Actual source code: snes.c
1: #include <petsc/private/snesimpl.h>
2: #include <petscdmshell.h>
3: #include <petscdraw.h>
4: #include <petscds.h>
5: #include <petscdmadaptor.h>
6: #include <petscconvest.h>
8: PetscBool SNESRegisterAllCalled = PETSC_FALSE;
9: PetscFunctionList SNESList = NULL;
11: /* Logging support */
12: PetscClassId SNES_CLASSID, DMSNES_CLASSID;
13: PetscLogEvent SNES_Solve, SNES_SetUp, SNES_FunctionEval, SNES_JacobianEval, SNES_NGSEval, SNES_NGSFuncEval, SNES_NPCSolve, SNES_ObjectiveEval;
15: /*@
16: SNESSetErrorIfNotConverged - Causes `SNESSolve()` to generate an error immediately if the solver has not converged.
18: Logically Collective
20: Input Parameters:
21: + snes - iterative context obtained from `SNESCreate()`
22: - flg - `PETSC_TRUE` indicates you want the error generated
24: Options database keys:
25: . -snes_error_if_not_converged <true,false> - cause an immediate error condition and stop the program if the solver does not converge
27: Level: intermediate
29: Note:
30: Normally PETSc continues if a solver fails to converge, you can call `SNESGetConvergedReason()` after a `SNESSolve()`
31: to determine if it has converged. Otherwise the solution may be inaccurate or wrong
33: .seealso: [](chapter_snes), `SNES`, `SNESGetErrorIfNotConverged()`, `KSPGetErrorIfNotConverged()`, `KSPSetErrorIfNotConverged()`
34: @*/
35: PetscErrorCode SNESSetErrorIfNotConverged(SNES snes, PetscBool flg)
36: {
37: PetscFunctionBegin;
40: snes->errorifnotconverged = flg;
41: PetscFunctionReturn(PETSC_SUCCESS);
42: }
44: /*@
45: SNESGetErrorIfNotConverged - Indicates if `SNESSolve()` will generate an error if the solver does not converge?
47: Not Collective
49: Input Parameter:
50: . snes - iterative context obtained from `SNESCreate()`
52: Output Parameter:
53: . flag - `PETSC_TRUE` if it will generate an error, else `PETSC_FALSE`
55: Level: intermediate
57: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESSetErrorIfNotConverged()`, `KSPGetErrorIfNotConverged()`, `KSPSetErrorIfNotConverged()`
58: @*/
59: PetscErrorCode SNESGetErrorIfNotConverged(SNES snes, PetscBool *flag)
60: {
61: PetscFunctionBegin;
64: *flag = snes->errorifnotconverged;
65: PetscFunctionReturn(PETSC_SUCCESS);
66: }
68: /*@
69: SNESSetAlwaysComputesFinalResidual - tells the `SNES` to always compute the residual (nonlinear function value) at the final solution
71: Logically Collective
73: Input Parameters:
74: + snes - the shell `SNES`
75: - flg - `PETSC_TRUE` to always compute the residual
77: Level: advanced
79: Note:
80: Some solvers (such as smoothers in a `SNESFAS`) do not need the residual computed at the final solution so skip computing it
81: to save time.
83: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetAlwaysComputesFinalResidual()`
84: @*/
85: PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES snes, PetscBool flg)
86: {
87: PetscFunctionBegin;
89: snes->alwayscomputesfinalresidual = flg;
90: PetscFunctionReturn(PETSC_SUCCESS);
91: }
93: /*@
94: SNESGetAlwaysComputesFinalResidual - checks if the `SNES` always computes the residual at the final solution
96: Logically Collective
98: Input Parameter:
99: . snes - the `SNES` context
101: Output Parameter:
102: . flg - `PETSC_TRUE` if the residual is computed
104: Level: advanced
106: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESSetAlwaysComputesFinalResidual()`
107: @*/
108: PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES snes, PetscBool *flg)
109: {
110: PetscFunctionBegin;
112: *flg = snes->alwayscomputesfinalresidual;
113: PetscFunctionReturn(PETSC_SUCCESS);
114: }
116: /*@
117: SNESSetFunctionDomainError - tells `SNES` that the input vector, a proposed new solution, to your function you provided to `SNESSetFunction()` is not
118: in the functions domain. For example, a step with negative pressure.
120: Logically Collective
122: Input Parameters:
123: . snes - the `SNES` context
125: Level: advanced
127: Note:
128: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
129: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
131: .seealso: [](chapter_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunction`, `SNESSetJacobianDomainError()`, `SNESVISetVariableBounds()`,
132: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
133: @*/
134: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
135: {
136: PetscFunctionBegin;
138: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates input vector is not in the function domain");
139: snes->domainerror = PETSC_TRUE;
140: PetscFunctionReturn(PETSC_SUCCESS);
141: }
143: /*@
144: SNESSetJacobianDomainError - tells `SNES` that the function you provided to `SNESSetJacobian()` at the proposed step. For example there is a negative element transformation.
146: Logically Collective
148: Input Parameters:
149: . snes - the `SNES` context
151: Level: advanced
153: Note:
154: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
155: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
157: .seealso: [](chapter_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESVISetVariableBounds()`,
158: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
159: @*/
160: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
161: {
162: PetscFunctionBegin;
164: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates computeJacobian does not make sense");
165: snes->jacobiandomainerror = PETSC_TRUE;
166: PetscFunctionReturn(PETSC_SUCCESS);
167: }
169: /*@
170: SNESSetCheckJacobianDomainError - tells `SNESSolve()` whether to check if the user called `SNESSetJacobianDomainError()` Jacobian domain error after
171: each Jacobian evaluation. By default, we check Jacobian domain error in the debug mode, and do not check it in the optimized mode.
173: Logically Collective
175: Input Parameters:
176: + snes - the SNES context
177: - flg - indicates if or not to check Jacobian domain error after each Jacobian evaluation
179: Level: advanced
181: Note:
182: Checks require one extra parallel synchronization for each Jacobian evaluation
184: .seealso: [](chapter_snes), `SNES`, `SNESConvergedReason`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESGetCheckJacobianDomainError()`
185: @*/
186: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
187: {
188: PetscFunctionBegin;
190: snes->checkjacdomainerror = flg;
191: PetscFunctionReturn(PETSC_SUCCESS);
192: }
194: /*@
195: SNESGetCheckJacobianDomainError - Get an indicator whether or not we are checking Jacobian domain errors after each Jacobian evaluation.
197: Logically Collective
199: Input Parameters:
200: . snes - the `SNES` context
202: Output Parameters:
203: . flg - `PETSC_FALSE` indicates that we don't check Jacobian domain errors after each Jacobian evaluation
205: Level: advanced
207: .seealso: [](chapter_snes), `SNES`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESSetCheckJacobianDomainError()`
208: @*/
209: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
210: {
211: PetscFunctionBegin;
214: *flg = snes->checkjacdomainerror;
215: PetscFunctionReturn(PETSC_SUCCESS);
216: }
218: /*@
219: SNESGetFunctionDomainError - Gets the status of the domain error after a call to `SNESComputeFunction()`;
221: Logically Collective
223: Input Parameters:
224: . snes - the `SNES` context
226: Output Parameters:
227: . domainerror - Set to `PETSC_TRUE` if there's a domain error; `PETSC_FALSE` otherwise.
229: Level: developer
231: .seealso: [](chapter_snes), `SNES`, `SNESSetFunctionDomainError()`, `SNESComputeFunction()`
232: @*/
233: PetscErrorCode SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
234: {
235: PetscFunctionBegin;
238: *domainerror = snes->domainerror;
239: PetscFunctionReturn(PETSC_SUCCESS);
240: }
242: /*@
243: SNESGetJacobianDomainError - Gets the status of the Jacobian domain error after a call to `SNESComputeJacobian()`;
245: Logically Collective
247: Input Parameters:
248: . snes - the `SNES` context
250: Output Parameters:
251: . domainerror - Set to `PETSC_TRUE` if there's a Jacobian domain error; `PETSC_FALSE` otherwise.
253: Level: advanced
255: .seealso: [](chapter_snes), `SNES`, `SNESSetFunctionDomainError()`, `SNESComputeFunction()`, `SNESGetFunctionDomainError()`
256: @*/
257: PetscErrorCode SNESGetJacobianDomainError(SNES snes, PetscBool *domainerror)
258: {
259: PetscFunctionBegin;
262: *domainerror = snes->jacobiandomainerror;
263: PetscFunctionReturn(PETSC_SUCCESS);
264: }
266: /*@C
267: SNESLoad - Loads a `SNES` that has been stored in `PETSCVIEWERBINARY` with `SNESView()`.
269: Collective
271: Input Parameters:
272: + newdm - the newly loaded `SNES`, this needs to have been created with `SNESCreate()` or
273: some related function before a call to `SNESLoad()`.
274: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()`
276: Level: intermediate
278: Note:
279: The type is determined by the data in the file, any type set into the `SNES` before this call is ignored.
281: .seealso: [](chapter_snes), `SNES`, `PetscViewer`, `SNESCreate()`, `SNESType`, `PetscViewerBinaryOpen()`, `SNESView()`, `MatLoad()`, `VecLoad()`
282: @*/
283: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
284: {
285: PetscBool isbinary;
286: PetscInt classid;
287: char type[256];
288: KSP ksp;
289: DM dm;
290: DMSNES dmsnes;
292: PetscFunctionBegin;
295: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
296: PetscCheck(isbinary, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen()");
298: PetscCall(PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT));
299: PetscCheck(classid == SNES_FILE_CLASSID, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Not SNES next in file");
300: PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
301: PetscCall(SNESSetType(snes, type));
302: PetscTryTypeMethod(snes, load, viewer);
303: PetscCall(SNESGetDM(snes, &dm));
304: PetscCall(DMGetDMSNES(dm, &dmsnes));
305: PetscCall(DMSNESLoad(dmsnes, viewer));
306: PetscCall(SNESGetKSP(snes, &ksp));
307: PetscCall(KSPLoad(ksp, viewer));
308: PetscFunctionReturn(PETSC_SUCCESS);
309: }
311: #include <petscdraw.h>
312: #if defined(PETSC_HAVE_SAWS)
313: #include <petscviewersaws.h>
314: #endif
316: /*@C
317: SNESViewFromOptions - View a `SNES` based on values in the options database
319: Collective
321: Input Parameters:
322: + A - the `SNES` context
323: . obj - Optional object that provides the options prefix for the checks
324: - name - command line option
326: Level: intermediate
328: .seealso: [](chapter_snes), `SNES`, `SNESView`, `PetscObjectViewFromOptions()`, `SNESCreate()`
329: @*/
330: PetscErrorCode SNESViewFromOptions(SNES A, PetscObject obj, const char name[])
331: {
332: PetscFunctionBegin;
334: PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
335: PetscFunctionReturn(PETSC_SUCCESS);
336: }
338: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES, Vec, Mat, Mat, void *);
340: /*@C
341: SNESView - Prints or visualizes the `SNES` data structure.
343: Collective
345: Input Parameters:
346: + snes - the `SNES` context
347: - viewer - the `PetscViewer`
349: Options Database Key:
350: . -snes_view - Calls `SNESView()` at end of `SNESSolve()`
352: Level: beginner
354: Notes:
355: The available visualization contexts include
356: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
357: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
358: output where only the first processor opens
359: the file. All other processors send their
360: data to the first processor to print.
362: The available formats include
363: + `PETSC_VIEWER_DEFAULT` - standard output (default)
364: - `PETSC_VIEWER_ASCII_INFO_DETAIL` - more verbose output for `SNESNASM`
366: The user can open an alternative visualization context with
367: `PetscViewerASCIIOpen()` - output to a specified file.
369: In the debugger you can do "call `SNESView`(snes,0)" to display the `SNES` solver. (The same holds for any PETSc object viewer).
371: .seealso: [](chapter_snes), `SNES`, `SNESLoad()`, `SNESCreate()`, `PetscViewerASCIIOpen()`
372: @*/
373: PetscErrorCode SNESView(SNES snes, PetscViewer viewer)
374: {
375: SNESKSPEW *kctx;
376: KSP ksp;
377: SNESLineSearch linesearch;
378: PetscBool iascii, isstring, isbinary, isdraw;
379: DMSNES dmsnes;
380: #if defined(PETSC_HAVE_SAWS)
381: PetscBool issaws;
382: #endif
384: PetscFunctionBegin;
386: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &viewer));
388: PetscCheckSameComm(snes, 1, viewer, 2);
390: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
391: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
392: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
393: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
394: #if defined(PETSC_HAVE_SAWS)
395: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
396: #endif
397: if (iascii) {
398: SNESNormSchedule normschedule;
399: DM dm;
400: PetscErrorCode (*cJ)(SNES, Vec, Mat, Mat, void *);
401: void *ctx;
402: const char *pre = "";
404: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)snes, viewer));
405: if (!snes->setupcalled) PetscCall(PetscViewerASCIIPrintf(viewer, " SNES has not been set up so information may be incomplete\n"));
406: if (snes->ops->view) {
407: PetscCall(PetscViewerASCIIPushTab(viewer));
408: PetscUseTypeMethod(snes, view, viewer);
409: PetscCall(PetscViewerASCIIPopTab(viewer));
410: }
411: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=%" PetscInt_FMT "\n", snes->max_its, snes->max_funcs));
412: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, solution=%g\n", (double)snes->rtol, (double)snes->abstol, (double)snes->stol));
413: if (snes->usesksp) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of linear solver iterations=%" PetscInt_FMT "\n", snes->linear_its));
414: PetscCall(PetscViewerASCIIPrintf(viewer, " total number of function evaluations=%" PetscInt_FMT "\n", snes->nfuncs));
415: PetscCall(SNESGetNormSchedule(snes, &normschedule));
416: if (normschedule > 0) PetscCall(PetscViewerASCIIPrintf(viewer, " norm schedule %s\n", SNESNormSchedules[normschedule]));
417: if (snes->gridsequence) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of grid sequence refinements=%" PetscInt_FMT "\n", snes->gridsequence));
418: if (snes->ksp_ewconv) {
419: kctx = (SNESKSPEW *)snes->kspconvctx;
420: if (kctx) {
421: PetscCall(PetscViewerASCIIPrintf(viewer, " Eisenstat-Walker computation of KSP relative tolerance (version %" PetscInt_FMT ")\n", kctx->version));
422: PetscCall(PetscViewerASCIIPrintf(viewer, " rtol_0=%g, rtol_max=%g, threshold=%g\n", (double)kctx->rtol_0, (double)kctx->rtol_max, (double)kctx->threshold));
423: PetscCall(PetscViewerASCIIPrintf(viewer, " gamma=%g, alpha=%g, alpha2=%g\n", (double)kctx->gamma, (double)kctx->alpha, (double)kctx->alpha2));
424: }
425: }
426: if (snes->lagpreconditioner == -1) {
427: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is never rebuilt\n"));
428: } else if (snes->lagpreconditioner > 1) {
429: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is rebuilt every %" PetscInt_FMT " new Jacobians\n", snes->lagpreconditioner));
430: }
431: if (snes->lagjacobian == -1) {
432: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is never rebuilt\n"));
433: } else if (snes->lagjacobian > 1) {
434: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is rebuilt every %" PetscInt_FMT " SNES iterations\n", snes->lagjacobian));
435: }
436: PetscCall(SNESGetDM(snes, &dm));
437: PetscCall(DMSNESGetJacobian(dm, &cJ, &ctx));
438: if (snes->mf_operator) {
439: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing\n"));
440: pre = "Preconditioning ";
441: }
442: if (cJ == SNESComputeJacobianDefault) {
443: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences one column at a time\n", pre));
444: } else if (cJ == SNESComputeJacobianDefaultColor) {
445: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences with coloring\n", pre));
446: /* it slightly breaks data encapsulation for access the DMDA information directly */
447: } else if (cJ == SNESComputeJacobian_DMDA) {
448: MatFDColoring fdcoloring;
449: PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
450: if (fdcoloring) {
451: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using colored finite differences on a DMDA\n", pre));
452: } else {
453: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using a DMDA local Jacobian\n", pre));
454: }
455: } else if (snes->mf) {
456: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing, no explicit Jacobian\n"));
457: }
458: } else if (isstring) {
459: const char *type;
460: PetscCall(SNESGetType(snes, &type));
461: PetscCall(PetscViewerStringSPrintf(viewer, " SNESType: %-7.7s", type));
462: PetscTryTypeMethod(snes, view, viewer);
463: } else if (isbinary) {
464: PetscInt classid = SNES_FILE_CLASSID;
465: MPI_Comm comm;
466: PetscMPIInt rank;
467: char type[256];
469: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
470: PetscCallMPI(MPI_Comm_rank(comm, &rank));
471: if (rank == 0) {
472: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
473: PetscCall(PetscStrncpy(type, ((PetscObject)snes)->type_name, sizeof(type)));
474: PetscCall(PetscViewerBinaryWrite(viewer, type, sizeof(type), PETSC_CHAR));
475: }
476: PetscTryTypeMethod(snes, view, viewer);
477: } else if (isdraw) {
478: PetscDraw draw;
479: char str[36];
480: PetscReal x, y, bottom, h;
482: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
483: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
484: PetscCall(PetscStrncpy(str, "SNES: ", sizeof(str)));
485: PetscCall(PetscStrlcat(str, ((PetscObject)snes)->type_name, sizeof(str)));
486: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_BLUE, PETSC_DRAW_BLACK, str, NULL, &h));
487: bottom = y - h;
488: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
489: PetscTryTypeMethod(snes, view, viewer);
490: #if defined(PETSC_HAVE_SAWS)
491: } else if (issaws) {
492: PetscMPIInt rank;
493: const char *name;
495: PetscCall(PetscObjectGetName((PetscObject)snes, &name));
496: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
497: if (!((PetscObject)snes)->amsmem && rank == 0) {
498: char dir[1024];
500: PetscCall(PetscObjectViewSAWs((PetscObject)snes, viewer));
501: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
502: PetscCallSAWs(SAWs_Register, (dir, &snes->iter, 1, SAWs_READ, SAWs_INT));
503: if (!snes->conv_hist) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, PETSC_DECIDE, PETSC_TRUE));
504: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/conv_hist", name));
505: PetscCallSAWs(SAWs_Register, (dir, snes->conv_hist, 10, SAWs_READ, SAWs_DOUBLE));
506: }
507: #endif
508: }
509: if (snes->linesearch) {
510: PetscCall(SNESGetLineSearch(snes, &linesearch));
511: PetscCall(PetscViewerASCIIPushTab(viewer));
512: PetscCall(SNESLineSearchView(linesearch, viewer));
513: PetscCall(PetscViewerASCIIPopTab(viewer));
514: }
515: if (snes->npc && snes->usesnpc) {
516: PetscCall(PetscViewerASCIIPushTab(viewer));
517: PetscCall(SNESView(snes->npc, viewer));
518: PetscCall(PetscViewerASCIIPopTab(viewer));
519: }
520: PetscCall(PetscViewerASCIIPushTab(viewer));
521: PetscCall(DMGetDMSNES(snes->dm, &dmsnes));
522: PetscCall(DMSNESView(dmsnes, viewer));
523: PetscCall(PetscViewerASCIIPopTab(viewer));
524: if (snes->usesksp) {
525: PetscCall(SNESGetKSP(snes, &ksp));
526: PetscCall(PetscViewerASCIIPushTab(viewer));
527: PetscCall(KSPView(ksp, viewer));
528: PetscCall(PetscViewerASCIIPopTab(viewer));
529: }
530: if (isdraw) {
531: PetscDraw draw;
532: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
533: PetscCall(PetscDrawPopCurrentPoint(draw));
534: }
535: PetscFunctionReturn(PETSC_SUCCESS);
536: }
538: /*
539: We retain a list of functions that also take SNES command
540: line options. These are called at the end SNESSetFromOptions()
541: */
542: #define MAXSETFROMOPTIONS 5
543: static PetscInt numberofsetfromoptions;
544: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
546: /*@C
547: SNESAddOptionsChecker - Adds an additional function to check for `SNES` options.
549: Not Collective
551: Input Parameter:
552: . snescheck - function that checks for options
554: Level: developer
556: .seealso: [](chapter_snes), `SNES`, `SNESSetFromOptions()`
557: @*/
558: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
559: {
560: PetscFunctionBegin;
561: PetscCheck(numberofsetfromoptions < MAXSETFROMOPTIONS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %d allowed", MAXSETFROMOPTIONS);
562: othersetfromoptions[numberofsetfromoptions++] = snescheck;
563: PetscFunctionReturn(PETSC_SUCCESS);
564: }
566: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
567: {
568: Mat J;
569: MatNullSpace nullsp;
571: PetscFunctionBegin;
574: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
575: Mat A = snes->jacobian, B = snes->jacobian_pre;
576: PetscCall(MatCreateVecs(A ? A : B, NULL, &snes->vec_func));
577: }
579: PetscCheck(version == 1 || version == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator routines, only version 1 and 2");
580: if (version == 1) {
581: PetscCall(MatCreateSNESMF(snes, &J));
582: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
583: PetscCall(MatSetFromOptions(J));
584: /* TODO: the version 2 code should be merged into the MatCreateSNESMF() and MatCreateMFFD() infrastructure and then removed */
585: } else /* if (version == 2) */ {
586: PetscCheck(snes->vec_func, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "SNESSetFunction() must be called first");
587: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
588: PetscCall(MatCreateSNESMFMore(snes, snes->vec_func, &J));
589: #else
590: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "matrix-free operator routines (version 2)");
591: #endif
592: }
594: /* attach any user provided null space that was on Amat to the newly created matrix free matrix */
595: if (snes->jacobian) {
596: PetscCall(MatGetNullSpace(snes->jacobian, &nullsp));
597: if (nullsp) PetscCall(MatSetNullSpace(J, nullsp));
598: }
600: PetscCall(PetscInfo(snes, "Setting default matrix-free operator routines (version %" PetscInt_FMT ")\n", version));
601: if (hasOperator) {
602: /* This version replaces the user provided Jacobian matrix with a
603: matrix-free version but still employs the user-provided preconditioner matrix. */
604: PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
605: } else {
606: /* This version replaces both the user-provided Jacobian and the user-
607: provided preconditioner Jacobian with the default matrix free version. */
608: if (snes->npcside == PC_LEFT && snes->npc) {
609: if (!snes->jacobian) PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
610: } else {
611: KSP ksp;
612: PC pc;
613: PetscBool match;
615: PetscCall(SNESSetJacobian(snes, J, J, MatMFFDComputeJacobian, NULL));
616: /* Force no preconditioner */
617: PetscCall(SNESGetKSP(snes, &ksp));
618: PetscCall(KSPGetPC(ksp, &pc));
619: PetscCall(PetscObjectTypeCompareAny((PetscObject)pc, &match, PCSHELL, PCH2OPUS, ""));
620: if (!match) {
621: PetscCall(PetscInfo(snes, "Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n"));
622: PetscCall(PCSetType(pc, PCNONE));
623: }
624: }
625: }
626: PetscCall(MatDestroy(&J));
627: PetscFunctionReturn(PETSC_SUCCESS);
628: }
630: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine, Mat Restrict, Vec Rscale, Mat Inject, DM dmcoarse, void *ctx)
631: {
632: SNES snes = (SNES)ctx;
633: Vec Xfine, Xfine_named = NULL, Xcoarse;
635: PetscFunctionBegin;
636: if (PetscLogPrintInfo) {
637: PetscInt finelevel, coarselevel, fineclevel, coarseclevel;
638: PetscCall(DMGetRefineLevel(dmfine, &finelevel));
639: PetscCall(DMGetCoarsenLevel(dmfine, &fineclevel));
640: PetscCall(DMGetRefineLevel(dmcoarse, &coarselevel));
641: PetscCall(DMGetCoarsenLevel(dmcoarse, &coarseclevel));
642: PetscCall(PetscInfo(dmfine, "Restricting SNES solution vector from level %" PetscInt_FMT "-%" PetscInt_FMT " to level %" PetscInt_FMT "-%" PetscInt_FMT "\n", finelevel, fineclevel, coarselevel, coarseclevel));
643: }
644: if (dmfine == snes->dm) Xfine = snes->vec_sol;
645: else {
646: PetscCall(DMGetNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
647: Xfine = Xfine_named;
648: }
649: PetscCall(DMGetNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
650: if (Inject) {
651: PetscCall(MatRestrict(Inject, Xfine, Xcoarse));
652: } else {
653: PetscCall(MatRestrict(Restrict, Xfine, Xcoarse));
654: PetscCall(VecPointwiseMult(Xcoarse, Xcoarse, Rscale));
655: }
656: PetscCall(DMRestoreNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
657: if (Xfine_named) PetscCall(DMRestoreNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
658: PetscFunctionReturn(PETSC_SUCCESS);
659: }
661: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm, DM dmc, void *ctx)
662: {
663: PetscFunctionBegin;
664: PetscCall(DMCoarsenHookAdd(dmc, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, ctx));
665: PetscFunctionReturn(PETSC_SUCCESS);
666: }
668: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
669: * safely call SNESGetDM() in their residual evaluation routine. */
670: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp, Mat A, Mat B, void *ctx)
671: {
672: SNES snes = (SNES)ctx;
673: Vec X, Xnamed = NULL;
674: DM dmsave;
675: void *ctxsave;
676: PetscErrorCode (*jac)(SNES, Vec, Mat, Mat, void *) = NULL;
678: PetscFunctionBegin;
679: dmsave = snes->dm;
680: PetscCall(KSPGetDM(ksp, &snes->dm));
681: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
682: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */ PetscCall(DMGetNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
683: X = Xnamed;
684: PetscCall(SNESGetJacobian(snes, NULL, NULL, &jac, &ctxsave));
685: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
686: if (jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, SNESComputeJacobianDefaultColor, NULL));
687: }
688: /* Make sure KSP DM has the Jacobian computation routine */
689: {
690: DMSNES sdm;
692: PetscCall(DMGetDMSNES(snes->dm, &sdm));
693: if (!sdm->ops->computejacobian) PetscCall(DMCopyDMSNES(dmsave, snes->dm));
694: }
695: /* Compute the operators */
696: PetscCall(SNESComputeJacobian(snes, X, A, B));
697: /* Put the previous context back */
698: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, jac, ctxsave));
700: if (Xnamed) PetscCall(DMRestoreNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
701: snes->dm = dmsave;
702: PetscFunctionReturn(PETSC_SUCCESS);
703: }
705: /*@
706: SNESSetUpMatrices - ensures that matrices are available for `SNES` Newton-like methods, this is called by `SNESSetUp_XXX()`
708: Collective
710: Input Parameter:
711: . snes - snes to configure
713: Level: developer
715: Note:
716: If the matrices do not yet exist it attempts to create them based on options previously set for the `SNES` such as `-snes_mf`
718: .seealso: [](chapter_snes), `SNES`, `SNESSetUp()`
719: @*/
720: PetscErrorCode SNESSetUpMatrices(SNES snes)
721: {
722: DM dm;
723: DMSNES sdm;
725: PetscFunctionBegin;
726: PetscCall(SNESGetDM(snes, &dm));
727: PetscCall(DMGetDMSNES(dm, &sdm));
728: if (!snes->jacobian && snes->mf) {
729: Mat J;
730: void *functx;
731: PetscCall(MatCreateSNESMF(snes, &J));
732: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
733: PetscCall(MatSetFromOptions(J));
734: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
735: PetscCall(SNESSetJacobian(snes, J, J, NULL, NULL));
736: PetscCall(MatDestroy(&J));
737: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
738: Mat J, B;
739: PetscCall(MatCreateSNESMF(snes, &J));
740: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
741: PetscCall(MatSetFromOptions(J));
742: PetscCall(DMCreateMatrix(snes->dm, &B));
743: /* sdm->computejacobian was already set to reach here */
744: PetscCall(SNESSetJacobian(snes, J, B, NULL, NULL));
745: PetscCall(MatDestroy(&J));
746: PetscCall(MatDestroy(&B));
747: } else if (!snes->jacobian_pre) {
748: PetscDS prob;
749: Mat J, B;
750: PetscBool hasPrec = PETSC_FALSE;
752: J = snes->jacobian;
753: PetscCall(DMGetDS(dm, &prob));
754: if (prob) PetscCall(PetscDSHasJacobianPreconditioner(prob, &hasPrec));
755: if (J) PetscCall(PetscObjectReference((PetscObject)J));
756: else if (hasPrec) PetscCall(DMCreateMatrix(snes->dm, &J));
757: PetscCall(DMCreateMatrix(snes->dm, &B));
758: PetscCall(SNESSetJacobian(snes, J ? J : B, B, NULL, NULL));
759: PetscCall(MatDestroy(&J));
760: PetscCall(MatDestroy(&B));
761: }
762: {
763: KSP ksp;
764: PetscCall(SNESGetKSP(snes, &ksp));
765: PetscCall(KSPSetComputeOperators(ksp, KSPComputeOperators_SNES, snes));
766: PetscCall(DMCoarsenHookAdd(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
767: }
768: PetscFunctionReturn(PETSC_SUCCESS);
769: }
771: static PetscErrorCode SNESMonitorPauseFinal_Internal(SNES snes)
772: {
773: PetscInt i;
775: PetscFunctionBegin;
776: if (!snes->pauseFinal) PetscFunctionReturn(PETSC_SUCCESS);
777: for (i = 0; i < snes->numbermonitors; ++i) {
778: PetscViewerAndFormat *vf = (PetscViewerAndFormat *)snes->monitorcontext[i];
779: PetscDraw draw;
780: PetscReal lpause;
782: if (!vf) continue;
783: if (vf->lg) {
784: if (!PetscCheckPointer(vf->lg, PETSC_OBJECT)) continue;
785: if (((PetscObject)vf->lg)->classid != PETSC_DRAWLG_CLASSID) continue;
786: PetscCall(PetscDrawLGGetDraw(vf->lg, &draw));
787: PetscCall(PetscDrawGetPause(draw, &lpause));
788: PetscCall(PetscDrawSetPause(draw, -1.0));
789: PetscCall(PetscDrawPause(draw));
790: PetscCall(PetscDrawSetPause(draw, lpause));
791: } else {
792: PetscBool isdraw;
794: if (!PetscCheckPointer(vf->viewer, PETSC_OBJECT)) continue;
795: if (((PetscObject)vf->viewer)->classid != PETSC_VIEWER_CLASSID) continue;
796: PetscCall(PetscObjectTypeCompare((PetscObject)vf->viewer, PETSCVIEWERDRAW, &isdraw));
797: if (!isdraw) continue;
798: PetscCall(PetscViewerDrawGetDraw(vf->viewer, 0, &draw));
799: PetscCall(PetscDrawGetPause(draw, &lpause));
800: PetscCall(PetscDrawSetPause(draw, -1.0));
801: PetscCall(PetscDrawPause(draw));
802: PetscCall(PetscDrawSetPause(draw, lpause));
803: }
804: }
805: PetscFunctionReturn(PETSC_SUCCESS);
806: }
808: /*@C
809: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
811: Collective
813: Input Parameters:
814: + snes - `SNES` object you wish to monitor
815: . name - the monitor type one is seeking
816: . help - message indicating what monitoring is done
817: . manual - manual page for the monitor
818: . monitor - the monitor function
819: - monitorsetup - a function that is called once ONLY if the user selected this monitor that may set additional features of the `SNES` or `PetscViewer` objects
821: Options Database Key:
822: . -name - trigger the use of this monitor in `SNESSetFromOptions()`
824: Level: advanced
826: .seealso: [](chapter_snes), `PetscOptionsGetViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
827: `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`
828: `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`, `PetscOptionsBool()`,
829: `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
830: `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
831: `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
832: `PetscOptionsFList()`, `PetscOptionsEList()`
833: @*/
834: PetscErrorCode SNESMonitorSetFromOptions(SNES snes, const char name[], const char help[], const char manual[], PetscErrorCode (*monitor)(SNES, PetscInt, PetscReal, PetscViewerAndFormat *), PetscErrorCode (*monitorsetup)(SNES, PetscViewerAndFormat *))
835: {
836: PetscViewer viewer;
837: PetscViewerFormat format;
838: PetscBool flg;
840: PetscFunctionBegin;
841: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, name, &viewer, &format, &flg));
842: if (flg) {
843: PetscViewerAndFormat *vf;
844: PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
845: PetscCall(PetscObjectDereference((PetscObject)viewer));
846: if (monitorsetup) PetscCall((*monitorsetup)(snes, vf));
847: PetscCall(SNESMonitorSet(snes, (PetscErrorCode(*)(SNES, PetscInt, PetscReal, void *))monitor, vf, (PetscErrorCode(*)(void **))PetscViewerAndFormatDestroy));
848: }
849: PetscFunctionReturn(PETSC_SUCCESS);
850: }
852: PetscErrorCode SNESEWSetFromOptions_Private(SNESKSPEW *kctx, MPI_Comm comm, const char *prefix)
853: {
854: PetscFunctionBegin;
855: PetscOptionsBegin(comm, prefix, "Eisenstat and Walker type forcing options", "KSP");
856: PetscCall(PetscOptionsInt("-ksp_ew_version", "Version 1, 2 or 3", NULL, kctx->version, &kctx->version, NULL));
857: PetscCall(PetscOptionsReal("-ksp_ew_rtol0", "0 <= rtol0 < 1", NULL, kctx->rtol_0, &kctx->rtol_0, NULL));
858: PetscCall(PetscOptionsReal("-ksp_ew_rtolmax", "0 <= rtolmax < 1", NULL, kctx->rtol_max, &kctx->rtol_max, NULL));
859: PetscCall(PetscOptionsReal("-ksp_ew_gamma", "0 <= gamma <= 1", NULL, kctx->gamma, &kctx->gamma, NULL));
860: PetscCall(PetscOptionsReal("-ksp_ew_alpha", "1 < alpha <= 2", NULL, kctx->alpha, &kctx->alpha, NULL));
861: PetscCall(PetscOptionsReal("-ksp_ew_alpha2", "alpha2", NULL, kctx->alpha2, &kctx->alpha2, NULL));
862: PetscCall(PetscOptionsReal("-ksp_ew_threshold", "0 < threshold < 1", NULL, kctx->threshold, &kctx->threshold, NULL));
863: PetscCall(PetscOptionsReal("-ksp_ew_v4_p1", "p1", NULL, kctx->v4_p1, &kctx->v4_p1, NULL));
864: PetscCall(PetscOptionsReal("-ksp_ew_v4_p2", "p2", NULL, kctx->v4_p2, &kctx->v4_p2, NULL));
865: PetscCall(PetscOptionsReal("-ksp_ew_v4_p3", "p3", NULL, kctx->v4_p3, &kctx->v4_p3, NULL));
866: PetscCall(PetscOptionsReal("-ksp_ew_v4_m1", "Scaling when rk-1 in [p2,p3)", NULL, kctx->v4_m1, &kctx->v4_m1, NULL));
867: PetscCall(PetscOptionsReal("-ksp_ew_v4_m2", "Scaling when rk-1 in [p3,+infty)", NULL, kctx->v4_m2, &kctx->v4_m2, NULL));
868: PetscCall(PetscOptionsReal("-ksp_ew_v4_m3", "Threshold for successive rtol (0.1 in Eq.7)", NULL, kctx->v4_m3, &kctx->v4_m3, NULL));
869: PetscCall(PetscOptionsReal("-ksp_ew_v4_m4", "Adaptation scaling (0.5 in Eq.7)", NULL, kctx->v4_m4, &kctx->v4_m4, NULL));
870: PetscOptionsEnd();
871: PetscFunctionReturn(PETSC_SUCCESS);
872: }
874: /*@
875: SNESSetFromOptions - Sets various `SNES` and `KSP` parameters from user options.
877: Collective
879: Input Parameter:
880: . snes - the `SNES` context
882: Options Database Keys:
883: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, `SNESType` for complete list
884: . -snes_stol - convergence tolerance in terms of the norm
885: of the change in the solution between steps
886: . -snes_atol <abstol> - absolute tolerance of residual norm
887: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
888: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
889: . -snes_force_iteration <force> - force SNESSolve() to take at least one iteration
890: . -snes_max_it <max_it> - maximum number of iterations
891: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
892: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
893: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
894: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
895: . -snes_lag_preconditioner_persists <true,false> - retains the -snes_lag_preconditioner information across multiple SNESSolve()
896: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
897: . -snes_lag_jacobian_persists <true,false> - retains the -snes_lag_jacobian information across multiple SNESSolve()
898: . -snes_trtol <trtol> - trust region tolerance
899: . -snes_convergence_test - <default,skip,correct_pressure> convergence test in nonlinear solver.
900: default `SNESConvergedDefault()`. skip `SNESConvergedSkip()` means continue iterating until max_it or some other criterion is reached, saving expense
901: of convergence test. correct_pressure S`NESConvergedCorrectPressure()` has special handling of a pressure null space.
902: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
903: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
904: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
905: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
906: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
907: . -snes_monitor_lg_range - plots residual norm at each iteration
908: . -snes_monitor_pause_final - Pauses all monitor drawing after the solver ends
909: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
910: . -snes_fd_color - use finite differences with coloring to compute Jacobian
911: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each KSP iteration
912: . -snes_converged_reason - print the reason for convergence/divergence after each solve
913: . -npc_snes_type <type> - the SNES type to use as a nonlinear preconditioner
914: . -snes_test_jacobian <optional threshold> - compare the user provided Jacobian with one computed via finite differences to check for errors. If a threshold is given, display only those entries whose difference is greater than the threshold.
915: - -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference between them to help users detect the location of errors in the user provided Jacobian.
917: Options Database Keys for Eisenstat-Walker method:
918: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
919: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
920: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
921: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
922: . -snes_ksp_ew_gamma <gamma> - Sets gamma
923: . -snes_ksp_ew_alpha <alpha> - Sets alpha
924: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
925: - -snes_ksp_ew_threshold <threshold> - Sets threshold
927: Level: beginner
929: Notes:
930: To see all options, run your program with the -help option or consult the users manual
932: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix free, and computing explicitly with
933: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
935: .seealso: [](chapter_snes), `SNESType`, `SNESSetOptionsPrefix()`, `SNESResetFromOptions()`, `SNES`, `SNESCreate()`
936: @*/
937: PetscErrorCode SNESSetFromOptions(SNES snes)
938: {
939: PetscBool flg, pcset, persist, set;
940: PetscInt i, indx, lag, grids;
941: const char *deft = SNESNEWTONLS;
942: const char *convtests[] = {"default", "skip", "correct_pressure"};
943: SNESKSPEW *kctx = NULL;
944: char type[256], monfilename[PETSC_MAX_PATH_LEN], ewprefix[256];
945: PCSide pcside;
946: const char *optionsprefix;
948: PetscFunctionBegin;
950: PetscCall(SNESRegisterAll());
951: PetscObjectOptionsBegin((PetscObject)snes);
952: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
953: PetscCall(PetscOptionsFList("-snes_type", "Nonlinear solver method", "SNESSetType", SNESList, deft, type, 256, &flg));
954: if (flg) {
955: PetscCall(SNESSetType(snes, type));
956: } else if (!((PetscObject)snes)->type_name) {
957: PetscCall(SNESSetType(snes, deft));
958: }
959: PetscCall(PetscOptionsReal("-snes_stol", "Stop if step length less than", "SNESSetTolerances", snes->stol, &snes->stol, NULL));
960: PetscCall(PetscOptionsReal("-snes_atol", "Stop if function norm less than", "SNESSetTolerances", snes->abstol, &snes->abstol, NULL));
962: PetscCall(PetscOptionsReal("-snes_rtol", "Stop if decrease in function norm less than", "SNESSetTolerances", snes->rtol, &snes->rtol, NULL));
963: PetscCall(PetscOptionsReal("-snes_divergence_tolerance", "Stop if residual norm increases by this factor", "SNESSetDivergenceTolerance", snes->divtol, &snes->divtol, NULL));
964: PetscCall(PetscOptionsInt("-snes_max_it", "Maximum iterations", "SNESSetTolerances", snes->max_its, &snes->max_its, NULL));
965: PetscCall(PetscOptionsInt("-snes_max_funcs", "Maximum function evaluations", "SNESSetTolerances", snes->max_funcs, &snes->max_funcs, NULL));
966: PetscCall(PetscOptionsInt("-snes_max_fail", "Maximum nonlinear step failures", "SNESSetMaxNonlinearStepFailures", snes->maxFailures, &snes->maxFailures, NULL));
967: PetscCall(PetscOptionsInt("-snes_max_linear_solve_fail", "Maximum failures in linear solves allowed", "SNESSetMaxLinearSolveFailures", snes->maxLinearSolveFailures, &snes->maxLinearSolveFailures, NULL));
968: PetscCall(PetscOptionsBool("-snes_error_if_not_converged", "Generate error if solver does not converge", "SNESSetErrorIfNotConverged", snes->errorifnotconverged, &snes->errorifnotconverged, NULL));
969: PetscCall(PetscOptionsBool("-snes_force_iteration", "Force SNESSolve() to take at least one iteration", "SNESSetForceIteration", snes->forceiteration, &snes->forceiteration, NULL));
970: PetscCall(PetscOptionsBool("-snes_check_jacobian_domain_error", "Check Jacobian domain error after Jacobian evaluation", "SNESCheckJacobianDomainError", snes->checkjacdomainerror, &snes->checkjacdomainerror, NULL));
972: PetscCall(PetscOptionsInt("-snes_lag_preconditioner", "How often to rebuild preconditioner", "SNESSetLagPreconditioner", snes->lagpreconditioner, &lag, &flg));
973: if (flg) {
974: PetscCheck(lag != -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_USER, "Cannot set the lag to -1 from the command line since the preconditioner must be built as least once, perhaps you mean -2");
975: PetscCall(SNESSetLagPreconditioner(snes, lag));
976: }
977: PetscCall(PetscOptionsBool("-snes_lag_preconditioner_persists", "Preconditioner lagging through multiple SNES solves", "SNESSetLagPreconditionerPersists", snes->lagjac_persist, &persist, &flg));
978: if (flg) PetscCall(SNESSetLagPreconditionerPersists(snes, persist));
979: PetscCall(PetscOptionsInt("-snes_lag_jacobian", "How often to rebuild Jacobian", "SNESSetLagJacobian", snes->lagjacobian, &lag, &flg));
980: if (flg) {
981: PetscCheck(lag != -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_USER, "Cannot set the lag to -1 from the command line since the Jacobian must be built as least once, perhaps you mean -2");
982: PetscCall(SNESSetLagJacobian(snes, lag));
983: }
984: PetscCall(PetscOptionsBool("-snes_lag_jacobian_persists", "Jacobian lagging through multiple SNES solves", "SNESSetLagJacobianPersists", snes->lagjac_persist, &persist, &flg));
985: if (flg) PetscCall(SNESSetLagJacobianPersists(snes, persist));
987: PetscCall(PetscOptionsInt("-snes_grid_sequence", "Use grid sequencing to generate initial guess", "SNESSetGridSequence", snes->gridsequence, &grids, &flg));
988: if (flg) PetscCall(SNESSetGridSequence(snes, grids));
990: PetscCall(PetscOptionsEList("-snes_convergence_test", "Convergence test", "SNESSetConvergenceTest", convtests, sizeof(convtests) / sizeof(char *), "default", &indx, &flg));
991: if (flg) {
992: switch (indx) {
993: case 0:
994: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedDefault, NULL, NULL));
995: break;
996: case 1:
997: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedSkip, NULL, NULL));
998: break;
999: case 2:
1000: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedCorrectPressure, NULL, NULL));
1001: break;
1002: }
1003: }
1005: PetscCall(PetscOptionsEList("-snes_norm_schedule", "SNES Norm schedule", "SNESSetNormSchedule", SNESNormSchedules, 5, "function", &indx, &flg));
1006: if (flg) PetscCall(SNESSetNormSchedule(snes, (SNESNormSchedule)indx));
1008: PetscCall(PetscOptionsEList("-snes_function_type", "SNES Norm schedule", "SNESSetFunctionType", SNESFunctionTypes, 2, "unpreconditioned", &indx, &flg));
1009: if (flg) PetscCall(SNESSetFunctionType(snes, (SNESFunctionType)indx));
1011: kctx = (SNESKSPEW *)snes->kspconvctx;
1013: PetscCall(PetscOptionsBool("-snes_ksp_ew", "Use Eisentat-Walker linear system convergence test", "SNESKSPSetUseEW", snes->ksp_ewconv, &snes->ksp_ewconv, NULL));
1015: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1016: PetscCall(PetscSNPrintf(ewprefix, sizeof(ewprefix), "%s%s", optionsprefix ? optionsprefix : "", "snes_"));
1017: PetscCall(SNESEWSetFromOptions_Private(kctx, PetscObjectComm((PetscObject)snes), ewprefix));
1019: PetscCall(PetscOptionsInt("-snes_ksp_ew_version", "Version 1, 2 or 3", "SNESKSPSetParametersEW", kctx->version, &kctx->version, NULL));
1020: PetscCall(PetscOptionsReal("-snes_ksp_ew_rtol0", "0 <= rtol0 < 1", "SNESKSPSetParametersEW", kctx->rtol_0, &kctx->rtol_0, NULL));
1021: PetscCall(PetscOptionsReal("-snes_ksp_ew_rtolmax", "0 <= rtolmax < 1", "SNESKSPSetParametersEW", kctx->rtol_max, &kctx->rtol_max, NULL));
1022: PetscCall(PetscOptionsReal("-snes_ksp_ew_gamma", "0 <= gamma <= 1", "SNESKSPSetParametersEW", kctx->gamma, &kctx->gamma, NULL));
1023: PetscCall(PetscOptionsReal("-snes_ksp_ew_alpha", "1 < alpha <= 2", "SNESKSPSetParametersEW", kctx->alpha, &kctx->alpha, NULL));
1024: PetscCall(PetscOptionsReal("-snes_ksp_ew_alpha2", "alpha2", "SNESKSPSetParametersEW", kctx->alpha2, &kctx->alpha2, NULL));
1025: PetscCall(PetscOptionsReal("-snes_ksp_ew_threshold", "0 < threshold < 1", "SNESKSPSetParametersEW", kctx->threshold, &kctx->threshold, NULL));
1027: flg = PETSC_FALSE;
1028: PetscCall(PetscOptionsBool("-snes_monitor_cancel", "Remove all monitors", "SNESMonitorCancel", flg, &flg, &set));
1029: if (set && flg) PetscCall(SNESMonitorCancel(snes));
1031: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor", "Monitor norm of function", "SNESMonitorDefault", SNESMonitorDefault, SNESMonitorDefaultSetUp));
1032: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_short", "Monitor norm of function with fewer digits", "SNESMonitorDefaultShort", SNESMonitorDefaultShort, NULL));
1033: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_range", "Monitor range of elements of function", "SNESMonitorRange", SNESMonitorRange, NULL));
1035: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_ratio", "Monitor ratios of the norm of function for consecutive steps", "SNESMonitorRatio", SNESMonitorRatio, SNESMonitorRatioSetUp));
1036: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_field", "Monitor norm of function (split into fields)", "SNESMonitorDefaultField", SNESMonitorDefaultField, NULL));
1037: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution", "View solution at each iteration", "SNESMonitorSolution", SNESMonitorSolution, NULL));
1038: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution_update", "View correction at each iteration", "SNESMonitorSolutionUpdate", SNESMonitorSolutionUpdate, NULL));
1039: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_residual", "View residual at each iteration", "SNESMonitorResidual", SNESMonitorResidual, NULL));
1040: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_jacupdate_spectrum", "Print the change in the spectrum of the Jacobian", "SNESMonitorJacUpdateSpectrum", SNESMonitorJacUpdateSpectrum, NULL));
1041: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_fields", "Monitor norm of function per field", "SNESMonitorSet", SNESMonitorFields, NULL));
1042: PetscCall(PetscOptionsBool("-snes_monitor_pause_final", "Pauses all draw monitors at the final iterate", "SNESMonitorPauseFinal_Internal", PETSC_FALSE, &snes->pauseFinal, NULL));
1044: PetscCall(PetscOptionsString("-snes_monitor_python", "Use Python function", "SNESMonitorSet", NULL, monfilename, sizeof(monfilename), &flg));
1045: if (flg) PetscCall(PetscPythonMonitorSet((PetscObject)snes, monfilename));
1047: flg = PETSC_FALSE;
1048: PetscCall(PetscOptionsBool("-snes_monitor_lg_range", "Plot function range at each iteration", "SNESMonitorLGRange", flg, &flg, NULL));
1049: if (flg) {
1050: PetscViewer ctx;
1052: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &ctx));
1053: PetscCall(SNESMonitorSet(snes, SNESMonitorLGRange, ctx, (PetscErrorCode(*)(void **))PetscViewerDestroy));
1054: }
1056: flg = PETSC_FALSE;
1057: PetscCall(PetscOptionsBool("-snes_converged_reason_view_cancel", "Remove all converged reason viewers", "SNESConvergedReasonViewCancel", flg, &flg, &set));
1058: if (set && flg) PetscCall(SNESConvergedReasonViewCancel(snes));
1060: flg = PETSC_FALSE;
1061: PetscCall(PetscOptionsBool("-snes_fd", "Use finite differences (slow) to compute Jacobian", "SNESComputeJacobianDefault", flg, &flg, NULL));
1062: if (flg) {
1063: void *functx;
1064: DM dm;
1065: PetscCall(SNESGetDM(snes, &dm));
1066: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1067: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
1068: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefault, functx));
1069: PetscCall(PetscInfo(snes, "Setting default finite difference Jacobian matrix\n"));
1070: }
1072: flg = PETSC_FALSE;
1073: PetscCall(PetscOptionsBool("-snes_fd_function", "Use finite differences (slow) to compute function from user objective", "SNESObjectiveComputeFunctionDefaultFD", flg, &flg, NULL));
1074: if (flg) PetscCall(SNESSetFunction(snes, NULL, SNESObjectiveComputeFunctionDefaultFD, NULL));
1076: flg = PETSC_FALSE;
1077: PetscCall(PetscOptionsBool("-snes_fd_color", "Use finite differences with coloring to compute Jacobian", "SNESComputeJacobianDefaultColor", flg, &flg, NULL));
1078: if (flg) {
1079: DM dm;
1080: PetscCall(SNESGetDM(snes, &dm));
1081: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1082: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefaultColor, NULL));
1083: PetscCall(PetscInfo(snes, "Setting default finite difference coloring Jacobian matrix\n"));
1084: }
1086: flg = PETSC_FALSE;
1087: PetscCall(PetscOptionsBool("-snes_mf_operator", "Use a Matrix-Free Jacobian with user-provided preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf_operator, &flg));
1088: if (flg && snes->mf_operator) {
1089: snes->mf_operator = PETSC_TRUE;
1090: snes->mf = PETSC_TRUE;
1091: }
1092: flg = PETSC_FALSE;
1093: PetscCall(PetscOptionsBool("-snes_mf", "Use a Matrix-Free Jacobian with no preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf, &flg));
1094: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1095: PetscCall(PetscOptionsInt("-snes_mf_version", "Matrix-Free routines version 1 or 2", "None", snes->mf_version, &snes->mf_version, NULL));
1097: flg = PETSC_FALSE;
1098: PetscCall(SNESGetNPCSide(snes, &pcside));
1099: PetscCall(PetscOptionsEnum("-snes_npc_side", "SNES nonlinear preconditioner side", "SNESSetNPCSide", PCSides, (PetscEnum)pcside, (PetscEnum *)&pcside, &flg));
1100: if (flg) PetscCall(SNESSetNPCSide(snes, pcside));
1102: #if defined(PETSC_HAVE_SAWS)
1103: /*
1104: Publish convergence information using SAWs
1105: */
1106: flg = PETSC_FALSE;
1107: PetscCall(PetscOptionsBool("-snes_monitor_saws", "Publish SNES progress using SAWs", "SNESMonitorSet", flg, &flg, NULL));
1108: if (flg) {
1109: void *ctx;
1110: PetscCall(SNESMonitorSAWsCreate(snes, &ctx));
1111: PetscCall(SNESMonitorSet(snes, SNESMonitorSAWs, ctx, SNESMonitorSAWsDestroy));
1112: }
1113: #endif
1114: #if defined(PETSC_HAVE_SAWS)
1115: {
1116: PetscBool set;
1117: flg = PETSC_FALSE;
1118: PetscCall(PetscOptionsBool("-snes_saws_block", "Block for SAWs at end of SNESSolve", "PetscObjectSAWsBlock", ((PetscObject)snes)->amspublishblock, &flg, &set));
1119: if (set) PetscCall(PetscObjectSAWsSetBlock((PetscObject)snes, flg));
1120: }
1121: #endif
1123: for (i = 0; i < numberofsetfromoptions; i++) PetscCall((*othersetfromoptions[i])(snes));
1125: PetscTryTypeMethod(snes, setfromoptions, PetscOptionsObject);
1127: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1128: PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)snes, PetscOptionsObject));
1129: PetscOptionsEnd();
1131: if (snes->linesearch) {
1132: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
1133: PetscCall(SNESLineSearchSetFromOptions(snes->linesearch));
1134: }
1136: if (snes->usesksp) {
1137: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
1138: PetscCall(KSPSetOperators(snes->ksp, snes->jacobian, snes->jacobian_pre));
1139: PetscCall(KSPSetFromOptions(snes->ksp));
1140: }
1142: /* if user has set the SNES NPC type via options database, create it. */
1143: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1144: PetscCall(PetscOptionsHasName(((PetscObject)snes)->options, optionsprefix, "-npc_snes_type", &pcset));
1145: if (pcset && (!snes->npc)) PetscCall(SNESGetNPC(snes, &snes->npc));
1146: if (snes->npc) PetscCall(SNESSetFromOptions(snes->npc));
1147: snes->setfromoptionscalled++;
1148: PetscFunctionReturn(PETSC_SUCCESS);
1149: }
1151: /*@
1152: SNESResetFromOptions - Sets various `SNES` and `KSP` parameters from user options ONLY if the `SNESSetFromOptions()` was previously set from options
1154: Collective
1156: Input Parameter:
1157: . snes - the `SNES` context
1159: Level: beginner
1161: .seealso: [](chapter_snes), `SNES`, `SNESSetFromOptions()`, `SNESSetOptionsPrefix()`
1162: @*/
1163: PetscErrorCode SNESResetFromOptions(SNES snes)
1164: {
1165: PetscFunctionBegin;
1166: if (snes->setfromoptionscalled) PetscCall(SNESSetFromOptions(snes));
1167: PetscFunctionReturn(PETSC_SUCCESS);
1168: }
1170: /*@C
1171: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1172: the nonlinear solvers.
1174: Logically Collective; No Fortran Support
1176: Input Parameters:
1177: + snes - the `SNES` context
1178: . compute - function to compute the context
1179: - destroy - function to destroy the context
1181: Level: intermediate
1183: Note:
1184: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1186: Use `SNESSetApplicationContext()` to see the context immediately
1188: .seealso: [](chapter_snes), `SNESGetApplicationContext()`, `SNESSetComputeApplicationContext()`, `SNESSetApplicationContext()`
1189: @*/
1190: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES, void **), PetscErrorCode (*destroy)(void **))
1191: {
1192: PetscFunctionBegin;
1194: snes->ops->usercompute = compute;
1195: snes->ops->userdestroy = destroy;
1196: PetscFunctionReturn(PETSC_SUCCESS);
1197: }
1199: /*@
1200: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1202: Logically Collective
1204: Input Parameters:
1205: + snes - the `SNES` context
1206: - usrP - optional user context
1208: Level: intermediate
1210: Notes:
1211: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian, or other evaluation function
1212: with `SNESGetApplicationContext()`
1214: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1216: Fortran Note:
1217: You must write a Fortran interface definition for this
1218: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1220: .seealso: [](chapter_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1221: @*/
1222: PetscErrorCode SNESSetApplicationContext(SNES snes, void *usrP)
1223: {
1224: KSP ksp;
1226: PetscFunctionBegin;
1228: PetscCall(SNESGetKSP(snes, &ksp));
1229: PetscCall(KSPSetApplicationContext(ksp, usrP));
1230: snes->user = usrP;
1231: PetscFunctionReturn(PETSC_SUCCESS);
1232: }
1234: /*@
1235: SNESGetApplicationContext - Gets the user-defined context for the
1236: nonlinear solvers set with `SNESGetApplicationContext()` or with `SNESSetComputeApplicationContext()`
1238: Not Collective
1240: Input Parameter:
1241: . snes - `SNES` context
1243: Output Parameter:
1244: . usrP - user context
1246: Level: intermediate
1248: Fortran Note:
1249: You must write a Fortran interface definition for this
1250: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1252: .seealso: [](chapter_snes), `SNESSetApplicationContext()`
1253: @*/
1254: PetscErrorCode SNESGetApplicationContext(SNES snes, void *usrP)
1255: {
1256: PetscFunctionBegin;
1258: *(void **)usrP = snes->user;
1259: PetscFunctionReturn(PETSC_SUCCESS);
1260: }
1262: /*@
1263: SNESSetUseMatrixFree - indicates that `SNES` should use matrix free finite difference matrix vector products to apply the Jacobian.
1265: Logically Collective
1267: Input Parameters:
1268: + snes - `SNES` context
1269: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1270: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored. With
1271: this option no matrix element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1273: Options Database Keys:
1274: + -snes_mf_operator - use matrix free only for the mat operator
1275: . -snes_mf - use matrix-free for both the mat and pmat operator
1276: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1277: - -snes_fd - compute the Jacobian via finite differences (slow)
1279: Level: intermediate
1281: Note:
1282: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free, and computing explicitly with
1283: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1285: .seealso: [](chapter_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`
1286: @*/
1287: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1288: {
1289: PetscFunctionBegin;
1293: snes->mf = mf_operator ? PETSC_TRUE : mf;
1294: snes->mf_operator = mf_operator;
1295: PetscFunctionReturn(PETSC_SUCCESS);
1296: }
1298: /*@
1299: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1301: Not Collective, but the resulting flags will be the same on all MPI ranks
1303: Input Parameter:
1304: . snes - `SNES` context
1306: Output Parameters:
1307: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1308: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1310: Level: intermediate
1312: .seealso: [](chapter_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1313: @*/
1314: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1315: {
1316: PetscFunctionBegin;
1318: if (mf) *mf = snes->mf;
1319: if (mf_operator) *mf_operator = snes->mf_operator;
1320: PetscFunctionReturn(PETSC_SUCCESS);
1321: }
1323: /*@
1324: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1325: at this time.
1327: Not Collective
1329: Input Parameter:
1330: . snes - `SNES` context
1332: Output Parameter:
1333: . iter - iteration number
1335: Level: intermediate
1337: Notes:
1338: For example, during the computation of iteration 2 this would return 1.
1340: This is useful for using lagged Jacobians (where one does not recompute the
1341: Jacobian at each `SNES` iteration). For example, the code
1342: .vb
1343: ierr = SNESGetIterationNumber(snes,&it);
1344: if (!(it % 2)) {
1345: [compute Jacobian here]
1346: }
1347: .ve
1348: can be used in your function that computes the Jacobian to cause the Jacobian to be
1349: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1351: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1353: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`
1354: @*/
1355: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1356: {
1357: PetscFunctionBegin;
1360: *iter = snes->iter;
1361: PetscFunctionReturn(PETSC_SUCCESS);
1362: }
1364: /*@
1365: SNESSetIterationNumber - Sets the current iteration number.
1367: Not Collective
1369: Input Parameters:
1370: + snes - `SNES` context
1371: - iter - iteration number
1373: Level: developer
1375: .seealso: [](chapter_snes), `SNESGetLinearSolveIterations()`
1376: @*/
1377: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1378: {
1379: PetscFunctionBegin;
1381: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1382: snes->iter = iter;
1383: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1384: PetscFunctionReturn(PETSC_SUCCESS);
1385: }
1387: /*@
1388: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1389: attempted by the nonlinear solver.
1391: Not Collective
1393: Input Parameter:
1394: . snes - `SNES` context
1396: Output Parameter:
1397: . nfails - number of unsuccessful steps attempted
1399: Level: intermediate
1401: Note:
1402: This counter is reset to zero for each successive call to `SNESSolve()`.
1404: .seealso: [](chapter_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1405: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1406: @*/
1407: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1408: {
1409: PetscFunctionBegin;
1412: *nfails = snes->numFailures;
1413: PetscFunctionReturn(PETSC_SUCCESS);
1414: }
1416: /*@
1417: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1418: attempted by the nonlinear solver before it gives up and generates an error
1420: Not Collective
1422: Input Parameters:
1423: + snes - `SNES` context
1424: - maxFails - maximum of unsuccessful steps
1426: Level: intermediate
1428: .seealso: [](chapter_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1429: `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1430: @*/
1431: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1432: {
1433: PetscFunctionBegin;
1435: snes->maxFailures = maxFails;
1436: PetscFunctionReturn(PETSC_SUCCESS);
1437: }
1439: /*@
1440: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1441: attempted by the nonlinear solver before it gives up and generates an error
1443: Not Collective
1445: Input Parameter:
1446: . snes - SNES context
1448: Output Parameter:
1449: . maxFails - maximum of unsuccessful steps
1451: Level: intermediate
1453: .seealso: [](chapter_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1454: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1455: @*/
1456: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1457: {
1458: PetscFunctionBegin;
1461: *maxFails = snes->maxFailures;
1462: PetscFunctionReturn(PETSC_SUCCESS);
1463: }
1465: /*@
1466: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1467: done by the `SNES` object
1469: Not Collective
1471: Input Parameter:
1472: . snes - `SNES` context
1474: Output Parameter:
1475: . nfuncs - number of evaluations
1477: Level: intermediate
1479: Note:
1480: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1482: .seealso: [](chapter_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1483: @*/
1484: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1485: {
1486: PetscFunctionBegin;
1489: *nfuncs = snes->nfuncs;
1490: PetscFunctionReturn(PETSC_SUCCESS);
1491: }
1493: /*@
1494: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1495: linear solvers.
1497: Not Collective
1499: Input Parameter:
1500: . snes - `SNES` context
1502: Output Parameter:
1503: . nfails - number of failed solves
1505: Options Database Key:
1506: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1508: Level: intermediate
1510: Note:
1511: This counter is reset to zero for each successive call to `SNESSolve()`.
1513: .seealso: [](chapter_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1514: @*/
1515: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1516: {
1517: PetscFunctionBegin;
1520: *nfails = snes->numLinearSolveFailures;
1521: PetscFunctionReturn(PETSC_SUCCESS);
1522: }
1524: /*@
1525: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1526: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1528: Logically Collective
1530: Input Parameters:
1531: + snes - `SNES` context
1532: - maxFails - maximum allowed linear solve failures
1534: Options Database Key:
1535: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1537: Level: intermediate
1539: Note:
1540: By default this is 0; that is `SNES` returns on the first failed linear solve
1542: .seealso: [](chapter_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1543: @*/
1544: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1545: {
1546: PetscFunctionBegin;
1549: snes->maxLinearSolveFailures = maxFails;
1550: PetscFunctionReturn(PETSC_SUCCESS);
1551: }
1553: /*@
1554: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1555: are allowed before `SNES` returns as unsuccessful
1557: Not Collective
1559: Input Parameter:
1560: . snes - `SNES` context
1562: Output Parameter:
1563: . maxFails - maximum of unsuccessful solves allowed
1565: Level: intermediate
1567: Note:
1568: By default this is 1; that is `SNES` returns on the first failed linear solve
1570: .seealso: [](chapter_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1571: @*/
1572: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1573: {
1574: PetscFunctionBegin;
1577: *maxFails = snes->maxLinearSolveFailures;
1578: PetscFunctionReturn(PETSC_SUCCESS);
1579: }
1581: /*@
1582: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1583: used by the nonlinear solver.
1585: Not Collective
1587: Input Parameter:
1588: . snes - `SNES` context
1590: Output Parameter:
1591: . lits - number of linear iterations
1593: Level: intermediate
1595: Notes:
1596: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1598: If the linear solver fails inside the `SNESSolve()` the iterations for that call to the linear solver are not included. If you wish to count them
1599: then call `KSPGetIterationNumber()` after the failed solve.
1601: .seealso: [](chapter_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1602: @*/
1603: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1604: {
1605: PetscFunctionBegin;
1608: *lits = snes->linear_its;
1609: PetscFunctionReturn(PETSC_SUCCESS);
1610: }
1612: /*@
1613: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1614: are reset every time `SNESSolve()` is called.
1616: Logically Collective
1618: Input Parameters:
1619: + snes - `SNES` context
1620: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1622: Level: developer
1624: .seealso: [](chapter_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1625: @*/
1626: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1627: {
1628: PetscFunctionBegin;
1631: snes->counters_reset = reset;
1632: PetscFunctionReturn(PETSC_SUCCESS);
1633: }
1635: /*@
1636: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1638: Not Collective, but the `SNES` and `KSP` objects must live on the same MPI_Comm
1640: Input Parameters:
1641: + snes - the `SNES` context
1642: - ksp - the `KSP` context
1644: Level: developer
1646: Notes:
1647: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1648: so this routine is rarely needed.
1650: The `KSP` object that is already in the `SNES` object has its reference count
1651: decreased by one.
1653: .seealso: [](chapter_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
1654: @*/
1655: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1656: {
1657: PetscFunctionBegin;
1660: PetscCheckSameComm(snes, 1, ksp, 2);
1661: PetscCall(PetscObjectReference((PetscObject)ksp));
1662: if (snes->ksp) PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1663: snes->ksp = ksp;
1664: PetscFunctionReturn(PETSC_SUCCESS);
1665: }
1667: /*@
1668: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1670: Collective
1672: Input Parameter:
1673: . comm - MPI communicator
1675: Output Parameter:
1676: . outsnes - the new SNES context
1678: Options Database Keys:
1679: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no preconditioning matrix
1680: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided preconditioning matrix
1681: as set by `SNESSetJacobian()`
1682: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1683: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1685: Level: beginner
1687: Developer Notes:
1688: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1689: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1690: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1691: in `SNESView()`.
1693: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1694: by help messages about meaningless `SNES` options.
1696: `SNES` always creates the snes->kspconvctx even though it is used by only one type. This should be fixed.
1698: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNES`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1699: @*/
1700: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1701: {
1702: SNES snes;
1703: SNESKSPEW *kctx;
1705: PetscFunctionBegin;
1707: *outsnes = NULL;
1708: PetscCall(SNESInitializePackage());
1710: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1712: snes->ops->converged = SNESConvergedDefault;
1713: snes->usesksp = PETSC_TRUE;
1714: snes->tolerancesset = PETSC_FALSE;
1715: snes->max_its = 50;
1716: snes->max_funcs = 10000;
1717: snes->norm = 0.0;
1718: snes->xnorm = 0.0;
1719: snes->ynorm = 0.0;
1720: snes->normschedule = SNES_NORM_ALWAYS;
1721: snes->functype = SNES_FUNCTION_DEFAULT;
1722: #if defined(PETSC_USE_REAL_SINGLE)
1723: snes->rtol = 1.e-5;
1724: #else
1725: snes->rtol = 1.e-8;
1726: #endif
1727: snes->ttol = 0.0;
1728: #if defined(PETSC_USE_REAL_SINGLE)
1729: snes->abstol = 1.e-25;
1730: #else
1731: snes->abstol = 1.e-50;
1732: #endif
1733: #if defined(PETSC_USE_REAL_SINGLE)
1734: snes->stol = 1.e-5;
1735: #else
1736: snes->stol = 1.e-8;
1737: #endif
1738: #if defined(PETSC_USE_REAL_SINGLE)
1739: snes->deltatol = 1.e-6;
1740: #else
1741: snes->deltatol = 1.e-12;
1742: #endif
1743: snes->divtol = 1.e4;
1744: snes->rnorm0 = 0;
1745: snes->nfuncs = 0;
1746: snes->numFailures = 0;
1747: snes->maxFailures = 1;
1748: snes->linear_its = 0;
1749: snes->lagjacobian = 1;
1750: snes->jac_iter = 0;
1751: snes->lagjac_persist = PETSC_FALSE;
1752: snes->lagpreconditioner = 1;
1753: snes->pre_iter = 0;
1754: snes->lagpre_persist = PETSC_FALSE;
1755: snes->numbermonitors = 0;
1756: snes->numberreasonviews = 0;
1757: snes->data = NULL;
1758: snes->setupcalled = PETSC_FALSE;
1759: snes->ksp_ewconv = PETSC_FALSE;
1760: snes->nwork = 0;
1761: snes->work = NULL;
1762: snes->nvwork = 0;
1763: snes->vwork = NULL;
1764: snes->conv_hist_len = 0;
1765: snes->conv_hist_max = 0;
1766: snes->conv_hist = NULL;
1767: snes->conv_hist_its = NULL;
1768: snes->conv_hist_reset = PETSC_TRUE;
1769: snes->counters_reset = PETSC_TRUE;
1770: snes->vec_func_init_set = PETSC_FALSE;
1771: snes->reason = SNES_CONVERGED_ITERATING;
1772: snes->npcside = PC_RIGHT;
1773: snes->setfromoptionscalled = 0;
1775: snes->mf = PETSC_FALSE;
1776: snes->mf_operator = PETSC_FALSE;
1777: snes->mf_version = 1;
1779: snes->numLinearSolveFailures = 0;
1780: snes->maxLinearSolveFailures = 1;
1782: snes->vizerotolerance = 1.e-8;
1783: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1785: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1786: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1788: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1789: PetscCall(PetscNew(&kctx));
1791: snes->kspconvctx = (void *)kctx;
1792: kctx->version = 2;
1793: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1794: this was too large for some test cases */
1795: kctx->rtol_last = 0.0;
1796: kctx->rtol_max = 0.9;
1797: kctx->gamma = 1.0;
1798: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1799: kctx->alpha2 = kctx->alpha;
1800: kctx->threshold = 0.1;
1801: kctx->lresid_last = 0.0;
1802: kctx->norm_last = 0.0;
1804: kctx->rk_last = 0.0;
1805: kctx->rk_last_2 = 0.0;
1806: kctx->rtol_last_2 = 0.0;
1807: kctx->v4_p1 = 0.1;
1808: kctx->v4_p2 = 0.4;
1809: kctx->v4_p3 = 0.7;
1810: kctx->v4_m1 = 0.8;
1811: kctx->v4_m2 = 0.5;
1812: kctx->v4_m3 = 0.1;
1813: kctx->v4_m4 = 0.5;
1815: *outsnes = snes;
1816: PetscFunctionReturn(PETSC_SUCCESS);
1817: }
1819: /*MC
1820: SNESFunction - Functional form used to convey the nonlinear function to `SNES` in `SNESSetFunction()`
1822: Synopsis:
1823: #include "petscsnes.h"
1824: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1826: Collective
1828: Input Parameters:
1829: + snes - the `SNES` context
1830: . x - state at which to evaluate residual
1831: - ctx - optional user-defined function context, passed in with `SNESSetFunction()`
1833: Output Parameter:
1834: . f - vector to put residual (function value)
1836: Level: intermediate
1838: .seealso: [](chapter_snes), `SNESSetFunction()`, `SNESGetFunction()`
1839: M*/
1841: /*@C
1842: SNESSetFunction - Sets the function evaluation routine and function
1843: vector for use by the `SNES` routines in solving systems of nonlinear
1844: equations.
1846: Logically Collective
1848: Input Parameters:
1849: + snes - the `SNES` context
1850: . r - vector to store function values, may be `NULL`
1851: . f - function evaluation routine; see `SNESFunction` for calling sequence details
1852: - ctx - [optional] user-defined context for private data for the
1853: function evaluation routine (may be `NULL`)
1855: Level: beginner
1857: .seealso: [](chapter_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunction`
1858: @*/
1859: PetscErrorCode SNESSetFunction(SNES snes, Vec r, PetscErrorCode (*f)(SNES, Vec, Vec, void *), void *ctx)
1860: {
1861: DM dm;
1863: PetscFunctionBegin;
1865: if (r) {
1867: PetscCheckSameComm(snes, 1, r, 2);
1868: PetscCall(PetscObjectReference((PetscObject)r));
1869: PetscCall(VecDestroy(&snes->vec_func));
1870: snes->vec_func = r;
1871: }
1872: PetscCall(SNESGetDM(snes, &dm));
1873: PetscCall(DMSNESSetFunction(dm, f, ctx));
1874: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1875: PetscFunctionReturn(PETSC_SUCCESS);
1876: }
1878: /*@C
1879: SNESSetInitialFunction - Sets the function vector to be used as the
1880: initial function value at the initialization of the method. In some
1881: instances, the user has precomputed the function before calling
1882: `SNESSolve()`. This function allows one to avoid a redundant call
1883: to `SNESComputeFunction()` in that case.
1885: Logically Collective
1887: Input Parameters:
1888: + snes - the `SNES` context
1889: - f - vector to store function value
1891: Level: developer
1893: Notes:
1894: This should not be modified during the solution procedure.
1896: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1898: .seealso: [](chapter_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1899: @*/
1900: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1901: {
1902: Vec vec_func;
1904: PetscFunctionBegin;
1907: PetscCheckSameComm(snes, 1, f, 2);
1908: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1909: snes->vec_func_init_set = PETSC_FALSE;
1910: PetscFunctionReturn(PETSC_SUCCESS);
1911: }
1912: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
1913: PetscCall(VecCopy(f, vec_func));
1915: snes->vec_func_init_set = PETSC_TRUE;
1916: PetscFunctionReturn(PETSC_SUCCESS);
1917: }
1919: /*@
1920: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
1921: of the `SNES` method, when norms are computed in the solving process
1923: Logically Collective
1925: Input Parameters:
1926: + snes - the `SNES` context
1927: - normschedule - the frequency of norm computation
1929: Options Database Key:
1930: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
1932: Level: advanced
1934: Notes:
1935: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
1936: of the nonlinear function and the taking of its norm at every iteration to
1937: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1938: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
1939: may either be monitored for convergence or not. As these are often used as nonlinear
1940: preconditioners, monitoring the norm of their error is not a useful enterprise within
1941: their solution.
1943: .seealso: [](chapter_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1944: @*/
1945: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1946: {
1947: PetscFunctionBegin;
1949: snes->normschedule = normschedule;
1950: PetscFunctionReturn(PETSC_SUCCESS);
1951: }
1953: /*@
1954: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
1955: of the `SNES` method.
1957: Logically Collective
1959: Input Parameters:
1960: + snes - the `SNES` context
1961: - normschedule - the type of the norm used
1963: Level: advanced
1965: .seealso: [](chapter_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1966: @*/
1967: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1968: {
1969: PetscFunctionBegin;
1971: *normschedule = snes->normschedule;
1972: PetscFunctionReturn(PETSC_SUCCESS);
1973: }
1975: /*@
1976: SNESSetFunctionNorm - Sets the last computed residual norm.
1978: Logically Collective
1980: Input Parameters:
1981: + snes - the `SNES` context
1982: - norm - the value of the norm
1984: Level: developer
1986: .seealso: [](chapter_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1987: @*/
1988: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1989: {
1990: PetscFunctionBegin;
1992: snes->norm = norm;
1993: PetscFunctionReturn(PETSC_SUCCESS);
1994: }
1996: /*@
1997: SNESGetFunctionNorm - Gets the last computed norm of the residual
1999: Not Collective
2001: Input Parameter:
2002: . snes - the `SNES` context
2004: Output Parameter:
2005: . norm - the last computed residual norm
2007: Level: developer
2009: .seealso: [](chapter_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2010: @*/
2011: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2012: {
2013: PetscFunctionBegin;
2016: *norm = snes->norm;
2017: PetscFunctionReturn(PETSC_SUCCESS);
2018: }
2020: /*@
2021: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2023: Not Collective
2025: Input Parameter:
2026: . snes - the `SNES` context
2028: Output Parameter:
2029: . ynorm - the last computed update norm
2031: Level: developer
2033: Note:
2034: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2036: .seealso: [](chapter_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2037: @*/
2038: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2039: {
2040: PetscFunctionBegin;
2043: *ynorm = snes->ynorm;
2044: PetscFunctionReturn(PETSC_SUCCESS);
2045: }
2047: /*@
2048: SNESGetSolutionNorm - Gets the last computed norm of the solution
2050: Not Collective
2052: Input Parameter:
2053: . snes - the `SNES` context
2055: Output Parameter:
2056: . xnorm - the last computed solution norm
2058: Level: developer
2060: .seealso: [](chapter_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2061: @*/
2062: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2063: {
2064: PetscFunctionBegin;
2067: *xnorm = snes->xnorm;
2068: PetscFunctionReturn(PETSC_SUCCESS);
2069: }
2071: /*@C
2072: SNESSetFunctionType - Sets the `SNESFunctionType`
2073: of the `SNES` method.
2075: Logically Collective
2077: Input Parameters:
2078: + snes - the `SNES` context
2079: - type - the function type
2081: Level: developer
2083: Notes:
2084: Possible values of the function type
2085: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2086: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2087: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2089: Different `SNESType`s use this value in different ways
2091: .seealso: [](chapter_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2092: @*/
2093: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2094: {
2095: PetscFunctionBegin;
2097: snes->functype = type;
2098: PetscFunctionReturn(PETSC_SUCCESS);
2099: }
2101: /*@C
2102: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2103: of the SNES method.
2105: Logically Collective
2107: Input Parameters:
2108: + snes - the `SNES` context
2109: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2111: Level: advanced
2113: .seealso: [](chapter_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2114: @*/
2115: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2116: {
2117: PetscFunctionBegin;
2119: *type = snes->functype;
2120: PetscFunctionReturn(PETSC_SUCCESS);
2121: }
2123: /*MC
2124: SNESNGSFunction - function used to apply a Gauss-Seidel sweep on the nonlinear function
2126: Synopsis:
2127: #include <petscsnes.h>
2128: $ SNESNGSFunction(SNES snes,Vec x,Vec b,void *ctx);
2130: Collective
2132: Input Parameters:
2133: + X - solution vector
2134: . B - RHS vector
2135: - ctx - optional user-defined Gauss-Seidel context
2137: Output Parameter:
2138: . X - solution vector
2140: Level: intermediate
2142: .seealso: [](chapter_snes), `SNESNGS`, `SNESSetNGS()`, `SNESGetNGS()`
2143: M*/
2145: /*@C
2146: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2147: use with composed nonlinear solvers.
2149: Input Parameters:
2150: + snes - the `SNES` context
2151: . f - function evaluation routine to apply Gauss-Seidel see `SNESNGSFunction`
2152: - ctx - [optional] user-defined context for private data for the
2153: smoother evaluation routine (may be `NULL`)
2155: Calling sequence of f:
2156: $ PetscErrorCode f(SNES snes,Vec X,Vec B,void *ctx);
2158: Arguments of f:
2159: + snes - the `SNES` context
2160: . X - the current solution
2161: . B - the right hand side vector (which may be `NULL`)
2162: - ctx - a user provided context
2164: Level: intermediate
2166: Note:
2167: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2168: a problem appropriate update to the solution, particularly `SNESFAS`.
2170: .seealso: [](chapter_snes), `SNESGetNGS()`, `SNESNGSFunction`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`
2171: @*/
2172: PetscErrorCode SNESSetNGS(SNES snes, PetscErrorCode (*f)(SNES, Vec, Vec, void *), void *ctx)
2173: {
2174: DM dm;
2176: PetscFunctionBegin;
2178: PetscCall(SNESGetDM(snes, &dm));
2179: PetscCall(DMSNESSetNGS(dm, f, ctx));
2180: PetscFunctionReturn(PETSC_SUCCESS);
2181: }
2183: /*
2184: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2185: changed during the KSPSolve()
2186: */
2187: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, void *ctx)
2188: {
2189: DM dm;
2190: DMSNES sdm;
2192: PetscFunctionBegin;
2193: PetscCall(SNESGetDM(snes, &dm));
2194: PetscCall(DMGetDMSNES(dm, &sdm));
2195: /* A(x)*x - b(x) */
2196: if (sdm->ops->computepfunction) {
2197: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2198: PetscCall(VecScale(f, -1.0));
2199: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2200: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2201: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2202: PetscCall(MatMultAdd(snes->picard, x, f, f));
2203: } else {
2204: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2205: PetscCall(MatMult(snes->picard, x, f));
2206: }
2207: PetscFunctionReturn(PETSC_SUCCESS);
2208: }
2210: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, void *ctx)
2211: {
2212: DM dm;
2213: DMSNES sdm;
2215: PetscFunctionBegin;
2216: PetscCall(SNESGetDM(snes, &dm));
2217: PetscCall(DMGetDMSNES(dm, &sdm));
2218: /* A(x)*x - b(x) */
2219: if (sdm->ops->computepfunction) {
2220: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2221: PetscCall(VecScale(f, -1.0));
2222: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2223: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2224: } else {
2225: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2226: PetscCall(MatMult(snes->jacobian_pre, x, f));
2227: }
2228: PetscFunctionReturn(PETSC_SUCCESS);
2229: }
2231: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, void *ctx)
2232: {
2233: PetscFunctionBegin;
2234: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2235: /* must assembly if matrix-free to get the last SNES solution */
2236: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2237: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2238: PetscFunctionReturn(PETSC_SUCCESS);
2239: }
2241: /*@C
2242: SNESSetPicard - Use `SNES` to solve the system A(x) x = bp(x) + b via a Picard type iteration (Picard linearization)
2244: Logically Collective
2246: Input Parameters:
2247: + snes - the `SNES` context
2248: . r - vector to store function values, may be `NULL`
2249: . bp - function evaluation routine, may be `NULL`
2250: . Amat - matrix with which A(x) x - bp(x) - b is to be computed
2251: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2252: . J - function to compute matrix values, see `SNESJacobianFunction()` for details on its calling sequence
2253: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2255: Level: intermediate
2257: Notes:
2258: It is often better to provide the nonlinear function F() and some approximation to its Jacobian directly and use
2259: an approximate Newton solver. This interface is provided to allow porting/testing a previous Picard based code in PETSc before converting it to approximate Newton.
2261: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2263: Solves the equation A(x) x = bp(x) - b via the defect correction algorithm A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}.
2264: When an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = bp(x^{n}) + b iteration.
2266: Run with `-snes_mf_operator` to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2268: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2269: the direct Picard iteration A(x^n) x^{n+1} = bp(x^n) + b
2271: There is some controversity over the definition of a Picard iteration for nonlinear systems but almost everyone agrees that it involves a linear solve and some
2272: believe it is the iteration A(x^{n}) x^{n+1} = b(x^{n}) hence we use the name Picard. If anyone has an authoritative reference that defines the Picard iteration
2273: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2275: When used with `-snes_mf_operator` this will run matrix-free Newton's method where the matrix-vector product is of the true Jacobian of A(x)x - bp(x) -b and
2276: A(x^{n}) is used to build the preconditioner
2278: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at at time) and thus represent Newton's method.
2280: When used with `-snes_fd_coloring` this will compute the Jacobian via coloring and thus represent a faster implementation of Newton's method. But the
2281: the nonzero structure of the Jacobian is, in general larger than that of the Picard matrix A so you must provide in A the needed nonzero structure for the correct
2282: coloring. When using `DMDA` this may mean creating the matrix A with `DMCreateMatrix()` using a wider stencil than strictly needed for A or with a `DMDA_STENCIL_BOX`.
2283: See the commment in src/snes/tutorials/ex15.c.
2285: .seealso: [](chapter_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`, `SNESJacobianFunction`
2286: @*/
2287: PetscErrorCode SNESSetPicard(SNES snes, Vec r, PetscErrorCode (*bp)(SNES, Vec, Vec, void *), Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *), void *ctx)
2288: {
2289: DM dm;
2291: PetscFunctionBegin;
2293: PetscCall(SNESGetDM(snes, &dm));
2294: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2295: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2296: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2297: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2298: PetscFunctionReturn(PETSC_SUCCESS);
2299: }
2301: /*@C
2302: SNESGetPicard - Returns the context for the Picard iteration
2304: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2306: Input Parameter:
2307: . snes - the `SNES` context
2309: Output Parameters:
2310: + r - the function (or `NULL`)
2311: . f - the function (or `NULL`); see `SNESFunction` for calling sequence details
2312: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2313: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2314: . J - the function for matrix evaluation (or `NULL`); see `SNESJacobianFunction` for calling sequence details
2315: - ctx - the function context (or `NULL`)
2317: Level: advanced
2319: .seealso: [](chapter_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunction`, `SNESJacobianFunction`
2320: @*/
2321: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, PetscErrorCode (**f)(SNES, Vec, Vec, void *), Mat *Amat, Mat *Pmat, PetscErrorCode (**J)(SNES, Vec, Mat, Mat, void *), void **ctx)
2322: {
2323: DM dm;
2325: PetscFunctionBegin;
2327: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2328: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2329: PetscCall(SNESGetDM(snes, &dm));
2330: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2331: PetscFunctionReturn(PETSC_SUCCESS);
2332: }
2334: /*@C
2335: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2337: Logically Collective
2339: Input Parameters:
2340: + snes - the `SNES` context
2341: . func - function evaluation routine
2342: - ctx - [optional] user-defined context for private data for the
2343: function evaluation routine (may be `NULL`)
2345: Calling sequence of func:
2346: $ func (SNES snes,Vec x,void *ctx);
2348: . f - function vector
2349: - ctx - optional user-defined function context
2351: Level: intermediate
2353: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`
2354: @*/
2355: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, PetscErrorCode (*func)(SNES, Vec, void *), void *ctx)
2356: {
2357: PetscFunctionBegin;
2359: if (func) snes->ops->computeinitialguess = func;
2360: if (ctx) snes->initialguessP = ctx;
2361: PetscFunctionReturn(PETSC_SUCCESS);
2362: }
2364: /*@C
2365: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2366: it assumes a zero right hand side.
2368: Logically Collective
2370: Input Parameter:
2371: . snes - the `SNES` context
2373: Output Parameter:
2374: . rhs - the right hand side vector or `NULL` if the right hand side vector is null
2376: Level: intermediate
2378: .seealso: [](chapter_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2379: @*/
2380: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2381: {
2382: PetscFunctionBegin;
2385: *rhs = snes->vec_rhs;
2386: PetscFunctionReturn(PETSC_SUCCESS);
2387: }
2389: /*@
2390: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2392: Collective
2394: Input Parameters:
2395: + snes - the `SNES` context
2396: - x - input vector
2398: Output Parameter:
2399: . y - function vector, as set by `SNESSetFunction()`
2401: Level: developer
2403: Note:
2404: `SNESComputeFunction()` is typically used within nonlinear solvers
2405: implementations, so users would not generally call this routine themselves.
2407: .seealso: [](chapter_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`
2408: @*/
2409: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec y)
2410: {
2411: DM dm;
2412: DMSNES sdm;
2414: PetscFunctionBegin;
2418: PetscCheckSameComm(snes, 1, x, 2);
2419: PetscCheckSameComm(snes, 1, y, 3);
2420: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2422: PetscCall(SNESGetDM(snes, &dm));
2423: PetscCall(DMGetDMSNES(dm, &sdm));
2424: PetscCheck(sdm->ops->computefunction || snes->vec_rhs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetFunction() or SNESSetDM() before SNESComputeFunction(), likely called from SNESSolve().");
2425: if (sdm->ops->computefunction) {
2426: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2427: PetscCall(VecLockReadPush(x));
2428: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2429: snes->domainerror = PETSC_FALSE;
2430: {
2431: void *ctx;
2432: PetscErrorCode (*computefunction)(SNES, Vec, Vec, void *);
2433: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2434: PetscCallBack("SNES callback function", (*computefunction)(snes, x, y, ctx));
2435: }
2436: PetscCall(VecLockReadPop(x));
2437: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2438: } else /* if (snes->vec_rhs) */ {
2439: PetscCall(MatMult(snes->jacobian, x, y));
2440: }
2441: if (snes->vec_rhs) PetscCall(VecAXPY(y, -1.0, snes->vec_rhs));
2442: snes->nfuncs++;
2443: /*
2444: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2445: propagate the value to all processes
2446: */
2447: if (snes->domainerror) PetscCall(VecSetInf(y));
2448: PetscFunctionReturn(PETSC_SUCCESS);
2449: }
2451: /*@
2452: SNESComputeMFFunction - Calls the function that has been set with `SNESSetMFFunction()`.
2454: Collective
2456: Input Parameters:
2457: + snes - the `SNES` context
2458: - x - input vector
2460: Output Parameter:
2461: . y - function vector, as set by `SNESSetMFFunction()`
2463: Level: developer
2465: Notes:
2466: `SNESComputeMFFunction()` is used within the matrix vector products called by the matrix created with `MatCreateSNESMF()`
2467: so users would not generally call this routine themselves.
2469: Since this function is intended for use with finite differencing it does not subtract the right hand side vector provided with `SNESSolve()`
2470: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2471: same function as `SNESComputeFunction()` if a `SNESSolve()` right hand side vector is use because the two functions difference would include this right hand side function.
2473: .seealso: [](chapter_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF`
2474: @*/
2475: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2476: {
2477: DM dm;
2478: DMSNES sdm;
2480: PetscFunctionBegin;
2484: PetscCheckSameComm(snes, 1, x, 2);
2485: PetscCheckSameComm(snes, 1, y, 3);
2486: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2488: PetscCall(SNESGetDM(snes, &dm));
2489: PetscCall(DMGetDMSNES(dm, &sdm));
2490: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2491: PetscCall(VecLockReadPush(x));
2492: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2493: snes->domainerror = PETSC_FALSE;
2494: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2495: PetscCall(VecLockReadPop(x));
2496: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2497: snes->nfuncs++;
2498: /*
2499: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2500: propagate the value to all processes
2501: */
2502: if (snes->domainerror) PetscCall(VecSetInf(y));
2503: PetscFunctionReturn(PETSC_SUCCESS);
2504: }
2506: /*@
2507: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2509: Collective
2511: Input Parameters:
2512: + snes - the `SNES` context
2513: . x - input vector
2514: - b - rhs vector
2516: Output Parameter:
2517: . x - new solution vector
2519: Level: developer
2521: Note:
2522: `SNESComputeNGS()` is typically used within composed nonlinear solver
2523: implementations, so most users would not generally call this routine
2524: themselves.
2526: .seealso: [](chapter_snes), `SNESNGS`, `SNESSetNGS()`, `SNESComputeFunction()`
2527: @*/
2528: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2529: {
2530: DM dm;
2531: DMSNES sdm;
2533: PetscFunctionBegin;
2537: PetscCheckSameComm(snes, 1, x, 3);
2538: if (b) PetscCheckSameComm(snes, 1, b, 2);
2539: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2540: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2541: PetscCall(SNESGetDM(snes, &dm));
2542: PetscCall(DMGetDMSNES(dm, &sdm));
2543: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2544: if (b) PetscCall(VecLockReadPush(b));
2545: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2546: if (b) PetscCall(VecLockReadPop(b));
2547: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2548: PetscFunctionReturn(PETSC_SUCCESS);
2549: }
2551: PetscErrorCode SNESTestJacobian(SNES snes)
2552: {
2553: Mat A, B, C, D, jacobian;
2554: Vec x = snes->vec_sol, f = snes->vec_func;
2555: PetscReal nrm, gnorm;
2556: PetscReal threshold = 1.e-5;
2557: MatType mattype;
2558: PetscInt m, n, M, N;
2559: void *functx;
2560: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, test = PETSC_FALSE, flg, istranspose;
2561: PetscViewer viewer, mviewer;
2562: MPI_Comm comm;
2563: PetscInt tabs;
2564: static PetscBool directionsprinted = PETSC_FALSE;
2565: PetscViewerFormat format;
2567: PetscFunctionBegin;
2568: PetscObjectOptionsBegin((PetscObject)snes);
2569: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &test));
2570: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2571: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2572: if (!complete_print) {
2573: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2574: PetscCall(PetscOptionsViewer("-snes_test_jacobian_display", "Display difference between hand-coded and finite difference Jacobians", "None", &mviewer, &format, &complete_print));
2575: }
2576: /* for compatibility with PETSc 3.9 and older. */
2577: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2578: PetscCall(PetscOptionsReal("-snes_test_jacobian_display_threshold", "Display difference between hand-coded and finite difference Jacobians which exceed input threshold", "None", threshold, &threshold, &threshold_print));
2579: PetscOptionsEnd();
2580: if (!test) PetscFunctionReturn(PETSC_SUCCESS);
2582: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2583: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2584: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2585: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2586: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2587: if (!complete_print && !directionsprinted) {
2588: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2589: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2590: }
2591: if (!directionsprinted) {
2592: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2593: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2594: directionsprinted = PETSC_TRUE;
2595: }
2596: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2598: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2599: if (!flg) jacobian = snes->jacobian;
2600: else jacobian = snes->jacobian_pre;
2602: if (!x) {
2603: PetscCall(MatCreateVecs(jacobian, &x, NULL));
2604: } else {
2605: PetscCall(PetscObjectReference((PetscObject)x));
2606: }
2607: if (!f) {
2608: PetscCall(VecDuplicate(x, &f));
2609: } else {
2610: PetscCall(PetscObjectReference((PetscObject)f));
2611: }
2612: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2613: PetscCall(SNESComputeFunction(snes, x, f));
2614: PetscCall(VecDestroy(&f));
2615: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2616: while (jacobian) {
2617: Mat JT = NULL, Jsave = NULL;
2619: if (istranspose) {
2620: PetscCall(MatCreateTranspose(jacobian, &JT));
2621: Jsave = jacobian;
2622: jacobian = JT;
2623: }
2624: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2625: if (flg) {
2626: A = jacobian;
2627: PetscCall(PetscObjectReference((PetscObject)A));
2628: } else {
2629: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2630: }
2632: PetscCall(MatGetType(A, &mattype));
2633: PetscCall(MatGetSize(A, &M, &N));
2634: PetscCall(MatGetLocalSize(A, &m, &n));
2635: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2636: PetscCall(MatSetType(B, mattype));
2637: PetscCall(MatSetSizes(B, m, n, M, N));
2638: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2639: PetscCall(MatSetUp(B));
2640: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2642: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2643: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2645: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2646: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2647: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2648: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2649: PetscCall(MatDestroy(&D));
2650: if (!gnorm) gnorm = 1; /* just in case */
2651: PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2653: if (complete_print) {
2654: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2655: PetscCall(MatView(A, mviewer));
2656: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2657: PetscCall(MatView(B, mviewer));
2658: }
2660: if (threshold_print || complete_print) {
2661: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2662: PetscScalar *cvals;
2663: const PetscInt *bcols;
2664: const PetscScalar *bvals;
2666: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2667: PetscCall(MatSetType(C, mattype));
2668: PetscCall(MatSetSizes(C, m, n, M, N));
2669: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2670: PetscCall(MatSetUp(C));
2671: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2673: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2674: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2676: for (row = Istart; row < Iend; row++) {
2677: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2678: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2679: for (j = 0, cncols = 0; j < bncols; j++) {
2680: if (PetscAbsScalar(bvals[j]) > threshold) {
2681: ccols[cncols] = bcols[j];
2682: cvals[cncols] = bvals[j];
2683: cncols += 1;
2684: }
2685: }
2686: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2687: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2688: PetscCall(PetscFree2(ccols, cvals));
2689: }
2690: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2691: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2692: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2693: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2694: PetscCall(MatDestroy(&C));
2695: }
2696: PetscCall(MatDestroy(&A));
2697: PetscCall(MatDestroy(&B));
2698: PetscCall(MatDestroy(&JT));
2699: if (Jsave) jacobian = Jsave;
2700: if (jacobian != snes->jacobian_pre) {
2701: jacobian = snes->jacobian_pre;
2702: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2703: } else jacobian = NULL;
2704: }
2705: PetscCall(VecDestroy(&x));
2706: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2707: if (mviewer) PetscCall(PetscViewerDestroy(&mviewer));
2708: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2709: PetscFunctionReturn(PETSC_SUCCESS);
2710: }
2712: /*@
2713: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2715: Collective
2717: Input Parameters:
2718: + snes - the `SNES` context
2719: - x - input vector
2721: Output Parameters:
2722: + A - Jacobian matrix
2723: - B - optional matrix for building the preconditioner
2725: Options Database Keys:
2726: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2727: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2728: . -snes_test_jacobian <optional threshold> - compare the user provided Jacobian with one compute via finite differences to check for errors. If a threshold is given, display only those entries whose difference is greater than the threshold.
2729: . -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference between them to help users detect the location of errors in the user provided Jacobian
2730: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2731: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2732: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2733: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2734: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2735: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2736: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2737: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2738: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2739: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2740: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2742: Level: developer
2744: Note:
2745: Most users should not need to explicitly call this routine, as it
2746: is used internally within the nonlinear solvers.
2748: Developer Note:
2749: This has duplicative ways of checking the accuracy of the user provided Jacobian (see the options above). This is for historical reasons, the routine `SNESTestJacobian()` use to used
2750: for with the `SNESType` of test that has been removed.
2752: .seealso: [](chapter_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
2753: @*/
2754: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2755: {
2756: PetscBool flag;
2757: DM dm;
2758: DMSNES sdm;
2759: KSP ksp;
2761: PetscFunctionBegin;
2764: PetscCheckSameComm(snes, 1, X, 2);
2765: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2766: PetscCall(SNESGetDM(snes, &dm));
2767: PetscCall(DMGetDMSNES(dm, &sdm));
2769: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2770: if (snes->lagjacobian == -2) {
2771: snes->lagjacobian = -1;
2773: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2774: } else if (snes->lagjacobian == -1) {
2775: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2776: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2777: if (flag) {
2778: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2779: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2780: }
2781: PetscFunctionReturn(PETSC_SUCCESS);
2782: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2783: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2784: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2785: if (flag) {
2786: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2787: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2788: }
2789: PetscFunctionReturn(PETSC_SUCCESS);
2790: }
2791: if (snes->npc && snes->npcside == PC_LEFT) {
2792: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2793: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2794: PetscFunctionReturn(PETSC_SUCCESS);
2795: }
2797: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2798: PetscCall(VecLockReadPush(X));
2799: {
2800: void *ctx;
2801: PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *);
2802: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2803: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2804: }
2805: PetscCall(VecLockReadPop(X));
2806: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
2808: /* attach latest linearization point to the preconditioning matrix */
2809: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
2811: /* the next line ensures that snes->ksp exists */
2812: PetscCall(SNESGetKSP(snes, &ksp));
2813: if (snes->lagpreconditioner == -2) {
2814: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
2815: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2816: snes->lagpreconditioner = -1;
2817: } else if (snes->lagpreconditioner == -1) {
2818: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
2819: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2820: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2821: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
2822: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2823: } else {
2824: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
2825: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2826: }
2828: PetscCall(SNESTestJacobian(snes));
2829: /* make sure user returned a correct Jacobian and preconditioner */
2832: {
2833: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
2834: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
2835: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
2836: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
2837: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
2838: if (flag || flag_draw || flag_contour) {
2839: Mat Bexp_mine = NULL, Bexp, FDexp;
2840: PetscViewer vdraw, vstdout;
2841: PetscBool flg;
2842: if (flag_operator) {
2843: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
2844: Bexp = Bexp_mine;
2845: } else {
2846: /* See if the preconditioning matrix can be viewed and added directly */
2847: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPIBAIJ, ""));
2848: if (flg) Bexp = B;
2849: else {
2850: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2851: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
2852: Bexp = Bexp_mine;
2853: }
2854: }
2855: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
2856: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
2857: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2858: if (flag_draw || flag_contour) {
2859: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2860: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2861: } else vdraw = NULL;
2862: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
2863: if (flag) PetscCall(MatView(Bexp, vstdout));
2864: if (vdraw) PetscCall(MatView(Bexp, vdraw));
2865: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
2866: if (flag) PetscCall(MatView(FDexp, vstdout));
2867: if (vdraw) PetscCall(MatView(FDexp, vdraw));
2868: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
2869: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
2870: if (flag) PetscCall(MatView(FDexp, vstdout));
2871: if (vdraw) { /* Always use contour for the difference */
2872: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2873: PetscCall(MatView(FDexp, vdraw));
2874: PetscCall(PetscViewerPopFormat(vdraw));
2875: }
2876: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2877: PetscCall(PetscViewerDestroy(&vdraw));
2878: PetscCall(MatDestroy(&Bexp_mine));
2879: PetscCall(MatDestroy(&FDexp));
2880: }
2881: }
2882: {
2883: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
2884: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
2885: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
2886: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
2887: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
2888: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
2889: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
2890: if (flag_threshold) {
2891: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
2892: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
2893: }
2894: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2895: Mat Bfd;
2896: PetscViewer vdraw, vstdout;
2897: MatColoring coloring;
2898: ISColoring iscoloring;
2899: MatFDColoring matfdcoloring;
2900: PetscErrorCode (*func)(SNES, Vec, Vec, void *);
2901: void *funcctx;
2902: PetscReal norm1, norm2, normmax;
2904: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
2905: PetscCall(MatColoringCreate(Bfd, &coloring));
2906: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
2907: PetscCall(MatColoringSetFromOptions(coloring));
2908: PetscCall(MatColoringApply(coloring, &iscoloring));
2909: PetscCall(MatColoringDestroy(&coloring));
2910: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
2911: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2912: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
2913: PetscCall(ISColoringDestroy(&iscoloring));
2915: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2916: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
2917: PetscCall(MatFDColoringSetFunction(matfdcoloring, (PetscErrorCode(*)(void))func, funcctx));
2918: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
2919: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
2920: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2921: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
2922: PetscCall(MatFDColoringDestroy(&matfdcoloring));
2924: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2925: if (flag_draw || flag_contour) {
2926: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2927: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2928: } else vdraw = NULL;
2929: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
2930: if (flag_display) PetscCall(MatView(B, vstdout));
2931: if (vdraw) PetscCall(MatView(B, vdraw));
2932: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
2933: if (flag_display) PetscCall(MatView(Bfd, vstdout));
2934: if (vdraw) PetscCall(MatView(Bfd, vdraw));
2935: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
2936: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
2937: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
2938: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
2939: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
2940: if (flag_display) PetscCall(MatView(Bfd, vstdout));
2941: if (vdraw) { /* Always use contour for the difference */
2942: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2943: PetscCall(MatView(Bfd, vdraw));
2944: PetscCall(PetscViewerPopFormat(vdraw));
2945: }
2946: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2948: if (flag_threshold) {
2949: PetscInt bs, rstart, rend, i;
2950: PetscCall(MatGetBlockSize(B, &bs));
2951: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
2952: for (i = rstart; i < rend; i++) {
2953: const PetscScalar *ba, *ca;
2954: const PetscInt *bj, *cj;
2955: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
2956: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
2957: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
2958: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
2959: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2960: for (j = 0; j < bn; j++) {
2961: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
2962: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2963: maxentrycol = bj[j];
2964: maxentry = PetscRealPart(ba[j]);
2965: }
2966: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2967: maxdiffcol = bj[j];
2968: maxdiff = PetscRealPart(ca[j]);
2969: }
2970: if (rdiff > maxrdiff) {
2971: maxrdiffcol = bj[j];
2972: maxrdiff = rdiff;
2973: }
2974: }
2975: if (maxrdiff > 1) {
2976: PetscCall(PetscViewerASCIIPrintf(vstdout, "row %" PetscInt_FMT " (maxentry=%g at %" PetscInt_FMT ", maxdiff=%g at %" PetscInt_FMT ", maxrdiff=%g at %" PetscInt_FMT "):", i, (double)maxentry, maxentrycol, (double)maxdiff, maxdiffcol, (double)maxrdiff, maxrdiffcol));
2977: for (j = 0; j < bn; j++) {
2978: PetscReal rdiff;
2979: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
2980: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
2981: }
2982: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
2983: }
2984: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
2985: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
2986: }
2987: }
2988: PetscCall(PetscViewerDestroy(&vdraw));
2989: PetscCall(MatDestroy(&Bfd));
2990: }
2991: }
2992: PetscFunctionReturn(PETSC_SUCCESS);
2993: }
2995: /*MC
2996: SNESJacobianFunction - Function used by `SNES` to compute the nonlinear Jacobian of the function to be solved by `SNES`
2998: Synopsis:
2999: #include "petscsnes.h"
3000: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
3002: Collective
3004: Input Parameters:
3005: + x - input vector, the Jacobian is to be computed at this value
3006: - ctx - [optional] user-defined Jacobian context
3008: Output Parameters:
3009: + Amat - the matrix that defines the (approximate) Jacobian
3010: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3012: Level: intermediate
3014: .seealso: [](chapter_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESSetJacobian()`, `SNESGetJacobian()`
3015: M*/
3017: /*@C
3018: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3019: location to store the matrix.
3021: Logically Collective
3023: Input Parameters:
3024: + snes - the `SNES` context
3025: . Amat - the matrix that defines the (approximate) Jacobian
3026: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3027: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFunction` for details
3028: - ctx - [optional] user-defined context for private data for the
3029: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3031: Level: beginner
3033: Notes:
3034: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3035: each matrix.
3037: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3038: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3040: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3041: must be a `MatFDColoring`.
3043: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3044: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3046: .seealso: [](chapter_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3047: `SNESSetPicard()`, `SNESJacobianFunction`
3048: @*/
3049: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *), void *ctx)
3050: {
3051: DM dm;
3053: PetscFunctionBegin;
3057: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3058: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3059: PetscCall(SNESGetDM(snes, &dm));
3060: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3061: if (Amat) {
3062: PetscCall(PetscObjectReference((PetscObject)Amat));
3063: PetscCall(MatDestroy(&snes->jacobian));
3065: snes->jacobian = Amat;
3066: }
3067: if (Pmat) {
3068: PetscCall(PetscObjectReference((PetscObject)Pmat));
3069: PetscCall(MatDestroy(&snes->jacobian_pre));
3071: snes->jacobian_pre = Pmat;
3072: }
3073: PetscFunctionReturn(PETSC_SUCCESS);
3074: }
3076: /*@C
3077: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3078: provided context for evaluating the Jacobian.
3080: Not Collective, but `Mat` object will be parallel if `SNES` object is
3082: Input Parameter:
3083: . snes - the nonlinear solver context
3085: Output Parameters:
3086: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3087: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3088: . J - location to put Jacobian function (or `NULL`), see `SNESJacobianFunction` for details on its calling sequence
3089: - ctx - location to stash Jacobian ctx (or `NULL`)
3091: Level: advanced
3093: .seealso: [](chapter_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFunction`, `SNESGetFunction()`
3094: @*/
3095: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, PetscErrorCode (**J)(SNES, Vec, Mat, Mat, void *), void **ctx)
3096: {
3097: DM dm;
3099: PetscFunctionBegin;
3101: if (Amat) *Amat = snes->jacobian;
3102: if (Pmat) *Pmat = snes->jacobian_pre;
3103: PetscCall(SNESGetDM(snes, &dm));
3104: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3105: PetscFunctionReturn(PETSC_SUCCESS);
3106: }
3108: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3109: {
3110: DM dm;
3111: DMSNES sdm;
3113: PetscFunctionBegin;
3114: PetscCall(SNESGetDM(snes, &dm));
3115: PetscCall(DMGetDMSNES(dm, &sdm));
3116: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3117: DM dm;
3118: PetscBool isdense, ismf;
3120: PetscCall(SNESGetDM(snes, &dm));
3121: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3122: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3123: if (isdense) {
3124: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3125: } else if (!ismf) {
3126: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3127: }
3128: }
3129: PetscFunctionReturn(PETSC_SUCCESS);
3130: }
3132: /*@
3133: SNESSetUp - Sets up the internal data structures for the later use
3134: of a nonlinear solver.
3136: Collective
3138: Input Parameters:
3139: . snes - the `SNES` context
3141: Level: advanced
3143: Note:
3144: For basic use of the `SNES` solvers the user need not explicitly call
3145: `SNESSetUp()`, since these actions will automatically occur during
3146: the call to `SNESSolve()`. However, if one wishes to control this
3147: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3148: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3150: .seealso: [](chapter_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`
3151: @*/
3152: PetscErrorCode SNESSetUp(SNES snes)
3153: {
3154: DM dm;
3155: DMSNES sdm;
3156: SNESLineSearch linesearch, pclinesearch;
3157: void *lsprectx, *lspostctx;
3158: PetscBool mf_operator, mf;
3159: Vec f, fpc;
3160: void *funcctx;
3161: void *jacctx, *appctx;
3162: Mat j, jpre;
3163: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3164: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3165: PetscErrorCode (*func)(SNES, Vec, Vec, void *);
3166: PetscErrorCode (*jac)(SNES, Vec, Mat, Mat, void *);
3168: PetscFunctionBegin;
3170: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3171: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3173: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3175: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3177: PetscCall(SNESGetDM(snes, &dm));
3178: PetscCall(DMGetDMSNES(dm, &sdm));
3179: PetscCall(SNESSetDefaultComputeJacobian(snes));
3181: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3183: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3185: if (snes->linesearch) {
3186: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3187: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3188: }
3190: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3191: if (snes->npc && snes->npcside == PC_LEFT) {
3192: snes->mf = PETSC_TRUE;
3193: snes->mf_operator = PETSC_FALSE;
3194: }
3196: if (snes->npc) {
3197: /* copy the DM over */
3198: PetscCall(SNESGetDM(snes, &dm));
3199: PetscCall(SNESSetDM(snes->npc, dm));
3201: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3202: PetscCall(VecDuplicate(f, &fpc));
3203: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3204: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3205: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3206: PetscCall(SNESGetApplicationContext(snes, &appctx));
3207: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3208: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3209: PetscCall(VecDestroy(&fpc));
3211: /* copy the function pointers over */
3212: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3214: /* default to 1 iteration */
3215: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3216: if (snes->npcside == PC_RIGHT) {
3217: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3218: } else {
3219: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3220: }
3221: PetscCall(SNESSetFromOptions(snes->npc));
3223: /* copy the line search context over */
3224: if (snes->linesearch && snes->npc->linesearch) {
3225: PetscCall(SNESGetLineSearch(snes, &linesearch));
3226: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3227: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3228: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3229: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3230: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3231: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3232: }
3233: }
3234: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3235: if (snes->ops->usercompute && !snes->user) PetscCall((*snes->ops->usercompute)(snes, (void **)&snes->user));
3237: snes->jac_iter = 0;
3238: snes->pre_iter = 0;
3240: PetscTryTypeMethod(snes, setup);
3242: PetscCall(SNESSetDefaultComputeJacobian(snes));
3244: if (snes->npc && snes->npcside == PC_LEFT) {
3245: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3246: if (snes->linesearch) {
3247: PetscCall(SNESGetLineSearch(snes, &linesearch));
3248: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3249: }
3250: }
3251: }
3252: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3253: snes->setupcalled = PETSC_TRUE;
3254: PetscFunctionReturn(PETSC_SUCCESS);
3255: }
3257: /*@
3258: SNESReset - Resets a `SNES` context to the snessetupcalled = 0 state and removes any allocated `Vec`s and `Mat`s
3260: Collective
3262: Input Parameter:
3263: . snes - iterative context obtained from `SNESCreate()`
3265: Level: intermediate
3267: Notes:
3268: Call this if you wish to reuse a `SNES` but with different size vectors
3270: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3272: .seealso: [](chapter_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3273: @*/
3274: PetscErrorCode SNESReset(SNES snes)
3275: {
3276: PetscFunctionBegin;
3278: if (snes->ops->userdestroy && snes->user) {
3279: PetscCall((*snes->ops->userdestroy)((void **)&snes->user));
3280: snes->user = NULL;
3281: }
3282: if (snes->npc) PetscCall(SNESReset(snes->npc));
3284: PetscTryTypeMethod(snes, reset);
3285: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3287: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3289: PetscCall(VecDestroy(&snes->vec_rhs));
3290: PetscCall(VecDestroy(&snes->vec_sol));
3291: PetscCall(VecDestroy(&snes->vec_sol_update));
3292: PetscCall(VecDestroy(&snes->vec_func));
3293: PetscCall(MatDestroy(&snes->jacobian));
3294: PetscCall(MatDestroy(&snes->jacobian_pre));
3295: PetscCall(MatDestroy(&snes->picard));
3296: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3297: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3299: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3301: snes->nwork = snes->nvwork = 0;
3302: snes->setupcalled = PETSC_FALSE;
3303: PetscFunctionReturn(PETSC_SUCCESS);
3304: }
3306: /*@
3307: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object.
3309: Collective
3311: Input Parameter:
3312: . snes - iterative context obtained from `SNESCreate()`
3314: Level: intermediate
3316: .seealso: [](chapter_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`
3317: @*/
3318: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3319: {
3320: PetscInt i;
3322: PetscFunctionBegin;
3324: for (i = 0; i < snes->numberreasonviews; i++) {
3325: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3326: }
3327: snes->numberreasonviews = 0;
3328: PetscFunctionReturn(PETSC_SUCCESS);
3329: }
3331: /*@C
3332: SNESDestroy - Destroys the nonlinear solver context that was created
3333: with `SNESCreate()`.
3335: Collective
3337: Input Parameter:
3338: . snes - the `SNES` context
3340: Level: beginner
3342: .seealso: [](chapter_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3343: @*/
3344: PetscErrorCode SNESDestroy(SNES *snes)
3345: {
3346: PetscFunctionBegin;
3347: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3349: if (--((PetscObject)(*snes))->refct > 0) {
3350: *snes = NULL;
3351: PetscFunctionReturn(PETSC_SUCCESS);
3352: }
3354: PetscCall(SNESReset((*snes)));
3355: PetscCall(SNESDestroy(&(*snes)->npc));
3357: /* if memory was published with SAWs then destroy it */
3358: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3359: PetscTryTypeMethod((*snes), destroy);
3361: if ((*snes)->dm) PetscCall(DMCoarsenHookRemove((*snes)->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3362: PetscCall(DMDestroy(&(*snes)->dm));
3363: PetscCall(KSPDestroy(&(*snes)->ksp));
3364: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3366: PetscCall(PetscFree((*snes)->kspconvctx));
3367: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)((*snes)->cnvP));
3368: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3369: PetscCall(SNESMonitorCancel((*snes)));
3370: PetscCall(SNESConvergedReasonViewCancel((*snes)));
3371: PetscCall(PetscHeaderDestroy(snes));
3372: PetscFunctionReturn(PETSC_SUCCESS);
3373: }
3375: /* ----------- Routines to set solver parameters ---------- */
3377: /*@
3378: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3380: Logically Collective
3382: Input Parameters:
3383: + snes - the `SNES` context
3384: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3385: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3387: Options Database Keys:
3388: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3389: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3390: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3391: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3393: Notes:
3394: Level: intermediate
3396: The default is 1
3397: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3399: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3401: .seealso: [](chapter_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3402: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3403: @*/
3404: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3405: {
3406: PetscFunctionBegin;
3408: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3409: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3411: snes->lagpreconditioner = lag;
3412: PetscFunctionReturn(PETSC_SUCCESS);
3413: }
3415: /*@
3416: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3418: Logically Collective
3420: Input Parameters:
3421: + snes - the `SNES` context
3422: - steps - the number of refinements to do, defaults to 0
3424: Options Database Key:
3425: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3427: Level: intermediate
3429: Note:
3430: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3432: .seealso: [](chapter_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`
3433: @*/
3434: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3435: {
3436: PetscFunctionBegin;
3439: snes->gridsequence = steps;
3440: PetscFunctionReturn(PETSC_SUCCESS);
3441: }
3443: /*@
3444: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3446: Logically Collective
3448: Input Parameter:
3449: . snes - the `SNES` context
3451: Output Parameter:
3452: . steps - the number of refinements to do, defaults to 0
3454: Options Database Key:
3455: . -snes_grid_sequence <steps> - set number of refinements
3457: Level: intermediate
3459: Note:
3460: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3462: .seealso: [](chapter_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3463: @*/
3464: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3465: {
3466: PetscFunctionBegin;
3468: *steps = snes->gridsequence;
3469: PetscFunctionReturn(PETSC_SUCCESS);
3470: }
3472: /*@
3473: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3475: Not Collective
3477: Input Parameter:
3478: . snes - the `SNES` context
3480: Output Parameter:
3481: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3482: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3484: Options Database Keys:
3485: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3486: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3487: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3488: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3490: Level: intermediate
3492: Notes:
3493: The default is 1
3495: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3497: .seealso: [](chapter_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3498: @*/
3499: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3500: {
3501: PetscFunctionBegin;
3503: *lag = snes->lagpreconditioner;
3504: PetscFunctionReturn(PETSC_SUCCESS);
3505: }
3507: /*@
3508: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3509: often the preconditioner is rebuilt.
3511: Logically Collective
3513: Input Parameters:
3514: + snes - the `SNES` context
3515: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3516: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3518: Options Database Keys:
3519: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3520: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3521: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3522: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3524: Level: intermediate
3526: Notes:
3527: The default is 1
3529: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3531: If -1 is used before the very first nonlinear solve the CODE WILL FAIL! because no Jacobian is used, use -2 to indicate you want it recomputed
3532: at the next Newton step but never again (unless it is reset to another value)
3534: .seealso: [](chapter_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3535: @*/
3536: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3537: {
3538: PetscFunctionBegin;
3540: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3541: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3543: snes->lagjacobian = lag;
3544: PetscFunctionReturn(PETSC_SUCCESS);
3545: }
3547: /*@
3548: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3550: Not Collective
3552: Input Parameter:
3553: . snes - the `SNES` context
3555: Output Parameter:
3556: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3557: the Jacobian is built etc.
3559: Level: intermediate
3561: Notes:
3562: The default is 1
3564: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3566: .seealso: [](chapter_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3568: @*/
3569: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3570: {
3571: PetscFunctionBegin;
3573: *lag = snes->lagjacobian;
3574: PetscFunctionReturn(PETSC_SUCCESS);
3575: }
3577: /*@
3578: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3580: Logically collective
3582: Input Parameters:
3583: + snes - the `SNES` context
3584: - flg - jacobian lagging persists if true
3586: Options Database Keys:
3587: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3588: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3589: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3590: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3592: Level: advanced
3594: Notes:
3595: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that.
3597: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3598: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3599: timesteps may present huge efficiency gains.
3601: .seealso: [](chapter_snes), `SNES, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagJacobianPersists()`
3602: @*/
3603: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3604: {
3605: PetscFunctionBegin;
3608: snes->lagjac_persist = flg;
3609: PetscFunctionReturn(PETSC_SUCCESS);
3610: }
3612: /*@
3613: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3615: Logically Collective
3617: Input Parameters:
3618: + snes - the `SNES` context
3619: - flg - preconditioner lagging persists if true
3621: Options Database Keys:
3622: + -snes_lag_jacobian_persists <true,false> - sets the persistence
3623: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3624: . -snes_lag_preconditioner_persists <true,false> - sets the persistence
3625: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3627: Level: developer
3629: Notes:
3630: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that.
3632: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3633: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3634: several timesteps may present huge efficiency gains.
3636: .seealso: [](chapter_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3637: @*/
3638: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3639: {
3640: PetscFunctionBegin;
3643: snes->lagpre_persist = flg;
3644: PetscFunctionReturn(PETSC_SUCCESS);
3645: }
3647: /*@
3648: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3650: Logically Collective
3652: Input Parameters:
3653: + snes - the `SNES` context
3654: - force - `PETSC_TRUE` require at least one iteration
3656: Options Database Key:
3657: . -snes_force_iteration <force> - Sets forcing an iteration
3659: Level: intermediate
3661: Note:
3662: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3664: .seealso: [](chapter_snes), `SNES`, `TS`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3665: @*/
3666: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3667: {
3668: PetscFunctionBegin;
3670: snes->forceiteration = force;
3671: PetscFunctionReturn(PETSC_SUCCESS);
3672: }
3674: /*@
3675: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3677: Logically Collective
3679: Input Parameters:
3680: . snes - the `SNES` context
3682: Output Parameter:
3683: . force - `PETSC_TRUE` requires at least one iteration.
3685: Level: intermediate
3687: .seealso: [](chapter_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3688: @*/
3689: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3690: {
3691: PetscFunctionBegin;
3693: *force = snes->forceiteration;
3694: PetscFunctionReturn(PETSC_SUCCESS);
3695: }
3697: /*@
3698: SNESSetTolerances - Sets `SNES` various parameters used in convergence tests.
3700: Logically Collective
3702: Input Parameters:
3703: + snes - the `SNES` context
3704: . abstol - absolute convergence tolerance
3705: . rtol - relative convergence tolerance
3706: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3707: . maxit - maximum number of iterations, default 50.
3708: - maxf - maximum number of function evaluations (-1 indicates no limit), default 1000
3710: Options Database Keys:
3711: + -snes_atol <abstol> - Sets abstol
3712: . -snes_rtol <rtol> - Sets rtol
3713: . -snes_stol <stol> - Sets stol
3714: . -snes_max_it <maxit> - Sets maxit
3715: - -snes_max_funcs <maxf> - Sets maxf
3717: Level: intermediate
3719: .seealso: [](chapter_snes), `SNESolve()`, `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3720: @*/
3721: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3722: {
3723: PetscFunctionBegin;
3731: if (abstol != PETSC_DEFAULT) {
3732: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3733: snes->abstol = abstol;
3734: }
3735: if (rtol != PETSC_DEFAULT) {
3736: PetscCheck(rtol >= 0.0 && 1.0 > rtol, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Relative tolerance %g must be non-negative and less than 1.0", (double)rtol);
3737: snes->rtol = rtol;
3738: }
3739: if (stol != PETSC_DEFAULT) {
3740: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3741: snes->stol = stol;
3742: }
3743: if (maxit != PETSC_DEFAULT) {
3744: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3745: snes->max_its = maxit;
3746: }
3747: if (maxf != PETSC_DEFAULT) {
3748: PetscCheck(maxf >= -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be -1 or nonnegative", maxf);
3749: snes->max_funcs = maxf;
3750: }
3751: snes->tolerancesset = PETSC_TRUE;
3752: PetscFunctionReturn(PETSC_SUCCESS);
3753: }
3755: /*@
3756: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3758: Logically Collective
3760: Input Parameters:
3761: + snes - the `SNES` context
3762: - divtol - the divergence tolerance. Use -1 to deactivate the test, default is 1e4
3764: Options Database Key:
3765: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3767: Level: intermediate
3769: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance`
3770: @*/
3771: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3772: {
3773: PetscFunctionBegin;
3777: if (divtol != PETSC_DEFAULT) {
3778: snes->divtol = divtol;
3779: } else {
3780: snes->divtol = 1.0e4;
3781: }
3782: PetscFunctionReturn(PETSC_SUCCESS);
3783: }
3785: /*@
3786: SNESGetTolerances - Gets various parameters used in convergence tests.
3788: Not Collective
3790: Input Parameters:
3791: + snes - the `SNES` context
3792: . atol - absolute convergence tolerance
3793: . rtol - relative convergence tolerance
3794: . stol - convergence tolerance in terms of the norm
3795: of the change in the solution between steps
3796: . maxit - maximum number of iterations
3797: - maxf - maximum number of function evaluations
3799: Level: intermediate
3801: Note:
3802: The user can specify `NULL` for any parameter that is not needed.
3804: .seealso: [](chapter_snes), `SNES`, `SNESSetTolerances()`
3805: @*/
3806: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
3807: {
3808: PetscFunctionBegin;
3810: if (atol) *atol = snes->abstol;
3811: if (rtol) *rtol = snes->rtol;
3812: if (stol) *stol = snes->stol;
3813: if (maxit) *maxit = snes->max_its;
3814: if (maxf) *maxf = snes->max_funcs;
3815: PetscFunctionReturn(PETSC_SUCCESS);
3816: }
3818: /*@
3819: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3821: Not Collective
3823: Input Parameters:
3824: + snes - the `SNES` context
3825: - divtol - divergence tolerance
3827: Level: intermediate
3829: .seealso: [](chapter_snes), `SNES`, `SNESSetDivergenceTolerance()`
3830: @*/
3831: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
3832: {
3833: PetscFunctionBegin;
3835: if (divtol) *divtol = snes->divtol;
3836: PetscFunctionReturn(PETSC_SUCCESS);
3837: }
3839: /*@
3840: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3842: Logically Collective
3844: Input Parameters:
3845: + snes - the `SNES` context
3846: - tol - tolerance
3848: Options Database Key:
3849: . -snes_trtol <tol> - Sets tol
3851: Level: intermediate
3853: .seealso: [](chapter_snes), `SNES`, `SNESNEWTONTRDC`, `SNESSetTolerances()`
3854: @*/
3855: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes, PetscReal tol)
3856: {
3857: PetscFunctionBegin;
3860: snes->deltatol = tol;
3861: PetscFunctionReturn(PETSC_SUCCESS);
3862: }
3864: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
3866: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
3867: {
3868: PetscDrawLG lg;
3869: PetscReal x, y, per;
3870: PetscViewer v = (PetscViewer)monctx;
3871: static PetscReal prev; /* should be in the context */
3872: PetscDraw draw;
3874: PetscFunctionBegin;
3876: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
3877: if (!n) PetscCall(PetscDrawLGReset(lg));
3878: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3879: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
3880: x = (PetscReal)n;
3881: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3882: else y = -15.0;
3883: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3884: if (n < 20 || !(n % 5) || snes->reason) {
3885: PetscCall(PetscDrawLGDraw(lg));
3886: PetscCall(PetscDrawLGSave(lg));
3887: }
3889: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
3890: if (!n) PetscCall(PetscDrawLGReset(lg));
3891: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3892: PetscCall(PetscDrawSetTitle(draw, "% elemts > .2*max elemt"));
3893: PetscCall(SNESMonitorRange_Private(snes, n, &per));
3894: x = (PetscReal)n;
3895: y = 100.0 * per;
3896: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3897: if (n < 20 || !(n % 5) || snes->reason) {
3898: PetscCall(PetscDrawLGDraw(lg));
3899: PetscCall(PetscDrawLGSave(lg));
3900: }
3902: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
3903: if (!n) {
3904: prev = rnorm;
3905: PetscCall(PetscDrawLGReset(lg));
3906: }
3907: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3908: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
3909: x = (PetscReal)n;
3910: y = (prev - rnorm) / prev;
3911: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3912: if (n < 20 || !(n % 5) || snes->reason) {
3913: PetscCall(PetscDrawLGDraw(lg));
3914: PetscCall(PetscDrawLGSave(lg));
3915: }
3917: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
3918: if (!n) PetscCall(PetscDrawLGReset(lg));
3919: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3920: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
3921: x = (PetscReal)n;
3922: y = (prev - rnorm) / (prev * per);
3923: if (n > 2) { /*skip initial crazy value */
3924: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3925: }
3926: if (n < 20 || !(n % 5) || snes->reason) {
3927: PetscCall(PetscDrawLGDraw(lg));
3928: PetscCall(PetscDrawLGSave(lg));
3929: }
3930: prev = rnorm;
3931: PetscFunctionReturn(PETSC_SUCCESS);
3932: }
3934: /*@
3935: SNESMonitor - runs the user provided monitor routines, if they exist
3937: Collective
3939: Input Parameters:
3940: + snes - nonlinear solver context obtained from `SNESCreate()`
3941: . iter - iteration number
3942: - rnorm - relative norm of the residual
3944: Level: developer
3946: Note:
3947: This routine is called by the `SNES` implementations.
3948: It does not typically need to be called by the user.
3950: .seealso: [](chapter_snes), `SNES`, `SNESMonitorSet()`
3951: @*/
3952: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
3953: {
3954: PetscInt i, n = snes->numbermonitors;
3956: PetscFunctionBegin;
3957: PetscCall(VecLockReadPush(snes->vec_sol));
3958: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
3959: PetscCall(VecLockReadPop(snes->vec_sol));
3960: PetscFunctionReturn(PETSC_SUCCESS);
3961: }
3963: /* ------------ Routines to set performance monitoring options ----------- */
3965: /*MC
3966: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
3968: Synopsis:
3969: #include <petscsnes.h>
3970: $ PetscErrorCode SNESMonitorFunction(SNES snes,PetscInt its, PetscReal norm,void *mctx)
3972: Collective
3974: Input Parameters:
3975: + snes - the `SNES` context
3976: . its - iteration number
3977: . norm - 2-norm function value (may be estimated)
3978: - mctx - [optional] monitoring context
3980: Level: advanced
3982: .seealso: [](chapter_snes), `SNESMonitorSet()`, `SNESMonitorSet()`, `SNESMonitorGet()`
3983: M*/
3985: /*@C
3986: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3987: iteration of the nonlinear solver to display the iteration's
3988: progress.
3990: Logically Collective
3992: Input Parameters:
3993: + snes - the `SNES` context
3994: . f - the monitor function, see `SNESMonitorFunction` for the calling sequence
3995: . mctx - [optional] user-defined context for private data for the
3996: monitor routine (use `NULL` if no context is desired)
3997: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`)
3999: Options Database Keys:
4000: + -snes_monitor - sets `SNESMonitorDefault()`
4001: . -snes_monitor draw::draw_lg - sets line graph monitor,
4002: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4003: the options database.
4005: Level: intermediate
4007: Note:
4008: Several different monitoring routines may be set by calling
4009: `SNESMonitorSet()` multiple times; all will be called in the
4010: order in which they were set.
4012: Fortran Note:
4013: Only a single monitor function can be set for each `SNES` object
4015: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`
4016: @*/
4017: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscErrorCode (*monitordestroy)(void **))
4018: {
4019: PetscInt i;
4020: PetscBool identical;
4022: PetscFunctionBegin;
4024: for (i = 0; i < snes->numbermonitors; i++) {
4025: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, mctx, monitordestroy, (PetscErrorCode(*)(void))snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4026: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4027: }
4028: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4029: snes->monitor[snes->numbermonitors] = f;
4030: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4031: snes->monitorcontext[snes->numbermonitors++] = (void *)mctx;
4032: PetscFunctionReturn(PETSC_SUCCESS);
4033: }
4035: /*@
4036: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4038: Logically Collective
4040: Input Parameters:
4041: . snes - the `SNES` context
4043: Options Database Key:
4044: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4045: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4046: set via the options database
4048: Level: intermediate
4050: Note:
4051: There is no way to clear one specific monitor from a `SNES` object.
4053: .seealso: [](chapter_snes), `SNES`, `SNESMonitorGet()`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4054: @*/
4055: PetscErrorCode SNESMonitorCancel(SNES snes)
4056: {
4057: PetscInt i;
4059: PetscFunctionBegin;
4061: for (i = 0; i < snes->numbermonitors; i++) {
4062: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4063: }
4064: snes->numbermonitors = 0;
4065: PetscFunctionReturn(PETSC_SUCCESS);
4066: }
4068: /*MC
4069: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4071: Synopsis:
4072: #include <petscsnes.h>
4073: $ PetscErrorCode SNESConvergenceTest(SNES snes,PetscInt it,PetscReal xnorm,PetscReal gnorm,PetscReal f,SNESConvergedReason *reason,void *cctx)
4075: Collective
4077: Input Parameters:
4078: + snes - the `SNES` context
4079: . it - current iteration (0 is the first and is before any Newton step)
4080: . xnorm - 2-norm of current iterate
4081: . gnorm - 2-norm of current step
4082: . f - 2-norm of function
4083: - cctx - [optional] convergence context
4085: Output Parameter:
4086: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4088: Level: intermediate
4090: .seealso: [](chapter_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4091: M*/
4093: /*@C
4094: SNESSetConvergenceTest - Sets the function that is to be used
4095: to test for convergence of the nonlinear iterative solution.
4097: Logically Collective
4099: Input Parameters:
4100: + snes - the `SNES` context
4101: . `SNESConvergenceTestFunction` - routine to test for convergence
4102: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4103: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4105: Level: advanced
4107: .seealso: [](chapter_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4108: @*/
4109: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscErrorCode (*destroy)(void *))
4110: {
4111: PetscFunctionBegin;
4113: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4114: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(snes->cnvP));
4115: snes->ops->converged = SNESConvergenceTestFunction;
4116: snes->ops->convergeddestroy = destroy;
4117: snes->cnvP = cctx;
4118: PetscFunctionReturn(PETSC_SUCCESS);
4119: }
4121: /*@
4122: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped.
4124: Not Collective
4126: Input Parameter:
4127: . snes - the `SNES` context
4129: Output Parameter:
4130: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4132: Options Database Key:
4133: . -snes_converged_reason - prints the reason to standard out
4135: Level: intermediate
4137: Note:
4138: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4140: .seealso: [](chapter_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4141: @*/
4142: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4143: {
4144: PetscFunctionBegin;
4147: *reason = snes->reason;
4148: PetscFunctionReturn(PETSC_SUCCESS);
4149: }
4151: /*@C
4152: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4154: Not Collective
4156: Input Parameter:
4157: . snes - the `SNES` context
4159: Output Parameter:
4160: . strreason - a human readable string that describes `SNES` converged reason
4162: Level: beginner
4164: .seealso: [](chapter_snes), `SNES`, `SNESGetConvergedReason()`
4165: @*/
4166: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4167: {
4168: PetscFunctionBegin;
4171: *strreason = SNESConvergedReasons[snes->reason];
4172: PetscFunctionReturn(PETSC_SUCCESS);
4173: }
4175: /*@
4176: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4178: Not Collective
4180: Input Parameters:
4181: + snes - the `SNES` context
4182: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4183: manual pages for the individual convergence tests for complete lists
4185: Level: developer
4187: Developer Note:
4188: Called inside the various `SNESSolve()` implementations
4190: .seealso: [](chapter_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4191: @*/
4192: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4193: {
4194: PetscFunctionBegin;
4196: snes->reason = reason;
4197: PetscFunctionReturn(PETSC_SUCCESS);
4198: }
4200: /*@
4201: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4203: Logically Collective
4205: Input Parameters:
4206: + snes - iterative context obtained from `SNESCreate()`
4207: . a - array to hold history, this array will contain the function norms computed at each step
4208: . its - integer array holds the number of linear iterations for each solve.
4209: . na - size of a and its
4210: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4211: else it continues storing new values for new nonlinear solves after the old ones
4213: Level: intermediate
4215: Notes:
4216: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' `PETSC_DECIDE` or `PETSC_DEFAULT` then a
4217: default array of length 10000 is allocated.
4219: This routine is useful, e.g., when running a code for purposes
4220: of accurate performance monitoring, when no I/O should be done
4221: during the section of code that is being timed.
4223: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4224: @*/
4225: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4226: {
4227: PetscFunctionBegin;
4231: if (!a) {
4232: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4233: PetscCall(PetscCalloc2(na, &a, na, &its));
4234: snes->conv_hist_alloc = PETSC_TRUE;
4235: }
4236: snes->conv_hist = a;
4237: snes->conv_hist_its = its;
4238: snes->conv_hist_max = (size_t)na;
4239: snes->conv_hist_len = 0;
4240: snes->conv_hist_reset = reset;
4241: PetscFunctionReturn(PETSC_SUCCESS);
4242: }
4244: #if defined(PETSC_HAVE_MATLAB)
4245: #include <engine.h> /* MATLAB include file */
4246: #include <mex.h> /* MATLAB include file */
4248: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4249: {
4250: mxArray *mat;
4251: PetscInt i;
4252: PetscReal *ar;
4254: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4255: ar = (PetscReal *)mxGetData(mat);
4256: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4257: return mat;
4258: }
4259: #endif
4261: /*@C
4262: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4264: Not Collective
4266: Input Parameter:
4267: . snes - iterative context obtained from `SNESCreate()`
4269: Output Parameters:
4270: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4271: . its - integer array holds the number of linear iterations (or
4272: negative if not converged) for each solve.
4273: - na - size of a and its
4275: Level: intermediate
4277: Notes:
4278: The calling sequence for this routine in Fortran is
4279: .vb
4280: call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4281: .ve
4283: This routine is useful, e.g., when running a code for purposes
4284: of accurate performance monitoring, when no I/O should be done
4285: during the section of code that is being timed.
4287: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4288: @*/
4289: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4290: {
4291: PetscFunctionBegin;
4293: if (a) *a = snes->conv_hist;
4294: if (its) *its = snes->conv_hist_its;
4295: if (na) *na = (PetscInt)snes->conv_hist_len;
4296: PetscFunctionReturn(PETSC_SUCCESS);
4297: }
4299: /*@C
4300: SNESSetUpdate - Sets the general-purpose update function called
4301: at the beginning of every iteration of the nonlinear solve. Specifically
4302: it is called just before the Jacobian is "evaluated".
4304: Logically Collective
4306: Input Parameters:
4307: + snes - The nonlinear solver context
4308: - func - The function
4310: Calling sequence of func:
4311: $ func (SNES snes, PetscInt step);
4313: . step - The current step of the iteration
4315: Level: advanced
4317: Note:
4318: This is NOT what one uses to update the ghost points before a function evaluation, that should be done at the beginning of your function provided
4319: to `SNESSetFunction()`, or `SNESSetPicard()`
4320: This is not used by most users.
4322: There are a varity of function hooks one many set that are called at different stages of the nonlinear solution process, see the functions listed below.
4324: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESSolve()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4325: `SNESMonitorSet()`, `SNESSetDivergenceTest()`
4326: @*/
4327: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4328: {
4329: PetscFunctionBegin;
4331: snes->ops->update = func;
4332: PetscFunctionReturn(PETSC_SUCCESS);
4333: }
4335: /*
4336: SNESScaleStep_Private - Scales a step so that its length is less than the
4337: positive parameter delta.
4339: Input Parameters:
4340: + snes - the `SNES` context
4341: . y - approximate solution of linear system
4342: . fnorm - 2-norm of current function
4343: - delta - trust region size
4345: Output Parameters:
4346: + gpnorm - predicted function norm at the new point, assuming local
4347: linearization. The value is zero if the step lies within the trust
4348: region, and exceeds zero otherwise.
4349: - ynorm - 2-norm of the step
4351: Level: developer
4353: Note:
4354: For non-trust region methods such as `SNESNEWTONLS`, the parameter delta
4355: is set to be the maximum allowable step size.
4356: */
4357: PetscErrorCode SNESScaleStep_Private(SNES snes, Vec y, PetscReal *fnorm, PetscReal *delta, PetscReal *gpnorm, PetscReal *ynorm)
4358: {
4359: PetscReal nrm;
4360: PetscScalar cnorm;
4362: PetscFunctionBegin;
4365: PetscCheckSameComm(snes, 1, y, 2);
4367: PetscCall(VecNorm(y, NORM_2, &nrm));
4368: if (nrm > *delta) {
4369: nrm = *delta / nrm;
4370: *gpnorm = (1.0 - nrm) * (*fnorm);
4371: cnorm = nrm;
4372: PetscCall(VecScale(y, cnorm));
4373: *ynorm = *delta;
4374: } else {
4375: *gpnorm = 0.0;
4376: *ynorm = nrm;
4377: }
4378: PetscFunctionReturn(PETSC_SUCCESS);
4379: }
4381: /*@C
4382: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4384: Collective
4386: Parameter:
4387: + snes - iterative context obtained from `SNESCreate()`
4388: - viewer - the viewer to display the reason
4390: Options Database Keys:
4391: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4392: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4394: Note:
4395: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4396: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4398: Level: beginner
4400: .seealso: [](chapter_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4401: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4402: `SNESConvergedReasonViewFromOptions()`,
4403: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4404: @*/
4405: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4406: {
4407: PetscViewerFormat format;
4408: PetscBool isAscii;
4410: PetscFunctionBegin;
4411: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4412: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4413: if (isAscii) {
4414: PetscCall(PetscViewerGetFormat(viewer, &format));
4415: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
4416: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4417: DM dm;
4418: Vec u;
4419: PetscDS prob;
4420: PetscInt Nf, f;
4421: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4422: void **exactCtx;
4423: PetscReal error;
4425: PetscCall(SNESGetDM(snes, &dm));
4426: PetscCall(SNESGetSolution(snes, &u));
4427: PetscCall(DMGetDS(dm, &prob));
4428: PetscCall(PetscDSGetNumFields(prob, &Nf));
4429: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4430: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4431: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4432: PetscCall(PetscFree2(exactSol, exactCtx));
4433: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4434: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4435: }
4436: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4437: if (((PetscObject)snes)->prefix) {
4438: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4439: } else {
4440: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4441: }
4442: } else if (snes->reason <= 0) {
4443: if (((PetscObject)snes)->prefix) {
4444: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4445: } else {
4446: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4447: }
4448: }
4449: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
4450: }
4451: PetscFunctionReturn(PETSC_SUCCESS);
4452: }
4454: /*@C
4455: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4456: end of the nonlinear solver to display the conver reason of the nonlinear solver.
4458: Logically Collective
4460: Input Parameters:
4461: + snes - the `SNES` context
4462: . f - the snes converged reason view function
4463: . vctx - [optional] user-defined context for private data for the
4464: snes converged reason view routine (use `NULL` if no context is desired)
4465: - reasonviewdestroy - [optional] routine that frees reasonview context (may be `NULL`)
4467: Options Database Keys:
4468: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4469: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have
4470: been hardwired into a code by
4471: calls to `SNESConvergedReasonViewSet()`, but
4472: does not cancel those set via
4473: the options database.
4475: Level: intermediate
4477: Note:
4478: Several different converged reason view routines may be set by calling
4479: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4480: order in which they were set.
4482: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`
4483: @*/
4484: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES, void *), void *vctx, PetscErrorCode (*reasonviewdestroy)(void **))
4485: {
4486: PetscInt i;
4487: PetscBool identical;
4489: PetscFunctionBegin;
4491: for (i = 0; i < snes->numberreasonviews; i++) {
4492: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, vctx, reasonviewdestroy, (PetscErrorCode(*)(void))snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4493: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4494: }
4495: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4496: snes->reasonview[snes->numberreasonviews] = f;
4497: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4498: snes->reasonviewcontext[snes->numberreasonviews++] = (void *)vctx;
4499: PetscFunctionReturn(PETSC_SUCCESS);
4500: }
4502: /*@
4503: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed.
4504: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4506: Collective
4508: Input Parameters:
4509: . snes - the `SNES` object
4511: Level: advanced
4513: .seealso: [](chapter_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4514: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4515: @*/
4516: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4517: {
4518: PetscViewer viewer;
4519: PetscBool flg;
4520: static PetscBool incall = PETSC_FALSE;
4521: PetscViewerFormat format;
4522: PetscInt i;
4524: PetscFunctionBegin;
4525: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4526: incall = PETSC_TRUE;
4528: /* All user-provided viewers are called first, if they exist. */
4529: for (i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4531: /* Call PETSc default routine if users ask for it */
4532: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &viewer, &format, &flg));
4533: if (flg) {
4534: PetscCall(PetscViewerPushFormat(viewer, format));
4535: PetscCall(SNESConvergedReasonView(snes, viewer));
4536: PetscCall(PetscViewerPopFormat(viewer));
4537: PetscCall(PetscViewerDestroy(&viewer));
4538: }
4539: incall = PETSC_FALSE;
4540: PetscFunctionReturn(PETSC_SUCCESS);
4541: }
4543: /*@
4544: SNESSolve - Solves a nonlinear system F(x) = b.
4545: Call `SNESSolve()` after calling `SNESCreate()` and optional routines of the form `SNESSetXXX()`.
4547: Collective
4549: Input Parameters:
4550: + snes - the `SNES` context
4551: . b - the constant part of the equation F(x) = b, or `NULL` to use zero.
4552: - x - the solution vector.
4554: Level: beginner
4556: Note:
4557: The user should initialize the vector,x, with the initial guess
4558: for the nonlinear solve prior to calling `SNESSolve()`. In particular,
4559: to employ an initial guess of zero, the user should explicitly set
4560: this vector to zero by calling `VecSet()`.
4562: .seealso: [](chapter_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4563: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4564: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`
4565: @*/
4566: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4567: {
4568: PetscBool flg;
4569: PetscInt grid;
4570: Vec xcreated = NULL;
4571: DM dm;
4573: PetscFunctionBegin;
4576: if (x) PetscCheckSameComm(snes, 1, x, 3);
4578: if (b) PetscCheckSameComm(snes, 1, b, 2);
4580: /* High level operations using the nonlinear solver */
4581: {
4582: PetscViewer viewer;
4583: PetscViewerFormat format;
4584: PetscInt num;
4585: PetscBool flg;
4586: static PetscBool incall = PETSC_FALSE;
4588: if (!incall) {
4589: /* Estimate the convergence rate of the discretization */
4590: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4591: if (flg) {
4592: PetscConvEst conv;
4593: DM dm;
4594: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4595: PetscInt Nf;
4597: incall = PETSC_TRUE;
4598: PetscCall(SNESGetDM(snes, &dm));
4599: PetscCall(DMGetNumFields(dm, &Nf));
4600: PetscCall(PetscCalloc1(Nf, &alpha));
4601: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4602: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4603: PetscCall(PetscConvEstSetFromOptions(conv));
4604: PetscCall(PetscConvEstSetUp(conv));
4605: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4606: PetscCall(PetscViewerPushFormat(viewer, format));
4607: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4608: PetscCall(PetscViewerPopFormat(viewer));
4609: PetscCall(PetscViewerDestroy(&viewer));
4610: PetscCall(PetscConvEstDestroy(&conv));
4611: PetscCall(PetscFree(alpha));
4612: incall = PETSC_FALSE;
4613: }
4614: /* Adaptively refine the initial grid */
4615: num = 1;
4616: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4617: if (flg) {
4618: DMAdaptor adaptor;
4620: incall = PETSC_TRUE;
4621: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4622: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4623: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4624: PetscCall(DMAdaptorSetFromOptions(adaptor));
4625: PetscCall(DMAdaptorSetUp(adaptor));
4626: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4627: PetscCall(DMAdaptorDestroy(&adaptor));
4628: incall = PETSC_FALSE;
4629: }
4630: /* Use grid sequencing to adapt */
4631: num = 0;
4632: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4633: if (num) {
4634: DMAdaptor adaptor;
4636: incall = PETSC_TRUE;
4637: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4638: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4639: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4640: PetscCall(DMAdaptorSetFromOptions(adaptor));
4641: PetscCall(DMAdaptorSetUp(adaptor));
4642: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4643: PetscCall(DMAdaptorDestroy(&adaptor));
4644: incall = PETSC_FALSE;
4645: }
4646: }
4647: }
4648: if (!x) x = snes->vec_sol;
4649: if (!x) {
4650: PetscCall(SNESGetDM(snes, &dm));
4651: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4652: x = xcreated;
4653: }
4654: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4656: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4657: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4658: /* set solution vector */
4659: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4660: PetscCall(VecDestroy(&snes->vec_sol));
4661: snes->vec_sol = x;
4662: PetscCall(SNESGetDM(snes, &dm));
4664: /* set affine vector if provided */
4665: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4666: PetscCall(VecDestroy(&snes->vec_rhs));
4667: snes->vec_rhs = b;
4669: if (snes->vec_rhs) PetscCheck(snes->vec_func != snes->vec_rhs, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Right hand side vector cannot be function vector");
4670: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4671: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right hand side vector");
4672: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4673: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4674: PetscCall(SNESSetUp(snes));
4676: if (!grid) {
4677: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4678: }
4680: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4681: if (snes->counters_reset) {
4682: snes->nfuncs = 0;
4683: snes->linear_its = 0;
4684: snes->numFailures = 0;
4685: }
4687: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4688: PetscUseTypeMethod(snes, solve);
4689: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4690: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver returned without setting converged reason");
4691: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4693: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4694: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4696: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4697: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4698: /* Call converged reason views. This may involve user-provided viewers as well */
4699: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4701: if (snes->errorifnotconverged) PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4702: if (snes->reason < 0) break;
4703: if (grid < snes->gridsequence) {
4704: DM fine;
4705: Vec xnew;
4706: Mat interp;
4708: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4709: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4710: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4711: PetscCall(DMCreateGlobalVector(fine, &xnew));
4712: PetscCall(MatInterpolate(interp, x, xnew));
4713: PetscCall(DMInterpolate(snes->dm, interp, fine));
4714: PetscCall(MatDestroy(&interp));
4715: x = xnew;
4717: PetscCall(SNESReset(snes));
4718: PetscCall(SNESSetDM(snes, fine));
4719: PetscCall(SNESResetFromOptions(snes));
4720: PetscCall(DMDestroy(&fine));
4721: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4722: }
4723: }
4724: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4725: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4726: PetscCall(DMMonitor(snes->dm));
4727: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4729: PetscCall(VecDestroy(&xcreated));
4730: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4731: PetscFunctionReturn(PETSC_SUCCESS);
4732: }
4734: /* --------- Internal routines for SNES Package --------- */
4736: /*@C
4737: SNESSetType - Sets the method for the nonlinear solver.
4739: Collective
4741: Input Parameters:
4742: + snes - the `SNES` context
4743: - type - a known method
4745: Options Database Key:
4746: . -snes_type <type> - Sets the method; use -help for a list
4747: of available methods (for instance, newtonls or newtontr)
4749: Level: intermediate
4751: Notes:
4752: See "petsc/include/petscsnes.h" for available methods (for instance)
4753: + `SNESNEWTONLS` - Newton's method with line search
4754: (systems of nonlinear equations)
4755: - `SNESNEWTONTRDC` - Newton's method with trust region
4756: (systems of nonlinear equations)
4758: Normally, it is best to use the `SNESSetFromOptions()` command and then
4759: set the `SNES` solver type from the options database rather than by using
4760: this routine. Using the options database provides the user with
4761: maximum flexibility in evaluating the many nonlinear solvers.
4762: The `SNESSetType()` routine is provided for those situations where it
4763: is necessary to set the nonlinear solver independently of the command
4764: line or options database. This might be the case, for example, when
4765: the choice of solver changes during the execution of the program,
4766: and the user's application is taking responsibility for choosing the
4767: appropriate method.
4769: Developer Note:
4770: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4771: the constructor in that list and calls it to create the specific object.
4773: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4774: @*/
4775: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4776: {
4777: PetscBool match;
4778: PetscErrorCode (*r)(SNES);
4780: PetscFunctionBegin;
4784: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4785: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4787: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4788: PetscCheck(r, PETSC_COMM_SELF, PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4789: /* Destroy the previous private SNES context */
4790: PetscTryTypeMethod(snes, destroy);
4791: /* Reinitialize function pointers in SNESOps structure */
4792: snes->ops->setup = NULL;
4793: snes->ops->solve = NULL;
4794: snes->ops->view = NULL;
4795: snes->ops->setfromoptions = NULL;
4796: snes->ops->destroy = NULL;
4798: /* It may happen the user has customized the line search before calling SNESSetType */
4799: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
4801: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4802: snes->setupcalled = PETSC_FALSE;
4804: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
4805: PetscCall((*r)(snes));
4806: PetscFunctionReturn(PETSC_SUCCESS);
4807: }
4809: /*@C
4810: SNESGetType - Gets the `SNES` method type and name (as a string).
4812: Not Collective
4814: Input Parameter:
4815: . snes - nonlinear solver context
4817: Output Parameter:
4818: . type - `SNES` method (a character string)
4820: Level: intermediate
4822: .seealso: [](chapter_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
4823: @*/
4824: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
4825: {
4826: PetscFunctionBegin;
4829: *type = ((PetscObject)snes)->type_name;
4830: PetscFunctionReturn(PETSC_SUCCESS);
4831: }
4833: /*@
4834: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
4836: Logically Collective
4838: Input Parameters:
4839: + snes - the `SNES` context obtained from `SNESCreate()`
4840: - u - the solution vector
4842: Level: beginner
4844: .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
4845: @*/
4846: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4847: {
4848: DM dm;
4850: PetscFunctionBegin;
4853: PetscCall(PetscObjectReference((PetscObject)u));
4854: PetscCall(VecDestroy(&snes->vec_sol));
4856: snes->vec_sol = u;
4858: PetscCall(SNESGetDM(snes, &dm));
4859: PetscCall(DMShellSetGlobalVector(dm, u));
4860: PetscFunctionReturn(PETSC_SUCCESS);
4861: }
4863: /*@
4864: SNESGetSolution - Returns the vector where the approximate solution is
4865: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
4867: Not Collective, but x is parallel if snes is parallel
4869: Input Parameter:
4870: . snes - the `SNES` context
4872: Output Parameter:
4873: . x - the solution
4875: Level: intermediate
4877: .seealso: [](chapter_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
4878: @*/
4879: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
4880: {
4881: PetscFunctionBegin;
4884: *x = snes->vec_sol;
4885: PetscFunctionReturn(PETSC_SUCCESS);
4886: }
4888: /*@
4889: SNESGetSolutionUpdate - Returns the vector where the solution update is
4890: stored.
4892: Not Collective, but x is parallel if snes is parallel
4894: Input Parameter:
4895: . snes - the `SNES` context
4897: Output Parameter:
4898: . x - the solution update
4900: Level: advanced
4902: .seealso: [](chapter_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
4903: @*/
4904: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
4905: {
4906: PetscFunctionBegin;
4909: *x = snes->vec_sol_update;
4910: PetscFunctionReturn(PETSC_SUCCESS);
4911: }
4913: /*@C
4914: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
4916: Not Collective, but r is parallel if snes is parallel. Collective if r is requested, but has not been created yet.
4918: Input Parameter:
4919: . snes - the `SNES` context
4921: Output Parameters:
4922: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
4923: . f - the function (or `NULL` if you don't want it); see `SNESFunction` for calling sequence details
4924: - ctx - the function context (or `NULL` if you don't want it)
4926: Level: advanced
4928: Note:
4929: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
4931: .seealso: [](chapter_snes), `SNES, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunction`
4932: @*/
4933: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, PetscErrorCode (**f)(SNES, Vec, Vec, void *), void **ctx)
4934: {
4935: DM dm;
4937: PetscFunctionBegin;
4939: if (r) {
4940: if (!snes->vec_func) {
4941: if (snes->vec_rhs) {
4942: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
4943: } else if (snes->vec_sol) {
4944: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
4945: } else if (snes->dm) {
4946: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
4947: }
4948: }
4949: *r = snes->vec_func;
4950: }
4951: PetscCall(SNESGetDM(snes, &dm));
4952: PetscCall(DMSNESGetFunction(dm, f, ctx));
4953: PetscFunctionReturn(PETSC_SUCCESS);
4954: }
4956: /*@C
4957: SNESGetNGS - Returns the `SNESNGS` function and context set with `SNESSetNGS()`
4959: Input Parameter:
4960: . snes - the `SNES` context
4962: Output Parameters:
4963: + f - the function (or `NULL`) see `SNESNGSFunction` for details
4964: - ctx - the function context (or `NULL`)
4966: Level: advanced
4968: .seealso: [](chapter_snes), `SNESSetNGS()`, `SNESGetFunction()`
4969: @*/
4971: PetscErrorCode SNESGetNGS(SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void *), void **ctx)
4972: {
4973: DM dm;
4975: PetscFunctionBegin;
4977: PetscCall(SNESGetDM(snes, &dm));
4978: PetscCall(DMSNESGetNGS(dm, f, ctx));
4979: PetscFunctionReturn(PETSC_SUCCESS);
4980: }
4982: /*@C
4983: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4984: `SNES` options in the database.
4986: Logically Collective
4988: Input Parameters:
4989: + snes - the `SNES` context
4990: - prefix - the prefix to prepend to all option names
4992: Level: advanced
4994: Note:
4995: A hyphen (-) must NOT be given at the beginning of the prefix name.
4996: The first character of all runtime options is AUTOMATICALLY the hyphen.
4998: .seealso: [](chapter_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
4999: @*/
5000: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
5001: {
5002: PetscFunctionBegin;
5004: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
5005: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5006: if (snes->linesearch) {
5007: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5008: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
5009: }
5010: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
5011: PetscFunctionReturn(PETSC_SUCCESS);
5012: }
5014: /*@C
5015: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5016: `SNES` options in the database.
5018: Logically Collective
5020: Input Parameters:
5021: + snes - the `SNES` context
5022: - prefix - the prefix to prepend to all option names
5024: Level: advanced
5026: Note:
5027: A hyphen (-) must NOT be given at the beginning of the prefix name.
5028: The first character of all runtime options is AUTOMATICALLY the hyphen.
5030: .seealso: [](chapter_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5031: @*/
5032: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5033: {
5034: PetscFunctionBegin;
5036: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5037: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5038: if (snes->linesearch) {
5039: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5040: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5041: }
5042: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5043: PetscFunctionReturn(PETSC_SUCCESS);
5044: }
5046: /*@C
5047: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5048: `SNES` options in the database.
5050: Not Collective
5052: Input Parameter:
5053: . snes - the `SNES` context
5055: Output Parameter:
5056: . prefix - pointer to the prefix string used
5058: Level: advanced
5060: Fortran Note:
5061: The user should pass in a string 'prefix' of
5062: sufficient length to hold the prefix.
5064: .seealso: [](chapter_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5065: @*/
5066: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5067: {
5068: PetscFunctionBegin;
5070: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5071: PetscFunctionReturn(PETSC_SUCCESS);
5072: }
5074: /*@C
5075: SNESRegister - Adds a method to the nonlinear solver package.
5077: Not collective
5079: Input Parameters:
5080: + name_solver - name of a new user-defined solver
5081: - routine_create - routine to create method context
5083: Level: advanced
5085: Note:
5086: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5088: Sample usage:
5089: .vb
5090: SNESRegister("my_solver",MySolverCreate);
5091: .ve
5093: Then, your solver can be chosen with the procedural interface via
5094: $ SNESSetType(snes,"my_solver")
5095: or at runtime via the option
5096: $ -snes_type my_solver
5098: .seealso: [](chapter_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5099: @*/
5100: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5101: {
5102: PetscFunctionBegin;
5103: PetscCall(SNESInitializePackage());
5104: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5105: PetscFunctionReturn(PETSC_SUCCESS);
5106: }
5108: PetscErrorCode SNESTestLocalMin(SNES snes)
5109: {
5110: PetscInt N, i, j;
5111: Vec u, uh, fh;
5112: PetscScalar value;
5113: PetscReal norm;
5115: PetscFunctionBegin;
5116: PetscCall(SNESGetSolution(snes, &u));
5117: PetscCall(VecDuplicate(u, &uh));
5118: PetscCall(VecDuplicate(u, &fh));
5120: /* currently only works for sequential */
5121: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5122: PetscCall(VecGetSize(u, &N));
5123: for (i = 0; i < N; i++) {
5124: PetscCall(VecCopy(u, uh));
5125: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5126: for (j = -10; j < 11; j++) {
5127: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5128: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5129: PetscCall(SNESComputeFunction(snes, uh, fh));
5130: PetscCall(VecNorm(fh, NORM_2, &norm));
5131: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5132: value = -value;
5133: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5134: }
5135: }
5136: PetscCall(VecDestroy(&uh));
5137: PetscCall(VecDestroy(&fh));
5138: PetscFunctionReturn(PETSC_SUCCESS);
5139: }
5141: /*@
5142: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5143: computing relative tolerance for linear solvers within an inexact
5144: Newton method.
5146: Logically Collective
5148: Input Parameters:
5149: + snes - `SNES` context
5150: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5152: Options Database Keys:
5153: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5154: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5155: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5156: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5157: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5158: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5159: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5160: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5162: Level: advanced
5164: Note:
5165: The default is to use a constant relative tolerance for
5166: the inner linear solvers. Alternatively, one can use the
5167: Eisenstat-Walker method, where the relative convergence tolerance
5168: is reset at each Newton iteration according progress of the nonlinear
5169: solver.
5171: Reference:
5172: . - * S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5174: .seealso: [](chapter_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5175: @*/
5176: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5177: {
5178: PetscFunctionBegin;
5181: snes->ksp_ewconv = flag;
5182: PetscFunctionReturn(PETSC_SUCCESS);
5183: }
5185: /*@
5186: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5187: for computing relative tolerance for linear solvers within an
5188: inexact Newton method.
5190: Not Collective
5192: Input Parameter:
5193: . snes - `SNES` context
5195: Output Parameter:
5196: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5198: Level: advanced
5200: .seealso: [](chapter_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5201: @*/
5202: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5203: {
5204: PetscFunctionBegin;
5207: *flag = snes->ksp_ewconv;
5208: PetscFunctionReturn(PETSC_SUCCESS);
5209: }
5211: /*@
5212: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5213: convergence criteria for the linear solvers within an inexact
5214: Newton method.
5216: Logically Collective
5218: Input Parameters:
5219: + snes - `SNES` context
5220: . version - version 1, 2 (default is 2), 3 or 4
5221: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5222: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5223: . gamma - multiplicative factor for version 2 rtol computation
5224: (0 <= gamma2 <= 1)
5225: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5226: . alpha2 - power for safeguard
5227: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5229: Level: advanced
5231: Notes:
5232: Version 3 was contributed by Luis Chacon, June 2006.
5234: Use `PETSC_DEFAULT` to retain the default for any of the parameters.
5236: .seealso: [](chapter_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5237: @*/
5238: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5239: {
5240: SNESKSPEW *kctx;
5242: PetscFunctionBegin;
5244: kctx = (SNESKSPEW *)snes->kspconvctx;
5245: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5254: if (version != PETSC_DEFAULT) kctx->version = version;
5255: if (rtol_0 != PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5256: if (rtol_max != PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5257: if (gamma != PETSC_DEFAULT) kctx->gamma = gamma;
5258: if (alpha != PETSC_DEFAULT) kctx->alpha = alpha;
5259: if (alpha2 != PETSC_DEFAULT) kctx->alpha2 = alpha2;
5260: if (threshold != PETSC_DEFAULT) kctx->threshold = threshold;
5262: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1 to 4 are supported: %" PetscInt_FMT, kctx->version);
5263: PetscCheck(kctx->rtol_0 >= 0.0 && kctx->rtol_0 < 1.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "0.0 <= rtol_0 < 1.0: %g", (double)kctx->rtol_0);
5264: PetscCheck(kctx->rtol_max >= 0.0 && kctx->rtol_max < 1.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "0.0 <= rtol_max (%g) < 1.0", (double)kctx->rtol_max);
5265: PetscCheck(kctx->gamma >= 0.0 && kctx->gamma <= 1.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "0.0 <= gamma (%g) <= 1.0", (double)kctx->gamma);
5266: PetscCheck(kctx->alpha > 1.0 && kctx->alpha <= 2.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "1.0 < alpha (%g) <= 2.0", (double)kctx->alpha);
5267: PetscCheck(kctx->threshold > 0.0 && kctx->threshold < 1.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "0.0 < threshold (%g) < 1.0", (double)kctx->threshold);
5268: PetscFunctionReturn(PETSC_SUCCESS);
5269: }
5271: /*@
5272: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5273: convergence criteria for the linear solvers within an inexact
5274: Newton method.
5276: Not Collective
5278: Input Parameter:
5279: . snes - `SNES` context
5281: Output Parameters:
5282: + version - version 1, 2 (default is 2), 3 or 4
5283: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5284: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5285: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5286: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5287: . alpha2 - power for safeguard
5288: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5290: Level: advanced
5292: .seealso: [](chapter_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5293: @*/
5294: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5295: {
5296: SNESKSPEW *kctx;
5298: PetscFunctionBegin;
5300: kctx = (SNESKSPEW *)snes->kspconvctx;
5301: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5302: if (version) *version = kctx->version;
5303: if (rtol_0) *rtol_0 = kctx->rtol_0;
5304: if (rtol_max) *rtol_max = kctx->rtol_max;
5305: if (gamma) *gamma = kctx->gamma;
5306: if (alpha) *alpha = kctx->alpha;
5307: if (alpha2) *alpha2 = kctx->alpha2;
5308: if (threshold) *threshold = kctx->threshold;
5309: PetscFunctionReturn(PETSC_SUCCESS);
5310: }
5312: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5313: {
5314: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5315: PetscReal rtol = PETSC_DEFAULT, stol;
5317: PetscFunctionBegin;
5318: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5319: if (!snes->iter) {
5320: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5321: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5322: } else {
5323: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5324: if (kctx->version == 1) {
5325: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5326: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5327: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5328: } else if (kctx->version == 2) {
5329: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5330: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5331: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5332: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5333: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5334: /* safeguard: avoid sharp decrease of rtol */
5335: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5336: stol = PetscMax(rtol, stol);
5337: rtol = PetscMin(kctx->rtol_0, stol);
5338: /* safeguard: avoid oversolving */
5339: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5340: stol = PetscMax(rtol, stol);
5341: rtol = PetscMin(kctx->rtol_0, stol);
5342: } else /* if (kctx->version == 4) */ {
5343: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5344: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5345: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5346: PetscReal rk = ared / pred;
5347: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5348: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5349: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5350: else rtol = kctx->v4_m2 * kctx->rtol_last;
5352: if (kctx->rtol_last_2 > kctx->v4_m3 && kctx->rtol_last > kctx->v4_m3 && kctx->rk_last_2 < kctx->v4_p1 && kctx->rk_last < kctx->v4_p1) {
5353: rtol = kctx->v4_m4 * kctx->rtol_last;
5354: //printf("iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g (rk %g ps %g %g %g) (AD)\n",snes->iter,kctx->version,(double)rtol,rk,kctx->v4_p1,kctx->v4_p2,kctx->v4_p3);
5355: } else {
5356: //printf("iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g (rk %g ps %g %g %g)\n",snes->iter,kctx->version,(double)rtol,rk,kctx->v4_p1,kctx->v4_p2,kctx->v4_p3);
5357: }
5358: kctx->rtol_last_2 = kctx->rtol_last;
5359: kctx->rk_last_2 = kctx->rk_last;
5360: kctx->rk_last = rk;
5361: }
5362: }
5363: /* safeguard: avoid rtol greater than rtol_max */
5364: rtol = PetscMin(rtol, kctx->rtol_max);
5365: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_DEFAULT, PETSC_DEFAULT, PETSC_DEFAULT));
5366: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5367: PetscFunctionReturn(PETSC_SUCCESS);
5368: }
5370: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5371: {
5372: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5373: PCSide pcside;
5374: Vec lres;
5376: PetscFunctionBegin;
5377: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5378: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5379: kctx->norm_last = snes->norm;
5380: if (kctx->version == 1 || kctx->version == 4) {
5381: PC pc;
5382: PetscBool getRes;
5384: PetscCall(KSPGetPC(ksp, &pc));
5385: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5386: if (!getRes) {
5387: KSPNormType normtype;
5389: PetscCall(KSPGetNormType(ksp, &normtype));
5390: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5391: }
5392: PetscCall(KSPGetPCSide(ksp, &pcside));
5393: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5394: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5395: } else {
5396: /* KSP residual is preconditioned residual */
5397: /* compute true linear residual norm */
5398: Mat J;
5399: PetscCall(KSPGetOperators(ksp, &J, NULL));
5400: PetscCall(VecDuplicate(b, &lres));
5401: PetscCall(MatMult(J, x, lres));
5402: PetscCall(VecAYPX(lres, -1.0, b));
5403: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5404: PetscCall(VecDestroy(&lres));
5405: }
5406: }
5407: PetscFunctionReturn(PETSC_SUCCESS);
5408: }
5410: /*@
5411: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5413: Not Collective, but if snes is parallel, then ksp is parallel
5415: Input Parameter:
5416: . snes - the `SNES` context
5418: Output Parameter:
5419: . ksp - the `KSP` context
5421: Level: beginner
5423: Notes:
5424: The user can then directly manipulate the `KSP` context to set various
5425: options, etc. Likewise, the user can then extract and manipulate the
5426: `PC` contexts as well.
5428: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function
5430: .seealso: [](chapter_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5431: @*/
5432: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5433: {
5434: PetscFunctionBegin;
5438: if (!snes->ksp) {
5439: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5440: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5442: PetscCall(KSPSetPreSolve(snes->ksp, (PetscErrorCode(*)(KSP, Vec, Vec, void *))KSPPreSolve_SNESEW, snes));
5443: PetscCall(KSPSetPostSolve(snes->ksp, (PetscErrorCode(*)(KSP, Vec, Vec, void *))KSPPostSolve_SNESEW, snes));
5445: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5446: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5447: }
5448: *ksp = snes->ksp;
5449: PetscFunctionReturn(PETSC_SUCCESS);
5450: }
5452: #include <petsc/private/dmimpl.h>
5453: /*@
5454: SNESSetDM - Sets the `DM` that may be used by some nonlinear solvers or their underlying preconditioners
5456: Logically Collective
5458: Input Parameters:
5459: + snes - the nonlinear solver context
5460: - dm - the dm, cannot be `NULL`
5462: Level: intermediate
5464: Note:
5465: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5466: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5467: problems using the same function space.
5469: .seealso: [](chapter_snes), `DM`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5470: @*/
5471: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5472: {
5473: KSP ksp;
5474: DMSNES sdm;
5476: PetscFunctionBegin;
5479: PetscCall(PetscObjectReference((PetscObject)dm));
5480: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5481: if (snes->dm->dmsnes && !dm->dmsnes) {
5482: PetscCall(DMCopyDMSNES(snes->dm, dm));
5483: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5484: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5485: }
5486: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5487: PetscCall(DMDestroy(&snes->dm));
5488: }
5489: snes->dm = dm;
5490: snes->dmAuto = PETSC_FALSE;
5492: PetscCall(SNESGetKSP(snes, &ksp));
5493: PetscCall(KSPSetDM(ksp, dm));
5494: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5495: if (snes->npc) {
5496: PetscCall(SNESSetDM(snes->npc, snes->dm));
5497: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5498: }
5499: PetscFunctionReturn(PETSC_SUCCESS);
5500: }
5502: /*@
5503: SNESGetDM - Gets the `DM` that may be used by some preconditioners
5505: Not Collective but dm obtained is parallel on snes
5507: Input Parameter:
5508: . snes - the preconditioner context
5510: Output Parameter:
5511: . dm - the dm
5513: Level: intermediate
5515: .seealso: [](chapter_snes), `DM`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5516: @*/
5517: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5518: {
5519: PetscFunctionBegin;
5521: if (!snes->dm) {
5522: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5523: snes->dmAuto = PETSC_TRUE;
5524: }
5525: *dm = snes->dm;
5526: PetscFunctionReturn(PETSC_SUCCESS);
5527: }
5529: /*@
5530: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5532: Collective
5534: Input Parameters:
5535: + snes - iterative context obtained from `SNESCreate()`
5536: - npc - the preconditioner object
5538: Level: developer
5540: Notes:
5541: Use `SNESGetNPC()` to retrieve the preconditioner context (for example,
5542: to configure it using the API).
5544: Only some `SNESType` can use a nonlinear preconditioner
5546: .seealso: [](chapter_snes), `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5547: @*/
5548: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5549: {
5550: PetscFunctionBegin;
5553: PetscCheckSameComm(snes, 1, npc, 2);
5554: PetscCall(PetscObjectReference((PetscObject)npc));
5555: PetscCall(SNESDestroy(&snes->npc));
5556: snes->npc = npc;
5557: PetscFunctionReturn(PETSC_SUCCESS);
5558: }
5560: /*@
5561: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5563: Not Collective; but any changes to the obtained the npc object must be applied collectively
5565: Input Parameter:
5566: . snes - iterative context obtained from `SNESCreate()`
5568: Output Parameter:
5569: . npc - preconditioner context
5571: Options Database Key:
5572: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5574: Level: developer
5576: Notes:
5577: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created.
5579: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5580: `SNES`
5582: .seealso: [](chapter_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5583: @*/
5584: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5585: {
5586: const char *optionsprefix;
5588: PetscFunctionBegin;
5591: if (!snes->npc) {
5592: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5593: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5594: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5595: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5596: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5597: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5598: }
5599: *pc = snes->npc;
5600: PetscFunctionReturn(PETSC_SUCCESS);
5601: }
5603: /*@
5604: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5606: Not Collective
5608: Input Parameter:
5609: . snes - iterative context obtained from `SNESCreate()`
5611: Output Parameter:
5612: . has_npc - whether the `SNES` has an NPC or not
5614: Level: developer
5616: .seealso: [](chapter_snes), `SNESSetNPC()`, `SNESGetNPC()`
5617: @*/
5618: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5619: {
5620: PetscFunctionBegin;
5622: *has_npc = (PetscBool)(snes->npc ? PETSC_TRUE : PETSC_FALSE);
5623: PetscFunctionReturn(PETSC_SUCCESS);
5624: }
5626: /*@
5627: SNESSetNPCSide - Sets the preconditioning side.
5629: Logically Collective
5631: Input Parameter:
5632: . snes - iterative context obtained from `SNESCreate()`
5634: Output Parameter:
5635: . side - the preconditioning side, where side is one of
5636: .vb
5637: PC_LEFT - left preconditioning
5638: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5639: .ve
5641: Options Database Key:
5642: . -snes_npc_side <right,left> - nonlinear preconditioner side
5644: Level: intermediate
5646: Note:
5647: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5649: .seealso: [](chapter_snes), `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`
5650: @*/
5651: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5652: {
5653: PetscFunctionBegin;
5656: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5657: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5658: snes->npcside = side;
5659: PetscFunctionReturn(PETSC_SUCCESS);
5660: }
5662: /*@
5663: SNESGetNPCSide - Gets the preconditioning side.
5665: Not Collective
5667: Input Parameter:
5668: . snes - iterative context obtained from `SNESCreate()`
5670: Output Parameter:
5671: . side - the preconditioning side, where side is one of
5672: .vb
5673: `PC_LEFT` - left preconditioning
5674: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5675: .ve
5677: Level: intermediate
5679: .seealso: [](chapter_snes), `SNES`, `SNESSetNPCSide()`, `KSPGetPCSide()`
5680: @*/
5681: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5682: {
5683: PetscFunctionBegin;
5686: *side = snes->npcside;
5687: PetscFunctionReturn(PETSC_SUCCESS);
5688: }
5690: /*@
5691: SNESSetLineSearch - Sets the linesearch on the `SNES` instance.
5693: Collective
5695: Input Parameters:
5696: + snes - iterative context obtained from `SNESCreate()`
5697: - linesearch - the linesearch object
5699: Level: developer
5701: Note:
5702: Use `SNESGetLineSearch()` to retrieve the preconditioner context (for example,
5703: to configure it using the API).
5705: .seealso: [](chapter_snes), `SNESGetLineSearch()`
5706: @*/
5707: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5708: {
5709: PetscFunctionBegin;
5712: PetscCheckSameComm(snes, 1, linesearch, 2);
5713: PetscCall(PetscObjectReference((PetscObject)linesearch));
5714: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5716: snes->linesearch = linesearch;
5718: PetscFunctionReturn(PETSC_SUCCESS);
5719: }
5721: /*@
5722: SNESGetLineSearch - Returns the line search context set with `SNESSetLineSearch()`
5723: or creates a default line search instance associated with the `SNES` and returns it.
5725: Not Collective
5727: Input Parameter:
5728: . snes - iterative context obtained from `SNESCreate()`
5730: Output Parameter:
5731: . linesearch - linesearch context
5733: Level: beginner
5735: .seealso: [](chapter_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`
5736: @*/
5737: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5738: {
5739: const char *optionsprefix;
5741: PetscFunctionBegin;
5744: if (!snes->linesearch) {
5745: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5746: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5747: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5748: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5749: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5750: }
5751: *linesearch = snes->linesearch;
5752: PetscFunctionReturn(PETSC_SUCCESS);
5753: }