Actual source code: dmdasnes.c

  1: #include <petscdmda.h>
  2: #include <petsc/private/dmimpl.h>
  3: #include <petsc/private/snesimpl.h>

  5: /* This structure holds the user-provided DMDA callbacks */
  6: typedef struct {
  7:   /* array versions for vector data */
  8:   DMDASNESFunctionFn  *residuallocal;
  9:   DMDASNESJacobianFn  *jacobianlocal;
 10:   DMDASNESObjectiveFn *objectivelocal;

 12:   /* Vec version for vector data */
 13:   DMDASNESFunctionVecFn  *residuallocalvec;
 14:   DMDASNESJacobianVecFn  *jacobianlocalvec;
 15:   DMDASNESObjectiveVecFn *objectivelocalvec;

 17:   /* user contexts */
 18:   void      *residuallocalctx;
 19:   void      *jacobianlocalctx;
 20:   void      *objectivelocalctx;
 21:   InsertMode residuallocalimode;

 23:   /*   For Picard iteration defined locally */
 24:   PetscErrorCode (*rhsplocal)(DMDALocalInfo *, void *, void *, void *);
 25:   PetscErrorCode (*jacobianplocal)(DMDALocalInfo *, void *, Mat, Mat, void *);
 26:   void *picardlocalctx;
 27: } DMSNES_DA;

 29: static PetscErrorCode DMSNESDestroy_DMDA(DMSNES sdm)
 30: {
 31:   PetscFunctionBegin;
 32:   PetscCall(PetscFree(sdm->data));
 33:   PetscFunctionReturn(PETSC_SUCCESS);
 34: }

 36: static PetscErrorCode DMSNESDuplicate_DMDA(DMSNES oldsdm, DMSNES sdm)
 37: {
 38:   PetscFunctionBegin;
 39:   PetscCall(PetscNew((DMSNES_DA **)&sdm->data));
 40:   if (oldsdm->data) PetscCall(PetscMemcpy(sdm->data, oldsdm->data, sizeof(DMSNES_DA)));
 41:   PetscFunctionReturn(PETSC_SUCCESS);
 42: }

 44: static PetscErrorCode DMDASNESGetContext(DM dm, DMSNES sdm, DMSNES_DA **dmdasnes)
 45: {
 46:   PetscFunctionBegin;
 47:   *dmdasnes = NULL;
 48:   if (!sdm->data) {
 49:     PetscCall(PetscNew((DMSNES_DA **)&sdm->data));
 50:     sdm->ops->destroy   = DMSNESDestroy_DMDA;
 51:     sdm->ops->duplicate = DMSNESDuplicate_DMDA;
 52:   }
 53:   *dmdasnes = (DMSNES_DA *)sdm->data;
 54:   PetscFunctionReturn(PETSC_SUCCESS);
 55: }

 57: static PetscErrorCode SNESComputeFunction_DMDA(SNES snes, Vec X, Vec F, void *ctx)
 58: {
 59:   DM            dm;
 60:   DMSNES_DA    *dmdasnes = (DMSNES_DA *)ctx;
 61:   DMDALocalInfo info;
 62:   Vec           Xloc;
 63:   void         *x, *f, *rctx;

 65:   PetscFunctionBegin;
 69:   PetscCheck(dmdasnes->residuallocal || dmdasnes->residuallocalvec, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "Corrupt context");
 70:   PetscCall(SNESGetDM(snes, &dm));
 71:   PetscCall(DMGetLocalVector(dm, &Xloc));
 72:   PetscCall(DMGlobalToLocalBegin(dm, X, INSERT_VALUES, Xloc));
 73:   PetscCall(DMGlobalToLocalEnd(dm, X, INSERT_VALUES, Xloc));
 74:   PetscCall(DMDAGetLocalInfo(dm, &info));
 75:   rctx = dmdasnes->residuallocalctx ? dmdasnes->residuallocalctx : snes->ctx;
 76:   switch (dmdasnes->residuallocalimode) {
 77:   case INSERT_VALUES: {
 78:     PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, X, F, 0));
 79:     if (dmdasnes->residuallocalvec) PetscCallBack("SNES DMDA local callback function", (*dmdasnes->residuallocalvec)(&info, Xloc, F, rctx));
 80:     else {
 81:       PetscCall(DMDAVecGetArray(dm, Xloc, &x));
 82:       PetscCall(DMDAVecGetArray(dm, F, &f));
 83:       PetscCallBack("SNES DMDA local callback function", (*dmdasnes->residuallocal)(&info, x, f, rctx));
 84:       PetscCall(DMDAVecRestoreArray(dm, Xloc, &x));
 85:       PetscCall(DMDAVecRestoreArray(dm, F, &f));
 86:     }
 87:     PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, X, F, 0));
 88:   } break;
 89:   case ADD_VALUES: {
 90:     Vec Floc;
 91:     PetscCall(DMGetLocalVector(dm, &Floc));
 92:     PetscCall(VecZeroEntries(Floc));
 93:     PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, X, F, 0));
 94:     if (dmdasnes->residuallocalvec) PetscCallBack("SNES DMDA local callback function", (*dmdasnes->residuallocalvec)(&info, Xloc, Floc, rctx));
 95:     else {
 96:       PetscCall(DMDAVecGetArray(dm, Xloc, &x));
 97:       PetscCall(DMDAVecGetArray(dm, Floc, &f));
 98:       PetscCallBack("SNES DMDA local callback function", (*dmdasnes->residuallocal)(&info, x, f, rctx));
 99:       PetscCall(DMDAVecRestoreArray(dm, Xloc, &x));
100:       PetscCall(DMDAVecRestoreArray(dm, Floc, &f));
101:     }
102:     PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, X, F, 0));
103:     PetscCall(VecZeroEntries(F));
104:     PetscCall(DMLocalToGlobalBegin(dm, Floc, ADD_VALUES, F));
105:     PetscCall(DMLocalToGlobalEnd(dm, Floc, ADD_VALUES, F));
106:     PetscCall(DMRestoreLocalVector(dm, &Floc));
107:   } break;
108:   default:
109:     SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "Cannot use imode=%d", (int)dmdasnes->residuallocalimode);
110:   }
111:   PetscCall(DMRestoreLocalVector(dm, &Xloc));
112:   PetscCall(VecFlag(F, snes->domainerror));
113:   PetscFunctionReturn(PETSC_SUCCESS);
114: }

116: static PetscErrorCode SNESComputeObjective_DMDA(SNES snes, Vec X, PetscReal *ob, void *ctx)
117: {
118:   DM            dm;
119:   DMSNES_DA    *dmdasnes = (DMSNES_DA *)ctx;
120:   DMDALocalInfo info;
121:   Vec           Xloc;
122:   void         *x, *octx;

124:   PetscFunctionBegin;
127:   PetscAssertPointer(ob, 3);
128:   PetscCheck(dmdasnes->objectivelocal || dmdasnes->objectivelocalvec, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "Corrupt context");
129:   PetscCall(SNESGetDM(snes, &dm));
130:   PetscCall(DMGetLocalVector(dm, &Xloc));
131:   PetscCall(DMGlobalToLocalBegin(dm, X, INSERT_VALUES, Xloc));
132:   PetscCall(DMGlobalToLocalEnd(dm, X, INSERT_VALUES, Xloc));
133:   PetscCall(DMDAGetLocalInfo(dm, &info));
134:   octx = dmdasnes->objectivelocalctx ? dmdasnes->objectivelocalctx : snes->ctx;
135:   if (dmdasnes->objectivelocalvec) PetscCallBack("SNES DMDA local callback objective", (*dmdasnes->objectivelocalvec)(&info, Xloc, ob, octx));
136:   else {
137:     PetscCall(DMDAVecGetArray(dm, Xloc, &x));
138:     PetscCallBack("SNES DMDA local callback objective", (*dmdasnes->objectivelocal)(&info, x, ob, octx));
139:     PetscCall(DMDAVecRestoreArray(dm, Xloc, &x));
140:   }
141:   PetscCall(DMRestoreLocalVector(dm, &Xloc));
142:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, ob, 1, MPIU_REAL, MPIU_SUM, PetscObjectComm((PetscObject)snes)));
143:   PetscFunctionReturn(PETSC_SUCCESS);
144: }

146: /* Routine is called by example, hence must be labeled PETSC_EXTERN */
147: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES snes, Vec X, Mat A, Mat B, void *ctx)
148: {
149:   DM            dm;
150:   DMSNES_DA    *dmdasnes = (DMSNES_DA *)ctx;
151:   DMDALocalInfo info;
152:   Vec           Xloc;
153:   void         *x, *jctx;

155:   PetscFunctionBegin;
156:   PetscCheck(dmdasnes->residuallocal || dmdasnes->residuallocalvec, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "Corrupt context");
157:   PetscCall(SNESGetDM(snes, &dm));
158:   jctx = dmdasnes->jacobianlocalctx ? dmdasnes->jacobianlocalctx : snes->ctx;
159:   if (dmdasnes->jacobianlocal || dmdasnes->jacobianlocalvec) {
160:     PetscCall(DMGetLocalVector(dm, &Xloc));
161:     PetscCall(DMGlobalToLocalBegin(dm, X, INSERT_VALUES, Xloc));
162:     PetscCall(DMGlobalToLocalEnd(dm, X, INSERT_VALUES, Xloc));
163:     PetscCall(DMDAGetLocalInfo(dm, &info));
164:     if (dmdasnes->jacobianlocalvec) PetscCallBack("SNES DMDA local callback Jacobian", (*dmdasnes->jacobianlocalvec)(&info, Xloc, A, B, jctx));
165:     else {
166:       PetscCall(DMDAVecGetArray(dm, Xloc, &x));
167:       PetscCallBack("SNES DMDA local callback Jacobian", (*dmdasnes->jacobianlocal)(&info, x, A, B, jctx));
168:       PetscCall(DMDAVecRestoreArray(dm, Xloc, &x));
169:     }
170:     PetscCall(DMRestoreLocalVector(dm, &Xloc));
171:   } else {
172:     MatFDColoring fdcoloring;
173:     PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
174:     if (!fdcoloring) {
175:       ISColoring coloring;

177:       PetscCall(DMCreateColoring(dm, dm->coloringtype, &coloring));
178:       PetscCall(MatFDColoringCreate(B, coloring, &fdcoloring));
179:       switch (dm->coloringtype) {
180:       case IS_COLORING_GLOBAL:
181:         PetscCall(MatFDColoringSetFunction(fdcoloring, (PetscErrorCode (*)(void))SNESComputeFunction_DMDA, dmdasnes));
182:         break;
183:       default:
184:         SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_SUP, "No support for coloring type '%s'", ISColoringTypes[dm->coloringtype]);
185:       }
186:       PetscCall(PetscObjectSetOptionsPrefix((PetscObject)fdcoloring, ((PetscObject)dm)->prefix));
187:       PetscCall(MatFDColoringSetFromOptions(fdcoloring));
188:       PetscCall(MatFDColoringSetUp(B, coloring, fdcoloring));
189:       PetscCall(ISColoringDestroy(&coloring));
190:       PetscCall(PetscObjectCompose((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject)fdcoloring));
191:       PetscCall(PetscObjectDereference((PetscObject)fdcoloring));

193:       /* The following breaks an ugly reference counting loop that deserves a paragraph. MatFDColoringApply() will call
194:        * VecDuplicate() with the state Vec and store inside the MatFDColoring. This Vec will duplicate the Vec, but the
195:        * MatFDColoring is composed with the DM. We dereference the DM here so that the reference count will eventually
196:        * drop to 0. Note the code in DMDestroy() that exits early for a negative reference count. That code path will be
197:        * taken when the PetscObjectList for the Vec inside MatFDColoring is destroyed.
198:        */
199:       PetscCall(PetscObjectDereference((PetscObject)dm));
200:     }
201:     PetscCall(MatFDColoringApply(B, fdcoloring, X, snes));
202:   }
203:   /* This will be redundant if the user called both, but it's too common to forget. */
204:   if (A != B) {
205:     PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
206:     PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
207:   }
208:   PetscFunctionReturn(PETSC_SUCCESS);
209: }

211: /*@C
212:   DMDASNESSetFunctionLocal - set a local residual evaluation function for use with `DMDA`

214:   Logically Collective

216:   Input Parameters:
217: + dm    - `DM` to associate callback with
218: . imode - `INSERT_VALUES` if local function computes owned part, `ADD_VALUES` if it contributes to ghosted part
219: . func  - local residual evaluation
220: - ctx   - optional context for local residual evaluation

222:   Calling sequence of `func`:
223: + info - `DMDALocalInfo` defining the subdomain to evaluate the residual on
224: . x    - dimensional pointer to state at which to evaluate residual (e.g. PetscScalar *x or **x or ***x)
225: . f    - dimensional pointer to residual, write the residual here (e.g. PetscScalar *f or **f or ***f)
226: - ctx  - optional context passed above

228:   Level: beginner

230: .seealso: [](ch_snes), `DMDA`, `DMDASNESSetJacobianLocal()`, `DMSNESSetFunction()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`
231: @*/
232: PetscErrorCode DMDASNESSetFunctionLocal(DM dm, InsertMode imode, PetscErrorCode (*func)(DMDALocalInfo *info, void *x, void *f, void *ctx), void *ctx)
233: {
234:   DMSNES     sdm;
235:   DMSNES_DA *dmdasnes;

237:   PetscFunctionBegin;
239:   PetscCall(DMGetDMSNESWrite(dm, &sdm));
240:   PetscCall(DMDASNESGetContext(dm, sdm, &dmdasnes));

242:   dmdasnes->residuallocalimode = imode;
243:   dmdasnes->residuallocal      = func;
244:   dmdasnes->residuallocalctx   = ctx;

246:   PetscCall(DMSNESSetFunction(dm, SNESComputeFunction_DMDA, dmdasnes));
247:   if (!sdm->ops->computejacobian) { /* Call us for the Jacobian too, can be overridden by the user. */
248:     PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobian_DMDA, dmdasnes));
249:   }
250:   PetscFunctionReturn(PETSC_SUCCESS);
251: }

253: /*@C
254:   DMDASNESSetFunctionLocalVec - set a local residual evaluation function that operates on a local vector for `DMDA`

256:   Logically Collective

258:   Input Parameters:
259: + dm    - `DM` to associate callback with
260: . imode - `INSERT_VALUES` if local function computes owned part, `ADD_VALUES` if it contributes to ghosted part
261: . func  - local residual evaluation
262: - ctx   - optional context for local residual evaluation

264:   Calling sequence of `func`:
265: + info - `DMDALocalInfo` defining the subdomain to evaluate the residual on
266: . x    - state vector at which to evaluate residual
267: . f    - residual vector
268: - ctx  - optional context passed above

270:   Level: beginner

272: .seealso: [](ch_snes), `DMDA`, `DMDASNESSetFunctionLocal()`, `DMDASNESSetJacobianLocalVec()`, `DMSNESSetFunction()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`
273: @*/
274: PetscErrorCode DMDASNESSetFunctionLocalVec(DM dm, InsertMode imode, PetscErrorCode (*func)(DMDALocalInfo *info, Vec x, Vec f, void *ctx), void *ctx)
275: {
276:   DMSNES     sdm;
277:   DMSNES_DA *dmdasnes;

279:   PetscFunctionBegin;
281:   PetscCall(DMGetDMSNESWrite(dm, &sdm));
282:   PetscCall(DMDASNESGetContext(dm, sdm, &dmdasnes));

284:   dmdasnes->residuallocalimode = imode;
285:   dmdasnes->residuallocalvec   = func;
286:   dmdasnes->residuallocalctx   = ctx;

288:   PetscCall(DMSNESSetFunction(dm, SNESComputeFunction_DMDA, dmdasnes));
289:   if (!sdm->ops->computejacobian) { /* Call us for the Jacobian too, can be overridden by the user. */
290:     PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobian_DMDA, dmdasnes));
291:   }
292:   PetscFunctionReturn(PETSC_SUCCESS);
293: }

295: /*@C
296:   DMDASNESSetJacobianLocal - set a local Jacobian evaluation function for use with `DMDA`

298:   Logically Collective

300:   Input Parameters:
301: + dm   - `DM` to associate callback with
302: . func - local Jacobian evaluation function
303: - ctx  - optional context for local Jacobian evaluation

305:   Calling sequence of `func`:
306: + info - `DMDALocalInfo` defining the subdomain to evaluate the Jacobian at
307: . x    - dimensional pointer to state at which to evaluate Jacobian (e.g. PetscScalar *x or **x or ***x)
308: . J    - `Mat` object for the Jacobian
309: . M    - `Mat` object for the Jacobian preconditioner matrix, often `J`
310: - ctx  - optional context passed above

312:   Level: beginner

314:   Note:
315:   The `J` and `M` matrices are created internally by `DMCreateMatrix()`

317: .seealso: [](ch_snes), `DMDA`, `DMDASNESSetFunctionLocal()`, `DMSNESSetJacobian()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`
318: @*/
319: PetscErrorCode DMDASNESSetJacobianLocal(DM dm, PetscErrorCode (*func)(DMDALocalInfo *info, void *x, Mat J, Mat M, void *ctx), void *ctx)
320: {
321:   DMSNES     sdm;
322:   DMSNES_DA *dmdasnes;

324:   PetscFunctionBegin;
326:   PetscCall(DMGetDMSNESWrite(dm, &sdm));
327:   PetscCall(DMDASNESGetContext(dm, sdm, &dmdasnes));

329:   dmdasnes->jacobianlocal    = func;
330:   dmdasnes->jacobianlocalctx = ctx;

332:   PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobian_DMDA, dmdasnes));
333:   PetscFunctionReturn(PETSC_SUCCESS);
334: }

336: /*@C
337:   DMDASNESSetJacobianLocalVec - set a local Jacobian evaluation function that operates on a local vector with `DMDA`

339:   Logically Collective

341:   Input Parameters:
342: + dm   - `DM` to associate callback with
343: . func - local Jacobian evaluation
344: - ctx  - optional context for local Jacobian evaluation

346:   Calling sequence of `func`:
347: + info - `DMDALocalInfo` defining the subdomain to evaluate the Jacobian at
348: . x    - state vector at which to evaluate Jacobian
349: . J    - the Jacobian
350: . M    - approximate Jacobian from which the preconditioner will be computed, often `J`
351: - ctx  - optional context passed above

353:   Level: beginner

355: .seealso: [](ch_snes), `DMDA`, `DMDASNESSetJacobianLocal()`, `DMDASNESSetFunctionLocalVec()`, `DMSNESSetJacobian()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`
356: @*/
357: PetscErrorCode DMDASNESSetJacobianLocalVec(DM dm, PetscErrorCode (*func)(DMDALocalInfo *info, Vec x, Mat J, Mat M, void *), void *ctx)
358: {
359:   DMSNES     sdm;
360:   DMSNES_DA *dmdasnes;

362:   PetscFunctionBegin;
364:   PetscCall(DMGetDMSNESWrite(dm, &sdm));
365:   PetscCall(DMDASNESGetContext(dm, sdm, &dmdasnes));

367:   dmdasnes->jacobianlocalvec = func;
368:   dmdasnes->jacobianlocalctx = ctx;

370:   PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobian_DMDA, dmdasnes));
371:   PetscFunctionReturn(PETSC_SUCCESS);
372: }

374: /*@C
375:   DMDASNESSetObjectiveLocal - set a local residual evaluation function to used with a `DMDA`

377:   Logically Collective

379:   Input Parameters:
380: + dm   - `DM` to associate callback with
381: . func - local objective evaluation, see `DMDASNESSetObjectiveLocal` for the calling sequence
382: - ctx  - optional context for local residual evaluation

384:   Calling sequence of `func`:
385: + info - `DMDALocalInfo` defining the subdomain to evaluate the Jacobian at
386: . x    - dimensional pointer to state at which to evaluate the objective (e.g. PetscScalar *x or **x or ***x)
387: . obj  - returned objective value for the local subdomain
388: - ctx  - optional context passed above

390:   Level: beginner

392: .seealso: [](ch_snes), `DMDA`, `DMSNESSetFunction()`, `DMDASNESSetJacobianLocal()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMDASNESObjectiveFn`
393: @*/
394: PetscErrorCode DMDASNESSetObjectiveLocal(DM dm, PetscErrorCode (*func)(DMDALocalInfo *info, void *x, PetscReal *obj, void *), void *ctx)
395: {
396:   DMSNES     sdm;
397:   DMSNES_DA *dmdasnes;

399:   PetscFunctionBegin;
401:   PetscCall(DMGetDMSNESWrite(dm, &sdm));
402:   PetscCall(DMDASNESGetContext(dm, sdm, &dmdasnes));

404:   dmdasnes->objectivelocal    = func;
405:   dmdasnes->objectivelocalctx = ctx;

407:   PetscCall(DMSNESSetObjective(dm, SNESComputeObjective_DMDA, dmdasnes));
408:   PetscFunctionReturn(PETSC_SUCCESS);
409: }

411: /*@C
412:   DMDASNESSetObjectiveLocalVec - set a local residual evaluation function that operates on a local vector with `DMDA`

414:   Logically Collective

416:   Input Parameters:
417: + dm   - `DM` to associate callback with
418: . func - local objective evaluation, see `DMDASNESSetObjectiveLocalVec` for the calling sequence
419: - ctx  - optional context for local residual evaluation

421:   Calling sequence of `func`:
422: + info - `DMDALocalInfo` defining the subdomain to evaluate the Jacobian at
423: . x    - state vector at which to evaluate the objective
424: . obj  - returned objective value for the local subdomain
425: - ctx  - optional context passed above

427:   Level: beginner

429: .seealso: [](ch_snes), `DMDA`, `DMDASNESSetObjectiveLocal()`, `DMSNESSetFunction()`, `DMDASNESSetJacobianLocalVec()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMDASNESObjectiveVecFn`
430: @*/
431: PetscErrorCode DMDASNESSetObjectiveLocalVec(DM dm, PetscErrorCode (*func)(DMDALocalInfo *info, Vec x, PetscReal *obj, void *), void *ctx)
432: {
433:   DMSNES     sdm;
434:   DMSNES_DA *dmdasnes;

436:   PetscFunctionBegin;
438:   PetscCall(DMGetDMSNESWrite(dm, &sdm));
439:   PetscCall(DMDASNESGetContext(dm, sdm, &dmdasnes));

441:   dmdasnes->objectivelocalvec = func;
442:   dmdasnes->objectivelocalctx = ctx;

444:   PetscCall(DMSNESSetObjective(dm, SNESComputeObjective_DMDA, dmdasnes));
445:   PetscFunctionReturn(PETSC_SUCCESS);
446: }

448: static PetscErrorCode SNESComputePicard_DMDA(SNES snes, Vec X, Vec F, void *ctx)
449: {
450:   DM            dm;
451:   DMSNES_DA    *dmdasnes = (DMSNES_DA *)ctx;
452:   DMDALocalInfo info;
453:   Vec           Xloc;
454:   void         *x, *f;

456:   PetscFunctionBegin;
460:   PetscCheck(dmdasnes->rhsplocal, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "Corrupt context");
461:   PetscCall(SNESGetDM(snes, &dm));
462:   PetscCall(DMGetLocalVector(dm, &Xloc));
463:   PetscCall(DMGlobalToLocalBegin(dm, X, INSERT_VALUES, Xloc));
464:   PetscCall(DMGlobalToLocalEnd(dm, X, INSERT_VALUES, Xloc));
465:   PetscCall(DMDAGetLocalInfo(dm, &info));
466:   PetscCall(DMDAVecGetArray(dm, Xloc, &x));
467:   switch (dmdasnes->residuallocalimode) {
468:   case INSERT_VALUES: {
469:     PetscCall(DMDAVecGetArray(dm, F, &f));
470:     PetscCallBack("SNES Picard DMDA local callback function", (*dmdasnes->rhsplocal)(&info, x, f, dmdasnes->picardlocalctx));
471:     PetscCall(DMDAVecRestoreArray(dm, F, &f));
472:   } break;
473:   case ADD_VALUES: {
474:     Vec Floc;
475:     PetscCall(DMGetLocalVector(dm, &Floc));
476:     PetscCall(VecZeroEntries(Floc));
477:     PetscCall(DMDAVecGetArray(dm, Floc, &f));
478:     PetscCallBack("SNES Picard DMDA local callback function", (*dmdasnes->rhsplocal)(&info, x, f, dmdasnes->picardlocalctx));
479:     PetscCall(DMDAVecRestoreArray(dm, Floc, &f));
480:     PetscCall(VecZeroEntries(F));
481:     PetscCall(DMLocalToGlobalBegin(dm, Floc, ADD_VALUES, F));
482:     PetscCall(DMLocalToGlobalEnd(dm, Floc, ADD_VALUES, F));
483:     PetscCall(DMRestoreLocalVector(dm, &Floc));
484:   } break;
485:   default:
486:     SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "Cannot use imode=%d", (int)dmdasnes->residuallocalimode);
487:   }
488:   PetscCall(DMDAVecRestoreArray(dm, Xloc, &x));
489:   PetscCall(DMRestoreLocalVector(dm, &Xloc));
490:   PetscFunctionReturn(PETSC_SUCCESS);
491: }

493: static PetscErrorCode SNESComputePicardJacobian_DMDA(SNES snes, Vec X, Mat A, Mat B, void *ctx)
494: {
495:   DM            dm;
496:   DMSNES_DA    *dmdasnes = (DMSNES_DA *)ctx;
497:   DMDALocalInfo info;
498:   Vec           Xloc;
499:   void         *x;

501:   PetscFunctionBegin;
502:   PetscCheck(dmdasnes->jacobianplocal, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "Corrupt context");
503:   PetscCall(SNESGetDM(snes, &dm));

505:   PetscCall(DMGetLocalVector(dm, &Xloc));
506:   PetscCall(DMGlobalToLocalBegin(dm, X, INSERT_VALUES, Xloc));
507:   PetscCall(DMGlobalToLocalEnd(dm, X, INSERT_VALUES, Xloc));
508:   PetscCall(DMDAGetLocalInfo(dm, &info));
509:   PetscCall(DMDAVecGetArray(dm, Xloc, &x));
510:   PetscCallBack("SNES Picard DMDA local callback Jacobian", (*dmdasnes->jacobianplocal)(&info, x, A, B, dmdasnes->picardlocalctx));
511:   PetscCall(DMDAVecRestoreArray(dm, Xloc, &x));
512:   PetscCall(DMRestoreLocalVector(dm, &Xloc));
513:   if (A != B) {
514:     PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
515:     PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
516:   }
517:   PetscFunctionReturn(PETSC_SUCCESS);
518: }

520: /*@C
521:   DMDASNESSetPicardLocal - set a local right-hand side and matrix evaluation function for Picard iteration with `DMDA`

523:   Logically Collective

525:   Input Parameters:
526: + dm    - `DM` to associate callback with
527: . imode - `INSERT_VALUES` if local function computes owned part, `ADD_VALUES` if it contributes to ghosted part
528: . func  - local residual evaluation
529: . jac   - function to compute Jacobian
530: - ctx   - optional context for local residual evaluation

532:   Calling sequence of `func`:
533: + info - defines the subdomain to evaluate the residual on
534: . x    - dimensional pointer to state at which to evaluate residual
535: . f    - dimensional pointer to residual, write the residual here
536: - ctx  - optional context passed above

538:   Calling sequence of `jac`:
539: + info - defines the subdomain to evaluate the residual on
540: . x    - dimensional pointer to state at which to evaluate residual
541: . jac  - the Jacobian
542: . Jp   - approximation to the Jacobian used to compute the preconditioner, often `J`
543: - ctx  - optional context passed above

545:   Level: beginner

547:   Note:
548:   The user must use `SNESSetFunction`(`snes`,`NULL`,`SNESPicardComputeFunction`,&user));
549:   in their code before calling this routine.

551: .seealso: [](ch_snes), `SNES`, `DMDA`, `DMSNESSetFunction()`, `DMDASNESSetJacobian()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`
552: @*/
553: PetscErrorCode DMDASNESSetPicardLocal(DM dm, InsertMode imode, PetscErrorCode (*func)(DMDALocalInfo *info, void *x, void *f, void *ctx), PetscErrorCode (*jac)(DMDALocalInfo *info, void *x, Mat jac, Mat Jp, void *ctx), void *ctx)
554: {
555:   DMSNES     sdm;
556:   DMSNES_DA *dmdasnes;

558:   PetscFunctionBegin;
560:   PetscCall(DMGetDMSNESWrite(dm, &sdm));
561:   PetscCall(DMDASNESGetContext(dm, sdm, &dmdasnes));

563:   dmdasnes->residuallocalimode = imode;
564:   dmdasnes->rhsplocal          = func;
565:   dmdasnes->jacobianplocal     = jac;
566:   dmdasnes->picardlocalctx     = ctx;

568:   PetscCall(DMSNESSetPicard(dm, SNESComputePicard_DMDA, SNESComputePicardJacobian_DMDA, dmdasnes));
569:   PetscCall(DMSNESSetMFFunction(dm, SNESComputeFunction_DMDA, dmdasnes));
570:   PetscFunctionReturn(PETSC_SUCCESS);
571: }