Actual source code: snesut.c

  1: #include <petsc/private/snesimpl.h>
  2: #include <petscdm.h>
  3: #include <petscsection.h>
  4: #include <petscblaslapack.h>

  6: /*@C
  7:   SNESMonitorSolution - Monitors progress of a `SNES` `SNESSolve()` by calling
  8:   `VecView()` for the approximate solution at each iteration.

 10:   Collective

 12:   Input Parameters:
 13: + snes   - the `SNES` context
 14: . its    - iteration number
 15: . fgnorm - 2-norm of residual
 16: - vf     - a viewer

 18:   Options Database Key:
 19: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration

 21:   Level: intermediate

 23:   Note:
 24:   This is not called directly by users, rather one calls `SNESMonitorSet()`, with this function as an argument, to cause the monitor
 25:   to be used during the `SNESSolve()`

 27: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`, `SNESMonitorDefault()`, `VecView()`
 28: @*/
 29: PetscErrorCode SNESMonitorSolution(SNES snes, PetscInt its, PetscReal fgnorm, PetscViewerAndFormat *vf)
 30: {
 31:   Vec         x;
 32:   PetscViewer viewer = vf->viewer;

 34:   PetscFunctionBegin;
 36:   PetscCall(SNESGetSolution(snes, &x));
 37:   PetscCall(PetscViewerPushFormat(viewer, vf->format));
 38:   PetscCall(VecView(x, viewer));
 39:   PetscCall(PetscViewerPopFormat(viewer));
 40:   PetscFunctionReturn(PETSC_SUCCESS);
 41: }

 43: /*@C
 44:   SNESMonitorResidual - Monitors progress of a `SNESSolve()` by calling
 45:   `VecView()` for the residual at each iteration.

 47:   Collective

 49:   Input Parameters:
 50: + snes   - the `SNES` context
 51: . its    - iteration number
 52: . fgnorm - 2-norm of residual
 53: - vf     - a viewer

 55:   Options Database Key:
 56: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration

 58:   Level: intermediate

 60:   Note:
 61:   This is not called directly by users, rather one calls `SNESMonitorSet()`, with this function as an argument, to cause the monitor
 62:   to be used during the `SNES` solve.

 64: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`, `SNESMonitorDefault()`, `VecView()`, `SNESMonitor()`
 65: @*/
 66: PetscErrorCode SNESMonitorResidual(SNES snes, PetscInt its, PetscReal fgnorm, PetscViewerAndFormat *vf)
 67: {
 68:   Vec x;

 70:   PetscFunctionBegin;
 72:   PetscCall(SNESGetFunction(snes, &x, NULL, NULL));
 73:   PetscCall(PetscViewerPushFormat(vf->viewer, vf->format));
 74:   PetscCall(VecView(x, vf->viewer));
 75:   PetscCall(PetscViewerPopFormat(vf->viewer));
 76:   PetscFunctionReturn(PETSC_SUCCESS);
 77: }

 79: /*@C
 80:   SNESMonitorSolutionUpdate - Monitors progress of a `SNESSolve()` by calling
 81:   `VecView()` for the UPDATE to the solution at each iteration.

 83:   Collective

 85:   Input Parameters:
 86: + snes   - the `SNES` context
 87: . its    - iteration number
 88: . fgnorm - 2-norm of residual
 89: - vf     - a viewer

 91:   Options Database Key:
 92: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration

 94:   Level: intermediate

 96:   Note:
 97:   This is not called directly by users, rather one calls `SNESMonitorSet()`, with this function as an argument, to cause the monitor
 98:   to be used during the `SNES` solve.

100: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorDefault()`, `VecView()`, `SNESMonitor()`
101: @*/
102: PetscErrorCode SNESMonitorSolutionUpdate(SNES snes, PetscInt its, PetscReal fgnorm, PetscViewerAndFormat *vf)
103: {
104:   Vec         x;
105:   PetscViewer viewer = vf->viewer;

107:   PetscFunctionBegin;
109:   PetscCall(SNESGetSolutionUpdate(snes, &x));
110:   PetscCall(PetscViewerPushFormat(viewer, vf->format));
111:   PetscCall(VecView(x, viewer));
112:   PetscCall(PetscViewerPopFormat(viewer));
113:   PetscFunctionReturn(PETSC_SUCCESS);
114: }

116: #include <petscdraw.h>

118: /*@C
119:   KSPMonitorSNESResidual - Prints the `SNES` residual norm, as well as the `KSP` residual norm, at each iteration of a `KSPSolve()` called within a `SNESSolve()`.

121:   Collective

123:   Input Parameters:
124: + ksp   - iterative context
125: . n     - iteration number
126: . rnorm - 2-norm (preconditioned) residual value (may be estimated).
127: - vf    - The viewer context

129:   Options Database Key:
130: . -snes_monitor_ksp - Activates `KSPMonitorSNESResidual()`

132:   Level: intermediate

134:   Note:
135:   This is not called directly by users, rather one calls `KSPMonitorSet()`, with this function as an argument, to cause the monitor
136:   to be used during the `KSP` solve.

138: .seealso: [](ch_snes), `SNES`, `KSPMonitorSet()`, `KSPMonitorResidual()`, `KSPMonitorTrueResidualMaxNorm()`, `KSPMonitor()`, `SNESMonitor()`, `PetscViewerAndFormat()`
139: @*/
140: PetscErrorCode KSPMonitorSNESResidual(KSP ksp, PetscInt n, PetscReal rnorm, PetscViewerAndFormat *vf)
141: {
142:   PetscViewer       viewer = vf->viewer;
143:   PetscViewerFormat format = vf->format;
144:   SNES              snes   = (SNES)vf->data;
145:   Vec               snes_solution, work1, work2;
146:   PetscReal         snorm;
147:   PetscInt          tablevel;
148:   const char       *prefix;

150:   PetscFunctionBegin;
152:   PetscCall(SNESGetSolution(snes, &snes_solution));
153:   PetscCall(VecDuplicate(snes_solution, &work1));
154:   PetscCall(VecDuplicate(snes_solution, &work2));
155:   PetscCall(KSPBuildSolution(ksp, work1, NULL));
156:   PetscCall(VecAYPX(work1, -1.0, snes_solution));
157:   PetscCall(SNESComputeFunction(snes, work1, work2));
158:   PetscCall(VecNorm(work2, NORM_2, &snorm));
159:   PetscCall(VecDestroy(&work1));
160:   PetscCall(VecDestroy(&work2));

162:   PetscCall(PetscObjectGetTabLevel((PetscObject)ksp, &tablevel));
163:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)ksp, &prefix));
164:   PetscCall(PetscViewerPushFormat(viewer, format));
165:   PetscCall(PetscViewerASCIIAddTab(viewer, tablevel));
166:   if (n == 0 && prefix) PetscCall(PetscViewerASCIIPrintf(viewer, "  Residual norms for %s solve.\n", prefix));
167:   PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES Residual norm %5.3e KSP Residual norm %5.3e\n", n, (double)snorm, (double)rnorm));
168:   PetscCall(PetscViewerASCIISubtractTab(viewer, tablevel));
169:   PetscCall(PetscViewerPopFormat(viewer));
170:   PetscFunctionReturn(PETSC_SUCCESS);
171: }

173: /*@C
174:   KSPMonitorSNESResidualDrawLG - Plots the linear `KSP` residual norm and the `SNES` residual norm of a `KSPSolve()` called within a `SNESSolve()`.

176:   Collective

178:   Input Parameters:
179: + ksp   - iterative context
180: . n     - iteration number
181: . rnorm - 2-norm (preconditioned) residual value (may be estimated).
182: - vf    - The viewer context, created with `KSPMonitorSNESResidualDrawLGCreate()`

184:   Options Database Key:
185: . -snes_monitor_ksp draw::draw_lg - Activates `KSPMonitorSNESResidualDrawLG()`

187:   Level: intermediate

189:   Note:
190:   This is not called directly by users, rather one calls `SNESMonitorSet()`, with this function as an argument, to cause the monitor
191:   to be used during the `SNESSolve()`

193: .seealso: [](ch_snes), `KSPMonitorSet()`, `KSPMonitorTrueResidual()`, `SNESMonitor()`, `KSPMonitor()`, `KSPMonitorSNESResidualDrawLGCreate()`
194: @*/
195: PetscErrorCode KSPMonitorSNESResidualDrawLG(KSP ksp, PetscInt n, PetscReal rnorm, PetscViewerAndFormat *vf)
196: {
197:   PetscViewer        viewer = vf->viewer;
198:   PetscViewerFormat  format = vf->format;
199:   PetscDrawLG        lg     = vf->lg;
200:   SNES               snes   = (SNES)vf->data;
201:   Vec                snes_solution, work1, work2;
202:   PetscReal          snorm;
203:   KSPConvergedReason reason;
204:   PetscReal          x[2], y[2];

206:   PetscFunctionBegin;
209:   PetscCall(SNESGetSolution(snes, &snes_solution));
210:   PetscCall(VecDuplicate(snes_solution, &work1));
211:   PetscCall(VecDuplicate(snes_solution, &work2));
212:   PetscCall(KSPBuildSolution(ksp, work1, NULL));
213:   PetscCall(VecAYPX(work1, -1.0, snes_solution));
214:   PetscCall(SNESComputeFunction(snes, work1, work2));
215:   PetscCall(VecNorm(work2, NORM_2, &snorm));
216:   PetscCall(VecDestroy(&work1));
217:   PetscCall(VecDestroy(&work2));

219:   PetscCall(PetscViewerPushFormat(viewer, format));
220:   if (!n) PetscCall(PetscDrawLGReset(lg));
221:   x[0] = (PetscReal)n;
222:   if (rnorm > 0.0) y[0] = PetscLog10Real(rnorm);
223:   else y[0] = -15.0;
224:   x[1] = (PetscReal)n;
225:   if (snorm > 0.0) y[1] = PetscLog10Real(snorm);
226:   else y[1] = -15.0;
227:   PetscCall(PetscDrawLGAddPoint(lg, x, y));
228:   PetscCall(KSPGetConvergedReason(ksp, &reason));
229:   if (n <= 20 || !(n % 5) || reason) {
230:     PetscCall(PetscDrawLGDraw(lg));
231:     PetscCall(PetscDrawLGSave(lg));
232:   }
233:   PetscCall(PetscViewerPopFormat(viewer));
234:   PetscFunctionReturn(PETSC_SUCCESS);
235: }

237: /*@C
238:   KSPMonitorSNESResidualDrawLGCreate - Creates the `PetscViewer` used by `KSPMonitorSNESResidualDrawLG()`

240:   Collective

242:   Input Parameters:
243: + viewer - The `PetscViewer`
244: . format - The viewer format
245: - ctx    - An optional user context

247:   Output Parameter:
248: . vf - The viewer context

250:   Level: intermediate

252: .seealso: [](ch_snes), `KSP`, `SNES`, `PetscViewerFormat`, `PetscViewerAndFormat`, `KSPMonitorSet()`, `KSPMonitorTrueResidual()`
253: @*/
254: PetscErrorCode KSPMonitorSNESResidualDrawLGCreate(PetscViewer viewer, PetscViewerFormat format, void *ctx, PetscViewerAndFormat **vf)
255: {
256:   const char *names[] = {"linear", "nonlinear"};

258:   PetscFunctionBegin;
259:   PetscCall(PetscViewerAndFormatCreate(viewer, format, vf));
260:   (*vf)->data = ctx;
261:   PetscCall(KSPMonitorLGCreate(PetscObjectComm((PetscObject)viewer), NULL, NULL, "Log Residual Norm", 2, names, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &(*vf)->lg));
262:   PetscFunctionReturn(PETSC_SUCCESS);
263: }

265: PetscErrorCode SNESMonitorDefaultSetUp(SNES snes, PetscViewerAndFormat *vf)
266: {
267:   PetscFunctionBegin;
268:   if (vf->format == PETSC_VIEWER_DRAW_LG) PetscCall(KSPMonitorLGCreate(PetscObjectComm((PetscObject)vf->viewer), NULL, NULL, "Log Residual Norm", 1, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &vf->lg));
269:   PetscFunctionReturn(PETSC_SUCCESS);
270: }

272: /*@C
273:   SNESMonitorDefault - Monitors progress of a `SNESSolve()` (default).

275:   Collective

277:   Input Parameters:
278: + snes   - the `SNES` context
279: . its    - iteration number
280: . fgnorm - 2-norm of residual
281: - vf     - viewer and format structure

283:   Options Database Key:
284: . -snes_monitor - use this function to monitor the convergence of the nonlinear solver

286:   Level: intermediate

288:   Notes:
289:   Prints the residual norm at each iteration.

291:   This is not called directly by users, rather one calls `SNESMonitorSet()`, with this function as an argument, to cause the monitor
292:   to be used during the `SNES` solve.

294: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSolution()`, `SNESMonitorFunction()`, `SNESMonitorResidual()`,
295:           `SNESMonitorSolutionUpdate()`, `SNESMonitorScaling()`, `SNESMonitorRange()`, `SNESMonitorRatio()`,
296:           `SNESMonitorDefaultField()`, `PetscViewerFormat`, `PetscViewerAndFormat`
297: @*/
298: PetscErrorCode SNESMonitorDefault(SNES snes, PetscInt its, PetscReal fgnorm, PetscViewerAndFormat *vf)
299: {
300:   PetscViewer       viewer = vf->viewer;
301:   PetscViewerFormat format = vf->format;
302:   PetscBool         isascii, isdraw;

304:   PetscFunctionBegin;
306:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
307:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
308:   PetscCall(PetscViewerPushFormat(viewer, format));
309:   if (isascii) {
310:     PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
311:     if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
312:       Vec              dx;
313:       PetscReal        upnorm;
314:       SNESObjectiveFn *objective;

316:       PetscCall(SNESGetSolutionUpdate(snes, &dx));
317:       PetscCall(VecNorm(dx, NORM_2, &upnorm));
318:       PetscCall(SNESGetObjective(snes, &objective, NULL));
319:       if (objective) {
320:         Vec       x;
321:         PetscReal obj;

323:         PetscCall(SNESGetSolution(snes, &x));
324:         PetscCall(SNESComputeObjective(snes, x, &obj));
325:         PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES Function norm %14.12e, Update norm %14.12e, Objective %14.12e\n", its, (double)fgnorm, (double)upnorm, (double)obj));
326:       } else {
327:         PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES Function norm %14.12e, Update norm %14.12e\n", its, (double)fgnorm, (double)upnorm));
328:       }
329:     } else {
330:       PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES Function norm %14.12e\n", its, (double)fgnorm));
331:     }
332:     PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
333:   } else if (isdraw) {
334:     if (format == PETSC_VIEWER_DRAW_LG) {
335:       PetscDrawLG lg = (PetscDrawLG)vf->lg;
336:       PetscReal   x, y;

339:       if (!its) PetscCall(PetscDrawLGReset(lg));
340:       x = (PetscReal)its;
341:       if (fgnorm > 0.0) y = PetscLog10Real(fgnorm);
342:       else y = -15.0;
343:       PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
344:       if (its <= 20 || !(its % 5) || snes->reason) {
345:         PetscCall(PetscDrawLGDraw(lg));
346:         PetscCall(PetscDrawLGSave(lg));
347:       }
348:     }
349:   }
350:   PetscCall(PetscViewerPopFormat(viewer));
351:   PetscFunctionReturn(PETSC_SUCCESS);
352: }

354: /*@C
355:   SNESMonitorScaling - Monitors the largest value in each row of the Jacobian of a `SNESSolve()`

357:   Collective

359:   Input Parameters:
360: + snes   - the `SNES` context
361: . its    - iteration number
362: . fgnorm - 2-norm of residual
363: - vf     - viewer and format structure

365:   Level: intermediate

367:   Notes:
368:   This routine prints the largest value in each row of the Jacobian

370:   This is not called directly by users, rather one calls `SNESMonitorSet()`, with this function as an argument, to cause the monitor
371:   to be used during the `SNES` solve.

373: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSolution()`, `SNESMonitorRange()`, `SNESMonitorJacUpdateSpectrum()`,
374:           `PetscViewerFormat`, `PetscViewerAndFormat`
375: @*/
376: PetscErrorCode SNESMonitorScaling(SNES snes, PetscInt its, PetscReal fgnorm, PetscViewerAndFormat *vf)
377: {
378:   PetscViewer viewer = vf->viewer;
379:   KSP         ksp;
380:   Mat         J;
381:   Vec         v;

383:   PetscFunctionBegin;
385:   PetscCall(SNESGetKSP(snes, &ksp));
386:   PetscCall(KSPGetOperators(ksp, &J, NULL));
387:   PetscCall(MatCreateVecs(J, &v, NULL));
388:   PetscCall(MatGetRowMaxAbs(J, v, NULL));
389:   PetscCall(PetscViewerPushFormat(viewer, vf->format));
390:   PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
391:   PetscCall(PetscViewerASCIIPrintf(viewer, "SNES Jacobian maximum row entries\n"));
392:   PetscCall(VecView(v, viewer));
393:   PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
394:   PetscCall(PetscViewerPopFormat(viewer));
395:   PetscCall(VecDestroy(&v));
396:   PetscFunctionReturn(PETSC_SUCCESS);
397: }

399: /*@C
400:   SNESMonitorJacUpdateSpectrum - Monitors the spectrun of the change in the Jacobian from the last Jacobian evaluation of a `SNESSolve()`

402:   Collective

404:   Input Parameters:
405: + snes  - the `SNES` context
406: . it    - iteration number
407: . fnorm - 2-norm of residual
408: - vf    - viewer and format structure

410:   Options Database Key:
411: . -snes_monitor_jacupdate_spectrum - activates this monitor

413:   Level: intermediate

415:   Notes:
416:   This routine prints the eigenvalues of the difference in the Jacobians

418:   This is not called directly by users, rather one calls `SNESMonitorSet()`, with this function as an argument, to cause the monitor
419:   to be used during the `SNES` solve.

421: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSolution()`, `SNESMonitorRange()`, `PetscViewerFormat`, `PetscViewerAndFormat`
422: @*/
423: PetscErrorCode SNESMonitorJacUpdateSpectrum(SNES snes, PetscInt it, PetscReal fnorm, PetscViewerAndFormat *vf)
424: {
425:   Vec X;
426:   Mat J, dJ, dJdense;
427:   PetscErrorCode (*func)(SNES, Vec, Mat, Mat, void *);
428:   PetscInt     n;
429:   PetscBLASInt nb = 0, lwork;
430:   PetscReal   *eigr, *eigi;
431:   PetscScalar *work;
432:   PetscScalar *a;

434:   PetscFunctionBegin;
435:   if (it == 0) PetscFunctionReturn(PETSC_SUCCESS);
436:   /* create the difference between the current update and the current Jacobian */
437:   PetscCall(SNESGetSolution(snes, &X));
438:   PetscCall(SNESGetJacobian(snes, NULL, &J, &func, NULL));
439:   PetscCall(MatDuplicate(J, MAT_COPY_VALUES, &dJ));
440:   PetscCall(SNESComputeJacobian(snes, X, dJ, dJ));
441:   PetscCall(MatAXPY(dJ, -1.0, J, SAME_NONZERO_PATTERN));

443:   /* compute the spectrum directly */
444:   PetscCall(MatConvert(dJ, MATSEQDENSE, MAT_INITIAL_MATRIX, &dJdense));
445:   PetscCall(MatGetSize(dJ, &n, NULL));
446:   PetscCall(PetscBLASIntCast(n, &nb));
447:   lwork = 3 * nb;
448:   PetscCall(PetscMalloc1(n, &eigr));
449:   PetscCall(PetscMalloc1(n, &eigi));
450:   PetscCall(PetscMalloc1(lwork, &work));
451:   PetscCall(MatDenseGetArray(dJdense, &a));
452: #if !defined(PETSC_USE_COMPLEX)
453:   {
454:     PetscBLASInt lierr;
455:     PetscInt     i;
456:     PetscCall(PetscFPTrapPush(PETSC_FP_TRAP_OFF));
457:     PetscCallBLAS("LAPACKgeev", LAPACKgeev_("N", "N", &nb, a, &nb, eigr, eigi, NULL, &nb, NULL, &nb, work, &lwork, &lierr));
458:     PetscCheck(!lierr, PETSC_COMM_SELF, PETSC_ERR_LIB, "geev() error %" PetscBLASInt_FMT, lierr);
459:     PetscCall(PetscFPTrapPop());
460:     PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Eigenvalues of J_%" PetscInt_FMT " - J_%" PetscInt_FMT ":\n", it, it - 1));
461:     for (i = 0; i < n; i++) PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "%5" PetscInt_FMT ": %20.5g + %20.5gi\n", i, (double)eigr[i], (double)eigi[i]));
462:   }
463:   PetscCall(MatDenseRestoreArray(dJdense, &a));
464:   PetscCall(MatDestroy(&dJ));
465:   PetscCall(MatDestroy(&dJdense));
466:   PetscCall(PetscFree(eigr));
467:   PetscCall(PetscFree(eigi));
468:   PetscCall(PetscFree(work));
469:   PetscFunctionReturn(PETSC_SUCCESS);
470: #else
471:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Not coded for complex");
472: #endif
473: }

475: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);

477: PetscErrorCode SNESMonitorRange_Private(SNES snes, PetscInt it, PetscReal *per)
478: {
479:   Vec          resid;
480:   PetscReal    rmax, pwork;
481:   PetscInt     i, n, N;
482:   PetscScalar *r;

484:   PetscFunctionBegin;
485:   PetscCall(SNESGetFunction(snes, &resid, NULL, NULL));
486:   PetscCall(VecNorm(resid, NORM_INFINITY, &rmax));
487:   PetscCall(VecGetLocalSize(resid, &n));
488:   PetscCall(VecGetSize(resid, &N));
489:   PetscCall(VecGetArray(resid, &r));
490:   pwork = 0.0;
491:   for (i = 0; i < n; i++) pwork += (PetscAbsScalar(r[i]) > .20 * rmax);
492:   PetscCallMPI(MPIU_Allreduce(&pwork, per, 1, MPIU_REAL, MPIU_SUM, PetscObjectComm((PetscObject)snes)));
493:   PetscCall(VecRestoreArray(resid, &r));
494:   *per = *per / N;
495:   PetscFunctionReturn(PETSC_SUCCESS);
496: }

498: /*@C
499:   SNESMonitorRange - Prints the percentage of residual elements that are more than 10 percent of the maximum entry in the residual in each iteration of a `SNESSolve()`

501:   Collective

503:   Input Parameters:
504: + snes  - `SNES` iterative context
505: . it    - iteration number
506: . rnorm - 2-norm (preconditioned) residual value (may be estimated).
507: - vf    - unused monitor context

509:   Options Database Key:
510: . -snes_monitor_range - Activates `SNESMonitorRange()`

512:   Level: intermediate

514:   Note:
515:   This is not called directly by users, rather one calls `SNESMonitorSet()`, with this function as an argument, to cause the monitor
516:   to be used during the `SNES` solve.

518: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorDefault()`, `SNESMonitorLGCreate()`, `SNESMonitorScaling()`, `PetscViewerFormat`, `PetscViewerAndFormat`
519: @*/
520: PetscErrorCode SNESMonitorRange(SNES snes, PetscInt it, PetscReal rnorm, PetscViewerAndFormat *vf)
521: {
522:   PetscReal   perc, rel;
523:   PetscViewer viewer = vf->viewer;
524:   /* should be in a MonitorRangeContext */
525:   static PetscReal prev;

527:   PetscFunctionBegin;
529:   if (!it) prev = rnorm;
530:   PetscCall(SNESMonitorRange_Private(snes, it, &perc));

532:   rel  = (prev - rnorm) / prev;
533:   prev = rnorm;
534:   PetscCall(PetscViewerPushFormat(viewer, vf->format));
535:   PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
536:   PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES preconditioned resid norm %14.12e Percent values above 20 percent of maximum %5.2g relative decrease %5.2e ratio %5.2e\n", it, (double)rnorm, (double)(100.0 * perc), (double)rel, (double)(rel / perc)));
537:   PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
538:   PetscCall(PetscViewerPopFormat(viewer));
539:   PetscFunctionReturn(PETSC_SUCCESS);
540: }

542: /*@C
543:   SNESMonitorRatio - Monitors progress of a `SNESSolve()` by printing the ratio of residual norm at each iteration to the previous.

545:   Collective

547:   Input Parameters:
548: + snes   - the `SNES` context
549: . its    - iteration number
550: . fgnorm - 2-norm of residual (or gradient)
551: - vf     - context of monitor

553:   Options Database Key:
554: . -snes_monitor_ratio - activate this monitor

556:   Level: intermediate

558:   Notes:
559:   This is not called directly by users, rather one calls `SNESMonitorSet()`, with this function as an argument, to cause the monitor
560:   to be used during the `SNES` solve.

562:   Be sure to call `SNESMonitorRationSetUp()` before using this monitor.

564: .seealso: [](ch_snes), `SNESMonitorRationSetUp()`, `SNESMonitorSet()`, `SNESMonitorSolution()`, `SNESMonitorDefault()`, `PetscViewerFormat`, `PetscViewerAndFormat`
565: @*/
566: PetscErrorCode SNESMonitorRatio(SNES snes, PetscInt its, PetscReal fgnorm, PetscViewerAndFormat *vf)
567: {
568:   PetscInt    len;
569:   PetscReal  *history;
570:   PetscViewer viewer = vf->viewer;

572:   PetscFunctionBegin;
573:   PetscCall(SNESGetConvergenceHistory(snes, &history, NULL, &len));
574:   PetscCall(PetscViewerPushFormat(viewer, vf->format));
575:   PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
576:   if (!its || !history || its > len) {
577:     PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES Function norm %14.12e\n", its, (double)fgnorm));
578:   } else {
579:     PetscReal ratio = fgnorm / history[its - 1];
580:     PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES Function norm %14.12e %14.12e\n", its, (double)fgnorm, (double)ratio));
581:   }
582:   PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
583:   PetscCall(PetscViewerPopFormat(viewer));
584:   PetscFunctionReturn(PETSC_SUCCESS);
585: }

587: /*@C
588:   SNESMonitorRatioSetUp - Insures the `SNES` object is saving its history since this monitor needs access to it

590:   Collective

592:   Input Parameters:
593: + snes - the `SNES` context
594: - vf   - `PetscViewerAndFormat` (ignored)

596:   Level: intermediate

598: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSolution()`, `SNESMonitorDefault()`, `SNESMonitorRatio()`, `PetscViewerFormat`, `PetscViewerAndFormat`
599: @*/
600: PetscErrorCode SNESMonitorRatioSetUp(SNES snes, PetscViewerAndFormat *vf)
601: {
602:   PetscReal *history;

604:   PetscFunctionBegin;
605:   PetscCall(SNESGetConvergenceHistory(snes, &history, NULL, NULL));
606:   if (!history) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, 100, PETSC_TRUE));
607:   PetscFunctionReturn(PETSC_SUCCESS);
608: }

610: /*
611:      Default (short) SNES Monitor, same as SNESMonitorDefault() except
612:   it prints fewer digits of the residual as the residual gets smaller.
613:   This is because the later digits are meaningless and are often
614:   different on different machines; by using this routine different
615:   machines will usually generate the same output.

617:   Deprecated: Intentionally has no manual page
618: */
619: PetscErrorCode SNESMonitorDefaultShort(SNES snes, PetscInt its, PetscReal fgnorm, PetscViewerAndFormat *vf)
620: {
621:   PetscViewer viewer = vf->viewer;

623:   PetscFunctionBegin;
625:   PetscCall(PetscViewerPushFormat(viewer, vf->format));
626:   PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
627:   if (fgnorm > 1.e-9) {
628:     PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES Function norm %g\n", its, (double)fgnorm));
629:   } else if (fgnorm > 1.e-11) {
630:     PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES Function norm %5.3e\n", its, (double)fgnorm));
631:   } else {
632:     PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES Function norm < 1.e-11\n", its));
633:   }
634:   PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
635:   PetscCall(PetscViewerPopFormat(viewer));
636:   PetscFunctionReturn(PETSC_SUCCESS);
637: }

639: /*@C
640:   SNESMonitorDefaultField - Monitors progress of a `SNESSolve()`, separated into fields.

642:   Collective

644:   Input Parameters:
645: + snes   - the `SNES` context
646: . its    - iteration number
647: . fgnorm - 2-norm of residual
648: - vf     - the PetscViewer

650:   Options Database Key:
651: . -snes_monitor_field - activate this monitor

653:   Level: intermediate

655:   Notes:
656:   This routine uses the `DM` attached to the residual vector to define the fields.

658:   This is not called directly by users, rather one calls `SNESMonitorSet()`, with this function as an argument, to cause the monitor
659:   to be used during the `SNES` solve.

661: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSolution()`, `SNESMonitorDefault()`, `PetscViewerFormat`, `PetscViewerAndFormat`
662: @*/
663: PetscErrorCode SNESMonitorDefaultField(SNES snes, PetscInt its, PetscReal fgnorm, PetscViewerAndFormat *vf)
664: {
665:   PetscViewer viewer = vf->viewer;
666:   Vec         r;
667:   DM          dm;
668:   PetscReal   res[256];
669:   PetscInt    tablevel;

671:   PetscFunctionBegin;
673:   PetscCall(SNESGetFunction(snes, &r, NULL, NULL));
674:   PetscCall(VecGetDM(r, &dm));
675:   if (!dm) PetscCall(SNESMonitorDefault(snes, its, fgnorm, vf));
676:   else {
677:     PetscSection s, gs;
678:     PetscInt     Nf, f;

680:     PetscCall(DMGetLocalSection(dm, &s));
681:     PetscCall(DMGetGlobalSection(dm, &gs));
682:     if (!s || !gs) PetscCall(SNESMonitorDefault(snes, its, fgnorm, vf));
683:     PetscCall(PetscSectionGetNumFields(s, &Nf));
684:     PetscCheck(Nf <= 256, PetscObjectComm((PetscObject)snes), PETSC_ERR_SUP, "Do not support %" PetscInt_FMT " fields > 256", Nf);
685:     PetscCall(PetscSectionVecNorm(s, gs, r, NORM_2, res));
686:     PetscCall(PetscObjectGetTabLevel((PetscObject)snes, &tablevel));
687:     PetscCall(PetscViewerPushFormat(viewer, vf->format));
688:     PetscCall(PetscViewerASCIIAddTab(viewer, tablevel));
689:     PetscCall(PetscViewerASCIIPrintf(viewer, "%3" PetscInt_FMT " SNES Function norm %14.12e [", its, (double)fgnorm));
690:     for (f = 0; f < Nf; ++f) {
691:       if (f) PetscCall(PetscViewerASCIIPrintf(viewer, ", "));
692:       PetscCall(PetscViewerASCIIPrintf(viewer, "%14.12e", (double)res[f]));
693:     }
694:     PetscCall(PetscViewerASCIIPrintf(viewer, "] \n"));
695:     PetscCall(PetscViewerASCIISubtractTab(viewer, tablevel));
696:     PetscCall(PetscViewerPopFormat(viewer));
697:   }
698:   PetscFunctionReturn(PETSC_SUCCESS);
699: }

701: /*@C
702:   SNESConvergedDefault - Default convergence test for `SNESSolve()`.

704:   Collective

706:   Input Parameters:
707: + snes  - the `SNES` context
708: . it    - the iteration (0 indicates before any Newton steps)
709: . xnorm - 2-norm of current iterate
710: . snorm - 2-norm of current step
711: . fnorm - 2-norm of function at current iterate
712: - dummy - unused context

714:   Output Parameter:
715: . reason - converged reason, see `SNESConvergedReason`

717:   Options Database Keys:
718: + -snes_convergence_test default      - see `SNESSetFromOptions()`
719: . -snes_stol                          - convergence tolerance in terms of the norm of the change in the solution between steps
720: . -snes_atol <abstol>                 - absolute tolerance of residual norm
721: . -snes_rtol <rtol>                   - relative decrease in tolerance norm from the initial 2-norm of the solution
722: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
723: . -snes_max_funcs <max_funcs>         - maximum number of function evaluations, use `unlimited` for no maximum
724: . -snes_max_fail <max_fail>           - maximum number of line search failures allowed before stopping, default is none
725: - -snes_max_linear_solve_fail         - number of linear solver failures before `SNESSolve()` stops

727:   Level: developer

729:   Notes:
730:   This routine is not generally called directly. It is set with `SNESSetConvergenceTest()` automatically before the `SNESSolve()`.

732:   It can be called within a custom convergence test that should also apply the standard convergence tests

734: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESConvergedSkip()`, `SNESSetTolerances()`, `SNESSetDivergenceTolerance()`,
735:           `SNESConvergedReason`
736: @*/
737: PetscErrorCode SNESConvergedDefault(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm, SNESConvergedReason *reason, void *dummy)
738: {
739:   PetscFunctionBegin;
741:   PetscAssertPointer(reason, 6);

743:   *reason = SNES_CONVERGED_ITERATING;
744:   if (!it) {
745:     /* set parameter for default relative tolerance convergence test */
746:     snes->ttol   = fnorm * snes->rtol;
747:     snes->rnorm0 = fnorm;
748:   }
749:   if (PetscIsInfOrNanReal(fnorm)) {
750:     PetscCall(PetscInfo(snes, "Failed to converged, function norm is NaN\n"));
751:     *reason = SNES_DIVERGED_FNORM_NAN;
752:   } else if (fnorm < snes->abstol && (it || !snes->forceiteration)) {
753:     PetscCall(PetscInfo(snes, "Converged due to function norm %14.12e < %14.12e\n", (double)fnorm, (double)snes->abstol));
754:     *reason = SNES_CONVERGED_FNORM_ABS;
755:   } else if (snes->nfuncs >= snes->max_funcs && snes->max_funcs >= 0) {
756:     PetscCall(PetscInfo(snes, "Exceeded maximum number of function evaluations: %" PetscInt_FMT " > %" PetscInt_FMT "\n", snes->nfuncs, snes->max_funcs));
757:     *reason = SNES_DIVERGED_FUNCTION_COUNT;
758:   }

760:   if (it && !*reason) {
761:     if (fnorm <= snes->ttol) {
762:       PetscCall(PetscInfo(snes, "Converged due to function norm %14.12e < %14.12e (relative tolerance)\n", (double)fnorm, (double)snes->ttol));
763:       *reason = SNES_CONVERGED_FNORM_RELATIVE;
764:     } else if (snorm < snes->stol * xnorm) {
765:       PetscCall(PetscInfo(snes, "Converged due to small update length: %14.12e < %14.12e * %14.12e\n", (double)snorm, (double)snes->stol, (double)xnorm));
766:       *reason = SNES_CONVERGED_SNORM_RELATIVE;
767:     } else if (snes->divtol != PETSC_UNLIMITED && (fnorm > snes->divtol * snes->rnorm0)) {
768:       PetscCall(PetscInfo(snes, "Diverged due to increase in function norm: %14.12e > %14.12e * %14.12e\n", (double)fnorm, (double)snes->divtol, (double)snes->rnorm0));
769:       *reason = SNES_DIVERGED_DTOL;
770:     }
771:   }
772:   PetscFunctionReturn(PETSC_SUCCESS);
773: }

775: /*@C
776:   SNESConvergedSkip - Convergence test for `SNES` that NEVER returns as
777:   converged, UNLESS the maximum number of iteration have been reached.

779:   Logically Collective

781:   Input Parameters:
782: + snes  - the `SNES` context
783: . it    - the iteration (0 indicates before any Newton steps)
784: . xnorm - 2-norm of current iterate
785: . snorm - 2-norm of current step
786: . fnorm - 2-norm of function at current iterate
787: - dummy - unused context

789:   Output Parameter:
790: . reason - `SNES_CONVERGED_ITERATING`, `SNES_CONVERGED_ITS`, or `SNES_DIVERGED_FNORM_NAN`

792:   Options Database Key:
793: . -snes_convergence_test skip - see `SNESSetFromOptions()`

795:   Level: advanced

797: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedDefault()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
798: @*/
799: PetscErrorCode SNESConvergedSkip(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm, SNESConvergedReason *reason, void *dummy)
800: {
801:   PetscFunctionBegin;
803:   PetscAssertPointer(reason, 6);

805:   *reason = SNES_CONVERGED_ITERATING;

807:   if (fnorm != fnorm) {
808:     PetscCall(PetscInfo(snes, "Failed to converged, function norm is NaN\n"));
809:     *reason = SNES_DIVERGED_FNORM_NAN;
810:   } else if (it == snes->max_its) {
811:     *reason = SNES_CONVERGED_ITS;
812:   }
813:   PetscFunctionReturn(PETSC_SUCCESS);
814: }

816: /*@
817:   SNESSetWorkVecs - Allocates a number of work vectors to be used internally by `SNES` solvers

819:   Input Parameters:
820: + snes - the `SNES` context
821: - nw   - number of work vectors to allocate

823:   Level: developer

825:   Note:
826:   Each `SNESType` calls this with the number of work vectors that particular type needs.

828: .seealso: [](ch_snes), `SNES`
829: @*/
830: PetscErrorCode SNESSetWorkVecs(SNES snes, PetscInt nw)
831: {
832:   DM  dm;
833:   Vec v;

835:   PetscFunctionBegin;
836:   if (snes->work) PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
837:   snes->nwork = nw;

839:   PetscCall(SNESGetDM(snes, &dm));
840:   PetscCall(DMGetGlobalVector(dm, &v));
841:   PetscCall(VecDuplicateVecs(v, snes->nwork, &snes->work));
842:   PetscCall(DMRestoreGlobalVector(dm, &v));
843:   PetscFunctionReturn(PETSC_SUCCESS);
844: }