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_NewtonALEval, 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, this must use a `PetscViewerFormat` as its context
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, (PetscCtxDestroyFn *)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_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.
948: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
949: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
950: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
951: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
952: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
953: . -snes_monitor_lg_range - plots residual norm at each iteration
954: . -snes_monitor_pause_final - Pauses all monitor drawing after the solver ends
955: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
956: . -snes_fd_color - use finite differences with coloring to compute Jacobian
957: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each `KSP` iteration
958: . -snes_converged_reason - print the reason for convergence/divergence after each solve
959: . -npc_snes_type <type> - the `SNES` type to use as a nonlinear preconditioner
960: . -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.
961: - -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.
963: Options Database Keys for Eisenstat-Walker method:
964: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
965: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
966: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
967: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
968: . -snes_ksp_ew_gamma <gamma> - Sets gamma
969: . -snes_ksp_ew_alpha <alpha> - Sets alpha
970: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
971: - -snes_ksp_ew_threshold <threshold> - Sets threshold
973: Level: beginner
975: Notes:
976: To see all options, run your program with the -help option or consult the users manual
978: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
979: and computing explicitly with
980: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
982: .seealso: [](ch_snes), `SNESType`, `SNESSetOptionsPrefix()`, `SNESResetFromOptions()`, `SNES`, `SNESCreate()`, `MatCreateSNESMF()`, `MatFDColoring`
983: @*/
984: PetscErrorCode SNESSetFromOptions(SNES snes)
985: {
986: PetscBool flg, pcset, persist, set;
987: PetscInt i, indx, lag, grids, max_its, max_funcs;
988: const char *deft = SNESNEWTONLS;
989: const char *convtests[] = {"default", "skip", "correct_pressure"};
990: SNESKSPEW *kctx = NULL;
991: char type[256], monfilename[PETSC_MAX_PATH_LEN], ewprefix[256];
992: PCSide pcside;
993: const char *optionsprefix;
994: PetscReal rtol, abstol, stol;
996: PetscFunctionBegin;
998: PetscCall(SNESRegisterAll());
999: PetscObjectOptionsBegin((PetscObject)snes);
1000: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
1001: PetscCall(PetscOptionsFList("-snes_type", "Nonlinear solver method", "SNESSetType", SNESList, deft, type, 256, &flg));
1002: if (flg) {
1003: PetscCall(SNESSetType(snes, type));
1004: } else if (!((PetscObject)snes)->type_name) {
1005: PetscCall(SNESSetType(snes, deft));
1006: }
1008: abstol = snes->abstol;
1009: rtol = snes->rtol;
1010: stol = snes->stol;
1011: max_its = snes->max_its;
1012: max_funcs = snes->max_funcs;
1013: PetscCall(PetscOptionsReal("-snes_rtol", "Stop if decrease in function norm less than", "SNESSetTolerances", snes->rtol, &rtol, NULL));
1014: PetscCall(PetscOptionsReal("-snes_atol", "Stop if function norm less than", "SNESSetTolerances", snes->abstol, &abstol, NULL));
1015: PetscCall(PetscOptionsReal("-snes_stol", "Stop if step length less than", "SNESSetTolerances", snes->stol, &stol, NULL));
1016: PetscCall(PetscOptionsInt("-snes_max_it", "Maximum iterations", "SNESSetTolerances", snes->max_its, &max_its, NULL));
1017: PetscCall(PetscOptionsInt("-snes_max_funcs", "Maximum function evaluations", "SNESSetTolerances", snes->max_funcs, &max_funcs, NULL));
1018: PetscCall(SNESSetTolerances(snes, abstol, rtol, stol, max_its, max_funcs));
1020: PetscCall(PetscOptionsReal("-snes_divergence_tolerance", "Stop if residual norm increases by this factor", "SNESSetDivergenceTolerance", snes->divtol, &snes->divtol, &flg));
1021: if (flg) PetscCall(SNESSetDivergenceTolerance(snes, snes->divtol));
1023: PetscCall(PetscOptionsInt("-snes_max_fail", "Maximum nonlinear step failures", "SNESSetMaxNonlinearStepFailures", snes->maxFailures, &snes->maxFailures, &flg));
1024: if (flg) PetscCall(SNESSetMaxNonlinearStepFailures(snes, snes->maxFailures));
1026: PetscCall(PetscOptionsInt("-snes_max_linear_solve_fail", "Maximum failures in linear solves allowed", "SNESSetMaxLinearSolveFailures", snes->maxLinearSolveFailures, &snes->maxLinearSolveFailures, &flg));
1027: if (flg) PetscCall(SNESSetMaxLinearSolveFailures(snes, snes->maxLinearSolveFailures));
1029: PetscCall(PetscOptionsBool("-snes_error_if_not_converged", "Generate error if solver does not converge", "SNESSetErrorIfNotConverged", snes->errorifnotconverged, &snes->errorifnotconverged, NULL));
1030: PetscCall(PetscOptionsBool("-snes_force_iteration", "Force SNESSolve() to take at least one iteration", "SNESSetForceIteration", snes->forceiteration, &snes->forceiteration, NULL));
1031: PetscCall(PetscOptionsBool("-snes_check_jacobian_domain_error", "Check Jacobian domain error after Jacobian evaluation", "SNESCheckJacobianDomainError", snes->checkjacdomainerror, &snes->checkjacdomainerror, NULL));
1033: PetscCall(PetscOptionsInt("-snes_lag_preconditioner", "How often to rebuild preconditioner", "SNESSetLagPreconditioner", snes->lagpreconditioner, &lag, &flg));
1034: if (flg) {
1035: 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");
1036: PetscCall(SNESSetLagPreconditioner(snes, lag));
1037: }
1038: PetscCall(PetscOptionsBool("-snes_lag_preconditioner_persists", "Preconditioner lagging through multiple SNES solves", "SNESSetLagPreconditionerPersists", snes->lagjac_persist, &persist, &flg));
1039: if (flg) PetscCall(SNESSetLagPreconditionerPersists(snes, persist));
1040: PetscCall(PetscOptionsInt("-snes_lag_jacobian", "How often to rebuild Jacobian", "SNESSetLagJacobian", snes->lagjacobian, &lag, &flg));
1041: if (flg) {
1042: 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");
1043: PetscCall(SNESSetLagJacobian(snes, lag));
1044: }
1045: PetscCall(PetscOptionsBool("-snes_lag_jacobian_persists", "Jacobian lagging through multiple SNES solves", "SNESSetLagJacobianPersists", snes->lagjac_persist, &persist, &flg));
1046: if (flg) PetscCall(SNESSetLagJacobianPersists(snes, persist));
1048: PetscCall(PetscOptionsInt("-snes_grid_sequence", "Use grid sequencing to generate initial guess", "SNESSetGridSequence", snes->gridsequence, &grids, &flg));
1049: if (flg) PetscCall(SNESSetGridSequence(snes, grids));
1051: PetscCall(PetscOptionsEList("-snes_convergence_test", "Convergence test", "SNESSetConvergenceTest", convtests, PETSC_STATIC_ARRAY_LENGTH(convtests), "default", &indx, &flg));
1052: if (flg) {
1053: switch (indx) {
1054: case 0:
1055: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedDefault, NULL, NULL));
1056: break;
1057: case 1:
1058: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedSkip, NULL, NULL));
1059: break;
1060: case 2:
1061: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedCorrectPressure, NULL, NULL));
1062: break;
1063: }
1064: }
1066: PetscCall(PetscOptionsEList("-snes_norm_schedule", "SNES Norm schedule", "SNESSetNormSchedule", SNESNormSchedules, 5, "function", &indx, &flg));
1067: if (flg) PetscCall(SNESSetNormSchedule(snes, (SNESNormSchedule)indx));
1069: PetscCall(PetscOptionsEList("-snes_function_type", "SNES Norm schedule", "SNESSetFunctionType", SNESFunctionTypes, 2, "unpreconditioned", &indx, &flg));
1070: if (flg) PetscCall(SNESSetFunctionType(snes, (SNESFunctionType)indx));
1072: kctx = (SNESKSPEW *)snes->kspconvctx;
1074: PetscCall(PetscOptionsBool("-snes_ksp_ew", "Use Eisentat-Walker linear system convergence test", "SNESKSPSetUseEW", snes->ksp_ewconv, &snes->ksp_ewconv, NULL));
1076: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1077: PetscCall(PetscSNPrintf(ewprefix, sizeof(ewprefix), "%s%s", optionsprefix ? optionsprefix : "", "snes_"));
1078: PetscCall(SNESEWSetFromOptions_Private(kctx, PETSC_TRUE, PetscObjectComm((PetscObject)snes), ewprefix));
1080: flg = PETSC_FALSE;
1081: PetscCall(PetscOptionsBool("-snes_monitor_cancel", "Remove all monitors", "SNESMonitorCancel", flg, &flg, &set));
1082: if (set && flg) PetscCall(SNESMonitorCancel(snes));
1084: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor", "Monitor norm of function", "SNESMonitorDefault", SNESMonitorDefault, SNESMonitorDefaultSetUp));
1085: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_short", "Monitor norm of function with fewer digits", "SNESMonitorDefaultShort", SNESMonitorDefaultShort, NULL));
1086: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_range", "Monitor range of elements of function", "SNESMonitorRange", SNESMonitorRange, NULL));
1088: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_ratio", "Monitor ratios of the norm of function for consecutive steps", "SNESMonitorRatio", SNESMonitorRatio, SNESMonitorRatioSetUp));
1089: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_field", "Monitor norm of function (split into fields)", "SNESMonitorDefaultField", SNESMonitorDefaultField, NULL));
1090: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution", "View solution at each iteration", "SNESMonitorSolution", SNESMonitorSolution, NULL));
1091: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution_update", "View correction at each iteration", "SNESMonitorSolutionUpdate", SNESMonitorSolutionUpdate, NULL));
1092: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_residual", "View residual at each iteration", "SNESMonitorResidual", SNESMonitorResidual, NULL));
1093: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_jacupdate_spectrum", "Print the change in the spectrum of the Jacobian", "SNESMonitorJacUpdateSpectrum", SNESMonitorJacUpdateSpectrum, NULL));
1094: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_fields", "Monitor norm of function per field", "SNESMonitorSet", SNESMonitorFields, NULL));
1095: PetscCall(PetscOptionsBool("-snes_monitor_pause_final", "Pauses all draw monitors at the final iterate", "SNESMonitorPauseFinal_Internal", PETSC_FALSE, &snes->pauseFinal, NULL));
1097: PetscCall(PetscOptionsString("-snes_monitor_python", "Use Python function", "SNESMonitorSet", NULL, monfilename, sizeof(monfilename), &flg));
1098: if (flg) PetscCall(PetscPythonMonitorSet((PetscObject)snes, monfilename));
1100: flg = PETSC_FALSE;
1101: PetscCall(PetscOptionsBool("-snes_monitor_lg_range", "Plot function range at each iteration", "SNESMonitorLGRange", flg, &flg, NULL));
1102: if (flg) {
1103: PetscViewer ctx;
1105: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &ctx));
1106: PetscCall(SNESMonitorSet(snes, SNESMonitorLGRange, ctx, (PetscCtxDestroyFn *)PetscViewerDestroy));
1107: }
1109: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
1110: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &snes->convergedreasonviewer, &snes->convergedreasonformat, NULL));
1111: flg = PETSC_FALSE;
1112: PetscCall(PetscOptionsBool("-snes_converged_reason_view_cancel", "Remove all converged reason viewers", "SNESConvergedReasonViewCancel", flg, &flg, &set));
1113: if (set && flg) PetscCall(SNESConvergedReasonViewCancel(snes));
1115: flg = PETSC_FALSE;
1116: PetscCall(PetscOptionsBool("-snes_fd", "Use finite differences (slow) to compute Jacobian", "SNESComputeJacobianDefault", flg, &flg, NULL));
1117: if (flg) {
1118: void *functx;
1119: DM dm;
1120: PetscCall(SNESGetDM(snes, &dm));
1121: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1122: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
1123: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefault, functx));
1124: PetscCall(PetscInfo(snes, "Setting default finite difference Jacobian matrix\n"));
1125: }
1127: flg = PETSC_FALSE;
1128: PetscCall(PetscOptionsBool("-snes_fd_function", "Use finite differences (slow) to compute function from user objective", "SNESObjectiveComputeFunctionDefaultFD", flg, &flg, NULL));
1129: if (flg) PetscCall(SNESSetFunction(snes, NULL, SNESObjectiveComputeFunctionDefaultFD, NULL));
1131: flg = PETSC_FALSE;
1132: PetscCall(PetscOptionsBool("-snes_fd_color", "Use finite differences with coloring to compute Jacobian", "SNESComputeJacobianDefaultColor", flg, &flg, NULL));
1133: if (flg) {
1134: DM dm;
1135: PetscCall(SNESGetDM(snes, &dm));
1136: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1137: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefaultColor, NULL));
1138: PetscCall(PetscInfo(snes, "Setting default finite difference coloring Jacobian matrix\n"));
1139: }
1141: flg = PETSC_FALSE;
1142: PetscCall(PetscOptionsBool("-snes_mf_operator", "Use a Matrix-Free Jacobian with user-provided preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf_operator, &flg));
1143: if (flg && snes->mf_operator) {
1144: snes->mf_operator = PETSC_TRUE;
1145: snes->mf = PETSC_TRUE;
1146: }
1147: flg = PETSC_FALSE;
1148: PetscCall(PetscOptionsBool("-snes_mf", "Use a Matrix-Free Jacobian with no preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf, &flg));
1149: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1150: PetscCall(PetscOptionsInt("-snes_mf_version", "Matrix-Free routines version 1 or 2", "None", snes->mf_version, &snes->mf_version, NULL));
1152: flg = PETSC_FALSE;
1153: PetscCall(SNESGetNPCSide(snes, &pcside));
1154: PetscCall(PetscOptionsEnum("-snes_npc_side", "SNES nonlinear preconditioner side", "SNESSetNPCSide", PCSides, (PetscEnum)pcside, (PetscEnum *)&pcside, &flg));
1155: if (flg) PetscCall(SNESSetNPCSide(snes, pcside));
1157: #if defined(PETSC_HAVE_SAWS)
1158: /*
1159: Publish convergence information using SAWs
1160: */
1161: flg = PETSC_FALSE;
1162: PetscCall(PetscOptionsBool("-snes_monitor_saws", "Publish SNES progress using SAWs", "SNESMonitorSet", flg, &flg, NULL));
1163: if (flg) {
1164: void *ctx;
1165: PetscCall(SNESMonitorSAWsCreate(snes, &ctx));
1166: PetscCall(SNESMonitorSet(snes, SNESMonitorSAWs, ctx, SNESMonitorSAWsDestroy));
1167: }
1168: #endif
1169: #if defined(PETSC_HAVE_SAWS)
1170: {
1171: PetscBool set;
1172: flg = PETSC_FALSE;
1173: PetscCall(PetscOptionsBool("-snes_saws_block", "Block for SAWs at end of SNESSolve", "PetscObjectSAWsBlock", ((PetscObject)snes)->amspublishblock, &flg, &set));
1174: if (set) PetscCall(PetscObjectSAWsSetBlock((PetscObject)snes, flg));
1175: }
1176: #endif
1178: for (i = 0; i < numberofsetfromoptions; i++) PetscCall((*othersetfromoptions[i])(snes));
1180: PetscTryTypeMethod(snes, setfromoptions, PetscOptionsObject);
1182: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1183: PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)snes, PetscOptionsObject));
1184: PetscOptionsEnd();
1186: if (snes->linesearch) {
1187: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
1188: PetscCall(SNESLineSearchSetFromOptions(snes->linesearch));
1189: }
1191: if (snes->usesksp) {
1192: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
1193: PetscCall(KSPSetOperators(snes->ksp, snes->jacobian, snes->jacobian_pre));
1194: PetscCall(KSPSetFromOptions(snes->ksp));
1195: }
1197: /* if user has set the SNES NPC type via options database, create it. */
1198: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1199: PetscCall(PetscOptionsHasName(((PetscObject)snes)->options, optionsprefix, "-npc_snes_type", &pcset));
1200: if (pcset && (!snes->npc)) PetscCall(SNESGetNPC(snes, &snes->npc));
1201: if (snes->npc) PetscCall(SNESSetFromOptions(snes->npc));
1202: snes->setfromoptionscalled++;
1203: PetscFunctionReturn(PETSC_SUCCESS);
1204: }
1206: /*@
1207: SNESResetFromOptions - Sets various `SNES` and `KSP` parameters from user options ONLY if the `SNESSetFromOptions()` was previously called
1209: Collective
1211: Input Parameter:
1212: . snes - the `SNES` context
1214: Level: advanced
1216: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESSetOptionsPrefix()`
1217: @*/
1218: PetscErrorCode SNESResetFromOptions(SNES snes)
1219: {
1220: PetscFunctionBegin;
1221: if (snes->setfromoptionscalled) PetscCall(SNESSetFromOptions(snes));
1222: PetscFunctionReturn(PETSC_SUCCESS);
1223: }
1225: /*@C
1226: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1227: the nonlinear solvers.
1229: Logically Collective; No Fortran Support
1231: Input Parameters:
1232: + snes - the `SNES` context
1233: . compute - function to compute the context
1234: - destroy - function to destroy the context, see `PetscCtxDestroyFn` for the calling sequence
1236: Calling sequence of `compute`:
1237: + snes - the `SNES` context
1238: - ctx - context to be computed
1240: Level: intermediate
1242: Note:
1243: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1245: Use `SNESSetApplicationContext()` to see the context immediately
1247: .seealso: [](ch_snes), `SNESGetApplicationContext()`, `SNESSetApplicationContext()`, `PetscCtxDestroyFn`
1248: @*/
1249: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES snes, void **ctx), PetscCtxDestroyFn *destroy)
1250: {
1251: PetscFunctionBegin;
1253: snes->ops->usercompute = compute;
1254: snes->ops->ctxdestroy = destroy;
1255: PetscFunctionReturn(PETSC_SUCCESS);
1256: }
1258: /*@
1259: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1261: Logically Collective
1263: Input Parameters:
1264: + snes - the `SNES` context
1265: - ctx - optional user context
1267: Level: intermediate
1269: Notes:
1270: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian, or other evaluation function
1271: with `SNESGetApplicationContext()`
1273: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1275: Fortran Note:
1276: You must write a Fortran interface definition for this
1277: function that tells Fortran the Fortran derived data type that you are passing in as the `usrP` argument.
1279: .seealso: [](ch_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1280: @*/
1281: PetscErrorCode SNESSetApplicationContext(SNES snes, void *ctx)
1282: {
1283: KSP ksp;
1285: PetscFunctionBegin;
1287: PetscCall(SNESGetKSP(snes, &ksp));
1288: PetscCall(KSPSetApplicationContext(ksp, ctx));
1289: snes->ctx = ctx;
1290: PetscFunctionReturn(PETSC_SUCCESS);
1291: }
1293: /*@
1294: SNESGetApplicationContext - Gets the user-defined context for the
1295: nonlinear solvers set with `SNESGetApplicationContext()` or `SNESSetComputeApplicationContext()`
1297: Not Collective
1299: Input Parameter:
1300: . snes - `SNES` context
1302: Output Parameter:
1303: . ctx - user context
1305: Level: intermediate
1307: Fortran Note:
1308: You must write a Fortran interface definition for this
1309: function that tells Fortran the Fortran derived data type that you are passing in as the `usrP` argument.
1311: .seealso: [](ch_snes), `SNESSetApplicationContext()`, `SNESSetComputeApplicationContext()`
1312: @*/
1313: PetscErrorCode SNESGetApplicationContext(SNES snes, void *ctx)
1314: {
1315: PetscFunctionBegin;
1317: *(void **)ctx = snes->ctx;
1318: PetscFunctionReturn(PETSC_SUCCESS);
1319: }
1321: /*@
1322: SNESSetUseMatrixFree - indicates that `SNES` should use matrix-free finite difference matrix-vector products to apply the Jacobian.
1324: Logically Collective
1326: Input Parameters:
1327: + snes - `SNES` context
1328: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1329: - 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
1330: this option no matrix-element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1332: Options Database Keys:
1333: + -snes_mf_operator - use matrix-free only for the mat operator
1334: . -snes_mf - use matrix-free for both the mat and pmat operator
1335: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1336: - -snes_fd - compute the Jacobian via finite differences (slow)
1338: Level: intermediate
1340: Note:
1341: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
1342: and computing explicitly with
1343: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1345: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`, `MatFDColoring`
1346: @*/
1347: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1348: {
1349: PetscFunctionBegin;
1353: snes->mf = mf_operator ? PETSC_TRUE : mf;
1354: snes->mf_operator = mf_operator;
1355: PetscFunctionReturn(PETSC_SUCCESS);
1356: }
1358: /*@
1359: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1361: Not Collective, but the resulting flags will be the same on all MPI processes
1363: Input Parameter:
1364: . snes - `SNES` context
1366: Output Parameters:
1367: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1368: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1370: Level: intermediate
1372: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1373: @*/
1374: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1375: {
1376: PetscFunctionBegin;
1378: if (mf) *mf = snes->mf;
1379: if (mf_operator) *mf_operator = snes->mf_operator;
1380: PetscFunctionReturn(PETSC_SUCCESS);
1381: }
1383: /*@
1384: SNESGetIterationNumber - Gets the number of nonlinear iterations completed in the current or most recent `SNESSolve()`
1386: Not Collective
1388: Input Parameter:
1389: . snes - `SNES` context
1391: Output Parameter:
1392: . iter - iteration number
1394: Level: intermediate
1396: Notes:
1397: For example, during the computation of iteration 2 this would return 1.
1399: This is useful for using lagged Jacobians (where one does not recompute the
1400: Jacobian at each `SNES` iteration). For example, the code
1401: .vb
1402: ierr = SNESGetIterationNumber(snes,&it);
1403: if (!(it % 2)) {
1404: [compute Jacobian here]
1405: }
1406: .ve
1407: can be used in your function that computes the Jacobian to cause the Jacobian to be
1408: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1410: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1412: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`, `SNESSetMonitor()`
1413: @*/
1414: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1415: {
1416: PetscFunctionBegin;
1418: PetscAssertPointer(iter, 2);
1419: *iter = snes->iter;
1420: PetscFunctionReturn(PETSC_SUCCESS);
1421: }
1423: /*@
1424: SNESSetIterationNumber - Sets the current iteration number.
1426: Not Collective
1428: Input Parameters:
1429: + snes - `SNES` context
1430: - iter - iteration number
1432: Level: developer
1434: Note:
1435: This should only be called inside a `SNES` nonlinear solver.
1437: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1438: @*/
1439: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1440: {
1441: PetscFunctionBegin;
1443: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1444: snes->iter = iter;
1445: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1446: PetscFunctionReturn(PETSC_SUCCESS);
1447: }
1449: /*@
1450: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1451: attempted by the nonlinear solver in the current or most recent `SNESSolve()` .
1453: Not Collective
1455: Input Parameter:
1456: . snes - `SNES` context
1458: Output Parameter:
1459: . nfails - number of unsuccessful steps attempted
1461: Level: intermediate
1463: Note:
1464: This counter is reset to zero for each successive call to `SNESSolve()`.
1466: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1467: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1468: @*/
1469: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1470: {
1471: PetscFunctionBegin;
1473: PetscAssertPointer(nfails, 2);
1474: *nfails = snes->numFailures;
1475: PetscFunctionReturn(PETSC_SUCCESS);
1476: }
1478: /*@
1479: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1480: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1482: Not Collective
1484: Input Parameters:
1485: + snes - `SNES` context
1486: - maxFails - maximum of unsuccessful steps allowed, use `PETSC_UNLIMITED` to have no limit on the number of failures
1488: Options Database Key:
1489: . -snes_max_fail <n> - maximum number of unsuccessful steps allowed
1491: Level: intermediate
1493: Developer Note:
1494: The options database key is wrong for this function name
1496: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1497: `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1498: @*/
1499: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1500: {
1501: PetscFunctionBegin;
1504: if (maxFails == PETSC_UNLIMITED) {
1505: snes->maxFailures = PETSC_INT_MAX;
1506: } else {
1507: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1508: snes->maxFailures = maxFails;
1509: }
1510: PetscFunctionReturn(PETSC_SUCCESS);
1511: }
1513: /*@
1514: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1515: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1517: Not Collective
1519: Input Parameter:
1520: . snes - `SNES` context
1522: Output Parameter:
1523: . maxFails - maximum of unsuccessful steps
1525: Level: intermediate
1527: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1528: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1529: @*/
1530: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1531: {
1532: PetscFunctionBegin;
1534: PetscAssertPointer(maxFails, 2);
1535: *maxFails = snes->maxFailures;
1536: PetscFunctionReturn(PETSC_SUCCESS);
1537: }
1539: /*@
1540: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1541: done by the `SNES` object in the current or most recent `SNESSolve()`
1543: Not Collective
1545: Input Parameter:
1546: . snes - `SNES` context
1548: Output Parameter:
1549: . nfuncs - number of evaluations
1551: Level: intermediate
1553: Note:
1554: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1556: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1557: @*/
1558: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1559: {
1560: PetscFunctionBegin;
1562: PetscAssertPointer(nfuncs, 2);
1563: *nfuncs = snes->nfuncs;
1564: PetscFunctionReturn(PETSC_SUCCESS);
1565: }
1567: /*@
1568: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1569: linear solvers in the current or most recent `SNESSolve()`
1571: Not Collective
1573: Input Parameter:
1574: . snes - `SNES` context
1576: Output Parameter:
1577: . nfails - number of failed solves
1579: Options Database Key:
1580: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1582: Level: intermediate
1584: Note:
1585: This counter is reset to zero for each successive call to `SNESSolve()`.
1587: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1588: @*/
1589: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1590: {
1591: PetscFunctionBegin;
1593: PetscAssertPointer(nfails, 2);
1594: *nfails = snes->numLinearSolveFailures;
1595: PetscFunctionReturn(PETSC_SUCCESS);
1596: }
1598: /*@
1599: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1600: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1602: Logically Collective
1604: Input Parameters:
1605: + snes - `SNES` context
1606: - maxFails - maximum allowed linear solve failures, use `PETSC_UNLIMITED` to have no limit on the number of failures
1608: Options Database Key:
1609: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1611: Level: intermediate
1613: Note:
1614: By default this is 0; that is `SNES` returns on the first failed linear solve
1616: Developer Note:
1617: The options database key is wrong for this function name
1619: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1620: @*/
1621: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1622: {
1623: PetscFunctionBegin;
1627: if (maxFails == PETSC_UNLIMITED) {
1628: snes->maxLinearSolveFailures = PETSC_INT_MAX;
1629: } else {
1630: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1631: snes->maxLinearSolveFailures = maxFails;
1632: }
1633: PetscFunctionReturn(PETSC_SUCCESS);
1634: }
1636: /*@
1637: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1638: are allowed before `SNES` returns as unsuccessful
1640: Not Collective
1642: Input Parameter:
1643: . snes - `SNES` context
1645: Output Parameter:
1646: . maxFails - maximum of unsuccessful solves allowed
1648: Level: intermediate
1650: Note:
1651: By default this is 1; that is `SNES` returns on the first failed linear solve
1653: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1654: @*/
1655: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1656: {
1657: PetscFunctionBegin;
1659: PetscAssertPointer(maxFails, 2);
1660: *maxFails = snes->maxLinearSolveFailures;
1661: PetscFunctionReturn(PETSC_SUCCESS);
1662: }
1664: /*@
1665: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1666: used by the nonlinear solver in the most recent `SNESSolve()`
1668: Not Collective
1670: Input Parameter:
1671: . snes - `SNES` context
1673: Output Parameter:
1674: . lits - number of linear iterations
1676: Level: intermediate
1678: Notes:
1679: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1681: 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
1682: then call `KSPGetIterationNumber()` after the failed solve.
1684: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1685: @*/
1686: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1687: {
1688: PetscFunctionBegin;
1690: PetscAssertPointer(lits, 2);
1691: *lits = snes->linear_its;
1692: PetscFunctionReturn(PETSC_SUCCESS);
1693: }
1695: /*@
1696: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1697: are reset every time `SNESSolve()` is called.
1699: Logically Collective
1701: Input Parameters:
1702: + snes - `SNES` context
1703: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1705: Level: developer
1707: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1708: @*/
1709: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1710: {
1711: PetscFunctionBegin;
1714: snes->counters_reset = reset;
1715: PetscFunctionReturn(PETSC_SUCCESS);
1716: }
1718: /*@
1719: SNESResetCounters - Reset counters for linear iterations and function evaluations.
1721: Logically Collective
1723: Input Parameters:
1724: . snes - `SNES` context
1726: Level: developer
1728: Note:
1729: It honors the flag set with `SNESSetCountersReset()`
1731: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1732: @*/
1733: PetscErrorCode SNESResetCounters(SNES snes)
1734: {
1735: PetscFunctionBegin;
1737: if (snes->counters_reset) {
1738: snes->nfuncs = 0;
1739: snes->linear_its = 0;
1740: snes->numFailures = 0;
1741: }
1742: PetscFunctionReturn(PETSC_SUCCESS);
1743: }
1745: /*@
1746: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1748: Not Collective, but the `SNES` and `KSP` objects must live on the same `MPI_Comm`
1750: Input Parameters:
1751: + snes - the `SNES` context
1752: - ksp - the `KSP` context
1754: Level: developer
1756: Notes:
1757: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1758: so this routine is rarely needed.
1760: The `KSP` object that is already in the `SNES` object has its reference count
1761: decreased by one when this is called.
1763: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`
1764: @*/
1765: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1766: {
1767: PetscFunctionBegin;
1770: PetscCheckSameComm(snes, 1, ksp, 2);
1771: PetscCall(PetscObjectReference((PetscObject)ksp));
1772: if (snes->ksp) PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1773: snes->ksp = ksp;
1774: PetscFunctionReturn(PETSC_SUCCESS);
1775: }
1777: /*@
1778: SNESParametersInitialize - Sets all the parameters in `snes` to their default value (when `SNESCreate()` was called) if they
1779: currently contain default values
1781: Collective
1783: Input Parameter:
1784: . snes - the `SNES` object
1786: Level: developer
1788: Developer Note:
1789: This is called by all the `SNESCreate_XXX()` routines.
1791: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
1792: `PetscObjectParameterSetDefault()`
1793: @*/
1794: PetscErrorCode SNESParametersInitialize(SNES snes)
1795: {
1796: PetscObjectParameterSetDefault(snes, max_its, 50);
1797: PetscObjectParameterSetDefault(snes, max_funcs, 10000);
1798: PetscObjectParameterSetDefault(snes, rtol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1799: PetscObjectParameterSetDefault(snes, abstol, PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50);
1800: PetscObjectParameterSetDefault(snes, stol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1801: PetscObjectParameterSetDefault(snes, divtol, 1.e4);
1802: return PETSC_SUCCESS;
1803: }
1805: /*@
1806: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1808: Collective
1810: Input Parameter:
1811: . comm - MPI communicator
1813: Output Parameter:
1814: . outsnes - the new `SNES` context
1816: Options Database Keys:
1817: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no preconditioning matrix
1818: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided preconditioning matrix
1819: as set by `SNESSetJacobian()`
1820: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1821: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1823: Level: beginner
1825: Developer Notes:
1826: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1827: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1828: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1829: in `SNESView()`.
1831: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1832: by help messages about meaningless `SNES` options.
1834: `SNES` always creates the snes->kspconvctx even though it is used by only one type. This should be fixed.
1836: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1837: @*/
1838: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1839: {
1840: SNES snes;
1841: SNESKSPEW *kctx;
1843: PetscFunctionBegin;
1844: PetscAssertPointer(outsnes, 2);
1845: PetscCall(SNESInitializePackage());
1847: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1848: snes->ops->converged = SNESConvergedDefault;
1849: snes->usesksp = PETSC_TRUE;
1850: snes->norm = 0.0;
1851: snes->xnorm = 0.0;
1852: snes->ynorm = 0.0;
1853: snes->normschedule = SNES_NORM_ALWAYS;
1854: snes->functype = SNES_FUNCTION_DEFAULT;
1855: snes->ttol = 0.0;
1857: snes->rnorm0 = 0;
1858: snes->nfuncs = 0;
1859: snes->numFailures = 0;
1860: snes->maxFailures = 1;
1861: snes->linear_its = 0;
1862: snes->lagjacobian = 1;
1863: snes->jac_iter = 0;
1864: snes->lagjac_persist = PETSC_FALSE;
1865: snes->lagpreconditioner = 1;
1866: snes->pre_iter = 0;
1867: snes->lagpre_persist = PETSC_FALSE;
1868: snes->numbermonitors = 0;
1869: snes->numberreasonviews = 0;
1870: snes->data = NULL;
1871: snes->setupcalled = PETSC_FALSE;
1872: snes->ksp_ewconv = PETSC_FALSE;
1873: snes->nwork = 0;
1874: snes->work = NULL;
1875: snes->nvwork = 0;
1876: snes->vwork = NULL;
1877: snes->conv_hist_len = 0;
1878: snes->conv_hist_max = 0;
1879: snes->conv_hist = NULL;
1880: snes->conv_hist_its = NULL;
1881: snes->conv_hist_reset = PETSC_TRUE;
1882: snes->counters_reset = PETSC_TRUE;
1883: snes->vec_func_init_set = PETSC_FALSE;
1884: snes->reason = SNES_CONVERGED_ITERATING;
1885: snes->npcside = PC_RIGHT;
1886: snes->setfromoptionscalled = 0;
1888: snes->mf = PETSC_FALSE;
1889: snes->mf_operator = PETSC_FALSE;
1890: snes->mf_version = 1;
1892: snes->numLinearSolveFailures = 0;
1893: snes->maxLinearSolveFailures = 1;
1895: snes->vizerotolerance = 1.e-8;
1896: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1898: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1899: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1901: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1902: PetscCall(PetscNew(&kctx));
1904: snes->kspconvctx = kctx;
1905: kctx->version = 2;
1906: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1907: this was too large for some test cases */
1908: kctx->rtol_last = 0.0;
1909: kctx->rtol_max = 0.9;
1910: kctx->gamma = 1.0;
1911: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1912: kctx->alpha2 = kctx->alpha;
1913: kctx->threshold = 0.1;
1914: kctx->lresid_last = 0.0;
1915: kctx->norm_last = 0.0;
1917: kctx->rk_last = 0.0;
1918: kctx->rk_last_2 = 0.0;
1919: kctx->rtol_last_2 = 0.0;
1920: kctx->v4_p1 = 0.1;
1921: kctx->v4_p2 = 0.4;
1922: kctx->v4_p3 = 0.7;
1923: kctx->v4_m1 = 0.8;
1924: kctx->v4_m2 = 0.5;
1925: kctx->v4_m3 = 0.1;
1926: kctx->v4_m4 = 0.5;
1928: PetscCall(SNESParametersInitialize(snes));
1929: *outsnes = snes;
1930: PetscFunctionReturn(PETSC_SUCCESS);
1931: }
1933: /*@C
1934: SNESSetFunction - Sets the function evaluation routine and function
1935: vector for use by the `SNES` routines in solving systems of nonlinear
1936: equations.
1938: Logically Collective
1940: Input Parameters:
1941: + snes - the `SNES` context
1942: . r - vector to store function values, may be `NULL`
1943: . f - function evaluation routine; for calling sequence see `SNESFunctionFn`
1944: - ctx - [optional] user-defined context for private data for the
1945: function evaluation routine (may be `NULL`)
1947: Level: beginner
1949: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunctionFn`
1950: @*/
1951: PetscErrorCode SNESSetFunction(SNES snes, Vec r, SNESFunctionFn *f, void *ctx)
1952: {
1953: DM dm;
1955: PetscFunctionBegin;
1957: if (r) {
1959: PetscCheckSameComm(snes, 1, r, 2);
1960: PetscCall(PetscObjectReference((PetscObject)r));
1961: PetscCall(VecDestroy(&snes->vec_func));
1962: snes->vec_func = r;
1963: }
1964: PetscCall(SNESGetDM(snes, &dm));
1965: PetscCall(DMSNESSetFunction(dm, f, ctx));
1966: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1967: PetscFunctionReturn(PETSC_SUCCESS);
1968: }
1970: /*@C
1971: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1973: Logically Collective
1975: Input Parameters:
1976: + snes - the `SNES` context
1977: - f - vector to store function value
1979: Level: developer
1981: Notes:
1982: This should not be modified during the solution procedure.
1984: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1986: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1987: @*/
1988: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1989: {
1990: Vec vec_func;
1992: PetscFunctionBegin;
1995: PetscCheckSameComm(snes, 1, f, 2);
1996: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1997: snes->vec_func_init_set = PETSC_FALSE;
1998: PetscFunctionReturn(PETSC_SUCCESS);
1999: }
2000: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
2001: PetscCall(VecCopy(f, vec_func));
2003: snes->vec_func_init_set = PETSC_TRUE;
2004: PetscFunctionReturn(PETSC_SUCCESS);
2005: }
2007: /*@
2008: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
2009: of the `SNES` method, when norms are computed in the solving process
2011: Logically Collective
2013: Input Parameters:
2014: + snes - the `SNES` context
2015: - normschedule - the frequency of norm computation
2017: Options Database Key:
2018: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
2020: Level: advanced
2022: Notes:
2023: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
2024: of the nonlinear function and the taking of its norm at every iteration to
2025: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2026: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
2027: may either be monitored for convergence or not. As these are often used as nonlinear
2028: preconditioners, monitoring the norm of their error is not a useful enterprise within
2029: their solution.
2031: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
2032: @*/
2033: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
2034: {
2035: PetscFunctionBegin;
2037: snes->normschedule = normschedule;
2038: PetscFunctionReturn(PETSC_SUCCESS);
2039: }
2041: /*@
2042: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
2043: of the `SNES` method.
2045: Logically Collective
2047: Input Parameters:
2048: + snes - the `SNES` context
2049: - normschedule - the type of the norm used
2051: Level: advanced
2053: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2054: @*/
2055: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
2056: {
2057: PetscFunctionBegin;
2059: *normschedule = snes->normschedule;
2060: PetscFunctionReturn(PETSC_SUCCESS);
2061: }
2063: /*@
2064: SNESSetFunctionNorm - Sets the last computed residual norm.
2066: Logically Collective
2068: Input Parameters:
2069: + snes - the `SNES` context
2070: - norm - the value of the norm
2072: Level: developer
2074: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2075: @*/
2076: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
2077: {
2078: PetscFunctionBegin;
2080: snes->norm = norm;
2081: PetscFunctionReturn(PETSC_SUCCESS);
2082: }
2084: /*@
2085: SNESGetFunctionNorm - Gets the last computed norm of the residual
2087: Not Collective
2089: Input Parameter:
2090: . snes - the `SNES` context
2092: Output Parameter:
2093: . norm - the last computed residual norm
2095: Level: developer
2097: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2098: @*/
2099: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2100: {
2101: PetscFunctionBegin;
2103: PetscAssertPointer(norm, 2);
2104: *norm = snes->norm;
2105: PetscFunctionReturn(PETSC_SUCCESS);
2106: }
2108: /*@
2109: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2111: Not Collective
2113: Input Parameter:
2114: . snes - the `SNES` context
2116: Output Parameter:
2117: . ynorm - the last computed update norm
2119: Level: developer
2121: Note:
2122: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2124: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2125: @*/
2126: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2127: {
2128: PetscFunctionBegin;
2130: PetscAssertPointer(ynorm, 2);
2131: *ynorm = snes->ynorm;
2132: PetscFunctionReturn(PETSC_SUCCESS);
2133: }
2135: /*@
2136: SNESGetSolutionNorm - Gets the last computed norm of the solution
2138: Not Collective
2140: Input Parameter:
2141: . snes - the `SNES` context
2143: Output Parameter:
2144: . xnorm - the last computed solution norm
2146: Level: developer
2148: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2149: @*/
2150: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2151: {
2152: PetscFunctionBegin;
2154: PetscAssertPointer(xnorm, 2);
2155: *xnorm = snes->xnorm;
2156: PetscFunctionReturn(PETSC_SUCCESS);
2157: }
2159: /*@
2160: SNESSetFunctionType - Sets the `SNESFunctionType`
2161: of the `SNES` method.
2163: Logically Collective
2165: Input Parameters:
2166: + snes - the `SNES` context
2167: - type - the function type
2169: Level: developer
2171: Values of the function type\:
2172: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2173: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2174: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2176: Note:
2177: Different `SNESType`s use this value in different ways
2179: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2180: @*/
2181: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2182: {
2183: PetscFunctionBegin;
2185: snes->functype = type;
2186: PetscFunctionReturn(PETSC_SUCCESS);
2187: }
2189: /*@
2190: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2191: of the SNES method.
2193: Logically Collective
2195: Input Parameters:
2196: + snes - the `SNES` context
2197: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2199: Level: advanced
2201: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2202: @*/
2203: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2204: {
2205: PetscFunctionBegin;
2207: *type = snes->functype;
2208: PetscFunctionReturn(PETSC_SUCCESS);
2209: }
2211: /*@C
2212: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2213: use with composed nonlinear solvers.
2215: Input Parameters:
2216: + snes - the `SNES` context, usually of the `SNESType` `SNESNGS`
2217: . f - function evaluation routine to apply Gauss-Seidel, see `SNESNGSFn` for calling sequence
2218: - ctx - [optional] user-defined context for private data for the smoother evaluation routine (may be `NULL`)
2220: Level: intermediate
2222: Note:
2223: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2224: a problem appropriate update to the solution, particularly `SNESFAS`.
2226: .seealso: [](ch_snes), `SNESNGS`, `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`, `SNESNGSFn`
2227: @*/
2228: PetscErrorCode SNESSetNGS(SNES snes, SNESNGSFn *f, void *ctx)
2229: {
2230: DM dm;
2232: PetscFunctionBegin;
2234: PetscCall(SNESGetDM(snes, &dm));
2235: PetscCall(DMSNESSetNGS(dm, f, ctx));
2236: PetscFunctionReturn(PETSC_SUCCESS);
2237: }
2239: /*
2240: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2241: changed during the KSPSolve()
2242: */
2243: PetscErrorCode SNESPicardComputeMFFunction(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: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2256: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2257: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2258: PetscCall(MatMultAdd(snes->picard, x, f, f));
2259: } else {
2260: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2261: PetscCall(MatMult(snes->picard, x, f));
2262: }
2263: PetscFunctionReturn(PETSC_SUCCESS);
2264: }
2266: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, void *ctx)
2267: {
2268: DM dm;
2269: DMSNES sdm;
2271: PetscFunctionBegin;
2272: PetscCall(SNESGetDM(snes, &dm));
2273: PetscCall(DMGetDMSNES(dm, &sdm));
2274: /* A(x)*x - b(x) */
2275: if (sdm->ops->computepfunction) {
2276: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2277: PetscCall(VecScale(f, -1.0));
2278: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2279: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2280: } else {
2281: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2282: PetscCall(MatMult(snes->jacobian_pre, x, f));
2283: }
2284: PetscFunctionReturn(PETSC_SUCCESS);
2285: }
2287: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, void *ctx)
2288: {
2289: PetscFunctionBegin;
2290: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2291: /* must assembly if matrix-free to get the last SNES solution */
2292: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2293: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2294: PetscFunctionReturn(PETSC_SUCCESS);
2295: }
2297: /*@C
2298: SNESSetPicard - Use `SNES` to solve the system $A(x) x = bp(x) + b $ via a Picard type iteration (Picard linearization)
2300: Logically Collective
2302: Input Parameters:
2303: + snes - the `SNES` context
2304: . r - vector to store function values, may be `NULL`
2305: . bp - function evaluation routine, may be `NULL`, for the calling sequence see `SNESFunctionFn`
2306: . Amat - matrix with which A(x) x - bp(x) - b is to be computed
2307: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2308: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFn`
2309: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2311: Level: intermediate
2313: Notes:
2314: It is often better to provide the nonlinear function F() and some approximation to its Jacobian directly and use
2315: 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.
2317: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2319: Solves the equation $A(x) x = bp(x) - b$ via the defect correction algorithm $A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}$.
2320: When an exact solver is used this corresponds to the "classic" Picard $A(x^{n}) x^{n+1} = bp(x^{n}) + b$ iteration.
2322: Run with `-snes_mf_operator` to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2324: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2325: the direct Picard iteration $A(x^n) x^{n+1} = bp(x^n) + b$
2327: 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
2328: 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
2329: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument \:-).
2331: 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
2332: A(x^{n}) is used to build the preconditioner
2334: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at a time) and thus represent Newton's method.
2336: 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
2337: 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
2338: 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`.
2339: See the comment in src/snes/tutorials/ex15.c.
2341: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`,
2342: `SNESFunctionFn`, `SNESJacobianFn`
2343: @*/
2344: PetscErrorCode SNESSetPicard(SNES snes, Vec r, SNESFunctionFn *bp, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
2345: {
2346: DM dm;
2348: PetscFunctionBegin;
2350: PetscCall(SNESGetDM(snes, &dm));
2351: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2352: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2353: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2354: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2355: PetscFunctionReturn(PETSC_SUCCESS);
2356: }
2358: /*@C
2359: SNESGetPicard - Returns the context for the Picard iteration
2361: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2363: Input Parameter:
2364: . snes - the `SNES` context
2366: Output Parameters:
2367: + r - the function (or `NULL`)
2368: . f - the function (or `NULL`); for calling sequence see `SNESFunctionFn`
2369: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2370: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2371: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFn`
2372: - ctx - the function context (or `NULL`)
2374: Level: advanced
2376: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunctionFn`, `SNESJacobianFn`
2377: @*/
2378: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, SNESFunctionFn **f, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
2379: {
2380: DM dm;
2382: PetscFunctionBegin;
2384: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2385: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2386: PetscCall(SNESGetDM(snes, &dm));
2387: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2388: PetscFunctionReturn(PETSC_SUCCESS);
2389: }
2391: /*@C
2392: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2394: Logically Collective
2396: Input Parameters:
2397: + snes - the `SNES` context
2398: . func - function evaluation routine, see `SNESInitialGuessFn` for the calling sequence
2399: - ctx - [optional] user-defined context for private data for the
2400: function evaluation routine (may be `NULL`)
2402: Level: intermediate
2404: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESInitialGuessFn`
2405: @*/
2406: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, SNESInitialGuessFn *func, void *ctx)
2407: {
2408: PetscFunctionBegin;
2410: if (func) snes->ops->computeinitialguess = func;
2411: if (ctx) snes->initialguessP = ctx;
2412: PetscFunctionReturn(PETSC_SUCCESS);
2413: }
2415: /*@C
2416: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2417: it assumes a zero right-hand side.
2419: Logically Collective
2421: Input Parameter:
2422: . snes - the `SNES` context
2424: Output Parameter:
2425: . rhs - the right-hand side vector or `NULL` if there is no right-hand side vector
2427: Level: intermediate
2429: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2430: @*/
2431: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2432: {
2433: PetscFunctionBegin;
2435: PetscAssertPointer(rhs, 2);
2436: *rhs = snes->vec_rhs;
2437: PetscFunctionReturn(PETSC_SUCCESS);
2438: }
2440: /*@
2441: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2443: Collective
2445: Input Parameters:
2446: + snes - the `SNES` context
2447: - x - input vector
2449: Output Parameter:
2450: . y - function vector, as set by `SNESSetFunction()`
2452: Level: developer
2454: Notes:
2455: `SNESComputeFunction()` is typically used within nonlinear solvers
2456: implementations, so users would not generally call this routine themselves.
2458: When solving for $F(x) = b$, this routine computes $y = F(x) - b$.
2460: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`
2461: @*/
2462: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec y)
2463: {
2464: DM dm;
2465: DMSNES sdm;
2467: PetscFunctionBegin;
2471: PetscCheckSameComm(snes, 1, x, 2);
2472: PetscCheckSameComm(snes, 1, y, 3);
2473: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2475: PetscCall(SNESGetDM(snes, &dm));
2476: PetscCall(DMGetDMSNES(dm, &sdm));
2477: 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().");
2478: if (sdm->ops->computefunction) {
2479: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2480: PetscCall(VecLockReadPush(x));
2481: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2482: snes->domainerror = PETSC_FALSE;
2483: {
2484: void *ctx;
2485: SNESFunctionFn *computefunction;
2486: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2487: PetscCallBack("SNES callback function", (*computefunction)(snes, x, y, ctx));
2488: }
2489: PetscCall(VecLockReadPop(x));
2490: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2491: } else /* if (snes->vec_rhs) */ {
2492: PetscCall(MatMult(snes->jacobian, x, y));
2493: }
2494: if (snes->vec_rhs) PetscCall(VecAXPY(y, -1.0, snes->vec_rhs));
2495: snes->nfuncs++;
2496: /*
2497: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2498: propagate the value to all processes
2499: */
2500: PetscCall(VecFlag(y, snes->domainerror));
2501: PetscFunctionReturn(PETSC_SUCCESS);
2502: }
2504: /*@
2505: SNESComputeMFFunction - Calls the function that has been set with `SNESSetMFFunction()`.
2507: Collective
2509: Input Parameters:
2510: + snes - the `SNES` context
2511: - x - input vector
2513: Output Parameter:
2514: . y - function vector, as set by `SNESSetMFFunction()`
2516: Level: developer
2518: Notes:
2519: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2520: so users would not generally call this routine themselves.
2522: Since this function is intended for use with finite differencing it does not subtract the right-hand side vector provided with `SNESSolve()`
2523: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2524: 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.
2526: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF`
2527: @*/
2528: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2529: {
2530: DM dm;
2531: DMSNES sdm;
2533: PetscFunctionBegin;
2537: PetscCheckSameComm(snes, 1, x, 2);
2538: PetscCheckSameComm(snes, 1, y, 3);
2539: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2541: PetscCall(SNESGetDM(snes, &dm));
2542: PetscCall(DMGetDMSNES(dm, &sdm));
2543: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2544: PetscCall(VecLockReadPush(x));
2545: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2546: snes->domainerror = PETSC_FALSE;
2547: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2548: PetscCall(VecLockReadPop(x));
2549: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2550: snes->nfuncs++;
2551: /*
2552: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2553: propagate the value to all processes
2554: */
2555: PetscCall(VecFlag(y, snes->domainerror));
2556: PetscFunctionReturn(PETSC_SUCCESS);
2557: }
2559: /*@
2560: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2562: Collective
2564: Input Parameters:
2565: + snes - the `SNES` context
2566: . x - input vector
2567: - b - rhs vector
2569: Output Parameter:
2570: . x - new solution vector
2572: Level: developer
2574: Note:
2575: `SNESComputeNGS()` is typically used within composed nonlinear solver
2576: implementations, so most users would not generally call this routine
2577: themselves.
2579: .seealso: [](ch_snes), `SNESNGSFn`, `SNESSetNGS()`, `SNESComputeFunction()`, `SNESNGS`
2580: @*/
2581: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2582: {
2583: DM dm;
2584: DMSNES sdm;
2586: PetscFunctionBegin;
2590: PetscCheckSameComm(snes, 1, x, 3);
2591: if (b) PetscCheckSameComm(snes, 1, b, 2);
2592: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2593: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2594: PetscCall(SNESGetDM(snes, &dm));
2595: PetscCall(DMGetDMSNES(dm, &sdm));
2596: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2597: if (b) PetscCall(VecLockReadPush(b));
2598: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2599: if (b) PetscCall(VecLockReadPop(b));
2600: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2601: PetscFunctionReturn(PETSC_SUCCESS);
2602: }
2604: static PetscErrorCode SNESComputeFunction_FD(SNES snes, Vec Xin, Vec G)
2605: {
2606: Vec X;
2607: PetscScalar *g;
2608: PetscReal f, f2;
2609: PetscInt low, high, N, i;
2610: PetscBool flg;
2611: PetscReal h = .5 * PETSC_SQRT_MACHINE_EPSILON;
2613: PetscFunctionBegin;
2614: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_fd_delta", &h, &flg));
2615: PetscCall(VecDuplicate(Xin, &X));
2616: PetscCall(VecCopy(Xin, X));
2617: PetscCall(VecGetSize(X, &N));
2618: PetscCall(VecGetOwnershipRange(X, &low, &high));
2619: PetscCall(VecSetOption(X, VEC_IGNORE_OFF_PROC_ENTRIES, PETSC_TRUE));
2620: PetscCall(VecGetArray(G, &g));
2621: for (i = 0; i < N; i++) {
2622: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2623: PetscCall(VecAssemblyBegin(X));
2624: PetscCall(VecAssemblyEnd(X));
2625: PetscCall(SNESComputeObjective(snes, X, &f));
2626: PetscCall(VecSetValue(X, i, 2.0 * h, ADD_VALUES));
2627: PetscCall(VecAssemblyBegin(X));
2628: PetscCall(VecAssemblyEnd(X));
2629: PetscCall(SNESComputeObjective(snes, X, &f2));
2630: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2631: PetscCall(VecAssemblyBegin(X));
2632: PetscCall(VecAssemblyEnd(X));
2633: if (i >= low && i < high) g[i - low] = (f2 - f) / (2.0 * h);
2634: }
2635: PetscCall(VecRestoreArray(G, &g));
2636: PetscCall(VecDestroy(&X));
2637: PetscFunctionReturn(PETSC_SUCCESS);
2638: }
2640: PetscErrorCode SNESTestFunction(SNES snes)
2641: {
2642: Vec x, g1, g2, g3;
2643: PetscBool complete_print = PETSC_FALSE, test = PETSC_FALSE;
2644: PetscReal hcnorm, fdnorm, hcmax, fdmax, diffmax, diffnorm;
2645: PetscScalar dot;
2646: MPI_Comm comm;
2647: PetscViewer viewer, mviewer;
2648: PetscViewerFormat format;
2649: PetscInt tabs;
2650: static PetscBool directionsprinted = PETSC_FALSE;
2651: SNESObjectiveFn *objective;
2653: PetscFunctionBegin;
2654: PetscCall(SNESGetObjective(snes, &objective, NULL));
2655: if (!objective) PetscFunctionReturn(PETSC_SUCCESS);
2657: PetscObjectOptionsBegin((PetscObject)snes);
2658: PetscCall(PetscOptionsName("-snes_test_function", "Compare hand-coded and finite difference function", "None", &test));
2659: PetscCall(PetscOptionsViewer("-snes_test_function_view", "View difference between hand-coded and finite difference function element entries", "None", &mviewer, &format, &complete_print));
2660: PetscOptionsEnd();
2661: if (!test) {
2662: if (complete_print) PetscCall(PetscViewerDestroy(&mviewer));
2663: PetscFunctionReturn(PETSC_SUCCESS);
2664: }
2666: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2667: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2668: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2669: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2670: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Function -------------\n"));
2671: if (!complete_print && !directionsprinted) {
2672: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_function_view and optionally -snes_test_function <threshold> to show difference\n"));
2673: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference function entries greater than <threshold>.\n"));
2674: }
2675: if (!directionsprinted) {
2676: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Function, if (for double precision runs) ||F - Ffd||/||F|| is\n"));
2677: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Function is probably correct.\n"));
2678: directionsprinted = PETSC_TRUE;
2679: }
2680: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2682: PetscCall(SNESGetSolution(snes, &x));
2683: PetscCall(VecDuplicate(x, &g1));
2684: PetscCall(VecDuplicate(x, &g2));
2685: PetscCall(VecDuplicate(x, &g3));
2686: PetscCall(SNESComputeFunction(snes, x, g1));
2687: PetscCall(SNESComputeFunction_FD(snes, x, g2));
2689: PetscCall(VecNorm(g2, NORM_2, &fdnorm));
2690: PetscCall(VecNorm(g1, NORM_2, &hcnorm));
2691: PetscCall(VecNorm(g2, NORM_INFINITY, &fdmax));
2692: PetscCall(VecNorm(g1, NORM_INFINITY, &hcmax));
2693: PetscCall(VecDot(g1, g2, &dot));
2694: PetscCall(VecCopy(g1, g3));
2695: PetscCall(VecAXPY(g3, -1.0, g2));
2696: PetscCall(VecNorm(g3, NORM_2, &diffnorm));
2697: PetscCall(VecNorm(g3, NORM_INFINITY, &diffmax));
2698: PetscCall(PetscViewerASCIIPrintf(viewer, " ||Ffd|| %g, ||F|| = %g, angle cosine = (Ffd'F)/||Ffd||||F|| = %g\n", (double)fdnorm, (double)hcnorm, (double)(PetscRealPart(dot) / (fdnorm * hcnorm))));
2699: PetscCall(PetscViewerASCIIPrintf(viewer, " 2-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffnorm / PetscMax(hcnorm, fdnorm)), (double)diffnorm));
2700: PetscCall(PetscViewerASCIIPrintf(viewer, " max-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffmax / PetscMax(hcmax, fdmax)), (double)diffmax));
2702: if (complete_print) {
2703: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded function ----------\n"));
2704: PetscCall(VecView(g1, mviewer));
2705: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference function ----------\n"));
2706: PetscCall(VecView(g2, mviewer));
2707: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference function ----------\n"));
2708: PetscCall(VecView(g3, mviewer));
2709: }
2710: PetscCall(VecDestroy(&g1));
2711: PetscCall(VecDestroy(&g2));
2712: PetscCall(VecDestroy(&g3));
2714: if (complete_print) {
2715: PetscCall(PetscViewerPopFormat(mviewer));
2716: PetscCall(PetscViewerDestroy(&mviewer));
2717: }
2718: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2719: PetscFunctionReturn(PETSC_SUCCESS);
2720: }
2722: PetscErrorCode SNESTestJacobian(SNES snes)
2723: {
2724: Mat A, B, C, D, jacobian;
2725: Vec x = snes->vec_sol, f;
2726: PetscReal nrm, gnorm;
2727: PetscReal threshold = 1.e-5;
2728: MatType mattype;
2729: PetscInt m, n, M, N;
2730: void *functx;
2731: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, test = PETSC_FALSE, flg, istranspose;
2732: PetscViewer viewer, mviewer;
2733: MPI_Comm comm;
2734: PetscInt tabs;
2735: static PetscBool directionsprinted = PETSC_FALSE;
2736: PetscViewerFormat format;
2738: PetscFunctionBegin;
2739: PetscObjectOptionsBegin((PetscObject)snes);
2740: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &test));
2741: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2742: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2743: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2744: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2745: 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));
2746: PetscOptionsEnd();
2747: if (!test) PetscFunctionReturn(PETSC_SUCCESS);
2749: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2750: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2751: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2752: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2753: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2754: if (!complete_print && !directionsprinted) {
2755: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2756: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2757: }
2758: if (!directionsprinted) {
2759: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2760: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2761: directionsprinted = PETSC_TRUE;
2762: }
2763: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2765: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2766: if (!flg) jacobian = snes->jacobian;
2767: else jacobian = snes->jacobian_pre;
2769: if (!x) PetscCall(MatCreateVecs(jacobian, &x, NULL));
2770: else PetscCall(PetscObjectReference((PetscObject)x));
2771: PetscCall(VecDuplicate(x, &f));
2773: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2774: PetscCall(SNESComputeFunction(snes, x, f));
2775: PetscCall(VecDestroy(&f));
2776: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2777: while (jacobian) {
2778: Mat JT = NULL, Jsave = NULL;
2780: if (istranspose) {
2781: PetscCall(MatCreateTranspose(jacobian, &JT));
2782: Jsave = jacobian;
2783: jacobian = JT;
2784: }
2785: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2786: if (flg) {
2787: A = jacobian;
2788: PetscCall(PetscObjectReference((PetscObject)A));
2789: } else {
2790: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2791: }
2793: PetscCall(MatGetType(A, &mattype));
2794: PetscCall(MatGetSize(A, &M, &N));
2795: PetscCall(MatGetLocalSize(A, &m, &n));
2796: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2797: PetscCall(MatSetType(B, mattype));
2798: PetscCall(MatSetSizes(B, m, n, M, N));
2799: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2800: PetscCall(MatSetUp(B));
2801: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2803: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2804: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2806: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2807: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2808: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2809: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2810: PetscCall(MatDestroy(&D));
2811: if (!gnorm) gnorm = 1; /* just in case */
2812: PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2814: if (complete_print) {
2815: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2816: PetscCall(MatView(A, mviewer));
2817: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2818: PetscCall(MatView(B, mviewer));
2819: }
2821: if (threshold_print || complete_print) {
2822: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2823: PetscScalar *cvals;
2824: const PetscInt *bcols;
2825: const PetscScalar *bvals;
2827: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2828: PetscCall(MatSetType(C, mattype));
2829: PetscCall(MatSetSizes(C, m, n, M, N));
2830: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2831: PetscCall(MatSetUp(C));
2832: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2834: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2835: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2837: for (row = Istart; row < Iend; row++) {
2838: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2839: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2840: for (j = 0, cncols = 0; j < bncols; j++) {
2841: if (PetscAbsScalar(bvals[j]) > threshold) {
2842: ccols[cncols] = bcols[j];
2843: cvals[cncols] = bvals[j];
2844: cncols += 1;
2845: }
2846: }
2847: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2848: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2849: PetscCall(PetscFree2(ccols, cvals));
2850: }
2851: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2852: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2853: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2854: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2855: PetscCall(MatDestroy(&C));
2856: }
2857: PetscCall(MatDestroy(&A));
2858: PetscCall(MatDestroy(&B));
2859: PetscCall(MatDestroy(&JT));
2860: if (Jsave) jacobian = Jsave;
2861: if (jacobian != snes->jacobian_pre) {
2862: jacobian = snes->jacobian_pre;
2863: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2864: } else jacobian = NULL;
2865: }
2866: PetscCall(VecDestroy(&x));
2867: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2868: if (mviewer) PetscCall(PetscViewerDestroy(&mviewer));
2869: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2870: PetscFunctionReturn(PETSC_SUCCESS);
2871: }
2873: /*@
2874: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2876: Collective
2878: Input Parameters:
2879: + snes - the `SNES` context
2880: - X - input vector
2882: Output Parameters:
2883: + A - Jacobian matrix
2884: - B - optional matrix for building the preconditioner, usually the same as `A`
2886: Options Database Keys:
2887: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2888: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2889: . -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.
2890: . -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
2891: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2892: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2893: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2894: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2895: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2896: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2897: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2898: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2899: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2900: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2901: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2903: Level: developer
2905: Note:
2906: Most users should not need to explicitly call this routine, as it
2907: is used internally within the nonlinear solvers.
2909: Developer Note:
2910: 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
2911: with the `SNESType` of test that has been removed.
2913: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
2914: @*/
2915: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2916: {
2917: PetscBool flag;
2918: DM dm;
2919: DMSNES sdm;
2920: KSP ksp;
2922: PetscFunctionBegin;
2925: PetscCheckSameComm(snes, 1, X, 2);
2926: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2927: PetscCall(SNESGetDM(snes, &dm));
2928: PetscCall(DMGetDMSNES(dm, &sdm));
2930: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2931: if (snes->lagjacobian == -2) {
2932: snes->lagjacobian = -1;
2934: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2935: } else if (snes->lagjacobian == -1) {
2936: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2937: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2938: if (flag) {
2939: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2940: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2941: }
2942: PetscFunctionReturn(PETSC_SUCCESS);
2943: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2944: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2945: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2946: if (flag) {
2947: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2948: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2949: }
2950: PetscFunctionReturn(PETSC_SUCCESS);
2951: }
2952: if (snes->npc && snes->npcside == PC_LEFT) {
2953: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2954: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2955: PetscFunctionReturn(PETSC_SUCCESS);
2956: }
2958: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2959: PetscCall(VecLockReadPush(X));
2960: {
2961: void *ctx;
2962: SNESJacobianFn *J;
2963: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2964: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2965: }
2966: PetscCall(VecLockReadPop(X));
2967: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
2969: /* attach latest linearization point to the preconditioning matrix */
2970: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
2972: /* the next line ensures that snes->ksp exists */
2973: PetscCall(SNESGetKSP(snes, &ksp));
2974: if (snes->lagpreconditioner == -2) {
2975: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
2976: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2977: snes->lagpreconditioner = -1;
2978: } else if (snes->lagpreconditioner == -1) {
2979: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
2980: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2981: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2982: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
2983: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2984: } else {
2985: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
2986: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2987: }
2989: /* monkey business to allow testing Jacobians in multilevel solvers.
2990: This is needed because the SNESTestXXX interface does not accept vectors and matrices */
2991: {
2992: Vec xsave = snes->vec_sol;
2993: Mat jacobiansave = snes->jacobian;
2994: Mat jacobian_presave = snes->jacobian_pre;
2996: snes->vec_sol = X;
2997: snes->jacobian = A;
2998: snes->jacobian_pre = B;
2999: PetscCall(SNESTestFunction(snes));
3000: PetscCall(SNESTestJacobian(snes));
3002: snes->vec_sol = xsave;
3003: snes->jacobian = jacobiansave;
3004: snes->jacobian_pre = jacobian_presave;
3005: }
3007: {
3008: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
3009: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
3010: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
3011: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
3012: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
3013: if (flag || flag_draw || flag_contour) {
3014: Mat Bexp_mine = NULL, Bexp, FDexp;
3015: PetscViewer vdraw, vstdout;
3016: PetscBool flg;
3017: if (flag_operator) {
3018: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
3019: Bexp = Bexp_mine;
3020: } else {
3021: /* See if the preconditioning matrix can be viewed and added directly */
3022: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPIBAIJ, ""));
3023: if (flg) Bexp = B;
3024: else {
3025: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
3026: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
3027: Bexp = Bexp_mine;
3028: }
3029: }
3030: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
3031: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
3032: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3033: if (flag_draw || flag_contour) {
3034: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3035: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3036: } else vdraw = NULL;
3037: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
3038: if (flag) PetscCall(MatView(Bexp, vstdout));
3039: if (vdraw) PetscCall(MatView(Bexp, vdraw));
3040: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
3041: if (flag) PetscCall(MatView(FDexp, vstdout));
3042: if (vdraw) PetscCall(MatView(FDexp, vdraw));
3043: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
3044: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
3045: if (flag) PetscCall(MatView(FDexp, vstdout));
3046: if (vdraw) { /* Always use contour for the difference */
3047: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3048: PetscCall(MatView(FDexp, vdraw));
3049: PetscCall(PetscViewerPopFormat(vdraw));
3050: }
3051: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3052: PetscCall(PetscViewerDestroy(&vdraw));
3053: PetscCall(MatDestroy(&Bexp_mine));
3054: PetscCall(MatDestroy(&FDexp));
3055: }
3056: }
3057: {
3058: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
3059: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
3060: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
3061: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
3062: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
3063: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
3064: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
3065: if (flag_threshold) {
3066: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
3067: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
3068: }
3069: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
3070: Mat Bfd;
3071: PetscViewer vdraw, vstdout;
3072: MatColoring coloring;
3073: ISColoring iscoloring;
3074: MatFDColoring matfdcoloring;
3075: SNESFunctionFn *func;
3076: void *funcctx;
3077: PetscReal norm1, norm2, normmax;
3079: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
3080: PetscCall(MatColoringCreate(Bfd, &coloring));
3081: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
3082: PetscCall(MatColoringSetFromOptions(coloring));
3083: PetscCall(MatColoringApply(coloring, &iscoloring));
3084: PetscCall(MatColoringDestroy(&coloring));
3085: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
3086: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3087: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
3088: PetscCall(ISColoringDestroy(&iscoloring));
3090: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
3091: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
3092: PetscCall(MatFDColoringSetFunction(matfdcoloring, (PetscErrorCode (*)(void))func, funcctx));
3093: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
3094: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
3095: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3096: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
3097: PetscCall(MatFDColoringDestroy(&matfdcoloring));
3099: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3100: if (flag_draw || flag_contour) {
3101: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3102: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3103: } else vdraw = NULL;
3104: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
3105: if (flag_display) PetscCall(MatView(B, vstdout));
3106: if (vdraw) PetscCall(MatView(B, vdraw));
3107: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
3108: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3109: if (vdraw) PetscCall(MatView(Bfd, vdraw));
3110: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
3111: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
3112: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
3113: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
3114: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
3115: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3116: if (vdraw) { /* Always use contour for the difference */
3117: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3118: PetscCall(MatView(Bfd, vdraw));
3119: PetscCall(PetscViewerPopFormat(vdraw));
3120: }
3121: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3123: if (flag_threshold) {
3124: PetscInt bs, rstart, rend, i;
3125: PetscCall(MatGetBlockSize(B, &bs));
3126: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
3127: for (i = rstart; i < rend; i++) {
3128: const PetscScalar *ba, *ca;
3129: const PetscInt *bj, *cj;
3130: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
3131: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
3132: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
3133: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
3134: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
3135: for (j = 0; j < bn; j++) {
3136: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3137: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
3138: maxentrycol = bj[j];
3139: maxentry = PetscRealPart(ba[j]);
3140: }
3141: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
3142: maxdiffcol = bj[j];
3143: maxdiff = PetscRealPart(ca[j]);
3144: }
3145: if (rdiff > maxrdiff) {
3146: maxrdiffcol = bj[j];
3147: maxrdiff = rdiff;
3148: }
3149: }
3150: if (maxrdiff > 1) {
3151: 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));
3152: for (j = 0; j < bn; j++) {
3153: PetscReal rdiff;
3154: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3155: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
3156: }
3157: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
3158: }
3159: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
3160: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
3161: }
3162: }
3163: PetscCall(PetscViewerDestroy(&vdraw));
3164: PetscCall(MatDestroy(&Bfd));
3165: }
3166: }
3167: PetscFunctionReturn(PETSC_SUCCESS);
3168: }
3170: /*@C
3171: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3172: location to store the matrix.
3174: Logically Collective
3176: Input Parameters:
3177: + snes - the `SNES` context
3178: . Amat - the matrix that defines the (approximate) Jacobian
3179: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3180: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFn` for details
3181: - ctx - [optional] user-defined context for private data for the
3182: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3184: Level: beginner
3186: Notes:
3187: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3188: each matrix.
3190: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3191: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3193: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3194: must be a `MatFDColoring`.
3196: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3197: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3199: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3200: `SNESSetPicard()`, `SNESJacobianFn`, `SNESFunctionFn`
3201: @*/
3202: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
3203: {
3204: DM dm;
3206: PetscFunctionBegin;
3210: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3211: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3212: PetscCall(SNESGetDM(snes, &dm));
3213: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3214: if (Amat) {
3215: PetscCall(PetscObjectReference((PetscObject)Amat));
3216: PetscCall(MatDestroy(&snes->jacobian));
3218: snes->jacobian = Amat;
3219: }
3220: if (Pmat) {
3221: PetscCall(PetscObjectReference((PetscObject)Pmat));
3222: PetscCall(MatDestroy(&snes->jacobian_pre));
3224: snes->jacobian_pre = Pmat;
3225: }
3226: PetscFunctionReturn(PETSC_SUCCESS);
3227: }
3229: /*@C
3230: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3231: provided context for evaluating the Jacobian.
3233: Not Collective, but `Mat` object will be parallel if `SNES` is
3235: Input Parameter:
3236: . snes - the nonlinear solver context
3238: Output Parameters:
3239: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3240: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3241: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFn`
3242: - ctx - location to stash Jacobian ctx (or `NULL`)
3244: Level: advanced
3246: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFn`, `SNESGetFunction()`
3247: @*/
3248: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
3249: {
3250: DM dm;
3252: PetscFunctionBegin;
3254: if (Amat) *Amat = snes->jacobian;
3255: if (Pmat) *Pmat = snes->jacobian_pre;
3256: PetscCall(SNESGetDM(snes, &dm));
3257: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3258: PetscFunctionReturn(PETSC_SUCCESS);
3259: }
3261: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3262: {
3263: DM dm;
3264: DMSNES sdm;
3266: PetscFunctionBegin;
3267: PetscCall(SNESGetDM(snes, &dm));
3268: PetscCall(DMGetDMSNES(dm, &sdm));
3269: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3270: DM dm;
3271: PetscBool isdense, ismf;
3273: PetscCall(SNESGetDM(snes, &dm));
3274: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3275: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3276: if (isdense) {
3277: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3278: } else if (!ismf) {
3279: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3280: }
3281: }
3282: PetscFunctionReturn(PETSC_SUCCESS);
3283: }
3285: /*@
3286: SNESSetUp - Sets up the internal data structures for the later use
3287: of a nonlinear solver.
3289: Collective
3291: Input Parameter:
3292: . snes - the `SNES` context
3294: Level: advanced
3296: Note:
3297: For basic use of the `SNES` solvers the user need not explicitly call
3298: `SNESSetUp()`, since these actions will automatically occur during
3299: the call to `SNESSolve()`. However, if one wishes to control this
3300: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3301: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3303: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`
3304: @*/
3305: PetscErrorCode SNESSetUp(SNES snes)
3306: {
3307: DM dm;
3308: DMSNES sdm;
3309: SNESLineSearch linesearch, pclinesearch;
3310: void *lsprectx, *lspostctx;
3311: PetscBool mf_operator, mf;
3312: Vec f, fpc;
3313: void *funcctx;
3314: void *jacctx, *appctx;
3315: Mat j, jpre;
3316: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3317: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3318: SNESFunctionFn *func;
3319: SNESJacobianFn *jac;
3321: PetscFunctionBegin;
3323: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3324: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3326: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3328: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3330: PetscCall(SNESGetDM(snes, &dm));
3331: PetscCall(DMGetDMSNES(dm, &sdm));
3332: PetscCall(SNESSetDefaultComputeJacobian(snes));
3334: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3336: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3338: if (snes->linesearch) {
3339: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3340: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3341: }
3343: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3344: if (snes->npc && snes->npcside == PC_LEFT) {
3345: snes->mf = PETSC_TRUE;
3346: snes->mf_operator = PETSC_FALSE;
3347: }
3349: if (snes->npc) {
3350: /* copy the DM over */
3351: PetscCall(SNESGetDM(snes, &dm));
3352: PetscCall(SNESSetDM(snes->npc, dm));
3354: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3355: PetscCall(VecDuplicate(f, &fpc));
3356: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3357: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3358: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3359: PetscCall(SNESGetApplicationContext(snes, &appctx));
3360: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3361: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3362: PetscCall(VecDestroy(&fpc));
3364: /* copy the function pointers over */
3365: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3367: /* default to 1 iteration */
3368: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3369: if (snes->npcside == PC_RIGHT) {
3370: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3371: } else {
3372: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3373: }
3374: PetscCall(SNESSetFromOptions(snes->npc));
3376: /* copy the line search context over */
3377: if (snes->linesearch && snes->npc->linesearch) {
3378: PetscCall(SNESGetLineSearch(snes, &linesearch));
3379: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3380: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3381: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3382: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3383: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3384: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3385: }
3386: }
3387: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3388: if (snes->ops->usercompute && !snes->ctx) PetscCallBack("SNES callback compute application context", (*snes->ops->usercompute)(snes, &snes->ctx));
3390: snes->jac_iter = 0;
3391: snes->pre_iter = 0;
3393: PetscTryTypeMethod(snes, setup);
3395: PetscCall(SNESSetDefaultComputeJacobian(snes));
3397: if (snes->npc && snes->npcside == PC_LEFT) {
3398: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3399: if (snes->linesearch) {
3400: PetscCall(SNESGetLineSearch(snes, &linesearch));
3401: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3402: }
3403: }
3404: }
3405: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3406: snes->setupcalled = PETSC_TRUE;
3407: PetscFunctionReturn(PETSC_SUCCESS);
3408: }
3410: /*@
3411: SNESReset - Resets a `SNES` context to the snessetupcalled = 0 state and removes any allocated `Vec`s and `Mat`s
3413: Collective
3415: Input Parameter:
3416: . snes - iterative context obtained from `SNESCreate()`
3418: Level: intermediate
3420: Notes:
3421: Call this if you wish to reuse a `SNES` but with different size vectors
3423: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3425: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3426: @*/
3427: PetscErrorCode SNESReset(SNES snes)
3428: {
3429: PetscFunctionBegin;
3431: if (snes->ops->ctxdestroy && snes->ctx) {
3432: PetscCallBack("SNES callback destroy application context", (*snes->ops->ctxdestroy)(&snes->ctx));
3433: snes->ctx = NULL;
3434: }
3435: if (snes->npc) PetscCall(SNESReset(snes->npc));
3437: PetscTryTypeMethod(snes, reset);
3438: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3440: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3442: PetscCall(VecDestroy(&snes->vec_rhs));
3443: PetscCall(VecDestroy(&snes->vec_sol));
3444: PetscCall(VecDestroy(&snes->vec_sol_update));
3445: PetscCall(VecDestroy(&snes->vec_func));
3446: PetscCall(MatDestroy(&snes->jacobian));
3447: PetscCall(MatDestroy(&snes->jacobian_pre));
3448: PetscCall(MatDestroy(&snes->picard));
3449: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3450: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3452: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3454: snes->nwork = snes->nvwork = 0;
3455: snes->setupcalled = PETSC_FALSE;
3456: PetscFunctionReturn(PETSC_SUCCESS);
3457: }
3459: /*@
3460: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()` also
3461: removes the default viewer.
3463: Collective
3465: Input Parameter:
3466: . snes - iterative context obtained from `SNESCreate()`
3468: Level: intermediate
3470: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3471: @*/
3472: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3473: {
3474: PetscInt i;
3476: PetscFunctionBegin;
3478: for (i = 0; i < snes->numberreasonviews; i++) {
3479: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3480: }
3481: snes->numberreasonviews = 0;
3482: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
3483: PetscFunctionReturn(PETSC_SUCCESS);
3484: }
3486: /*@
3487: SNESDestroy - Destroys the nonlinear solver context that was created
3488: with `SNESCreate()`.
3490: Collective
3492: Input Parameter:
3493: . snes - the `SNES` context
3495: Level: beginner
3497: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3498: @*/
3499: PetscErrorCode SNESDestroy(SNES *snes)
3500: {
3501: PetscFunctionBegin;
3502: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3504: if (--((PetscObject)*snes)->refct > 0) {
3505: *snes = NULL;
3506: PetscFunctionReturn(PETSC_SUCCESS);
3507: }
3509: PetscCall(SNESReset(*snes));
3510: PetscCall(SNESDestroy(&(*snes)->npc));
3512: /* if memory was published with SAWs then destroy it */
3513: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3514: PetscTryTypeMethod(*snes, destroy);
3516: if ((*snes)->dm) PetscCall(DMCoarsenHookRemove((*snes)->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3517: PetscCall(DMDestroy(&(*snes)->dm));
3518: PetscCall(KSPDestroy(&(*snes)->ksp));
3519: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3521: PetscCall(PetscFree((*snes)->kspconvctx));
3522: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)((*snes)->cnvP));
3523: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3524: PetscCall(SNESMonitorCancel(*snes));
3525: PetscCall(SNESConvergedReasonViewCancel(*snes));
3526: PetscCall(PetscHeaderDestroy(snes));
3527: PetscFunctionReturn(PETSC_SUCCESS);
3528: }
3530: /* ----------- Routines to set solver parameters ---------- */
3532: /*@
3533: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3535: Logically Collective
3537: Input Parameters:
3538: + snes - the `SNES` context
3539: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3540: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3542: Options Database Keys:
3543: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3544: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3545: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3546: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3548: Level: intermediate
3550: Notes:
3551: The default is 1
3553: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3555: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3557: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3558: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3559: @*/
3560: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3561: {
3562: PetscFunctionBegin;
3564: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3565: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3567: snes->lagpreconditioner = lag;
3568: PetscFunctionReturn(PETSC_SUCCESS);
3569: }
3571: /*@
3572: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3574: Logically Collective
3576: Input Parameters:
3577: + snes - the `SNES` context
3578: - steps - the number of refinements to do, defaults to 0
3580: Options Database Key:
3581: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3583: Level: intermediate
3585: Note:
3586: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3588: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3589: `SNESetDM()`
3590: @*/
3591: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3592: {
3593: PetscFunctionBegin;
3596: snes->gridsequence = steps;
3597: PetscFunctionReturn(PETSC_SUCCESS);
3598: }
3600: /*@
3601: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3603: Logically Collective
3605: Input Parameter:
3606: . snes - the `SNES` context
3608: Output Parameter:
3609: . steps - the number of refinements to do, defaults to 0
3611: Level: intermediate
3613: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3614: @*/
3615: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3616: {
3617: PetscFunctionBegin;
3619: *steps = snes->gridsequence;
3620: PetscFunctionReturn(PETSC_SUCCESS);
3621: }
3623: /*@
3624: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3626: Not Collective
3628: Input Parameter:
3629: . snes - the `SNES` context
3631: Output Parameter:
3632: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3633: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3635: Level: intermediate
3637: Notes:
3638: The default is 1
3640: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3642: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3643: @*/
3644: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3645: {
3646: PetscFunctionBegin;
3648: *lag = snes->lagpreconditioner;
3649: PetscFunctionReturn(PETSC_SUCCESS);
3650: }
3652: /*@
3653: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3654: often the preconditioner is rebuilt.
3656: Logically Collective
3658: Input Parameters:
3659: + snes - the `SNES` context
3660: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3661: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3663: Options Database Keys:
3664: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3665: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3666: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3667: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3669: Level: intermediate
3671: Notes:
3672: The default is 1
3674: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3676: 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
3677: at the next Newton step but never again (unless it is reset to another value)
3679: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3680: @*/
3681: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3682: {
3683: PetscFunctionBegin;
3685: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3686: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3688: snes->lagjacobian = lag;
3689: PetscFunctionReturn(PETSC_SUCCESS);
3690: }
3692: /*@
3693: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3695: Not Collective
3697: Input Parameter:
3698: . snes - the `SNES` context
3700: Output Parameter:
3701: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3702: the Jacobian is built etc.
3704: Level: intermediate
3706: Notes:
3707: The default is 1
3709: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3711: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3713: @*/
3714: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3715: {
3716: PetscFunctionBegin;
3718: *lag = snes->lagjacobian;
3719: PetscFunctionReturn(PETSC_SUCCESS);
3720: }
3722: /*@
3723: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3725: Logically collective
3727: Input Parameters:
3728: + snes - the `SNES` context
3729: - flg - jacobian lagging persists if true
3731: Options Database Keys:
3732: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3733: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3734: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3735: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3737: Level: advanced
3739: Notes:
3740: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3742: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3743: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3744: timesteps may present huge efficiency gains.
3746: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3747: @*/
3748: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3749: {
3750: PetscFunctionBegin;
3753: snes->lagjac_persist = flg;
3754: PetscFunctionReturn(PETSC_SUCCESS);
3755: }
3757: /*@
3758: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3760: Logically Collective
3762: Input Parameters:
3763: + snes - the `SNES` context
3764: - flg - preconditioner lagging persists if true
3766: Options Database Keys:
3767: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3768: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3769: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3770: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3772: Level: developer
3774: Notes:
3775: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3777: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3778: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3779: several timesteps may present huge efficiency gains.
3781: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3782: @*/
3783: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3784: {
3785: PetscFunctionBegin;
3788: snes->lagpre_persist = flg;
3789: PetscFunctionReturn(PETSC_SUCCESS);
3790: }
3792: /*@
3793: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3795: Logically Collective
3797: Input Parameters:
3798: + snes - the `SNES` context
3799: - force - `PETSC_TRUE` require at least one iteration
3801: Options Database Key:
3802: . -snes_force_iteration <force> - Sets forcing an iteration
3804: Level: intermediate
3806: Note:
3807: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3809: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetDivergenceTolerance()`
3810: @*/
3811: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3812: {
3813: PetscFunctionBegin;
3815: snes->forceiteration = force;
3816: PetscFunctionReturn(PETSC_SUCCESS);
3817: }
3819: /*@
3820: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3822: Logically Collective
3824: Input Parameter:
3825: . snes - the `SNES` context
3827: Output Parameter:
3828: . force - `PETSC_TRUE` requires at least one iteration.
3830: Level: intermediate
3832: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetDivergenceTolerance()`
3833: @*/
3834: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3835: {
3836: PetscFunctionBegin;
3838: *force = snes->forceiteration;
3839: PetscFunctionReturn(PETSC_SUCCESS);
3840: }
3842: /*@
3843: SNESSetTolerances - Sets `SNES` various parameters used in convergence tests.
3845: Logically Collective
3847: Input Parameters:
3848: + snes - the `SNES` context
3849: . abstol - absolute convergence tolerance
3850: . rtol - relative convergence tolerance
3851: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3852: . maxit - maximum number of iterations, default 50.
3853: - maxf - maximum number of function evaluations (use `PETSC_UNLIMITED` indicates no limit), default 10,000
3855: Options Database Keys:
3856: + -snes_atol <abstol> - Sets `abstol`
3857: . -snes_rtol <rtol> - Sets `rtol`
3858: . -snes_stol <stol> - Sets `stol`
3859: . -snes_max_it <maxit> - Sets `maxit`
3860: - -snes_max_funcs <maxf> - Sets `maxf` (use `unlimited` to have no maximum)
3862: Level: intermediate
3864: Note:
3865: All parameters must be non-negative
3867: Use `PETSC_CURRENT` to retain the current value of any parameter and `PETSC_DETERMINE` to use the default value for the given `SNES`.
3868: The default value is the value in the object when its type is set.
3870: Use `PETSC_UNLIMITED` on `maxit` or `maxf` to indicate there is no bound on the number of iterations or number of function evaluations.
3872: Fortran Note:
3873: Use `PETSC_CURRENT_INTEGER`, `PETSC_CURRENT_REAL`, `PETSC_UNLIMITED_INTEGER`, `PETSC_DETERMINE_INTEGER`, or `PETSC_DETERMINE_REAL`
3875: .seealso: [](ch_snes), `SNESSolve()`, `SNES`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3876: @*/
3877: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3878: {
3879: PetscFunctionBegin;
3887: if (abstol == (PetscReal)PETSC_DETERMINE) {
3888: snes->abstol = snes->default_abstol;
3889: } else if (abstol != (PetscReal)PETSC_CURRENT) {
3890: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3891: snes->abstol = abstol;
3892: }
3894: if (rtol == (PetscReal)PETSC_DETERMINE) {
3895: snes->rtol = snes->default_rtol;
3896: } else if (rtol != (PetscReal)PETSC_CURRENT) {
3897: 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);
3898: snes->rtol = rtol;
3899: }
3901: if (stol == (PetscReal)PETSC_DETERMINE) {
3902: snes->stol = snes->default_stol;
3903: } else if (stol != (PetscReal)PETSC_CURRENT) {
3904: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3905: snes->stol = stol;
3906: }
3908: if (maxit == PETSC_DETERMINE) {
3909: snes->max_its = snes->default_max_its;
3910: } else if (maxit == PETSC_UNLIMITED) {
3911: snes->max_its = PETSC_INT_MAX;
3912: } else if (maxit != PETSC_CURRENT) {
3913: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3914: snes->max_its = maxit;
3915: }
3917: if (maxf == PETSC_DETERMINE) {
3918: snes->max_funcs = snes->default_max_funcs;
3919: } else if (maxf == PETSC_UNLIMITED || maxf == -1) {
3920: snes->max_funcs = PETSC_UNLIMITED;
3921: } else if (maxf != PETSC_CURRENT) {
3922: PetscCheck(maxf >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be nonnegative", maxf);
3923: snes->max_funcs = maxf;
3924: }
3925: PetscFunctionReturn(PETSC_SUCCESS);
3926: }
3928: /*@
3929: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3931: Logically Collective
3933: Input Parameters:
3934: + snes - the `SNES` context
3935: - divtol - the divergence tolerance. Use `PETSC_UNLIMITED` to deactivate the test.
3937: Options Database Key:
3938: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3940: Level: intermediate
3942: Notes:
3943: Use `PETSC_DETERMINE` to use the default value from when the object's type was set.
3945: Fortran Note:
3946: Use ``PETSC_DETERMINE_REAL` or `PETSC_UNLIMITED_REAL`
3948: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance()`
3949: @*/
3950: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3951: {
3952: PetscFunctionBegin;
3956: if (divtol == (PetscReal)PETSC_DETERMINE) {
3957: snes->divtol = snes->default_divtol;
3958: } else if (divtol == (PetscReal)PETSC_UNLIMITED || divtol == -1) {
3959: snes->divtol = PETSC_UNLIMITED;
3960: } else if (divtol != (PetscReal)PETSC_CURRENT) {
3961: PetscCheck(divtol >= 1.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Divergence tolerance %g must be greater than 1.0", (double)divtol);
3962: snes->divtol = divtol;
3963: }
3964: PetscFunctionReturn(PETSC_SUCCESS);
3965: }
3967: /*@
3968: SNESGetTolerances - Gets various parameters used in convergence tests.
3970: Not Collective
3972: Input Parameter:
3973: . snes - the `SNES` context
3975: Output Parameters:
3976: + atol - absolute convergence tolerance
3977: . rtol - relative convergence tolerance
3978: . stol - convergence tolerance in terms of the norm of the change in the solution between steps
3979: . maxit - maximum number of iterations
3980: - maxf - maximum number of function evaluations, `PETSC_UNLIMITED` indicates no bound
3982: Level: intermediate
3984: Note:
3985: The user can specify `NULL` for any parameter that is not needed.
3987: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
3988: @*/
3989: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
3990: {
3991: PetscFunctionBegin;
3993: if (atol) *atol = snes->abstol;
3994: if (rtol) *rtol = snes->rtol;
3995: if (stol) *stol = snes->stol;
3996: if (maxit) *maxit = snes->max_its;
3997: if (maxf) *maxf = snes->max_funcs;
3998: PetscFunctionReturn(PETSC_SUCCESS);
3999: }
4001: /*@
4002: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
4004: Not Collective
4006: Input Parameters:
4007: + snes - the `SNES` context
4008: - divtol - divergence tolerance
4010: Level: intermediate
4012: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
4013: @*/
4014: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
4015: {
4016: PetscFunctionBegin;
4018: if (divtol) *divtol = snes->divtol;
4019: PetscFunctionReturn(PETSC_SUCCESS);
4020: }
4022: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
4024: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
4025: {
4026: PetscDrawLG lg;
4027: PetscReal x, y, per;
4028: PetscViewer v = (PetscViewer)monctx;
4029: static PetscReal prev; /* should be in the context */
4030: PetscDraw draw;
4032: PetscFunctionBegin;
4034: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
4035: if (!n) PetscCall(PetscDrawLGReset(lg));
4036: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4037: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
4038: x = (PetscReal)n;
4039: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
4040: else y = -15.0;
4041: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4042: if (n < 20 || !(n % 5) || snes->reason) {
4043: PetscCall(PetscDrawLGDraw(lg));
4044: PetscCall(PetscDrawLGSave(lg));
4045: }
4047: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
4048: if (!n) PetscCall(PetscDrawLGReset(lg));
4049: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4050: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
4051: PetscCall(SNESMonitorRange_Private(snes, n, &per));
4052: x = (PetscReal)n;
4053: y = 100.0 * per;
4054: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4055: if (n < 20 || !(n % 5) || snes->reason) {
4056: PetscCall(PetscDrawLGDraw(lg));
4057: PetscCall(PetscDrawLGSave(lg));
4058: }
4060: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
4061: if (!n) {
4062: prev = rnorm;
4063: PetscCall(PetscDrawLGReset(lg));
4064: }
4065: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4066: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
4067: x = (PetscReal)n;
4068: y = (prev - rnorm) / prev;
4069: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4070: if (n < 20 || !(n % 5) || snes->reason) {
4071: PetscCall(PetscDrawLGDraw(lg));
4072: PetscCall(PetscDrawLGSave(lg));
4073: }
4075: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
4076: if (!n) PetscCall(PetscDrawLGReset(lg));
4077: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4078: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
4079: x = (PetscReal)n;
4080: y = (prev - rnorm) / (prev * per);
4081: if (n > 2) { /*skip initial crazy value */
4082: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4083: }
4084: if (n < 20 || !(n % 5) || snes->reason) {
4085: PetscCall(PetscDrawLGDraw(lg));
4086: PetscCall(PetscDrawLGSave(lg));
4087: }
4088: prev = rnorm;
4089: PetscFunctionReturn(PETSC_SUCCESS);
4090: }
4092: /*@
4093: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
4095: Collective
4097: Input Parameters:
4098: + snes - the `SNES` context
4099: . it - current iteration
4100: . xnorm - 2-norm of current iterate
4101: . snorm - 2-norm of current step
4102: - fnorm - 2-norm of function
4104: Level: developer
4106: Note:
4107: This routine is called by the `SNESSolve()` implementations.
4108: It does not typically need to be called by the user.
4110: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4111: @*/
4112: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
4113: {
4114: PetscFunctionBegin;
4115: if (!snes->reason) {
4116: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
4117: if (it == snes->max_its && !snes->reason) {
4118: if (snes->normschedule == SNES_NORM_ALWAYS) {
4119: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
4120: snes->reason = SNES_DIVERGED_MAX_IT;
4121: } else snes->reason = SNES_CONVERGED_ITS;
4122: }
4123: }
4124: PetscFunctionReturn(PETSC_SUCCESS);
4125: }
4127: /*@
4128: SNESMonitor - runs the user provided monitor routines, if they exist
4130: Collective
4132: Input Parameters:
4133: + snes - nonlinear solver context obtained from `SNESCreate()`
4134: . iter - iteration number
4135: - rnorm - relative norm of the residual
4137: Level: developer
4139: Note:
4140: This routine is called by the `SNESSolve()` implementations.
4141: It does not typically need to be called by the user.
4143: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
4144: @*/
4145: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
4146: {
4147: PetscInt i, n = snes->numbermonitors;
4149: PetscFunctionBegin;
4150: if (n > 0) SNESCheckFunctionNorm(snes, rnorm);
4151: PetscCall(VecLockReadPush(snes->vec_sol));
4152: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
4153: PetscCall(VecLockReadPop(snes->vec_sol));
4154: PetscFunctionReturn(PETSC_SUCCESS);
4155: }
4157: /* ------------ Routines to set performance monitoring options ----------- */
4159: /*MC
4160: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
4162: Synopsis:
4163: #include <petscsnes.h>
4164: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, void *mctx)
4166: Collective
4168: Input Parameters:
4169: + snes - the `SNES` context
4170: . its - iteration number
4171: . norm - 2-norm function value (may be estimated)
4172: - mctx - [optional] monitoring context
4174: Level: advanced
4176: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSet()`, `SNESMonitorGet()`
4177: M*/
4179: /*@C
4180: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
4181: iteration of the nonlinear solver to display the iteration's
4182: progress.
4184: Logically Collective
4186: Input Parameters:
4187: + snes - the `SNES` context
4188: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4189: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4190: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence
4192: Options Database Keys:
4193: + -snes_monitor - sets `SNESMonitorDefault()`
4194: . -snes_monitor draw::draw_lg - sets line graph monitor,
4195: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4196: the options database.
4198: Level: intermediate
4200: Note:
4201: Several different monitoring routines may be set by calling
4202: `SNESMonitorSet()` multiple times; all will be called in the
4203: order in which they were set.
4205: Fortran Note:
4206: Only a single monitor function can be set for each `SNES` object
4208: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`, `PetscCtxDestroyFn`
4209: @*/
4210: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscCtxDestroyFn *monitordestroy)
4211: {
4212: PetscInt i;
4213: PetscBool identical;
4215: PetscFunctionBegin;
4217: for (i = 0; i < snes->numbermonitors; i++) {
4218: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))f, mctx, monitordestroy, (PetscErrorCode (*)(void))snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4219: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4220: }
4221: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4222: snes->monitor[snes->numbermonitors] = f;
4223: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4224: snes->monitorcontext[snes->numbermonitors++] = mctx;
4225: PetscFunctionReturn(PETSC_SUCCESS);
4226: }
4228: /*@
4229: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4231: Logically Collective
4233: Input Parameter:
4234: . snes - the `SNES` context
4236: Options Database Key:
4237: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4238: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4239: set via the options database
4241: Level: intermediate
4243: Note:
4244: There is no way to clear one specific monitor from a `SNES` object.
4246: .seealso: [](ch_snes), `SNES`, `SNESMonitorGet()`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4247: @*/
4248: PetscErrorCode SNESMonitorCancel(SNES snes)
4249: {
4250: PetscInt i;
4252: PetscFunctionBegin;
4254: for (i = 0; i < snes->numbermonitors; i++) {
4255: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4256: }
4257: snes->numbermonitors = 0;
4258: PetscFunctionReturn(PETSC_SUCCESS);
4259: }
4261: /*MC
4262: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4264: Synopsis:
4265: #include <petscsnes.h>
4266: PetscErrorCode SNESConvergenceTest(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *cctx)
4268: Collective
4270: Input Parameters:
4271: + snes - the `SNES` context
4272: . it - current iteration (0 is the first and is before any Newton step)
4273: . xnorm - 2-norm of current iterate
4274: . gnorm - 2-norm of current step
4275: . f - 2-norm of function
4276: - cctx - [optional] convergence context
4278: Output Parameter:
4279: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4281: Level: intermediate
4283: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4284: M*/
4286: /*@C
4287: SNESSetConvergenceTest - Sets the function that is to be used
4288: to test for convergence of the nonlinear iterative solution.
4290: Logically Collective
4292: Input Parameters:
4293: + snes - the `SNES` context
4294: . SNESConvergenceTestFunction - routine to test for convergence
4295: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4296: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4298: Level: advanced
4300: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4301: @*/
4302: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscErrorCode (*destroy)(void *))
4303: {
4304: PetscFunctionBegin;
4306: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4307: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(snes->cnvP));
4308: snes->ops->converged = SNESConvergenceTestFunction;
4309: snes->ops->convergeddestroy = destroy;
4310: snes->cnvP = cctx;
4311: PetscFunctionReturn(PETSC_SUCCESS);
4312: }
4314: /*@
4315: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped.
4317: Not Collective
4319: Input Parameter:
4320: . snes - the `SNES` context
4322: Output Parameter:
4323: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4325: Options Database Key:
4326: . -snes_converged_reason - prints the reason to standard out
4328: Level: intermediate
4330: Note:
4331: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4333: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4334: @*/
4335: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4336: {
4337: PetscFunctionBegin;
4339: PetscAssertPointer(reason, 2);
4340: *reason = snes->reason;
4341: PetscFunctionReturn(PETSC_SUCCESS);
4342: }
4344: /*@C
4345: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4347: Not Collective
4349: Input Parameter:
4350: . snes - the `SNES` context
4352: Output Parameter:
4353: . strreason - a human readable string that describes `SNES` converged reason
4355: Level: beginner
4357: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4358: @*/
4359: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4360: {
4361: PetscFunctionBegin;
4363: PetscAssertPointer(strreason, 2);
4364: *strreason = SNESConvergedReasons[snes->reason];
4365: PetscFunctionReturn(PETSC_SUCCESS);
4366: }
4368: /*@
4369: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4371: Not Collective
4373: Input Parameters:
4374: + snes - the `SNES` context
4375: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4376: manual pages for the individual convergence tests for complete lists
4378: Level: developer
4380: Developer Note:
4381: Called inside the various `SNESSolve()` implementations
4383: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4384: @*/
4385: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4386: {
4387: PetscFunctionBegin;
4389: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4390: snes->reason = reason;
4391: PetscFunctionReturn(PETSC_SUCCESS);
4392: }
4394: /*@
4395: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4397: Logically Collective
4399: Input Parameters:
4400: + snes - iterative context obtained from `SNESCreate()`
4401: . a - array to hold history, this array will contain the function norms computed at each step
4402: . its - integer array holds the number of linear iterations for each solve.
4403: . na - size of `a` and `its`
4404: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4405: else it continues storing new values for new nonlinear solves after the old ones
4407: Level: intermediate
4409: Notes:
4410: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' is `PETSC_DECIDE` then a
4411: default array of length 1,000 is allocated.
4413: This routine is useful, e.g., when running a code for purposes
4414: of accurate performance monitoring, when no I/O should be done
4415: during the section of code that is being timed.
4417: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4419: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4420: @*/
4421: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4422: {
4423: PetscFunctionBegin;
4425: if (a) PetscAssertPointer(a, 2);
4426: if (its) PetscAssertPointer(its, 3);
4427: if (!a) {
4428: if (na == PETSC_DECIDE) na = 1000;
4429: PetscCall(PetscCalloc2(na, &a, na, &its));
4430: snes->conv_hist_alloc = PETSC_TRUE;
4431: }
4432: snes->conv_hist = a;
4433: snes->conv_hist_its = its;
4434: snes->conv_hist_max = (size_t)na;
4435: snes->conv_hist_len = 0;
4436: snes->conv_hist_reset = reset;
4437: PetscFunctionReturn(PETSC_SUCCESS);
4438: }
4440: #if defined(PETSC_HAVE_MATLAB)
4441: #include <engine.h> /* MATLAB include file */
4442: #include <mex.h> /* MATLAB include file */
4444: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4445: {
4446: mxArray *mat;
4447: PetscInt i;
4448: PetscReal *ar;
4450: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4451: ar = (PetscReal *)mxGetData(mat);
4452: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4453: return mat;
4454: }
4455: #endif
4457: /*@C
4458: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4460: Not Collective
4462: Input Parameter:
4463: . snes - iterative context obtained from `SNESCreate()`
4465: Output Parameters:
4466: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4467: . its - integer array holds the number of linear iterations (or
4468: negative if not converged) for each solve.
4469: - na - size of `a` and `its`
4471: Level: intermediate
4473: Note:
4474: This routine is useful, e.g., when running a code for purposes
4475: of accurate performance monitoring, when no I/O should be done
4476: during the section of code that is being timed.
4478: Fortran Note:
4479: The calling sequence for this routine in Fortran is
4480: .vb
4481: call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4482: .ve
4484: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4485: @*/
4486: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4487: {
4488: PetscFunctionBegin;
4490: if (a) *a = snes->conv_hist;
4491: if (its) *its = snes->conv_hist_its;
4492: if (na) *na = (PetscInt)snes->conv_hist_len;
4493: PetscFunctionReturn(PETSC_SUCCESS);
4494: }
4496: /*@C
4497: SNESSetUpdate - Sets the general-purpose update function called
4498: at the beginning of every iteration of the nonlinear solve. Specifically
4499: it is called just before the Jacobian is "evaluated" and after the function
4500: evaluation.
4502: Logically Collective
4504: Input Parameters:
4505: + snes - The nonlinear solver context
4506: - func - The update function; for calling sequence see `SNESUpdateFn`
4508: Level: advanced
4510: Notes:
4511: 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
4512: to `SNESSetFunction()`, or `SNESSetPicard()`
4513: This is not used by most users, and it is intended to provide a general hook that is run
4514: right before the direction step is computed.
4515: Users are free to modify the current residual vector,
4516: the current linearization point, or any other vector associated to the specific solver used.
4517: If such modifications take place, it is the user responsibility to update all the relevant
4518: vectors.
4520: 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.
4522: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4523: `SNESMonitorSet()`
4524: @*/
4525: PetscErrorCode SNESSetUpdate(SNES snes, SNESUpdateFn *func)
4526: {
4527: PetscFunctionBegin;
4529: snes->ops->update = func;
4530: PetscFunctionReturn(PETSC_SUCCESS);
4531: }
4533: /*@
4534: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4536: Collective
4538: Input Parameters:
4539: + snes - iterative context obtained from `SNESCreate()`
4540: - viewer - the viewer to display the reason
4542: Options Database Keys:
4543: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4544: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4546: Level: beginner
4548: Note:
4549: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4550: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4552: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4553: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4554: `SNESConvergedReasonViewFromOptions()`,
4555: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4556: @*/
4557: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4558: {
4559: PetscViewerFormat format;
4560: PetscBool isAscii;
4562: PetscFunctionBegin;
4563: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4564: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4565: if (isAscii) {
4566: PetscCall(PetscViewerGetFormat(viewer, &format));
4567: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel + 1));
4568: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4569: DM dm;
4570: Vec u;
4571: PetscDS prob;
4572: PetscInt Nf, f;
4573: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4574: void **exactCtx;
4575: PetscReal error;
4577: PetscCall(SNESGetDM(snes, &dm));
4578: PetscCall(SNESGetSolution(snes, &u));
4579: PetscCall(DMGetDS(dm, &prob));
4580: PetscCall(PetscDSGetNumFields(prob, &Nf));
4581: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4582: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4583: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4584: PetscCall(PetscFree2(exactSol, exactCtx));
4585: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4586: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4587: }
4588: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4589: if (((PetscObject)snes)->prefix) {
4590: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4591: } else {
4592: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4593: }
4594: } else if (snes->reason <= 0) {
4595: if (((PetscObject)snes)->prefix) {
4596: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4597: } else {
4598: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4599: }
4600: }
4601: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel + 1));
4602: }
4603: PetscFunctionReturn(PETSC_SUCCESS);
4604: }
4606: /*@C
4607: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4608: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4610: Logically Collective
4612: Input Parameters:
4613: + snes - the `SNES` context
4614: . f - the `SNESConvergedReason` view function
4615: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4616: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence
4618: Calling sequence of `f`:
4619: + snes - the `SNES` context
4620: - vctx - [optional] context for private data for the function
4622: Options Database Keys:
4623: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4624: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4625: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4627: Level: intermediate
4629: Note:
4630: Several different converged reason view routines may be set by calling
4631: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4632: order in which they were set.
4634: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`,
4635: `PetscCtxDestroyFn`
4636: @*/
4637: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, void *vctx), void *vctx, PetscCtxDestroyFn *reasonviewdestroy)
4638: {
4639: PetscInt i;
4640: PetscBool identical;
4642: PetscFunctionBegin;
4644: for (i = 0; i < snes->numberreasonviews; i++) {
4645: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))f, vctx, reasonviewdestroy, (PetscErrorCode (*)(void))snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4646: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4647: }
4648: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4649: snes->reasonview[snes->numberreasonviews] = f;
4650: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4651: snes->reasonviewcontext[snes->numberreasonviews++] = vctx;
4652: PetscFunctionReturn(PETSC_SUCCESS);
4653: }
4655: /*@
4656: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4657: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4659: Collective
4661: Input Parameter:
4662: . snes - the `SNES` object
4664: Level: advanced
4666: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4667: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4668: @*/
4669: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4670: {
4671: static PetscBool incall = PETSC_FALSE;
4673: PetscFunctionBegin;
4674: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4675: incall = PETSC_TRUE;
4677: /* All user-provided viewers are called first, if they exist. */
4678: for (PetscInt i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4680: /* Call PETSc default routine if users ask for it */
4681: if (snes->convergedreasonviewer) {
4682: PetscCall(PetscViewerPushFormat(snes->convergedreasonviewer, snes->convergedreasonformat));
4683: PetscCall(SNESConvergedReasonView(snes, snes->convergedreasonviewer));
4684: PetscCall(PetscViewerPopFormat(snes->convergedreasonviewer));
4685: }
4686: incall = PETSC_FALSE;
4687: PetscFunctionReturn(PETSC_SUCCESS);
4688: }
4690: /*@
4691: SNESSolve - Solves a nonlinear system F(x) = b.
4693: Collective
4695: Input Parameters:
4696: + snes - the `SNES` context
4697: . b - the constant part of the equation F(x) = b, or `NULL` to use zero.
4698: - x - the solution vector.
4700: Level: beginner
4702: Note:
4703: The user should initialize the vector, `x`, with the initial guess
4704: for the nonlinear solve prior to calling `SNESSolve()` or use `SNESSetInitialSolution()`. In particular,
4705: to employ an initial guess of zero, the user should explicitly set
4706: this vector to zero by calling `VecSet()`.
4708: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4709: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4710: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`, `SNESSetInitialSolution()`
4711: @*/
4712: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4713: {
4714: PetscBool flg;
4715: PetscInt grid;
4716: Vec xcreated = NULL;
4717: DM dm;
4719: PetscFunctionBegin;
4722: if (x) PetscCheckSameComm(snes, 1, x, 3);
4724: if (b) PetscCheckSameComm(snes, 1, b, 2);
4726: /* High level operations using the nonlinear solver */
4727: {
4728: PetscViewer viewer;
4729: PetscViewerFormat format;
4730: PetscInt num;
4731: PetscBool flg;
4732: static PetscBool incall = PETSC_FALSE;
4734: if (!incall) {
4735: /* Estimate the convergence rate of the discretization */
4736: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4737: if (flg) {
4738: PetscConvEst conv;
4739: DM dm;
4740: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4741: PetscInt Nf;
4743: incall = PETSC_TRUE;
4744: PetscCall(SNESGetDM(snes, &dm));
4745: PetscCall(DMGetNumFields(dm, &Nf));
4746: PetscCall(PetscCalloc1(Nf, &alpha));
4747: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4748: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4749: PetscCall(PetscConvEstSetFromOptions(conv));
4750: PetscCall(PetscConvEstSetUp(conv));
4751: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4752: PetscCall(PetscViewerPushFormat(viewer, format));
4753: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4754: PetscCall(PetscViewerPopFormat(viewer));
4755: PetscCall(PetscViewerDestroy(&viewer));
4756: PetscCall(PetscConvEstDestroy(&conv));
4757: PetscCall(PetscFree(alpha));
4758: incall = PETSC_FALSE;
4759: }
4760: /* Adaptively refine the initial grid */
4761: num = 1;
4762: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4763: if (flg) {
4764: DMAdaptor adaptor;
4766: incall = PETSC_TRUE;
4767: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4768: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4769: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4770: PetscCall(DMAdaptorSetFromOptions(adaptor));
4771: PetscCall(DMAdaptorSetUp(adaptor));
4772: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4773: PetscCall(DMAdaptorDestroy(&adaptor));
4774: incall = PETSC_FALSE;
4775: }
4776: /* Use grid sequencing to adapt */
4777: num = 0;
4778: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4779: if (num) {
4780: DMAdaptor adaptor;
4781: const char *prefix;
4783: incall = PETSC_TRUE;
4784: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4785: PetscCall(SNESGetOptionsPrefix(snes, &prefix));
4786: PetscCall(DMAdaptorSetOptionsPrefix(adaptor, prefix));
4787: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4788: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4789: PetscCall(DMAdaptorSetFromOptions(adaptor));
4790: PetscCall(DMAdaptorSetUp(adaptor));
4791: PetscCall(PetscObjectViewFromOptions((PetscObject)adaptor, NULL, "-snes_adapt_view"));
4792: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4793: PetscCall(DMAdaptorDestroy(&adaptor));
4794: incall = PETSC_FALSE;
4795: }
4796: }
4797: }
4798: if (!x) x = snes->vec_sol;
4799: if (!x) {
4800: PetscCall(SNESGetDM(snes, &dm));
4801: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4802: x = xcreated;
4803: }
4804: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4806: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4807: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4808: /* set solution vector */
4809: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4810: PetscCall(VecDestroy(&snes->vec_sol));
4811: snes->vec_sol = x;
4812: PetscCall(SNESGetDM(snes, &dm));
4814: /* set affine vector if provided */
4815: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4816: PetscCall(VecDestroy(&snes->vec_rhs));
4817: snes->vec_rhs = b;
4819: 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");
4820: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4821: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right-hand side vector");
4822: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4823: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4824: PetscCall(SNESSetUp(snes));
4826: if (!grid) {
4827: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback compute initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4828: }
4830: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4831: PetscCall(SNESResetCounters(snes));
4832: snes->reason = SNES_CONVERGED_ITERATING;
4833: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4834: PetscUseTypeMethod(snes, solve);
4835: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4836: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4837: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4839: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4840: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4842: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4843: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4844: /* Call converged reason views. This may involve user-provided viewers as well */
4845: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4847: if (snes->errorifnotconverged) PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4848: if (snes->reason < 0) break;
4849: if (grid < snes->gridsequence) {
4850: DM fine;
4851: Vec xnew;
4852: Mat interp;
4854: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4855: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4856: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4857: PetscCall(DMCreateGlobalVector(fine, &xnew));
4858: PetscCall(MatInterpolate(interp, x, xnew));
4859: PetscCall(DMInterpolate(snes->dm, interp, fine));
4860: PetscCall(MatDestroy(&interp));
4861: x = xnew;
4863: PetscCall(SNESReset(snes));
4864: PetscCall(SNESSetDM(snes, fine));
4865: PetscCall(SNESResetFromOptions(snes));
4866: PetscCall(DMDestroy(&fine));
4867: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4868: }
4869: }
4870: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4871: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4872: PetscCall(DMMonitor(snes->dm));
4873: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4875: PetscCall(VecDestroy(&xcreated));
4876: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4877: PetscFunctionReturn(PETSC_SUCCESS);
4878: }
4880: /* --------- Internal routines for SNES Package --------- */
4882: /*@
4883: SNESSetType - Sets the method for the nonlinear solver.
4885: Collective
4887: Input Parameters:
4888: + snes - the `SNES` context
4889: - type - a known method
4891: Options Database Key:
4892: . -snes_type <type> - Sets the method; use -help for a list
4893: of available methods (for instance, newtonls or newtontr)
4895: Level: intermediate
4897: Notes:
4898: See "petsc/include/petscsnes.h" for available methods (for instance)
4899: + `SNESNEWTONLS` - Newton's method with line search
4900: (systems of nonlinear equations)
4901: - `SNESNEWTONTR` - Newton's method with trust region
4902: (systems of nonlinear equations)
4904: Normally, it is best to use the `SNESSetFromOptions()` command and then
4905: set the `SNES` solver type from the options database rather than by using
4906: this routine. Using the options database provides the user with
4907: maximum flexibility in evaluating the many nonlinear solvers.
4908: The `SNESSetType()` routine is provided for those situations where it
4909: is necessary to set the nonlinear solver independently of the command
4910: line or options database. This might be the case, for example, when
4911: the choice of solver changes during the execution of the program,
4912: and the user's application is taking responsibility for choosing the
4913: appropriate method.
4915: Developer Note:
4916: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4917: the constructor in that list and calls it to create the specific object.
4919: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4920: @*/
4921: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4922: {
4923: PetscBool match;
4924: PetscErrorCode (*r)(SNES);
4926: PetscFunctionBegin;
4928: PetscAssertPointer(type, 2);
4930: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4931: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4933: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4934: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4935: /* Destroy the previous private SNES context */
4936: PetscTryTypeMethod(snes, destroy);
4937: /* Reinitialize function pointers in SNESOps structure */
4938: snes->ops->setup = NULL;
4939: snes->ops->solve = NULL;
4940: snes->ops->view = NULL;
4941: snes->ops->setfromoptions = NULL;
4942: snes->ops->destroy = NULL;
4944: /* It may happen the user has customized the line search before calling SNESSetType */
4945: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
4947: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4948: snes->setupcalled = PETSC_FALSE;
4950: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
4951: PetscCall((*r)(snes));
4952: PetscFunctionReturn(PETSC_SUCCESS);
4953: }
4955: /*@
4956: SNESGetType - Gets the `SNES` method type and name (as a string).
4958: Not Collective
4960: Input Parameter:
4961: . snes - nonlinear solver context
4963: Output Parameter:
4964: . type - `SNES` method (a character string)
4966: Level: intermediate
4968: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
4969: @*/
4970: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
4971: {
4972: PetscFunctionBegin;
4974: PetscAssertPointer(type, 2);
4975: *type = ((PetscObject)snes)->type_name;
4976: PetscFunctionReturn(PETSC_SUCCESS);
4977: }
4979: /*@
4980: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
4982: Logically Collective
4984: Input Parameters:
4985: + snes - the `SNES` context obtained from `SNESCreate()`
4986: - u - the solution vector
4988: Level: beginner
4990: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
4991: @*/
4992: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4993: {
4994: DM dm;
4996: PetscFunctionBegin;
4999: PetscCall(PetscObjectReference((PetscObject)u));
5000: PetscCall(VecDestroy(&snes->vec_sol));
5002: snes->vec_sol = u;
5004: PetscCall(SNESGetDM(snes, &dm));
5005: PetscCall(DMShellSetGlobalVector(dm, u));
5006: PetscFunctionReturn(PETSC_SUCCESS);
5007: }
5009: /*@
5010: SNESGetSolution - Returns the vector where the approximate solution is
5011: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
5013: Not Collective, but `x` is parallel if `snes` is parallel
5015: Input Parameter:
5016: . snes - the `SNES` context
5018: Output Parameter:
5019: . x - the solution
5021: Level: intermediate
5023: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
5024: @*/
5025: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
5026: {
5027: PetscFunctionBegin;
5029: PetscAssertPointer(x, 2);
5030: *x = snes->vec_sol;
5031: PetscFunctionReturn(PETSC_SUCCESS);
5032: }
5034: /*@
5035: SNESGetSolutionUpdate - Returns the vector where the solution update is
5036: stored.
5038: Not Collective, but `x` is parallel if `snes` is parallel
5040: Input Parameter:
5041: . snes - the `SNES` context
5043: Output Parameter:
5044: . x - the solution update
5046: Level: advanced
5048: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
5049: @*/
5050: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
5051: {
5052: PetscFunctionBegin;
5054: PetscAssertPointer(x, 2);
5055: *x = snes->vec_sol_update;
5056: PetscFunctionReturn(PETSC_SUCCESS);
5057: }
5059: /*@C
5060: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
5062: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
5064: Input Parameter:
5065: . snes - the `SNES` context
5067: Output Parameters:
5068: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
5069: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunctionFn`
5070: - ctx - the function context (or `NULL` if you don't want it)
5072: Level: advanced
5074: Note:
5075: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
5077: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunctionFn`
5078: @*/
5079: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, SNESFunctionFn **f, void **ctx)
5080: {
5081: DM dm;
5083: PetscFunctionBegin;
5085: if (r) {
5086: if (!snes->vec_func) {
5087: if (snes->vec_rhs) {
5088: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
5089: } else if (snes->vec_sol) {
5090: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
5091: } else if (snes->dm) {
5092: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
5093: }
5094: }
5095: *r = snes->vec_func;
5096: }
5097: PetscCall(SNESGetDM(snes, &dm));
5098: PetscCall(DMSNESGetFunction(dm, f, ctx));
5099: PetscFunctionReturn(PETSC_SUCCESS);
5100: }
5102: /*@C
5103: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
5105: Input Parameter:
5106: . snes - the `SNES` context
5108: Output Parameters:
5109: + f - the function (or `NULL`) see `SNESNGSFn` for calling sequence
5110: - ctx - the function context (or `NULL`)
5112: Level: advanced
5114: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`, `SNESNGSFn`
5115: @*/
5116: PetscErrorCode SNESGetNGS(SNES snes, SNESNGSFn **f, void **ctx)
5117: {
5118: DM dm;
5120: PetscFunctionBegin;
5122: PetscCall(SNESGetDM(snes, &dm));
5123: PetscCall(DMSNESGetNGS(dm, f, ctx));
5124: PetscFunctionReturn(PETSC_SUCCESS);
5125: }
5127: /*@
5128: SNESSetOptionsPrefix - Sets the prefix used for searching for all
5129: `SNES` options in the database.
5131: Logically Collective
5133: Input Parameters:
5134: + snes - the `SNES` context
5135: - prefix - the prefix to prepend to all option names
5137: Level: advanced
5139: Note:
5140: A hyphen (-) must NOT be given at the beginning of the prefix name.
5141: The first character of all runtime options is AUTOMATICALLY the hyphen.
5143: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
5144: @*/
5145: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
5146: {
5147: PetscFunctionBegin;
5149: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
5150: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5151: if (snes->linesearch) {
5152: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5153: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
5154: }
5155: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
5156: PetscFunctionReturn(PETSC_SUCCESS);
5157: }
5159: /*@
5160: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5161: `SNES` options in the database.
5163: Logically Collective
5165: Input Parameters:
5166: + snes - the `SNES` context
5167: - prefix - the prefix to prepend to all option names
5169: Level: advanced
5171: Note:
5172: A hyphen (-) must NOT be given at the beginning of the prefix name.
5173: The first character of all runtime options is AUTOMATICALLY the hyphen.
5175: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5176: @*/
5177: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5178: {
5179: PetscFunctionBegin;
5181: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5182: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5183: if (snes->linesearch) {
5184: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5185: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5186: }
5187: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5188: PetscFunctionReturn(PETSC_SUCCESS);
5189: }
5191: /*@
5192: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5193: `SNES` options in the database.
5195: Not Collective
5197: Input Parameter:
5198: . snes - the `SNES` context
5200: Output Parameter:
5201: . prefix - pointer to the prefix string used
5203: Level: advanced
5205: Fortran Note:
5206: The user should pass in a string 'prefix' of
5207: sufficient length to hold the prefix.
5209: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5210: @*/
5211: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5212: {
5213: PetscFunctionBegin;
5215: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5216: PetscFunctionReturn(PETSC_SUCCESS);
5217: }
5219: /*@C
5220: SNESRegister - Adds a method to the nonlinear solver package.
5222: Not Collective
5224: Input Parameters:
5225: + sname - name of a new user-defined solver
5226: - function - routine to create method context
5228: Level: advanced
5230: Note:
5231: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5233: Example Usage:
5234: .vb
5235: SNESRegister("my_solver", MySolverCreate);
5236: .ve
5238: Then, your solver can be chosen with the procedural interface via
5239: $ SNESSetType(snes, "my_solver")
5240: or at runtime via the option
5241: $ -snes_type my_solver
5243: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5244: @*/
5245: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5246: {
5247: PetscFunctionBegin;
5248: PetscCall(SNESInitializePackage());
5249: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5250: PetscFunctionReturn(PETSC_SUCCESS);
5251: }
5253: PetscErrorCode SNESTestLocalMin(SNES snes)
5254: {
5255: PetscInt N, i, j;
5256: Vec u, uh, fh;
5257: PetscScalar value;
5258: PetscReal norm;
5260: PetscFunctionBegin;
5261: PetscCall(SNESGetSolution(snes, &u));
5262: PetscCall(VecDuplicate(u, &uh));
5263: PetscCall(VecDuplicate(u, &fh));
5265: /* currently only works for sequential */
5266: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5267: PetscCall(VecGetSize(u, &N));
5268: for (i = 0; i < N; i++) {
5269: PetscCall(VecCopy(u, uh));
5270: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5271: for (j = -10; j < 11; j++) {
5272: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5273: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5274: PetscCall(SNESComputeFunction(snes, uh, fh));
5275: PetscCall(VecNorm(fh, NORM_2, &norm));
5276: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5277: value = -value;
5278: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5279: }
5280: }
5281: PetscCall(VecDestroy(&uh));
5282: PetscCall(VecDestroy(&fh));
5283: PetscFunctionReturn(PETSC_SUCCESS);
5284: }
5286: /*@
5287: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5288: computing relative tolerance for linear solvers within an inexact
5289: Newton method.
5291: Logically Collective
5293: Input Parameters:
5294: + snes - `SNES` context
5295: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5297: Options Database Keys:
5298: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5299: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5300: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5301: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5302: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5303: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5304: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5305: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5307: Level: advanced
5309: Note:
5310: The default is to use a constant relative tolerance for
5311: the inner linear solvers. Alternatively, one can use the
5312: Eisenstat-Walker method {cite}`ew96`, where the relative convergence tolerance
5313: is reset at each Newton iteration according progress of the nonlinear
5314: solver.
5316: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5317: @*/
5318: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5319: {
5320: PetscFunctionBegin;
5323: snes->ksp_ewconv = flag;
5324: PetscFunctionReturn(PETSC_SUCCESS);
5325: }
5327: /*@
5328: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5329: for computing relative tolerance for linear solvers within an
5330: inexact Newton method.
5332: Not Collective
5334: Input Parameter:
5335: . snes - `SNES` context
5337: Output Parameter:
5338: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5340: Level: advanced
5342: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5343: @*/
5344: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5345: {
5346: PetscFunctionBegin;
5348: PetscAssertPointer(flag, 2);
5349: *flag = snes->ksp_ewconv;
5350: PetscFunctionReturn(PETSC_SUCCESS);
5351: }
5353: /*@
5354: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5355: convergence criteria for the linear solvers within an inexact
5356: Newton method.
5358: Logically Collective
5360: Input Parameters:
5361: + snes - `SNES` context
5362: . version - version 1, 2 (default is 2), 3 or 4
5363: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5364: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5365: . gamma - multiplicative factor for version 2 rtol computation
5366: (0 <= gamma2 <= 1)
5367: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5368: . alpha2 - power for safeguard
5369: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5371: Level: advanced
5373: Notes:
5374: Version 3 was contributed by Luis Chacon, June 2006.
5376: Use `PETSC_CURRENT` to retain the default for any of the parameters.
5378: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5379: @*/
5380: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5381: {
5382: SNESKSPEW *kctx;
5384: PetscFunctionBegin;
5386: kctx = (SNESKSPEW *)snes->kspconvctx;
5387: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5396: if (version != PETSC_CURRENT) kctx->version = version;
5397: if (rtol_0 != (PetscReal)PETSC_CURRENT) kctx->rtol_0 = rtol_0;
5398: if (rtol_max != (PetscReal)PETSC_CURRENT) kctx->rtol_max = rtol_max;
5399: if (gamma != (PetscReal)PETSC_CURRENT) kctx->gamma = gamma;
5400: if (alpha != (PetscReal)PETSC_CURRENT) kctx->alpha = alpha;
5401: if (alpha2 != (PetscReal)PETSC_CURRENT) kctx->alpha2 = alpha2;
5402: if (threshold != (PetscReal)PETSC_CURRENT) kctx->threshold = threshold;
5404: 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);
5405: 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);
5406: 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);
5407: 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);
5408: 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);
5409: 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);
5410: PetscFunctionReturn(PETSC_SUCCESS);
5411: }
5413: /*@
5414: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5415: convergence criteria for the linear solvers within an inexact
5416: Newton method.
5418: Not Collective
5420: Input Parameter:
5421: . snes - `SNES` context
5423: Output Parameters:
5424: + version - version 1, 2 (default is 2), 3 or 4
5425: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5426: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5427: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5428: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5429: . alpha2 - power for safeguard
5430: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5432: Level: advanced
5434: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5435: @*/
5436: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5437: {
5438: SNESKSPEW *kctx;
5440: PetscFunctionBegin;
5442: kctx = (SNESKSPEW *)snes->kspconvctx;
5443: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5444: if (version) *version = kctx->version;
5445: if (rtol_0) *rtol_0 = kctx->rtol_0;
5446: if (rtol_max) *rtol_max = kctx->rtol_max;
5447: if (gamma) *gamma = kctx->gamma;
5448: if (alpha) *alpha = kctx->alpha;
5449: if (alpha2) *alpha2 = kctx->alpha2;
5450: if (threshold) *threshold = kctx->threshold;
5451: PetscFunctionReturn(PETSC_SUCCESS);
5452: }
5454: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5455: {
5456: SNES snes = (SNES)ctx;
5457: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5458: PetscReal rtol = PETSC_CURRENT, stol;
5460: PetscFunctionBegin;
5461: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5462: if (!snes->iter) {
5463: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5464: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5465: } else {
5466: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5467: if (kctx->version == 1) {
5468: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5469: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5470: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5471: } else if (kctx->version == 2) {
5472: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5473: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5474: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5475: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5476: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5477: /* safeguard: avoid sharp decrease of rtol */
5478: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5479: stol = PetscMax(rtol, stol);
5480: rtol = PetscMin(kctx->rtol_0, stol);
5481: /* safeguard: avoid oversolving */
5482: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5483: stol = PetscMax(rtol, stol);
5484: rtol = PetscMin(kctx->rtol_0, stol);
5485: } else /* if (kctx->version == 4) */ {
5486: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5487: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5488: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5489: PetscReal rk = ared / pred;
5490: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5491: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5492: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5493: else rtol = kctx->v4_m2 * kctx->rtol_last;
5495: 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;
5496: kctx->rtol_last_2 = kctx->rtol_last;
5497: kctx->rk_last_2 = kctx->rk_last;
5498: kctx->rk_last = rk;
5499: }
5500: }
5501: /* safeguard: avoid rtol greater than rtol_max */
5502: rtol = PetscMin(rtol, kctx->rtol_max);
5503: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_CURRENT, PETSC_CURRENT, PETSC_CURRENT));
5504: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5505: PetscFunctionReturn(PETSC_SUCCESS);
5506: }
5508: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5509: {
5510: SNES snes = (SNES)ctx;
5511: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5512: PCSide pcside;
5513: Vec lres;
5515: PetscFunctionBegin;
5516: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5517: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5518: kctx->norm_last = snes->norm;
5519: if (kctx->version == 1 || kctx->version == 4) {
5520: PC pc;
5521: PetscBool getRes;
5523: PetscCall(KSPGetPC(ksp, &pc));
5524: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5525: if (!getRes) {
5526: KSPNormType normtype;
5528: PetscCall(KSPGetNormType(ksp, &normtype));
5529: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5530: }
5531: PetscCall(KSPGetPCSide(ksp, &pcside));
5532: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5533: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5534: } else {
5535: /* KSP residual is preconditioned residual */
5536: /* compute true linear residual norm */
5537: Mat J;
5538: PetscCall(KSPGetOperators(ksp, &J, NULL));
5539: PetscCall(VecDuplicate(b, &lres));
5540: PetscCall(MatMult(J, x, lres));
5541: PetscCall(VecAYPX(lres, -1.0, b));
5542: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5543: PetscCall(VecDestroy(&lres));
5544: }
5545: }
5546: PetscFunctionReturn(PETSC_SUCCESS);
5547: }
5549: /*@
5550: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5552: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5554: Input Parameter:
5555: . snes - the `SNES` context
5557: Output Parameter:
5558: . ksp - the `KSP` context
5560: Level: beginner
5562: Notes:
5563: The user can then directly manipulate the `KSP` context to set various
5564: options, etc. Likewise, the user can then extract and manipulate the
5565: `PC` contexts as well.
5567: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function
5569: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5570: @*/
5571: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5572: {
5573: PetscFunctionBegin;
5575: PetscAssertPointer(ksp, 2);
5577: if (!snes->ksp) {
5578: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5579: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5581: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5582: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5584: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5585: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5586: }
5587: *ksp = snes->ksp;
5588: PetscFunctionReturn(PETSC_SUCCESS);
5589: }
5591: #include <petsc/private/dmimpl.h>
5592: /*@
5593: SNESSetDM - Sets the `DM` that may be used by some nonlinear solvers or their underlying preconditioners
5595: Logically Collective
5597: Input Parameters:
5598: + snes - the nonlinear solver context
5599: - dm - the `DM`, cannot be `NULL`
5601: Level: intermediate
5603: Note:
5604: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5605: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5606: problems using the same function space.
5608: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5609: @*/
5610: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5611: {
5612: KSP ksp;
5613: DMSNES sdm;
5615: PetscFunctionBegin;
5618: PetscCall(PetscObjectReference((PetscObject)dm));
5619: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5620: if (snes->dm->dmsnes && !dm->dmsnes) {
5621: PetscCall(DMCopyDMSNES(snes->dm, dm));
5622: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5623: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5624: }
5625: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5626: PetscCall(DMDestroy(&snes->dm));
5627: }
5628: snes->dm = dm;
5629: snes->dmAuto = PETSC_FALSE;
5631: PetscCall(SNESGetKSP(snes, &ksp));
5632: PetscCall(KSPSetDM(ksp, dm));
5633: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5634: if (snes->npc) {
5635: PetscCall(SNESSetDM(snes->npc, snes->dm));
5636: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5637: }
5638: PetscFunctionReturn(PETSC_SUCCESS);
5639: }
5641: /*@
5642: SNESGetDM - Gets the `DM` that may be used by some solvers/preconditioners
5644: Not Collective but dm obtained is parallel on snes
5646: Input Parameter:
5647: . snes - the `SNES` context
5649: Output Parameter:
5650: . dm - the `DM`
5652: Level: intermediate
5654: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5655: @*/
5656: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5657: {
5658: PetscFunctionBegin;
5660: if (!snes->dm) {
5661: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5662: snes->dmAuto = PETSC_TRUE;
5663: }
5664: *dm = snes->dm;
5665: PetscFunctionReturn(PETSC_SUCCESS);
5666: }
5668: /*@
5669: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5671: Collective
5673: Input Parameters:
5674: + snes - iterative context obtained from `SNESCreate()`
5675: - npc - the nonlinear preconditioner object
5677: Level: developer
5679: Notes:
5680: Use `SNESGetNPC()` to retrieve the preconditioner context (for example,
5681: to configure it using the API).
5683: Only some `SNESType` can use a nonlinear preconditioner
5685: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5686: @*/
5687: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5688: {
5689: PetscFunctionBegin;
5692: PetscCheckSameComm(snes, 1, npc, 2);
5693: PetscCall(PetscObjectReference((PetscObject)npc));
5694: PetscCall(SNESDestroy(&snes->npc));
5695: snes->npc = npc;
5696: PetscFunctionReturn(PETSC_SUCCESS);
5697: }
5699: /*@
5700: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5702: Not Collective; but any changes to the obtained the npc object must be applied collectively
5704: Input Parameter:
5705: . snes - iterative context obtained from `SNESCreate()`
5707: Output Parameter:
5708: . pc - preconditioner context
5710: Options Database Key:
5711: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5713: Level: developer
5715: Notes:
5716: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created.
5718: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5719: `SNES`
5721: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5722: @*/
5723: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5724: {
5725: const char *optionsprefix;
5727: PetscFunctionBegin;
5729: PetscAssertPointer(pc, 2);
5730: if (!snes->npc) {
5731: void *ctx;
5733: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5734: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5735: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5736: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5737: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5738: if (snes->ops->usercompute) {
5739: PetscCall(SNESSetComputeApplicationContext(snes, snes->ops->usercompute, snes->ops->ctxdestroy));
5740: } else {
5741: PetscCall(SNESGetApplicationContext(snes, &ctx));
5742: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5743: }
5744: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5745: }
5746: *pc = snes->npc;
5747: PetscFunctionReturn(PETSC_SUCCESS);
5748: }
5750: /*@
5751: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5753: Not Collective
5755: Input Parameter:
5756: . snes - iterative context obtained from `SNESCreate()`
5758: Output Parameter:
5759: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5761: Level: developer
5763: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5764: @*/
5765: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5766: {
5767: PetscFunctionBegin;
5769: PetscAssertPointer(has_npc, 2);
5770: *has_npc = snes->npc ? PETSC_TRUE : PETSC_FALSE;
5771: PetscFunctionReturn(PETSC_SUCCESS);
5772: }
5774: /*@
5775: SNESSetNPCSide - Sets the nonlinear preconditioning side.
5777: Logically Collective
5779: Input Parameter:
5780: . snes - iterative context obtained from `SNESCreate()`
5782: Output Parameter:
5783: . side - the preconditioning side, where side is one of
5784: .vb
5785: PC_LEFT - left preconditioning
5786: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5787: .ve
5789: Options Database Key:
5790: . -snes_npc_side <right,left> - nonlinear preconditioner side
5792: Level: intermediate
5794: Note:
5795: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5797: .seealso: [](ch_snes), `SNES`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5798: @*/
5799: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5800: {
5801: PetscFunctionBegin;
5804: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5805: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5806: snes->npcside = side;
5807: PetscFunctionReturn(PETSC_SUCCESS);
5808: }
5810: /*@
5811: SNESGetNPCSide - Gets the preconditioning side.
5813: Not Collective
5815: Input Parameter:
5816: . snes - iterative context obtained from `SNESCreate()`
5818: Output Parameter:
5819: . side - the preconditioning side, where side is one of
5820: .vb
5821: `PC_LEFT` - left preconditioning
5822: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5823: .ve
5825: Level: intermediate
5827: .seealso: [](ch_snes), `SNES`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5828: @*/
5829: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5830: {
5831: PetscFunctionBegin;
5833: PetscAssertPointer(side, 2);
5834: *side = snes->npcside;
5835: PetscFunctionReturn(PETSC_SUCCESS);
5836: }
5838: /*@
5839: SNESSetLineSearch - Sets the linesearch to be used for `SNES`
5841: Collective
5843: Input Parameters:
5844: + snes - iterative context obtained from `SNESCreate()`
5845: - linesearch - the linesearch object
5847: Level: developer
5849: Note:
5850: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
5851: to configure it using the API).
5853: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
5854: @*/
5855: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5856: {
5857: PetscFunctionBegin;
5860: PetscCheckSameComm(snes, 1, linesearch, 2);
5861: PetscCall(PetscObjectReference((PetscObject)linesearch));
5862: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5864: snes->linesearch = linesearch;
5865: PetscFunctionReturn(PETSC_SUCCESS);
5866: }
5868: /*@
5869: SNESGetLineSearch - Returns the line search context possibly set with `SNESSetLineSearch()`
5870: or creates a default line search instance associated with the `SNES` and returns it.
5872: Not Collective
5874: Input Parameter:
5875: . snes - iterative context obtained from `SNESCreate()`
5877: Output Parameter:
5878: . linesearch - linesearch context
5880: Level: beginner
5882: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`
5883: @*/
5884: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5885: {
5886: const char *optionsprefix;
5888: PetscFunctionBegin;
5890: PetscAssertPointer(linesearch, 2);
5891: if (!snes->linesearch) {
5892: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5893: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5894: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5895: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5896: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5897: }
5898: *linesearch = snes->linesearch;
5899: PetscFunctionReturn(PETSC_SUCCESS);
5900: }