xref: /petsc/src/ts/utils/dmplexts.c (revision 4959657a92a4f83dcab1236effce6b892bff335e)
1 #include <petscdmplex.h>          /*I "petscdmplex.h" I*/
2 #include <petsc-private/tsimpl.h>   /*I "petscts.h" I*/
3 #include <petscfv.h>
4 
5 /* TODO Move LS stuff to dtfv.c */
6 #include <petscblaslapack.h>
7 
8 PETSC_STATIC_INLINE void WaxpyD(PetscInt dim, PetscScalar a, const PetscScalar *x, const PetscScalar *y, PetscScalar *w) {PetscInt d; for (d = 0; d < dim; ++d) w[d] = a*x[d] + y[d];}
9 PETSC_STATIC_INLINE PetscScalar DotD(PetscInt dim, const PetscScalar *x, const PetscScalar *y) {PetscScalar sum = 0.0; PetscInt d; for (d = 0; d < dim; ++d) sum += x[d]*y[d]; return sum;}
10 PETSC_STATIC_INLINE PetscReal NormD(PetscInt dim, const PetscScalar *x) {return PetscSqrtReal(PetscAbsScalar(DotD(dim,x,x)));}
11 
12 typedef struct {
13   PetscBool setupGeom; /* Flag for geometry setup */
14   PetscBool setupGrad; /* Flag for gradient calculation setup */
15   Vec       facegeom;  /* FaceGeom struct for each face */
16   Vec       cellgeom;  /* CellGeom struct for each cell */
17   DM        dmGrad;    /* Layout for the gradient data */
18   PetscReal minradius; /* Minimum distance from centroid to face */
19   void    (*riemann)(const PetscReal[], const PetscReal[], const PetscScalar[], const PetscScalar[], PetscScalar[], void *);
20   void     *rhsfunctionlocalctx;
21 } DMTS_Plex;
22 
23 #undef __FUNCT__
24 #define __FUNCT__ "DMTSDestroy_Plex"
25 static PetscErrorCode DMTSDestroy_Plex(DMTS dmts)
26 {
27   DMTS_Plex     *dmplexts = (DMTS_Plex *) dmts->data;
28   PetscErrorCode ierr;
29 
30   PetscFunctionBegin;
31   ierr = DMDestroy(&dmplexts->dmGrad);CHKERRQ(ierr);
32   ierr = VecDestroy(&dmplexts->facegeom);CHKERRQ(ierr);
33   ierr = VecDestroy(&dmplexts->cellgeom);CHKERRQ(ierr);
34   ierr = PetscFree(dmts->data);CHKERRQ(ierr);
35   PetscFunctionReturn(0);
36 }
37 
38 #undef __FUNCT__
39 #define __FUNCT__ "DMTSDuplicate_Plex"
40 static PetscErrorCode DMTSDuplicate_Plex(DMTS olddmts, DMTS dmts)
41 {
42   PetscErrorCode ierr;
43 
44   PetscFunctionBegin;
45   ierr = PetscNewLog(dmts, (DMTS_Plex **) &dmts->data);CHKERRQ(ierr);
46   if (olddmts->data) {ierr = PetscMemcpy(dmts->data, olddmts->data, sizeof(DMTS_Plex));CHKERRQ(ierr);}
47   PetscFunctionReturn(0);
48 }
49 
50 #undef __FUNCT__
51 #define __FUNCT__ "DMPlexTSGetContext"
52 static PetscErrorCode DMPlexTSGetContext(DM dm, DMTS dmts, DMTS_Plex **dmplexts)
53 {
54   PetscErrorCode ierr;
55 
56   PetscFunctionBegin;
57   *dmplexts = NULL;
58   if (!dmts->data) {
59     ierr = PetscNewLog(dm, (DMTS_Plex **) &dmts->data);CHKERRQ(ierr);
60     dmts->ops->destroy   = DMTSDestroy_Plex;
61     dmts->ops->duplicate = DMTSDuplicate_Plex;
62   }
63   *dmplexts = (DMTS_Plex *) dmts->data;
64   PetscFunctionReturn(0);
65 }
66 
67 #undef __FUNCT__
68 #define __FUNCT__ "DMPlexTSSetupGeometry"
69 static PetscErrorCode DMPlexTSSetupGeometry(DM dm, PetscFV fvm, DMTS_Plex *dmplexts)
70 {
71   DM             dmFace, dmCell;
72   DMLabel        ghostLabel;
73   PetscSection   sectionFace, sectionCell;
74   PetscSection   coordSection;
75   Vec            coordinates;
76   PetscReal      minradius;
77   PetscScalar   *fgeom, *cgeom;
78   PetscInt       dim, cStart, cEnd, cEndInterior, c, fStart, fEnd, f;
79   PetscErrorCode ierr;
80 
81   PetscFunctionBegin;
82   if (dmplexts->setupGeom) PetscFunctionReturn(0);
83   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
84   ierr = DMGetCoordinateSection(dm, &coordSection);CHKERRQ(ierr);
85   ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
86   /* Make cell centroids and volumes */
87   ierr = DMClone(dm, &dmCell);CHKERRQ(ierr);
88   ierr = DMSetCoordinateSection(dmCell, coordSection);CHKERRQ(ierr);
89   ierr = DMSetCoordinatesLocal(dmCell, coordinates);CHKERRQ(ierr);
90   ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &sectionCell);CHKERRQ(ierr);
91   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
92   ierr = DMPlexGetHybridBounds(dm, &cEndInterior, NULL, NULL, NULL);CHKERRQ(ierr);
93   ierr = PetscSectionSetChart(sectionCell, cStart, cEnd);CHKERRQ(ierr);
94   for (c = cStart; c < cEnd; ++c) {ierr = PetscSectionSetDof(sectionCell, c, sizeof(CellGeom)/sizeof(PetscScalar));CHKERRQ(ierr);}
95   ierr = PetscSectionSetUp(sectionCell);CHKERRQ(ierr);
96   ierr = DMSetDefaultSection(dmCell, sectionCell);CHKERRQ(ierr);
97   ierr = PetscSectionDestroy(&sectionCell);CHKERRQ(ierr);
98   ierr = DMCreateLocalVector(dmCell, &dmplexts->cellgeom);CHKERRQ(ierr);
99   ierr = VecGetArray(dmplexts->cellgeom, &cgeom);CHKERRQ(ierr);
100   for (c = cStart; c < cEndInterior; ++c) {
101     CellGeom *cg;
102 
103     ierr = DMPlexPointLocalRef(dmCell, c, cgeom, &cg);CHKERRQ(ierr);
104     ierr = PetscMemzero(cg, sizeof(*cg));CHKERRQ(ierr);
105     ierr = DMPlexComputeCellGeometryFVM(dmCell, c, &cg->volume, cg->centroid, NULL);CHKERRQ(ierr);
106   }
107   /* Compute face normals and minimum cell radius */
108   ierr = DMClone(dm, &dmFace);CHKERRQ(ierr);
109   ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &sectionFace);CHKERRQ(ierr);
110   ierr = DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd);CHKERRQ(ierr);
111   ierr = PetscSectionSetChart(sectionFace, fStart, fEnd);CHKERRQ(ierr);
112   for (f = fStart; f < fEnd; ++f) {ierr = PetscSectionSetDof(sectionFace, f, sizeof(FaceGeom)/sizeof(PetscScalar));CHKERRQ(ierr);}
113   ierr = PetscSectionSetUp(sectionFace);CHKERRQ(ierr);
114   ierr = DMSetDefaultSection(dmFace, sectionFace);CHKERRQ(ierr);
115   ierr = PetscSectionDestroy(&sectionFace);CHKERRQ(ierr);
116   ierr = DMCreateLocalVector(dmFace, &dmplexts->facegeom);CHKERRQ(ierr);
117   ierr = VecGetArray(dmplexts->facegeom, &fgeom);CHKERRQ(ierr);
118   ierr = DMPlexGetLabel(dm, "ghost", &ghostLabel);CHKERRQ(ierr);
119   minradius = PETSC_MAX_REAL;
120   for (f = fStart; f < fEnd; ++f) {
121     FaceGeom *fg;
122     PetscReal area;
123     PetscInt  ghost, d;
124 
125     ierr = DMLabelGetValue(ghostLabel, f, &ghost);CHKERRQ(ierr);
126     if (ghost >= 0) continue;
127     ierr = DMPlexPointLocalRef(dmFace, f, fgeom, &fg);CHKERRQ(ierr);
128     ierr = DMPlexComputeCellGeometryFVM(dm, f, &area, fg->centroid, fg->normal);CHKERRQ(ierr);
129     for (d = 0; d < dim; ++d) fg->normal[d] *= area;
130     /* Flip face orientation if necessary to match ordering in support, and Update minimum radius */
131     {
132       CellGeom       *cL, *cR;
133       const PetscInt *cells;
134       PetscReal      *lcentroid, *rcentroid;
135       PetscScalar     v[3];
136 
137       ierr = DMPlexGetSupport(dm, f, &cells);CHKERRQ(ierr);
138       ierr = DMPlexPointLocalRead(dmCell, cells[0], cgeom, &cL);CHKERRQ(ierr);
139       ierr = DMPlexPointLocalRead(dmCell, cells[1], cgeom, &cR);CHKERRQ(ierr);
140       lcentroid = cells[0] >= cEndInterior ? fg->centroid : cL->centroid;
141       rcentroid = cells[1] >= cEndInterior ? fg->centroid : cR->centroid;
142       WaxpyD(dim, -1, lcentroid, rcentroid, v);
143       if (DotD(dim, fg->normal, v) < 0) {
144         for (d = 0; d < dim; ++d) fg->normal[d] = -fg->normal[d];
145       }
146       if (DotD(dim, fg->normal, v) <= 0) {
147         if (dim == 2) SETERRQ5(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Direction for face %d could not be fixed, normal (%g,%g) v (%g,%g)", f, fg->normal[0], fg->normal[1], v[0], v[1]);
148         if (dim == 3) SETERRQ7(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Direction for face %d could not be fixed, normal (%g,%g,%g) v (%g,%g,%g)", f, fg->normal[0], fg->normal[1], fg->normal[2], v[0], v[1], v[2]);
149         SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Direction for face %d could not be fixed", f);
150       }
151       if (cells[0] < cEndInterior) {
152         WaxpyD(dim, -1, fg->centroid, cL->centroid, v);
153         minradius = PetscMin(minradius, NormD(dim, v));
154       }
155       if (cells[1] < cEndInterior) {
156         WaxpyD(dim, -1, fg->centroid, cR->centroid, v);
157         minradius = PetscMin(minradius, NormD(dim, v));
158       }
159     }
160   }
161   ierr = MPI_Allreduce(&minradius, &dmplexts->minradius, 1, MPIU_SCALAR, MPI_MIN, PetscObjectComm((PetscObject)dm));CHKERRQ(ierr);
162   /* Compute centroids of ghost cells */
163   for (c = cEndInterior; c < cEnd; ++c) {
164     FaceGeom       *fg;
165     const PetscInt *cone,    *support;
166     PetscInt        coneSize, supportSize, s;
167 
168     ierr = DMPlexGetConeSize(dmCell, c, &coneSize);CHKERRQ(ierr);
169     if (coneSize != 1) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Ghost cell %d has cone size %d != 1", c, coneSize);
170     ierr = DMPlexGetCone(dmCell, c, &cone);CHKERRQ(ierr);
171     ierr = DMPlexGetSupportSize(dmCell, cone[0], &supportSize);CHKERRQ(ierr);
172     if (supportSize != 2) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %d has support size %d != 1", cone[0], supportSize);
173     ierr = DMPlexGetSupport(dmCell, cone[0], &support);CHKERRQ(ierr);
174     ierr = DMPlexPointLocalRef(dmFace, cone[0], fgeom, &fg);CHKERRQ(ierr);
175     for (s = 0; s < 2; ++s) {
176       /* Reflect ghost centroid across plane of face */
177       if (support[s] == c) {
178         const CellGeom *ci;
179         CellGeom       *cg;
180         PetscScalar     c2f[3], a;
181 
182         ierr = DMPlexPointLocalRead(dmCell, support[(s+1)%2], cgeom, &ci);CHKERRQ(ierr);
183         WaxpyD(dim, -1, ci->centroid, fg->centroid, c2f); /* cell to face centroid */
184         a    = DotD(dim, c2f, fg->normal)/DotD(dim, fg->normal, fg->normal);
185         ierr = DMPlexPointLocalRef(dmCell, support[s], cgeom, &cg);CHKERRQ(ierr);
186         WaxpyD(dim, 2*a, fg->normal, ci->centroid, cg->centroid);
187         cg->volume = ci->volume;
188       }
189     }
190   }
191   ierr = VecRestoreArray(dmplexts->facegeom, &fgeom);CHKERRQ(ierr);
192   ierr = VecRestoreArray(dmplexts->cellgeom, &cgeom);CHKERRQ(ierr);
193   ierr = DMDestroy(&dmCell);CHKERRQ(ierr);
194   ierr = DMDestroy(&dmFace);CHKERRQ(ierr);
195   dmplexts->setupGeom = PETSC_TRUE;
196   PetscFunctionReturn(0);
197 }
198 
199 #undef __FUNCT__
200 #define __FUNCT__ "PseudoInverse"
201 /* Overwrites A. Can only handle full-rank problems with m>=n */
202 static PetscErrorCode PseudoInverse(PetscInt m,PetscInt mstride,PetscInt n,PetscScalar *A,PetscScalar *Ainv,PetscScalar *tau,PetscInt worksize,PetscScalar *work)
203 {
204   PetscBool      debug = PETSC_FALSE;
205   PetscErrorCode ierr;
206   PetscBLASInt   M,N,K,lda,ldb,ldwork,info;
207   PetscScalar    *R,*Q,*Aback,Alpha;
208 
209   PetscFunctionBegin;
210   if (debug) {
211     ierr = PetscMalloc1(m*n,&Aback);CHKERRQ(ierr);
212     ierr = PetscMemcpy(Aback,A,m*n*sizeof(PetscScalar));CHKERRQ(ierr);
213   }
214 
215   ierr = PetscBLASIntCast(m,&M);CHKERRQ(ierr);
216   ierr = PetscBLASIntCast(n,&N);CHKERRQ(ierr);
217   ierr = PetscBLASIntCast(mstride,&lda);CHKERRQ(ierr);
218   ierr = PetscBLASIntCast(worksize,&ldwork);CHKERRQ(ierr);
219   ierr = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr);
220   LAPACKgeqrf_(&M,&N,A,&lda,tau,work,&ldwork,&info);
221   ierr = PetscFPTrapPop();CHKERRQ(ierr);
222   if (info) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"xGEQRF error");
223   R = A; /* Upper triangular part of A now contains R, the rest contains the elementary reflectors */
224 
225   /* Extract an explicit representation of Q */
226   Q    = Ainv;
227   ierr = PetscMemcpy(Q,A,mstride*n*sizeof(PetscScalar));CHKERRQ(ierr);
228   K    = N;                     /* full rank */
229   LAPACKungqr_(&M,&N,&K,Q,&lda,tau,work,&ldwork,&info);
230   if (info) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"xORGQR/xUNGQR error");
231 
232   /* Compute A^{-T} = (R^{-1} Q^T)^T = Q R^{-T} */
233   Alpha = 1.0;
234   ldb   = lda;
235   BLAStrsm_("Right","Upper","ConjugateTranspose","NotUnitTriangular",&M,&N,&Alpha,R,&lda,Q,&ldb);
236   /* Ainv is Q, overwritten with inverse */
237 
238   if (debug) {                      /* Check that pseudo-inverse worked */
239     PetscScalar Beta = 0.0;
240     PetscInt    ldc;
241     K   = N;
242     ldc = N;
243     BLASgemm_("ConjugateTranspose","Normal",&N,&K,&M,&Alpha,Ainv,&lda,Aback,&ldb,&Beta,work,&ldc);
244     ierr = PetscScalarView(n*n,work,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
245     ierr = PetscFree(Aback);CHKERRQ(ierr);
246   }
247   PetscFunctionReturn(0);
248 }
249 
250 #undef __FUNCT__
251 #define __FUNCT__ "PseudoInverseGetWorkRequired"
252 static PetscErrorCode PseudoInverseGetWorkRequired(PetscInt maxFaces, PetscInt *work)
253 {
254   PetscInt m,n,nrhs,minwork;
255 
256   PetscFunctionBegin;
257   m       = maxFaces;
258   n       = 3; /* spatial dimension */
259   nrhs    = maxFaces;
260   minwork = 3*PetscMin(m,n) + PetscMax(2*PetscMin(m,n), PetscMax(PetscMax(m,n), nrhs)); /* required by LAPACK */
261   *work   = 5*minwork;          /* We can afford to be extra generous */
262   PetscFunctionReturn(0);
263 }
264 
265 #undef __FUNCT__
266 #define __FUNCT__ "PseudoInverseSVD"
267 /* Overwrites A. Can handle degenerate problems and m<n. */
268 static PetscErrorCode PseudoInverseSVD(PetscInt m,PetscInt mstride,PetscInt n,PetscScalar *A,PetscScalar *Ainv,PetscScalar *tau,PetscInt worksize,PetscScalar *work)
269 {
270   PetscBool      debug = PETSC_FALSE;
271   PetscErrorCode ierr;
272   PetscInt       i,j,maxmn;
273   PetscBLASInt   M,N,nrhs,lda,ldb,irank,ldwork,info;
274   PetscScalar    rcond,*tmpwork,*Brhs,*Aback;
275 
276   PetscFunctionBegin;
277   if (debug) {
278     ierr = PetscMalloc1(m*n,&Aback);CHKERRQ(ierr);
279     ierr = PetscMemcpy(Aback,A,m*n*sizeof(PetscScalar));CHKERRQ(ierr);
280   }
281 
282   /* initialize to identity */
283   tmpwork = Ainv;
284   Brhs = work;
285   maxmn = PetscMax(m,n);
286   for (j=0; j<maxmn; j++) {
287     for (i=0; i<maxmn; i++) Brhs[i + j*maxmn] = 1.0*(i == j);
288   }
289 
290   ierr  = PetscBLASIntCast(m,&M);CHKERRQ(ierr);
291   ierr  = PetscBLASIntCast(n,&N);CHKERRQ(ierr);
292   nrhs  = M;
293   ierr  = PetscBLASIntCast(mstride,&lda);CHKERRQ(ierr);
294   ierr  = PetscBLASIntCast(maxmn,&ldb);CHKERRQ(ierr);
295   ierr  = PetscBLASIntCast(worksize,&ldwork);CHKERRQ(ierr);
296   rcond = -1;
297   ierr  = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr);
298   LAPACKgelss_(&M,&N,&nrhs,A,&lda,Brhs,&ldb,tau,&rcond,&irank,tmpwork,&ldwork,&info);
299   ierr = PetscFPTrapPop();CHKERRQ(ierr);
300   if (info) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"xGELSS error");
301   /* The following check should be turned into a diagnostic as soon as someone wants to do this intentionally */
302   if (irank < PetscMin(M,N)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Rank deficient least squares fit, indicates an isolated cell with two colinear points");
303 
304   /* Brhs shaped (M,nrhs) column-major coldim=mstride was overwritten by Ainv shaped (N,nrhs) column-major coldim=maxmn.
305    * Here we transpose to (N,nrhs) row-major rowdim=mstride. */
306   for (i=0; i<n; i++) {
307     for (j=0; j<nrhs; j++) Ainv[i*mstride+j] = Brhs[i + j*maxmn];
308   }
309   PetscFunctionReturn(0);
310 }
311 
312 #undef __FUNCT__
313 #define __FUNCT__ "BuildLeastSquares"
314 /* Build least squares gradient reconstruction operators */
315 static PetscErrorCode BuildLeastSquares(DM dm,PetscInt cEndInterior,DM dmFace,PetscScalar *fgeom,DM dmCell,PetscScalar *cgeom)
316 {
317   DMLabel        ghostLabel, bdLabel;
318   PetscScalar   *B,*Binv,*work,*tau,**gref;
319   PetscInt       dim, c,cStart,cEnd,maxNumFaces,worksize;
320   PetscBool      useSVD = PETSC_TRUE;
321   PetscErrorCode ierr;
322 
323   PetscFunctionBegin;
324   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
325   ierr = DMPlexGetHeightStratum(dm,0,&cStart,&cEnd);CHKERRQ(ierr);
326   ierr = DMPlexGetMaxSizes(dm,&maxNumFaces,NULL);CHKERRQ(ierr);
327   ierr = DMPlexGetLabel(dm, "ghost", &ghostLabel);CHKERRQ(ierr);
328   /* TODO: Get this from the BC */
329   ierr = DMPlexGetLabel(dm, "Face Sets", &bdLabel);CHKERRQ(ierr);
330   ierr = PseudoInverseGetWorkRequired(maxNumFaces,&worksize);CHKERRQ(ierr);
331   ierr = PetscMalloc5(maxNumFaces*dim,&B,worksize,&Binv,worksize,&work,maxNumFaces,&tau,maxNumFaces,&gref);CHKERRQ(ierr);
332   for (c=cStart; c<cEndInterior; c++) {
333     const PetscInt *faces;
334     PetscInt       numFaces,usedFaces,f,i,j;
335     const CellGeom *cg;
336     PetscInt        ghost, boundary;
337     ierr = DMPlexGetConeSize(dm,c,&numFaces);CHKERRQ(ierr);
338     if (numFaces < dim) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Cell %D has only %D faces, not enough for gradient reconstruction",c,numFaces);
339     ierr = DMPlexGetCone(dm,c,&faces);CHKERRQ(ierr);
340     ierr = DMPlexPointLocalRead(dmCell,c,cgeom,&cg);CHKERRQ(ierr);
341     for (f=0,usedFaces=0; f<numFaces; f++) {
342       const PetscInt *fcells;
343       PetscInt       ncell,side;
344       FaceGeom       *fg;
345       const CellGeom *cg1;
346 
347       ierr = DMLabelGetValue(ghostLabel, faces[f], &ghost);CHKERRQ(ierr);
348       ierr = DMLabelGetValue(bdLabel, faces[f], &boundary);CHKERRQ(ierr);
349       if ((ghost >= 0) || (boundary >= 0)) continue;
350       ierr  = DMPlexGetSupport(dm,faces[f],&fcells);CHKERRQ(ierr);
351       side  = (c != fcells[0]); /* c is on left=0 or right=1 of face */
352       ncell = fcells[!side];   /* the neighbor */
353       ierr  = DMPlexPointLocalRef(dmFace,faces[f],fgeom,&fg);CHKERRQ(ierr);
354       ierr  = DMPlexPointLocalRead(dmCell,ncell,cgeom,&cg1);CHKERRQ(ierr);
355       for (j=0; j<dim; j++) B[j*numFaces+usedFaces] = cg1->centroid[j] - cg->centroid[j];
356       gref[usedFaces++] = fg->grad[side];  /* Gradient reconstruction term will go here */
357     }
358     if (!usedFaces) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Mesh contains isolated cell (no neighbors). Is it intentional?");
359     /* Overwrites B with garbage, returns Binv in row-major format */
360     if (useSVD) {
361       ierr = PseudoInverseSVD(usedFaces,numFaces,dim,B,Binv,tau,worksize,work);CHKERRQ(ierr);
362     } else {
363       ierr = PseudoInverse(usedFaces,numFaces,dim,B,Binv,tau,worksize,work);CHKERRQ(ierr);
364     }
365     for (f=0,i=0; f<numFaces; f++) {
366       ierr = DMLabelGetValue(ghostLabel, faces[f], &ghost);CHKERRQ(ierr);
367       ierr = DMLabelGetValue(bdLabel, faces[f], &boundary);CHKERRQ(ierr);
368       if ((ghost >= 0) || (boundary >= 0)) continue;
369       for (j=0; j<dim; j++) gref[i][j] = Binv[j*numFaces+i];
370       i++;
371     }
372 
373     if (0) {
374       PetscReal grad[2] = {0,0};
375       for (f=0; f<numFaces; f++) {
376         const PetscInt *fcells;
377         const CellGeom *cg1;
378         const FaceGeom *fg;
379         ierr = DMPlexGetSupport(dm,faces[f],&fcells);CHKERRQ(ierr);
380         ierr = DMPlexPointLocalRead(dmFace,faces[f],fgeom,&fg);CHKERRQ(ierr);
381         for (i=0; i<2; i++) {
382           if (fcells[i] == c) continue;
383           ierr = DMPlexPointLocalRead(dmCell,fcells[i],cgeom,&cg1);CHKERRQ(ierr);
384           PetscScalar du = cg1->centroid[0] + 3*cg1->centroid[1] - (cg->centroid[0] + 3*cg->centroid[1]);
385           grad[0] += fg->grad[!i][0] * du;
386           grad[1] += fg->grad[!i][1] * du;
387         }
388       }
389       printf("cell[%d] grad (%g,%g)\n",c,grad[0],grad[1]);
390     }
391   }
392   ierr = PetscFree5(B,Binv,work,tau,gref);CHKERRQ(ierr);
393   PetscFunctionReturn(0);
394 }
395 
396 #undef __FUNCT__
397 #define __FUNCT__ "DMPlexTSSetupGradient"
398 static PetscErrorCode DMPlexTSSetupGradient(DM dm, PetscFV fvm, DMTS_Plex *dmplexts)
399 {
400   DM             dmFace, dmCell;
401   PetscScalar   *fgeom, *cgeom;
402   PetscSection   sectionGrad;
403   PetscInt       dim, pdim, cStart, cEnd, cEndInterior, c;
404   PetscErrorCode ierr;
405 
406   PetscFunctionBegin;
407   if (dmplexts->setupGrad) PetscFunctionReturn(0);
408   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
409   ierr = PetscFVGetNumComponents(fvm, &pdim);CHKERRQ(ierr);
410   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
411   ierr = DMPlexGetHybridBounds(dm, &cEndInterior, NULL, NULL, NULL);CHKERRQ(ierr);
412   /* Construct the interpolant corresponding to each face from the leat-square solution over the cell neighborhood */
413   ierr = VecGetDM(dmplexts->facegeom, &dmFace);CHKERRQ(ierr);
414   ierr = VecGetDM(dmplexts->cellgeom, &dmCell);CHKERRQ(ierr);
415   ierr = VecGetArray(dmplexts->facegeom, &fgeom);CHKERRQ(ierr);
416   ierr = VecGetArray(dmplexts->cellgeom, &cgeom);CHKERRQ(ierr);
417   ierr = BuildLeastSquares(dm, cEndInterior, dmFace, fgeom, dmCell, cgeom);CHKERRQ(ierr);
418   ierr = VecRestoreArray(dmplexts->facegeom, &fgeom);CHKERRQ(ierr);
419   ierr = VecRestoreArray(dmplexts->cellgeom, &cgeom);CHKERRQ(ierr);
420   /* Create storage for gradients */
421   ierr = DMClone(dm, &dmplexts->dmGrad);CHKERRQ(ierr);
422   ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &sectionGrad);CHKERRQ(ierr);
423   ierr = PetscSectionSetChart(sectionGrad, cStart, cEnd);CHKERRQ(ierr);
424   for (c = cStart; c < cEnd; ++c) {ierr = PetscSectionSetDof(sectionGrad, c, pdim*dim);CHKERRQ(ierr);}
425   ierr = PetscSectionSetUp(sectionGrad);CHKERRQ(ierr);
426   ierr = DMSetDefaultSection(dmplexts->dmGrad, sectionGrad);CHKERRQ(ierr);
427   ierr = PetscSectionDestroy(&sectionGrad);CHKERRQ(ierr);
428   dmplexts->setupGrad = PETSC_TRUE;
429   PetscFunctionReturn(0);
430 }
431 
432 #undef __FUNCT__
433 #define __FUNCT__ "DMPlexInsertBoundaryValuesFVM_Static"
434 static PetscErrorCode DMPlexInsertBoundaryValuesFVM_Static(DM dm, PetscFV fvm, PetscReal time, Vec locX, Vec Grad, DMTS_Plex *dmplexts)
435 {
436   Vec                faceGeometry = dmplexts->facegeom;
437   Vec                cellGeometry = dmplexts->cellgeom;
438   DM                 dmFace, dmCell;
439   DMLabel            label;
440   const PetscScalar *facegeom, *cellgeom, *grad;
441   PetscScalar       *x, *fx;
442   PetscInt           numBd, b, dim, pdim, fStart, fEnd;
443   PetscErrorCode     ierr;
444 
445   PetscFunctionBegin;
446   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
447   ierr = PetscFVGetNumComponents(fvm, &pdim);CHKERRQ(ierr);
448   /* TODO Get from BC data */
449   ierr = DMPlexGetLabel(dm, "Face Sets", &label);CHKERRQ(ierr);
450   ierr = DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd);CHKERRQ(ierr);
451   ierr = DMPlexGetNumBoundary(dm, &numBd);CHKERRQ(ierr);
452   if (Grad) {
453     ierr = VecGetDM(cellGeometry, &dmCell);CHKERRQ(ierr);
454     ierr = VecGetArrayRead(cellGeometry, &cellgeom);CHKERRQ(ierr);
455     ierr = DMGetWorkArray(dm, pdim, PETSC_SCALAR, &fx);CHKERRQ(ierr);
456     ierr = VecGetArrayRead(Grad, &grad);CHKERRQ(ierr);
457   }
458   ierr = VecGetDM(faceGeometry, &dmFace);CHKERRQ(ierr);
459   ierr = VecGetArrayRead(faceGeometry, &facegeom);CHKERRQ(ierr);
460   ierr = VecGetArray(locX, &x);CHKERRQ(ierr);
461   for (b = 0; b < numBd; ++b) {
462     PetscErrorCode (*func)(PetscReal,const PetscScalar*,const PetscScalar*,const PetscScalar*,PetscScalar*,void*);
463     const PetscInt  *ids;
464     PetscInt         numids, i;
465     void            *ctx;
466 
467     ierr = DMPlexGetBoundary(dm, b, NULL, NULL, NULL, (void (**)()) &func, &numids, &ids, &ctx);CHKERRQ(ierr);
468     for (i = 0; i < numids; ++i) {
469       IS              faceIS;
470       const PetscInt *faces;
471       PetscInt        numFaces, f;
472 
473       ierr = DMLabelGetStratumIS(label, ids[i], &faceIS);CHKERRQ(ierr);
474       if (!faceIS) continue; /* No points with that id on this process */
475       ierr = ISGetLocalSize(faceIS, &numFaces);CHKERRQ(ierr);
476       ierr = ISGetIndices(faceIS, &faces);CHKERRQ(ierr);
477       for (f = 0; f < numFaces; ++f) {
478         const PetscInt     face = faces[f], *cells;
479         const FaceGeom    *fg;
480 
481         if ((face < fStart) || (face >= fEnd)) continue; /* Refinement adds non-faces to labels */
482         ierr = DMPlexPointLocalRead(dmFace, face, facegeom, &fg);CHKERRQ(ierr);
483         ierr = DMPlexGetSupport(dm, face, &cells);CHKERRQ(ierr);
484         if (Grad) {
485           const CellGeom    *cg;
486           const PetscScalar *cx, *cgrad;
487           PetscScalar       *xG, dx[3];
488           PetscInt           d;
489 
490           ierr = DMPlexPointLocalRead(dmCell, cells[0], cellgeom, &cg);CHKERRQ(ierr);
491           ierr = DMPlexPointLocalRead(dm, cells[0], x, &cx);CHKERRQ(ierr);
492           ierr = DMPlexPointLocalRead(dmplexts->dmGrad, cells[0], grad, &cgrad);CHKERRQ(ierr);
493           ierr = DMPlexPointLocalRef(dm, cells[1], x, &xG);CHKERRQ(ierr);
494           WaxpyD(dim, -1, cg->centroid, fg->centroid, dx);
495           for (d = 0; d < pdim; ++d) fx[d] = cx[d] + DotD(dim, &cgrad[d*dim], dx);
496           ierr = (*func)(time, fg->centroid, fg->normal, fx, xG, ctx);CHKERRQ(ierr);
497         } else {
498           const PetscScalar *xI;
499           PetscScalar       *xG;
500 
501           ierr = DMPlexPointLocalRead(dm, cells[0], x, &xI);CHKERRQ(ierr);
502           ierr = DMPlexPointLocalRef(dm, cells[1], x, &xG);CHKERRQ(ierr);
503           ierr = (*func)(time, fg->centroid, fg->normal, xI, xG, ctx);CHKERRQ(ierr);
504         }
505       }
506       ierr = ISRestoreIndices(faceIS, &faces);CHKERRQ(ierr);
507       ierr = ISDestroy(&faceIS);CHKERRQ(ierr);
508     }
509   }
510   ierr = VecRestoreArrayRead(faceGeometry, &facegeom);CHKERRQ(ierr);
511   ierr = VecRestoreArray(locX, &x);CHKERRQ(ierr);
512   if (Grad) {
513     ierr = DMRestoreWorkArray(dm, pdim, PETSC_SCALAR, &fx);CHKERRQ(ierr);
514     ierr = VecRestoreArrayRead(Grad, &grad);CHKERRQ(ierr);
515   }
516   PetscFunctionReturn(0);
517 }
518 
519 #undef __FUNCT__
520 #define __FUNCT__ "TSComputeRHSFunction_DMPlex"
521 static PetscErrorCode TSComputeRHSFunction_DMPlex(TS ts, PetscReal time, Vec X, Vec F, void *ctx)
522 {
523   DM                 dm;
524   DMTS_Plex         *dmplexts = (DMTS_Plex *) ctx;
525   void             (*riemann)(const PetscReal[], const PetscReal[], const PetscScalar[], const PetscScalar[], PetscScalar[], void *) = dmplexts->riemann;
526   PetscFV            fvm;
527   PetscLimiter       lim;
528   Vec                faceGeometry = dmplexts->facegeom;
529   Vec                cellGeometry = dmplexts->cellgeom;
530   Vec                Grad = NULL, locGrad, locX;
531   DM                 dmFace, dmCell;
532   DMLabel            ghostLabel, bdLabel;
533   PetscCellGeometry  fgeom, cgeom;
534   const PetscScalar *facegeom, *cellgeom, *x, *lgrad;
535   PetscScalar       *grad, *f, *uL, *uR, *fluxL, *fluxR;
536   PetscReal         *centroid, *normal, *vol, *cellPhi;
537   PetscBool          computeGradients;
538   PetscInt           Nf, dim, pdim, fStart, fEnd, numFaces = 0, face, iface, cell, cStart, cEnd, cEndInterior;
539   PetscErrorCode     ierr;
540 
541   PetscFunctionBegin;
542   PetscValidHeaderSpecific(ts,TS_CLASSID,1);
543   PetscValidHeaderSpecific(X,VEC_CLASSID,3);
544   PetscValidHeaderSpecific(F,VEC_CLASSID,5);
545   ierr = TSGetDM(ts, &dm);CHKERRQ(ierr);
546   ierr = DMGetLocalVector(dm, &locX);CHKERRQ(ierr);
547   ierr = VecZeroEntries(locX);CHKERRQ(ierr);
548   ierr = DMGlobalToLocalBegin(dm, X, INSERT_VALUES, locX);CHKERRQ(ierr);
549   ierr = DMGlobalToLocalEnd(dm, X, INSERT_VALUES, locX);CHKERRQ(ierr);
550   ierr = VecZeroEntries(F);CHKERRQ(ierr);
551   ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
552   ierr = DMGetNumFields(dm, &Nf);CHKERRQ(ierr);
553   ierr = DMGetField(dm, 0, (PetscObject *) &fvm);CHKERRQ(ierr);
554   ierr = PetscFVGetLimiter(fvm, &lim);CHKERRQ(ierr);
555   ierr = PetscFVGetNumComponents(fvm, &pdim);CHKERRQ(ierr);
556   ierr = PetscFVGetComputeGradients(fvm, &computeGradients);CHKERRQ(ierr);
557   if (computeGradients) {
558     ierr = DMGetGlobalVector(dmplexts->dmGrad, &Grad);CHKERRQ(ierr);
559     ierr = VecZeroEntries(Grad);CHKERRQ(ierr);
560     ierr = VecGetArray(Grad, &grad);CHKERRQ(ierr);
561   }
562   ierr = DMPlexGetLabel(dm, "ghost", &ghostLabel);CHKERRQ(ierr);
563   /* TODO: Get this from the BC */
564   ierr = DMPlexGetLabel(dm, "Face Sets", &bdLabel);CHKERRQ(ierr);
565   ierr = DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd);CHKERRQ(ierr);
566   ierr = VecGetDM(faceGeometry, &dmFace);CHKERRQ(ierr);
567   ierr = VecGetDM(cellGeometry, &dmCell);CHKERRQ(ierr);
568   ierr = VecGetArrayRead(faceGeometry, &facegeom);CHKERRQ(ierr);
569   ierr = VecGetArrayRead(cellGeometry, &cellgeom);CHKERRQ(ierr);
570   ierr = VecGetArrayRead(locX, &x);CHKERRQ(ierr);
571   /* Count faces and reconstruct gradients */
572   for (face = fStart; face < fEnd; ++face) {
573     const PetscInt    *cells;
574     const FaceGeom    *fg;
575     const PetscScalar *cx[2];
576     PetscScalar       *cgrad[2];
577     PetscInt           ghost, boundary, c, pd, d;
578 
579     ierr = DMLabelGetValue(ghostLabel, face, &ghost);CHKERRQ(ierr);
580     if (ghost >= 0) continue;
581     ++numFaces;
582     if (!computeGradients) continue;
583     ierr = DMLabelGetValue(bdLabel, face, &boundary);CHKERRQ(ierr);
584     if (boundary >= 0) continue;
585     ierr = DMPlexGetSupport(dm, face, &cells);CHKERRQ(ierr);
586     ierr = DMPlexPointLocalRead(dmFace, face, facegeom, &fg);CHKERRQ(ierr);
587     for (c = 0; c < 2; ++c) {
588       ierr = DMPlexPointLocalRead(dm, cells[c], x, &cx[c]);CHKERRQ(ierr);
589       ierr = DMPlexPointGlobalRef(dmplexts->dmGrad, cells[c], grad, &cgrad[c]);CHKERRQ(ierr);
590     }
591     for (pd = 0; pd < pdim; ++pd) {
592       PetscScalar delta = cx[1][pd] - cx[0][pd];
593 
594       for (d = 0; d < dim; ++d) {
595         if (cgrad[0]) cgrad[0][pd*dim+d] += fg->grad[0][d] * delta;
596         if (cgrad[1]) cgrad[1][pd*dim+d] -= fg->grad[1][d] * delta;
597       }
598     }
599   }
600   /* Limit interior gradients (using cell-based loop because it generalizes better to vector limiters) */
601   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
602   ierr = DMPlexGetHybridBounds(dm, &cEndInterior, NULL, NULL, NULL);CHKERRQ(ierr);
603   ierr = DMGetWorkArray(dm, pdim, PETSC_REAL, &cellPhi);CHKERRQ(ierr);
604   for (cell = computeGradients && lim ? cStart : cEnd; cell < cEndInterior; ++cell) {
605     const PetscInt    *faces;
606     const PetscScalar *cx;
607     const CellGeom    *cg;
608     PetscScalar       *cgrad;
609     PetscInt           coneSize, f, pd, d;
610 
611     ierr = DMPlexGetConeSize(dm, cell, &coneSize);CHKERRQ(ierr);
612     ierr = DMPlexGetCone(dm, cell, &faces);CHKERRQ(ierr);
613     ierr = DMPlexPointLocalRead(dm, cell, x, &cx);CHKERRQ(ierr);
614     ierr = DMPlexPointLocalRead(dmCell, cell, cellgeom, &cg);CHKERRQ(ierr);
615     ierr = DMPlexPointGlobalRef(dmplexts->dmGrad, cell, grad, &cgrad);CHKERRQ(ierr);
616     if (!cgrad) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Supposedly ghost cell %d, but this should be impossible", cell);
617     /* Limiter will be minimum value over all neighbors */
618     for (d = 0; d < pdim; ++d) cellPhi[d] = PETSC_MAX_REAL;
619     for (f = 0; f < coneSize; ++f) {
620       const PetscScalar *ncx;
621       const CellGeom    *ncg;
622       const PetscInt    *fcells;
623       PetscInt           face = faces[f], ncell;
624       PetscScalar        v[3];
625       PetscInt           ghost, boundary;
626 
627       ierr = DMLabelGetValue(ghostLabel, face, &ghost);CHKERRQ(ierr);
628       ierr = DMLabelGetValue(bdLabel, face, &boundary);CHKERRQ(ierr);
629       if ((ghost >= 0) || (boundary >= 0)) continue;
630       ierr  = DMPlexGetSupport(dm, face, &fcells);CHKERRQ(ierr);
631       ncell = cell == fcells[0] ? fcells[1] : fcells[0];
632       ierr  = DMPlexPointLocalRead(dm, ncell, x, &ncx);CHKERRQ(ierr);
633       ierr  = DMPlexPointLocalRead(dmCell, ncell, cellgeom, &ncg);CHKERRQ(ierr);
634       WaxpyD(dim, -1, cg->centroid, ncg->centroid, v);
635       for (d = 0; d < pdim; ++d) {
636         /* We use the symmetric slope limited form of Berger, Aftosmis, and Murman 2005 */
637         PetscScalar phi, flim = 0.5 * (ncx[d] - cx[d]) / DotD(dim, &cgrad[d*dim], v);
638 
639         ierr = PetscLimiterLimit(lim, flim, &phi);CHKERRQ(ierr);
640         cellPhi[d] = PetscMin(cellPhi[d], phi);
641       }
642     }
643     /* Apply limiter to gradient */
644     for (pd = 0; pd < pdim; ++pd)
645       /* Scalar limiter applied to each component separately */
646       for (d = 0; d < dim; ++d) cgrad[pd*dim+d] *= cellPhi[pd];
647   }
648   ierr = DMRestoreWorkArray(dm, pdim, PETSC_REAL, &cellPhi);CHKERRQ(ierr);
649   ierr = DMPlexInsertBoundaryValuesFVM_Static(dm, fvm, time, locX, Grad, dmplexts);CHKERRQ(ierr);
650   if (computeGradients) {
651     ierr = VecRestoreArray(Grad, &grad);CHKERRQ(ierr);
652     ierr = DMGetLocalVector(dmplexts->dmGrad, &locGrad);CHKERRQ(ierr);
653     ierr = DMGlobalToLocalBegin(dmplexts->dmGrad, Grad, INSERT_VALUES, locGrad);CHKERRQ(ierr);
654     ierr = DMGlobalToLocalEnd(dmplexts->dmGrad, Grad, INSERT_VALUES, locGrad);CHKERRQ(ierr);
655     ierr = DMRestoreGlobalVector(dmplexts->dmGrad, &Grad);CHKERRQ(ierr);
656     ierr = VecGetArrayRead(locGrad, &lgrad);CHKERRQ(ierr);
657   }
658   ierr = PetscMalloc7(numFaces*dim,&centroid,numFaces*dim,&normal,numFaces*2,&vol,numFaces*pdim,&uL,numFaces*pdim,&uR,numFaces*pdim,&fluxL,numFaces*pdim,&fluxR);CHKERRQ(ierr);
659   /* Read out values */
660   for (face = fStart, iface = 0; face < fEnd; ++face) {
661     const PetscInt    *cells;
662     const FaceGeom    *fg;
663     const CellGeom    *cgL, *cgR;
664     const PetscScalar *xL, *xR, *gL, *gR;
665     PetscInt           ghost, d;
666 
667     ierr = DMLabelGetValue(ghostLabel, face, &ghost);CHKERRQ(ierr);
668     if (ghost >= 0) continue;
669     ierr = DMPlexPointLocalRead(dmFace, face, facegeom, &fg);CHKERRQ(ierr);
670     ierr = DMPlexGetSupport(dm, face, &cells);CHKERRQ(ierr);
671     ierr = DMPlexPointLocalRead(dmCell, cells[0], cellgeom, &cgL);CHKERRQ(ierr);
672     ierr = DMPlexPointLocalRead(dmCell, cells[1], cellgeom, &cgR);CHKERRQ(ierr);
673     ierr = DMPlexPointLocalRead(dm, cells[0], x, &xL);CHKERRQ(ierr);
674     ierr = DMPlexPointLocalRead(dm, cells[1], x, &xR);CHKERRQ(ierr);
675     if (computeGradients) {
676       PetscScalar dxL[3], dxR[3];
677 
678       ierr = DMPlexPointLocalRead(dmplexts->dmGrad, cells[0], lgrad, &gL);CHKERRQ(ierr);
679       ierr = DMPlexPointLocalRead(dmplexts->dmGrad, cells[1], lgrad, &gR);CHKERRQ(ierr);
680       WaxpyD(dim, -1, cgL->centroid, fg->centroid, dxL);
681       WaxpyD(dim, -1, cgR->centroid, fg->centroid, dxR);
682       for (d = 0; d < pdim; ++d) {
683         uL[iface*pdim+d] = xL[d] + DotD(dim, &gL[d*dim], dxL);
684         uR[iface*pdim+d] = xR[d] + DotD(dim, &gR[d*dim], dxR);
685       }
686     } else {
687       for (d = 0; d < pdim; ++d) {
688         uL[iface*pdim+d] = xL[d];
689         uR[iface*pdim+d] = xR[d];
690       }
691     }
692     for (d = 0; d < dim; ++d) {
693       centroid[iface*dim+d] = fg->centroid[d];
694       normal[iface*dim+d]   = fg->normal[d];
695     }
696     vol[iface*2+0] = cgL->volume;
697     vol[iface*2+1] = cgR->volume;
698     ++iface;
699   }
700   if (computeGradients) {
701     ierr = VecRestoreArrayRead(locGrad,&lgrad);CHKERRQ(ierr);
702     ierr = DMRestoreLocalVector(dmplexts->dmGrad, &locGrad);CHKERRQ(ierr);
703   }
704   ierr = VecRestoreArrayRead(locX, &x);CHKERRQ(ierr);
705   ierr = VecRestoreArrayRead(faceGeometry, &facegeom);CHKERRQ(ierr);
706   ierr = VecRestoreArrayRead(cellGeometry, &cellgeom);CHKERRQ(ierr);
707   fgeom.v0  = centroid;
708   fgeom.n   = normal;
709   cgeom.vol = vol;
710   /* Riemann solve */
711   ierr = PetscFVIntegrateRHSFunction(fvm, numFaces, Nf, &fvm, 0, fgeom, cgeom, uL, uR, riemann, fluxL, fluxR, dmplexts->rhsfunctionlocalctx);CHKERRQ(ierr);
712   /* Insert fluxes */
713   ierr = VecGetArray(F, &f);CHKERRQ(ierr);
714   for (face = fStart, iface = 0; face < fEnd; ++face) {
715     const PetscInt *cells;
716     PetscScalar    *fL, *fR;
717     PetscInt        ghost, d;
718 
719     ierr = DMLabelGetValue(ghostLabel, face, &ghost);CHKERRQ(ierr);
720     if (ghost >= 0) continue;
721     ierr = DMPlexGetSupport(dm, face, &cells);CHKERRQ(ierr);
722     ierr = DMPlexPointGlobalRef(dm, cells[0], f, &fL);CHKERRQ(ierr);
723     ierr = DMPlexPointGlobalRef(dm, cells[1], f, &fR);CHKERRQ(ierr);
724     for (d = 0; d < pdim; ++d) {
725       if (fL) fL[d] -= fluxL[iface*pdim+d];
726       if (fR) fR[d] += fluxR[iface*pdim+d];
727     }
728     ++iface;
729   }
730   ierr = VecRestoreArray(F, &f);CHKERRQ(ierr);
731   ierr = PetscFree7(centroid,normal,vol,uL,uR,fluxL,fluxR);CHKERRQ(ierr);
732   ierr = DMRestoreLocalVector(dm, &locX);CHKERRQ(ierr);
733   PetscFunctionReturn(0);
734 }
735 
736 #undef __FUNCT__
737 #define __FUNCT__ "DMPlexTSSetRHSFunctionLocal"
738 /*@C
739   DMPlexTSSetRHSFunctionLocal - set a local residual evaluation function
740 
741   Logically Collective
742 
743   Input Arguments:
744 + dm      - DM to associate callback with
745 . riemann - Riemann solver
746 - ctx     - optional context for Riemann solve
747 
748   Calling sequence for riemann:
749 
750 $ riemann(const PetscReal x[], const PetscReal n[], const PetscScalar uL[], const PetscScalar uR[], PetscScalar flux[], void *ctx)
751 
752 + x    - The coordinates at a point on the interface
753 . n    - The normal vector to the interface
754 . uL   - The state vector to the left of the interface
755 . uR   - The state vector to the right of the interface
756 . flux - output array of flux through the interface
757 - ctx  - optional user context
758 
759   Level: beginner
760 
761 .seealso: DMTSSetRHSFunctionLocal()
762 @*/
763 PetscErrorCode DMPlexTSSetRHSFunctionLocal(DM dm, void (*riemann)(const PetscReal x[], const PetscReal n[], const PetscScalar uL[], const PetscScalar uR[], PetscScalar flux[], void *ctx), void *ctx)
764 {
765   DMTS           dmts;
766   DMTS_Plex     *dmplexts;
767   PetscFV        fvm;
768   PetscInt       Nf;
769   PetscBool      computeGradients;
770   PetscErrorCode ierr;
771 
772   PetscFunctionBegin;
773   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
774   ierr = DMGetDMTSWrite(dm, &dmts);CHKERRQ(ierr);
775   ierr = DMPlexTSGetContext(dm, dmts, &dmplexts);CHKERRQ(ierr);
776   dmplexts->riemann             = riemann;
777   dmplexts->rhsfunctionlocalctx = ctx;
778   ierr = DMGetNumFields(dm, &Nf);CHKERRQ(ierr);
779   ierr = DMGetField(dm, 0, (PetscObject *) &fvm);CHKERRQ(ierr);
780   ierr = DMPlexTSSetupGeometry(dm, fvm, dmplexts);CHKERRQ(ierr);
781   ierr = PetscFVGetComputeGradients(fvm, &computeGradients);CHKERRQ(ierr);
782   if (computeGradients) {ierr = DMPlexTSSetupGradient(dm, fvm, dmplexts);CHKERRQ(ierr);}
783   ierr = DMTSSetRHSFunction(dm, TSComputeRHSFunction_DMPlex, dmplexts);CHKERRQ(ierr);
784   PetscFunctionReturn(0);
785 }
786