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: Notes:
2391: `SNESComputeFunction()` is typically used within nonlinear solvers
2392: implementations, so users would not generally call this routine themselves.
2394: When solving for $F(x) = b$, this routine computes $y = F(x) - b$.
2396: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`
2397: @*/
2398: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec y)
2399: {
2400: DM dm;
2401: DMSNES sdm;
2403: PetscFunctionBegin;
2407: PetscCheckSameComm(snes, 1, x, 2);
2408: PetscCheckSameComm(snes, 1, y, 3);
2409: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2411: PetscCall(SNESGetDM(snes, &dm));
2412: PetscCall(DMGetDMSNES(dm, &sdm));
2413: 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().");
2414: if (sdm->ops->computefunction) {
2415: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2416: PetscCall(VecLockReadPush(x));
2417: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2418: snes->domainerror = PETSC_FALSE;
2419: {
2420: void *ctx;
2421: PetscErrorCode (*computefunction)(SNES, Vec, Vec, void *);
2422: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2423: PetscCallBack("SNES callback function", (*computefunction)(snes, x, y, ctx));
2424: }
2425: PetscCall(VecLockReadPop(x));
2426: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2427: } else /* if (snes->vec_rhs) */ {
2428: PetscCall(MatMult(snes->jacobian, x, y));
2429: }
2430: if (snes->vec_rhs) PetscCall(VecAXPY(y, -1.0, snes->vec_rhs));
2431: snes->nfuncs++;
2432: /*
2433: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2434: propagate the value to all processes
2435: */
2436: if (snes->domainerror) PetscCall(VecSetInf(y));
2437: PetscFunctionReturn(PETSC_SUCCESS);
2438: }
2440: /*@
2441: SNESComputeMFFunction - Calls the function that has been set with `SNESSetMFFunction()`.
2443: Collective
2445: Input Parameters:
2446: + snes - the `SNES` context
2447: - x - input vector
2449: Output Parameter:
2450: . y - function vector, as set by `SNESSetMFFunction()`
2452: Level: developer
2454: Notes:
2455: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2456: so users would not generally call this routine themselves.
2458: Since this function is intended for use with finite differencing it does not subtract the right hand side vector provided with `SNESSolve()`
2459: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2460: 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.
2462: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF`
2463: @*/
2464: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2465: {
2466: DM dm;
2467: DMSNES sdm;
2469: PetscFunctionBegin;
2473: PetscCheckSameComm(snes, 1, x, 2);
2474: PetscCheckSameComm(snes, 1, y, 3);
2475: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2477: PetscCall(SNESGetDM(snes, &dm));
2478: PetscCall(DMGetDMSNES(dm, &sdm));
2479: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2480: PetscCall(VecLockReadPush(x));
2481: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2482: snes->domainerror = PETSC_FALSE;
2483: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2484: PetscCall(VecLockReadPop(x));
2485: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2486: snes->nfuncs++;
2487: /*
2488: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2489: propagate the value to all processes
2490: */
2491: if (snes->domainerror) PetscCall(VecSetInf(y));
2492: PetscFunctionReturn(PETSC_SUCCESS);
2493: }
2495: /*@
2496: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2498: Collective
2500: Input Parameters:
2501: + snes - the `SNES` context
2502: . x - input vector
2503: - b - rhs vector
2505: Output Parameter:
2506: . x - new solution vector
2508: Level: developer
2510: Note:
2511: `SNESComputeNGS()` is typically used within composed nonlinear solver
2512: implementations, so most users would not generally call this routine
2513: themselves.
2515: .seealso: [](ch_snes), `SNESNGS`, `SNESSetNGS()`, `SNESComputeFunction()`
2516: @*/
2517: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2518: {
2519: DM dm;
2520: DMSNES sdm;
2522: PetscFunctionBegin;
2526: PetscCheckSameComm(snes, 1, x, 3);
2527: if (b) PetscCheckSameComm(snes, 1, b, 2);
2528: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2529: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2530: PetscCall(SNESGetDM(snes, &dm));
2531: PetscCall(DMGetDMSNES(dm, &sdm));
2532: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2533: if (b) PetscCall(VecLockReadPush(b));
2534: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2535: if (b) PetscCall(VecLockReadPop(b));
2536: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2537: PetscFunctionReturn(PETSC_SUCCESS);
2538: }
2540: PetscErrorCode SNESTestJacobian(SNES snes)
2541: {
2542: Mat A, B, C, D, jacobian;
2543: Vec x = snes->vec_sol, f = snes->vec_func;
2544: PetscReal nrm, gnorm;
2545: PetscReal threshold = 1.e-5;
2546: MatType mattype;
2547: PetscInt m, n, M, N;
2548: void *functx;
2549: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, test = PETSC_FALSE, flg, istranspose;
2550: PetscViewer viewer, mviewer;
2551: MPI_Comm comm;
2552: PetscInt tabs;
2553: static PetscBool directionsprinted = PETSC_FALSE;
2554: PetscViewerFormat format;
2556: PetscFunctionBegin;
2557: PetscObjectOptionsBegin((PetscObject)snes);
2558: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &test));
2559: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2560: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2561: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2562: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2563: /* 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 */
2564: 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));
2565: PetscOptionsEnd();
2566: if (!test) PetscFunctionReturn(PETSC_SUCCESS);
2568: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2569: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2570: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2571: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2572: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2573: if (!complete_print && !directionsprinted) {
2574: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2575: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2576: }
2577: if (!directionsprinted) {
2578: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2579: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2580: directionsprinted = PETSC_TRUE;
2581: }
2582: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2584: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2585: if (!flg) jacobian = snes->jacobian;
2586: else jacobian = snes->jacobian_pre;
2588: if (!x) {
2589: PetscCall(MatCreateVecs(jacobian, &x, NULL));
2590: } else {
2591: PetscCall(PetscObjectReference((PetscObject)x));
2592: }
2593: if (!f) {
2594: PetscCall(VecDuplicate(x, &f));
2595: } else {
2596: PetscCall(PetscObjectReference((PetscObject)f));
2597: }
2598: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2599: PetscCall(SNESComputeFunction(snes, x, f));
2600: PetscCall(VecDestroy(&f));
2601: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2602: while (jacobian) {
2603: Mat JT = NULL, Jsave = NULL;
2605: if (istranspose) {
2606: PetscCall(MatCreateTranspose(jacobian, &JT));
2607: Jsave = jacobian;
2608: jacobian = JT;
2609: }
2610: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2611: if (flg) {
2612: A = jacobian;
2613: PetscCall(PetscObjectReference((PetscObject)A));
2614: } else {
2615: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2616: }
2618: PetscCall(MatGetType(A, &mattype));
2619: PetscCall(MatGetSize(A, &M, &N));
2620: PetscCall(MatGetLocalSize(A, &m, &n));
2621: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2622: PetscCall(MatSetType(B, mattype));
2623: PetscCall(MatSetSizes(B, m, n, M, N));
2624: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2625: PetscCall(MatSetUp(B));
2626: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2628: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2629: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2631: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2632: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2633: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2634: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2635: PetscCall(MatDestroy(&D));
2636: if (!gnorm) gnorm = 1; /* just in case */
2637: PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2639: if (complete_print) {
2640: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2641: PetscCall(MatView(A, mviewer));
2642: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2643: PetscCall(MatView(B, mviewer));
2644: }
2646: if (threshold_print || complete_print) {
2647: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2648: PetscScalar *cvals;
2649: const PetscInt *bcols;
2650: const PetscScalar *bvals;
2652: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2653: PetscCall(MatSetType(C, mattype));
2654: PetscCall(MatSetSizes(C, m, n, M, N));
2655: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2656: PetscCall(MatSetUp(C));
2657: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2659: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2660: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2662: for (row = Istart; row < Iend; row++) {
2663: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2664: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2665: for (j = 0, cncols = 0; j < bncols; j++) {
2666: if (PetscAbsScalar(bvals[j]) > threshold) {
2667: ccols[cncols] = bcols[j];
2668: cvals[cncols] = bvals[j];
2669: cncols += 1;
2670: }
2671: }
2672: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2673: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2674: PetscCall(PetscFree2(ccols, cvals));
2675: }
2676: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2677: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2678: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2679: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2680: PetscCall(MatDestroy(&C));
2681: }
2682: PetscCall(MatDestroy(&A));
2683: PetscCall(MatDestroy(&B));
2684: PetscCall(MatDestroy(&JT));
2685: if (Jsave) jacobian = Jsave;
2686: if (jacobian != snes->jacobian_pre) {
2687: jacobian = snes->jacobian_pre;
2688: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2689: } else jacobian = NULL;
2690: }
2691: PetscCall(VecDestroy(&x));
2692: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2693: if (mviewer) PetscCall(PetscViewerDestroy(&mviewer));
2694: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2695: PetscFunctionReturn(PETSC_SUCCESS);
2696: }
2698: /*@
2699: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2701: Collective
2703: Input Parameters:
2704: + snes - the `SNES` context
2705: - X - input vector
2707: Output Parameters:
2708: + A - Jacobian matrix
2709: - B - optional matrix for building the preconditioner, usually the same as `A`
2711: Options Database Keys:
2712: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2713: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2714: . -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.
2715: . -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
2716: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2717: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2718: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2719: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2720: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2721: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2722: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2723: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2724: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2725: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2726: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2728: Level: developer
2730: Note:
2731: Most users should not need to explicitly call this routine, as it
2732: is used internally within the nonlinear solvers.
2734: Developer Note:
2735: 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
2736: with the `SNESType` of test that has been removed.
2738: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
2739: @*/
2740: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2741: {
2742: PetscBool flag;
2743: DM dm;
2744: DMSNES sdm;
2745: KSP ksp;
2747: PetscFunctionBegin;
2750: PetscCheckSameComm(snes, 1, X, 2);
2751: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2752: PetscCall(SNESGetDM(snes, &dm));
2753: PetscCall(DMGetDMSNES(dm, &sdm));
2755: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2756: if (snes->lagjacobian == -2) {
2757: snes->lagjacobian = -1;
2759: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2760: } else if (snes->lagjacobian == -1) {
2761: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2762: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2763: if (flag) {
2764: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2765: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2766: }
2767: PetscFunctionReturn(PETSC_SUCCESS);
2768: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2769: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2770: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2771: if (flag) {
2772: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2773: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2774: }
2775: PetscFunctionReturn(PETSC_SUCCESS);
2776: }
2777: if (snes->npc && snes->npcside == PC_LEFT) {
2778: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2779: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2780: PetscFunctionReturn(PETSC_SUCCESS);
2781: }
2783: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2784: PetscCall(VecLockReadPush(X));
2785: {
2786: void *ctx;
2787: PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *);
2788: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2789: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2790: }
2791: PetscCall(VecLockReadPop(X));
2792: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
2794: /* attach latest linearization point to the preconditioning matrix */
2795: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
2797: /* the next line ensures that snes->ksp exists */
2798: PetscCall(SNESGetKSP(snes, &ksp));
2799: if (snes->lagpreconditioner == -2) {
2800: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
2801: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2802: snes->lagpreconditioner = -1;
2803: } else if (snes->lagpreconditioner == -1) {
2804: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
2805: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2806: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2807: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
2808: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2809: } else {
2810: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
2811: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2812: }
2814: PetscCall(SNESTestJacobian(snes));
2815: /* make sure user returned a correct Jacobian and preconditioner */
2818: {
2819: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
2820: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
2821: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
2822: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
2823: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
2824: if (flag || flag_draw || flag_contour) {
2825: Mat Bexp_mine = NULL, Bexp, FDexp;
2826: PetscViewer vdraw, vstdout;
2827: PetscBool flg;
2828: if (flag_operator) {
2829: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
2830: Bexp = Bexp_mine;
2831: } else {
2832: /* See if the preconditioning matrix can be viewed and added directly */
2833: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPIBAIJ, ""));
2834: if (flg) Bexp = B;
2835: else {
2836: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2837: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
2838: Bexp = Bexp_mine;
2839: }
2840: }
2841: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
2842: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
2843: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2844: if (flag_draw || flag_contour) {
2845: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2846: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2847: } else vdraw = NULL;
2848: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
2849: if (flag) PetscCall(MatView(Bexp, vstdout));
2850: if (vdraw) PetscCall(MatView(Bexp, vdraw));
2851: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
2852: if (flag) PetscCall(MatView(FDexp, vstdout));
2853: if (vdraw) PetscCall(MatView(FDexp, vdraw));
2854: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
2855: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
2856: if (flag) PetscCall(MatView(FDexp, vstdout));
2857: if (vdraw) { /* Always use contour for the difference */
2858: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2859: PetscCall(MatView(FDexp, vdraw));
2860: PetscCall(PetscViewerPopFormat(vdraw));
2861: }
2862: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2863: PetscCall(PetscViewerDestroy(&vdraw));
2864: PetscCall(MatDestroy(&Bexp_mine));
2865: PetscCall(MatDestroy(&FDexp));
2866: }
2867: }
2868: {
2869: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
2870: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
2871: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
2872: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
2873: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
2874: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
2875: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
2876: if (flag_threshold) {
2877: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
2878: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
2879: }
2880: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2881: Mat Bfd;
2882: PetscViewer vdraw, vstdout;
2883: MatColoring coloring;
2884: ISColoring iscoloring;
2885: MatFDColoring matfdcoloring;
2886: PetscErrorCode (*func)(SNES, Vec, Vec, void *);
2887: void *funcctx;
2888: PetscReal norm1, norm2, normmax;
2890: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
2891: PetscCall(MatColoringCreate(Bfd, &coloring));
2892: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
2893: PetscCall(MatColoringSetFromOptions(coloring));
2894: PetscCall(MatColoringApply(coloring, &iscoloring));
2895: PetscCall(MatColoringDestroy(&coloring));
2896: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
2897: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2898: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
2899: PetscCall(ISColoringDestroy(&iscoloring));
2901: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
2902: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
2903: PetscCall(MatFDColoringSetFunction(matfdcoloring, (PetscErrorCode(*)(void))func, funcctx));
2904: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
2905: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
2906: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2907: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
2908: PetscCall(MatFDColoringDestroy(&matfdcoloring));
2910: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2911: if (flag_draw || flag_contour) {
2912: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2913: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2914: } else vdraw = NULL;
2915: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
2916: if (flag_display) PetscCall(MatView(B, vstdout));
2917: if (vdraw) PetscCall(MatView(B, vdraw));
2918: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
2919: if (flag_display) PetscCall(MatView(Bfd, vstdout));
2920: if (vdraw) PetscCall(MatView(Bfd, vdraw));
2921: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
2922: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
2923: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
2924: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
2925: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
2926: if (flag_display) PetscCall(MatView(Bfd, vstdout));
2927: if (vdraw) { /* Always use contour for the difference */
2928: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2929: PetscCall(MatView(Bfd, vdraw));
2930: PetscCall(PetscViewerPopFormat(vdraw));
2931: }
2932: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2934: if (flag_threshold) {
2935: PetscInt bs, rstart, rend, i;
2936: PetscCall(MatGetBlockSize(B, &bs));
2937: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
2938: for (i = rstart; i < rend; i++) {
2939: const PetscScalar *ba, *ca;
2940: const PetscInt *bj, *cj;
2941: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
2942: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
2943: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
2944: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
2945: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
2946: for (j = 0; j < bn; j++) {
2947: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
2948: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
2949: maxentrycol = bj[j];
2950: maxentry = PetscRealPart(ba[j]);
2951: }
2952: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
2953: maxdiffcol = bj[j];
2954: maxdiff = PetscRealPart(ca[j]);
2955: }
2956: if (rdiff > maxrdiff) {
2957: maxrdiffcol = bj[j];
2958: maxrdiff = rdiff;
2959: }
2960: }
2961: if (maxrdiff > 1) {
2962: 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));
2963: for (j = 0; j < bn; j++) {
2964: PetscReal rdiff;
2965: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
2966: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
2967: }
2968: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
2969: }
2970: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
2971: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
2972: }
2973: }
2974: PetscCall(PetscViewerDestroy(&vdraw));
2975: PetscCall(MatDestroy(&Bfd));
2976: }
2977: }
2978: PetscFunctionReturn(PETSC_SUCCESS);
2979: }
2981: /*MC
2982: SNESJacobianFunction - Functional form used by `SNES` to compute the nonlinear Jacobian of the function to be solved by `SNES`
2984: Synopsis:
2985: #include "petscsnes.h"
2986: PetscErrorCode SNESJacobianFunction(SNES snes,Vec x,Mat Amat,Mat Pmat,void *ctx);
2988: Collective
2990: Input Parameters:
2991: + x - input vector, the Jacobian is to be computed at this value
2992: - ctx - [optional] user-defined Jacobian context
2994: Output Parameters:
2995: + Amat - the matrix that defines the (approximate) Jacobian
2996: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
2998: Level: intermediate
3000: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESSetJacobian()`, `SNESGetJacobian()`
3001: M*/
3003: /*@C
3004: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3005: location to store the matrix.
3007: Logically Collective
3009: Input Parameters:
3010: + snes - the `SNES` context
3011: . Amat - the matrix that defines the (approximate) Jacobian
3012: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3013: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFunction` for details
3014: - ctx - [optional] user-defined context for private data for the
3015: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3017: Level: beginner
3019: Notes:
3020: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3021: each matrix.
3023: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3024: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3026: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3027: must be a `MatFDColoring`.
3029: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3030: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3032: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3033: `SNESSetPicard()`, `SNESJacobianFunction`
3034: @*/
3035: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, PetscErrorCode (*J)(SNES, Vec, Mat, Mat, void *), void *ctx)
3036: {
3037: DM dm;
3039: PetscFunctionBegin;
3043: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3044: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3045: PetscCall(SNESGetDM(snes, &dm));
3046: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3047: if (Amat) {
3048: PetscCall(PetscObjectReference((PetscObject)Amat));
3049: PetscCall(MatDestroy(&snes->jacobian));
3051: snes->jacobian = Amat;
3052: }
3053: if (Pmat) {
3054: PetscCall(PetscObjectReference((PetscObject)Pmat));
3055: PetscCall(MatDestroy(&snes->jacobian_pre));
3057: snes->jacobian_pre = Pmat;
3058: }
3059: PetscFunctionReturn(PETSC_SUCCESS);
3060: }
3062: /*@C
3063: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3064: provided context for evaluating the Jacobian.
3066: Not Collective, but `Mat` object will be parallel if `SNES` is
3068: Input Parameter:
3069: . snes - the nonlinear solver context
3071: Output Parameters:
3072: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3073: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3074: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFunction`
3075: - ctx - location to stash Jacobian ctx (or `NULL`)
3077: Level: advanced
3079: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFunction`, `SNESGetFunction()`
3080: @*/
3081: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, PetscErrorCode (**J)(SNES, Vec, Mat, Mat, void *), void **ctx)
3082: {
3083: DM dm;
3085: PetscFunctionBegin;
3087: if (Amat) *Amat = snes->jacobian;
3088: if (Pmat) *Pmat = snes->jacobian_pre;
3089: PetscCall(SNESGetDM(snes, &dm));
3090: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3091: PetscFunctionReturn(PETSC_SUCCESS);
3092: }
3094: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3095: {
3096: DM dm;
3097: DMSNES sdm;
3099: PetscFunctionBegin;
3100: PetscCall(SNESGetDM(snes, &dm));
3101: PetscCall(DMGetDMSNES(dm, &sdm));
3102: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3103: DM dm;
3104: PetscBool isdense, ismf;
3106: PetscCall(SNESGetDM(snes, &dm));
3107: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3108: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3109: if (isdense) {
3110: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3111: } else if (!ismf) {
3112: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3113: }
3114: }
3115: PetscFunctionReturn(PETSC_SUCCESS);
3116: }
3118: /*@
3119: SNESSetUp - Sets up the internal data structures for the later use
3120: of a nonlinear solver.
3122: Collective
3124: Input Parameter:
3125: . snes - the `SNES` context
3127: Level: advanced
3129: Note:
3130: For basic use of the `SNES` solvers the user need not explicitly call
3131: `SNESSetUp()`, since these actions will automatically occur during
3132: the call to `SNESSolve()`. However, if one wishes to control this
3133: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3134: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3136: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`
3137: @*/
3138: PetscErrorCode SNESSetUp(SNES snes)
3139: {
3140: DM dm;
3141: DMSNES sdm;
3142: SNESLineSearch linesearch, pclinesearch;
3143: void *lsprectx, *lspostctx;
3144: PetscBool mf_operator, mf;
3145: Vec f, fpc;
3146: void *funcctx;
3147: void *jacctx, *appctx;
3148: Mat j, jpre;
3149: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3150: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3151: PetscErrorCode (*func)(SNES, Vec, Vec, void *);
3152: PetscErrorCode (*jac)(SNES, Vec, Mat, Mat, void *);
3154: PetscFunctionBegin;
3156: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3157: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3159: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3161: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3163: PetscCall(SNESGetDM(snes, &dm));
3164: PetscCall(DMGetDMSNES(dm, &sdm));
3165: PetscCall(SNESSetDefaultComputeJacobian(snes));
3167: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3169: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3171: if (snes->linesearch) {
3172: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3173: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3174: }
3176: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3177: if (snes->npc && snes->npcside == PC_LEFT) {
3178: snes->mf = PETSC_TRUE;
3179: snes->mf_operator = PETSC_FALSE;
3180: }
3182: if (snes->npc) {
3183: /* copy the DM over */
3184: PetscCall(SNESGetDM(snes, &dm));
3185: PetscCall(SNESSetDM(snes->npc, dm));
3187: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3188: PetscCall(VecDuplicate(f, &fpc));
3189: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3190: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3191: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3192: PetscCall(SNESGetApplicationContext(snes, &appctx));
3193: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3194: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3195: PetscCall(VecDestroy(&fpc));
3197: /* copy the function pointers over */
3198: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3200: /* default to 1 iteration */
3201: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3202: if (snes->npcside == PC_RIGHT) {
3203: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3204: } else {
3205: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3206: }
3207: PetscCall(SNESSetFromOptions(snes->npc));
3209: /* copy the line search context over */
3210: if (snes->linesearch && snes->npc->linesearch) {
3211: PetscCall(SNESGetLineSearch(snes, &linesearch));
3212: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3213: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3214: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3215: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3216: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3217: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3218: }
3219: }
3220: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3221: if (snes->ops->usercompute && !snes->user) PetscCall((*snes->ops->usercompute)(snes, (void **)&snes->user));
3223: snes->jac_iter = 0;
3224: snes->pre_iter = 0;
3226: PetscTryTypeMethod(snes, setup);
3228: PetscCall(SNESSetDefaultComputeJacobian(snes));
3230: if (snes->npc && snes->npcside == PC_LEFT) {
3231: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3232: if (snes->linesearch) {
3233: PetscCall(SNESGetLineSearch(snes, &linesearch));
3234: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3235: }
3236: }
3237: }
3238: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3239: snes->setupcalled = PETSC_TRUE;
3240: PetscFunctionReturn(PETSC_SUCCESS);
3241: }
3243: /*@
3244: SNESReset - Resets a `SNES` context to the snessetupcalled = 0 state and removes any allocated `Vec`s and `Mat`s
3246: Collective
3248: Input Parameter:
3249: . snes - iterative context obtained from `SNESCreate()`
3251: Level: intermediate
3253: Notes:
3254: Call this if you wish to reuse a `SNES` but with different size vectors
3256: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3258: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3259: @*/
3260: PetscErrorCode SNESReset(SNES snes)
3261: {
3262: PetscFunctionBegin;
3264: if (snes->ops->userdestroy && snes->user) {
3265: PetscCall((*snes->ops->userdestroy)((void **)&snes->user));
3266: snes->user = NULL;
3267: }
3268: if (snes->npc) PetscCall(SNESReset(snes->npc));
3270: PetscTryTypeMethod(snes, reset);
3271: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3273: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3275: PetscCall(VecDestroy(&snes->vec_rhs));
3276: PetscCall(VecDestroy(&snes->vec_sol));
3277: PetscCall(VecDestroy(&snes->vec_sol_update));
3278: PetscCall(VecDestroy(&snes->vec_func));
3279: PetscCall(MatDestroy(&snes->jacobian));
3280: PetscCall(MatDestroy(&snes->jacobian_pre));
3281: PetscCall(MatDestroy(&snes->picard));
3282: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3283: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3285: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3287: snes->nwork = snes->nvwork = 0;
3288: snes->setupcalled = PETSC_FALSE;
3289: PetscFunctionReturn(PETSC_SUCCESS);
3290: }
3292: /*@
3293: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()`
3295: Collective
3297: Input Parameter:
3298: . snes - iterative context obtained from `SNESCreate()`
3300: Level: intermediate
3302: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3303: @*/
3304: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3305: {
3306: PetscInt i;
3308: PetscFunctionBegin;
3310: for (i = 0; i < snes->numberreasonviews; i++) {
3311: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3312: }
3313: snes->numberreasonviews = 0;
3314: PetscFunctionReturn(PETSC_SUCCESS);
3315: }
3317: /*@C
3318: SNESDestroy - Destroys the nonlinear solver context that was created
3319: with `SNESCreate()`.
3321: Collective
3323: Input Parameter:
3324: . snes - the `SNES` context
3326: Level: beginner
3328: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3329: @*/
3330: PetscErrorCode SNESDestroy(SNES *snes)
3331: {
3332: PetscFunctionBegin;
3333: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3335: if (--((PetscObject)(*snes))->refct > 0) {
3336: *snes = NULL;
3337: PetscFunctionReturn(PETSC_SUCCESS);
3338: }
3340: PetscCall(SNESReset((*snes)));
3341: PetscCall(SNESDestroy(&(*snes)->npc));
3343: /* if memory was published with SAWs then destroy it */
3344: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3345: PetscTryTypeMethod((*snes), destroy);
3347: if ((*snes)->dm) PetscCall(DMCoarsenHookRemove((*snes)->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3348: PetscCall(DMDestroy(&(*snes)->dm));
3349: PetscCall(KSPDestroy(&(*snes)->ksp));
3350: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3352: PetscCall(PetscFree((*snes)->kspconvctx));
3353: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)((*snes)->cnvP));
3354: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3355: PetscCall(SNESMonitorCancel((*snes)));
3356: PetscCall(SNESConvergedReasonViewCancel((*snes)));
3357: PetscCall(PetscHeaderDestroy(snes));
3358: PetscFunctionReturn(PETSC_SUCCESS);
3359: }
3361: /* ----------- Routines to set solver parameters ---------- */
3363: /*@
3364: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3366: Logically Collective
3368: Input Parameters:
3369: + snes - the `SNES` context
3370: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3371: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3373: Options Database Keys:
3374: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3375: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3376: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3377: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3379: Level: intermediate
3381: Notes:
3382: The default is 1
3384: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3386: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3388: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3389: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3390: @*/
3391: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3392: {
3393: PetscFunctionBegin;
3395: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3396: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3398: snes->lagpreconditioner = lag;
3399: PetscFunctionReturn(PETSC_SUCCESS);
3400: }
3402: /*@
3403: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3405: Logically Collective
3407: Input Parameters:
3408: + snes - the `SNES` context
3409: - steps - the number of refinements to do, defaults to 0
3411: Options Database Key:
3412: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3414: Level: intermediate
3416: Note:
3417: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3419: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3420: `SNESetDM()`
3421: @*/
3422: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3423: {
3424: PetscFunctionBegin;
3427: snes->gridsequence = steps;
3428: PetscFunctionReturn(PETSC_SUCCESS);
3429: }
3431: /*@
3432: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3434: Logically Collective
3436: Input Parameter:
3437: . snes - the `SNES` context
3439: Output Parameter:
3440: . steps - the number of refinements to do, defaults to 0
3442: Level: intermediate
3444: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3445: @*/
3446: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3447: {
3448: PetscFunctionBegin;
3450: *steps = snes->gridsequence;
3451: PetscFunctionReturn(PETSC_SUCCESS);
3452: }
3454: /*@
3455: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3457: Not Collective
3459: Input Parameter:
3460: . snes - the `SNES` context
3462: Output Parameter:
3463: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3464: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3466: Level: intermediate
3468: Notes:
3469: The default is 1
3471: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3473: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3474: @*/
3475: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3476: {
3477: PetscFunctionBegin;
3479: *lag = snes->lagpreconditioner;
3480: PetscFunctionReturn(PETSC_SUCCESS);
3481: }
3483: /*@
3484: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3485: often the preconditioner is rebuilt.
3487: Logically Collective
3489: Input Parameters:
3490: + snes - the `SNES` context
3491: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3492: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3494: Options Database Keys:
3495: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3496: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3497: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3498: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3500: Level: intermediate
3502: Notes:
3503: The default is 1
3505: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3507: 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
3508: at the next Newton step but never again (unless it is reset to another value)
3510: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3511: @*/
3512: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3513: {
3514: PetscFunctionBegin;
3516: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3517: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3519: snes->lagjacobian = lag;
3520: PetscFunctionReturn(PETSC_SUCCESS);
3521: }
3523: /*@
3524: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3526: Not Collective
3528: Input Parameter:
3529: . snes - the `SNES` context
3531: Output Parameter:
3532: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3533: the Jacobian is built etc.
3535: Level: intermediate
3537: Notes:
3538: The default is 1
3540: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3542: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3544: @*/
3545: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3546: {
3547: PetscFunctionBegin;
3549: *lag = snes->lagjacobian;
3550: PetscFunctionReturn(PETSC_SUCCESS);
3551: }
3553: /*@
3554: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3556: Logically collective
3558: Input Parameters:
3559: + snes - the `SNES` context
3560: - flg - jacobian lagging persists if true
3562: Options Database Keys:
3563: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3564: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3565: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3566: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3568: Level: advanced
3570: Notes:
3571: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3573: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3574: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3575: timesteps may present huge efficiency gains.
3577: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3578: @*/
3579: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3580: {
3581: PetscFunctionBegin;
3584: snes->lagjac_persist = flg;
3585: PetscFunctionReturn(PETSC_SUCCESS);
3586: }
3588: /*@
3589: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3591: Logically Collective
3593: Input Parameters:
3594: + snes - the `SNES` context
3595: - flg - preconditioner lagging persists if true
3597: Options Database Keys:
3598: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3599: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3600: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3601: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3603: Level: developer
3605: Notes:
3606: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3608: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3609: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3610: several timesteps may present huge efficiency gains.
3612: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3613: @*/
3614: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3615: {
3616: PetscFunctionBegin;
3619: snes->lagpre_persist = flg;
3620: PetscFunctionReturn(PETSC_SUCCESS);
3621: }
3623: /*@
3624: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3626: Logically Collective
3628: Input Parameters:
3629: + snes - the `SNES` context
3630: - force - `PETSC_TRUE` require at least one iteration
3632: Options Database Key:
3633: . -snes_force_iteration <force> - Sets forcing an iteration
3635: Level: intermediate
3637: Note:
3638: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3640: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3641: @*/
3642: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3643: {
3644: PetscFunctionBegin;
3646: snes->forceiteration = force;
3647: PetscFunctionReturn(PETSC_SUCCESS);
3648: }
3650: /*@
3651: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3653: Logically Collective
3655: Input Parameter:
3656: . snes - the `SNES` context
3658: Output Parameter:
3659: . force - `PETSC_TRUE` requires at least one iteration.
3661: Level: intermediate
3663: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3664: @*/
3665: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3666: {
3667: PetscFunctionBegin;
3669: *force = snes->forceiteration;
3670: PetscFunctionReturn(PETSC_SUCCESS);
3671: }
3673: /*@
3674: SNESSetTolerances - Sets `SNES` various parameters used in convergence tests.
3676: Logically Collective
3678: Input Parameters:
3679: + snes - the `SNES` context
3680: . abstol - absolute convergence tolerance
3681: . rtol - relative convergence tolerance
3682: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3683: . maxit - maximum number of iterations, default 50.
3684: - maxf - maximum number of function evaluations (-1 indicates no limit), default 1000
3686: Options Database Keys:
3687: + -snes_atol <abstol> - Sets abstol
3688: . -snes_rtol <rtol> - Sets rtol
3689: . -snes_stol <stol> - Sets stol
3690: . -snes_max_it <maxit> - Sets maxit
3691: - -snes_max_funcs <maxf> - Sets maxf
3693: Level: intermediate
3695: .seealso: [](ch_snes), `SNESSolve()`, `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3696: @*/
3697: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3698: {
3699: PetscFunctionBegin;
3707: if (abstol != (PetscReal)PETSC_DEFAULT) {
3708: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3709: snes->abstol = abstol;
3710: }
3711: if (rtol != (PetscReal)PETSC_DEFAULT) {
3712: 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);
3713: snes->rtol = rtol;
3714: }
3715: if (stol != (PetscReal)PETSC_DEFAULT) {
3716: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3717: snes->stol = stol;
3718: }
3719: if (maxit != PETSC_DEFAULT) {
3720: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3721: snes->max_its = maxit;
3722: }
3723: if (maxf != PETSC_DEFAULT) {
3724: PetscCheck(maxf >= -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be -1 or nonnegative", maxf);
3725: snes->max_funcs = maxf;
3726: }
3727: snes->tolerancesset = PETSC_TRUE;
3728: PetscFunctionReturn(PETSC_SUCCESS);
3729: }
3731: /*@
3732: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3734: Logically Collective
3736: Input Parameters:
3737: + snes - the `SNES` context
3738: - divtol - the divergence tolerance. Use -1 to deactivate the test, default is 1e4
3740: Options Database Key:
3741: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3743: Level: intermediate
3745: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance`
3746: @*/
3747: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3748: {
3749: PetscFunctionBegin;
3753: if (divtol != (PetscReal)PETSC_DEFAULT) {
3754: snes->divtol = divtol;
3755: } else {
3756: snes->divtol = 1.0e4;
3757: }
3758: PetscFunctionReturn(PETSC_SUCCESS);
3759: }
3761: /*@
3762: SNESGetTolerances - Gets various parameters used in convergence tests.
3764: Not Collective
3766: Input Parameters:
3767: + snes - the `SNES` context
3768: . atol - absolute convergence tolerance
3769: . rtol - relative convergence tolerance
3770: . stol - convergence tolerance in terms of the norm
3771: of the change in the solution between steps
3772: . maxit - maximum number of iterations
3773: - maxf - maximum number of function evaluations
3775: Level: intermediate
3777: Note:
3778: The user can specify `NULL` for any parameter that is not needed.
3780: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
3781: @*/
3782: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
3783: {
3784: PetscFunctionBegin;
3786: if (atol) *atol = snes->abstol;
3787: if (rtol) *rtol = snes->rtol;
3788: if (stol) *stol = snes->stol;
3789: if (maxit) *maxit = snes->max_its;
3790: if (maxf) *maxf = snes->max_funcs;
3791: PetscFunctionReturn(PETSC_SUCCESS);
3792: }
3794: /*@
3795: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3797: Not Collective
3799: Input Parameters:
3800: + snes - the `SNES` context
3801: - divtol - divergence tolerance
3803: Level: intermediate
3805: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
3806: @*/
3807: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
3808: {
3809: PetscFunctionBegin;
3811: if (divtol) *divtol = snes->divtol;
3812: PetscFunctionReturn(PETSC_SUCCESS);
3813: }
3815: /*@
3816: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3818: Logically Collective
3820: Input Parameters:
3821: + snes - the `SNES` context
3822: - tol - tolerance
3824: Options Database Key:
3825: . -snes_tr_tol <tol> - Sets tol
3827: Level: intermediate
3829: .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`, `SNESSetTolerances()`
3830: @*/
3831: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes, PetscReal tol)
3832: {
3833: PetscFunctionBegin;
3836: snes->deltatol = tol;
3837: PetscFunctionReturn(PETSC_SUCCESS);
3838: }
3840: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
3842: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
3843: {
3844: PetscDrawLG lg;
3845: PetscReal x, y, per;
3846: PetscViewer v = (PetscViewer)monctx;
3847: static PetscReal prev; /* should be in the context */
3848: PetscDraw draw;
3850: PetscFunctionBegin;
3852: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
3853: if (!n) PetscCall(PetscDrawLGReset(lg));
3854: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3855: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
3856: x = (PetscReal)n;
3857: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3858: else y = -15.0;
3859: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3860: if (n < 20 || !(n % 5) || snes->reason) {
3861: PetscCall(PetscDrawLGDraw(lg));
3862: PetscCall(PetscDrawLGSave(lg));
3863: }
3865: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
3866: if (!n) PetscCall(PetscDrawLGReset(lg));
3867: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3868: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
3869: PetscCall(SNESMonitorRange_Private(snes, n, &per));
3870: x = (PetscReal)n;
3871: y = 100.0 * per;
3872: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3873: if (n < 20 || !(n % 5) || snes->reason) {
3874: PetscCall(PetscDrawLGDraw(lg));
3875: PetscCall(PetscDrawLGSave(lg));
3876: }
3878: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
3879: if (!n) {
3880: prev = rnorm;
3881: PetscCall(PetscDrawLGReset(lg));
3882: }
3883: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3884: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
3885: x = (PetscReal)n;
3886: y = (prev - rnorm) / prev;
3887: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3888: if (n < 20 || !(n % 5) || snes->reason) {
3889: PetscCall(PetscDrawLGDraw(lg));
3890: PetscCall(PetscDrawLGSave(lg));
3891: }
3893: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
3894: if (!n) PetscCall(PetscDrawLGReset(lg));
3895: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3896: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
3897: x = (PetscReal)n;
3898: y = (prev - rnorm) / (prev * per);
3899: if (n > 2) { /*skip initial crazy value */
3900: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3901: }
3902: if (n < 20 || !(n % 5) || snes->reason) {
3903: PetscCall(PetscDrawLGDraw(lg));
3904: PetscCall(PetscDrawLGSave(lg));
3905: }
3906: prev = rnorm;
3907: PetscFunctionReturn(PETSC_SUCCESS);
3908: }
3910: /*@
3911: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
3913: Collective
3915: Input Parameters:
3916: + snes - the `SNES` context
3917: . it - current iteration
3918: . xnorm - 2-norm of current iterate
3919: . snorm - 2-norm of current step
3920: - fnorm - 2-norm of function
3922: Level: developer
3924: Note:
3925: This routine is called by the `SNESSolve()` implementations.
3926: It does not typically need to be called by the user.
3928: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
3929: @*/
3930: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
3931: {
3932: PetscFunctionBegin;
3933: if (!snes->reason) {
3934: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
3935: if (it == snes->max_its && !snes->reason) {
3936: if (snes->normschedule == SNES_NORM_ALWAYS) {
3937: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
3938: snes->reason = SNES_DIVERGED_MAX_IT;
3939: } else snes->reason = SNES_CONVERGED_ITS;
3940: }
3941: }
3942: PetscFunctionReturn(PETSC_SUCCESS);
3943: }
3945: /*@
3946: SNESMonitor - runs the user provided monitor routines, if they exist
3948: Collective
3950: Input Parameters:
3951: + snes - nonlinear solver context obtained from `SNESCreate()`
3952: . iter - iteration number
3953: - rnorm - relative norm of the residual
3955: Level: developer
3957: Note:
3958: This routine is called by the `SNESSolve()` implementations.
3959: It does not typically need to be called by the user.
3961: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
3962: @*/
3963: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
3964: {
3965: PetscInt i, n = snes->numbermonitors;
3967: PetscFunctionBegin;
3968: if (n > 0) SNESCheckFunctionNorm(snes, rnorm);
3969: PetscCall(VecLockReadPush(snes->vec_sol));
3970: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
3971: PetscCall(VecLockReadPop(snes->vec_sol));
3972: PetscFunctionReturn(PETSC_SUCCESS);
3973: }
3975: /* ------------ Routines to set performance monitoring options ----------- */
3977: /*MC
3978: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
3980: Synopsis:
3981: #include <petscsnes.h>
3982: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, void *mctx)
3984: Collective
3986: Input Parameters:
3987: + snes - the `SNES` context
3988: . its - iteration number
3989: . norm - 2-norm function value (may be estimated)
3990: - mctx - [optional] monitoring context
3992: Level: advanced
3994: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSet()`, `SNESMonitorGet()`
3995: M*/
3997: /*@C
3998: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
3999: iteration of the nonlinear solver to display the iteration's
4000: progress.
4002: Logically Collective
4004: Input Parameters:
4005: + snes - the `SNES` context
4006: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4007: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4008: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`)
4010: Options Database Keys:
4011: + -snes_monitor - sets `SNESMonitorDefault()`
4012: . -snes_monitor draw::draw_lg - sets line graph monitor,
4013: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4014: the options database.
4016: Level: intermediate
4018: Note:
4019: Several different monitoring routines may be set by calling
4020: `SNESMonitorSet()` multiple times; all will be called in the
4021: order in which they were set.
4023: Fortran Note:
4024: Only a single monitor function can be set for each `SNES` object
4026: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`
4027: @*/
4028: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscErrorCode (*monitordestroy)(void **))
4029: {
4030: PetscInt i;
4031: PetscBool identical;
4033: PetscFunctionBegin;
4035: for (i = 0; i < snes->numbermonitors; i++) {
4036: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, mctx, monitordestroy, (PetscErrorCode(*)(void))snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4037: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4038: }
4039: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4040: snes->monitor[snes->numbermonitors] = f;
4041: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4042: snes->monitorcontext[snes->numbermonitors++] = (void *)mctx;
4043: PetscFunctionReturn(PETSC_SUCCESS);
4044: }
4046: /*@
4047: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4049: Logically Collective
4051: Input Parameter:
4052: . snes - the `SNES` context
4054: Options Database Key:
4055: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4056: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4057: set via the options database
4059: Level: intermediate
4061: Note:
4062: There is no way to clear one specific monitor from a `SNES` object.
4064: .seealso: [](ch_snes), `SNES`, `SNESMonitorGet()`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4065: @*/
4066: PetscErrorCode SNESMonitorCancel(SNES snes)
4067: {
4068: PetscInt i;
4070: PetscFunctionBegin;
4072: for (i = 0; i < snes->numbermonitors; i++) {
4073: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4074: }
4075: snes->numbermonitors = 0;
4076: PetscFunctionReturn(PETSC_SUCCESS);
4077: }
4079: /*MC
4080: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4082: Synopsis:
4083: #include <petscsnes.h>
4084: PetscErrorCode SNESConvergenceTest(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *cctx)
4086: Collective
4088: Input Parameters:
4089: + snes - the `SNES` context
4090: . it - current iteration (0 is the first and is before any Newton step)
4091: . xnorm - 2-norm of current iterate
4092: . gnorm - 2-norm of current step
4093: . f - 2-norm of function
4094: - cctx - [optional] convergence context
4096: Output Parameter:
4097: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4099: Level: intermediate
4101: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4102: M*/
4104: /*@C
4105: SNESSetConvergenceTest - Sets the function that is to be used
4106: to test for convergence of the nonlinear iterative solution.
4108: Logically Collective
4110: Input Parameters:
4111: + snes - the `SNES` context
4112: . SNESConvergenceTestFunction - routine to test for convergence
4113: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4114: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4116: Level: advanced
4118: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4119: @*/
4120: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscErrorCode (*destroy)(void *))
4121: {
4122: PetscFunctionBegin;
4124: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4125: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(snes->cnvP));
4126: snes->ops->converged = SNESConvergenceTestFunction;
4127: snes->ops->convergeddestroy = destroy;
4128: snes->cnvP = cctx;
4129: PetscFunctionReturn(PETSC_SUCCESS);
4130: }
4132: /*@
4133: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped.
4135: Not Collective
4137: Input Parameter:
4138: . snes - the `SNES` context
4140: Output Parameter:
4141: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4143: Options Database Key:
4144: . -snes_converged_reason - prints the reason to standard out
4146: Level: intermediate
4148: Note:
4149: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4151: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4152: @*/
4153: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4154: {
4155: PetscFunctionBegin;
4157: PetscAssertPointer(reason, 2);
4158: *reason = snes->reason;
4159: PetscFunctionReturn(PETSC_SUCCESS);
4160: }
4162: /*@C
4163: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4165: Not Collective
4167: Input Parameter:
4168: . snes - the `SNES` context
4170: Output Parameter:
4171: . strreason - a human readable string that describes `SNES` converged reason
4173: Level: beginner
4175: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4176: @*/
4177: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4178: {
4179: PetscFunctionBegin;
4181: PetscAssertPointer(strreason, 2);
4182: *strreason = SNESConvergedReasons[snes->reason];
4183: PetscFunctionReturn(PETSC_SUCCESS);
4184: }
4186: /*@
4187: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4189: Not Collective
4191: Input Parameters:
4192: + snes - the `SNES` context
4193: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4194: manual pages for the individual convergence tests for complete lists
4196: Level: developer
4198: Developer Note:
4199: Called inside the various `SNESSolve()` implementations
4201: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4202: @*/
4203: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4204: {
4205: PetscFunctionBegin;
4207: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4208: snes->reason = reason;
4209: PetscFunctionReturn(PETSC_SUCCESS);
4210: }
4212: /*@
4213: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4215: Logically Collective
4217: Input Parameters:
4218: + snes - iterative context obtained from `SNESCreate()`
4219: . a - array to hold history, this array will contain the function norms computed at each step
4220: . its - integer array holds the number of linear iterations for each solve.
4221: . na - size of `a` and `its`
4222: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4223: else it continues storing new values for new nonlinear solves after the old ones
4225: Level: intermediate
4227: Notes:
4228: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' `PETSC_DECIDE` or `PETSC_DEFAULT` then a
4229: default array of length 10000 is allocated.
4231: This routine is useful, e.g., when running a code for purposes
4232: of accurate performance monitoring, when no I/O should be done
4233: during the section of code that is being timed.
4235: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4237: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4238: @*/
4239: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4240: {
4241: PetscFunctionBegin;
4243: if (a) PetscAssertPointer(a, 2);
4244: if (its) PetscAssertPointer(its, 3);
4245: if (!a) {
4246: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4247: PetscCall(PetscCalloc2(na, &a, na, &its));
4248: snes->conv_hist_alloc = PETSC_TRUE;
4249: }
4250: snes->conv_hist = a;
4251: snes->conv_hist_its = its;
4252: snes->conv_hist_max = (size_t)na;
4253: snes->conv_hist_len = 0;
4254: snes->conv_hist_reset = reset;
4255: PetscFunctionReturn(PETSC_SUCCESS);
4256: }
4258: #if defined(PETSC_HAVE_MATLAB)
4259: #include <engine.h> /* MATLAB include file */
4260: #include <mex.h> /* MATLAB include file */
4262: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4263: {
4264: mxArray *mat;
4265: PetscInt i;
4266: PetscReal *ar;
4268: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4269: ar = (PetscReal *)mxGetData(mat);
4270: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4271: return mat;
4272: }
4273: #endif
4275: /*@C
4276: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4278: Not Collective
4280: Input Parameter:
4281: . snes - iterative context obtained from `SNESCreate()`
4283: Output Parameters:
4284: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4285: . its - integer array holds the number of linear iterations (or
4286: negative if not converged) for each solve.
4287: - na - size of `a` and `its`
4289: Level: intermediate
4291: Note:
4292: This routine is useful, e.g., when running a code for purposes
4293: of accurate performance monitoring, when no I/O should be done
4294: during the section of code that is being timed.
4296: Fortran Note:
4297: The calling sequence for this routine in Fortran is
4298: .vb
4299: call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4300: .ve
4302: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4303: @*/
4304: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4305: {
4306: PetscFunctionBegin;
4308: if (a) *a = snes->conv_hist;
4309: if (its) *its = snes->conv_hist_its;
4310: if (na) *na = (PetscInt)snes->conv_hist_len;
4311: PetscFunctionReturn(PETSC_SUCCESS);
4312: }
4314: /*@C
4315: SNESSetUpdate - Sets the general-purpose update function called
4316: at the beginning of every iteration of the nonlinear solve. Specifically
4317: it is called just before the Jacobian is "evaluated".
4319: Logically Collective
4321: Input Parameters:
4322: + snes - The nonlinear solver context
4323: - func - The function
4325: Calling sequence of `func`:
4326: + snes - the nonlinear solver context
4327: - step - The current step of the iteration
4329: Level: advanced
4331: Notes:
4332: 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
4333: to `SNESSetFunction()`, or `SNESSetPicard()`
4334: This is not used by most users.
4336: 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.
4338: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4339: `SNESMonitorSet()`, `SNESSetDivergenceTest()`
4340: @*/
4341: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES snes, PetscInt step))
4342: {
4343: PetscFunctionBegin;
4345: snes->ops->update = func;
4346: PetscFunctionReturn(PETSC_SUCCESS);
4347: }
4349: /*@C
4350: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4352: Collective
4354: Input Parameters:
4355: + snes - iterative context obtained from `SNESCreate()`
4356: - viewer - the viewer to display the reason
4358: Options Database Keys:
4359: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4360: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4362: Level: beginner
4364: Note:
4365: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4366: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4368: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4369: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4370: `SNESConvergedReasonViewFromOptions()`,
4371: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4372: @*/
4373: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4374: {
4375: PetscViewerFormat format;
4376: PetscBool isAscii;
4378: PetscFunctionBegin;
4379: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4380: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4381: if (isAscii) {
4382: PetscCall(PetscViewerGetFormat(viewer, &format));
4383: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
4384: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4385: DM dm;
4386: Vec u;
4387: PetscDS prob;
4388: PetscInt Nf, f;
4389: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4390: void **exactCtx;
4391: PetscReal error;
4393: PetscCall(SNESGetDM(snes, &dm));
4394: PetscCall(SNESGetSolution(snes, &u));
4395: PetscCall(DMGetDS(dm, &prob));
4396: PetscCall(PetscDSGetNumFields(prob, &Nf));
4397: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4398: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4399: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4400: PetscCall(PetscFree2(exactSol, exactCtx));
4401: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4402: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4403: }
4404: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4405: if (((PetscObject)snes)->prefix) {
4406: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4407: } else {
4408: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4409: }
4410: } else if (snes->reason <= 0) {
4411: if (((PetscObject)snes)->prefix) {
4412: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4413: } else {
4414: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4415: }
4416: }
4417: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
4418: }
4419: PetscFunctionReturn(PETSC_SUCCESS);
4420: }
4422: /*@C
4423: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4424: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4426: Logically Collective
4428: Input Parameters:
4429: + snes - the `SNES` context
4430: . f - the `SNESConvergedReason` view function
4431: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4432: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`)
4434: Calling sequence of `f`:
4435: + snes - the `SNES` context
4436: - vctx - [optional] user-defined context for private data for the function
4438: Calling sequence of `reasonviewerdestroy`:
4439: . vctx - [optional] user-defined context for private data for the function
4441: Options Database Keys:
4442: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4443: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4444: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4446: Level: intermediate
4448: Note:
4449: Several different converged reason view routines may be set by calling
4450: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4451: order in which they were set.
4453: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`
4454: @*/
4455: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, void *vctx), void *vctx, PetscErrorCode (*reasonviewdestroy)(void **vctx))
4456: {
4457: PetscInt i;
4458: PetscBool identical;
4460: PetscFunctionBegin;
4462: for (i = 0; i < snes->numberreasonviews; i++) {
4463: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, vctx, reasonviewdestroy, (PetscErrorCode(*)(void))snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4464: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4465: }
4466: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4467: snes->reasonview[snes->numberreasonviews] = f;
4468: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4469: snes->reasonviewcontext[snes->numberreasonviews++] = (void *)vctx;
4470: PetscFunctionReturn(PETSC_SUCCESS);
4471: }
4473: /*@
4474: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4475: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4477: Collective
4479: Input Parameter:
4480: . snes - the `SNES` object
4482: Level: advanced
4484: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4485: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4486: @*/
4487: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4488: {
4489: PetscViewer viewer;
4490: PetscBool flg;
4491: static PetscBool incall = PETSC_FALSE;
4492: PetscViewerFormat format;
4493: PetscInt i;
4495: PetscFunctionBegin;
4496: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4497: incall = PETSC_TRUE;
4499: /* All user-provided viewers are called first, if they exist. */
4500: for (i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4502: /* Call PETSc default routine if users ask for it */
4503: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &viewer, &format, &flg));
4504: if (flg) {
4505: PetscCall(PetscViewerPushFormat(viewer, format));
4506: PetscCall(SNESConvergedReasonView(snes, viewer));
4507: PetscCall(PetscViewerPopFormat(viewer));
4508: PetscCall(PetscViewerDestroy(&viewer));
4509: }
4510: incall = PETSC_FALSE;
4511: PetscFunctionReturn(PETSC_SUCCESS);
4512: }
4514: /*@
4515: SNESSolve - Solves a nonlinear system F(x) = b.
4517: Collective
4519: Input Parameters:
4520: + snes - the `SNES` context
4521: . b - the constant part of the equation F(x) = b, or `NULL` to use zero.
4522: - x - the solution vector.
4524: Level: beginner
4526: Note:
4527: The user should initialize the vector, `x`, with the initial guess
4528: for the nonlinear solve prior to calling `SNESSolve()` or use `SNESSetInitialSolution()`. In particular,
4529: to employ an initial guess of zero, the user should explicitly set
4530: this vector to zero by calling `VecSet()`.
4532: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4533: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4534: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`, `SNESSetInitialSolution()`
4535: @*/
4536: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4537: {
4538: PetscBool flg;
4539: PetscInt grid;
4540: Vec xcreated = NULL;
4541: DM dm;
4543: PetscFunctionBegin;
4546: if (x) PetscCheckSameComm(snes, 1, x, 3);
4548: if (b) PetscCheckSameComm(snes, 1, b, 2);
4550: /* High level operations using the nonlinear solver */
4551: {
4552: PetscViewer viewer;
4553: PetscViewerFormat format;
4554: PetscInt num;
4555: PetscBool flg;
4556: static PetscBool incall = PETSC_FALSE;
4558: if (!incall) {
4559: /* Estimate the convergence rate of the discretization */
4560: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4561: if (flg) {
4562: PetscConvEst conv;
4563: DM dm;
4564: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4565: PetscInt Nf;
4567: incall = PETSC_TRUE;
4568: PetscCall(SNESGetDM(snes, &dm));
4569: PetscCall(DMGetNumFields(dm, &Nf));
4570: PetscCall(PetscCalloc1(Nf, &alpha));
4571: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4572: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4573: PetscCall(PetscConvEstSetFromOptions(conv));
4574: PetscCall(PetscConvEstSetUp(conv));
4575: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4576: PetscCall(PetscViewerPushFormat(viewer, format));
4577: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4578: PetscCall(PetscViewerPopFormat(viewer));
4579: PetscCall(PetscViewerDestroy(&viewer));
4580: PetscCall(PetscConvEstDestroy(&conv));
4581: PetscCall(PetscFree(alpha));
4582: incall = PETSC_FALSE;
4583: }
4584: /* Adaptively refine the initial grid */
4585: num = 1;
4586: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4587: if (flg) {
4588: DMAdaptor adaptor;
4590: incall = PETSC_TRUE;
4591: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4592: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4593: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4594: PetscCall(DMAdaptorSetFromOptions(adaptor));
4595: PetscCall(DMAdaptorSetUp(adaptor));
4596: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4597: PetscCall(DMAdaptorDestroy(&adaptor));
4598: incall = PETSC_FALSE;
4599: }
4600: /* Use grid sequencing to adapt */
4601: num = 0;
4602: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4603: if (num) {
4604: DMAdaptor adaptor;
4606: incall = PETSC_TRUE;
4607: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4608: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4609: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4610: PetscCall(DMAdaptorSetFromOptions(adaptor));
4611: PetscCall(DMAdaptorSetUp(adaptor));
4612: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4613: PetscCall(DMAdaptorDestroy(&adaptor));
4614: incall = PETSC_FALSE;
4615: }
4616: }
4617: }
4618: if (!x) x = snes->vec_sol;
4619: if (!x) {
4620: PetscCall(SNESGetDM(snes, &dm));
4621: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4622: x = xcreated;
4623: }
4624: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4626: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4627: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4628: /* set solution vector */
4629: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4630: PetscCall(VecDestroy(&snes->vec_sol));
4631: snes->vec_sol = x;
4632: PetscCall(SNESGetDM(snes, &dm));
4634: /* set affine vector if provided */
4635: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4636: PetscCall(VecDestroy(&snes->vec_rhs));
4637: snes->vec_rhs = b;
4639: 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");
4640: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4641: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right hand side vector");
4642: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4643: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4644: PetscCall(SNESSetUp(snes));
4646: if (!grid) {
4647: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4648: }
4650: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4651: if (snes->counters_reset) {
4652: snes->nfuncs = 0;
4653: snes->linear_its = 0;
4654: snes->numFailures = 0;
4655: }
4657: snes->reason = SNES_CONVERGED_ITERATING;
4658: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4659: PetscUseTypeMethod(snes, solve);
4660: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4661: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4662: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4664: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4665: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4667: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4668: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4669: /* Call converged reason views. This may involve user-provided viewers as well */
4670: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4672: if (snes->errorifnotconverged) PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4673: if (snes->reason < 0) break;
4674: if (grid < snes->gridsequence) {
4675: DM fine;
4676: Vec xnew;
4677: Mat interp;
4679: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4680: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4681: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4682: PetscCall(DMCreateGlobalVector(fine, &xnew));
4683: PetscCall(MatInterpolate(interp, x, xnew));
4684: PetscCall(DMInterpolate(snes->dm, interp, fine));
4685: PetscCall(MatDestroy(&interp));
4686: x = xnew;
4688: PetscCall(SNESReset(snes));
4689: PetscCall(SNESSetDM(snes, fine));
4690: PetscCall(SNESResetFromOptions(snes));
4691: PetscCall(DMDestroy(&fine));
4692: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4693: }
4694: }
4695: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4696: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4697: PetscCall(DMMonitor(snes->dm));
4698: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4700: PetscCall(VecDestroy(&xcreated));
4701: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4702: PetscFunctionReturn(PETSC_SUCCESS);
4703: }
4705: /* --------- Internal routines for SNES Package --------- */
4707: /*@C
4708: SNESSetType - Sets the method for the nonlinear solver.
4710: Collective
4712: Input Parameters:
4713: + snes - the `SNES` context
4714: - type - a known method
4716: Options Database Key:
4717: . -snes_type <type> - Sets the method; use -help for a list
4718: of available methods (for instance, newtonls or newtontr)
4720: Level: intermediate
4722: Notes:
4723: See "petsc/include/petscsnes.h" for available methods (for instance)
4724: + `SNESNEWTONLS` - Newton's method with line search
4725: (systems of nonlinear equations)
4726: - `SNESNEWTONTR` - Newton's method with trust region
4727: (systems of nonlinear equations)
4729: Normally, it is best to use the `SNESSetFromOptions()` command and then
4730: set the `SNES` solver type from the options database rather than by using
4731: this routine. Using the options database provides the user with
4732: maximum flexibility in evaluating the many nonlinear solvers.
4733: The `SNESSetType()` routine is provided for those situations where it
4734: is necessary to set the nonlinear solver independently of the command
4735: line or options database. This might be the case, for example, when
4736: the choice of solver changes during the execution of the program,
4737: and the user's application is taking responsibility for choosing the
4738: appropriate method.
4740: Developer Note:
4741: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4742: the constructor in that list and calls it to create the specific object.
4744: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4745: @*/
4746: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4747: {
4748: PetscBool match;
4749: PetscErrorCode (*r)(SNES);
4751: PetscFunctionBegin;
4753: PetscAssertPointer(type, 2);
4755: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4756: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4758: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4759: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4760: /* Destroy the previous private SNES context */
4761: PetscTryTypeMethod(snes, destroy);
4762: /* Reinitialize function pointers in SNESOps structure */
4763: snes->ops->setup = NULL;
4764: snes->ops->solve = NULL;
4765: snes->ops->view = NULL;
4766: snes->ops->setfromoptions = NULL;
4767: snes->ops->destroy = NULL;
4769: /* It may happen the user has customized the line search before calling SNESSetType */
4770: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
4772: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4773: snes->setupcalled = PETSC_FALSE;
4775: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
4776: PetscCall((*r)(snes));
4777: PetscFunctionReturn(PETSC_SUCCESS);
4778: }
4780: /*@C
4781: SNESGetType - Gets the `SNES` method type and name (as a string).
4783: Not Collective
4785: Input Parameter:
4786: . snes - nonlinear solver context
4788: Output Parameter:
4789: . type - `SNES` method (a character string)
4791: Level: intermediate
4793: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
4794: @*/
4795: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
4796: {
4797: PetscFunctionBegin;
4799: PetscAssertPointer(type, 2);
4800: *type = ((PetscObject)snes)->type_name;
4801: PetscFunctionReturn(PETSC_SUCCESS);
4802: }
4804: /*@
4805: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
4807: Logically Collective
4809: Input Parameters:
4810: + snes - the `SNES` context obtained from `SNESCreate()`
4811: - u - the solution vector
4813: Level: beginner
4815: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
4816: @*/
4817: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4818: {
4819: DM dm;
4821: PetscFunctionBegin;
4824: PetscCall(PetscObjectReference((PetscObject)u));
4825: PetscCall(VecDestroy(&snes->vec_sol));
4827: snes->vec_sol = u;
4829: PetscCall(SNESGetDM(snes, &dm));
4830: PetscCall(DMShellSetGlobalVector(dm, u));
4831: PetscFunctionReturn(PETSC_SUCCESS);
4832: }
4834: /*@
4835: SNESGetSolution - Returns the vector where the approximate solution is
4836: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
4838: Not Collective, but `x` is parallel if `snes` is parallel
4840: Input Parameter:
4841: . snes - the `SNES` context
4843: Output Parameter:
4844: . x - the solution
4846: Level: intermediate
4848: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
4849: @*/
4850: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
4851: {
4852: PetscFunctionBegin;
4854: PetscAssertPointer(x, 2);
4855: *x = snes->vec_sol;
4856: PetscFunctionReturn(PETSC_SUCCESS);
4857: }
4859: /*@
4860: SNESGetSolutionUpdate - Returns the vector where the solution update is
4861: stored.
4863: Not Collective, but `x` is parallel if `snes` is parallel
4865: Input Parameter:
4866: . snes - the `SNES` context
4868: Output Parameter:
4869: . x - the solution update
4871: Level: advanced
4873: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
4874: @*/
4875: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
4876: {
4877: PetscFunctionBegin;
4879: PetscAssertPointer(x, 2);
4880: *x = snes->vec_sol_update;
4881: PetscFunctionReturn(PETSC_SUCCESS);
4882: }
4884: /*@C
4885: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
4887: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
4889: Input Parameter:
4890: . snes - the `SNES` context
4892: Output Parameters:
4893: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
4894: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunction`
4895: - ctx - the function context (or `NULL` if you don't want it)
4897: Level: advanced
4899: Note:
4900: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
4902: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunction`
4903: @*/
4904: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, PetscErrorCode (**f)(SNES, Vec, Vec, void *), void **ctx)
4905: {
4906: DM dm;
4908: PetscFunctionBegin;
4910: if (r) {
4911: if (!snes->vec_func) {
4912: if (snes->vec_rhs) {
4913: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
4914: } else if (snes->vec_sol) {
4915: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
4916: } else if (snes->dm) {
4917: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
4918: }
4919: }
4920: *r = snes->vec_func;
4921: }
4922: PetscCall(SNESGetDM(snes, &dm));
4923: PetscCall(DMSNESGetFunction(dm, f, ctx));
4924: PetscFunctionReturn(PETSC_SUCCESS);
4925: }
4927: /*@C
4928: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
4930: Input Parameter:
4931: . snes - the `SNES` context
4933: Output Parameters:
4934: + f - the function (or `NULL`) see `SNESSetNGS()` for details
4935: - ctx - the function context (or `NULL`)
4937: Level: advanced
4939: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`
4940: @*/
4941: PetscErrorCode SNESGetNGS(SNES snes, PetscErrorCode (**f)(SNES, Vec, Vec, void *), void **ctx)
4942: {
4943: DM dm;
4945: PetscFunctionBegin;
4947: PetscCall(SNESGetDM(snes, &dm));
4948: PetscCall(DMSNESGetNGS(dm, f, ctx));
4949: PetscFunctionReturn(PETSC_SUCCESS);
4950: }
4952: /*@C
4953: SNESSetOptionsPrefix - Sets the prefix used for searching for all
4954: `SNES` options in the database.
4956: Logically Collective
4958: Input Parameters:
4959: + snes - the `SNES` context
4960: - prefix - the prefix to prepend to all option names
4962: Level: advanced
4964: Note:
4965: A hyphen (-) must NOT be given at the beginning of the prefix name.
4966: The first character of all runtime options is AUTOMATICALLY the hyphen.
4968: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
4969: @*/
4970: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
4971: {
4972: PetscFunctionBegin;
4974: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
4975: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
4976: if (snes->linesearch) {
4977: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
4978: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
4979: }
4980: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
4981: PetscFunctionReturn(PETSC_SUCCESS);
4982: }
4984: /*@C
4985: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
4986: `SNES` options in the database.
4988: Logically Collective
4990: Input Parameters:
4991: + snes - the `SNES` context
4992: - prefix - the prefix to prepend to all option names
4994: Level: advanced
4996: Note:
4997: A hyphen (-) must NOT be given at the beginning of the prefix name.
4998: The first character of all runtime options is AUTOMATICALLY the hyphen.
5000: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5001: @*/
5002: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5003: {
5004: PetscFunctionBegin;
5006: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5007: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5008: if (snes->linesearch) {
5009: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5010: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5011: }
5012: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5013: PetscFunctionReturn(PETSC_SUCCESS);
5014: }
5016: /*@C
5017: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5018: `SNES` options in the database.
5020: Not Collective
5022: Input Parameter:
5023: . snes - the `SNES` context
5025: Output Parameter:
5026: . prefix - pointer to the prefix string used
5028: Level: advanced
5030: Fortran Note:
5031: The user should pass in a string 'prefix' of
5032: sufficient length to hold the prefix.
5034: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5035: @*/
5036: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5037: {
5038: PetscFunctionBegin;
5040: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5041: PetscFunctionReturn(PETSC_SUCCESS);
5042: }
5044: /*@C
5045: SNESRegister - Adds a method to the nonlinear solver package.
5047: Not Collective
5049: Input Parameters:
5050: + sname - name of a new user-defined solver
5051: - function - routine to create method context
5053: Level: advanced
5055: Note:
5056: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5058: Example Usage:
5059: .vb
5060: SNESRegister("my_solver", MySolverCreate);
5061: .ve
5063: Then, your solver can be chosen with the procedural interface via
5064: $ SNESSetType(snes, "my_solver")
5065: or at runtime via the option
5066: $ -snes_type my_solver
5068: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5069: @*/
5070: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5071: {
5072: PetscFunctionBegin;
5073: PetscCall(SNESInitializePackage());
5074: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5075: PetscFunctionReturn(PETSC_SUCCESS);
5076: }
5078: PetscErrorCode SNESTestLocalMin(SNES snes)
5079: {
5080: PetscInt N, i, j;
5081: Vec u, uh, fh;
5082: PetscScalar value;
5083: PetscReal norm;
5085: PetscFunctionBegin;
5086: PetscCall(SNESGetSolution(snes, &u));
5087: PetscCall(VecDuplicate(u, &uh));
5088: PetscCall(VecDuplicate(u, &fh));
5090: /* currently only works for sequential */
5091: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5092: PetscCall(VecGetSize(u, &N));
5093: for (i = 0; i < N; i++) {
5094: PetscCall(VecCopy(u, uh));
5095: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5096: for (j = -10; j < 11; j++) {
5097: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5098: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5099: PetscCall(SNESComputeFunction(snes, uh, fh));
5100: PetscCall(VecNorm(fh, NORM_2, &norm));
5101: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5102: value = -value;
5103: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5104: }
5105: }
5106: PetscCall(VecDestroy(&uh));
5107: PetscCall(VecDestroy(&fh));
5108: PetscFunctionReturn(PETSC_SUCCESS);
5109: }
5111: /*@
5112: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5113: computing relative tolerance for linear solvers within an inexact
5114: Newton method.
5116: Logically Collective
5118: Input Parameters:
5119: + snes - `SNES` context
5120: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5122: Options Database Keys:
5123: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5124: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5125: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5126: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5127: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5128: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5129: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5130: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5132: Level: advanced
5134: Note:
5135: The default is to use a constant relative tolerance for
5136: the inner linear solvers. Alternatively, one can use the
5137: Eisenstat-Walker method {cite}`ew96`, where the relative convergence tolerance
5138: is reset at each Newton iteration according progress of the nonlinear
5139: solver.
5141: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5142: @*/
5143: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5144: {
5145: PetscFunctionBegin;
5148: snes->ksp_ewconv = flag;
5149: PetscFunctionReturn(PETSC_SUCCESS);
5150: }
5152: /*@
5153: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5154: for computing relative tolerance for linear solvers within an
5155: inexact Newton method.
5157: Not Collective
5159: Input Parameter:
5160: . snes - `SNES` context
5162: Output Parameter:
5163: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5165: Level: advanced
5167: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5168: @*/
5169: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5170: {
5171: PetscFunctionBegin;
5173: PetscAssertPointer(flag, 2);
5174: *flag = snes->ksp_ewconv;
5175: PetscFunctionReturn(PETSC_SUCCESS);
5176: }
5178: /*@
5179: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5180: convergence criteria for the linear solvers within an inexact
5181: Newton method.
5183: Logically Collective
5185: Input Parameters:
5186: + snes - `SNES` context
5187: . version - version 1, 2 (default is 2), 3 or 4
5188: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5189: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5190: . gamma - multiplicative factor for version 2 rtol computation
5191: (0 <= gamma2 <= 1)
5192: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5193: . alpha2 - power for safeguard
5194: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5196: Level: advanced
5198: Notes:
5199: Version 3 was contributed by Luis Chacon, June 2006.
5201: Use `PETSC_DEFAULT` to retain the default for any of the parameters.
5203: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5204: @*/
5205: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5206: {
5207: SNESKSPEW *kctx;
5209: PetscFunctionBegin;
5211: kctx = (SNESKSPEW *)snes->kspconvctx;
5212: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5221: if (version != PETSC_DEFAULT) kctx->version = version;
5222: if (rtol_0 != (PetscReal)PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5223: if (rtol_max != (PetscReal)PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5224: if (gamma != (PetscReal)PETSC_DEFAULT) kctx->gamma = gamma;
5225: if (alpha != (PetscReal)PETSC_DEFAULT) kctx->alpha = alpha;
5226: if (alpha2 != (PetscReal)PETSC_DEFAULT) kctx->alpha2 = alpha2;
5227: if (threshold != (PetscReal)PETSC_DEFAULT) kctx->threshold = threshold;
5229: 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);
5230: 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);
5231: 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);
5232: 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);
5233: 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);
5234: 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);
5235: PetscFunctionReturn(PETSC_SUCCESS);
5236: }
5238: /*@
5239: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5240: convergence criteria for the linear solvers within an inexact
5241: Newton method.
5243: Not Collective
5245: Input Parameter:
5246: . snes - `SNES` context
5248: Output Parameters:
5249: + version - version 1, 2 (default is 2), 3 or 4
5250: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5251: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5252: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5253: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5254: . alpha2 - power for safeguard
5255: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5257: Level: advanced
5259: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5260: @*/
5261: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5262: {
5263: SNESKSPEW *kctx;
5265: PetscFunctionBegin;
5267: kctx = (SNESKSPEW *)snes->kspconvctx;
5268: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5269: if (version) *version = kctx->version;
5270: if (rtol_0) *rtol_0 = kctx->rtol_0;
5271: if (rtol_max) *rtol_max = kctx->rtol_max;
5272: if (gamma) *gamma = kctx->gamma;
5273: if (alpha) *alpha = kctx->alpha;
5274: if (alpha2) *alpha2 = kctx->alpha2;
5275: if (threshold) *threshold = kctx->threshold;
5276: PetscFunctionReturn(PETSC_SUCCESS);
5277: }
5279: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5280: {
5281: SNES snes = (SNES)ctx;
5282: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5283: PetscReal rtol = PETSC_DEFAULT, stol;
5285: PetscFunctionBegin;
5286: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5287: if (!snes->iter) {
5288: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5289: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5290: } else {
5291: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5292: if (kctx->version == 1) {
5293: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5294: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5295: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5296: } else if (kctx->version == 2) {
5297: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5298: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5299: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5300: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5301: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5302: /* safeguard: avoid sharp decrease of rtol */
5303: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5304: stol = PetscMax(rtol, stol);
5305: rtol = PetscMin(kctx->rtol_0, stol);
5306: /* safeguard: avoid oversolving */
5307: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5308: stol = PetscMax(rtol, stol);
5309: rtol = PetscMin(kctx->rtol_0, stol);
5310: } else /* if (kctx->version == 4) */ {
5311: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5312: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5313: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5314: PetscReal rk = ared / pred;
5315: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5316: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5317: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5318: else rtol = kctx->v4_m2 * kctx->rtol_last;
5320: 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;
5321: kctx->rtol_last_2 = kctx->rtol_last;
5322: kctx->rk_last_2 = kctx->rk_last;
5323: kctx->rk_last = rk;
5324: }
5325: }
5326: /* safeguard: avoid rtol greater than rtol_max */
5327: rtol = PetscMin(rtol, kctx->rtol_max);
5328: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_DEFAULT, PETSC_DEFAULT, PETSC_DEFAULT));
5329: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5330: PetscFunctionReturn(PETSC_SUCCESS);
5331: }
5333: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5334: {
5335: SNES snes = (SNES)ctx;
5336: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5337: PCSide pcside;
5338: Vec lres;
5340: PetscFunctionBegin;
5341: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5342: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5343: kctx->norm_last = snes->norm;
5344: if (kctx->version == 1 || kctx->version == 4) {
5345: PC pc;
5346: PetscBool getRes;
5348: PetscCall(KSPGetPC(ksp, &pc));
5349: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5350: if (!getRes) {
5351: KSPNormType normtype;
5353: PetscCall(KSPGetNormType(ksp, &normtype));
5354: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5355: }
5356: PetscCall(KSPGetPCSide(ksp, &pcside));
5357: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5358: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5359: } else {
5360: /* KSP residual is preconditioned residual */
5361: /* compute true linear residual norm */
5362: Mat J;
5363: PetscCall(KSPGetOperators(ksp, &J, NULL));
5364: PetscCall(VecDuplicate(b, &lres));
5365: PetscCall(MatMult(J, x, lres));
5366: PetscCall(VecAYPX(lres, -1.0, b));
5367: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5368: PetscCall(VecDestroy(&lres));
5369: }
5370: }
5371: PetscFunctionReturn(PETSC_SUCCESS);
5372: }
5374: /*@
5375: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5377: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5379: Input Parameter:
5380: . snes - the `SNES` context
5382: Output Parameter:
5383: . ksp - the `KSP` context
5385: Level: beginner
5387: Notes:
5388: The user can then directly manipulate the `KSP` context to set various
5389: options, etc. Likewise, the user can then extract and manipulate the
5390: `PC` contexts as well.
5392: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function
5394: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5395: @*/
5396: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5397: {
5398: PetscFunctionBegin;
5400: PetscAssertPointer(ksp, 2);
5402: if (!snes->ksp) {
5403: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5404: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5406: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5407: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5409: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5410: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5411: }
5412: *ksp = snes->ksp;
5413: PetscFunctionReturn(PETSC_SUCCESS);
5414: }
5416: #include <petsc/private/dmimpl.h>
5417: /*@
5418: SNESSetDM - Sets the `DM` that may be used by some nonlinear solvers or their underlying preconditioners
5420: Logically Collective
5422: Input Parameters:
5423: + snes - the nonlinear solver context
5424: - dm - the `DM`, cannot be `NULL`
5426: Level: intermediate
5428: Note:
5429: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5430: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5431: problems using the same function space.
5433: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5434: @*/
5435: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5436: {
5437: KSP ksp;
5438: DMSNES sdm;
5440: PetscFunctionBegin;
5443: PetscCall(PetscObjectReference((PetscObject)dm));
5444: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5445: if (snes->dm->dmsnes && !dm->dmsnes) {
5446: PetscCall(DMCopyDMSNES(snes->dm, dm));
5447: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5448: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5449: }
5450: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5451: PetscCall(DMDestroy(&snes->dm));
5452: }
5453: snes->dm = dm;
5454: snes->dmAuto = PETSC_FALSE;
5456: PetscCall(SNESGetKSP(snes, &ksp));
5457: PetscCall(KSPSetDM(ksp, dm));
5458: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5459: if (snes->npc) {
5460: PetscCall(SNESSetDM(snes->npc, snes->dm));
5461: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5462: }
5463: PetscFunctionReturn(PETSC_SUCCESS);
5464: }
5466: /*@
5467: SNESGetDM - Gets the `DM` that may be used by some solvers/preconditioners
5469: Not Collective but dm obtained is parallel on snes
5471: Input Parameter:
5472: . snes - the `SNES` context
5474: Output Parameter:
5475: . dm - the `DM`
5477: Level: intermediate
5479: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5480: @*/
5481: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5482: {
5483: PetscFunctionBegin;
5485: if (!snes->dm) {
5486: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5487: snes->dmAuto = PETSC_TRUE;
5488: }
5489: *dm = snes->dm;
5490: PetscFunctionReturn(PETSC_SUCCESS);
5491: }
5493: /*@
5494: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5496: Collective
5498: Input Parameters:
5499: + snes - iterative context obtained from `SNESCreate()`
5500: - npc - the nonlinear preconditioner object
5502: Level: developer
5504: Notes:
5505: Use `SNESGetNPC()` to retrieve the preconditioner context (for example,
5506: to configure it using the API).
5508: Only some `SNESType` can use a nonlinear preconditioner
5510: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5511: @*/
5512: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5513: {
5514: PetscFunctionBegin;
5517: PetscCheckSameComm(snes, 1, npc, 2);
5518: PetscCall(PetscObjectReference((PetscObject)npc));
5519: PetscCall(SNESDestroy(&snes->npc));
5520: snes->npc = npc;
5521: PetscFunctionReturn(PETSC_SUCCESS);
5522: }
5524: /*@
5525: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5527: Not Collective; but any changes to the obtained the npc object must be applied collectively
5529: Input Parameter:
5530: . snes - iterative context obtained from `SNESCreate()`
5532: Output Parameter:
5533: . pc - preconditioner context
5535: Options Database Key:
5536: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5538: Level: developer
5540: Notes:
5541: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created.
5543: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5544: `SNES`
5546: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5547: @*/
5548: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5549: {
5550: const char *optionsprefix;
5552: PetscFunctionBegin;
5554: PetscAssertPointer(pc, 2);
5555: if (!snes->npc) {
5556: void *ctx;
5558: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5559: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5560: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5561: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5562: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5563: PetscCall(SNESGetApplicationContext(snes, &ctx));
5564: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5565: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5566: }
5567: *pc = snes->npc;
5568: PetscFunctionReturn(PETSC_SUCCESS);
5569: }
5571: /*@
5572: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5574: Not Collective
5576: Input Parameter:
5577: . snes - iterative context obtained from `SNESCreate()`
5579: Output Parameter:
5580: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5582: Level: developer
5584: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5585: @*/
5586: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5587: {
5588: PetscFunctionBegin;
5590: *has_npc = (PetscBool)(snes->npc ? PETSC_TRUE : PETSC_FALSE);
5591: PetscFunctionReturn(PETSC_SUCCESS);
5592: }
5594: /*@
5595: SNESSetNPCSide - Sets the nonlinear preconditioning side.
5597: Logically Collective
5599: Input Parameter:
5600: . snes - iterative context obtained from `SNESCreate()`
5602: Output Parameter:
5603: . side - the preconditioning side, where side is one of
5604: .vb
5605: PC_LEFT - left preconditioning
5606: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5607: .ve
5609: Options Database Key:
5610: . -snes_npc_side <right,left> - nonlinear preconditioner side
5612: Level: intermediate
5614: Note:
5615: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5617: .seealso: [](ch_snes), `SNES`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5618: @*/
5619: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5620: {
5621: PetscFunctionBegin;
5624: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5625: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5626: snes->npcside = side;
5627: PetscFunctionReturn(PETSC_SUCCESS);
5628: }
5630: /*@
5631: SNESGetNPCSide - Gets the preconditioning side.
5633: Not Collective
5635: Input Parameter:
5636: . snes - iterative context obtained from `SNESCreate()`
5638: Output Parameter:
5639: . side - the preconditioning side, where side is one of
5640: .vb
5641: `PC_LEFT` - left preconditioning
5642: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5643: .ve
5645: Level: intermediate
5647: .seealso: [](ch_snes), `SNES`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5648: @*/
5649: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5650: {
5651: PetscFunctionBegin;
5653: PetscAssertPointer(side, 2);
5654: *side = snes->npcside;
5655: PetscFunctionReturn(PETSC_SUCCESS);
5656: }
5658: /*@
5659: SNESSetLineSearch - Sets the linesearch to be used for `SNES`
5661: Collective
5663: Input Parameters:
5664: + snes - iterative context obtained from `SNESCreate()`
5665: - linesearch - the linesearch object
5667: Level: developer
5669: Note:
5670: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
5671: to configure it using the API).
5673: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
5674: @*/
5675: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5676: {
5677: PetscFunctionBegin;
5680: PetscCheckSameComm(snes, 1, linesearch, 2);
5681: PetscCall(PetscObjectReference((PetscObject)linesearch));
5682: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5684: snes->linesearch = linesearch;
5686: PetscFunctionReturn(PETSC_SUCCESS);
5687: }
5689: /*@
5690: SNESGetLineSearch - Returns the line search context possibly set with `SNESSetLineSearch()`
5691: or creates a default line search instance associated with the `SNES` and returns it.
5693: Not Collective
5695: Input Parameter:
5696: . snes - iterative context obtained from `SNESCreate()`
5698: Output Parameter:
5699: . linesearch - linesearch context
5701: Level: beginner
5703: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`
5704: @*/
5705: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5706: {
5707: const char *optionsprefix;
5709: PetscFunctionBegin;
5711: PetscAssertPointer(linesearch, 2);
5712: if (!snes->linesearch) {
5713: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5714: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5715: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5716: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5717: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5718: }
5719: *linesearch = snes->linesearch;
5720: PetscFunctionReturn(PETSC_SUCCESS);
5721: }