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()`, `SNESFunction`, `SNESSetJacobianDomainError()`, `SNESVISetVariableBounds()`,
136: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
137: @*/
138: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
139: {
140: PetscFunctionBegin;
142: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates input vector is not in the function domain");
143: snes->domainerror = PETSC_TRUE;
144: PetscFunctionReturn(PETSC_SUCCESS);
145: }
147: /*@
148: SNESSetJacobianDomainError - tells `SNES` that the function you provided to `SNESSetJacobian()` at the proposed step. For example there is a negative element transformation.
150: Logically Collective
152: Input Parameter:
153: . snes - the `SNES` context
155: Level: advanced
157: Notes:
158: If this is called the `SNESSolve()` stops iterating and returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_DOMAIN`
160: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
162: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
163: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
165: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESVISetVariableBounds()`,
166: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
167: @*/
168: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
169: {
170: PetscFunctionBegin;
172: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates computeJacobian does not make sense");
173: snes->jacobiandomainerror = PETSC_TRUE;
174: PetscFunctionReturn(PETSC_SUCCESS);
175: }
177: /*@
178: SNESSetCheckJacobianDomainError - tells `SNESSolve()` whether to check if the user called `SNESSetJacobianDomainError()` Jacobian domain error after
179: each Jacobian evaluation. By default, 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()`, `SNESFunction()`, `SNESSetFunctionDomainError()`, `SNESGetCheckJacobianDomainError()`
193: @*/
194: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
195: {
196: PetscFunctionBegin;
198: snes->checkjacdomainerror = flg;
199: PetscFunctionReturn(PETSC_SUCCESS);
200: }
202: /*@
203: SNESGetCheckJacobianDomainError - Get an indicator whether or not `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()`, `SNESFunction()`, `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: PetscErrorCode (*cJ)(SNES, Vec, Mat, Mat, void *);
409: void *ctx;
410: const char *pre = "";
412: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)snes, viewer));
413: if (!snes->setupcalled) PetscCall(PetscViewerASCIIPrintf(viewer, " SNES has not been set up so information may be incomplete\n"));
414: if (snes->ops->view) {
415: PetscCall(PetscViewerASCIIPushTab(viewer));
416: PetscUseTypeMethod(snes, view, viewer);
417: PetscCall(PetscViewerASCIIPopTab(viewer));
418: }
419: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=%" PetscInt_FMT "\n", snes->max_its, snes->max_funcs));
420: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, solution=%g\n", (double)snes->rtol, (double)snes->abstol, (double)snes->stol));
421: if (snes->usesksp) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of linear solver iterations=%" PetscInt_FMT "\n", snes->linear_its));
422: PetscCall(PetscViewerASCIIPrintf(viewer, " total number of function evaluations=%" PetscInt_FMT "\n", snes->nfuncs));
423: PetscCall(SNESGetNormSchedule(snes, &normschedule));
424: if (normschedule > 0) PetscCall(PetscViewerASCIIPrintf(viewer, " norm schedule %s\n", SNESNormSchedules[normschedule]));
425: if (snes->gridsequence) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of grid sequence refinements=%" PetscInt_FMT "\n", snes->gridsequence));
426: if (snes->ksp_ewconv) {
427: kctx = (SNESKSPEW *)snes->kspconvctx;
428: if (kctx) {
429: PetscCall(PetscViewerASCIIPrintf(viewer, " Eisenstat-Walker computation of KSP relative tolerance (version %" PetscInt_FMT ")\n", kctx->version));
430: PetscCall(PetscViewerASCIIPrintf(viewer, " rtol_0=%g, rtol_max=%g, threshold=%g\n", (double)kctx->rtol_0, (double)kctx->rtol_max, (double)kctx->threshold));
431: PetscCall(PetscViewerASCIIPrintf(viewer, " gamma=%g, alpha=%g, alpha2=%g\n", (double)kctx->gamma, (double)kctx->alpha, (double)kctx->alpha2));
432: }
433: }
434: if (snes->lagpreconditioner == -1) {
435: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is never rebuilt\n"));
436: } else if (snes->lagpreconditioner > 1) {
437: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is rebuilt every %" PetscInt_FMT " new Jacobians\n", snes->lagpreconditioner));
438: }
439: if (snes->lagjacobian == -1) {
440: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is never rebuilt\n"));
441: } else if (snes->lagjacobian > 1) {
442: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is rebuilt every %" PetscInt_FMT " SNES iterations\n", snes->lagjacobian));
443: }
444: PetscCall(SNESGetDM(snes, &dm));
445: PetscCall(DMSNESGetJacobian(dm, &cJ, &ctx));
446: if (snes->mf_operator) {
447: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing\n"));
448: pre = "Preconditioning ";
449: }
450: if (cJ == SNESComputeJacobianDefault) {
451: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences one column at a time\n", pre));
452: } else if (cJ == SNESComputeJacobianDefaultColor) {
453: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences with coloring\n", pre));
454: /* it slightly breaks data encapsulation for access the DMDA information directly */
455: } else if (cJ == SNESComputeJacobian_DMDA) {
456: MatFDColoring fdcoloring;
457: PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
458: if (fdcoloring) {
459: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using colored finite differences on a DMDA\n", pre));
460: } else {
461: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using a DMDA local Jacobian\n", pre));
462: }
463: } else if (snes->mf && !snes->mf_operator) {
464: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing, no explicit Jacobian\n"));
465: }
466: } else if (isstring) {
467: const char *type;
468: PetscCall(SNESGetType(snes, &type));
469: PetscCall(PetscViewerStringSPrintf(viewer, " SNESType: %-7.7s", type));
470: PetscTryTypeMethod(snes, view, viewer);
471: } else if (isbinary) {
472: PetscInt classid = SNES_FILE_CLASSID;
473: MPI_Comm comm;
474: PetscMPIInt rank;
475: char type[256];
477: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
478: PetscCallMPI(MPI_Comm_rank(comm, &rank));
479: if (rank == 0) {
480: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
481: PetscCall(PetscStrncpy(type, ((PetscObject)snes)->type_name, sizeof(type)));
482: PetscCall(PetscViewerBinaryWrite(viewer, type, sizeof(type), PETSC_CHAR));
483: }
484: PetscTryTypeMethod(snes, view, viewer);
485: } else if (isdraw) {
486: PetscDraw draw;
487: char str[36];
488: PetscReal x, y, bottom, h;
490: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
491: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
492: PetscCall(PetscStrncpy(str, "SNES: ", sizeof(str)));
493: PetscCall(PetscStrlcat(str, ((PetscObject)snes)->type_name, sizeof(str)));
494: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_BLUE, PETSC_DRAW_BLACK, str, NULL, &h));
495: bottom = y - h;
496: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
497: PetscTryTypeMethod(snes, view, viewer);
498: #if defined(PETSC_HAVE_SAWS)
499: } else if (issaws) {
500: PetscMPIInt rank;
501: const char *name;
503: PetscCall(PetscObjectGetName((PetscObject)snes, &name));
504: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
505: if (!((PetscObject)snes)->amsmem && rank == 0) {
506: char dir[1024];
508: PetscCall(PetscObjectViewSAWs((PetscObject)snes, viewer));
509: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
510: PetscCallSAWs(SAWs_Register, (dir, &snes->iter, 1, SAWs_READ, SAWs_INT));
511: if (!snes->conv_hist) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, PETSC_DECIDE, PETSC_TRUE));
512: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/conv_hist", name));
513: PetscCallSAWs(SAWs_Register, (dir, snes->conv_hist, 10, SAWs_READ, SAWs_DOUBLE));
514: }
515: #endif
516: }
517: if (snes->linesearch) {
518: PetscCall(SNESGetLineSearch(snes, &linesearch));
519: PetscCall(PetscViewerASCIIPushTab(viewer));
520: PetscCall(SNESLineSearchView(linesearch, viewer));
521: PetscCall(PetscViewerASCIIPopTab(viewer));
522: }
523: if (snes->npc && snes->usesnpc) {
524: PetscCall(PetscViewerASCIIPushTab(viewer));
525: PetscCall(SNESView(snes->npc, viewer));
526: PetscCall(PetscViewerASCIIPopTab(viewer));
527: }
528: PetscCall(PetscViewerASCIIPushTab(viewer));
529: PetscCall(DMGetDMSNES(snes->dm, &dmsnes));
530: PetscCall(DMSNESView(dmsnes, viewer));
531: PetscCall(PetscViewerASCIIPopTab(viewer));
532: if (snes->usesksp) {
533: PetscCall(SNESGetKSP(snes, &ksp));
534: PetscCall(PetscViewerASCIIPushTab(viewer));
535: PetscCall(KSPView(ksp, viewer));
536: PetscCall(PetscViewerASCIIPopTab(viewer));
537: }
538: if (isdraw) {
539: PetscDraw draw;
540: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
541: PetscCall(PetscDrawPopCurrentPoint(draw));
542: }
543: PetscFunctionReturn(PETSC_SUCCESS);
544: }
546: /*
547: We retain a list of functions that also take SNES command
548: line options. These are called at the end SNESSetFromOptions()
549: */
550: #define MAXSETFROMOPTIONS 5
551: static PetscInt numberofsetfromoptions;
552: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
554: /*@C
555: SNESAddOptionsChecker - Adds an additional function to check for `SNES` options.
557: Not Collective
559: Input Parameter:
560: . snescheck - function that checks for options
562: 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: PetscErrorCode (*jac)(SNES, Vec, Mat, Mat, void *) = 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(PetscObjectDereference((PetscObject)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: /*MC
1837: SNESFunction - Functional form used to convey the nonlinear function to `SNES` in `SNESSetFunction()`
1839: Synopsis:
1840: #include "petscsnes.h"
1841: PetscErrorCode SNESFunction(SNES snes,Vec x,Vec f,void *ctx);
1843: Collective
1845: Input Parameters:
1846: + snes - the `SNES` context
1847: . x - state at which to evaluate residual
1848: - ctx - optional user-defined function context, passed in with `SNESSetFunction()`
1850: Output Parameter:
1851: . f - vector to put residual (function value)
1853: Level: intermediate
1855: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESGetFunction()`
1856: M*/
1858: /*@C
1859: SNESSetFunction - Sets the function evaluation routine and function
1860: vector for use by the `SNES` routines in solving systems of nonlinear
1861: equations.
1863: Logically Collective
1865: Input Parameters:
1866: + snes - the `SNES` context
1867: . r - vector to store function values, may be `NULL`
1868: . f - function evaluation routine; for calling sequence see `SNESFunction`
1869: - ctx - [optional] user-defined context for private data for the
1870: function evaluation routine (may be `NULL`)
1872: Level: beginner
1874: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunction`
1875: @*/
1876: PetscErrorCode SNESSetFunction(SNES snes, Vec r, PetscErrorCode (*f)(SNES, Vec, Vec, void *), void *ctx)
1877: {
1878: DM dm;
1880: PetscFunctionBegin;
1882: if (r) {
1884: PetscCheckSameComm(snes, 1, r, 2);
1885: PetscCall(PetscObjectReference((PetscObject)r));
1886: PetscCall(VecDestroy(&snes->vec_func));
1887: snes->vec_func = r;
1888: }
1889: PetscCall(SNESGetDM(snes, &dm));
1890: PetscCall(DMSNESSetFunction(dm, f, ctx));
1891: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1892: PetscFunctionReturn(PETSC_SUCCESS);
1893: }
1895: /*@C
1896: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1898: Logically Collective
1900: Input Parameters:
1901: + snes - the `SNES` context
1902: - f - vector to store function value
1904: Level: developer
1906: Notes:
1907: This should not be modified during the solution procedure.
1909: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1911: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1912: @*/
1913: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1914: {
1915: Vec vec_func;
1917: PetscFunctionBegin;
1920: PetscCheckSameComm(snes, 1, f, 2);
1921: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1922: snes->vec_func_init_set = PETSC_FALSE;
1923: PetscFunctionReturn(PETSC_SUCCESS);
1924: }
1925: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
1926: PetscCall(VecCopy(f, vec_func));
1928: snes->vec_func_init_set = PETSC_TRUE;
1929: PetscFunctionReturn(PETSC_SUCCESS);
1930: }
1932: /*@
1933: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
1934: of the `SNES` method, when norms are computed in the solving process
1936: Logically Collective
1938: Input Parameters:
1939: + snes - the `SNES` context
1940: - normschedule - the frequency of norm computation
1942: Options Database Key:
1943: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
1945: Level: advanced
1947: Notes:
1948: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
1949: of the nonlinear function and the taking of its norm at every iteration to
1950: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1951: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
1952: may either be monitored for convergence or not. As these are often used as nonlinear
1953: preconditioners, monitoring the norm of their error is not a useful enterprise within
1954: their solution.
1956: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
1957: @*/
1958: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1959: {
1960: PetscFunctionBegin;
1962: snes->normschedule = normschedule;
1963: PetscFunctionReturn(PETSC_SUCCESS);
1964: }
1966: /*@
1967: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
1968: of the `SNES` method.
1970: Logically Collective
1972: Input Parameters:
1973: + snes - the `SNES` context
1974: - normschedule - the type of the norm used
1976: Level: advanced
1978: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1979: @*/
1980: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1981: {
1982: PetscFunctionBegin;
1984: *normschedule = snes->normschedule;
1985: PetscFunctionReturn(PETSC_SUCCESS);
1986: }
1988: /*@
1989: SNESSetFunctionNorm - Sets the last computed residual norm.
1991: Logically Collective
1993: Input Parameters:
1994: + snes - the `SNES` context
1995: - norm - the value of the norm
1997: Level: developer
1999: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2000: @*/
2001: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
2002: {
2003: PetscFunctionBegin;
2005: snes->norm = norm;
2006: PetscFunctionReturn(PETSC_SUCCESS);
2007: }
2009: /*@
2010: SNESGetFunctionNorm - Gets the last computed norm of the residual
2012: Not Collective
2014: Input Parameter:
2015: . snes - the `SNES` context
2017: Output Parameter:
2018: . norm - the last computed residual norm
2020: Level: developer
2022: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2023: @*/
2024: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2025: {
2026: PetscFunctionBegin;
2028: PetscAssertPointer(norm, 2);
2029: *norm = snes->norm;
2030: PetscFunctionReturn(PETSC_SUCCESS);
2031: }
2033: /*@
2034: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2036: Not Collective
2038: Input Parameter:
2039: . snes - the `SNES` context
2041: Output Parameter:
2042: . ynorm - the last computed update norm
2044: Level: developer
2046: Note:
2047: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2049: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2050: @*/
2051: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2052: {
2053: PetscFunctionBegin;
2055: PetscAssertPointer(ynorm, 2);
2056: *ynorm = snes->ynorm;
2057: PetscFunctionReturn(PETSC_SUCCESS);
2058: }
2060: /*@
2061: SNESGetSolutionNorm - Gets the last computed norm of the solution
2063: Not Collective
2065: Input Parameter:
2066: . snes - the `SNES` context
2068: Output Parameter:
2069: . xnorm - the last computed solution norm
2071: Level: developer
2073: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2074: @*/
2075: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2076: {
2077: PetscFunctionBegin;
2079: PetscAssertPointer(xnorm, 2);
2080: *xnorm = snes->xnorm;
2081: PetscFunctionReturn(PETSC_SUCCESS);
2082: }
2084: /*@C
2085: SNESSetFunctionType - Sets the `SNESFunctionType`
2086: of the `SNES` method.
2088: Logically Collective
2090: Input Parameters:
2091: + snes - the `SNES` context
2092: - type - the function type
2094: Level: developer
2096: Values of the function type\:
2097: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2098: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2099: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2101: Note:
2102: Different `SNESType`s use this value in different ways
2104: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2105: @*/
2106: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2107: {
2108: PetscFunctionBegin;
2110: snes->functype = type;
2111: PetscFunctionReturn(PETSC_SUCCESS);
2112: }
2114: /*@C
2115: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2116: of the SNES method.
2118: Logically Collective
2120: Input Parameters:
2121: + snes - the `SNES` context
2122: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2124: Level: advanced
2126: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2127: @*/
2128: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2129: {
2130: PetscFunctionBegin;
2132: *type = snes->functype;
2133: PetscFunctionReturn(PETSC_SUCCESS);
2134: }
2136: /*@C
2137: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2138: use with composed nonlinear solvers.
2140: Input Parameters:
2141: + snes - the `SNES` context
2142: . f - function evaluation routine to apply Gauss-Seidel
2143: - ctx - [optional] user-defined context for private data for the
2144: smoother evaluation routine (may be `NULL`)
2146: Calling sequence of `f`:
2147: + snes - the `SNES` context
2148: . X - the current solution
2149: . B - the right hand side vector (which may be `NULL`)
2150: - ctx - a user provided context
2152: Level: intermediate
2154: Note:
2155: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2156: a problem appropriate update to the solution, particularly `SNESFAS`.
2158: .seealso: [](ch_snes), `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`
2159: @*/
2160: PetscErrorCode SNESSetNGS(SNES snes, PetscErrorCode (*f)(SNES snes, Vec X, Vec B, void *ctx), void *ctx)
2161: {
2162: DM dm;
2164: PetscFunctionBegin;
2166: PetscCall(SNESGetDM(snes, &dm));
2167: PetscCall(DMSNESSetNGS(dm, f, ctx));
2168: PetscFunctionReturn(PETSC_SUCCESS);
2169: }
2171: /*
2172: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2173: changed during the KSPSolve()
2174: */
2175: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, void *ctx)
2176: {
2177: DM dm;
2178: DMSNES sdm;
2180: PetscFunctionBegin;
2181: PetscCall(SNESGetDM(snes, &dm));
2182: PetscCall(DMGetDMSNES(dm, &sdm));
2183: /* A(x)*x - b(x) */
2184: if (sdm->ops->computepfunction) {
2185: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2186: PetscCall(VecScale(f, -1.0));
2187: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2188: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2189: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2190: PetscCall(MatMultAdd(snes->picard, x, f, f));
2191: } else {
2192: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2193: PetscCall(MatMult(snes->picard, x, f));
2194: }
2195: PetscFunctionReturn(PETSC_SUCCESS);
2196: }
2198: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, void *ctx)
2199: {
2200: DM dm;
2201: DMSNES sdm;
2203: PetscFunctionBegin;
2204: PetscCall(SNESGetDM(snes, &dm));
2205: PetscCall(DMGetDMSNES(dm, &sdm));
2206: /* A(x)*x - b(x) */
2207: if (sdm->ops->computepfunction) {
2208: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2209: PetscCall(VecScale(f, -1.0));
2210: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2211: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2212: } else {
2213: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2214: PetscCall(MatMult(snes->jacobian_pre, x, f));
2215: }
2216: PetscFunctionReturn(PETSC_SUCCESS);
2217: }
2219: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, void *ctx)
2220: {
2221: PetscFunctionBegin;
2222: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2223: /* must assembly if matrix-free to get the last SNES solution */
2224: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2225: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2226: PetscFunctionReturn(PETSC_SUCCESS);
2227: }
2229: /*@C
2230: SNESSetPicard - Use `SNES` to solve the system A(x) x = bp(x) + b via a Picard type iteration (Picard linearization)
2232: Logically Collective
2234: Input Parameters:
2235: + snes - the `SNES` context
2236: . r - vector to store function values, may be `NULL`
2237: . bp - function evaluation routine, may be `NULL`, for the calling sequence see `SNESJacobianFunction`
2238: . Amat - matrix with which A(x) x - bp(x) - b is to be computed
2239: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2240: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFunction`
2241: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2243: Level: intermediate
2245: Notes:
2246: It is often better to provide the nonlinear function F() and some approximation to its Jacobian directly and use
2247: 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.
2249: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2251: 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}.
2252: When an exact solver is used this corresponds to the "classic" Picard A(x^{n}) x^{n+1} = bp(x^{n}) + b iteration.
2254: Run with `-snes_mf_operator` to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2256: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2257: the direct Picard iteration A(x^n) x^{n+1} = bp(x^n) + b
2259: 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
2260: 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
2261: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument :-).
2263: 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
2264: A(x^{n}) is used to build the preconditioner
2266: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at at time) and thus represent Newton's method.
2268: 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
2269: 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
2270: 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`.
2271: See the comment in src/snes/tutorials/ex15.c.
2273: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`, `SNESJacobianFunction`
2274: @*/
2275: PetscErrorCode SNESSetPicard(SNES snes, Vec r, PetscErrorCode (*bp)(SNES, Vec, Vec, void *), Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *), void *ctx)
2276: {
2277: DM dm;
2279: PetscFunctionBegin;
2281: PetscCall(SNESGetDM(snes, &dm));
2282: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2283: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2284: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2285: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2286: PetscFunctionReturn(PETSC_SUCCESS);
2287: }
2289: /*@C
2290: SNESGetPicard - Returns the context for the Picard iteration
2292: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2294: Input Parameter:
2295: . snes - the `SNES` context
2297: Output Parameters:
2298: + r - the function (or `NULL`)
2299: . f - the function (or `NULL`); for calling sequence see `SNESFunction`
2300: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2301: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2302: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFunction`
2303: - ctx - the function context (or `NULL`)
2305: Level: advanced
2307: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunction`, `SNESJacobianFunction`
2308: @*/
2309: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, PetscErrorCode (**f)(SNES, Vec, Vec, void *), Mat *Amat, Mat *Pmat, PetscErrorCode (**J)(SNES, Vec, Mat, Mat, void *), void **ctx)
2310: {
2311: DM dm;
2313: PetscFunctionBegin;
2315: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2316: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2317: PetscCall(SNESGetDM(snes, &dm));
2318: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2319: PetscFunctionReturn(PETSC_SUCCESS);
2320: }
2322: /*@C
2323: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2325: Logically Collective
2327: Input Parameters:
2328: + snes - the `SNES` context
2329: . func - function evaluation routine
2330: - ctx - [optional] user-defined context for private data for the
2331: function evaluation routine (may be `NULL`)
2333: Calling sequence of `func`:
2334: + snes - the `SNES` solver
2335: . x - vector to put initial guess
2336: - ctx - optional user-defined function context
2338: Level: intermediate
2340: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`
2341: @*/
2342: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, PetscErrorCode (*func)(SNES snes, Vec x, void *ctx), void *ctx)
2343: {
2344: PetscFunctionBegin;
2346: if (func) snes->ops->computeinitialguess = func;
2347: if (ctx) snes->initialguessP = ctx;
2348: PetscFunctionReturn(PETSC_SUCCESS);
2349: }
2351: /*@C
2352: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2353: it assumes a zero right hand side.
2355: Logically Collective
2357: Input Parameter:
2358: . snes - the `SNES` context
2360: Output Parameter:
2361: . rhs - the right hand side vector or `NULL` if there is no right-hand side vector
2363: Level: intermediate
2365: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2366: @*/
2367: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2368: {
2369: PetscFunctionBegin;
2371: PetscAssertPointer(rhs, 2);
2372: *rhs = snes->vec_rhs;
2373: PetscFunctionReturn(PETSC_SUCCESS);
2374: }
2376: /*@
2377: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2379: Collective
2381: Input Parameters:
2382: + snes - the `SNES` context
2383: - x - input vector
2385: Output Parameter:
2386: . y - function vector, as set by `SNESSetFunction()`
2388: Level: developer
2390: Note:
2391: `SNESComputeFunction()` is typically used within nonlinear solvers
2392: implementations, so users would not generally call this routine themselves.
2394: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`
2395: @*/
2396: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec y)
2397: {
2398: DM dm;
2399: DMSNES sdm;
2401: PetscFunctionBegin;
2405: PetscCheckSameComm(snes, 1, x, 2);
2406: PetscCheckSameComm(snes, 1, y, 3);
2407: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2409: PetscCall(SNESGetDM(snes, &dm));
2410: PetscCall(DMGetDMSNES(dm, &sdm));
2411: 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().");
2412: if (sdm->ops->computefunction) {
2413: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2414: PetscCall(VecLockReadPush(x));
2415: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2416: snes->domainerror = PETSC_FALSE;
2417: {
2418: void *ctx;
2419: PetscErrorCode (*computefunction)(SNES, Vec, Vec, void *);
2420: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2421: PetscCallBack("SNES callback function", (*computefunction)(snes, x, y, ctx));
2422: }
2423: PetscCall(VecLockReadPop(x));
2424: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2425: } else /* if (snes->vec_rhs) */ {
2426: PetscCall(MatMult(snes->jacobian, x, y));
2427: }
2428: if (snes->vec_rhs) PetscCall(VecAXPY(y, -1.0, snes->vec_rhs));
2429: snes->nfuncs++;
2430: /*
2431: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2432: propagate the value to all processes
2433: */
2434: if (snes->domainerror) PetscCall(VecSetInf(y));
2435: PetscFunctionReturn(PETSC_SUCCESS);
2436: }
2438: /*@
2439: SNESComputeMFFunction - Calls the function that has been set with `SNESSetMFFunction()`.
2441: Collective
2443: Input Parameters:
2444: + snes - the `SNES` context
2445: - x - input vector
2447: Output Parameter:
2448: . y - function vector, as set by `SNESSetMFFunction()`
2450: Level: developer
2452: Notes:
2453: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2454: so users would not generally call this routine themselves.
2456: Since this function is intended for use with finite differencing it does not subtract the right hand side vector provided with `SNESSolve()`
2457: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2458: 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.
2460: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF`
2461: @*/
2462: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2463: {
2464: DM dm;
2465: DMSNES sdm;
2467: PetscFunctionBegin;
2471: PetscCheckSameComm(snes, 1, x, 2);
2472: PetscCheckSameComm(snes, 1, y, 3);
2473: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2475: PetscCall(SNESGetDM(snes, &dm));
2476: PetscCall(DMGetDMSNES(dm, &sdm));
2477: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2478: PetscCall(VecLockReadPush(x));
2479: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2480: snes->domainerror = PETSC_FALSE;
2481: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2482: PetscCall(VecLockReadPop(x));
2483: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2484: snes->nfuncs++;
2485: /*
2486: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2487: propagate the value to all processes
2488: */
2489: if (snes->domainerror) PetscCall(VecSetInf(y));
2490: PetscFunctionReturn(PETSC_SUCCESS);
2491: }
2493: /*@
2494: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2496: Collective
2498: Input Parameters:
2499: + snes - the `SNES` context
2500: . x - input vector
2501: - b - rhs vector
2503: Output Parameter:
2504: . x - new solution vector
2506: Level: developer
2508: Note:
2509: `SNESComputeNGS()` is typically used within composed nonlinear solver
2510: implementations, so most users would not generally call this routine
2511: themselves.
2513: .seealso: [](ch_snes), `SNESNGS`, `SNESSetNGS()`, `SNESComputeFunction()`
2514: @*/
2515: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2516: {
2517: DM dm;
2518: DMSNES sdm;
2520: PetscFunctionBegin;
2524: PetscCheckSameComm(snes, 1, x, 3);
2525: if (b) PetscCheckSameComm(snes, 1, b, 2);
2526: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2527: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2528: PetscCall(SNESGetDM(snes, &dm));
2529: PetscCall(DMGetDMSNES(dm, &sdm));
2530: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2531: if (b) PetscCall(VecLockReadPush(b));
2532: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2533: if (b) PetscCall(VecLockReadPop(b));
2534: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2535: PetscFunctionReturn(PETSC_SUCCESS);
2536: }
2538: PetscErrorCode SNESTestJacobian(SNES snes)
2539: {
2540: Mat A, B, C, D, jacobian;
2541: Vec x = snes->vec_sol, f = snes->vec_func;
2542: PetscReal nrm, gnorm;
2543: PetscReal threshold = 1.e-5;
2544: MatType mattype;
2545: PetscInt m, n, M, N;
2546: void *functx;
2547: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, test = PETSC_FALSE, flg, istranspose;
2548: PetscViewer viewer, mviewer;
2549: MPI_Comm comm;
2550: PetscInt tabs;
2551: static PetscBool directionsprinted = PETSC_FALSE;
2552: PetscViewerFormat format;
2554: PetscFunctionBegin;
2555: PetscObjectOptionsBegin((PetscObject)snes);
2556: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &test));
2557: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2558: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2559: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2560: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2561: /* Cannot remove the what otherwise would be redundant call to (PetscOptionsReal("-snes_test_jacobian_display_threshold") below because its usage is different than the replacement usage */
2562: 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));
2563: PetscOptionsEnd();
2564: if (!test) PetscFunctionReturn(PETSC_SUCCESS);
2566: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2567: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2568: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2569: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2570: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2571: if (!complete_print && !directionsprinted) {
2572: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2573: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2574: }
2575: if (!directionsprinted) {
2576: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2577: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2578: directionsprinted = PETSC_TRUE;
2579: }
2580: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2582: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2583: if (!flg) jacobian = snes->jacobian;
2584: else jacobian = snes->jacobian_pre;
2586: if (!x) {
2587: PetscCall(MatCreateVecs(jacobian, &x, NULL));
2588: } else {
2589: PetscCall(PetscObjectReference((PetscObject)x));
2590: }
2591: if (!f) {
2592: PetscCall(VecDuplicate(x, &f));
2593: } else {
2594: PetscCall(PetscObjectReference((PetscObject)f));
2595: }
2596: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2597: PetscCall(SNESComputeFunction(snes, x, f));
2598: PetscCall(VecDestroy(&f));
2599: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2600: while (jacobian) {
2601: Mat JT = NULL, Jsave = NULL;
2603: if (istranspose) {
2604: PetscCall(MatCreateTranspose(jacobian, &JT));
2605: Jsave = jacobian;
2606: jacobian = JT;
2607: }
2608: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2609: if (flg) {
2610: A = jacobian;
2611: PetscCall(PetscObjectReference((PetscObject)A));
2612: } else {
2613: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2614: }
2616: PetscCall(MatGetType(A, &mattype));
2617: PetscCall(MatGetSize(A, &M, &N));
2618: PetscCall(MatGetLocalSize(A, &m, &n));
2619: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2620: PetscCall(MatSetType(B, mattype));
2621: PetscCall(MatSetSizes(B, m, n, M, N));
2622: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2623: PetscCall(MatSetUp(B));
2624: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2626: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2627: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2629: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2630: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2631: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2632: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2633: PetscCall(MatDestroy(&D));
2634: if (!gnorm) gnorm = 1; /* just in case */
2635: PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2637: if (complete_print) {
2638: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2639: PetscCall(MatView(A, mviewer));
2640: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2641: PetscCall(MatView(B, mviewer));
2642: }
2644: if (threshold_print || complete_print) {
2645: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2646: PetscScalar *cvals;
2647: const PetscInt *bcols;
2648: const PetscScalar *bvals;
2650: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2651: PetscCall(MatSetType(C, mattype));
2652: PetscCall(MatSetSizes(C, m, n, M, N));
2653: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2654: PetscCall(MatSetUp(C));
2655: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2657: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2658: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2660: for (row = Istart; row < Iend; row++) {
2661: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2662: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2663: for (j = 0, cncols = 0; j < bncols; j++) {
2664: if (PetscAbsScalar(bvals[j]) > threshold) {
2665: ccols[cncols] = bcols[j];
2666: cvals[cncols] = bvals[j];
2667: cncols += 1;
2668: }
2669: }
2670: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2671: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2672: PetscCall(PetscFree2(ccols, cvals));
2673: }
2674: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2675: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2676: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2677: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2678: PetscCall(MatDestroy(&C));
2679: }
2680: PetscCall(MatDestroy(&A));
2681: PetscCall(MatDestroy(&B));
2682: PetscCall(MatDestroy(&JT));
2683: if (Jsave) jacobian = Jsave;
2684: if (jacobian != snes->jacobian_pre) {
2685: jacobian = snes->jacobian_pre;
2686: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2687: } else jacobian = NULL;
2688: }
2689: PetscCall(VecDestroy(&x));
2690: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2691: if (mviewer) PetscCall(PetscViewerDestroy(&mviewer));
2692: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2693: PetscFunctionReturn(PETSC_SUCCESS);
2694: }
2696: /*@
2697: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2699: Collective
2701: Input Parameters:
2702: + snes - the `SNES` context
2703: - X - input vector
2705: Output Parameters:
2706: + A - Jacobian matrix
2707: - B - optional matrix for building the preconditioner, usually the same as `A`
2709: Options Database Keys:
2710: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2711: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2712: . -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.
2713: . -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
2714: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2715: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2716: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2717: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2718: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2719: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2720: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2721: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2722: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2723: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2724: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2726: Level: developer
2728: Note:
2729: Most users should not need to explicitly call this routine, as it
2730: is used internally within the nonlinear solvers.
2732: Developer Note:
2733: 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
2734: with the `SNESType` of test that has been removed.
2736: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
2737: @*/
2738: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2739: {
2740: PetscBool flag;
2741: DM dm;
2742: DMSNES sdm;
2743: KSP ksp;
2745: PetscFunctionBegin;
2748: PetscCheckSameComm(snes, 1, X, 2);
2749: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2750: PetscCall(SNESGetDM(snes, &dm));
2751: PetscCall(DMGetDMSNES(dm, &sdm));
2753: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2754: if (snes->lagjacobian == -2) {
2755: snes->lagjacobian = -1;
2757: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2758: } else if (snes->lagjacobian == -1) {
2759: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2760: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2761: if (flag) {
2762: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2763: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2764: }
2765: PetscFunctionReturn(PETSC_SUCCESS);
2766: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2767: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2768: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2769: if (flag) {
2770: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2771: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2772: }
2773: PetscFunctionReturn(PETSC_SUCCESS);
2774: }
2775: if (snes->npc && snes->npcside == PC_LEFT) {
2776: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2777: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2778: PetscFunctionReturn(PETSC_SUCCESS);
2779: }
2781: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2782: PetscCall(VecLockReadPush(X));
2783: {
2784: void *ctx;
2785: PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *);
2786: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2787: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2788: }
2789: PetscCall(VecLockReadPop(X));
2790: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
2792: /* attach latest linearization point to the preconditioning matrix */
2793: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
2795: /* the next line ensures that snes->ksp exists */
2796: PetscCall(SNESGetKSP(snes, &ksp));
2797: if (snes->lagpreconditioner == -2) {
2798: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
2799: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2800: snes->lagpreconditioner = -1;
2801: } else if (snes->lagpreconditioner == -1) {
2802: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
2803: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2804: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2805: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
2806: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2807: } else {
2808: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
2809: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2810: }
2812: PetscCall(SNESTestJacobian(snes));
2813: /* make sure user returned a correct Jacobian and preconditioner */
2816: {
2817: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
2818: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
2819: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
2820: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
2821: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
2822: if (flag || flag_draw || flag_contour) {
2823: Mat Bexp_mine = NULL, Bexp, FDexp;
2824: PetscViewer vdraw, vstdout;
2825: PetscBool flg;
2826: if (flag_operator) {
2827: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
2828: Bexp = Bexp_mine;
2829: } else {
2830: /* See if the preconditioning matrix can be viewed and added directly */
2831: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPIBAIJ, ""));
2832: if (flg) Bexp = B;
2833: else {
2834: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2835: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
2836: Bexp = Bexp_mine;
2837: }
2838: }
2839: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
2840: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
2841: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2842: if (flag_draw || flag_contour) {
2843: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2844: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2845: } else vdraw = NULL;
2846: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
2847: if (flag) PetscCall(MatView(Bexp, vstdout));
2848: if (vdraw) PetscCall(MatView(Bexp, vdraw));
2849: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
2850: if (flag) PetscCall(MatView(FDexp, vstdout));
2851: if (vdraw) PetscCall(MatView(FDexp, vdraw));
2852: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
2853: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
2854: if (flag) PetscCall(MatView(FDexp, vstdout));
2855: if (vdraw) { /* Always use contour for the difference */
2856: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2857: PetscCall(MatView(FDexp, vdraw));
2858: PetscCall(PetscViewerPopFormat(vdraw));
2859: }
2860: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2861: PetscCall(PetscViewerDestroy(&vdraw));
2862: PetscCall(MatDestroy(&Bexp_mine));
2863: PetscCall(MatDestroy(&FDexp));
2864: }
2865: }
2866: {
2867: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
2868: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
2869: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
2870: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
2871: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
2872: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
2873: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
2874: if (flag_threshold) {
2875: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
2876: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
2877: }
2878: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2879: Mat Bfd;
2880: PetscViewer vdraw, vstdout;
2881: MatColoring coloring;
2882: ISColoring iscoloring;
2883: MatFDColoring matfdcoloring;
2884: PetscErrorCode (*func)(SNES, Vec, Vec, void *);
2885: void *funcctx;
2886: PetscReal norm1, norm2, normmax;
2888: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
2889: PetscCall(MatColoringCreate(Bfd, &coloring));
2890: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
2891: PetscCall(MatColoringSetFromOptions(coloring));
2892: PetscCall(MatColoringApply(coloring, &iscoloring));
2893: PetscCall(MatColoringDestroy(&coloring));
2894: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
2895: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2896: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
2897: PetscCall(ISColoringDestroy(&iscoloring));
2899: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2900: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
2901: PetscCall(MatFDColoringSetFunction(matfdcoloring, (PetscErrorCode(*)(void))func, funcctx));
2902: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
2903: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
2904: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2905: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
2906: PetscCall(MatFDColoringDestroy(&matfdcoloring));
2908: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2909: if (flag_draw || flag_contour) {
2910: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2911: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2912: } else vdraw = NULL;
2913: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
2914: if (flag_display) PetscCall(MatView(B, vstdout));
2915: if (vdraw) PetscCall(MatView(B, vdraw));
2916: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
2917: if (flag_display) PetscCall(MatView(Bfd, vstdout));
2918: if (vdraw) PetscCall(MatView(Bfd, vdraw));
2919: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
2920: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
2921: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
2922: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
2923: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
2924: if (flag_display) PetscCall(MatView(Bfd, vstdout));
2925: if (vdraw) { /* Always use contour for the difference */
2926: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2927: PetscCall(MatView(Bfd, vdraw));
2928: PetscCall(PetscViewerPopFormat(vdraw));
2929: }
2930: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2932: if (flag_threshold) {
2933: PetscInt bs, rstart, rend, i;
2934: PetscCall(MatGetBlockSize(B, &bs));
2935: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
2936: for (i = rstart; i < rend; i++) {
2937: const PetscScalar *ba, *ca;
2938: const PetscInt *bj, *cj;
2939: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
2940: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
2941: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
2942: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
2943: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2944: for (j = 0; j < bn; j++) {
2945: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
2946: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2947: maxentrycol = bj[j];
2948: maxentry = PetscRealPart(ba[j]);
2949: }
2950: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2951: maxdiffcol = bj[j];
2952: maxdiff = PetscRealPart(ca[j]);
2953: }
2954: if (rdiff > maxrdiff) {
2955: maxrdiffcol = bj[j];
2956: maxrdiff = rdiff;
2957: }
2958: }
2959: if (maxrdiff > 1) {
2960: 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));
2961: for (j = 0; j < bn; j++) {
2962: PetscReal rdiff;
2963: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
2964: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
2965: }
2966: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
2967: }
2968: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
2969: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
2970: }
2971: }
2972: PetscCall(PetscViewerDestroy(&vdraw));
2973: PetscCall(MatDestroy(&Bfd));
2974: }
2975: }
2976: PetscFunctionReturn(PETSC_SUCCESS);
2977: }
2979: /*MC
2980: SNESJacobianFunction - Functional form used by `SNES` to compute the nonlinear Jacobian of the function to be solved by `SNES`
2982: Synopsis:
2983: #include "petscsnes.h"
2984: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2986: Collective
2988: Input Parameters:
2989: + x - input vector, the Jacobian is to be computed at this value
2990: - ctx - [optional] user-defined Jacobian context
2992: Output Parameters:
2993: + Amat - the matrix that defines the (approximate) Jacobian
2994: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
2996: Level: intermediate
2998: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESSetJacobian()`, `SNESGetJacobian()`
2999: M*/
3001: /*@C
3002: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3003: location to store the matrix.
3005: Logically Collective
3007: Input Parameters:
3008: + snes - the `SNES` context
3009: . Amat - the matrix that defines the (approximate) Jacobian
3010: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3011: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFunction` for details
3012: - ctx - [optional] user-defined context for private data for the
3013: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3015: Level: beginner
3017: Notes:
3018: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3019: each matrix.
3021: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3022: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3024: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3025: must be a `MatFDColoring`.
3027: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3028: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3030: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3031: `SNESSetPicard()`, `SNESJacobianFunction`
3032: @*/
3033: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *), void *ctx)
3034: {
3035: DM dm;
3037: PetscFunctionBegin;
3041: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3042: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3043: PetscCall(SNESGetDM(snes, &dm));
3044: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3045: if (Amat) {
3046: PetscCall(PetscObjectReference((PetscObject)Amat));
3047: PetscCall(MatDestroy(&snes->jacobian));
3049: snes->jacobian = Amat;
3050: }
3051: if (Pmat) {
3052: PetscCall(PetscObjectReference((PetscObject)Pmat));
3053: PetscCall(MatDestroy(&snes->jacobian_pre));
3055: snes->jacobian_pre = Pmat;
3056: }
3057: PetscFunctionReturn(PETSC_SUCCESS);
3058: }
3060: /*@C
3061: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3062: provided context for evaluating the Jacobian.
3064: Not Collective, but `Mat` object will be parallel if `SNES` is
3066: Input Parameter:
3067: . snes - the nonlinear solver context
3069: Output Parameters:
3070: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3071: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3072: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFunction`
3073: - ctx - location to stash Jacobian ctx (or `NULL`)
3075: Level: advanced
3077: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFunction`, `SNESGetFunction()`
3078: @*/
3079: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, PetscErrorCode (**J)(SNES, Vec, Mat, Mat, void *), void **ctx)
3080: {
3081: DM dm;
3083: PetscFunctionBegin;
3085: if (Amat) *Amat = snes->jacobian;
3086: if (Pmat) *Pmat = snes->jacobian_pre;
3087: PetscCall(SNESGetDM(snes, &dm));
3088: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3089: PetscFunctionReturn(PETSC_SUCCESS);
3090: }
3092: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3093: {
3094: DM dm;
3095: DMSNES sdm;
3097: PetscFunctionBegin;
3098: PetscCall(SNESGetDM(snes, &dm));
3099: PetscCall(DMGetDMSNES(dm, &sdm));
3100: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3101: DM dm;
3102: PetscBool isdense, ismf;
3104: PetscCall(SNESGetDM(snes, &dm));
3105: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3106: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3107: if (isdense) {
3108: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3109: } else if (!ismf) {
3110: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3111: }
3112: }
3113: PetscFunctionReturn(PETSC_SUCCESS);
3114: }
3116: /*@
3117: SNESSetUp - Sets up the internal data structures for the later use
3118: of a nonlinear solver.
3120: Collective
3122: Input Parameter:
3123: . snes - the `SNES` context
3125: Level: advanced
3127: Note:
3128: For basic use of the `SNES` solvers the user need not explicitly call
3129: `SNESSetUp()`, since these actions will automatically occur during
3130: the call to `SNESSolve()`. However, if one wishes to control this
3131: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3132: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3134: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`
3135: @*/
3136: PetscErrorCode SNESSetUp(SNES snes)
3137: {
3138: DM dm;
3139: DMSNES sdm;
3140: SNESLineSearch linesearch, pclinesearch;
3141: void *lsprectx, *lspostctx;
3142: PetscBool mf_operator, mf;
3143: Vec f, fpc;
3144: void *funcctx;
3145: void *jacctx, *appctx;
3146: Mat j, jpre;
3147: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3148: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3149: PetscErrorCode (*func)(SNES, Vec, Vec, void *);
3150: PetscErrorCode (*jac)(SNES, Vec, Mat, Mat, void *);
3152: PetscFunctionBegin;
3154: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3155: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3157: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3159: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3161: PetscCall(SNESGetDM(snes, &dm));
3162: PetscCall(DMGetDMSNES(dm, &sdm));
3163: PetscCall(SNESSetDefaultComputeJacobian(snes));
3165: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3167: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3169: if (snes->linesearch) {
3170: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3171: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3172: }
3174: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3175: if (snes->npc && snes->npcside == PC_LEFT) {
3176: snes->mf = PETSC_TRUE;
3177: snes->mf_operator = PETSC_FALSE;
3178: }
3180: if (snes->npc) {
3181: /* copy the DM over */
3182: PetscCall(SNESGetDM(snes, &dm));
3183: PetscCall(SNESSetDM(snes->npc, dm));
3185: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3186: PetscCall(VecDuplicate(f, &fpc));
3187: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3188: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3189: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3190: PetscCall(SNESGetApplicationContext(snes, &appctx));
3191: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3192: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3193: PetscCall(VecDestroy(&fpc));
3195: /* copy the function pointers over */
3196: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3198: /* default to 1 iteration */
3199: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3200: if (snes->npcside == PC_RIGHT) {
3201: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3202: } else {
3203: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3204: }
3205: PetscCall(SNESSetFromOptions(snes->npc));
3207: /* copy the line search context over */
3208: if (snes->linesearch && snes->npc->linesearch) {
3209: PetscCall(SNESGetLineSearch(snes, &linesearch));
3210: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3211: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3212: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3213: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3214: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3215: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3216: }
3217: }
3218: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3219: if (snes->ops->usercompute && !snes->user) PetscCall((*snes->ops->usercompute)(snes, (void **)&snes->user));
3221: snes->jac_iter = 0;
3222: snes->pre_iter = 0;
3224: PetscTryTypeMethod(snes, setup);
3226: PetscCall(SNESSetDefaultComputeJacobian(snes));
3228: if (snes->npc && snes->npcside == PC_LEFT) {
3229: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3230: if (snes->linesearch) {
3231: PetscCall(SNESGetLineSearch(snes, &linesearch));
3232: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3233: }
3234: }
3235: }
3236: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3237: snes->setupcalled = PETSC_TRUE;
3238: PetscFunctionReturn(PETSC_SUCCESS);
3239: }
3241: /*@
3242: SNESReset - Resets a `SNES` context to the snessetupcalled = 0 state and removes any allocated `Vec`s and `Mat`s
3244: Collective
3246: Input Parameter:
3247: . snes - iterative context obtained from `SNESCreate()`
3249: Level: intermediate
3251: Notes:
3252: Call this if you wish to reuse a `SNES` but with different size vectors
3254: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3256: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3257: @*/
3258: PetscErrorCode SNESReset(SNES snes)
3259: {
3260: PetscFunctionBegin;
3262: if (snes->ops->userdestroy && snes->user) {
3263: PetscCall((*snes->ops->userdestroy)((void **)&snes->user));
3264: snes->user = NULL;
3265: }
3266: if (snes->npc) PetscCall(SNESReset(snes->npc));
3268: PetscTryTypeMethod(snes, reset);
3269: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3271: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3273: PetscCall(VecDestroy(&snes->vec_rhs));
3274: PetscCall(VecDestroy(&snes->vec_sol));
3275: PetscCall(VecDestroy(&snes->vec_sol_update));
3276: PetscCall(VecDestroy(&snes->vec_func));
3277: PetscCall(MatDestroy(&snes->jacobian));
3278: PetscCall(MatDestroy(&snes->jacobian_pre));
3279: PetscCall(MatDestroy(&snes->picard));
3280: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3281: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3283: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3285: snes->nwork = snes->nvwork = 0;
3286: snes->setupcalled = PETSC_FALSE;
3287: PetscFunctionReturn(PETSC_SUCCESS);
3288: }
3290: /*@
3291: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()`
3293: Collective
3295: Input Parameter:
3296: . snes - iterative context obtained from `SNESCreate()`
3298: Level: intermediate
3300: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3301: @*/
3302: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3303: {
3304: PetscInt i;
3306: PetscFunctionBegin;
3308: for (i = 0; i < snes->numberreasonviews; i++) {
3309: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3310: }
3311: snes->numberreasonviews = 0;
3312: PetscFunctionReturn(PETSC_SUCCESS);
3313: }
3315: /*@C
3316: SNESDestroy - Destroys the nonlinear solver context that was created
3317: with `SNESCreate()`.
3319: Collective
3321: Input Parameter:
3322: . snes - the `SNES` context
3324: Level: beginner
3326: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3327: @*/
3328: PetscErrorCode SNESDestroy(SNES *snes)
3329: {
3330: PetscFunctionBegin;
3331: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3333: if (--((PetscObject)(*snes))->refct > 0) {
3334: *snes = NULL;
3335: PetscFunctionReturn(PETSC_SUCCESS);
3336: }
3338: PetscCall(SNESReset((*snes)));
3339: PetscCall(SNESDestroy(&(*snes)->npc));
3341: /* if memory was published with SAWs then destroy it */
3342: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3343: PetscTryTypeMethod((*snes), destroy);
3345: if ((*snes)->dm) PetscCall(DMCoarsenHookRemove((*snes)->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3346: PetscCall(DMDestroy(&(*snes)->dm));
3347: PetscCall(KSPDestroy(&(*snes)->ksp));
3348: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3350: PetscCall(PetscFree((*snes)->kspconvctx));
3351: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)((*snes)->cnvP));
3352: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3353: PetscCall(SNESMonitorCancel((*snes)));
3354: PetscCall(SNESConvergedReasonViewCancel((*snes)));
3355: PetscCall(PetscHeaderDestroy(snes));
3356: PetscFunctionReturn(PETSC_SUCCESS);
3357: }
3359: /* ----------- Routines to set solver parameters ---------- */
3361: /*@
3362: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3364: Logically Collective
3366: Input Parameters:
3367: + snes - the `SNES` context
3368: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3369: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3371: Options Database Keys:
3372: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3373: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3374: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3375: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3377: Level: intermediate
3379: Notes:
3380: The default is 1
3382: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3384: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3386: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3387: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3388: @*/
3389: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3390: {
3391: PetscFunctionBegin;
3393: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3394: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3396: snes->lagpreconditioner = lag;
3397: PetscFunctionReturn(PETSC_SUCCESS);
3398: }
3400: /*@
3401: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3403: Logically Collective
3405: Input Parameters:
3406: + snes - the `SNES` context
3407: - steps - the number of refinements to do, defaults to 0
3409: Options Database Key:
3410: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3412: Level: intermediate
3414: Note:
3415: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3417: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3418: `SNESetDM()`
3419: @*/
3420: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3421: {
3422: PetscFunctionBegin;
3425: snes->gridsequence = steps;
3426: PetscFunctionReturn(PETSC_SUCCESS);
3427: }
3429: /*@
3430: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3432: Logically Collective
3434: Input Parameter:
3435: . snes - the `SNES` context
3437: Output Parameter:
3438: . steps - the number of refinements to do, defaults to 0
3440: Level: intermediate
3442: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3443: @*/
3444: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3445: {
3446: PetscFunctionBegin;
3448: *steps = snes->gridsequence;
3449: PetscFunctionReturn(PETSC_SUCCESS);
3450: }
3452: /*@
3453: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3455: Not Collective
3457: Input Parameter:
3458: . snes - the `SNES` context
3460: Output Parameter:
3461: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3462: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3464: Level: intermediate
3466: Notes:
3467: The default is 1
3469: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3471: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3472: @*/
3473: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3474: {
3475: PetscFunctionBegin;
3477: *lag = snes->lagpreconditioner;
3478: PetscFunctionReturn(PETSC_SUCCESS);
3479: }
3481: /*@
3482: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3483: often the preconditioner is rebuilt.
3485: Logically Collective
3487: Input Parameters:
3488: + snes - the `SNES` context
3489: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3490: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3492: Options Database Keys:
3493: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3494: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3495: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3496: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3498: Level: intermediate
3500: Notes:
3501: The default is 1
3503: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3505: 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
3506: at the next Newton step but never again (unless it is reset to another value)
3508: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3509: @*/
3510: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3511: {
3512: PetscFunctionBegin;
3514: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3515: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3517: snes->lagjacobian = lag;
3518: PetscFunctionReturn(PETSC_SUCCESS);
3519: }
3521: /*@
3522: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3524: Not Collective
3526: Input Parameter:
3527: . snes - the `SNES` context
3529: Output Parameter:
3530: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3531: the Jacobian is built etc.
3533: Level: intermediate
3535: Notes:
3536: The default is 1
3538: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3540: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3542: @*/
3543: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3544: {
3545: PetscFunctionBegin;
3547: *lag = snes->lagjacobian;
3548: PetscFunctionReturn(PETSC_SUCCESS);
3549: }
3551: /*@
3552: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3554: Logically collective
3556: Input Parameters:
3557: + snes - the `SNES` context
3558: - flg - jacobian lagging persists if true
3560: Options Database Keys:
3561: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3562: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3563: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3564: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3566: Level: advanced
3568: Notes:
3569: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3571: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3572: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3573: timesteps may present huge efficiency gains.
3575: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3576: @*/
3577: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3578: {
3579: PetscFunctionBegin;
3582: snes->lagjac_persist = flg;
3583: PetscFunctionReturn(PETSC_SUCCESS);
3584: }
3586: /*@
3587: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3589: Logically Collective
3591: Input Parameters:
3592: + snes - the `SNES` context
3593: - flg - preconditioner lagging persists if true
3595: Options Database Keys:
3596: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3597: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3598: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3599: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3601: Level: developer
3603: Notes:
3604: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3606: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3607: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3608: several timesteps may present huge efficiency gains.
3610: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3611: @*/
3612: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3613: {
3614: PetscFunctionBegin;
3617: snes->lagpre_persist = flg;
3618: PetscFunctionReturn(PETSC_SUCCESS);
3619: }
3621: /*@
3622: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3624: Logically Collective
3626: Input Parameters:
3627: + snes - the `SNES` context
3628: - force - `PETSC_TRUE` require at least one iteration
3630: Options Database Key:
3631: . -snes_force_iteration <force> - Sets forcing an iteration
3633: Level: intermediate
3635: Note:
3636: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3638: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3639: @*/
3640: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3641: {
3642: PetscFunctionBegin;
3644: snes->forceiteration = force;
3645: PetscFunctionReturn(PETSC_SUCCESS);
3646: }
3648: /*@
3649: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3651: Logically Collective
3653: Input Parameter:
3654: . snes - the `SNES` context
3656: Output Parameter:
3657: . force - `PETSC_TRUE` requires at least one iteration.
3659: Level: intermediate
3661: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3662: @*/
3663: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3664: {
3665: PetscFunctionBegin;
3667: *force = snes->forceiteration;
3668: PetscFunctionReturn(PETSC_SUCCESS);
3669: }
3671: /*@
3672: SNESSetTolerances - Sets `SNES` various parameters used in convergence tests.
3674: Logically Collective
3676: Input Parameters:
3677: + snes - the `SNES` context
3678: . abstol - absolute convergence tolerance
3679: . rtol - relative convergence tolerance
3680: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3681: . maxit - maximum number of iterations, default 50.
3682: - maxf - maximum number of function evaluations (-1 indicates no limit), default 1000
3684: Options Database Keys:
3685: + -snes_atol <abstol> - Sets abstol
3686: . -snes_rtol <rtol> - Sets rtol
3687: . -snes_stol <stol> - Sets stol
3688: . -snes_max_it <maxit> - Sets maxit
3689: - -snes_max_funcs <maxf> - Sets maxf
3691: Level: intermediate
3693: .seealso: [](ch_snes), `SNESolve()`, `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3694: @*/
3695: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3696: {
3697: PetscFunctionBegin;
3705: if (abstol != (PetscReal)PETSC_DEFAULT) {
3706: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3707: snes->abstol = abstol;
3708: }
3709: if (rtol != (PetscReal)PETSC_DEFAULT) {
3710: 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);
3711: snes->rtol = rtol;
3712: }
3713: if (stol != (PetscReal)PETSC_DEFAULT) {
3714: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3715: snes->stol = stol;
3716: }
3717: if (maxit != PETSC_DEFAULT) {
3718: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3719: snes->max_its = maxit;
3720: }
3721: if (maxf != PETSC_DEFAULT) {
3722: PetscCheck(maxf >= -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be -1 or nonnegative", maxf);
3723: snes->max_funcs = maxf;
3724: }
3725: snes->tolerancesset = PETSC_TRUE;
3726: PetscFunctionReturn(PETSC_SUCCESS);
3727: }
3729: /*@
3730: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3732: Logically Collective
3734: Input Parameters:
3735: + snes - the `SNES` context
3736: - divtol - the divergence tolerance. Use -1 to deactivate the test, default is 1e4
3738: Options Database Key:
3739: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3741: Level: intermediate
3743: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance`
3744: @*/
3745: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3746: {
3747: PetscFunctionBegin;
3751: if (divtol != (PetscReal)PETSC_DEFAULT) {
3752: snes->divtol = divtol;
3753: } else {
3754: snes->divtol = 1.0e4;
3755: }
3756: PetscFunctionReturn(PETSC_SUCCESS);
3757: }
3759: /*@
3760: SNESGetTolerances - Gets various parameters used in convergence tests.
3762: Not Collective
3764: Input Parameters:
3765: + snes - the `SNES` context
3766: . atol - absolute convergence tolerance
3767: . rtol - relative convergence tolerance
3768: . stol - convergence tolerance in terms of the norm
3769: of the change in the solution between steps
3770: . maxit - maximum number of iterations
3771: - maxf - maximum number of function evaluations
3773: Level: intermediate
3775: Note:
3776: The user can specify `NULL` for any parameter that is not needed.
3778: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
3779: @*/
3780: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
3781: {
3782: PetscFunctionBegin;
3784: if (atol) *atol = snes->abstol;
3785: if (rtol) *rtol = snes->rtol;
3786: if (stol) *stol = snes->stol;
3787: if (maxit) *maxit = snes->max_its;
3788: if (maxf) *maxf = snes->max_funcs;
3789: PetscFunctionReturn(PETSC_SUCCESS);
3790: }
3792: /*@
3793: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3795: Not Collective
3797: Input Parameters:
3798: + snes - the `SNES` context
3799: - divtol - divergence tolerance
3801: Level: intermediate
3803: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
3804: @*/
3805: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
3806: {
3807: PetscFunctionBegin;
3809: if (divtol) *divtol = snes->divtol;
3810: PetscFunctionReturn(PETSC_SUCCESS);
3811: }
3813: /*@
3814: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3816: Logically Collective
3818: Input Parameters:
3819: + snes - the `SNES` context
3820: - tol - tolerance
3822: Options Database Key:
3823: . -snes_tr_tol <tol> - Sets tol
3825: Level: intermediate
3827: .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`, `SNESSetTolerances()`
3828: @*/
3829: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes, PetscReal tol)
3830: {
3831: PetscFunctionBegin;
3834: snes->deltatol = tol;
3835: PetscFunctionReturn(PETSC_SUCCESS);
3836: }
3838: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
3840: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
3841: {
3842: PetscDrawLG lg;
3843: PetscReal x, y, per;
3844: PetscViewer v = (PetscViewer)monctx;
3845: static PetscReal prev; /* should be in the context */
3846: PetscDraw draw;
3848: PetscFunctionBegin;
3850: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
3851: if (!n) PetscCall(PetscDrawLGReset(lg));
3852: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3853: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
3854: x = (PetscReal)n;
3855: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3856: else y = -15.0;
3857: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3858: if (n < 20 || !(n % 5) || snes->reason) {
3859: PetscCall(PetscDrawLGDraw(lg));
3860: PetscCall(PetscDrawLGSave(lg));
3861: }
3863: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
3864: if (!n) PetscCall(PetscDrawLGReset(lg));
3865: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3866: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
3867: PetscCall(SNESMonitorRange_Private(snes, n, &per));
3868: x = (PetscReal)n;
3869: y = 100.0 * per;
3870: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3871: if (n < 20 || !(n % 5) || snes->reason) {
3872: PetscCall(PetscDrawLGDraw(lg));
3873: PetscCall(PetscDrawLGSave(lg));
3874: }
3876: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
3877: if (!n) {
3878: prev = rnorm;
3879: PetscCall(PetscDrawLGReset(lg));
3880: }
3881: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3882: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
3883: x = (PetscReal)n;
3884: y = (prev - rnorm) / prev;
3885: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3886: if (n < 20 || !(n % 5) || snes->reason) {
3887: PetscCall(PetscDrawLGDraw(lg));
3888: PetscCall(PetscDrawLGSave(lg));
3889: }
3891: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
3892: if (!n) PetscCall(PetscDrawLGReset(lg));
3893: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3894: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
3895: x = (PetscReal)n;
3896: y = (prev - rnorm) / (prev * per);
3897: if (n > 2) { /*skip initial crazy value */
3898: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3899: }
3900: if (n < 20 || !(n % 5) || snes->reason) {
3901: PetscCall(PetscDrawLGDraw(lg));
3902: PetscCall(PetscDrawLGSave(lg));
3903: }
3904: prev = rnorm;
3905: PetscFunctionReturn(PETSC_SUCCESS);
3906: }
3908: /*@
3909: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
3911: Collective
3913: Input Parameters:
3914: + snes - the `SNES` context
3915: . it - current iteration
3916: . xnorm - 2-norm of current iterate
3917: . snorm - 2-norm of current step
3918: - fnorm - 2-norm of function
3920: Level: developer
3922: Note:
3923: This routine is called by the `SNESSolve()` implementations.
3924: It does not typically need to be called by the user.
3926: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
3927: @*/
3928: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
3929: {
3930: PetscFunctionBegin;
3931: if (!snes->reason) {
3932: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
3933: if (it == snes->max_its && !snes->reason) {
3934: if (snes->normschedule == SNES_NORM_ALWAYS) {
3935: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
3936: snes->reason = SNES_DIVERGED_MAX_IT;
3937: } else snes->reason = SNES_CONVERGED_ITS;
3938: }
3939: }
3940: PetscFunctionReturn(PETSC_SUCCESS);
3941: }
3943: /*@
3944: SNESMonitor - runs the user provided monitor routines, if they exist
3946: Collective
3948: Input Parameters:
3949: + snes - nonlinear solver context obtained from `SNESCreate()`
3950: . iter - iteration number
3951: - rnorm - relative norm of the residual
3953: Level: developer
3955: Note:
3956: This routine is called by the `SNESSolve()` implementations.
3957: It does not typically need to be called by the user.
3959: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
3960: @*/
3961: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
3962: {
3963: PetscInt i, n = snes->numbermonitors;
3965: PetscFunctionBegin;
3966: if (n > 0) SNESCheckFunctionNorm(snes, rnorm);
3967: PetscCall(VecLockReadPush(snes->vec_sol));
3968: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
3969: PetscCall(VecLockReadPop(snes->vec_sol));
3970: PetscFunctionReturn(PETSC_SUCCESS);
3971: }
3973: /* ------------ Routines to set performance monitoring options ----------- */
3975: /*MC
3976: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
3978: Synopsis:
3979: #include <petscsnes.h>
3980: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, void *mctx)
3982: Collective
3984: Input Parameters:
3985: + snes - the `SNES` context
3986: . its - iteration number
3987: . norm - 2-norm function value (may be estimated)
3988: - mctx - [optional] monitoring context
3990: Level: advanced
3992: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSet()`, `SNESMonitorGet()`
3993: M*/
3995: /*@C
3996: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3997: iteration of the nonlinear solver to display the iteration's
3998: progress.
4000: Logically Collective
4002: Input Parameters:
4003: + snes - the `SNES` context
4004: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4005: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4006: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`)
4008: Options Database Keys:
4009: + -snes_monitor - sets `SNESMonitorDefault()`
4010: . -snes_monitor draw::draw_lg - sets line graph monitor,
4011: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4012: the options database.
4014: Level: intermediate
4016: Note:
4017: Several different monitoring routines may be set by calling
4018: `SNESMonitorSet()` multiple times; all will be called in the
4019: order in which they were set.
4021: Fortran Note:
4022: Only a single monitor function can be set for each `SNES` object
4024: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`
4025: @*/
4026: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscErrorCode (*monitordestroy)(void **))
4027: {
4028: PetscInt i;
4029: PetscBool identical;
4031: PetscFunctionBegin;
4033: for (i = 0; i < snes->numbermonitors; i++) {
4034: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, mctx, monitordestroy, (PetscErrorCode(*)(void))snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4035: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4036: }
4037: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4038: snes->monitor[snes->numbermonitors] = f;
4039: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4040: snes->monitorcontext[snes->numbermonitors++] = (void *)mctx;
4041: PetscFunctionReturn(PETSC_SUCCESS);
4042: }
4044: /*@
4045: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4047: Logically Collective
4049: Input Parameter:
4050: . snes - the `SNES` context
4052: Options Database Key:
4053: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4054: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4055: set via the options database
4057: Level: intermediate
4059: Note:
4060: There is no way to clear one specific monitor from a `SNES` object.
4062: .seealso: [](ch_snes), `SNES`, `SNESMonitorGet()`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4063: @*/
4064: PetscErrorCode SNESMonitorCancel(SNES snes)
4065: {
4066: PetscInt i;
4068: PetscFunctionBegin;
4070: for (i = 0; i < snes->numbermonitors; i++) {
4071: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4072: }
4073: snes->numbermonitors = 0;
4074: PetscFunctionReturn(PETSC_SUCCESS);
4075: }
4077: /*MC
4078: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4080: Synopsis:
4081: #include <petscsnes.h>
4082: PetscErrorCode SNESConvergenceTest(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *cctx)
4084: Collective
4086: Input Parameters:
4087: + snes - the `SNES` context
4088: . it - current iteration (0 is the first and is before any Newton step)
4089: . xnorm - 2-norm of current iterate
4090: . gnorm - 2-norm of current step
4091: . f - 2-norm of function
4092: - cctx - [optional] convergence context
4094: Output Parameter:
4095: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4097: Level: intermediate
4099: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4100: M*/
4102: /*@C
4103: SNESSetConvergenceTest - Sets the function that is to be used
4104: to test for convergence of the nonlinear iterative solution.
4106: Logically Collective
4108: Input Parameters:
4109: + snes - the `SNES` context
4110: . SNESConvergenceTestFunction - routine to test for convergence
4111: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4112: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4114: Level: advanced
4116: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4117: @*/
4118: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscErrorCode (*destroy)(void *))
4119: {
4120: PetscFunctionBegin;
4122: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4123: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(snes->cnvP));
4124: snes->ops->converged = SNESConvergenceTestFunction;
4125: snes->ops->convergeddestroy = destroy;
4126: snes->cnvP = cctx;
4127: PetscFunctionReturn(PETSC_SUCCESS);
4128: }
4130: /*@
4131: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped.
4133: Not Collective
4135: Input Parameter:
4136: . snes - the `SNES` context
4138: Output Parameter:
4139: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4141: Options Database Key:
4142: . -snes_converged_reason - prints the reason to standard out
4144: Level: intermediate
4146: Note:
4147: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4149: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4150: @*/
4151: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4152: {
4153: PetscFunctionBegin;
4155: PetscAssertPointer(reason, 2);
4156: *reason = snes->reason;
4157: PetscFunctionReturn(PETSC_SUCCESS);
4158: }
4160: /*@C
4161: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4163: Not Collective
4165: Input Parameter:
4166: . snes - the `SNES` context
4168: Output Parameter:
4169: . strreason - a human readable string that describes `SNES` converged reason
4171: Level: beginner
4173: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4174: @*/
4175: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4176: {
4177: PetscFunctionBegin;
4179: PetscAssertPointer(strreason, 2);
4180: *strreason = SNESConvergedReasons[snes->reason];
4181: PetscFunctionReturn(PETSC_SUCCESS);
4182: }
4184: /*@
4185: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4187: Not Collective
4189: Input Parameters:
4190: + snes - the `SNES` context
4191: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4192: manual pages for the individual convergence tests for complete lists
4194: Level: developer
4196: Developer Note:
4197: Called inside the various `SNESSolve()` implementations
4199: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4200: @*/
4201: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4202: {
4203: PetscFunctionBegin;
4205: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4206: snes->reason = reason;
4207: PetscFunctionReturn(PETSC_SUCCESS);
4208: }
4210: /*@
4211: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4213: Logically Collective
4215: Input Parameters:
4216: + snes - iterative context obtained from `SNESCreate()`
4217: . a - array to hold history, this array will contain the function norms computed at each step
4218: . its - integer array holds the number of linear iterations for each solve.
4219: . na - size of `a` and `its`
4220: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4221: else it continues storing new values for new nonlinear solves after the old ones
4223: Level: intermediate
4225: Notes:
4226: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' `PETSC_DECIDE` or `PETSC_DEFAULT` then a
4227: default array of length 10000 is allocated.
4229: This routine is useful, e.g., when running a code for purposes
4230: of accurate performance monitoring, when no I/O should be done
4231: during the section of code that is being timed.
4233: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4235: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4236: @*/
4237: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4238: {
4239: PetscFunctionBegin;
4241: if (a) PetscAssertPointer(a, 2);
4242: if (its) PetscAssertPointer(its, 3);
4243: if (!a) {
4244: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4245: PetscCall(PetscCalloc2(na, &a, na, &its));
4246: snes->conv_hist_alloc = PETSC_TRUE;
4247: }
4248: snes->conv_hist = a;
4249: snes->conv_hist_its = its;
4250: snes->conv_hist_max = (size_t)na;
4251: snes->conv_hist_len = 0;
4252: snes->conv_hist_reset = reset;
4253: PetscFunctionReturn(PETSC_SUCCESS);
4254: }
4256: #if defined(PETSC_HAVE_MATLAB)
4257: #include <engine.h> /* MATLAB include file */
4258: #include <mex.h> /* MATLAB include file */
4260: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4261: {
4262: mxArray *mat;
4263: PetscInt i;
4264: PetscReal *ar;
4266: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4267: ar = (PetscReal *)mxGetData(mat);
4268: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4269: return mat;
4270: }
4271: #endif
4273: /*@C
4274: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4276: Not Collective
4278: Input Parameter:
4279: . snes - iterative context obtained from `SNESCreate()`
4281: Output Parameters:
4282: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4283: . its - integer array holds the number of linear iterations (or
4284: negative if not converged) for each solve.
4285: - na - size of `a` and `its`
4287: Level: intermediate
4289: Note:
4290: This routine is useful, e.g., when running a code for purposes
4291: of accurate performance monitoring, when no I/O should be done
4292: during the section of code that is being timed.
4294: Fortran Note:
4295: The calling sequence for this routine in Fortran is
4296: .vb
4297: call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4298: .ve
4300: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4301: @*/
4302: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4303: {
4304: PetscFunctionBegin;
4306: if (a) *a = snes->conv_hist;
4307: if (its) *its = snes->conv_hist_its;
4308: if (na) *na = (PetscInt)snes->conv_hist_len;
4309: PetscFunctionReturn(PETSC_SUCCESS);
4310: }
4312: /*@C
4313: SNESSetUpdate - Sets the general-purpose update function called
4314: at the beginning of every iteration of the nonlinear solve. Specifically
4315: it is called just before the Jacobian is "evaluated".
4317: Logically Collective
4319: Input Parameters:
4320: + snes - The nonlinear solver context
4321: - func - The function
4323: Calling sequence of `func`:
4324: + snes - the nonlinear solver context
4325: - step - The current step of the iteration
4327: Level: advanced
4329: Notes:
4330: 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
4331: to `SNESSetFunction()`, or `SNESSetPicard()`
4332: This is not used by most users.
4334: 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.
4336: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4337: `SNESMonitorSet()`, `SNESSetDivergenceTest()`
4338: @*/
4339: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES snes, PetscInt step))
4340: {
4341: PetscFunctionBegin;
4343: snes->ops->update = func;
4344: PetscFunctionReturn(PETSC_SUCCESS);
4345: }
4347: /*@C
4348: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4350: Collective
4352: Input Parameters:
4353: + snes - iterative context obtained from `SNESCreate()`
4354: - viewer - the viewer to display the reason
4356: Options Database Keys:
4357: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4358: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4360: Level: beginner
4362: Note:
4363: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4364: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4366: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4367: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4368: `SNESConvergedReasonViewFromOptions()`,
4369: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4370: @*/
4371: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4372: {
4373: PetscViewerFormat format;
4374: PetscBool isAscii;
4376: PetscFunctionBegin;
4377: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4378: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4379: if (isAscii) {
4380: PetscCall(PetscViewerGetFormat(viewer, &format));
4381: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
4382: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4383: DM dm;
4384: Vec u;
4385: PetscDS prob;
4386: PetscInt Nf, f;
4387: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4388: void **exactCtx;
4389: PetscReal error;
4391: PetscCall(SNESGetDM(snes, &dm));
4392: PetscCall(SNESGetSolution(snes, &u));
4393: PetscCall(DMGetDS(dm, &prob));
4394: PetscCall(PetscDSGetNumFields(prob, &Nf));
4395: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4396: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4397: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4398: PetscCall(PetscFree2(exactSol, exactCtx));
4399: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4400: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4401: }
4402: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4403: if (((PetscObject)snes)->prefix) {
4404: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4405: } else {
4406: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4407: }
4408: } else if (snes->reason <= 0) {
4409: if (((PetscObject)snes)->prefix) {
4410: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4411: } else {
4412: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4413: }
4414: }
4415: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
4416: }
4417: PetscFunctionReturn(PETSC_SUCCESS);
4418: }
4420: /*@C
4421: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4422: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4424: Logically Collective
4426: Input Parameters:
4427: + snes - the `SNES` context
4428: . f - the `SNESConvergedReason` view function
4429: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4430: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`)
4432: Calling sequence of `f`:
4433: + snes - the `SNES` context
4434: - vctx - [optional] user-defined context for private data for the function
4436: Calling sequence of `reasonviewerdestroy`:
4437: . vctx - [optional] user-defined context for private data for the function
4439: Options Database Keys:
4440: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4441: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4442: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4444: Level: intermediate
4446: Note:
4447: Several different converged reason view routines may be set by calling
4448: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4449: order in which they were set.
4451: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`
4452: @*/
4453: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, void *vctx), void *vctx, PetscErrorCode (*reasonviewdestroy)(void **vctx))
4454: {
4455: PetscInt i;
4456: PetscBool identical;
4458: PetscFunctionBegin;
4460: for (i = 0; i < snes->numberreasonviews; i++) {
4461: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, vctx, reasonviewdestroy, (PetscErrorCode(*)(void))snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4462: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4463: }
4464: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4465: snes->reasonview[snes->numberreasonviews] = f;
4466: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4467: snes->reasonviewcontext[snes->numberreasonviews++] = (void *)vctx;
4468: PetscFunctionReturn(PETSC_SUCCESS);
4469: }
4471: /*@
4472: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4473: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4475: Collective
4477: Input Parameter:
4478: . snes - the `SNES` object
4480: Level: advanced
4482: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4483: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4484: @*/
4485: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4486: {
4487: PetscViewer viewer;
4488: PetscBool flg;
4489: static PetscBool incall = PETSC_FALSE;
4490: PetscViewerFormat format;
4491: PetscInt i;
4493: PetscFunctionBegin;
4494: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4495: incall = PETSC_TRUE;
4497: /* All user-provided viewers are called first, if they exist. */
4498: for (i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4500: /* Call PETSc default routine if users ask for it */
4501: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &viewer, &format, &flg));
4502: if (flg) {
4503: PetscCall(PetscViewerPushFormat(viewer, format));
4504: PetscCall(SNESConvergedReasonView(snes, viewer));
4505: PetscCall(PetscViewerPopFormat(viewer));
4506: PetscCall(PetscViewerDestroy(&viewer));
4507: }
4508: incall = PETSC_FALSE;
4509: PetscFunctionReturn(PETSC_SUCCESS);
4510: }
4512: /*@
4513: SNESSolve - Solves a nonlinear system F(x) = b.
4515: Collective
4517: Input Parameters:
4518: + snes - the `SNES` context
4519: . b - the constant part of the equation F(x) = b, or `NULL` to use zero.
4520: - x - the solution vector.
4522: Level: beginner
4524: Note:
4525: The user should initialize the vector, `x`, with the initial guess
4526: for the nonlinear solve prior to calling `SNESSolve()` or use `SNESSetInitialSolution()`. In particular,
4527: to employ an initial guess of zero, the user should explicitly set
4528: this vector to zero by calling `VecSet()`.
4530: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4531: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4532: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`, `SNESSetInitialSolution()`
4533: @*/
4534: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4535: {
4536: PetscBool flg;
4537: PetscInt grid;
4538: Vec xcreated = NULL;
4539: DM dm;
4541: PetscFunctionBegin;
4544: if (x) PetscCheckSameComm(snes, 1, x, 3);
4546: if (b) PetscCheckSameComm(snes, 1, b, 2);
4548: /* High level operations using the nonlinear solver */
4549: {
4550: PetscViewer viewer;
4551: PetscViewerFormat format;
4552: PetscInt num;
4553: PetscBool flg;
4554: static PetscBool incall = PETSC_FALSE;
4556: if (!incall) {
4557: /* Estimate the convergence rate of the discretization */
4558: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4559: if (flg) {
4560: PetscConvEst conv;
4561: DM dm;
4562: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4563: PetscInt Nf;
4565: incall = PETSC_TRUE;
4566: PetscCall(SNESGetDM(snes, &dm));
4567: PetscCall(DMGetNumFields(dm, &Nf));
4568: PetscCall(PetscCalloc1(Nf, &alpha));
4569: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4570: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4571: PetscCall(PetscConvEstSetFromOptions(conv));
4572: PetscCall(PetscConvEstSetUp(conv));
4573: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4574: PetscCall(PetscViewerPushFormat(viewer, format));
4575: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4576: PetscCall(PetscViewerPopFormat(viewer));
4577: PetscCall(PetscViewerDestroy(&viewer));
4578: PetscCall(PetscConvEstDestroy(&conv));
4579: PetscCall(PetscFree(alpha));
4580: incall = PETSC_FALSE;
4581: }
4582: /* Adaptively refine the initial grid */
4583: num = 1;
4584: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4585: if (flg) {
4586: DMAdaptor adaptor;
4588: incall = PETSC_TRUE;
4589: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4590: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4591: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4592: PetscCall(DMAdaptorSetFromOptions(adaptor));
4593: PetscCall(DMAdaptorSetUp(adaptor));
4594: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4595: PetscCall(DMAdaptorDestroy(&adaptor));
4596: incall = PETSC_FALSE;
4597: }
4598: /* Use grid sequencing to adapt */
4599: num = 0;
4600: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4601: if (num) {
4602: DMAdaptor adaptor;
4604: incall = PETSC_TRUE;
4605: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4606: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4607: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4608: PetscCall(DMAdaptorSetFromOptions(adaptor));
4609: PetscCall(DMAdaptorSetUp(adaptor));
4610: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4611: PetscCall(DMAdaptorDestroy(&adaptor));
4612: incall = PETSC_FALSE;
4613: }
4614: }
4615: }
4616: if (!x) x = snes->vec_sol;
4617: if (!x) {
4618: PetscCall(SNESGetDM(snes, &dm));
4619: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4620: x = xcreated;
4621: }
4622: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4624: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4625: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4626: /* set solution vector */
4627: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4628: PetscCall(VecDestroy(&snes->vec_sol));
4629: snes->vec_sol = x;
4630: PetscCall(SNESGetDM(snes, &dm));
4632: /* set affine vector if provided */
4633: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4634: PetscCall(VecDestroy(&snes->vec_rhs));
4635: snes->vec_rhs = b;
4637: 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");
4638: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4639: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right hand side vector");
4640: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4641: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4642: PetscCall(SNESSetUp(snes));
4644: if (!grid) {
4645: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4646: }
4648: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4649: if (snes->counters_reset) {
4650: snes->nfuncs = 0;
4651: snes->linear_its = 0;
4652: snes->numFailures = 0;
4653: }
4655: snes->reason = SNES_CONVERGED_ITERATING;
4656: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4657: PetscUseTypeMethod(snes, solve);
4658: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4659: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4660: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4662: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4663: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4665: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4666: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4667: /* Call converged reason views. This may involve user-provided viewers as well */
4668: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4670: if (snes->errorifnotconverged) PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4671: if (snes->reason < 0) break;
4672: if (grid < snes->gridsequence) {
4673: DM fine;
4674: Vec xnew;
4675: Mat interp;
4677: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4678: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4679: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4680: PetscCall(DMCreateGlobalVector(fine, &xnew));
4681: PetscCall(MatInterpolate(interp, x, xnew));
4682: PetscCall(DMInterpolate(snes->dm, interp, fine));
4683: PetscCall(MatDestroy(&interp));
4684: x = xnew;
4686: PetscCall(SNESReset(snes));
4687: PetscCall(SNESSetDM(snes, fine));
4688: PetscCall(SNESResetFromOptions(snes));
4689: PetscCall(DMDestroy(&fine));
4690: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4691: }
4692: }
4693: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4694: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4695: PetscCall(DMMonitor(snes->dm));
4696: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4698: PetscCall(VecDestroy(&xcreated));
4699: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4700: PetscFunctionReturn(PETSC_SUCCESS);
4701: }
4703: /* --------- Internal routines for SNES Package --------- */
4705: /*@C
4706: SNESSetType - Sets the method for the nonlinear solver.
4708: Collective
4710: Input Parameters:
4711: + snes - the `SNES` context
4712: - type - a known method
4714: Options Database Key:
4715: . -snes_type <type> - Sets the method; use -help for a list
4716: of available methods (for instance, newtonls or newtontr)
4718: Level: intermediate
4720: Notes:
4721: See "petsc/include/petscsnes.h" for available methods (for instance)
4722: + `SNESNEWTONLS` - Newton's method with line search
4723: (systems of nonlinear equations)
4724: - `SNESNEWTONTR` - Newton's method with trust region
4725: (systems of nonlinear equations)
4727: Normally, it is best to use the `SNESSetFromOptions()` command and then
4728: set the `SNES` solver type from the options database rather than by using
4729: this routine. Using the options database provides the user with
4730: maximum flexibility in evaluating the many nonlinear solvers.
4731: The `SNESSetType()` routine is provided for those situations where it
4732: is necessary to set the nonlinear solver independently of the command
4733: line or options database. This might be the case, for example, when
4734: the choice of solver changes during the execution of the program,
4735: and the user's application is taking responsibility for choosing the
4736: appropriate method.
4738: Developer Note:
4739: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4740: the constructor in that list and calls it to create the specific object.
4742: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4743: @*/
4744: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4745: {
4746: PetscBool match;
4747: PetscErrorCode (*r)(SNES);
4749: PetscFunctionBegin;
4751: PetscAssertPointer(type, 2);
4753: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4754: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4756: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4757: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4758: /* Destroy the previous private SNES context */
4759: PetscTryTypeMethod(snes, destroy);
4760: /* Reinitialize function pointers in SNESOps structure */
4761: snes->ops->setup = NULL;
4762: snes->ops->solve = NULL;
4763: snes->ops->view = NULL;
4764: snes->ops->setfromoptions = NULL;
4765: snes->ops->destroy = NULL;
4767: /* It may happen the user has customized the line search before calling SNESSetType */
4768: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
4770: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4771: snes->setupcalled = PETSC_FALSE;
4773: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
4774: PetscCall((*r)(snes));
4775: PetscFunctionReturn(PETSC_SUCCESS);
4776: }
4778: /*@C
4779: SNESGetType - Gets the `SNES` method type and name (as a string).
4781: Not Collective
4783: Input Parameter:
4784: . snes - nonlinear solver context
4786: Output Parameter:
4787: . type - `SNES` method (a character string)
4789: Level: intermediate
4791: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
4792: @*/
4793: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
4794: {
4795: PetscFunctionBegin;
4797: PetscAssertPointer(type, 2);
4798: *type = ((PetscObject)snes)->type_name;
4799: PetscFunctionReturn(PETSC_SUCCESS);
4800: }
4802: /*@
4803: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
4805: Logically Collective
4807: Input Parameters:
4808: + snes - the `SNES` context obtained from `SNESCreate()`
4809: - u - the solution vector
4811: Level: beginner
4813: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
4814: @*/
4815: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4816: {
4817: DM dm;
4819: PetscFunctionBegin;
4822: PetscCall(PetscObjectReference((PetscObject)u));
4823: PetscCall(VecDestroy(&snes->vec_sol));
4825: snes->vec_sol = u;
4827: PetscCall(SNESGetDM(snes, &dm));
4828: PetscCall(DMShellSetGlobalVector(dm, u));
4829: PetscFunctionReturn(PETSC_SUCCESS);
4830: }
4832: /*@
4833: SNESGetSolution - Returns the vector where the approximate solution is
4834: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
4836: Not Collective, but `x` is parallel if `snes` is parallel
4838: Input Parameter:
4839: . snes - the `SNES` context
4841: Output Parameter:
4842: . x - the solution
4844: Level: intermediate
4846: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
4847: @*/
4848: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
4849: {
4850: PetscFunctionBegin;
4852: PetscAssertPointer(x, 2);
4853: *x = snes->vec_sol;
4854: PetscFunctionReturn(PETSC_SUCCESS);
4855: }
4857: /*@
4858: SNESGetSolutionUpdate - Returns the vector where the solution update is
4859: stored.
4861: Not Collective, but `x` is parallel if `snes` is parallel
4863: Input Parameter:
4864: . snes - the `SNES` context
4866: Output Parameter:
4867: . x - the solution update
4869: Level: advanced
4871: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
4872: @*/
4873: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
4874: {
4875: PetscFunctionBegin;
4877: PetscAssertPointer(x, 2);
4878: *x = snes->vec_sol_update;
4879: PetscFunctionReturn(PETSC_SUCCESS);
4880: }
4882: /*@C
4883: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
4885: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
4887: Input Parameter:
4888: . snes - the `SNES` context
4890: Output Parameters:
4891: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
4892: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunction`
4893: - ctx - the function context (or `NULL` if you don't want it)
4895: Level: advanced
4897: Note:
4898: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
4900: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunction`
4901: @*/
4902: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, PetscErrorCode (**f)(SNES, Vec, Vec, void *), void **ctx)
4903: {
4904: DM dm;
4906: PetscFunctionBegin;
4908: if (r) {
4909: if (!snes->vec_func) {
4910: if (snes->vec_rhs) {
4911: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
4912: } else if (snes->vec_sol) {
4913: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
4914: } else if (snes->dm) {
4915: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
4916: }
4917: }
4918: *r = snes->vec_func;
4919: }
4920: PetscCall(SNESGetDM(snes, &dm));
4921: PetscCall(DMSNESGetFunction(dm, f, ctx));
4922: PetscFunctionReturn(PETSC_SUCCESS);
4923: }
4925: /*@C
4926: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
4928: Input Parameter:
4929: . snes - the `SNES` context
4931: Output Parameters:
4932: + f - the function (or `NULL`) see `SNESSetNGS()` for details
4933: - ctx - the function context (or `NULL`)
4935: Level: advanced
4937: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`
4938: @*/
4939: PetscErrorCode SNESGetNGS(SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void *), void **ctx)
4940: {
4941: DM dm;
4943: PetscFunctionBegin;
4945: PetscCall(SNESGetDM(snes, &dm));
4946: PetscCall(DMSNESGetNGS(dm, f, ctx));
4947: PetscFunctionReturn(PETSC_SUCCESS);
4948: }
4950: /*@C
4951: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4952: `SNES` options in the database.
4954: Logically Collective
4956: Input Parameters:
4957: + snes - the `SNES` context
4958: - prefix - the prefix to prepend to all option names
4960: Level: advanced
4962: Note:
4963: A hyphen (-) must NOT be given at the beginning of the prefix name.
4964: The first character of all runtime options is AUTOMATICALLY the hyphen.
4966: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
4967: @*/
4968: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
4969: {
4970: PetscFunctionBegin;
4972: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
4973: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
4974: if (snes->linesearch) {
4975: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
4976: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
4977: }
4978: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
4979: PetscFunctionReturn(PETSC_SUCCESS);
4980: }
4982: /*@C
4983: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4984: `SNES` options in the database.
4986: Logically Collective
4988: Input Parameters:
4989: + snes - the `SNES` context
4990: - prefix - the prefix to prepend to all option names
4992: Level: advanced
4994: Note:
4995: A hyphen (-) must NOT be given at the beginning of the prefix name.
4996: The first character of all runtime options is AUTOMATICALLY the hyphen.
4998: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
4999: @*/
5000: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5001: {
5002: PetscFunctionBegin;
5004: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5005: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5006: if (snes->linesearch) {
5007: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5008: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5009: }
5010: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5011: PetscFunctionReturn(PETSC_SUCCESS);
5012: }
5014: /*@C
5015: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5016: `SNES` options in the database.
5018: Not Collective
5020: Input Parameter:
5021: . snes - the `SNES` context
5023: Output Parameter:
5024: . prefix - pointer to the prefix string used
5026: Level: advanced
5028: Fortran Note:
5029: The user should pass in a string 'prefix' of
5030: sufficient length to hold the prefix.
5032: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5033: @*/
5034: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5035: {
5036: PetscFunctionBegin;
5038: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5039: PetscFunctionReturn(PETSC_SUCCESS);
5040: }
5042: /*@C
5043: SNESRegister - Adds a method to the nonlinear solver package.
5045: Not Collective
5047: Input Parameters:
5048: + sname - name of a new user-defined solver
5049: - function - routine to create method context
5051: Level: advanced
5053: Note:
5054: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5056: Example Usage:
5057: .vb
5058: SNESRegister("my_solver", MySolverCreate);
5059: .ve
5061: Then, your solver can be chosen with the procedural interface via
5062: $ SNESSetType(snes, "my_solver")
5063: or at runtime via the option
5064: $ -snes_type my_solver
5066: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5067: @*/
5068: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5069: {
5070: PetscFunctionBegin;
5071: PetscCall(SNESInitializePackage());
5072: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5073: PetscFunctionReturn(PETSC_SUCCESS);
5074: }
5076: PetscErrorCode SNESTestLocalMin(SNES snes)
5077: {
5078: PetscInt N, i, j;
5079: Vec u, uh, fh;
5080: PetscScalar value;
5081: PetscReal norm;
5083: PetscFunctionBegin;
5084: PetscCall(SNESGetSolution(snes, &u));
5085: PetscCall(VecDuplicate(u, &uh));
5086: PetscCall(VecDuplicate(u, &fh));
5088: /* currently only works for sequential */
5089: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5090: PetscCall(VecGetSize(u, &N));
5091: for (i = 0; i < N; i++) {
5092: PetscCall(VecCopy(u, uh));
5093: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5094: for (j = -10; j < 11; j++) {
5095: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5096: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5097: PetscCall(SNESComputeFunction(snes, uh, fh));
5098: PetscCall(VecNorm(fh, NORM_2, &norm));
5099: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5100: value = -value;
5101: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5102: }
5103: }
5104: PetscCall(VecDestroy(&uh));
5105: PetscCall(VecDestroy(&fh));
5106: PetscFunctionReturn(PETSC_SUCCESS);
5107: }
5109: /*@
5110: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5111: computing relative tolerance for linear solvers within an inexact
5112: Newton method.
5114: Logically Collective
5116: Input Parameters:
5117: + snes - `SNES` context
5118: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5120: Options Database Keys:
5121: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5122: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5123: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5124: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5125: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5126: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5127: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5128: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5130: Level: advanced
5132: Note:
5133: The default is to use a constant relative tolerance for
5134: the inner linear solvers. Alternatively, one can use the
5135: Eisenstat-Walker method, where the relative convergence tolerance
5136: is reset at each Newton iteration according progress of the nonlinear
5137: solver.
5139: References:
5140: . - * S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an inexact Newton method", SISC 17 (1), pp.16-32, 1996.
5142: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5143: @*/
5144: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5145: {
5146: PetscFunctionBegin;
5149: snes->ksp_ewconv = flag;
5150: PetscFunctionReturn(PETSC_SUCCESS);
5151: }
5153: /*@
5154: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5155: for computing relative tolerance for linear solvers within an
5156: inexact Newton method.
5158: Not Collective
5160: Input Parameter:
5161: . snes - `SNES` context
5163: Output Parameter:
5164: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5166: Level: advanced
5168: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5169: @*/
5170: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5171: {
5172: PetscFunctionBegin;
5174: PetscAssertPointer(flag, 2);
5175: *flag = snes->ksp_ewconv;
5176: PetscFunctionReturn(PETSC_SUCCESS);
5177: }
5179: /*@
5180: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5181: convergence criteria for the linear solvers within an inexact
5182: Newton method.
5184: Logically Collective
5186: Input Parameters:
5187: + snes - `SNES` context
5188: . version - version 1, 2 (default is 2), 3 or 4
5189: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5190: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5191: . gamma - multiplicative factor for version 2 rtol computation
5192: (0 <= gamma2 <= 1)
5193: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5194: . alpha2 - power for safeguard
5195: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5197: Level: advanced
5199: Notes:
5200: Version 3 was contributed by Luis Chacon, June 2006.
5202: Use `PETSC_DEFAULT` to retain the default for any of the parameters.
5204: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5205: @*/
5206: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5207: {
5208: SNESKSPEW *kctx;
5210: PetscFunctionBegin;
5212: kctx = (SNESKSPEW *)snes->kspconvctx;
5213: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5222: if (version != PETSC_DEFAULT) kctx->version = version;
5223: if (rtol_0 != (PetscReal)PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5224: if (rtol_max != (PetscReal)PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5225: if (gamma != (PetscReal)PETSC_DEFAULT) kctx->gamma = gamma;
5226: if (alpha != (PetscReal)PETSC_DEFAULT) kctx->alpha = alpha;
5227: if (alpha2 != (PetscReal)PETSC_DEFAULT) kctx->alpha2 = alpha2;
5228: if (threshold != (PetscReal)PETSC_DEFAULT) kctx->threshold = threshold;
5230: 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);
5231: 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);
5232: 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);
5233: 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);
5234: 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);
5235: 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);
5236: PetscFunctionReturn(PETSC_SUCCESS);
5237: }
5239: /*@
5240: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5241: convergence criteria for the linear solvers within an inexact
5242: Newton method.
5244: Not Collective
5246: Input Parameter:
5247: . snes - `SNES` context
5249: Output Parameters:
5250: + version - version 1, 2 (default is 2), 3 or 4
5251: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5252: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5253: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5254: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5255: . alpha2 - power for safeguard
5256: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5258: Level: advanced
5260: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5261: @*/
5262: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5263: {
5264: SNESKSPEW *kctx;
5266: PetscFunctionBegin;
5268: kctx = (SNESKSPEW *)snes->kspconvctx;
5269: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5270: if (version) *version = kctx->version;
5271: if (rtol_0) *rtol_0 = kctx->rtol_0;
5272: if (rtol_max) *rtol_max = kctx->rtol_max;
5273: if (gamma) *gamma = kctx->gamma;
5274: if (alpha) *alpha = kctx->alpha;
5275: if (alpha2) *alpha2 = kctx->alpha2;
5276: if (threshold) *threshold = kctx->threshold;
5277: PetscFunctionReturn(PETSC_SUCCESS);
5278: }
5280: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5281: {
5282: SNES snes = (SNES)ctx;
5283: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5284: PetscReal rtol = PETSC_DEFAULT, stol;
5286: PetscFunctionBegin;
5287: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5288: if (!snes->iter) {
5289: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5290: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5291: } else {
5292: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5293: if (kctx->version == 1) {
5294: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5295: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5296: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5297: } else if (kctx->version == 2) {
5298: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5299: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5300: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5301: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5302: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5303: /* safeguard: avoid sharp decrease of rtol */
5304: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5305: stol = PetscMax(rtol, stol);
5306: rtol = PetscMin(kctx->rtol_0, stol);
5307: /* safeguard: avoid oversolving */
5308: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5309: stol = PetscMax(rtol, stol);
5310: rtol = PetscMin(kctx->rtol_0, stol);
5311: } else /* if (kctx->version == 4) */ {
5312: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5313: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5314: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5315: PetscReal rk = ared / pred;
5316: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5317: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5318: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5319: else rtol = kctx->v4_m2 * kctx->rtol_last;
5321: 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;
5322: kctx->rtol_last_2 = kctx->rtol_last;
5323: kctx->rk_last_2 = kctx->rk_last;
5324: kctx->rk_last = rk;
5325: }
5326: }
5327: /* safeguard: avoid rtol greater than rtol_max */
5328: rtol = PetscMin(rtol, kctx->rtol_max);
5329: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_DEFAULT, PETSC_DEFAULT, PETSC_DEFAULT));
5330: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5331: PetscFunctionReturn(PETSC_SUCCESS);
5332: }
5334: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5335: {
5336: SNES snes = (SNES)ctx;
5337: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5338: PCSide pcside;
5339: Vec lres;
5341: PetscFunctionBegin;
5342: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5343: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5344: kctx->norm_last = snes->norm;
5345: if (kctx->version == 1 || kctx->version == 4) {
5346: PC pc;
5347: PetscBool getRes;
5349: PetscCall(KSPGetPC(ksp, &pc));
5350: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5351: if (!getRes) {
5352: KSPNormType normtype;
5354: PetscCall(KSPGetNormType(ksp, &normtype));
5355: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5356: }
5357: PetscCall(KSPGetPCSide(ksp, &pcside));
5358: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5359: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5360: } else {
5361: /* KSP residual is preconditioned residual */
5362: /* compute true linear residual norm */
5363: Mat J;
5364: PetscCall(KSPGetOperators(ksp, &J, NULL));
5365: PetscCall(VecDuplicate(b, &lres));
5366: PetscCall(MatMult(J, x, lres));
5367: PetscCall(VecAYPX(lres, -1.0, b));
5368: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5369: PetscCall(VecDestroy(&lres));
5370: }
5371: }
5372: PetscFunctionReturn(PETSC_SUCCESS);
5373: }
5375: /*@
5376: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5378: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5380: Input Parameter:
5381: . snes - the `SNES` context
5383: Output Parameter:
5384: . ksp - the `KSP` context
5386: Level: beginner
5388: Notes:
5389: The user can then directly manipulate the `KSP` context to set various
5390: options, etc. Likewise, the user can then extract and manipulate the
5391: `PC` contexts as well.
5393: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function
5395: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5396: @*/
5397: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5398: {
5399: PetscFunctionBegin;
5401: PetscAssertPointer(ksp, 2);
5403: if (!snes->ksp) {
5404: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5405: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5407: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5408: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5410: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5411: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5412: }
5413: *ksp = snes->ksp;
5414: PetscFunctionReturn(PETSC_SUCCESS);
5415: }
5417: #include <petsc/private/dmimpl.h>
5418: /*@
5419: SNESSetDM - Sets the `DM` that may be used by some nonlinear solvers or their underlying preconditioners
5421: Logically Collective
5423: Input Parameters:
5424: + snes - the nonlinear solver context
5425: - dm - the `DM`, cannot be `NULL`
5427: Level: intermediate
5429: Note:
5430: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5431: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5432: problems using the same function space.
5434: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5435: @*/
5436: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5437: {
5438: KSP ksp;
5439: DMSNES sdm;
5441: PetscFunctionBegin;
5444: PetscCall(PetscObjectReference((PetscObject)dm));
5445: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5446: if (snes->dm->dmsnes && !dm->dmsnes) {
5447: PetscCall(DMCopyDMSNES(snes->dm, dm));
5448: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5449: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5450: }
5451: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5452: PetscCall(DMDestroy(&snes->dm));
5453: }
5454: snes->dm = dm;
5455: snes->dmAuto = PETSC_FALSE;
5457: PetscCall(SNESGetKSP(snes, &ksp));
5458: PetscCall(KSPSetDM(ksp, dm));
5459: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5460: if (snes->npc) {
5461: PetscCall(SNESSetDM(snes->npc, snes->dm));
5462: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5463: }
5464: PetscFunctionReturn(PETSC_SUCCESS);
5465: }
5467: /*@
5468: SNESGetDM - Gets the `DM` that may be used by some solvers/preconditioners
5470: Not Collective but dm obtained is parallel on snes
5472: Input Parameter:
5473: . snes - the `SNES` context
5475: Output Parameter:
5476: . dm - the `DM`
5478: Level: intermediate
5480: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5481: @*/
5482: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5483: {
5484: PetscFunctionBegin;
5486: if (!snes->dm) {
5487: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5488: snes->dmAuto = PETSC_TRUE;
5489: }
5490: *dm = snes->dm;
5491: PetscFunctionReturn(PETSC_SUCCESS);
5492: }
5494: /*@
5495: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5497: Collective
5499: Input Parameters:
5500: + snes - iterative context obtained from `SNESCreate()`
5501: - npc - the nonlinear preconditioner object
5503: Level: developer
5505: Notes:
5506: Use `SNESGetNPC()` to retrieve the preconditioner context (for example,
5507: to configure it using the API).
5509: Only some `SNESType` can use a nonlinear preconditioner
5511: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5512: @*/
5513: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5514: {
5515: PetscFunctionBegin;
5518: PetscCheckSameComm(snes, 1, npc, 2);
5519: PetscCall(PetscObjectReference((PetscObject)npc));
5520: PetscCall(SNESDestroy(&snes->npc));
5521: snes->npc = npc;
5522: PetscFunctionReturn(PETSC_SUCCESS);
5523: }
5525: /*@
5526: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5528: Not Collective; but any changes to the obtained the npc object must be applied collectively
5530: Input Parameter:
5531: . snes - iterative context obtained from `SNESCreate()`
5533: Output Parameter:
5534: . pc - preconditioner context
5536: Options Database Key:
5537: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5539: Level: developer
5541: Notes:
5542: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created.
5544: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5545: `SNES`
5547: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5548: @*/
5549: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5550: {
5551: const char *optionsprefix;
5553: PetscFunctionBegin;
5555: PetscAssertPointer(pc, 2);
5556: if (!snes->npc) {
5557: void *ctx;
5559: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5560: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5561: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5562: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5563: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5564: PetscCall(SNESGetApplicationContext(snes, &ctx));
5565: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5566: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5567: }
5568: *pc = snes->npc;
5569: PetscFunctionReturn(PETSC_SUCCESS);
5570: }
5572: /*@
5573: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5575: Not Collective
5577: Input Parameter:
5578: . snes - iterative context obtained from `SNESCreate()`
5580: Output Parameter:
5581: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5583: Level: developer
5585: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5586: @*/
5587: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5588: {
5589: PetscFunctionBegin;
5591: *has_npc = (PetscBool)(snes->npc ? PETSC_TRUE : PETSC_FALSE);
5592: PetscFunctionReturn(PETSC_SUCCESS);
5593: }
5595: /*@
5596: SNESSetNPCSide - Sets the nonlinear preconditioning side.
5598: Logically Collective
5600: Input Parameter:
5601: . snes - iterative context obtained from `SNESCreate()`
5603: Output Parameter:
5604: . side - the preconditioning side, where side is one of
5605: .vb
5606: PC_LEFT - left preconditioning
5607: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5608: .ve
5610: Options Database Key:
5611: . -snes_npc_side <right,left> - nonlinear preconditioner side
5613: Level: intermediate
5615: Note:
5616: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5618: .seealso: [](ch_snes), `SNES`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5619: @*/
5620: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5621: {
5622: PetscFunctionBegin;
5625: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5626: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5627: snes->npcside = side;
5628: PetscFunctionReturn(PETSC_SUCCESS);
5629: }
5631: /*@
5632: SNESGetNPCSide - Gets the preconditioning side.
5634: Not Collective
5636: Input Parameter:
5637: . snes - iterative context obtained from `SNESCreate()`
5639: Output Parameter:
5640: . side - the preconditioning side, where side is one of
5641: .vb
5642: `PC_LEFT` - left preconditioning
5643: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5644: .ve
5646: Level: intermediate
5648: .seealso: [](ch_snes), `SNES`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5649: @*/
5650: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5651: {
5652: PetscFunctionBegin;
5654: PetscAssertPointer(side, 2);
5655: *side = snes->npcside;
5656: PetscFunctionReturn(PETSC_SUCCESS);
5657: }
5659: /*@
5660: SNESSetLineSearch - Sets the linesearch to be used for `SNES`
5662: Collective
5664: Input Parameters:
5665: + snes - iterative context obtained from `SNESCreate()`
5666: - linesearch - the linesearch object
5668: Level: developer
5670: Note:
5671: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
5672: to configure it using the API).
5674: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
5675: @*/
5676: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5677: {
5678: PetscFunctionBegin;
5681: PetscCheckSameComm(snes, 1, linesearch, 2);
5682: PetscCall(PetscObjectReference((PetscObject)linesearch));
5683: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5685: snes->linesearch = linesearch;
5687: PetscFunctionReturn(PETSC_SUCCESS);
5688: }
5690: /*@
5691: SNESGetLineSearch - Returns the line search context possibly set with `SNESSetLineSearch()`
5692: or creates a default line search instance associated with the `SNES` and returns it.
5694: Not Collective
5696: Input Parameter:
5697: . snes - iterative context obtained from `SNESCreate()`
5699: Output Parameter:
5700: . linesearch - linesearch context
5702: Level: beginner
5704: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`
5705: @*/
5706: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5707: {
5708: const char *optionsprefix;
5710: PetscFunctionBegin;
5712: PetscAssertPointer(linesearch, 2);
5713: if (!snes->linesearch) {
5714: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5715: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5716: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5717: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5718: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5719: }
5720: *linesearch = snes->linesearch;
5721: PetscFunctionReturn(PETSC_SUCCESS);
5722: }