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 Key:
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: [](ch_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: [](ch_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: [](ch_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: [](ch_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 Parameter:
123: . snes - the `SNES` context
125: Level: advanced
127: Notes:
128: If this is called the `SNESSolve()` stops iterating and returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_DOMAIN`
130: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
132: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
133: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
135: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunction`, `SNESSetJacobianDomainError()`, `SNESVISetVariableBounds()`,
136: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
137: @*/
138: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
139: {
140: PetscFunctionBegin;
142: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates input vector is not in the function domain");
143: snes->domainerror = PETSC_TRUE;
144: PetscFunctionReturn(PETSC_SUCCESS);
145: }
147: /*@
148: SNESSetJacobianDomainError - tells `SNES` that the function you provided to `SNESSetJacobian()` at the proposed step. For example there is a negative element transformation.
150: Logically Collective
152: Input Parameter:
153: . snes - the `SNES` context
155: Level: advanced
157: Notes:
158: If this is called the `SNESSolve()` stops iterating and returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_DOMAIN`
160: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
162: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
163: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
165: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESVISetVariableBounds()`,
166: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
167: @*/
168: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
169: {
170: PetscFunctionBegin;
172: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates computeJacobian does not make sense");
173: snes->jacobiandomainerror = PETSC_TRUE;
174: PetscFunctionReturn(PETSC_SUCCESS);
175: }
177: /*@
178: SNESSetCheckJacobianDomainError - tells `SNESSolve()` whether to check if the user called `SNESSetJacobianDomainError()` Jacobian domain error after
179: each Jacobian evaluation. By default, we check Jacobian domain error in the debug mode, and do not check it in the optimized mode.
181: Logically Collective
183: Input Parameters:
184: + snes - the `SNES` context
185: - flg - indicates if or not to check Jacobian domain error after each Jacobian evaluation
187: Level: advanced
189: Note:
190: Checks require one extra parallel synchronization for each Jacobian evaluation
192: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESGetCheckJacobianDomainError()`
193: @*/
194: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
195: {
196: PetscFunctionBegin;
198: snes->checkjacdomainerror = flg;
199: PetscFunctionReturn(PETSC_SUCCESS);
200: }
202: /*@
203: SNESGetCheckJacobianDomainError - Get an indicator whether or not we are checking Jacobian domain errors after each Jacobian evaluation.
205: Logically Collective
207: Input Parameter:
208: . snes - the `SNES` context
210: Output Parameter:
211: . flg - `PETSC_FALSE` indicates that we don't check Jacobian domain errors after each Jacobian evaluation
213: Level: advanced
215: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESSetCheckJacobianDomainError()`
216: @*/
217: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
218: {
219: PetscFunctionBegin;
222: *flg = snes->checkjacdomainerror;
223: PetscFunctionReturn(PETSC_SUCCESS);
224: }
226: /*@
227: SNESGetFunctionDomainError - Gets the status of the domain error after a call to `SNESComputeFunction()`;
229: Logically Collective
231: Input Parameter:
232: . snes - the `SNES` context
234: Output Parameter:
235: . domainerror - Set to `PETSC_TRUE` if there's a domain error; `PETSC_FALSE` otherwise.
237: Level: developer
239: .seealso: [](ch_snes), `SNES`, `SNESSetFunctionDomainError()`, `SNESComputeFunction()`
240: @*/
241: PetscErrorCode SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
242: {
243: PetscFunctionBegin;
246: *domainerror = snes->domainerror;
247: PetscFunctionReturn(PETSC_SUCCESS);
248: }
250: /*@
251: SNESGetJacobianDomainError - Gets the status of the Jacobian domain error after a call to `SNESComputeJacobian()`;
253: Logically Collective
255: Input Parameter:
256: . snes - the `SNES` context
258: Output Parameter:
259: . domainerror - Set to `PETSC_TRUE` if there's a Jacobian domain error; `PETSC_FALSE` otherwise.
261: Level: advanced
263: .seealso: [](ch_snes), `SNES`, `SNESSetFunctionDomainError()`, `SNESComputeFunction()`, `SNESGetFunctionDomainError()`
264: @*/
265: PetscErrorCode SNESGetJacobianDomainError(SNES snes, PetscBool *domainerror)
266: {
267: PetscFunctionBegin;
270: *domainerror = snes->jacobiandomainerror;
271: PetscFunctionReturn(PETSC_SUCCESS);
272: }
274: /*@C
275: SNESLoad - Loads a `SNES` that has been stored in `PETSCVIEWERBINARY` with `SNESView()`.
277: Collective
279: Input Parameters:
280: + newdm - the newly loaded `SNES`, this needs to have been created with `SNESCreate()` or
281: some related function before a call to `SNESLoad()`.
282: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()`
284: Level: intermediate
286: Note:
287: The type is determined by the data in the file, any type set into the `SNES` before this call is ignored.
289: .seealso: [](ch_snes), `SNES`, `PetscViewer`, `SNESCreate()`, `SNESType`, `PetscViewerBinaryOpen()`, `SNESView()`, `MatLoad()`, `VecLoad()`
290: @*/
291: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
292: {
293: PetscBool isbinary;
294: PetscInt classid;
295: char type[256];
296: KSP ksp;
297: DM dm;
298: DMSNES dmsnes;
300: PetscFunctionBegin;
303: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
304: PetscCheck(isbinary, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen()");
306: PetscCall(PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT));
307: PetscCheck(classid == SNES_FILE_CLASSID, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Not SNES next in file");
308: PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
309: PetscCall(SNESSetType(snes, type));
310: PetscTryTypeMethod(snes, load, viewer);
311: PetscCall(SNESGetDM(snes, &dm));
312: PetscCall(DMGetDMSNES(dm, &dmsnes));
313: PetscCall(DMSNESLoad(dmsnes, viewer));
314: PetscCall(SNESGetKSP(snes, &ksp));
315: PetscCall(KSPLoad(ksp, viewer));
316: PetscFunctionReturn(PETSC_SUCCESS);
317: }
319: #include <petscdraw.h>
320: #if defined(PETSC_HAVE_SAWS)
321: #include <petscviewersaws.h>
322: #endif
324: /*@C
325: SNESViewFromOptions - View a `SNES` based on values in the options database
327: Collective
329: Input Parameters:
330: + A - the `SNES` context
331: . obj - Optional object that provides the options prefix for the checks
332: - name - command line option
334: Level: intermediate
336: .seealso: [](ch_snes), `SNES`, `SNESView`, `PetscObjectViewFromOptions()`, `SNESCreate()`
337: @*/
338: PetscErrorCode SNESViewFromOptions(SNES A, PetscObject obj, const char name[])
339: {
340: PetscFunctionBegin;
342: PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
343: PetscFunctionReturn(PETSC_SUCCESS);
344: }
346: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES, Vec, Mat, Mat, void *);
348: /*@C
349: SNESView - Prints or visualizes the `SNES` data structure.
351: Collective
353: Input Parameters:
354: + snes - the `SNES` context
355: - viewer - the `PetscViewer`
357: Options Database Key:
358: . -snes_view - Calls `SNESView()` at end of `SNESSolve()`
360: Level: beginner
362: Notes:
363: The available visualization contexts include
364: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
365: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
366: output where only the first processor opens
367: the file. All other processors send their
368: data to the first processor to print.
370: The available formats include
371: + `PETSC_VIEWER_DEFAULT` - standard output (default)
372: - `PETSC_VIEWER_ASCII_INFO_DETAIL` - more verbose output for `SNESNASM`
374: The user can open an alternative visualization context with
375: `PetscViewerASCIIOpen()` - output to a specified file.
377: In the debugger you can do "call `SNESView`(snes,0)" to display the `SNES` solver. (The same holds for any PETSc object viewer).
379: .seealso: [](ch_snes), `SNES`, `SNESLoad()`, `SNESCreate()`, `PetscViewerASCIIOpen()`
380: @*/
381: PetscErrorCode SNESView(SNES snes, PetscViewer viewer)
382: {
383: SNESKSPEW *kctx;
384: KSP ksp;
385: SNESLineSearch linesearch;
386: PetscBool iascii, isstring, isbinary, isdraw;
387: DMSNES dmsnes;
388: #if defined(PETSC_HAVE_SAWS)
389: PetscBool issaws;
390: #endif
392: PetscFunctionBegin;
394: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &viewer));
396: PetscCheckSameComm(snes, 1, viewer, 2);
398: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
399: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
400: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
401: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
402: #if defined(PETSC_HAVE_SAWS)
403: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
404: #endif
405: if (iascii) {
406: SNESNormSchedule normschedule;
407: DM dm;
408: PetscErrorCode (*cJ)(SNES, Vec, Mat, Mat, void *);
409: void *ctx;
410: const char *pre = "";
412: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)snes, viewer));
413: if (!snes->setupcalled) PetscCall(PetscViewerASCIIPrintf(viewer, " SNES has not been set up so information may be incomplete\n"));
414: if (snes->ops->view) {
415: PetscCall(PetscViewerASCIIPushTab(viewer));
416: PetscUseTypeMethod(snes, view, viewer);
417: PetscCall(PetscViewerASCIIPopTab(viewer));
418: }
419: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=%" PetscInt_FMT "\n", snes->max_its, snes->max_funcs));
420: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, solution=%g\n", (double)snes->rtol, (double)snes->abstol, (double)snes->stol));
421: if (snes->usesksp) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of linear solver iterations=%" PetscInt_FMT "\n", snes->linear_its));
422: PetscCall(PetscViewerASCIIPrintf(viewer, " total number of function evaluations=%" PetscInt_FMT "\n", snes->nfuncs));
423: PetscCall(SNESGetNormSchedule(snes, &normschedule));
424: if (normschedule > 0) PetscCall(PetscViewerASCIIPrintf(viewer, " norm schedule %s\n", SNESNormSchedules[normschedule]));
425: if (snes->gridsequence) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of grid sequence refinements=%" PetscInt_FMT "\n", snes->gridsequence));
426: if (snes->ksp_ewconv) {
427: kctx = (SNESKSPEW *)snes->kspconvctx;
428: if (kctx) {
429: PetscCall(PetscViewerASCIIPrintf(viewer, " Eisenstat-Walker computation of KSP relative tolerance (version %" PetscInt_FMT ")\n", kctx->version));
430: PetscCall(PetscViewerASCIIPrintf(viewer, " rtol_0=%g, rtol_max=%g, threshold=%g\n", (double)kctx->rtol_0, (double)kctx->rtol_max, (double)kctx->threshold));
431: PetscCall(PetscViewerASCIIPrintf(viewer, " gamma=%g, alpha=%g, alpha2=%g\n", (double)kctx->gamma, (double)kctx->alpha, (double)kctx->alpha2));
432: }
433: }
434: if (snes->lagpreconditioner == -1) {
435: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is never rebuilt\n"));
436: } else if (snes->lagpreconditioner > 1) {
437: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is rebuilt every %" PetscInt_FMT " new Jacobians\n", snes->lagpreconditioner));
438: }
439: if (snes->lagjacobian == -1) {
440: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is never rebuilt\n"));
441: } else if (snes->lagjacobian > 1) {
442: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is rebuilt every %" PetscInt_FMT " SNES iterations\n", snes->lagjacobian));
443: }
444: PetscCall(SNESGetDM(snes, &dm));
445: PetscCall(DMSNESGetJacobian(dm, &cJ, &ctx));
446: if (snes->mf_operator) {
447: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing\n"));
448: pre = "Preconditioning ";
449: }
450: if (cJ == SNESComputeJacobianDefault) {
451: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences one column at a time\n", pre));
452: } else if (cJ == SNESComputeJacobianDefaultColor) {
453: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences with coloring\n", pre));
454: /* it slightly breaks data encapsulation for access the DMDA information directly */
455: } else if (cJ == SNESComputeJacobian_DMDA) {
456: MatFDColoring fdcoloring;
457: PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
458: if (fdcoloring) {
459: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using colored finite differences on a DMDA\n", pre));
460: } else {
461: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using a DMDA local Jacobian\n", pre));
462: }
463: } else if (snes->mf && !snes->mf_operator) {
464: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing, no explicit Jacobian\n"));
465: }
466: } else if (isstring) {
467: const char *type;
468: PetscCall(SNESGetType(snes, &type));
469: PetscCall(PetscViewerStringSPrintf(viewer, " SNESType: %-7.7s", type));
470: PetscTryTypeMethod(snes, view, viewer);
471: } else if (isbinary) {
472: PetscInt classid = SNES_FILE_CLASSID;
473: MPI_Comm comm;
474: PetscMPIInt rank;
475: char type[256];
477: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
478: PetscCallMPI(MPI_Comm_rank(comm, &rank));
479: if (rank == 0) {
480: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
481: PetscCall(PetscStrncpy(type, ((PetscObject)snes)->type_name, sizeof(type)));
482: PetscCall(PetscViewerBinaryWrite(viewer, type, sizeof(type), PETSC_CHAR));
483: }
484: PetscTryTypeMethod(snes, view, viewer);
485: } else if (isdraw) {
486: PetscDraw draw;
487: char str[36];
488: PetscReal x, y, bottom, h;
490: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
491: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
492: PetscCall(PetscStrncpy(str, "SNES: ", sizeof(str)));
493: PetscCall(PetscStrlcat(str, ((PetscObject)snes)->type_name, sizeof(str)));
494: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_BLUE, PETSC_DRAW_BLACK, str, NULL, &h));
495: bottom = y - h;
496: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
497: PetscTryTypeMethod(snes, view, viewer);
498: #if defined(PETSC_HAVE_SAWS)
499: } else if (issaws) {
500: PetscMPIInt rank;
501: const char *name;
503: PetscCall(PetscObjectGetName((PetscObject)snes, &name));
504: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
505: if (!((PetscObject)snes)->amsmem && rank == 0) {
506: char dir[1024];
508: PetscCall(PetscObjectViewSAWs((PetscObject)snes, viewer));
509: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
510: PetscCallSAWs(SAWs_Register, (dir, &snes->iter, 1, SAWs_READ, SAWs_INT));
511: if (!snes->conv_hist) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, PETSC_DECIDE, PETSC_TRUE));
512: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/conv_hist", name));
513: PetscCallSAWs(SAWs_Register, (dir, snes->conv_hist, 10, SAWs_READ, SAWs_DOUBLE));
514: }
515: #endif
516: }
517: if (snes->linesearch) {
518: PetscCall(SNESGetLineSearch(snes, &linesearch));
519: PetscCall(PetscViewerASCIIPushTab(viewer));
520: PetscCall(SNESLineSearchView(linesearch, viewer));
521: PetscCall(PetscViewerASCIIPopTab(viewer));
522: }
523: if (snes->npc && snes->usesnpc) {
524: PetscCall(PetscViewerASCIIPushTab(viewer));
525: PetscCall(SNESView(snes->npc, viewer));
526: PetscCall(PetscViewerASCIIPopTab(viewer));
527: }
528: PetscCall(PetscViewerASCIIPushTab(viewer));
529: PetscCall(DMGetDMSNES(snes->dm, &dmsnes));
530: PetscCall(DMSNESView(dmsnes, viewer));
531: PetscCall(PetscViewerASCIIPopTab(viewer));
532: if (snes->usesksp) {
533: PetscCall(SNESGetKSP(snes, &ksp));
534: PetscCall(PetscViewerASCIIPushTab(viewer));
535: PetscCall(KSPView(ksp, viewer));
536: PetscCall(PetscViewerASCIIPopTab(viewer));
537: }
538: if (isdraw) {
539: PetscDraw draw;
540: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
541: PetscCall(PetscDrawPopCurrentPoint(draw));
542: }
543: PetscFunctionReturn(PETSC_SUCCESS);
544: }
546: /*
547: We retain a list of functions that also take SNES command
548: line options. These are called at the end SNESSetFromOptions()
549: */
550: #define MAXSETFROMOPTIONS 5
551: static PetscInt numberofsetfromoptions;
552: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
554: /*@C
555: SNESAddOptionsChecker - Adds an additional function to check for `SNES` options.
557: Not Collective
559: Input Parameter:
560: . snescheck - function that checks for options
562: Level: developer
564: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`
565: @*/
566: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES))
567: {
568: PetscFunctionBegin;
569: PetscCheck(numberofsetfromoptions < MAXSETFROMOPTIONS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %d allowed", MAXSETFROMOPTIONS);
570: othersetfromoptions[numberofsetfromoptions++] = snescheck;
571: PetscFunctionReturn(PETSC_SUCCESS);
572: }
574: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
575: {
576: Mat J;
577: MatNullSpace nullsp;
579: PetscFunctionBegin;
582: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
583: Mat A = snes->jacobian, B = snes->jacobian_pre;
584: PetscCall(MatCreateVecs(A ? A : B, NULL, &snes->vec_func));
585: }
587: PetscCheck(version == 1 || version == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator routines, only version 1 and 2");
588: if (version == 1) {
589: PetscCall(MatCreateSNESMF(snes, &J));
590: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
591: PetscCall(MatSetFromOptions(J));
592: /* TODO: the version 2 code should be merged into the MatCreateSNESMF() and MatCreateMFFD() infrastructure and then removed */
593: } else /* if (version == 2) */ {
594: PetscCheck(snes->vec_func, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "SNESSetFunction() must be called first");
595: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
596: PetscCall(MatCreateSNESMFMore(snes, snes->vec_func, &J));
597: #else
598: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "matrix-free operator routines (version 2)");
599: #endif
600: }
602: /* attach any user provided null space that was on Amat to the newly created matrix free matrix */
603: if (snes->jacobian) {
604: PetscCall(MatGetNullSpace(snes->jacobian, &nullsp));
605: if (nullsp) PetscCall(MatSetNullSpace(J, nullsp));
606: }
608: PetscCall(PetscInfo(snes, "Setting default matrix-free operator routines (version %" PetscInt_FMT ")\n", version));
609: if (hasOperator) {
610: /* This version replaces the user provided Jacobian matrix with a
611: matrix-free version but still employs the user-provided preconditioner matrix. */
612: PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
613: } else {
614: /* This version replaces both the user-provided Jacobian and the user-
615: provided preconditioner Jacobian with the default matrix free version. */
616: if (snes->npcside == PC_LEFT && snes->npc) {
617: if (!snes->jacobian) PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
618: } else {
619: KSP ksp;
620: PC pc;
621: PetscBool match;
623: PetscCall(SNESSetJacobian(snes, J, J, MatMFFDComputeJacobian, NULL));
624: /* Force no preconditioner */
625: PetscCall(SNESGetKSP(snes, &ksp));
626: PetscCall(KSPGetPC(ksp, &pc));
627: PetscCall(PetscObjectTypeCompareAny((PetscObject)pc, &match, PCSHELL, PCH2OPUS, ""));
628: if (!match) {
629: PetscCall(PetscInfo(snes, "Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n"));
630: PetscCall(PCSetType(pc, PCNONE));
631: }
632: }
633: }
634: PetscCall(MatDestroy(&J));
635: PetscFunctionReturn(PETSC_SUCCESS);
636: }
638: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine, Mat Restrict, Vec Rscale, Mat Inject, DM dmcoarse, void *ctx)
639: {
640: SNES snes = (SNES)ctx;
641: Vec Xfine, Xfine_named = NULL, Xcoarse;
643: PetscFunctionBegin;
644: if (PetscLogPrintInfo) {
645: PetscInt finelevel, coarselevel, fineclevel, coarseclevel;
646: PetscCall(DMGetRefineLevel(dmfine, &finelevel));
647: PetscCall(DMGetCoarsenLevel(dmfine, &fineclevel));
648: PetscCall(DMGetRefineLevel(dmcoarse, &coarselevel));
649: PetscCall(DMGetCoarsenLevel(dmcoarse, &coarseclevel));
650: PetscCall(PetscInfo(dmfine, "Restricting SNES solution vector from level %" PetscInt_FMT "-%" PetscInt_FMT " to level %" PetscInt_FMT "-%" PetscInt_FMT "\n", finelevel, fineclevel, coarselevel, coarseclevel));
651: }
652: if (dmfine == snes->dm) Xfine = snes->vec_sol;
653: else {
654: PetscCall(DMGetNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
655: Xfine = Xfine_named;
656: }
657: PetscCall(DMGetNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
658: if (Inject) {
659: PetscCall(MatRestrict(Inject, Xfine, Xcoarse));
660: } else {
661: PetscCall(MatRestrict(Restrict, Xfine, Xcoarse));
662: PetscCall(VecPointwiseMult(Xcoarse, Xcoarse, Rscale));
663: }
664: PetscCall(DMRestoreNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
665: if (Xfine_named) PetscCall(DMRestoreNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
666: PetscFunctionReturn(PETSC_SUCCESS);
667: }
669: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm, DM dmc, void *ctx)
670: {
671: PetscFunctionBegin;
672: PetscCall(DMCoarsenHookAdd(dmc, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, ctx));
673: PetscFunctionReturn(PETSC_SUCCESS);
674: }
676: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
677: * safely call SNESGetDM() in their residual evaluation routine. */
678: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp, Mat A, Mat B, void *ctx)
679: {
680: SNES snes = (SNES)ctx;
681: Vec X, Xnamed = NULL;
682: DM dmsave;
683: void *ctxsave;
684: PetscErrorCode (*jac)(SNES, Vec, Mat, Mat, void *) = NULL;
686: PetscFunctionBegin;
687: dmsave = snes->dm;
688: PetscCall(KSPGetDM(ksp, &snes->dm));
689: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
690: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */ PetscCall(DMGetNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
691: X = Xnamed;
692: PetscCall(SNESGetJacobian(snes, NULL, NULL, &jac, &ctxsave));
693: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
694: if (jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, SNESComputeJacobianDefaultColor, NULL));
695: }
696: /* Make sure KSP DM has the Jacobian computation routine */
697: {
698: DMSNES sdm;
700: PetscCall(DMGetDMSNES(snes->dm, &sdm));
701: if (!sdm->ops->computejacobian) PetscCall(DMCopyDMSNES(dmsave, snes->dm));
702: }
703: /* Compute the operators */
704: PetscCall(SNESComputeJacobian(snes, X, A, B));
705: /* Put the previous context back */
706: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, jac, ctxsave));
708: if (Xnamed) PetscCall(DMRestoreNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
709: snes->dm = dmsave;
710: PetscFunctionReturn(PETSC_SUCCESS);
711: }
713: /*@
714: SNESSetUpMatrices - ensures that matrices are available for `SNES` Newton-like methods, this is called by `SNESSetUp_XXX()`
716: Collective
718: Input Parameter:
719: . snes - `SNES` object to configure
721: Level: developer
723: Note:
724: If the matrices do not yet exist it attempts to create them based on options previously set for the `SNES` such as `-snes_mf`
726: .seealso: [](ch_snes), `SNES`, `SNESSetUp()`
727: @*/
728: PetscErrorCode SNESSetUpMatrices(SNES snes)
729: {
730: DM dm;
731: DMSNES sdm;
733: PetscFunctionBegin;
734: PetscCall(SNESGetDM(snes, &dm));
735: PetscCall(DMGetDMSNES(dm, &sdm));
736: if (!snes->jacobian && snes->mf) {
737: Mat J;
738: void *functx;
739: PetscCall(MatCreateSNESMF(snes, &J));
740: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
741: PetscCall(MatSetFromOptions(J));
742: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
743: PetscCall(SNESSetJacobian(snes, J, J, NULL, NULL));
744: PetscCall(MatDestroy(&J));
745: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
746: Mat J, B;
747: PetscCall(MatCreateSNESMF(snes, &J));
748: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
749: PetscCall(MatSetFromOptions(J));
750: PetscCall(DMCreateMatrix(snes->dm, &B));
751: /* sdm->computejacobian was already set to reach here */
752: PetscCall(SNESSetJacobian(snes, J, B, NULL, NULL));
753: PetscCall(MatDestroy(&J));
754: PetscCall(MatDestroy(&B));
755: } else if (!snes->jacobian_pre) {
756: PetscDS prob;
757: Mat J, B;
758: PetscBool hasPrec = PETSC_FALSE;
760: J = snes->jacobian;
761: PetscCall(DMGetDS(dm, &prob));
762: if (prob) PetscCall(PetscDSHasJacobianPreconditioner(prob, &hasPrec));
763: if (J) PetscCall(PetscObjectReference((PetscObject)J));
764: else if (hasPrec) PetscCall(DMCreateMatrix(snes->dm, &J));
765: PetscCall(DMCreateMatrix(snes->dm, &B));
766: PetscCall(SNESSetJacobian(snes, J ? J : B, B, NULL, NULL));
767: PetscCall(MatDestroy(&J));
768: PetscCall(MatDestroy(&B));
769: }
770: {
771: KSP ksp;
772: PetscCall(SNESGetKSP(snes, &ksp));
773: PetscCall(KSPSetComputeOperators(ksp, KSPComputeOperators_SNES, snes));
774: PetscCall(DMCoarsenHookAdd(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
775: }
776: PetscFunctionReturn(PETSC_SUCCESS);
777: }
779: static PetscErrorCode SNESMonitorPauseFinal_Internal(SNES snes)
780: {
781: PetscInt i;
783: PetscFunctionBegin;
784: if (!snes->pauseFinal) PetscFunctionReturn(PETSC_SUCCESS);
785: for (i = 0; i < snes->numbermonitors; ++i) {
786: PetscViewerAndFormat *vf = (PetscViewerAndFormat *)snes->monitorcontext[i];
787: PetscDraw draw;
788: PetscReal lpause;
790: if (!vf) continue;
791: if (vf->lg) {
792: if (!PetscCheckPointer(vf->lg, PETSC_OBJECT)) continue;
793: if (((PetscObject)vf->lg)->classid != PETSC_DRAWLG_CLASSID) continue;
794: PetscCall(PetscDrawLGGetDraw(vf->lg, &draw));
795: PetscCall(PetscDrawGetPause(draw, &lpause));
796: PetscCall(PetscDrawSetPause(draw, -1.0));
797: PetscCall(PetscDrawPause(draw));
798: PetscCall(PetscDrawSetPause(draw, lpause));
799: } else {
800: PetscBool isdraw;
802: if (!PetscCheckPointer(vf->viewer, PETSC_OBJECT)) continue;
803: if (((PetscObject)vf->viewer)->classid != PETSC_VIEWER_CLASSID) continue;
804: PetscCall(PetscObjectTypeCompare((PetscObject)vf->viewer, PETSCVIEWERDRAW, &isdraw));
805: if (!isdraw) continue;
806: PetscCall(PetscViewerDrawGetDraw(vf->viewer, 0, &draw));
807: PetscCall(PetscDrawGetPause(draw, &lpause));
808: PetscCall(PetscDrawSetPause(draw, -1.0));
809: PetscCall(PetscDrawPause(draw));
810: PetscCall(PetscDrawSetPause(draw, lpause));
811: }
812: }
813: PetscFunctionReturn(PETSC_SUCCESS);
814: }
816: /*@C
817: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
819: Collective
821: Input Parameters:
822: + snes - `SNES` object you wish to monitor
823: . name - the monitor type one is seeking
824: . help - message indicating what monitoring is done
825: . manual - manual page for the monitor
826: . monitor - the monitor function
827: - 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
829: Options Database Key:
830: . -name - trigger the use of this monitor in `SNESSetFromOptions()`
832: Level: advanced
834: .seealso: [](ch_snes), `PetscOptionsGetViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
835: `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`
836: `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`, `PetscOptionsBool()`,
837: `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
838: `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
839: `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
840: `PetscOptionsFList()`, `PetscOptionsEList()`
841: @*/
842: PetscErrorCode SNESMonitorSetFromOptions(SNES snes, const char name[], const char help[], const char manual[], PetscErrorCode (*monitor)(SNES, PetscInt, PetscReal, PetscViewerAndFormat *), PetscErrorCode (*monitorsetup)(SNES, PetscViewerAndFormat *))
843: {
844: PetscViewer viewer;
845: PetscViewerFormat format;
846: PetscBool flg;
848: PetscFunctionBegin;
849: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, name, &viewer, &format, &flg));
850: if (flg) {
851: PetscViewerAndFormat *vf;
852: PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
853: PetscCall(PetscObjectDereference((PetscObject)viewer));
854: if (monitorsetup) PetscCall((*monitorsetup)(snes, vf));
855: PetscCall(SNESMonitorSet(snes, (PetscErrorCode(*)(SNES, PetscInt, PetscReal, void *))monitor, vf, (PetscErrorCode(*)(void **))PetscViewerAndFormatDestroy));
856: }
857: PetscFunctionReturn(PETSC_SUCCESS);
858: }
860: PetscErrorCode SNESEWSetFromOptions_Private(SNESKSPEW *kctx, PetscBool print_api, MPI_Comm comm, const char *prefix)
861: {
862: const char *api = print_api ? "SNESKSPSetParametersEW" : NULL;
864: PetscFunctionBegin;
865: PetscOptionsBegin(comm, prefix, "Eisenstat and Walker type forcing options", "KSP");
866: PetscCall(PetscOptionsInt("-ksp_ew_version", "Version 1, 2 or 3", api, kctx->version, &kctx->version, NULL));
867: PetscCall(PetscOptionsReal("-ksp_ew_rtol0", "0 <= rtol0 < 1", api, kctx->rtol_0, &kctx->rtol_0, NULL));
868: kctx->rtol_max = PetscMax(kctx->rtol_0, kctx->rtol_max);
869: PetscCall(PetscOptionsReal("-ksp_ew_rtolmax", "0 <= rtolmax < 1", api, kctx->rtol_max, &kctx->rtol_max, NULL));
870: PetscCall(PetscOptionsReal("-ksp_ew_gamma", "0 <= gamma <= 1", api, kctx->gamma, &kctx->gamma, NULL));
871: PetscCall(PetscOptionsReal("-ksp_ew_alpha", "1 < alpha <= 2", api, kctx->alpha, &kctx->alpha, NULL));
872: PetscCall(PetscOptionsReal("-ksp_ew_alpha2", "alpha2", NULL, kctx->alpha2, &kctx->alpha2, NULL));
873: PetscCall(PetscOptionsReal("-ksp_ew_threshold", "0 < threshold < 1", api, kctx->threshold, &kctx->threshold, NULL));
874: PetscCall(PetscOptionsReal("-ksp_ew_v4_p1", "p1", NULL, kctx->v4_p1, &kctx->v4_p1, NULL));
875: PetscCall(PetscOptionsReal("-ksp_ew_v4_p2", "p2", NULL, kctx->v4_p2, &kctx->v4_p2, NULL));
876: PetscCall(PetscOptionsReal("-ksp_ew_v4_p3", "p3", NULL, kctx->v4_p3, &kctx->v4_p3, NULL));
877: PetscCall(PetscOptionsReal("-ksp_ew_v4_m1", "Scaling when rk-1 in [p2,p3)", NULL, kctx->v4_m1, &kctx->v4_m1, NULL));
878: PetscCall(PetscOptionsReal("-ksp_ew_v4_m2", "Scaling when rk-1 in [p3,+infty)", NULL, kctx->v4_m2, &kctx->v4_m2, NULL));
879: PetscCall(PetscOptionsReal("-ksp_ew_v4_m3", "Threshold for successive rtol (0.1 in Eq.7)", NULL, kctx->v4_m3, &kctx->v4_m3, NULL));
880: PetscCall(PetscOptionsReal("-ksp_ew_v4_m4", "Adaptation scaling (0.5 in Eq.7)", NULL, kctx->v4_m4, &kctx->v4_m4, NULL));
881: PetscOptionsEnd();
882: PetscFunctionReturn(PETSC_SUCCESS);
883: }
885: /*@
886: SNESSetFromOptions - Sets various `SNES` and `KSP` parameters from user options.
888: Collective
890: Input Parameter:
891: . snes - the `SNES` context
893: Options Database Keys:
894: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, `SNESType` for complete list
895: . -snes_stol - convergence tolerance in terms of the norm
896: of the change in the solution between steps
897: . -snes_atol <abstol> - absolute tolerance of residual norm
898: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
899: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
900: . -snes_force_iteration <force> - force SNESSolve() to take at least one iteration
901: . -snes_max_it <max_it> - maximum number of iterations
902: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
903: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
904: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
905: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
906: . -snes_lag_preconditioner_persists <true,false> - retains the -snes_lag_preconditioner information across multiple SNESSolve()
907: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
908: . -snes_lag_jacobian_persists <true,false> - retains the -snes_lag_jacobian information across multiple SNESSolve()
909: . -snes_tr_tol <trtol> - trust region tolerance
910: . -snes_convergence_test - <default,skip,correct_pressure> convergence test in nonlinear solver.
911: default `SNESConvergedDefault()`. skip `SNESConvergedSkip()` means continue iterating until max_it or some other criterion is reached, saving expense
912: of convergence test. correct_pressure S`NESConvergedCorrectPressure()` has special handling of a pressure null space.
913: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
914: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
915: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
916: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
917: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
918: . -snes_monitor_lg_range - plots residual norm at each iteration
919: . -snes_monitor_pause_final - Pauses all monitor drawing after the solver ends
920: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
921: . -snes_fd_color - use finite differences with coloring to compute Jacobian
922: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each KSP iteration
923: . -snes_converged_reason - print the reason for convergence/divergence after each solve
924: . -npc_snes_type <type> - the SNES type to use as a nonlinear preconditioner
925: . -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.
926: - -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.
928: Options Database Keys for Eisenstat-Walker method:
929: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
930: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
931: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
932: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
933: . -snes_ksp_ew_gamma <gamma> - Sets gamma
934: . -snes_ksp_ew_alpha <alpha> - Sets alpha
935: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
936: - -snes_ksp_ew_threshold <threshold> - Sets threshold
938: Level: beginner
940: Notes:
941: To see all options, run your program with the -help option or consult the users manual
943: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix free, and computing explicitly with
944: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
946: .seealso: [](ch_snes), `SNESType`, `SNESSetOptionsPrefix()`, `SNESResetFromOptions()`, `SNES`, `SNESCreate()`
947: @*/
948: PetscErrorCode SNESSetFromOptions(SNES snes)
949: {
950: PetscBool flg, pcset, persist, set;
951: PetscInt i, indx, lag, grids;
952: const char *deft = SNESNEWTONLS;
953: const char *convtests[] = {"default", "skip", "correct_pressure"};
954: SNESKSPEW *kctx = NULL;
955: char type[256], monfilename[PETSC_MAX_PATH_LEN], ewprefix[256];
956: PCSide pcside;
957: const char *optionsprefix;
959: PetscFunctionBegin;
961: PetscCall(SNESRegisterAll());
962: PetscObjectOptionsBegin((PetscObject)snes);
963: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
964: PetscCall(PetscOptionsFList("-snes_type", "Nonlinear solver method", "SNESSetType", SNESList, deft, type, 256, &flg));
965: if (flg) {
966: PetscCall(SNESSetType(snes, type));
967: } else if (!((PetscObject)snes)->type_name) {
968: PetscCall(SNESSetType(snes, deft));
969: }
970: PetscCall(PetscOptionsReal("-snes_stol", "Stop if step length less than", "SNESSetTolerances", snes->stol, &snes->stol, NULL));
971: PetscCall(PetscOptionsReal("-snes_atol", "Stop if function norm less than", "SNESSetTolerances", snes->abstol, &snes->abstol, NULL));
973: PetscCall(PetscOptionsReal("-snes_rtol", "Stop if decrease in function norm less than", "SNESSetTolerances", snes->rtol, &snes->rtol, NULL));
974: PetscCall(PetscOptionsReal("-snes_divergence_tolerance", "Stop if residual norm increases by this factor", "SNESSetDivergenceTolerance", snes->divtol, &snes->divtol, NULL));
975: PetscCall(PetscOptionsInt("-snes_max_it", "Maximum iterations", "SNESSetTolerances", snes->max_its, &snes->max_its, NULL));
976: PetscCall(PetscOptionsInt("-snes_max_funcs", "Maximum function evaluations", "SNESSetTolerances", snes->max_funcs, &snes->max_funcs, NULL));
977: PetscCall(PetscOptionsInt("-snes_max_fail", "Maximum nonlinear step failures", "SNESSetMaxNonlinearStepFailures", snes->maxFailures, &snes->maxFailures, NULL));
978: PetscCall(PetscOptionsInt("-snes_max_linear_solve_fail", "Maximum failures in linear solves allowed", "SNESSetMaxLinearSolveFailures", snes->maxLinearSolveFailures, &snes->maxLinearSolveFailures, NULL));
979: PetscCall(PetscOptionsBool("-snes_error_if_not_converged", "Generate error if solver does not converge", "SNESSetErrorIfNotConverged", snes->errorifnotconverged, &snes->errorifnotconverged, NULL));
980: PetscCall(PetscOptionsBool("-snes_force_iteration", "Force SNESSolve() to take at least one iteration", "SNESSetForceIteration", snes->forceiteration, &snes->forceiteration, NULL));
981: PetscCall(PetscOptionsBool("-snes_check_jacobian_domain_error", "Check Jacobian domain error after Jacobian evaluation", "SNESCheckJacobianDomainError", snes->checkjacdomainerror, &snes->checkjacdomainerror, NULL));
983: PetscCall(PetscOptionsInt("-snes_lag_preconditioner", "How often to rebuild preconditioner", "SNESSetLagPreconditioner", snes->lagpreconditioner, &lag, &flg));
984: if (flg) {
985: 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");
986: PetscCall(SNESSetLagPreconditioner(snes, lag));
987: }
988: PetscCall(PetscOptionsBool("-snes_lag_preconditioner_persists", "Preconditioner lagging through multiple SNES solves", "SNESSetLagPreconditionerPersists", snes->lagjac_persist, &persist, &flg));
989: if (flg) PetscCall(SNESSetLagPreconditionerPersists(snes, persist));
990: PetscCall(PetscOptionsInt("-snes_lag_jacobian", "How often to rebuild Jacobian", "SNESSetLagJacobian", snes->lagjacobian, &lag, &flg));
991: if (flg) {
992: 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");
993: PetscCall(SNESSetLagJacobian(snes, lag));
994: }
995: PetscCall(PetscOptionsBool("-snes_lag_jacobian_persists", "Jacobian lagging through multiple SNES solves", "SNESSetLagJacobianPersists", snes->lagjac_persist, &persist, &flg));
996: if (flg) PetscCall(SNESSetLagJacobianPersists(snes, persist));
998: PetscCall(PetscOptionsInt("-snes_grid_sequence", "Use grid sequencing to generate initial guess", "SNESSetGridSequence", snes->gridsequence, &grids, &flg));
999: if (flg) PetscCall(SNESSetGridSequence(snes, grids));
1001: PetscCall(PetscOptionsEList("-snes_convergence_test", "Convergence test", "SNESSetConvergenceTest", convtests, sizeof(convtests) / sizeof(char *), "default", &indx, &flg));
1002: if (flg) {
1003: switch (indx) {
1004: case 0:
1005: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedDefault, NULL, NULL));
1006: break;
1007: case 1:
1008: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedSkip, NULL, NULL));
1009: break;
1010: case 2:
1011: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedCorrectPressure, NULL, NULL));
1012: break;
1013: }
1014: }
1016: PetscCall(PetscOptionsEList("-snes_norm_schedule", "SNES Norm schedule", "SNESSetNormSchedule", SNESNormSchedules, 5, "function", &indx, &flg));
1017: if (flg) PetscCall(SNESSetNormSchedule(snes, (SNESNormSchedule)indx));
1019: PetscCall(PetscOptionsEList("-snes_function_type", "SNES Norm schedule", "SNESSetFunctionType", SNESFunctionTypes, 2, "unpreconditioned", &indx, &flg));
1020: if (flg) PetscCall(SNESSetFunctionType(snes, (SNESFunctionType)indx));
1022: kctx = (SNESKSPEW *)snes->kspconvctx;
1024: PetscCall(PetscOptionsBool("-snes_ksp_ew", "Use Eisentat-Walker linear system convergence test", "SNESKSPSetUseEW", snes->ksp_ewconv, &snes->ksp_ewconv, NULL));
1026: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1027: PetscCall(PetscSNPrintf(ewprefix, sizeof(ewprefix), "%s%s", optionsprefix ? optionsprefix : "", "snes_"));
1028: PetscCall(SNESEWSetFromOptions_Private(kctx, PETSC_TRUE, PetscObjectComm((PetscObject)snes), ewprefix));
1030: flg = PETSC_FALSE;
1031: PetscCall(PetscOptionsBool("-snes_monitor_cancel", "Remove all monitors", "SNESMonitorCancel", flg, &flg, &set));
1032: if (set && flg) PetscCall(SNESMonitorCancel(snes));
1034: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor", "Monitor norm of function", "SNESMonitorDefault", SNESMonitorDefault, SNESMonitorDefaultSetUp));
1035: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_short", "Monitor norm of function with fewer digits", "SNESMonitorDefaultShort", SNESMonitorDefaultShort, NULL));
1036: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_range", "Monitor range of elements of function", "SNESMonitorRange", SNESMonitorRange, NULL));
1038: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_ratio", "Monitor ratios of the norm of function for consecutive steps", "SNESMonitorRatio", SNESMonitorRatio, SNESMonitorRatioSetUp));
1039: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_field", "Monitor norm of function (split into fields)", "SNESMonitorDefaultField", SNESMonitorDefaultField, NULL));
1040: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution", "View solution at each iteration", "SNESMonitorSolution", SNESMonitorSolution, NULL));
1041: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution_update", "View correction at each iteration", "SNESMonitorSolutionUpdate", SNESMonitorSolutionUpdate, NULL));
1042: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_residual", "View residual at each iteration", "SNESMonitorResidual", SNESMonitorResidual, NULL));
1043: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_jacupdate_spectrum", "Print the change in the spectrum of the Jacobian", "SNESMonitorJacUpdateSpectrum", SNESMonitorJacUpdateSpectrum, NULL));
1044: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_fields", "Monitor norm of function per field", "SNESMonitorSet", SNESMonitorFields, NULL));
1045: PetscCall(PetscOptionsBool("-snes_monitor_pause_final", "Pauses all draw monitors at the final iterate", "SNESMonitorPauseFinal_Internal", PETSC_FALSE, &snes->pauseFinal, NULL));
1047: PetscCall(PetscOptionsString("-snes_monitor_python", "Use Python function", "SNESMonitorSet", NULL, monfilename, sizeof(monfilename), &flg));
1048: if (flg) PetscCall(PetscPythonMonitorSet((PetscObject)snes, monfilename));
1050: flg = PETSC_FALSE;
1051: PetscCall(PetscOptionsBool("-snes_monitor_lg_range", "Plot function range at each iteration", "SNESMonitorLGRange", flg, &flg, NULL));
1052: if (flg) {
1053: PetscViewer ctx;
1055: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &ctx));
1056: PetscCall(SNESMonitorSet(snes, SNESMonitorLGRange, ctx, (PetscErrorCode(*)(void **))PetscViewerDestroy));
1057: }
1059: flg = PETSC_FALSE;
1060: PetscCall(PetscOptionsBool("-snes_converged_reason_view_cancel", "Remove all converged reason viewers", "SNESConvergedReasonViewCancel", flg, &flg, &set));
1061: if (set && flg) PetscCall(SNESConvergedReasonViewCancel(snes));
1063: flg = PETSC_FALSE;
1064: PetscCall(PetscOptionsBool("-snes_fd", "Use finite differences (slow) to compute Jacobian", "SNESComputeJacobianDefault", flg, &flg, NULL));
1065: if (flg) {
1066: void *functx;
1067: DM dm;
1068: PetscCall(SNESGetDM(snes, &dm));
1069: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1070: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
1071: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefault, functx));
1072: PetscCall(PetscInfo(snes, "Setting default finite difference Jacobian matrix\n"));
1073: }
1075: flg = PETSC_FALSE;
1076: PetscCall(PetscOptionsBool("-snes_fd_function", "Use finite differences (slow) to compute function from user objective", "SNESObjectiveComputeFunctionDefaultFD", flg, &flg, NULL));
1077: if (flg) PetscCall(SNESSetFunction(snes, NULL, SNESObjectiveComputeFunctionDefaultFD, NULL));
1079: flg = PETSC_FALSE;
1080: PetscCall(PetscOptionsBool("-snes_fd_color", "Use finite differences with coloring to compute Jacobian", "SNESComputeJacobianDefaultColor", flg, &flg, NULL));
1081: if (flg) {
1082: DM dm;
1083: PetscCall(SNESGetDM(snes, &dm));
1084: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1085: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefaultColor, NULL));
1086: PetscCall(PetscInfo(snes, "Setting default finite difference coloring Jacobian matrix\n"));
1087: }
1089: flg = PETSC_FALSE;
1090: PetscCall(PetscOptionsBool("-snes_mf_operator", "Use a Matrix-Free Jacobian with user-provided preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf_operator, &flg));
1091: if (flg && snes->mf_operator) {
1092: snes->mf_operator = PETSC_TRUE;
1093: snes->mf = PETSC_TRUE;
1094: }
1095: flg = PETSC_FALSE;
1096: PetscCall(PetscOptionsBool("-snes_mf", "Use a Matrix-Free Jacobian with no preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf, &flg));
1097: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1098: PetscCall(PetscOptionsInt("-snes_mf_version", "Matrix-Free routines version 1 or 2", "None", snes->mf_version, &snes->mf_version, NULL));
1100: flg = PETSC_FALSE;
1101: PetscCall(SNESGetNPCSide(snes, &pcside));
1102: PetscCall(PetscOptionsEnum("-snes_npc_side", "SNES nonlinear preconditioner side", "SNESSetNPCSide", PCSides, (PetscEnum)pcside, (PetscEnum *)&pcside, &flg));
1103: if (flg) PetscCall(SNESSetNPCSide(snes, pcside));
1105: #if defined(PETSC_HAVE_SAWS)
1106: /*
1107: Publish convergence information using SAWs
1108: */
1109: flg = PETSC_FALSE;
1110: PetscCall(PetscOptionsBool("-snes_monitor_saws", "Publish SNES progress using SAWs", "SNESMonitorSet", flg, &flg, NULL));
1111: if (flg) {
1112: void *ctx;
1113: PetscCall(SNESMonitorSAWsCreate(snes, &ctx));
1114: PetscCall(SNESMonitorSet(snes, SNESMonitorSAWs, ctx, SNESMonitorSAWsDestroy));
1115: }
1116: #endif
1117: #if defined(PETSC_HAVE_SAWS)
1118: {
1119: PetscBool set;
1120: flg = PETSC_FALSE;
1121: PetscCall(PetscOptionsBool("-snes_saws_block", "Block for SAWs at end of SNESSolve", "PetscObjectSAWsBlock", ((PetscObject)snes)->amspublishblock, &flg, &set));
1122: if (set) PetscCall(PetscObjectSAWsSetBlock((PetscObject)snes, flg));
1123: }
1124: #endif
1126: for (i = 0; i < numberofsetfromoptions; i++) PetscCall((*othersetfromoptions[i])(snes));
1128: PetscTryTypeMethod(snes, setfromoptions, PetscOptionsObject);
1130: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1131: PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)snes, PetscOptionsObject));
1132: PetscOptionsEnd();
1134: if (snes->linesearch) {
1135: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
1136: PetscCall(SNESLineSearchSetFromOptions(snes->linesearch));
1137: }
1139: if (snes->usesksp) {
1140: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
1141: PetscCall(KSPSetOperators(snes->ksp, snes->jacobian, snes->jacobian_pre));
1142: PetscCall(KSPSetFromOptions(snes->ksp));
1143: }
1145: /* if user has set the SNES NPC type via options database, create it. */
1146: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1147: PetscCall(PetscOptionsHasName(((PetscObject)snes)->options, optionsprefix, "-npc_snes_type", &pcset));
1148: if (pcset && (!snes->npc)) PetscCall(SNESGetNPC(snes, &snes->npc));
1149: if (snes->npc) PetscCall(SNESSetFromOptions(snes->npc));
1150: snes->setfromoptionscalled++;
1151: PetscFunctionReturn(PETSC_SUCCESS);
1152: }
1154: /*@
1155: SNESResetFromOptions - Sets various `SNES` and `KSP` parameters from user options ONLY if the `SNESSetFromOptions()` was previously set from options
1157: Collective
1159: Input Parameter:
1160: . snes - the `SNES` context
1162: Level: beginner
1164: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESSetOptionsPrefix()`
1165: @*/
1166: PetscErrorCode SNESResetFromOptions(SNES snes)
1167: {
1168: PetscFunctionBegin;
1169: if (snes->setfromoptionscalled) PetscCall(SNESSetFromOptions(snes));
1170: PetscFunctionReturn(PETSC_SUCCESS);
1171: }
1173: /*@C
1174: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1175: the nonlinear solvers.
1177: Logically Collective; No Fortran Support
1179: Input Parameters:
1180: + snes - the `SNES` context
1181: . compute - function to compute the context
1182: - destroy - function to destroy the context
1184: Level: intermediate
1186: Note:
1187: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1189: Use `SNESSetApplicationContext()` to see the context immediately
1191: .seealso: [](ch_snes), `SNESGetApplicationContext()`, `SNESSetComputeApplicationContext()`, `SNESSetApplicationContext()`
1192: @*/
1193: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES, void **), PetscErrorCode (*destroy)(void **))
1194: {
1195: PetscFunctionBegin;
1197: snes->ops->usercompute = compute;
1198: snes->ops->userdestroy = destroy;
1199: PetscFunctionReturn(PETSC_SUCCESS);
1200: }
1202: /*@
1203: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1205: Logically Collective
1207: Input Parameters:
1208: + snes - the `SNES` context
1209: - usrP - optional user context
1211: Level: intermediate
1213: Notes:
1214: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian, or other evaluation function
1215: with `SNESGetApplicationContext()`
1217: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1219: Fortran Note:
1220: You must write a Fortran interface definition for this
1221: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1223: .seealso: [](ch_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1224: @*/
1225: PetscErrorCode SNESSetApplicationContext(SNES snes, void *usrP)
1226: {
1227: KSP ksp;
1229: PetscFunctionBegin;
1231: PetscCall(SNESGetKSP(snes, &ksp));
1232: PetscCall(KSPSetApplicationContext(ksp, usrP));
1233: snes->user = usrP;
1234: PetscFunctionReturn(PETSC_SUCCESS);
1235: }
1237: /*@
1238: SNESGetApplicationContext - Gets the user-defined context for the
1239: nonlinear solvers set with `SNESGetApplicationContext()` or with `SNESSetComputeApplicationContext()`
1241: Not Collective
1243: Input Parameter:
1244: . snes - `SNES` context
1246: Output Parameter:
1247: . usrP - user context
1249: Level: intermediate
1251: Fortran Note:
1252: You must write a Fortran interface definition for this
1253: function that tells Fortran the Fortran derived data type that you are passing in as the ctx argument.
1255: .seealso: [](ch_snes), `SNESSetApplicationContext()`
1256: @*/
1257: PetscErrorCode SNESGetApplicationContext(SNES snes, void *usrP)
1258: {
1259: PetscFunctionBegin;
1261: *(void **)usrP = snes->user;
1262: PetscFunctionReturn(PETSC_SUCCESS);
1263: }
1265: /*@
1266: SNESSetUseMatrixFree - indicates that `SNES` should use matrix free finite difference matrix vector products to apply the Jacobian.
1268: Logically Collective
1270: Input Parameters:
1271: + snes - `SNES` context
1272: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1273: - 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
1274: this option no matrix element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1276: Options Database Keys:
1277: + -snes_mf_operator - use matrix free only for the mat operator
1278: . -snes_mf - use matrix-free for both the mat and pmat operator
1279: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1280: - -snes_fd - compute the Jacobian via finite differences (slow)
1282: Level: intermediate
1284: Note:
1285: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free, and computing explicitly with
1286: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1288: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`
1289: @*/
1290: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1291: {
1292: PetscFunctionBegin;
1296: snes->mf = mf_operator ? PETSC_TRUE : mf;
1297: snes->mf_operator = mf_operator;
1298: PetscFunctionReturn(PETSC_SUCCESS);
1299: }
1301: /*@
1302: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1304: Not Collective, but the resulting flags will be the same on all MPI ranks
1306: Input Parameter:
1307: . snes - `SNES` context
1309: Output Parameters:
1310: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1311: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1313: Level: intermediate
1315: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1316: @*/
1317: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1318: {
1319: PetscFunctionBegin;
1321: if (mf) *mf = snes->mf;
1322: if (mf_operator) *mf_operator = snes->mf_operator;
1323: PetscFunctionReturn(PETSC_SUCCESS);
1324: }
1326: /*@
1327: SNESGetIterationNumber - Gets the number of nonlinear iterations completed
1328: at this time.
1330: Not Collective
1332: Input Parameter:
1333: . snes - `SNES` context
1335: Output Parameter:
1336: . iter - iteration number
1338: Level: intermediate
1340: Notes:
1341: For example, during the computation of iteration 2 this would return 1.
1343: This is useful for using lagged Jacobians (where one does not recompute the
1344: Jacobian at each `SNES` iteration). For example, the code
1345: .vb
1346: ierr = SNESGetIterationNumber(snes,&it);
1347: if (!(it % 2)) {
1348: [compute Jacobian here]
1349: }
1350: .ve
1351: can be used in your function that computes the Jacobian to cause the Jacobian to be
1352: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1354: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1356: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`
1357: @*/
1358: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1359: {
1360: PetscFunctionBegin;
1363: *iter = snes->iter;
1364: PetscFunctionReturn(PETSC_SUCCESS);
1365: }
1367: /*@
1368: SNESSetIterationNumber - Sets the current iteration number.
1370: Not Collective
1372: Input Parameters:
1373: + snes - `SNES` context
1374: - iter - iteration number
1376: Level: developer
1378: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1379: @*/
1380: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1381: {
1382: PetscFunctionBegin;
1384: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1385: snes->iter = iter;
1386: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1387: PetscFunctionReturn(PETSC_SUCCESS);
1388: }
1390: /*@
1391: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1392: attempted by the nonlinear solver.
1394: Not Collective
1396: Input Parameter:
1397: . snes - `SNES` context
1399: Output Parameter:
1400: . nfails - number of unsuccessful steps attempted
1402: Level: intermediate
1404: Note:
1405: This counter is reset to zero for each successive call to `SNESSolve()`.
1407: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1408: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1409: @*/
1410: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1411: {
1412: PetscFunctionBegin;
1415: *nfails = snes->numFailures;
1416: PetscFunctionReturn(PETSC_SUCCESS);
1417: }
1419: /*@
1420: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1421: attempted by the nonlinear solver before it gives up and generates an error
1423: Not Collective
1425: Input Parameters:
1426: + snes - `SNES` context
1427: - maxFails - maximum of unsuccessful steps
1429: Level: intermediate
1431: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1432: `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1433: @*/
1434: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1435: {
1436: PetscFunctionBegin;
1438: snes->maxFailures = maxFails;
1439: PetscFunctionReturn(PETSC_SUCCESS);
1440: }
1442: /*@
1443: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1444: attempted by the nonlinear solver before it gives up and generates an error
1446: Not Collective
1448: Input Parameter:
1449: . snes - `SNES` context
1451: Output Parameter:
1452: . maxFails - maximum of unsuccessful steps
1454: Level: intermediate
1456: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1457: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1458: @*/
1459: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1460: {
1461: PetscFunctionBegin;
1464: *maxFails = snes->maxFailures;
1465: PetscFunctionReturn(PETSC_SUCCESS);
1466: }
1468: /*@
1469: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1470: done by the `SNES` object
1472: Not Collective
1474: Input Parameter:
1475: . snes - `SNES` context
1477: Output Parameter:
1478: . nfuncs - number of evaluations
1480: Level: intermediate
1482: Note:
1483: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1485: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1486: @*/
1487: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1488: {
1489: PetscFunctionBegin;
1492: *nfuncs = snes->nfuncs;
1493: PetscFunctionReturn(PETSC_SUCCESS);
1494: }
1496: /*@
1497: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1498: linear solvers.
1500: Not Collective
1502: Input Parameter:
1503: . snes - `SNES` context
1505: Output Parameter:
1506: . nfails - number of failed solves
1508: Options Database Key:
1509: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1511: Level: intermediate
1513: Note:
1514: This counter is reset to zero for each successive call to `SNESSolve()`.
1516: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1517: @*/
1518: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1519: {
1520: PetscFunctionBegin;
1523: *nfails = snes->numLinearSolveFailures;
1524: PetscFunctionReturn(PETSC_SUCCESS);
1525: }
1527: /*@
1528: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1529: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1531: Logically Collective
1533: Input Parameters:
1534: + snes - `SNES` context
1535: - maxFails - maximum allowed linear solve failures
1537: Options Database Key:
1538: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1540: Level: intermediate
1542: Note:
1543: By default this is 0; that is `SNES` returns on the first failed linear solve
1545: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1546: @*/
1547: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1548: {
1549: PetscFunctionBegin;
1552: snes->maxLinearSolveFailures = maxFails;
1553: PetscFunctionReturn(PETSC_SUCCESS);
1554: }
1556: /*@
1557: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1558: are allowed before `SNES` returns as unsuccessful
1560: Not Collective
1562: Input Parameter:
1563: . snes - `SNES` context
1565: Output Parameter:
1566: . maxFails - maximum of unsuccessful solves allowed
1568: Level: intermediate
1570: Note:
1571: By default this is 1; that is `SNES` returns on the first failed linear solve
1573: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1574: @*/
1575: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1576: {
1577: PetscFunctionBegin;
1580: *maxFails = snes->maxLinearSolveFailures;
1581: PetscFunctionReturn(PETSC_SUCCESS);
1582: }
1584: /*@
1585: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1586: used by the nonlinear solver.
1588: Not Collective
1590: Input Parameter:
1591: . snes - `SNES` context
1593: Output Parameter:
1594: . lits - number of linear iterations
1596: Level: intermediate
1598: Notes:
1599: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1601: 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
1602: then call `KSPGetIterationNumber()` after the failed solve.
1604: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1605: @*/
1606: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1607: {
1608: PetscFunctionBegin;
1611: *lits = snes->linear_its;
1612: PetscFunctionReturn(PETSC_SUCCESS);
1613: }
1615: /*@
1616: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1617: are reset every time `SNESSolve()` is called.
1619: Logically Collective
1621: Input Parameters:
1622: + snes - `SNES` context
1623: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1625: Level: developer
1627: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1628: @*/
1629: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1630: {
1631: PetscFunctionBegin;
1634: snes->counters_reset = reset;
1635: PetscFunctionReturn(PETSC_SUCCESS);
1636: }
1638: /*@
1639: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1641: Not Collective, but the `SNES` and `KSP` objects must live on the same MPI_Comm
1643: Input Parameters:
1644: + snes - the `SNES` context
1645: - ksp - the `KSP` context
1647: Level: developer
1649: Notes:
1650: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1651: so this routine is rarely needed.
1653: The `KSP` object that is already in the `SNES` object has its reference count
1654: decreased by one.
1656: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
1657: @*/
1658: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1659: {
1660: PetscFunctionBegin;
1663: PetscCheckSameComm(snes, 1, ksp, 2);
1664: PetscCall(PetscObjectReference((PetscObject)ksp));
1665: if (snes->ksp) PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1666: snes->ksp = ksp;
1667: PetscFunctionReturn(PETSC_SUCCESS);
1668: }
1670: /*@
1671: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1673: Collective
1675: Input Parameter:
1676: . comm - MPI communicator
1678: Output Parameter:
1679: . outsnes - the new `SNES` context
1681: Options Database Keys:
1682: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no preconditioning matrix
1683: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided preconditioning matrix
1684: as set by `SNESSetJacobian()`
1685: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1686: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1688: Level: beginner
1690: Developer Notes:
1691: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1692: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1693: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1694: in `SNESView()`.
1696: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1697: by help messages about meaningless `SNES` options.
1699: `SNES` always creates the snes->kspconvctx even though it is used by only one type. This should be fixed.
1701: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNES`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1702: @*/
1703: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1704: {
1705: SNES snes;
1706: SNESKSPEW *kctx;
1708: PetscFunctionBegin;
1710: *outsnes = NULL;
1711: PetscCall(SNESInitializePackage());
1713: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1715: snes->ops->converged = SNESConvergedDefault;
1716: snes->usesksp = PETSC_TRUE;
1717: snes->tolerancesset = PETSC_FALSE;
1718: snes->max_its = 50;
1719: snes->max_funcs = 10000;
1720: snes->norm = 0.0;
1721: snes->xnorm = 0.0;
1722: snes->ynorm = 0.0;
1723: snes->normschedule = SNES_NORM_ALWAYS;
1724: snes->functype = SNES_FUNCTION_DEFAULT;
1725: snes->rtol = PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8;
1726: snes->ttol = 0.0;
1727: snes->abstol = PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50;
1728: snes->stol = PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8;
1729: snes->deltatol = PetscDefined(USE_REAL_SINGLE) ? 1.e-6 : 1.e-12;
1730: snes->divtol = 1.e4;
1731: snes->rnorm0 = 0;
1732: snes->nfuncs = 0;
1733: snes->numFailures = 0;
1734: snes->maxFailures = 1;
1735: snes->linear_its = 0;
1736: snes->lagjacobian = 1;
1737: snes->jac_iter = 0;
1738: snes->lagjac_persist = PETSC_FALSE;
1739: snes->lagpreconditioner = 1;
1740: snes->pre_iter = 0;
1741: snes->lagpre_persist = PETSC_FALSE;
1742: snes->numbermonitors = 0;
1743: snes->numberreasonviews = 0;
1744: snes->data = NULL;
1745: snes->setupcalled = PETSC_FALSE;
1746: snes->ksp_ewconv = PETSC_FALSE;
1747: snes->nwork = 0;
1748: snes->work = NULL;
1749: snes->nvwork = 0;
1750: snes->vwork = NULL;
1751: snes->conv_hist_len = 0;
1752: snes->conv_hist_max = 0;
1753: snes->conv_hist = NULL;
1754: snes->conv_hist_its = NULL;
1755: snes->conv_hist_reset = PETSC_TRUE;
1756: snes->counters_reset = PETSC_TRUE;
1757: snes->vec_func_init_set = PETSC_FALSE;
1758: snes->reason = SNES_CONVERGED_ITERATING;
1759: snes->npcside = PC_RIGHT;
1760: snes->setfromoptionscalled = 0;
1762: snes->mf = PETSC_FALSE;
1763: snes->mf_operator = PETSC_FALSE;
1764: snes->mf_version = 1;
1766: snes->numLinearSolveFailures = 0;
1767: snes->maxLinearSolveFailures = 1;
1769: snes->vizerotolerance = 1.e-8;
1770: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1772: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1773: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1775: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1776: PetscCall(PetscNew(&kctx));
1778: snes->kspconvctx = (void *)kctx;
1779: kctx->version = 2;
1780: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1781: this was too large for some test cases */
1782: kctx->rtol_last = 0.0;
1783: kctx->rtol_max = 0.9;
1784: kctx->gamma = 1.0;
1785: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1786: kctx->alpha2 = kctx->alpha;
1787: kctx->threshold = 0.1;
1788: kctx->lresid_last = 0.0;
1789: kctx->norm_last = 0.0;
1791: kctx->rk_last = 0.0;
1792: kctx->rk_last_2 = 0.0;
1793: kctx->rtol_last_2 = 0.0;
1794: kctx->v4_p1 = 0.1;
1795: kctx->v4_p2 = 0.4;
1796: kctx->v4_p3 = 0.7;
1797: kctx->v4_m1 = 0.8;
1798: kctx->v4_m2 = 0.5;
1799: kctx->v4_m3 = 0.1;
1800: kctx->v4_m4 = 0.5;
1802: *outsnes = snes;
1803: PetscFunctionReturn(PETSC_SUCCESS);
1804: }
1806: /*MC
1807: SNESFunction - Functional form used to convey the nonlinear function to `SNES` in `SNESSetFunction()`
1809: Synopsis:
1810: #include "petscsnes.h"
1811: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1813: Collective
1815: Input Parameters:
1816: + snes - the `SNES` context
1817: . x - state at which to evaluate residual
1818: - ctx - optional user-defined function context, passed in with `SNESSetFunction()`
1820: Output Parameter:
1821: . f - vector to put residual (function value)
1823: Level: intermediate
1825: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESGetFunction()`
1826: M*/
1828: /*@C
1829: SNESSetFunction - Sets the function evaluation routine and function
1830: vector for use by the `SNES` routines in solving systems of nonlinear
1831: equations.
1833: Logically Collective
1835: Input Parameters:
1836: + snes - the `SNES` context
1837: . r - vector to store function values, may be `NULL`
1838: . f - function evaluation routine; for calling sequence see `SNESFunction`
1839: - ctx - [optional] user-defined context for private data for the
1840: function evaluation routine (may be `NULL`)
1842: Level: beginner
1844: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunction`
1845: @*/
1846: PetscErrorCode SNESSetFunction(SNES snes, Vec r, PetscErrorCode (*f)(SNES, Vec, Vec, void *), void *ctx)
1847: {
1848: DM dm;
1850: PetscFunctionBegin;
1852: if (r) {
1854: PetscCheckSameComm(snes, 1, r, 2);
1855: PetscCall(PetscObjectReference((PetscObject)r));
1856: PetscCall(VecDestroy(&snes->vec_func));
1857: snes->vec_func = r;
1858: }
1859: PetscCall(SNESGetDM(snes, &dm));
1860: PetscCall(DMSNESSetFunction(dm, f, ctx));
1861: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1862: PetscFunctionReturn(PETSC_SUCCESS);
1863: }
1865: /*@C
1866: SNESSetInitialFunction - Sets the function vector to be used as the
1867: initial function value at the initialization of the method. In some
1868: instances, the user has precomputed the function before calling
1869: `SNESSolve()`. This function allows one to avoid a redundant call
1870: to `SNESComputeFunction()` in that case.
1872: Logically Collective
1874: Input Parameters:
1875: + snes - the `SNES` context
1876: - f - vector to store function value
1878: Level: developer
1880: Notes:
1881: This should not be modified during the solution procedure.
1883: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1885: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1886: @*/
1887: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1888: {
1889: Vec vec_func;
1891: PetscFunctionBegin;
1894: PetscCheckSameComm(snes, 1, f, 2);
1895: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1896: snes->vec_func_init_set = PETSC_FALSE;
1897: PetscFunctionReturn(PETSC_SUCCESS);
1898: }
1899: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
1900: PetscCall(VecCopy(f, vec_func));
1902: snes->vec_func_init_set = PETSC_TRUE;
1903: PetscFunctionReturn(PETSC_SUCCESS);
1904: }
1906: /*@
1907: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
1908: of the `SNES` method, when norms are computed in the solving process
1910: Logically Collective
1912: Input Parameters:
1913: + snes - the `SNES` context
1914: - normschedule - the frequency of norm computation
1916: Options Database Key:
1917: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
1919: Level: advanced
1921: Notes:
1922: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
1923: of the nonlinear function and the taking of its norm at every iteration to
1924: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1925: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
1926: may either be monitored for convergence or not. As these are often used as nonlinear
1927: preconditioners, monitoring the norm of their error is not a useful enterprise within
1928: their solution.
1930: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1931: @*/
1932: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1933: {
1934: PetscFunctionBegin;
1936: snes->normschedule = normschedule;
1937: PetscFunctionReturn(PETSC_SUCCESS);
1938: }
1940: /*@
1941: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
1942: of the `SNES` method.
1944: Logically Collective
1946: Input Parameters:
1947: + snes - the `SNES` context
1948: - normschedule - the type of the norm used
1950: Level: advanced
1952: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1953: @*/
1954: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1955: {
1956: PetscFunctionBegin;
1958: *normschedule = snes->normschedule;
1959: PetscFunctionReturn(PETSC_SUCCESS);
1960: }
1962: /*@
1963: SNESSetFunctionNorm - Sets the last computed residual norm.
1965: Logically Collective
1967: Input Parameters:
1968: + snes - the `SNES` context
1969: - norm - the value of the norm
1971: Level: developer
1973: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1974: @*/
1975: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1976: {
1977: PetscFunctionBegin;
1979: snes->norm = norm;
1980: PetscFunctionReturn(PETSC_SUCCESS);
1981: }
1983: /*@
1984: SNESGetFunctionNorm - Gets the last computed norm of the residual
1986: Not Collective
1988: Input Parameter:
1989: . snes - the `SNES` context
1991: Output Parameter:
1992: . norm - the last computed residual norm
1994: Level: developer
1996: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1997: @*/
1998: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
1999: {
2000: PetscFunctionBegin;
2003: *norm = snes->norm;
2004: PetscFunctionReturn(PETSC_SUCCESS);
2005: }
2007: /*@
2008: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2010: Not Collective
2012: Input Parameter:
2013: . snes - the `SNES` context
2015: Output Parameter:
2016: . ynorm - the last computed update norm
2018: Level: developer
2020: Note:
2021: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2023: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2024: @*/
2025: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2026: {
2027: PetscFunctionBegin;
2030: *ynorm = snes->ynorm;
2031: PetscFunctionReturn(PETSC_SUCCESS);
2032: }
2034: /*@
2035: SNESGetSolutionNorm - Gets the last computed norm of the solution
2037: Not Collective
2039: Input Parameter:
2040: . snes - the `SNES` context
2042: Output Parameter:
2043: . xnorm - the last computed solution norm
2045: Level: developer
2047: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2048: @*/
2049: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2050: {
2051: PetscFunctionBegin;
2054: *xnorm = snes->xnorm;
2055: PetscFunctionReturn(PETSC_SUCCESS);
2056: }
2058: /*@C
2059: SNESSetFunctionType - Sets the `SNESFunctionType`
2060: of the `SNES` method.
2062: Logically Collective
2064: Input Parameters:
2065: + snes - the `SNES` context
2066: - type - the function type
2068: Level: developer
2070: Notes:
2071: Possible values of the function type
2072: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2073: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2074: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2076: Different `SNESType`s use this value in different ways
2078: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2079: @*/
2080: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2081: {
2082: PetscFunctionBegin;
2084: snes->functype = type;
2085: PetscFunctionReturn(PETSC_SUCCESS);
2086: }
2088: /*@C
2089: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2090: of the SNES method.
2092: Logically Collective
2094: Input Parameters:
2095: + snes - the `SNES` context
2096: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2098: Level: advanced
2100: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2101: @*/
2102: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2103: {
2104: PetscFunctionBegin;
2106: *type = snes->functype;
2107: PetscFunctionReturn(PETSC_SUCCESS);
2108: }
2110: /*@C
2111: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2112: use with composed nonlinear solvers.
2114: Input Parameters:
2115: + snes - the `SNES` context
2116: . f - function evaluation routine to apply Gauss-Seidel
2117: - ctx - [optional] user-defined context for private data for the
2118: smoother evaluation routine (may be `NULL`)
2120: Calling sequence of `f`:
2121: $ PetscErrorCode f(SNES snes, Vec X, Vec B, void *ctx)
2122: + snes - the `SNES` context
2123: . X - the current solution
2124: . B - the right hand side vector (which may be `NULL`)
2125: - ctx - a user provided context
2127: Level: intermediate
2129: Note:
2130: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2131: a problem appropriate update to the solution, particularly `SNESFAS`.
2133: .seealso: [](ch_snes), `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`
2134: @*/
2135: PetscErrorCode SNESSetNGS(SNES snes, PetscErrorCode (*f)(SNES, Vec, Vec, void *), void *ctx)
2136: {
2137: DM dm;
2139: PetscFunctionBegin;
2141: PetscCall(SNESGetDM(snes, &dm));
2142: PetscCall(DMSNESSetNGS(dm, f, ctx));
2143: PetscFunctionReturn(PETSC_SUCCESS);
2144: }
2146: /*
2147: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2148: changed during the KSPSolve()
2149: */
2150: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, void *ctx)
2151: {
2152: DM dm;
2153: DMSNES sdm;
2155: PetscFunctionBegin;
2156: PetscCall(SNESGetDM(snes, &dm));
2157: PetscCall(DMGetDMSNES(dm, &sdm));
2158: /* A(x)*x - b(x) */
2159: if (sdm->ops->computepfunction) {
2160: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2161: PetscCall(VecScale(f, -1.0));
2162: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2163: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2164: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2165: PetscCall(MatMultAdd(snes->picard, x, f, f));
2166: } else {
2167: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2168: PetscCall(MatMult(snes->picard, x, f));
2169: }
2170: PetscFunctionReturn(PETSC_SUCCESS);
2171: }
2173: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, void *ctx)
2174: {
2175: DM dm;
2176: DMSNES sdm;
2178: PetscFunctionBegin;
2179: PetscCall(SNESGetDM(snes, &dm));
2180: PetscCall(DMGetDMSNES(dm, &sdm));
2181: /* A(x)*x - b(x) */
2182: if (sdm->ops->computepfunction) {
2183: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2184: PetscCall(VecScale(f, -1.0));
2185: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2186: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2187: } else {
2188: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2189: PetscCall(MatMult(snes->jacobian_pre, x, f));
2190: }
2191: PetscFunctionReturn(PETSC_SUCCESS);
2192: }
2194: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, void *ctx)
2195: {
2196: PetscFunctionBegin;
2197: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2198: /* must assembly if matrix-free to get the last SNES solution */
2199: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2200: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2201: PetscFunctionReturn(PETSC_SUCCESS);
2202: }
2204: /*@C
2205: SNESSetPicard - Use `SNES` to solve the system A(x) x = bp(x) + b via a Picard type iteration (Picard linearization)
2207: Logically Collective
2209: Input Parameters:
2210: + snes - the `SNES` context
2211: . r - vector to store function values, may be `NULL`
2212: . bp - function evaluation routine, may be `NULL`
2213: . Amat - matrix with which A(x) x - bp(x) - b is to be computed
2214: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2215: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFunction()`
2216: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2218: Level: intermediate
2220: Notes:
2221: It is often better to provide the nonlinear function F() and some approximation to its Jacobian directly and use
2222: 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.
2224: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2226: 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}.
2227: When an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = bp(x^{n}) + b iteration.
2229: Run with `-snes_mf_operator` to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2231: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2232: the direct Picard iteration A(x^n) x^{n+1} = bp(x^n) + b
2234: 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
2235: 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
2236: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2238: 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
2239: A(x^{n}) is used to build the preconditioner
2241: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at at time) and thus represent Newton's method.
2243: 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
2244: 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
2245: 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`.
2246: See the comment in src/snes/tutorials/ex15.c.
2248: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`, `SNESJacobianFunction`
2249: @*/
2250: 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)
2251: {
2252: DM dm;
2254: PetscFunctionBegin;
2256: PetscCall(SNESGetDM(snes, &dm));
2257: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2258: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2259: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2260: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2261: PetscFunctionReturn(PETSC_SUCCESS);
2262: }
2264: /*@C
2265: SNESGetPicard - Returns the context for the Picard iteration
2267: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2269: Input Parameter:
2270: . snes - the `SNES` context
2272: Output Parameters:
2273: + r - the function (or `NULL`)
2274: . f - the function (or `NULL`); for calling sequence see `SNESFunction`
2275: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2276: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2277: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFunction`
2278: - ctx - the function context (or `NULL`)
2280: Level: advanced
2282: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunction`, `SNESJacobianFunction`
2283: @*/
2284: 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)
2285: {
2286: DM dm;
2288: PetscFunctionBegin;
2290: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2291: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2292: PetscCall(SNESGetDM(snes, &dm));
2293: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2294: PetscFunctionReturn(PETSC_SUCCESS);
2295: }
2297: /*@C
2298: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2300: Logically Collective
2302: Input Parameters:
2303: + snes - the `SNES` context
2304: . func - function evaluation routine
2305: - ctx - [optional] user-defined context for private data for the
2306: function evaluation routine (may be `NULL`)
2308: Calling sequence of `func`:
2309: $ PetscErrorCode func(SNES snes, Vec x, void *ctx);
2310: + snes - the `SNES` solver
2311: . x - vector to put initial guess
2312: - ctx - optional user-defined function context
2314: Level: intermediate
2316: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`
2317: @*/
2318: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, PetscErrorCode (*func)(SNES, Vec, void *), void *ctx)
2319: {
2320: PetscFunctionBegin;
2322: if (func) snes->ops->computeinitialguess = func;
2323: if (ctx) snes->initialguessP = ctx;
2324: PetscFunctionReturn(PETSC_SUCCESS);
2325: }
2327: /*@C
2328: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2329: it assumes a zero right hand side.
2331: Logically Collective
2333: Input Parameter:
2334: . snes - the `SNES` context
2336: Output Parameter:
2337: . rhs - the right hand side vector or `NULL` if the right hand side vector is null
2339: Level: intermediate
2341: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2342: @*/
2343: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2344: {
2345: PetscFunctionBegin;
2348: *rhs = snes->vec_rhs;
2349: PetscFunctionReturn(PETSC_SUCCESS);
2350: }
2352: /*@
2353: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2355: Collective
2357: Input Parameters:
2358: + snes - the `SNES` context
2359: - x - input vector
2361: Output Parameter:
2362: . y - function vector, as set by `SNESSetFunction()`
2364: Level: developer
2366: Note:
2367: `SNESComputeFunction()` is typically used within nonlinear solvers
2368: implementations, so users would not generally call this routine themselves.
2370: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`
2371: @*/
2372: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec y)
2373: {
2374: DM dm;
2375: DMSNES sdm;
2377: PetscFunctionBegin;
2381: PetscCheckSameComm(snes, 1, x, 2);
2382: PetscCheckSameComm(snes, 1, y, 3);
2383: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2385: PetscCall(SNESGetDM(snes, &dm));
2386: PetscCall(DMGetDMSNES(dm, &sdm));
2387: 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().");
2388: if (sdm->ops->computefunction) {
2389: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2390: PetscCall(VecLockReadPush(x));
2391: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2392: snes->domainerror = PETSC_FALSE;
2393: {
2394: void *ctx;
2395: PetscErrorCode (*computefunction)(SNES, Vec, Vec, void *);
2396: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2397: PetscCallBack("SNES callback function", (*computefunction)(snes, x, y, ctx));
2398: }
2399: PetscCall(VecLockReadPop(x));
2400: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2401: } else /* if (snes->vec_rhs) */ {
2402: PetscCall(MatMult(snes->jacobian, x, y));
2403: }
2404: if (snes->vec_rhs) PetscCall(VecAXPY(y, -1.0, snes->vec_rhs));
2405: snes->nfuncs++;
2406: /*
2407: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2408: propagate the value to all processes
2409: */
2410: if (snes->domainerror) PetscCall(VecSetInf(y));
2411: PetscFunctionReturn(PETSC_SUCCESS);
2412: }
2414: /*@
2415: SNESComputeMFFunction - Calls the function that has been set with `SNESSetMFFunction()`.
2417: Collective
2419: Input Parameters:
2420: + snes - the `SNES` context
2421: - x - input vector
2423: Output Parameter:
2424: . y - function vector, as set by `SNESSetMFFunction()`
2426: Level: developer
2428: Notes:
2429: `SNESComputeMFFunction()` is used within the matrix vector products called by the matrix created with `MatCreateSNESMF()`
2430: so users would not generally call this routine themselves.
2432: Since this function is intended for use with finite differencing it does not subtract the right hand side vector provided with `SNESSolve()`
2433: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2434: 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.
2436: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF`
2437: @*/
2438: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2439: {
2440: DM dm;
2441: DMSNES sdm;
2443: PetscFunctionBegin;
2447: PetscCheckSameComm(snes, 1, x, 2);
2448: PetscCheckSameComm(snes, 1, y, 3);
2449: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2451: PetscCall(SNESGetDM(snes, &dm));
2452: PetscCall(DMGetDMSNES(dm, &sdm));
2453: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2454: PetscCall(VecLockReadPush(x));
2455: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2456: snes->domainerror = PETSC_FALSE;
2457: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2458: PetscCall(VecLockReadPop(x));
2459: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2460: snes->nfuncs++;
2461: /*
2462: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2463: propagate the value to all processes
2464: */
2465: if (snes->domainerror) PetscCall(VecSetInf(y));
2466: PetscFunctionReturn(PETSC_SUCCESS);
2467: }
2469: /*@
2470: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2472: Collective
2474: Input Parameters:
2475: + snes - the `SNES` context
2476: . x - input vector
2477: - b - rhs vector
2479: Output Parameter:
2480: . x - new solution vector
2482: Level: developer
2484: Note:
2485: `SNESComputeNGS()` is typically used within composed nonlinear solver
2486: implementations, so most users would not generally call this routine
2487: themselves.
2489: .seealso: [](ch_snes), `SNESNGS`, `SNESSetNGS()`, `SNESComputeFunction()`
2490: @*/
2491: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2492: {
2493: DM dm;
2494: DMSNES sdm;
2496: PetscFunctionBegin;
2500: PetscCheckSameComm(snes, 1, x, 3);
2501: if (b) PetscCheckSameComm(snes, 1, b, 2);
2502: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2503: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2504: PetscCall(SNESGetDM(snes, &dm));
2505: PetscCall(DMGetDMSNES(dm, &sdm));
2506: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2507: if (b) PetscCall(VecLockReadPush(b));
2508: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2509: if (b) PetscCall(VecLockReadPop(b));
2510: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2511: PetscFunctionReturn(PETSC_SUCCESS);
2512: }
2514: PetscErrorCode SNESTestJacobian(SNES snes)
2515: {
2516: Mat A, B, C, D, jacobian;
2517: Vec x = snes->vec_sol, f = snes->vec_func;
2518: PetscReal nrm, gnorm;
2519: PetscReal threshold = 1.e-5;
2520: MatType mattype;
2521: PetscInt m, n, M, N;
2522: void *functx;
2523: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, test = PETSC_FALSE, flg, istranspose;
2524: PetscViewer viewer, mviewer;
2525: MPI_Comm comm;
2526: PetscInt tabs;
2527: static PetscBool directionsprinted = PETSC_FALSE;
2528: PetscViewerFormat format;
2530: PetscFunctionBegin;
2531: PetscObjectOptionsBegin((PetscObject)snes);
2532: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &test));
2533: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2534: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2535: if (!complete_print) {
2536: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2537: PetscCall(PetscOptionsViewer("-snes_test_jacobian_display", "Display difference between hand-coded and finite difference Jacobians", "None", &mviewer, &format, &complete_print));
2538: }
2539: /* for compatibility with PETSc 3.9 and older. */
2540: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2541: 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));
2542: PetscOptionsEnd();
2543: if (!test) PetscFunctionReturn(PETSC_SUCCESS);
2545: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2546: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2547: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2548: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2549: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2550: if (!complete_print && !directionsprinted) {
2551: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2552: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2553: }
2554: if (!directionsprinted) {
2555: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2556: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2557: directionsprinted = PETSC_TRUE;
2558: }
2559: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2561: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2562: if (!flg) jacobian = snes->jacobian;
2563: else jacobian = snes->jacobian_pre;
2565: if (!x) {
2566: PetscCall(MatCreateVecs(jacobian, &x, NULL));
2567: } else {
2568: PetscCall(PetscObjectReference((PetscObject)x));
2569: }
2570: if (!f) {
2571: PetscCall(VecDuplicate(x, &f));
2572: } else {
2573: PetscCall(PetscObjectReference((PetscObject)f));
2574: }
2575: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2576: PetscCall(SNESComputeFunction(snes, x, f));
2577: PetscCall(VecDestroy(&f));
2578: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2579: while (jacobian) {
2580: Mat JT = NULL, Jsave = NULL;
2582: if (istranspose) {
2583: PetscCall(MatCreateTranspose(jacobian, &JT));
2584: Jsave = jacobian;
2585: jacobian = JT;
2586: }
2587: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2588: if (flg) {
2589: A = jacobian;
2590: PetscCall(PetscObjectReference((PetscObject)A));
2591: } else {
2592: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2593: }
2595: PetscCall(MatGetType(A, &mattype));
2596: PetscCall(MatGetSize(A, &M, &N));
2597: PetscCall(MatGetLocalSize(A, &m, &n));
2598: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2599: PetscCall(MatSetType(B, mattype));
2600: PetscCall(MatSetSizes(B, m, n, M, N));
2601: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2602: PetscCall(MatSetUp(B));
2603: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2605: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2606: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2608: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2609: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2610: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2611: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2612: PetscCall(MatDestroy(&D));
2613: if (!gnorm) gnorm = 1; /* just in case */
2614: PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2616: if (complete_print) {
2617: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2618: PetscCall(MatView(A, mviewer));
2619: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2620: PetscCall(MatView(B, mviewer));
2621: }
2623: if (threshold_print || complete_print) {
2624: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2625: PetscScalar *cvals;
2626: const PetscInt *bcols;
2627: const PetscScalar *bvals;
2629: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2630: PetscCall(MatSetType(C, mattype));
2631: PetscCall(MatSetSizes(C, m, n, M, N));
2632: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2633: PetscCall(MatSetUp(C));
2634: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2636: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2637: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2639: for (row = Istart; row < Iend; row++) {
2640: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2641: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2642: for (j = 0, cncols = 0; j < bncols; j++) {
2643: if (PetscAbsScalar(bvals[j]) > threshold) {
2644: ccols[cncols] = bcols[j];
2645: cvals[cncols] = bvals[j];
2646: cncols += 1;
2647: }
2648: }
2649: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2650: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2651: PetscCall(PetscFree2(ccols, cvals));
2652: }
2653: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2654: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2655: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2656: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2657: PetscCall(MatDestroy(&C));
2658: }
2659: PetscCall(MatDestroy(&A));
2660: PetscCall(MatDestroy(&B));
2661: PetscCall(MatDestroy(&JT));
2662: if (Jsave) jacobian = Jsave;
2663: if (jacobian != snes->jacobian_pre) {
2664: jacobian = snes->jacobian_pre;
2665: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2666: } else jacobian = NULL;
2667: }
2668: PetscCall(VecDestroy(&x));
2669: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2670: if (mviewer) PetscCall(PetscViewerDestroy(&mviewer));
2671: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2672: PetscFunctionReturn(PETSC_SUCCESS);
2673: }
2675: /*@
2676: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2678: Collective
2680: Input Parameters:
2681: + snes - the `SNES` context
2682: - x - input vector
2684: Output Parameters:
2685: + A - Jacobian matrix
2686: - B - optional matrix for building the preconditioner
2688: Options Database Keys:
2689: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2690: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2691: . -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.
2692: . -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
2693: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2694: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2695: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2696: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2697: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2698: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2699: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2700: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2701: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2702: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2703: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2705: Level: developer
2707: Note:
2708: Most users should not need to explicitly call this routine, as it
2709: is used internally within the nonlinear solvers.
2711: Developer Note:
2712: 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
2713: for with the `SNESType` of test that has been removed.
2715: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
2716: @*/
2717: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2718: {
2719: PetscBool flag;
2720: DM dm;
2721: DMSNES sdm;
2722: KSP ksp;
2724: PetscFunctionBegin;
2727: PetscCheckSameComm(snes, 1, X, 2);
2728: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2729: PetscCall(SNESGetDM(snes, &dm));
2730: PetscCall(DMGetDMSNES(dm, &sdm));
2732: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix free */
2733: if (snes->lagjacobian == -2) {
2734: snes->lagjacobian = -1;
2736: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2737: } else if (snes->lagjacobian == -1) {
2738: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2739: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2740: if (flag) {
2741: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2742: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2743: }
2744: PetscFunctionReturn(PETSC_SUCCESS);
2745: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2746: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2747: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2748: if (flag) {
2749: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2750: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2751: }
2752: PetscFunctionReturn(PETSC_SUCCESS);
2753: }
2754: if (snes->npc && snes->npcside == PC_LEFT) {
2755: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2756: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2757: PetscFunctionReturn(PETSC_SUCCESS);
2758: }
2760: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2761: PetscCall(VecLockReadPush(X));
2762: {
2763: void *ctx;
2764: PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *);
2765: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2766: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2767: }
2768: PetscCall(VecLockReadPop(X));
2769: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
2771: /* attach latest linearization point to the preconditioning matrix */
2772: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
2774: /* the next line ensures that snes->ksp exists */
2775: PetscCall(SNESGetKSP(snes, &ksp));
2776: if (snes->lagpreconditioner == -2) {
2777: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
2778: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2779: snes->lagpreconditioner = -1;
2780: } else if (snes->lagpreconditioner == -1) {
2781: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
2782: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2783: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2784: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
2785: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2786: } else {
2787: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
2788: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2789: }
2791: PetscCall(SNESTestJacobian(snes));
2792: /* make sure user returned a correct Jacobian and preconditioner */
2795: {
2796: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
2797: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
2798: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
2799: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
2800: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
2801: if (flag || flag_draw || flag_contour) {
2802: Mat Bexp_mine = NULL, Bexp, FDexp;
2803: PetscViewer vdraw, vstdout;
2804: PetscBool flg;
2805: if (flag_operator) {
2806: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
2807: Bexp = Bexp_mine;
2808: } else {
2809: /* See if the preconditioning matrix can be viewed and added directly */
2810: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPIBAIJ, ""));
2811: if (flg) Bexp = B;
2812: else {
2813: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2814: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
2815: Bexp = Bexp_mine;
2816: }
2817: }
2818: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
2819: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
2820: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2821: if (flag_draw || flag_contour) {
2822: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2823: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2824: } else vdraw = NULL;
2825: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
2826: if (flag) PetscCall(MatView(Bexp, vstdout));
2827: if (vdraw) PetscCall(MatView(Bexp, vdraw));
2828: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
2829: if (flag) PetscCall(MatView(FDexp, vstdout));
2830: if (vdraw) PetscCall(MatView(FDexp, vdraw));
2831: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
2832: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
2833: if (flag) PetscCall(MatView(FDexp, vstdout));
2834: if (vdraw) { /* Always use contour for the difference */
2835: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2836: PetscCall(MatView(FDexp, vdraw));
2837: PetscCall(PetscViewerPopFormat(vdraw));
2838: }
2839: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2840: PetscCall(PetscViewerDestroy(&vdraw));
2841: PetscCall(MatDestroy(&Bexp_mine));
2842: PetscCall(MatDestroy(&FDexp));
2843: }
2844: }
2845: {
2846: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
2847: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
2848: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
2849: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
2850: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
2851: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
2852: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
2853: if (flag_threshold) {
2854: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
2855: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
2856: }
2857: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2858: Mat Bfd;
2859: PetscViewer vdraw, vstdout;
2860: MatColoring coloring;
2861: ISColoring iscoloring;
2862: MatFDColoring matfdcoloring;
2863: PetscErrorCode (*func)(SNES, Vec, Vec, void *);
2864: void *funcctx;
2865: PetscReal norm1, norm2, normmax;
2867: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
2868: PetscCall(MatColoringCreate(Bfd, &coloring));
2869: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
2870: PetscCall(MatColoringSetFromOptions(coloring));
2871: PetscCall(MatColoringApply(coloring, &iscoloring));
2872: PetscCall(MatColoringDestroy(&coloring));
2873: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
2874: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2875: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
2876: PetscCall(ISColoringDestroy(&iscoloring));
2878: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2879: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
2880: PetscCall(MatFDColoringSetFunction(matfdcoloring, (PetscErrorCode(*)(void))func, funcctx));
2881: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
2882: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
2883: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2884: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
2885: PetscCall(MatFDColoringDestroy(&matfdcoloring));
2887: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2888: if (flag_draw || flag_contour) {
2889: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2890: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2891: } else vdraw = NULL;
2892: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
2893: if (flag_display) PetscCall(MatView(B, vstdout));
2894: if (vdraw) PetscCall(MatView(B, vdraw));
2895: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
2896: if (flag_display) PetscCall(MatView(Bfd, vstdout));
2897: if (vdraw) PetscCall(MatView(Bfd, vdraw));
2898: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
2899: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
2900: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
2901: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
2902: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
2903: if (flag_display) PetscCall(MatView(Bfd, vstdout));
2904: if (vdraw) { /* Always use contour for the difference */
2905: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2906: PetscCall(MatView(Bfd, vdraw));
2907: PetscCall(PetscViewerPopFormat(vdraw));
2908: }
2909: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2911: if (flag_threshold) {
2912: PetscInt bs, rstart, rend, i;
2913: PetscCall(MatGetBlockSize(B, &bs));
2914: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
2915: for (i = rstart; i < rend; i++) {
2916: const PetscScalar *ba, *ca;
2917: const PetscInt *bj, *cj;
2918: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
2919: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
2920: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
2921: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
2922: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2923: for (j = 0; j < bn; j++) {
2924: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
2925: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2926: maxentrycol = bj[j];
2927: maxentry = PetscRealPart(ba[j]);
2928: }
2929: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2930: maxdiffcol = bj[j];
2931: maxdiff = PetscRealPart(ca[j]);
2932: }
2933: if (rdiff > maxrdiff) {
2934: maxrdiffcol = bj[j];
2935: maxrdiff = rdiff;
2936: }
2937: }
2938: if (maxrdiff > 1) {
2939: 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));
2940: for (j = 0; j < bn; j++) {
2941: PetscReal rdiff;
2942: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
2943: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
2944: }
2945: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
2946: }
2947: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
2948: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
2949: }
2950: }
2951: PetscCall(PetscViewerDestroy(&vdraw));
2952: PetscCall(MatDestroy(&Bfd));
2953: }
2954: }
2955: PetscFunctionReturn(PETSC_SUCCESS);
2956: }
2958: /*MC
2959: SNESJacobianFunction - Function used by `SNES` to compute the nonlinear Jacobian of the function to be solved by `SNES`
2961: Synopsis:
2962: #include "petscsnes.h"
2963: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2965: Collective
2967: Input Parameters:
2968: + x - input vector, the Jacobian is to be computed at this value
2969: - ctx - [optional] user-defined Jacobian context
2971: Output Parameters:
2972: + Amat - the matrix that defines the (approximate) Jacobian
2973: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
2975: Level: intermediate
2977: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESSetJacobian()`, `SNESGetJacobian()`
2978: M*/
2980: /*@C
2981: SNESSetJacobian - Sets the function to compute Jacobian as well as the
2982: location to store the matrix.
2984: Logically Collective
2986: Input Parameters:
2987: + snes - the `SNES` context
2988: . Amat - the matrix that defines the (approximate) Jacobian
2989: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
2990: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFunction` for details
2991: - ctx - [optional] user-defined context for private data for the
2992: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
2994: Level: beginner
2996: Notes:
2997: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
2998: each matrix.
3000: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3001: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3003: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3004: must be a `MatFDColoring`.
3006: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3007: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3009: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3010: `SNESSetPicard()`, `SNESJacobianFunction`
3011: @*/
3012: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *), void *ctx)
3013: {
3014: DM dm;
3016: PetscFunctionBegin;
3020: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3021: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3022: PetscCall(SNESGetDM(snes, &dm));
3023: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3024: if (Amat) {
3025: PetscCall(PetscObjectReference((PetscObject)Amat));
3026: PetscCall(MatDestroy(&snes->jacobian));
3028: snes->jacobian = Amat;
3029: }
3030: if (Pmat) {
3031: PetscCall(PetscObjectReference((PetscObject)Pmat));
3032: PetscCall(MatDestroy(&snes->jacobian_pre));
3034: snes->jacobian_pre = Pmat;
3035: }
3036: PetscFunctionReturn(PETSC_SUCCESS);
3037: }
3039: /*@C
3040: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3041: provided context for evaluating the Jacobian.
3043: Not Collective, but `Mat` object will be parallel if `SNES` object is
3045: Input Parameter:
3046: . snes - the nonlinear solver context
3048: Output Parameters:
3049: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3050: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3051: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFunction`
3052: - ctx - location to stash Jacobian ctx (or `NULL`)
3054: Level: advanced
3056: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFunction`, `SNESGetFunction()`
3057: @*/
3058: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, PetscErrorCode (**J)(SNES, Vec, Mat, Mat, void *), void **ctx)
3059: {
3060: DM dm;
3062: PetscFunctionBegin;
3064: if (Amat) *Amat = snes->jacobian;
3065: if (Pmat) *Pmat = snes->jacobian_pre;
3066: PetscCall(SNESGetDM(snes, &dm));
3067: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3068: PetscFunctionReturn(PETSC_SUCCESS);
3069: }
3071: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3072: {
3073: DM dm;
3074: DMSNES sdm;
3076: PetscFunctionBegin;
3077: PetscCall(SNESGetDM(snes, &dm));
3078: PetscCall(DMGetDMSNES(dm, &sdm));
3079: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3080: DM dm;
3081: PetscBool isdense, ismf;
3083: PetscCall(SNESGetDM(snes, &dm));
3084: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3085: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3086: if (isdense) {
3087: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3088: } else if (!ismf) {
3089: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3090: }
3091: }
3092: PetscFunctionReturn(PETSC_SUCCESS);
3093: }
3095: /*@
3096: SNESSetUp - Sets up the internal data structures for the later use
3097: of a nonlinear solver.
3099: Collective
3101: Input Parameter:
3102: . snes - the `SNES` context
3104: Level: advanced
3106: Note:
3107: For basic use of the `SNES` solvers the user need not explicitly call
3108: `SNESSetUp()`, since these actions will automatically occur during
3109: the call to `SNESSolve()`. However, if one wishes to control this
3110: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3111: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3113: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`
3114: @*/
3115: PetscErrorCode SNESSetUp(SNES snes)
3116: {
3117: DM dm;
3118: DMSNES sdm;
3119: SNESLineSearch linesearch, pclinesearch;
3120: void *lsprectx, *lspostctx;
3121: PetscBool mf_operator, mf;
3122: Vec f, fpc;
3123: void *funcctx;
3124: void *jacctx, *appctx;
3125: Mat j, jpre;
3126: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3127: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3128: PetscErrorCode (*func)(SNES, Vec, Vec, void *);
3129: PetscErrorCode (*jac)(SNES, Vec, Mat, Mat, void *);
3131: PetscFunctionBegin;
3133: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3134: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3136: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3138: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3140: PetscCall(SNESGetDM(snes, &dm));
3141: PetscCall(DMGetDMSNES(dm, &sdm));
3142: PetscCall(SNESSetDefaultComputeJacobian(snes));
3144: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3146: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3148: if (snes->linesearch) {
3149: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3150: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3151: }
3153: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3154: if (snes->npc && snes->npcside == PC_LEFT) {
3155: snes->mf = PETSC_TRUE;
3156: snes->mf_operator = PETSC_FALSE;
3157: }
3159: if (snes->npc) {
3160: /* copy the DM over */
3161: PetscCall(SNESGetDM(snes, &dm));
3162: PetscCall(SNESSetDM(snes->npc, dm));
3164: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3165: PetscCall(VecDuplicate(f, &fpc));
3166: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3167: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3168: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3169: PetscCall(SNESGetApplicationContext(snes, &appctx));
3170: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3171: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3172: PetscCall(VecDestroy(&fpc));
3174: /* copy the function pointers over */
3175: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3177: /* default to 1 iteration */
3178: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3179: if (snes->npcside == PC_RIGHT) {
3180: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3181: } else {
3182: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3183: }
3184: PetscCall(SNESSetFromOptions(snes->npc));
3186: /* copy the line search context over */
3187: if (snes->linesearch && snes->npc->linesearch) {
3188: PetscCall(SNESGetLineSearch(snes, &linesearch));
3189: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3190: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3191: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3192: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3193: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3194: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3195: }
3196: }
3197: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3198: if (snes->ops->usercompute && !snes->user) PetscCall((*snes->ops->usercompute)(snes, (void **)&snes->user));
3200: snes->jac_iter = 0;
3201: snes->pre_iter = 0;
3203: PetscTryTypeMethod(snes, setup);
3205: PetscCall(SNESSetDefaultComputeJacobian(snes));
3207: if (snes->npc && snes->npcside == PC_LEFT) {
3208: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3209: if (snes->linesearch) {
3210: PetscCall(SNESGetLineSearch(snes, &linesearch));
3211: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3212: }
3213: }
3214: }
3215: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3216: snes->setupcalled = PETSC_TRUE;
3217: PetscFunctionReturn(PETSC_SUCCESS);
3218: }
3220: /*@
3221: SNESReset - Resets a `SNES` context to the snessetupcalled = 0 state and removes any allocated `Vec`s and `Mat`s
3223: Collective
3225: Input Parameter:
3226: . snes - iterative context obtained from `SNESCreate()`
3228: Level: intermediate
3230: Notes:
3231: Call this if you wish to reuse a `SNES` but with different size vectors
3233: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3235: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3236: @*/
3237: PetscErrorCode SNESReset(SNES snes)
3238: {
3239: PetscFunctionBegin;
3241: if (snes->ops->userdestroy && snes->user) {
3242: PetscCall((*snes->ops->userdestroy)((void **)&snes->user));
3243: snes->user = NULL;
3244: }
3245: if (snes->npc) PetscCall(SNESReset(snes->npc));
3247: PetscTryTypeMethod(snes, reset);
3248: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3250: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3252: PetscCall(VecDestroy(&snes->vec_rhs));
3253: PetscCall(VecDestroy(&snes->vec_sol));
3254: PetscCall(VecDestroy(&snes->vec_sol_update));
3255: PetscCall(VecDestroy(&snes->vec_func));
3256: PetscCall(MatDestroy(&snes->jacobian));
3257: PetscCall(MatDestroy(&snes->jacobian_pre));
3258: PetscCall(MatDestroy(&snes->picard));
3259: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3260: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3262: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3264: snes->nwork = snes->nvwork = 0;
3265: snes->setupcalled = PETSC_FALSE;
3266: PetscFunctionReturn(PETSC_SUCCESS);
3267: }
3269: /*@
3270: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object.
3272: Collective
3274: Input Parameter:
3275: . snes - iterative context obtained from `SNESCreate()`
3277: Level: intermediate
3279: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`
3280: @*/
3281: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3282: {
3283: PetscInt i;
3285: PetscFunctionBegin;
3287: for (i = 0; i < snes->numberreasonviews; i++) {
3288: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3289: }
3290: snes->numberreasonviews = 0;
3291: PetscFunctionReturn(PETSC_SUCCESS);
3292: }
3294: /*@C
3295: SNESDestroy - Destroys the nonlinear solver context that was created
3296: with `SNESCreate()`.
3298: Collective
3300: Input Parameter:
3301: . snes - the `SNES` context
3303: Level: beginner
3305: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3306: @*/
3307: PetscErrorCode SNESDestroy(SNES *snes)
3308: {
3309: PetscFunctionBegin;
3310: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3312: if (--((PetscObject)(*snes))->refct > 0) {
3313: *snes = NULL;
3314: PetscFunctionReturn(PETSC_SUCCESS);
3315: }
3317: PetscCall(SNESReset((*snes)));
3318: PetscCall(SNESDestroy(&(*snes)->npc));
3320: /* if memory was published with SAWs then destroy it */
3321: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3322: PetscTryTypeMethod((*snes), destroy);
3324: if ((*snes)->dm) PetscCall(DMCoarsenHookRemove((*snes)->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3325: PetscCall(DMDestroy(&(*snes)->dm));
3326: PetscCall(KSPDestroy(&(*snes)->ksp));
3327: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3329: PetscCall(PetscFree((*snes)->kspconvctx));
3330: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)((*snes)->cnvP));
3331: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3332: PetscCall(SNESMonitorCancel((*snes)));
3333: PetscCall(SNESConvergedReasonViewCancel((*snes)));
3334: PetscCall(PetscHeaderDestroy(snes));
3335: PetscFunctionReturn(PETSC_SUCCESS);
3336: }
3338: /* ----------- Routines to set solver parameters ---------- */
3340: /*@
3341: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3343: Logically Collective
3345: Input Parameters:
3346: + snes - the `SNES` context
3347: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3348: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3350: Options Database Keys:
3351: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3352: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3353: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3354: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3356: Notes:
3357: Level: intermediate
3359: The default is 1
3360: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3362: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3364: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3365: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3366: @*/
3367: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3368: {
3369: PetscFunctionBegin;
3371: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3372: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3374: snes->lagpreconditioner = lag;
3375: PetscFunctionReturn(PETSC_SUCCESS);
3376: }
3378: /*@
3379: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3381: Logically Collective
3383: Input Parameters:
3384: + snes - the `SNES` context
3385: - steps - the number of refinements to do, defaults to 0
3387: Options Database Key:
3388: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3390: Level: intermediate
3392: Note:
3393: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3395: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`
3396: @*/
3397: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3398: {
3399: PetscFunctionBegin;
3402: snes->gridsequence = steps;
3403: PetscFunctionReturn(PETSC_SUCCESS);
3404: }
3406: /*@
3407: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3409: Logically Collective
3411: Input Parameter:
3412: . snes - the `SNES` context
3414: Output Parameter:
3415: . steps - the number of refinements to do, defaults to 0
3417: Options Database Key:
3418: . -snes_grid_sequence <steps> - set number of refinements
3420: Level: intermediate
3422: Note:
3423: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3425: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3426: @*/
3427: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3428: {
3429: PetscFunctionBegin;
3431: *steps = snes->gridsequence;
3432: PetscFunctionReturn(PETSC_SUCCESS);
3433: }
3435: /*@
3436: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3438: Not Collective
3440: Input Parameter:
3441: . snes - the `SNES` context
3443: Output Parameter:
3444: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3445: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3447: Options Database Keys:
3448: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3449: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3450: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3451: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3453: Level: intermediate
3455: Notes:
3456: The default is 1
3458: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3460: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3461: @*/
3462: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3463: {
3464: PetscFunctionBegin;
3466: *lag = snes->lagpreconditioner;
3467: PetscFunctionReturn(PETSC_SUCCESS);
3468: }
3470: /*@
3471: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3472: often the preconditioner is rebuilt.
3474: Logically Collective
3476: Input Parameters:
3477: + snes - the `SNES` context
3478: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3479: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3481: Options Database Keys:
3482: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3483: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3484: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3485: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3487: Level: intermediate
3489: Notes:
3490: The default is 1
3492: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3494: 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
3495: at the next Newton step but never again (unless it is reset to another value)
3497: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3498: @*/
3499: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3500: {
3501: PetscFunctionBegin;
3503: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3504: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3506: snes->lagjacobian = lag;
3507: PetscFunctionReturn(PETSC_SUCCESS);
3508: }
3510: /*@
3511: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3513: Not Collective
3515: Input Parameter:
3516: . snes - the `SNES` context
3518: Output Parameter:
3519: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3520: the Jacobian is built etc.
3522: Level: intermediate
3524: Notes:
3525: The default is 1
3527: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3529: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3531: @*/
3532: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3533: {
3534: PetscFunctionBegin;
3536: *lag = snes->lagjacobian;
3537: PetscFunctionReturn(PETSC_SUCCESS);
3538: }
3540: /*@
3541: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3543: Logically collective
3545: Input Parameters:
3546: + snes - the `SNES` context
3547: - flg - jacobian lagging persists if true
3549: Options Database Keys:
3550: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3551: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3552: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3553: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3555: Level: advanced
3557: Notes:
3558: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that.
3560: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3561: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3562: timesteps may present huge efficiency gains.
3564: .seealso: [](ch_snes), `SNES, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagJacobianPersists()`
3565: @*/
3566: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3567: {
3568: PetscFunctionBegin;
3571: snes->lagjac_persist = flg;
3572: PetscFunctionReturn(PETSC_SUCCESS);
3573: }
3575: /*@
3576: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3578: Logically Collective
3580: Input Parameters:
3581: + snes - the `SNES` context
3582: - flg - preconditioner lagging persists if true
3584: Options Database Keys:
3585: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3586: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3587: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3588: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3590: Level: developer
3592: Notes:
3593: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that.
3595: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3596: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3597: several timesteps may present huge efficiency gains.
3599: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3600: @*/
3601: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3602: {
3603: PetscFunctionBegin;
3606: snes->lagpre_persist = flg;
3607: PetscFunctionReturn(PETSC_SUCCESS);
3608: }
3610: /*@
3611: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3613: Logically Collective
3615: Input Parameters:
3616: + snes - the `SNES` context
3617: - force - `PETSC_TRUE` require at least one iteration
3619: Options Database Key:
3620: . -snes_force_iteration <force> - Sets forcing an iteration
3622: Level: intermediate
3624: Note:
3625: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3627: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3628: @*/
3629: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3630: {
3631: PetscFunctionBegin;
3633: snes->forceiteration = force;
3634: PetscFunctionReturn(PETSC_SUCCESS);
3635: }
3637: /*@
3638: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3640: Logically Collective
3642: Input Parameter:
3643: . snes - the `SNES` context
3645: Output Parameter:
3646: . force - `PETSC_TRUE` requires at least one iteration.
3648: Level: intermediate
3650: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3651: @*/
3652: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3653: {
3654: PetscFunctionBegin;
3656: *force = snes->forceiteration;
3657: PetscFunctionReturn(PETSC_SUCCESS);
3658: }
3660: /*@
3661: SNESSetTolerances - Sets `SNES` various parameters used in convergence tests.
3663: Logically Collective
3665: Input Parameters:
3666: + snes - the `SNES` context
3667: . abstol - absolute convergence tolerance
3668: . rtol - relative convergence tolerance
3669: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3670: . maxit - maximum number of iterations, default 50.
3671: - maxf - maximum number of function evaluations (-1 indicates no limit), default 1000
3673: Options Database Keys:
3674: + -snes_atol <abstol> - Sets abstol
3675: . -snes_rtol <rtol> - Sets rtol
3676: . -snes_stol <stol> - Sets stol
3677: . -snes_max_it <maxit> - Sets maxit
3678: - -snes_max_funcs <maxf> - Sets maxf
3680: Level: intermediate
3682: .seealso: [](ch_snes), `SNESolve()`, `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3683: @*/
3684: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3685: {
3686: PetscFunctionBegin;
3694: if (abstol != (PetscReal)PETSC_DEFAULT) {
3695: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3696: snes->abstol = abstol;
3697: }
3698: if (rtol != (PetscReal)PETSC_DEFAULT) {
3699: 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);
3700: snes->rtol = rtol;
3701: }
3702: if (stol != (PetscReal)PETSC_DEFAULT) {
3703: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3704: snes->stol = stol;
3705: }
3706: if (maxit != PETSC_DEFAULT) {
3707: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3708: snes->max_its = maxit;
3709: }
3710: if (maxf != PETSC_DEFAULT) {
3711: PetscCheck(maxf >= -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be -1 or nonnegative", maxf);
3712: snes->max_funcs = maxf;
3713: }
3714: snes->tolerancesset = PETSC_TRUE;
3715: PetscFunctionReturn(PETSC_SUCCESS);
3716: }
3718: /*@
3719: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3721: Logically Collective
3723: Input Parameters:
3724: + snes - the `SNES` context
3725: - divtol - the divergence tolerance. Use -1 to deactivate the test, default is 1e4
3727: Options Database Key:
3728: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3730: Level: intermediate
3732: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance`
3733: @*/
3734: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3735: {
3736: PetscFunctionBegin;
3740: if (divtol != (PetscReal)PETSC_DEFAULT) {
3741: snes->divtol = divtol;
3742: } else {
3743: snes->divtol = 1.0e4;
3744: }
3745: PetscFunctionReturn(PETSC_SUCCESS);
3746: }
3748: /*@
3749: SNESGetTolerances - Gets various parameters used in convergence tests.
3751: Not Collective
3753: Input Parameters:
3754: + snes - the `SNES` context
3755: . atol - absolute convergence tolerance
3756: . rtol - relative convergence tolerance
3757: . stol - convergence tolerance in terms of the norm
3758: of the change in the solution between steps
3759: . maxit - maximum number of iterations
3760: - maxf - maximum number of function evaluations
3762: Level: intermediate
3764: Note:
3765: The user can specify `NULL` for any parameter that is not needed.
3767: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
3768: @*/
3769: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
3770: {
3771: PetscFunctionBegin;
3773: if (atol) *atol = snes->abstol;
3774: if (rtol) *rtol = snes->rtol;
3775: if (stol) *stol = snes->stol;
3776: if (maxit) *maxit = snes->max_its;
3777: if (maxf) *maxf = snes->max_funcs;
3778: PetscFunctionReturn(PETSC_SUCCESS);
3779: }
3781: /*@
3782: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3784: Not Collective
3786: Input Parameters:
3787: + snes - the `SNES` context
3788: - divtol - divergence tolerance
3790: Level: intermediate
3792: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
3793: @*/
3794: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
3795: {
3796: PetscFunctionBegin;
3798: if (divtol) *divtol = snes->divtol;
3799: PetscFunctionReturn(PETSC_SUCCESS);
3800: }
3802: /*@
3803: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3805: Logically Collective
3807: Input Parameters:
3808: + snes - the `SNES` context
3809: - tol - tolerance
3811: Options Database Key:
3812: . -snes_tr_tol <tol> - Sets tol
3814: Level: intermediate
3816: .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`, `SNESSetTolerances()`
3817: @*/
3818: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes, PetscReal tol)
3819: {
3820: PetscFunctionBegin;
3823: snes->deltatol = tol;
3824: PetscFunctionReturn(PETSC_SUCCESS);
3825: }
3827: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
3829: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
3830: {
3831: PetscDrawLG lg;
3832: PetscReal x, y, per;
3833: PetscViewer v = (PetscViewer)monctx;
3834: static PetscReal prev; /* should be in the context */
3835: PetscDraw draw;
3837: PetscFunctionBegin;
3839: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
3840: if (!n) PetscCall(PetscDrawLGReset(lg));
3841: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3842: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
3843: x = (PetscReal)n;
3844: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3845: else y = -15.0;
3846: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3847: if (n < 20 || !(n % 5) || snes->reason) {
3848: PetscCall(PetscDrawLGDraw(lg));
3849: PetscCall(PetscDrawLGSave(lg));
3850: }
3852: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
3853: if (!n) PetscCall(PetscDrawLGReset(lg));
3854: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3855: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
3856: PetscCall(SNESMonitorRange_Private(snes, n, &per));
3857: x = (PetscReal)n;
3858: y = 100.0 * per;
3859: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3860: if (n < 20 || !(n % 5) || snes->reason) {
3861: PetscCall(PetscDrawLGDraw(lg));
3862: PetscCall(PetscDrawLGSave(lg));
3863: }
3865: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
3866: if (!n) {
3867: prev = rnorm;
3868: PetscCall(PetscDrawLGReset(lg));
3869: }
3870: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3871: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
3872: x = (PetscReal)n;
3873: y = (prev - rnorm) / prev;
3874: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3875: if (n < 20 || !(n % 5) || snes->reason) {
3876: PetscCall(PetscDrawLGDraw(lg));
3877: PetscCall(PetscDrawLGSave(lg));
3878: }
3880: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
3881: if (!n) PetscCall(PetscDrawLGReset(lg));
3882: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3883: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
3884: x = (PetscReal)n;
3885: y = (prev - rnorm) / (prev * per);
3886: if (n > 2) { /*skip initial crazy value */
3887: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3888: }
3889: if (n < 20 || !(n % 5) || snes->reason) {
3890: PetscCall(PetscDrawLGDraw(lg));
3891: PetscCall(PetscDrawLGSave(lg));
3892: }
3893: prev = rnorm;
3894: PetscFunctionReturn(PETSC_SUCCESS);
3895: }
3897: /*@
3898: SNESMonitor - runs the user provided monitor routines, if they exist
3900: Collective
3902: Input Parameters:
3903: + snes - nonlinear solver context obtained from `SNESCreate()`
3904: . iter - iteration number
3905: - rnorm - relative norm of the residual
3907: Level: developer
3909: Note:
3910: This routine is called by the `SNES` implementations.
3911: It does not typically need to be called by the user.
3913: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
3914: @*/
3915: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
3916: {
3917: PetscInt i, n = snes->numbermonitors;
3919: PetscFunctionBegin;
3920: PetscCall(VecLockReadPush(snes->vec_sol));
3921: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
3922: PetscCall(VecLockReadPop(snes->vec_sol));
3923: PetscFunctionReturn(PETSC_SUCCESS);
3924: }
3926: /* ------------ Routines to set performance monitoring options ----------- */
3928: /*MC
3929: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
3931: Synopsis:
3932: #include <petscsnes.h>
3933: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, void *mctx)
3935: Collective
3937: Input Parameters:
3938: + snes - the `SNES` context
3939: . its - iteration number
3940: . norm - 2-norm function value (may be estimated)
3941: - mctx - [optional] monitoring context
3943: Level: advanced
3945: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSet()`, `SNESMonitorGet()`
3946: M*/
3948: /*@C
3949: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3950: iteration of the nonlinear solver to display the iteration's
3951: progress.
3953: Logically Collective
3955: Input Parameters:
3956: + snes - the `SNES` context
3957: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
3958: . mctx - [optional] user-defined context for private data for the
3959: monitor routine (use `NULL` if no context is desired)
3960: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`)
3962: Options Database Keys:
3963: + -snes_monitor - sets `SNESMonitorDefault()`
3964: . -snes_monitor draw::draw_lg - sets line graph monitor,
3965: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
3966: the options database.
3968: Level: intermediate
3970: Note:
3971: Several different monitoring routines may be set by calling
3972: `SNESMonitorSet()` multiple times; all will be called in the
3973: order in which they were set.
3975: Fortran Note:
3976: Only a single monitor function can be set for each `SNES` object
3978: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`
3979: @*/
3980: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscErrorCode (*monitordestroy)(void **))
3981: {
3982: PetscInt i;
3983: PetscBool identical;
3985: PetscFunctionBegin;
3987: for (i = 0; i < snes->numbermonitors; i++) {
3988: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, mctx, monitordestroy, (PetscErrorCode(*)(void))snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
3989: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
3990: }
3991: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
3992: snes->monitor[snes->numbermonitors] = f;
3993: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
3994: snes->monitorcontext[snes->numbermonitors++] = (void *)mctx;
3995: PetscFunctionReturn(PETSC_SUCCESS);
3996: }
3998: /*@
3999: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4001: Logically Collective
4003: Input Parameter:
4004: . snes - the `SNES` context
4006: Options Database Key:
4007: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4008: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4009: set via the options database
4011: Level: intermediate
4013: Note:
4014: There is no way to clear one specific monitor from a `SNES` object.
4016: .seealso: [](ch_snes), `SNES`, `SNESMonitorGet()`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4017: @*/
4018: PetscErrorCode SNESMonitorCancel(SNES snes)
4019: {
4020: PetscInt i;
4022: PetscFunctionBegin;
4024: for (i = 0; i < snes->numbermonitors; i++) {
4025: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4026: }
4027: snes->numbermonitors = 0;
4028: PetscFunctionReturn(PETSC_SUCCESS);
4029: }
4031: /*MC
4032: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4034: Synopsis:
4035: #include <petscsnes.h>
4036: PetscErrorCode SNESConvergenceTest(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *cctx)
4038: Collective
4040: Input Parameters:
4041: + snes - the `SNES` context
4042: . it - current iteration (0 is the first and is before any Newton step)
4043: . xnorm - 2-norm of current iterate
4044: . gnorm - 2-norm of current step
4045: . f - 2-norm of function
4046: - cctx - [optional] convergence context
4048: Output Parameter:
4049: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4051: Level: intermediate
4053: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4054: M*/
4056: /*@C
4057: SNESSetConvergenceTest - Sets the function that is to be used
4058: to test for convergence of the nonlinear iterative solution.
4060: Logically Collective
4062: Input Parameters:
4063: + snes - the `SNES` context
4064: . `SNESConvergenceTestFunction` - routine to test for convergence
4065: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4066: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4068: Level: advanced
4070: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4071: @*/
4072: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscErrorCode (*destroy)(void *))
4073: {
4074: PetscFunctionBegin;
4076: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4077: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(snes->cnvP));
4078: snes->ops->converged = SNESConvergenceTestFunction;
4079: snes->ops->convergeddestroy = destroy;
4080: snes->cnvP = cctx;
4081: PetscFunctionReturn(PETSC_SUCCESS);
4082: }
4084: /*@
4085: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped.
4087: Not Collective
4089: Input Parameter:
4090: . snes - the `SNES` context
4092: Output Parameter:
4093: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4095: Options Database Key:
4096: . -snes_converged_reason - prints the reason to standard out
4098: Level: intermediate
4100: Note:
4101: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4103: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4104: @*/
4105: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4106: {
4107: PetscFunctionBegin;
4110: *reason = snes->reason;
4111: PetscFunctionReturn(PETSC_SUCCESS);
4112: }
4114: /*@C
4115: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4117: Not Collective
4119: Input Parameter:
4120: . snes - the `SNES` context
4122: Output Parameter:
4123: . strreason - a human readable string that describes `SNES` converged reason
4125: Level: beginner
4127: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4128: @*/
4129: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4130: {
4131: PetscFunctionBegin;
4134: *strreason = SNESConvergedReasons[snes->reason];
4135: PetscFunctionReturn(PETSC_SUCCESS);
4136: }
4138: /*@
4139: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4141: Not Collective
4143: Input Parameters:
4144: + snes - the `SNES` context
4145: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4146: manual pages for the individual convergence tests for complete lists
4148: Level: developer
4150: Developer Note:
4151: Called inside the various `SNESSolve()` implementations
4153: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4154: @*/
4155: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4156: {
4157: PetscFunctionBegin;
4159: snes->reason = reason;
4160: PetscFunctionReturn(PETSC_SUCCESS);
4161: }
4163: /*@
4164: SNESSetConvergenceHistory - Sets the array used to hold the convergence history.
4166: Logically Collective
4168: Input Parameters:
4169: + snes - iterative context obtained from `SNESCreate()`
4170: . a - array to hold history, this array will contain the function norms computed at each step
4171: . its - integer array holds the number of linear iterations for each solve.
4172: . na - size of a and its
4173: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4174: else it continues storing new values for new nonlinear solves after the old ones
4176: Level: intermediate
4178: Notes:
4179: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' `PETSC_DECIDE` or `PETSC_DEFAULT` then a
4180: default array of length 10000 is allocated.
4182: This routine is useful, e.g., when running a code for purposes
4183: of accurate performance monitoring, when no I/O should be done
4184: during the section of code that is being timed.
4186: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4187: @*/
4188: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4189: {
4190: PetscFunctionBegin;
4194: if (!a) {
4195: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4196: PetscCall(PetscCalloc2(na, &a, na, &its));
4197: snes->conv_hist_alloc = PETSC_TRUE;
4198: }
4199: snes->conv_hist = a;
4200: snes->conv_hist_its = its;
4201: snes->conv_hist_max = (size_t)na;
4202: snes->conv_hist_len = 0;
4203: snes->conv_hist_reset = reset;
4204: PetscFunctionReturn(PETSC_SUCCESS);
4205: }
4207: #if defined(PETSC_HAVE_MATLAB)
4208: #include <engine.h> /* MATLAB include file */
4209: #include <mex.h> /* MATLAB include file */
4211: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4212: {
4213: mxArray *mat;
4214: PetscInt i;
4215: PetscReal *ar;
4217: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4218: ar = (PetscReal *)mxGetData(mat);
4219: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4220: return mat;
4221: }
4222: #endif
4224: /*@C
4225: SNESGetConvergenceHistory - Gets the array used to hold the convergence history.
4227: Not Collective
4229: Input Parameter:
4230: . snes - iterative context obtained from `SNESCreate()`
4232: Output Parameters:
4233: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4234: . its - integer array holds the number of linear iterations (or
4235: negative if not converged) for each solve.
4236: - na - size of `a` and `its`
4238: Level: intermediate
4240: Note:
4241: This routine is useful, e.g., when running a code for purposes
4242: of accurate performance monitoring, when no I/O should be done
4243: during the section of code that is being timed.
4245: Fortran Note:
4246: The calling sequence for this routine in Fortran is
4247: .vb
4248: call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4249: .ve
4251: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4252: @*/
4253: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4254: {
4255: PetscFunctionBegin;
4257: if (a) *a = snes->conv_hist;
4258: if (its) *its = snes->conv_hist_its;
4259: if (na) *na = (PetscInt)snes->conv_hist_len;
4260: PetscFunctionReturn(PETSC_SUCCESS);
4261: }
4263: /*@C
4264: SNESSetUpdate - Sets the general-purpose update function called
4265: at the beginning of every iteration of the nonlinear solve. Specifically
4266: it is called just before the Jacobian is "evaluated".
4268: Logically Collective
4270: Input Parameters:
4271: + snes - The nonlinear solver context
4272: - func - The function
4274: Calling sequence of `func`:
4275: $ PetscErrorCode func(SNES snes, PetscInt step);
4276: + snes - the nonlinear solver context
4277: - step - The current step of the iteration
4279: Level: advanced
4281: Note:
4282: 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
4283: to `SNESSetFunction()`, or `SNESSetPicard()`
4284: This is not used by most users.
4286: There are a variety of function hooks one many set that are called at different stages of the nonlinear solution process, see the functions listed below.
4288: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESSolve()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4289: `SNESMonitorSet()`, `SNESSetDivergenceTest()`
4290: @*/
4291: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
4292: {
4293: PetscFunctionBegin;
4295: snes->ops->update = func;
4296: PetscFunctionReturn(PETSC_SUCCESS);
4297: }
4299: /*
4300: SNESScaleStep_Private - Scales a step so that its length is less than the
4301: positive parameter delta.
4303: Input Parameters:
4304: + snes - the `SNES` context
4305: . y - approximate solution of linear system
4306: . fnorm - 2-norm of current function
4307: - delta - trust region size
4309: Output Parameters:
4310: + gpnorm - predicted function norm at the new point, assuming local
4311: linearization. The value is zero if the step lies within the trust
4312: region, and exceeds zero otherwise.
4313: - ynorm - 2-norm of the step
4315: Level: developer
4317: Note:
4318: For non-trust region methods such as `SNESNEWTONLS`, the parameter delta
4319: is set to be the maximum allowable step size.
4320: */
4321: PetscErrorCode SNESScaleStep_Private(SNES snes, Vec y, PetscReal *fnorm, PetscReal *delta, PetscReal *gpnorm, PetscReal *ynorm)
4322: {
4323: PetscReal nrm;
4324: PetscScalar cnorm;
4326: PetscFunctionBegin;
4329: PetscCheckSameComm(snes, 1, y, 2);
4331: PetscCall(VecNorm(y, NORM_2, &nrm));
4332: if (nrm > *delta) {
4333: nrm = *delta / nrm;
4334: *gpnorm = (1.0 - nrm) * (*fnorm);
4335: cnorm = nrm;
4336: PetscCall(VecScale(y, cnorm));
4337: *ynorm = *delta;
4338: } else {
4339: *gpnorm = 0.0;
4340: *ynorm = nrm;
4341: }
4342: PetscFunctionReturn(PETSC_SUCCESS);
4343: }
4345: /*@C
4346: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4348: Collective
4350: Parameter:
4351: + snes - iterative context obtained from `SNESCreate()`
4352: - viewer - the viewer to display the reason
4354: Options Database Keys:
4355: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4356: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4358: Note:
4359: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4360: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4362: Level: beginner
4364: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4365: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4366: `SNESConvergedReasonViewFromOptions()`,
4367: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4368: @*/
4369: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4370: {
4371: PetscViewerFormat format;
4372: PetscBool isAscii;
4374: PetscFunctionBegin;
4375: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4376: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4377: if (isAscii) {
4378: PetscCall(PetscViewerGetFormat(viewer, &format));
4379: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
4380: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4381: DM dm;
4382: Vec u;
4383: PetscDS prob;
4384: PetscInt Nf, f;
4385: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4386: void **exactCtx;
4387: PetscReal error;
4389: PetscCall(SNESGetDM(snes, &dm));
4390: PetscCall(SNESGetSolution(snes, &u));
4391: PetscCall(DMGetDS(dm, &prob));
4392: PetscCall(PetscDSGetNumFields(prob, &Nf));
4393: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4394: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4395: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4396: PetscCall(PetscFree2(exactSol, exactCtx));
4397: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4398: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4399: }
4400: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4401: if (((PetscObject)snes)->prefix) {
4402: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4403: } else {
4404: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4405: }
4406: } else if (snes->reason <= 0) {
4407: if (((PetscObject)snes)->prefix) {
4408: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4409: } else {
4410: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4411: }
4412: }
4413: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
4414: }
4415: PetscFunctionReturn(PETSC_SUCCESS);
4416: }
4418: /*@C
4419: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4420: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4422: Logically Collective
4424: Input Parameters:
4425: + snes - the `SNES` context
4426: . f - the snes converged reason view function
4427: . vctx - [optional] user-defined context for private data for the
4428: snes converged reason view routine (use `NULL` if no context is desired)
4429: - reasonviewdestroy - [optional] routine that frees reasonview context (may be `NULL`)
4431: Options Database Keys:
4432: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4433: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have
4434: been hardwired into a code by
4435: calls to `SNESConvergedReasonViewSet()`, but
4436: does not cancel those set via
4437: the options database.
4439: Level: intermediate
4441: Note:
4442: Several different converged reason view routines may be set by calling
4443: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4444: order in which they were set.
4446: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`
4447: @*/
4448: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES, void *), void *vctx, PetscErrorCode (*reasonviewdestroy)(void **))
4449: {
4450: PetscInt i;
4451: PetscBool identical;
4453: PetscFunctionBegin;
4455: for (i = 0; i < snes->numberreasonviews; i++) {
4456: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, vctx, reasonviewdestroy, (PetscErrorCode(*)(void))snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4457: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4458: }
4459: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4460: snes->reasonview[snes->numberreasonviews] = f;
4461: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4462: snes->reasonviewcontext[snes->numberreasonviews++] = (void *)vctx;
4463: PetscFunctionReturn(PETSC_SUCCESS);
4464: }
4466: /*@
4467: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed.
4468: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4470: Collective
4472: Input Parameter:
4473: . snes - the `SNES` object
4475: Level: advanced
4477: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4478: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4479: @*/
4480: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4481: {
4482: PetscViewer viewer;
4483: PetscBool flg;
4484: static PetscBool incall = PETSC_FALSE;
4485: PetscViewerFormat format;
4486: PetscInt i;
4488: PetscFunctionBegin;
4489: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4490: incall = PETSC_TRUE;
4492: /* All user-provided viewers are called first, if they exist. */
4493: for (i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4495: /* Call PETSc default routine if users ask for it */
4496: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &viewer, &format, &flg));
4497: if (flg) {
4498: PetscCall(PetscViewerPushFormat(viewer, format));
4499: PetscCall(SNESConvergedReasonView(snes, viewer));
4500: PetscCall(PetscViewerPopFormat(viewer));
4501: PetscCall(PetscViewerDestroy(&viewer));
4502: }
4503: incall = PETSC_FALSE;
4504: PetscFunctionReturn(PETSC_SUCCESS);
4505: }
4507: /*@
4508: SNESSolve - Solves a nonlinear system F(x) = b.
4509: Call `SNESSolve()` after calling `SNESCreate()` and optional routines of the form `SNESSetXXX()`.
4511: Collective
4513: Input Parameters:
4514: + snes - the `SNES` context
4515: . b - the constant part of the equation F(x) = b, or `NULL` to use zero.
4516: - x - the solution vector.
4518: Level: beginner
4520: Note:
4521: The user should initialize the vector,x, with the initial guess
4522: for the nonlinear solve prior to calling `SNESSolve()`. In particular,
4523: to employ an initial guess of zero, the user should explicitly set
4524: this vector to zero by calling `VecSet()`.
4526: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4527: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4528: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`
4529: @*/
4530: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4531: {
4532: PetscBool flg;
4533: PetscInt grid;
4534: Vec xcreated = NULL;
4535: DM dm;
4537: PetscFunctionBegin;
4540: if (x) PetscCheckSameComm(snes, 1, x, 3);
4542: if (b) PetscCheckSameComm(snes, 1, b, 2);
4544: /* High level operations using the nonlinear solver */
4545: {
4546: PetscViewer viewer;
4547: PetscViewerFormat format;
4548: PetscInt num;
4549: PetscBool flg;
4550: static PetscBool incall = PETSC_FALSE;
4552: if (!incall) {
4553: /* Estimate the convergence rate of the discretization */
4554: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4555: if (flg) {
4556: PetscConvEst conv;
4557: DM dm;
4558: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4559: PetscInt Nf;
4561: incall = PETSC_TRUE;
4562: PetscCall(SNESGetDM(snes, &dm));
4563: PetscCall(DMGetNumFields(dm, &Nf));
4564: PetscCall(PetscCalloc1(Nf, &alpha));
4565: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4566: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4567: PetscCall(PetscConvEstSetFromOptions(conv));
4568: PetscCall(PetscConvEstSetUp(conv));
4569: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4570: PetscCall(PetscViewerPushFormat(viewer, format));
4571: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4572: PetscCall(PetscViewerPopFormat(viewer));
4573: PetscCall(PetscViewerDestroy(&viewer));
4574: PetscCall(PetscConvEstDestroy(&conv));
4575: PetscCall(PetscFree(alpha));
4576: incall = PETSC_FALSE;
4577: }
4578: /* Adaptively refine the initial grid */
4579: num = 1;
4580: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4581: if (flg) {
4582: DMAdaptor adaptor;
4584: incall = PETSC_TRUE;
4585: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4586: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4587: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4588: PetscCall(DMAdaptorSetFromOptions(adaptor));
4589: PetscCall(DMAdaptorSetUp(adaptor));
4590: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4591: PetscCall(DMAdaptorDestroy(&adaptor));
4592: incall = PETSC_FALSE;
4593: }
4594: /* Use grid sequencing to adapt */
4595: num = 0;
4596: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4597: if (num) {
4598: DMAdaptor adaptor;
4600: incall = PETSC_TRUE;
4601: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4602: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4603: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4604: PetscCall(DMAdaptorSetFromOptions(adaptor));
4605: PetscCall(DMAdaptorSetUp(adaptor));
4606: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4607: PetscCall(DMAdaptorDestroy(&adaptor));
4608: incall = PETSC_FALSE;
4609: }
4610: }
4611: }
4612: if (!x) x = snes->vec_sol;
4613: if (!x) {
4614: PetscCall(SNESGetDM(snes, &dm));
4615: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4616: x = xcreated;
4617: }
4618: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4620: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4621: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4622: /* set solution vector */
4623: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4624: PetscCall(VecDestroy(&snes->vec_sol));
4625: snes->vec_sol = x;
4626: PetscCall(SNESGetDM(snes, &dm));
4628: /* set affine vector if provided */
4629: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4630: PetscCall(VecDestroy(&snes->vec_rhs));
4631: snes->vec_rhs = b;
4633: 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");
4634: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4635: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right hand side vector");
4636: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4637: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4638: PetscCall(SNESSetUp(snes));
4640: if (!grid) {
4641: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4642: }
4644: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4645: if (snes->counters_reset) {
4646: snes->nfuncs = 0;
4647: snes->linear_its = 0;
4648: snes->numFailures = 0;
4649: }
4651: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4652: PetscUseTypeMethod(snes, solve);
4653: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4654: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver returned without setting converged reason");
4655: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4657: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4658: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4660: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4661: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4662: /* Call converged reason views. This may involve user-provided viewers as well */
4663: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4665: if (snes->errorifnotconverged) PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4666: if (snes->reason < 0) break;
4667: if (grid < snes->gridsequence) {
4668: DM fine;
4669: Vec xnew;
4670: Mat interp;
4672: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4673: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4674: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4675: PetscCall(DMCreateGlobalVector(fine, &xnew));
4676: PetscCall(MatInterpolate(interp, x, xnew));
4677: PetscCall(DMInterpolate(snes->dm, interp, fine));
4678: PetscCall(MatDestroy(&interp));
4679: x = xnew;
4681: PetscCall(SNESReset(snes));
4682: PetscCall(SNESSetDM(snes, fine));
4683: PetscCall(SNESResetFromOptions(snes));
4684: PetscCall(DMDestroy(&fine));
4685: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4686: }
4687: }
4688: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4689: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4690: PetscCall(DMMonitor(snes->dm));
4691: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4693: PetscCall(VecDestroy(&xcreated));
4694: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4695: PetscFunctionReturn(PETSC_SUCCESS);
4696: }
4698: /* --------- Internal routines for SNES Package --------- */
4700: /*@C
4701: SNESSetType - Sets the method for the nonlinear solver.
4703: Collective
4705: Input Parameters:
4706: + snes - the `SNES` context
4707: - type - a known method
4709: Options Database Key:
4710: . -snes_type <type> - Sets the method; use -help for a list
4711: of available methods (for instance, newtonls or newtontr)
4713: Level: intermediate
4715: Notes:
4716: See "petsc/include/petscsnes.h" for available methods (for instance)
4717: + `SNESNEWTONLS` - Newton's method with line search
4718: (systems of nonlinear equations)
4719: - `SNESNEWTONTR` - Newton's method with trust region
4720: (systems of nonlinear equations)
4722: Normally, it is best to use the `SNESSetFromOptions()` command and then
4723: set the `SNES` solver type from the options database rather than by using
4724: this routine. Using the options database provides the user with
4725: maximum flexibility in evaluating the many nonlinear solvers.
4726: The `SNESSetType()` routine is provided for those situations where it
4727: is necessary to set the nonlinear solver independently of the command
4728: line or options database. This might be the case, for example, when
4729: the choice of solver changes during the execution of the program,
4730: and the user's application is taking responsibility for choosing the
4731: appropriate method.
4733: Developer Note:
4734: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4735: the constructor in that list and calls it to create the specific object.
4737: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4738: @*/
4739: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4740: {
4741: PetscBool match;
4742: PetscErrorCode (*r)(SNES);
4744: PetscFunctionBegin;
4748: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4749: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4751: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4752: PetscCheck(r, PETSC_COMM_SELF, PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4753: /* Destroy the previous private SNES context */
4754: PetscTryTypeMethod(snes, destroy);
4755: /* Reinitialize function pointers in SNESOps structure */
4756: snes->ops->setup = NULL;
4757: snes->ops->solve = NULL;
4758: snes->ops->view = NULL;
4759: snes->ops->setfromoptions = NULL;
4760: snes->ops->destroy = NULL;
4762: /* It may happen the user has customized the line search before calling SNESSetType */
4763: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
4765: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4766: snes->setupcalled = PETSC_FALSE;
4768: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
4769: PetscCall((*r)(snes));
4770: PetscFunctionReturn(PETSC_SUCCESS);
4771: }
4773: /*@C
4774: SNESGetType - Gets the `SNES` method type and name (as a string).
4776: Not Collective
4778: Input Parameter:
4779: . snes - nonlinear solver context
4781: Output Parameter:
4782: . type - `SNES` method (a character string)
4784: Level: intermediate
4786: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
4787: @*/
4788: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
4789: {
4790: PetscFunctionBegin;
4793: *type = ((PetscObject)snes)->type_name;
4794: PetscFunctionReturn(PETSC_SUCCESS);
4795: }
4797: /*@
4798: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
4800: Logically Collective
4802: Input Parameters:
4803: + snes - the `SNES` context obtained from `SNESCreate()`
4804: - u - the solution vector
4806: Level: beginner
4808: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
4809: @*/
4810: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4811: {
4812: DM dm;
4814: PetscFunctionBegin;
4817: PetscCall(PetscObjectReference((PetscObject)u));
4818: PetscCall(VecDestroy(&snes->vec_sol));
4820: snes->vec_sol = u;
4822: PetscCall(SNESGetDM(snes, &dm));
4823: PetscCall(DMShellSetGlobalVector(dm, u));
4824: PetscFunctionReturn(PETSC_SUCCESS);
4825: }
4827: /*@
4828: SNESGetSolution - Returns the vector where the approximate solution is
4829: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
4831: Not Collective, but x is parallel if snes is parallel
4833: Input Parameter:
4834: . snes - the `SNES` context
4836: Output Parameter:
4837: . x - the solution
4839: Level: intermediate
4841: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
4842: @*/
4843: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
4844: {
4845: PetscFunctionBegin;
4848: *x = snes->vec_sol;
4849: PetscFunctionReturn(PETSC_SUCCESS);
4850: }
4852: /*@
4853: SNESGetSolutionUpdate - Returns the vector where the solution update is
4854: stored.
4856: Not Collective, but x is parallel if snes is parallel
4858: Input Parameter:
4859: . snes - the `SNES` context
4861: Output Parameter:
4862: . x - the solution update
4864: Level: advanced
4866: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
4867: @*/
4868: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
4869: {
4870: PetscFunctionBegin;
4873: *x = snes->vec_sol_update;
4874: PetscFunctionReturn(PETSC_SUCCESS);
4875: }
4877: /*@C
4878: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
4880: Not Collective, but r is parallel if snes is parallel. Collective if r is requested, but has not been created yet.
4882: Input Parameter:
4883: . snes - the `SNES` context
4885: Output Parameters:
4886: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
4887: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunction`
4888: - ctx - the function context (or `NULL` if you don't want it)
4890: Level: advanced
4892: Note:
4893: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
4895: .seealso: [](ch_snes), `SNES, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunction`
4896: @*/
4897: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, PetscErrorCode (**f)(SNES, Vec, Vec, void *), void **ctx)
4898: {
4899: DM dm;
4901: PetscFunctionBegin;
4903: if (r) {
4904: if (!snes->vec_func) {
4905: if (snes->vec_rhs) {
4906: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
4907: } else if (snes->vec_sol) {
4908: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
4909: } else if (snes->dm) {
4910: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
4911: }
4912: }
4913: *r = snes->vec_func;
4914: }
4915: PetscCall(SNESGetDM(snes, &dm));
4916: PetscCall(DMSNESGetFunction(dm, f, ctx));
4917: PetscFunctionReturn(PETSC_SUCCESS);
4918: }
4920: /*@C
4921: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
4923: Input Parameter:
4924: . snes - the `SNES` context
4926: Output Parameters:
4927: + f - the function (or `NULL`) see `SNESSetNGS()` for details
4928: - ctx - the function context (or `NULL`)
4930: Level: advanced
4932: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`
4933: @*/
4935: PetscErrorCode SNESGetNGS(SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void *), void **ctx)
4936: {
4937: DM dm;
4939: PetscFunctionBegin;
4941: PetscCall(SNESGetDM(snes, &dm));
4942: PetscCall(DMSNESGetNGS(dm, f, ctx));
4943: PetscFunctionReturn(PETSC_SUCCESS);
4944: }
4946: /*@C
4947: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4948: `SNES` options in the database.
4950: Logically Collective
4952: Input Parameters:
4953: + snes - the `SNES` context
4954: - prefix - the prefix to prepend to all option names
4956: Level: advanced
4958: Note:
4959: A hyphen (-) must NOT be given at the beginning of the prefix name.
4960: The first character of all runtime options is AUTOMATICALLY the hyphen.
4962: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
4963: @*/
4964: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
4965: {
4966: PetscFunctionBegin;
4968: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
4969: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
4970: if (snes->linesearch) {
4971: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
4972: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
4973: }
4974: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
4975: PetscFunctionReturn(PETSC_SUCCESS);
4976: }
4978: /*@C
4979: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4980: `SNES` options in the database.
4982: Logically Collective
4984: Input Parameters:
4985: + snes - the `SNES` context
4986: - prefix - the prefix to prepend to all option names
4988: Level: advanced
4990: Note:
4991: A hyphen (-) must NOT be given at the beginning of the prefix name.
4992: The first character of all runtime options is AUTOMATICALLY the hyphen.
4994: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
4995: @*/
4996: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
4997: {
4998: PetscFunctionBegin;
5000: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5001: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5002: if (snes->linesearch) {
5003: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5004: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5005: }
5006: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5007: PetscFunctionReturn(PETSC_SUCCESS);
5008: }
5010: /*@C
5011: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5012: `SNES` options in the database.
5014: Not Collective
5016: Input Parameter:
5017: . snes - the `SNES` context
5019: Output Parameter:
5020: . prefix - pointer to the prefix string used
5022: Level: advanced
5024: Fortran Note:
5025: The user should pass in a string 'prefix' of
5026: sufficient length to hold the prefix.
5028: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5029: @*/
5030: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5031: {
5032: PetscFunctionBegin;
5034: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5035: PetscFunctionReturn(PETSC_SUCCESS);
5036: }
5038: /*@C
5039: SNESRegister - Adds a method to the nonlinear solver package.
5041: Not Collective
5043: Input Parameters:
5044: + sname - name of a new user-defined solver
5045: - function - routine to create method context
5047: Level: advanced
5049: Note:
5050: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5052: Sample usage:
5053: .vb
5054: SNESRegister("my_solver", MySolverCreate);
5055: .ve
5057: Then, your solver can be chosen with the procedural interface via
5058: $ SNESSetType(snes, "my_solver")
5059: or at runtime via the option
5060: $ -snes_type my_solver
5062: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5063: @*/
5064: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5065: {
5066: PetscFunctionBegin;
5067: PetscCall(SNESInitializePackage());
5068: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5069: PetscFunctionReturn(PETSC_SUCCESS);
5070: }
5072: PetscErrorCode SNESTestLocalMin(SNES snes)
5073: {
5074: PetscInt N, i, j;
5075: Vec u, uh, fh;
5076: PetscScalar value;
5077: PetscReal norm;
5079: PetscFunctionBegin;
5080: PetscCall(SNESGetSolution(snes, &u));
5081: PetscCall(VecDuplicate(u, &uh));
5082: PetscCall(VecDuplicate(u, &fh));
5084: /* currently only works for sequential */
5085: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5086: PetscCall(VecGetSize(u, &N));
5087: for (i = 0; i < N; i++) {
5088: PetscCall(VecCopy(u, uh));
5089: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5090: for (j = -10; j < 11; j++) {
5091: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5092: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5093: PetscCall(SNESComputeFunction(snes, uh, fh));
5094: PetscCall(VecNorm(fh, NORM_2, &norm));
5095: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5096: value = -value;
5097: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5098: }
5099: }
5100: PetscCall(VecDestroy(&uh));
5101: PetscCall(VecDestroy(&fh));
5102: PetscFunctionReturn(PETSC_SUCCESS);
5103: }
5105: /*@
5106: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5107: computing relative tolerance for linear solvers within an inexact
5108: Newton method.
5110: Logically Collective
5112: Input Parameters:
5113: + snes - `SNES` context
5114: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5116: Options Database Keys:
5117: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5118: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5119: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5120: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5121: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5122: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5123: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5124: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5126: Level: advanced
5128: Note:
5129: The default is to use a constant relative tolerance for
5130: the inner linear solvers. Alternatively, one can use the
5131: Eisenstat-Walker method, where the relative convergence tolerance
5132: is reset at each Newton iteration according progress of the nonlinear
5133: solver.
5135: Reference:
5136: . - * S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5138: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5139: @*/
5140: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5141: {
5142: PetscFunctionBegin;
5145: snes->ksp_ewconv = flag;
5146: PetscFunctionReturn(PETSC_SUCCESS);
5147: }
5149: /*@
5150: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5151: for computing relative tolerance for linear solvers within an
5152: inexact Newton method.
5154: Not Collective
5156: Input Parameter:
5157: . snes - `SNES` context
5159: Output Parameter:
5160: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5162: Level: advanced
5164: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5165: @*/
5166: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5167: {
5168: PetscFunctionBegin;
5171: *flag = snes->ksp_ewconv;
5172: PetscFunctionReturn(PETSC_SUCCESS);
5173: }
5175: /*@
5176: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5177: convergence criteria for the linear solvers within an inexact
5178: Newton method.
5180: Logically Collective
5182: Input Parameters:
5183: + snes - `SNES` context
5184: . version - version 1, 2 (default is 2), 3 or 4
5185: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5186: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5187: . gamma - multiplicative factor for version 2 rtol computation
5188: (0 <= gamma2 <= 1)
5189: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5190: . alpha2 - power for safeguard
5191: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5193: Level: advanced
5195: Notes:
5196: Version 3 was contributed by Luis Chacon, June 2006.
5198: Use `PETSC_DEFAULT` to retain the default for any of the parameters.
5200: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5201: @*/
5202: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5203: {
5204: SNESKSPEW *kctx;
5206: PetscFunctionBegin;
5208: kctx = (SNESKSPEW *)snes->kspconvctx;
5209: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5218: if (version != PETSC_DEFAULT) kctx->version = version;
5219: if (rtol_0 != (PetscReal)PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5220: if (rtol_max != (PetscReal)PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5221: if (gamma != (PetscReal)PETSC_DEFAULT) kctx->gamma = gamma;
5222: if (alpha != (PetscReal)PETSC_DEFAULT) kctx->alpha = alpha;
5223: if (alpha2 != (PetscReal)PETSC_DEFAULT) kctx->alpha2 = alpha2;
5224: if (threshold != (PetscReal)PETSC_DEFAULT) kctx->threshold = threshold;
5226: 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);
5227: 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);
5228: 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);
5229: 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);
5230: 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);
5231: 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);
5232: PetscFunctionReturn(PETSC_SUCCESS);
5233: }
5235: /*@
5236: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5237: convergence criteria for the linear solvers within an inexact
5238: Newton method.
5240: Not Collective
5242: Input Parameter:
5243: . snes - `SNES` context
5245: Output Parameters:
5246: + version - version 1, 2 (default is 2), 3 or 4
5247: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5248: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5249: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5250: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5251: . alpha2 - power for safeguard
5252: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5254: Level: advanced
5256: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5257: @*/
5258: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5259: {
5260: SNESKSPEW *kctx;
5262: PetscFunctionBegin;
5264: kctx = (SNESKSPEW *)snes->kspconvctx;
5265: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5266: if (version) *version = kctx->version;
5267: if (rtol_0) *rtol_0 = kctx->rtol_0;
5268: if (rtol_max) *rtol_max = kctx->rtol_max;
5269: if (gamma) *gamma = kctx->gamma;
5270: if (alpha) *alpha = kctx->alpha;
5271: if (alpha2) *alpha2 = kctx->alpha2;
5272: if (threshold) *threshold = kctx->threshold;
5273: PetscFunctionReturn(PETSC_SUCCESS);
5274: }
5276: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5277: {
5278: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5279: PetscReal rtol = PETSC_DEFAULT, stol;
5281: PetscFunctionBegin;
5282: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5283: if (!snes->iter) {
5284: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5285: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5286: } else {
5287: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5288: if (kctx->version == 1) {
5289: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5290: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5291: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5292: } else if (kctx->version == 2) {
5293: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5294: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5295: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5296: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5297: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5298: /* safeguard: avoid sharp decrease of rtol */
5299: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5300: stol = PetscMax(rtol, stol);
5301: rtol = PetscMin(kctx->rtol_0, stol);
5302: /* safeguard: avoid oversolving */
5303: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5304: stol = PetscMax(rtol, stol);
5305: rtol = PetscMin(kctx->rtol_0, stol);
5306: } else /* if (kctx->version == 4) */ {
5307: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5308: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5309: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5310: PetscReal rk = ared / pred;
5311: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5312: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5313: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5314: else rtol = kctx->v4_m2 * kctx->rtol_last;
5316: 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) rtol = kctx->v4_m4 * kctx->rtol_last;
5317: kctx->rtol_last_2 = kctx->rtol_last;
5318: kctx->rk_last_2 = kctx->rk_last;
5319: kctx->rk_last = rk;
5320: }
5321: }
5322: /* safeguard: avoid rtol greater than rtol_max */
5323: rtol = PetscMin(rtol, kctx->rtol_max);
5324: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_DEFAULT, PETSC_DEFAULT, PETSC_DEFAULT));
5325: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5326: PetscFunctionReturn(PETSC_SUCCESS);
5327: }
5329: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, SNES snes)
5330: {
5331: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5332: PCSide pcside;
5333: Vec lres;
5335: PetscFunctionBegin;
5336: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5337: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5338: kctx->norm_last = snes->norm;
5339: if (kctx->version == 1 || kctx->version == 4) {
5340: PC pc;
5341: PetscBool getRes;
5343: PetscCall(KSPGetPC(ksp, &pc));
5344: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5345: if (!getRes) {
5346: KSPNormType normtype;
5348: PetscCall(KSPGetNormType(ksp, &normtype));
5349: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5350: }
5351: PetscCall(KSPGetPCSide(ksp, &pcside));
5352: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5353: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5354: } else {
5355: /* KSP residual is preconditioned residual */
5356: /* compute true linear residual norm */
5357: Mat J;
5358: PetscCall(KSPGetOperators(ksp, &J, NULL));
5359: PetscCall(VecDuplicate(b, &lres));
5360: PetscCall(MatMult(J, x, lres));
5361: PetscCall(VecAYPX(lres, -1.0, b));
5362: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5363: PetscCall(VecDestroy(&lres));
5364: }
5365: }
5366: PetscFunctionReturn(PETSC_SUCCESS);
5367: }
5369: /*@
5370: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5372: Not Collective, but if snes is parallel, then ksp is parallel
5374: Input Parameter:
5375: . snes - the `SNES` context
5377: Output Parameter:
5378: . ksp - the `KSP` context
5380: Level: beginner
5382: Notes:
5383: The user can then directly manipulate the `KSP` context to set various
5384: options, etc. Likewise, the user can then extract and manipulate the
5385: `PC` contexts as well.
5387: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function
5389: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5390: @*/
5391: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5392: {
5393: PetscFunctionBegin;
5397: if (!snes->ksp) {
5398: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5399: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5401: PetscCall(KSPSetPreSolve(snes->ksp, (PetscErrorCode(*)(KSP, Vec, Vec, void *))KSPPreSolve_SNESEW, snes));
5402: PetscCall(KSPSetPostSolve(snes->ksp, (PetscErrorCode(*)(KSP, Vec, Vec, void *))KSPPostSolve_SNESEW, snes));
5404: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5405: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5406: }
5407: *ksp = snes->ksp;
5408: PetscFunctionReturn(PETSC_SUCCESS);
5409: }
5411: #include <petsc/private/dmimpl.h>
5412: /*@
5413: SNESSetDM - Sets the `DM` that may be used by some nonlinear solvers or their underlying preconditioners
5415: Logically Collective
5417: Input Parameters:
5418: + snes - the nonlinear solver context
5419: - dm - the dm, cannot be `NULL`
5421: Level: intermediate
5423: Note:
5424: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5425: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5426: problems using the same function space.
5428: .seealso: [](ch_snes), `DM`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5429: @*/
5430: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5431: {
5432: KSP ksp;
5433: DMSNES sdm;
5435: PetscFunctionBegin;
5438: PetscCall(PetscObjectReference((PetscObject)dm));
5439: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5440: if (snes->dm->dmsnes && !dm->dmsnes) {
5441: PetscCall(DMCopyDMSNES(snes->dm, dm));
5442: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5443: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5444: }
5445: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5446: PetscCall(DMDestroy(&snes->dm));
5447: }
5448: snes->dm = dm;
5449: snes->dmAuto = PETSC_FALSE;
5451: PetscCall(SNESGetKSP(snes, &ksp));
5452: PetscCall(KSPSetDM(ksp, dm));
5453: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5454: if (snes->npc) {
5455: PetscCall(SNESSetDM(snes->npc, snes->dm));
5456: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5457: }
5458: PetscFunctionReturn(PETSC_SUCCESS);
5459: }
5461: /*@
5462: SNESGetDM - Gets the `DM` that may be used by some preconditioners
5464: Not Collective but dm obtained is parallel on snes
5466: Input Parameter:
5467: . snes - the preconditioner context
5469: Output Parameter:
5470: . dm - the dm
5472: Level: intermediate
5474: .seealso: [](ch_snes), `DM`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5475: @*/
5476: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5477: {
5478: PetscFunctionBegin;
5480: if (!snes->dm) {
5481: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5482: snes->dmAuto = PETSC_TRUE;
5483: }
5484: *dm = snes->dm;
5485: PetscFunctionReturn(PETSC_SUCCESS);
5486: }
5488: /*@
5489: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5491: Collective
5493: Input Parameters:
5494: + snes - iterative context obtained from `SNESCreate()`
5495: - npc - the preconditioner object
5497: Level: developer
5499: Notes:
5500: Use `SNESGetNPC()` to retrieve the preconditioner context (for example,
5501: to configure it using the API).
5503: Only some `SNESType` can use a nonlinear preconditioner
5505: .seealso: [](ch_snes), `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5506: @*/
5507: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5508: {
5509: PetscFunctionBegin;
5512: PetscCheckSameComm(snes, 1, npc, 2);
5513: PetscCall(PetscObjectReference((PetscObject)npc));
5514: PetscCall(SNESDestroy(&snes->npc));
5515: snes->npc = npc;
5516: PetscFunctionReturn(PETSC_SUCCESS);
5517: }
5519: /*@
5520: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5522: Not Collective; but any changes to the obtained the npc object must be applied collectively
5524: Input Parameter:
5525: . snes - iterative context obtained from `SNESCreate()`
5527: Output Parameter:
5528: . npc - preconditioner context
5530: Options Database Key:
5531: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5533: Level: developer
5535: Notes:
5536: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created.
5538: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5539: `SNES`
5541: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5542: @*/
5543: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5544: {
5545: const char *optionsprefix;
5547: PetscFunctionBegin;
5550: if (!snes->npc) {
5551: void *ctx;
5553: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5554: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5555: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5556: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5557: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5558: PetscCall(SNESGetApplicationContext(snes, &ctx));
5559: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5560: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5561: }
5562: *pc = snes->npc;
5563: PetscFunctionReturn(PETSC_SUCCESS);
5564: }
5566: /*@
5567: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5569: Not Collective
5571: Input Parameter:
5572: . snes - iterative context obtained from `SNESCreate()`
5574: Output Parameter:
5575: . has_npc - whether the `SNES` has an NPC or not
5577: Level: developer
5579: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5580: @*/
5581: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5582: {
5583: PetscFunctionBegin;
5585: *has_npc = (PetscBool)(snes->npc ? PETSC_TRUE : PETSC_FALSE);
5586: PetscFunctionReturn(PETSC_SUCCESS);
5587: }
5589: /*@
5590: SNESSetNPCSide - Sets the preconditioning side.
5592: Logically Collective
5594: Input Parameter:
5595: . snes - iterative context obtained from `SNESCreate()`
5597: Output Parameter:
5598: . side - the preconditioning side, where side is one of
5599: .vb
5600: PC_LEFT - left preconditioning
5601: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5602: .ve
5604: Options Database Key:
5605: . -snes_npc_side <right,left> - nonlinear preconditioner side
5607: Level: intermediate
5609: Note:
5610: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5612: .seealso: [](ch_snes), `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`
5613: @*/
5614: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5615: {
5616: PetscFunctionBegin;
5619: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5620: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5621: snes->npcside = side;
5622: PetscFunctionReturn(PETSC_SUCCESS);
5623: }
5625: /*@
5626: SNESGetNPCSide - Gets the preconditioning side.
5628: Not Collective
5630: Input Parameter:
5631: . snes - iterative context obtained from `SNESCreate()`
5633: Output Parameter:
5634: . side - the preconditioning side, where side is one of
5635: .vb
5636: `PC_LEFT` - left preconditioning
5637: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5638: .ve
5640: Level: intermediate
5642: .seealso: [](ch_snes), `SNES`, `SNESSetNPCSide()`, `KSPGetPCSide()`
5643: @*/
5644: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5645: {
5646: PetscFunctionBegin;
5649: *side = snes->npcside;
5650: PetscFunctionReturn(PETSC_SUCCESS);
5651: }
5653: /*@
5654: SNESSetLineSearch - Sets the linesearch on the `SNES` instance.
5656: Collective
5658: Input Parameters:
5659: + snes - iterative context obtained from `SNESCreate()`
5660: - linesearch - the linesearch object
5662: Level: developer
5664: Note:
5665: Use `SNESGetLineSearch()` to retrieve the preconditioner context (for example,
5666: to configure it using the API).
5668: .seealso: [](ch_snes), `SNESGetLineSearch()`
5669: @*/
5670: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5671: {
5672: PetscFunctionBegin;
5675: PetscCheckSameComm(snes, 1, linesearch, 2);
5676: PetscCall(PetscObjectReference((PetscObject)linesearch));
5677: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5679: snes->linesearch = linesearch;
5681: PetscFunctionReturn(PETSC_SUCCESS);
5682: }
5684: /*@
5685: SNESGetLineSearch - Returns the line search context set with `SNESSetLineSearch()`
5686: or creates a default line search instance associated with the `SNES` and returns it.
5688: Not Collective
5690: Input Parameter:
5691: . snes - iterative context obtained from `SNESCreate()`
5693: Output Parameter:
5694: . linesearch - linesearch context
5696: Level: beginner
5698: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`
5699: @*/
5700: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5701: {
5702: const char *optionsprefix;
5704: PetscFunctionBegin;
5707: if (!snes->linesearch) {
5708: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5709: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5710: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5711: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5712: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5713: }
5714: *linesearch = snes->linesearch;
5715: PetscFunctionReturn(PETSC_SUCCESS);
5716: }