Actual source code: snes.c
1: #include <petsc/private/snesimpl.h>
2: #include <petscdmshell.h>
3: #include <petscdraw.h>
4: #include <petscds.h>
5: #include <petscdmadaptor.h>
6: #include <petscconvest.h>
8: PetscBool SNESRegisterAllCalled = PETSC_FALSE;
9: PetscFunctionList SNESList = NULL;
11: /* Logging support */
12: PetscClassId SNES_CLASSID, DMSNES_CLASSID;
13: PetscLogEvent SNES_Solve, SNES_SetUp, SNES_FunctionEval, SNES_JacobianEval, SNES_NGSEval, SNES_NGSFuncEval, SNES_NPCSolve, SNES_ObjectiveEval;
15: /*@
16: SNESSetErrorIfNotConverged - Causes `SNESSolve()` to generate an error immediately if the solver has not converged.
18: Logically Collective
20: Input Parameters:
21: + snes - iterative context obtained from `SNESCreate()`
22: - flg - `PETSC_TRUE` indicates you want the error generated
24: Options Database Key:
25: . -snes_error_if_not_converged <true,false> - cause an immediate error condition and stop the program if the solver does not converge
27: Level: intermediate
29: Note:
30: Normally PETSc continues if a solver fails to converge, you can call `SNESGetConvergedReason()` after a `SNESSolve()`
31: to determine if it has converged. Otherwise the solution may be inaccurate or wrong
33: .seealso: [](ch_snes), `SNES`, `SNESGetErrorIfNotConverged()`, `KSPGetErrorIfNotConverged()`, `KSPSetErrorIfNotConverged()`
34: @*/
35: PetscErrorCode SNESSetErrorIfNotConverged(SNES snes, PetscBool flg)
36: {
37: PetscFunctionBegin;
40: snes->errorifnotconverged = flg;
41: PetscFunctionReturn(PETSC_SUCCESS);
42: }
44: /*@
45: SNESGetErrorIfNotConverged - Indicates if `SNESSolve()` will generate an error if the solver does not converge?
47: Not Collective
49: Input Parameter:
50: . snes - iterative context obtained from `SNESCreate()`
52: Output Parameter:
53: . flag - `PETSC_TRUE` if it will generate an error, else `PETSC_FALSE`
55: Level: intermediate
57: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetErrorIfNotConverged()`, `KSPGetErrorIfNotConverged()`, `KSPSetErrorIfNotConverged()`
58: @*/
59: PetscErrorCode SNESGetErrorIfNotConverged(SNES snes, PetscBool *flag)
60: {
61: PetscFunctionBegin;
63: PetscAssertPointer(flag, 2);
64: *flag = snes->errorifnotconverged;
65: PetscFunctionReturn(PETSC_SUCCESS);
66: }
68: /*@
69: SNESSetAlwaysComputesFinalResidual - tells the `SNES` to always compute the residual (nonlinear function value) at the final solution
71: Logically Collective
73: Input Parameters:
74: + snes - the shell `SNES`
75: - flg - `PETSC_TRUE` to always compute the residual
77: Level: advanced
79: Note:
80: Some solvers (such as smoothers in a `SNESFAS`) do not need the residual computed at the final solution so skip computing it
81: to save time.
83: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSolve()`, `SNESGetAlwaysComputesFinalResidual()`
84: @*/
85: PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES snes, PetscBool flg)
86: {
87: PetscFunctionBegin;
89: snes->alwayscomputesfinalresidual = flg;
90: PetscFunctionReturn(PETSC_SUCCESS);
91: }
93: /*@
94: SNESGetAlwaysComputesFinalResidual - checks if the `SNES` always computes the residual at the final solution
96: Logically Collective
98: Input Parameter:
99: . snes - the `SNES` context
101: Output Parameter:
102: . flg - `PETSC_TRUE` if the residual is computed
104: Level: advanced
106: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSolve()`, `SNESSetAlwaysComputesFinalResidual()`
107: @*/
108: PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES snes, PetscBool *flg)
109: {
110: PetscFunctionBegin;
112: *flg = snes->alwayscomputesfinalresidual;
113: PetscFunctionReturn(PETSC_SUCCESS);
114: }
116: /*@
117: SNESSetFunctionDomainError - tells `SNES` that the input vector, a proposed new solution, to your function you provided to `SNESSetFunction()` is not
118: in the functions domain. For example, a step with negative pressure.
120: Logically Collective
122: Input Parameter:
123: . snes - the `SNES` context
125: Level: advanced
127: Notes:
128: If this is called the `SNESSolve()` stops iterating and returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_DOMAIN`
130: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
132: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
133: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
135: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetJacobianDomainError()`, `SNESVISetVariableBounds()`,
136: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
137: @*/
138: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
139: {
140: PetscFunctionBegin;
142: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates input vector is not in the function domain");
143: snes->domainerror = PETSC_TRUE;
144: PetscFunctionReturn(PETSC_SUCCESS);
145: }
147: /*@
148: SNESSetJacobianDomainError - tells `SNES` that the function you provided to `SNESSetJacobian()` at the proposed step. For example there is a negative element transformation.
150: Logically Collective
152: Input Parameter:
153: . snes - the `SNES` context
155: Level: advanced
157: Notes:
158: If this is called the `SNESSolve()` stops iterating and returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_DOMAIN`
160: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
162: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
163: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
165: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESVISetVariableBounds()`,
166: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
167: @*/
168: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
169: {
170: PetscFunctionBegin;
172: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates computeJacobian does not make sense");
173: snes->jacobiandomainerror = PETSC_TRUE;
174: PetscFunctionReturn(PETSC_SUCCESS);
175: }
177: /*@
178: SNESSetCheckJacobianDomainError - tells `SNESSolve()` whether to check if the user called `SNESSetJacobianDomainError()` Jacobian domain error after
179: each Jacobian evaluation. By default, it checks for the Jacobian domain error in the debug mode, and does not check it in the optimized mode.
181: Logically Collective
183: Input Parameters:
184: + snes - the `SNES` context
185: - flg - indicates if or not to check Jacobian domain error after each Jacobian evaluation
187: Level: advanced
189: Note:
190: Checks require one extra parallel synchronization for each Jacobian evaluation
192: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESGetCheckJacobianDomainError()`
193: @*/
194: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
195: {
196: PetscFunctionBegin;
198: snes->checkjacdomainerror = flg;
199: PetscFunctionReturn(PETSC_SUCCESS);
200: }
202: /*@
203: SNESGetCheckJacobianDomainError - Get an indicator whether or not `SNES` is checking Jacobian domain errors after each Jacobian evaluation.
205: Logically Collective
207: Input Parameter:
208: . snes - the `SNES` context
210: Output Parameter:
211: . flg - `PETSC_FALSE` indicates that it is not checking Jacobian domain errors after each Jacobian evaluation
213: Level: advanced
215: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESSetCheckJacobianDomainError()`
216: @*/
217: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
218: {
219: PetscFunctionBegin;
221: PetscAssertPointer(flg, 2);
222: *flg = snes->checkjacdomainerror;
223: PetscFunctionReturn(PETSC_SUCCESS);
224: }
226: /*@
227: SNESGetFunctionDomainError - Gets the status of the domain error after a call to `SNESComputeFunction()`
229: Logically Collective
231: Input Parameter:
232: . snes - the `SNES` context
234: Output Parameter:
235: . domainerror - Set to `PETSC_TRUE` if there's a domain error; `PETSC_FALSE` otherwise.
237: Level: developer
239: .seealso: [](ch_snes), `SNES`, `SNESSetFunctionDomainError()`, `SNESComputeFunction()`
240: @*/
241: PetscErrorCode SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
242: {
243: PetscFunctionBegin;
245: PetscAssertPointer(domainerror, 2);
246: *domainerror = snes->domainerror;
247: PetscFunctionReturn(PETSC_SUCCESS);
248: }
250: /*@
251: SNESGetJacobianDomainError - Gets the status of the Jacobian domain error after a call to `SNESComputeJacobian()`
253: Logically Collective
255: Input Parameter:
256: . snes - the `SNES` context
258: Output Parameter:
259: . domainerror - Set to `PETSC_TRUE` if there's a Jacobian domain error; `PETSC_FALSE` otherwise.
261: Level: advanced
263: .seealso: [](ch_snes), `SNES`, `SNESSetFunctionDomainError()`, `SNESComputeFunction()`, `SNESGetFunctionDomainError()`
264: @*/
265: PetscErrorCode SNESGetJacobianDomainError(SNES snes, PetscBool *domainerror)
266: {
267: PetscFunctionBegin;
269: PetscAssertPointer(domainerror, 2);
270: *domainerror = snes->jacobiandomainerror;
271: PetscFunctionReturn(PETSC_SUCCESS);
272: }
274: /*@C
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: /*@C
325: SNESViewFromOptions - View a `SNES` based on values in the options database
327: Collective
329: Input Parameters:
330: + A - the `SNES` context
331: . obj - Optional object that provides the options prefix for the checks
332: - name - command line option
334: Level: intermediate
336: .seealso: [](ch_snes), `SNES`, `SNESView`, `PetscObjectViewFromOptions()`, `SNESCreate()`
337: @*/
338: PetscErrorCode SNESViewFromOptions(SNES A, PetscObject obj, const char name[])
339: {
340: PetscFunctionBegin;
342: PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
343: PetscFunctionReturn(PETSC_SUCCESS);
344: }
346: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES, Vec, Mat, Mat, void *);
348: /*@C
349: SNESView - Prints or visualizes the `SNES` data structure.
351: Collective
353: Input Parameters:
354: + snes - the `SNES` context
355: - viewer - the `PetscViewer`
357: Options Database Key:
358: . -snes_view - Calls `SNESView()` at end of `SNESSolve()`
360: Level: beginner
362: Notes:
363: The available visualization contexts include
364: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
365: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
366: output where only the first processor opens
367: the file. All other processors send their
368: data to the first processor to print.
370: The available formats include
371: + `PETSC_VIEWER_DEFAULT` - standard output (default)
372: - `PETSC_VIEWER_ASCII_INFO_DETAIL` - more verbose output for `SNESNASM`
374: The user can open an alternative visualization context with
375: `PetscViewerASCIIOpen()` - output to a specified file.
377: In the debugger you can do "call `SNESView`(snes,0)" to display the `SNES` solver. (The same holds for any PETSc object viewer).
379: .seealso: [](ch_snes), `SNES`, `SNESLoad()`, `SNESCreate()`, `PetscViewerASCIIOpen()`
380: @*/
381: PetscErrorCode SNESView(SNES snes, PetscViewer viewer)
382: {
383: SNESKSPEW *kctx;
384: KSP ksp;
385: SNESLineSearch linesearch;
386: PetscBool iascii, isstring, isbinary, isdraw;
387: DMSNES dmsnes;
388: #if defined(PETSC_HAVE_SAWS)
389: PetscBool issaws;
390: #endif
392: PetscFunctionBegin;
394: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &viewer));
396: PetscCheckSameComm(snes, 1, viewer, 2);
398: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
399: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
400: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
401: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
402: #if defined(PETSC_HAVE_SAWS)
403: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
404: #endif
405: if (iascii) {
406: SNESNormSchedule normschedule;
407: DM dm;
408: 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: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=%" PetscInt_FMT "\n", snes->max_its, snes->max_funcs));
420: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, solution=%g\n", (double)snes->rtol, (double)snes->abstol, (double)snes->stol));
421: if (snes->usesksp) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of linear solver iterations=%" PetscInt_FMT "\n", snes->linear_its));
422: PetscCall(PetscViewerASCIIPrintf(viewer, " total number of function evaluations=%" PetscInt_FMT "\n", snes->nfuncs));
423: PetscCall(SNESGetNormSchedule(snes, &normschedule));
424: if (normschedule > 0) PetscCall(PetscViewerASCIIPrintf(viewer, " norm schedule %s\n", SNESNormSchedules[normschedule]));
425: if (snes->gridsequence) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of grid sequence refinements=%" PetscInt_FMT "\n", snes->gridsequence));
426: if (snes->ksp_ewconv) {
427: kctx = (SNESKSPEW *)snes->kspconvctx;
428: if (kctx) {
429: PetscCall(PetscViewerASCIIPrintf(viewer, " Eisenstat-Walker computation of KSP relative tolerance (version %" PetscInt_FMT ")\n", kctx->version));
430: PetscCall(PetscViewerASCIIPrintf(viewer, " rtol_0=%g, rtol_max=%g, threshold=%g\n", (double)kctx->rtol_0, (double)kctx->rtol_max, (double)kctx->threshold));
431: PetscCall(PetscViewerASCIIPrintf(viewer, " gamma=%g, alpha=%g, alpha2=%g\n", (double)kctx->gamma, (double)kctx->alpha, (double)kctx->alpha2));
432: }
433: }
434: if (snes->lagpreconditioner == -1) {
435: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is never rebuilt\n"));
436: } else if (snes->lagpreconditioner > 1) {
437: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is rebuilt every %" PetscInt_FMT " new Jacobians\n", snes->lagpreconditioner));
438: }
439: if (snes->lagjacobian == -1) {
440: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is never rebuilt\n"));
441: } else if (snes->lagjacobian > 1) {
442: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is rebuilt every %" PetscInt_FMT " SNES iterations\n", snes->lagjacobian));
443: }
444: PetscCall(SNESGetDM(snes, &dm));
445: PetscCall(DMSNESGetJacobian(dm, &cJ, &ctx));
446: if (snes->mf_operator) {
447: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing\n"));
448: pre = "Preconditioning ";
449: }
450: if (cJ == SNESComputeJacobianDefault) {
451: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences one column at a time\n", pre));
452: } else if (cJ == SNESComputeJacobianDefaultColor) {
453: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences with coloring\n", pre));
454: /* it slightly breaks data encapsulation for access the DMDA information directly */
455: } else if (cJ == SNESComputeJacobian_DMDA) {
456: MatFDColoring fdcoloring;
457: PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
458: if (fdcoloring) {
459: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using colored finite differences on a DMDA\n", pre));
460: } else {
461: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using a DMDA local Jacobian\n", pre));
462: }
463: } else if (snes->mf && !snes->mf_operator) {
464: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing, no explicit Jacobian\n"));
465: }
466: } else if (isstring) {
467: const char *type;
468: PetscCall(SNESGetType(snes, &type));
469: PetscCall(PetscViewerStringSPrintf(viewer, " SNESType: %-7.7s", type));
470: PetscTryTypeMethod(snes, view, viewer);
471: } else if (isbinary) {
472: PetscInt classid = SNES_FILE_CLASSID;
473: MPI_Comm comm;
474: PetscMPIInt rank;
475: char type[256];
477: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
478: PetscCallMPI(MPI_Comm_rank(comm, &rank));
479: if (rank == 0) {
480: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
481: PetscCall(PetscStrncpy(type, ((PetscObject)snes)->type_name, sizeof(type)));
482: PetscCall(PetscViewerBinaryWrite(viewer, type, sizeof(type), PETSC_CHAR));
483: }
484: PetscTryTypeMethod(snes, view, viewer);
485: } else if (isdraw) {
486: PetscDraw draw;
487: char str[36];
488: PetscReal x, y, bottom, h;
490: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
491: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
492: PetscCall(PetscStrncpy(str, "SNES: ", sizeof(str)));
493: PetscCall(PetscStrlcat(str, ((PetscObject)snes)->type_name, sizeof(str)));
494: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_BLUE, PETSC_DRAW_BLACK, str, NULL, &h));
495: bottom = y - h;
496: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
497: PetscTryTypeMethod(snes, view, viewer);
498: #if defined(PETSC_HAVE_SAWS)
499: } else if (issaws) {
500: PetscMPIInt rank;
501: const char *name;
503: PetscCall(PetscObjectGetName((PetscObject)snes, &name));
504: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
505: if (!((PetscObject)snes)->amsmem && rank == 0) {
506: char dir[1024];
508: PetscCall(PetscObjectViewSAWs((PetscObject)snes, viewer));
509: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
510: PetscCallSAWs(SAWs_Register, (dir, &snes->iter, 1, SAWs_READ, SAWs_INT));
511: if (!snes->conv_hist) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, PETSC_DECIDE, PETSC_TRUE));
512: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/conv_hist", name));
513: PetscCallSAWs(SAWs_Register, (dir, snes->conv_hist, 10, SAWs_READ, SAWs_DOUBLE));
514: }
515: #endif
516: }
517: if (snes->linesearch) {
518: PetscCall(SNESGetLineSearch(snes, &linesearch));
519: PetscCall(PetscViewerASCIIPushTab(viewer));
520: PetscCall(SNESLineSearchView(linesearch, viewer));
521: PetscCall(PetscViewerASCIIPopTab(viewer));
522: }
523: if (snes->npc && snes->usesnpc) {
524: PetscCall(PetscViewerASCIIPushTab(viewer));
525: PetscCall(SNESView(snes->npc, viewer));
526: PetscCall(PetscViewerASCIIPopTab(viewer));
527: }
528: PetscCall(PetscViewerASCIIPushTab(viewer));
529: PetscCall(DMGetDMSNES(snes->dm, &dmsnes));
530: PetscCall(DMSNESView(dmsnes, viewer));
531: PetscCall(PetscViewerASCIIPopTab(viewer));
532: if (snes->usesksp) {
533: PetscCall(SNESGetKSP(snes, &ksp));
534: PetscCall(PetscViewerASCIIPushTab(viewer));
535: PetscCall(KSPView(ksp, viewer));
536: PetscCall(PetscViewerASCIIPopTab(viewer));
537: }
538: if (isdraw) {
539: PetscDraw draw;
540: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
541: PetscCall(PetscDrawPopCurrentPoint(draw));
542: }
543: PetscFunctionReturn(PETSC_SUCCESS);
544: }
546: /*
547: We retain a list of functions that also take SNES command
548: line options. These are called at the end SNESSetFromOptions()
549: */
550: #define MAXSETFROMOPTIONS 5
551: static PetscInt numberofsetfromoptions;
552: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
554: /*@C
555: SNESAddOptionsChecker - Adds an additional function to check for `SNES` options.
557: Not Collective
559: Input Parameter:
560: . snescheck - function that checks for options
562: Calling sequence of `snescheck`:
563: . snes - the `SNES` object for which it is checking options
565: Level: developer
567: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`
568: @*/
569: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES snes))
570: {
571: PetscFunctionBegin;
572: PetscCheck(numberofsetfromoptions < MAXSETFROMOPTIONS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %d allowed", MAXSETFROMOPTIONS);
573: othersetfromoptions[numberofsetfromoptions++] = snescheck;
574: PetscFunctionReturn(PETSC_SUCCESS);
575: }
577: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
578: {
579: Mat J;
580: MatNullSpace nullsp;
582: PetscFunctionBegin;
585: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
586: Mat A = snes->jacobian, B = snes->jacobian_pre;
587: PetscCall(MatCreateVecs(A ? A : B, NULL, &snes->vec_func));
588: }
590: PetscCheck(version == 1 || version == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator routines, only version 1 and 2");
591: if (version == 1) {
592: PetscCall(MatCreateSNESMF(snes, &J));
593: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
594: PetscCall(MatSetFromOptions(J));
595: /* TODO: the version 2 code should be merged into the MatCreateSNESMF() and MatCreateMFFD() infrastructure and then removed */
596: } else /* if (version == 2) */ {
597: PetscCheck(snes->vec_func, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "SNESSetFunction() must be called first");
598: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
599: PetscCall(MatCreateSNESMFMore(snes, snes->vec_func, &J));
600: #else
601: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "matrix-free operator routines (version 2)");
602: #endif
603: }
605: /* attach any user provided null space that was on Amat to the newly created matrix-free matrix */
606: if (snes->jacobian) {
607: PetscCall(MatGetNullSpace(snes->jacobian, &nullsp));
608: if (nullsp) PetscCall(MatSetNullSpace(J, nullsp));
609: }
611: PetscCall(PetscInfo(snes, "Setting default matrix-free operator routines (version %" PetscInt_FMT ")\n", version));
612: if (hasOperator) {
613: /* This version replaces the user provided Jacobian matrix with a
614: matrix-free version but still employs the user-provided preconditioner matrix. */
615: PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
616: } else {
617: /* This version replaces both the user-provided Jacobian and the user-
618: provided preconditioner Jacobian with the default matrix-free version. */
619: if (snes->npcside == PC_LEFT && snes->npc) {
620: if (!snes->jacobian) PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
621: } else {
622: KSP ksp;
623: PC pc;
624: PetscBool match;
626: PetscCall(SNESSetJacobian(snes, J, J, MatMFFDComputeJacobian, NULL));
627: /* Force no preconditioner */
628: PetscCall(SNESGetKSP(snes, &ksp));
629: PetscCall(KSPGetPC(ksp, &pc));
630: PetscCall(PetscObjectTypeCompareAny((PetscObject)pc, &match, PCSHELL, PCH2OPUS, ""));
631: if (!match) {
632: PetscCall(PetscInfo(snes, "Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n"));
633: PetscCall(PCSetType(pc, PCNONE));
634: }
635: }
636: }
637: PetscCall(MatDestroy(&J));
638: PetscFunctionReturn(PETSC_SUCCESS);
639: }
641: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine, Mat Restrict, Vec Rscale, Mat Inject, DM dmcoarse, void *ctx)
642: {
643: SNES snes = (SNES)ctx;
644: Vec Xfine, Xfine_named = NULL, Xcoarse;
646: PetscFunctionBegin;
647: if (PetscLogPrintInfo) {
648: PetscInt finelevel, coarselevel, fineclevel, coarseclevel;
649: PetscCall(DMGetRefineLevel(dmfine, &finelevel));
650: PetscCall(DMGetCoarsenLevel(dmfine, &fineclevel));
651: PetscCall(DMGetRefineLevel(dmcoarse, &coarselevel));
652: PetscCall(DMGetCoarsenLevel(dmcoarse, &coarseclevel));
653: PetscCall(PetscInfo(dmfine, "Restricting SNES solution vector from level %" PetscInt_FMT "-%" PetscInt_FMT " to level %" PetscInt_FMT "-%" PetscInt_FMT "\n", finelevel, fineclevel, coarselevel, coarseclevel));
654: }
655: if (dmfine == snes->dm) Xfine = snes->vec_sol;
656: else {
657: PetscCall(DMGetNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
658: Xfine = Xfine_named;
659: }
660: PetscCall(DMGetNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
661: if (Inject) {
662: PetscCall(MatRestrict(Inject, Xfine, Xcoarse));
663: } else {
664: PetscCall(MatRestrict(Restrict, Xfine, Xcoarse));
665: PetscCall(VecPointwiseMult(Xcoarse, Xcoarse, Rscale));
666: }
667: PetscCall(DMRestoreNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
668: if (Xfine_named) PetscCall(DMRestoreNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
669: PetscFunctionReturn(PETSC_SUCCESS);
670: }
672: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm, DM dmc, void *ctx)
673: {
674: PetscFunctionBegin;
675: PetscCall(DMCoarsenHookAdd(dmc, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, ctx));
676: PetscFunctionReturn(PETSC_SUCCESS);
677: }
679: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
680: * safely call SNESGetDM() in their residual evaluation routine. */
681: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp, Mat A, Mat B, void *ctx)
682: {
683: SNES snes = (SNES)ctx;
684: Vec X, Xnamed = NULL;
685: DM dmsave;
686: void *ctxsave;
687: SNESJacobianFn *jac = NULL;
689: PetscFunctionBegin;
690: dmsave = snes->dm;
691: PetscCall(KSPGetDM(ksp, &snes->dm));
692: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
693: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */ PetscCall(DMGetNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
694: X = Xnamed;
695: PetscCall(SNESGetJacobian(snes, NULL, NULL, &jac, &ctxsave));
696: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
697: if (jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, SNESComputeJacobianDefaultColor, NULL));
698: }
699: /* Make sure KSP DM has the Jacobian computation routine */
700: {
701: DMSNES sdm;
703: PetscCall(DMGetDMSNES(snes->dm, &sdm));
704: if (!sdm->ops->computejacobian) PetscCall(DMCopyDMSNES(dmsave, snes->dm));
705: }
706: /* Compute the operators */
707: PetscCall(SNESComputeJacobian(snes, X, A, B));
708: /* Put the previous context back */
709: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, jac, ctxsave));
711: if (Xnamed) PetscCall(DMRestoreNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
712: snes->dm = dmsave;
713: PetscFunctionReturn(PETSC_SUCCESS);
714: }
716: /*@
717: SNESSetUpMatrices - ensures that matrices are available for `SNES` Newton-like methods, this is called by `SNESSetUp_XXX()`
719: Collective
721: Input Parameter:
722: . snes - `SNES` object to configure
724: Level: developer
726: Note:
727: If the matrices do not yet exist it attempts to create them based on options previously set for the `SNES` such as `-snes_mf`
729: .seealso: [](ch_snes), `SNES`, `SNESSetUp()`
730: @*/
731: PetscErrorCode SNESSetUpMatrices(SNES snes)
732: {
733: DM dm;
734: DMSNES sdm;
736: PetscFunctionBegin;
737: PetscCall(SNESGetDM(snes, &dm));
738: PetscCall(DMGetDMSNES(dm, &sdm));
739: if (!snes->jacobian && snes->mf) {
740: Mat J;
741: void *functx;
742: PetscCall(MatCreateSNESMF(snes, &J));
743: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
744: PetscCall(MatSetFromOptions(J));
745: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
746: PetscCall(SNESSetJacobian(snes, J, J, NULL, NULL));
747: PetscCall(MatDestroy(&J));
748: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
749: Mat J, B;
750: PetscCall(MatCreateSNESMF(snes, &J));
751: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
752: PetscCall(MatSetFromOptions(J));
753: PetscCall(DMCreateMatrix(snes->dm, &B));
754: /* sdm->computejacobian was already set to reach here */
755: PetscCall(SNESSetJacobian(snes, J, B, NULL, NULL));
756: PetscCall(MatDestroy(&J));
757: PetscCall(MatDestroy(&B));
758: } else if (!snes->jacobian_pre) {
759: PetscDS prob;
760: Mat J, B;
761: PetscBool hasPrec = PETSC_FALSE;
763: J = snes->jacobian;
764: PetscCall(DMGetDS(dm, &prob));
765: if (prob) PetscCall(PetscDSHasJacobianPreconditioner(prob, &hasPrec));
766: if (J) PetscCall(PetscObjectReference((PetscObject)J));
767: else if (hasPrec) PetscCall(DMCreateMatrix(snes->dm, &J));
768: PetscCall(DMCreateMatrix(snes->dm, &B));
769: PetscCall(SNESSetJacobian(snes, J ? J : B, B, NULL, NULL));
770: PetscCall(MatDestroy(&J));
771: PetscCall(MatDestroy(&B));
772: }
773: {
774: KSP ksp;
775: PetscCall(SNESGetKSP(snes, &ksp));
776: PetscCall(KSPSetComputeOperators(ksp, KSPComputeOperators_SNES, snes));
777: PetscCall(DMCoarsenHookAdd(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
778: }
779: PetscFunctionReturn(PETSC_SUCCESS);
780: }
782: static PetscErrorCode SNESMonitorPauseFinal_Internal(SNES snes)
783: {
784: PetscInt i;
786: PetscFunctionBegin;
787: if (!snes->pauseFinal) PetscFunctionReturn(PETSC_SUCCESS);
788: for (i = 0; i < snes->numbermonitors; ++i) {
789: PetscViewerAndFormat *vf = (PetscViewerAndFormat *)snes->monitorcontext[i];
790: PetscDraw draw;
791: PetscReal lpause;
793: if (!vf) continue;
794: if (vf->lg) {
795: if (!PetscCheckPointer(vf->lg, PETSC_OBJECT)) continue;
796: if (((PetscObject)vf->lg)->classid != PETSC_DRAWLG_CLASSID) continue;
797: PetscCall(PetscDrawLGGetDraw(vf->lg, &draw));
798: PetscCall(PetscDrawGetPause(draw, &lpause));
799: PetscCall(PetscDrawSetPause(draw, -1.0));
800: PetscCall(PetscDrawPause(draw));
801: PetscCall(PetscDrawSetPause(draw, lpause));
802: } else {
803: PetscBool isdraw;
805: if (!PetscCheckPointer(vf->viewer, PETSC_OBJECT)) continue;
806: if (((PetscObject)vf->viewer)->classid != PETSC_VIEWER_CLASSID) continue;
807: PetscCall(PetscObjectTypeCompare((PetscObject)vf->viewer, PETSCVIEWERDRAW, &isdraw));
808: if (!isdraw) continue;
809: PetscCall(PetscViewerDrawGetDraw(vf->viewer, 0, &draw));
810: PetscCall(PetscDrawGetPause(draw, &lpause));
811: PetscCall(PetscDrawSetPause(draw, -1.0));
812: PetscCall(PetscDrawPause(draw));
813: PetscCall(PetscDrawSetPause(draw, lpause));
814: }
815: }
816: PetscFunctionReturn(PETSC_SUCCESS);
817: }
819: /*@C
820: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
822: Collective
824: Input Parameters:
825: + snes - `SNES` object you wish to monitor
826: . name - the monitor type one is seeking
827: . help - message indicating what monitoring is done
828: . manual - manual page for the monitor
829: . monitor - the monitor function
830: - 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
832: Calling sequence of `monitor`:
833: + snes - the nonlinear solver context
834: . it - the current iteration
835: . r - the current function norm
836: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
838: Calling sequence of `monitorsetup`:
839: + snes - the nonlinear solver context
840: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
842: Options Database Key:
843: . -name - trigger the use of this monitor in `SNESSetFromOptions()`
845: Level: advanced
847: .seealso: [](ch_snes), `PetscOptionsGetViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
848: `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`
849: `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
850: `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
851: `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
852: `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
853: `PetscOptionsFList()`, `PetscOptionsEList()`
854: @*/
855: 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))
856: {
857: PetscViewer viewer;
858: PetscViewerFormat format;
859: PetscBool flg;
861: PetscFunctionBegin;
862: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, name, &viewer, &format, &flg));
863: if (flg) {
864: PetscViewerAndFormat *vf;
865: PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
866: PetscCall(PetscOptionsRestoreViewer(&viewer));
867: if (monitorsetup) PetscCall((*monitorsetup)(snes, vf));
868: PetscCall(SNESMonitorSet(snes, (PetscErrorCode(*)(SNES, PetscInt, PetscReal, void *))monitor, vf, (PetscErrorCode(*)(void **))PetscViewerAndFormatDestroy));
869: }
870: PetscFunctionReturn(PETSC_SUCCESS);
871: }
873: PetscErrorCode SNESEWSetFromOptions_Private(SNESKSPEW *kctx, PetscBool print_api, MPI_Comm comm, const char *prefix)
874: {
875: const char *api = print_api ? "SNESKSPSetParametersEW" : NULL;
877: PetscFunctionBegin;
878: PetscOptionsBegin(comm, prefix, "Eisenstat and Walker type forcing options", "KSP");
879: PetscCall(PetscOptionsInt("-ksp_ew_version", "Version 1, 2 or 3", api, kctx->version, &kctx->version, NULL));
880: PetscCall(PetscOptionsReal("-ksp_ew_rtol0", "0 <= rtol0 < 1", api, kctx->rtol_0, &kctx->rtol_0, NULL));
881: kctx->rtol_max = PetscMax(kctx->rtol_0, kctx->rtol_max);
882: PetscCall(PetscOptionsReal("-ksp_ew_rtolmax", "0 <= rtolmax < 1", api, kctx->rtol_max, &kctx->rtol_max, NULL));
883: PetscCall(PetscOptionsReal("-ksp_ew_gamma", "0 <= gamma <= 1", api, kctx->gamma, &kctx->gamma, NULL));
884: PetscCall(PetscOptionsReal("-ksp_ew_alpha", "1 < alpha <= 2", api, kctx->alpha, &kctx->alpha, NULL));
885: PetscCall(PetscOptionsReal("-ksp_ew_alpha2", "alpha2", NULL, kctx->alpha2, &kctx->alpha2, NULL));
886: PetscCall(PetscOptionsReal("-ksp_ew_threshold", "0 < threshold < 1", api, kctx->threshold, &kctx->threshold, NULL));
887: PetscCall(PetscOptionsReal("-ksp_ew_v4_p1", "p1", NULL, kctx->v4_p1, &kctx->v4_p1, NULL));
888: PetscCall(PetscOptionsReal("-ksp_ew_v4_p2", "p2", NULL, kctx->v4_p2, &kctx->v4_p2, NULL));
889: PetscCall(PetscOptionsReal("-ksp_ew_v4_p3", "p3", NULL, kctx->v4_p3, &kctx->v4_p3, NULL));
890: PetscCall(PetscOptionsReal("-ksp_ew_v4_m1", "Scaling when rk-1 in [p2,p3)", NULL, kctx->v4_m1, &kctx->v4_m1, NULL));
891: PetscCall(PetscOptionsReal("-ksp_ew_v4_m2", "Scaling when rk-1 in [p3,+infty)", NULL, kctx->v4_m2, &kctx->v4_m2, NULL));
892: PetscCall(PetscOptionsReal("-ksp_ew_v4_m3", "Threshold for successive rtol (0.1 in Eq.7)", NULL, kctx->v4_m3, &kctx->v4_m3, NULL));
893: PetscCall(PetscOptionsReal("-ksp_ew_v4_m4", "Adaptation scaling (0.5 in Eq.7)", NULL, kctx->v4_m4, &kctx->v4_m4, NULL));
894: PetscOptionsEnd();
895: PetscFunctionReturn(PETSC_SUCCESS);
896: }
898: /*@
899: SNESSetFromOptions - Sets various `SNES` and `KSP` parameters from user options.
901: Collective
903: Input Parameter:
904: . snes - the `SNES` context
906: Options Database Keys:
907: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, `SNESType` for complete list
908: . -snes_stol <stol> - convergence tolerance in terms of the norm of the change in the solution between steps
909: . -snes_atol <abstol> - absolute tolerance of residual norm
910: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
911: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
912: . -snes_force_iteration <force> - force `SNESSolve()` to take at least one iteration
913: . -snes_max_it <max_it> - maximum number of iterations
914: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
915: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
916: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
917: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
918: . -snes_lag_preconditioner_persists <true,false> - retains the -snes_lag_preconditioner information across multiple SNESSolve()
919: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
920: . -snes_lag_jacobian_persists <true,false> - retains the -snes_lag_jacobian information across multiple SNESSolve()
921: . -snes_tr_tol <trtol> - trust region tolerance
922: . -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.
923: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
924: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
925: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
926: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
927: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
928: . -snes_monitor_lg_range - plots residual norm at each iteration
929: . -snes_monitor_pause_final - Pauses all monitor drawing after the solver ends
930: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
931: . -snes_fd_color - use finite differences with coloring to compute Jacobian
932: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each `KSP` iteration
933: . -snes_converged_reason - print the reason for convergence/divergence after each solve
934: . -npc_snes_type <type> - the `SNES` type to use as a nonlinear preconditioner
935: . -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.
936: - -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.
938: Options Database Keys for Eisenstat-Walker method:
939: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
940: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
941: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
942: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
943: . -snes_ksp_ew_gamma <gamma> - Sets gamma
944: . -snes_ksp_ew_alpha <alpha> - Sets alpha
945: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
946: - -snes_ksp_ew_threshold <threshold> - Sets threshold
948: Level: beginner
950: Notes:
951: To see all options, run your program with the -help option or consult the users manual
953: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
954: and computing explicitly with
955: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
957: .seealso: [](ch_snes), `SNESType`, `SNESSetOptionsPrefix()`, `SNESResetFromOptions()`, `SNES`, `SNESCreate()`, `MatCreateSNESMF()`, `MatFDColoring`
958: @*/
959: PetscErrorCode SNESSetFromOptions(SNES snes)
960: {
961: PetscBool flg, pcset, persist, set;
962: PetscInt i, indx, lag, grids;
963: const char *deft = SNESNEWTONLS;
964: const char *convtests[] = {"default", "skip", "correct_pressure"};
965: SNESKSPEW *kctx = NULL;
966: char type[256], monfilename[PETSC_MAX_PATH_LEN], ewprefix[256];
967: PCSide pcside;
968: const char *optionsprefix;
970: PetscFunctionBegin;
972: PetscCall(SNESRegisterAll());
973: PetscObjectOptionsBegin((PetscObject)snes);
974: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
975: PetscCall(PetscOptionsFList("-snes_type", "Nonlinear solver method", "SNESSetType", SNESList, deft, type, 256, &flg));
976: if (flg) {
977: PetscCall(SNESSetType(snes, type));
978: } else if (!((PetscObject)snes)->type_name) {
979: PetscCall(SNESSetType(snes, deft));
980: }
981: PetscCall(PetscOptionsReal("-snes_stol", "Stop if step length less than", "SNESSetTolerances", snes->stol, &snes->stol, NULL));
982: PetscCall(PetscOptionsReal("-snes_atol", "Stop if function norm less than", "SNESSetTolerances", snes->abstol, &snes->abstol, NULL));
984: PetscCall(PetscOptionsReal("-snes_rtol", "Stop if decrease in function norm less than", "SNESSetTolerances", snes->rtol, &snes->rtol, NULL));
985: PetscCall(PetscOptionsReal("-snes_divergence_tolerance", "Stop if residual norm increases by this factor", "SNESSetDivergenceTolerance", snes->divtol, &snes->divtol, NULL));
986: PetscCall(PetscOptionsInt("-snes_max_it", "Maximum iterations", "SNESSetTolerances", snes->max_its, &snes->max_its, NULL));
987: PetscCall(PetscOptionsInt("-snes_max_funcs", "Maximum function evaluations", "SNESSetTolerances", snes->max_funcs, &snes->max_funcs, NULL));
988: PetscCall(PetscOptionsInt("-snes_max_fail", "Maximum nonlinear step failures", "SNESSetMaxNonlinearStepFailures", snes->maxFailures, &snes->maxFailures, NULL));
989: PetscCall(PetscOptionsInt("-snes_max_linear_solve_fail", "Maximum failures in linear solves allowed", "SNESSetMaxLinearSolveFailures", snes->maxLinearSolveFailures, &snes->maxLinearSolveFailures, NULL));
990: PetscCall(PetscOptionsBool("-snes_error_if_not_converged", "Generate error if solver does not converge", "SNESSetErrorIfNotConverged", snes->errorifnotconverged, &snes->errorifnotconverged, NULL));
991: PetscCall(PetscOptionsBool("-snes_force_iteration", "Force SNESSolve() to take at least one iteration", "SNESSetForceIteration", snes->forceiteration, &snes->forceiteration, NULL));
992: PetscCall(PetscOptionsBool("-snes_check_jacobian_domain_error", "Check Jacobian domain error after Jacobian evaluation", "SNESCheckJacobianDomainError", snes->checkjacdomainerror, &snes->checkjacdomainerror, NULL));
994: PetscCall(PetscOptionsInt("-snes_lag_preconditioner", "How often to rebuild preconditioner", "SNESSetLagPreconditioner", snes->lagpreconditioner, &lag, &flg));
995: if (flg) {
996: 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");
997: PetscCall(SNESSetLagPreconditioner(snes, lag));
998: }
999: PetscCall(PetscOptionsBool("-snes_lag_preconditioner_persists", "Preconditioner lagging through multiple SNES solves", "SNESSetLagPreconditionerPersists", snes->lagjac_persist, &persist, &flg));
1000: if (flg) PetscCall(SNESSetLagPreconditionerPersists(snes, persist));
1001: PetscCall(PetscOptionsInt("-snes_lag_jacobian", "How often to rebuild Jacobian", "SNESSetLagJacobian", snes->lagjacobian, &lag, &flg));
1002: if (flg) {
1003: 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");
1004: PetscCall(SNESSetLagJacobian(snes, lag));
1005: }
1006: PetscCall(PetscOptionsBool("-snes_lag_jacobian_persists", "Jacobian lagging through multiple SNES solves", "SNESSetLagJacobianPersists", snes->lagjac_persist, &persist, &flg));
1007: if (flg) PetscCall(SNESSetLagJacobianPersists(snes, persist));
1009: PetscCall(PetscOptionsInt("-snes_grid_sequence", "Use grid sequencing to generate initial guess", "SNESSetGridSequence", snes->gridsequence, &grids, &flg));
1010: if (flg) PetscCall(SNESSetGridSequence(snes, grids));
1012: PetscCall(PetscOptionsEList("-snes_convergence_test", "Convergence test", "SNESSetConvergenceTest", convtests, PETSC_STATIC_ARRAY_LENGTH(convtests), "default", &indx, &flg));
1013: if (flg) {
1014: switch (indx) {
1015: case 0:
1016: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedDefault, NULL, NULL));
1017: break;
1018: case 1:
1019: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedSkip, NULL, NULL));
1020: break;
1021: case 2:
1022: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedCorrectPressure, NULL, NULL));
1023: break;
1024: }
1025: }
1027: PetscCall(PetscOptionsEList("-snes_norm_schedule", "SNES Norm schedule", "SNESSetNormSchedule", SNESNormSchedules, 5, "function", &indx, &flg));
1028: if (flg) PetscCall(SNESSetNormSchedule(snes, (SNESNormSchedule)indx));
1030: PetscCall(PetscOptionsEList("-snes_function_type", "SNES Norm schedule", "SNESSetFunctionType", SNESFunctionTypes, 2, "unpreconditioned", &indx, &flg));
1031: if (flg) PetscCall(SNESSetFunctionType(snes, (SNESFunctionType)indx));
1033: kctx = (SNESKSPEW *)snes->kspconvctx;
1035: PetscCall(PetscOptionsBool("-snes_ksp_ew", "Use Eisentat-Walker linear system convergence test", "SNESKSPSetUseEW", snes->ksp_ewconv, &snes->ksp_ewconv, NULL));
1037: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1038: PetscCall(PetscSNPrintf(ewprefix, sizeof(ewprefix), "%s%s", optionsprefix ? optionsprefix : "", "snes_"));
1039: PetscCall(SNESEWSetFromOptions_Private(kctx, PETSC_TRUE, PetscObjectComm((PetscObject)snes), ewprefix));
1041: flg = PETSC_FALSE;
1042: PetscCall(PetscOptionsBool("-snes_monitor_cancel", "Remove all monitors", "SNESMonitorCancel", flg, &flg, &set));
1043: if (set && flg) PetscCall(SNESMonitorCancel(snes));
1045: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor", "Monitor norm of function", "SNESMonitorDefault", SNESMonitorDefault, SNESMonitorDefaultSetUp));
1046: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_short", "Monitor norm of function with fewer digits", "SNESMonitorDefaultShort", SNESMonitorDefaultShort, NULL));
1047: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_range", "Monitor range of elements of function", "SNESMonitorRange", SNESMonitorRange, NULL));
1049: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_ratio", "Monitor ratios of the norm of function for consecutive steps", "SNESMonitorRatio", SNESMonitorRatio, SNESMonitorRatioSetUp));
1050: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_field", "Monitor norm of function (split into fields)", "SNESMonitorDefaultField", SNESMonitorDefaultField, NULL));
1051: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution", "View solution at each iteration", "SNESMonitorSolution", SNESMonitorSolution, NULL));
1052: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution_update", "View correction at each iteration", "SNESMonitorSolutionUpdate", SNESMonitorSolutionUpdate, NULL));
1053: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_residual", "View residual at each iteration", "SNESMonitorResidual", SNESMonitorResidual, NULL));
1054: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_jacupdate_spectrum", "Print the change in the spectrum of the Jacobian", "SNESMonitorJacUpdateSpectrum", SNESMonitorJacUpdateSpectrum, NULL));
1055: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_fields", "Monitor norm of function per field", "SNESMonitorSet", SNESMonitorFields, NULL));
1056: PetscCall(PetscOptionsBool("-snes_monitor_pause_final", "Pauses all draw monitors at the final iterate", "SNESMonitorPauseFinal_Internal", PETSC_FALSE, &snes->pauseFinal, NULL));
1058: PetscCall(PetscOptionsString("-snes_monitor_python", "Use Python function", "SNESMonitorSet", NULL, monfilename, sizeof(monfilename), &flg));
1059: if (flg) PetscCall(PetscPythonMonitorSet((PetscObject)snes, monfilename));
1061: flg = PETSC_FALSE;
1062: PetscCall(PetscOptionsBool("-snes_monitor_lg_range", "Plot function range at each iteration", "SNESMonitorLGRange", flg, &flg, NULL));
1063: if (flg) {
1064: PetscViewer ctx;
1066: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &ctx));
1067: PetscCall(SNESMonitorSet(snes, SNESMonitorLGRange, ctx, (PetscErrorCode(*)(void **))PetscViewerDestroy));
1068: }
1070: flg = PETSC_FALSE;
1071: PetscCall(PetscOptionsBool("-snes_converged_reason_view_cancel", "Remove all converged reason viewers", "SNESConvergedReasonViewCancel", flg, &flg, &set));
1072: if (set && flg) PetscCall(SNESConvergedReasonViewCancel(snes));
1074: flg = PETSC_FALSE;
1075: PetscCall(PetscOptionsBool("-snes_fd", "Use finite differences (slow) to compute Jacobian", "SNESComputeJacobianDefault", flg, &flg, NULL));
1076: if (flg) {
1077: void *functx;
1078: DM dm;
1079: PetscCall(SNESGetDM(snes, &dm));
1080: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1081: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
1082: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefault, functx));
1083: PetscCall(PetscInfo(snes, "Setting default finite difference Jacobian matrix\n"));
1084: }
1086: flg = PETSC_FALSE;
1087: PetscCall(PetscOptionsBool("-snes_fd_function", "Use finite differences (slow) to compute function from user objective", "SNESObjectiveComputeFunctionDefaultFD", flg, &flg, NULL));
1088: if (flg) PetscCall(SNESSetFunction(snes, NULL, SNESObjectiveComputeFunctionDefaultFD, NULL));
1090: flg = PETSC_FALSE;
1091: PetscCall(PetscOptionsBool("-snes_fd_color", "Use finite differences with coloring to compute Jacobian", "SNESComputeJacobianDefaultColor", flg, &flg, NULL));
1092: if (flg) {
1093: DM dm;
1094: PetscCall(SNESGetDM(snes, &dm));
1095: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1096: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefaultColor, NULL));
1097: PetscCall(PetscInfo(snes, "Setting default finite difference coloring Jacobian matrix\n"));
1098: }
1100: flg = PETSC_FALSE;
1101: PetscCall(PetscOptionsBool("-snes_mf_operator", "Use a Matrix-Free Jacobian with user-provided preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf_operator, &flg));
1102: if (flg && snes->mf_operator) {
1103: snes->mf_operator = PETSC_TRUE;
1104: snes->mf = PETSC_TRUE;
1105: }
1106: flg = PETSC_FALSE;
1107: PetscCall(PetscOptionsBool("-snes_mf", "Use a Matrix-Free Jacobian with no preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf, &flg));
1108: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1109: PetscCall(PetscOptionsInt("-snes_mf_version", "Matrix-Free routines version 1 or 2", "None", snes->mf_version, &snes->mf_version, NULL));
1111: flg = PETSC_FALSE;
1112: PetscCall(SNESGetNPCSide(snes, &pcside));
1113: PetscCall(PetscOptionsEnum("-snes_npc_side", "SNES nonlinear preconditioner side", "SNESSetNPCSide", PCSides, (PetscEnum)pcside, (PetscEnum *)&pcside, &flg));
1114: if (flg) PetscCall(SNESSetNPCSide(snes, pcside));
1116: #if defined(PETSC_HAVE_SAWS)
1117: /*
1118: Publish convergence information using SAWs
1119: */
1120: flg = PETSC_FALSE;
1121: PetscCall(PetscOptionsBool("-snes_monitor_saws", "Publish SNES progress using SAWs", "SNESMonitorSet", flg, &flg, NULL));
1122: if (flg) {
1123: void *ctx;
1124: PetscCall(SNESMonitorSAWsCreate(snes, &ctx));
1125: PetscCall(SNESMonitorSet(snes, SNESMonitorSAWs, ctx, SNESMonitorSAWsDestroy));
1126: }
1127: #endif
1128: #if defined(PETSC_HAVE_SAWS)
1129: {
1130: PetscBool set;
1131: flg = PETSC_FALSE;
1132: PetscCall(PetscOptionsBool("-snes_saws_block", "Block for SAWs at end of SNESSolve", "PetscObjectSAWsBlock", ((PetscObject)snes)->amspublishblock, &flg, &set));
1133: if (set) PetscCall(PetscObjectSAWsSetBlock((PetscObject)snes, flg));
1134: }
1135: #endif
1137: for (i = 0; i < numberofsetfromoptions; i++) PetscCall((*othersetfromoptions[i])(snes));
1139: PetscTryTypeMethod(snes, setfromoptions, PetscOptionsObject);
1141: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1142: PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)snes, PetscOptionsObject));
1143: PetscOptionsEnd();
1145: if (snes->linesearch) {
1146: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
1147: PetscCall(SNESLineSearchSetFromOptions(snes->linesearch));
1148: }
1150: if (snes->usesksp) {
1151: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
1152: PetscCall(KSPSetOperators(snes->ksp, snes->jacobian, snes->jacobian_pre));
1153: PetscCall(KSPSetFromOptions(snes->ksp));
1154: }
1156: /* if user has set the SNES NPC type via options database, create it. */
1157: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1158: PetscCall(PetscOptionsHasName(((PetscObject)snes)->options, optionsprefix, "-npc_snes_type", &pcset));
1159: if (pcset && (!snes->npc)) PetscCall(SNESGetNPC(snes, &snes->npc));
1160: if (snes->npc) PetscCall(SNESSetFromOptions(snes->npc));
1161: snes->setfromoptionscalled++;
1162: PetscFunctionReturn(PETSC_SUCCESS);
1163: }
1165: /*@
1166: SNESResetFromOptions - Sets various `SNES` and `KSP` parameters from user options ONLY if the `SNESSetFromOptions()` was previously called
1168: Collective
1170: Input Parameter:
1171: . snes - the `SNES` context
1173: Level: advanced
1175: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESSetOptionsPrefix()`
1176: @*/
1177: PetscErrorCode SNESResetFromOptions(SNES snes)
1178: {
1179: PetscFunctionBegin;
1180: if (snes->setfromoptionscalled) PetscCall(SNESSetFromOptions(snes));
1181: PetscFunctionReturn(PETSC_SUCCESS);
1182: }
1184: /*@C
1185: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1186: the nonlinear solvers.
1188: Logically Collective; No Fortran Support
1190: Input Parameters:
1191: + snes - the `SNES` context
1192: . compute - function to compute the context
1193: - destroy - function to destroy the context
1195: Calling sequence of `compute`:
1196: + snes - the `SNES` context
1197: - ctx - context to be computed
1199: Calling sequence of `destroy`:
1200: . ctx - context to be computed by `compute()`
1202: Level: intermediate
1204: Note:
1205: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1207: Use `SNESSetApplicationContext()` to see the context immediately
1209: .seealso: [](ch_snes), `SNESGetApplicationContext()`, `SNESSetApplicationContext()`
1210: @*/
1211: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES snes, void **ctx), PetscErrorCode (*destroy)(void **ctx))
1212: {
1213: PetscFunctionBegin;
1215: snes->ops->usercompute = compute;
1216: snes->ops->userdestroy = destroy;
1217: PetscFunctionReturn(PETSC_SUCCESS);
1218: }
1220: /*@
1221: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1223: Logically Collective
1225: Input Parameters:
1226: + snes - the `SNES` context
1227: - usrP - optional user context
1229: Level: intermediate
1231: Notes:
1232: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian, or other evaluation function
1233: with `SNESGetApplicationContext()`
1235: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1237: Fortran Note:
1238: You must write a Fortran interface definition for this
1239: function that tells Fortran the Fortran derived data type that you are passing in as the `usrP` argument.
1241: .seealso: [](ch_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1242: @*/
1243: PetscErrorCode SNESSetApplicationContext(SNES snes, void *usrP)
1244: {
1245: KSP ksp;
1247: PetscFunctionBegin;
1249: PetscCall(SNESGetKSP(snes, &ksp));
1250: PetscCall(KSPSetApplicationContext(ksp, usrP));
1251: snes->user = usrP;
1252: PetscFunctionReturn(PETSC_SUCCESS);
1253: }
1255: /*@
1256: SNESGetApplicationContext - Gets the user-defined context for the
1257: nonlinear solvers set with `SNESGetApplicationContext()` or `SNESSetComputeApplicationContext()`
1259: Not Collective
1261: Input Parameter:
1262: . snes - `SNES` context
1264: Output Parameter:
1265: . usrP - user context
1267: Level: intermediate
1269: Fortran Note:
1270: You must write a Fortran interface definition for this
1271: function that tells Fortran the Fortran derived data type that you are passing in as the `usrP` argument.
1273: .seealso: [](ch_snes), `SNESSetApplicationContext()`, `SNESSetComputeApplicationContext()`
1274: @*/
1275: PetscErrorCode SNESGetApplicationContext(SNES snes, void *usrP)
1276: {
1277: PetscFunctionBegin;
1279: *(void **)usrP = snes->user;
1280: PetscFunctionReturn(PETSC_SUCCESS);
1281: }
1283: /*@
1284: SNESSetUseMatrixFree - indicates that `SNES` should use matrix-free finite difference matrix-vector products to apply the Jacobian.
1286: Logically Collective
1288: Input Parameters:
1289: + snes - `SNES` context
1290: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1291: - 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
1292: this option no matrix-element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1294: Options Database Keys:
1295: + -snes_mf_operator - use matrix-free only for the mat operator
1296: . -snes_mf - use matrix-free for both the mat and pmat operator
1297: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1298: - -snes_fd - compute the Jacobian via finite differences (slow)
1300: Level: intermediate
1302: Note:
1303: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
1304: and computing explicitly with
1305: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1307: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`, `MatFDColoring`
1308: @*/
1309: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1310: {
1311: PetscFunctionBegin;
1315: snes->mf = mf_operator ? PETSC_TRUE : mf;
1316: snes->mf_operator = mf_operator;
1317: PetscFunctionReturn(PETSC_SUCCESS);
1318: }
1320: /*@
1321: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1323: Not Collective, but the resulting flags will be the same on all MPI processes
1325: Input Parameter:
1326: . snes - `SNES` context
1328: Output Parameters:
1329: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1330: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1332: Level: intermediate
1334: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1335: @*/
1336: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1337: {
1338: PetscFunctionBegin;
1340: if (mf) *mf = snes->mf;
1341: if (mf_operator) *mf_operator = snes->mf_operator;
1342: PetscFunctionReturn(PETSC_SUCCESS);
1343: }
1345: /*@
1346: SNESGetIterationNumber - Gets the number of nonlinear iterations completed in the current or most recent `SNESSolve()`
1348: Not Collective
1350: Input Parameter:
1351: . snes - `SNES` context
1353: Output Parameter:
1354: . iter - iteration number
1356: Level: intermediate
1358: Notes:
1359: For example, during the computation of iteration 2 this would return 1.
1361: This is useful for using lagged Jacobians (where one does not recompute the
1362: Jacobian at each `SNES` iteration). For example, the code
1363: .vb
1364: ierr = SNESGetIterationNumber(snes,&it);
1365: if (!(it % 2)) {
1366: [compute Jacobian here]
1367: }
1368: .ve
1369: can be used in your function that computes the Jacobian to cause the Jacobian to be
1370: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1372: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1374: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`, `SNESSetMonitor()`
1375: @*/
1376: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1377: {
1378: PetscFunctionBegin;
1380: PetscAssertPointer(iter, 2);
1381: *iter = snes->iter;
1382: PetscFunctionReturn(PETSC_SUCCESS);
1383: }
1385: /*@
1386: SNESSetIterationNumber - Sets the current iteration number.
1388: Not Collective
1390: Input Parameters:
1391: + snes - `SNES` context
1392: - iter - iteration number
1394: Level: developer
1396: Note:
1397: This should only be called inside a `SNES` nonlinear solver.
1399: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1400: @*/
1401: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1402: {
1403: PetscFunctionBegin;
1405: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1406: snes->iter = iter;
1407: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1408: PetscFunctionReturn(PETSC_SUCCESS);
1409: }
1411: /*@
1412: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1413: attempted by the nonlinear solver in the current or most recent `SNESSolve()` .
1415: Not Collective
1417: Input Parameter:
1418: . snes - `SNES` context
1420: Output Parameter:
1421: . nfails - number of unsuccessful steps attempted
1423: Level: intermediate
1425: Note:
1426: This counter is reset to zero for each successive call to `SNESSolve()`.
1428: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1429: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1430: @*/
1431: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1432: {
1433: PetscFunctionBegin;
1435: PetscAssertPointer(nfails, 2);
1436: *nfails = snes->numFailures;
1437: PetscFunctionReturn(PETSC_SUCCESS);
1438: }
1440: /*@
1441: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1442: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1444: Not Collective
1446: Input Parameters:
1447: + snes - `SNES` context
1448: - maxFails - maximum of unsuccessful steps
1450: Options Database Key:
1451: . -snes_max_fail <n> - maximum number of unsuccessful steps allowed
1453: Level: intermediate
1455: Developer Note:
1456: The options database key is wrong for this function name
1458: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1459: `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1460: @*/
1461: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1462: {
1463: PetscFunctionBegin;
1465: snes->maxFailures = maxFails;
1466: PetscFunctionReturn(PETSC_SUCCESS);
1467: }
1469: /*@
1470: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1471: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1473: Not Collective
1475: Input Parameter:
1476: . snes - `SNES` context
1478: Output Parameter:
1479: . maxFails - maximum of unsuccessful steps
1481: Level: intermediate
1483: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1484: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1485: @*/
1486: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1487: {
1488: PetscFunctionBegin;
1490: PetscAssertPointer(maxFails, 2);
1491: *maxFails = snes->maxFailures;
1492: PetscFunctionReturn(PETSC_SUCCESS);
1493: }
1495: /*@
1496: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1497: done by the `SNES` object in the current or most recent `SNESSolve()`
1499: Not Collective
1501: Input Parameter:
1502: . snes - `SNES` context
1504: Output Parameter:
1505: . nfuncs - number of evaluations
1507: Level: intermediate
1509: Note:
1510: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1512: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1513: @*/
1514: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1515: {
1516: PetscFunctionBegin;
1518: PetscAssertPointer(nfuncs, 2);
1519: *nfuncs = snes->nfuncs;
1520: PetscFunctionReturn(PETSC_SUCCESS);
1521: }
1523: /*@
1524: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1525: linear solvers in the current or most recent `SNESSolve()`
1527: Not Collective
1529: Input Parameter:
1530: . snes - `SNES` context
1532: Output Parameter:
1533: . nfails - number of failed solves
1535: Options Database Key:
1536: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1538: Level: intermediate
1540: Note:
1541: This counter is reset to zero for each successive call to `SNESSolve()`.
1543: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1544: @*/
1545: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1546: {
1547: PetscFunctionBegin;
1549: PetscAssertPointer(nfails, 2);
1550: *nfails = snes->numLinearSolveFailures;
1551: PetscFunctionReturn(PETSC_SUCCESS);
1552: }
1554: /*@
1555: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1556: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1558: Logically Collective
1560: Input Parameters:
1561: + snes - `SNES` context
1562: - maxFails - maximum allowed linear solve failures
1564: Options Database Key:
1565: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1567: Level: intermediate
1569: Note:
1570: By default this is 0; that is `SNES` returns on the first failed linear solve
1572: Developer Note:
1573: The options database key is wrong for this function name
1575: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1576: @*/
1577: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1578: {
1579: PetscFunctionBegin;
1582: snes->maxLinearSolveFailures = maxFails;
1583: PetscFunctionReturn(PETSC_SUCCESS);
1584: }
1586: /*@
1587: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1588: are allowed before `SNES` returns as unsuccessful
1590: Not Collective
1592: Input Parameter:
1593: . snes - `SNES` context
1595: Output Parameter:
1596: . maxFails - maximum of unsuccessful solves allowed
1598: Level: intermediate
1600: Note:
1601: By default this is 1; that is `SNES` returns on the first failed linear solve
1603: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1604: @*/
1605: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1606: {
1607: PetscFunctionBegin;
1609: PetscAssertPointer(maxFails, 2);
1610: *maxFails = snes->maxLinearSolveFailures;
1611: PetscFunctionReturn(PETSC_SUCCESS);
1612: }
1614: /*@
1615: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1616: used by the nonlinear solver in the most recent `SNESSolve()`
1618: Not Collective
1620: Input Parameter:
1621: . snes - `SNES` context
1623: Output Parameter:
1624: . lits - number of linear iterations
1626: Level: intermediate
1628: Notes:
1629: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1631: 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
1632: then call `KSPGetIterationNumber()` after the failed solve.
1634: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1635: @*/
1636: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1637: {
1638: PetscFunctionBegin;
1640: PetscAssertPointer(lits, 2);
1641: *lits = snes->linear_its;
1642: PetscFunctionReturn(PETSC_SUCCESS);
1643: }
1645: /*@
1646: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1647: are reset every time `SNESSolve()` is called.
1649: Logically Collective
1651: Input Parameters:
1652: + snes - `SNES` context
1653: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1655: Level: developer
1657: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1658: @*/
1659: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1660: {
1661: PetscFunctionBegin;
1664: snes->counters_reset = reset;
1665: PetscFunctionReturn(PETSC_SUCCESS);
1666: }
1668: /*@
1669: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1671: Not Collective, but the `SNES` and `KSP` objects must live on the same `MPI_Comm`
1673: Input Parameters:
1674: + snes - the `SNES` context
1675: - ksp - the `KSP` context
1677: Level: developer
1679: Notes:
1680: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1681: so this routine is rarely needed.
1683: The `KSP` object that is already in the `SNES` object has its reference count
1684: decreased by one when this is called.
1686: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`
1687: @*/
1688: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1689: {
1690: PetscFunctionBegin;
1693: PetscCheckSameComm(snes, 1, ksp, 2);
1694: PetscCall(PetscObjectReference((PetscObject)ksp));
1695: if (snes->ksp) PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1696: snes->ksp = ksp;
1697: PetscFunctionReturn(PETSC_SUCCESS);
1698: }
1700: /*@
1701: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1703: Collective
1705: Input Parameter:
1706: . comm - MPI communicator
1708: Output Parameter:
1709: . outsnes - the new `SNES` context
1711: Options Database Keys:
1712: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no preconditioning matrix
1713: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided preconditioning matrix
1714: as set by `SNESSetJacobian()`
1715: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1716: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1718: Level: beginner
1720: Developer Notes:
1721: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1722: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1723: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1724: in `SNESView()`.
1726: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1727: by help messages about meaningless `SNES` options.
1729: `SNES` always creates the snes->kspconvctx even though it is used by only one type. This should be fixed.
1731: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1732: @*/
1733: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1734: {
1735: SNES snes;
1736: SNESKSPEW *kctx;
1738: PetscFunctionBegin;
1739: PetscAssertPointer(outsnes, 2);
1740: *outsnes = NULL;
1741: PetscCall(SNESInitializePackage());
1743: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1745: snes->ops->converged = SNESConvergedDefault;
1746: snes->usesksp = PETSC_TRUE;
1747: snes->tolerancesset = PETSC_FALSE;
1748: snes->max_its = 50;
1749: snes->max_funcs = 10000;
1750: snes->norm = 0.0;
1751: snes->xnorm = 0.0;
1752: snes->ynorm = 0.0;
1753: snes->normschedule = SNES_NORM_ALWAYS;
1754: snes->functype = SNES_FUNCTION_DEFAULT;
1755: snes->rtol = PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8;
1756: snes->ttol = 0.0;
1757: snes->abstol = PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50;
1758: snes->stol = PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8;
1759: snes->deltatol = PetscDefined(USE_REAL_SINGLE) ? 1.e-6 : 1.e-12;
1760: snes->divtol = 1.e4;
1761: snes->rnorm0 = 0;
1762: snes->nfuncs = 0;
1763: snes->numFailures = 0;
1764: snes->maxFailures = 1;
1765: snes->linear_its = 0;
1766: snes->lagjacobian = 1;
1767: snes->jac_iter = 0;
1768: snes->lagjac_persist = PETSC_FALSE;
1769: snes->lagpreconditioner = 1;
1770: snes->pre_iter = 0;
1771: snes->lagpre_persist = PETSC_FALSE;
1772: snes->numbermonitors = 0;
1773: snes->numberreasonviews = 0;
1774: snes->data = NULL;
1775: snes->setupcalled = PETSC_FALSE;
1776: snes->ksp_ewconv = PETSC_FALSE;
1777: snes->nwork = 0;
1778: snes->work = NULL;
1779: snes->nvwork = 0;
1780: snes->vwork = NULL;
1781: snes->conv_hist_len = 0;
1782: snes->conv_hist_max = 0;
1783: snes->conv_hist = NULL;
1784: snes->conv_hist_its = NULL;
1785: snes->conv_hist_reset = PETSC_TRUE;
1786: snes->counters_reset = PETSC_TRUE;
1787: snes->vec_func_init_set = PETSC_FALSE;
1788: snes->reason = SNES_CONVERGED_ITERATING;
1789: snes->npcside = PC_RIGHT;
1790: snes->setfromoptionscalled = 0;
1792: snes->mf = PETSC_FALSE;
1793: snes->mf_operator = PETSC_FALSE;
1794: snes->mf_version = 1;
1796: snes->numLinearSolveFailures = 0;
1797: snes->maxLinearSolveFailures = 1;
1799: snes->vizerotolerance = 1.e-8;
1800: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1802: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1803: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1805: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1806: PetscCall(PetscNew(&kctx));
1808: snes->kspconvctx = (void *)kctx;
1809: kctx->version = 2;
1810: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1811: this was too large for some test cases */
1812: kctx->rtol_last = 0.0;
1813: kctx->rtol_max = 0.9;
1814: kctx->gamma = 1.0;
1815: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1816: kctx->alpha2 = kctx->alpha;
1817: kctx->threshold = 0.1;
1818: kctx->lresid_last = 0.0;
1819: kctx->norm_last = 0.0;
1821: kctx->rk_last = 0.0;
1822: kctx->rk_last_2 = 0.0;
1823: kctx->rtol_last_2 = 0.0;
1824: kctx->v4_p1 = 0.1;
1825: kctx->v4_p2 = 0.4;
1826: kctx->v4_p3 = 0.7;
1827: kctx->v4_m1 = 0.8;
1828: kctx->v4_m2 = 0.5;
1829: kctx->v4_m3 = 0.1;
1830: kctx->v4_m4 = 0.5;
1832: *outsnes = snes;
1833: PetscFunctionReturn(PETSC_SUCCESS);
1834: }
1836: /*@C
1837: SNESSetFunction - Sets the function evaluation routine and function
1838: vector for use by the `SNES` routines in solving systems of nonlinear
1839: equations.
1841: Logically Collective
1843: Input Parameters:
1844: + snes - the `SNES` context
1845: . r - vector to store function values, may be `NULL`
1846: . f - function evaluation routine; for calling sequence see `SNESFunctionFn`
1847: - ctx - [optional] user-defined context for private data for the
1848: function evaluation routine (may be `NULL`)
1850: Level: beginner
1852: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunctionFn`
1853: @*/
1854: PetscErrorCode SNESSetFunction(SNES snes, Vec r, SNESFunctionFn *f, void *ctx)
1855: {
1856: DM dm;
1858: PetscFunctionBegin;
1860: if (r) {
1862: PetscCheckSameComm(snes, 1, r, 2);
1863: PetscCall(PetscObjectReference((PetscObject)r));
1864: PetscCall(VecDestroy(&snes->vec_func));
1865: snes->vec_func = r;
1866: }
1867: PetscCall(SNESGetDM(snes, &dm));
1868: PetscCall(DMSNESSetFunction(dm, f, ctx));
1869: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1870: PetscFunctionReturn(PETSC_SUCCESS);
1871: }
1873: /*@C
1874: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1876: Logically Collective
1878: Input Parameters:
1879: + snes - the `SNES` context
1880: - f - vector to store function value
1882: Level: developer
1884: Notes:
1885: This should not be modified during the solution procedure.
1887: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1889: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1890: @*/
1891: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1892: {
1893: Vec vec_func;
1895: PetscFunctionBegin;
1898: PetscCheckSameComm(snes, 1, f, 2);
1899: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1900: snes->vec_func_init_set = PETSC_FALSE;
1901: PetscFunctionReturn(PETSC_SUCCESS);
1902: }
1903: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
1904: PetscCall(VecCopy(f, vec_func));
1906: snes->vec_func_init_set = PETSC_TRUE;
1907: PetscFunctionReturn(PETSC_SUCCESS);
1908: }
1910: /*@
1911: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
1912: of the `SNES` method, when norms are computed in the solving process
1914: Logically Collective
1916: Input Parameters:
1917: + snes - the `SNES` context
1918: - normschedule - the frequency of norm computation
1920: Options Database Key:
1921: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
1923: Level: advanced
1925: Notes:
1926: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
1927: of the nonlinear function and the taking of its norm at every iteration to
1928: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1929: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
1930: may either be monitored for convergence or not. As these are often used as nonlinear
1931: preconditioners, monitoring the norm of their error is not a useful enterprise within
1932: their solution.
1934: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
1935: @*/
1936: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1937: {
1938: PetscFunctionBegin;
1940: snes->normschedule = normschedule;
1941: PetscFunctionReturn(PETSC_SUCCESS);
1942: }
1944: /*@
1945: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
1946: of the `SNES` method.
1948: Logically Collective
1950: Input Parameters:
1951: + snes - the `SNES` context
1952: - normschedule - the type of the norm used
1954: Level: advanced
1956: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1957: @*/
1958: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1959: {
1960: PetscFunctionBegin;
1962: *normschedule = snes->normschedule;
1963: PetscFunctionReturn(PETSC_SUCCESS);
1964: }
1966: /*@
1967: SNESSetFunctionNorm - Sets the last computed residual norm.
1969: Logically Collective
1971: Input Parameters:
1972: + snes - the `SNES` context
1973: - norm - the value of the norm
1975: Level: developer
1977: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1978: @*/
1979: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1980: {
1981: PetscFunctionBegin;
1983: snes->norm = norm;
1984: PetscFunctionReturn(PETSC_SUCCESS);
1985: }
1987: /*@
1988: SNESGetFunctionNorm - Gets the last computed norm of the residual
1990: Not Collective
1992: Input Parameter:
1993: . snes - the `SNES` context
1995: Output Parameter:
1996: . norm - the last computed residual norm
1998: Level: developer
2000: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2001: @*/
2002: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2003: {
2004: PetscFunctionBegin;
2006: PetscAssertPointer(norm, 2);
2007: *norm = snes->norm;
2008: PetscFunctionReturn(PETSC_SUCCESS);
2009: }
2011: /*@
2012: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2014: Not Collective
2016: Input Parameter:
2017: . snes - the `SNES` context
2019: Output Parameter:
2020: . ynorm - the last computed update norm
2022: Level: developer
2024: Note:
2025: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2027: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2028: @*/
2029: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2030: {
2031: PetscFunctionBegin;
2033: PetscAssertPointer(ynorm, 2);
2034: *ynorm = snes->ynorm;
2035: PetscFunctionReturn(PETSC_SUCCESS);
2036: }
2038: /*@
2039: SNESGetSolutionNorm - Gets the last computed norm of the solution
2041: Not Collective
2043: Input Parameter:
2044: . snes - the `SNES` context
2046: Output Parameter:
2047: . xnorm - the last computed solution norm
2049: Level: developer
2051: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2052: @*/
2053: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2054: {
2055: PetscFunctionBegin;
2057: PetscAssertPointer(xnorm, 2);
2058: *xnorm = snes->xnorm;
2059: PetscFunctionReturn(PETSC_SUCCESS);
2060: }
2062: /*@C
2063: SNESSetFunctionType - Sets the `SNESFunctionType`
2064: of the `SNES` method.
2066: Logically Collective
2068: Input Parameters:
2069: + snes - the `SNES` context
2070: - type - the function type
2072: Level: developer
2074: Values of the function type\:
2075: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2076: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2077: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2079: Note:
2080: Different `SNESType`s use this value in different ways
2082: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2083: @*/
2084: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2085: {
2086: PetscFunctionBegin;
2088: snes->functype = type;
2089: PetscFunctionReturn(PETSC_SUCCESS);
2090: }
2092: /*@C
2093: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2094: of the SNES method.
2096: Logically Collective
2098: Input Parameters:
2099: + snes - the `SNES` context
2100: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2102: Level: advanced
2104: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2105: @*/
2106: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2107: {
2108: PetscFunctionBegin;
2110: *type = snes->functype;
2111: PetscFunctionReturn(PETSC_SUCCESS);
2112: }
2114: /*@C
2115: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2116: use with composed nonlinear solvers.
2118: Input Parameters:
2119: + snes - the `SNES` context, usually of the `SNESType` `SNESNGS`
2120: . f - function evaluation routine to apply Gauss-Seidel, see `SNESNGSFn` for calling sequence
2121: - ctx - [optional] user-defined context for private data for the
2122: smoother evaluation routine (may be `NULL`)
2124: Level: intermediate
2126: Note:
2127: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2128: a problem appropriate update to the solution, particularly `SNESFAS`.
2130: .seealso: [](ch_snes), `SNESNGS`, `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`, `SNESNGSFn`
2131: @*/
2132: PetscErrorCode SNESSetNGS(SNES snes, SNESNGSFn *f, void *ctx)
2133: {
2134: DM dm;
2136: PetscFunctionBegin;
2138: PetscCall(SNESGetDM(snes, &dm));
2139: PetscCall(DMSNESSetNGS(dm, f, ctx));
2140: PetscFunctionReturn(PETSC_SUCCESS);
2141: }
2143: /*
2144: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2145: changed during the KSPSolve()
2146: */
2147: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, void *ctx)
2148: {
2149: DM dm;
2150: DMSNES sdm;
2152: PetscFunctionBegin;
2153: PetscCall(SNESGetDM(snes, &dm));
2154: PetscCall(DMGetDMSNES(dm, &sdm));
2155: /* A(x)*x - b(x) */
2156: if (sdm->ops->computepfunction) {
2157: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2158: PetscCall(VecScale(f, -1.0));
2159: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2160: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2161: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2162: PetscCall(MatMultAdd(snes->picard, x, f, f));
2163: } else {
2164: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2165: PetscCall(MatMult(snes->picard, x, f));
2166: }
2167: PetscFunctionReturn(PETSC_SUCCESS);
2168: }
2170: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, void *ctx)
2171: {
2172: DM dm;
2173: DMSNES sdm;
2175: PetscFunctionBegin;
2176: PetscCall(SNESGetDM(snes, &dm));
2177: PetscCall(DMGetDMSNES(dm, &sdm));
2178: /* A(x)*x - b(x) */
2179: if (sdm->ops->computepfunction) {
2180: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2181: PetscCall(VecScale(f, -1.0));
2182: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2183: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2184: } else {
2185: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2186: PetscCall(MatMult(snes->jacobian_pre, x, f));
2187: }
2188: PetscFunctionReturn(PETSC_SUCCESS);
2189: }
2191: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, void *ctx)
2192: {
2193: PetscFunctionBegin;
2194: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2195: /* must assembly if matrix-free to get the last SNES solution */
2196: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2197: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2198: PetscFunctionReturn(PETSC_SUCCESS);
2199: }
2201: /*@C
2202: SNESSetPicard - Use `SNES` to solve the system $A(x) x = bp(x) + b $ via a Picard type iteration (Picard linearization)
2204: Logically Collective
2206: Input Parameters:
2207: + snes - the `SNES` context
2208: . r - vector to store function values, may be `NULL`
2209: . bp - function evaluation routine, may be `NULL`, for the calling sequence see `SNESFunctionFn`
2210: . Amat - matrix with which A(x) x - bp(x) - b is to be computed
2211: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2212: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFn`
2213: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2215: Level: intermediate
2217: Notes:
2218: It is often better to provide the nonlinear function F() and some approximation to its Jacobian directly and use
2219: 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.
2221: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2223: Solves the equation $A(x) x = bp(x) - b$ via the defect correction algorithm $A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}$.
2224: When an exact solver is used this corresponds to the "classic" Picard $A(x^{n}) x^{n+1} = bp(x^{n}) + b$ iteration.
2226: Run with `-snes_mf_operator` to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2228: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2229: the direct Picard iteration $A(x^n) x^{n+1} = bp(x^n) + b$
2231: 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
2232: 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
2233: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument \:-).
2235: 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
2236: A(x^{n}) is used to build the preconditioner
2238: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at a time) and thus represent Newton's method.
2240: 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
2241: 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
2242: 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`.
2243: See the comment in src/snes/tutorials/ex15.c.
2245: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`,
2246: `SNESFunctionFn`, `SNESJacobianFn`
2247: @*/
2248: PetscErrorCode SNESSetPicard(SNES snes, Vec r, SNESFunctionFn *bp, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
2249: {
2250: DM dm;
2252: PetscFunctionBegin;
2254: PetscCall(SNESGetDM(snes, &dm));
2255: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2256: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2257: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2258: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2259: PetscFunctionReturn(PETSC_SUCCESS);
2260: }
2262: /*@C
2263: SNESGetPicard - Returns the context for the Picard iteration
2265: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2267: Input Parameter:
2268: . snes - the `SNES` context
2270: Output Parameters:
2271: + r - the function (or `NULL`)
2272: . f - the function (or `NULL`); for calling sequence see `SNESFunctionFn`
2273: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2274: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2275: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFn`
2276: - ctx - the function context (or `NULL`)
2278: Level: advanced
2280: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunctionFn`, `SNESJacobianFn`
2281: @*/
2282: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, SNESFunctionFn **f, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
2283: {
2284: DM dm;
2286: PetscFunctionBegin;
2288: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2289: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2290: PetscCall(SNESGetDM(snes, &dm));
2291: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2292: PetscFunctionReturn(PETSC_SUCCESS);
2293: }
2295: /*@C
2296: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2298: Logically Collective
2300: Input Parameters:
2301: + snes - the `SNES` context
2302: . func - function evaluation routine, see `SNESInitialGuessFn` for the calling sequence
2303: - ctx - [optional] user-defined context for private data for the
2304: function evaluation routine (may be `NULL`)
2306: Level: intermediate
2308: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESInitialGuessFn`
2309: @*/
2310: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, SNESInitialGuessFn *func, void *ctx)
2311: {
2312: PetscFunctionBegin;
2314: if (func) snes->ops->computeinitialguess = func;
2315: if (ctx) snes->initialguessP = ctx;
2316: PetscFunctionReturn(PETSC_SUCCESS);
2317: }
2319: /*@C
2320: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2321: it assumes a zero right hand side.
2323: Logically Collective
2325: Input Parameter:
2326: . snes - the `SNES` context
2328: Output Parameter:
2329: . rhs - the right hand side vector or `NULL` if there is no right-hand side vector
2331: Level: intermediate
2333: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2334: @*/
2335: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2336: {
2337: PetscFunctionBegin;
2339: PetscAssertPointer(rhs, 2);
2340: *rhs = snes->vec_rhs;
2341: PetscFunctionReturn(PETSC_SUCCESS);
2342: }
2344: /*@
2345: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2347: Collective
2349: Input Parameters:
2350: + snes - the `SNES` context
2351: - x - input vector
2353: Output Parameter:
2354: . y - function vector, as set by `SNESSetFunction()`
2356: Level: developer
2358: Notes:
2359: `SNESComputeFunction()` is typically used within nonlinear solvers
2360: implementations, so users would not generally call this routine themselves.
2362: When solving for $F(x) = b$, this routine computes $y = F(x) - b$.
2364: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`
2365: @*/
2366: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec y)
2367: {
2368: DM dm;
2369: DMSNES sdm;
2371: PetscFunctionBegin;
2375: PetscCheckSameComm(snes, 1, x, 2);
2376: PetscCheckSameComm(snes, 1, y, 3);
2377: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2379: PetscCall(SNESGetDM(snes, &dm));
2380: PetscCall(DMGetDMSNES(dm, &sdm));
2381: 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().");
2382: if (sdm->ops->computefunction) {
2383: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2384: PetscCall(VecLockReadPush(x));
2385: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2386: snes->domainerror = PETSC_FALSE;
2387: {
2388: void *ctx;
2389: SNESFunctionFn *computefunction;
2390: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2391: PetscCallBack("SNES callback function", (*computefunction)(snes, x, y, ctx));
2392: }
2393: PetscCall(VecLockReadPop(x));
2394: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2395: } else /* if (snes->vec_rhs) */ {
2396: PetscCall(MatMult(snes->jacobian, x, y));
2397: }
2398: if (snes->vec_rhs) PetscCall(VecAXPY(y, -1.0, snes->vec_rhs));
2399: snes->nfuncs++;
2400: /*
2401: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2402: propagate the value to all processes
2403: */
2404: if (snes->domainerror) PetscCall(VecSetInf(y));
2405: PetscFunctionReturn(PETSC_SUCCESS);
2406: }
2408: /*@
2409: SNESComputeMFFunction - Calls the function that has been set with `SNESSetMFFunction()`.
2411: Collective
2413: Input Parameters:
2414: + snes - the `SNES` context
2415: - x - input vector
2417: Output Parameter:
2418: . y - function vector, as set by `SNESSetMFFunction()`
2420: Level: developer
2422: Notes:
2423: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2424: so users would not generally call this routine themselves.
2426: Since this function is intended for use with finite differencing it does not subtract the right hand side vector provided with `SNESSolve()`
2427: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2428: 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.
2430: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF`
2431: @*/
2432: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2433: {
2434: DM dm;
2435: DMSNES sdm;
2437: PetscFunctionBegin;
2441: PetscCheckSameComm(snes, 1, x, 2);
2442: PetscCheckSameComm(snes, 1, y, 3);
2443: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2445: PetscCall(SNESGetDM(snes, &dm));
2446: PetscCall(DMGetDMSNES(dm, &sdm));
2447: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2448: PetscCall(VecLockReadPush(x));
2449: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2450: snes->domainerror = PETSC_FALSE;
2451: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2452: PetscCall(VecLockReadPop(x));
2453: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2454: snes->nfuncs++;
2455: /*
2456: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2457: propagate the value to all processes
2458: */
2459: if (snes->domainerror) PetscCall(VecSetInf(y));
2460: PetscFunctionReturn(PETSC_SUCCESS);
2461: }
2463: /*@
2464: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2466: Collective
2468: Input Parameters:
2469: + snes - the `SNES` context
2470: . x - input vector
2471: - b - rhs vector
2473: Output Parameter:
2474: . x - new solution vector
2476: Level: developer
2478: Note:
2479: `SNESComputeNGS()` is typically used within composed nonlinear solver
2480: implementations, so most users would not generally call this routine
2481: themselves.
2483: .seealso: [](ch_snes), `SNESNGSFn`, `SNESSetNGS()`, `SNESComputeFunction()`, `SNESNGS`
2484: @*/
2485: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2486: {
2487: DM dm;
2488: DMSNES sdm;
2490: PetscFunctionBegin;
2494: PetscCheckSameComm(snes, 1, x, 3);
2495: if (b) PetscCheckSameComm(snes, 1, b, 2);
2496: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2497: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2498: PetscCall(SNESGetDM(snes, &dm));
2499: PetscCall(DMGetDMSNES(dm, &sdm));
2500: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2501: if (b) PetscCall(VecLockReadPush(b));
2502: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2503: if (b) PetscCall(VecLockReadPop(b));
2504: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2505: PetscFunctionReturn(PETSC_SUCCESS);
2506: }
2508: static PetscErrorCode SNESComputeFunction_FD(SNES snes, Vec Xin, Vec G)
2509: {
2510: Vec X;
2511: PetscScalar *g;
2512: PetscReal f, f2;
2513: PetscInt low, high, N, i;
2514: PetscBool flg;
2515: PetscReal h = .5 * PETSC_SQRT_MACHINE_EPSILON;
2517: PetscFunctionBegin;
2518: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_fd_delta", &h, &flg));
2519: PetscCall(VecDuplicate(Xin, &X));
2520: PetscCall(VecCopy(Xin, X));
2521: PetscCall(VecGetSize(X, &N));
2522: PetscCall(VecGetOwnershipRange(X, &low, &high));
2523: PetscCall(VecSetOption(X, VEC_IGNORE_OFF_PROC_ENTRIES, PETSC_TRUE));
2524: PetscCall(VecGetArray(G, &g));
2525: for (i = 0; i < N; i++) {
2526: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2527: PetscCall(VecAssemblyBegin(X));
2528: PetscCall(VecAssemblyEnd(X));
2529: PetscCall(SNESComputeObjective(snes, X, &f));
2530: PetscCall(VecSetValue(X, i, 2.0 * h, ADD_VALUES));
2531: PetscCall(VecAssemblyBegin(X));
2532: PetscCall(VecAssemblyEnd(X));
2533: PetscCall(SNESComputeObjective(snes, X, &f2));
2534: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2535: PetscCall(VecAssemblyBegin(X));
2536: PetscCall(VecAssemblyEnd(X));
2537: if (i >= low && i < high) g[i - low] = (f2 - f) / (2.0 * h);
2538: }
2539: PetscCall(VecRestoreArray(G, &g));
2540: PetscCall(VecDestroy(&X));
2541: PetscFunctionReturn(PETSC_SUCCESS);
2542: }
2544: PetscErrorCode SNESTestFunction(SNES snes)
2545: {
2546: Vec x, g1, g2, g3;
2547: PetscBool complete_print = PETSC_FALSE, test = PETSC_FALSE;
2548: PetscReal hcnorm, fdnorm, hcmax, fdmax, diffmax, diffnorm;
2549: PetscScalar dot;
2550: MPI_Comm comm;
2551: PetscViewer viewer, mviewer;
2552: PetscViewerFormat format;
2553: PetscInt tabs;
2554: static PetscBool directionsprinted = PETSC_FALSE;
2555: SNESObjectiveFn *objective;
2557: PetscFunctionBegin;
2558: PetscCall(SNESGetObjective(snes, &objective, NULL));
2559: if (!objective) PetscFunctionReturn(PETSC_SUCCESS);
2561: PetscObjectOptionsBegin((PetscObject)snes);
2562: PetscCall(PetscOptionsName("-snes_test_function", "Compare hand-coded and finite difference function", "None", &test));
2563: PetscCall(PetscOptionsViewer("-snes_test_function_view", "View difference between hand-coded and finite difference function element entries", "None", &mviewer, &format, &complete_print));
2564: PetscOptionsEnd();
2565: if (!test) {
2566: if (complete_print) PetscCall(PetscViewerDestroy(&mviewer));
2567: PetscFunctionReturn(PETSC_SUCCESS);
2568: }
2570: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2571: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2572: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2573: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2574: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Function -------------\n"));
2575: if (!complete_print && !directionsprinted) {
2576: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_function_view and optionally -snes_test_function <threshold> to show difference\n"));
2577: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference function entries greater than <threshold>.\n"));
2578: }
2579: if (!directionsprinted) {
2580: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Function, if (for double precision runs) ||F - Ffd||/||F|| is\n"));
2581: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Function is probably correct.\n"));
2582: directionsprinted = PETSC_TRUE;
2583: }
2584: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2586: PetscCall(SNESGetSolution(snes, &x));
2587: PetscCall(VecDuplicate(x, &g1));
2588: PetscCall(VecDuplicate(x, &g2));
2589: PetscCall(VecDuplicate(x, &g3));
2590: PetscCall(SNESComputeFunction(snes, x, g1));
2591: PetscCall(SNESComputeFunction_FD(snes, x, g2));
2593: PetscCall(VecNorm(g2, NORM_2, &fdnorm));
2594: PetscCall(VecNorm(g1, NORM_2, &hcnorm));
2595: PetscCall(VecNorm(g2, NORM_INFINITY, &fdmax));
2596: PetscCall(VecNorm(g1, NORM_INFINITY, &hcmax));
2597: PetscCall(VecDot(g1, g2, &dot));
2598: PetscCall(VecCopy(g1, g3));
2599: PetscCall(VecAXPY(g3, -1.0, g2));
2600: PetscCall(VecNorm(g3, NORM_2, &diffnorm));
2601: PetscCall(VecNorm(g3, NORM_INFINITY, &diffmax));
2602: PetscCall(PetscViewerASCIIPrintf(viewer, " ||Ffd|| %g, ||F|| = %g, angle cosine = (Ffd'F)/||Ffd||||F|| = %g\n", (double)fdnorm, (double)hcnorm, (double)(PetscRealPart(dot) / (fdnorm * hcnorm))));
2603: PetscCall(PetscViewerASCIIPrintf(viewer, " 2-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffnorm / PetscMax(hcnorm, fdnorm)), (double)diffnorm));
2604: PetscCall(PetscViewerASCIIPrintf(viewer, " max-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffmax / PetscMax(hcmax, fdmax)), (double)diffmax));
2606: if (complete_print) {
2607: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded function ----------\n"));
2608: PetscCall(VecView(g1, mviewer));
2609: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference function ----------\n"));
2610: PetscCall(VecView(g2, mviewer));
2611: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference function ----------\n"));
2612: PetscCall(VecView(g3, mviewer));
2613: }
2614: PetscCall(VecDestroy(&g1));
2615: PetscCall(VecDestroy(&g2));
2616: PetscCall(VecDestroy(&g3));
2618: if (complete_print) {
2619: PetscCall(PetscViewerPopFormat(mviewer));
2620: PetscCall(PetscViewerDestroy(&mviewer));
2621: }
2622: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2623: PetscFunctionReturn(PETSC_SUCCESS);
2624: }
2626: PetscErrorCode SNESTestJacobian(SNES snes)
2627: {
2628: Mat A, B, C, D, jacobian;
2629: Vec x = snes->vec_sol, f;
2630: PetscReal nrm, gnorm;
2631: PetscReal threshold = 1.e-5;
2632: MatType mattype;
2633: PetscInt m, n, M, N;
2634: void *functx;
2635: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, test = PETSC_FALSE, flg, istranspose;
2636: PetscViewer viewer, mviewer;
2637: MPI_Comm comm;
2638: PetscInt tabs;
2639: static PetscBool directionsprinted = PETSC_FALSE;
2640: PetscViewerFormat format;
2642: PetscFunctionBegin;
2643: PetscObjectOptionsBegin((PetscObject)snes);
2644: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &test));
2645: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2646: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2647: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2648: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2649: 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));
2650: PetscOptionsEnd();
2651: if (!test) PetscFunctionReturn(PETSC_SUCCESS);
2653: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2654: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2655: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2656: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2657: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2658: if (!complete_print && !directionsprinted) {
2659: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2660: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2661: }
2662: if (!directionsprinted) {
2663: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2664: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2665: directionsprinted = PETSC_TRUE;
2666: }
2667: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2669: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2670: if (!flg) jacobian = snes->jacobian;
2671: else jacobian = snes->jacobian_pre;
2673: if (!x) PetscCall(MatCreateVecs(jacobian, &x, NULL));
2674: else PetscCall(PetscObjectReference((PetscObject)x));
2675: PetscCall(VecDuplicate(x, &f));
2677: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2678: PetscCall(SNESComputeFunction(snes, x, f));
2679: PetscCall(VecDestroy(&f));
2680: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2681: while (jacobian) {
2682: Mat JT = NULL, Jsave = NULL;
2684: if (istranspose) {
2685: PetscCall(MatCreateTranspose(jacobian, &JT));
2686: Jsave = jacobian;
2687: jacobian = JT;
2688: }
2689: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2690: if (flg) {
2691: A = jacobian;
2692: PetscCall(PetscObjectReference((PetscObject)A));
2693: } else {
2694: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2695: }
2697: PetscCall(MatGetType(A, &mattype));
2698: PetscCall(MatGetSize(A, &M, &N));
2699: PetscCall(MatGetLocalSize(A, &m, &n));
2700: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2701: PetscCall(MatSetType(B, mattype));
2702: PetscCall(MatSetSizes(B, m, n, M, N));
2703: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2704: PetscCall(MatSetUp(B));
2705: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2707: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2708: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2710: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2711: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2712: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2713: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2714: PetscCall(MatDestroy(&D));
2715: if (!gnorm) gnorm = 1; /* just in case */
2716: PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2718: if (complete_print) {
2719: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2720: PetscCall(MatView(A, mviewer));
2721: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2722: PetscCall(MatView(B, mviewer));
2723: }
2725: if (threshold_print || complete_print) {
2726: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2727: PetscScalar *cvals;
2728: const PetscInt *bcols;
2729: const PetscScalar *bvals;
2731: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2732: PetscCall(MatSetType(C, mattype));
2733: PetscCall(MatSetSizes(C, m, n, M, N));
2734: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2735: PetscCall(MatSetUp(C));
2736: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2738: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2739: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2741: for (row = Istart; row < Iend; row++) {
2742: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2743: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2744: for (j = 0, cncols = 0; j < bncols; j++) {
2745: if (PetscAbsScalar(bvals[j]) > threshold) {
2746: ccols[cncols] = bcols[j];
2747: cvals[cncols] = bvals[j];
2748: cncols += 1;
2749: }
2750: }
2751: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2752: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2753: PetscCall(PetscFree2(ccols, cvals));
2754: }
2755: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2756: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2757: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2758: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2759: PetscCall(MatDestroy(&C));
2760: }
2761: PetscCall(MatDestroy(&A));
2762: PetscCall(MatDestroy(&B));
2763: PetscCall(MatDestroy(&JT));
2764: if (Jsave) jacobian = Jsave;
2765: if (jacobian != snes->jacobian_pre) {
2766: jacobian = snes->jacobian_pre;
2767: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2768: } else jacobian = NULL;
2769: }
2770: PetscCall(VecDestroy(&x));
2771: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2772: if (mviewer) PetscCall(PetscOptionsRestoreViewer(&mviewer));
2773: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2774: PetscFunctionReturn(PETSC_SUCCESS);
2775: }
2777: /*@
2778: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2780: Collective
2782: Input Parameters:
2783: + snes - the `SNES` context
2784: - X - input vector
2786: Output Parameters:
2787: + A - Jacobian matrix
2788: - B - optional matrix for building the preconditioner, usually the same as `A`
2790: Options Database Keys:
2791: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2792: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2793: . -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.
2794: . -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
2795: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2796: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2797: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2798: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2799: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2800: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2801: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2802: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2803: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2804: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2805: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2807: Level: developer
2809: Note:
2810: Most users should not need to explicitly call this routine, as it
2811: is used internally within the nonlinear solvers.
2813: Developer Note:
2814: 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
2815: with the `SNESType` of test that has been removed.
2817: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
2818: @*/
2819: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2820: {
2821: PetscBool flag;
2822: DM dm;
2823: DMSNES sdm;
2824: KSP ksp;
2826: PetscFunctionBegin;
2829: PetscCheckSameComm(snes, 1, X, 2);
2830: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2831: PetscCall(SNESGetDM(snes, &dm));
2832: PetscCall(DMGetDMSNES(dm, &sdm));
2834: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2835: if (snes->lagjacobian == -2) {
2836: snes->lagjacobian = -1;
2838: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2839: } else if (snes->lagjacobian == -1) {
2840: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2841: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2842: if (flag) {
2843: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2844: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2845: }
2846: PetscFunctionReturn(PETSC_SUCCESS);
2847: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2848: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2849: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2850: if (flag) {
2851: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2852: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2853: }
2854: PetscFunctionReturn(PETSC_SUCCESS);
2855: }
2856: if (snes->npc && snes->npcside == PC_LEFT) {
2857: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2858: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2859: PetscFunctionReturn(PETSC_SUCCESS);
2860: }
2862: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2863: PetscCall(VecLockReadPush(X));
2864: {
2865: void *ctx;
2866: SNESJacobianFn *J;
2867: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2868: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2869: }
2870: PetscCall(VecLockReadPop(X));
2871: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
2873: /* attach latest linearization point to the preconditioning matrix */
2874: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
2876: /* the next line ensures that snes->ksp exists */
2877: PetscCall(SNESGetKSP(snes, &ksp));
2878: if (snes->lagpreconditioner == -2) {
2879: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
2880: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2881: snes->lagpreconditioner = -1;
2882: } else if (snes->lagpreconditioner == -1) {
2883: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
2884: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2885: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2886: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
2887: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2888: } else {
2889: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
2890: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2891: }
2893: /* monkey business to allow testing Jacobians in multilevel solvers.
2894: This is needed because the SNESTestXXX interface does not accept vectors and matrices */
2895: {
2896: Vec xsave = snes->vec_sol;
2897: Mat jacobiansave = snes->jacobian;
2898: Mat jacobian_presave = snes->jacobian_pre;
2900: snes->vec_sol = X;
2901: snes->jacobian = A;
2902: snes->jacobian_pre = B;
2903: PetscCall(SNESTestFunction(snes));
2904: PetscCall(SNESTestJacobian(snes));
2906: snes->vec_sol = xsave;
2907: snes->jacobian = jacobiansave;
2908: snes->jacobian_pre = jacobian_presave;
2909: }
2911: {
2912: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
2913: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
2914: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
2915: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
2916: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
2917: if (flag || flag_draw || flag_contour) {
2918: Mat Bexp_mine = NULL, Bexp, FDexp;
2919: PetscViewer vdraw, vstdout;
2920: PetscBool flg;
2921: if (flag_operator) {
2922: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
2923: Bexp = Bexp_mine;
2924: } else {
2925: /* See if the preconditioning matrix can be viewed and added directly */
2926: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPIBAIJ, ""));
2927: if (flg) Bexp = B;
2928: else {
2929: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2930: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
2931: Bexp = Bexp_mine;
2932: }
2933: }
2934: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
2935: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
2936: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2937: if (flag_draw || flag_contour) {
2938: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2939: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2940: } else vdraw = NULL;
2941: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
2942: if (flag) PetscCall(MatView(Bexp, vstdout));
2943: if (vdraw) PetscCall(MatView(Bexp, vdraw));
2944: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
2945: if (flag) PetscCall(MatView(FDexp, vstdout));
2946: if (vdraw) PetscCall(MatView(FDexp, vdraw));
2947: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
2948: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
2949: if (flag) PetscCall(MatView(FDexp, vstdout));
2950: if (vdraw) { /* Always use contour for the difference */
2951: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2952: PetscCall(MatView(FDexp, vdraw));
2953: PetscCall(PetscViewerPopFormat(vdraw));
2954: }
2955: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2956: PetscCall(PetscViewerDestroy(&vdraw));
2957: PetscCall(MatDestroy(&Bexp_mine));
2958: PetscCall(MatDestroy(&FDexp));
2959: }
2960: }
2961: {
2962: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
2963: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
2964: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
2965: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
2966: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
2967: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
2968: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
2969: if (flag_threshold) {
2970: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
2971: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
2972: }
2973: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2974: Mat Bfd;
2975: PetscViewer vdraw, vstdout;
2976: MatColoring coloring;
2977: ISColoring iscoloring;
2978: MatFDColoring matfdcoloring;
2979: SNESFunctionFn *func;
2980: void *funcctx;
2981: PetscReal norm1, norm2, normmax;
2983: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
2984: PetscCall(MatColoringCreate(Bfd, &coloring));
2985: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
2986: PetscCall(MatColoringSetFromOptions(coloring));
2987: PetscCall(MatColoringApply(coloring, &iscoloring));
2988: PetscCall(MatColoringDestroy(&coloring));
2989: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
2990: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2991: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
2992: PetscCall(ISColoringDestroy(&iscoloring));
2994: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2995: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
2996: PetscCall(MatFDColoringSetFunction(matfdcoloring, (PetscErrorCode(*)(void))func, funcctx));
2997: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
2998: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
2999: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3000: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
3001: PetscCall(MatFDColoringDestroy(&matfdcoloring));
3003: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3004: if (flag_draw || flag_contour) {
3005: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3006: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3007: } else vdraw = NULL;
3008: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
3009: if (flag_display) PetscCall(MatView(B, vstdout));
3010: if (vdraw) PetscCall(MatView(B, vdraw));
3011: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
3012: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3013: if (vdraw) PetscCall(MatView(Bfd, vdraw));
3014: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
3015: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
3016: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
3017: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
3018: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
3019: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3020: if (vdraw) { /* Always use contour for the difference */
3021: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3022: PetscCall(MatView(Bfd, vdraw));
3023: PetscCall(PetscViewerPopFormat(vdraw));
3024: }
3025: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3027: if (flag_threshold) {
3028: PetscInt bs, rstart, rend, i;
3029: PetscCall(MatGetBlockSize(B, &bs));
3030: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
3031: for (i = rstart; i < rend; i++) {
3032: const PetscScalar *ba, *ca;
3033: const PetscInt *bj, *cj;
3034: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
3035: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
3036: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
3037: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
3038: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
3039: for (j = 0; j < bn; j++) {
3040: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3041: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
3042: maxentrycol = bj[j];
3043: maxentry = PetscRealPart(ba[j]);
3044: }
3045: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
3046: maxdiffcol = bj[j];
3047: maxdiff = PetscRealPart(ca[j]);
3048: }
3049: if (rdiff > maxrdiff) {
3050: maxrdiffcol = bj[j];
3051: maxrdiff = rdiff;
3052: }
3053: }
3054: if (maxrdiff > 1) {
3055: 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));
3056: for (j = 0; j < bn; j++) {
3057: PetscReal rdiff;
3058: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3059: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
3060: }
3061: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
3062: }
3063: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
3064: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
3065: }
3066: }
3067: PetscCall(PetscViewerDestroy(&vdraw));
3068: PetscCall(MatDestroy(&Bfd));
3069: }
3070: }
3071: PetscFunctionReturn(PETSC_SUCCESS);
3072: }
3074: /*@C
3075: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3076: location to store the matrix.
3078: Logically Collective
3080: Input Parameters:
3081: + snes - the `SNES` context
3082: . Amat - the matrix that defines the (approximate) Jacobian
3083: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3084: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFn` for details
3085: - ctx - [optional] user-defined context for private data for the
3086: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3088: Level: beginner
3090: Notes:
3091: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3092: each matrix.
3094: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3095: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3097: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3098: must be a `MatFDColoring`.
3100: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3101: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3103: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3104: `SNESSetPicard()`, `SNESJacobianFn`, `SNESFunctionFn`
3105: @*/
3106: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
3107: {
3108: DM dm;
3110: PetscFunctionBegin;
3114: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3115: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3116: PetscCall(SNESGetDM(snes, &dm));
3117: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3118: if (Amat) {
3119: PetscCall(PetscObjectReference((PetscObject)Amat));
3120: PetscCall(MatDestroy(&snes->jacobian));
3122: snes->jacobian = Amat;
3123: }
3124: if (Pmat) {
3125: PetscCall(PetscObjectReference((PetscObject)Pmat));
3126: PetscCall(MatDestroy(&snes->jacobian_pre));
3128: snes->jacobian_pre = Pmat;
3129: }
3130: PetscFunctionReturn(PETSC_SUCCESS);
3131: }
3133: /*@C
3134: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3135: provided context for evaluating the Jacobian.
3137: Not Collective, but `Mat` object will be parallel if `SNES` is
3139: Input Parameter:
3140: . snes - the nonlinear solver context
3142: Output Parameters:
3143: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3144: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3145: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFn`
3146: - ctx - location to stash Jacobian ctx (or `NULL`)
3148: Level: advanced
3150: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFn`, `SNESGetFunction()`
3151: @*/
3152: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
3153: {
3154: DM dm;
3156: PetscFunctionBegin;
3158: if (Amat) *Amat = snes->jacobian;
3159: if (Pmat) *Pmat = snes->jacobian_pre;
3160: PetscCall(SNESGetDM(snes, &dm));
3161: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3162: PetscFunctionReturn(PETSC_SUCCESS);
3163: }
3165: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3166: {
3167: DM dm;
3168: DMSNES sdm;
3170: PetscFunctionBegin;
3171: PetscCall(SNESGetDM(snes, &dm));
3172: PetscCall(DMGetDMSNES(dm, &sdm));
3173: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3174: DM dm;
3175: PetscBool isdense, ismf;
3177: PetscCall(SNESGetDM(snes, &dm));
3178: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3179: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3180: if (isdense) {
3181: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3182: } else if (!ismf) {
3183: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3184: }
3185: }
3186: PetscFunctionReturn(PETSC_SUCCESS);
3187: }
3189: /*@
3190: SNESSetUp - Sets up the internal data structures for the later use
3191: of a nonlinear solver.
3193: Collective
3195: Input Parameter:
3196: . snes - the `SNES` context
3198: Level: advanced
3200: Note:
3201: For basic use of the `SNES` solvers the user need not explicitly call
3202: `SNESSetUp()`, since these actions will automatically occur during
3203: the call to `SNESSolve()`. However, if one wishes to control this
3204: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3205: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3207: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`
3208: @*/
3209: PetscErrorCode SNESSetUp(SNES snes)
3210: {
3211: DM dm;
3212: DMSNES sdm;
3213: SNESLineSearch linesearch, pclinesearch;
3214: void *lsprectx, *lspostctx;
3215: PetscBool mf_operator, mf;
3216: Vec f, fpc;
3217: void *funcctx;
3218: void *jacctx, *appctx;
3219: Mat j, jpre;
3220: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3221: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3222: SNESFunctionFn *func;
3223: SNESJacobianFn *jac;
3225: PetscFunctionBegin;
3227: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3228: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3230: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3232: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3234: PetscCall(SNESGetDM(snes, &dm));
3235: PetscCall(DMGetDMSNES(dm, &sdm));
3236: PetscCall(SNESSetDefaultComputeJacobian(snes));
3238: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3240: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3242: if (snes->linesearch) {
3243: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3244: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3245: }
3247: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3248: if (snes->npc && snes->npcside == PC_LEFT) {
3249: snes->mf = PETSC_TRUE;
3250: snes->mf_operator = PETSC_FALSE;
3251: }
3253: if (snes->npc) {
3254: /* copy the DM over */
3255: PetscCall(SNESGetDM(snes, &dm));
3256: PetscCall(SNESSetDM(snes->npc, dm));
3258: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3259: PetscCall(VecDuplicate(f, &fpc));
3260: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3261: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3262: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3263: PetscCall(SNESGetApplicationContext(snes, &appctx));
3264: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3265: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3266: PetscCall(VecDestroy(&fpc));
3268: /* copy the function pointers over */
3269: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3271: /* default to 1 iteration */
3272: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3273: if (snes->npcside == PC_RIGHT) {
3274: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3275: } else {
3276: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3277: }
3278: PetscCall(SNESSetFromOptions(snes->npc));
3280: /* copy the line search context over */
3281: if (snes->linesearch && snes->npc->linesearch) {
3282: PetscCall(SNESGetLineSearch(snes, &linesearch));
3283: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3284: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3285: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3286: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3287: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3288: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3289: }
3290: }
3291: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3292: if (snes->ops->usercompute && !snes->user) PetscCallBack("SNES callback compute application context", (*snes->ops->usercompute)(snes, (void **)&snes->user));
3294: snes->jac_iter = 0;
3295: snes->pre_iter = 0;
3297: PetscTryTypeMethod(snes, setup);
3299: PetscCall(SNESSetDefaultComputeJacobian(snes));
3301: if (snes->npc && snes->npcside == PC_LEFT) {
3302: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3303: if (snes->linesearch) {
3304: PetscCall(SNESGetLineSearch(snes, &linesearch));
3305: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3306: }
3307: }
3308: }
3309: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3310: snes->setupcalled = PETSC_TRUE;
3311: PetscFunctionReturn(PETSC_SUCCESS);
3312: }
3314: /*@
3315: SNESReset - Resets a `SNES` context to the snessetupcalled = 0 state and removes any allocated `Vec`s and `Mat`s
3317: Collective
3319: Input Parameter:
3320: . snes - iterative context obtained from `SNESCreate()`
3322: Level: intermediate
3324: Notes:
3325: Call this if you wish to reuse a `SNES` but with different size vectors
3327: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3329: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3330: @*/
3331: PetscErrorCode SNESReset(SNES snes)
3332: {
3333: PetscFunctionBegin;
3335: if (snes->ops->userdestroy && snes->user) {
3336: PetscCallBack("SNES callback destroy application context", (*snes->ops->userdestroy)((void **)&snes->user));
3337: snes->user = NULL;
3338: }
3339: if (snes->npc) PetscCall(SNESReset(snes->npc));
3341: PetscTryTypeMethod(snes, reset);
3342: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3344: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3346: PetscCall(VecDestroy(&snes->vec_rhs));
3347: PetscCall(VecDestroy(&snes->vec_sol));
3348: PetscCall(VecDestroy(&snes->vec_sol_update));
3349: PetscCall(VecDestroy(&snes->vec_func));
3350: PetscCall(MatDestroy(&snes->jacobian));
3351: PetscCall(MatDestroy(&snes->jacobian_pre));
3352: PetscCall(MatDestroy(&snes->picard));
3353: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3354: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3356: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3358: snes->nwork = snes->nvwork = 0;
3359: snes->setupcalled = PETSC_FALSE;
3360: PetscFunctionReturn(PETSC_SUCCESS);
3361: }
3363: /*@
3364: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()`
3366: Collective
3368: Input Parameter:
3369: . snes - iterative context obtained from `SNESCreate()`
3371: Level: intermediate
3373: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3374: @*/
3375: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3376: {
3377: PetscInt i;
3379: PetscFunctionBegin;
3381: for (i = 0; i < snes->numberreasonviews; i++) {
3382: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3383: }
3384: snes->numberreasonviews = 0;
3385: PetscFunctionReturn(PETSC_SUCCESS);
3386: }
3388: /*@C
3389: SNESDestroy - Destroys the nonlinear solver context that was created
3390: with `SNESCreate()`.
3392: Collective
3394: Input Parameter:
3395: . snes - the `SNES` context
3397: Level: beginner
3399: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3400: @*/
3401: PetscErrorCode SNESDestroy(SNES *snes)
3402: {
3403: PetscFunctionBegin;
3404: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3406: if (--((PetscObject)*snes)->refct > 0) {
3407: *snes = NULL;
3408: PetscFunctionReturn(PETSC_SUCCESS);
3409: }
3411: PetscCall(SNESReset(*snes));
3412: PetscCall(SNESDestroy(&(*snes)->npc));
3414: /* if memory was published with SAWs then destroy it */
3415: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3416: PetscTryTypeMethod(*snes, destroy);
3418: if ((*snes)->dm) PetscCall(DMCoarsenHookRemove((*snes)->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3419: PetscCall(DMDestroy(&(*snes)->dm));
3420: PetscCall(KSPDestroy(&(*snes)->ksp));
3421: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3423: PetscCall(PetscFree((*snes)->kspconvctx));
3424: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)((*snes)->cnvP));
3425: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3426: PetscCall(SNESMonitorCancel(*snes));
3427: PetscCall(SNESConvergedReasonViewCancel(*snes));
3428: PetscCall(PetscHeaderDestroy(snes));
3429: PetscFunctionReturn(PETSC_SUCCESS);
3430: }
3432: /* ----------- Routines to set solver parameters ---------- */
3434: /*@
3435: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3437: Logically Collective
3439: Input Parameters:
3440: + snes - the `SNES` context
3441: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3442: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3444: Options Database Keys:
3445: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3446: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3447: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3448: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3450: Level: intermediate
3452: Notes:
3453: The default is 1
3455: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3457: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3459: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3460: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3461: @*/
3462: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3463: {
3464: PetscFunctionBegin;
3466: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3467: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3469: snes->lagpreconditioner = lag;
3470: PetscFunctionReturn(PETSC_SUCCESS);
3471: }
3473: /*@
3474: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3476: Logically Collective
3478: Input Parameters:
3479: + snes - the `SNES` context
3480: - steps - the number of refinements to do, defaults to 0
3482: Options Database Key:
3483: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3485: Level: intermediate
3487: Note:
3488: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3490: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3491: `SNESetDM()`
3492: @*/
3493: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3494: {
3495: PetscFunctionBegin;
3498: snes->gridsequence = steps;
3499: PetscFunctionReturn(PETSC_SUCCESS);
3500: }
3502: /*@
3503: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3505: Logically Collective
3507: Input Parameter:
3508: . snes - the `SNES` context
3510: Output Parameter:
3511: . steps - the number of refinements to do, defaults to 0
3513: Level: intermediate
3515: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3516: @*/
3517: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3518: {
3519: PetscFunctionBegin;
3521: *steps = snes->gridsequence;
3522: PetscFunctionReturn(PETSC_SUCCESS);
3523: }
3525: /*@
3526: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3528: Not Collective
3530: Input Parameter:
3531: . snes - the `SNES` context
3533: Output Parameter:
3534: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3535: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3537: Level: intermediate
3539: Notes:
3540: The default is 1
3542: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3544: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3545: @*/
3546: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3547: {
3548: PetscFunctionBegin;
3550: *lag = snes->lagpreconditioner;
3551: PetscFunctionReturn(PETSC_SUCCESS);
3552: }
3554: /*@
3555: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3556: often the preconditioner is rebuilt.
3558: Logically Collective
3560: Input Parameters:
3561: + snes - the `SNES` context
3562: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3563: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3565: Options Database Keys:
3566: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3567: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3568: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3569: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3571: Level: intermediate
3573: Notes:
3574: The default is 1
3576: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3578: 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
3579: at the next Newton step but never again (unless it is reset to another value)
3581: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3582: @*/
3583: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3584: {
3585: PetscFunctionBegin;
3587: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3588: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3590: snes->lagjacobian = lag;
3591: PetscFunctionReturn(PETSC_SUCCESS);
3592: }
3594: /*@
3595: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3597: Not Collective
3599: Input Parameter:
3600: . snes - the `SNES` context
3602: Output Parameter:
3603: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3604: the Jacobian is built etc.
3606: Level: intermediate
3608: Notes:
3609: The default is 1
3611: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3613: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3615: @*/
3616: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3617: {
3618: PetscFunctionBegin;
3620: *lag = snes->lagjacobian;
3621: PetscFunctionReturn(PETSC_SUCCESS);
3622: }
3624: /*@
3625: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3627: Logically collective
3629: Input Parameters:
3630: + snes - the `SNES` context
3631: - flg - jacobian lagging persists if true
3633: Options Database Keys:
3634: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3635: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3636: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3637: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3639: Level: advanced
3641: Notes:
3642: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3644: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3645: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3646: timesteps may present huge efficiency gains.
3648: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3649: @*/
3650: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3651: {
3652: PetscFunctionBegin;
3655: snes->lagjac_persist = flg;
3656: PetscFunctionReturn(PETSC_SUCCESS);
3657: }
3659: /*@
3660: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3662: Logically Collective
3664: Input Parameters:
3665: + snes - the `SNES` context
3666: - flg - preconditioner lagging persists if true
3668: Options Database Keys:
3669: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3670: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3671: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3672: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3674: Level: developer
3676: Notes:
3677: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3679: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3680: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3681: several timesteps may present huge efficiency gains.
3683: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3684: @*/
3685: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3686: {
3687: PetscFunctionBegin;
3690: snes->lagpre_persist = flg;
3691: PetscFunctionReturn(PETSC_SUCCESS);
3692: }
3694: /*@
3695: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3697: Logically Collective
3699: Input Parameters:
3700: + snes - the `SNES` context
3701: - force - `PETSC_TRUE` require at least one iteration
3703: Options Database Key:
3704: . -snes_force_iteration <force> - Sets forcing an iteration
3706: Level: intermediate
3708: Note:
3709: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3711: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3712: @*/
3713: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3714: {
3715: PetscFunctionBegin;
3717: snes->forceiteration = force;
3718: PetscFunctionReturn(PETSC_SUCCESS);
3719: }
3721: /*@
3722: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3724: Logically Collective
3726: Input Parameter:
3727: . snes - the `SNES` context
3729: Output Parameter:
3730: . force - `PETSC_TRUE` requires at least one iteration.
3732: Level: intermediate
3734: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3735: @*/
3736: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3737: {
3738: PetscFunctionBegin;
3740: *force = snes->forceiteration;
3741: PetscFunctionReturn(PETSC_SUCCESS);
3742: }
3744: /*@
3745: SNESSetTolerances - Sets `SNES` various parameters used in convergence tests.
3747: Logically Collective
3749: Input Parameters:
3750: + snes - the `SNES` context
3751: . abstol - absolute convergence tolerance
3752: . rtol - relative convergence tolerance
3753: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3754: . maxit - maximum number of iterations, default 50.
3755: - maxf - maximum number of function evaluations (-1 indicates no limit), default 1000
3757: Options Database Keys:
3758: + -snes_atol <abstol> - Sets abstol
3759: . -snes_rtol <rtol> - Sets rtol
3760: . -snes_stol <stol> - Sets stol
3761: . -snes_max_it <maxit> - Sets maxit
3762: - -snes_max_funcs <maxf> - Sets maxf
3764: Level: intermediate
3766: .seealso: [](ch_snes), `SNESSolve()`, `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3767: @*/
3768: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3769: {
3770: PetscFunctionBegin;
3778: if (abstol != (PetscReal)PETSC_DEFAULT) {
3779: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3780: snes->abstol = abstol;
3781: }
3782: if (rtol != (PetscReal)PETSC_DEFAULT) {
3783: 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);
3784: snes->rtol = rtol;
3785: }
3786: if (stol != (PetscReal)PETSC_DEFAULT) {
3787: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3788: snes->stol = stol;
3789: }
3790: if (maxit != PETSC_DEFAULT) {
3791: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3792: snes->max_its = maxit;
3793: }
3794: if (maxf != PETSC_DEFAULT) {
3795: PetscCheck(maxf >= -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be -1 or nonnegative", maxf);
3796: snes->max_funcs = maxf;
3797: }
3798: snes->tolerancesset = PETSC_TRUE;
3799: PetscFunctionReturn(PETSC_SUCCESS);
3800: }
3802: /*@
3803: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3805: Logically Collective
3807: Input Parameters:
3808: + snes - the `SNES` context
3809: - divtol - the divergence tolerance. Use -1 to deactivate the test, default is 1e4
3811: Options Database Key:
3812: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3814: Level: intermediate
3816: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance`
3817: @*/
3818: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3819: {
3820: PetscFunctionBegin;
3824: if (divtol != (PetscReal)PETSC_DEFAULT) {
3825: snes->divtol = divtol;
3826: } else {
3827: snes->divtol = 1.0e4;
3828: }
3829: PetscFunctionReturn(PETSC_SUCCESS);
3830: }
3832: /*@
3833: SNESGetTolerances - Gets various parameters used in convergence tests.
3835: Not Collective
3837: Input Parameters:
3838: + snes - the `SNES` context
3839: . atol - absolute convergence tolerance
3840: . rtol - relative convergence tolerance
3841: . stol - convergence tolerance in terms of the norm
3842: of the change in the solution between steps
3843: . maxit - maximum number of iterations
3844: - maxf - maximum number of function evaluations
3846: Level: intermediate
3848: Note:
3849: The user can specify `NULL` for any parameter that is not needed.
3851: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
3852: @*/
3853: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
3854: {
3855: PetscFunctionBegin;
3857: if (atol) *atol = snes->abstol;
3858: if (rtol) *rtol = snes->rtol;
3859: if (stol) *stol = snes->stol;
3860: if (maxit) *maxit = snes->max_its;
3861: if (maxf) *maxf = snes->max_funcs;
3862: PetscFunctionReturn(PETSC_SUCCESS);
3863: }
3865: /*@
3866: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3868: Not Collective
3870: Input Parameters:
3871: + snes - the `SNES` context
3872: - divtol - divergence tolerance
3874: Level: intermediate
3876: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
3877: @*/
3878: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
3879: {
3880: PetscFunctionBegin;
3882: if (divtol) *divtol = snes->divtol;
3883: PetscFunctionReturn(PETSC_SUCCESS);
3884: }
3886: /*@
3887: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3889: Logically Collective
3891: Input Parameters:
3892: + snes - the `SNES` context
3893: - tol - tolerance
3895: Options Database Key:
3896: . -snes_tr_tol <tol> - Sets tol
3898: Level: intermediate
3900: Developer Note:
3901: Should be SNESTrustRegionSetTolerance()
3903: .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`, `SNESSetTolerances()`
3904: @*/
3905: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes, PetscReal tol)
3906: {
3907: PetscFunctionBegin;
3910: snes->deltatol = tol;
3911: PetscFunctionReturn(PETSC_SUCCESS);
3912: }
3914: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
3916: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
3917: {
3918: PetscDrawLG lg;
3919: PetscReal x, y, per;
3920: PetscViewer v = (PetscViewer)monctx;
3921: static PetscReal prev; /* should be in the context */
3922: PetscDraw draw;
3924: PetscFunctionBegin;
3926: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
3927: if (!n) PetscCall(PetscDrawLGReset(lg));
3928: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3929: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
3930: x = (PetscReal)n;
3931: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3932: else y = -15.0;
3933: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3934: if (n < 20 || !(n % 5) || snes->reason) {
3935: PetscCall(PetscDrawLGDraw(lg));
3936: PetscCall(PetscDrawLGSave(lg));
3937: }
3939: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
3940: if (!n) PetscCall(PetscDrawLGReset(lg));
3941: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3942: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
3943: PetscCall(SNESMonitorRange_Private(snes, n, &per));
3944: x = (PetscReal)n;
3945: y = 100.0 * per;
3946: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3947: if (n < 20 || !(n % 5) || snes->reason) {
3948: PetscCall(PetscDrawLGDraw(lg));
3949: PetscCall(PetscDrawLGSave(lg));
3950: }
3952: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
3953: if (!n) {
3954: prev = rnorm;
3955: PetscCall(PetscDrawLGReset(lg));
3956: }
3957: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3958: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
3959: x = (PetscReal)n;
3960: y = (prev - rnorm) / prev;
3961: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3962: if (n < 20 || !(n % 5) || snes->reason) {
3963: PetscCall(PetscDrawLGDraw(lg));
3964: PetscCall(PetscDrawLGSave(lg));
3965: }
3967: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
3968: if (!n) PetscCall(PetscDrawLGReset(lg));
3969: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3970: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
3971: x = (PetscReal)n;
3972: y = (prev - rnorm) / (prev * per);
3973: if (n > 2) { /*skip initial crazy value */
3974: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3975: }
3976: if (n < 20 || !(n % 5) || snes->reason) {
3977: PetscCall(PetscDrawLGDraw(lg));
3978: PetscCall(PetscDrawLGSave(lg));
3979: }
3980: prev = rnorm;
3981: PetscFunctionReturn(PETSC_SUCCESS);
3982: }
3984: /*@
3985: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
3987: Collective
3989: Input Parameters:
3990: + snes - the `SNES` context
3991: . it - current iteration
3992: . xnorm - 2-norm of current iterate
3993: . snorm - 2-norm of current step
3994: - fnorm - 2-norm of function
3996: Level: developer
3998: Note:
3999: This routine is called by the `SNESSolve()` implementations.
4000: It does not typically need to be called by the user.
4002: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4003: @*/
4004: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
4005: {
4006: PetscFunctionBegin;
4007: if (!snes->reason) {
4008: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
4009: if (it == snes->max_its && !snes->reason) {
4010: if (snes->normschedule == SNES_NORM_ALWAYS) {
4011: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
4012: snes->reason = SNES_DIVERGED_MAX_IT;
4013: } else snes->reason = SNES_CONVERGED_ITS;
4014: }
4015: }
4016: PetscFunctionReturn(PETSC_SUCCESS);
4017: }
4019: /*@
4020: SNESMonitor - runs the user provided monitor routines, if they exist
4022: Collective
4024: Input Parameters:
4025: + snes - nonlinear solver context obtained from `SNESCreate()`
4026: . iter - iteration number
4027: - rnorm - relative norm of the residual
4029: Level: developer
4031: Note:
4032: This routine is called by the `SNESSolve()` implementations.
4033: It does not typically need to be called by the user.
4035: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
4036: @*/
4037: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
4038: {
4039: PetscInt i, n = snes->numbermonitors;
4041: PetscFunctionBegin;
4042: if (n > 0) SNESCheckFunctionNorm(snes, rnorm);
4043: PetscCall(VecLockReadPush(snes->vec_sol));
4044: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
4045: PetscCall(VecLockReadPop(snes->vec_sol));
4046: PetscFunctionReturn(PETSC_SUCCESS);
4047: }
4049: /* ------------ Routines to set performance monitoring options ----------- */
4051: /*MC
4052: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
4054: Synopsis:
4055: #include <petscsnes.h>
4056: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, void *mctx)
4058: Collective
4060: Input Parameters:
4061: + snes - the `SNES` context
4062: . its - iteration number
4063: . norm - 2-norm function value (may be estimated)
4064: - mctx - [optional] monitoring context
4066: Level: advanced
4068: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSet()`, `SNESMonitorGet()`
4069: M*/
4071: /*@C
4072: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
4073: iteration of the nonlinear solver to display the iteration's
4074: progress.
4076: Logically Collective
4078: Input Parameters:
4079: + snes - the `SNES` context
4080: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4081: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4082: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`)
4084: Options Database Keys:
4085: + -snes_monitor - sets `SNESMonitorDefault()`
4086: . -snes_monitor draw::draw_lg - sets line graph monitor,
4087: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4088: the options database.
4090: Level: intermediate
4092: Note:
4093: Several different monitoring routines may be set by calling
4094: `SNESMonitorSet()` multiple times; all will be called in the
4095: order in which they were set.
4097: Fortran Note:
4098: Only a single monitor function can be set for each `SNES` object
4100: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`
4101: @*/
4102: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscErrorCode (*monitordestroy)(void **))
4103: {
4104: PetscInt i;
4105: PetscBool identical;
4107: PetscFunctionBegin;
4109: for (i = 0; i < snes->numbermonitors; i++) {
4110: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, mctx, monitordestroy, (PetscErrorCode(*)(void))snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4111: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4112: }
4113: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4114: snes->monitor[snes->numbermonitors] = f;
4115: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4116: snes->monitorcontext[snes->numbermonitors++] = (void *)mctx;
4117: PetscFunctionReturn(PETSC_SUCCESS);
4118: }
4120: /*@
4121: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4123: Logically Collective
4125: Input Parameter:
4126: . snes - the `SNES` context
4128: Options Database Key:
4129: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4130: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4131: set via the options database
4133: Level: intermediate
4135: Note:
4136: There is no way to clear one specific monitor from a `SNES` object.
4138: .seealso: [](ch_snes), `SNES`, `SNESMonitorGet()`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4139: @*/
4140: PetscErrorCode SNESMonitorCancel(SNES snes)
4141: {
4142: PetscInt i;
4144: PetscFunctionBegin;
4146: for (i = 0; i < snes->numbermonitors; i++) {
4147: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4148: }
4149: snes->numbermonitors = 0;
4150: PetscFunctionReturn(PETSC_SUCCESS);
4151: }
4153: /*MC
4154: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4156: Synopsis:
4157: #include <petscsnes.h>
4158: PetscErrorCode SNESConvergenceTest(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *cctx)
4160: Collective
4162: Input Parameters:
4163: + snes - the `SNES` context
4164: . it - current iteration (0 is the first and is before any Newton step)
4165: . xnorm - 2-norm of current iterate
4166: . gnorm - 2-norm of current step
4167: . f - 2-norm of function
4168: - cctx - [optional] convergence context
4170: Output Parameter:
4171: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4173: Level: intermediate
4175: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4176: M*/
4178: /*@C
4179: SNESSetConvergenceTest - Sets the function that is to be used
4180: to test for convergence of the nonlinear iterative solution.
4182: Logically Collective
4184: Input Parameters:
4185: + snes - the `SNES` context
4186: . SNESConvergenceTestFunction - routine to test for convergence
4187: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4188: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4190: Level: advanced
4192: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4193: @*/
4194: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscErrorCode (*destroy)(void *))
4195: {
4196: PetscFunctionBegin;
4198: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4199: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(snes->cnvP));
4200: snes->ops->converged = SNESConvergenceTestFunction;
4201: snes->ops->convergeddestroy = destroy;
4202: snes->cnvP = cctx;
4203: PetscFunctionReturn(PETSC_SUCCESS);
4204: }
4206: /*@
4207: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped.
4209: Not Collective
4211: Input Parameter:
4212: . snes - the `SNES` context
4214: Output Parameter:
4215: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4217: Options Database Key:
4218: . -snes_converged_reason - prints the reason to standard out
4220: Level: intermediate
4222: Note:
4223: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4225: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4226: @*/
4227: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4228: {
4229: PetscFunctionBegin;
4231: PetscAssertPointer(reason, 2);
4232: *reason = snes->reason;
4233: PetscFunctionReturn(PETSC_SUCCESS);
4234: }
4236: /*@C
4237: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4239: Not Collective
4241: Input Parameter:
4242: . snes - the `SNES` context
4244: Output Parameter:
4245: . strreason - a human readable string that describes `SNES` converged reason
4247: Level: beginner
4249: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4250: @*/
4251: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4252: {
4253: PetscFunctionBegin;
4255: PetscAssertPointer(strreason, 2);
4256: *strreason = SNESConvergedReasons[snes->reason];
4257: PetscFunctionReturn(PETSC_SUCCESS);
4258: }
4260: /*@
4261: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4263: Not Collective
4265: Input Parameters:
4266: + snes - the `SNES` context
4267: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4268: manual pages for the individual convergence tests for complete lists
4270: Level: developer
4272: Developer Note:
4273: Called inside the various `SNESSolve()` implementations
4275: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4276: @*/
4277: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4278: {
4279: PetscFunctionBegin;
4281: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4282: snes->reason = reason;
4283: PetscFunctionReturn(PETSC_SUCCESS);
4284: }
4286: /*@
4287: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4289: Logically Collective
4291: Input Parameters:
4292: + snes - iterative context obtained from `SNESCreate()`
4293: . a - array to hold history, this array will contain the function norms computed at each step
4294: . its - integer array holds the number of linear iterations for each solve.
4295: . na - size of `a` and `its`
4296: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4297: else it continues storing new values for new nonlinear solves after the old ones
4299: Level: intermediate
4301: Notes:
4302: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' `PETSC_DECIDE` or `PETSC_DEFAULT` then a
4303: default array of length 10000 is allocated.
4305: This routine is useful, e.g., when running a code for purposes
4306: of accurate performance monitoring, when no I/O should be done
4307: during the section of code that is being timed.
4309: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4311: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4312: @*/
4313: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4314: {
4315: PetscFunctionBegin;
4317: if (a) PetscAssertPointer(a, 2);
4318: if (its) PetscAssertPointer(its, 3);
4319: if (!a) {
4320: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4321: PetscCall(PetscCalloc2(na, &a, na, &its));
4322: snes->conv_hist_alloc = PETSC_TRUE;
4323: }
4324: snes->conv_hist = a;
4325: snes->conv_hist_its = its;
4326: snes->conv_hist_max = (size_t)na;
4327: snes->conv_hist_len = 0;
4328: snes->conv_hist_reset = reset;
4329: PetscFunctionReturn(PETSC_SUCCESS);
4330: }
4332: #if defined(PETSC_HAVE_MATLAB)
4333: #include <engine.h> /* MATLAB include file */
4334: #include <mex.h> /* MATLAB include file */
4336: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4337: {
4338: mxArray *mat;
4339: PetscInt i;
4340: PetscReal *ar;
4342: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4343: ar = (PetscReal *)mxGetData(mat);
4344: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4345: return mat;
4346: }
4347: #endif
4349: /*@C
4350: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4352: Not Collective
4354: Input Parameter:
4355: . snes - iterative context obtained from `SNESCreate()`
4357: Output Parameters:
4358: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4359: . its - integer array holds the number of linear iterations (or
4360: negative if not converged) for each solve.
4361: - na - size of `a` and `its`
4363: Level: intermediate
4365: Note:
4366: This routine is useful, e.g., when running a code for purposes
4367: of accurate performance monitoring, when no I/O should be done
4368: during the section of code that is being timed.
4370: Fortran Note:
4371: The calling sequence for this routine in Fortran is
4372: .vb
4373: call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4374: .ve
4376: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4377: @*/
4378: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4379: {
4380: PetscFunctionBegin;
4382: if (a) *a = snes->conv_hist;
4383: if (its) *its = snes->conv_hist_its;
4384: if (na) *na = (PetscInt)snes->conv_hist_len;
4385: PetscFunctionReturn(PETSC_SUCCESS);
4386: }
4388: /*@C
4389: SNESSetUpdate - Sets the general-purpose update function called
4390: at the beginning of every iteration of the nonlinear solve. Specifically
4391: it is called just before the Jacobian is "evaluated".
4393: Logically Collective
4395: Input Parameters:
4396: + snes - The nonlinear solver context
4397: - func - The function
4399: Calling sequence of `func`:
4400: + snes - the nonlinear solver context
4401: - step - The current step of the iteration
4403: Level: advanced
4405: Notes:
4406: 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
4407: to `SNESSetFunction()`, or `SNESSetPicard()`
4408: This is not used by most users.
4410: 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.
4412: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4413: `SNESMonitorSet()`, `SNESSetDivergenceTest()`
4414: @*/
4415: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES snes, PetscInt step))
4416: {
4417: PetscFunctionBegin;
4419: snes->ops->update = func;
4420: PetscFunctionReturn(PETSC_SUCCESS);
4421: }
4423: /*@C
4424: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4426: Collective
4428: Input Parameters:
4429: + snes - iterative context obtained from `SNESCreate()`
4430: - viewer - the viewer to display the reason
4432: Options Database Keys:
4433: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4434: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4436: Level: beginner
4438: Note:
4439: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4440: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4442: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4443: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4444: `SNESConvergedReasonViewFromOptions()`,
4445: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4446: @*/
4447: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4448: {
4449: PetscViewerFormat format;
4450: PetscBool isAscii;
4452: PetscFunctionBegin;
4453: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4454: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4455: if (isAscii) {
4456: PetscCall(PetscViewerGetFormat(viewer, &format));
4457: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
4458: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4459: DM dm;
4460: Vec u;
4461: PetscDS prob;
4462: PetscInt Nf, f;
4463: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4464: void **exactCtx;
4465: PetscReal error;
4467: PetscCall(SNESGetDM(snes, &dm));
4468: PetscCall(SNESGetSolution(snes, &u));
4469: PetscCall(DMGetDS(dm, &prob));
4470: PetscCall(PetscDSGetNumFields(prob, &Nf));
4471: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4472: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4473: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4474: PetscCall(PetscFree2(exactSol, exactCtx));
4475: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4476: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4477: }
4478: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4479: if (((PetscObject)snes)->prefix) {
4480: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4481: } else {
4482: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4483: }
4484: } else if (snes->reason <= 0) {
4485: if (((PetscObject)snes)->prefix) {
4486: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4487: } else {
4488: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4489: }
4490: }
4491: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
4492: }
4493: PetscFunctionReturn(PETSC_SUCCESS);
4494: }
4496: /*@C
4497: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4498: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4500: Logically Collective
4502: Input Parameters:
4503: + snes - the `SNES` context
4504: . f - the `SNESConvergedReason` view function
4505: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4506: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`)
4508: Calling sequence of `f`:
4509: + snes - the `SNES` context
4510: - vctx - [optional] user-defined context for private data for the function
4512: Calling sequence of `reasonviewerdestroy`:
4513: . vctx - [optional] user-defined context for private data for the function
4515: Options Database Keys:
4516: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4517: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4518: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4520: Level: intermediate
4522: Note:
4523: Several different converged reason view routines may be set by calling
4524: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4525: order in which they were set.
4527: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`
4528: @*/
4529: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, void *vctx), void *vctx, PetscErrorCode (*reasonviewdestroy)(void **vctx))
4530: {
4531: PetscInt i;
4532: PetscBool identical;
4534: PetscFunctionBegin;
4536: for (i = 0; i < snes->numberreasonviews; i++) {
4537: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, vctx, reasonviewdestroy, (PetscErrorCode(*)(void))snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4538: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4539: }
4540: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4541: snes->reasonview[snes->numberreasonviews] = f;
4542: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4543: snes->reasonviewcontext[snes->numberreasonviews++] = (void *)vctx;
4544: PetscFunctionReturn(PETSC_SUCCESS);
4545: }
4547: /*@
4548: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4549: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4551: Collective
4553: Input Parameter:
4554: . snes - the `SNES` object
4556: Level: advanced
4558: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4559: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4560: @*/
4561: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4562: {
4563: PetscViewer viewer;
4564: PetscBool flg;
4565: static PetscBool incall = PETSC_FALSE;
4566: PetscViewerFormat format;
4567: PetscInt i;
4569: PetscFunctionBegin;
4570: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4571: incall = PETSC_TRUE;
4573: /* All user-provided viewers are called first, if they exist. */
4574: for (i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4576: /* Call PETSc default routine if users ask for it */
4577: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &viewer, &format, &flg));
4578: if (flg) {
4579: PetscCall(PetscViewerPushFormat(viewer, format));
4580: PetscCall(SNESConvergedReasonView(snes, viewer));
4581: PetscCall(PetscViewerPopFormat(viewer));
4582: PetscCall(PetscOptionsRestoreViewer(&viewer));
4583: }
4584: incall = PETSC_FALSE;
4585: PetscFunctionReturn(PETSC_SUCCESS);
4586: }
4588: /*@
4589: SNESSolve - Solves a nonlinear system F(x) = b.
4591: Collective
4593: Input Parameters:
4594: + snes - the `SNES` context
4595: . b - the constant part of the equation F(x) = b, or `NULL` to use zero.
4596: - x - the solution vector.
4598: Level: beginner
4600: Note:
4601: The user should initialize the vector, `x`, with the initial guess
4602: for the nonlinear solve prior to calling `SNESSolve()` or use `SNESSetInitialSolution()`. In particular,
4603: to employ an initial guess of zero, the user should explicitly set
4604: this vector to zero by calling `VecSet()`.
4606: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4607: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4608: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`, `SNESSetInitialSolution()`
4609: @*/
4610: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4611: {
4612: PetscBool flg;
4613: PetscInt grid;
4614: Vec xcreated = NULL;
4615: DM dm;
4617: PetscFunctionBegin;
4620: if (x) PetscCheckSameComm(snes, 1, x, 3);
4622: if (b) PetscCheckSameComm(snes, 1, b, 2);
4624: /* High level operations using the nonlinear solver */
4625: {
4626: PetscViewer viewer;
4627: PetscViewerFormat format;
4628: PetscInt num;
4629: PetscBool flg;
4630: static PetscBool incall = PETSC_FALSE;
4632: if (!incall) {
4633: /* Estimate the convergence rate of the discretization */
4634: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4635: if (flg) {
4636: PetscConvEst conv;
4637: DM dm;
4638: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4639: PetscInt Nf;
4641: incall = PETSC_TRUE;
4642: PetscCall(SNESGetDM(snes, &dm));
4643: PetscCall(DMGetNumFields(dm, &Nf));
4644: PetscCall(PetscCalloc1(Nf, &alpha));
4645: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4646: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4647: PetscCall(PetscConvEstSetFromOptions(conv));
4648: PetscCall(PetscConvEstSetUp(conv));
4649: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4650: PetscCall(PetscViewerPushFormat(viewer, format));
4651: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4652: PetscCall(PetscViewerPopFormat(viewer));
4653: PetscCall(PetscOptionsRestoreViewer(&viewer));
4654: PetscCall(PetscConvEstDestroy(&conv));
4655: PetscCall(PetscFree(alpha));
4656: incall = PETSC_FALSE;
4657: }
4658: /* Adaptively refine the initial grid */
4659: num = 1;
4660: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4661: if (flg) {
4662: DMAdaptor adaptor;
4664: incall = PETSC_TRUE;
4665: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4666: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4667: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4668: PetscCall(DMAdaptorSetFromOptions(adaptor));
4669: PetscCall(DMAdaptorSetUp(adaptor));
4670: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4671: PetscCall(DMAdaptorDestroy(&adaptor));
4672: incall = PETSC_FALSE;
4673: }
4674: /* Use grid sequencing to adapt */
4675: num = 0;
4676: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4677: if (num) {
4678: DMAdaptor adaptor;
4680: incall = PETSC_TRUE;
4681: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4682: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4683: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4684: PetscCall(DMAdaptorSetFromOptions(adaptor));
4685: PetscCall(DMAdaptorSetUp(adaptor));
4686: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4687: PetscCall(DMAdaptorDestroy(&adaptor));
4688: incall = PETSC_FALSE;
4689: }
4690: }
4691: }
4692: if (!x) x = snes->vec_sol;
4693: if (!x) {
4694: PetscCall(SNESGetDM(snes, &dm));
4695: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4696: x = xcreated;
4697: }
4698: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4700: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4701: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4702: /* set solution vector */
4703: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4704: PetscCall(VecDestroy(&snes->vec_sol));
4705: snes->vec_sol = x;
4706: PetscCall(SNESGetDM(snes, &dm));
4708: /* set affine vector if provided */
4709: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4710: PetscCall(VecDestroy(&snes->vec_rhs));
4711: snes->vec_rhs = b;
4713: 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");
4714: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4715: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right hand side vector");
4716: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4717: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4718: PetscCall(SNESSetUp(snes));
4720: if (!grid) {
4721: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback compute initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4722: }
4724: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4725: if (snes->counters_reset) {
4726: snes->nfuncs = 0;
4727: snes->linear_its = 0;
4728: snes->numFailures = 0;
4729: }
4731: snes->reason = SNES_CONVERGED_ITERATING;
4732: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4733: PetscUseTypeMethod(snes, solve);
4734: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4735: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4736: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4738: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4739: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4741: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4742: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4743: /* Call converged reason views. This may involve user-provided viewers as well */
4744: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4746: if (snes->errorifnotconverged) PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4747: if (snes->reason < 0) break;
4748: if (grid < snes->gridsequence) {
4749: DM fine;
4750: Vec xnew;
4751: Mat interp;
4753: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4754: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4755: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4756: PetscCall(DMCreateGlobalVector(fine, &xnew));
4757: PetscCall(MatInterpolate(interp, x, xnew));
4758: PetscCall(DMInterpolate(snes->dm, interp, fine));
4759: PetscCall(MatDestroy(&interp));
4760: x = xnew;
4762: PetscCall(SNESReset(snes));
4763: PetscCall(SNESSetDM(snes, fine));
4764: PetscCall(SNESResetFromOptions(snes));
4765: PetscCall(DMDestroy(&fine));
4766: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4767: }
4768: }
4769: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4770: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4771: PetscCall(DMMonitor(snes->dm));
4772: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4774: PetscCall(VecDestroy(&xcreated));
4775: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4776: PetscFunctionReturn(PETSC_SUCCESS);
4777: }
4779: /* --------- Internal routines for SNES Package --------- */
4781: /*@C
4782: SNESSetType - Sets the method for the nonlinear solver.
4784: Collective
4786: Input Parameters:
4787: + snes - the `SNES` context
4788: - type - a known method
4790: Options Database Key:
4791: . -snes_type <type> - Sets the method; use -help for a list
4792: of available methods (for instance, newtonls or newtontr)
4794: Level: intermediate
4796: Notes:
4797: See "petsc/include/petscsnes.h" for available methods (for instance)
4798: + `SNESNEWTONLS` - Newton's method with line search
4799: (systems of nonlinear equations)
4800: - `SNESNEWTONTR` - Newton's method with trust region
4801: (systems of nonlinear equations)
4803: Normally, it is best to use the `SNESSetFromOptions()` command and then
4804: set the `SNES` solver type from the options database rather than by using
4805: this routine. Using the options database provides the user with
4806: maximum flexibility in evaluating the many nonlinear solvers.
4807: The `SNESSetType()` routine is provided for those situations where it
4808: is necessary to set the nonlinear solver independently of the command
4809: line or options database. This might be the case, for example, when
4810: the choice of solver changes during the execution of the program,
4811: and the user's application is taking responsibility for choosing the
4812: appropriate method.
4814: Developer Note:
4815: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4816: the constructor in that list and calls it to create the specific object.
4818: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4819: @*/
4820: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4821: {
4822: PetscBool match;
4823: PetscErrorCode (*r)(SNES);
4825: PetscFunctionBegin;
4827: PetscAssertPointer(type, 2);
4829: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4830: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4832: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4833: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4834: /* Destroy the previous private SNES context */
4835: PetscTryTypeMethod(snes, destroy);
4836: /* Reinitialize function pointers in SNESOps structure */
4837: snes->ops->setup = NULL;
4838: snes->ops->solve = NULL;
4839: snes->ops->view = NULL;
4840: snes->ops->setfromoptions = NULL;
4841: snes->ops->destroy = NULL;
4843: /* It may happen the user has customized the line search before calling SNESSetType */
4844: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
4846: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4847: snes->setupcalled = PETSC_FALSE;
4849: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
4850: PetscCall((*r)(snes));
4851: PetscFunctionReturn(PETSC_SUCCESS);
4852: }
4854: /*@C
4855: SNESGetType - Gets the `SNES` method type and name (as a string).
4857: Not Collective
4859: Input Parameter:
4860: . snes - nonlinear solver context
4862: Output Parameter:
4863: . type - `SNES` method (a character string)
4865: Level: intermediate
4867: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
4868: @*/
4869: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
4870: {
4871: PetscFunctionBegin;
4873: PetscAssertPointer(type, 2);
4874: *type = ((PetscObject)snes)->type_name;
4875: PetscFunctionReturn(PETSC_SUCCESS);
4876: }
4878: /*@
4879: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
4881: Logically Collective
4883: Input Parameters:
4884: + snes - the `SNES` context obtained from `SNESCreate()`
4885: - u - the solution vector
4887: Level: beginner
4889: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
4890: @*/
4891: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4892: {
4893: DM dm;
4895: PetscFunctionBegin;
4898: PetscCall(PetscObjectReference((PetscObject)u));
4899: PetscCall(VecDestroy(&snes->vec_sol));
4901: snes->vec_sol = u;
4903: PetscCall(SNESGetDM(snes, &dm));
4904: PetscCall(DMShellSetGlobalVector(dm, u));
4905: PetscFunctionReturn(PETSC_SUCCESS);
4906: }
4908: /*@
4909: SNESGetSolution - Returns the vector where the approximate solution is
4910: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
4912: Not Collective, but `x` is parallel if `snes` is parallel
4914: Input Parameter:
4915: . snes - the `SNES` context
4917: Output Parameter:
4918: . x - the solution
4920: Level: intermediate
4922: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
4923: @*/
4924: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
4925: {
4926: PetscFunctionBegin;
4928: PetscAssertPointer(x, 2);
4929: *x = snes->vec_sol;
4930: PetscFunctionReturn(PETSC_SUCCESS);
4931: }
4933: /*@
4934: SNESGetSolutionUpdate - Returns the vector where the solution update is
4935: stored.
4937: Not Collective, but `x` is parallel if `snes` is parallel
4939: Input Parameter:
4940: . snes - the `SNES` context
4942: Output Parameter:
4943: . x - the solution update
4945: Level: advanced
4947: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
4948: @*/
4949: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
4950: {
4951: PetscFunctionBegin;
4953: PetscAssertPointer(x, 2);
4954: *x = snes->vec_sol_update;
4955: PetscFunctionReturn(PETSC_SUCCESS);
4956: }
4958: /*@C
4959: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
4961: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
4963: Input Parameter:
4964: . snes - the `SNES` context
4966: Output Parameters:
4967: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
4968: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunctionFn`
4969: - ctx - the function context (or `NULL` if you don't want it)
4971: Level: advanced
4973: Note:
4974: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
4976: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunctionFn`
4977: @*/
4978: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, SNESFunctionFn **f, void **ctx)
4979: {
4980: DM dm;
4982: PetscFunctionBegin;
4984: if (r) {
4985: if (!snes->vec_func) {
4986: if (snes->vec_rhs) {
4987: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
4988: } else if (snes->vec_sol) {
4989: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
4990: } else if (snes->dm) {
4991: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
4992: }
4993: }
4994: *r = snes->vec_func;
4995: }
4996: PetscCall(SNESGetDM(snes, &dm));
4997: PetscCall(DMSNESGetFunction(dm, f, ctx));
4998: PetscFunctionReturn(PETSC_SUCCESS);
4999: }
5001: /*@C
5002: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
5004: Input Parameter:
5005: . snes - the `SNES` context
5007: Output Parameters:
5008: + f - the function (or `NULL`) see `SNESNGSFn` for calling sequence
5009: - ctx - the function context (or `NULL`)
5011: Level: advanced
5013: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`, `SNESNGSFn`
5014: @*/
5015: PetscErrorCode SNESGetNGS(SNES snes, SNESNGSFn **f, void **ctx)
5016: {
5017: DM dm;
5019: PetscFunctionBegin;
5021: PetscCall(SNESGetDM(snes, &dm));
5022: PetscCall(DMSNESGetNGS(dm, f, ctx));
5023: PetscFunctionReturn(PETSC_SUCCESS);
5024: }
5026: /*@C
5027: SNESSetOptionsPrefix - Sets the prefix used for searching for all
5028: `SNES` options in the database.
5030: Logically Collective
5032: Input Parameters:
5033: + snes - the `SNES` context
5034: - prefix - the prefix to prepend to all option names
5036: Level: advanced
5038: Note:
5039: A hyphen (-) must NOT be given at the beginning of the prefix name.
5040: The first character of all runtime options is AUTOMATICALLY the hyphen.
5042: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
5043: @*/
5044: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
5045: {
5046: PetscFunctionBegin;
5048: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
5049: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5050: if (snes->linesearch) {
5051: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5052: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
5053: }
5054: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
5055: PetscFunctionReturn(PETSC_SUCCESS);
5056: }
5058: /*@C
5059: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5060: `SNES` options in the database.
5062: Logically Collective
5064: Input Parameters:
5065: + snes - the `SNES` context
5066: - prefix - the prefix to prepend to all option names
5068: Level: advanced
5070: Note:
5071: A hyphen (-) must NOT be given at the beginning of the prefix name.
5072: The first character of all runtime options is AUTOMATICALLY the hyphen.
5074: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5075: @*/
5076: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5077: {
5078: PetscFunctionBegin;
5080: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5081: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5082: if (snes->linesearch) {
5083: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5084: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5085: }
5086: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5087: PetscFunctionReturn(PETSC_SUCCESS);
5088: }
5090: /*@C
5091: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5092: `SNES` options in the database.
5094: Not Collective
5096: Input Parameter:
5097: . snes - the `SNES` context
5099: Output Parameter:
5100: . prefix - pointer to the prefix string used
5102: Level: advanced
5104: Fortran Note:
5105: The user should pass in a string 'prefix' of
5106: sufficient length to hold the prefix.
5108: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5109: @*/
5110: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5111: {
5112: PetscFunctionBegin;
5114: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5115: PetscFunctionReturn(PETSC_SUCCESS);
5116: }
5118: /*@C
5119: SNESRegister - Adds a method to the nonlinear solver package.
5121: Not Collective
5123: Input Parameters:
5124: + sname - name of a new user-defined solver
5125: - function - routine to create method context
5127: Level: advanced
5129: Note:
5130: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5132: Example Usage:
5133: .vb
5134: SNESRegister("my_solver", MySolverCreate);
5135: .ve
5137: Then, your solver can be chosen with the procedural interface via
5138: $ SNESSetType(snes, "my_solver")
5139: or at runtime via the option
5140: $ -snes_type my_solver
5142: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5143: @*/
5144: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5145: {
5146: PetscFunctionBegin;
5147: PetscCall(SNESInitializePackage());
5148: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5149: PetscFunctionReturn(PETSC_SUCCESS);
5150: }
5152: PetscErrorCode SNESTestLocalMin(SNES snes)
5153: {
5154: PetscInt N, i, j;
5155: Vec u, uh, fh;
5156: PetscScalar value;
5157: PetscReal norm;
5159: PetscFunctionBegin;
5160: PetscCall(SNESGetSolution(snes, &u));
5161: PetscCall(VecDuplicate(u, &uh));
5162: PetscCall(VecDuplicate(u, &fh));
5164: /* currently only works for sequential */
5165: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5166: PetscCall(VecGetSize(u, &N));
5167: for (i = 0; i < N; i++) {
5168: PetscCall(VecCopy(u, uh));
5169: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5170: for (j = -10; j < 11; j++) {
5171: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5172: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5173: PetscCall(SNESComputeFunction(snes, uh, fh));
5174: PetscCall(VecNorm(fh, NORM_2, &norm));
5175: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5176: value = -value;
5177: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5178: }
5179: }
5180: PetscCall(VecDestroy(&uh));
5181: PetscCall(VecDestroy(&fh));
5182: PetscFunctionReturn(PETSC_SUCCESS);
5183: }
5185: /*@
5186: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5187: computing relative tolerance for linear solvers within an inexact
5188: Newton method.
5190: Logically Collective
5192: Input Parameters:
5193: + snes - `SNES` context
5194: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5196: Options Database Keys:
5197: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5198: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5199: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5200: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5201: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5202: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5203: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5204: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5206: Level: advanced
5208: Note:
5209: The default is to use a constant relative tolerance for
5210: the inner linear solvers. Alternatively, one can use the
5211: Eisenstat-Walker method {cite}`ew96`, where the relative convergence tolerance
5212: is reset at each Newton iteration according progress of the nonlinear
5213: solver.
5215: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5216: @*/
5217: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5218: {
5219: PetscFunctionBegin;
5222: snes->ksp_ewconv = flag;
5223: PetscFunctionReturn(PETSC_SUCCESS);
5224: }
5226: /*@
5227: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5228: for computing relative tolerance for linear solvers within an
5229: inexact Newton method.
5231: Not Collective
5233: Input Parameter:
5234: . snes - `SNES` context
5236: Output Parameter:
5237: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5239: Level: advanced
5241: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5242: @*/
5243: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5244: {
5245: PetscFunctionBegin;
5247: PetscAssertPointer(flag, 2);
5248: *flag = snes->ksp_ewconv;
5249: PetscFunctionReturn(PETSC_SUCCESS);
5250: }
5252: /*@
5253: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5254: convergence criteria for the linear solvers within an inexact
5255: Newton method.
5257: Logically Collective
5259: Input Parameters:
5260: + snes - `SNES` context
5261: . version - version 1, 2 (default is 2), 3 or 4
5262: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5263: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5264: . gamma - multiplicative factor for version 2 rtol computation
5265: (0 <= gamma2 <= 1)
5266: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5267: . alpha2 - power for safeguard
5268: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5270: Level: advanced
5272: Notes:
5273: Version 3 was contributed by Luis Chacon, June 2006.
5275: Use `PETSC_DEFAULT` to retain the default for any of the parameters.
5277: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5278: @*/
5279: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5280: {
5281: SNESKSPEW *kctx;
5283: PetscFunctionBegin;
5285: kctx = (SNESKSPEW *)snes->kspconvctx;
5286: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5295: if (version != PETSC_DEFAULT) kctx->version = version;
5296: if (rtol_0 != (PetscReal)PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5297: if (rtol_max != (PetscReal)PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5298: if (gamma != (PetscReal)PETSC_DEFAULT) kctx->gamma = gamma;
5299: if (alpha != (PetscReal)PETSC_DEFAULT) kctx->alpha = alpha;
5300: if (alpha2 != (PetscReal)PETSC_DEFAULT) kctx->alpha2 = alpha2;
5301: if (threshold != (PetscReal)PETSC_DEFAULT) kctx->threshold = threshold;
5303: 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);
5304: 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);
5305: 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);
5306: 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);
5307: 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);
5308: 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);
5309: PetscFunctionReturn(PETSC_SUCCESS);
5310: }
5312: /*@
5313: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5314: convergence criteria for the linear solvers within an inexact
5315: Newton method.
5317: Not Collective
5319: Input Parameter:
5320: . snes - `SNES` context
5322: Output Parameters:
5323: + version - version 1, 2 (default is 2), 3 or 4
5324: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5325: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5326: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5327: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5328: . alpha2 - power for safeguard
5329: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5331: Level: advanced
5333: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5334: @*/
5335: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5336: {
5337: SNESKSPEW *kctx;
5339: PetscFunctionBegin;
5341: kctx = (SNESKSPEW *)snes->kspconvctx;
5342: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5343: if (version) *version = kctx->version;
5344: if (rtol_0) *rtol_0 = kctx->rtol_0;
5345: if (rtol_max) *rtol_max = kctx->rtol_max;
5346: if (gamma) *gamma = kctx->gamma;
5347: if (alpha) *alpha = kctx->alpha;
5348: if (alpha2) *alpha2 = kctx->alpha2;
5349: if (threshold) *threshold = kctx->threshold;
5350: PetscFunctionReturn(PETSC_SUCCESS);
5351: }
5353: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5354: {
5355: SNES snes = (SNES)ctx;
5356: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5357: PetscReal rtol = PETSC_DEFAULT, stol;
5359: PetscFunctionBegin;
5360: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5361: if (!snes->iter) {
5362: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5363: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5364: } else {
5365: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5366: if (kctx->version == 1) {
5367: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5368: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5369: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5370: } else if (kctx->version == 2) {
5371: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5372: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5373: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5374: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5375: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5376: /* safeguard: avoid sharp decrease of rtol */
5377: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5378: stol = PetscMax(rtol, stol);
5379: rtol = PetscMin(kctx->rtol_0, stol);
5380: /* safeguard: avoid oversolving */
5381: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5382: stol = PetscMax(rtol, stol);
5383: rtol = PetscMin(kctx->rtol_0, stol);
5384: } else /* if (kctx->version == 4) */ {
5385: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5386: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5387: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5388: PetscReal rk = ared / pred;
5389: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5390: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5391: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5392: else rtol = kctx->v4_m2 * kctx->rtol_last;
5394: 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;
5395: kctx->rtol_last_2 = kctx->rtol_last;
5396: kctx->rk_last_2 = kctx->rk_last;
5397: kctx->rk_last = rk;
5398: }
5399: }
5400: /* safeguard: avoid rtol greater than rtol_max */
5401: rtol = PetscMin(rtol, kctx->rtol_max);
5402: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_DEFAULT, PETSC_DEFAULT, PETSC_DEFAULT));
5403: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5404: PetscFunctionReturn(PETSC_SUCCESS);
5405: }
5407: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5408: {
5409: SNES snes = (SNES)ctx;
5410: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5411: PCSide pcside;
5412: Vec lres;
5414: PetscFunctionBegin;
5415: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5416: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5417: kctx->norm_last = snes->norm;
5418: if (kctx->version == 1 || kctx->version == 4) {
5419: PC pc;
5420: PetscBool getRes;
5422: PetscCall(KSPGetPC(ksp, &pc));
5423: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5424: if (!getRes) {
5425: KSPNormType normtype;
5427: PetscCall(KSPGetNormType(ksp, &normtype));
5428: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5429: }
5430: PetscCall(KSPGetPCSide(ksp, &pcside));
5431: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5432: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5433: } else {
5434: /* KSP residual is preconditioned residual */
5435: /* compute true linear residual norm */
5436: Mat J;
5437: PetscCall(KSPGetOperators(ksp, &J, NULL));
5438: PetscCall(VecDuplicate(b, &lres));
5439: PetscCall(MatMult(J, x, lres));
5440: PetscCall(VecAYPX(lres, -1.0, b));
5441: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5442: PetscCall(VecDestroy(&lres));
5443: }
5444: }
5445: PetscFunctionReturn(PETSC_SUCCESS);
5446: }
5448: /*@
5449: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5451: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5453: Input Parameter:
5454: . snes - the `SNES` context
5456: Output Parameter:
5457: . ksp - the `KSP` context
5459: Level: beginner
5461: Notes:
5462: The user can then directly manipulate the `KSP` context to set various
5463: options, etc. Likewise, the user can then extract and manipulate the
5464: `PC` contexts as well.
5466: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function
5468: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5469: @*/
5470: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5471: {
5472: PetscFunctionBegin;
5474: PetscAssertPointer(ksp, 2);
5476: if (!snes->ksp) {
5477: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5478: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5480: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5481: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5483: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5484: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5485: }
5486: *ksp = snes->ksp;
5487: PetscFunctionReturn(PETSC_SUCCESS);
5488: }
5490: #include <petsc/private/dmimpl.h>
5491: /*@
5492: SNESSetDM - Sets the `DM` that may be used by some nonlinear solvers or their underlying preconditioners
5494: Logically Collective
5496: Input Parameters:
5497: + snes - the nonlinear solver context
5498: - dm - the `DM`, cannot be `NULL`
5500: Level: intermediate
5502: Note:
5503: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5504: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5505: problems using the same function space.
5507: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5508: @*/
5509: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5510: {
5511: KSP ksp;
5512: DMSNES sdm;
5514: PetscFunctionBegin;
5517: PetscCall(PetscObjectReference((PetscObject)dm));
5518: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5519: if (snes->dm->dmsnes && !dm->dmsnes) {
5520: PetscCall(DMCopyDMSNES(snes->dm, dm));
5521: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5522: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5523: }
5524: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5525: PetscCall(DMDestroy(&snes->dm));
5526: }
5527: snes->dm = dm;
5528: snes->dmAuto = PETSC_FALSE;
5530: PetscCall(SNESGetKSP(snes, &ksp));
5531: PetscCall(KSPSetDM(ksp, dm));
5532: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5533: if (snes->npc) {
5534: PetscCall(SNESSetDM(snes->npc, snes->dm));
5535: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5536: }
5537: PetscFunctionReturn(PETSC_SUCCESS);
5538: }
5540: /*@
5541: SNESGetDM - Gets the `DM` that may be used by some solvers/preconditioners
5543: Not Collective but dm obtained is parallel on snes
5545: Input Parameter:
5546: . snes - the `SNES` context
5548: Output Parameter:
5549: . dm - the `DM`
5551: Level: intermediate
5553: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5554: @*/
5555: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5556: {
5557: PetscFunctionBegin;
5559: if (!snes->dm) {
5560: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5561: snes->dmAuto = PETSC_TRUE;
5562: }
5563: *dm = snes->dm;
5564: PetscFunctionReturn(PETSC_SUCCESS);
5565: }
5567: /*@
5568: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5570: Collective
5572: Input Parameters:
5573: + snes - iterative context obtained from `SNESCreate()`
5574: - npc - the nonlinear preconditioner object
5576: Level: developer
5578: Notes:
5579: Use `SNESGetNPC()` to retrieve the preconditioner context (for example,
5580: to configure it using the API).
5582: Only some `SNESType` can use a nonlinear preconditioner
5584: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5585: @*/
5586: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5587: {
5588: PetscFunctionBegin;
5591: PetscCheckSameComm(snes, 1, npc, 2);
5592: PetscCall(PetscObjectReference((PetscObject)npc));
5593: PetscCall(SNESDestroy(&snes->npc));
5594: snes->npc = npc;
5595: PetscFunctionReturn(PETSC_SUCCESS);
5596: }
5598: /*@
5599: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5601: Not Collective; but any changes to the obtained the npc object must be applied collectively
5603: Input Parameter:
5604: . snes - iterative context obtained from `SNESCreate()`
5606: Output Parameter:
5607: . pc - preconditioner context
5609: Options Database Key:
5610: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5612: Level: developer
5614: Notes:
5615: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created.
5617: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5618: `SNES`
5620: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5621: @*/
5622: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5623: {
5624: const char *optionsprefix;
5626: PetscFunctionBegin;
5628: PetscAssertPointer(pc, 2);
5629: if (!snes->npc) {
5630: void *ctx;
5632: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5633: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5634: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5635: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5636: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5637: if (snes->ops->usercompute) {
5638: PetscCall(SNESSetComputeApplicationContext(snes, snes->ops->usercompute, snes->ops->userdestroy));
5639: } else {
5640: PetscCall(SNESGetApplicationContext(snes, &ctx));
5641: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5642: }
5643: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5644: }
5645: *pc = snes->npc;
5646: PetscFunctionReturn(PETSC_SUCCESS);
5647: }
5649: /*@
5650: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5652: Not Collective
5654: Input Parameter:
5655: . snes - iterative context obtained from `SNESCreate()`
5657: Output Parameter:
5658: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5660: Level: developer
5662: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5663: @*/
5664: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5665: {
5666: PetscFunctionBegin;
5668: *has_npc = (PetscBool)(snes->npc ? PETSC_TRUE : PETSC_FALSE);
5669: PetscFunctionReturn(PETSC_SUCCESS);
5670: }
5672: /*@
5673: SNESSetNPCSide - Sets the nonlinear preconditioning side.
5675: Logically Collective
5677: Input Parameter:
5678: . snes - iterative context obtained from `SNESCreate()`
5680: Output Parameter:
5681: . side - the preconditioning side, where side is one of
5682: .vb
5683: PC_LEFT - left preconditioning
5684: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5685: .ve
5687: Options Database Key:
5688: . -snes_npc_side <right,left> - nonlinear preconditioner side
5690: Level: intermediate
5692: Note:
5693: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5695: .seealso: [](ch_snes), `SNES`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5696: @*/
5697: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5698: {
5699: PetscFunctionBegin;
5702: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5703: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5704: snes->npcside = side;
5705: PetscFunctionReturn(PETSC_SUCCESS);
5706: }
5708: /*@
5709: SNESGetNPCSide - Gets the preconditioning side.
5711: Not Collective
5713: Input Parameter:
5714: . snes - iterative context obtained from `SNESCreate()`
5716: Output Parameter:
5717: . side - the preconditioning side, where side is one of
5718: .vb
5719: `PC_LEFT` - left preconditioning
5720: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5721: .ve
5723: Level: intermediate
5725: .seealso: [](ch_snes), `SNES`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5726: @*/
5727: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5728: {
5729: PetscFunctionBegin;
5731: PetscAssertPointer(side, 2);
5732: *side = snes->npcside;
5733: PetscFunctionReturn(PETSC_SUCCESS);
5734: }
5736: /*@
5737: SNESSetLineSearch - Sets the linesearch to be used for `SNES`
5739: Collective
5741: Input Parameters:
5742: + snes - iterative context obtained from `SNESCreate()`
5743: - linesearch - the linesearch object
5745: Level: developer
5747: Note:
5748: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
5749: to configure it using the API).
5751: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
5752: @*/
5753: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5754: {
5755: PetscFunctionBegin;
5758: PetscCheckSameComm(snes, 1, linesearch, 2);
5759: PetscCall(PetscObjectReference((PetscObject)linesearch));
5760: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5762: snes->linesearch = linesearch;
5763: PetscFunctionReturn(PETSC_SUCCESS);
5764: }
5766: /*@
5767: SNESGetLineSearch - Returns the line search context possibly set with `SNESSetLineSearch()`
5768: or creates a default line search instance associated with the `SNES` and returns it.
5770: Not Collective
5772: Input Parameter:
5773: . snes - iterative context obtained from `SNESCreate()`
5775: Output Parameter:
5776: . linesearch - linesearch context
5778: Level: beginner
5780: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`
5781: @*/
5782: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5783: {
5784: const char *optionsprefix;
5786: PetscFunctionBegin;
5788: PetscAssertPointer(linesearch, 2);
5789: if (!snes->linesearch) {
5790: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5791: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5792: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5793: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5794: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5795: }
5796: *linesearch = snes->linesearch;
5797: PetscFunctionReturn(PETSC_SUCCESS);
5798: }