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
856: - monitorsetup - a function that is called once ONLY if the user selected this monitor that may set additional features of the `SNES` or `PetscViewer` objects
858: Calling sequence of `monitor`:
859: + snes - the nonlinear solver context
860: . it - the current iteration
861: . r - the current function norm
862: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
864: Calling sequence of `monitorsetup`:
865: + snes - the nonlinear solver context
866: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
868: Options Database Key:
869: . -name - trigger the use of this monitor in `SNESSetFromOptions()`
871: Level: advanced
873: .seealso: [](ch_snes), `PetscOptionsCreateViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
874: `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`
875: `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
876: `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
877: `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
878: `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
879: `PetscOptionsFList()`, `PetscOptionsEList()`
880: @*/
881: PetscErrorCode SNESMonitorSetFromOptions(SNES snes, const char name[], const char help[], const char manual[], PetscErrorCode (*monitor)(SNES snes, PetscInt it, PetscReal r, PetscViewerAndFormat *vf), PetscErrorCode (*monitorsetup)(SNES snes, PetscViewerAndFormat *vf))
882: {
883: PetscViewer viewer;
884: PetscViewerFormat format;
885: PetscBool flg;
887: PetscFunctionBegin;
888: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, name, &viewer, &format, &flg));
889: if (flg) {
890: PetscViewerAndFormat *vf;
891: PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
892: PetscCall(PetscViewerDestroy(&viewer));
893: if (monitorsetup) PetscCall((*monitorsetup)(snes, vf));
894: PetscCall(SNESMonitorSet(snes, (PetscErrorCode (*)(SNES, PetscInt, PetscReal, void *))monitor, vf, (PetscErrorCode (*)(void **))PetscViewerAndFormatDestroy));
895: }
896: PetscFunctionReturn(PETSC_SUCCESS);
897: }
899: PetscErrorCode SNESEWSetFromOptions_Private(SNESKSPEW *kctx, PetscBool print_api, MPI_Comm comm, const char *prefix)
900: {
901: const char *api = print_api ? "SNESKSPSetParametersEW" : NULL;
903: PetscFunctionBegin;
904: PetscOptionsBegin(comm, prefix, "Eisenstat and Walker type forcing options", "KSP");
905: PetscCall(PetscOptionsInt("-ksp_ew_version", "Version 1, 2 or 3", api, kctx->version, &kctx->version, NULL));
906: PetscCall(PetscOptionsReal("-ksp_ew_rtol0", "0 <= rtol0 < 1", api, kctx->rtol_0, &kctx->rtol_0, NULL));
907: kctx->rtol_max = PetscMax(kctx->rtol_0, kctx->rtol_max);
908: PetscCall(PetscOptionsReal("-ksp_ew_rtolmax", "0 <= rtolmax < 1", api, kctx->rtol_max, &kctx->rtol_max, NULL));
909: PetscCall(PetscOptionsReal("-ksp_ew_gamma", "0 <= gamma <= 1", api, kctx->gamma, &kctx->gamma, NULL));
910: PetscCall(PetscOptionsReal("-ksp_ew_alpha", "1 < alpha <= 2", api, kctx->alpha, &kctx->alpha, NULL));
911: PetscCall(PetscOptionsReal("-ksp_ew_alpha2", "alpha2", NULL, kctx->alpha2, &kctx->alpha2, NULL));
912: PetscCall(PetscOptionsReal("-ksp_ew_threshold", "0 < threshold < 1", api, kctx->threshold, &kctx->threshold, NULL));
913: PetscCall(PetscOptionsReal("-ksp_ew_v4_p1", "p1", NULL, kctx->v4_p1, &kctx->v4_p1, NULL));
914: PetscCall(PetscOptionsReal("-ksp_ew_v4_p2", "p2", NULL, kctx->v4_p2, &kctx->v4_p2, NULL));
915: PetscCall(PetscOptionsReal("-ksp_ew_v4_p3", "p3", NULL, kctx->v4_p3, &kctx->v4_p3, NULL));
916: PetscCall(PetscOptionsReal("-ksp_ew_v4_m1", "Scaling when rk-1 in [p2,p3)", NULL, kctx->v4_m1, &kctx->v4_m1, NULL));
917: PetscCall(PetscOptionsReal("-ksp_ew_v4_m2", "Scaling when rk-1 in [p3,+infty)", NULL, kctx->v4_m2, &kctx->v4_m2, NULL));
918: PetscCall(PetscOptionsReal("-ksp_ew_v4_m3", "Threshold for successive rtol (0.1 in Eq.7)", NULL, kctx->v4_m3, &kctx->v4_m3, NULL));
919: PetscCall(PetscOptionsReal("-ksp_ew_v4_m4", "Adaptation scaling (0.5 in Eq.7)", NULL, kctx->v4_m4, &kctx->v4_m4, NULL));
920: PetscOptionsEnd();
921: PetscFunctionReturn(PETSC_SUCCESS);
922: }
924: /*@
925: SNESSetFromOptions - Sets various `SNES` and `KSP` parameters from user options.
927: Collective
929: Input Parameter:
930: . snes - the `SNES` context
932: Options Database Keys:
933: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, `SNESType` for complete list
934: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
935: . -snes_atol <abstol> - absolute tolerance of residual norm
936: . -snes_stol <stol> - convergence tolerance in terms of the norm of the change in the solution between steps
937: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
938: . -snes_max_it <max_it> - maximum number of iterations
939: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
940: . -snes_force_iteration <force> - force `SNESSolve()` to take at least one iteration
941: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
942: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
943: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
944: . -snes_lag_preconditioner_persists <true,false> - retains the -snes_lag_preconditioner information across multiple SNESSolve()
945: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
946: . -snes_lag_jacobian_persists <true,false> - retains the -snes_lag_jacobian information across multiple SNESSolve()
947: . -snes_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, (PetscErrorCode (*)(void **))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
1236: Calling sequence of `compute`:
1237: + snes - the `SNES` context
1238: - ctx - context to be computed
1240: Calling sequence of `destroy`:
1241: . ctx - context to be computed by `compute()`
1243: Level: intermediate
1245: Note:
1246: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1248: Use `SNESSetApplicationContext()` to see the context immediately
1250: .seealso: [](ch_snes), `SNESGetApplicationContext()`, `SNESSetApplicationContext()`
1251: @*/
1252: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES snes, void **ctx), PetscErrorCode (*destroy)(void **ctx))
1253: {
1254: PetscFunctionBegin;
1256: snes->ops->usercompute = compute;
1257: snes->ops->userdestroy = destroy;
1258: PetscFunctionReturn(PETSC_SUCCESS);
1259: }
1261: /*@
1262: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1264: Logically Collective
1266: Input Parameters:
1267: + snes - the `SNES` context
1268: - usrP - optional user context
1270: Level: intermediate
1272: Notes:
1273: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian, or other evaluation function
1274: with `SNESGetApplicationContext()`
1276: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1278: Fortran Note:
1279: You must write a Fortran interface definition for this
1280: function that tells Fortran the Fortran derived data type that you are passing in as the `usrP` argument.
1282: .seealso: [](ch_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1283: @*/
1284: PetscErrorCode SNESSetApplicationContext(SNES snes, void *usrP)
1285: {
1286: KSP ksp;
1288: PetscFunctionBegin;
1290: PetscCall(SNESGetKSP(snes, &ksp));
1291: PetscCall(KSPSetApplicationContext(ksp, usrP));
1292: snes->user = usrP;
1293: PetscFunctionReturn(PETSC_SUCCESS);
1294: }
1296: /*@
1297: SNESGetApplicationContext - Gets the user-defined context for the
1298: nonlinear solvers set with `SNESGetApplicationContext()` or `SNESSetComputeApplicationContext()`
1300: Not Collective
1302: Input Parameter:
1303: . snes - `SNES` context
1305: Output Parameter:
1306: . usrP - user context
1308: Level: intermediate
1310: Fortran Note:
1311: You must write a Fortran interface definition for this
1312: function that tells Fortran the Fortran derived data type that you are passing in as the `usrP` argument.
1314: .seealso: [](ch_snes), `SNESSetApplicationContext()`, `SNESSetComputeApplicationContext()`
1315: @*/
1316: PetscErrorCode SNESGetApplicationContext(SNES snes, void *usrP)
1317: {
1318: PetscFunctionBegin;
1320: *(void **)usrP = snes->user;
1321: PetscFunctionReturn(PETSC_SUCCESS);
1322: }
1324: /*@
1325: SNESSetUseMatrixFree - indicates that `SNES` should use matrix-free finite difference matrix-vector products to apply the Jacobian.
1327: Logically Collective
1329: Input Parameters:
1330: + snes - `SNES` context
1331: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1332: - 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
1333: this option no matrix-element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1335: Options Database Keys:
1336: + -snes_mf_operator - use matrix-free only for the mat operator
1337: . -snes_mf - use matrix-free for both the mat and pmat operator
1338: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1339: - -snes_fd - compute the Jacobian via finite differences (slow)
1341: Level: intermediate
1343: Note:
1344: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
1345: and computing explicitly with
1346: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1348: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`, `MatFDColoring`
1349: @*/
1350: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1351: {
1352: PetscFunctionBegin;
1356: snes->mf = mf_operator ? PETSC_TRUE : mf;
1357: snes->mf_operator = mf_operator;
1358: PetscFunctionReturn(PETSC_SUCCESS);
1359: }
1361: /*@
1362: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1364: Not Collective, but the resulting flags will be the same on all MPI processes
1366: Input Parameter:
1367: . snes - `SNES` context
1369: Output Parameters:
1370: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1371: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1373: Level: intermediate
1375: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1376: @*/
1377: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1378: {
1379: PetscFunctionBegin;
1381: if (mf) *mf = snes->mf;
1382: if (mf_operator) *mf_operator = snes->mf_operator;
1383: PetscFunctionReturn(PETSC_SUCCESS);
1384: }
1386: /*@
1387: SNESGetIterationNumber - Gets the number of nonlinear iterations completed in the current or most recent `SNESSolve()`
1389: Not Collective
1391: Input Parameter:
1392: . snes - `SNES` context
1394: Output Parameter:
1395: . iter - iteration number
1397: Level: intermediate
1399: Notes:
1400: For example, during the computation of iteration 2 this would return 1.
1402: This is useful for using lagged Jacobians (where one does not recompute the
1403: Jacobian at each `SNES` iteration). For example, the code
1404: .vb
1405: ierr = SNESGetIterationNumber(snes,&it);
1406: if (!(it % 2)) {
1407: [compute Jacobian here]
1408: }
1409: .ve
1410: can be used in your function that computes the Jacobian to cause the Jacobian to be
1411: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1413: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1415: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`, `SNESSetMonitor()`
1416: @*/
1417: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1418: {
1419: PetscFunctionBegin;
1421: PetscAssertPointer(iter, 2);
1422: *iter = snes->iter;
1423: PetscFunctionReturn(PETSC_SUCCESS);
1424: }
1426: /*@
1427: SNESSetIterationNumber - Sets the current iteration number.
1429: Not Collective
1431: Input Parameters:
1432: + snes - `SNES` context
1433: - iter - iteration number
1435: Level: developer
1437: Note:
1438: This should only be called inside a `SNES` nonlinear solver.
1440: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1441: @*/
1442: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1443: {
1444: PetscFunctionBegin;
1446: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1447: snes->iter = iter;
1448: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1449: PetscFunctionReturn(PETSC_SUCCESS);
1450: }
1452: /*@
1453: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1454: attempted by the nonlinear solver in the current or most recent `SNESSolve()` .
1456: Not Collective
1458: Input Parameter:
1459: . snes - `SNES` context
1461: Output Parameter:
1462: . nfails - number of unsuccessful steps attempted
1464: Level: intermediate
1466: Note:
1467: This counter is reset to zero for each successive call to `SNESSolve()`.
1469: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1470: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1471: @*/
1472: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1473: {
1474: PetscFunctionBegin;
1476: PetscAssertPointer(nfails, 2);
1477: *nfails = snes->numFailures;
1478: PetscFunctionReturn(PETSC_SUCCESS);
1479: }
1481: /*@
1482: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1483: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1485: Not Collective
1487: Input Parameters:
1488: + snes - `SNES` context
1489: - maxFails - maximum of unsuccessful steps allowed, use `PETSC_UNLIMITED` to have no limit on the number of failures
1491: Options Database Key:
1492: . -snes_max_fail <n> - maximum number of unsuccessful steps allowed
1494: Level: intermediate
1496: Developer Note:
1497: The options database key is wrong for this function name
1499: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1500: `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1501: @*/
1502: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1503: {
1504: PetscFunctionBegin;
1507: if (maxFails == PETSC_UNLIMITED) {
1508: snes->maxFailures = PETSC_INT_MAX;
1509: } else {
1510: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1511: snes->maxFailures = maxFails;
1512: }
1513: PetscFunctionReturn(PETSC_SUCCESS);
1514: }
1516: /*@
1517: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1518: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1520: Not Collective
1522: Input Parameter:
1523: . snes - `SNES` context
1525: Output Parameter:
1526: . maxFails - maximum of unsuccessful steps
1528: Level: intermediate
1530: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1531: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1532: @*/
1533: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1534: {
1535: PetscFunctionBegin;
1537: PetscAssertPointer(maxFails, 2);
1538: *maxFails = snes->maxFailures;
1539: PetscFunctionReturn(PETSC_SUCCESS);
1540: }
1542: /*@
1543: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1544: done by the `SNES` object in the current or most recent `SNESSolve()`
1546: Not Collective
1548: Input Parameter:
1549: . snes - `SNES` context
1551: Output Parameter:
1552: . nfuncs - number of evaluations
1554: Level: intermediate
1556: Note:
1557: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1559: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1560: @*/
1561: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1562: {
1563: PetscFunctionBegin;
1565: PetscAssertPointer(nfuncs, 2);
1566: *nfuncs = snes->nfuncs;
1567: PetscFunctionReturn(PETSC_SUCCESS);
1568: }
1570: /*@
1571: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1572: linear solvers in the current or most recent `SNESSolve()`
1574: Not Collective
1576: Input Parameter:
1577: . snes - `SNES` context
1579: Output Parameter:
1580: . nfails - number of failed solves
1582: Options Database Key:
1583: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1585: Level: intermediate
1587: Note:
1588: This counter is reset to zero for each successive call to `SNESSolve()`.
1590: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1591: @*/
1592: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1593: {
1594: PetscFunctionBegin;
1596: PetscAssertPointer(nfails, 2);
1597: *nfails = snes->numLinearSolveFailures;
1598: PetscFunctionReturn(PETSC_SUCCESS);
1599: }
1601: /*@
1602: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1603: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1605: Logically Collective
1607: Input Parameters:
1608: + snes - `SNES` context
1609: - maxFails - maximum allowed linear solve failures, use `PETSC_UNLIMITED` to have no limit on the number of failures
1611: Options Database Key:
1612: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1614: Level: intermediate
1616: Note:
1617: By default this is 0; that is `SNES` returns on the first failed linear solve
1619: Developer Note:
1620: The options database key is wrong for this function name
1622: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1623: @*/
1624: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1625: {
1626: PetscFunctionBegin;
1630: if (maxFails == PETSC_UNLIMITED) {
1631: snes->maxLinearSolveFailures = PETSC_INT_MAX;
1632: } else {
1633: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1634: snes->maxLinearSolveFailures = maxFails;
1635: }
1636: PetscFunctionReturn(PETSC_SUCCESS);
1637: }
1639: /*@
1640: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1641: are allowed before `SNES` returns as unsuccessful
1643: Not Collective
1645: Input Parameter:
1646: . snes - `SNES` context
1648: Output Parameter:
1649: . maxFails - maximum of unsuccessful solves allowed
1651: Level: intermediate
1653: Note:
1654: By default this is 1; that is `SNES` returns on the first failed linear solve
1656: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1657: @*/
1658: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1659: {
1660: PetscFunctionBegin;
1662: PetscAssertPointer(maxFails, 2);
1663: *maxFails = snes->maxLinearSolveFailures;
1664: PetscFunctionReturn(PETSC_SUCCESS);
1665: }
1667: /*@
1668: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1669: used by the nonlinear solver in the most recent `SNESSolve()`
1671: Not Collective
1673: Input Parameter:
1674: . snes - `SNES` context
1676: Output Parameter:
1677: . lits - number of linear iterations
1679: Level: intermediate
1681: Notes:
1682: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1684: 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
1685: then call `KSPGetIterationNumber()` after the failed solve.
1687: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1688: @*/
1689: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1690: {
1691: PetscFunctionBegin;
1693: PetscAssertPointer(lits, 2);
1694: *lits = snes->linear_its;
1695: PetscFunctionReturn(PETSC_SUCCESS);
1696: }
1698: /*@
1699: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1700: are reset every time `SNESSolve()` is called.
1702: Logically Collective
1704: Input Parameters:
1705: + snes - `SNES` context
1706: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1708: Level: developer
1710: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1711: @*/
1712: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1713: {
1714: PetscFunctionBegin;
1717: snes->counters_reset = reset;
1718: PetscFunctionReturn(PETSC_SUCCESS);
1719: }
1721: /*@
1722: SNESResetCounters - Reset counters for linear iterations and function evaluations.
1724: Logically Collective
1726: Input Parameters:
1727: . snes - `SNES` context
1729: Level: developer
1731: Note:
1732: It honors the flag set with `SNESSetCountersReset()`
1734: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1735: @*/
1736: PetscErrorCode SNESResetCounters(SNES snes)
1737: {
1738: PetscFunctionBegin;
1740: if (snes->counters_reset) {
1741: snes->nfuncs = 0;
1742: snes->linear_its = 0;
1743: snes->numFailures = 0;
1744: }
1745: PetscFunctionReturn(PETSC_SUCCESS);
1746: }
1748: /*@
1749: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1751: Not Collective, but the `SNES` and `KSP` objects must live on the same `MPI_Comm`
1753: Input Parameters:
1754: + snes - the `SNES` context
1755: - ksp - the `KSP` context
1757: Level: developer
1759: Notes:
1760: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1761: so this routine is rarely needed.
1763: The `KSP` object that is already in the `SNES` object has its reference count
1764: decreased by one when this is called.
1766: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`
1767: @*/
1768: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1769: {
1770: PetscFunctionBegin;
1773: PetscCheckSameComm(snes, 1, ksp, 2);
1774: PetscCall(PetscObjectReference((PetscObject)ksp));
1775: if (snes->ksp) PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1776: snes->ksp = ksp;
1777: PetscFunctionReturn(PETSC_SUCCESS);
1778: }
1780: /*@
1781: SNESParametersInitialize - Sets all the parameters in `snes` to their default value (when `SNESCreate()` was called) if they
1782: currently contain default values
1784: Collective
1786: Input Parameter:
1787: . snes - the `SNES` object
1789: Level: developer
1791: Developer Note:
1792: This is called by all the `SNESCreate_XXX()` routines.
1794: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
1795: `PetscObjectParameterSetDefault()`
1796: @*/
1797: PetscErrorCode SNESParametersInitialize(SNES snes)
1798: {
1799: PetscObjectParameterSetDefault(snes, max_its, 50);
1800: PetscObjectParameterSetDefault(snes, max_funcs, 10000);
1801: PetscObjectParameterSetDefault(snes, rtol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1802: PetscObjectParameterSetDefault(snes, abstol, PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50);
1803: PetscObjectParameterSetDefault(snes, stol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1804: PetscObjectParameterSetDefault(snes, divtol, 1.e4);
1805: return PETSC_SUCCESS;
1806: }
1808: /*@
1809: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1811: Collective
1813: Input Parameter:
1814: . comm - MPI communicator
1816: Output Parameter:
1817: . outsnes - the new `SNES` context
1819: Options Database Keys:
1820: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no preconditioning matrix
1821: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided preconditioning matrix
1822: as set by `SNESSetJacobian()`
1823: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1824: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1826: Level: beginner
1828: Developer Notes:
1829: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1830: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1831: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1832: in `SNESView()`.
1834: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1835: by help messages about meaningless `SNES` options.
1837: `SNES` always creates the snes->kspconvctx even though it is used by only one type. This should be fixed.
1839: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1840: @*/
1841: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1842: {
1843: SNES snes;
1844: SNESKSPEW *kctx;
1846: PetscFunctionBegin;
1847: PetscAssertPointer(outsnes, 2);
1848: PetscCall(SNESInitializePackage());
1850: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1851: snes->ops->converged = SNESConvergedDefault;
1852: snes->usesksp = PETSC_TRUE;
1853: snes->norm = 0.0;
1854: snes->xnorm = 0.0;
1855: snes->ynorm = 0.0;
1856: snes->normschedule = SNES_NORM_ALWAYS;
1857: snes->functype = SNES_FUNCTION_DEFAULT;
1858: snes->ttol = 0.0;
1860: snes->rnorm0 = 0;
1861: snes->nfuncs = 0;
1862: snes->numFailures = 0;
1863: snes->maxFailures = 1;
1864: snes->linear_its = 0;
1865: snes->lagjacobian = 1;
1866: snes->jac_iter = 0;
1867: snes->lagjac_persist = PETSC_FALSE;
1868: snes->lagpreconditioner = 1;
1869: snes->pre_iter = 0;
1870: snes->lagpre_persist = PETSC_FALSE;
1871: snes->numbermonitors = 0;
1872: snes->numberreasonviews = 0;
1873: snes->data = NULL;
1874: snes->setupcalled = PETSC_FALSE;
1875: snes->ksp_ewconv = PETSC_FALSE;
1876: snes->nwork = 0;
1877: snes->work = NULL;
1878: snes->nvwork = 0;
1879: snes->vwork = NULL;
1880: snes->conv_hist_len = 0;
1881: snes->conv_hist_max = 0;
1882: snes->conv_hist = NULL;
1883: snes->conv_hist_its = NULL;
1884: snes->conv_hist_reset = PETSC_TRUE;
1885: snes->counters_reset = PETSC_TRUE;
1886: snes->vec_func_init_set = PETSC_FALSE;
1887: snes->reason = SNES_CONVERGED_ITERATING;
1888: snes->npcside = PC_RIGHT;
1889: snes->setfromoptionscalled = 0;
1891: snes->mf = PETSC_FALSE;
1892: snes->mf_operator = PETSC_FALSE;
1893: snes->mf_version = 1;
1895: snes->numLinearSolveFailures = 0;
1896: snes->maxLinearSolveFailures = 1;
1898: snes->vizerotolerance = 1.e-8;
1899: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1901: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1902: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1904: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1905: PetscCall(PetscNew(&kctx));
1907: snes->kspconvctx = (void *)kctx;
1908: kctx->version = 2;
1909: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1910: this was too large for some test cases */
1911: kctx->rtol_last = 0.0;
1912: kctx->rtol_max = 0.9;
1913: kctx->gamma = 1.0;
1914: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1915: kctx->alpha2 = kctx->alpha;
1916: kctx->threshold = 0.1;
1917: kctx->lresid_last = 0.0;
1918: kctx->norm_last = 0.0;
1920: kctx->rk_last = 0.0;
1921: kctx->rk_last_2 = 0.0;
1922: kctx->rtol_last_2 = 0.0;
1923: kctx->v4_p1 = 0.1;
1924: kctx->v4_p2 = 0.4;
1925: kctx->v4_p3 = 0.7;
1926: kctx->v4_m1 = 0.8;
1927: kctx->v4_m2 = 0.5;
1928: kctx->v4_m3 = 0.1;
1929: kctx->v4_m4 = 0.5;
1931: PetscCall(SNESParametersInitialize(snes));
1932: *outsnes = snes;
1933: PetscFunctionReturn(PETSC_SUCCESS);
1934: }
1936: /*@C
1937: SNESSetFunction - Sets the function evaluation routine and function
1938: vector for use by the `SNES` routines in solving systems of nonlinear
1939: equations.
1941: Logically Collective
1943: Input Parameters:
1944: + snes - the `SNES` context
1945: . r - vector to store function values, may be `NULL`
1946: . f - function evaluation routine; for calling sequence see `SNESFunctionFn`
1947: - ctx - [optional] user-defined context for private data for the
1948: function evaluation routine (may be `NULL`)
1950: Level: beginner
1952: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunctionFn`
1953: @*/
1954: PetscErrorCode SNESSetFunction(SNES snes, Vec r, SNESFunctionFn *f, void *ctx)
1955: {
1956: DM dm;
1958: PetscFunctionBegin;
1960: if (r) {
1962: PetscCheckSameComm(snes, 1, r, 2);
1963: PetscCall(PetscObjectReference((PetscObject)r));
1964: PetscCall(VecDestroy(&snes->vec_func));
1965: snes->vec_func = r;
1966: }
1967: PetscCall(SNESGetDM(snes, &dm));
1968: PetscCall(DMSNESSetFunction(dm, f, ctx));
1969: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1970: PetscFunctionReturn(PETSC_SUCCESS);
1971: }
1973: /*@C
1974: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1976: Logically Collective
1978: Input Parameters:
1979: + snes - the `SNES` context
1980: - f - vector to store function value
1982: Level: developer
1984: Notes:
1985: This should not be modified during the solution procedure.
1987: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1989: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1990: @*/
1991: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1992: {
1993: Vec vec_func;
1995: PetscFunctionBegin;
1998: PetscCheckSameComm(snes, 1, f, 2);
1999: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
2000: snes->vec_func_init_set = PETSC_FALSE;
2001: PetscFunctionReturn(PETSC_SUCCESS);
2002: }
2003: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
2004: PetscCall(VecCopy(f, vec_func));
2006: snes->vec_func_init_set = PETSC_TRUE;
2007: PetscFunctionReturn(PETSC_SUCCESS);
2008: }
2010: /*@
2011: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
2012: of the `SNES` method, when norms are computed in the solving process
2014: Logically Collective
2016: Input Parameters:
2017: + snes - the `SNES` context
2018: - normschedule - the frequency of norm computation
2020: Options Database Key:
2021: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
2023: Level: advanced
2025: Notes:
2026: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
2027: of the nonlinear function and the taking of its norm at every iteration to
2028: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2029: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
2030: may either be monitored for convergence or not. As these are often used as nonlinear
2031: preconditioners, monitoring the norm of their error is not a useful enterprise within
2032: their solution.
2034: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
2035: @*/
2036: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
2037: {
2038: PetscFunctionBegin;
2040: snes->normschedule = normschedule;
2041: PetscFunctionReturn(PETSC_SUCCESS);
2042: }
2044: /*@
2045: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
2046: of the `SNES` method.
2048: Logically Collective
2050: Input Parameters:
2051: + snes - the `SNES` context
2052: - normschedule - the type of the norm used
2054: Level: advanced
2056: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2057: @*/
2058: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
2059: {
2060: PetscFunctionBegin;
2062: *normschedule = snes->normschedule;
2063: PetscFunctionReturn(PETSC_SUCCESS);
2064: }
2066: /*@
2067: SNESSetFunctionNorm - Sets the last computed residual norm.
2069: Logically Collective
2071: Input Parameters:
2072: + snes - the `SNES` context
2073: - norm - the value of the norm
2075: Level: developer
2077: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2078: @*/
2079: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
2080: {
2081: PetscFunctionBegin;
2083: snes->norm = norm;
2084: PetscFunctionReturn(PETSC_SUCCESS);
2085: }
2087: /*@
2088: SNESGetFunctionNorm - Gets the last computed norm of the residual
2090: Not Collective
2092: Input Parameter:
2093: . snes - the `SNES` context
2095: Output Parameter:
2096: . norm - the last computed residual norm
2098: Level: developer
2100: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2101: @*/
2102: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2103: {
2104: PetscFunctionBegin;
2106: PetscAssertPointer(norm, 2);
2107: *norm = snes->norm;
2108: PetscFunctionReturn(PETSC_SUCCESS);
2109: }
2111: /*@
2112: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2114: Not Collective
2116: Input Parameter:
2117: . snes - the `SNES` context
2119: Output Parameter:
2120: . ynorm - the last computed update norm
2122: Level: developer
2124: Note:
2125: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2127: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2128: @*/
2129: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2130: {
2131: PetscFunctionBegin;
2133: PetscAssertPointer(ynorm, 2);
2134: *ynorm = snes->ynorm;
2135: PetscFunctionReturn(PETSC_SUCCESS);
2136: }
2138: /*@
2139: SNESGetSolutionNorm - Gets the last computed norm of the solution
2141: Not Collective
2143: Input Parameter:
2144: . snes - the `SNES` context
2146: Output Parameter:
2147: . xnorm - the last computed solution norm
2149: Level: developer
2151: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2152: @*/
2153: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2154: {
2155: PetscFunctionBegin;
2157: PetscAssertPointer(xnorm, 2);
2158: *xnorm = snes->xnorm;
2159: PetscFunctionReturn(PETSC_SUCCESS);
2160: }
2162: /*@
2163: SNESSetFunctionType - Sets the `SNESFunctionType`
2164: of the `SNES` method.
2166: Logically Collective
2168: Input Parameters:
2169: + snes - the `SNES` context
2170: - type - the function type
2172: Level: developer
2174: Values of the function type\:
2175: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2176: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2177: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2179: Note:
2180: Different `SNESType`s use this value in different ways
2182: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2183: @*/
2184: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2185: {
2186: PetscFunctionBegin;
2188: snes->functype = type;
2189: PetscFunctionReturn(PETSC_SUCCESS);
2190: }
2192: /*@
2193: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2194: of the SNES method.
2196: Logically Collective
2198: Input Parameters:
2199: + snes - the `SNES` context
2200: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2202: Level: advanced
2204: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2205: @*/
2206: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2207: {
2208: PetscFunctionBegin;
2210: *type = snes->functype;
2211: PetscFunctionReturn(PETSC_SUCCESS);
2212: }
2214: /*@C
2215: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2216: use with composed nonlinear solvers.
2218: Input Parameters:
2219: + snes - the `SNES` context, usually of the `SNESType` `SNESNGS`
2220: . f - function evaluation routine to apply Gauss-Seidel, see `SNESNGSFn` for calling sequence
2221: - ctx - [optional] user-defined context for private data for the smoother evaluation routine (may be `NULL`)
2223: Level: intermediate
2225: Note:
2226: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2227: a problem appropriate update to the solution, particularly `SNESFAS`.
2229: .seealso: [](ch_snes), `SNESNGS`, `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`, `SNESNGSFn`
2230: @*/
2231: PetscErrorCode SNESSetNGS(SNES snes, SNESNGSFn *f, void *ctx)
2232: {
2233: DM dm;
2235: PetscFunctionBegin;
2237: PetscCall(SNESGetDM(snes, &dm));
2238: PetscCall(DMSNESSetNGS(dm, f, ctx));
2239: PetscFunctionReturn(PETSC_SUCCESS);
2240: }
2242: /*
2243: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2244: changed during the KSPSolve()
2245: */
2246: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, void *ctx)
2247: {
2248: DM dm;
2249: DMSNES sdm;
2251: PetscFunctionBegin;
2252: PetscCall(SNESGetDM(snes, &dm));
2253: PetscCall(DMGetDMSNES(dm, &sdm));
2254: /* A(x)*x - b(x) */
2255: if (sdm->ops->computepfunction) {
2256: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2257: PetscCall(VecScale(f, -1.0));
2258: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2259: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2260: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2261: PetscCall(MatMultAdd(snes->picard, x, f, f));
2262: } else {
2263: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2264: PetscCall(MatMult(snes->picard, x, f));
2265: }
2266: PetscFunctionReturn(PETSC_SUCCESS);
2267: }
2269: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, void *ctx)
2270: {
2271: DM dm;
2272: DMSNES sdm;
2274: PetscFunctionBegin;
2275: PetscCall(SNESGetDM(snes, &dm));
2276: PetscCall(DMGetDMSNES(dm, &sdm));
2277: /* A(x)*x - b(x) */
2278: if (sdm->ops->computepfunction) {
2279: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2280: PetscCall(VecScale(f, -1.0));
2281: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2282: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2283: } else {
2284: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2285: PetscCall(MatMult(snes->jacobian_pre, x, f));
2286: }
2287: PetscFunctionReturn(PETSC_SUCCESS);
2288: }
2290: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, void *ctx)
2291: {
2292: PetscFunctionBegin;
2293: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2294: /* must assembly if matrix-free to get the last SNES solution */
2295: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2296: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2297: PetscFunctionReturn(PETSC_SUCCESS);
2298: }
2300: /*@C
2301: SNESSetPicard - Use `SNES` to solve the system $A(x) x = bp(x) + b $ via a Picard type iteration (Picard linearization)
2303: Logically Collective
2305: Input Parameters:
2306: + snes - the `SNES` context
2307: . r - vector to store function values, may be `NULL`
2308: . bp - function evaluation routine, may be `NULL`, for the calling sequence see `SNESFunctionFn`
2309: . Amat - matrix with which A(x) x - bp(x) - b is to be computed
2310: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2311: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFn`
2312: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2314: Level: intermediate
2316: Notes:
2317: It is often better to provide the nonlinear function F() and some approximation to its Jacobian directly and use
2318: 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.
2320: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2322: Solves the equation $A(x) x = bp(x) - b$ via the defect correction algorithm $A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}$.
2323: When an exact solver is used this corresponds to the "classic" Picard $A(x^{n}) x^{n+1} = bp(x^{n}) + b$ iteration.
2325: Run with `-snes_mf_operator` to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2327: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2328: the direct Picard iteration $A(x^n) x^{n+1} = bp(x^n) + b$
2330: 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
2331: 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
2332: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument \:-).
2334: 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
2335: A(x^{n}) is used to build the preconditioner
2337: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at a time) and thus represent Newton's method.
2339: 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
2340: 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
2341: 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`.
2342: See the comment in src/snes/tutorials/ex15.c.
2344: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`,
2345: `SNESFunctionFn`, `SNESJacobianFn`
2346: @*/
2347: PetscErrorCode SNESSetPicard(SNES snes, Vec r, SNESFunctionFn *bp, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
2348: {
2349: DM dm;
2351: PetscFunctionBegin;
2353: PetscCall(SNESGetDM(snes, &dm));
2354: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2355: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2356: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2357: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2358: PetscFunctionReturn(PETSC_SUCCESS);
2359: }
2361: /*@C
2362: SNESGetPicard - Returns the context for the Picard iteration
2364: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2366: Input Parameter:
2367: . snes - the `SNES` context
2369: Output Parameters:
2370: + r - the function (or `NULL`)
2371: . f - the function (or `NULL`); for calling sequence see `SNESFunctionFn`
2372: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2373: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2374: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFn`
2375: - ctx - the function context (or `NULL`)
2377: Level: advanced
2379: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunctionFn`, `SNESJacobianFn`
2380: @*/
2381: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, SNESFunctionFn **f, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
2382: {
2383: DM dm;
2385: PetscFunctionBegin;
2387: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2388: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2389: PetscCall(SNESGetDM(snes, &dm));
2390: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2391: PetscFunctionReturn(PETSC_SUCCESS);
2392: }
2394: /*@C
2395: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2397: Logically Collective
2399: Input Parameters:
2400: + snes - the `SNES` context
2401: . func - function evaluation routine, see `SNESInitialGuessFn` for the calling sequence
2402: - ctx - [optional] user-defined context for private data for the
2403: function evaluation routine (may be `NULL`)
2405: Level: intermediate
2407: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESInitialGuessFn`
2408: @*/
2409: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, SNESInitialGuessFn *func, void *ctx)
2410: {
2411: PetscFunctionBegin;
2413: if (func) snes->ops->computeinitialguess = func;
2414: if (ctx) snes->initialguessP = ctx;
2415: PetscFunctionReturn(PETSC_SUCCESS);
2416: }
2418: /*@C
2419: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2420: it assumes a zero right-hand side.
2422: Logically Collective
2424: Input Parameter:
2425: . snes - the `SNES` context
2427: Output Parameter:
2428: . rhs - the right-hand side vector or `NULL` if there is no right-hand side vector
2430: Level: intermediate
2432: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2433: @*/
2434: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2435: {
2436: PetscFunctionBegin;
2438: PetscAssertPointer(rhs, 2);
2439: *rhs = snes->vec_rhs;
2440: PetscFunctionReturn(PETSC_SUCCESS);
2441: }
2443: /*@
2444: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2446: Collective
2448: Input Parameters:
2449: + snes - the `SNES` context
2450: - x - input vector
2452: Output Parameter:
2453: . y - function vector, as set by `SNESSetFunction()`
2455: Level: developer
2457: Notes:
2458: `SNESComputeFunction()` is typically used within nonlinear solvers
2459: implementations, so users would not generally call this routine themselves.
2461: When solving for $F(x) = b$, this routine computes $y = F(x) - b$.
2463: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`
2464: @*/
2465: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec y)
2466: {
2467: DM dm;
2468: DMSNES sdm;
2470: PetscFunctionBegin;
2474: PetscCheckSameComm(snes, 1, x, 2);
2475: PetscCheckSameComm(snes, 1, y, 3);
2476: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2478: PetscCall(SNESGetDM(snes, &dm));
2479: PetscCall(DMGetDMSNES(dm, &sdm));
2480: 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().");
2481: if (sdm->ops->computefunction) {
2482: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2483: PetscCall(VecLockReadPush(x));
2484: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2485: snes->domainerror = PETSC_FALSE;
2486: {
2487: void *ctx;
2488: SNESFunctionFn *computefunction;
2489: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2490: PetscCallBack("SNES callback function", (*computefunction)(snes, x, y, ctx));
2491: }
2492: PetscCall(VecLockReadPop(x));
2493: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2494: } else /* if (snes->vec_rhs) */ {
2495: PetscCall(MatMult(snes->jacobian, x, y));
2496: }
2497: if (snes->vec_rhs) PetscCall(VecAXPY(y, -1.0, snes->vec_rhs));
2498: snes->nfuncs++;
2499: /*
2500: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2501: propagate the value to all processes
2502: */
2503: PetscCall(VecFlag(y, snes->domainerror));
2504: PetscFunctionReturn(PETSC_SUCCESS);
2505: }
2507: /*@
2508: SNESComputeMFFunction - Calls the function that has been set with `DMSNESSetMFFunction()`.
2510: Collective
2512: Input Parameters:
2513: + snes - the `SNES` context
2514: - x - input vector
2516: Output Parameter:
2517: . y - output vector
2519: Level: developer
2521: Notes:
2522: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2523: so users would not generally call this routine themselves.
2525: Since this function is intended for use with finite differencing it does not subtract the right-hand side vector provided with `SNESSolve()`
2526: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2527: 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.
2529: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF()`, `DMSNESSetMFFunction()`
2530: @*/
2531: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2532: {
2533: DM dm;
2534: DMSNES sdm;
2536: PetscFunctionBegin;
2540: PetscCheckSameComm(snes, 1, x, 2);
2541: PetscCheckSameComm(snes, 1, y, 3);
2542: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2544: PetscCall(SNESGetDM(snes, &dm));
2545: PetscCall(DMGetDMSNES(dm, &sdm));
2546: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2547: PetscCall(VecLockReadPush(x));
2548: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2549: snes->domainerror = PETSC_FALSE;
2550: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2551: PetscCall(VecLockReadPop(x));
2552: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2553: snes->nfuncs++;
2554: /*
2555: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2556: propagate the value to all processes
2557: */
2558: PetscCall(VecFlag(y, snes->domainerror));
2559: PetscFunctionReturn(PETSC_SUCCESS);
2560: }
2562: /*@
2563: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2565: Collective
2567: Input Parameters:
2568: + snes - the `SNES` context
2569: . x - input vector
2570: - b - rhs vector
2572: Output Parameter:
2573: . x - new solution vector
2575: Level: developer
2577: Note:
2578: `SNESComputeNGS()` is typically used within composed nonlinear solver
2579: implementations, so most users would not generally call this routine
2580: themselves.
2582: .seealso: [](ch_snes), `SNESNGSFn`, `SNESSetNGS()`, `SNESComputeFunction()`, `SNESNGS`
2583: @*/
2584: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2585: {
2586: DM dm;
2587: DMSNES sdm;
2589: PetscFunctionBegin;
2593: PetscCheckSameComm(snes, 1, x, 3);
2594: if (b) PetscCheckSameComm(snes, 1, b, 2);
2595: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2596: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2597: PetscCall(SNESGetDM(snes, &dm));
2598: PetscCall(DMGetDMSNES(dm, &sdm));
2599: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2600: if (b) PetscCall(VecLockReadPush(b));
2601: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2602: if (b) PetscCall(VecLockReadPop(b));
2603: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2604: PetscFunctionReturn(PETSC_SUCCESS);
2605: }
2607: static PetscErrorCode SNESComputeFunction_FD(SNES snes, Vec Xin, Vec G)
2608: {
2609: Vec X;
2610: PetscScalar *g;
2611: PetscReal f, f2;
2612: PetscInt low, high, N, i;
2613: PetscBool flg;
2614: PetscReal h = .5 * PETSC_SQRT_MACHINE_EPSILON;
2616: PetscFunctionBegin;
2617: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_fd_delta", &h, &flg));
2618: PetscCall(VecDuplicate(Xin, &X));
2619: PetscCall(VecCopy(Xin, X));
2620: PetscCall(VecGetSize(X, &N));
2621: PetscCall(VecGetOwnershipRange(X, &low, &high));
2622: PetscCall(VecSetOption(X, VEC_IGNORE_OFF_PROC_ENTRIES, PETSC_TRUE));
2623: PetscCall(VecGetArray(G, &g));
2624: for (i = 0; i < N; i++) {
2625: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2626: PetscCall(VecAssemblyBegin(X));
2627: PetscCall(VecAssemblyEnd(X));
2628: PetscCall(SNESComputeObjective(snes, X, &f));
2629: PetscCall(VecSetValue(X, i, 2.0 * h, ADD_VALUES));
2630: PetscCall(VecAssemblyBegin(X));
2631: PetscCall(VecAssemblyEnd(X));
2632: PetscCall(SNESComputeObjective(snes, X, &f2));
2633: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2634: PetscCall(VecAssemblyBegin(X));
2635: PetscCall(VecAssemblyEnd(X));
2636: if (i >= low && i < high) g[i - low] = (f2 - f) / (2.0 * h);
2637: }
2638: PetscCall(VecRestoreArray(G, &g));
2639: PetscCall(VecDestroy(&X));
2640: PetscFunctionReturn(PETSC_SUCCESS);
2641: }
2643: PetscErrorCode SNESTestFunction(SNES snes)
2644: {
2645: Vec x, g1, g2, g3;
2646: PetscBool complete_print = PETSC_FALSE, test = PETSC_FALSE;
2647: PetscReal hcnorm, fdnorm, hcmax, fdmax, diffmax, diffnorm;
2648: PetscScalar dot;
2649: MPI_Comm comm;
2650: PetscViewer viewer, mviewer;
2651: PetscViewerFormat format;
2652: PetscInt tabs;
2653: static PetscBool directionsprinted = PETSC_FALSE;
2654: SNESObjectiveFn *objective;
2656: PetscFunctionBegin;
2657: PetscCall(SNESGetObjective(snes, &objective, NULL));
2658: if (!objective) PetscFunctionReturn(PETSC_SUCCESS);
2660: PetscObjectOptionsBegin((PetscObject)snes);
2661: PetscCall(PetscOptionsName("-snes_test_function", "Compare hand-coded and finite difference function", "None", &test));
2662: PetscCall(PetscOptionsViewer("-snes_test_function_view", "View difference between hand-coded and finite difference function element entries", "None", &mviewer, &format, &complete_print));
2663: PetscOptionsEnd();
2664: if (!test) {
2665: if (complete_print) PetscCall(PetscViewerDestroy(&mviewer));
2666: PetscFunctionReturn(PETSC_SUCCESS);
2667: }
2669: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2670: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2671: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2672: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2673: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Function -------------\n"));
2674: if (!complete_print && !directionsprinted) {
2675: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_function_view and optionally -snes_test_function <threshold> to show difference\n"));
2676: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference function entries greater than <threshold>.\n"));
2677: }
2678: if (!directionsprinted) {
2679: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Function, if (for double precision runs) ||F - Ffd||/||F|| is\n"));
2680: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Function is probably correct.\n"));
2681: directionsprinted = PETSC_TRUE;
2682: }
2683: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2685: PetscCall(SNESGetSolution(snes, &x));
2686: PetscCall(VecDuplicate(x, &g1));
2687: PetscCall(VecDuplicate(x, &g2));
2688: PetscCall(VecDuplicate(x, &g3));
2689: PetscCall(SNESComputeFunction(snes, x, g1));
2690: PetscCall(SNESComputeFunction_FD(snes, x, g2));
2692: PetscCall(VecNorm(g2, NORM_2, &fdnorm));
2693: PetscCall(VecNorm(g1, NORM_2, &hcnorm));
2694: PetscCall(VecNorm(g2, NORM_INFINITY, &fdmax));
2695: PetscCall(VecNorm(g1, NORM_INFINITY, &hcmax));
2696: PetscCall(VecDot(g1, g2, &dot));
2697: PetscCall(VecCopy(g1, g3));
2698: PetscCall(VecAXPY(g3, -1.0, g2));
2699: PetscCall(VecNorm(g3, NORM_2, &diffnorm));
2700: PetscCall(VecNorm(g3, NORM_INFINITY, &diffmax));
2701: PetscCall(PetscViewerASCIIPrintf(viewer, " ||Ffd|| %g, ||F|| = %g, angle cosine = (Ffd'F)/||Ffd||||F|| = %g\n", (double)fdnorm, (double)hcnorm, (double)(PetscRealPart(dot) / (fdnorm * hcnorm))));
2702: PetscCall(PetscViewerASCIIPrintf(viewer, " 2-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffnorm / PetscMax(hcnorm, fdnorm)), (double)diffnorm));
2703: PetscCall(PetscViewerASCIIPrintf(viewer, " max-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffmax / PetscMax(hcmax, fdmax)), (double)diffmax));
2705: if (complete_print) {
2706: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded function ----------\n"));
2707: PetscCall(VecView(g1, mviewer));
2708: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference function ----------\n"));
2709: PetscCall(VecView(g2, mviewer));
2710: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference function ----------\n"));
2711: PetscCall(VecView(g3, mviewer));
2712: }
2713: PetscCall(VecDestroy(&g1));
2714: PetscCall(VecDestroy(&g2));
2715: PetscCall(VecDestroy(&g3));
2717: if (complete_print) {
2718: PetscCall(PetscViewerPopFormat(mviewer));
2719: PetscCall(PetscViewerDestroy(&mviewer));
2720: }
2721: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2722: PetscFunctionReturn(PETSC_SUCCESS);
2723: }
2725: PetscErrorCode SNESTestJacobian(SNES snes)
2726: {
2727: Mat A, B, C, D, jacobian;
2728: Vec x = snes->vec_sol, f;
2729: PetscReal nrm, gnorm;
2730: PetscReal threshold = 1.e-5;
2731: MatType mattype;
2732: PetscInt m, n, M, N;
2733: void *functx;
2734: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, test = PETSC_FALSE, flg, istranspose;
2735: PetscViewer viewer, mviewer;
2736: MPI_Comm comm;
2737: PetscInt tabs;
2738: static PetscBool directionsprinted = PETSC_FALSE;
2739: PetscViewerFormat format;
2741: PetscFunctionBegin;
2742: PetscObjectOptionsBegin((PetscObject)snes);
2743: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &test));
2744: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2745: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2746: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2747: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2748: 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));
2749: PetscOptionsEnd();
2750: if (!test) PetscFunctionReturn(PETSC_SUCCESS);
2752: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2753: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2754: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2755: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2756: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2757: if (!complete_print && !directionsprinted) {
2758: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2759: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2760: }
2761: if (!directionsprinted) {
2762: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2763: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2764: directionsprinted = PETSC_TRUE;
2765: }
2766: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2768: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2769: if (!flg) jacobian = snes->jacobian;
2770: else jacobian = snes->jacobian_pre;
2772: if (!x) PetscCall(MatCreateVecs(jacobian, &x, NULL));
2773: else PetscCall(PetscObjectReference((PetscObject)x));
2774: PetscCall(VecDuplicate(x, &f));
2776: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2777: PetscCall(SNESComputeFunction(snes, x, f));
2778: PetscCall(VecDestroy(&f));
2779: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2780: while (jacobian) {
2781: Mat JT = NULL, Jsave = NULL;
2783: if (istranspose) {
2784: PetscCall(MatCreateTranspose(jacobian, &JT));
2785: Jsave = jacobian;
2786: jacobian = JT;
2787: }
2788: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2789: if (flg) {
2790: A = jacobian;
2791: PetscCall(PetscObjectReference((PetscObject)A));
2792: } else {
2793: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2794: }
2796: PetscCall(MatGetType(A, &mattype));
2797: PetscCall(MatGetSize(A, &M, &N));
2798: PetscCall(MatGetLocalSize(A, &m, &n));
2799: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2800: PetscCall(MatSetType(B, mattype));
2801: PetscCall(MatSetSizes(B, m, n, M, N));
2802: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2803: PetscCall(MatSetUp(B));
2804: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2806: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2807: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2809: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2810: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2811: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2812: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2813: PetscCall(MatDestroy(&D));
2814: if (!gnorm) gnorm = 1; /* just in case */
2815: PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2817: if (complete_print) {
2818: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2819: PetscCall(MatView(A, mviewer));
2820: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2821: PetscCall(MatView(B, mviewer));
2822: }
2824: if (threshold_print || complete_print) {
2825: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2826: PetscScalar *cvals;
2827: const PetscInt *bcols;
2828: const PetscScalar *bvals;
2830: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2831: PetscCall(MatSetType(C, mattype));
2832: PetscCall(MatSetSizes(C, m, n, M, N));
2833: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2834: PetscCall(MatSetUp(C));
2835: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2837: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2838: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2840: for (row = Istart; row < Iend; row++) {
2841: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2842: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2843: for (j = 0, cncols = 0; j < bncols; j++) {
2844: if (PetscAbsScalar(bvals[j]) > threshold) {
2845: ccols[cncols] = bcols[j];
2846: cvals[cncols] = bvals[j];
2847: cncols += 1;
2848: }
2849: }
2850: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2851: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2852: PetscCall(PetscFree2(ccols, cvals));
2853: }
2854: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2855: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2856: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2857: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2858: PetscCall(MatDestroy(&C));
2859: }
2860: PetscCall(MatDestroy(&A));
2861: PetscCall(MatDestroy(&B));
2862: PetscCall(MatDestroy(&JT));
2863: if (Jsave) jacobian = Jsave;
2864: if (jacobian != snes->jacobian_pre) {
2865: jacobian = snes->jacobian_pre;
2866: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2867: } else jacobian = NULL;
2868: }
2869: PetscCall(VecDestroy(&x));
2870: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2871: if (mviewer) PetscCall(PetscViewerDestroy(&mviewer));
2872: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2873: PetscFunctionReturn(PETSC_SUCCESS);
2874: }
2876: /*@
2877: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2879: Collective
2881: Input Parameters:
2882: + snes - the `SNES` context
2883: - X - input vector
2885: Output Parameters:
2886: + A - Jacobian matrix
2887: - B - optional matrix for building the preconditioner, usually the same as `A`
2889: Options Database Keys:
2890: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2891: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2892: . -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.
2893: . -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
2894: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2895: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2896: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2897: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2898: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2899: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2900: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2901: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2902: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2903: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2904: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2906: Level: developer
2908: Note:
2909: Most users should not need to explicitly call this routine, as it
2910: is used internally within the nonlinear solvers.
2912: Developer Note:
2913: 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
2914: with the `SNESType` of test that has been removed.
2916: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
2917: @*/
2918: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2919: {
2920: PetscBool flag;
2921: DM dm;
2922: DMSNES sdm;
2923: KSP ksp;
2925: PetscFunctionBegin;
2928: PetscCheckSameComm(snes, 1, X, 2);
2929: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2930: PetscCall(SNESGetDM(snes, &dm));
2931: PetscCall(DMGetDMSNES(dm, &sdm));
2933: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2934: if (snes->lagjacobian == -2) {
2935: snes->lagjacobian = -1;
2937: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2938: } else if (snes->lagjacobian == -1) {
2939: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2940: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2941: if (flag) {
2942: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2943: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2944: }
2945: PetscFunctionReturn(PETSC_SUCCESS);
2946: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2947: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2948: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2949: if (flag) {
2950: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2951: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2952: }
2953: PetscFunctionReturn(PETSC_SUCCESS);
2954: }
2955: if (snes->npc && snes->npcside == PC_LEFT) {
2956: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2957: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2958: PetscFunctionReturn(PETSC_SUCCESS);
2959: }
2961: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2962: PetscCall(VecLockReadPush(X));
2963: {
2964: void *ctx;
2965: SNESJacobianFn *J;
2966: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2967: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2968: }
2969: PetscCall(VecLockReadPop(X));
2970: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
2972: /* attach latest linearization point to the preconditioning matrix */
2973: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
2975: /* the next line ensures that snes->ksp exists */
2976: PetscCall(SNESGetKSP(snes, &ksp));
2977: if (snes->lagpreconditioner == -2) {
2978: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
2979: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2980: snes->lagpreconditioner = -1;
2981: } else if (snes->lagpreconditioner == -1) {
2982: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
2983: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2984: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2985: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
2986: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2987: } else {
2988: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
2989: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2990: }
2992: /* monkey business to allow testing Jacobians in multilevel solvers.
2993: This is needed because the SNESTestXXX interface does not accept vectors and matrices */
2994: {
2995: Vec xsave = snes->vec_sol;
2996: Mat jacobiansave = snes->jacobian;
2997: Mat jacobian_presave = snes->jacobian_pre;
2999: snes->vec_sol = X;
3000: snes->jacobian = A;
3001: snes->jacobian_pre = B;
3002: PetscCall(SNESTestFunction(snes));
3003: PetscCall(SNESTestJacobian(snes));
3005: snes->vec_sol = xsave;
3006: snes->jacobian = jacobiansave;
3007: snes->jacobian_pre = jacobian_presave;
3008: }
3010: {
3011: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
3012: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
3013: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
3014: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
3015: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
3016: if (flag || flag_draw || flag_contour) {
3017: Mat Bexp_mine = NULL, Bexp, FDexp;
3018: PetscViewer vdraw, vstdout;
3019: PetscBool flg;
3020: if (flag_operator) {
3021: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
3022: Bexp = Bexp_mine;
3023: } else {
3024: /* See if the preconditioning matrix can be viewed and added directly */
3025: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPIBAIJ, ""));
3026: if (flg) Bexp = B;
3027: else {
3028: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
3029: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
3030: Bexp = Bexp_mine;
3031: }
3032: }
3033: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
3034: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
3035: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3036: if (flag_draw || flag_contour) {
3037: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3038: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3039: } else vdraw = NULL;
3040: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
3041: if (flag) PetscCall(MatView(Bexp, vstdout));
3042: if (vdraw) PetscCall(MatView(Bexp, vdraw));
3043: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
3044: if (flag) PetscCall(MatView(FDexp, vstdout));
3045: if (vdraw) PetscCall(MatView(FDexp, vdraw));
3046: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
3047: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
3048: if (flag) PetscCall(MatView(FDexp, vstdout));
3049: if (vdraw) { /* Always use contour for the difference */
3050: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3051: PetscCall(MatView(FDexp, vdraw));
3052: PetscCall(PetscViewerPopFormat(vdraw));
3053: }
3054: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3055: PetscCall(PetscViewerDestroy(&vdraw));
3056: PetscCall(MatDestroy(&Bexp_mine));
3057: PetscCall(MatDestroy(&FDexp));
3058: }
3059: }
3060: {
3061: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
3062: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
3063: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
3064: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
3065: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
3066: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
3067: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
3068: if (flag_threshold) {
3069: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
3070: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
3071: }
3072: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
3073: Mat Bfd;
3074: PetscViewer vdraw, vstdout;
3075: MatColoring coloring;
3076: ISColoring iscoloring;
3077: MatFDColoring matfdcoloring;
3078: SNESFunctionFn *func;
3079: void *funcctx;
3080: PetscReal norm1, norm2, normmax;
3082: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
3083: PetscCall(MatColoringCreate(Bfd, &coloring));
3084: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
3085: PetscCall(MatColoringSetFromOptions(coloring));
3086: PetscCall(MatColoringApply(coloring, &iscoloring));
3087: PetscCall(MatColoringDestroy(&coloring));
3088: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
3089: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3090: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
3091: PetscCall(ISColoringDestroy(&iscoloring));
3093: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
3094: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
3095: PetscCall(MatFDColoringSetFunction(matfdcoloring, (PetscErrorCode (*)(void))func, funcctx));
3096: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
3097: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
3098: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3099: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
3100: PetscCall(MatFDColoringDestroy(&matfdcoloring));
3102: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3103: if (flag_draw || flag_contour) {
3104: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3105: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3106: } else vdraw = NULL;
3107: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
3108: if (flag_display) PetscCall(MatView(B, vstdout));
3109: if (vdraw) PetscCall(MatView(B, vdraw));
3110: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
3111: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3112: if (vdraw) PetscCall(MatView(Bfd, vdraw));
3113: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
3114: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
3115: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
3116: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
3117: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
3118: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3119: if (vdraw) { /* Always use contour for the difference */
3120: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3121: PetscCall(MatView(Bfd, vdraw));
3122: PetscCall(PetscViewerPopFormat(vdraw));
3123: }
3124: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3126: if (flag_threshold) {
3127: PetscInt bs, rstart, rend, i;
3128: PetscCall(MatGetBlockSize(B, &bs));
3129: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
3130: for (i = rstart; i < rend; i++) {
3131: const PetscScalar *ba, *ca;
3132: const PetscInt *bj, *cj;
3133: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
3134: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
3135: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
3136: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
3137: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
3138: for (j = 0; j < bn; j++) {
3139: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3140: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
3141: maxentrycol = bj[j];
3142: maxentry = PetscRealPart(ba[j]);
3143: }
3144: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
3145: maxdiffcol = bj[j];
3146: maxdiff = PetscRealPart(ca[j]);
3147: }
3148: if (rdiff > maxrdiff) {
3149: maxrdiffcol = bj[j];
3150: maxrdiff = rdiff;
3151: }
3152: }
3153: if (maxrdiff > 1) {
3154: 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));
3155: for (j = 0; j < bn; j++) {
3156: PetscReal rdiff;
3157: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3158: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
3159: }
3160: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
3161: }
3162: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
3163: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
3164: }
3165: }
3166: PetscCall(PetscViewerDestroy(&vdraw));
3167: PetscCall(MatDestroy(&Bfd));
3168: }
3169: }
3170: PetscFunctionReturn(PETSC_SUCCESS);
3171: }
3173: /*@C
3174: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3175: location to store the matrix.
3177: Logically Collective
3179: Input Parameters:
3180: + snes - the `SNES` context
3181: . Amat - the matrix that defines the (approximate) Jacobian
3182: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3183: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFn` for details
3184: - ctx - [optional] user-defined context for private data for the
3185: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3187: Level: beginner
3189: Notes:
3190: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3191: each matrix.
3193: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3194: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3196: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3197: must be a `MatFDColoring`.
3199: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3200: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3202: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3203: `SNESSetPicard()`, `SNESJacobianFn`, `SNESFunctionFn`
3204: @*/
3205: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
3206: {
3207: DM dm;
3209: PetscFunctionBegin;
3213: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3214: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3215: PetscCall(SNESGetDM(snes, &dm));
3216: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3217: if (Amat) {
3218: PetscCall(PetscObjectReference((PetscObject)Amat));
3219: PetscCall(MatDestroy(&snes->jacobian));
3221: snes->jacobian = Amat;
3222: }
3223: if (Pmat) {
3224: PetscCall(PetscObjectReference((PetscObject)Pmat));
3225: PetscCall(MatDestroy(&snes->jacobian_pre));
3227: snes->jacobian_pre = Pmat;
3228: }
3229: PetscFunctionReturn(PETSC_SUCCESS);
3230: }
3232: /*@C
3233: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3234: provided context for evaluating the Jacobian.
3236: Not Collective, but `Mat` object will be parallel if `SNES` is
3238: Input Parameter:
3239: . snes - the nonlinear solver context
3241: Output Parameters:
3242: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3243: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3244: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFn`
3245: - ctx - location to stash Jacobian ctx (or `NULL`)
3247: Level: advanced
3249: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFn`, `SNESGetFunction()`
3250: @*/
3251: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
3252: {
3253: DM dm;
3255: PetscFunctionBegin;
3257: if (Amat) *Amat = snes->jacobian;
3258: if (Pmat) *Pmat = snes->jacobian_pre;
3259: PetscCall(SNESGetDM(snes, &dm));
3260: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3261: PetscFunctionReturn(PETSC_SUCCESS);
3262: }
3264: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3265: {
3266: DM dm;
3267: DMSNES sdm;
3269: PetscFunctionBegin;
3270: PetscCall(SNESGetDM(snes, &dm));
3271: PetscCall(DMGetDMSNES(dm, &sdm));
3272: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3273: DM dm;
3274: PetscBool isdense, ismf;
3276: PetscCall(SNESGetDM(snes, &dm));
3277: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3278: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3279: if (isdense) {
3280: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3281: } else if (!ismf) {
3282: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3283: }
3284: }
3285: PetscFunctionReturn(PETSC_SUCCESS);
3286: }
3288: /*@
3289: SNESSetUp - Sets up the internal data structures for the later use
3290: of a nonlinear solver `SNESSolve()`.
3292: Collective
3294: Input Parameter:
3295: . snes - the `SNES` context
3297: Level: advanced
3299: Note:
3300: For basic use of the `SNES` solvers the user does not need to explicitly call
3301: `SNESSetUp()`, since these actions will automatically occur during
3302: the call to `SNESSolve()`. However, if one wishes to control this
3303: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3304: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3306: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`, `SNESSetFromOptions()`
3307: @*/
3308: PetscErrorCode SNESSetUp(SNES snes)
3309: {
3310: DM dm;
3311: DMSNES sdm;
3312: SNESLineSearch linesearch, pclinesearch;
3313: void *lsprectx, *lspostctx;
3314: PetscBool mf_operator, mf;
3315: Vec f, fpc;
3316: void *funcctx;
3317: void *jacctx, *appctx;
3318: Mat j, jpre;
3319: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3320: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3321: SNESFunctionFn *func;
3322: SNESJacobianFn *jac;
3324: PetscFunctionBegin;
3326: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3327: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3329: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3331: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3333: PetscCall(SNESGetDM(snes, &dm));
3334: PetscCall(DMGetDMSNES(dm, &sdm));
3335: PetscCall(SNESSetDefaultComputeJacobian(snes));
3337: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3339: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3341: if (snes->linesearch) {
3342: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3343: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3344: }
3346: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3347: if (snes->npc && snes->npcside == PC_LEFT) {
3348: snes->mf = PETSC_TRUE;
3349: snes->mf_operator = PETSC_FALSE;
3350: }
3352: if (snes->npc) {
3353: /* copy the DM over */
3354: PetscCall(SNESGetDM(snes, &dm));
3355: PetscCall(SNESSetDM(snes->npc, dm));
3357: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3358: PetscCall(VecDuplicate(f, &fpc));
3359: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3360: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3361: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3362: PetscCall(SNESGetApplicationContext(snes, &appctx));
3363: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3364: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3365: PetscCall(VecDestroy(&fpc));
3367: /* copy the function pointers over */
3368: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3370: /* default to 1 iteration */
3371: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3372: if (snes->npcside == PC_RIGHT) {
3373: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3374: } else {
3375: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3376: }
3377: PetscCall(SNESSetFromOptions(snes->npc));
3379: /* copy the line search context over */
3380: if (snes->linesearch && snes->npc->linesearch) {
3381: PetscCall(SNESGetLineSearch(snes, &linesearch));
3382: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3383: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3384: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3385: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3386: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3387: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3388: }
3389: }
3390: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3391: if (snes->ops->usercompute && !snes->user) PetscCallBack("SNES callback compute application context", (*snes->ops->usercompute)(snes, (void **)&snes->user));
3393: snes->jac_iter = 0;
3394: snes->pre_iter = 0;
3396: PetscTryTypeMethod(snes, setup);
3398: PetscCall(SNESSetDefaultComputeJacobian(snes));
3400: if (snes->npc && snes->npcside == PC_LEFT) {
3401: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3402: if (snes->linesearch) {
3403: PetscCall(SNESGetLineSearch(snes, &linesearch));
3404: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3405: }
3406: }
3407: }
3408: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3409: snes->setupcalled = PETSC_TRUE;
3410: PetscFunctionReturn(PETSC_SUCCESS);
3411: }
3413: /*@
3414: SNESReset - Resets a `SNES` context to the state it was in before `SNESSetUp()` was called and removes any allocated `Vec` and `Mat` from its data structures
3416: Collective
3418: Input Parameter:
3419: . snes - the nonlinear iterative solver context obtained from `SNESCreate()`
3421: Level: intermediate
3423: Notes:
3424: Any options set on the `SNES` object, including those set with `SNESSetFromOptions()` remain.
3426: Call this if you wish to reuse a `SNES` but with different size vectors
3428: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3430: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3431: @*/
3432: PetscErrorCode SNESReset(SNES snes)
3433: {
3434: PetscFunctionBegin;
3436: if (snes->ops->userdestroy && snes->user) {
3437: PetscCallBack("SNES callback destroy application context", (*snes->ops->userdestroy)((void **)&snes->user));
3438: snes->user = NULL;
3439: }
3440: if (snes->npc) PetscCall(SNESReset(snes->npc));
3442: PetscTryTypeMethod(snes, reset);
3443: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3445: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3447: PetscCall(VecDestroy(&snes->vec_rhs));
3448: PetscCall(VecDestroy(&snes->vec_sol));
3449: PetscCall(VecDestroy(&snes->vec_sol_update));
3450: PetscCall(VecDestroy(&snes->vec_func));
3451: PetscCall(MatDestroy(&snes->jacobian));
3452: PetscCall(MatDestroy(&snes->jacobian_pre));
3453: PetscCall(MatDestroy(&snes->picard));
3454: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3455: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3457: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3459: snes->nwork = snes->nvwork = 0;
3460: snes->setupcalled = PETSC_FALSE;
3461: PetscFunctionReturn(PETSC_SUCCESS);
3462: }
3464: /*@
3465: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()` also
3466: removes the default viewer.
3468: Collective
3470: Input Parameter:
3471: . snes - the nonlinear iterative solver context obtained from `SNESCreate()`
3473: Level: intermediate
3475: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3476: @*/
3477: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3478: {
3479: PetscInt i;
3481: PetscFunctionBegin;
3483: for (i = 0; i < snes->numberreasonviews; i++) {
3484: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3485: }
3486: snes->numberreasonviews = 0;
3487: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
3488: PetscFunctionReturn(PETSC_SUCCESS);
3489: }
3491: /*@
3492: SNESDestroy - Destroys the nonlinear solver context that was created
3493: with `SNESCreate()`.
3495: Collective
3497: Input Parameter:
3498: . snes - the `SNES` context
3500: Level: beginner
3502: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3503: @*/
3504: PetscErrorCode SNESDestroy(SNES *snes)
3505: {
3506: PetscFunctionBegin;
3507: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3509: if (--((PetscObject)*snes)->refct > 0) {
3510: *snes = NULL;
3511: PetscFunctionReturn(PETSC_SUCCESS);
3512: }
3514: PetscCall(SNESReset(*snes));
3515: PetscCall(SNESDestroy(&(*snes)->npc));
3517: /* if memory was published with SAWs then destroy it */
3518: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3519: PetscTryTypeMethod(*snes, destroy);
3521: if ((*snes)->dm) PetscCall(DMCoarsenHookRemove((*snes)->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3522: PetscCall(DMDestroy(&(*snes)->dm));
3523: PetscCall(KSPDestroy(&(*snes)->ksp));
3524: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3526: PetscCall(PetscFree((*snes)->kspconvctx));
3527: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)((*snes)->cnvP));
3528: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3529: PetscCall(SNESMonitorCancel(*snes));
3530: PetscCall(SNESConvergedReasonViewCancel(*snes));
3531: PetscCall(PetscHeaderDestroy(snes));
3532: PetscFunctionReturn(PETSC_SUCCESS);
3533: }
3535: /* ----------- Routines to set solver parameters ---------- */
3537: /*@
3538: SNESSetLagPreconditioner - Sets when the preconditioner is rebuilt in the nonlinear solve `SNESSolve()`.
3540: Logically Collective
3542: Input Parameters:
3543: + snes - the `SNES` context
3544: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3545: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3547: Options Database Keys:
3548: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3549: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3550: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3551: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3553: Level: intermediate
3555: Notes:
3556: The default is 1
3558: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3560: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3562: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3563: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3564: @*/
3565: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3566: {
3567: PetscFunctionBegin;
3569: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3570: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3572: snes->lagpreconditioner = lag;
3573: PetscFunctionReturn(PETSC_SUCCESS);
3574: }
3576: /*@
3577: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3579: Logically Collective
3581: Input Parameters:
3582: + snes - the `SNES` context
3583: - steps - the number of refinements to do, defaults to 0
3585: Options Database Key:
3586: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3588: Level: intermediate
3590: Notes:
3591: Once grid sequencing is turned on `SNESSolve()` will automatically perform the solve on each grid refinement.
3593: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3595: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3596: `SNESetDM()`, `SNESSolve()`
3597: @*/
3598: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3599: {
3600: PetscFunctionBegin;
3603: snes->gridsequence = steps;
3604: PetscFunctionReturn(PETSC_SUCCESS);
3605: }
3607: /*@
3608: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3610: Logically Collective
3612: Input Parameter:
3613: . snes - the `SNES` context
3615: Output Parameter:
3616: . steps - the number of refinements to do, defaults to 0
3618: Level: intermediate
3620: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3621: @*/
3622: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3623: {
3624: PetscFunctionBegin;
3626: *steps = snes->gridsequence;
3627: PetscFunctionReturn(PETSC_SUCCESS);
3628: }
3630: /*@
3631: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3633: Not Collective
3635: Input Parameter:
3636: . snes - the `SNES` context
3638: Output Parameter:
3639: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3640: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3642: Level: intermediate
3644: Notes:
3645: The default is 1
3647: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3649: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3650: @*/
3651: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3652: {
3653: PetscFunctionBegin;
3655: *lag = snes->lagpreconditioner;
3656: PetscFunctionReturn(PETSC_SUCCESS);
3657: }
3659: /*@
3660: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3661: often the preconditioner is rebuilt.
3663: Logically Collective
3665: Input Parameters:
3666: + snes - the `SNES` context
3667: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3668: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3670: Options Database Keys:
3671: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3672: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3673: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3674: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3676: Level: intermediate
3678: Notes:
3679: The default is 1
3681: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3683: 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
3684: at the next Newton step but never again (unless it is reset to another value)
3686: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3687: @*/
3688: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3689: {
3690: PetscFunctionBegin;
3692: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3693: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3695: snes->lagjacobian = lag;
3696: PetscFunctionReturn(PETSC_SUCCESS);
3697: }
3699: /*@
3700: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3702: Not Collective
3704: Input Parameter:
3705: . snes - the `SNES` context
3707: Output Parameter:
3708: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3709: the Jacobian is built etc.
3711: Level: intermediate
3713: Notes:
3714: The default is 1
3716: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3718: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3720: @*/
3721: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3722: {
3723: PetscFunctionBegin;
3725: *lag = snes->lagjacobian;
3726: PetscFunctionReturn(PETSC_SUCCESS);
3727: }
3729: /*@
3730: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3732: Logically collective
3734: Input Parameters:
3735: + snes - the `SNES` context
3736: - flg - jacobian lagging persists if true
3738: Options Database Keys:
3739: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3740: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3741: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3742: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3744: Level: advanced
3746: Notes:
3747: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3749: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3750: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3751: timesteps may present huge efficiency gains.
3753: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3754: @*/
3755: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3756: {
3757: PetscFunctionBegin;
3760: snes->lagjac_persist = flg;
3761: PetscFunctionReturn(PETSC_SUCCESS);
3762: }
3764: /*@
3765: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3767: Logically Collective
3769: Input Parameters:
3770: + snes - the `SNES` context
3771: - flg - preconditioner lagging persists if true
3773: Options Database Keys:
3774: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3775: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3776: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3777: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3779: Level: developer
3781: Notes:
3782: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3784: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3785: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3786: several timesteps may present huge efficiency gains.
3788: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3789: @*/
3790: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3791: {
3792: PetscFunctionBegin;
3795: snes->lagpre_persist = flg;
3796: PetscFunctionReturn(PETSC_SUCCESS);
3797: }
3799: /*@
3800: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3802: Logically Collective
3804: Input Parameters:
3805: + snes - the `SNES` context
3806: - force - `PETSC_TRUE` require at least one iteration
3808: Options Database Key:
3809: . -snes_force_iteration <force> - Sets forcing an iteration
3811: Level: intermediate
3813: Note:
3814: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3816: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetDivergenceTolerance()`
3817: @*/
3818: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3819: {
3820: PetscFunctionBegin;
3822: snes->forceiteration = force;
3823: PetscFunctionReturn(PETSC_SUCCESS);
3824: }
3826: /*@
3827: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3829: Logically Collective
3831: Input Parameter:
3832: . snes - the `SNES` context
3834: Output Parameter:
3835: . force - `PETSC_TRUE` requires at least one iteration.
3837: Level: intermediate
3839: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetDivergenceTolerance()`
3840: @*/
3841: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3842: {
3843: PetscFunctionBegin;
3845: *force = snes->forceiteration;
3846: PetscFunctionReturn(PETSC_SUCCESS);
3847: }
3849: /*@
3850: SNESSetTolerances - Sets various parameters used in `SNES` convergence tests.
3852: Logically Collective
3854: Input Parameters:
3855: + snes - the `SNES` context
3856: . abstol - the absolute convergence tolerance, $ F(x^n) \le abstol $
3857: . rtol - the relative convergence tolerance, $ F(x^n) \le reltol * F(x^0) $
3858: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3859: . maxit - the maximum number of iterations allowed in the solver, default 50.
3860: - maxf - the maximum number of function evaluations allowed in the solver (use `PETSC_UNLIMITED` indicates no limit), default 10,000
3862: Options Database Keys:
3863: + -snes_atol <abstol> - Sets `abstol`
3864: . -snes_rtol <rtol> - Sets `rtol`
3865: . -snes_stol <stol> - Sets `stol`
3866: . -snes_max_it <maxit> - Sets `maxit`
3867: - -snes_max_funcs <maxf> - Sets `maxf` (use `unlimited` to have no maximum)
3869: Level: intermediate
3871: Note:
3872: All parameters must be non-negative
3874: Use `PETSC_CURRENT` to retain the current value of any parameter and `PETSC_DETERMINE` to use the default value for the given `SNES`.
3875: The default value is the value in the object when its type is set.
3877: Use `PETSC_UNLIMITED` on `maxit` or `maxf` to indicate there is no bound on the number of iterations or number of function evaluations.
3879: Fortran Note:
3880: Use `PETSC_CURRENT_INTEGER`, `PETSC_CURRENT_REAL`, `PETSC_UNLIMITED_INTEGER`, `PETSC_DETERMINE_INTEGER`, or `PETSC_DETERMINE_REAL`
3882: .seealso: [](ch_snes), `SNESSolve()`, `SNES`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3883: @*/
3884: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3885: {
3886: PetscFunctionBegin;
3894: if (abstol == (PetscReal)PETSC_DETERMINE) {
3895: snes->abstol = snes->default_abstol;
3896: } else if (abstol != (PetscReal)PETSC_CURRENT) {
3897: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3898: snes->abstol = abstol;
3899: }
3901: if (rtol == (PetscReal)PETSC_DETERMINE) {
3902: snes->rtol = snes->default_rtol;
3903: } else if (rtol != (PetscReal)PETSC_CURRENT) {
3904: 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);
3905: snes->rtol = rtol;
3906: }
3908: if (stol == (PetscReal)PETSC_DETERMINE) {
3909: snes->stol = snes->default_stol;
3910: } else if (stol != (PetscReal)PETSC_CURRENT) {
3911: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3912: snes->stol = stol;
3913: }
3915: if (maxit == (PetscInt)PETSC_DETERMINE) {
3916: snes->max_its = snes->default_max_its;
3917: } else if (maxit == (PetscInt)PETSC_UNLIMITED) {
3918: snes->max_its = PETSC_INT_MAX;
3919: } else if (maxit != PETSC_CURRENT) {
3920: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3921: snes->max_its = maxit;
3922: }
3924: if (maxf == (PetscInt)PETSC_DETERMINE) {
3925: snes->max_funcs = snes->default_max_funcs;
3926: } else if (maxf == (PetscInt)PETSC_UNLIMITED || maxf == -1) {
3927: snes->max_funcs = PETSC_UNLIMITED;
3928: } else if (maxf != PETSC_CURRENT) {
3929: PetscCheck(maxf >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be nonnegative", maxf);
3930: snes->max_funcs = maxf;
3931: }
3932: PetscFunctionReturn(PETSC_SUCCESS);
3933: }
3935: /*@
3936: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3938: Logically Collective
3940: Input Parameters:
3941: + snes - the `SNES` context
3942: - divtol - the divergence tolerance. Use `PETSC_UNLIMITED` to deactivate the test. If the residual norm $ F(x^n) \ge divtol * F(x^0) $ the solver
3943: is stopped due to divergence.
3945: Options Database Key:
3946: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3948: Level: intermediate
3950: Notes:
3951: Use `PETSC_DETERMINE` to use the default value from when the object's type was set.
3953: Fortran Note:
3954: Use ``PETSC_DETERMINE_REAL` or `PETSC_UNLIMITED_REAL`
3956: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance()`
3957: @*/
3958: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3959: {
3960: PetscFunctionBegin;
3964: if (divtol == (PetscReal)PETSC_DETERMINE) {
3965: snes->divtol = snes->default_divtol;
3966: } else if (divtol == (PetscReal)PETSC_UNLIMITED || divtol == -1) {
3967: snes->divtol = PETSC_UNLIMITED;
3968: } else if (divtol != (PetscReal)PETSC_CURRENT) {
3969: PetscCheck(divtol >= 1.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Divergence tolerance %g must be greater than 1.0", (double)divtol);
3970: snes->divtol = divtol;
3971: }
3972: PetscFunctionReturn(PETSC_SUCCESS);
3973: }
3975: /*@
3976: SNESGetTolerances - Gets various parameters used in `SNES` convergence tests.
3978: Not Collective
3980: Input Parameter:
3981: . snes - the `SNES` context
3983: Output Parameters:
3984: + atol - the absolute convergence tolerance
3985: . rtol - the relative convergence tolerance
3986: . stol - convergence tolerance in terms of the norm of the change in the solution between steps
3987: . maxit - the maximum number of iterations allowed
3988: - maxf - the maximum number of function evaluations allowed, `PETSC_UNLIMITED` indicates no bound
3990: Level: intermediate
3992: Notes:
3993: See `SNESSetTolerances()` for details on the parameters.
3995: The user can specify `NULL` for any parameter that is not needed.
3997: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
3998: @*/
3999: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
4000: {
4001: PetscFunctionBegin;
4003: if (atol) *atol = snes->abstol;
4004: if (rtol) *rtol = snes->rtol;
4005: if (stol) *stol = snes->stol;
4006: if (maxit) *maxit = snes->max_its;
4007: if (maxf) *maxf = snes->max_funcs;
4008: PetscFunctionReturn(PETSC_SUCCESS);
4009: }
4011: /*@
4012: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
4014: Not Collective
4016: Input Parameters:
4017: + snes - the `SNES` context
4018: - divtol - divergence tolerance
4020: Level: intermediate
4022: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
4023: @*/
4024: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
4025: {
4026: PetscFunctionBegin;
4028: if (divtol) *divtol = snes->divtol;
4029: PetscFunctionReturn(PETSC_SUCCESS);
4030: }
4032: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
4034: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
4035: {
4036: PetscDrawLG lg;
4037: PetscReal x, y, per;
4038: PetscViewer v = (PetscViewer)monctx;
4039: static PetscReal prev; /* should be in the context */
4040: PetscDraw draw;
4042: PetscFunctionBegin;
4044: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
4045: if (!n) PetscCall(PetscDrawLGReset(lg));
4046: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4047: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
4048: x = (PetscReal)n;
4049: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
4050: else y = -15.0;
4051: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4052: if (n < 20 || !(n % 5) || snes->reason) {
4053: PetscCall(PetscDrawLGDraw(lg));
4054: PetscCall(PetscDrawLGSave(lg));
4055: }
4057: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
4058: if (!n) PetscCall(PetscDrawLGReset(lg));
4059: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4060: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
4061: PetscCall(SNESMonitorRange_Private(snes, n, &per));
4062: x = (PetscReal)n;
4063: y = 100.0 * per;
4064: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4065: if (n < 20 || !(n % 5) || snes->reason) {
4066: PetscCall(PetscDrawLGDraw(lg));
4067: PetscCall(PetscDrawLGSave(lg));
4068: }
4070: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
4071: if (!n) {
4072: prev = rnorm;
4073: PetscCall(PetscDrawLGReset(lg));
4074: }
4075: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4076: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
4077: x = (PetscReal)n;
4078: y = (prev - rnorm) / prev;
4079: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4080: if (n < 20 || !(n % 5) || snes->reason) {
4081: PetscCall(PetscDrawLGDraw(lg));
4082: PetscCall(PetscDrawLGSave(lg));
4083: }
4085: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
4086: if (!n) PetscCall(PetscDrawLGReset(lg));
4087: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4088: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
4089: x = (PetscReal)n;
4090: y = (prev - rnorm) / (prev * per);
4091: if (n > 2) { /*skip initial crazy value */
4092: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4093: }
4094: if (n < 20 || !(n % 5) || snes->reason) {
4095: PetscCall(PetscDrawLGDraw(lg));
4096: PetscCall(PetscDrawLGSave(lg));
4097: }
4098: prev = rnorm;
4099: PetscFunctionReturn(PETSC_SUCCESS);
4100: }
4102: /*@
4103: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
4105: Collective
4107: Input Parameters:
4108: + snes - the `SNES` context
4109: . it - current iteration
4110: . xnorm - 2-norm of current iterate
4111: . snorm - 2-norm of current step
4112: - fnorm - 2-norm of function
4114: Level: developer
4116: Note:
4117: This routine is called by the `SNESSolve()` implementations.
4118: It does not typically need to be called by the user.
4120: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4121: @*/
4122: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
4123: {
4124: PetscFunctionBegin;
4125: if (!snes->reason) {
4126: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
4127: if (it == snes->max_its && !snes->reason) {
4128: if (snes->normschedule == SNES_NORM_ALWAYS) {
4129: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
4130: snes->reason = SNES_DIVERGED_MAX_IT;
4131: } else snes->reason = SNES_CONVERGED_ITS;
4132: }
4133: }
4134: PetscFunctionReturn(PETSC_SUCCESS);
4135: }
4137: /*@
4138: SNESMonitor - runs any `SNES` monitor routines provided with `SNESMonitor()` or the options database
4140: Collective
4142: Input Parameters:
4143: + snes - nonlinear solver context obtained from `SNESCreate()`
4144: . iter - current iteration number
4145: - rnorm - current relative norm of the residual
4147: Level: developer
4149: Note:
4150: This routine is called by the `SNESSolve()` implementations.
4151: It does not typically need to be called by the user.
4153: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
4154: @*/
4155: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
4156: {
4157: PetscInt i, n = snes->numbermonitors;
4159: PetscFunctionBegin;
4160: if (n > 0) SNESCheckFunctionNorm(snes, rnorm);
4161: PetscCall(VecLockReadPush(snes->vec_sol));
4162: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
4163: PetscCall(VecLockReadPop(snes->vec_sol));
4164: PetscFunctionReturn(PETSC_SUCCESS);
4165: }
4167: /* ------------ Routines to set performance monitoring options ----------- */
4169: /*MC
4170: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
4172: Synopsis:
4173: #include <petscsnes.h>
4174: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, void *mctx)
4176: Collective
4178: Input Parameters:
4179: + snes - the `SNES` context
4180: . its - iteration number
4181: . norm - 2-norm function value (may be estimated)
4182: - mctx - [optional] monitoring context
4184: Level: advanced
4186: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSet()`, `SNESMonitorGet()`
4187: M*/
4189: /*@C
4190: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
4191: iteration of the `SNES` nonlinear solver to display the iteration's
4192: progress.
4194: Logically Collective
4196: Input Parameters:
4197: + snes - the `SNES` context
4198: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4199: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4200: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`)
4202: Options Database Keys:
4203: + -snes_monitor - sets `SNESMonitorDefault()`
4204: . -snes_monitor draw::draw_lg - sets line graph monitor,
4205: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4206: the options database.
4208: Level: intermediate
4210: Note:
4211: Several different monitoring routines may be set by calling
4212: `SNESMonitorSet()` multiple times; all will be called in the
4213: order in which they were set.
4215: Fortran Note:
4216: Only a single monitor function can be set for each `SNES` object
4218: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`
4219: @*/
4220: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscErrorCode (*monitordestroy)(void **))
4221: {
4222: PetscInt i;
4223: PetscBool identical;
4225: PetscFunctionBegin;
4227: for (i = 0; i < snes->numbermonitors; i++) {
4228: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))f, mctx, monitordestroy, (PetscErrorCode (*)(void))snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4229: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4230: }
4231: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4232: snes->monitor[snes->numbermonitors] = f;
4233: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4234: snes->monitorcontext[snes->numbermonitors++] = (void *)mctx;
4235: PetscFunctionReturn(PETSC_SUCCESS);
4236: }
4238: /*@
4239: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4241: Logically Collective
4243: Input Parameter:
4244: . snes - the `SNES` context
4246: Options Database Key:
4247: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4248: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4249: set via the options database
4251: Level: intermediate
4253: Note:
4254: There is no way to clear one specific monitor from a `SNES` object.
4256: .seealso: [](ch_snes), `SNES`, `SNESMonitorGet()`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4257: @*/
4258: PetscErrorCode SNESMonitorCancel(SNES snes)
4259: {
4260: PetscInt i;
4262: PetscFunctionBegin;
4264: for (i = 0; i < snes->numbermonitors; i++) {
4265: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4266: }
4267: snes->numbermonitors = 0;
4268: PetscFunctionReturn(PETSC_SUCCESS);
4269: }
4271: /*MC
4272: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4274: Synopsis:
4275: #include <petscsnes.h>
4276: PetscErrorCode SNESConvergenceTest(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *cctx)
4278: Collective
4280: Input Parameters:
4281: + snes - the `SNES` context
4282: . it - current iteration (0 is the first and is before any Newton step)
4283: . xnorm - 2-norm of current iterate
4284: . gnorm - 2-norm of current step
4285: . f - 2-norm of function
4286: - cctx - [optional] convergence context
4288: Output Parameter:
4289: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4291: Level: intermediate
4293: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4294: M*/
4296: /*@C
4297: SNESSetConvergenceTest - Sets the function that is to be used
4298: to test for convergence of the nonlinear iterative solution.
4300: Logically Collective
4302: Input Parameters:
4303: + snes - the `SNES` context
4304: . SNESConvergenceTestFunction - routine to test for convergence
4305: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4306: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4308: Level: advanced
4310: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4311: @*/
4312: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscErrorCode (*destroy)(void *))
4313: {
4314: PetscFunctionBegin;
4316: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4317: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(snes->cnvP));
4318: snes->ops->converged = SNESConvergenceTestFunction;
4319: snes->ops->convergeddestroy = destroy;
4320: snes->cnvP = cctx;
4321: PetscFunctionReturn(PETSC_SUCCESS);
4322: }
4324: /*@
4325: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped, which may be due to convergence, divergence, or stagnation
4327: Not Collective
4329: Input Parameter:
4330: . snes - the `SNES` context
4332: Output Parameter:
4333: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4335: Options Database Key:
4336: . -snes_converged_reason - prints the reason to standard out
4338: Level: intermediate
4340: Note:
4341: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4343: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4344: @*/
4345: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4346: {
4347: PetscFunctionBegin;
4349: PetscAssertPointer(reason, 2);
4350: *reason = snes->reason;
4351: PetscFunctionReturn(PETSC_SUCCESS);
4352: }
4354: /*@C
4355: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4357: Not Collective
4359: Input Parameter:
4360: . snes - the `SNES` context
4362: Output Parameter:
4363: . strreason - a human readable string that describes `SNES` converged reason
4365: Level: beginner
4367: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4368: @*/
4369: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4370: {
4371: PetscFunctionBegin;
4373: PetscAssertPointer(strreason, 2);
4374: *strreason = SNESConvergedReasons[snes->reason];
4375: PetscFunctionReturn(PETSC_SUCCESS);
4376: }
4378: /*@
4379: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4381: Not Collective
4383: Input Parameters:
4384: + snes - the `SNES` context
4385: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4386: manual pages for the individual convergence tests for complete lists
4388: Level: developer
4390: Developer Note:
4391: Called inside the various `SNESSolve()` implementations
4393: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4394: @*/
4395: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4396: {
4397: PetscFunctionBegin;
4399: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4400: snes->reason = reason;
4401: PetscFunctionReturn(PETSC_SUCCESS);
4402: }
4404: /*@
4405: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4407: Logically Collective
4409: Input Parameters:
4410: + snes - iterative context obtained from `SNESCreate()`
4411: . a - array to hold history, this array will contain the function norms computed at each step
4412: . its - integer array holds the number of linear iterations for each solve.
4413: . na - size of `a` and `its`
4414: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4415: else it continues storing new values for new nonlinear solves after the old ones
4417: Level: intermediate
4419: Notes:
4420: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' is `PETSC_DECIDE` then a
4421: default array of length 1,000 is allocated.
4423: This routine is useful, e.g., when running a code for purposes
4424: of accurate performance monitoring, when no I/O should be done
4425: during the section of code that is being timed.
4427: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4429: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4430: @*/
4431: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4432: {
4433: PetscFunctionBegin;
4435: if (a) PetscAssertPointer(a, 2);
4436: if (its) PetscAssertPointer(its, 3);
4437: if (!a) {
4438: if (na == PETSC_DECIDE) na = 1000;
4439: PetscCall(PetscCalloc2(na, &a, na, &its));
4440: snes->conv_hist_alloc = PETSC_TRUE;
4441: }
4442: snes->conv_hist = a;
4443: snes->conv_hist_its = its;
4444: snes->conv_hist_max = (size_t)na;
4445: snes->conv_hist_len = 0;
4446: snes->conv_hist_reset = reset;
4447: PetscFunctionReturn(PETSC_SUCCESS);
4448: }
4450: #if defined(PETSC_HAVE_MATLAB)
4451: #include <engine.h> /* MATLAB include file */
4452: #include <mex.h> /* MATLAB include file */
4454: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4455: {
4456: mxArray *mat;
4457: PetscInt i;
4458: PetscReal *ar;
4460: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4461: ar = (PetscReal *)mxGetData(mat);
4462: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4463: return mat;
4464: }
4465: #endif
4467: /*@C
4468: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4470: Not Collective
4472: Input Parameter:
4473: . snes - iterative context obtained from `SNESCreate()`
4475: Output Parameters:
4476: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4477: . its - integer array holds the number of linear iterations (or
4478: negative if not converged) for each solve.
4479: - na - size of `a` and `its`
4481: Level: intermediate
4483: Note:
4484: This routine is useful, e.g., when running a code for purposes
4485: of accurate performance monitoring, when no I/O should be done
4486: during the section of code that is being timed.
4488: Fortran Note:
4489: The calling sequence for this routine in Fortran is
4490: .vb
4491: call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4492: .ve
4494: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4495: @*/
4496: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4497: {
4498: PetscFunctionBegin;
4500: if (a) *a = snes->conv_hist;
4501: if (its) *its = snes->conv_hist_its;
4502: if (na) *na = (PetscInt)snes->conv_hist_len;
4503: PetscFunctionReturn(PETSC_SUCCESS);
4504: }
4506: /*@C
4507: SNESSetUpdate - Sets the general-purpose update function called
4508: at the beginning of every iteration of the nonlinear solve. Specifically
4509: it is called just before the Jacobian is "evaluated" and after the function
4510: evaluation.
4512: Logically Collective
4514: Input Parameters:
4515: + snes - The nonlinear solver context
4516: - func - The update function; for calling sequence see `SNESUpdateFn`
4518: Level: advanced
4520: Notes:
4521: 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
4522: to `SNESSetFunction()`, or `SNESSetPicard()`
4523: This is not used by most users, and it is intended to provide a general hook that is run
4524: right before the direction step is computed.
4525: Users are free to modify the current residual vector,
4526: the current linearization point, or any other vector associated to the specific solver used.
4527: If such modifications take place, it is the user responsibility to update all the relevant
4528: vectors.
4530: 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.
4532: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4533: `SNESMonitorSet()`
4534: @*/
4535: PetscErrorCode SNESSetUpdate(SNES snes, SNESUpdateFn *func)
4536: {
4537: PetscFunctionBegin;
4539: snes->ops->update = func;
4540: PetscFunctionReturn(PETSC_SUCCESS);
4541: }
4543: /*@
4544: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4546: Collective
4548: Input Parameters:
4549: + snes - iterative context obtained from `SNESCreate()`
4550: - viewer - the viewer to display the reason
4552: Options Database Keys:
4553: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4554: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4556: Level: beginner
4558: Note:
4559: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4560: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4562: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4563: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4564: `SNESConvergedReasonViewFromOptions()`,
4565: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4566: @*/
4567: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4568: {
4569: PetscViewerFormat format;
4570: PetscBool isAscii;
4572: PetscFunctionBegin;
4573: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4574: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4575: if (isAscii) {
4576: PetscCall(PetscViewerGetFormat(viewer, &format));
4577: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel + 1));
4578: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4579: DM dm;
4580: Vec u;
4581: PetscDS prob;
4582: PetscInt Nf, f;
4583: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4584: void **exactCtx;
4585: PetscReal error;
4587: PetscCall(SNESGetDM(snes, &dm));
4588: PetscCall(SNESGetSolution(snes, &u));
4589: PetscCall(DMGetDS(dm, &prob));
4590: PetscCall(PetscDSGetNumFields(prob, &Nf));
4591: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4592: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4593: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4594: PetscCall(PetscFree2(exactSol, exactCtx));
4595: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4596: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4597: }
4598: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4599: if (((PetscObject)snes)->prefix) {
4600: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4601: } else {
4602: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4603: }
4604: } else if (snes->reason <= 0) {
4605: if (((PetscObject)snes)->prefix) {
4606: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4607: } else {
4608: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4609: }
4610: }
4611: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel + 1));
4612: }
4613: PetscFunctionReturn(PETSC_SUCCESS);
4614: }
4616: /*@C
4617: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4618: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4620: Logically Collective
4622: Input Parameters:
4623: + snes - the `SNES` context
4624: . f - the `SNESConvergedReason` view function
4625: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4626: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`)
4628: Calling sequence of `f`:
4629: + snes - the `SNES` context
4630: - vctx - [optional] user-defined context for private data for the function
4632: Calling sequence of `reasonviewerdestroy`:
4633: . vctx - [optional] user-defined context for private data for the function
4635: Options Database Keys:
4636: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4637: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4638: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4640: Level: intermediate
4642: Note:
4643: Several different converged reason view routines may be set by calling
4644: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4645: order in which they were set.
4647: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`
4648: @*/
4649: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, void *vctx), void *vctx, PetscErrorCode (*reasonviewdestroy)(void **vctx))
4650: {
4651: PetscInt i;
4652: PetscBool identical;
4654: PetscFunctionBegin;
4656: for (i = 0; i < snes->numberreasonviews; i++) {
4657: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))f, vctx, reasonviewdestroy, (PetscErrorCode (*)(void))snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4658: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4659: }
4660: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4661: snes->reasonview[snes->numberreasonviews] = f;
4662: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4663: snes->reasonviewcontext[snes->numberreasonviews++] = (void *)vctx;
4664: PetscFunctionReturn(PETSC_SUCCESS);
4665: }
4667: /*@
4668: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4669: All the user-provided viewer routines set with `SNESConvergedReasonViewSet()` will be called, if they exist.
4671: Collective
4673: Input Parameter:
4674: . snes - the `SNES` object
4676: Level: advanced
4678: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4679: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4680: @*/
4681: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4682: {
4683: static PetscBool incall = PETSC_FALSE;
4685: PetscFunctionBegin;
4686: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4687: incall = PETSC_TRUE;
4689: /* All user-provided viewers are called first, if they exist. */
4690: for (PetscInt i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4692: /* Call PETSc default routine if users ask for it */
4693: if (snes->convergedreasonviewer) {
4694: PetscCall(PetscViewerPushFormat(snes->convergedreasonviewer, snes->convergedreasonformat));
4695: PetscCall(SNESConvergedReasonView(snes, snes->convergedreasonviewer));
4696: PetscCall(PetscViewerPopFormat(snes->convergedreasonviewer));
4697: }
4698: incall = PETSC_FALSE;
4699: PetscFunctionReturn(PETSC_SUCCESS);
4700: }
4702: /*@
4703: SNESSolve - Solves a nonlinear system $F(x) = b $ associated with a `SNES` object
4705: Collective
4707: Input Parameters:
4708: + snes - the `SNES` context
4709: . b - the constant part of the equation $F(x) = b$, or `NULL` to use zero.
4710: - x - the solution vector.
4712: Level: beginner
4714: Note:
4715: The user should initialize the vector, `x`, with the initial guess
4716: for the nonlinear solve prior to calling `SNESSolve()` .
4718: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4719: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4720: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`
4721: @*/
4722: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4723: {
4724: PetscBool flg;
4725: PetscInt grid;
4726: Vec xcreated = NULL;
4727: DM dm;
4729: PetscFunctionBegin;
4732: if (x) PetscCheckSameComm(snes, 1, x, 3);
4734: if (b) PetscCheckSameComm(snes, 1, b, 2);
4736: /* High level operations using the nonlinear solver */
4737: {
4738: PetscViewer viewer;
4739: PetscViewerFormat format;
4740: PetscInt num;
4741: PetscBool flg;
4742: static PetscBool incall = PETSC_FALSE;
4744: if (!incall) {
4745: /* Estimate the convergence rate of the discretization */
4746: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4747: if (flg) {
4748: PetscConvEst conv;
4749: DM dm;
4750: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4751: PetscInt Nf;
4753: incall = PETSC_TRUE;
4754: PetscCall(SNESGetDM(snes, &dm));
4755: PetscCall(DMGetNumFields(dm, &Nf));
4756: PetscCall(PetscCalloc1(Nf, &alpha));
4757: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4758: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4759: PetscCall(PetscConvEstSetFromOptions(conv));
4760: PetscCall(PetscConvEstSetUp(conv));
4761: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4762: PetscCall(PetscViewerPushFormat(viewer, format));
4763: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4764: PetscCall(PetscViewerPopFormat(viewer));
4765: PetscCall(PetscViewerDestroy(&viewer));
4766: PetscCall(PetscConvEstDestroy(&conv));
4767: PetscCall(PetscFree(alpha));
4768: incall = PETSC_FALSE;
4769: }
4770: /* Adaptively refine the initial grid */
4771: num = 1;
4772: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4773: if (flg) {
4774: DMAdaptor adaptor;
4776: incall = PETSC_TRUE;
4777: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4778: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4779: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4780: PetscCall(DMAdaptorSetFromOptions(adaptor));
4781: PetscCall(DMAdaptorSetUp(adaptor));
4782: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4783: PetscCall(DMAdaptorDestroy(&adaptor));
4784: incall = PETSC_FALSE;
4785: }
4786: /* Use grid sequencing to adapt */
4787: num = 0;
4788: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4789: if (num) {
4790: DMAdaptor adaptor;
4791: const char *prefix;
4793: incall = PETSC_TRUE;
4794: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4795: PetscCall(SNESGetOptionsPrefix(snes, &prefix));
4796: PetscCall(DMAdaptorSetOptionsPrefix(adaptor, prefix));
4797: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4798: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4799: PetscCall(DMAdaptorSetFromOptions(adaptor));
4800: PetscCall(DMAdaptorSetUp(adaptor));
4801: PetscCall(PetscObjectViewFromOptions((PetscObject)adaptor, NULL, "-snes_adapt_view"));
4802: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4803: PetscCall(DMAdaptorDestroy(&adaptor));
4804: incall = PETSC_FALSE;
4805: }
4806: }
4807: }
4808: if (!x) x = snes->vec_sol;
4809: if (!x) {
4810: PetscCall(SNESGetDM(snes, &dm));
4811: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4812: x = xcreated;
4813: }
4814: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4816: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4817: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4818: /* set solution vector */
4819: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4820: PetscCall(VecDestroy(&snes->vec_sol));
4821: snes->vec_sol = x;
4822: PetscCall(SNESGetDM(snes, &dm));
4824: /* set affine vector if provided */
4825: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4826: PetscCall(VecDestroy(&snes->vec_rhs));
4827: snes->vec_rhs = b;
4829: 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");
4830: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4831: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right-hand side vector");
4832: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4833: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4834: PetscCall(SNESSetUp(snes));
4836: if (!grid) {
4837: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback compute initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4838: }
4840: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4841: PetscCall(SNESResetCounters(snes));
4842: snes->reason = SNES_CONVERGED_ITERATING;
4843: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4844: PetscUseTypeMethod(snes, solve);
4845: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4846: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4847: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4849: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4850: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4852: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4853: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4854: /* Call converged reason views. This may involve user-provided viewers as well */
4855: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4857: if (snes->errorifnotconverged) PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4858: if (snes->reason < 0) break;
4859: if (grid < snes->gridsequence) {
4860: DM fine;
4861: Vec xnew;
4862: Mat interp;
4864: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4865: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4866: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4867: PetscCall(DMCreateGlobalVector(fine, &xnew));
4868: PetscCall(MatInterpolate(interp, x, xnew));
4869: PetscCall(DMInterpolate(snes->dm, interp, fine));
4870: PetscCall(MatDestroy(&interp));
4871: x = xnew;
4873: PetscCall(SNESReset(snes));
4874: PetscCall(SNESSetDM(snes, fine));
4875: PetscCall(SNESResetFromOptions(snes));
4876: PetscCall(DMDestroy(&fine));
4877: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4878: }
4879: }
4880: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4881: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4882: PetscCall(DMMonitor(snes->dm));
4883: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4885: PetscCall(VecDestroy(&xcreated));
4886: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4887: PetscFunctionReturn(PETSC_SUCCESS);
4888: }
4890: /* --------- Internal routines for SNES Package --------- */
4892: /*@
4893: SNESSetType - Sets the algorithm/method to be used to solve the nonlinear system with the given `SNES`
4895: Collective
4897: Input Parameters:
4898: + snes - the `SNES` context
4899: - type - a known method
4901: Options Database Key:
4902: . -snes_type <type> - Sets the method; use -help for a list
4903: of available methods (for instance, newtonls or newtontr)
4905: Level: intermediate
4907: Notes:
4908: See `SNESType` for available methods (for instance)
4909: + `SNESNEWTONLS` - Newton's method with line search
4910: (systems of nonlinear equations)
4911: - `SNESNEWTONTR` - Newton's method with trust region
4912: (systems of nonlinear equations)
4914: Normally, it is best to use the `SNESSetFromOptions()` command and then
4915: set the `SNES` solver type from the options database rather than by using
4916: this routine. Using the options database provides the user with
4917: maximum flexibility in evaluating the many nonlinear solvers.
4918: The `SNESSetType()` routine is provided for those situations where it
4919: is necessary to set the nonlinear solver independently of the command
4920: line or options database. This might be the case, for example, when
4921: the choice of solver changes during the execution of the program,
4922: and the user's application is taking responsibility for choosing the
4923: appropriate method.
4925: Developer Note:
4926: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4927: the constructor in that list and calls it to create the specific object.
4929: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4930: @*/
4931: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4932: {
4933: PetscBool match;
4934: PetscErrorCode (*r)(SNES);
4936: PetscFunctionBegin;
4938: PetscAssertPointer(type, 2);
4940: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4941: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4943: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4944: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4945: /* Destroy the previous private SNES context */
4946: PetscTryTypeMethod(snes, destroy);
4947: /* Reinitialize function pointers in SNESOps structure */
4948: snes->ops->setup = NULL;
4949: snes->ops->solve = NULL;
4950: snes->ops->view = NULL;
4951: snes->ops->setfromoptions = NULL;
4952: snes->ops->destroy = NULL;
4954: /* It may happen the user has customized the line search before calling SNESSetType */
4955: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
4957: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4958: snes->setupcalled = PETSC_FALSE;
4960: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
4961: PetscCall((*r)(snes));
4962: PetscFunctionReturn(PETSC_SUCCESS);
4963: }
4965: /*@
4966: SNESGetType - Gets the `SNES` method type and name (as a string).
4968: Not Collective
4970: Input Parameter:
4971: . snes - nonlinear solver context
4973: Output Parameter:
4974: . type - `SNES` method (a character string)
4976: Level: intermediate
4978: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
4979: @*/
4980: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
4981: {
4982: PetscFunctionBegin;
4984: PetscAssertPointer(type, 2);
4985: *type = ((PetscObject)snes)->type_name;
4986: PetscFunctionReturn(PETSC_SUCCESS);
4987: }
4989: /*@
4990: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
4992: Logically Collective
4994: Input Parameters:
4995: + snes - the `SNES` context obtained from `SNESCreate()`
4996: - u - the solution vector
4998: Level: beginner
5000: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
5001: @*/
5002: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
5003: {
5004: DM dm;
5006: PetscFunctionBegin;
5009: PetscCall(PetscObjectReference((PetscObject)u));
5010: PetscCall(VecDestroy(&snes->vec_sol));
5012: snes->vec_sol = u;
5014: PetscCall(SNESGetDM(snes, &dm));
5015: PetscCall(DMShellSetGlobalVector(dm, u));
5016: PetscFunctionReturn(PETSC_SUCCESS);
5017: }
5019: /*@
5020: SNESGetSolution - Returns the vector where the approximate solution is
5021: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
5023: Not Collective, but `x` is parallel if `snes` is parallel
5025: Input Parameter:
5026: . snes - the `SNES` context
5028: Output Parameter:
5029: . x - the solution
5031: Level: intermediate
5033: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
5034: @*/
5035: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
5036: {
5037: PetscFunctionBegin;
5039: PetscAssertPointer(x, 2);
5040: *x = snes->vec_sol;
5041: PetscFunctionReturn(PETSC_SUCCESS);
5042: }
5044: /*@
5045: SNESGetSolutionUpdate - Returns the vector where the solution update is
5046: stored.
5048: Not Collective, but `x` is parallel if `snes` is parallel
5050: Input Parameter:
5051: . snes - the `SNES` context
5053: Output Parameter:
5054: . x - the solution update
5056: Level: advanced
5058: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
5059: @*/
5060: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
5061: {
5062: PetscFunctionBegin;
5064: PetscAssertPointer(x, 2);
5065: *x = snes->vec_sol_update;
5066: PetscFunctionReturn(PETSC_SUCCESS);
5067: }
5069: /*@C
5070: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
5072: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
5074: Input Parameter:
5075: . snes - the `SNES` context
5077: Output Parameters:
5078: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
5079: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunctionFn`
5080: - ctx - the function context (or `NULL` if you don't want it)
5082: Level: advanced
5084: Note:
5085: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
5087: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunctionFn`
5088: @*/
5089: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, SNESFunctionFn **f, void **ctx)
5090: {
5091: DM dm;
5093: PetscFunctionBegin;
5095: if (r) {
5096: if (!snes->vec_func) {
5097: if (snes->vec_rhs) {
5098: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
5099: } else if (snes->vec_sol) {
5100: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
5101: } else if (snes->dm) {
5102: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
5103: }
5104: }
5105: *r = snes->vec_func;
5106: }
5107: PetscCall(SNESGetDM(snes, &dm));
5108: PetscCall(DMSNESGetFunction(dm, f, ctx));
5109: PetscFunctionReturn(PETSC_SUCCESS);
5110: }
5112: /*@C
5113: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
5115: Input Parameter:
5116: . snes - the `SNES` context
5118: Output Parameters:
5119: + f - the function (or `NULL`) see `SNESNGSFn` for calling sequence
5120: - ctx - the function context (or `NULL`)
5122: Level: advanced
5124: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`, `SNESNGSFn`
5125: @*/
5126: PetscErrorCode SNESGetNGS(SNES snes, SNESNGSFn **f, void **ctx)
5127: {
5128: DM dm;
5130: PetscFunctionBegin;
5132: PetscCall(SNESGetDM(snes, &dm));
5133: PetscCall(DMSNESGetNGS(dm, f, ctx));
5134: PetscFunctionReturn(PETSC_SUCCESS);
5135: }
5137: /*@
5138: SNESSetOptionsPrefix - Sets the prefix used for searching for all
5139: `SNES` options in the database.
5141: Logically Collective
5143: Input Parameters:
5144: + snes - the `SNES` context
5145: - prefix - the prefix to prepend to all option names
5147: Level: advanced
5149: Note:
5150: A hyphen (-) must NOT be given at the beginning of the prefix name.
5151: The first character of all runtime options is AUTOMATICALLY the hyphen.
5153: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
5154: @*/
5155: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
5156: {
5157: PetscFunctionBegin;
5159: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
5160: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5161: if (snes->linesearch) {
5162: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5163: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
5164: }
5165: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
5166: PetscFunctionReturn(PETSC_SUCCESS);
5167: }
5169: /*@
5170: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5171: `SNES` options in the database.
5173: Logically Collective
5175: Input Parameters:
5176: + snes - the `SNES` context
5177: - prefix - the prefix to prepend to all option names
5179: Level: advanced
5181: Note:
5182: A hyphen (-) must NOT be given at the beginning of the prefix name.
5183: The first character of all runtime options is AUTOMATICALLY the hyphen.
5185: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5186: @*/
5187: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5188: {
5189: PetscFunctionBegin;
5191: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5192: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5193: if (snes->linesearch) {
5194: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5195: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5196: }
5197: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5198: PetscFunctionReturn(PETSC_SUCCESS);
5199: }
5201: /*@
5202: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5203: `SNES` options in the database.
5205: Not Collective
5207: Input Parameter:
5208: . snes - the `SNES` context
5210: Output Parameter:
5211: . prefix - pointer to the prefix string used
5213: Level: advanced
5215: Fortran Note:
5216: The user should pass in a string 'prefix' of
5217: sufficient length to hold the prefix.
5219: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5220: @*/
5221: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5222: {
5223: PetscFunctionBegin;
5225: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5226: PetscFunctionReturn(PETSC_SUCCESS);
5227: }
5229: /*@C
5230: SNESRegister - Adds a method to the nonlinear solver package.
5232: Not Collective
5234: Input Parameters:
5235: + sname - name of a new user-defined solver
5236: - function - routine to create method context
5238: Level: advanced
5240: Note:
5241: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5243: Example Usage:
5244: .vb
5245: SNESRegister("my_solver", MySolverCreate);
5246: .ve
5248: Then, your solver can be chosen with the procedural interface via
5249: $ SNESSetType(snes, "my_solver")
5250: or at runtime via the option
5251: $ -snes_type my_solver
5253: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5254: @*/
5255: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5256: {
5257: PetscFunctionBegin;
5258: PetscCall(SNESInitializePackage());
5259: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5260: PetscFunctionReturn(PETSC_SUCCESS);
5261: }
5263: PetscErrorCode SNESTestLocalMin(SNES snes)
5264: {
5265: PetscInt N, i, j;
5266: Vec u, uh, fh;
5267: PetscScalar value;
5268: PetscReal norm;
5270: PetscFunctionBegin;
5271: PetscCall(SNESGetSolution(snes, &u));
5272: PetscCall(VecDuplicate(u, &uh));
5273: PetscCall(VecDuplicate(u, &fh));
5275: /* currently only works for sequential */
5276: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5277: PetscCall(VecGetSize(u, &N));
5278: for (i = 0; i < N; i++) {
5279: PetscCall(VecCopy(u, uh));
5280: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5281: for (j = -10; j < 11; j++) {
5282: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5283: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5284: PetscCall(SNESComputeFunction(snes, uh, fh));
5285: PetscCall(VecNorm(fh, NORM_2, &norm));
5286: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5287: value = -value;
5288: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5289: }
5290: }
5291: PetscCall(VecDestroy(&uh));
5292: PetscCall(VecDestroy(&fh));
5293: PetscFunctionReturn(PETSC_SUCCESS);
5294: }
5296: /*@
5297: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5298: computing relative tolerance for linear solvers within an inexact
5299: Newton method.
5301: Logically Collective
5303: Input Parameters:
5304: + snes - `SNES` context
5305: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5307: Options Database Keys:
5308: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5309: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5310: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5311: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5312: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5313: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5314: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5315: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5317: Level: advanced
5319: Note:
5320: The default is to use a constant relative tolerance for
5321: the inner linear solvers. Alternatively, one can use the
5322: Eisenstat-Walker method {cite}`ew96`, where the relative convergence tolerance
5323: is reset at each Newton iteration according progress of the nonlinear
5324: solver.
5326: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5327: @*/
5328: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5329: {
5330: PetscFunctionBegin;
5333: snes->ksp_ewconv = flag;
5334: PetscFunctionReturn(PETSC_SUCCESS);
5335: }
5337: /*@
5338: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5339: for computing relative tolerance for linear solvers within an
5340: inexact Newton method.
5342: Not Collective
5344: Input Parameter:
5345: . snes - `SNES` context
5347: Output Parameter:
5348: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5350: Level: advanced
5352: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5353: @*/
5354: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5355: {
5356: PetscFunctionBegin;
5358: PetscAssertPointer(flag, 2);
5359: *flag = snes->ksp_ewconv;
5360: PetscFunctionReturn(PETSC_SUCCESS);
5361: }
5363: /*@
5364: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5365: convergence criteria for the linear solvers within an inexact
5366: Newton method.
5368: Logically Collective
5370: Input Parameters:
5371: + snes - `SNES` context
5372: . version - version 1, 2 (default is 2), 3 or 4
5373: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5374: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5375: . gamma - multiplicative factor for version 2 rtol computation
5376: (0 <= gamma2 <= 1)
5377: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5378: . alpha2 - power for safeguard
5379: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5381: Level: advanced
5383: Notes:
5384: Version 3 was contributed by Luis Chacon, June 2006.
5386: Use `PETSC_CURRENT` to retain the default for any of the parameters.
5388: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5389: @*/
5390: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5391: {
5392: SNESKSPEW *kctx;
5394: PetscFunctionBegin;
5396: kctx = (SNESKSPEW *)snes->kspconvctx;
5397: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5406: if (version != PETSC_CURRENT) kctx->version = version;
5407: if (rtol_0 != (PetscReal)PETSC_CURRENT) kctx->rtol_0 = rtol_0;
5408: if (rtol_max != (PetscReal)PETSC_CURRENT) kctx->rtol_max = rtol_max;
5409: if (gamma != (PetscReal)PETSC_CURRENT) kctx->gamma = gamma;
5410: if (alpha != (PetscReal)PETSC_CURRENT) kctx->alpha = alpha;
5411: if (alpha2 != (PetscReal)PETSC_CURRENT) kctx->alpha2 = alpha2;
5412: if (threshold != (PetscReal)PETSC_CURRENT) kctx->threshold = threshold;
5414: 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);
5415: 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);
5416: 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);
5417: 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);
5418: 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);
5419: 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);
5420: PetscFunctionReturn(PETSC_SUCCESS);
5421: }
5423: /*@
5424: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5425: convergence criteria for the linear solvers within an inexact
5426: Newton method.
5428: Not Collective
5430: Input Parameter:
5431: . snes - `SNES` context
5433: Output Parameters:
5434: + version - version 1, 2 (default is 2), 3 or 4
5435: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5436: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5437: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5438: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5439: . alpha2 - power for safeguard
5440: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5442: Level: advanced
5444: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5445: @*/
5446: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5447: {
5448: SNESKSPEW *kctx;
5450: PetscFunctionBegin;
5452: kctx = (SNESKSPEW *)snes->kspconvctx;
5453: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5454: if (version) *version = kctx->version;
5455: if (rtol_0) *rtol_0 = kctx->rtol_0;
5456: if (rtol_max) *rtol_max = kctx->rtol_max;
5457: if (gamma) *gamma = kctx->gamma;
5458: if (alpha) *alpha = kctx->alpha;
5459: if (alpha2) *alpha2 = kctx->alpha2;
5460: if (threshold) *threshold = kctx->threshold;
5461: PetscFunctionReturn(PETSC_SUCCESS);
5462: }
5464: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5465: {
5466: SNES snes = (SNES)ctx;
5467: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5468: PetscReal rtol = PETSC_CURRENT, stol;
5470: PetscFunctionBegin;
5471: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5472: if (!snes->iter) {
5473: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5474: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5475: } else {
5476: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5477: if (kctx->version == 1) {
5478: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5479: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5480: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5481: } else if (kctx->version == 2) {
5482: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5483: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5484: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5485: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5486: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5487: /* safeguard: avoid sharp decrease of rtol */
5488: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5489: stol = PetscMax(rtol, stol);
5490: rtol = PetscMin(kctx->rtol_0, stol);
5491: /* safeguard: avoid oversolving */
5492: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5493: stol = PetscMax(rtol, stol);
5494: rtol = PetscMin(kctx->rtol_0, stol);
5495: } else /* if (kctx->version == 4) */ {
5496: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5497: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5498: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5499: PetscReal rk = ared / pred;
5500: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5501: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5502: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5503: else rtol = kctx->v4_m2 * kctx->rtol_last;
5505: 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;
5506: kctx->rtol_last_2 = kctx->rtol_last;
5507: kctx->rk_last_2 = kctx->rk_last;
5508: kctx->rk_last = rk;
5509: }
5510: }
5511: /* safeguard: avoid rtol greater than rtol_max */
5512: rtol = PetscMin(rtol, kctx->rtol_max);
5513: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_CURRENT, PETSC_CURRENT, PETSC_CURRENT));
5514: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5515: PetscFunctionReturn(PETSC_SUCCESS);
5516: }
5518: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5519: {
5520: SNES snes = (SNES)ctx;
5521: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5522: PCSide pcside;
5523: Vec lres;
5525: PetscFunctionBegin;
5526: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5527: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5528: kctx->norm_last = snes->norm;
5529: if (kctx->version == 1 || kctx->version == 4) {
5530: PC pc;
5531: PetscBool getRes;
5533: PetscCall(KSPGetPC(ksp, &pc));
5534: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5535: if (!getRes) {
5536: KSPNormType normtype;
5538: PetscCall(KSPGetNormType(ksp, &normtype));
5539: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5540: }
5541: PetscCall(KSPGetPCSide(ksp, &pcside));
5542: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5543: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5544: } else {
5545: /* KSP residual is preconditioned residual */
5546: /* compute true linear residual norm */
5547: Mat J;
5548: PetscCall(KSPGetOperators(ksp, &J, NULL));
5549: PetscCall(VecDuplicate(b, &lres));
5550: PetscCall(MatMult(J, x, lres));
5551: PetscCall(VecAYPX(lres, -1.0, b));
5552: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5553: PetscCall(VecDestroy(&lres));
5554: }
5555: }
5556: PetscFunctionReturn(PETSC_SUCCESS);
5557: }
5559: /*@
5560: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5562: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5564: Input Parameter:
5565: . snes - the `SNES` context
5567: Output Parameter:
5568: . ksp - the `KSP` context
5570: Level: beginner
5572: Notes:
5573: The user can then directly manipulate the `KSP` context to set various
5574: options, etc. Likewise, the user can then extract and manipulate the
5575: `PC` contexts as well.
5577: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function, changes to that `KSP` will have no effect.
5579: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5580: @*/
5581: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5582: {
5583: PetscFunctionBegin;
5585: PetscAssertPointer(ksp, 2);
5587: if (!snes->ksp) {
5588: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5589: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5591: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5592: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5594: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5595: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5596: }
5597: *ksp = snes->ksp;
5598: PetscFunctionReturn(PETSC_SUCCESS);
5599: }
5601: #include <petsc/private/dmimpl.h>
5602: /*@
5603: SNESSetDM - Sets the `DM` that may be used by some `SNES` nonlinear solvers or their underlying preconditioners
5605: Logically Collective
5607: Input Parameters:
5608: + snes - the nonlinear solver context
5609: - dm - the `DM`, cannot be `NULL`
5611: Level: intermediate
5613: Note:
5614: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5615: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5616: problems using the same function space.
5618: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5619: @*/
5620: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5621: {
5622: KSP ksp;
5623: DMSNES sdm;
5625: PetscFunctionBegin;
5628: PetscCall(PetscObjectReference((PetscObject)dm));
5629: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5630: if (snes->dm->dmsnes && !dm->dmsnes) {
5631: PetscCall(DMCopyDMSNES(snes->dm, dm));
5632: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5633: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5634: }
5635: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5636: PetscCall(DMDestroy(&snes->dm));
5637: }
5638: snes->dm = dm;
5639: snes->dmAuto = PETSC_FALSE;
5641: PetscCall(SNESGetKSP(snes, &ksp));
5642: PetscCall(KSPSetDM(ksp, dm));
5643: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5644: if (snes->npc) {
5645: PetscCall(SNESSetDM(snes->npc, snes->dm));
5646: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5647: }
5648: PetscFunctionReturn(PETSC_SUCCESS);
5649: }
5651: /*@
5652: SNESGetDM - Gets the `DM` that may be used by some `SNES` nonlinear solvers/preconditioners
5654: Not Collective but `dm` obtained is parallel on `snes`
5656: Input Parameter:
5657: . snes - the `SNES` context
5659: Output Parameter:
5660: . dm - the `DM`
5662: Level: intermediate
5664: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5665: @*/
5666: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5667: {
5668: PetscFunctionBegin;
5670: if (!snes->dm) {
5671: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5672: snes->dmAuto = PETSC_TRUE;
5673: }
5674: *dm = snes->dm;
5675: PetscFunctionReturn(PETSC_SUCCESS);
5676: }
5678: /*@
5679: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5681: Collective
5683: Input Parameters:
5684: + snes - iterative context obtained from `SNESCreate()`
5685: - npc - the nonlinear preconditioner object
5687: Level: developer
5689: Notes:
5690: Use `SNESGetNPC()` to retrieve the preconditioner context (for example,
5691: to configure it using the API).
5693: Only some `SNESType` can use a nonlinear preconditioner
5695: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5696: @*/
5697: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5698: {
5699: PetscFunctionBegin;
5702: PetscCheckSameComm(snes, 1, npc, 2);
5703: PetscCall(PetscObjectReference((PetscObject)npc));
5704: PetscCall(SNESDestroy(&snes->npc));
5705: snes->npc = npc;
5706: PetscFunctionReturn(PETSC_SUCCESS);
5707: }
5709: /*@
5710: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5712: Not Collective; but any changes to the obtained the `pc` object must be applied collectively
5714: Input Parameter:
5715: . snes - iterative context obtained from `SNESCreate()`
5717: Output Parameter:
5718: . pc - preconditioner context
5720: Options Database Key:
5721: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5723: Level: advanced
5725: Notes:
5726: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created that will
5727: be used as the nonlinear preconditioner for the current `SNES`.
5729: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5730: `SNES`
5732: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5733: @*/
5734: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5735: {
5736: const char *optionsprefix;
5738: PetscFunctionBegin;
5740: PetscAssertPointer(pc, 2);
5741: if (!snes->npc) {
5742: void *ctx;
5744: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5745: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5746: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5747: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5748: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5749: if (snes->ops->usercompute) {
5750: PetscCall(SNESSetComputeApplicationContext(snes, snes->ops->usercompute, snes->ops->userdestroy));
5751: } else {
5752: PetscCall(SNESGetApplicationContext(snes, &ctx));
5753: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5754: }
5755: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5756: }
5757: *pc = snes->npc;
5758: PetscFunctionReturn(PETSC_SUCCESS);
5759: }
5761: /*@
5762: SNESHasNPC - Returns whether a nonlinear preconditioner is associated with the given `SNES`
5764: Not Collective
5766: Input Parameter:
5767: . snes - iterative context obtained from `SNESCreate()`
5769: Output Parameter:
5770: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5772: Level: developer
5774: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5775: @*/
5776: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5777: {
5778: PetscFunctionBegin;
5780: *has_npc = (PetscBool)(snes->npc ? PETSC_TRUE : PETSC_FALSE);
5781: PetscFunctionReturn(PETSC_SUCCESS);
5782: }
5784: /*@
5785: SNESSetNPCSide - Sets the nonlinear preconditioning side used by the given `SNES`.
5787: Logically Collective
5789: Input Parameter:
5790: . snes - iterative context obtained from `SNESCreate()`
5792: Output Parameter:
5793: . side - the preconditioning side, where side is one of
5794: .vb
5795: PC_LEFT - left preconditioning
5796: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5797: .ve
5799: Options Database Key:
5800: . -snes_npc_side <right,left> - nonlinear preconditioner side
5802: Level: intermediate
5804: Note:
5805: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5807: .seealso: [](ch_snes), `SNES`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5808: @*/
5809: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5810: {
5811: PetscFunctionBegin;
5814: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5815: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5816: snes->npcside = side;
5817: PetscFunctionReturn(PETSC_SUCCESS);
5818: }
5820: /*@
5821: SNESGetNPCSide - Gets the preconditioning side.
5823: Not Collective
5825: Input Parameter:
5826: . snes - iterative context obtained from `SNESCreate()`
5828: Output Parameter:
5829: . side - the preconditioning side, where side is one of
5830: .vb
5831: `PC_LEFT` - left preconditioning
5832: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5833: .ve
5835: Level: intermediate
5837: .seealso: [](ch_snes), `SNES`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5838: @*/
5839: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5840: {
5841: PetscFunctionBegin;
5843: PetscAssertPointer(side, 2);
5844: *side = snes->npcside;
5845: PetscFunctionReturn(PETSC_SUCCESS);
5846: }
5848: /*@
5849: SNESSetLineSearch - Sets the `SNESLineSearch` to be used for a given `SNES`
5851: Collective
5853: Input Parameters:
5854: + snes - iterative context obtained from `SNESCreate()`
5855: - linesearch - the linesearch object
5857: Level: developer
5859: Note:
5860: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
5861: to configure it using the API).
5863: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
5864: @*/
5865: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5866: {
5867: PetscFunctionBegin;
5870: PetscCheckSameComm(snes, 1, linesearch, 2);
5871: PetscCall(PetscObjectReference((PetscObject)linesearch));
5872: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5874: snes->linesearch = linesearch;
5875: PetscFunctionReturn(PETSC_SUCCESS);
5876: }
5878: /*@
5879: SNESGetLineSearch - Returns the line search context possibly set with `SNESSetLineSearch()`
5880: or creates a default line search instance associated with the `SNES` and returns it.
5882: Not Collective
5884: Input Parameter:
5885: . snes - iterative context obtained from `SNESCreate()`
5887: Output Parameter:
5888: . linesearch - linesearch context
5890: Level: beginner
5892: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`
5893: @*/
5894: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5895: {
5896: const char *optionsprefix;
5898: PetscFunctionBegin;
5900: PetscAssertPointer(linesearch, 2);
5901: if (!snes->linesearch) {
5902: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5903: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5904: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5905: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5906: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5907: }
5908: *linesearch = snes->linesearch;
5909: PetscFunctionReturn(PETSC_SUCCESS);
5910: }