = cellFace[1];
434         key.k = cellFace[2];
435         key.l = faceSize > 3 ? (cellFace[3] < 0 ? faceSizeH = 3, PETSC_MAX_INT : cellFace[3]) : PETSC_MAX_INT;
436         ierr  = PetscSortInt(faceSize, (PetscInt *) &key);CHKERRQ(ierr);
437       }
438       if (faceSizeH != faceSizeAllH) SETERRQ4(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unexpected number of vertices for hybrid face %D of point %D -> %D != %D", cf, c, faceSizeH, faceSizeAllH);
439       ierr = PetscHashIJKLPut(faceTable, key, &iter, &missing);CHKERRQ(ierr);
440       if (missing) {ierr = PetscHashIJKLIterSet(faceTable, iter, face++);CHKERRQ(ierr);}
441     }
442     ierr = DMPlexRestoreRawFacesHybrid_Internal(dm, cellDim, coneSize, cone, &numCellFaces, &numCellFacesN, &faceSize, &cellFaces);CHKERRQ(ierr);
443   }
444   faceH = face - pEnd[faceDepth];
445   if (faceH) {
446     if (fMax == PETSC_DETERMINE) fMax = pEnd[faceDepth];
447     else if (eMax == PETSC_DETERMINE) eMax = pEnd[faceDepth];
448     else SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Number of unassigned hybrid facets %D for cellDim %D and dimension %D", faceH, cellDim, dim);
449   }
450   pEnd[faceDepth] = face;
451   ierr = PetscHashIJKLDestroy(&faceTable);CHKERRQ(ierr);
452   /* Count new points */
453   for (d = 0; d <= depth; ++d) {
454     numPoints += pEnd[d]-pStart[d];
455   }
456   ierr = DMPlexSetChart(idm, 0, numPoints);CHKERRQ(ierr);
457   /* Set cone sizes */
458   for (d = 0; d <= depth; ++d) {
459     PetscInt coneSize, p;
460 
461     if (d == faceDepth) {
462       /* I see no way to do this if we admit faces of different shapes */
463       for (p = pStart[d]; p < pEnd[d]-faceH; ++p) {
464         ierr = DMPlexSetConeSize(idm, p, faceSizeAll);CHKERRQ(ierr);
465       }
466       for (p = pEnd[d]-faceH; p < pEnd[d]; ++p) {
467         ierr = DMPlexSetConeSize(idm, p, faceSizeAllH);CHKERRQ(ierr);
468       }
469     } else if (d == cellDepth) {
470       for (p = pStart[d]; p < pEnd[d]; ++p) {
471         /* Number of cell faces may be different from number of cell vertices*/
472         if (p < pMax) {
473           ierr = DMPlexGetFaces_Internal(dm, cellDim, p, &coneSize, NULL, NULL);CHKERRQ(ierr);
474         } else {
475           ierr = DMPlexGetFacesHybrid_Internal(dm, cellDim, p, &coneSize, NULL, NULL, NULL);CHKERRQ(ierr);
476         }
477         ierr = DMPlexSetConeSize(idm, p, coneSize);CHKERRQ(ierr);
478       }
479     } else {
480       for (p = pStart[d]; p < pEnd[d]; ++p) {
481         ierr = DMPlexGetConeSize(dm, p, &coneSize);CHKERRQ(ierr);
482         ierr = DMPlexSetConeSize(idm, p, coneSize);CHKERRQ(ierr);
483       }
484     }
485   }
486   ierr = DMSetUp(idm);CHKERRQ(ierr);
487   /* Get face cones from subsets of cell vertices */
488   if (faceSizeAll > 4) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Do not support interpolation of meshes with faces of %D vertices", faceSizeAll);
489   ierr = PetscHashIJKLCreate(&faceTable);CHKERRQ(ierr);
490   for (d = depth; d > cellDepth; --d) {
491     const PetscInt *cone;
492     PetscInt        p;
493 
494     for (p = pStart[d]; p < pEnd[d]; ++p) {
495       ierr = DMPlexGetCone(dm, p, &cone);CHKERRQ(ierr);
496       ierr = DMPlexSetCone(idm, p, cone);CHKERRQ(ierr);
497       ierr = DMPlexGetConeOrientation(dm, p, &cone);CHKERRQ(ierr);
498       ierr = DMPlexSetConeOrientation(idm, p, cone);CHKERRQ(ierr);
499     }
500   }
501   for (outerloop = 0, face = pStart[faceDepth]; outerloop < 2; outerloop++) {
502     PetscInt start, end;
503 
504     start = outerloop == 0 ? pMax : pStart[cellDepth];
505     end = outerloop == 0 ? pEnd[cellDepth] : pMax;
506     for (c = start; c < end; ++c) {
507       const PetscInt *cellFaces;
508       PetscInt        numCellFaces, faceSize, faceSizeInc, cf;
509 
510       if (c < pMax) {
511         ierr = DMPlexGetFaces_Internal(dm, cellDim, c, &numCellFaces, &faceSize, &cellFaces);CHKERRQ(ierr);
512         if (faceSize != faceSizeAll) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Inconsistent face for cell %D of size %D != %D", c, faceSize, faceSizeAll);
513       } else {
514         const PetscInt *cone;
515         PetscInt        numCellFacesN, coneSize;
516 
517         ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
518         if (coneSize != coneSizeH) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unexpected hybrid coneSize %D != %D", coneSize, coneSizeH);
519         ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
520         ierr = DMPlexGetRawFacesHybrid_Internal(dm, cellDim, coneSize, cone, &numCellFaces, &numCellFacesN, &faceSize, &cellFaces);CHKERRQ(ierr);
521         if (numCellFaces != numCellFacesH) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unexpected numCellFaces %D != %D for hybrid cell %D", numCellFaces, numCellFacesH, c);
522         faceSize = PetscMax(faceSize, -faceSize);
523         if (faceSize > 4) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Do not support interpolation of meshes with faces of %D vertices", faceSize);
524         numCellFaces = numCellFacesN; /* process only non-hybrid faces */
525       }
526       faceSizeInc = faceSize;
527       for (cf = 0; cf < numCellFaces; ++cf) {
528         const PetscInt  *cellFace = &cellFaces[cf*faceSizeInc];
529         PetscHashIJKLKey key;
530         PetscHashIter    iter;
531         PetscBool        missing;
532 
533         if (faceSizeInc == 2) {
534           key.i = PetscMin(cellFace[0], cellFace[1]);
535           key.j = PetscMax(cellFace[0], cellFace[1]);
536           key.k = PETSC_MAX_INT;
537           key.l = PETSC_MAX_INT;
538         } else {
539           key.i = cellFace[0];
540           key.j = cellFace[1];
541           key.k = cellFace[2];
542           key.l = faceSizeInc > 3 ? (cellFace[3] < 0 ? faceSize = 3, PETSC_MAX_INT : cellFace[3]) : PETSC_MAX_INT;
543           ierr  = PetscSortInt(faceSizeInc, (PetscInt *) &key);CHKERRQ(ierr);
544         }
545         ierr = PetscHashIJKLPut(faceTable, key, &iter, &missing);CHKERRQ(ierr);
546         if (missing) {
547           ierr = DMPlexSetCone(idm, face, cellFace);CHKERRQ(ierr);
548           ierr = PetscHashIJKLIterSet(faceTable, iter, face);CHKERRQ(ierr);
549           ierr = DMPlexInsertCone(idm, c, cf, face++);CHKERRQ(ierr);
550         } else {
551           const PetscInt *cone;
552           PetscInt        coneSize, ornt, i, j, f;
553 
554           ierr = PetscHashIJKLIterGet(faceTable, iter, &f);CHKERRQ(ierr);
555           ierr = DMPlexInsertCone(idm, c, cf, f);CHKERRQ(ierr);
556           /* Orient face: Do not allow reverse orientation at the first vertex */
557           ierr = DMPlexGetConeSize(idm, f, &coneSize);CHKERRQ(ierr);
558           ierr = DMPlexGetCone(idm, f, &cone);CHKERRQ(ierr);
559           if (coneSize != faceSize) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid number of face vertices %D for face %D should be %D", coneSize, f, faceSize);
560           /* - First find the initial vertex */
561           for (i = 0; i < faceSize; ++i) if (cellFace[0] == cone[i]) break;
562           /* - Try forward comparison */
563           for (j = 0; j < faceSize; ++j) if (cellFace[j] != cone[(i+j)%faceSize]) break;
564           if (j == faceSize) {
565             if ((faceSize == 2) && (i == 1)) ornt = -2;
566             else                             ornt = i;
567           } else {
568             /* - Try backward comparison */
569             for (j = 0; j < faceSize; ++j) if (cellFace[j] != cone[(i+faceSize-j)%faceSize]) break;
570             if (j == faceSize) {
571               if (i == 0) ornt = -faceSize;
572               else        ornt = -i;
573             } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Could not determine face orientation");
574           }
575           ierr = DMPlexInsertConeOrientation(idm, c, cf, ornt);CHKERRQ(ierr);
576         }
577       }
578       if (c < pMax) {
579         ierr = DMPlexRestoreFaces_Internal(dm, cellDim, c, &numCellFaces, &faceSize, &cellFaces);CHKERRQ(ierr);
580       } else {
581         ierr = DMPlexRestoreRawFacesHybrid_Internal(dm, cellDim, coneSizeH, NULL, NULL, NULL, NULL, &cellFaces);CHKERRQ(ierr);
582       }
583     }
584   }
585   /* Second pass for hybrid meshes: orient hybrid faces */
586   for (c = pMax; c < pEnd[cellDepth]; ++c) {
587     const PetscInt *cellFaces, *cone;
588     PetscInt        numCellFaces, numCellFacesN, faceSize, cf, coneSize;
589 
590     ierr = DMPlexGetConeSize(dm, c, &coneSize);CHKERRQ(ierr);
591     ierr = DMPlexGetCone(dm, c, &cone);CHKERRQ(ierr);
592     ierr = DMPlexGetRawFacesHybrid_Internal(dm, cellDim, coneSize, cone, &numCellFaces, &numCellFacesN, &faceSize, &cellFaces);CHKERRQ(ierr);
593     if (numCellFaces != numCellFacesH) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unexpected hybrid numCellFaces %D != %D", numCellFaces, numCellFacesH);
594     faceSize = PetscMax(faceSize, -faceSize);
595     for (cf = numCellFacesN; cf < numCellFaces; ++cf) { /* These are the hybrid faces */
596       const PetscInt   *cellFace = &cellFaces[cf*faceSize];
597       PetscHashIJKLKey key;
598       PetscHashIter    iter;
599       PetscBool        missing;
600       PetscInt         faceSizeH = faceSize;
601 
602       if (faceSize == 2) {
603         key.i = PetscMin(cellFace[0], cellFace[1]);
604         key.j = PetscMax(cellFace[0], cellFace[1]);
605         key.k = PETSC_MAX_INT;
606         key.l = PETSC_MAX_INT;
607       } else {
608         key.i = cellFace[0];
609         key.j = cellFace[1];
610         key.k = cellFace[2];
611         key.l = faceSize > 3 ? (cellFace[3] < 0 ? faceSizeH = 3, PETSC_MAX_INT : cellFace[3]) : PETSC_MAX_INT;
612         ierr  = PetscSortInt(faceSize, (PetscInt *) &key);CHKERRQ(ierr);
613       }
614       if (faceSizeH != faceSizeAllH) SETERRQ4(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unexpected number of vertices for hybrid face %D of point %D -> %D != %D", cf, c, faceSizeH, faceSizeAllH);
615       ierr = PetscHashIJKLPut(faceTable, key, &iter, &missing);CHKERRQ(ierr);
616       if (missing) {
617         ierr = DMPlexSetCone(idm, face, cellFace);CHKERRQ(ierr);
618         ierr = PetscHashIJKLIterSet(faceTable, iter, face);CHKERRQ(ierr);
619         ierr = DMPlexInsertCone(idm, c, cf, face++);CHKERRQ(ierr);
620       } else {
621         const PetscInt *cone;
622         PetscInt        coneSize, ornt, i, j, f;
623 
624         ierr = PetscHashIJKLIterGet(faceTable, iter, &f);CHKERRQ(ierr);
625         ierr = DMPlexInsertCone(idm, c, cf, f);CHKERRQ(ierr);
626         /* Orient face: Do not allow reverse orientation at the first vertex */
627         ierr = DMPlexGetConeSize(idm, f, &coneSize);CHKERRQ(ierr);
628         ierr = DMPlexGetCone(idm, f, &cone);CHKERRQ(ierr);
629         if (coneSize != faceSizeH) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid number of face vertices %D for face %D should be %D", coneSize, f, faceSizeH);
630         /* - First find the initial vertex */
631         for (i = 0; i < faceSizeH; ++i) if (cellFace[0] == cone[i]) break;
632         /* - Try forward comparison */
633         for (j = 0; j < faceSizeH; ++j) if (cellFace[j] != cone[(i+j)%faceSizeH]) break;
634         if (j == faceSizeH) {
635           if ((faceSizeH == 2) && (i == 1)) ornt = -2;
636           else                             ornt = i;
637         } else {
638           /* - Try backward comparison */
639           for (j = 0; j < faceSizeH; ++j) if (cellFace[j] != cone[(i+faceSizeH-j)%faceSizeH]) break;
640           if (j == faceSizeH) {
641             if (i == 0) ornt = -faceSizeH;
642             else        ornt = -i;
643           } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Could not determine face orientation");
644         }
645         ierr = DMPlexInsertConeOrientation(idm, c, cf, ornt);CHKERRQ(ierr);
646       }
647     }
648     ierr = DMPlexRestoreRawFacesHybrid_Internal(dm, cellDim, coneSize, cone, &numCellFaces, &numCellFacesN, &faceSize, &cellFaces);CHKERRQ(ierr);
649   }
650   if (face != pEnd[faceDepth]) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid number of faces %D should be %D", face-pStart[faceDepth], pEnd[faceDepth]-pStart[faceDepth]);
651   ierr = PetscFree2(pStart,pEnd);CHKERRQ(ierr);
652   ierr = PetscHashIJKLDestroy(&faceTable);CHKERRQ(ierr);
653   ierr = PetscFree2(pStart,pEnd);CHKERRQ(ierr);
654   ierr = DMPlexSetHybridBounds(idm, cMax, fMax, eMax, vMax);CHKERRQ(ierr);
655   ierr = DMPlexSymmetrize(idm);CHKERRQ(ierr);
656   ierr = DMPlexStratify(idm);CHKERRQ(ierr);
657   PetscFunctionReturn(0);
658 }
659 
660 static PetscErrorCode DMPlexOrientPointSF_Internal(DM dm, PetscSF sf)
661 {
662   PetscInt          (*roots)[2], (*leaves)[2];
663   PetscMPIInt       (*rootsRanks)[2], (*leavesRanks)[2];
664   const PetscInt    *locals;
665   const PetscSFNode *remotes;
666   PetscInt           nroots, nleaves, p, c;
667   const PetscInt    *cone;
668   PetscInt           coneSize, ind0, ind1;
669   MPI_Comm           comm;
670   PetscMPIInt        rank;
671   PetscInt           debug = 0;
672   PetscErrorCode     ierr;
673 
674   PetscFunctionBegin;
675   ierr = PetscSFGetGraph(sf, &nroots, &nleaves, &locals, &remotes);CHKERRQ(ierr);
676   if (nroots < 0) PetscFunctionReturn(0);
677   ierr = PetscMalloc4(nroots, &roots, nroots, &leaves, nroots, &rootsRanks, nroots, &leavesRanks);CHKERRQ(ierr);
678   ierr = PetscObjectGetComm((PetscObject) dm, &comm);CHKERRQ(ierr);
679   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
680   if (debug && rank == 0) {ierr = PetscSynchronizedPrintf(comm, "Roots\n");CHKERRQ(ierr);}
681   for (p = 0; p < nroots; ++p) {
682     ierr = DMPlexGetConeSize(dm, p, &coneSize);CHKERRQ(ierr);
683     ierr = DMPlexGetCone(dm, p, &cone);CHKERRQ(ierr);
684     /* Translate all points to root numbering */
685     for (c = 0; c < 2; c++) {
686       if (coneSize > 1) {
687         ierr = PetscFindInt(cone[c], nleaves, locals, &ind0);CHKERRQ(ierr);
688         if (ind0 < 0) {
689           roots[p][c] = cone[c];
690           rootsRanks[p][c] = rank;
691         } else {
692           roots[p][c] = remotes[ind0].index;
693           rootsRanks[p][c] = remotes[ind0].rank;
694         }
695       } else {
696         roots[p][c] = -1;
697         rootsRanks[p][c] = -1;
698       }
699     }
700   }
701   if (debug) {
702     for (p = 0; p < nroots; ++p) {
703       ierr = DMPlexGetConeSize(dm, p, &coneSize);CHKERRQ(ierr);
704       ierr = DMPlexGetCone(dm, p, &cone);CHKERRQ(ierr);
705       if (coneSize > 1) {
706         ierr = PetscSynchronizedPrintf(comm, "[%d]  %D: cone=[%D %D] roots=[%D %D] rootsRanks=[%D %D]\n", rank, p, cone[0], cone[1], roots[p][0], roots[p][1], rootsRanks[p][0], rootsRanks[p][1]);CHKERRQ(ierr);
707       }
708     }
709     ierr = PetscSynchronizedFlush(comm, NULL);CHKERRQ(ierr);
710   }
711   for (p = 0; p < nroots; ++p) {
712     leaves[p][0] = -2;
713     leaves[p][1] = -2;
714   }
715   ierr = PetscSFBcastBegin(sf, MPIU_2INT, roots, leaves);CHKERRQ(ierr);
716   ierr = PetscSFBcastBegin(sf, MPI_2INT, rootsRanks, leavesRanks);CHKERRQ(ierr);
717   ierr = PetscSFBcastEnd(sf, MPIU_2INT, roots, leaves);CHKERRQ(ierr);
718   ierr = PetscSFBcastEnd(sf, MPI_2INT, rootsRanks, leavesRanks);CHKERRQ(ierr);
719   if (debug) {ierr = PetscSynchronizedFlush(comm, NULL);CHKERRQ(ierr);}
720   if (debug && rank == 0) {ierr = PetscSynchronizedPrintf(comm, "Referred leaves\n");CHKERRQ(ierr);}
721   for (p = 0; p < nroots; ++p) {
722     if (leaves[p][0] < 0) continue;
723     ierr = DMPlexGetConeSize(dm, p, &coneSize);CHKERRQ(ierr);
724     ierr = DMPlexGetCone(dm, p, &cone);CHKERRQ(ierr);
725     if (debug) {ierr = PetscSynchronizedPrintf(comm, "[%d]  %D: cone=[%D %D] leaves=[%D %D] roots=[%D %D] leavesRanks=[%D %D] rootsRanks=[%D %D]\n", rank, p, cone[0], cone[1], leaves[p][0], leaves[p][1], roots[p][0], roots[p][1], leavesRanks[p][0], leavesRanks[p][1], rootsRanks[p][0], rootsRanks[p][1]);CHKERRQ(ierr);}
726     {
727       if ((leaves[p][0] != roots[p][0]) || (leaves[p][1] != roots[p][1]) || (leavesRanks[p][0] != rootsRanks[p][0]) || (leavesRanks[p][0] != rootsRanks[p][0])) {
728         /* TODO Generalize this to correct an arbitrary orientation */
729         ierr = DMPlexReverseCell(dm, p);CHKERRQ(ierr);
730         if (debug) {ierr = PetscSynchronizedPrintf(comm, "[%d]  reversed point %D\n", rank, p);CHKERRQ(ierr);}
731         ierr = DMPlexGetCone(dm, p, &cone);CHKERRQ(ierr);
732         ierr = PetscFindInt(cone[0], nleaves, locals, &ind0);CHKERRQ(ierr);
733         ierr = PetscFindInt(cone[1], nleaves, locals, &ind1);CHKERRQ(ierr);
734         if (ind0 < 0) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Point SF contains %D but is missing cone point %D = %D", p, 0, cone[0]);
735         if (ind1 < 0) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Point SF contains %D but is missing cone point %D = %D", p, 1, cone[1]);
736         if (leaves[p][0]  != remotes[ind0].index)
737           SETERRQ9(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Point %D Cone[%D] %D --> (%D, %D) != %D Cone[%D] SF Point (%D, %D)", p, 0, cone[0], remotes[ind0].rank, remotes[ind0].index, leaves[p][0], 0, remotes[p].rank, remotes[p].index);
738         if (leaves[p][1] != remotes[ind1].index)
739           SETERRQ9(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Point %D Cone[%D] %D --> (%D, %D) != %D Cone[%D] SF Point (%D, %D)", p, 1, cone[1], remotes[ind1].rank, remotes[ind1].index, leaves[p][1], 1, remotes[p].rank, remotes[p].index);
740       }
741     }
742   }
743   if (debug) {ierr = PetscSynchronizedFlush(comm, NULL);CHKERRQ(ierr);}
744   ierr = PetscFree4(roots, leaves, rootsRanks, leavesRanks);CHKERRQ(ierr);
745   PetscFunctionReturn(0);
746 }
747 
748 /* This interpolates the PointSF in parallel following local interpolation */
749 static PetscErrorCode DMPlexInterpolatePointSF(DM dm, PetscSF pointSF, PetscInt depth)
750 {
751   PetscMPIInt        size, rank;
752   PetscInt           p, c, d, dof, offset;
753   PetscInt           numLeaves, numRoots, candidatesSize, candidatesRemoteSize;
754   const PetscInt    *localPoints;
755   const PetscSFNode *remotePoints;
756   PetscSFNode       *candidates, *candidatesRemote, *claims;
757   PetscSection       candidateSection, candidateSectionRemote, claimSection;
758   PetscHMapI         leafhash;
759   PetscHMapIJ        roothash;
760   PetscHashIJKey     key;
761   PetscErrorCode     ierr;
762 
763   PetscFunctionBegin;
764   ierr = MPI_Comm_size(PetscObjectComm((PetscObject) dm), &size);CHKERRQ(ierr);
765   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject) dm), &rank);CHKERRQ(ierr);
766   ierr = PetscSFGetGraph(pointSF, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
767   if (size < 2 || numRoots < 0) PetscFunctionReturn(0);
768   ierr = PetscLogEventBegin(DMPLEX_InterpolateSF,dm,0,0,0);CHKERRQ(ierr);
769   /* Build hashes of points in the SF for efficient lookup */
770   ierr = PetscHMapICreate(&leafhash);CHKERRQ(ierr);
771   ierr = PetscHMapIJCreate(&roothash);CHKERRQ(ierr);
772   for (p = 0; p < numLeaves; ++p) {
773     ierr = PetscHMapISet(leafhash, localPoints[p], p);CHKERRQ(ierr);
774     key.i = remotePoints[p].index;
775     key.j = remotePoints[p].rank;
776     ierr = PetscHMapIJSet(roothash, key, p);CHKERRQ(ierr);
777   }
778   /* Build a section / SFNode array of candidate points in the single-level adjacency of leaves,
779      where each candidate is defined by the root entry for the other vertex that defines the edge. */
780   ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &candidateSection);CHKERRQ(ierr);
781   ierr = PetscSectionSetChart(candidateSection, 0, numRoots);CHKERRQ(ierr);
782   {
783     PetscInt leaf, root, idx, a, *adj = NULL;
784     for (p = 0; p < numLeaves; ++p) {
785       PetscInt adjSize = PETSC_DETERMINE;
786       ierr = DMPlexGetAdjacency_Internal(dm, localPoints[p], PETSC_FALSE, PETSC_FALSE, PETSC_FALSE, &adjSize, &adj);CHKERRQ(ierr);
787       for (a = 0; a < adjSize; ++a) {
788         ierr = PetscHMapIGet(leafhash, adj[a], &leaf);CHKERRQ(ierr);
789         if (leaf >= 0) {ierr = PetscSectionAddDof(candidateSection, localPoints[p], 1);CHKERRQ(ierr);}
790       }
791     }
792     ierr = PetscSectionSetUp(candidateSection);CHKERRQ(ierr);
793     ierr = PetscSectionGetStorageSize(candidateSection, &candidatesSize);CHKERRQ(ierr);
794     ierr = PetscMalloc1(candidatesSize, &candidates);CHKERRQ(ierr);
795     for (p = 0; p < numLeaves; ++p) {
796       PetscInt adjSize = PETSC_DETERMINE;
797       ierr = PetscSectionGetOffset(candidateSection, localPoints[p], &offset);CHKERRQ(ierr);
798       ierr = DMPlexGetAdjacency_Internal(dm, localPoints[p], PETSC_FALSE, PETSC_FALSE, PETSC_FALSE, &adjSize, &adj);CHKERRQ(ierr);
799       for (idx = 0, a = 0; a < adjSize; ++a) {
800         ierr = PetscHMapIGet(leafhash, adj[a], &root);CHKERRQ(ierr);
801         if (root >= 0) candidates[offset+idx++] = remotePoints[root];
802       }
803     }
804     ierr = PetscFree(adj);CHKERRQ(ierr);
805   }
806   /* Gather candidate section / array pair into the root partition via inverse(multi(pointSF)). */
807   {
808     PetscSF   sfMulti, sfInverse, sfCandidates;
809     PetscInt *remoteOffsets;
810     ierr = PetscSFGetMultiSF(pointSF, &sfMulti);CHKERRQ(ierr);
811     ierr = PetscSFCreateInverseSF(sfMulti, &sfInverse);CHKERRQ(ierr);
812     ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &candidateSectionRemote);CHKERRQ(ierr);
813     ierr = PetscSFDistributeSection(sfInverse, candidateSection, &remoteOffsets, candidateSectionRemote);CHKERRQ(ierr);
814     ierr = PetscSFCreateSectionSF(sfInverse, candidateSection, remoteOffsets, candidateSectionRemote, &sfCandidates);CHKERRQ(ierr);
815     ierr = PetscSectionGetStorageSize(candidateSectionRemote, &candidatesRemoteSize);CHKERRQ(ierr);
816     ierr = PetscMalloc1(candidatesRemoteSize, &candidatesRemote);CHKERRQ(ierr);
817     ierr = PetscSFBcastBegin(sfCandidates, MPIU_2INT, candidates, candidatesRemote);CHKERRQ(ierr);
818     ierr = PetscSFBcastEnd(sfCandidates, MPIU_2INT, candidates, candidatesRemote);CHKERRQ(ierr);
819     ierr = PetscSFDestroy(&sfInverse);CHKERRQ(ierr);
820     ierr = PetscSFDestroy(&sfCandidates);CHKERRQ(ierr);
821     ierr = PetscFree(remoteOffsets);CHKERRQ(ierr);
822   }
823   /* Walk local roots and check for each remote candidate whether we know all required points,
824      either from owning it or having a root entry in the point SF. If we do we place a claim
825      by replacing the vertex number with our edge ID. */
826   {
827     PetscInt        idx, root, joinSize, vertices[2];
828     const PetscInt *rootdegree, *join = NULL;
829     ierr = PetscSFComputeDegreeBegin(pointSF, &rootdegree);CHKERRQ(ierr);
830     ierr = PetscSFComputeDegreeEnd(pointSF, &rootdegree);CHKERRQ(ierr);
831     /* Loop remote edge connections and put in a claim if both vertices are known */
832     for (idx = 0, p = 0; p < numRoots; ++p) {
833       for (d = 0; d < rootdegree[p]; ++d) {
834         ierr = PetscSectionGetDof(candidateSectionRemote, idx, &dof);CHKERRQ(ierr);
835         ierr = PetscSectionGetOffset(candidateSectionRemote, idx, &offset);CHKERRQ(ierr);
836         for (c = 0; c < dof; ++c) {
837           /* We own both vertices, so we claim the edge by replacing vertex with edge */
838           if (candidatesRemote[offset+c].rank == rank) {
839             vertices[0] = p; vertices[1] = candidatesRemote[offset+c].index;
840             ierr = DMPlexGetJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
841             if (joinSize == 1) candidatesRemote[offset+c].index = join[0];
842             ierr = DMPlexRestoreJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
843             continue;
844           }
845           /* If we own one vertex and share a root with the other, we claim it */
846           key.i = candidatesRemote[offset+c].index;
847           key.j = candidatesRemote[offset+c].rank;
848           ierr = PetscHMapIJGet(roothash, key, &root);CHKERRQ(ierr);
849           if (root >= 0) {
850             vertices[0] = p; vertices[1] = localPoints[root];
851             ierr = DMPlexGetJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
852             if (joinSize == 1) {
853               candidatesRemote[offset+c].index = join[0];
854               candidatesRemote[offset+c].rank = rank;
855             }
856             ierr = DMPlexRestoreJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
857           }
858         }
859         idx++;
860       }
861     }
862   }
863   /* Push claims back to receiver via the MultiSF and derive new pointSF mapping on receiver */
864   {
865     PetscSF         sfMulti, sfClaims, sfPointNew;
866     PetscHMapI      claimshash;
867     PetscInt        size, pStart, pEnd, root, joinSize, numLocalNew;
868     PetscInt       *remoteOffsets, *localPointsNew, vertices[2];
869     const PetscInt *join = NULL;
870     PetscSFNode    *remotePointsNew;
871     ierr = PetscSFGetMultiSF(pointSF, &sfMulti);CHKERRQ(ierr);
872     ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &claimSection);CHKERRQ(ierr);
873     ierr = PetscSFDistributeSection(sfMulti, candidateSectionRemote, &remoteOffsets, claimSection);CHKERRQ(ierr);
874     ierr = PetscSFCreateSectionSF(sfMulti, candidateSectionRemote, remoteOffsets, claimSection, &sfClaims);CHKERRQ(ierr);
875     ierr = PetscSectionGetStorageSize(claimSection, &size);CHKERRQ(ierr);
876     ierr = PetscMalloc1(size, &claims);CHKERRQ(ierr);
877     ierr = PetscSFBcastBegin(sfClaims, MPIU_2INT, candidatesRemote, claims);CHKERRQ(ierr);
878     ierr = PetscSFBcastEnd(sfClaims, MPIU_2INT, candidatesRemote, claims);CHKERRQ(ierr);
879     ierr = PetscSFDestroy(&sfClaims);CHKERRQ(ierr);
880     ierr = PetscFree(remoteOffsets);CHKERRQ(ierr);
881     /* Walk the original section of local supports and add an SF entry for each updated item */
882     ierr = PetscHMapICreate(&claimshash);CHKERRQ(ierr);
883     for (p = 0; p < numRoots; ++p) {
884       ierr = PetscSectionGetDof(candidateSection, p, &dof);CHKERRQ(ierr);
885       ierr = PetscSectionGetOffset(candidateSection, p, &offset);CHKERRQ(ierr);
886       for (d = 0; d < dof; ++d) {
887         if (candidates[offset+d].index != claims[offset+d].index) {
888           key.i = candidates[offset+d].index;
889           key.j = candidates[offset+d].rank;
890           ierr = PetscHMapIJGet(roothash, key, &root);CHKERRQ(ierr);
891           if (root >= 0) {
892             vertices[0] = p; vertices[1] = localPoints[root];
893             ierr = DMPlexGetJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
894             if (joinSize == 1) {ierr = PetscHMapISet(claimshash, join[0], offset+d);CHKERRQ(ierr);}
895             ierr = DMPlexRestoreJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
896           }
897         }
898       }
899     }
900     /* Create new pointSF from hashed claims */
901     ierr = PetscHMapIGetSize(claimshash, &numLocalNew);CHKERRQ(ierr);
902     ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
903     ierr = PetscMalloc1(numLeaves + numLocalNew, &localPointsNew);CHKERRQ(ierr);
904     ierr = PetscMalloc1(numLeaves + numLocalNew, &remotePointsNew);CHKERRQ(ierr);
905     for (p = 0; p < numLeaves; ++p) {
906       localPointsNew[p] = localPoints[p];
907       remotePointsNew[p].index = remotePoints[p].index;
908       remotePointsNew[p].rank  = remotePoints[p].rank;
909     }
910     p = numLeaves;
911     ierr = PetscHMapIGetKeys(claimshash, &p, localPointsNew);CHKERRQ(ierr);
912     ierr = PetscSortInt(numLocalNew, &localPointsNew[numLeaves]);CHKERRQ(ierr);
913     for (p = numLeaves; p < numLeaves + numLocalNew; ++p) {
914       ierr = PetscHMapIGet(claimshash, localPointsNew[p], &offset);CHKERRQ(ierr);
915       remotePointsNew[p] = claims[offset];
916     }
917     ierr = PetscSFCreate(PetscObjectComm((PetscObject) dm), &sfPointNew);CHKERRQ(ierr);
918     ierr = PetscSFSetGraph(sfPointNew, pEnd-pStart, numLeaves+numLocalNew, localPointsNew, PETSC_OWN_POINTER, remotePointsNew, PETSC_OWN_POINTER);CHKERRQ(ierr);
919     ierr = DMSetPointSF(dm, sfPointNew);CHKERRQ(ierr);
920     ierr = PetscSFDestroy(&sfPointNew);CHKERRQ(ierr);
921     ierr = PetscHMapIDestroy(&claimshash);CHKERRQ(ierr);
922   }
923   ierr = PetscHMapIDestroy(&leafhash);CHKERRQ(ierr);
924   ierr = PetscHMapIJDestroy(&roothash);CHKERRQ(ierr);
925   ierr = PetscSectionDestroy(&candidateSection);CHKERRQ(ierr);
926   ierr = PetscSectionDestroy(&candidateSectionRemote);CHKERRQ(ierr);
927   ierr = PetscSectionDestroy(&claimSection);CHKERRQ(ierr);
928   ierr = PetscFree(candidates);CHKERRQ(ierr);
929   ierr = PetscFree(candidatesRemote);CHKERRQ(ierr);
930   ierr = PetscFree(claims);CHKERRQ(ierr);
931   ierr = PetscLogEventEnd(DMPLEX_InterpolateSF,dm,0,0,0);CHKERRQ(ierr);
932   PetscFunctionReturn(0);
933 }
934 
935 /*@C
936   DMPlexInterpolate - Take in a cell-vertex mesh and return one with all intermediate faces, edges, etc.
937 
938   Collective on DM
939 
940   Input Parameters:
941 + dm - The DMPlex object with only cells and vertices
942 - dmInt - The interpolated DM
943 
944   Output Parameter:
945 . dmInt - The complete DMPlex object
946 
947   Level: intermediate
948 
949   Notes:
950     It does not copy over the coordinates.
951 
952 .keywords: mesh
953 .seealso: DMPlexUninterpolate(), DMPlexCreateFromCellList(), DMPlexCopyCoordinates()
954 @*/
955 PetscErrorCode DMPlexInterpolate(DM dm, DM *dmInt)
956 {
957   DM             idm, odm = dm;
958   PetscSF        sfPoint;
959   PetscInt       depth, dim, d;
960   const char    *name;
961   PetscErrorCode ierr;
962 
963   PetscFunctionBegin;
964   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
965   PetscValidPointer(dmInt, 2);
966   ierr = PetscLogEventBegin(DMPLEX_Interpolate,dm,0,0,0);CHKERRQ(ierr);
967   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
968   ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr);
969   if ((depth == dim) || (dim <= 1)) {
970     ierr = PetscObjectReference((PetscObject) dm);CHKERRQ(ierr);
971     idm  = dm;
972   } else {
973     for (d = 1; d < dim; ++d) {
974       /* Create interpolated mesh */
975       ierr = DMCreate(PetscObjectComm((PetscObject)dm), &idm);CHKERRQ(ierr);
976       ierr = DMSetType(idm, DMPLEX);CHKERRQ(ierr);
977       ierr = DMSetDimension(idm, dim);CHKERRQ(ierr);
978       if (depth > 0) {
979         ierr = DMPlexInterpolateFaces_Internal(odm, 1, idm);CHKERRQ(ierr);
980         ierr = DMGetPointSF(odm, &sfPoint);CHKERRQ(ierr);
981         ierr = DMPlexInterpolatePointSF(idm, sfPoint, depth);CHKERRQ(ierr);
982       }
983       if (odm != dm) {ierr = DMDestroy(&odm);CHKERRQ(ierr);}
984       odm = idm;
985     }
986     ierr = PetscObjectGetName((PetscObject) dm,  &name);CHKERRQ(ierr);
987     ierr = PetscObjectSetName((PetscObject) idm,  name);CHKERRQ(ierr);
988     ierr = DMPlexCopyCoordinates(dm, idm);CHKERRQ(ierr);
989     ierr = DMCopyLabels(dm, idm);CHKERRQ(ierr);
990     {
991       /* TODO temporary */
992       PetscBool flg=PETSC_FALSE;
993       ierr = PetscOptionsGetBool(NULL,NULL, "-dm_plex_check_point_sf", &flg, NULL);CHKERRQ(ierr);
994       if (flg) {ierr = DMPlexCheckPointSF(idm);CHKERRQ(ierr);}
995       ierr = DMViewFromOptions(idm, NULL, "-before_fix_dm_view");CHKERRQ(ierr);
996     }
997     ierr = DMGetPointSF(idm, &sfPoint);CHKERRQ(ierr);
998     ierr = DMPlexOrientPointSF_Internal(idm, sfPoint);CHKERRQ(ierr);
999   }
1000   {
1001     PetscBool            isper;
1002     const PetscReal      *maxCell, *L;
1003     const DMBoundaryType *bd;
1004 
1005     ierr = DMGetPeriodicity(dm,&isper,&maxCell,&L,&bd);CHKERRQ(ierr);
1006     ierr = DMSetPeriodicity(idm,isper,maxCell,L,bd);CHKERRQ(ierr);
1007   }
1008   *dmInt = idm;
1009   ierr = PetscLogEventEnd(DMPLEX_Interpolate,dm,0,0,0);CHKERRQ(ierr);
1010   PetscFunctionReturn(0);
1011 }
1012 
1013 /*@
1014   DMPlexCopyCoordinates - Copy coordinates from one mesh to another with the same vertices
1015 
1016   Collective on DM
1017 
1018   Input Parameter:
1019 . dmA - The DMPlex object with initial coordinates
1020 
1021   Output Parameter:
1022 . dmB - The DMPlex object with copied coordinates
1023 
1024   Level: intermediate
1025 
1026   Note: This is typically used when adding pieces other than vertices to a mesh
1027 
1028 .keywords: mesh
1029 .seealso: DMCopyLabels(), DMGetCoordinates(), DMGetCoordinatesLocal(), DMGetCoordinateDM(), DMGetCoordinateSection()
1030 @*/
1031 PetscErrorCode DMPlexCopyCoordinates(DM dmA, DM dmB)
1032 {
1033   Vec            coordinatesA, coordinatesB;
1034   VecType        vtype;
1035   PetscSection   coordSectionA, coordSectionB;
1036   PetscScalar   *coordsA, *coordsB;
1037   PetscInt       spaceDim, Nf, vStartA, vStartB, vEndA, vEndB, coordSizeB, v, d;
1038   PetscInt       cStartA, cEndA, cStartB, cEndB, cS, cE;
1039   PetscBool      lc = PETSC_FALSE;
1040   PetscErrorCode ierr;
1041 
1042   PetscFunctionBegin;
1043   PetscValidHeaderSpecific(dmA, DM_CLASSID, 1);
1044   PetscValidHeaderSpecific(dmB, DM_CLASSID, 2);
1045   if (dmA == dmB) PetscFunctionReturn(0);
1046   ierr = DMPlexGetDepthStratum(dmA, 0, &vStartA, &vEndA);CHKERRQ(ierr);
1047   ierr = DMPlexGetDepthStratum(dmB, 0, &vStartB, &vEndB);CHKERRQ(ierr);
1048   if ((vEndA-vStartA) != (vEndB-vStartB)) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "The number of vertices in first DM %d != %d in the second DM", vEndA-vStartA, vEndB-vStartB);
1049   ierr = DMPlexGetHeightStratum(dmA, 0, &cStartA, &cEndA);CHKERRQ(ierr);
1050   ierr = DMPlexGetHeightStratum(dmB, 0, &cStartB, &cEndB);CHKERRQ(ierr);
1051   ierr = DMGetCoordinateSection(dmA, &coordSectionA);CHKERRQ(ierr);
1052   ierr = DMGetCoordinateSection(dmB, &coordSectionB);CHKERRQ(ierr);
1053   if (coordSectionA == coordSectionB) PetscFunctionReturn(0);
1054   ierr = PetscSectionGetNumFields(coordSectionA, &Nf);CHKERRQ(ierr);
1055   if (!Nf) PetscFunctionReturn(0);
1056   if (Nf > 1) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "The number of coordinate fields must be 1, not %D", Nf);
1057   if (!coordSectionB) {
1058     PetscInt dim;
1059 
1060     ierr = PetscSectionCreate(PetscObjectComm((PetscObject) coordSectionA), &coordSectionB);CHKERRQ(ierr);
1061     ierr = DMGetCoordinateDim(dmA, &dim);CHKERRQ(ierr);
1062     ierr = DMSetCoordinateSection(dmB, dim, coordSectionB);CHKERRQ(ierr);
1063     ierr = PetscObjectDereference((PetscObject) coordSectionB);CHKERRQ(ierr);
1064   }
1065   ierr = PetscSectionSetNumFields(coordSectionB, 1);CHKERRQ(ierr);
1066   ierr = PetscSectionGetFieldComponents(coordSectionA, 0, &spaceDim);CHKERRQ(ierr);
1067   ierr = PetscSectionSetFieldComponents(coordSectionB, 0, spaceDim);CHKERRQ(ierr);
1068   ierr = PetscSectionGetChart(coordSectionA, &cS, &cE);CHKERRQ(ierr);
1069   if (cStartA <= cS && cS < cEndA) { /* localized coordinates */
1070     if ((cEndA-cStartA) != (cEndB-cStartB)) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "The number of cellls in first DM %d != %d in the second DM", cEndA-cStartA, cEndB-cStartB);
1071     cS = cS - cStartA + cStartB;
1072     cE = vEndB;
1073     lc = PETSC_TRUE;
1074   } else {
1075     cS = vStartB;
1076     cE = vEndB;
1077   }
1078   ierr = PetscSectionSetChart(coordSectionB, cS, cE);CHKERRQ(ierr);
1079   for (v = vStartB; v < vEndB; ++v) {
1080     ierr = PetscSectionSetDof(coordSectionB, v, spaceDim);CHKERRQ(ierr);
1081     ierr = PetscSectionSetFieldDof(coordSectionB, v, 0, spaceDim);CHKERRQ(ierr);
1082   }
1083   if (lc) { /* localized coordinates */
1084     PetscInt c;
1085 
1086     for (c = cS-cStartB; c < cEndB-cStartB; c++) {
1087       PetscInt dof;
1088 
1089       ierr = PetscSectionGetDof(coordSectionA, c + cStartA, &dof);CHKERRQ(ierr);
1090       ierr = PetscSectionSetDof(coordSectionB, c + cStartB, dof);CHKERRQ(ierr);
1091       ierr = PetscSectionSetFieldDof(coordSectionB, c + cStartB, 0, dof);CHKERRQ(ierr);
1092     }
1093   }
1094   ierr = PetscSectionSetUp(coordSectionB);CHKERRQ(ierr);
1095   ierr = PetscSectionGetStorageSize(coordSectionB, &coordSizeB);CHKERRQ(ierr);
1096   ierr = DMGetCoordinatesLocal(dmA, &coordinatesA);CHKERRQ(ierr);
1097   ierr = VecCreate(PETSC_COMM_SELF, &coordinatesB);CHKERRQ(ierr);
1098   ierr = PetscObjectSetName((PetscObject) coordinatesB, "coordinates");CHKERRQ(ierr);
1099   ierr = VecSetSizes(coordinatesB, coordSizeB, PETSC_DETERMINE);CHKERRQ(ierr);
1100   ierr = VecGetBlockSize(coordinatesA, &d);CHKERRQ(ierr);
1101   ierr = VecSetBlockSize(coordinatesB, d);CHKERRQ(ierr);
1102   ierr = VecGetType(coordinatesA, &vtype);CHKERRQ(ierr);
1103   ierr = VecSetType(coordinatesB, vtype);CHKERRQ(ierr);
1104   ierr = VecGetArray(coordinatesA, &coordsA);CHKERRQ(ierr);
1105   ierr = VecGetArray(coordinatesB, &coordsB);CHKERRQ(ierr);
1106   for (v = 0; v < vEndB-vStartB; ++v) {
1107     PetscInt offA, offB;
1108 
1109     ierr = PetscSectionGetOffset(coordSectionA, v + vStartA, &offA);CHKERRQ(ierr);
1110     ierr = PetscSectionGetOffset(coordSectionB, v + vStartB, &offB);CHKERRQ(ierr);
1111     for (d = 0; d < spaceDim; ++d) {
1112       coordsB[offB+d] = coordsA[offA+d];
1113     }
1114   }
1115   if (lc) { /* localized coordinates */
1116     PetscInt c;
1117 
1118     for (c = cS-cStartB; c < cEndB-cStartB; c++) {
1119       PetscInt dof, offA, offB;
1120 
1121       ierr = PetscSectionGetOffset(coordSectionA, c + cStartA, &offA);CHKERRQ(ierr);
1122       ierr = PetscSectionGetOffset(coordSectionB, c + cStartB, &offB);CHKERRQ(ierr);
1123       ierr = PetscSectionGetDof(coordSectionA, c + cStartA, &dof);CHKERRQ(ierr);
1124       ierr = PetscMemcpy(coordsB + offB,coordsA + offA,dof*sizeof(*coordsB));CHKERRQ(ierr);
1125     }
1126   }
1127   ierr = VecRestoreArray(coordinatesA, &coordsA);CHKERRQ(ierr);
1128   ierr = VecRestoreArray(coordinatesB, &coordsB);CHKERRQ(ierr);
1129   ierr = DMSetCoordinatesLocal(dmB, coordinatesB);CHKERRQ(ierr);
1130   ierr = VecDestroy(&coordinatesB);CHKERRQ(ierr);
1131   PetscFunctionReturn(0);
1132 }
1133 
1134 /*@
1135   DMPlexUninterpolate - Take in a mesh with all intermediate faces, edges, etc. and return a cell-vertex mesh
1136 
1137   Collective on DM
1138 
1139   Input Parameter:
1140 . dm - The complete DMPlex object
1141 
1142   Output Parameter:
1143 . dmUnint - The DMPlex object with only cells and vertices
1144 
1145   Level: intermediate
1146 
1147   Notes:
1148     It does not copy over the coordinates.
1149 
1150 .keywords: mesh
1151 .seealso: DMPlexInterpolate(), DMPlexCreateFromCellList(), DMPlexCopyCoordinates()
1152 @*/
1153 PetscErrorCode DMPlexUninterpolate(DM dm, DM *dmUnint)
1154 {
1155   DM             udm;
1156   PetscInt       dim, vStart, vEnd, cStart, cEnd, cMax, c, maxConeSize = 0, *cone;
1157   PetscErrorCode ierr;
1158 
1159   PetscFunctionBegin;
1160   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
1161   PetscValidPointer(dmUnint, 2);
1162   ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr);
1163   if (dim <= 1) {
1164     ierr = PetscObjectReference((PetscObject) dm);CHKERRQ(ierr);
1165     *dmUnint = dm;
1166     PetscFunctionReturn(0);
1167   }
1168   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
1169   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
1170   ierr = DMPlexGetHybridBounds(dm, &cMax, NULL, NULL, NULL);CHKERRQ(ierr);
1171   ierr = DMCreate(PetscObjectComm((PetscObject) dm), &udm);CHKERRQ(ierr);
1172   ierr = DMSetType(udm, DMPLEX);CHKERRQ(ierr);
1173   ierr = DMSetDimension(udm, dim);CHKERRQ(ierr);
1174   ierr = DMPlexSetChart(udm, cStart, vEnd);CHKERRQ(ierr);
1175   for (c = cStart; c < cEnd; ++c) {
1176     PetscInt *closure = NULL, closureSize, cl, coneSize = 0;
1177 
1178     ierr = DMPlexGetTransitiveClosure(dm, c, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1179     for (cl = 0; cl < closureSize*2; cl += 2) {
1180       const PetscInt p = closure[cl];
1181 
1182       if ((p >= vStart) && (p < vEnd)) ++coneSize;
1183     }
1184     ierr = DMPlexRestoreTransitiveClosure(dm, c, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1185     ierr = DMPlexSetConeSize(udm, c, coneSize);CHKERRQ(ierr);
1186     maxConeSize = PetscMax(maxConeSize, coneSize);
1187   }
1188   ierr = DMSetUp(udm);CHKERRQ(ierr);
1189   ierr = PetscMalloc1(maxConeSize, &cone);CHKERRQ(ierr);
1190   for (c = cStart; c < cEnd; ++c) {
1191     PetscInt *closure = NULL, closureSize, cl, coneSize = 0;
1192 
1193     ierr = DMPlexGetTransitiveClosure(dm, c, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1194     for (cl = 0; cl < closureSize*2; cl += 2) {
1195       const PetscInt p = closure[cl];
1196 
1197       if ((p >= vStart) && (p < vEnd)) cone[coneSize++] = p;
1198     }
1199     ierr = DMPlexRestoreTransitiveClosure(dm, c, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
1200     ierr = DMPlexSetCone(udm, c, cone);CHKERRQ(ierr);
1201   }
1202   ierr = PetscFree(cone);CHKERRQ(ierr);
1203   ierr = DMPlexSetHybridBounds(udm, cMax, PETSC_DETERMINE, PETSC_DETERMINE, PETSC_DETERMINE);CHKERRQ(ierr);
1204   ierr = DMPlexSymmetrize(udm);CHKERRQ(ierr);
1205   ierr = DMPlexStratify(udm);CHKERRQ(ierr);
1206   /* Reduce SF */
1207   {
1208     PetscSF            sfPoint, sfPointUn;
1209     const PetscSFNode *remotePoints;
1210     const PetscInt    *localPoints;
1211     PetscSFNode       *remotePointsUn;
1212     PetscInt          *localPointsUn;
1213     PetscInt           vEnd, numRoots, numLeaves, l;
1214     PetscInt           numLeavesUn = 0, n = 0;
1215     PetscErrorCode     ierr;
1216 
1217     /* Get original SF information */
1218     ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
1219     ierr = DMGetPointSF(udm, &sfPointUn);CHKERRQ(ierr);
1220     ierr = DMPlexGetDepthStratum(dm, 0, NULL, &vEnd);CHKERRQ(ierr);
1221     ierr = PetscSFGetGraph(sfPoint, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
1222     /* Allocate space for cells and vertices */
1223     for (l = 0; l < numLeaves; ++l) if (localPoints[l] < vEnd) numLeavesUn++;
1224     /* Fill in leaves */
1225     if (vEnd >= 0) {
1226       ierr = PetscMalloc1(numLeavesUn, &remotePointsUn);CHKERRQ(ierr);
1227       ierr = PetscMalloc1(numLeavesUn, &localPointsUn);CHKERRQ(ierr);
1228       for (l = 0; l < numLeaves; l++) {
1229         if (localPoints[l] < vEnd) {
1230           localPointsUn[n]        = localPoints[l];
1231           remotePointsUn[n].rank  = remotePoints[l].rank;
1232           remotePointsUn[n].index = remotePoints[l].index;
1233           ++n;
1234         }
1235       }
1236       if (n != numLeavesUn) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Inconsistent number of leaves %d != %d", n, numLeavesUn);
1237       ierr = PetscSFSetGraph(sfPointUn, vEnd, numLeavesUn, localPointsUn, PETSC_OWN_POINTER, remotePointsUn, PETSC_OWN_POINTER);CHKERRQ(ierr);
1238     }
1239   }
1240   {
1241     PetscBool            isper;
1242     const PetscReal      *maxCell, *L;
1243     const DMBoundaryType *bd;
1244 
1245     ierr = DMGetPeriodicity(dm,&isper,&maxCell,&L,&bd);CHKERRQ(ierr);
1246     ierr = DMSetPeriodicity(udm,isper,maxCell,L,bd);CHKERRQ(ierr);
1247   }
1248 
1249   *dmUnint = udm;
1250   PetscFunctionReturn(0);
1251 }
1252