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;
63: PetscAssertPointer(flag, 2);
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`, `SNESFAS`, `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`, `SNESFAS`, `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()`, `SNESFunctionFn`, `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()`, `SNESFunctionFn`, `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, it checks for the Jacobian domain error in the debug mode, and does 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()`, `SNESFunctionFn`, `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 `SNES` is 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 it is not checking Jacobian domain errors after each Jacobian evaluation
213: Level: advanced
215: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESSetCheckJacobianDomainError()`
216: @*/
217: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
218: {
219: PetscFunctionBegin;
221: PetscAssertPointer(flg, 2);
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;
245: PetscAssertPointer(domainerror, 2);
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;
269: PetscAssertPointer(domainerror, 2);
270: *domainerror = snes->jacobiandomainerror;
271: PetscFunctionReturn(PETSC_SUCCESS);
272: }
274: /*@
275: SNESLoad - Loads a `SNES` that has been stored in `PETSCVIEWERBINARY` with `SNESView()`.
277: Collective
279: Input Parameters:
280: + snes - 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 `SNESType` 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: /*@
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: /*@
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: SNESJacobianFn *cJ;
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: if (snes->max_funcs == PETSC_UNLIMITED) {
420: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=unlimited\n", snes->max_its));
421: } else {
422: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=%" PetscInt_FMT "\n", snes->max_its, snes->max_funcs));
423: }
424: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, solution=%g\n", (double)snes->rtol, (double)snes->abstol, (double)snes->stol));
425: if (snes->usesksp) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of linear solver iterations=%" PetscInt_FMT "\n", snes->linear_its));
426: PetscCall(PetscViewerASCIIPrintf(viewer, " total number of function evaluations=%" PetscInt_FMT "\n", snes->nfuncs));
427: PetscCall(SNESGetNormSchedule(snes, &normschedule));
428: if (normschedule > 0) PetscCall(PetscViewerASCIIPrintf(viewer, " norm schedule %s\n", SNESNormSchedules[normschedule]));
429: if (snes->gridsequence) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of grid sequence refinements=%" PetscInt_FMT "\n", snes->gridsequence));
430: if (snes->ksp_ewconv) {
431: kctx = (SNESKSPEW *)snes->kspconvctx;
432: if (kctx) {
433: PetscCall(PetscViewerASCIIPrintf(viewer, " Eisenstat-Walker computation of KSP relative tolerance (version %" PetscInt_FMT ")\n", kctx->version));
434: PetscCall(PetscViewerASCIIPrintf(viewer, " rtol_0=%g, rtol_max=%g, threshold=%g\n", (double)kctx->rtol_0, (double)kctx->rtol_max, (double)kctx->threshold));
435: PetscCall(PetscViewerASCIIPrintf(viewer, " gamma=%g, alpha=%g, alpha2=%g\n", (double)kctx->gamma, (double)kctx->alpha, (double)kctx->alpha2));
436: }
437: }
438: if (snes->lagpreconditioner == -1) {
439: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is never rebuilt\n"));
440: } else if (snes->lagpreconditioner > 1) {
441: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is rebuilt every %" PetscInt_FMT " new Jacobians\n", snes->lagpreconditioner));
442: }
443: if (snes->lagjacobian == -1) {
444: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is never rebuilt\n"));
445: } else if (snes->lagjacobian > 1) {
446: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is rebuilt every %" PetscInt_FMT " SNES iterations\n", snes->lagjacobian));
447: }
448: PetscCall(SNESGetDM(snes, &dm));
449: PetscCall(DMSNESGetJacobian(dm, &cJ, &ctx));
450: if (snes->mf_operator) {
451: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing\n"));
452: pre = "Preconditioning ";
453: }
454: if (cJ == SNESComputeJacobianDefault) {
455: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences one column at a time\n", pre));
456: } else if (cJ == SNESComputeJacobianDefaultColor) {
457: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences with coloring\n", pre));
458: /* it slightly breaks data encapsulation for access the DMDA information directly */
459: } else if (cJ == SNESComputeJacobian_DMDA) {
460: MatFDColoring fdcoloring;
461: PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
462: if (fdcoloring) {
463: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using colored finite differences on a DMDA\n", pre));
464: } else {
465: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using a DMDA local Jacobian\n", pre));
466: }
467: } else if (snes->mf && !snes->mf_operator) {
468: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing, no explicit Jacobian\n"));
469: }
470: } else if (isstring) {
471: const char *type;
472: PetscCall(SNESGetType(snes, &type));
473: PetscCall(PetscViewerStringSPrintf(viewer, " SNESType: %-7.7s", type));
474: PetscTryTypeMethod(snes, view, viewer);
475: } else if (isbinary) {
476: PetscInt classid = SNES_FILE_CLASSID;
477: MPI_Comm comm;
478: PetscMPIInt rank;
479: char type[256];
481: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
482: PetscCallMPI(MPI_Comm_rank(comm, &rank));
483: if (rank == 0) {
484: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
485: PetscCall(PetscStrncpy(type, ((PetscObject)snes)->type_name, sizeof(type)));
486: PetscCall(PetscViewerBinaryWrite(viewer, type, sizeof(type), PETSC_CHAR));
487: }
488: PetscTryTypeMethod(snes, view, viewer);
489: } else if (isdraw) {
490: PetscDraw draw;
491: char str[36];
492: PetscReal x, y, bottom, h;
494: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
495: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
496: PetscCall(PetscStrncpy(str, "SNES: ", sizeof(str)));
497: PetscCall(PetscStrlcat(str, ((PetscObject)snes)->type_name, sizeof(str)));
498: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_BLUE, PETSC_DRAW_BLACK, str, NULL, &h));
499: bottom = y - h;
500: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
501: PetscTryTypeMethod(snes, view, viewer);
502: #if defined(PETSC_HAVE_SAWS)
503: } else if (issaws) {
504: PetscMPIInt rank;
505: const char *name;
507: PetscCall(PetscObjectGetName((PetscObject)snes, &name));
508: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
509: if (!((PetscObject)snes)->amsmem && rank == 0) {
510: char dir[1024];
512: PetscCall(PetscObjectViewSAWs((PetscObject)snes, viewer));
513: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
514: PetscCallSAWs(SAWs_Register, (dir, &snes->iter, 1, SAWs_READ, SAWs_INT));
515: if (!snes->conv_hist) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, PETSC_DECIDE, PETSC_TRUE));
516: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/conv_hist", name));
517: PetscCallSAWs(SAWs_Register, (dir, snes->conv_hist, 10, SAWs_READ, SAWs_DOUBLE));
518: }
519: #endif
520: }
521: if (snes->linesearch) {
522: PetscCall(SNESGetLineSearch(snes, &linesearch));
523: PetscCall(PetscViewerASCIIPushTab(viewer));
524: PetscCall(SNESLineSearchView(linesearch, viewer));
525: PetscCall(PetscViewerASCIIPopTab(viewer));
526: }
527: if (snes->npc && snes->usesnpc) {
528: PetscCall(PetscViewerASCIIPushTab(viewer));
529: PetscCall(SNESView(snes->npc, viewer));
530: PetscCall(PetscViewerASCIIPopTab(viewer));
531: }
532: PetscCall(PetscViewerASCIIPushTab(viewer));
533: PetscCall(DMGetDMSNES(snes->dm, &dmsnes));
534: PetscCall(DMSNESView(dmsnes, viewer));
535: PetscCall(PetscViewerASCIIPopTab(viewer));
536: if (snes->usesksp) {
537: PetscCall(SNESGetKSP(snes, &ksp));
538: PetscCall(PetscViewerASCIIPushTab(viewer));
539: PetscCall(KSPView(ksp, viewer));
540: PetscCall(PetscViewerASCIIPopTab(viewer));
541: }
542: if (isdraw) {
543: PetscDraw draw;
544: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
545: PetscCall(PetscDrawPopCurrentPoint(draw));
546: }
547: PetscFunctionReturn(PETSC_SUCCESS);
548: }
550: /*
551: We retain a list of functions that also take SNES command
552: line options. These are called at the end SNESSetFromOptions()
553: */
554: #define MAXSETFROMOPTIONS 5
555: static PetscInt numberofsetfromoptions;
556: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
558: /*@C
559: SNESAddOptionsChecker - Adds an additional function to check for `SNES` options.
561: Not Collective
563: Input Parameter:
564: . snescheck - function that checks for options
566: Calling sequence of `snescheck`:
567: . snes - the `SNES` object for which it is checking options
569: Level: developer
571: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`
572: @*/
573: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES snes))
574: {
575: PetscFunctionBegin;
576: PetscCheck(numberofsetfromoptions < MAXSETFROMOPTIONS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %d allowed", MAXSETFROMOPTIONS);
577: othersetfromoptions[numberofsetfromoptions++] = snescheck;
578: PetscFunctionReturn(PETSC_SUCCESS);
579: }
581: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
582: {
583: Mat J;
584: MatNullSpace nullsp;
586: PetscFunctionBegin;
589: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
590: Mat A = snes->jacobian, B = snes->jacobian_pre;
591: PetscCall(MatCreateVecs(A ? A : B, NULL, &snes->vec_func));
592: }
594: PetscCheck(version == 1 || version == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator routines, only version 1 and 2");
595: if (version == 1) {
596: PetscCall(MatCreateSNESMF(snes, &J));
597: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
598: PetscCall(MatSetFromOptions(J));
599: /* TODO: the version 2 code should be merged into the MatCreateSNESMF() and MatCreateMFFD() infrastructure and then removed */
600: } else /* if (version == 2) */ {
601: PetscCheck(snes->vec_func, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "SNESSetFunction() must be called first");
602: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
603: PetscCall(MatCreateSNESMFMore(snes, snes->vec_func, &J));
604: #else
605: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "matrix-free operator routines (version 2)");
606: #endif
607: }
609: /* attach any user provided null space that was on Amat to the newly created matrix-free matrix */
610: if (snes->jacobian) {
611: PetscCall(MatGetNullSpace(snes->jacobian, &nullsp));
612: if (nullsp) PetscCall(MatSetNullSpace(J, nullsp));
613: }
615: PetscCall(PetscInfo(snes, "Setting default matrix-free operator routines (version %" PetscInt_FMT ")\n", version));
616: if (hasOperator) {
617: /* This version replaces the user provided Jacobian matrix with a
618: matrix-free version but still employs the user-provided preconditioner matrix. */
619: PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
620: } else {
621: /* This version replaces both the user-provided Jacobian and the user-
622: provided preconditioner Jacobian with the default matrix-free version. */
623: if (snes->npcside == PC_LEFT && snes->npc) {
624: if (!snes->jacobian) PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
625: } else {
626: KSP ksp;
627: PC pc;
628: PetscBool match;
630: PetscCall(SNESSetJacobian(snes, J, J, MatMFFDComputeJacobian, NULL));
631: /* Force no preconditioner */
632: PetscCall(SNESGetKSP(snes, &ksp));
633: PetscCall(KSPGetPC(ksp, &pc));
634: PetscCall(PetscObjectTypeCompareAny((PetscObject)pc, &match, PCSHELL, PCH2OPUS, ""));
635: if (!match) {
636: PetscCall(PetscInfo(snes, "Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n"));
637: PetscCall(PCSetType(pc, PCNONE));
638: }
639: }
640: }
641: PetscCall(MatDestroy(&J));
642: PetscFunctionReturn(PETSC_SUCCESS);
643: }
645: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine, Mat Restrict, Vec Rscale, Mat Inject, DM dmcoarse, void *ctx)
646: {
647: SNES snes = (SNES)ctx;
648: Vec Xfine, Xfine_named = NULL, Xcoarse;
650: PetscFunctionBegin;
651: if (PetscLogPrintInfo) {
652: PetscInt finelevel, coarselevel, fineclevel, coarseclevel;
653: PetscCall(DMGetRefineLevel(dmfine, &finelevel));
654: PetscCall(DMGetCoarsenLevel(dmfine, &fineclevel));
655: PetscCall(DMGetRefineLevel(dmcoarse, &coarselevel));
656: PetscCall(DMGetCoarsenLevel(dmcoarse, &coarseclevel));
657: PetscCall(PetscInfo(dmfine, "Restricting SNES solution vector from level %" PetscInt_FMT "-%" PetscInt_FMT " to level %" PetscInt_FMT "-%" PetscInt_FMT "\n", finelevel, fineclevel, coarselevel, coarseclevel));
658: }
659: if (dmfine == snes->dm) Xfine = snes->vec_sol;
660: else {
661: PetscCall(DMGetNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
662: Xfine = Xfine_named;
663: }
664: PetscCall(DMGetNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
665: if (Inject) {
666: PetscCall(MatRestrict(Inject, Xfine, Xcoarse));
667: } else {
668: PetscCall(MatRestrict(Restrict, Xfine, Xcoarse));
669: PetscCall(VecPointwiseMult(Xcoarse, Xcoarse, Rscale));
670: }
671: PetscCall(DMRestoreNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
672: if (Xfine_named) PetscCall(DMRestoreNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
673: PetscFunctionReturn(PETSC_SUCCESS);
674: }
676: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm, DM dmc, void *ctx)
677: {
678: PetscFunctionBegin;
679: PetscCall(DMCoarsenHookAdd(dmc, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, ctx));
680: PetscFunctionReturn(PETSC_SUCCESS);
681: }
683: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
684: * safely call SNESGetDM() in their residual evaluation routine. */
685: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp, Mat A, Mat B, void *ctx)
686: {
687: SNES snes = (SNES)ctx;
688: DMSNES sdm;
689: Vec X, Xnamed = NULL;
690: DM dmsave;
691: void *ctxsave;
692: SNESJacobianFn *jac = NULL;
694: PetscFunctionBegin;
695: dmsave = snes->dm;
696: PetscCall(KSPGetDM(ksp, &snes->dm));
697: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
698: else {
699: PetscBool has;
701: /* We are on a coarser level, this vec was initialized using a DM restrict hook */
702: PetscCall(DMHasNamedGlobalVector(snes->dm, "SNESVecSol", &has));
703: PetscCheck(has, PetscObjectComm((PetscObject)snes->dm), PETSC_ERR_PLIB, "Missing SNESVecSol");
704: PetscCall(DMGetNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
705: X = Xnamed;
706: PetscCall(SNESGetJacobian(snes, NULL, NULL, &jac, &ctxsave));
707: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
708: if (jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, SNESComputeJacobianDefaultColor, NULL));
709: }
711: /* Compute the operators */
712: PetscCall(DMGetDMSNES(snes->dm, &sdm));
713: if (Xnamed && sdm->ops->computefunction) {
714: /* The SNES contract with the user is that ComputeFunction is always called before ComputeJacobian.
715: We make sure of this here. Disable affine shift since it is for the finest level */
716: Vec F, saverhs = snes->vec_rhs;
718: snes->vec_rhs = NULL;
719: PetscCall(DMGetGlobalVector(snes->dm, &F));
720: PetscCall(SNESComputeFunction(snes, X, F));
721: PetscCall(DMRestoreGlobalVector(snes->dm, &F));
722: snes->vec_rhs = saverhs;
723: snes->nfuncs--; /* Do not log coarser level evaluations */
724: }
725: /* Make sure KSP DM has the Jacobian computation routine */
726: if (!sdm->ops->computejacobian) PetscCall(DMCopyDMSNES(dmsave, snes->dm));
727: PetscCall(SNESComputeJacobian(snes, X, A, B));
729: /* Put the previous context back */
730: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, jac, ctxsave));
732: if (Xnamed) PetscCall(DMRestoreNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
733: snes->dm = dmsave;
734: PetscFunctionReturn(PETSC_SUCCESS);
735: }
737: /*@
738: SNESSetUpMatrices - ensures that matrices are available for `SNES` Newton-like methods, this is called by `SNESSetUp_XXX()`
740: Collective
742: Input Parameter:
743: . snes - `SNES` object to configure
745: Level: developer
747: Note:
748: If the matrices do not yet exist it attempts to create them based on options previously set for the `SNES` such as `-snes_mf`
750: Developer Note:
751: The functionality of this routine overlaps in a confusing way with the functionality of `SNESSetUpMatrixFree_Private()` which is called by
752: `SNESSetUp()` but sometimes `SNESSetUpMatrices()` is called without `SNESSetUp()` being called. A refactorization to simplify the
753: logic that handles the matrix-free case is desirable.
755: .seealso: [](ch_snes), `SNES`, `SNESSetUp()`
756: @*/
757: PetscErrorCode SNESSetUpMatrices(SNES snes)
758: {
759: DM dm;
760: DMSNES sdm;
762: PetscFunctionBegin;
763: PetscCall(SNESGetDM(snes, &dm));
764: PetscCall(DMGetDMSNES(dm, &sdm));
765: if (!snes->jacobian && snes->mf && !snes->mf_operator && !snes->jacobian_pre) {
766: Mat J;
767: void *functx;
768: PetscCall(MatCreateSNESMF(snes, &J));
769: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
770: PetscCall(MatSetFromOptions(J));
771: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
772: PetscCall(SNESSetJacobian(snes, J, J, NULL, NULL));
773: PetscCall(MatDestroy(&J));
774: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
775: Mat J, B;
776: PetscCall(MatCreateSNESMF(snes, &J));
777: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
778: PetscCall(MatSetFromOptions(J));
779: PetscCall(DMCreateMatrix(snes->dm, &B));
780: /* sdm->computejacobian was already set to reach here */
781: PetscCall(SNESSetJacobian(snes, J, B, NULL, NULL));
782: PetscCall(MatDestroy(&J));
783: PetscCall(MatDestroy(&B));
784: } else if (!snes->jacobian_pre) {
785: PetscDS prob;
786: Mat J, B;
787: PetscBool hasPrec = PETSC_FALSE;
789: J = snes->jacobian;
790: PetscCall(DMGetDS(dm, &prob));
791: if (prob) PetscCall(PetscDSHasJacobianPreconditioner(prob, &hasPrec));
792: if (J) PetscCall(PetscObjectReference((PetscObject)J));
793: else if (hasPrec) PetscCall(DMCreateMatrix(snes->dm, &J));
794: PetscCall(DMCreateMatrix(snes->dm, &B));
795: PetscCall(SNESSetJacobian(snes, J ? J : B, B, NULL, NULL));
796: PetscCall(MatDestroy(&J));
797: PetscCall(MatDestroy(&B));
798: }
799: {
800: KSP ksp;
801: PetscCall(SNESGetKSP(snes, &ksp));
802: PetscCall(KSPSetComputeOperators(ksp, KSPComputeOperators_SNES, snes));
803: PetscCall(DMCoarsenHookAdd(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
804: }
805: PetscFunctionReturn(PETSC_SUCCESS);
806: }
808: static PetscErrorCode SNESMonitorPauseFinal_Internal(SNES snes)
809: {
810: PetscInt i;
812: PetscFunctionBegin;
813: if (!snes->pauseFinal) PetscFunctionReturn(PETSC_SUCCESS);
814: for (i = 0; i < snes->numbermonitors; ++i) {
815: PetscViewerAndFormat *vf = (PetscViewerAndFormat *)snes->monitorcontext[i];
816: PetscDraw draw;
817: PetscReal lpause;
819: if (!vf) continue;
820: if (vf->lg) {
821: if (!PetscCheckPointer(vf->lg, PETSC_OBJECT)) continue;
822: if (((PetscObject)vf->lg)->classid != PETSC_DRAWLG_CLASSID) continue;
823: PetscCall(PetscDrawLGGetDraw(vf->lg, &draw));
824: PetscCall(PetscDrawGetPause(draw, &lpause));
825: PetscCall(PetscDrawSetPause(draw, -1.0));
826: PetscCall(PetscDrawPause(draw));
827: PetscCall(PetscDrawSetPause(draw, lpause));
828: } else {
829: PetscBool isdraw;
831: if (!PetscCheckPointer(vf->viewer, PETSC_OBJECT)) continue;
832: if (((PetscObject)vf->viewer)->classid != PETSC_VIEWER_CLASSID) continue;
833: PetscCall(PetscObjectTypeCompare((PetscObject)vf->viewer, PETSCVIEWERDRAW, &isdraw));
834: if (!isdraw) continue;
835: PetscCall(PetscViewerDrawGetDraw(vf->viewer, 0, &draw));
836: PetscCall(PetscDrawGetPause(draw, &lpause));
837: PetscCall(PetscDrawSetPause(draw, -1.0));
838: PetscCall(PetscDrawPause(draw));
839: PetscCall(PetscDrawSetPause(draw, lpause));
840: }
841: }
842: PetscFunctionReturn(PETSC_SUCCESS);
843: }
845: /*@C
846: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
848: Collective
850: Input Parameters:
851: + snes - `SNES` object you wish to monitor
852: . name - the monitor type one is seeking
853: . help - message indicating what monitoring is done
854: . manual - manual page for the monitor
855: . monitor - the monitor function
856: - 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
858: Calling sequence of `monitor`:
859: + snes - the nonlinear solver context
860: . it - the current iteration
861: . r - the current function norm
862: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
864: Calling sequence of `monitorsetup`:
865: + snes - the nonlinear solver context
866: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
868: Options Database Key:
869: . -name - trigger the use of this monitor in `SNESSetFromOptions()`
871: Level: advanced
873: .seealso: [](ch_snes), `PetscOptionsCreateViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
874: `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`
875: `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
876: `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
877: `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
878: `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
879: `PetscOptionsFList()`, `PetscOptionsEList()`
880: @*/
881: PetscErrorCode SNESMonitorSetFromOptions(SNES snes, const char name[], const char help[], const char manual[], PetscErrorCode (*monitor)(SNES snes, PetscInt it, PetscReal r, PetscViewerAndFormat *vf), PetscErrorCode (*monitorsetup)(SNES snes, PetscViewerAndFormat *vf))
882: {
883: PetscViewer viewer;
884: PetscViewerFormat format;
885: PetscBool flg;
887: PetscFunctionBegin;
888: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, name, &viewer, &format, &flg));
889: if (flg) {
890: PetscViewerAndFormat *vf;
891: PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
892: PetscCall(PetscViewerDestroy(&viewer));
893: if (monitorsetup) PetscCall((*monitorsetup)(snes, vf));
894: PetscCall(SNESMonitorSet(snes, (PetscErrorCode(*)(SNES, PetscInt, PetscReal, void *))monitor, vf, (PetscErrorCode(*)(void **))PetscViewerAndFormatDestroy));
895: }
896: PetscFunctionReturn(PETSC_SUCCESS);
897: }
899: PetscErrorCode SNESEWSetFromOptions_Private(SNESKSPEW *kctx, PetscBool print_api, MPI_Comm comm, const char *prefix)
900: {
901: const char *api = print_api ? "SNESKSPSetParametersEW" : NULL;
903: PetscFunctionBegin;
904: PetscOptionsBegin(comm, prefix, "Eisenstat and Walker type forcing options", "KSP");
905: PetscCall(PetscOptionsInt("-ksp_ew_version", "Version 1, 2 or 3", api, kctx->version, &kctx->version, NULL));
906: PetscCall(PetscOptionsReal("-ksp_ew_rtol0", "0 <= rtol0 < 1", api, kctx->rtol_0, &kctx->rtol_0, NULL));
907: kctx->rtol_max = PetscMax(kctx->rtol_0, kctx->rtol_max);
908: PetscCall(PetscOptionsReal("-ksp_ew_rtolmax", "0 <= rtolmax < 1", api, kctx->rtol_max, &kctx->rtol_max, NULL));
909: PetscCall(PetscOptionsReal("-ksp_ew_gamma", "0 <= gamma <= 1", api, kctx->gamma, &kctx->gamma, NULL));
910: PetscCall(PetscOptionsReal("-ksp_ew_alpha", "1 < alpha <= 2", api, kctx->alpha, &kctx->alpha, NULL));
911: PetscCall(PetscOptionsReal("-ksp_ew_alpha2", "alpha2", NULL, kctx->alpha2, &kctx->alpha2, NULL));
912: PetscCall(PetscOptionsReal("-ksp_ew_threshold", "0 < threshold < 1", api, kctx->threshold, &kctx->threshold, NULL));
913: PetscCall(PetscOptionsReal("-ksp_ew_v4_p1", "p1", NULL, kctx->v4_p1, &kctx->v4_p1, NULL));
914: PetscCall(PetscOptionsReal("-ksp_ew_v4_p2", "p2", NULL, kctx->v4_p2, &kctx->v4_p2, NULL));
915: PetscCall(PetscOptionsReal("-ksp_ew_v4_p3", "p3", NULL, kctx->v4_p3, &kctx->v4_p3, NULL));
916: PetscCall(PetscOptionsReal("-ksp_ew_v4_m1", "Scaling when rk-1 in [p2,p3)", NULL, kctx->v4_m1, &kctx->v4_m1, NULL));
917: PetscCall(PetscOptionsReal("-ksp_ew_v4_m2", "Scaling when rk-1 in [p3,+infty)", NULL, kctx->v4_m2, &kctx->v4_m2, NULL));
918: PetscCall(PetscOptionsReal("-ksp_ew_v4_m3", "Threshold for successive rtol (0.1 in Eq.7)", NULL, kctx->v4_m3, &kctx->v4_m3, NULL));
919: PetscCall(PetscOptionsReal("-ksp_ew_v4_m4", "Adaptation scaling (0.5 in Eq.7)", NULL, kctx->v4_m4, &kctx->v4_m4, NULL));
920: PetscOptionsEnd();
921: PetscFunctionReturn(PETSC_SUCCESS);
922: }
924: /*@
925: SNESSetFromOptions - Sets various `SNES` and `KSP` parameters from user options.
927: Collective
929: Input Parameter:
930: . snes - the `SNES` context
932: Options Database Keys:
933: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, `SNESType` for complete list
934: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
935: . -snes_atol <abstol> - absolute tolerance of residual norm
936: . -snes_stol <stol> - convergence tolerance in terms of the norm of the change in the solution between steps
937: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
938: . -snes_max_it <max_it> - maximum number of iterations
939: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
940: . -snes_force_iteration <force> - force `SNESSolve()` to take at least one iteration
941: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
942: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
943: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
944: . -snes_lag_preconditioner_persists <true,false> - retains the -snes_lag_preconditioner information across multiple SNESSolve()
945: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
946: . -snes_lag_jacobian_persists <true,false> - retains the -snes_lag_jacobian information across multiple SNESSolve()
947: . -snes_tr_tol <trtol> - trust region tolerance
948: . -snes_convergence_test <default,skip,correct_pressure> - convergence test in nonlinear solver. default `SNESConvergedDefault()`. skip `SNESConvergedSkip()` means continue iterating until max_it or some other criterion is reached, saving expense of convergence test. correct_pressure `SNESConvergedCorrectPressure()` has special handling of a pressure null space.
949: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
950: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
951: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
952: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
953: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
954: . -snes_monitor_lg_range - plots residual norm at each iteration
955: . -snes_monitor_pause_final - Pauses all monitor drawing after the solver ends
956: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
957: . -snes_fd_color - use finite differences with coloring to compute Jacobian
958: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each `KSP` iteration
959: . -snes_converged_reason - print the reason for convergence/divergence after each solve
960: . -npc_snes_type <type> - the `SNES` type to use as a nonlinear preconditioner
961: . -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.
962: - -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.
964: Options Database Keys for Eisenstat-Walker method:
965: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
966: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
967: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
968: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
969: . -snes_ksp_ew_gamma <gamma> - Sets gamma
970: . -snes_ksp_ew_alpha <alpha> - Sets alpha
971: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
972: - -snes_ksp_ew_threshold <threshold> - Sets threshold
974: Level: beginner
976: Notes:
977: To see all options, run your program with the -help option or consult the users manual
979: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
980: and computing explicitly with
981: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
983: .seealso: [](ch_snes), `SNESType`, `SNESSetOptionsPrefix()`, `SNESResetFromOptions()`, `SNES`, `SNESCreate()`, `MatCreateSNESMF()`, `MatFDColoring`
984: @*/
985: PetscErrorCode SNESSetFromOptions(SNES snes)
986: {
987: PetscBool flg, pcset, persist, set;
988: PetscInt i, indx, lag, grids, max_its, max_funcs;
989: const char *deft = SNESNEWTONLS;
990: const char *convtests[] = {"default", "skip", "correct_pressure"};
991: SNESKSPEW *kctx = NULL;
992: char type[256], monfilename[PETSC_MAX_PATH_LEN], ewprefix[256];
993: PCSide pcside;
994: const char *optionsprefix;
995: PetscReal rtol, abstol, stol;
997: PetscFunctionBegin;
999: PetscCall(SNESRegisterAll());
1000: PetscObjectOptionsBegin((PetscObject)snes);
1001: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
1002: PetscCall(PetscOptionsFList("-snes_type", "Nonlinear solver method", "SNESSetType", SNESList, deft, type, 256, &flg));
1003: if (flg) {
1004: PetscCall(SNESSetType(snes, type));
1005: } else if (!((PetscObject)snes)->type_name) {
1006: PetscCall(SNESSetType(snes, deft));
1007: }
1009: abstol = snes->abstol;
1010: rtol = snes->rtol;
1011: stol = snes->stol;
1012: max_its = snes->max_its;
1013: max_funcs = snes->max_funcs;
1014: PetscCall(PetscOptionsReal("-snes_rtol", "Stop if decrease in function norm less than", "SNESSetTolerances", snes->rtol, &rtol, NULL));
1015: PetscCall(PetscOptionsReal("-snes_atol", "Stop if function norm less than", "SNESSetTolerances", snes->abstol, &abstol, NULL));
1016: PetscCall(PetscOptionsReal("-snes_stol", "Stop if step length less than", "SNESSetTolerances", snes->stol, &stol, NULL));
1017: PetscCall(PetscOptionsInt("-snes_max_it", "Maximum iterations", "SNESSetTolerances", snes->max_its, &max_its, NULL));
1018: PetscCall(PetscOptionsInt("-snes_max_funcs", "Maximum function evaluations", "SNESSetTolerances", snes->max_funcs, &max_funcs, NULL));
1019: PetscCall(SNESSetTolerances(snes, abstol, rtol, stol, max_its, max_funcs));
1021: PetscCall(PetscOptionsReal("-snes_divergence_tolerance", "Stop if residual norm increases by this factor", "SNESSetDivergenceTolerance", snes->divtol, &snes->divtol, &flg));
1022: if (flg) PetscCall(SNESSetDivergenceTolerance(snes, snes->divtol));
1024: PetscCall(PetscOptionsInt("-snes_max_fail", "Maximum nonlinear step failures", "SNESSetMaxNonlinearStepFailures", snes->maxFailures, &snes->maxFailures, &flg));
1025: if (flg) PetscCall(SNESSetMaxNonlinearStepFailures(snes, snes->maxFailures));
1027: PetscCall(PetscOptionsInt("-snes_max_linear_solve_fail", "Maximum failures in linear solves allowed", "SNESSetMaxLinearSolveFailures", snes->maxLinearSolveFailures, &snes->maxLinearSolveFailures, &flg));
1028: if (flg) PetscCall(SNESSetMaxLinearSolveFailures(snes, snes->maxLinearSolveFailures));
1030: PetscCall(PetscOptionsBool("-snes_error_if_not_converged", "Generate error if solver does not converge", "SNESSetErrorIfNotConverged", snes->errorifnotconverged, &snes->errorifnotconverged, NULL));
1031: PetscCall(PetscOptionsBool("-snes_force_iteration", "Force SNESSolve() to take at least one iteration", "SNESSetForceIteration", snes->forceiteration, &snes->forceiteration, NULL));
1032: PetscCall(PetscOptionsBool("-snes_check_jacobian_domain_error", "Check Jacobian domain error after Jacobian evaluation", "SNESCheckJacobianDomainError", snes->checkjacdomainerror, &snes->checkjacdomainerror, NULL));
1034: PetscCall(PetscOptionsInt("-snes_lag_preconditioner", "How often to rebuild preconditioner", "SNESSetLagPreconditioner", snes->lagpreconditioner, &lag, &flg));
1035: if (flg) {
1036: 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");
1037: PetscCall(SNESSetLagPreconditioner(snes, lag));
1038: }
1039: PetscCall(PetscOptionsBool("-snes_lag_preconditioner_persists", "Preconditioner lagging through multiple SNES solves", "SNESSetLagPreconditionerPersists", snes->lagjac_persist, &persist, &flg));
1040: if (flg) PetscCall(SNESSetLagPreconditionerPersists(snes, persist));
1041: PetscCall(PetscOptionsInt("-snes_lag_jacobian", "How often to rebuild Jacobian", "SNESSetLagJacobian", snes->lagjacobian, &lag, &flg));
1042: if (flg) {
1043: 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");
1044: PetscCall(SNESSetLagJacobian(snes, lag));
1045: }
1046: PetscCall(PetscOptionsBool("-snes_lag_jacobian_persists", "Jacobian lagging through multiple SNES solves", "SNESSetLagJacobianPersists", snes->lagjac_persist, &persist, &flg));
1047: if (flg) PetscCall(SNESSetLagJacobianPersists(snes, persist));
1049: PetscCall(PetscOptionsInt("-snes_grid_sequence", "Use grid sequencing to generate initial guess", "SNESSetGridSequence", snes->gridsequence, &grids, &flg));
1050: if (flg) PetscCall(SNESSetGridSequence(snes, grids));
1052: PetscCall(PetscOptionsEList("-snes_convergence_test", "Convergence test", "SNESSetConvergenceTest", convtests, PETSC_STATIC_ARRAY_LENGTH(convtests), "default", &indx, &flg));
1053: if (flg) {
1054: switch (indx) {
1055: case 0:
1056: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedDefault, NULL, NULL));
1057: break;
1058: case 1:
1059: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedSkip, NULL, NULL));
1060: break;
1061: case 2:
1062: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedCorrectPressure, NULL, NULL));
1063: break;
1064: }
1065: }
1067: PetscCall(PetscOptionsEList("-snes_norm_schedule", "SNES Norm schedule", "SNESSetNormSchedule", SNESNormSchedules, 5, "function", &indx, &flg));
1068: if (flg) PetscCall(SNESSetNormSchedule(snes, (SNESNormSchedule)indx));
1070: PetscCall(PetscOptionsEList("-snes_function_type", "SNES Norm schedule", "SNESSetFunctionType", SNESFunctionTypes, 2, "unpreconditioned", &indx, &flg));
1071: if (flg) PetscCall(SNESSetFunctionType(snes, (SNESFunctionType)indx));
1073: kctx = (SNESKSPEW *)snes->kspconvctx;
1075: PetscCall(PetscOptionsBool("-snes_ksp_ew", "Use Eisentat-Walker linear system convergence test", "SNESKSPSetUseEW", snes->ksp_ewconv, &snes->ksp_ewconv, NULL));
1077: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1078: PetscCall(PetscSNPrintf(ewprefix, sizeof(ewprefix), "%s%s", optionsprefix ? optionsprefix : "", "snes_"));
1079: PetscCall(SNESEWSetFromOptions_Private(kctx, PETSC_TRUE, PetscObjectComm((PetscObject)snes), ewprefix));
1081: flg = PETSC_FALSE;
1082: PetscCall(PetscOptionsBool("-snes_monitor_cancel", "Remove all monitors", "SNESMonitorCancel", flg, &flg, &set));
1083: if (set && flg) PetscCall(SNESMonitorCancel(snes));
1085: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor", "Monitor norm of function", "SNESMonitorDefault", SNESMonitorDefault, SNESMonitorDefaultSetUp));
1086: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_short", "Monitor norm of function with fewer digits", "SNESMonitorDefaultShort", SNESMonitorDefaultShort, NULL));
1087: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_range", "Monitor range of elements of function", "SNESMonitorRange", SNESMonitorRange, NULL));
1089: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_ratio", "Monitor ratios of the norm of function for consecutive steps", "SNESMonitorRatio", SNESMonitorRatio, SNESMonitorRatioSetUp));
1090: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_field", "Monitor norm of function (split into fields)", "SNESMonitorDefaultField", SNESMonitorDefaultField, NULL));
1091: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution", "View solution at each iteration", "SNESMonitorSolution", SNESMonitorSolution, NULL));
1092: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution_update", "View correction at each iteration", "SNESMonitorSolutionUpdate", SNESMonitorSolutionUpdate, NULL));
1093: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_residual", "View residual at each iteration", "SNESMonitorResidual", SNESMonitorResidual, NULL));
1094: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_jacupdate_spectrum", "Print the change in the spectrum of the Jacobian", "SNESMonitorJacUpdateSpectrum", SNESMonitorJacUpdateSpectrum, NULL));
1095: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_fields", "Monitor norm of function per field", "SNESMonitorSet", SNESMonitorFields, NULL));
1096: PetscCall(PetscOptionsBool("-snes_monitor_pause_final", "Pauses all draw monitors at the final iterate", "SNESMonitorPauseFinal_Internal", PETSC_FALSE, &snes->pauseFinal, NULL));
1098: PetscCall(PetscOptionsString("-snes_monitor_python", "Use Python function", "SNESMonitorSet", NULL, monfilename, sizeof(monfilename), &flg));
1099: if (flg) PetscCall(PetscPythonMonitorSet((PetscObject)snes, monfilename));
1101: flg = PETSC_FALSE;
1102: PetscCall(PetscOptionsBool("-snes_monitor_lg_range", "Plot function range at each iteration", "SNESMonitorLGRange", flg, &flg, NULL));
1103: if (flg) {
1104: PetscViewer ctx;
1106: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &ctx));
1107: PetscCall(SNESMonitorSet(snes, SNESMonitorLGRange, ctx, (PetscErrorCode(*)(void **))PetscViewerDestroy));
1108: }
1110: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
1111: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &snes->convergedreasonviewer, &snes->convergedreasonformat, NULL));
1112: flg = PETSC_FALSE;
1113: PetscCall(PetscOptionsBool("-snes_converged_reason_view_cancel", "Remove all converged reason viewers", "SNESConvergedReasonViewCancel", flg, &flg, &set));
1114: if (set && flg) PetscCall(SNESConvergedReasonViewCancel(snes));
1116: flg = PETSC_FALSE;
1117: PetscCall(PetscOptionsBool("-snes_fd", "Use finite differences (slow) to compute Jacobian", "SNESComputeJacobianDefault", flg, &flg, NULL));
1118: if (flg) {
1119: void *functx;
1120: DM dm;
1121: PetscCall(SNESGetDM(snes, &dm));
1122: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1123: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
1124: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefault, functx));
1125: PetscCall(PetscInfo(snes, "Setting default finite difference Jacobian matrix\n"));
1126: }
1128: flg = PETSC_FALSE;
1129: PetscCall(PetscOptionsBool("-snes_fd_function", "Use finite differences (slow) to compute function from user objective", "SNESObjectiveComputeFunctionDefaultFD", flg, &flg, NULL));
1130: if (flg) PetscCall(SNESSetFunction(snes, NULL, SNESObjectiveComputeFunctionDefaultFD, NULL));
1132: flg = PETSC_FALSE;
1133: PetscCall(PetscOptionsBool("-snes_fd_color", "Use finite differences with coloring to compute Jacobian", "SNESComputeJacobianDefaultColor", flg, &flg, NULL));
1134: if (flg) {
1135: DM dm;
1136: PetscCall(SNESGetDM(snes, &dm));
1137: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1138: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefaultColor, NULL));
1139: PetscCall(PetscInfo(snes, "Setting default finite difference coloring Jacobian matrix\n"));
1140: }
1142: flg = PETSC_FALSE;
1143: PetscCall(PetscOptionsBool("-snes_mf_operator", "Use a Matrix-Free Jacobian with user-provided preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf_operator, &flg));
1144: if (flg && snes->mf_operator) {
1145: snes->mf_operator = PETSC_TRUE;
1146: snes->mf = PETSC_TRUE;
1147: }
1148: flg = PETSC_FALSE;
1149: PetscCall(PetscOptionsBool("-snes_mf", "Use a Matrix-Free Jacobian with no preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf, &flg));
1150: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1151: PetscCall(PetscOptionsInt("-snes_mf_version", "Matrix-Free routines version 1 or 2", "None", snes->mf_version, &snes->mf_version, NULL));
1153: flg = PETSC_FALSE;
1154: PetscCall(SNESGetNPCSide(snes, &pcside));
1155: PetscCall(PetscOptionsEnum("-snes_npc_side", "SNES nonlinear preconditioner side", "SNESSetNPCSide", PCSides, (PetscEnum)pcside, (PetscEnum *)&pcside, &flg));
1156: if (flg) PetscCall(SNESSetNPCSide(snes, pcside));
1158: #if defined(PETSC_HAVE_SAWS)
1159: /*
1160: Publish convergence information using SAWs
1161: */
1162: flg = PETSC_FALSE;
1163: PetscCall(PetscOptionsBool("-snes_monitor_saws", "Publish SNES progress using SAWs", "SNESMonitorSet", flg, &flg, NULL));
1164: if (flg) {
1165: void *ctx;
1166: PetscCall(SNESMonitorSAWsCreate(snes, &ctx));
1167: PetscCall(SNESMonitorSet(snes, SNESMonitorSAWs, ctx, SNESMonitorSAWsDestroy));
1168: }
1169: #endif
1170: #if defined(PETSC_HAVE_SAWS)
1171: {
1172: PetscBool set;
1173: flg = PETSC_FALSE;
1174: PetscCall(PetscOptionsBool("-snes_saws_block", "Block for SAWs at end of SNESSolve", "PetscObjectSAWsBlock", ((PetscObject)snes)->amspublishblock, &flg, &set));
1175: if (set) PetscCall(PetscObjectSAWsSetBlock((PetscObject)snes, flg));
1176: }
1177: #endif
1179: for (i = 0; i < numberofsetfromoptions; i++) PetscCall((*othersetfromoptions[i])(snes));
1181: PetscTryTypeMethod(snes, setfromoptions, PetscOptionsObject);
1183: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1184: PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)snes, PetscOptionsObject));
1185: PetscOptionsEnd();
1187: if (snes->linesearch) {
1188: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
1189: PetscCall(SNESLineSearchSetFromOptions(snes->linesearch));
1190: }
1192: if (snes->usesksp) {
1193: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
1194: PetscCall(KSPSetOperators(snes->ksp, snes->jacobian, snes->jacobian_pre));
1195: PetscCall(KSPSetFromOptions(snes->ksp));
1196: }
1198: /* if user has set the SNES NPC type via options database, create it. */
1199: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1200: PetscCall(PetscOptionsHasName(((PetscObject)snes)->options, optionsprefix, "-npc_snes_type", &pcset));
1201: if (pcset && (!snes->npc)) PetscCall(SNESGetNPC(snes, &snes->npc));
1202: if (snes->npc) PetscCall(SNESSetFromOptions(snes->npc));
1203: snes->setfromoptionscalled++;
1204: PetscFunctionReturn(PETSC_SUCCESS);
1205: }
1207: /*@
1208: SNESResetFromOptions - Sets various `SNES` and `KSP` parameters from user options ONLY if the `SNESSetFromOptions()` was previously called
1210: Collective
1212: Input Parameter:
1213: . snes - the `SNES` context
1215: Level: advanced
1217: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESSetOptionsPrefix()`
1218: @*/
1219: PetscErrorCode SNESResetFromOptions(SNES snes)
1220: {
1221: PetscFunctionBegin;
1222: if (snes->setfromoptionscalled) PetscCall(SNESSetFromOptions(snes));
1223: PetscFunctionReturn(PETSC_SUCCESS);
1224: }
1226: /*@C
1227: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1228: the nonlinear solvers.
1230: Logically Collective; No Fortran Support
1232: Input Parameters:
1233: + snes - the `SNES` context
1234: . compute - function to compute the context
1235: - destroy - function to destroy the context
1237: Calling sequence of `compute`:
1238: + snes - the `SNES` context
1239: - ctx - context to be computed
1241: Calling sequence of `destroy`:
1242: . ctx - context to be computed by `compute()`
1244: Level: intermediate
1246: Note:
1247: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1249: Use `SNESSetApplicationContext()` to see the context immediately
1251: .seealso: [](ch_snes), `SNESGetApplicationContext()`, `SNESSetApplicationContext()`
1252: @*/
1253: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES snes, void **ctx), PetscErrorCode (*destroy)(void **ctx))
1254: {
1255: PetscFunctionBegin;
1257: snes->ops->usercompute = compute;
1258: snes->ops->userdestroy = destroy;
1259: PetscFunctionReturn(PETSC_SUCCESS);
1260: }
1262: /*@
1263: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1265: Logically Collective
1267: Input Parameters:
1268: + snes - the `SNES` context
1269: - usrP - optional user context
1271: Level: intermediate
1273: Notes:
1274: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian, or other evaluation function
1275: with `SNESGetApplicationContext()`
1277: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1279: Fortran Note:
1280: You must write a Fortran interface definition for this
1281: function that tells Fortran the Fortran derived data type that you are passing in as the `usrP` argument.
1283: .seealso: [](ch_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1284: @*/
1285: PetscErrorCode SNESSetApplicationContext(SNES snes, void *usrP)
1286: {
1287: KSP ksp;
1289: PetscFunctionBegin;
1291: PetscCall(SNESGetKSP(snes, &ksp));
1292: PetscCall(KSPSetApplicationContext(ksp, usrP));
1293: snes->user = usrP;
1294: PetscFunctionReturn(PETSC_SUCCESS);
1295: }
1297: /*@
1298: SNESGetApplicationContext - Gets the user-defined context for the
1299: nonlinear solvers set with `SNESGetApplicationContext()` or `SNESSetComputeApplicationContext()`
1301: Not Collective
1303: Input Parameter:
1304: . snes - `SNES` context
1306: Output Parameter:
1307: . usrP - user context
1309: Level: intermediate
1311: Fortran Note:
1312: You must write a Fortran interface definition for this
1313: function that tells Fortran the Fortran derived data type that you are passing in as the `usrP` argument.
1315: .seealso: [](ch_snes), `SNESSetApplicationContext()`, `SNESSetComputeApplicationContext()`
1316: @*/
1317: PetscErrorCode SNESGetApplicationContext(SNES snes, void *usrP)
1318: {
1319: PetscFunctionBegin;
1321: *(void **)usrP = snes->user;
1322: PetscFunctionReturn(PETSC_SUCCESS);
1323: }
1325: /*@
1326: SNESSetUseMatrixFree - indicates that `SNES` should use matrix-free finite difference matrix-vector products to apply the Jacobian.
1328: Logically Collective
1330: Input Parameters:
1331: + snes - `SNES` context
1332: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1333: - 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
1334: this option no matrix-element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1336: Options Database Keys:
1337: + -snes_mf_operator - use matrix-free only for the mat operator
1338: . -snes_mf - use matrix-free for both the mat and pmat operator
1339: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1340: - -snes_fd - compute the Jacobian via finite differences (slow)
1342: Level: intermediate
1344: Note:
1345: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
1346: and computing explicitly with
1347: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1349: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`, `MatFDColoring`
1350: @*/
1351: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1352: {
1353: PetscFunctionBegin;
1357: snes->mf = mf_operator ? PETSC_TRUE : mf;
1358: snes->mf_operator = mf_operator;
1359: PetscFunctionReturn(PETSC_SUCCESS);
1360: }
1362: /*@
1363: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1365: Not Collective, but the resulting flags will be the same on all MPI processes
1367: Input Parameter:
1368: . snes - `SNES` context
1370: Output Parameters:
1371: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1372: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1374: Level: intermediate
1376: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1377: @*/
1378: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1379: {
1380: PetscFunctionBegin;
1382: if (mf) *mf = snes->mf;
1383: if (mf_operator) *mf_operator = snes->mf_operator;
1384: PetscFunctionReturn(PETSC_SUCCESS);
1385: }
1387: /*@
1388: SNESGetIterationNumber - Gets the number of nonlinear iterations completed in the current or most recent `SNESSolve()`
1390: Not Collective
1392: Input Parameter:
1393: . snes - `SNES` context
1395: Output Parameter:
1396: . iter - iteration number
1398: Level: intermediate
1400: Notes:
1401: For example, during the computation of iteration 2 this would return 1.
1403: This is useful for using lagged Jacobians (where one does not recompute the
1404: Jacobian at each `SNES` iteration). For example, the code
1405: .vb
1406: ierr = SNESGetIterationNumber(snes,&it);
1407: if (!(it % 2)) {
1408: [compute Jacobian here]
1409: }
1410: .ve
1411: can be used in your function that computes the Jacobian to cause the Jacobian to be
1412: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1414: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1416: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`, `SNESSetMonitor()`
1417: @*/
1418: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1419: {
1420: PetscFunctionBegin;
1422: PetscAssertPointer(iter, 2);
1423: *iter = snes->iter;
1424: PetscFunctionReturn(PETSC_SUCCESS);
1425: }
1427: /*@
1428: SNESSetIterationNumber - Sets the current iteration number.
1430: Not Collective
1432: Input Parameters:
1433: + snes - `SNES` context
1434: - iter - iteration number
1436: Level: developer
1438: Note:
1439: This should only be called inside a `SNES` nonlinear solver.
1441: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1442: @*/
1443: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1444: {
1445: PetscFunctionBegin;
1447: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1448: snes->iter = iter;
1449: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1450: PetscFunctionReturn(PETSC_SUCCESS);
1451: }
1453: /*@
1454: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1455: attempted by the nonlinear solver in the current or most recent `SNESSolve()` .
1457: Not Collective
1459: Input Parameter:
1460: . snes - `SNES` context
1462: Output Parameter:
1463: . nfails - number of unsuccessful steps attempted
1465: Level: intermediate
1467: Note:
1468: This counter is reset to zero for each successive call to `SNESSolve()`.
1470: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1471: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1472: @*/
1473: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1474: {
1475: PetscFunctionBegin;
1477: PetscAssertPointer(nfails, 2);
1478: *nfails = snes->numFailures;
1479: PetscFunctionReturn(PETSC_SUCCESS);
1480: }
1482: /*@
1483: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1484: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1486: Not Collective
1488: Input Parameters:
1489: + snes - `SNES` context
1490: - maxFails - maximum of unsuccessful steps allowed, use `PETSC_UNLIMITED` to have no limit on the number of failures
1492: Options Database Key:
1493: . -snes_max_fail <n> - maximum number of unsuccessful steps allowed
1495: Level: intermediate
1497: Developer Note:
1498: The options database key is wrong for this function name
1500: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1501: `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1502: @*/
1503: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1504: {
1505: PetscFunctionBegin;
1508: if (maxFails == PETSC_UNLIMITED) {
1509: snes->maxFailures = PETSC_MAX_INT;
1510: } else {
1511: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1512: snes->maxFailures = maxFails;
1513: }
1514: PetscFunctionReturn(PETSC_SUCCESS);
1515: }
1517: /*@
1518: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1519: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1521: Not Collective
1523: Input Parameter:
1524: . snes - `SNES` context
1526: Output Parameter:
1527: . maxFails - maximum of unsuccessful steps
1529: Level: intermediate
1531: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1532: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1533: @*/
1534: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1535: {
1536: PetscFunctionBegin;
1538: PetscAssertPointer(maxFails, 2);
1539: *maxFails = snes->maxFailures;
1540: PetscFunctionReturn(PETSC_SUCCESS);
1541: }
1543: /*@
1544: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1545: done by the `SNES` object in the current or most recent `SNESSolve()`
1547: Not Collective
1549: Input Parameter:
1550: . snes - `SNES` context
1552: Output Parameter:
1553: . nfuncs - number of evaluations
1555: Level: intermediate
1557: Note:
1558: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1560: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1561: @*/
1562: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1563: {
1564: PetscFunctionBegin;
1566: PetscAssertPointer(nfuncs, 2);
1567: *nfuncs = snes->nfuncs;
1568: PetscFunctionReturn(PETSC_SUCCESS);
1569: }
1571: /*@
1572: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1573: linear solvers in the current or most recent `SNESSolve()`
1575: Not Collective
1577: Input Parameter:
1578: . snes - `SNES` context
1580: Output Parameter:
1581: . nfails - number of failed solves
1583: Options Database Key:
1584: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1586: Level: intermediate
1588: Note:
1589: This counter is reset to zero for each successive call to `SNESSolve()`.
1591: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1592: @*/
1593: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1594: {
1595: PetscFunctionBegin;
1597: PetscAssertPointer(nfails, 2);
1598: *nfails = snes->numLinearSolveFailures;
1599: PetscFunctionReturn(PETSC_SUCCESS);
1600: }
1602: /*@
1603: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1604: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1606: Logically Collective
1608: Input Parameters:
1609: + snes - `SNES` context
1610: - maxFails - maximum allowed linear solve failures, use `PETSC_UNLIMITED` to have no limit on the number of failures
1612: Options Database Key:
1613: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1615: Level: intermediate
1617: Note:
1618: By default this is 0; that is `SNES` returns on the first failed linear solve
1620: Developer Note:
1621: The options database key is wrong for this function name
1623: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1624: @*/
1625: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1626: {
1627: PetscFunctionBegin;
1631: if (maxFails == PETSC_UNLIMITED) {
1632: snes->maxLinearSolveFailures = PETSC_MAX_INT;
1633: } else {
1634: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1635: snes->maxLinearSolveFailures = maxFails;
1636: }
1637: PetscFunctionReturn(PETSC_SUCCESS);
1638: }
1640: /*@
1641: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1642: are allowed before `SNES` returns as unsuccessful
1644: Not Collective
1646: Input Parameter:
1647: . snes - `SNES` context
1649: Output Parameter:
1650: . maxFails - maximum of unsuccessful solves allowed
1652: Level: intermediate
1654: Note:
1655: By default this is 1; that is `SNES` returns on the first failed linear solve
1657: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1658: @*/
1659: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1660: {
1661: PetscFunctionBegin;
1663: PetscAssertPointer(maxFails, 2);
1664: *maxFails = snes->maxLinearSolveFailures;
1665: PetscFunctionReturn(PETSC_SUCCESS);
1666: }
1668: /*@
1669: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1670: used by the nonlinear solver in the most recent `SNESSolve()`
1672: Not Collective
1674: Input Parameter:
1675: . snes - `SNES` context
1677: Output Parameter:
1678: . lits - number of linear iterations
1680: Level: intermediate
1682: Notes:
1683: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1685: 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
1686: then call `KSPGetIterationNumber()` after the failed solve.
1688: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1689: @*/
1690: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1691: {
1692: PetscFunctionBegin;
1694: PetscAssertPointer(lits, 2);
1695: *lits = snes->linear_its;
1696: PetscFunctionReturn(PETSC_SUCCESS);
1697: }
1699: /*@
1700: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1701: are reset every time `SNESSolve()` is called.
1703: Logically Collective
1705: Input Parameters:
1706: + snes - `SNES` context
1707: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1709: Level: developer
1711: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1712: @*/
1713: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1714: {
1715: PetscFunctionBegin;
1718: snes->counters_reset = reset;
1719: PetscFunctionReturn(PETSC_SUCCESS);
1720: }
1722: /*@
1723: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1725: Not Collective, but the `SNES` and `KSP` objects must live on the same `MPI_Comm`
1727: Input Parameters:
1728: + snes - the `SNES` context
1729: - ksp - the `KSP` context
1731: Level: developer
1733: Notes:
1734: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1735: so this routine is rarely needed.
1737: The `KSP` object that is already in the `SNES` object has its reference count
1738: decreased by one when this is called.
1740: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`
1741: @*/
1742: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1743: {
1744: PetscFunctionBegin;
1747: PetscCheckSameComm(snes, 1, ksp, 2);
1748: PetscCall(PetscObjectReference((PetscObject)ksp));
1749: if (snes->ksp) PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1750: snes->ksp = ksp;
1751: PetscFunctionReturn(PETSC_SUCCESS);
1752: }
1754: /*@
1755: SNESParametersInitialize - Sets all the parameters in `snes` to their default value (when `SNESCreate()` was called) if they
1756: currently contain default values
1758: Collective
1760: Input Parameter:
1761: . snes - the `SNES` object
1763: Level: developer
1765: Developer Note:
1766: This is called by all the `SNESCreate_XXX()` routines.
1768: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
1769: `PetscObjectParameterSetDefault()`
1770: @*/
1771: PetscErrorCode SNESParametersInitialize(SNES snes)
1772: {
1773: PetscObjectParameterSetDefault(snes, max_its, 50);
1774: PetscObjectParameterSetDefault(snes, max_funcs, 10000);
1775: PetscObjectParameterSetDefault(snes, rtol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1776: PetscObjectParameterSetDefault(snes, abstol, PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50);
1777: PetscObjectParameterSetDefault(snes, stol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1778: PetscObjectParameterSetDefault(snes, deltatol, PetscDefined(USE_REAL_SINGLE) ? 1.e-6 : 1.e-12);
1779: PetscObjectParameterSetDefault(snes, divtol, 1.e4);
1780: return PETSC_SUCCESS;
1781: }
1783: /*@
1784: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1786: Collective
1788: Input Parameter:
1789: . comm - MPI communicator
1791: Output Parameter:
1792: . outsnes - the new `SNES` context
1794: Options Database Keys:
1795: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no preconditioning matrix
1796: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided preconditioning matrix
1797: as set by `SNESSetJacobian()`
1798: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1799: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1801: Level: beginner
1803: Developer Notes:
1804: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1805: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1806: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1807: in `SNESView()`.
1809: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1810: by help messages about meaningless `SNES` options.
1812: `SNES` always creates the snes->kspconvctx even though it is used by only one type. This should be fixed.
1814: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1815: @*/
1816: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1817: {
1818: SNES snes;
1819: SNESKSPEW *kctx;
1821: PetscFunctionBegin;
1822: PetscAssertPointer(outsnes, 2);
1823: PetscCall(SNESInitializePackage());
1825: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1826: snes->ops->converged = SNESConvergedDefault;
1827: snes->usesksp = PETSC_TRUE;
1828: snes->norm = 0.0;
1829: snes->xnorm = 0.0;
1830: snes->ynorm = 0.0;
1831: snes->normschedule = SNES_NORM_ALWAYS;
1832: snes->functype = SNES_FUNCTION_DEFAULT;
1833: snes->ttol = 0.0;
1835: snes->rnorm0 = 0;
1836: snes->nfuncs = 0;
1837: snes->numFailures = 0;
1838: snes->maxFailures = 1;
1839: snes->linear_its = 0;
1840: snes->lagjacobian = 1;
1841: snes->jac_iter = 0;
1842: snes->lagjac_persist = PETSC_FALSE;
1843: snes->lagpreconditioner = 1;
1844: snes->pre_iter = 0;
1845: snes->lagpre_persist = PETSC_FALSE;
1846: snes->numbermonitors = 0;
1847: snes->numberreasonviews = 0;
1848: snes->data = NULL;
1849: snes->setupcalled = PETSC_FALSE;
1850: snes->ksp_ewconv = PETSC_FALSE;
1851: snes->nwork = 0;
1852: snes->work = NULL;
1853: snes->nvwork = 0;
1854: snes->vwork = NULL;
1855: snes->conv_hist_len = 0;
1856: snes->conv_hist_max = 0;
1857: snes->conv_hist = NULL;
1858: snes->conv_hist_its = NULL;
1859: snes->conv_hist_reset = PETSC_TRUE;
1860: snes->counters_reset = PETSC_TRUE;
1861: snes->vec_func_init_set = PETSC_FALSE;
1862: snes->reason = SNES_CONVERGED_ITERATING;
1863: snes->npcside = PC_RIGHT;
1864: snes->setfromoptionscalled = 0;
1866: snes->mf = PETSC_FALSE;
1867: snes->mf_operator = PETSC_FALSE;
1868: snes->mf_version = 1;
1870: snes->numLinearSolveFailures = 0;
1871: snes->maxLinearSolveFailures = 1;
1873: snes->vizerotolerance = 1.e-8;
1874: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1876: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1877: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1879: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1880: PetscCall(PetscNew(&kctx));
1882: snes->kspconvctx = (void *)kctx;
1883: kctx->version = 2;
1884: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1885: this was too large for some test cases */
1886: kctx->rtol_last = 0.0;
1887: kctx->rtol_max = 0.9;
1888: kctx->gamma = 1.0;
1889: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1890: kctx->alpha2 = kctx->alpha;
1891: kctx->threshold = 0.1;
1892: kctx->lresid_last = 0.0;
1893: kctx->norm_last = 0.0;
1895: kctx->rk_last = 0.0;
1896: kctx->rk_last_2 = 0.0;
1897: kctx->rtol_last_2 = 0.0;
1898: kctx->v4_p1 = 0.1;
1899: kctx->v4_p2 = 0.4;
1900: kctx->v4_p3 = 0.7;
1901: kctx->v4_m1 = 0.8;
1902: kctx->v4_m2 = 0.5;
1903: kctx->v4_m3 = 0.1;
1904: kctx->v4_m4 = 0.5;
1906: *outsnes = snes;
1907: PetscFunctionReturn(PETSC_SUCCESS);
1908: }
1910: /*@C
1911: SNESSetFunction - Sets the function evaluation routine and function
1912: vector for use by the `SNES` routines in solving systems of nonlinear
1913: equations.
1915: Logically Collective
1917: Input Parameters:
1918: + snes - the `SNES` context
1919: . r - vector to store function values, may be `NULL`
1920: . f - function evaluation routine; for calling sequence see `SNESFunctionFn`
1921: - ctx - [optional] user-defined context for private data for the
1922: function evaluation routine (may be `NULL`)
1924: Level: beginner
1926: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunctionFn`
1927: @*/
1928: PetscErrorCode SNESSetFunction(SNES snes, Vec r, SNESFunctionFn *f, void *ctx)
1929: {
1930: DM dm;
1932: PetscFunctionBegin;
1934: if (r) {
1936: PetscCheckSameComm(snes, 1, r, 2);
1937: PetscCall(PetscObjectReference((PetscObject)r));
1938: PetscCall(VecDestroy(&snes->vec_func));
1939: snes->vec_func = r;
1940: }
1941: PetscCall(SNESGetDM(snes, &dm));
1942: PetscCall(DMSNESSetFunction(dm, f, ctx));
1943: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1944: PetscFunctionReturn(PETSC_SUCCESS);
1945: }
1947: /*@C
1948: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1950: Logically Collective
1952: Input Parameters:
1953: + snes - the `SNES` context
1954: - f - vector to store function value
1956: Level: developer
1958: Notes:
1959: This should not be modified during the solution procedure.
1961: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1963: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1964: @*/
1965: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1966: {
1967: Vec vec_func;
1969: PetscFunctionBegin;
1972: PetscCheckSameComm(snes, 1, f, 2);
1973: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1974: snes->vec_func_init_set = PETSC_FALSE;
1975: PetscFunctionReturn(PETSC_SUCCESS);
1976: }
1977: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
1978: PetscCall(VecCopy(f, vec_func));
1980: snes->vec_func_init_set = PETSC_TRUE;
1981: PetscFunctionReturn(PETSC_SUCCESS);
1982: }
1984: /*@
1985: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
1986: of the `SNES` method, when norms are computed in the solving process
1988: Logically Collective
1990: Input Parameters:
1991: + snes - the `SNES` context
1992: - normschedule - the frequency of norm computation
1994: Options Database Key:
1995: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
1997: Level: advanced
1999: Notes:
2000: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
2001: of the nonlinear function and the taking of its norm at every iteration to
2002: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2003: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
2004: may either be monitored for convergence or not. As these are often used as nonlinear
2005: preconditioners, monitoring the norm of their error is not a useful enterprise within
2006: their solution.
2008: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
2009: @*/
2010: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
2011: {
2012: PetscFunctionBegin;
2014: snes->normschedule = normschedule;
2015: PetscFunctionReturn(PETSC_SUCCESS);
2016: }
2018: /*@
2019: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
2020: of the `SNES` method.
2022: Logically Collective
2024: Input Parameters:
2025: + snes - the `SNES` context
2026: - normschedule - the type of the norm used
2028: Level: advanced
2030: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2031: @*/
2032: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
2033: {
2034: PetscFunctionBegin;
2036: *normschedule = snes->normschedule;
2037: PetscFunctionReturn(PETSC_SUCCESS);
2038: }
2040: /*@
2041: SNESSetFunctionNorm - Sets the last computed residual norm.
2043: Logically Collective
2045: Input Parameters:
2046: + snes - the `SNES` context
2047: - norm - the value of the norm
2049: Level: developer
2051: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2052: @*/
2053: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
2054: {
2055: PetscFunctionBegin;
2057: snes->norm = norm;
2058: PetscFunctionReturn(PETSC_SUCCESS);
2059: }
2061: /*@
2062: SNESGetFunctionNorm - Gets the last computed norm of the residual
2064: Not Collective
2066: Input Parameter:
2067: . snes - the `SNES` context
2069: Output Parameter:
2070: . norm - the last computed residual norm
2072: Level: developer
2074: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2075: @*/
2076: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2077: {
2078: PetscFunctionBegin;
2080: PetscAssertPointer(norm, 2);
2081: *norm = snes->norm;
2082: PetscFunctionReturn(PETSC_SUCCESS);
2083: }
2085: /*@
2086: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2088: Not Collective
2090: Input Parameter:
2091: . snes - the `SNES` context
2093: Output Parameter:
2094: . ynorm - the last computed update norm
2096: Level: developer
2098: Note:
2099: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2101: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2102: @*/
2103: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2104: {
2105: PetscFunctionBegin;
2107: PetscAssertPointer(ynorm, 2);
2108: *ynorm = snes->ynorm;
2109: PetscFunctionReturn(PETSC_SUCCESS);
2110: }
2112: /*@
2113: SNESGetSolutionNorm - Gets the last computed norm of the solution
2115: Not Collective
2117: Input Parameter:
2118: . snes - the `SNES` context
2120: Output Parameter:
2121: . xnorm - the last computed solution norm
2123: Level: developer
2125: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2126: @*/
2127: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2128: {
2129: PetscFunctionBegin;
2131: PetscAssertPointer(xnorm, 2);
2132: *xnorm = snes->xnorm;
2133: PetscFunctionReturn(PETSC_SUCCESS);
2134: }
2136: /*@
2137: SNESSetFunctionType - Sets the `SNESFunctionType`
2138: of the `SNES` method.
2140: Logically Collective
2142: Input Parameters:
2143: + snes - the `SNES` context
2144: - type - the function type
2146: Level: developer
2148: Values of the function type\:
2149: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2150: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2151: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2153: Note:
2154: Different `SNESType`s use this value in different ways
2156: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2157: @*/
2158: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2159: {
2160: PetscFunctionBegin;
2162: snes->functype = type;
2163: PetscFunctionReturn(PETSC_SUCCESS);
2164: }
2166: /*@
2167: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2168: of the SNES method.
2170: Logically Collective
2172: Input Parameters:
2173: + snes - the `SNES` context
2174: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2176: Level: advanced
2178: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2179: @*/
2180: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2181: {
2182: PetscFunctionBegin;
2184: *type = snes->functype;
2185: PetscFunctionReturn(PETSC_SUCCESS);
2186: }
2188: /*@C
2189: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2190: use with composed nonlinear solvers.
2192: Input Parameters:
2193: + snes - the `SNES` context, usually of the `SNESType` `SNESNGS`
2194: . f - function evaluation routine to apply Gauss-Seidel, see `SNESNGSFn` for calling sequence
2195: - ctx - [optional] user-defined context for private data for the smoother evaluation routine (may be `NULL`)
2197: Level: intermediate
2199: Note:
2200: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2201: a problem appropriate update to the solution, particularly `SNESFAS`.
2203: .seealso: [](ch_snes), `SNESNGS`, `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`, `SNESNGSFn`
2204: @*/
2205: PetscErrorCode SNESSetNGS(SNES snes, SNESNGSFn *f, void *ctx)
2206: {
2207: DM dm;
2209: PetscFunctionBegin;
2211: PetscCall(SNESGetDM(snes, &dm));
2212: PetscCall(DMSNESSetNGS(dm, f, ctx));
2213: PetscFunctionReturn(PETSC_SUCCESS);
2214: }
2216: /*
2217: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2218: changed during the KSPSolve()
2219: */
2220: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, void *ctx)
2221: {
2222: DM dm;
2223: DMSNES sdm;
2225: PetscFunctionBegin;
2226: PetscCall(SNESGetDM(snes, &dm));
2227: PetscCall(DMGetDMSNES(dm, &sdm));
2228: /* A(x)*x - b(x) */
2229: if (sdm->ops->computepfunction) {
2230: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2231: PetscCall(VecScale(f, -1.0));
2232: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2233: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2234: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2235: PetscCall(MatMultAdd(snes->picard, x, f, f));
2236: } else {
2237: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2238: PetscCall(MatMult(snes->picard, x, f));
2239: }
2240: PetscFunctionReturn(PETSC_SUCCESS);
2241: }
2243: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, void *ctx)
2244: {
2245: DM dm;
2246: DMSNES sdm;
2248: PetscFunctionBegin;
2249: PetscCall(SNESGetDM(snes, &dm));
2250: PetscCall(DMGetDMSNES(dm, &sdm));
2251: /* A(x)*x - b(x) */
2252: if (sdm->ops->computepfunction) {
2253: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2254: PetscCall(VecScale(f, -1.0));
2255: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2256: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2257: } else {
2258: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2259: PetscCall(MatMult(snes->jacobian_pre, x, f));
2260: }
2261: PetscFunctionReturn(PETSC_SUCCESS);
2262: }
2264: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, void *ctx)
2265: {
2266: PetscFunctionBegin;
2267: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2268: /* must assembly if matrix-free to get the last SNES solution */
2269: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2270: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2271: PetscFunctionReturn(PETSC_SUCCESS);
2272: }
2274: /*@C
2275: SNESSetPicard - Use `SNES` to solve the system $A(x) x = bp(x) + b $ via a Picard type iteration (Picard linearization)
2277: Logically Collective
2279: Input Parameters:
2280: + snes - the `SNES` context
2281: . r - vector to store function values, may be `NULL`
2282: . bp - function evaluation routine, may be `NULL`, for the calling sequence see `SNESFunctionFn`
2283: . Amat - matrix with which A(x) x - bp(x) - b is to be computed
2284: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2285: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFn`
2286: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2288: Level: intermediate
2290: Notes:
2291: It is often better to provide the nonlinear function F() and some approximation to its Jacobian directly and use
2292: 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.
2294: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2296: Solves the equation $A(x) x = bp(x) - b$ via the defect correction algorithm $A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}$.
2297: When an exact solver is used this corresponds to the "classic" Picard $A(x^{n}) x^{n+1} = bp(x^{n}) + b$ iteration.
2299: Run with `-snes_mf_operator` to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2301: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2302: the direct Picard iteration $A(x^n) x^{n+1} = bp(x^n) + b$
2304: 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
2305: 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
2306: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument \:-).
2308: 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
2309: A(x^{n}) is used to build the preconditioner
2311: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at a time) and thus represent Newton's method.
2313: 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
2314: 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
2315: 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`.
2316: See the comment in src/snes/tutorials/ex15.c.
2318: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`,
2319: `SNESFunctionFn`, `SNESJacobianFn`
2320: @*/
2321: PetscErrorCode SNESSetPicard(SNES snes, Vec r, SNESFunctionFn *bp, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
2322: {
2323: DM dm;
2325: PetscFunctionBegin;
2327: PetscCall(SNESGetDM(snes, &dm));
2328: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2329: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2330: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2331: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2332: PetscFunctionReturn(PETSC_SUCCESS);
2333: }
2335: /*@C
2336: SNESGetPicard - Returns the context for the Picard iteration
2338: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2340: Input Parameter:
2341: . snes - the `SNES` context
2343: Output Parameters:
2344: + r - the function (or `NULL`)
2345: . f - the function (or `NULL`); for calling sequence see `SNESFunctionFn`
2346: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2347: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2348: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFn`
2349: - ctx - the function context (or `NULL`)
2351: Level: advanced
2353: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunctionFn`, `SNESJacobianFn`
2354: @*/
2355: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, SNESFunctionFn **f, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
2356: {
2357: DM dm;
2359: PetscFunctionBegin;
2361: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2362: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2363: PetscCall(SNESGetDM(snes, &dm));
2364: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2365: PetscFunctionReturn(PETSC_SUCCESS);
2366: }
2368: /*@C
2369: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2371: Logically Collective
2373: Input Parameters:
2374: + snes - the `SNES` context
2375: . func - function evaluation routine, see `SNESInitialGuessFn` for the calling sequence
2376: - ctx - [optional] user-defined context for private data for the
2377: function evaluation routine (may be `NULL`)
2379: Level: intermediate
2381: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESInitialGuessFn`
2382: @*/
2383: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, SNESInitialGuessFn *func, void *ctx)
2384: {
2385: PetscFunctionBegin;
2387: if (func) snes->ops->computeinitialguess = func;
2388: if (ctx) snes->initialguessP = ctx;
2389: PetscFunctionReturn(PETSC_SUCCESS);
2390: }
2392: /*@C
2393: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2394: it assumes a zero right-hand side.
2396: Logically Collective
2398: Input Parameter:
2399: . snes - the `SNES` context
2401: Output Parameter:
2402: . rhs - the right-hand side vector or `NULL` if there is no right-hand side vector
2404: Level: intermediate
2406: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2407: @*/
2408: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2409: {
2410: PetscFunctionBegin;
2412: PetscAssertPointer(rhs, 2);
2413: *rhs = snes->vec_rhs;
2414: PetscFunctionReturn(PETSC_SUCCESS);
2415: }
2417: /*@
2418: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2420: Collective
2422: Input Parameters:
2423: + snes - the `SNES` context
2424: - x - input vector
2426: Output Parameter:
2427: . y - function vector, as set by `SNESSetFunction()`
2429: Level: developer
2431: Notes:
2432: `SNESComputeFunction()` is typically used within nonlinear solvers
2433: implementations, so users would not generally call this routine themselves.
2435: When solving for $F(x) = b$, this routine computes $y = F(x) - b$.
2437: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`
2438: @*/
2439: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec y)
2440: {
2441: DM dm;
2442: DMSNES sdm;
2444: PetscFunctionBegin;
2448: PetscCheckSameComm(snes, 1, x, 2);
2449: PetscCheckSameComm(snes, 1, y, 3);
2450: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2452: PetscCall(SNESGetDM(snes, &dm));
2453: PetscCall(DMGetDMSNES(dm, &sdm));
2454: 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().");
2455: if (sdm->ops->computefunction) {
2456: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2457: PetscCall(VecLockReadPush(x));
2458: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2459: snes->domainerror = PETSC_FALSE;
2460: {
2461: void *ctx;
2462: SNESFunctionFn *computefunction;
2463: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2464: PetscCallBack("SNES callback function", (*computefunction)(snes, x, y, ctx));
2465: }
2466: PetscCall(VecLockReadPop(x));
2467: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2468: } else /* if (snes->vec_rhs) */ {
2469: PetscCall(MatMult(snes->jacobian, x, y));
2470: }
2471: if (snes->vec_rhs) PetscCall(VecAXPY(y, -1.0, snes->vec_rhs));
2472: snes->nfuncs++;
2473: /*
2474: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2475: propagate the value to all processes
2476: */
2477: PetscCall(VecFlag(y, snes->domainerror));
2478: PetscFunctionReturn(PETSC_SUCCESS);
2479: }
2481: /*@
2482: SNESComputeMFFunction - Calls the function that has been set with `SNESSetMFFunction()`.
2484: Collective
2486: Input Parameters:
2487: + snes - the `SNES` context
2488: - x - input vector
2490: Output Parameter:
2491: . y - function vector, as set by `SNESSetMFFunction()`
2493: Level: developer
2495: Notes:
2496: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2497: so users would not generally call this routine themselves.
2499: Since this function is intended for use with finite differencing it does not subtract the right-hand side vector provided with `SNESSolve()`
2500: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2501: 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.
2503: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF`
2504: @*/
2505: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2506: {
2507: DM dm;
2508: DMSNES sdm;
2510: PetscFunctionBegin;
2514: PetscCheckSameComm(snes, 1, x, 2);
2515: PetscCheckSameComm(snes, 1, y, 3);
2516: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2518: PetscCall(SNESGetDM(snes, &dm));
2519: PetscCall(DMGetDMSNES(dm, &sdm));
2520: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2521: PetscCall(VecLockReadPush(x));
2522: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2523: snes->domainerror = PETSC_FALSE;
2524: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2525: PetscCall(VecLockReadPop(x));
2526: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2527: snes->nfuncs++;
2528: /*
2529: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2530: propagate the value to all processes
2531: */
2532: PetscCall(VecFlag(y, snes->domainerror));
2533: PetscFunctionReturn(PETSC_SUCCESS);
2534: }
2536: /*@
2537: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2539: Collective
2541: Input Parameters:
2542: + snes - the `SNES` context
2543: . x - input vector
2544: - b - rhs vector
2546: Output Parameter:
2547: . x - new solution vector
2549: Level: developer
2551: Note:
2552: `SNESComputeNGS()` is typically used within composed nonlinear solver
2553: implementations, so most users would not generally call this routine
2554: themselves.
2556: .seealso: [](ch_snes), `SNESNGSFn`, `SNESSetNGS()`, `SNESComputeFunction()`, `SNESNGS`
2557: @*/
2558: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2559: {
2560: DM dm;
2561: DMSNES sdm;
2563: PetscFunctionBegin;
2567: PetscCheckSameComm(snes, 1, x, 3);
2568: if (b) PetscCheckSameComm(snes, 1, b, 2);
2569: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2570: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2571: PetscCall(SNESGetDM(snes, &dm));
2572: PetscCall(DMGetDMSNES(dm, &sdm));
2573: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2574: if (b) PetscCall(VecLockReadPush(b));
2575: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2576: if (b) PetscCall(VecLockReadPop(b));
2577: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2578: PetscFunctionReturn(PETSC_SUCCESS);
2579: }
2581: static PetscErrorCode SNESComputeFunction_FD(SNES snes, Vec Xin, Vec G)
2582: {
2583: Vec X;
2584: PetscScalar *g;
2585: PetscReal f, f2;
2586: PetscInt low, high, N, i;
2587: PetscBool flg;
2588: PetscReal h = .5 * PETSC_SQRT_MACHINE_EPSILON;
2590: PetscFunctionBegin;
2591: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_fd_delta", &h, &flg));
2592: PetscCall(VecDuplicate(Xin, &X));
2593: PetscCall(VecCopy(Xin, X));
2594: PetscCall(VecGetSize(X, &N));
2595: PetscCall(VecGetOwnershipRange(X, &low, &high));
2596: PetscCall(VecSetOption(X, VEC_IGNORE_OFF_PROC_ENTRIES, PETSC_TRUE));
2597: PetscCall(VecGetArray(G, &g));
2598: for (i = 0; i < N; i++) {
2599: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2600: PetscCall(VecAssemblyBegin(X));
2601: PetscCall(VecAssemblyEnd(X));
2602: PetscCall(SNESComputeObjective(snes, X, &f));
2603: PetscCall(VecSetValue(X, i, 2.0 * h, ADD_VALUES));
2604: PetscCall(VecAssemblyBegin(X));
2605: PetscCall(VecAssemblyEnd(X));
2606: PetscCall(SNESComputeObjective(snes, X, &f2));
2607: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2608: PetscCall(VecAssemblyBegin(X));
2609: PetscCall(VecAssemblyEnd(X));
2610: if (i >= low && i < high) g[i - low] = (f2 - f) / (2.0 * h);
2611: }
2612: PetscCall(VecRestoreArray(G, &g));
2613: PetscCall(VecDestroy(&X));
2614: PetscFunctionReturn(PETSC_SUCCESS);
2615: }
2617: PetscErrorCode SNESTestFunction(SNES snes)
2618: {
2619: Vec x, g1, g2, g3;
2620: PetscBool complete_print = PETSC_FALSE, test = PETSC_FALSE;
2621: PetscReal hcnorm, fdnorm, hcmax, fdmax, diffmax, diffnorm;
2622: PetscScalar dot;
2623: MPI_Comm comm;
2624: PetscViewer viewer, mviewer;
2625: PetscViewerFormat format;
2626: PetscInt tabs;
2627: static PetscBool directionsprinted = PETSC_FALSE;
2628: SNESObjectiveFn *objective;
2630: PetscFunctionBegin;
2631: PetscCall(SNESGetObjective(snes, &objective, NULL));
2632: if (!objective) PetscFunctionReturn(PETSC_SUCCESS);
2634: PetscObjectOptionsBegin((PetscObject)snes);
2635: PetscCall(PetscOptionsName("-snes_test_function", "Compare hand-coded and finite difference function", "None", &test));
2636: PetscCall(PetscOptionsViewer("-snes_test_function_view", "View difference between hand-coded and finite difference function element entries", "None", &mviewer, &format, &complete_print));
2637: PetscOptionsEnd();
2638: if (!test) {
2639: if (complete_print) PetscCall(PetscViewerDestroy(&mviewer));
2640: PetscFunctionReturn(PETSC_SUCCESS);
2641: }
2643: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2644: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2645: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2646: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2647: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Function -------------\n"));
2648: if (!complete_print && !directionsprinted) {
2649: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_function_view and optionally -snes_test_function <threshold> to show difference\n"));
2650: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference function entries greater than <threshold>.\n"));
2651: }
2652: if (!directionsprinted) {
2653: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Function, if (for double precision runs) ||F - Ffd||/||F|| is\n"));
2654: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Function is probably correct.\n"));
2655: directionsprinted = PETSC_TRUE;
2656: }
2657: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2659: PetscCall(SNESGetSolution(snes, &x));
2660: PetscCall(VecDuplicate(x, &g1));
2661: PetscCall(VecDuplicate(x, &g2));
2662: PetscCall(VecDuplicate(x, &g3));
2663: PetscCall(SNESComputeFunction(snes, x, g1));
2664: PetscCall(SNESComputeFunction_FD(snes, x, g2));
2666: PetscCall(VecNorm(g2, NORM_2, &fdnorm));
2667: PetscCall(VecNorm(g1, NORM_2, &hcnorm));
2668: PetscCall(VecNorm(g2, NORM_INFINITY, &fdmax));
2669: PetscCall(VecNorm(g1, NORM_INFINITY, &hcmax));
2670: PetscCall(VecDot(g1, g2, &dot));
2671: PetscCall(VecCopy(g1, g3));
2672: PetscCall(VecAXPY(g3, -1.0, g2));
2673: PetscCall(VecNorm(g3, NORM_2, &diffnorm));
2674: PetscCall(VecNorm(g3, NORM_INFINITY, &diffmax));
2675: PetscCall(PetscViewerASCIIPrintf(viewer, " ||Ffd|| %g, ||F|| = %g, angle cosine = (Ffd'F)/||Ffd||||F|| = %g\n", (double)fdnorm, (double)hcnorm, (double)(PetscRealPart(dot) / (fdnorm * hcnorm))));
2676: PetscCall(PetscViewerASCIIPrintf(viewer, " 2-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffnorm / PetscMax(hcnorm, fdnorm)), (double)diffnorm));
2677: PetscCall(PetscViewerASCIIPrintf(viewer, " max-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffmax / PetscMax(hcmax, fdmax)), (double)diffmax));
2679: if (complete_print) {
2680: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded function ----------\n"));
2681: PetscCall(VecView(g1, mviewer));
2682: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference function ----------\n"));
2683: PetscCall(VecView(g2, mviewer));
2684: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference function ----------\n"));
2685: PetscCall(VecView(g3, mviewer));
2686: }
2687: PetscCall(VecDestroy(&g1));
2688: PetscCall(VecDestroy(&g2));
2689: PetscCall(VecDestroy(&g3));
2691: if (complete_print) {
2692: PetscCall(PetscViewerPopFormat(mviewer));
2693: PetscCall(PetscViewerDestroy(&mviewer));
2694: }
2695: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2696: PetscFunctionReturn(PETSC_SUCCESS);
2697: }
2699: PetscErrorCode SNESTestJacobian(SNES snes)
2700: {
2701: Mat A, B, C, D, jacobian;
2702: Vec x = snes->vec_sol, f;
2703: PetscReal nrm, gnorm;
2704: PetscReal threshold = 1.e-5;
2705: MatType mattype;
2706: PetscInt m, n, M, N;
2707: void *functx;
2708: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, test = PETSC_FALSE, flg, istranspose;
2709: PetscViewer viewer, mviewer;
2710: MPI_Comm comm;
2711: PetscInt tabs;
2712: static PetscBool directionsprinted = PETSC_FALSE;
2713: PetscViewerFormat format;
2715: PetscFunctionBegin;
2716: PetscObjectOptionsBegin((PetscObject)snes);
2717: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &test));
2718: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2719: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2720: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2721: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2722: 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));
2723: PetscOptionsEnd();
2724: if (!test) PetscFunctionReturn(PETSC_SUCCESS);
2726: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2727: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2728: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2729: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2730: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2731: if (!complete_print && !directionsprinted) {
2732: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2733: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2734: }
2735: if (!directionsprinted) {
2736: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2737: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2738: directionsprinted = PETSC_TRUE;
2739: }
2740: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2742: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2743: if (!flg) jacobian = snes->jacobian;
2744: else jacobian = snes->jacobian_pre;
2746: if (!x) PetscCall(MatCreateVecs(jacobian, &x, NULL));
2747: else PetscCall(PetscObjectReference((PetscObject)x));
2748: PetscCall(VecDuplicate(x, &f));
2750: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2751: PetscCall(SNESComputeFunction(snes, x, f));
2752: PetscCall(VecDestroy(&f));
2753: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2754: while (jacobian) {
2755: Mat JT = NULL, Jsave = NULL;
2757: if (istranspose) {
2758: PetscCall(MatCreateTranspose(jacobian, &JT));
2759: Jsave = jacobian;
2760: jacobian = JT;
2761: }
2762: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2763: if (flg) {
2764: A = jacobian;
2765: PetscCall(PetscObjectReference((PetscObject)A));
2766: } else {
2767: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2768: }
2770: PetscCall(MatGetType(A, &mattype));
2771: PetscCall(MatGetSize(A, &M, &N));
2772: PetscCall(MatGetLocalSize(A, &m, &n));
2773: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2774: PetscCall(MatSetType(B, mattype));
2775: PetscCall(MatSetSizes(B, m, n, M, N));
2776: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2777: PetscCall(MatSetUp(B));
2778: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2780: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2781: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2783: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2784: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2785: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2786: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2787: PetscCall(MatDestroy(&D));
2788: if (!gnorm) gnorm = 1; /* just in case */
2789: PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2791: if (complete_print) {
2792: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2793: PetscCall(MatView(A, mviewer));
2794: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2795: PetscCall(MatView(B, mviewer));
2796: }
2798: if (threshold_print || complete_print) {
2799: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2800: PetscScalar *cvals;
2801: const PetscInt *bcols;
2802: const PetscScalar *bvals;
2804: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2805: PetscCall(MatSetType(C, mattype));
2806: PetscCall(MatSetSizes(C, m, n, M, N));
2807: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2808: PetscCall(MatSetUp(C));
2809: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2811: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2812: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2814: for (row = Istart; row < Iend; row++) {
2815: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2816: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2817: for (j = 0, cncols = 0; j < bncols; j++) {
2818: if (PetscAbsScalar(bvals[j]) > threshold) {
2819: ccols[cncols] = bcols[j];
2820: cvals[cncols] = bvals[j];
2821: cncols += 1;
2822: }
2823: }
2824: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2825: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2826: PetscCall(PetscFree2(ccols, cvals));
2827: }
2828: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2829: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2830: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2831: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2832: PetscCall(MatDestroy(&C));
2833: }
2834: PetscCall(MatDestroy(&A));
2835: PetscCall(MatDestroy(&B));
2836: PetscCall(MatDestroy(&JT));
2837: if (Jsave) jacobian = Jsave;
2838: if (jacobian != snes->jacobian_pre) {
2839: jacobian = snes->jacobian_pre;
2840: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2841: } else jacobian = NULL;
2842: }
2843: PetscCall(VecDestroy(&x));
2844: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2845: if (mviewer) PetscCall(PetscViewerDestroy(&mviewer));
2846: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2847: PetscFunctionReturn(PETSC_SUCCESS);
2848: }
2850: /*@
2851: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2853: Collective
2855: Input Parameters:
2856: + snes - the `SNES` context
2857: - X - input vector
2859: Output Parameters:
2860: + A - Jacobian matrix
2861: - B - optional matrix for building the preconditioner, usually the same as `A`
2863: Options Database Keys:
2864: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2865: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2866: . -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.
2867: . -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
2868: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2869: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2870: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2871: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2872: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2873: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2874: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2875: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2876: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2877: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2878: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2880: Level: developer
2882: Note:
2883: Most users should not need to explicitly call this routine, as it
2884: is used internally within the nonlinear solvers.
2886: Developer Note:
2887: 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
2888: with the `SNESType` of test that has been removed.
2890: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
2891: @*/
2892: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2893: {
2894: PetscBool flag;
2895: DM dm;
2896: DMSNES sdm;
2897: KSP ksp;
2899: PetscFunctionBegin;
2902: PetscCheckSameComm(snes, 1, X, 2);
2903: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2904: PetscCall(SNESGetDM(snes, &dm));
2905: PetscCall(DMGetDMSNES(dm, &sdm));
2907: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2908: if (snes->lagjacobian == -2) {
2909: snes->lagjacobian = -1;
2911: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2912: } else if (snes->lagjacobian == -1) {
2913: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2914: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2915: if (flag) {
2916: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2917: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2918: }
2919: PetscFunctionReturn(PETSC_SUCCESS);
2920: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2921: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2922: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2923: if (flag) {
2924: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2925: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2926: }
2927: PetscFunctionReturn(PETSC_SUCCESS);
2928: }
2929: if (snes->npc && snes->npcside == PC_LEFT) {
2930: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2931: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2932: PetscFunctionReturn(PETSC_SUCCESS);
2933: }
2935: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2936: PetscCall(VecLockReadPush(X));
2937: {
2938: void *ctx;
2939: SNESJacobianFn *J;
2940: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2941: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2942: }
2943: PetscCall(VecLockReadPop(X));
2944: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
2946: /* attach latest linearization point to the preconditioning matrix */
2947: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
2949: /* the next line ensures that snes->ksp exists */
2950: PetscCall(SNESGetKSP(snes, &ksp));
2951: if (snes->lagpreconditioner == -2) {
2952: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
2953: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2954: snes->lagpreconditioner = -1;
2955: } else if (snes->lagpreconditioner == -1) {
2956: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
2957: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2958: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2959: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
2960: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2961: } else {
2962: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
2963: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2964: }
2966: /* monkey business to allow testing Jacobians in multilevel solvers.
2967: This is needed because the SNESTestXXX interface does not accept vectors and matrices */
2968: {
2969: Vec xsave = snes->vec_sol;
2970: Mat jacobiansave = snes->jacobian;
2971: Mat jacobian_presave = snes->jacobian_pre;
2973: snes->vec_sol = X;
2974: snes->jacobian = A;
2975: snes->jacobian_pre = B;
2976: PetscCall(SNESTestFunction(snes));
2977: PetscCall(SNESTestJacobian(snes));
2979: snes->vec_sol = xsave;
2980: snes->jacobian = jacobiansave;
2981: snes->jacobian_pre = jacobian_presave;
2982: }
2984: {
2985: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
2986: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
2987: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
2988: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
2989: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
2990: if (flag || flag_draw || flag_contour) {
2991: Mat Bexp_mine = NULL, Bexp, FDexp;
2992: PetscViewer vdraw, vstdout;
2993: PetscBool flg;
2994: if (flag_operator) {
2995: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
2996: Bexp = Bexp_mine;
2997: } else {
2998: /* See if the preconditioning matrix can be viewed and added directly */
2999: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPIBAIJ, ""));
3000: if (flg) Bexp = B;
3001: else {
3002: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
3003: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
3004: Bexp = Bexp_mine;
3005: }
3006: }
3007: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
3008: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
3009: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3010: if (flag_draw || flag_contour) {
3011: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3012: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3013: } else vdraw = NULL;
3014: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
3015: if (flag) PetscCall(MatView(Bexp, vstdout));
3016: if (vdraw) PetscCall(MatView(Bexp, vdraw));
3017: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
3018: if (flag) PetscCall(MatView(FDexp, vstdout));
3019: if (vdraw) PetscCall(MatView(FDexp, vdraw));
3020: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
3021: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
3022: if (flag) PetscCall(MatView(FDexp, vstdout));
3023: if (vdraw) { /* Always use contour for the difference */
3024: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3025: PetscCall(MatView(FDexp, vdraw));
3026: PetscCall(PetscViewerPopFormat(vdraw));
3027: }
3028: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3029: PetscCall(PetscViewerDestroy(&vdraw));
3030: PetscCall(MatDestroy(&Bexp_mine));
3031: PetscCall(MatDestroy(&FDexp));
3032: }
3033: }
3034: {
3035: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
3036: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
3037: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
3038: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
3039: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
3040: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
3041: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
3042: if (flag_threshold) {
3043: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
3044: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
3045: }
3046: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
3047: Mat Bfd;
3048: PetscViewer vdraw, vstdout;
3049: MatColoring coloring;
3050: ISColoring iscoloring;
3051: MatFDColoring matfdcoloring;
3052: SNESFunctionFn *func;
3053: void *funcctx;
3054: PetscReal norm1, norm2, normmax;
3056: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
3057: PetscCall(MatColoringCreate(Bfd, &coloring));
3058: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
3059: PetscCall(MatColoringSetFromOptions(coloring));
3060: PetscCall(MatColoringApply(coloring, &iscoloring));
3061: PetscCall(MatColoringDestroy(&coloring));
3062: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
3063: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3064: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
3065: PetscCall(ISColoringDestroy(&iscoloring));
3067: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
3068: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
3069: PetscCall(MatFDColoringSetFunction(matfdcoloring, (PetscErrorCode(*)(void))func, funcctx));
3070: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
3071: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
3072: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3073: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
3074: PetscCall(MatFDColoringDestroy(&matfdcoloring));
3076: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3077: if (flag_draw || flag_contour) {
3078: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3079: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3080: } else vdraw = NULL;
3081: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
3082: if (flag_display) PetscCall(MatView(B, vstdout));
3083: if (vdraw) PetscCall(MatView(B, vdraw));
3084: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
3085: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3086: if (vdraw) PetscCall(MatView(Bfd, vdraw));
3087: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
3088: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
3089: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
3090: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
3091: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
3092: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3093: if (vdraw) { /* Always use contour for the difference */
3094: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3095: PetscCall(MatView(Bfd, vdraw));
3096: PetscCall(PetscViewerPopFormat(vdraw));
3097: }
3098: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3100: if (flag_threshold) {
3101: PetscInt bs, rstart, rend, i;
3102: PetscCall(MatGetBlockSize(B, &bs));
3103: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
3104: for (i = rstart; i < rend; i++) {
3105: const PetscScalar *ba, *ca;
3106: const PetscInt *bj, *cj;
3107: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
3108: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
3109: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
3110: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
3111: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
3112: for (j = 0; j < bn; j++) {
3113: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3114: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
3115: maxentrycol = bj[j];
3116: maxentry = PetscRealPart(ba[j]);
3117: }
3118: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
3119: maxdiffcol = bj[j];
3120: maxdiff = PetscRealPart(ca[j]);
3121: }
3122: if (rdiff > maxrdiff) {
3123: maxrdiffcol = bj[j];
3124: maxrdiff = rdiff;
3125: }
3126: }
3127: if (maxrdiff > 1) {
3128: 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));
3129: for (j = 0; j < bn; j++) {
3130: PetscReal rdiff;
3131: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3132: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
3133: }
3134: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
3135: }
3136: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
3137: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
3138: }
3139: }
3140: PetscCall(PetscViewerDestroy(&vdraw));
3141: PetscCall(MatDestroy(&Bfd));
3142: }
3143: }
3144: PetscFunctionReturn(PETSC_SUCCESS);
3145: }
3147: /*@C
3148: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3149: location to store the matrix.
3151: Logically Collective
3153: Input Parameters:
3154: + snes - the `SNES` context
3155: . Amat - the matrix that defines the (approximate) Jacobian
3156: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3157: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFn` for details
3158: - ctx - [optional] user-defined context for private data for the
3159: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3161: Level: beginner
3163: Notes:
3164: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3165: each matrix.
3167: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3168: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3170: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3171: must be a `MatFDColoring`.
3173: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3174: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3176: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3177: `SNESSetPicard()`, `SNESJacobianFn`, `SNESFunctionFn`
3178: @*/
3179: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
3180: {
3181: DM dm;
3183: PetscFunctionBegin;
3187: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3188: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3189: PetscCall(SNESGetDM(snes, &dm));
3190: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3191: if (Amat) {
3192: PetscCall(PetscObjectReference((PetscObject)Amat));
3193: PetscCall(MatDestroy(&snes->jacobian));
3195: snes->jacobian = Amat;
3196: }
3197: if (Pmat) {
3198: PetscCall(PetscObjectReference((PetscObject)Pmat));
3199: PetscCall(MatDestroy(&snes->jacobian_pre));
3201: snes->jacobian_pre = Pmat;
3202: }
3203: PetscFunctionReturn(PETSC_SUCCESS);
3204: }
3206: /*@C
3207: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3208: provided context for evaluating the Jacobian.
3210: Not Collective, but `Mat` object will be parallel if `SNES` is
3212: Input Parameter:
3213: . snes - the nonlinear solver context
3215: Output Parameters:
3216: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3217: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3218: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFn`
3219: - ctx - location to stash Jacobian ctx (or `NULL`)
3221: Level: advanced
3223: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFn`, `SNESGetFunction()`
3224: @*/
3225: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
3226: {
3227: DM dm;
3229: PetscFunctionBegin;
3231: if (Amat) *Amat = snes->jacobian;
3232: if (Pmat) *Pmat = snes->jacobian_pre;
3233: PetscCall(SNESGetDM(snes, &dm));
3234: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3235: PetscFunctionReturn(PETSC_SUCCESS);
3236: }
3238: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3239: {
3240: DM dm;
3241: DMSNES sdm;
3243: PetscFunctionBegin;
3244: PetscCall(SNESGetDM(snes, &dm));
3245: PetscCall(DMGetDMSNES(dm, &sdm));
3246: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3247: DM dm;
3248: PetscBool isdense, ismf;
3250: PetscCall(SNESGetDM(snes, &dm));
3251: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3252: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3253: if (isdense) {
3254: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3255: } else if (!ismf) {
3256: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3257: }
3258: }
3259: PetscFunctionReturn(PETSC_SUCCESS);
3260: }
3262: /*@
3263: SNESSetUp - Sets up the internal data structures for the later use
3264: of a nonlinear solver.
3266: Collective
3268: Input Parameter:
3269: . snes - the `SNES` context
3271: Level: advanced
3273: Note:
3274: For basic use of the `SNES` solvers the user need not explicitly call
3275: `SNESSetUp()`, since these actions will automatically occur during
3276: the call to `SNESSolve()`. However, if one wishes to control this
3277: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3278: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3280: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`
3281: @*/
3282: PetscErrorCode SNESSetUp(SNES snes)
3283: {
3284: DM dm;
3285: DMSNES sdm;
3286: SNESLineSearch linesearch, pclinesearch;
3287: void *lsprectx, *lspostctx;
3288: PetscBool mf_operator, mf;
3289: Vec f, fpc;
3290: void *funcctx;
3291: void *jacctx, *appctx;
3292: Mat j, jpre;
3293: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3294: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3295: SNESFunctionFn *func;
3296: SNESJacobianFn *jac;
3298: PetscFunctionBegin;
3300: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3301: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3303: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3305: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3307: PetscCall(SNESGetDM(snes, &dm));
3308: PetscCall(DMGetDMSNES(dm, &sdm));
3309: PetscCall(SNESSetDefaultComputeJacobian(snes));
3311: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3313: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3315: if (snes->linesearch) {
3316: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3317: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3318: }
3320: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3321: if (snes->npc && snes->npcside == PC_LEFT) {
3322: snes->mf = PETSC_TRUE;
3323: snes->mf_operator = PETSC_FALSE;
3324: }
3326: if (snes->npc) {
3327: /* copy the DM over */
3328: PetscCall(SNESGetDM(snes, &dm));
3329: PetscCall(SNESSetDM(snes->npc, dm));
3331: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3332: PetscCall(VecDuplicate(f, &fpc));
3333: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3334: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3335: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3336: PetscCall(SNESGetApplicationContext(snes, &appctx));
3337: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3338: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3339: PetscCall(VecDestroy(&fpc));
3341: /* copy the function pointers over */
3342: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3344: /* default to 1 iteration */
3345: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3346: if (snes->npcside == PC_RIGHT) {
3347: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3348: } else {
3349: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3350: }
3351: PetscCall(SNESSetFromOptions(snes->npc));
3353: /* copy the line search context over */
3354: if (snes->linesearch && snes->npc->linesearch) {
3355: PetscCall(SNESGetLineSearch(snes, &linesearch));
3356: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3357: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3358: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3359: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3360: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3361: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3362: }
3363: }
3364: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3365: if (snes->ops->usercompute && !snes->user) PetscCallBack("SNES callback compute application context", (*snes->ops->usercompute)(snes, (void **)&snes->user));
3367: snes->jac_iter = 0;
3368: snes->pre_iter = 0;
3370: PetscTryTypeMethod(snes, setup);
3372: PetscCall(SNESSetDefaultComputeJacobian(snes));
3374: if (snes->npc && snes->npcside == PC_LEFT) {
3375: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3376: if (snes->linesearch) {
3377: PetscCall(SNESGetLineSearch(snes, &linesearch));
3378: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3379: }
3380: }
3381: }
3382: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3383: snes->setupcalled = PETSC_TRUE;
3384: PetscFunctionReturn(PETSC_SUCCESS);
3385: }
3387: /*@
3388: SNESReset - Resets a `SNES` context to the snessetupcalled = 0 state and removes any allocated `Vec`s and `Mat`s
3390: Collective
3392: Input Parameter:
3393: . snes - iterative context obtained from `SNESCreate()`
3395: Level: intermediate
3397: Notes:
3398: Call this if you wish to reuse a `SNES` but with different size vectors
3400: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3402: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3403: @*/
3404: PetscErrorCode SNESReset(SNES snes)
3405: {
3406: PetscFunctionBegin;
3408: if (snes->ops->userdestroy && snes->user) {
3409: PetscCallBack("SNES callback destroy application context", (*snes->ops->userdestroy)((void **)&snes->user));
3410: snes->user = NULL;
3411: }
3412: if (snes->npc) PetscCall(SNESReset(snes->npc));
3414: PetscTryTypeMethod(snes, reset);
3415: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3417: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3419: PetscCall(VecDestroy(&snes->vec_rhs));
3420: PetscCall(VecDestroy(&snes->vec_sol));
3421: PetscCall(VecDestroy(&snes->vec_sol_update));
3422: PetscCall(VecDestroy(&snes->vec_func));
3423: PetscCall(MatDestroy(&snes->jacobian));
3424: PetscCall(MatDestroy(&snes->jacobian_pre));
3425: PetscCall(MatDestroy(&snes->picard));
3426: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3427: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3429: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3431: snes->nwork = snes->nvwork = 0;
3432: snes->setupcalled = PETSC_FALSE;
3433: PetscFunctionReturn(PETSC_SUCCESS);
3434: }
3436: /*@
3437: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()` also
3438: removes the default viewer.
3440: Collective
3442: Input Parameter:
3443: . snes - iterative context obtained from `SNESCreate()`
3445: Level: intermediate
3447: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3448: @*/
3449: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3450: {
3451: PetscInt i;
3453: PetscFunctionBegin;
3455: for (i = 0; i < snes->numberreasonviews; i++) {
3456: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3457: }
3458: snes->numberreasonviews = 0;
3459: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
3460: PetscFunctionReturn(PETSC_SUCCESS);
3461: }
3463: /*@
3464: SNESDestroy - Destroys the nonlinear solver context that was created
3465: with `SNESCreate()`.
3467: Collective
3469: Input Parameter:
3470: . snes - the `SNES` context
3472: Level: beginner
3474: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3475: @*/
3476: PetscErrorCode SNESDestroy(SNES *snes)
3477: {
3478: PetscFunctionBegin;
3479: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3481: if (--((PetscObject)*snes)->refct > 0) {
3482: *snes = NULL;
3483: PetscFunctionReturn(PETSC_SUCCESS);
3484: }
3486: PetscCall(SNESReset(*snes));
3487: PetscCall(SNESDestroy(&(*snes)->npc));
3489: /* if memory was published with SAWs then destroy it */
3490: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3491: PetscTryTypeMethod(*snes, destroy);
3493: if ((*snes)->dm) PetscCall(DMCoarsenHookRemove((*snes)->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3494: PetscCall(DMDestroy(&(*snes)->dm));
3495: PetscCall(KSPDestroy(&(*snes)->ksp));
3496: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3498: PetscCall(PetscFree((*snes)->kspconvctx));
3499: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)((*snes)->cnvP));
3500: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3501: PetscCall(SNESMonitorCancel(*snes));
3502: PetscCall(SNESConvergedReasonViewCancel(*snes));
3503: PetscCall(PetscHeaderDestroy(snes));
3504: PetscFunctionReturn(PETSC_SUCCESS);
3505: }
3507: /* ----------- Routines to set solver parameters ---------- */
3509: /*@
3510: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3512: Logically Collective
3514: Input Parameters:
3515: + snes - the `SNES` context
3516: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3517: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3519: Options Database Keys:
3520: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3521: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3522: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3523: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3525: Level: intermediate
3527: Notes:
3528: The default is 1
3530: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3532: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3534: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3535: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3536: @*/
3537: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3538: {
3539: PetscFunctionBegin;
3541: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3542: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3544: snes->lagpreconditioner = lag;
3545: PetscFunctionReturn(PETSC_SUCCESS);
3546: }
3548: /*@
3549: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3551: Logically Collective
3553: Input Parameters:
3554: + snes - the `SNES` context
3555: - steps - the number of refinements to do, defaults to 0
3557: Options Database Key:
3558: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3560: Level: intermediate
3562: Note:
3563: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3565: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3566: `SNESetDM()`
3567: @*/
3568: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3569: {
3570: PetscFunctionBegin;
3573: snes->gridsequence = steps;
3574: PetscFunctionReturn(PETSC_SUCCESS);
3575: }
3577: /*@
3578: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3580: Logically Collective
3582: Input Parameter:
3583: . snes - the `SNES` context
3585: Output Parameter:
3586: . steps - the number of refinements to do, defaults to 0
3588: Level: intermediate
3590: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3591: @*/
3592: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3593: {
3594: PetscFunctionBegin;
3596: *steps = snes->gridsequence;
3597: PetscFunctionReturn(PETSC_SUCCESS);
3598: }
3600: /*@
3601: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3603: Not Collective
3605: Input Parameter:
3606: . snes - the `SNES` context
3608: Output Parameter:
3609: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3610: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3612: Level: intermediate
3614: Notes:
3615: The default is 1
3617: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3619: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3620: @*/
3621: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3622: {
3623: PetscFunctionBegin;
3625: *lag = snes->lagpreconditioner;
3626: PetscFunctionReturn(PETSC_SUCCESS);
3627: }
3629: /*@
3630: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3631: often the preconditioner is rebuilt.
3633: Logically Collective
3635: Input Parameters:
3636: + snes - the `SNES` context
3637: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3638: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3640: Options Database Keys:
3641: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3642: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3643: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3644: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3646: Level: intermediate
3648: Notes:
3649: The default is 1
3651: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3653: 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
3654: at the next Newton step but never again (unless it is reset to another value)
3656: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3657: @*/
3658: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3659: {
3660: PetscFunctionBegin;
3662: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3663: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3665: snes->lagjacobian = lag;
3666: PetscFunctionReturn(PETSC_SUCCESS);
3667: }
3669: /*@
3670: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3672: Not Collective
3674: Input Parameter:
3675: . snes - the `SNES` context
3677: Output Parameter:
3678: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3679: the Jacobian is built etc.
3681: Level: intermediate
3683: Notes:
3684: The default is 1
3686: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3688: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3690: @*/
3691: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3692: {
3693: PetscFunctionBegin;
3695: *lag = snes->lagjacobian;
3696: PetscFunctionReturn(PETSC_SUCCESS);
3697: }
3699: /*@
3700: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3702: Logically collective
3704: Input Parameters:
3705: + snes - the `SNES` context
3706: - flg - jacobian lagging persists if true
3708: Options Database Keys:
3709: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3710: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3711: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3712: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3714: Level: advanced
3716: Notes:
3717: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3719: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3720: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3721: timesteps may present huge efficiency gains.
3723: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3724: @*/
3725: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3726: {
3727: PetscFunctionBegin;
3730: snes->lagjac_persist = flg;
3731: PetscFunctionReturn(PETSC_SUCCESS);
3732: }
3734: /*@
3735: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3737: Logically Collective
3739: Input Parameters:
3740: + snes - the `SNES` context
3741: - flg - preconditioner lagging persists if true
3743: Options Database Keys:
3744: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3745: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3746: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3747: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3749: Level: developer
3751: Notes:
3752: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3754: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3755: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3756: several timesteps may present huge efficiency gains.
3758: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3759: @*/
3760: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3761: {
3762: PetscFunctionBegin;
3765: snes->lagpre_persist = flg;
3766: PetscFunctionReturn(PETSC_SUCCESS);
3767: }
3769: /*@
3770: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3772: Logically Collective
3774: Input Parameters:
3775: + snes - the `SNES` context
3776: - force - `PETSC_TRUE` require at least one iteration
3778: Options Database Key:
3779: . -snes_force_iteration <force> - Sets forcing an iteration
3781: Level: intermediate
3783: Note:
3784: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3786: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3787: @*/
3788: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3789: {
3790: PetscFunctionBegin;
3792: snes->forceiteration = force;
3793: PetscFunctionReturn(PETSC_SUCCESS);
3794: }
3796: /*@
3797: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3799: Logically Collective
3801: Input Parameter:
3802: . snes - the `SNES` context
3804: Output Parameter:
3805: . force - `PETSC_TRUE` requires at least one iteration.
3807: Level: intermediate
3809: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3810: @*/
3811: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3812: {
3813: PetscFunctionBegin;
3815: *force = snes->forceiteration;
3816: PetscFunctionReturn(PETSC_SUCCESS);
3817: }
3819: /*@
3820: SNESSetTolerances - Sets `SNES` various parameters used in convergence tests.
3822: Logically Collective
3824: Input Parameters:
3825: + snes - the `SNES` context
3826: . abstol - absolute convergence tolerance
3827: . rtol - relative convergence tolerance
3828: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3829: . maxit - maximum number of iterations, default 50.
3830: - maxf - maximum number of function evaluations (use `PETSC_UNLIMITED` indicates no limit), default 10,000
3832: Options Database Keys:
3833: + -snes_atol <abstol> - Sets `abstol`
3834: . -snes_rtol <rtol> - Sets `rtol`
3835: . -snes_stol <stol> - Sets `stol`
3836: . -snes_max_it <maxit> - Sets `maxit`
3837: - -snes_max_funcs <maxf> - Sets `maxf` (use `unlimited` to have no maximum)
3839: Level: intermediate
3841: Note:
3842: All parameters must be non-negative
3844: Use `PETSC_CURRENT` to retain the current value of any parameter and `PETSC_DETERMINE` to use the default value for the given `SNES`.
3845: The default value is the value in the object when its type is set.
3847: Use `PETSC_UNLIMITED` on `maxit` or `maxf` to indicate there is no bound on the number of iterations or number of function evaluations.
3849: Fortran Note:
3850: Use `PETSC_CURRENT_INTEGER`, `PETSC_CURRENT_REAL`, `PETSC_UNLIMITED_INTEGER`, `PETSC_DETERMINE_INTEGER`, or `PETSC_DETERMINE_REAL`
3852: .seealso: [](ch_snes), `SNESSolve()`, `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3853: @*/
3854: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3855: {
3856: PetscFunctionBegin;
3864: if (abstol == (PetscReal)PETSC_DETERMINE) {
3865: snes->abstol = snes->default_abstol;
3866: } else if (abstol != (PetscReal)PETSC_CURRENT) {
3867: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3868: snes->abstol = abstol;
3869: }
3871: if (rtol == (PetscReal)PETSC_DETERMINE) {
3872: snes->rtol = snes->default_rtol;
3873: } else if (rtol != (PetscReal)PETSC_CURRENT) {
3874: 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);
3875: snes->rtol = rtol;
3876: }
3878: if (stol == (PetscReal)PETSC_DETERMINE) {
3879: snes->stol = snes->default_stol;
3880: } else if (stol != (PetscReal)PETSC_CURRENT) {
3881: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3882: snes->stol = stol;
3883: }
3885: if (maxit == (PetscInt)PETSC_DETERMINE) {
3886: snes->max_its = snes->default_max_its;
3887: } else if (maxit == (PetscInt)PETSC_UNLIMITED) {
3888: snes->max_its = PETSC_INT_MAX;
3889: } else if (maxit != PETSC_CURRENT) {
3890: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3891: snes->max_its = maxit;
3892: }
3894: if (maxf == (PetscInt)PETSC_DETERMINE) {
3895: snes->max_funcs = snes->default_max_funcs;
3896: } else if (maxf == (PetscInt)PETSC_UNLIMITED || maxf == -1) {
3897: snes->max_funcs = PETSC_UNLIMITED;
3898: } else if (maxf != PETSC_CURRENT) {
3899: PetscCheck(maxf >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be nonnegative", maxf);
3900: snes->max_funcs = maxf;
3901: }
3902: PetscFunctionReturn(PETSC_SUCCESS);
3903: }
3905: /*@
3906: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3908: Logically Collective
3910: Input Parameters:
3911: + snes - the `SNES` context
3912: - divtol - the divergence tolerance. Use `PETSC_UNLIMITED` to deactivate the test, default is 1e4
3914: Options Database Key:
3915: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3917: Level: intermediate
3919: Notes:
3920: Use `PETSC_DETERMINE` to use the default value from when the object's type was set.
3922: Fortran Note:
3923: Use ``PETSC_DETERMINE_REAL` or `PETSC_UNLIMITED_REAL`
3925: Developer Note:
3926: Also supports the deprecated -1 to indicate no bound on the growth of the residual
3928: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance()`
3929: @*/
3930: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3931: {
3932: PetscFunctionBegin;
3936: if (divtol == (PetscReal)PETSC_DETERMINE) {
3937: snes->divtol = snes->default_divtol;
3938: } else if (divtol == (PetscReal)PETSC_UNLIMITED || divtol == -1) {
3939: snes->divtol = PETSC_UNLIMITED;
3940: } else if (divtol != (PetscReal)PETSC_CURRENT) {
3941: PetscCheck(divtol >= 1.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Divergence tolerance %g must be greater than 1.0", (double)divtol);
3942: snes->divtol = divtol;
3943: }
3944: PetscFunctionReturn(PETSC_SUCCESS);
3945: }
3947: /*@
3948: SNESGetTolerances - Gets various parameters used in convergence tests.
3950: Not Collective
3952: Input Parameter:
3953: . snes - the `SNES` context
3955: Output Parameters:
3956: + atol - absolute convergence tolerance
3957: . rtol - relative convergence tolerance
3958: . stol - convergence tolerance in terms of the norm of the change in the solution between steps
3959: . maxit - maximum number of iterations
3960: - maxf - maximum number of function evaluations, `PETSC_UNLIMITED` indicates no bound
3962: Level: intermediate
3964: Note:
3965: The user can specify `NULL` for any parameter that is not needed.
3967: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
3968: @*/
3969: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
3970: {
3971: PetscFunctionBegin;
3973: if (atol) *atol = snes->abstol;
3974: if (rtol) *rtol = snes->rtol;
3975: if (stol) *stol = snes->stol;
3976: if (maxit) *maxit = snes->max_its;
3977: if (maxf) *maxf = snes->max_funcs;
3978: PetscFunctionReturn(PETSC_SUCCESS);
3979: }
3981: /*@
3982: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3984: Not Collective
3986: Input Parameters:
3987: + snes - the `SNES` context
3988: - divtol - divergence tolerance
3990: Level: intermediate
3992: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
3993: @*/
3994: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
3995: {
3996: PetscFunctionBegin;
3998: if (divtol) *divtol = snes->divtol;
3999: PetscFunctionReturn(PETSC_SUCCESS);
4000: }
4002: /*@
4003: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
4005: Logically Collective
4007: Input Parameters:
4008: + snes - the `SNES` context
4009: - tol - tolerance, must be non-negative
4011: Options Database Key:
4012: . -snes_tr_tol <tol> - Sets tol
4014: Level: intermediate
4016: Note:
4017: Use `PETSC_DETERMINE` to use the default value for the given `SNES`. The default value is the value in the object when its type is set
4019: Fortran Note:
4020: Use `PETSC_DETERMINE_REAL`
4022: Developer Note:
4023: Should be named `SNESTrustRegionSetTolerance()`
4025: .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`, `SNESSetTolerances()`
4026: @*/
4027: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes, PetscReal tol)
4028: {
4029: PetscFunctionBegin;
4032: if (tol == (PetscReal)PETSC_DETERMINE) {
4033: snes->deltatol = snes->default_deltatol;
4034: } else if (tol > 0) snes->deltatol = tol;
4035: else SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot set negative trust region tolerance");
4036: PetscFunctionReturn(PETSC_SUCCESS);
4037: }
4039: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
4041: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
4042: {
4043: PetscDrawLG lg;
4044: PetscReal x, y, per;
4045: PetscViewer v = (PetscViewer)monctx;
4046: static PetscReal prev; /* should be in the context */
4047: PetscDraw draw;
4049: PetscFunctionBegin;
4051: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
4052: if (!n) PetscCall(PetscDrawLGReset(lg));
4053: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4054: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
4055: x = (PetscReal)n;
4056: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
4057: else y = -15.0;
4058: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4059: if (n < 20 || !(n % 5) || snes->reason) {
4060: PetscCall(PetscDrawLGDraw(lg));
4061: PetscCall(PetscDrawLGSave(lg));
4062: }
4064: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
4065: if (!n) PetscCall(PetscDrawLGReset(lg));
4066: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4067: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
4068: PetscCall(SNESMonitorRange_Private(snes, n, &per));
4069: x = (PetscReal)n;
4070: y = 100.0 * per;
4071: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4072: if (n < 20 || !(n % 5) || snes->reason) {
4073: PetscCall(PetscDrawLGDraw(lg));
4074: PetscCall(PetscDrawLGSave(lg));
4075: }
4077: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
4078: if (!n) {
4079: prev = rnorm;
4080: PetscCall(PetscDrawLGReset(lg));
4081: }
4082: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4083: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
4084: x = (PetscReal)n;
4085: y = (prev - rnorm) / prev;
4086: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4087: if (n < 20 || !(n % 5) || snes->reason) {
4088: PetscCall(PetscDrawLGDraw(lg));
4089: PetscCall(PetscDrawLGSave(lg));
4090: }
4092: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
4093: if (!n) PetscCall(PetscDrawLGReset(lg));
4094: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4095: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
4096: x = (PetscReal)n;
4097: y = (prev - rnorm) / (prev * per);
4098: if (n > 2) { /*skip initial crazy value */
4099: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4100: }
4101: if (n < 20 || !(n % 5) || snes->reason) {
4102: PetscCall(PetscDrawLGDraw(lg));
4103: PetscCall(PetscDrawLGSave(lg));
4104: }
4105: prev = rnorm;
4106: PetscFunctionReturn(PETSC_SUCCESS);
4107: }
4109: /*@
4110: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
4112: Collective
4114: Input Parameters:
4115: + snes - the `SNES` context
4116: . it - current iteration
4117: . xnorm - 2-norm of current iterate
4118: . snorm - 2-norm of current step
4119: - fnorm - 2-norm of function
4121: Level: developer
4123: Note:
4124: This routine is called by the `SNESSolve()` implementations.
4125: It does not typically need to be called by the user.
4127: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4128: @*/
4129: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
4130: {
4131: PetscFunctionBegin;
4132: if (!snes->reason) {
4133: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
4134: if (it == snes->max_its && !snes->reason) {
4135: if (snes->normschedule == SNES_NORM_ALWAYS) {
4136: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
4137: snes->reason = SNES_DIVERGED_MAX_IT;
4138: } else snes->reason = SNES_CONVERGED_ITS;
4139: }
4140: }
4141: PetscFunctionReturn(PETSC_SUCCESS);
4142: }
4144: /*@
4145: SNESMonitor - runs the user provided monitor routines, if they exist
4147: Collective
4149: Input Parameters:
4150: + snes - nonlinear solver context obtained from `SNESCreate()`
4151: . iter - iteration number
4152: - rnorm - relative norm of the residual
4154: Level: developer
4156: Note:
4157: This routine is called by the `SNESSolve()` implementations.
4158: It does not typically need to be called by the user.
4160: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
4161: @*/
4162: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
4163: {
4164: PetscInt i, n = snes->numbermonitors;
4166: PetscFunctionBegin;
4167: if (n > 0) SNESCheckFunctionNorm(snes, rnorm);
4168: PetscCall(VecLockReadPush(snes->vec_sol));
4169: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
4170: PetscCall(VecLockReadPop(snes->vec_sol));
4171: PetscFunctionReturn(PETSC_SUCCESS);
4172: }
4174: /* ------------ Routines to set performance monitoring options ----------- */
4176: /*MC
4177: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
4179: Synopsis:
4180: #include <petscsnes.h>
4181: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, void *mctx)
4183: Collective
4185: Input Parameters:
4186: + snes - the `SNES` context
4187: . its - iteration number
4188: . norm - 2-norm function value (may be estimated)
4189: - mctx - [optional] monitoring context
4191: Level: advanced
4193: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSet()`, `SNESMonitorGet()`
4194: M*/
4196: /*@C
4197: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
4198: iteration of the nonlinear solver to display the iteration's
4199: progress.
4201: Logically Collective
4203: Input Parameters:
4204: + snes - the `SNES` context
4205: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4206: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4207: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`)
4209: Options Database Keys:
4210: + -snes_monitor - sets `SNESMonitorDefault()`
4211: . -snes_monitor draw::draw_lg - sets line graph monitor,
4212: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4213: the options database.
4215: Level: intermediate
4217: Note:
4218: Several different monitoring routines may be set by calling
4219: `SNESMonitorSet()` multiple times; all will be called in the
4220: order in which they were set.
4222: Fortran Note:
4223: Only a single monitor function can be set for each `SNES` object
4225: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`
4226: @*/
4227: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscErrorCode (*monitordestroy)(void **))
4228: {
4229: PetscInt i;
4230: PetscBool identical;
4232: PetscFunctionBegin;
4234: for (i = 0; i < snes->numbermonitors; i++) {
4235: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, mctx, monitordestroy, (PetscErrorCode(*)(void))snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4236: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4237: }
4238: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4239: snes->monitor[snes->numbermonitors] = f;
4240: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4241: snes->monitorcontext[snes->numbermonitors++] = (void *)mctx;
4242: PetscFunctionReturn(PETSC_SUCCESS);
4243: }
4245: /*@
4246: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4248: Logically Collective
4250: Input Parameter:
4251: . snes - the `SNES` context
4253: Options Database Key:
4254: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4255: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4256: set via the options database
4258: Level: intermediate
4260: Note:
4261: There is no way to clear one specific monitor from a `SNES` object.
4263: .seealso: [](ch_snes), `SNES`, `SNESMonitorGet()`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4264: @*/
4265: PetscErrorCode SNESMonitorCancel(SNES snes)
4266: {
4267: PetscInt i;
4269: PetscFunctionBegin;
4271: for (i = 0; i < snes->numbermonitors; i++) {
4272: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4273: }
4274: snes->numbermonitors = 0;
4275: PetscFunctionReturn(PETSC_SUCCESS);
4276: }
4278: /*MC
4279: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4281: Synopsis:
4282: #include <petscsnes.h>
4283: PetscErrorCode SNESConvergenceTest(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *cctx)
4285: Collective
4287: Input Parameters:
4288: + snes - the `SNES` context
4289: . it - current iteration (0 is the first and is before any Newton step)
4290: . xnorm - 2-norm of current iterate
4291: . gnorm - 2-norm of current step
4292: . f - 2-norm of function
4293: - cctx - [optional] convergence context
4295: Output Parameter:
4296: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4298: Level: intermediate
4300: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4301: M*/
4303: /*@C
4304: SNESSetConvergenceTest - Sets the function that is to be used
4305: to test for convergence of the nonlinear iterative solution.
4307: Logically Collective
4309: Input Parameters:
4310: + snes - the `SNES` context
4311: . SNESConvergenceTestFunction - routine to test for convergence
4312: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4313: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4315: Level: advanced
4317: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4318: @*/
4319: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscErrorCode (*destroy)(void *))
4320: {
4321: PetscFunctionBegin;
4323: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4324: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(snes->cnvP));
4325: snes->ops->converged = SNESConvergenceTestFunction;
4326: snes->ops->convergeddestroy = destroy;
4327: snes->cnvP = cctx;
4328: PetscFunctionReturn(PETSC_SUCCESS);
4329: }
4331: /*@
4332: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped.
4334: Not Collective
4336: Input Parameter:
4337: . snes - the `SNES` context
4339: Output Parameter:
4340: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4342: Options Database Key:
4343: . -snes_converged_reason - prints the reason to standard out
4345: Level: intermediate
4347: Note:
4348: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4350: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4351: @*/
4352: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4353: {
4354: PetscFunctionBegin;
4356: PetscAssertPointer(reason, 2);
4357: *reason = snes->reason;
4358: PetscFunctionReturn(PETSC_SUCCESS);
4359: }
4361: /*@C
4362: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4364: Not Collective
4366: Input Parameter:
4367: . snes - the `SNES` context
4369: Output Parameter:
4370: . strreason - a human readable string that describes `SNES` converged reason
4372: Level: beginner
4374: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4375: @*/
4376: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4377: {
4378: PetscFunctionBegin;
4380: PetscAssertPointer(strreason, 2);
4381: *strreason = SNESConvergedReasons[snes->reason];
4382: PetscFunctionReturn(PETSC_SUCCESS);
4383: }
4385: /*@
4386: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4388: Not Collective
4390: Input Parameters:
4391: + snes - the `SNES` context
4392: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4393: manual pages for the individual convergence tests for complete lists
4395: Level: developer
4397: Developer Note:
4398: Called inside the various `SNESSolve()` implementations
4400: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4401: @*/
4402: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4403: {
4404: PetscFunctionBegin;
4406: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4407: snes->reason = reason;
4408: PetscFunctionReturn(PETSC_SUCCESS);
4409: }
4411: /*@
4412: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4414: Logically Collective
4416: Input Parameters:
4417: + snes - iterative context obtained from `SNESCreate()`
4418: . a - array to hold history, this array will contain the function norms computed at each step
4419: . its - integer array holds the number of linear iterations for each solve.
4420: . na - size of `a` and `its`
4421: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4422: else it continues storing new values for new nonlinear solves after the old ones
4424: Level: intermediate
4426: Notes:
4427: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' is `PETSC_DECIDE` then a
4428: default array of length 1,000 is allocated.
4430: This routine is useful, e.g., when running a code for purposes
4431: of accurate performance monitoring, when no I/O should be done
4432: during the section of code that is being timed.
4434: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4436: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4437: @*/
4438: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4439: {
4440: PetscFunctionBegin;
4442: if (a) PetscAssertPointer(a, 2);
4443: if (its) PetscAssertPointer(its, 3);
4444: if (!a) {
4445: if (na == PETSC_DECIDE) na = 1000;
4446: PetscCall(PetscCalloc2(na, &a, na, &its));
4447: snes->conv_hist_alloc = PETSC_TRUE;
4448: }
4449: snes->conv_hist = a;
4450: snes->conv_hist_its = its;
4451: snes->conv_hist_max = (size_t)na;
4452: snes->conv_hist_len = 0;
4453: snes->conv_hist_reset = reset;
4454: PetscFunctionReturn(PETSC_SUCCESS);
4455: }
4457: #if defined(PETSC_HAVE_MATLAB)
4458: #include <engine.h> /* MATLAB include file */
4459: #include <mex.h> /* MATLAB include file */
4461: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4462: {
4463: mxArray *mat;
4464: PetscInt i;
4465: PetscReal *ar;
4467: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4468: ar = (PetscReal *)mxGetData(mat);
4469: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4470: return mat;
4471: }
4472: #endif
4474: /*@C
4475: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4477: Not Collective
4479: Input Parameter:
4480: . snes - iterative context obtained from `SNESCreate()`
4482: Output Parameters:
4483: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4484: . its - integer array holds the number of linear iterations (or
4485: negative if not converged) for each solve.
4486: - na - size of `a` and `its`
4488: Level: intermediate
4490: Note:
4491: This routine is useful, e.g., when running a code for purposes
4492: of accurate performance monitoring, when no I/O should be done
4493: during the section of code that is being timed.
4495: Fortran Note:
4496: The calling sequence for this routine in Fortran is
4497: .vb
4498: call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4499: .ve
4501: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4502: @*/
4503: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4504: {
4505: PetscFunctionBegin;
4507: if (a) *a = snes->conv_hist;
4508: if (its) *its = snes->conv_hist_its;
4509: if (na) *na = (PetscInt)snes->conv_hist_len;
4510: PetscFunctionReturn(PETSC_SUCCESS);
4511: }
4513: /*@C
4514: SNESSetUpdate - Sets the general-purpose update function called
4515: at the beginning of every iteration of the nonlinear solve. Specifically
4516: it is called just before the Jacobian is "evaluated" and after the function
4517: evaluation.
4519: Logically Collective
4521: Input Parameters:
4522: + snes - The nonlinear solver context
4523: - func - The update function; for calling sequence see `SNESUpdateFn`
4525: Level: advanced
4527: Notes:
4528: 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
4529: to `SNESSetFunction()`, or `SNESSetPicard()`
4530: This is not used by most users, and it is intended to provide a general hook that is run
4531: right before the direction step is computed.
4532: Users are free to modify the current residual vector,
4533: the current linearization point, or any other vector associated to the specific solver used.
4534: If such modifications take place, it is the user responsibility to update all the relevant
4535: vectors.
4537: 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.
4539: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4540: `SNESMonitorSet()`
4541: @*/
4542: PetscErrorCode SNESSetUpdate(SNES snes, SNESUpdateFn *func)
4543: {
4544: PetscFunctionBegin;
4546: snes->ops->update = func;
4547: PetscFunctionReturn(PETSC_SUCCESS);
4548: }
4550: /*@
4551: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4553: Collective
4555: Input Parameters:
4556: + snes - iterative context obtained from `SNESCreate()`
4557: - viewer - the viewer to display the reason
4559: Options Database Keys:
4560: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4561: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4563: Level: beginner
4565: Note:
4566: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4567: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4569: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4570: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4571: `SNESConvergedReasonViewFromOptions()`,
4572: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4573: @*/
4574: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4575: {
4576: PetscViewerFormat format;
4577: PetscBool isAscii;
4579: PetscFunctionBegin;
4580: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4581: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4582: if (isAscii) {
4583: PetscCall(PetscViewerGetFormat(viewer, &format));
4584: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel + 1));
4585: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4586: DM dm;
4587: Vec u;
4588: PetscDS prob;
4589: PetscInt Nf, f;
4590: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4591: void **exactCtx;
4592: PetscReal error;
4594: PetscCall(SNESGetDM(snes, &dm));
4595: PetscCall(SNESGetSolution(snes, &u));
4596: PetscCall(DMGetDS(dm, &prob));
4597: PetscCall(PetscDSGetNumFields(prob, &Nf));
4598: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4599: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4600: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4601: PetscCall(PetscFree2(exactSol, exactCtx));
4602: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4603: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4604: }
4605: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4606: if (((PetscObject)snes)->prefix) {
4607: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4608: } else {
4609: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4610: }
4611: } else if (snes->reason <= 0) {
4612: if (((PetscObject)snes)->prefix) {
4613: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4614: } else {
4615: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4616: }
4617: }
4618: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel + 1));
4619: }
4620: PetscFunctionReturn(PETSC_SUCCESS);
4621: }
4623: /*@C
4624: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4625: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4627: Logically Collective
4629: Input Parameters:
4630: + snes - the `SNES` context
4631: . f - the `SNESConvergedReason` view function
4632: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4633: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`)
4635: Calling sequence of `f`:
4636: + snes - the `SNES` context
4637: - vctx - [optional] user-defined context for private data for the function
4639: Calling sequence of `reasonviewerdestroy`:
4640: . vctx - [optional] user-defined context for private data for the function
4642: Options Database Keys:
4643: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4644: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4645: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4647: Level: intermediate
4649: Note:
4650: Several different converged reason view routines may be set by calling
4651: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4652: order in which they were set.
4654: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`
4655: @*/
4656: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, void *vctx), void *vctx, PetscErrorCode (*reasonviewdestroy)(void **vctx))
4657: {
4658: PetscInt i;
4659: PetscBool identical;
4661: PetscFunctionBegin;
4663: for (i = 0; i < snes->numberreasonviews; i++) {
4664: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, vctx, reasonviewdestroy, (PetscErrorCode(*)(void))snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4665: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4666: }
4667: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4668: snes->reasonview[snes->numberreasonviews] = f;
4669: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4670: snes->reasonviewcontext[snes->numberreasonviews++] = (void *)vctx;
4671: PetscFunctionReturn(PETSC_SUCCESS);
4672: }
4674: /*@
4675: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4676: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4678: Collective
4680: Input Parameter:
4681: . snes - the `SNES` object
4683: Level: advanced
4685: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4686: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4687: @*/
4688: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4689: {
4690: static PetscBool incall = PETSC_FALSE;
4692: PetscFunctionBegin;
4693: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4694: incall = PETSC_TRUE;
4696: /* All user-provided viewers are called first, if they exist. */
4697: for (PetscInt i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4699: /* Call PETSc default routine if users ask for it */
4700: if (snes->convergedreasonviewer) {
4701: PetscCall(PetscViewerPushFormat(snes->convergedreasonviewer, snes->convergedreasonformat));
4702: PetscCall(SNESConvergedReasonView(snes, snes->convergedreasonviewer));
4703: PetscCall(PetscViewerPopFormat(snes->convergedreasonviewer));
4704: }
4705: incall = PETSC_FALSE;
4706: PetscFunctionReturn(PETSC_SUCCESS);
4707: }
4709: /*@
4710: SNESSolve - Solves a nonlinear system F(x) = b.
4712: Collective
4714: Input Parameters:
4715: + snes - the `SNES` context
4716: . b - the constant part of the equation F(x) = b, or `NULL` to use zero.
4717: - x - the solution vector.
4719: Level: beginner
4721: Note:
4722: The user should initialize the vector, `x`, with the initial guess
4723: for the nonlinear solve prior to calling `SNESSolve()` or use `SNESSetInitialSolution()`. In particular,
4724: to employ an initial guess of zero, the user should explicitly set
4725: this vector to zero by calling `VecSet()`.
4727: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4728: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4729: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`, `SNESSetInitialSolution()`
4730: @*/
4731: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4732: {
4733: PetscBool flg;
4734: PetscInt grid;
4735: Vec xcreated = NULL;
4736: DM dm;
4738: PetscFunctionBegin;
4741: if (x) PetscCheckSameComm(snes, 1, x, 3);
4743: if (b) PetscCheckSameComm(snes, 1, b, 2);
4745: /* High level operations using the nonlinear solver */
4746: {
4747: PetscViewer viewer;
4748: PetscViewerFormat format;
4749: PetscInt num;
4750: PetscBool flg;
4751: static PetscBool incall = PETSC_FALSE;
4753: if (!incall) {
4754: /* Estimate the convergence rate of the discretization */
4755: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4756: if (flg) {
4757: PetscConvEst conv;
4758: DM dm;
4759: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4760: PetscInt Nf;
4762: incall = PETSC_TRUE;
4763: PetscCall(SNESGetDM(snes, &dm));
4764: PetscCall(DMGetNumFields(dm, &Nf));
4765: PetscCall(PetscCalloc1(Nf, &alpha));
4766: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4767: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4768: PetscCall(PetscConvEstSetFromOptions(conv));
4769: PetscCall(PetscConvEstSetUp(conv));
4770: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4771: PetscCall(PetscViewerPushFormat(viewer, format));
4772: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4773: PetscCall(PetscViewerPopFormat(viewer));
4774: PetscCall(PetscViewerDestroy(&viewer));
4775: PetscCall(PetscConvEstDestroy(&conv));
4776: PetscCall(PetscFree(alpha));
4777: incall = PETSC_FALSE;
4778: }
4779: /* Adaptively refine the initial grid */
4780: num = 1;
4781: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4782: if (flg) {
4783: DMAdaptor adaptor;
4785: incall = PETSC_TRUE;
4786: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4787: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4788: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4789: PetscCall(DMAdaptorSetFromOptions(adaptor));
4790: PetscCall(DMAdaptorSetUp(adaptor));
4791: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4792: PetscCall(DMAdaptorDestroy(&adaptor));
4793: incall = PETSC_FALSE;
4794: }
4795: /* Use grid sequencing to adapt */
4796: num = 0;
4797: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4798: if (num) {
4799: DMAdaptor adaptor;
4801: incall = PETSC_TRUE;
4802: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4803: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4804: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4805: PetscCall(DMAdaptorSetFromOptions(adaptor));
4806: PetscCall(DMAdaptorSetUp(adaptor));
4807: PetscCall(PetscObjectViewFromOptions((PetscObject)adaptor, NULL, "-snes_adapt_view"));
4808: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4809: PetscCall(DMAdaptorDestroy(&adaptor));
4810: incall = PETSC_FALSE;
4811: }
4812: }
4813: }
4814: if (!x) x = snes->vec_sol;
4815: if (!x) {
4816: PetscCall(SNESGetDM(snes, &dm));
4817: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4818: x = xcreated;
4819: }
4820: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4822: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4823: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4824: /* set solution vector */
4825: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4826: PetscCall(VecDestroy(&snes->vec_sol));
4827: snes->vec_sol = x;
4828: PetscCall(SNESGetDM(snes, &dm));
4830: /* set affine vector if provided */
4831: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4832: PetscCall(VecDestroy(&snes->vec_rhs));
4833: snes->vec_rhs = b;
4835: 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");
4836: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4837: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right-hand side vector");
4838: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4839: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4840: PetscCall(SNESSetUp(snes));
4842: if (!grid) {
4843: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback compute initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4844: }
4846: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4847: if (snes->counters_reset) {
4848: snes->nfuncs = 0;
4849: snes->linear_its = 0;
4850: snes->numFailures = 0;
4851: }
4853: snes->reason = SNES_CONVERGED_ITERATING;
4854: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4855: PetscUseTypeMethod(snes, solve);
4856: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4857: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4858: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4860: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4861: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4863: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4864: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4865: /* Call converged reason views. This may involve user-provided viewers as well */
4866: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4868: if (snes->errorifnotconverged) PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4869: if (snes->reason < 0) break;
4870: if (grid < snes->gridsequence) {
4871: DM fine;
4872: Vec xnew;
4873: Mat interp;
4875: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4876: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4877: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4878: PetscCall(DMCreateGlobalVector(fine, &xnew));
4879: PetscCall(MatInterpolate(interp, x, xnew));
4880: PetscCall(DMInterpolate(snes->dm, interp, fine));
4881: PetscCall(MatDestroy(&interp));
4882: x = xnew;
4884: PetscCall(SNESReset(snes));
4885: PetscCall(SNESSetDM(snes, fine));
4886: PetscCall(SNESResetFromOptions(snes));
4887: PetscCall(DMDestroy(&fine));
4888: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4889: }
4890: }
4891: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4892: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4893: PetscCall(DMMonitor(snes->dm));
4894: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4896: PetscCall(VecDestroy(&xcreated));
4897: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4898: PetscFunctionReturn(PETSC_SUCCESS);
4899: }
4901: /* --------- Internal routines for SNES Package --------- */
4903: /*@
4904: SNESSetType - Sets the method for the nonlinear solver.
4906: Collective
4908: Input Parameters:
4909: + snes - the `SNES` context
4910: - type - a known method
4912: Options Database Key:
4913: . -snes_type <type> - Sets the method; use -help for a list
4914: of available methods (for instance, newtonls or newtontr)
4916: Level: intermediate
4918: Notes:
4919: See "petsc/include/petscsnes.h" for available methods (for instance)
4920: + `SNESNEWTONLS` - Newton's method with line search
4921: (systems of nonlinear equations)
4922: - `SNESNEWTONTR` - Newton's method with trust region
4923: (systems of nonlinear equations)
4925: Normally, it is best to use the `SNESSetFromOptions()` command and then
4926: set the `SNES` solver type from the options database rather than by using
4927: this routine. Using the options database provides the user with
4928: maximum flexibility in evaluating the many nonlinear solvers.
4929: The `SNESSetType()` routine is provided for those situations where it
4930: is necessary to set the nonlinear solver independently of the command
4931: line or options database. This might be the case, for example, when
4932: the choice of solver changes during the execution of the program,
4933: and the user's application is taking responsibility for choosing the
4934: appropriate method.
4936: Developer Note:
4937: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4938: the constructor in that list and calls it to create the specific object.
4940: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4941: @*/
4942: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4943: {
4944: PetscBool match;
4945: PetscErrorCode (*r)(SNES);
4947: PetscFunctionBegin;
4949: PetscAssertPointer(type, 2);
4951: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4952: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4954: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4955: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4956: /* Destroy the previous private SNES context */
4957: PetscTryTypeMethod(snes, destroy);
4958: /* Reinitialize function pointers in SNESOps structure */
4959: snes->ops->setup = NULL;
4960: snes->ops->solve = NULL;
4961: snes->ops->view = NULL;
4962: snes->ops->setfromoptions = NULL;
4963: snes->ops->destroy = NULL;
4965: /* It may happen the user has customized the line search before calling SNESSetType */
4966: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
4968: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4969: snes->setupcalled = PETSC_FALSE;
4971: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
4972: PetscCall((*r)(snes));
4973: PetscFunctionReturn(PETSC_SUCCESS);
4974: }
4976: /*@
4977: SNESGetType - Gets the `SNES` method type and name (as a string).
4979: Not Collective
4981: Input Parameter:
4982: . snes - nonlinear solver context
4984: Output Parameter:
4985: . type - `SNES` method (a character string)
4987: Level: intermediate
4989: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
4990: @*/
4991: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
4992: {
4993: PetscFunctionBegin;
4995: PetscAssertPointer(type, 2);
4996: *type = ((PetscObject)snes)->type_name;
4997: PetscFunctionReturn(PETSC_SUCCESS);
4998: }
5000: /*@
5001: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
5003: Logically Collective
5005: Input Parameters:
5006: + snes - the `SNES` context obtained from `SNESCreate()`
5007: - u - the solution vector
5009: Level: beginner
5011: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
5012: @*/
5013: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
5014: {
5015: DM dm;
5017: PetscFunctionBegin;
5020: PetscCall(PetscObjectReference((PetscObject)u));
5021: PetscCall(VecDestroy(&snes->vec_sol));
5023: snes->vec_sol = u;
5025: PetscCall(SNESGetDM(snes, &dm));
5026: PetscCall(DMShellSetGlobalVector(dm, u));
5027: PetscFunctionReturn(PETSC_SUCCESS);
5028: }
5030: /*@
5031: SNESGetSolution - Returns the vector where the approximate solution is
5032: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
5034: Not Collective, but `x` is parallel if `snes` is parallel
5036: Input Parameter:
5037: . snes - the `SNES` context
5039: Output Parameter:
5040: . x - the solution
5042: Level: intermediate
5044: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
5045: @*/
5046: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
5047: {
5048: PetscFunctionBegin;
5050: PetscAssertPointer(x, 2);
5051: *x = snes->vec_sol;
5052: PetscFunctionReturn(PETSC_SUCCESS);
5053: }
5055: /*@
5056: SNESGetSolutionUpdate - Returns the vector where the solution update is
5057: stored.
5059: Not Collective, but `x` is parallel if `snes` is parallel
5061: Input Parameter:
5062: . snes - the `SNES` context
5064: Output Parameter:
5065: . x - the solution update
5067: Level: advanced
5069: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
5070: @*/
5071: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
5072: {
5073: PetscFunctionBegin;
5075: PetscAssertPointer(x, 2);
5076: *x = snes->vec_sol_update;
5077: PetscFunctionReturn(PETSC_SUCCESS);
5078: }
5080: /*@C
5081: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
5083: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
5085: Input Parameter:
5086: . snes - the `SNES` context
5088: Output Parameters:
5089: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
5090: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunctionFn`
5091: - ctx - the function context (or `NULL` if you don't want it)
5093: Level: advanced
5095: Note:
5096: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
5098: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunctionFn`
5099: @*/
5100: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, SNESFunctionFn **f, void **ctx)
5101: {
5102: DM dm;
5104: PetscFunctionBegin;
5106: if (r) {
5107: if (!snes->vec_func) {
5108: if (snes->vec_rhs) {
5109: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
5110: } else if (snes->vec_sol) {
5111: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
5112: } else if (snes->dm) {
5113: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
5114: }
5115: }
5116: *r = snes->vec_func;
5117: }
5118: PetscCall(SNESGetDM(snes, &dm));
5119: PetscCall(DMSNESGetFunction(dm, f, ctx));
5120: PetscFunctionReturn(PETSC_SUCCESS);
5121: }
5123: /*@C
5124: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
5126: Input Parameter:
5127: . snes - the `SNES` context
5129: Output Parameters:
5130: + f - the function (or `NULL`) see `SNESNGSFn` for calling sequence
5131: - ctx - the function context (or `NULL`)
5133: Level: advanced
5135: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`, `SNESNGSFn`
5136: @*/
5137: PetscErrorCode SNESGetNGS(SNES snes, SNESNGSFn **f, void **ctx)
5138: {
5139: DM dm;
5141: PetscFunctionBegin;
5143: PetscCall(SNESGetDM(snes, &dm));
5144: PetscCall(DMSNESGetNGS(dm, f, ctx));
5145: PetscFunctionReturn(PETSC_SUCCESS);
5146: }
5148: /*@
5149: SNESSetOptionsPrefix - Sets the prefix used for searching for all
5150: `SNES` options in the database.
5152: Logically Collective
5154: Input Parameters:
5155: + snes - the `SNES` context
5156: - prefix - the prefix to prepend to all option names
5158: Level: advanced
5160: Note:
5161: A hyphen (-) must NOT be given at the beginning of the prefix name.
5162: The first character of all runtime options is AUTOMATICALLY the hyphen.
5164: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
5165: @*/
5166: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
5167: {
5168: PetscFunctionBegin;
5170: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
5171: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5172: if (snes->linesearch) {
5173: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5174: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
5175: }
5176: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
5177: PetscFunctionReturn(PETSC_SUCCESS);
5178: }
5180: /*@
5181: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5182: `SNES` options in the database.
5184: Logically Collective
5186: Input Parameters:
5187: + snes - the `SNES` context
5188: - prefix - the prefix to prepend to all option names
5190: Level: advanced
5192: Note:
5193: A hyphen (-) must NOT be given at the beginning of the prefix name.
5194: The first character of all runtime options is AUTOMATICALLY the hyphen.
5196: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5197: @*/
5198: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5199: {
5200: PetscFunctionBegin;
5202: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5203: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5204: if (snes->linesearch) {
5205: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5206: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5207: }
5208: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5209: PetscFunctionReturn(PETSC_SUCCESS);
5210: }
5212: /*@
5213: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5214: `SNES` options in the database.
5216: Not Collective
5218: Input Parameter:
5219: . snes - the `SNES` context
5221: Output Parameter:
5222: . prefix - pointer to the prefix string used
5224: Level: advanced
5226: Fortran Note:
5227: The user should pass in a string 'prefix' of
5228: sufficient length to hold the prefix.
5230: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5231: @*/
5232: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5233: {
5234: PetscFunctionBegin;
5236: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5237: PetscFunctionReturn(PETSC_SUCCESS);
5238: }
5240: /*@C
5241: SNESRegister - Adds a method to the nonlinear solver package.
5243: Not Collective
5245: Input Parameters:
5246: + sname - name of a new user-defined solver
5247: - function - routine to create method context
5249: Level: advanced
5251: Note:
5252: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5254: Example Usage:
5255: .vb
5256: SNESRegister("my_solver", MySolverCreate);
5257: .ve
5259: Then, your solver can be chosen with the procedural interface via
5260: $ SNESSetType(snes, "my_solver")
5261: or at runtime via the option
5262: $ -snes_type my_solver
5264: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5265: @*/
5266: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5267: {
5268: PetscFunctionBegin;
5269: PetscCall(SNESInitializePackage());
5270: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5271: PetscFunctionReturn(PETSC_SUCCESS);
5272: }
5274: PetscErrorCode SNESTestLocalMin(SNES snes)
5275: {
5276: PetscInt N, i, j;
5277: Vec u, uh, fh;
5278: PetscScalar value;
5279: PetscReal norm;
5281: PetscFunctionBegin;
5282: PetscCall(SNESGetSolution(snes, &u));
5283: PetscCall(VecDuplicate(u, &uh));
5284: PetscCall(VecDuplicate(u, &fh));
5286: /* currently only works for sequential */
5287: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5288: PetscCall(VecGetSize(u, &N));
5289: for (i = 0; i < N; i++) {
5290: PetscCall(VecCopy(u, uh));
5291: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5292: for (j = -10; j < 11; j++) {
5293: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5294: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5295: PetscCall(SNESComputeFunction(snes, uh, fh));
5296: PetscCall(VecNorm(fh, NORM_2, &norm));
5297: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5298: value = -value;
5299: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5300: }
5301: }
5302: PetscCall(VecDestroy(&uh));
5303: PetscCall(VecDestroy(&fh));
5304: PetscFunctionReturn(PETSC_SUCCESS);
5305: }
5307: /*@
5308: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5309: computing relative tolerance for linear solvers within an inexact
5310: Newton method.
5312: Logically Collective
5314: Input Parameters:
5315: + snes - `SNES` context
5316: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5318: Options Database Keys:
5319: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5320: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5321: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5322: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5323: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5324: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5325: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5326: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5328: Level: advanced
5330: Note:
5331: The default is to use a constant relative tolerance for
5332: the inner linear solvers. Alternatively, one can use the
5333: Eisenstat-Walker method {cite}`ew96`, where the relative convergence tolerance
5334: is reset at each Newton iteration according progress of the nonlinear
5335: solver.
5337: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5338: @*/
5339: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5340: {
5341: PetscFunctionBegin;
5344: snes->ksp_ewconv = flag;
5345: PetscFunctionReturn(PETSC_SUCCESS);
5346: }
5348: /*@
5349: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5350: for computing relative tolerance for linear solvers within an
5351: inexact Newton method.
5353: Not Collective
5355: Input Parameter:
5356: . snes - `SNES` context
5358: Output Parameter:
5359: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5361: Level: advanced
5363: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5364: @*/
5365: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5366: {
5367: PetscFunctionBegin;
5369: PetscAssertPointer(flag, 2);
5370: *flag = snes->ksp_ewconv;
5371: PetscFunctionReturn(PETSC_SUCCESS);
5372: }
5374: /*@
5375: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5376: convergence criteria for the linear solvers within an inexact
5377: Newton method.
5379: Logically Collective
5381: Input Parameters:
5382: + snes - `SNES` context
5383: . version - version 1, 2 (default is 2), 3 or 4
5384: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5385: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5386: . gamma - multiplicative factor for version 2 rtol computation
5387: (0 <= gamma2 <= 1)
5388: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5389: . alpha2 - power for safeguard
5390: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5392: Level: advanced
5394: Notes:
5395: Version 3 was contributed by Luis Chacon, June 2006.
5397: Use `PETSC_CURRENT` to retain the default for any of the parameters.
5399: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5400: @*/
5401: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5402: {
5403: SNESKSPEW *kctx;
5405: PetscFunctionBegin;
5407: kctx = (SNESKSPEW *)snes->kspconvctx;
5408: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5417: if (version != PETSC_CURRENT) kctx->version = version;
5418: if (rtol_0 != (PetscReal)PETSC_CURRENT) kctx->rtol_0 = rtol_0;
5419: if (rtol_max != (PetscReal)PETSC_CURRENT) kctx->rtol_max = rtol_max;
5420: if (gamma != (PetscReal)PETSC_CURRENT) kctx->gamma = gamma;
5421: if (alpha != (PetscReal)PETSC_CURRENT) kctx->alpha = alpha;
5422: if (alpha2 != (PetscReal)PETSC_CURRENT) kctx->alpha2 = alpha2;
5423: if (threshold != (PetscReal)PETSC_CURRENT) kctx->threshold = threshold;
5425: 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);
5426: 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);
5427: 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);
5428: 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);
5429: 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);
5430: 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);
5431: PetscFunctionReturn(PETSC_SUCCESS);
5432: }
5434: /*@
5435: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5436: convergence criteria for the linear solvers within an inexact
5437: Newton method.
5439: Not Collective
5441: Input Parameter:
5442: . snes - `SNES` context
5444: Output Parameters:
5445: + version - version 1, 2 (default is 2), 3 or 4
5446: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5447: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5448: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5449: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5450: . alpha2 - power for safeguard
5451: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5453: Level: advanced
5455: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5456: @*/
5457: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5458: {
5459: SNESKSPEW *kctx;
5461: PetscFunctionBegin;
5463: kctx = (SNESKSPEW *)snes->kspconvctx;
5464: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5465: if (version) *version = kctx->version;
5466: if (rtol_0) *rtol_0 = kctx->rtol_0;
5467: if (rtol_max) *rtol_max = kctx->rtol_max;
5468: if (gamma) *gamma = kctx->gamma;
5469: if (alpha) *alpha = kctx->alpha;
5470: if (alpha2) *alpha2 = kctx->alpha2;
5471: if (threshold) *threshold = kctx->threshold;
5472: PetscFunctionReturn(PETSC_SUCCESS);
5473: }
5475: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5476: {
5477: SNES snes = (SNES)ctx;
5478: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5479: PetscReal rtol = PETSC_CURRENT, stol;
5481: PetscFunctionBegin;
5482: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5483: if (!snes->iter) {
5484: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5485: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5486: } else {
5487: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5488: if (kctx->version == 1) {
5489: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5490: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5491: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5492: } else if (kctx->version == 2) {
5493: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5494: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5495: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5496: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5497: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5498: /* safeguard: avoid sharp decrease of rtol */
5499: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5500: stol = PetscMax(rtol, stol);
5501: rtol = PetscMin(kctx->rtol_0, stol);
5502: /* safeguard: avoid oversolving */
5503: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5504: stol = PetscMax(rtol, stol);
5505: rtol = PetscMin(kctx->rtol_0, stol);
5506: } else /* if (kctx->version == 4) */ {
5507: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5508: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5509: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5510: PetscReal rk = ared / pred;
5511: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5512: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5513: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5514: else rtol = kctx->v4_m2 * kctx->rtol_last;
5516: 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;
5517: kctx->rtol_last_2 = kctx->rtol_last;
5518: kctx->rk_last_2 = kctx->rk_last;
5519: kctx->rk_last = rk;
5520: }
5521: }
5522: /* safeguard: avoid rtol greater than rtol_max */
5523: rtol = PetscMin(rtol, kctx->rtol_max);
5524: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_CURRENT, PETSC_CURRENT, PETSC_CURRENT));
5525: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5526: PetscFunctionReturn(PETSC_SUCCESS);
5527: }
5529: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5530: {
5531: SNES snes = (SNES)ctx;
5532: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5533: PCSide pcside;
5534: Vec lres;
5536: PetscFunctionBegin;
5537: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5538: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5539: kctx->norm_last = snes->norm;
5540: if (kctx->version == 1 || kctx->version == 4) {
5541: PC pc;
5542: PetscBool getRes;
5544: PetscCall(KSPGetPC(ksp, &pc));
5545: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5546: if (!getRes) {
5547: KSPNormType normtype;
5549: PetscCall(KSPGetNormType(ksp, &normtype));
5550: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5551: }
5552: PetscCall(KSPGetPCSide(ksp, &pcside));
5553: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5554: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5555: } else {
5556: /* KSP residual is preconditioned residual */
5557: /* compute true linear residual norm */
5558: Mat J;
5559: PetscCall(KSPGetOperators(ksp, &J, NULL));
5560: PetscCall(VecDuplicate(b, &lres));
5561: PetscCall(MatMult(J, x, lres));
5562: PetscCall(VecAYPX(lres, -1.0, b));
5563: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5564: PetscCall(VecDestroy(&lres));
5565: }
5566: }
5567: PetscFunctionReturn(PETSC_SUCCESS);
5568: }
5570: /*@
5571: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5573: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5575: Input Parameter:
5576: . snes - the `SNES` context
5578: Output Parameter:
5579: . ksp - the `KSP` context
5581: Level: beginner
5583: Notes:
5584: The user can then directly manipulate the `KSP` context to set various
5585: options, etc. Likewise, the user can then extract and manipulate the
5586: `PC` contexts as well.
5588: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function
5590: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5591: @*/
5592: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5593: {
5594: PetscFunctionBegin;
5596: PetscAssertPointer(ksp, 2);
5598: if (!snes->ksp) {
5599: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5600: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5602: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5603: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5605: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5606: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5607: }
5608: *ksp = snes->ksp;
5609: PetscFunctionReturn(PETSC_SUCCESS);
5610: }
5612: #include <petsc/private/dmimpl.h>
5613: /*@
5614: SNESSetDM - Sets the `DM` that may be used by some nonlinear solvers or their underlying preconditioners
5616: Logically Collective
5618: Input Parameters:
5619: + snes - the nonlinear solver context
5620: - dm - the `DM`, cannot be `NULL`
5622: Level: intermediate
5624: Note:
5625: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5626: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5627: problems using the same function space.
5629: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5630: @*/
5631: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5632: {
5633: KSP ksp;
5634: DMSNES sdm;
5636: PetscFunctionBegin;
5639: PetscCall(PetscObjectReference((PetscObject)dm));
5640: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5641: if (snes->dm->dmsnes && !dm->dmsnes) {
5642: PetscCall(DMCopyDMSNES(snes->dm, dm));
5643: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5644: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5645: }
5646: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5647: PetscCall(DMDestroy(&snes->dm));
5648: }
5649: snes->dm = dm;
5650: snes->dmAuto = PETSC_FALSE;
5652: PetscCall(SNESGetKSP(snes, &ksp));
5653: PetscCall(KSPSetDM(ksp, dm));
5654: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5655: if (snes->npc) {
5656: PetscCall(SNESSetDM(snes->npc, snes->dm));
5657: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5658: }
5659: PetscFunctionReturn(PETSC_SUCCESS);
5660: }
5662: /*@
5663: SNESGetDM - Gets the `DM` that may be used by some solvers/preconditioners
5665: Not Collective but dm obtained is parallel on snes
5667: Input Parameter:
5668: . snes - the `SNES` context
5670: Output Parameter:
5671: . dm - the `DM`
5673: Level: intermediate
5675: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5676: @*/
5677: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5678: {
5679: PetscFunctionBegin;
5681: if (!snes->dm) {
5682: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5683: snes->dmAuto = PETSC_TRUE;
5684: }
5685: *dm = snes->dm;
5686: PetscFunctionReturn(PETSC_SUCCESS);
5687: }
5689: /*@
5690: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5692: Collective
5694: Input Parameters:
5695: + snes - iterative context obtained from `SNESCreate()`
5696: - npc - the nonlinear preconditioner object
5698: Level: developer
5700: Notes:
5701: Use `SNESGetNPC()` to retrieve the preconditioner context (for example,
5702: to configure it using the API).
5704: Only some `SNESType` can use a nonlinear preconditioner
5706: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5707: @*/
5708: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5709: {
5710: PetscFunctionBegin;
5713: PetscCheckSameComm(snes, 1, npc, 2);
5714: PetscCall(PetscObjectReference((PetscObject)npc));
5715: PetscCall(SNESDestroy(&snes->npc));
5716: snes->npc = npc;
5717: PetscFunctionReturn(PETSC_SUCCESS);
5718: }
5720: /*@
5721: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5723: Not Collective; but any changes to the obtained the npc object must be applied collectively
5725: Input Parameter:
5726: . snes - iterative context obtained from `SNESCreate()`
5728: Output Parameter:
5729: . pc - preconditioner context
5731: Options Database Key:
5732: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5734: Level: developer
5736: Notes:
5737: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created.
5739: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5740: `SNES`
5742: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5743: @*/
5744: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5745: {
5746: const char *optionsprefix;
5748: PetscFunctionBegin;
5750: PetscAssertPointer(pc, 2);
5751: if (!snes->npc) {
5752: void *ctx;
5754: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5755: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5756: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5757: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5758: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5759: if (snes->ops->usercompute) {
5760: PetscCall(SNESSetComputeApplicationContext(snes, snes->ops->usercompute, snes->ops->userdestroy));
5761: } else {
5762: PetscCall(SNESGetApplicationContext(snes, &ctx));
5763: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5764: }
5765: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5766: }
5767: *pc = snes->npc;
5768: PetscFunctionReturn(PETSC_SUCCESS);
5769: }
5771: /*@
5772: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5774: Not Collective
5776: Input Parameter:
5777: . snes - iterative context obtained from `SNESCreate()`
5779: Output Parameter:
5780: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5782: Level: developer
5784: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5785: @*/
5786: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5787: {
5788: PetscFunctionBegin;
5790: *has_npc = (PetscBool)(snes->npc ? PETSC_TRUE : PETSC_FALSE);
5791: PetscFunctionReturn(PETSC_SUCCESS);
5792: }
5794: /*@
5795: SNESSetNPCSide - Sets the nonlinear preconditioning side.
5797: Logically Collective
5799: Input Parameter:
5800: . snes - iterative context obtained from `SNESCreate()`
5802: Output Parameter:
5803: . side - the preconditioning side, where side is one of
5804: .vb
5805: PC_LEFT - left preconditioning
5806: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5807: .ve
5809: Options Database Key:
5810: . -snes_npc_side <right,left> - nonlinear preconditioner side
5812: Level: intermediate
5814: Note:
5815: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5817: .seealso: [](ch_snes), `SNES`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5818: @*/
5819: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5820: {
5821: PetscFunctionBegin;
5824: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5825: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5826: snes->npcside = side;
5827: PetscFunctionReturn(PETSC_SUCCESS);
5828: }
5830: /*@
5831: SNESGetNPCSide - Gets the preconditioning side.
5833: Not Collective
5835: Input Parameter:
5836: . snes - iterative context obtained from `SNESCreate()`
5838: Output Parameter:
5839: . side - the preconditioning side, where side is one of
5840: .vb
5841: `PC_LEFT` - left preconditioning
5842: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5843: .ve
5845: Level: intermediate
5847: .seealso: [](ch_snes), `SNES`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5848: @*/
5849: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5850: {
5851: PetscFunctionBegin;
5853: PetscAssertPointer(side, 2);
5854: *side = snes->npcside;
5855: PetscFunctionReturn(PETSC_SUCCESS);
5856: }
5858: /*@
5859: SNESSetLineSearch - Sets the linesearch to be used for `SNES`
5861: Collective
5863: Input Parameters:
5864: + snes - iterative context obtained from `SNESCreate()`
5865: - linesearch - the linesearch object
5867: Level: developer
5869: Note:
5870: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
5871: to configure it using the API).
5873: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
5874: @*/
5875: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5876: {
5877: PetscFunctionBegin;
5880: PetscCheckSameComm(snes, 1, linesearch, 2);
5881: PetscCall(PetscObjectReference((PetscObject)linesearch));
5882: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5884: snes->linesearch = linesearch;
5885: PetscFunctionReturn(PETSC_SUCCESS);
5886: }
5888: /*@
5889: SNESGetLineSearch - Returns the line search context possibly set with `SNESSetLineSearch()`
5890: or creates a default line search instance associated with the `SNES` and returns it.
5892: Not Collective
5894: Input Parameter:
5895: . snes - iterative context obtained from `SNESCreate()`
5897: Output Parameter:
5898: . linesearch - linesearch context
5900: Level: beginner
5902: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`
5903: @*/
5904: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5905: {
5906: const char *optionsprefix;
5908: PetscFunctionBegin;
5910: PetscAssertPointer(linesearch, 2);
5911: if (!snes->linesearch) {
5912: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5913: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5914: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5915: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5916: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5917: }
5918: *linesearch = snes->linesearch;
5919: PetscFunctionReturn(PETSC_SUCCESS);
5920: }