Actual source code: convest.c

  1: #include <petscconvest.h>
  2: #include <petscdmplex.h>
  3: #include <petscds.h>

  5: #include <petsc/private/petscconvestimpl.h>

  7: static PetscErrorCode zero_private(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx)
  8: {
  9:   PetscInt c;
 10:   for (c = 0; c < Nc; ++c) u[c] = 0.0;
 11:   return PETSC_SUCCESS;
 12: }

 14: /*@
 15:   PetscConvEstDestroy - Destroys a PetscConvEst object

 17:   Collective

 19:   Input Parameter:
 20: . ce - The PetscConvEst object

 22:   Level: beginner

 24: .seealso: `PetscConvEstCreate()`, `PetscConvEstGetConvRate()`
 25: @*/
 26: PetscErrorCode PetscConvEstDestroy(PetscConvEst *ce)
 27: {
 28:   PetscFunctionBegin;
 29:   if (!*ce) PetscFunctionReturn(PETSC_SUCCESS);
 31:   if (--((PetscObject)(*ce))->refct > 0) {
 32:     *ce = NULL;
 33:     PetscFunctionReturn(PETSC_SUCCESS);
 34:   }
 35:   PetscCall(PetscFree3((*ce)->initGuess, (*ce)->exactSol, (*ce)->ctxs));
 36:   PetscCall(PetscFree2((*ce)->dofs, (*ce)->errors));
 37:   PetscCall(PetscHeaderDestroy(ce));
 38:   PetscFunctionReturn(PETSC_SUCCESS);
 39: }

 41: /*@
 42:   PetscConvEstSetFromOptions - Sets a PetscConvEst object from options

 44:   Collective

 46:   Input Parameters:
 47: . ce - The PetscConvEst object

 49:   Level: beginner

 51: .seealso: `PetscConvEstCreate()`, `PetscConvEstGetConvRate()`
 52: @*/
 53: PetscErrorCode PetscConvEstSetFromOptions(PetscConvEst ce)
 54: {
 55:   PetscFunctionBegin;
 56:   PetscOptionsBegin(PetscObjectComm((PetscObject)ce), "", "Convergence Estimator Options", "PetscConvEst");
 57:   PetscCall(PetscOptionsInt("-convest_num_refine", "The number of refinements for the convergence check", "PetscConvEst", ce->Nr, &ce->Nr, NULL));
 58:   PetscCall(PetscOptionsReal("-convest_refine_factor", "The increase in resolution in each dimension", "PetscConvEst", ce->r, &ce->r, NULL));
 59:   PetscCall(PetscOptionsBool("-convest_monitor", "Monitor the error for each convergence check", "PetscConvEst", ce->monitor, &ce->monitor, NULL));
 60:   PetscCall(PetscOptionsBool("-convest_no_refine", "Debugging flag to run on the same mesh each time", "PetscConvEst", ce->noRefine, &ce->noRefine, NULL));
 61:   PetscOptionsEnd();
 62:   PetscFunctionReturn(PETSC_SUCCESS);
 63: }

 65: /*@
 66:   PetscConvEstView - Views a PetscConvEst object

 68:   Collective

 70:   Input Parameters:
 71: + ce     - The PetscConvEst object
 72: - viewer - The PetscViewer object

 74:   Level: beginner

 76: .seealso: `PetscConvEstCreate()`, `PetscConvEstGetConvRate()`
 77: @*/
 78: PetscErrorCode PetscConvEstView(PetscConvEst ce, PetscViewer viewer)
 79: {
 80:   PetscFunctionBegin;
 81:   PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)ce, viewer));
 82:   PetscCall(PetscViewerASCIIPrintf(viewer, "ConvEst with %" PetscInt_FMT " levels\n", ce->Nr + 1));
 83:   PetscFunctionReturn(PETSC_SUCCESS);
 84: }

 86: /*@
 87:   PetscConvEstGetSolver - Gets the solver used to produce discrete solutions

 89:   Not collective

 91:   Input Parameter:
 92: . ce     - The PetscConvEst object

 94:   Output Parameter:
 95: . solver - The solver

 97:   Level: intermediate

 99: .seealso: `PetscConvEstSetSolver()`, `PetscConvEstCreate()`, `PetscConvEstGetConvRate()`
100: @*/
101: PetscErrorCode PetscConvEstGetSolver(PetscConvEst ce, PetscObject *solver)
102: {
103:   PetscFunctionBegin;
106:   *solver = ce->solver;
107:   PetscFunctionReturn(PETSC_SUCCESS);
108: }

110: /*@
111:   PetscConvEstSetSolver - Sets the solver used to produce discrete solutions

113:   Not collective

115:   Input Parameters:
116: + ce     - The PetscConvEst object
117: - solver - The solver

119:   Level: intermediate

121:   Note: The solver MUST have an attached DM/DS, so that we know the exact solution

123: .seealso: `PetscConvEstGetSNES()`, `PetscConvEstCreate()`, `PetscConvEstGetConvRate()`
124: @*/
125: PetscErrorCode PetscConvEstSetSolver(PetscConvEst ce, PetscObject solver)
126: {
127:   PetscFunctionBegin;
130:   ce->solver = solver;
131:   PetscUseTypeMethod(ce, setsolver, solver);
132:   PetscFunctionReturn(PETSC_SUCCESS);
133: }

135: /*@
136:   PetscConvEstSetUp - After the solver is specified, we create structures for estimating convergence

138:   Collective

140:   Input Parameters:
141: . ce - The PetscConvEst object

143:   Level: beginner

145: .seealso: `PetscConvEstCreate()`, `PetscConvEstGetConvRate()`
146: @*/
147: PetscErrorCode PetscConvEstSetUp(PetscConvEst ce)
148: {
149:   PetscInt Nf, f, Nds, s;

151:   PetscFunctionBegin;
152:   PetscCall(DMGetNumFields(ce->idm, &Nf));
153:   ce->Nf = PetscMax(Nf, 1);
154:   PetscCall(PetscMalloc2((ce->Nr + 1) * ce->Nf, &ce->dofs, (ce->Nr + 1) * ce->Nf, &ce->errors));
155:   PetscCall(PetscCalloc3(ce->Nf, &ce->initGuess, ce->Nf, &ce->exactSol, ce->Nf, &ce->ctxs));
156:   for (f = 0; f < Nf; ++f) ce->initGuess[f] = zero_private;
157:   PetscCall(DMGetNumDS(ce->idm, &Nds));
158:   for (s = 0; s < Nds; ++s) {
159:     PetscDS         ds;
160:     DMLabel         label;
161:     IS              fieldIS;
162:     const PetscInt *fields;
163:     PetscInt        dsNf;

165:     PetscCall(DMGetRegionNumDS(ce->idm, s, &label, &fieldIS, &ds));
166:     PetscCall(PetscDSGetNumFields(ds, &dsNf));
167:     if (fieldIS) PetscCall(ISGetIndices(fieldIS, &fields));
168:     for (f = 0; f < dsNf; ++f) {
169:       const PetscInt field = fields[f];
170:       PetscCall(PetscDSGetExactSolution(ds, field, &ce->exactSol[field], &ce->ctxs[field]));
171:     }
172:     if (fieldIS) PetscCall(ISRestoreIndices(fieldIS, &fields));
173:   }
174:   for (f = 0; f < Nf; ++f) PetscCheck(ce->exactSol[f], PetscObjectComm((PetscObject)ce), PETSC_ERR_ARG_WRONG, "DS must contain exact solution functions in order to estimate convergence, missing for field %" PetscInt_FMT, f);
175:   PetscFunctionReturn(PETSC_SUCCESS);
176: }

178: PetscErrorCode PetscConvEstComputeInitialGuess(PetscConvEst ce, PetscInt r, DM dm, Vec u)
179: {
180:   PetscFunctionBegin;
184:   PetscUseTypeMethod(ce, initguess, r, dm, u);
185:   PetscFunctionReturn(PETSC_SUCCESS);
186: }

188: PetscErrorCode PetscConvEstComputeError(PetscConvEst ce, PetscInt r, DM dm, Vec u, PetscReal errors[])
189: {
190:   PetscFunctionBegin;
195:   PetscUseTypeMethod(ce, computeerror, r, dm, u, errors);
196:   PetscFunctionReturn(PETSC_SUCCESS);
197: }

199: /*@
200:   PetscConvEstMonitorDefault - Monitors the convergence estimation loop

202:   Collective

204:   Input Parameters:
205: + ce - The `PetscConvEst` object
206: - r  - The refinement level

208:   Options database keys:
209: . -convest_monitor - Activate the monitor

211:   Level: intermediate

213: .seealso: `PetscConvEst`, `PetscConvEstCreate()`, `PetscConvEstGetConvRate()`, `SNESSolve()`, `TSSolve()`
214: @*/
215: PetscErrorCode PetscConvEstMonitorDefault(PetscConvEst ce, PetscInt r)
216: {
217:   MPI_Comm comm;
218:   PetscInt f;

220:   PetscFunctionBegin;
221:   if (ce->monitor) {
222:     PetscInt  *dofs   = &ce->dofs[r * ce->Nf];
223:     PetscReal *errors = &ce->errors[r * ce->Nf];

225:     PetscCall(PetscObjectGetComm((PetscObject)ce, &comm));
226:     PetscCall(PetscPrintf(comm, "N: "));
227:     if (ce->Nf > 1) PetscCall(PetscPrintf(comm, "["));
228:     for (f = 0; f < ce->Nf; ++f) {
229:       if (f > 0) PetscCall(PetscPrintf(comm, ", "));
230:       PetscCall(PetscPrintf(comm, "%7" PetscInt_FMT, dofs[f]));
231:     }
232:     if (ce->Nf > 1) PetscCall(PetscPrintf(comm, "]"));
233:     PetscCall(PetscPrintf(comm, "  "));
234:     PetscCall(PetscPrintf(comm, "L_2 Error: "));
235:     if (ce->Nf > 1) PetscCall(PetscPrintf(comm, "["));
236:     for (f = 0; f < ce->Nf; ++f) {
237:       if (f > 0) PetscCall(PetscPrintf(comm, ", "));
238:       if (errors[f] < 1.0e-11) PetscCall(PetscPrintf(comm, "< 1e-11"));
239:       else PetscCall(PetscPrintf(comm, "%g", (double)errors[f]));
240:     }
241:     if (ce->Nf > 1) PetscCall(PetscPrintf(comm, "]"));
242:     PetscCall(PetscPrintf(comm, "\n"));
243:   }
244:   PetscFunctionReturn(PETSC_SUCCESS);
245: }

247: static PetscErrorCode PetscConvEstSetSNES_Private(PetscConvEst ce, PetscObject solver)
248: {
249:   PetscClassId id;

251:   PetscFunctionBegin;
252:   PetscCall(PetscObjectGetClassId(ce->solver, &id));
253:   PetscCheck(id == SNES_CLASSID, PetscObjectComm((PetscObject)ce), PETSC_ERR_ARG_WRONG, "Solver was not a SNES");
254:   PetscCall(SNESGetDM((SNES)ce->solver, &ce->idm));
255:   PetscFunctionReturn(PETSC_SUCCESS);
256: }

258: static PetscErrorCode PetscConvEstInitGuessSNES_Private(PetscConvEst ce, PetscInt r, DM dm, Vec u)
259: {
260:   PetscFunctionBegin;
261:   PetscCall(DMProjectFunction(dm, 0.0, ce->initGuess, ce->ctxs, INSERT_VALUES, u));
262:   PetscFunctionReturn(PETSC_SUCCESS);
263: }

265: static PetscErrorCode PetscConvEstComputeErrorSNES_Private(PetscConvEst ce, PetscInt r, DM dm, Vec u, PetscReal errors[])
266: {
267:   PetscFunctionBegin;
268:   PetscCall(DMComputeL2FieldDiff(dm, 0.0, ce->exactSol, ce->ctxs, u, errors));
269:   PetscFunctionReturn(PETSC_SUCCESS);
270: }

272: static PetscErrorCode PetscConvEstSetJacobianNullSpace_Private(PetscConvEst ce, SNES snes)
273: {
274:   DM       dm;
275:   PetscInt f;

277:   PetscFunctionBegin;
278:   PetscCall(SNESGetDM(snes, &dm));
279:   for (f = 0; f < ce->Nf; ++f) {
280:     PetscErrorCode (*nspconstr)(DM, PetscInt, PetscInt, MatNullSpace *);

282:     PetscCall(DMGetNullSpaceConstructor(dm, f, &nspconstr));
283:     if (nspconstr) {
284:       MatNullSpace nullsp;
285:       Mat          J;

287:       PetscCall((*nspconstr)(dm, f, f, &nullsp));
288:       PetscCall(SNESSetUp(snes));
289:       PetscCall(SNESGetJacobian(snes, &J, NULL, NULL, NULL));
290:       PetscCall(MatSetNullSpace(J, nullsp));
291:       PetscCall(MatNullSpaceDestroy(&nullsp));
292:       break;
293:     }
294:   }
295:   PetscFunctionReturn(PETSC_SUCCESS);
296: }

298: static PetscErrorCode PetscConvEstGetConvRateSNES_Private(PetscConvEst ce, PetscReal alpha[])
299: {
300:   SNES        snes = (SNES)ce->solver;
301:   DM         *dm;
302:   PetscObject disc;
303:   PetscReal  *x, *y, slope, intercept;
304:   PetscInt    Nr = ce->Nr, r, f, dim, oldlevel, oldnlev;
305:   void       *ctx;

307:   PetscFunctionBegin;
308:   PetscCheck(ce->r == 2.0, PetscObjectComm((PetscObject)ce), PETSC_ERR_SUP, "Only refinement factor 2 is currently supported (not %g)", (double)ce->r);
309:   PetscCall(DMGetDimension(ce->idm, &dim));
310:   PetscCall(DMGetApplicationContext(ce->idm, &ctx));
311:   PetscCall(DMPlexSetRefinementUniform(ce->idm, PETSC_TRUE));
312:   PetscCall(DMGetRefineLevel(ce->idm, &oldlevel));
313:   PetscCall(PetscMalloc1((Nr + 1), &dm));
314:   /* Loop over meshes */
315:   dm[0] = ce->idm;
316:   for (r = 0; r <= Nr; ++r) {
317:     Vec u;
318: #if defined(PETSC_USE_LOG)
319:     PetscLogStage stage;
320: #endif
321:     char        stageName[PETSC_MAX_PATH_LEN];
322:     const char *dmname, *uname;

324:     PetscCall(PetscSNPrintf(stageName, PETSC_MAX_PATH_LEN - 1, "ConvEst Refinement Level %" PetscInt_FMT, r));
325: #if defined(PETSC_USE_LOG)
326:     PetscCall(PetscLogStageGetId(stageName, &stage));
327:     if (stage < 0) PetscCall(PetscLogStageRegister(stageName, &stage));
328: #endif
329:     PetscCall(PetscLogStagePush(stage));
330:     if (r > 0) {
331:       if (!ce->noRefine) {
332:         PetscCall(DMRefine(dm[r - 1], MPI_COMM_NULL, &dm[r]));
333:         PetscCall(DMSetCoarseDM(dm[r], dm[r - 1]));
334:       } else {
335:         DM cdm, rcdm;

337:         PetscCall(DMClone(dm[r - 1], &dm[r]));
338:         PetscCall(DMCopyDisc(dm[r - 1], dm[r]));
339:         PetscCall(DMGetCoordinateDM(dm[r - 1], &cdm));
340:         PetscCall(DMGetCoordinateDM(dm[r], &rcdm));
341:         PetscCall(DMCopyDisc(cdm, rcdm));
342:       }
343:       PetscCall(DMCopyTransform(ce->idm, dm[r]));
344:       PetscCall(PetscObjectGetName((PetscObject)dm[r - 1], &dmname));
345:       PetscCall(PetscObjectSetName((PetscObject)dm[r], dmname));
346:       for (f = 0; f < ce->Nf; ++f) {
347:         PetscErrorCode (*nspconstr)(DM, PetscInt, PetscInt, MatNullSpace *);

349:         PetscCall(DMGetNullSpaceConstructor(dm[r - 1], f, &nspconstr));
350:         PetscCall(DMSetNullSpaceConstructor(dm[r], f, nspconstr));
351:       }
352:     }
353:     PetscCall(DMViewFromOptions(dm[r], NULL, "-conv_dm_view"));
354:     /* Create solution */
355:     PetscCall(DMCreateGlobalVector(dm[r], &u));
356:     PetscCall(DMGetField(dm[r], 0, NULL, &disc));
357:     PetscCall(PetscObjectGetName(disc, &uname));
358:     PetscCall(PetscObjectSetName((PetscObject)u, uname));
359:     /* Setup solver */
360:     PetscCall(SNESReset(snes));
361:     PetscCall(SNESSetDM(snes, dm[r]));
362:     PetscCall(DMPlexSetSNESLocalFEM(dm[r], ctx, ctx, ctx));
363:     PetscCall(SNESSetFromOptions(snes));
364:     /* Set nullspace for Jacobian */
365:     PetscCall(PetscConvEstSetJacobianNullSpace_Private(ce, snes));
366:     /* Create initial guess */
367:     PetscCall(PetscConvEstComputeInitialGuess(ce, r, dm[r], u));
368:     PetscCall(SNESSolve(snes, NULL, u));
369:     PetscCall(PetscLogEventBegin(ce->event, ce, 0, 0, 0));
370:     PetscCall(PetscConvEstComputeError(ce, r, dm[r], u, &ce->errors[r * ce->Nf]));
371:     PetscCall(PetscLogEventEnd(ce->event, ce, 0, 0, 0));
372:     for (f = 0; f < ce->Nf; ++f) {
373:       PetscSection s, fs;
374:       PetscInt     lsize;

376:       /* Could use DMGetOutputDM() to add in Dirichlet dofs */
377:       PetscCall(DMGetLocalSection(dm[r], &s));
378:       PetscCall(PetscSectionGetField(s, f, &fs));
379:       PetscCall(PetscSectionGetConstrainedStorageSize(fs, &lsize));
380:       PetscCallMPI(MPI_Allreduce(&lsize, &ce->dofs[r * ce->Nf + f], 1, MPIU_INT, MPI_SUM, PetscObjectComm((PetscObject)snes)));
381:       PetscCall(PetscLogEventSetDof(ce->event, f, ce->dofs[r * ce->Nf + f]));
382:       PetscCall(PetscLogEventSetError(ce->event, f, ce->errors[r * ce->Nf + f]));
383:     }
384:     /* Monitor */
385:     PetscCall(PetscConvEstMonitorDefault(ce, r));
386:     if (!r) {
387:       /* PCReset() does not wipe out the level structure */
388:       KSP ksp;
389:       PC  pc;

391:       PetscCall(SNESGetKSP(snes, &ksp));
392:       PetscCall(KSPGetPC(ksp, &pc));
393:       PetscCall(PCMGGetLevels(pc, &oldnlev));
394:     }
395:     /* Cleanup */
396:     PetscCall(VecDestroy(&u));
397:     PetscCall(PetscLogStagePop());
398:   }
399:   for (r = 1; r <= Nr; ++r) PetscCall(DMDestroy(&dm[r]));
400:   /* Fit convergence rate */
401:   PetscCall(PetscMalloc2(Nr + 1, &x, Nr + 1, &y));
402:   for (f = 0; f < ce->Nf; ++f) {
403:     for (r = 0; r <= Nr; ++r) {
404:       x[r] = PetscLog10Real(ce->dofs[r * ce->Nf + f]);
405:       y[r] = PetscLog10Real(ce->errors[r * ce->Nf + f]);
406:     }
407:     PetscCall(PetscLinearRegression(Nr + 1, x, y, &slope, &intercept));
408:     /* Since h^{-dim} = N, lg err = s lg N + b = -s dim lg h + b */
409:     alpha[f] = -slope * dim;
410:   }
411:   PetscCall(PetscFree2(x, y));
412:   PetscCall(PetscFree(dm));
413:   /* Restore solver */
414:   PetscCall(SNESReset(snes));
415:   {
416:     /* PCReset() does not wipe out the level structure */
417:     KSP ksp;
418:     PC  pc;

420:     PetscCall(SNESGetKSP(snes, &ksp));
421:     PetscCall(KSPGetPC(ksp, &pc));
422:     PetscCall(PCMGSetLevels(pc, oldnlev, NULL));
423:     PetscCall(DMSetRefineLevel(ce->idm, oldlevel)); /* The damn DMCoarsen() calls in PCMG can reset this */
424:   }
425:   PetscCall(SNESSetDM(snes, ce->idm));
426:   PetscCall(DMPlexSetSNESLocalFEM(ce->idm, ctx, ctx, ctx));
427:   PetscCall(SNESSetFromOptions(snes));
428:   PetscCall(PetscConvEstSetJacobianNullSpace_Private(ce, snes));
429:   PetscFunctionReturn(PETSC_SUCCESS);
430: }

432: /*@
433:   PetscConvEstGetConvRate - Returns an estimate of the convergence rate for the discretization

435:   Not collective

437:   Input Parameter:
438: . ce   - The `PetscConvEst` object

440:   Output Parameter:
441: . alpha - The convergence rate for each field

443:   Options database keys:
444: + -snes_convergence_estimate - Execute convergence estimation inside `SNESSolve()` and print out the rate
445: - -ts_convergence_estimate - Execute convergence estimation inside `TSSolve()` and print out the rate

447:   Notes:
448:   The convergence rate alpha is defined by
449: $ || u_\Delta - u_exact || < C \Delta^alpha
450:   where u_\Delta is the discrete solution, and Delta is a measure of the discretization size. We usually use h for the
451:   spatial resolution and \Delta t for the temporal resolution.

453:   We solve a series of problems using increasing resolution (refined meshes or decreased timesteps), calculate an error
454:   based upon the exact solution in the DS, and then fit the result to our model above using linear regression.

456:   Level: intermediate

458: .seealso: `PetscConvEstSetSolver()`, `PetscConvEstCreate()`, `PetscConvEstGetConvRate()`, `SNESSolve()`, `TSSolve()`
459: @*/
460: PetscErrorCode PetscConvEstGetConvRate(PetscConvEst ce, PetscReal alpha[])
461: {
462:   PetscInt f;

464:   PetscFunctionBegin;
465:   if (ce->event < 0) PetscCall(PetscLogEventRegister("ConvEst Error", PETSC_OBJECT_CLASSID, &ce->event));
466:   for (f = 0; f < ce->Nf; ++f) alpha[f] = 0.0;
467:   PetscUseTypeMethod(ce, getconvrate, alpha);
468:   PetscFunctionReturn(PETSC_SUCCESS);
469: }

471: /*@
472:   PetscConvEstRateView - Displays the convergence rate to a viewer

474:    Collective

476:    Parameter:
477: +  snes - iterative context obtained from `SNESCreate()`
478: .  alpha - the convergence rate for each field
479: -  viewer - the viewer to display the reason

481:    Options Database Keys:
482: .  -snes_convergence_estimate - print the convergence rate

484:    Level: developer

486: .seealso: `PetscConvEst`, `PetscConvEstGetRate()`
487: @*/
488: PetscErrorCode PetscConvEstRateView(PetscConvEst ce, const PetscReal alpha[], PetscViewer viewer)
489: {
490:   PetscBool isAscii;

492:   PetscFunctionBegin;
493:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
494:   if (isAscii) {
495:     PetscInt Nf = ce->Nf, f;

497:     PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)ce)->tablevel));
498:     PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 convergence rate: "));
499:     if (Nf > 1) PetscCall(PetscViewerASCIIPrintf(viewer, "["));
500:     for (f = 0; f < Nf; ++f) {
501:       if (f > 0) PetscCall(PetscViewerASCIIPrintf(viewer, ", "));
502:       PetscCall(PetscViewerASCIIPrintf(viewer, "%#.2g", (double)alpha[f]));
503:     }
504:     if (Nf > 1) PetscCall(PetscViewerASCIIPrintf(viewer, "]"));
505:     PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
506:     PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)ce)->tablevel));
507:   }
508:   PetscFunctionReturn(PETSC_SUCCESS);
509: }

511: /*@
512:   PetscConvEstCreate - Create a `PetscConvEst` object

514:   Collective

516:   Input Parameter:
517: . comm - The communicator for the `PetscConvEst` object

519:   Output Parameter:
520: . ce   - The `PetscConvEst` object

522:   Level: beginner

524: .seealso: `PetscConvEst`, `PetscConvEstDestroy()`, `PetscConvEstGetConvRate()`
525: @*/
526: PetscErrorCode PetscConvEstCreate(MPI_Comm comm, PetscConvEst *ce)
527: {
528:   PetscFunctionBegin;
530:   PetscCall(PetscSysInitializePackage());
531:   PetscCall(PetscHeaderCreate(*ce, PETSC_OBJECT_CLASSID, "PetscConvEst", "ConvergenceEstimator", "SNES", comm, PetscConvEstDestroy, PetscConvEstView));
532:   (*ce)->monitor           = PETSC_FALSE;
533:   (*ce)->r                 = 2.0;
534:   (*ce)->Nr                = 4;
535:   (*ce)->event             = -1;
536:   (*ce)->ops->setsolver    = PetscConvEstSetSNES_Private;
537:   (*ce)->ops->initguess    = PetscConvEstInitGuessSNES_Private;
538:   (*ce)->ops->computeerror = PetscConvEstComputeErrorSNES_Private;
539:   (*ce)->ops->getconvrate  = PetscConvEstGetConvRateSNES_Private;
540:   PetscFunctionReturn(PETSC_SUCCESS);
541: }