xref: /petsc/src/dm/impls/plex/plexreorder.c (revision 5b6bfdb9644f185dbf5e5a09b808ec241507e1e7)
1 #include <petsc/private/dmpleximpl.h>   /*I      "petscdmplex.h"   I*/
2 #include <petsc/private/matorderimpl.h> /*I      "petscmat.h"      I*/
3 
4 static PetscErrorCode DMPlexCreateOrderingClosure_Static(DM dm, PetscInt numPoints, const PetscInt pperm[], PetscInt **clperm, PetscInt **invclperm)
5 {
6   PetscInt      *perm, *iperm;
7   PetscInt       depth, d, pStart, pEnd, fStart, fMax, fEnd, p;
8   PetscErrorCode ierr;
9 
10   PetscFunctionBegin;
11   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
12   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
13   ierr = PetscMalloc1(pEnd-pStart,&perm);CHKERRQ(ierr);
14   ierr = PetscMalloc1(pEnd-pStart,&iperm);CHKERRQ(ierr);
15   for (p = pStart; p < pEnd; ++p) iperm[p] = -1;
16   for (d = depth; d > 0; --d) {
17     ierr = DMPlexGetDepthStratum(dm, d,   &pStart, &pEnd);CHKERRQ(ierr);
18     ierr = DMPlexGetDepthStratum(dm, d-1, &fStart, &fEnd);CHKERRQ(ierr);
19     fMax = fStart;
20     for (p = pStart; p < pEnd; ++p) {
21       const PetscInt *cone;
22       PetscInt        point, coneSize, c;
23 
24       if (d == depth) {
25         perm[p]         = pperm[p];
26         iperm[pperm[p]] = p;
27       }
28       point = perm[p];
29       ierr = DMPlexGetConeSize(dm, point, &coneSize);CHKERRQ(ierr);
30       ierr = DMPlexGetCone(dm, point, &cone);CHKERRQ(ierr);
31       for (c = 0; c < coneSize; ++c) {
32         const PetscInt oldc = cone[c];
33         const PetscInt newc = iperm[oldc];
34 
35         if (newc < 0) {
36           perm[fMax]  = oldc;
37           iperm[oldc] = fMax++;
38         }
39       }
40     }
41     if (fMax != fEnd) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Number of depth %d faces %d does not match permuted nubmer %d", d, fEnd-fStart, fMax-fStart);
42   }
43   *clperm    = perm;
44   *invclperm = iperm;
45   PetscFunctionReturn(0);
46 }
47 
48 /*@
49   DMPlexGetOrdering - Calculate a reordering of the mesh
50 
51   Collective on DM
52 
53   Input Parameter:
54 + dm - The DMPlex object
55 . otype - type of reordering, one of the following:
56 $     MATORDERINGNATURAL - Natural
57 $     MATORDERINGND - Nested Dissection
58 $     MATORDERING1WD - One-way Dissection
59 $     MATORDERINGRCM - Reverse Cuthill-McKee
60 $     MATORDERINGQMD - Quotient Minimum Degree
61 - label - [Optional] Label used to segregate ordering into sets, or NULL
62 
63 
64   Output Parameter:
65 . perm - The point permutation as an IS, perm[old point number] = new point number
66 
67   Note: The label is used to group sets of points together by label value. This makes it easy to reorder a mesh which
68   has different types of cells, and then loop over each set of reordered cells for assembly.
69 
70   Level: intermediate
71 
72 .keywords: mesh
73 .seealso: MatGetOrdering()
74 @*/
75 PetscErrorCode DMPlexGetOrdering(DM dm, MatOrderingType otype, DMLabel label, IS *perm)
76 {
77   PetscInt       numCells = 0;
78   PetscInt      *start = NULL, *adjacency = NULL, *cperm, *clperm = NULL, *invclperm = NULL, *mask, *xls, pStart, pEnd, c, i;
79   PetscErrorCode ierr;
80 
81   PetscFunctionBegin;
82   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
83   PetscValidPointer(perm, 3);
84   ierr = DMPlexCreateNeighborCSR(dm, 0, &numCells, &start, &adjacency);CHKERRQ(ierr);
85   ierr = PetscMalloc3(numCells,&cperm,numCells,&mask,numCells*2,&xls);CHKERRQ(ierr);
86   if (numCells) {
87     /* Shift for Fortran numbering */
88     for (i = 0; i < start[numCells]; ++i) ++adjacency[i];
89     for (i = 0; i <= numCells; ++i)       ++start[i];
90     ierr = SPARSEPACKgenrcm(&numCells, start, adjacency, cperm, mask, xls);CHKERRQ(ierr);
91   }
92   ierr = PetscFree(start);CHKERRQ(ierr);
93   ierr = PetscFree(adjacency);CHKERRQ(ierr);
94   /* Shift for Fortran numbering */
95   for (c = 0; c < numCells; ++c) --cperm[c];
96   /* Segregate */
97   if (label) {
98     IS              valueIS;
99     const PetscInt *values;
100     PetscInt        numValues, numPoints = 0;
101     PetscInt       *sperm, *vsize, *voff, v;
102 
103     ierr = DMLabelGetValueIS(label, &valueIS);CHKERRQ(ierr);
104     ierr = ISSort(valueIS);CHKERRQ(ierr);
105     ierr = ISGetLocalSize(valueIS, &numValues);CHKERRQ(ierr);
106     ierr = ISGetIndices(valueIS, &values);CHKERRQ(ierr);
107     ierr = PetscCalloc3(numCells,&sperm,numValues,&vsize,numValues+1,&voff);CHKERRQ(ierr);
108     for (v = 0; v < numValues; ++v) {
109       ierr = DMLabelGetStratumSize(label, values[v], &vsize[v]);CHKERRQ(ierr);
110       if (v < numValues-1) voff[v+2] += vsize[v] + voff[v+1];
111       numPoints += vsize[v];
112     }
113     if (numPoints != numCells) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label only covers %D cells < %D total", numPoints, numCells);
114     for (c = 0; c < numCells; ++c) {
115       const PetscInt oldc = cperm[c];
116       PetscInt       val, vloc;
117 
118       ierr = DMLabelGetValue(label, oldc, &val);CHKERRQ(ierr);
119       if (val == -1) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Cell %D not present in label", oldc);
120       ierr = PetscFindInt(val, numValues, values, &vloc);CHKERRQ(ierr);
121       if (vloc < 0) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Value %D not present label", val);
122       sperm[voff[vloc+1]++] = oldc;
123     }
124     for (v = 0; v < numValues; ++v) {
125       if (voff[v+1] - voff[v] != vsize[v]) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Number of %D values found is %D != %D", values[v], voff[v+1] - voff[v], vsize[v]);
126     }
127     ierr = ISRestoreIndices(valueIS, &values);CHKERRQ(ierr);
128     ierr = ISDestroy(&valueIS);CHKERRQ(ierr);
129     ierr = PetscMemcpy(cperm, sperm, numCells * sizeof(PetscInt));CHKERRQ(ierr);
130     ierr = PetscFree3(sperm, vsize, voff);CHKERRQ(ierr);
131   }
132   /* Construct closure */
133   ierr = DMPlexCreateOrderingClosure_Static(dm, numCells, cperm, &clperm, &invclperm);CHKERRQ(ierr);
134   ierr = PetscFree3(cperm,mask,xls);CHKERRQ(ierr);
135   ierr = PetscFree(clperm);CHKERRQ(ierr);
136   /* Invert permutation */
137   ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
138   ierr = ISCreateGeneral(PetscObjectComm((PetscObject) dm), pEnd-pStart, invclperm, PETSC_OWN_POINTER, perm);CHKERRQ(ierr);
139   PetscFunctionReturn(0);
140 }
141 
142 /*@
143   DMPlexPermute - Reorder the mesh according to the input permutation
144 
145   Collective on DM
146 
147   Input Parameter:
148 + dm - The DMPlex object
149 - perm - The point permutation, perm[old point number] = new point number
150 
151   Output Parameter:
152 . pdm - The permuted DM
153 
154   Level: intermediate
155 
156 .keywords: mesh
157 .seealso: MatPermute()
158 @*/
159 PetscErrorCode DMPlexPermute(DM dm, IS perm, DM *pdm)
160 {
161   DM_Plex       *plex = (DM_Plex *) dm->data, *plexNew;
162   PetscSection   section, sectionNew;
163   PetscInt       dim;
164   PetscErrorCode ierr;
165 
166   PetscFunctionBegin;
167   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
168   PetscValidHeaderSpecific(perm, IS_CLASSID, 2);
169   PetscValidPointer(pdm, 3);
170   ierr = DMCreate(PetscObjectComm((PetscObject) dm), pdm);CHKERRQ(ierr);
171   ierr = DMSetType(*pdm, DMPLEX);CHKERRQ(ierr);
172   ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr);
173   ierr = DMSetDimension(*pdm, dim);CHKERRQ(ierr);
174   ierr = DMGetDefaultSection(dm, &section);CHKERRQ(ierr);
175   if (section) {
176     ierr = PetscSectionPermute(section, perm, &sectionNew);CHKERRQ(ierr);
177     ierr = DMSetDefaultSection(*pdm, sectionNew);CHKERRQ(ierr);
178     ierr = PetscSectionDestroy(&sectionNew);CHKERRQ(ierr);
179   }
180   plexNew = (DM_Plex *) (*pdm)->data;
181   /* Ignore ltogmap, ltogmapb */
182   /* Ignore sf, defaultSF */
183   /* Ignore globalVertexNumbers, globalCellNumbers */
184   /* Remap coordinates */
185   {
186     DM              cdm, cdmNew;
187     PetscSection    csection, csectionNew;
188     Vec             coordinates, coordinatesNew;
189     PetscScalar    *coords, *coordsNew;
190     const PetscInt *pperm;
191     PetscInt        pStart, pEnd, p;
192     const char     *name;
193 
194     ierr = DMGetCoordinateDM(dm, &cdm);CHKERRQ(ierr);
195     ierr = DMGetDefaultSection(cdm, &csection);CHKERRQ(ierr);
196     ierr = PetscSectionPermute(csection, perm, &csectionNew);CHKERRQ(ierr);
197     ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
198     ierr = VecDuplicate(coordinates, &coordinatesNew);CHKERRQ(ierr);
199     ierr = PetscObjectGetName((PetscObject)coordinates,&name);CHKERRQ(ierr);
200     ierr = PetscObjectSetName((PetscObject)coordinatesNew,name);CHKERRQ(ierr);
201     ierr = VecGetArray(coordinates, &coords);CHKERRQ(ierr);
202     ierr = VecGetArray(coordinatesNew, &coordsNew);CHKERRQ(ierr);
203     ierr = PetscSectionGetChart(csectionNew, &pStart, &pEnd);CHKERRQ(ierr);
204     ierr = ISGetIndices(perm, &pperm);CHKERRQ(ierr);
205     for (p = pStart; p < pEnd; ++p) {
206       PetscInt dof, off, offNew, d;
207 
208       ierr = PetscSectionGetDof(csectionNew, p, &dof);CHKERRQ(ierr);
209       ierr = PetscSectionGetOffset(csection, p, &off);CHKERRQ(ierr);
210       ierr = PetscSectionGetOffset(csectionNew, pperm[p], &offNew);CHKERRQ(ierr);
211       for (d = 0; d < dof; ++d) coordsNew[offNew+d] = coords[off+d];
212     }
213     ierr = ISRestoreIndices(perm, &pperm);CHKERRQ(ierr);
214     ierr = VecRestoreArray(coordinates, &coords);CHKERRQ(ierr);
215     ierr = VecRestoreArray(coordinatesNew, &coordsNew);CHKERRQ(ierr);
216     ierr = DMGetCoordinateDM(*pdm, &cdmNew);CHKERRQ(ierr);
217     ierr = DMSetDefaultSection(cdmNew, csectionNew);CHKERRQ(ierr);
218     ierr = DMSetCoordinatesLocal(*pdm, coordinatesNew);CHKERRQ(ierr);
219     ierr = PetscSectionDestroy(&csectionNew);CHKERRQ(ierr);
220     ierr = VecDestroy(&coordinatesNew);CHKERRQ(ierr);
221   }
222   /* Reorder labels */
223   {
224     PetscInt numLabels, l;
225     DMLabel  label, labelNew;
226 
227     ierr = DMGetNumLabels(dm, &numLabels);CHKERRQ(ierr);
228     for (l = numLabels-1; l >= 0; --l) {
229       ierr = DMGetLabelByNum(dm, l, &label);CHKERRQ(ierr);
230       ierr = DMLabelPermute(label, perm, &labelNew);CHKERRQ(ierr);
231       ierr = DMAddLabel(*pdm, labelNew);CHKERRQ(ierr);
232     }
233     if (plex->subpointMap) {ierr = DMLabelPermute(plex->subpointMap, perm, &plexNew->subpointMap);CHKERRQ(ierr);}
234   }
235   /* Reorder topology */
236   {
237     const PetscInt *pperm;
238     PetscInt        maxConeSize, maxSupportSize, n, pStart, pEnd, p;
239 
240     ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
241     plexNew->maxConeSize    = maxConeSize;
242     plexNew->maxSupportSize = maxSupportSize;
243     ierr = PetscSectionDestroy(&plexNew->coneSection);CHKERRQ(ierr);
244     ierr = PetscSectionPermute(plex->coneSection, perm, &plexNew->coneSection);CHKERRQ(ierr);
245     ierr = PetscSectionGetStorageSize(plexNew->coneSection, &n);CHKERRQ(ierr);
246     ierr = PetscMalloc1(n, &plexNew->cones);CHKERRQ(ierr);
247     ierr = PetscMalloc1(n, &plexNew->coneOrientations);CHKERRQ(ierr);
248     ierr = ISGetIndices(perm, &pperm);CHKERRQ(ierr);
249     ierr = PetscSectionGetChart(plex->coneSection, &pStart, &pEnd);CHKERRQ(ierr);
250     for (p = pStart; p < pEnd; ++p) {
251       PetscInt dof, off, offNew, d;
252 
253       ierr = PetscSectionGetDof(plexNew->coneSection, pperm[p], &dof);CHKERRQ(ierr);
254       ierr = PetscSectionGetOffset(plex->coneSection, p, &off);CHKERRQ(ierr);
255       ierr = PetscSectionGetOffset(plexNew->coneSection, pperm[p], &offNew);CHKERRQ(ierr);
256       for (d = 0; d < dof; ++d) {
257         plexNew->cones[offNew+d]            = pperm[plex->cones[off+d]];
258         plexNew->coneOrientations[offNew+d] = plex->coneOrientations[off+d];
259       }
260     }
261     ierr = PetscSectionDestroy(&plexNew->supportSection);CHKERRQ(ierr);
262     ierr = PetscSectionPermute(plex->supportSection, perm, &plexNew->supportSection);CHKERRQ(ierr);
263     ierr = PetscSectionGetStorageSize(plexNew->supportSection, &n);CHKERRQ(ierr);
264     ierr = PetscMalloc1(n, &plexNew->supports);CHKERRQ(ierr);
265     ierr = PetscSectionGetChart(plex->supportSection, &pStart, &pEnd);CHKERRQ(ierr);
266     for (p = pStart; p < pEnd; ++p) {
267       PetscInt dof, off, offNew, d;
268 
269       ierr = PetscSectionGetDof(plexNew->supportSection, pperm[p], &dof);CHKERRQ(ierr);
270       ierr = PetscSectionGetOffset(plex->supportSection, p, &off);CHKERRQ(ierr);
271       ierr = PetscSectionGetOffset(plexNew->supportSection, pperm[p], &offNew);CHKERRQ(ierr);
272       for (d = 0; d < dof; ++d) {
273         plexNew->supports[offNew+d] = pperm[plex->supports[off+d]];
274       }
275     }
276     ierr = ISRestoreIndices(perm, &pperm);CHKERRQ(ierr);
277   }
278   PetscFunctionReturn(0);
279 }
280