Actual source code: snes.c
1: #include <petsc/private/snesimpl.h>
2: #include <petscdmshell.h>
3: #include <petscdraw.h>
4: #include <petscds.h>
5: #include <petscdmadaptor.h>
6: #include <petscconvest.h>
8: PetscBool SNESRegisterAllCalled = PETSC_FALSE;
9: PetscFunctionList SNESList = NULL;
11: /* Logging support */
12: PetscClassId SNES_CLASSID, DMSNES_CLASSID;
13: PetscLogEvent SNES_Solve, SNES_SetUp, SNES_FunctionEval, SNES_JacobianEval, SNES_NGSEval, SNES_NGSFuncEval, SNES_NPCSolve, SNES_ObjectiveEval;
15: /*@
16: SNESSetErrorIfNotConverged - Causes `SNESSolve()` to generate an error immediately if the solver has not converged.
18: Logically Collective
20: Input Parameters:
21: + snes - iterative context obtained from `SNESCreate()`
22: - flg - `PETSC_TRUE` indicates you want the error generated
24: Options Database Key:
25: . -snes_error_if_not_converged <true,false> - cause an immediate error condition and stop the program if the solver does not converge
27: Level: intermediate
29: Note:
30: Normally PETSc continues if a solver fails to converge, you can call `SNESGetConvergedReason()` after a `SNESSolve()`
31: to determine if it has converged. Otherwise the solution may be inaccurate or wrong
33: .seealso: [](ch_snes), `SNES`, `SNESGetErrorIfNotConverged()`, `KSPGetErrorIfNotConverged()`, `KSPSetErrorIfNotConverged()`
34: @*/
35: PetscErrorCode SNESSetErrorIfNotConverged(SNES snes, PetscBool flg)
36: {
37: PetscFunctionBegin;
40: snes->errorifnotconverged = flg;
41: PetscFunctionReturn(PETSC_SUCCESS);
42: }
44: /*@
45: SNESGetErrorIfNotConverged - Indicates if `SNESSolve()` will generate an error if the solver does not converge?
47: Not Collective
49: Input Parameter:
50: . snes - iterative context obtained from `SNESCreate()`
52: Output Parameter:
53: . flag - `PETSC_TRUE` if it will generate an error, else `PETSC_FALSE`
55: Level: intermediate
57: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetErrorIfNotConverged()`, `KSPGetErrorIfNotConverged()`, `KSPSetErrorIfNotConverged()`
58: @*/
59: PetscErrorCode SNESGetErrorIfNotConverged(SNES snes, PetscBool *flag)
60: {
61: PetscFunctionBegin;
63: PetscAssertPointer(flag, 2);
64: *flag = snes->errorifnotconverged;
65: PetscFunctionReturn(PETSC_SUCCESS);
66: }
68: /*@
69: SNESSetAlwaysComputesFinalResidual - tells the `SNES` to always compute the residual (nonlinear function value) at the final solution
71: Logically Collective
73: Input Parameters:
74: + snes - the shell `SNES`
75: - flg - `PETSC_TRUE` to always compute the residual
77: Level: advanced
79: Note:
80: Some solvers (such as smoothers in a `SNESFAS`) do not need the residual computed at the final solution so skip computing it
81: to save time.
83: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSolve()`, `SNESGetAlwaysComputesFinalResidual()`
84: @*/
85: PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES snes, PetscBool flg)
86: {
87: PetscFunctionBegin;
89: snes->alwayscomputesfinalresidual = flg;
90: PetscFunctionReturn(PETSC_SUCCESS);
91: }
93: /*@
94: SNESGetAlwaysComputesFinalResidual - checks if the `SNES` always computes the residual at the final solution
96: Logically Collective
98: Input Parameter:
99: . snes - the `SNES` context
101: Output Parameter:
102: . flg - `PETSC_TRUE` if the residual is computed
104: Level: advanced
106: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSolve()`, `SNESSetAlwaysComputesFinalResidual()`
107: @*/
108: PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES snes, PetscBool *flg)
109: {
110: PetscFunctionBegin;
112: *flg = snes->alwayscomputesfinalresidual;
113: PetscFunctionReturn(PETSC_SUCCESS);
114: }
116: /*@
117: SNESSetFunctionDomainError - tells `SNES` that the input vector, a proposed new solution, to your function you provided to `SNESSetFunction()` is not
118: in the functions domain. For example, a step with negative pressure.
120: Logically Collective
122: Input Parameter:
123: . snes - the `SNES` context
125: Level: advanced
127: Notes:
128: If this is called the `SNESSolve()` stops iterating and returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_DOMAIN`
130: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
132: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
133: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
135: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetJacobianDomainError()`, `SNESVISetVariableBounds()`,
136: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
137: @*/
138: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
139: {
140: PetscFunctionBegin;
142: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates input vector is not in the function domain");
143: snes->domainerror = PETSC_TRUE;
144: PetscFunctionReturn(PETSC_SUCCESS);
145: }
147: /*@
148: SNESSetJacobianDomainError - tells `SNES` that the function you provided to `SNESSetJacobian()` at the proposed step. For example there is a negative element transformation.
150: Logically Collective
152: Input Parameter:
153: . snes - the `SNES` context
155: Level: advanced
157: Notes:
158: If this is called the `SNESSolve()` stops iterating and returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_DOMAIN`
160: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
162: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
163: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
165: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESVISetVariableBounds()`,
166: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
167: @*/
168: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
169: {
170: PetscFunctionBegin;
172: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates computeJacobian does not make sense");
173: snes->jacobiandomainerror = PETSC_TRUE;
174: PetscFunctionReturn(PETSC_SUCCESS);
175: }
177: /*@
178: SNESSetCheckJacobianDomainError - tells `SNESSolve()` whether to check if the user called `SNESSetJacobianDomainError()` Jacobian domain error after
179: each Jacobian evaluation. By default, it checks for the Jacobian domain error in the debug mode, and does not check it in the optimized mode.
181: Logically Collective
183: Input Parameters:
184: + snes - the `SNES` context
185: - flg - indicates if or not to check Jacobian domain error after each Jacobian evaluation
187: Level: advanced
189: Note:
190: Checks require one extra parallel synchronization for each Jacobian evaluation
192: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESGetCheckJacobianDomainError()`
193: @*/
194: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
195: {
196: PetscFunctionBegin;
198: snes->checkjacdomainerror = flg;
199: PetscFunctionReturn(PETSC_SUCCESS);
200: }
202: /*@
203: SNESGetCheckJacobianDomainError - Get an indicator whether or not `SNES` is checking Jacobian domain errors after each Jacobian evaluation.
205: Logically Collective
207: Input Parameter:
208: . snes - the `SNES` context
210: Output Parameter:
211: . flg - `PETSC_FALSE` indicates that it is not checking Jacobian domain errors after each Jacobian evaluation
213: Level: advanced
215: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESSetCheckJacobianDomainError()`
216: @*/
217: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
218: {
219: PetscFunctionBegin;
221: PetscAssertPointer(flg, 2);
222: *flg = snes->checkjacdomainerror;
223: PetscFunctionReturn(PETSC_SUCCESS);
224: }
226: /*@
227: SNESGetFunctionDomainError - Gets the status of the domain error after a call to `SNESComputeFunction()`
229: Logically Collective
231: Input Parameter:
232: . snes - the `SNES` context
234: Output Parameter:
235: . domainerror - Set to `PETSC_TRUE` if there's a domain error; `PETSC_FALSE` otherwise.
237: Level: developer
239: .seealso: [](ch_snes), `SNES`, `SNESSetFunctionDomainError()`, `SNESComputeFunction()`
240: @*/
241: PetscErrorCode SNESGetFunctionDomainError(SNES snes, PetscBool *domainerror)
242: {
243: PetscFunctionBegin;
245: PetscAssertPointer(domainerror, 2);
246: *domainerror = snes->domainerror;
247: PetscFunctionReturn(PETSC_SUCCESS);
248: }
250: /*@
251: SNESGetJacobianDomainError - Gets the status of the Jacobian domain error after a call to `SNESComputeJacobian()`
253: Logically Collective
255: Input Parameter:
256: . snes - the `SNES` context
258: Output Parameter:
259: . domainerror - Set to `PETSC_TRUE` if there's a Jacobian domain error; `PETSC_FALSE` otherwise.
261: Level: advanced
263: .seealso: [](ch_snes), `SNES`, `SNESSetFunctionDomainError()`, `SNESComputeFunction()`, `SNESGetFunctionDomainError()`
264: @*/
265: PetscErrorCode SNESGetJacobianDomainError(SNES snes, PetscBool *domainerror)
266: {
267: PetscFunctionBegin;
269: PetscAssertPointer(domainerror, 2);
270: *domainerror = snes->jacobiandomainerror;
271: PetscFunctionReturn(PETSC_SUCCESS);
272: }
274: /*@C
275: SNESLoad - Loads a `SNES` that has been stored in `PETSCVIEWERBINARY` with `SNESView()`.
277: Collective
279: Input Parameters:
280: + snes - the newly loaded `SNES`, this needs to have been created with `SNESCreate()` or
281: some related function before a call to `SNESLoad()`.
282: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()`
284: Level: intermediate
286: Note:
287: The `SNESType` is determined by the data in the file, any type set into the `SNES` before this call is ignored.
289: .seealso: [](ch_snes), `SNES`, `PetscViewer`, `SNESCreate()`, `SNESType`, `PetscViewerBinaryOpen()`, `SNESView()`, `MatLoad()`, `VecLoad()`
290: @*/
291: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
292: {
293: PetscBool isbinary;
294: PetscInt classid;
295: char type[256];
296: KSP ksp;
297: DM dm;
298: DMSNES dmsnes;
300: PetscFunctionBegin;
303: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
304: PetscCheck(isbinary, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen()");
306: PetscCall(PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT));
307: PetscCheck(classid == SNES_FILE_CLASSID, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Not SNES next in file");
308: PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
309: PetscCall(SNESSetType(snes, type));
310: PetscTryTypeMethod(snes, load, viewer);
311: PetscCall(SNESGetDM(snes, &dm));
312: PetscCall(DMGetDMSNES(dm, &dmsnes));
313: PetscCall(DMSNESLoad(dmsnes, viewer));
314: PetscCall(SNESGetKSP(snes, &ksp));
315: PetscCall(KSPLoad(ksp, viewer));
316: PetscFunctionReturn(PETSC_SUCCESS);
317: }
319: #include <petscdraw.h>
320: #if defined(PETSC_HAVE_SAWS)
321: #include <petscviewersaws.h>
322: #endif
324: /*@C
325: SNESViewFromOptions - View a `SNES` based on values in the options database
327: Collective
329: Input Parameters:
330: + A - the `SNES` context
331: . obj - Optional object that provides the options prefix for the checks
332: - name - command line option
334: Level: intermediate
336: .seealso: [](ch_snes), `SNES`, `SNESView`, `PetscObjectViewFromOptions()`, `SNESCreate()`
337: @*/
338: PetscErrorCode SNESViewFromOptions(SNES A, PetscObject obj, const char name[])
339: {
340: PetscFunctionBegin;
342: PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
343: PetscFunctionReturn(PETSC_SUCCESS);
344: }
346: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES, Vec, Mat, Mat, void *);
348: /*@C
349: SNESView - Prints or visualizes the `SNES` data structure.
351: Collective
353: Input Parameters:
354: + snes - the `SNES` context
355: - viewer - the `PetscViewer`
357: Options Database Key:
358: . -snes_view - Calls `SNESView()` at end of `SNESSolve()`
360: Level: beginner
362: Notes:
363: The available visualization contexts include
364: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
365: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
366: output where only the first processor opens
367: the file. All other processors send their
368: data to the first processor to print.
370: The available formats include
371: + `PETSC_VIEWER_DEFAULT` - standard output (default)
372: - `PETSC_VIEWER_ASCII_INFO_DETAIL` - more verbose output for `SNESNASM`
374: The user can open an alternative visualization context with
375: `PetscViewerASCIIOpen()` - output to a specified file.
377: In the debugger you can do "call `SNESView`(snes,0)" to display the `SNES` solver. (The same holds for any PETSc object viewer).
379: .seealso: [](ch_snes), `SNES`, `SNESLoad()`, `SNESCreate()`, `PetscViewerASCIIOpen()`
380: @*/
381: PetscErrorCode SNESView(SNES snes, PetscViewer viewer)
382: {
383: SNESKSPEW *kctx;
384: KSP ksp;
385: SNESLineSearch linesearch;
386: PetscBool iascii, isstring, isbinary, isdraw;
387: DMSNES dmsnes;
388: #if defined(PETSC_HAVE_SAWS)
389: PetscBool issaws;
390: #endif
392: PetscFunctionBegin;
394: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &viewer));
396: PetscCheckSameComm(snes, 1, viewer, 2);
398: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
399: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
400: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
401: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
402: #if defined(PETSC_HAVE_SAWS)
403: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
404: #endif
405: if (iascii) {
406: SNESNormSchedule normschedule;
407: DM dm;
408: SNESJacobianFn *cJ;
409: void *ctx;
410: const char *pre = "";
412: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)snes, viewer));
413: if (!snes->setupcalled) PetscCall(PetscViewerASCIIPrintf(viewer, " SNES has not been set up so information may be incomplete\n"));
414: if (snes->ops->view) {
415: PetscCall(PetscViewerASCIIPushTab(viewer));
416: PetscUseTypeMethod(snes, view, viewer);
417: PetscCall(PetscViewerASCIIPopTab(viewer));
418: }
419: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=%" PetscInt_FMT "\n", snes->max_its, snes->max_funcs));
420: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, solution=%g\n", (double)snes->rtol, (double)snes->abstol, (double)snes->stol));
421: if (snes->usesksp) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of linear solver iterations=%" PetscInt_FMT "\n", snes->linear_its));
422: PetscCall(PetscViewerASCIIPrintf(viewer, " total number of function evaluations=%" PetscInt_FMT "\n", snes->nfuncs));
423: PetscCall(SNESGetNormSchedule(snes, &normschedule));
424: if (normschedule > 0) PetscCall(PetscViewerASCIIPrintf(viewer, " norm schedule %s\n", SNESNormSchedules[normschedule]));
425: if (snes->gridsequence) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of grid sequence refinements=%" PetscInt_FMT "\n", snes->gridsequence));
426: if (snes->ksp_ewconv) {
427: kctx = (SNESKSPEW *)snes->kspconvctx;
428: if (kctx) {
429: PetscCall(PetscViewerASCIIPrintf(viewer, " Eisenstat-Walker computation of KSP relative tolerance (version %" PetscInt_FMT ")\n", kctx->version));
430: PetscCall(PetscViewerASCIIPrintf(viewer, " rtol_0=%g, rtol_max=%g, threshold=%g\n", (double)kctx->rtol_0, (double)kctx->rtol_max, (double)kctx->threshold));
431: PetscCall(PetscViewerASCIIPrintf(viewer, " gamma=%g, alpha=%g, alpha2=%g\n", (double)kctx->gamma, (double)kctx->alpha, (double)kctx->alpha2));
432: }
433: }
434: if (snes->lagpreconditioner == -1) {
435: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is never rebuilt\n"));
436: } else if (snes->lagpreconditioner > 1) {
437: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is rebuilt every %" PetscInt_FMT " new Jacobians\n", snes->lagpreconditioner));
438: }
439: if (snes->lagjacobian == -1) {
440: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is never rebuilt\n"));
441: } else if (snes->lagjacobian > 1) {
442: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is rebuilt every %" PetscInt_FMT " SNES iterations\n", snes->lagjacobian));
443: }
444: PetscCall(SNESGetDM(snes, &dm));
445: PetscCall(DMSNESGetJacobian(dm, &cJ, &ctx));
446: if (snes->mf_operator) {
447: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing\n"));
448: pre = "Preconditioning ";
449: }
450: if (cJ == SNESComputeJacobianDefault) {
451: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences one column at a time\n", pre));
452: } else if (cJ == SNESComputeJacobianDefaultColor) {
453: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences with coloring\n", pre));
454: /* it slightly breaks data encapsulation for access the DMDA information directly */
455: } else if (cJ == SNESComputeJacobian_DMDA) {
456: MatFDColoring fdcoloring;
457: PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
458: if (fdcoloring) {
459: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using colored finite differences on a DMDA\n", pre));
460: } else {
461: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using a DMDA local Jacobian\n", pre));
462: }
463: } else if (snes->mf && !snes->mf_operator) {
464: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing, no explicit Jacobian\n"));
465: }
466: } else if (isstring) {
467: const char *type;
468: PetscCall(SNESGetType(snes, &type));
469: PetscCall(PetscViewerStringSPrintf(viewer, " SNESType: %-7.7s", type));
470: PetscTryTypeMethod(snes, view, viewer);
471: } else if (isbinary) {
472: PetscInt classid = SNES_FILE_CLASSID;
473: MPI_Comm comm;
474: PetscMPIInt rank;
475: char type[256];
477: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
478: PetscCallMPI(MPI_Comm_rank(comm, &rank));
479: if (rank == 0) {
480: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
481: PetscCall(PetscStrncpy(type, ((PetscObject)snes)->type_name, sizeof(type)));
482: PetscCall(PetscViewerBinaryWrite(viewer, type, sizeof(type), PETSC_CHAR));
483: }
484: PetscTryTypeMethod(snes, view, viewer);
485: } else if (isdraw) {
486: PetscDraw draw;
487: char str[36];
488: PetscReal x, y, bottom, h;
490: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
491: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
492: PetscCall(PetscStrncpy(str, "SNES: ", sizeof(str)));
493: PetscCall(PetscStrlcat(str, ((PetscObject)snes)->type_name, sizeof(str)));
494: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_BLUE, PETSC_DRAW_BLACK, str, NULL, &h));
495: bottom = y - h;
496: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
497: PetscTryTypeMethod(snes, view, viewer);
498: #if defined(PETSC_HAVE_SAWS)
499: } else if (issaws) {
500: PetscMPIInt rank;
501: const char *name;
503: PetscCall(PetscObjectGetName((PetscObject)snes, &name));
504: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
505: if (!((PetscObject)snes)->amsmem && rank == 0) {
506: char dir[1024];
508: PetscCall(PetscObjectViewSAWs((PetscObject)snes, viewer));
509: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
510: PetscCallSAWs(SAWs_Register, (dir, &snes->iter, 1, SAWs_READ, SAWs_INT));
511: if (!snes->conv_hist) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, PETSC_DECIDE, PETSC_TRUE));
512: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/conv_hist", name));
513: PetscCallSAWs(SAWs_Register, (dir, snes->conv_hist, 10, SAWs_READ, SAWs_DOUBLE));
514: }
515: #endif
516: }
517: if (snes->linesearch) {
518: PetscCall(SNESGetLineSearch(snes, &linesearch));
519: PetscCall(PetscViewerASCIIPushTab(viewer));
520: PetscCall(SNESLineSearchView(linesearch, viewer));
521: PetscCall(PetscViewerASCIIPopTab(viewer));
522: }
523: if (snes->npc && snes->usesnpc) {
524: PetscCall(PetscViewerASCIIPushTab(viewer));
525: PetscCall(SNESView(snes->npc, viewer));
526: PetscCall(PetscViewerASCIIPopTab(viewer));
527: }
528: PetscCall(PetscViewerASCIIPushTab(viewer));
529: PetscCall(DMGetDMSNES(snes->dm, &dmsnes));
530: PetscCall(DMSNESView(dmsnes, viewer));
531: PetscCall(PetscViewerASCIIPopTab(viewer));
532: if (snes->usesksp) {
533: PetscCall(SNESGetKSP(snes, &ksp));
534: PetscCall(PetscViewerASCIIPushTab(viewer));
535: PetscCall(KSPView(ksp, viewer));
536: PetscCall(PetscViewerASCIIPopTab(viewer));
537: }
538: if (isdraw) {
539: PetscDraw draw;
540: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
541: PetscCall(PetscDrawPopCurrentPoint(draw));
542: }
543: PetscFunctionReturn(PETSC_SUCCESS);
544: }
546: /*
547: We retain a list of functions that also take SNES command
548: line options. These are called at the end SNESSetFromOptions()
549: */
550: #define MAXSETFROMOPTIONS 5
551: static PetscInt numberofsetfromoptions;
552: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
554: /*@C
555: SNESAddOptionsChecker - Adds an additional function to check for `SNES` options.
557: Not Collective
559: Input Parameter:
560: . snescheck - function that checks for options
562: Calling sequence of `snescheck`:
563: . snes - the `SNES` object for which it is checking options
565: Level: developer
567: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`
568: @*/
569: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES snes))
570: {
571: PetscFunctionBegin;
572: PetscCheck(numberofsetfromoptions < MAXSETFROMOPTIONS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %d allowed", MAXSETFROMOPTIONS);
573: othersetfromoptions[numberofsetfromoptions++] = snescheck;
574: PetscFunctionReturn(PETSC_SUCCESS);
575: }
577: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
578: {
579: Mat J;
580: MatNullSpace nullsp;
582: PetscFunctionBegin;
585: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
586: Mat A = snes->jacobian, B = snes->jacobian_pre;
587: PetscCall(MatCreateVecs(A ? A : B, NULL, &snes->vec_func));
588: }
590: PetscCheck(version == 1 || version == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator routines, only version 1 and 2");
591: if (version == 1) {
592: PetscCall(MatCreateSNESMF(snes, &J));
593: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
594: PetscCall(MatSetFromOptions(J));
595: /* TODO: the version 2 code should be merged into the MatCreateSNESMF() and MatCreateMFFD() infrastructure and then removed */
596: } else /* if (version == 2) */ {
597: PetscCheck(snes->vec_func, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "SNESSetFunction() must be called first");
598: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
599: PetscCall(MatCreateSNESMFMore(snes, snes->vec_func, &J));
600: #else
601: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "matrix-free operator routines (version 2)");
602: #endif
603: }
605: /* attach any user provided null space that was on Amat to the newly created matrix-free matrix */
606: if (snes->jacobian) {
607: PetscCall(MatGetNullSpace(snes->jacobian, &nullsp));
608: if (nullsp) PetscCall(MatSetNullSpace(J, nullsp));
609: }
611: PetscCall(PetscInfo(snes, "Setting default matrix-free operator routines (version %" PetscInt_FMT ")\n", version));
612: if (hasOperator) {
613: /* This version replaces the user provided Jacobian matrix with a
614: matrix-free version but still employs the user-provided preconditioner matrix. */
615: PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
616: } else {
617: /* This version replaces both the user-provided Jacobian and the user-
618: provided preconditioner Jacobian with the default matrix-free version. */
619: if (snes->npcside == PC_LEFT && snes->npc) {
620: if (!snes->jacobian) PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
621: } else {
622: KSP ksp;
623: PC pc;
624: PetscBool match;
626: PetscCall(SNESSetJacobian(snes, J, J, MatMFFDComputeJacobian, NULL));
627: /* Force no preconditioner */
628: PetscCall(SNESGetKSP(snes, &ksp));
629: PetscCall(KSPGetPC(ksp, &pc));
630: PetscCall(PetscObjectTypeCompareAny((PetscObject)pc, &match, PCSHELL, PCH2OPUS, ""));
631: if (!match) {
632: PetscCall(PetscInfo(snes, "Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n"));
633: PetscCall(PCSetType(pc, PCNONE));
634: }
635: }
636: }
637: PetscCall(MatDestroy(&J));
638: PetscFunctionReturn(PETSC_SUCCESS);
639: }
641: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine, Mat Restrict, Vec Rscale, Mat Inject, DM dmcoarse, void *ctx)
642: {
643: SNES snes = (SNES)ctx;
644: Vec Xfine, Xfine_named = NULL, Xcoarse;
646: PetscFunctionBegin;
647: if (PetscLogPrintInfo) {
648: PetscInt finelevel, coarselevel, fineclevel, coarseclevel;
649: PetscCall(DMGetRefineLevel(dmfine, &finelevel));
650: PetscCall(DMGetCoarsenLevel(dmfine, &fineclevel));
651: PetscCall(DMGetRefineLevel(dmcoarse, &coarselevel));
652: PetscCall(DMGetCoarsenLevel(dmcoarse, &coarseclevel));
653: PetscCall(PetscInfo(dmfine, "Restricting SNES solution vector from level %" PetscInt_FMT "-%" PetscInt_FMT " to level %" PetscInt_FMT "-%" PetscInt_FMT "\n", finelevel, fineclevel, coarselevel, coarseclevel));
654: }
655: if (dmfine == snes->dm) Xfine = snes->vec_sol;
656: else {
657: PetscCall(DMGetNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
658: Xfine = Xfine_named;
659: }
660: PetscCall(DMGetNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
661: if (Inject) {
662: PetscCall(MatRestrict(Inject, Xfine, Xcoarse));
663: } else {
664: PetscCall(MatRestrict(Restrict, Xfine, Xcoarse));
665: PetscCall(VecPointwiseMult(Xcoarse, Xcoarse, Rscale));
666: }
667: PetscCall(DMRestoreNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
668: if (Xfine_named) PetscCall(DMRestoreNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
669: PetscFunctionReturn(PETSC_SUCCESS);
670: }
672: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm, DM dmc, void *ctx)
673: {
674: PetscFunctionBegin;
675: PetscCall(DMCoarsenHookAdd(dmc, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, ctx));
676: PetscFunctionReturn(PETSC_SUCCESS);
677: }
679: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
680: * safely call SNESGetDM() in their residual evaluation routine. */
681: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp, Mat A, Mat B, void *ctx)
682: {
683: SNES snes = (SNES)ctx;
684: Vec X, Xnamed = NULL;
685: DM dmsave;
686: void *ctxsave;
687: SNESJacobianFn *jac = NULL;
689: PetscFunctionBegin;
690: dmsave = snes->dm;
691: PetscCall(KSPGetDM(ksp, &snes->dm));
692: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
693: else { /* We are on a coarser level, this vec was initialized using a DM restrict hook */ PetscCall(DMGetNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
694: X = Xnamed;
695: PetscCall(SNESGetJacobian(snes, NULL, NULL, &jac, &ctxsave));
696: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
697: if (jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, SNESComputeJacobianDefaultColor, NULL));
698: }
699: /* Make sure KSP DM has the Jacobian computation routine */
700: {
701: DMSNES sdm;
703: PetscCall(DMGetDMSNES(snes->dm, &sdm));
704: if (!sdm->ops->computejacobian) PetscCall(DMCopyDMSNES(dmsave, snes->dm));
705: }
706: /* Compute the operators */
707: PetscCall(SNESComputeJacobian(snes, X, A, B));
708: /* Put the previous context back */
709: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, jac, ctxsave));
711: if (Xnamed) PetscCall(DMRestoreNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
712: snes->dm = dmsave;
713: PetscFunctionReturn(PETSC_SUCCESS);
714: }
716: /*@
717: SNESSetUpMatrices - ensures that matrices are available for `SNES` Newton-like methods, this is called by `SNESSetUp_XXX()`
719: Collective
721: Input Parameter:
722: . snes - `SNES` object to configure
724: Level: developer
726: Note:
727: If the matrices do not yet exist it attempts to create them based on options previously set for the `SNES` such as `-snes_mf`
729: Developer Note:
730: The functionality of this routine overlaps in a confusing way with the functionality of `SNESSetUpMatrixFree_Private()` which is called by
731: `SNESSetUp()` but sometimes `SNESSetUpMatrices()` is called without `SNESSetUp()` being called. A refactorization to simplify the
732: logic that handles the matrix-free case is desirable.
734: .seealso: [](ch_snes), `SNES`, `SNESSetUp()`
735: @*/
736: PetscErrorCode SNESSetUpMatrices(SNES snes)
737: {
738: DM dm;
739: DMSNES sdm;
741: PetscFunctionBegin;
742: PetscCall(SNESGetDM(snes, &dm));
743: PetscCall(DMGetDMSNES(dm, &sdm));
744: if (!snes->jacobian && snes->mf && !snes->mf_operator && !snes->jacobian_pre) {
745: Mat J;
746: void *functx;
747: PetscCall(MatCreateSNESMF(snes, &J));
748: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
749: PetscCall(MatSetFromOptions(J));
750: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
751: PetscCall(SNESSetJacobian(snes, J, J, NULL, NULL));
752: PetscCall(MatDestroy(&J));
753: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
754: Mat J, B;
755: PetscCall(MatCreateSNESMF(snes, &J));
756: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
757: PetscCall(MatSetFromOptions(J));
758: PetscCall(DMCreateMatrix(snes->dm, &B));
759: /* sdm->computejacobian was already set to reach here */
760: PetscCall(SNESSetJacobian(snes, J, B, NULL, NULL));
761: PetscCall(MatDestroy(&J));
762: PetscCall(MatDestroy(&B));
763: } else if (!snes->jacobian_pre) {
764: PetscDS prob;
765: Mat J, B;
766: PetscBool hasPrec = PETSC_FALSE;
768: J = snes->jacobian;
769: PetscCall(DMGetDS(dm, &prob));
770: if (prob) PetscCall(PetscDSHasJacobianPreconditioner(prob, &hasPrec));
771: if (J) PetscCall(PetscObjectReference((PetscObject)J));
772: else if (hasPrec) PetscCall(DMCreateMatrix(snes->dm, &J));
773: PetscCall(DMCreateMatrix(snes->dm, &B));
774: PetscCall(SNESSetJacobian(snes, J ? J : B, B, NULL, NULL));
775: PetscCall(MatDestroy(&J));
776: PetscCall(MatDestroy(&B));
777: }
778: {
779: KSP ksp;
780: PetscCall(SNESGetKSP(snes, &ksp));
781: PetscCall(KSPSetComputeOperators(ksp, KSPComputeOperators_SNES, snes));
782: PetscCall(DMCoarsenHookAdd(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
783: }
784: PetscFunctionReturn(PETSC_SUCCESS);
785: }
787: static PetscErrorCode SNESMonitorPauseFinal_Internal(SNES snes)
788: {
789: PetscInt i;
791: PetscFunctionBegin;
792: if (!snes->pauseFinal) PetscFunctionReturn(PETSC_SUCCESS);
793: for (i = 0; i < snes->numbermonitors; ++i) {
794: PetscViewerAndFormat *vf = (PetscViewerAndFormat *)snes->monitorcontext[i];
795: PetscDraw draw;
796: PetscReal lpause;
798: if (!vf) continue;
799: if (vf->lg) {
800: if (!PetscCheckPointer(vf->lg, PETSC_OBJECT)) continue;
801: if (((PetscObject)vf->lg)->classid != PETSC_DRAWLG_CLASSID) continue;
802: PetscCall(PetscDrawLGGetDraw(vf->lg, &draw));
803: PetscCall(PetscDrawGetPause(draw, &lpause));
804: PetscCall(PetscDrawSetPause(draw, -1.0));
805: PetscCall(PetscDrawPause(draw));
806: PetscCall(PetscDrawSetPause(draw, lpause));
807: } else {
808: PetscBool isdraw;
810: if (!PetscCheckPointer(vf->viewer, PETSC_OBJECT)) continue;
811: if (((PetscObject)vf->viewer)->classid != PETSC_VIEWER_CLASSID) continue;
812: PetscCall(PetscObjectTypeCompare((PetscObject)vf->viewer, PETSCVIEWERDRAW, &isdraw));
813: if (!isdraw) continue;
814: PetscCall(PetscViewerDrawGetDraw(vf->viewer, 0, &draw));
815: PetscCall(PetscDrawGetPause(draw, &lpause));
816: PetscCall(PetscDrawSetPause(draw, -1.0));
817: PetscCall(PetscDrawPause(draw));
818: PetscCall(PetscDrawSetPause(draw, lpause));
819: }
820: }
821: PetscFunctionReturn(PETSC_SUCCESS);
822: }
824: /*@C
825: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
827: Collective
829: Input Parameters:
830: + snes - `SNES` object you wish to monitor
831: . name - the monitor type one is seeking
832: . help - message indicating what monitoring is done
833: . manual - manual page for the monitor
834: . monitor - the monitor function
835: - 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
837: Calling sequence of `monitor`:
838: + snes - the nonlinear solver context
839: . it - the current iteration
840: . r - the current function norm
841: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
843: Calling sequence of `monitorsetup`:
844: + snes - the nonlinear solver context
845: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
847: Options Database Key:
848: . -name - trigger the use of this monitor in `SNESSetFromOptions()`
850: Level: advanced
852: .seealso: [](ch_snes), `PetscOptionsGetViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
853: `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`
854: `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
855: `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
856: `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
857: `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
858: `PetscOptionsFList()`, `PetscOptionsEList()`
859: @*/
860: 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))
861: {
862: PetscViewer viewer;
863: PetscViewerFormat format;
864: PetscBool flg;
866: PetscFunctionBegin;
867: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, name, &viewer, &format, &flg));
868: if (flg) {
869: PetscViewerAndFormat *vf;
870: PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
871: PetscCall(PetscOptionsRestoreViewer(&viewer));
872: if (monitorsetup) PetscCall((*monitorsetup)(snes, vf));
873: PetscCall(SNESMonitorSet(snes, (PetscErrorCode(*)(SNES, PetscInt, PetscReal, void *))monitor, vf, (PetscErrorCode(*)(void **))PetscViewerAndFormatDestroy));
874: }
875: PetscFunctionReturn(PETSC_SUCCESS);
876: }
878: PetscErrorCode SNESEWSetFromOptions_Private(SNESKSPEW *kctx, PetscBool print_api, MPI_Comm comm, const char *prefix)
879: {
880: const char *api = print_api ? "SNESKSPSetParametersEW" : NULL;
882: PetscFunctionBegin;
883: PetscOptionsBegin(comm, prefix, "Eisenstat and Walker type forcing options", "KSP");
884: PetscCall(PetscOptionsInt("-ksp_ew_version", "Version 1, 2 or 3", api, kctx->version, &kctx->version, NULL));
885: PetscCall(PetscOptionsReal("-ksp_ew_rtol0", "0 <= rtol0 < 1", api, kctx->rtol_0, &kctx->rtol_0, NULL));
886: kctx->rtol_max = PetscMax(kctx->rtol_0, kctx->rtol_max);
887: PetscCall(PetscOptionsReal("-ksp_ew_rtolmax", "0 <= rtolmax < 1", api, kctx->rtol_max, &kctx->rtol_max, NULL));
888: PetscCall(PetscOptionsReal("-ksp_ew_gamma", "0 <= gamma <= 1", api, kctx->gamma, &kctx->gamma, NULL));
889: PetscCall(PetscOptionsReal("-ksp_ew_alpha", "1 < alpha <= 2", api, kctx->alpha, &kctx->alpha, NULL));
890: PetscCall(PetscOptionsReal("-ksp_ew_alpha2", "alpha2", NULL, kctx->alpha2, &kctx->alpha2, NULL));
891: PetscCall(PetscOptionsReal("-ksp_ew_threshold", "0 < threshold < 1", api, kctx->threshold, &kctx->threshold, NULL));
892: PetscCall(PetscOptionsReal("-ksp_ew_v4_p1", "p1", NULL, kctx->v4_p1, &kctx->v4_p1, NULL));
893: PetscCall(PetscOptionsReal("-ksp_ew_v4_p2", "p2", NULL, kctx->v4_p2, &kctx->v4_p2, NULL));
894: PetscCall(PetscOptionsReal("-ksp_ew_v4_p3", "p3", NULL, kctx->v4_p3, &kctx->v4_p3, NULL));
895: PetscCall(PetscOptionsReal("-ksp_ew_v4_m1", "Scaling when rk-1 in [p2,p3)", NULL, kctx->v4_m1, &kctx->v4_m1, NULL));
896: PetscCall(PetscOptionsReal("-ksp_ew_v4_m2", "Scaling when rk-1 in [p3,+infty)", NULL, kctx->v4_m2, &kctx->v4_m2, NULL));
897: PetscCall(PetscOptionsReal("-ksp_ew_v4_m3", "Threshold for successive rtol (0.1 in Eq.7)", NULL, kctx->v4_m3, &kctx->v4_m3, NULL));
898: PetscCall(PetscOptionsReal("-ksp_ew_v4_m4", "Adaptation scaling (0.5 in Eq.7)", NULL, kctx->v4_m4, &kctx->v4_m4, NULL));
899: PetscOptionsEnd();
900: PetscFunctionReturn(PETSC_SUCCESS);
901: }
903: /*@
904: SNESSetFromOptions - Sets various `SNES` and `KSP` parameters from user options.
906: Collective
908: Input Parameter:
909: . snes - the `SNES` context
911: Options Database Keys:
912: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, `SNESType` for complete list
913: . -snes_stol <stol> - convergence tolerance in terms of the norm of the change in the solution between steps
914: . -snes_atol <abstol> - absolute tolerance of residual norm
915: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
916: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
917: . -snes_force_iteration <force> - force `SNESSolve()` to take at least one iteration
918: . -snes_max_it <max_it> - maximum number of iterations
919: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
920: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
921: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
922: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
923: . -snes_lag_preconditioner_persists <true,false> - retains the -snes_lag_preconditioner information across multiple SNESSolve()
924: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
925: . -snes_lag_jacobian_persists <true,false> - retains the -snes_lag_jacobian information across multiple SNESSolve()
926: . -snes_tr_tol <trtol> - trust region tolerance
927: . -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.
928: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
929: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
930: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
931: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
932: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
933: . -snes_monitor_lg_range - plots residual norm at each iteration
934: . -snes_monitor_pause_final - Pauses all monitor drawing after the solver ends
935: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
936: . -snes_fd_color - use finite differences with coloring to compute Jacobian
937: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each `KSP` iteration
938: . -snes_converged_reason - print the reason for convergence/divergence after each solve
939: . -npc_snes_type <type> - the `SNES` type to use as a nonlinear preconditioner
940: . -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.
941: - -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.
943: Options Database Keys for Eisenstat-Walker method:
944: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
945: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
946: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
947: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
948: . -snes_ksp_ew_gamma <gamma> - Sets gamma
949: . -snes_ksp_ew_alpha <alpha> - Sets alpha
950: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
951: - -snes_ksp_ew_threshold <threshold> - Sets threshold
953: Level: beginner
955: Notes:
956: To see all options, run your program with the -help option or consult the users manual
958: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
959: and computing explicitly with
960: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
962: .seealso: [](ch_snes), `SNESType`, `SNESSetOptionsPrefix()`, `SNESResetFromOptions()`, `SNES`, `SNESCreate()`, `MatCreateSNESMF()`, `MatFDColoring`
963: @*/
964: PetscErrorCode SNESSetFromOptions(SNES snes)
965: {
966: PetscBool flg, pcset, persist, set;
967: PetscInt i, indx, lag, grids;
968: const char *deft = SNESNEWTONLS;
969: const char *convtests[] = {"default", "skip", "correct_pressure"};
970: SNESKSPEW *kctx = NULL;
971: char type[256], monfilename[PETSC_MAX_PATH_LEN], ewprefix[256];
972: PCSide pcside;
973: const char *optionsprefix;
975: PetscFunctionBegin;
977: PetscCall(SNESRegisterAll());
978: PetscObjectOptionsBegin((PetscObject)snes);
979: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
980: PetscCall(PetscOptionsFList("-snes_type", "Nonlinear solver method", "SNESSetType", SNESList, deft, type, 256, &flg));
981: if (flg) {
982: PetscCall(SNESSetType(snes, type));
983: } else if (!((PetscObject)snes)->type_name) {
984: PetscCall(SNESSetType(snes, deft));
985: }
986: PetscCall(PetscOptionsReal("-snes_stol", "Stop if step length less than", "SNESSetTolerances", snes->stol, &snes->stol, NULL));
987: PetscCall(PetscOptionsReal("-snes_atol", "Stop if function norm less than", "SNESSetTolerances", snes->abstol, &snes->abstol, NULL));
989: PetscCall(PetscOptionsReal("-snes_rtol", "Stop if decrease in function norm less than", "SNESSetTolerances", snes->rtol, &snes->rtol, NULL));
990: PetscCall(PetscOptionsReal("-snes_divergence_tolerance", "Stop if residual norm increases by this factor", "SNESSetDivergenceTolerance", snes->divtol, &snes->divtol, NULL));
991: PetscCall(PetscOptionsInt("-snes_max_it", "Maximum iterations", "SNESSetTolerances", snes->max_its, &snes->max_its, NULL));
992: PetscCall(PetscOptionsInt("-snes_max_funcs", "Maximum function evaluations", "SNESSetTolerances", snes->max_funcs, &snes->max_funcs, NULL));
993: PetscCall(PetscOptionsInt("-snes_max_fail", "Maximum nonlinear step failures", "SNESSetMaxNonlinearStepFailures", snes->maxFailures, &snes->maxFailures, NULL));
994: PetscCall(PetscOptionsInt("-snes_max_linear_solve_fail", "Maximum failures in linear solves allowed", "SNESSetMaxLinearSolveFailures", snes->maxLinearSolveFailures, &snes->maxLinearSolveFailures, NULL));
995: PetscCall(PetscOptionsBool("-snes_error_if_not_converged", "Generate error if solver does not converge", "SNESSetErrorIfNotConverged", snes->errorifnotconverged, &snes->errorifnotconverged, NULL));
996: PetscCall(PetscOptionsBool("-snes_force_iteration", "Force SNESSolve() to take at least one iteration", "SNESSetForceIteration", snes->forceiteration, &snes->forceiteration, NULL));
997: PetscCall(PetscOptionsBool("-snes_check_jacobian_domain_error", "Check Jacobian domain error after Jacobian evaluation", "SNESCheckJacobianDomainError", snes->checkjacdomainerror, &snes->checkjacdomainerror, NULL));
999: PetscCall(PetscOptionsInt("-snes_lag_preconditioner", "How often to rebuild preconditioner", "SNESSetLagPreconditioner", snes->lagpreconditioner, &lag, &flg));
1000: if (flg) {
1001: 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");
1002: PetscCall(SNESSetLagPreconditioner(snes, lag));
1003: }
1004: PetscCall(PetscOptionsBool("-snes_lag_preconditioner_persists", "Preconditioner lagging through multiple SNES solves", "SNESSetLagPreconditionerPersists", snes->lagjac_persist, &persist, &flg));
1005: if (flg) PetscCall(SNESSetLagPreconditionerPersists(snes, persist));
1006: PetscCall(PetscOptionsInt("-snes_lag_jacobian", "How often to rebuild Jacobian", "SNESSetLagJacobian", snes->lagjacobian, &lag, &flg));
1007: if (flg) {
1008: 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");
1009: PetscCall(SNESSetLagJacobian(snes, lag));
1010: }
1011: PetscCall(PetscOptionsBool("-snes_lag_jacobian_persists", "Jacobian lagging through multiple SNES solves", "SNESSetLagJacobianPersists", snes->lagjac_persist, &persist, &flg));
1012: if (flg) PetscCall(SNESSetLagJacobianPersists(snes, persist));
1014: PetscCall(PetscOptionsInt("-snes_grid_sequence", "Use grid sequencing to generate initial guess", "SNESSetGridSequence", snes->gridsequence, &grids, &flg));
1015: if (flg) PetscCall(SNESSetGridSequence(snes, grids));
1017: PetscCall(PetscOptionsEList("-snes_convergence_test", "Convergence test", "SNESSetConvergenceTest", convtests, PETSC_STATIC_ARRAY_LENGTH(convtests), "default", &indx, &flg));
1018: if (flg) {
1019: switch (indx) {
1020: case 0:
1021: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedDefault, NULL, NULL));
1022: break;
1023: case 1:
1024: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedSkip, NULL, NULL));
1025: break;
1026: case 2:
1027: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedCorrectPressure, NULL, NULL));
1028: break;
1029: }
1030: }
1032: PetscCall(PetscOptionsEList("-snes_norm_schedule", "SNES Norm schedule", "SNESSetNormSchedule", SNESNormSchedules, 5, "function", &indx, &flg));
1033: if (flg) PetscCall(SNESSetNormSchedule(snes, (SNESNormSchedule)indx));
1035: PetscCall(PetscOptionsEList("-snes_function_type", "SNES Norm schedule", "SNESSetFunctionType", SNESFunctionTypes, 2, "unpreconditioned", &indx, &flg));
1036: if (flg) PetscCall(SNESSetFunctionType(snes, (SNESFunctionType)indx));
1038: kctx = (SNESKSPEW *)snes->kspconvctx;
1040: PetscCall(PetscOptionsBool("-snes_ksp_ew", "Use Eisentat-Walker linear system convergence test", "SNESKSPSetUseEW", snes->ksp_ewconv, &snes->ksp_ewconv, NULL));
1042: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1043: PetscCall(PetscSNPrintf(ewprefix, sizeof(ewprefix), "%s%s", optionsprefix ? optionsprefix : "", "snes_"));
1044: PetscCall(SNESEWSetFromOptions_Private(kctx, PETSC_TRUE, PetscObjectComm((PetscObject)snes), ewprefix));
1046: flg = PETSC_FALSE;
1047: PetscCall(PetscOptionsBool("-snes_monitor_cancel", "Remove all monitors", "SNESMonitorCancel", flg, &flg, &set));
1048: if (set && flg) PetscCall(SNESMonitorCancel(snes));
1050: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor", "Monitor norm of function", "SNESMonitorDefault", SNESMonitorDefault, SNESMonitorDefaultSetUp));
1051: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_short", "Monitor norm of function with fewer digits", "SNESMonitorDefaultShort", SNESMonitorDefaultShort, NULL));
1052: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_range", "Monitor range of elements of function", "SNESMonitorRange", SNESMonitorRange, NULL));
1054: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_ratio", "Monitor ratios of the norm of function for consecutive steps", "SNESMonitorRatio", SNESMonitorRatio, SNESMonitorRatioSetUp));
1055: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_field", "Monitor norm of function (split into fields)", "SNESMonitorDefaultField", SNESMonitorDefaultField, NULL));
1056: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution", "View solution at each iteration", "SNESMonitorSolution", SNESMonitorSolution, NULL));
1057: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution_update", "View correction at each iteration", "SNESMonitorSolutionUpdate", SNESMonitorSolutionUpdate, NULL));
1058: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_residual", "View residual at each iteration", "SNESMonitorResidual", SNESMonitorResidual, NULL));
1059: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_jacupdate_spectrum", "Print the change in the spectrum of the Jacobian", "SNESMonitorJacUpdateSpectrum", SNESMonitorJacUpdateSpectrum, NULL));
1060: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_fields", "Monitor norm of function per field", "SNESMonitorSet", SNESMonitorFields, NULL));
1061: PetscCall(PetscOptionsBool("-snes_monitor_pause_final", "Pauses all draw monitors at the final iterate", "SNESMonitorPauseFinal_Internal", PETSC_FALSE, &snes->pauseFinal, NULL));
1063: PetscCall(PetscOptionsString("-snes_monitor_python", "Use Python function", "SNESMonitorSet", NULL, monfilename, sizeof(monfilename), &flg));
1064: if (flg) PetscCall(PetscPythonMonitorSet((PetscObject)snes, monfilename));
1066: flg = PETSC_FALSE;
1067: PetscCall(PetscOptionsBool("-snes_monitor_lg_range", "Plot function range at each iteration", "SNESMonitorLGRange", flg, &flg, NULL));
1068: if (flg) {
1069: PetscViewer ctx;
1071: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &ctx));
1072: PetscCall(SNESMonitorSet(snes, SNESMonitorLGRange, ctx, (PetscErrorCode(*)(void **))PetscViewerDestroy));
1073: }
1075: flg = PETSC_FALSE;
1076: PetscCall(PetscOptionsBool("-snes_converged_reason_view_cancel", "Remove all converged reason viewers", "SNESConvergedReasonViewCancel", flg, &flg, &set));
1077: if (set && flg) PetscCall(SNESConvergedReasonViewCancel(snes));
1079: flg = PETSC_FALSE;
1080: PetscCall(PetscOptionsBool("-snes_fd", "Use finite differences (slow) to compute Jacobian", "SNESComputeJacobianDefault", flg, &flg, NULL));
1081: if (flg) {
1082: void *functx;
1083: DM dm;
1084: PetscCall(SNESGetDM(snes, &dm));
1085: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1086: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
1087: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefault, functx));
1088: PetscCall(PetscInfo(snes, "Setting default finite difference Jacobian matrix\n"));
1089: }
1091: flg = PETSC_FALSE;
1092: PetscCall(PetscOptionsBool("-snes_fd_function", "Use finite differences (slow) to compute function from user objective", "SNESObjectiveComputeFunctionDefaultFD", flg, &flg, NULL));
1093: if (flg) PetscCall(SNESSetFunction(snes, NULL, SNESObjectiveComputeFunctionDefaultFD, NULL));
1095: flg = PETSC_FALSE;
1096: PetscCall(PetscOptionsBool("-snes_fd_color", "Use finite differences with coloring to compute Jacobian", "SNESComputeJacobianDefaultColor", flg, &flg, NULL));
1097: if (flg) {
1098: DM dm;
1099: PetscCall(SNESGetDM(snes, &dm));
1100: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1101: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefaultColor, NULL));
1102: PetscCall(PetscInfo(snes, "Setting default finite difference coloring Jacobian matrix\n"));
1103: }
1105: flg = PETSC_FALSE;
1106: PetscCall(PetscOptionsBool("-snes_mf_operator", "Use a Matrix-Free Jacobian with user-provided preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf_operator, &flg));
1107: if (flg && snes->mf_operator) {
1108: snes->mf_operator = PETSC_TRUE;
1109: snes->mf = PETSC_TRUE;
1110: }
1111: flg = PETSC_FALSE;
1112: PetscCall(PetscOptionsBool("-snes_mf", "Use a Matrix-Free Jacobian with no preconditioner matrix", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf, &flg));
1113: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1114: PetscCall(PetscOptionsInt("-snes_mf_version", "Matrix-Free routines version 1 or 2", "None", snes->mf_version, &snes->mf_version, NULL));
1116: flg = PETSC_FALSE;
1117: PetscCall(SNESGetNPCSide(snes, &pcside));
1118: PetscCall(PetscOptionsEnum("-snes_npc_side", "SNES nonlinear preconditioner side", "SNESSetNPCSide", PCSides, (PetscEnum)pcside, (PetscEnum *)&pcside, &flg));
1119: if (flg) PetscCall(SNESSetNPCSide(snes, pcside));
1121: #if defined(PETSC_HAVE_SAWS)
1122: /*
1123: Publish convergence information using SAWs
1124: */
1125: flg = PETSC_FALSE;
1126: PetscCall(PetscOptionsBool("-snes_monitor_saws", "Publish SNES progress using SAWs", "SNESMonitorSet", flg, &flg, NULL));
1127: if (flg) {
1128: void *ctx;
1129: PetscCall(SNESMonitorSAWsCreate(snes, &ctx));
1130: PetscCall(SNESMonitorSet(snes, SNESMonitorSAWs, ctx, SNESMonitorSAWsDestroy));
1131: }
1132: #endif
1133: #if defined(PETSC_HAVE_SAWS)
1134: {
1135: PetscBool set;
1136: flg = PETSC_FALSE;
1137: PetscCall(PetscOptionsBool("-snes_saws_block", "Block for SAWs at end of SNESSolve", "PetscObjectSAWsBlock", ((PetscObject)snes)->amspublishblock, &flg, &set));
1138: if (set) PetscCall(PetscObjectSAWsSetBlock((PetscObject)snes, flg));
1139: }
1140: #endif
1142: for (i = 0; i < numberofsetfromoptions; i++) PetscCall((*othersetfromoptions[i])(snes));
1144: PetscTryTypeMethod(snes, setfromoptions, PetscOptionsObject);
1146: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1147: PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)snes, PetscOptionsObject));
1148: PetscOptionsEnd();
1150: if (snes->linesearch) {
1151: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
1152: PetscCall(SNESLineSearchSetFromOptions(snes->linesearch));
1153: }
1155: if (snes->usesksp) {
1156: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
1157: PetscCall(KSPSetOperators(snes->ksp, snes->jacobian, snes->jacobian_pre));
1158: PetscCall(KSPSetFromOptions(snes->ksp));
1159: }
1161: /* if user has set the SNES NPC type via options database, create it. */
1162: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1163: PetscCall(PetscOptionsHasName(((PetscObject)snes)->options, optionsprefix, "-npc_snes_type", &pcset));
1164: if (pcset && (!snes->npc)) PetscCall(SNESGetNPC(snes, &snes->npc));
1165: if (snes->npc) PetscCall(SNESSetFromOptions(snes->npc));
1166: snes->setfromoptionscalled++;
1167: PetscFunctionReturn(PETSC_SUCCESS);
1168: }
1170: /*@
1171: SNESResetFromOptions - Sets various `SNES` and `KSP` parameters from user options ONLY if the `SNESSetFromOptions()` was previously called
1173: Collective
1175: Input Parameter:
1176: . snes - the `SNES` context
1178: Level: advanced
1180: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESSetOptionsPrefix()`
1181: @*/
1182: PetscErrorCode SNESResetFromOptions(SNES snes)
1183: {
1184: PetscFunctionBegin;
1185: if (snes->setfromoptionscalled) PetscCall(SNESSetFromOptions(snes));
1186: PetscFunctionReturn(PETSC_SUCCESS);
1187: }
1189: /*@C
1190: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1191: the nonlinear solvers.
1193: Logically Collective; No Fortran Support
1195: Input Parameters:
1196: + snes - the `SNES` context
1197: . compute - function to compute the context
1198: - destroy - function to destroy the context
1200: Calling sequence of `compute`:
1201: + snes - the `SNES` context
1202: - ctx - context to be computed
1204: Calling sequence of `destroy`:
1205: . ctx - context to be computed by `compute()`
1207: Level: intermediate
1209: Note:
1210: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1212: Use `SNESSetApplicationContext()` to see the context immediately
1214: .seealso: [](ch_snes), `SNESGetApplicationContext()`, `SNESSetApplicationContext()`
1215: @*/
1216: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES snes, void **ctx), PetscErrorCode (*destroy)(void **ctx))
1217: {
1218: PetscFunctionBegin;
1220: snes->ops->usercompute = compute;
1221: snes->ops->userdestroy = destroy;
1222: PetscFunctionReturn(PETSC_SUCCESS);
1223: }
1225: /*@
1226: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1228: Logically Collective
1230: Input Parameters:
1231: + snes - the `SNES` context
1232: - usrP - optional user context
1234: Level: intermediate
1236: Notes:
1237: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian, or other evaluation function
1238: with `SNESGetApplicationContext()`
1240: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1242: Fortran Note:
1243: You must write a Fortran interface definition for this
1244: function that tells Fortran the Fortran derived data type that you are passing in as the `usrP` argument.
1246: .seealso: [](ch_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1247: @*/
1248: PetscErrorCode SNESSetApplicationContext(SNES snes, void *usrP)
1249: {
1250: KSP ksp;
1252: PetscFunctionBegin;
1254: PetscCall(SNESGetKSP(snes, &ksp));
1255: PetscCall(KSPSetApplicationContext(ksp, usrP));
1256: snes->user = usrP;
1257: PetscFunctionReturn(PETSC_SUCCESS);
1258: }
1260: /*@
1261: SNESGetApplicationContext - Gets the user-defined context for the
1262: nonlinear solvers set with `SNESGetApplicationContext()` or `SNESSetComputeApplicationContext()`
1264: Not Collective
1266: Input Parameter:
1267: . snes - `SNES` context
1269: Output Parameter:
1270: . usrP - user context
1272: Level: intermediate
1274: Fortran Note:
1275: You must write a Fortran interface definition for this
1276: function that tells Fortran the Fortran derived data type that you are passing in as the `usrP` argument.
1278: .seealso: [](ch_snes), `SNESSetApplicationContext()`, `SNESSetComputeApplicationContext()`
1279: @*/
1280: PetscErrorCode SNESGetApplicationContext(SNES snes, void *usrP)
1281: {
1282: PetscFunctionBegin;
1284: *(void **)usrP = snes->user;
1285: PetscFunctionReturn(PETSC_SUCCESS);
1286: }
1288: /*@
1289: SNESSetUseMatrixFree - indicates that `SNES` should use matrix-free finite difference matrix-vector products to apply the Jacobian.
1291: Logically Collective
1293: Input Parameters:
1294: + snes - `SNES` context
1295: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1296: - 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
1297: this option no matrix-element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1299: Options Database Keys:
1300: + -snes_mf_operator - use matrix-free only for the mat operator
1301: . -snes_mf - use matrix-free for both the mat and pmat operator
1302: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1303: - -snes_fd - compute the Jacobian via finite differences (slow)
1305: Level: intermediate
1307: Note:
1308: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
1309: and computing explicitly with
1310: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1312: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`, `MatFDColoring`
1313: @*/
1314: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1315: {
1316: PetscFunctionBegin;
1320: snes->mf = mf_operator ? PETSC_TRUE : mf;
1321: snes->mf_operator = mf_operator;
1322: PetscFunctionReturn(PETSC_SUCCESS);
1323: }
1325: /*@
1326: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1328: Not Collective, but the resulting flags will be the same on all MPI processes
1330: Input Parameter:
1331: . snes - `SNES` context
1333: Output Parameters:
1334: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1335: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1337: Level: intermediate
1339: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1340: @*/
1341: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1342: {
1343: PetscFunctionBegin;
1345: if (mf) *mf = snes->mf;
1346: if (mf_operator) *mf_operator = snes->mf_operator;
1347: PetscFunctionReturn(PETSC_SUCCESS);
1348: }
1350: /*@
1351: SNESGetIterationNumber - Gets the number of nonlinear iterations completed in the current or most recent `SNESSolve()`
1353: Not Collective
1355: Input Parameter:
1356: . snes - `SNES` context
1358: Output Parameter:
1359: . iter - iteration number
1361: Level: intermediate
1363: Notes:
1364: For example, during the computation of iteration 2 this would return 1.
1366: This is useful for using lagged Jacobians (where one does not recompute the
1367: Jacobian at each `SNES` iteration). For example, the code
1368: .vb
1369: ierr = SNESGetIterationNumber(snes,&it);
1370: if (!(it % 2)) {
1371: [compute Jacobian here]
1372: }
1373: .ve
1374: can be used in your function that computes the Jacobian to cause the Jacobian to be
1375: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1377: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1379: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`, `SNESSetMonitor()`
1380: @*/
1381: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1382: {
1383: PetscFunctionBegin;
1385: PetscAssertPointer(iter, 2);
1386: *iter = snes->iter;
1387: PetscFunctionReturn(PETSC_SUCCESS);
1388: }
1390: /*@
1391: SNESSetIterationNumber - Sets the current iteration number.
1393: Not Collective
1395: Input Parameters:
1396: + snes - `SNES` context
1397: - iter - iteration number
1399: Level: developer
1401: Note:
1402: This should only be called inside a `SNES` nonlinear solver.
1404: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1405: @*/
1406: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1407: {
1408: PetscFunctionBegin;
1410: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1411: snes->iter = iter;
1412: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1413: PetscFunctionReturn(PETSC_SUCCESS);
1414: }
1416: /*@
1417: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1418: attempted by the nonlinear solver in the current or most recent `SNESSolve()` .
1420: Not Collective
1422: Input Parameter:
1423: . snes - `SNES` context
1425: Output Parameter:
1426: . nfails - number of unsuccessful steps attempted
1428: Level: intermediate
1430: Note:
1431: This counter is reset to zero for each successive call to `SNESSolve()`.
1433: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1434: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1435: @*/
1436: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1437: {
1438: PetscFunctionBegin;
1440: PetscAssertPointer(nfails, 2);
1441: *nfails = snes->numFailures;
1442: PetscFunctionReturn(PETSC_SUCCESS);
1443: }
1445: /*@
1446: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1447: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1449: Not Collective
1451: Input Parameters:
1452: + snes - `SNES` context
1453: - maxFails - maximum of unsuccessful steps
1455: Options Database Key:
1456: . -snes_max_fail <n> - maximum number of unsuccessful steps allowed
1458: Level: intermediate
1460: Developer Note:
1461: The options database key is wrong for this function name
1463: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1464: `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1465: @*/
1466: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1467: {
1468: PetscFunctionBegin;
1470: snes->maxFailures = maxFails;
1471: PetscFunctionReturn(PETSC_SUCCESS);
1472: }
1474: /*@
1475: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1476: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1478: Not Collective
1480: Input Parameter:
1481: . snes - `SNES` context
1483: Output Parameter:
1484: . maxFails - maximum of unsuccessful steps
1486: Level: intermediate
1488: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1489: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1490: @*/
1491: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1492: {
1493: PetscFunctionBegin;
1495: PetscAssertPointer(maxFails, 2);
1496: *maxFails = snes->maxFailures;
1497: PetscFunctionReturn(PETSC_SUCCESS);
1498: }
1500: /*@
1501: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1502: done by the `SNES` object in the current or most recent `SNESSolve()`
1504: Not Collective
1506: Input Parameter:
1507: . snes - `SNES` context
1509: Output Parameter:
1510: . nfuncs - number of evaluations
1512: Level: intermediate
1514: Note:
1515: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1517: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1518: @*/
1519: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1520: {
1521: PetscFunctionBegin;
1523: PetscAssertPointer(nfuncs, 2);
1524: *nfuncs = snes->nfuncs;
1525: PetscFunctionReturn(PETSC_SUCCESS);
1526: }
1528: /*@
1529: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1530: linear solvers in the current or most recent `SNESSolve()`
1532: Not Collective
1534: Input Parameter:
1535: . snes - `SNES` context
1537: Output Parameter:
1538: . nfails - number of failed solves
1540: Options Database Key:
1541: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1543: Level: intermediate
1545: Note:
1546: This counter is reset to zero for each successive call to `SNESSolve()`.
1548: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1549: @*/
1550: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1551: {
1552: PetscFunctionBegin;
1554: PetscAssertPointer(nfails, 2);
1555: *nfails = snes->numLinearSolveFailures;
1556: PetscFunctionReturn(PETSC_SUCCESS);
1557: }
1559: /*@
1560: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1561: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1563: Logically Collective
1565: Input Parameters:
1566: + snes - `SNES` context
1567: - maxFails - maximum allowed linear solve failures
1569: Options Database Key:
1570: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1572: Level: intermediate
1574: Note:
1575: By default this is 0; that is `SNES` returns on the first failed linear solve
1577: Developer Note:
1578: The options database key is wrong for this function name
1580: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1581: @*/
1582: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1583: {
1584: PetscFunctionBegin;
1587: snes->maxLinearSolveFailures = maxFails;
1588: PetscFunctionReturn(PETSC_SUCCESS);
1589: }
1591: /*@
1592: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1593: are allowed before `SNES` returns as unsuccessful
1595: Not Collective
1597: Input Parameter:
1598: . snes - `SNES` context
1600: Output Parameter:
1601: . maxFails - maximum of unsuccessful solves allowed
1603: Level: intermediate
1605: Note:
1606: By default this is 1; that is `SNES` returns on the first failed linear solve
1608: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1609: @*/
1610: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1611: {
1612: PetscFunctionBegin;
1614: PetscAssertPointer(maxFails, 2);
1615: *maxFails = snes->maxLinearSolveFailures;
1616: PetscFunctionReturn(PETSC_SUCCESS);
1617: }
1619: /*@
1620: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1621: used by the nonlinear solver in the most recent `SNESSolve()`
1623: Not Collective
1625: Input Parameter:
1626: . snes - `SNES` context
1628: Output Parameter:
1629: . lits - number of linear iterations
1631: Level: intermediate
1633: Notes:
1634: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1636: 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
1637: then call `KSPGetIterationNumber()` after the failed solve.
1639: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1640: @*/
1641: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1642: {
1643: PetscFunctionBegin;
1645: PetscAssertPointer(lits, 2);
1646: *lits = snes->linear_its;
1647: PetscFunctionReturn(PETSC_SUCCESS);
1648: }
1650: /*@
1651: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1652: are reset every time `SNESSolve()` is called.
1654: Logically Collective
1656: Input Parameters:
1657: + snes - `SNES` context
1658: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1660: Level: developer
1662: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1663: @*/
1664: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1665: {
1666: PetscFunctionBegin;
1669: snes->counters_reset = reset;
1670: PetscFunctionReturn(PETSC_SUCCESS);
1671: }
1673: /*@
1674: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1676: Not Collective, but the `SNES` and `KSP` objects must live on the same `MPI_Comm`
1678: Input Parameters:
1679: + snes - the `SNES` context
1680: - ksp - the `KSP` context
1682: Level: developer
1684: Notes:
1685: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1686: so this routine is rarely needed.
1688: The `KSP` object that is already in the `SNES` object has its reference count
1689: decreased by one when this is called.
1691: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`
1692: @*/
1693: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1694: {
1695: PetscFunctionBegin;
1698: PetscCheckSameComm(snes, 1, ksp, 2);
1699: PetscCall(PetscObjectReference((PetscObject)ksp));
1700: if (snes->ksp) PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1701: snes->ksp = ksp;
1702: PetscFunctionReturn(PETSC_SUCCESS);
1703: }
1705: /*@
1706: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1708: Collective
1710: Input Parameter:
1711: . comm - MPI communicator
1713: Output Parameter:
1714: . outsnes - the new `SNES` context
1716: Options Database Keys:
1717: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no preconditioning matrix
1718: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided preconditioning matrix
1719: as set by `SNESSetJacobian()`
1720: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1721: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1723: Level: beginner
1725: Developer Notes:
1726: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1727: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1728: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1729: in `SNESView()`.
1731: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1732: by help messages about meaningless `SNES` options.
1734: `SNES` always creates the snes->kspconvctx even though it is used by only one type. This should be fixed.
1736: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1737: @*/
1738: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1739: {
1740: SNES snes;
1741: SNESKSPEW *kctx;
1743: PetscFunctionBegin;
1744: PetscAssertPointer(outsnes, 2);
1745: *outsnes = NULL;
1746: PetscCall(SNESInitializePackage());
1748: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1750: snes->ops->converged = SNESConvergedDefault;
1751: snes->usesksp = PETSC_TRUE;
1752: snes->tolerancesset = PETSC_FALSE;
1753: snes->max_its = 50;
1754: snes->max_funcs = 10000;
1755: snes->norm = 0.0;
1756: snes->xnorm = 0.0;
1757: snes->ynorm = 0.0;
1758: snes->normschedule = SNES_NORM_ALWAYS;
1759: snes->functype = SNES_FUNCTION_DEFAULT;
1760: snes->rtol = PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8;
1761: snes->ttol = 0.0;
1762: snes->abstol = PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50;
1763: snes->stol = PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8;
1764: snes->deltatol = PetscDefined(USE_REAL_SINGLE) ? 1.e-6 : 1.e-12;
1765: snes->divtol = 1.e4;
1766: snes->rnorm0 = 0;
1767: snes->nfuncs = 0;
1768: snes->numFailures = 0;
1769: snes->maxFailures = 1;
1770: snes->linear_its = 0;
1771: snes->lagjacobian = 1;
1772: snes->jac_iter = 0;
1773: snes->lagjac_persist = PETSC_FALSE;
1774: snes->lagpreconditioner = 1;
1775: snes->pre_iter = 0;
1776: snes->lagpre_persist = PETSC_FALSE;
1777: snes->numbermonitors = 0;
1778: snes->numberreasonviews = 0;
1779: snes->data = NULL;
1780: snes->setupcalled = PETSC_FALSE;
1781: snes->ksp_ewconv = PETSC_FALSE;
1782: snes->nwork = 0;
1783: snes->work = NULL;
1784: snes->nvwork = 0;
1785: snes->vwork = NULL;
1786: snes->conv_hist_len = 0;
1787: snes->conv_hist_max = 0;
1788: snes->conv_hist = NULL;
1789: snes->conv_hist_its = NULL;
1790: snes->conv_hist_reset = PETSC_TRUE;
1791: snes->counters_reset = PETSC_TRUE;
1792: snes->vec_func_init_set = PETSC_FALSE;
1793: snes->reason = SNES_CONVERGED_ITERATING;
1794: snes->npcside = PC_RIGHT;
1795: snes->setfromoptionscalled = 0;
1797: snes->mf = PETSC_FALSE;
1798: snes->mf_operator = PETSC_FALSE;
1799: snes->mf_version = 1;
1801: snes->numLinearSolveFailures = 0;
1802: snes->maxLinearSolveFailures = 1;
1804: snes->vizerotolerance = 1.e-8;
1805: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1807: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1808: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1810: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1811: PetscCall(PetscNew(&kctx));
1813: snes->kspconvctx = (void *)kctx;
1814: kctx->version = 2;
1815: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1816: this was too large for some test cases */
1817: kctx->rtol_last = 0.0;
1818: kctx->rtol_max = 0.9;
1819: kctx->gamma = 1.0;
1820: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1821: kctx->alpha2 = kctx->alpha;
1822: kctx->threshold = 0.1;
1823: kctx->lresid_last = 0.0;
1824: kctx->norm_last = 0.0;
1826: kctx->rk_last = 0.0;
1827: kctx->rk_last_2 = 0.0;
1828: kctx->rtol_last_2 = 0.0;
1829: kctx->v4_p1 = 0.1;
1830: kctx->v4_p2 = 0.4;
1831: kctx->v4_p3 = 0.7;
1832: kctx->v4_m1 = 0.8;
1833: kctx->v4_m2 = 0.5;
1834: kctx->v4_m3 = 0.1;
1835: kctx->v4_m4 = 0.5;
1837: *outsnes = snes;
1838: PetscFunctionReturn(PETSC_SUCCESS);
1839: }
1841: /*@C
1842: SNESSetFunction - Sets the function evaluation routine and function
1843: vector for use by the `SNES` routines in solving systems of nonlinear
1844: equations.
1846: Logically Collective
1848: Input Parameters:
1849: + snes - the `SNES` context
1850: . r - vector to store function values, may be `NULL`
1851: . f - function evaluation routine; for calling sequence see `SNESFunctionFn`
1852: - ctx - [optional] user-defined context for private data for the
1853: function evaluation routine (may be `NULL`)
1855: Level: beginner
1857: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunctionFn`
1858: @*/
1859: PetscErrorCode SNESSetFunction(SNES snes, Vec r, SNESFunctionFn *f, void *ctx)
1860: {
1861: DM dm;
1863: PetscFunctionBegin;
1865: if (r) {
1867: PetscCheckSameComm(snes, 1, r, 2);
1868: PetscCall(PetscObjectReference((PetscObject)r));
1869: PetscCall(VecDestroy(&snes->vec_func));
1870: snes->vec_func = r;
1871: }
1872: PetscCall(SNESGetDM(snes, &dm));
1873: PetscCall(DMSNESSetFunction(dm, f, ctx));
1874: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1875: PetscFunctionReturn(PETSC_SUCCESS);
1876: }
1878: /*@C
1879: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1881: Logically Collective
1883: Input Parameters:
1884: + snes - the `SNES` context
1885: - f - vector to store function value
1887: Level: developer
1889: Notes:
1890: This should not be modified during the solution procedure.
1892: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1894: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1895: @*/
1896: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1897: {
1898: Vec vec_func;
1900: PetscFunctionBegin;
1903: PetscCheckSameComm(snes, 1, f, 2);
1904: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1905: snes->vec_func_init_set = PETSC_FALSE;
1906: PetscFunctionReturn(PETSC_SUCCESS);
1907: }
1908: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
1909: PetscCall(VecCopy(f, vec_func));
1911: snes->vec_func_init_set = PETSC_TRUE;
1912: PetscFunctionReturn(PETSC_SUCCESS);
1913: }
1915: /*@
1916: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
1917: of the `SNES` method, when norms are computed in the solving process
1919: Logically Collective
1921: Input Parameters:
1922: + snes - the `SNES` context
1923: - normschedule - the frequency of norm computation
1925: Options Database Key:
1926: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
1928: Level: advanced
1930: Notes:
1931: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
1932: of the nonlinear function and the taking of its norm at every iteration to
1933: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
1934: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
1935: may either be monitored for convergence or not. As these are often used as nonlinear
1936: preconditioners, monitoring the norm of their error is not a useful enterprise within
1937: their solution.
1939: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
1940: @*/
1941: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
1942: {
1943: PetscFunctionBegin;
1945: snes->normschedule = normschedule;
1946: PetscFunctionReturn(PETSC_SUCCESS);
1947: }
1949: /*@
1950: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
1951: of the `SNES` method.
1953: Logically Collective
1955: Input Parameters:
1956: + snes - the `SNES` context
1957: - normschedule - the type of the norm used
1959: Level: advanced
1961: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1962: @*/
1963: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
1964: {
1965: PetscFunctionBegin;
1967: *normschedule = snes->normschedule;
1968: PetscFunctionReturn(PETSC_SUCCESS);
1969: }
1971: /*@
1972: SNESSetFunctionNorm - Sets the last computed residual norm.
1974: Logically Collective
1976: Input Parameters:
1977: + snes - the `SNES` context
1978: - norm - the value of the norm
1980: Level: developer
1982: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
1983: @*/
1984: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
1985: {
1986: PetscFunctionBegin;
1988: snes->norm = norm;
1989: PetscFunctionReturn(PETSC_SUCCESS);
1990: }
1992: /*@
1993: SNESGetFunctionNorm - Gets the last computed norm of the residual
1995: Not Collective
1997: Input Parameter:
1998: . snes - the `SNES` context
2000: Output Parameter:
2001: . norm - the last computed residual norm
2003: Level: developer
2005: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2006: @*/
2007: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2008: {
2009: PetscFunctionBegin;
2011: PetscAssertPointer(norm, 2);
2012: *norm = snes->norm;
2013: PetscFunctionReturn(PETSC_SUCCESS);
2014: }
2016: /*@
2017: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2019: Not Collective
2021: Input Parameter:
2022: . snes - the `SNES` context
2024: Output Parameter:
2025: . ynorm - the last computed update norm
2027: Level: developer
2029: Note:
2030: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2032: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2033: @*/
2034: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2035: {
2036: PetscFunctionBegin;
2038: PetscAssertPointer(ynorm, 2);
2039: *ynorm = snes->ynorm;
2040: PetscFunctionReturn(PETSC_SUCCESS);
2041: }
2043: /*@
2044: SNESGetSolutionNorm - Gets the last computed norm of the solution
2046: Not Collective
2048: Input Parameter:
2049: . snes - the `SNES` context
2051: Output Parameter:
2052: . xnorm - the last computed solution norm
2054: Level: developer
2056: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2057: @*/
2058: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2059: {
2060: PetscFunctionBegin;
2062: PetscAssertPointer(xnorm, 2);
2063: *xnorm = snes->xnorm;
2064: PetscFunctionReturn(PETSC_SUCCESS);
2065: }
2067: /*@C
2068: SNESSetFunctionType - Sets the `SNESFunctionType`
2069: of the `SNES` method.
2071: Logically Collective
2073: Input Parameters:
2074: + snes - the `SNES` context
2075: - type - the function type
2077: Level: developer
2079: Values of the function type\:
2080: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2081: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2082: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2084: Note:
2085: Different `SNESType`s use this value in different ways
2087: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2088: @*/
2089: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2090: {
2091: PetscFunctionBegin;
2093: snes->functype = type;
2094: PetscFunctionReturn(PETSC_SUCCESS);
2095: }
2097: /*@C
2098: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2099: of the SNES method.
2101: Logically Collective
2103: Input Parameters:
2104: + snes - the `SNES` context
2105: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2107: Level: advanced
2109: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2110: @*/
2111: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2112: {
2113: PetscFunctionBegin;
2115: *type = snes->functype;
2116: PetscFunctionReturn(PETSC_SUCCESS);
2117: }
2119: /*@C
2120: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2121: use with composed nonlinear solvers.
2123: Input Parameters:
2124: + snes - the `SNES` context, usually of the `SNESType` `SNESNGS`
2125: . f - function evaluation routine to apply Gauss-Seidel, see `SNESNGSFn` for calling sequence
2126: - ctx - [optional] user-defined context for private data for the
2127: smoother evaluation routine (may be `NULL`)
2129: Level: intermediate
2131: Note:
2132: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2133: a problem appropriate update to the solution, particularly `SNESFAS`.
2135: .seealso: [](ch_snes), `SNESNGS`, `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`, `SNESNGSFn`
2136: @*/
2137: PetscErrorCode SNESSetNGS(SNES snes, SNESNGSFn *f, void *ctx)
2138: {
2139: DM dm;
2141: PetscFunctionBegin;
2143: PetscCall(SNESGetDM(snes, &dm));
2144: PetscCall(DMSNESSetNGS(dm, f, ctx));
2145: PetscFunctionReturn(PETSC_SUCCESS);
2146: }
2148: /*
2149: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2150: changed during the KSPSolve()
2151: */
2152: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, void *ctx)
2153: {
2154: DM dm;
2155: DMSNES sdm;
2157: PetscFunctionBegin;
2158: PetscCall(SNESGetDM(snes, &dm));
2159: PetscCall(DMGetDMSNES(dm, &sdm));
2160: /* A(x)*x - b(x) */
2161: if (sdm->ops->computepfunction) {
2162: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2163: PetscCall(VecScale(f, -1.0));
2164: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2165: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2166: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2167: PetscCall(MatMultAdd(snes->picard, x, f, f));
2168: } else {
2169: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2170: PetscCall(MatMult(snes->picard, x, f));
2171: }
2172: PetscFunctionReturn(PETSC_SUCCESS);
2173: }
2175: PetscErrorCode SNESPicardComputeFunction(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: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2188: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2189: } else {
2190: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2191: PetscCall(MatMult(snes->jacobian_pre, x, f));
2192: }
2193: PetscFunctionReturn(PETSC_SUCCESS);
2194: }
2196: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, void *ctx)
2197: {
2198: PetscFunctionBegin;
2199: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2200: /* must assembly if matrix-free to get the last SNES solution */
2201: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2202: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2203: PetscFunctionReturn(PETSC_SUCCESS);
2204: }
2206: /*@C
2207: SNESSetPicard - Use `SNES` to solve the system $A(x) x = bp(x) + b $ via a Picard type iteration (Picard linearization)
2209: Logically Collective
2211: Input Parameters:
2212: + snes - the `SNES` context
2213: . r - vector to store function values, may be `NULL`
2214: . bp - function evaluation routine, may be `NULL`, for the calling sequence see `SNESFunctionFn`
2215: . Amat - matrix with which A(x) x - bp(x) - b is to be computed
2216: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2217: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFn`
2218: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2220: Level: intermediate
2222: Notes:
2223: It is often better to provide the nonlinear function F() and some approximation to its Jacobian directly and use
2224: 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.
2226: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2228: Solves the equation $A(x) x = bp(x) - b$ via the defect correction algorithm $A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}$.
2229: When an exact solver is used this corresponds to the "classic" Picard $A(x^{n}) x^{n+1} = bp(x^{n}) + b$ iteration.
2231: Run with `-snes_mf_operator` to solve the system with Newton's method using A(x^{n}) to construct the preconditioner.
2233: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2234: the direct Picard iteration $A(x^n) x^{n+1} = bp(x^n) + b$
2236: 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
2237: 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
2238: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument \:-).
2240: 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
2241: A(x^{n}) is used to build the preconditioner
2243: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at a time) and thus represent Newton's method.
2245: 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
2246: 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
2247: 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`.
2248: See the comment in src/snes/tutorials/ex15.c.
2250: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`,
2251: `SNESFunctionFn`, `SNESJacobianFn`
2252: @*/
2253: PetscErrorCode SNESSetPicard(SNES snes, Vec r, SNESFunctionFn *bp, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
2254: {
2255: DM dm;
2257: PetscFunctionBegin;
2259: PetscCall(SNESGetDM(snes, &dm));
2260: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2261: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2262: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2263: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2264: PetscFunctionReturn(PETSC_SUCCESS);
2265: }
2267: /*@C
2268: SNESGetPicard - Returns the context for the Picard iteration
2270: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2272: Input Parameter:
2273: . snes - the `SNES` context
2275: Output Parameters:
2276: + r - the function (or `NULL`)
2277: . f - the function (or `NULL`); for calling sequence see `SNESFunctionFn`
2278: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2279: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2280: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFn`
2281: - ctx - the function context (or `NULL`)
2283: Level: advanced
2285: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunctionFn`, `SNESJacobianFn`
2286: @*/
2287: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, SNESFunctionFn **f, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
2288: {
2289: DM dm;
2291: PetscFunctionBegin;
2293: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2294: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2295: PetscCall(SNESGetDM(snes, &dm));
2296: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2297: PetscFunctionReturn(PETSC_SUCCESS);
2298: }
2300: /*@C
2301: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2303: Logically Collective
2305: Input Parameters:
2306: + snes - the `SNES` context
2307: . func - function evaluation routine, see `SNESInitialGuessFn` for the calling sequence
2308: - ctx - [optional] user-defined context for private data for the
2309: function evaluation routine (may be `NULL`)
2311: Level: intermediate
2313: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESInitialGuessFn`
2314: @*/
2315: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, SNESInitialGuessFn *func, void *ctx)
2316: {
2317: PetscFunctionBegin;
2319: if (func) snes->ops->computeinitialguess = func;
2320: if (ctx) snes->initialguessP = ctx;
2321: PetscFunctionReturn(PETSC_SUCCESS);
2322: }
2324: /*@C
2325: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2326: it assumes a zero right-hand side.
2328: Logically Collective
2330: Input Parameter:
2331: . snes - the `SNES` context
2333: Output Parameter:
2334: . rhs - the right-hand side vector or `NULL` if there is no right-hand side vector
2336: Level: intermediate
2338: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2339: @*/
2340: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2341: {
2342: PetscFunctionBegin;
2344: PetscAssertPointer(rhs, 2);
2345: *rhs = snes->vec_rhs;
2346: PetscFunctionReturn(PETSC_SUCCESS);
2347: }
2349: /*@
2350: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2352: Collective
2354: Input Parameters:
2355: + snes - the `SNES` context
2356: - x - input vector
2358: Output Parameter:
2359: . y - function vector, as set by `SNESSetFunction()`
2361: Level: developer
2363: Notes:
2364: `SNESComputeFunction()` is typically used within nonlinear solvers
2365: implementations, so users would not generally call this routine themselves.
2367: When solving for $F(x) = b$, this routine computes $y = F(x) - b$.
2369: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`
2370: @*/
2371: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec y)
2372: {
2373: DM dm;
2374: DMSNES sdm;
2376: PetscFunctionBegin;
2380: PetscCheckSameComm(snes, 1, x, 2);
2381: PetscCheckSameComm(snes, 1, y, 3);
2382: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2384: PetscCall(SNESGetDM(snes, &dm));
2385: PetscCall(DMGetDMSNES(dm, &sdm));
2386: 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().");
2387: if (sdm->ops->computefunction) {
2388: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2389: PetscCall(VecLockReadPush(x));
2390: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2391: snes->domainerror = PETSC_FALSE;
2392: {
2393: void *ctx;
2394: SNESFunctionFn *computefunction;
2395: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2396: PetscCallBack("SNES callback function", (*computefunction)(snes, x, y, ctx));
2397: }
2398: PetscCall(VecLockReadPop(x));
2399: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2400: } else /* if (snes->vec_rhs) */ {
2401: PetscCall(MatMult(snes->jacobian, x, y));
2402: }
2403: if (snes->vec_rhs) PetscCall(VecAXPY(y, -1.0, snes->vec_rhs));
2404: snes->nfuncs++;
2405: /*
2406: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2407: propagate the value to all processes
2408: */
2409: if (snes->domainerror) PetscCall(VecSetInf(y));
2410: PetscFunctionReturn(PETSC_SUCCESS);
2411: }
2413: /*@
2414: SNESComputeMFFunction - Calls the function that has been set with `SNESSetMFFunction()`.
2416: Collective
2418: Input Parameters:
2419: + snes - the `SNES` context
2420: - x - input vector
2422: Output Parameter:
2423: . y - function vector, as set by `SNESSetMFFunction()`
2425: Level: developer
2427: Notes:
2428: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2429: so users would not generally call this routine themselves.
2431: Since this function is intended for use with finite differencing it does not subtract the right-hand side vector provided with `SNESSolve()`
2432: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2433: 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.
2435: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF`
2436: @*/
2437: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2438: {
2439: DM dm;
2440: DMSNES sdm;
2442: PetscFunctionBegin;
2446: PetscCheckSameComm(snes, 1, x, 2);
2447: PetscCheckSameComm(snes, 1, y, 3);
2448: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2450: PetscCall(SNESGetDM(snes, &dm));
2451: PetscCall(DMGetDMSNES(dm, &sdm));
2452: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2453: PetscCall(VecLockReadPush(x));
2454: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2455: snes->domainerror = PETSC_FALSE;
2456: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2457: PetscCall(VecLockReadPop(x));
2458: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2459: snes->nfuncs++;
2460: /*
2461: domainerror might not be set on all processes; so we tag vector locally with Inf and the next inner product or norm will
2462: propagate the value to all processes
2463: */
2464: if (snes->domainerror) PetscCall(VecSetInf(y));
2465: PetscFunctionReturn(PETSC_SUCCESS);
2466: }
2468: /*@
2469: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2471: Collective
2473: Input Parameters:
2474: + snes - the `SNES` context
2475: . x - input vector
2476: - b - rhs vector
2478: Output Parameter:
2479: . x - new solution vector
2481: Level: developer
2483: Note:
2484: `SNESComputeNGS()` is typically used within composed nonlinear solver
2485: implementations, so most users would not generally call this routine
2486: themselves.
2488: .seealso: [](ch_snes), `SNESNGSFn`, `SNESSetNGS()`, `SNESComputeFunction()`, `SNESNGS`
2489: @*/
2490: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2491: {
2492: DM dm;
2493: DMSNES sdm;
2495: PetscFunctionBegin;
2499: PetscCheckSameComm(snes, 1, x, 3);
2500: if (b) PetscCheckSameComm(snes, 1, b, 2);
2501: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2502: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2503: PetscCall(SNESGetDM(snes, &dm));
2504: PetscCall(DMGetDMSNES(dm, &sdm));
2505: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2506: if (b) PetscCall(VecLockReadPush(b));
2507: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2508: if (b) PetscCall(VecLockReadPop(b));
2509: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2510: PetscFunctionReturn(PETSC_SUCCESS);
2511: }
2513: static PetscErrorCode SNESComputeFunction_FD(SNES snes, Vec Xin, Vec G)
2514: {
2515: Vec X;
2516: PetscScalar *g;
2517: PetscReal f, f2;
2518: PetscInt low, high, N, i;
2519: PetscBool flg;
2520: PetscReal h = .5 * PETSC_SQRT_MACHINE_EPSILON;
2522: PetscFunctionBegin;
2523: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_fd_delta", &h, &flg));
2524: PetscCall(VecDuplicate(Xin, &X));
2525: PetscCall(VecCopy(Xin, X));
2526: PetscCall(VecGetSize(X, &N));
2527: PetscCall(VecGetOwnershipRange(X, &low, &high));
2528: PetscCall(VecSetOption(X, VEC_IGNORE_OFF_PROC_ENTRIES, PETSC_TRUE));
2529: PetscCall(VecGetArray(G, &g));
2530: for (i = 0; i < N; i++) {
2531: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2532: PetscCall(VecAssemblyBegin(X));
2533: PetscCall(VecAssemblyEnd(X));
2534: PetscCall(SNESComputeObjective(snes, X, &f));
2535: PetscCall(VecSetValue(X, i, 2.0 * h, ADD_VALUES));
2536: PetscCall(VecAssemblyBegin(X));
2537: PetscCall(VecAssemblyEnd(X));
2538: PetscCall(SNESComputeObjective(snes, X, &f2));
2539: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2540: PetscCall(VecAssemblyBegin(X));
2541: PetscCall(VecAssemblyEnd(X));
2542: if (i >= low && i < high) g[i - low] = (f2 - f) / (2.0 * h);
2543: }
2544: PetscCall(VecRestoreArray(G, &g));
2545: PetscCall(VecDestroy(&X));
2546: PetscFunctionReturn(PETSC_SUCCESS);
2547: }
2549: PetscErrorCode SNESTestFunction(SNES snes)
2550: {
2551: Vec x, g1, g2, g3;
2552: PetscBool complete_print = PETSC_FALSE, test = PETSC_FALSE;
2553: PetscReal hcnorm, fdnorm, hcmax, fdmax, diffmax, diffnorm;
2554: PetscScalar dot;
2555: MPI_Comm comm;
2556: PetscViewer viewer, mviewer;
2557: PetscViewerFormat format;
2558: PetscInt tabs;
2559: static PetscBool directionsprinted = PETSC_FALSE;
2560: SNESObjectiveFn *objective;
2562: PetscFunctionBegin;
2563: PetscCall(SNESGetObjective(snes, &objective, NULL));
2564: if (!objective) PetscFunctionReturn(PETSC_SUCCESS);
2566: PetscObjectOptionsBegin((PetscObject)snes);
2567: PetscCall(PetscOptionsName("-snes_test_function", "Compare hand-coded and finite difference function", "None", &test));
2568: PetscCall(PetscOptionsViewer("-snes_test_function_view", "View difference between hand-coded and finite difference function element entries", "None", &mviewer, &format, &complete_print));
2569: PetscOptionsEnd();
2570: if (!test) {
2571: if (complete_print) PetscCall(PetscViewerDestroy(&mviewer));
2572: PetscFunctionReturn(PETSC_SUCCESS);
2573: }
2575: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2576: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2577: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2578: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2579: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Function -------------\n"));
2580: if (!complete_print && !directionsprinted) {
2581: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_function_view and optionally -snes_test_function <threshold> to show difference\n"));
2582: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference function entries greater than <threshold>.\n"));
2583: }
2584: if (!directionsprinted) {
2585: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Function, if (for double precision runs) ||F - Ffd||/||F|| is\n"));
2586: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Function is probably correct.\n"));
2587: directionsprinted = PETSC_TRUE;
2588: }
2589: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2591: PetscCall(SNESGetSolution(snes, &x));
2592: PetscCall(VecDuplicate(x, &g1));
2593: PetscCall(VecDuplicate(x, &g2));
2594: PetscCall(VecDuplicate(x, &g3));
2595: PetscCall(SNESComputeFunction(snes, x, g1));
2596: PetscCall(SNESComputeFunction_FD(snes, x, g2));
2598: PetscCall(VecNorm(g2, NORM_2, &fdnorm));
2599: PetscCall(VecNorm(g1, NORM_2, &hcnorm));
2600: PetscCall(VecNorm(g2, NORM_INFINITY, &fdmax));
2601: PetscCall(VecNorm(g1, NORM_INFINITY, &hcmax));
2602: PetscCall(VecDot(g1, g2, &dot));
2603: PetscCall(VecCopy(g1, g3));
2604: PetscCall(VecAXPY(g3, -1.0, g2));
2605: PetscCall(VecNorm(g3, NORM_2, &diffnorm));
2606: PetscCall(VecNorm(g3, NORM_INFINITY, &diffmax));
2607: PetscCall(PetscViewerASCIIPrintf(viewer, " ||Ffd|| %g, ||F|| = %g, angle cosine = (Ffd'F)/||Ffd||||F|| = %g\n", (double)fdnorm, (double)hcnorm, (double)(PetscRealPart(dot) / (fdnorm * hcnorm))));
2608: PetscCall(PetscViewerASCIIPrintf(viewer, " 2-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffnorm / PetscMax(hcnorm, fdnorm)), (double)diffnorm));
2609: PetscCall(PetscViewerASCIIPrintf(viewer, " max-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffmax / PetscMax(hcmax, fdmax)), (double)diffmax));
2611: if (complete_print) {
2612: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded function ----------\n"));
2613: PetscCall(VecView(g1, mviewer));
2614: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference function ----------\n"));
2615: PetscCall(VecView(g2, mviewer));
2616: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference function ----------\n"));
2617: PetscCall(VecView(g3, mviewer));
2618: }
2619: PetscCall(VecDestroy(&g1));
2620: PetscCall(VecDestroy(&g2));
2621: PetscCall(VecDestroy(&g3));
2623: if (complete_print) {
2624: PetscCall(PetscViewerPopFormat(mviewer));
2625: PetscCall(PetscViewerDestroy(&mviewer));
2626: }
2627: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2628: PetscFunctionReturn(PETSC_SUCCESS);
2629: }
2631: PetscErrorCode SNESTestJacobian(SNES snes)
2632: {
2633: Mat A, B, C, D, jacobian;
2634: Vec x = snes->vec_sol, f;
2635: PetscReal nrm, gnorm;
2636: PetscReal threshold = 1.e-5;
2637: MatType mattype;
2638: PetscInt m, n, M, N;
2639: void *functx;
2640: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, test = PETSC_FALSE, flg, istranspose;
2641: PetscViewer viewer, mviewer;
2642: MPI_Comm comm;
2643: PetscInt tabs;
2644: static PetscBool directionsprinted = PETSC_FALSE;
2645: PetscViewerFormat format;
2647: PetscFunctionBegin;
2648: PetscObjectOptionsBegin((PetscObject)snes);
2649: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &test));
2650: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2651: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2652: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2653: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2654: 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));
2655: PetscOptionsEnd();
2656: if (!test) PetscFunctionReturn(PETSC_SUCCESS);
2658: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2659: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2660: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2661: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2662: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2663: if (!complete_print && !directionsprinted) {
2664: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2665: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2666: }
2667: if (!directionsprinted) {
2668: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2669: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2670: directionsprinted = PETSC_TRUE;
2671: }
2672: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2674: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2675: if (!flg) jacobian = snes->jacobian;
2676: else jacobian = snes->jacobian_pre;
2678: if (!x) PetscCall(MatCreateVecs(jacobian, &x, NULL));
2679: else PetscCall(PetscObjectReference((PetscObject)x));
2680: PetscCall(VecDuplicate(x, &f));
2682: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2683: PetscCall(SNESComputeFunction(snes, x, f));
2684: PetscCall(VecDestroy(&f));
2685: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2686: while (jacobian) {
2687: Mat JT = NULL, Jsave = NULL;
2689: if (istranspose) {
2690: PetscCall(MatCreateTranspose(jacobian, &JT));
2691: Jsave = jacobian;
2692: jacobian = JT;
2693: }
2694: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2695: if (flg) {
2696: A = jacobian;
2697: PetscCall(PetscObjectReference((PetscObject)A));
2698: } else {
2699: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2700: }
2702: PetscCall(MatGetType(A, &mattype));
2703: PetscCall(MatGetSize(A, &M, &N));
2704: PetscCall(MatGetLocalSize(A, &m, &n));
2705: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2706: PetscCall(MatSetType(B, mattype));
2707: PetscCall(MatSetSizes(B, m, n, M, N));
2708: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2709: PetscCall(MatSetUp(B));
2710: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2712: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2713: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2715: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2716: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2717: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2718: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2719: PetscCall(MatDestroy(&D));
2720: if (!gnorm) gnorm = 1; /* just in case */
2721: PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2723: if (complete_print) {
2724: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2725: PetscCall(MatView(A, mviewer));
2726: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2727: PetscCall(MatView(B, mviewer));
2728: }
2730: if (threshold_print || complete_print) {
2731: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2732: PetscScalar *cvals;
2733: const PetscInt *bcols;
2734: const PetscScalar *bvals;
2736: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2737: PetscCall(MatSetType(C, mattype));
2738: PetscCall(MatSetSizes(C, m, n, M, N));
2739: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2740: PetscCall(MatSetUp(C));
2741: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2743: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2744: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2746: for (row = Istart; row < Iend; row++) {
2747: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2748: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2749: for (j = 0, cncols = 0; j < bncols; j++) {
2750: if (PetscAbsScalar(bvals[j]) > threshold) {
2751: ccols[cncols] = bcols[j];
2752: cvals[cncols] = bvals[j];
2753: cncols += 1;
2754: }
2755: }
2756: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2757: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2758: PetscCall(PetscFree2(ccols, cvals));
2759: }
2760: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2761: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2762: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2763: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2764: PetscCall(MatDestroy(&C));
2765: }
2766: PetscCall(MatDestroy(&A));
2767: PetscCall(MatDestroy(&B));
2768: PetscCall(MatDestroy(&JT));
2769: if (Jsave) jacobian = Jsave;
2770: if (jacobian != snes->jacobian_pre) {
2771: jacobian = snes->jacobian_pre;
2772: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2773: } else jacobian = NULL;
2774: }
2775: PetscCall(VecDestroy(&x));
2776: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2777: if (mviewer) PetscCall(PetscOptionsRestoreViewer(&mviewer));
2778: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2779: PetscFunctionReturn(PETSC_SUCCESS);
2780: }
2782: /*@
2783: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2785: Collective
2787: Input Parameters:
2788: + snes - the `SNES` context
2789: - X - input vector
2791: Output Parameters:
2792: + A - Jacobian matrix
2793: - B - optional matrix for building the preconditioner, usually the same as `A`
2795: Options Database Keys:
2796: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2797: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2798: . -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.
2799: . -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
2800: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2801: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2802: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2803: . -snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix
2804: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2805: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2806: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2807: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2808: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2809: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2810: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2812: Level: developer
2814: Note:
2815: Most users should not need to explicitly call this routine, as it
2816: is used internally within the nonlinear solvers.
2818: Developer Note:
2819: 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
2820: with the `SNESType` of test that has been removed.
2822: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
2823: @*/
2824: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2825: {
2826: PetscBool flag;
2827: DM dm;
2828: DMSNES sdm;
2829: KSP ksp;
2831: PetscFunctionBegin;
2834: PetscCheckSameComm(snes, 1, X, 2);
2835: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2836: PetscCall(SNESGetDM(snes, &dm));
2837: PetscCall(DMGetDMSNES(dm, &sdm));
2839: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2840: if (snes->lagjacobian == -2) {
2841: snes->lagjacobian = -1;
2843: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2844: } else if (snes->lagjacobian == -1) {
2845: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2846: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2847: if (flag) {
2848: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2849: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2850: }
2851: PetscFunctionReturn(PETSC_SUCCESS);
2852: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2853: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2854: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2855: if (flag) {
2856: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2857: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2858: }
2859: PetscFunctionReturn(PETSC_SUCCESS);
2860: }
2861: if (snes->npc && snes->npcside == PC_LEFT) {
2862: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2863: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2864: PetscFunctionReturn(PETSC_SUCCESS);
2865: }
2867: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2868: PetscCall(VecLockReadPush(X));
2869: {
2870: void *ctx;
2871: SNESJacobianFn *J;
2872: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2873: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2874: }
2875: PetscCall(VecLockReadPop(X));
2876: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
2878: /* attach latest linearization point to the preconditioning matrix */
2879: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
2881: /* the next line ensures that snes->ksp exists */
2882: PetscCall(SNESGetKSP(snes, &ksp));
2883: if (snes->lagpreconditioner == -2) {
2884: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
2885: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2886: snes->lagpreconditioner = -1;
2887: } else if (snes->lagpreconditioner == -1) {
2888: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
2889: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2890: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
2891: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
2892: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
2893: } else {
2894: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
2895: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
2896: }
2898: /* monkey business to allow testing Jacobians in multilevel solvers.
2899: This is needed because the SNESTestXXX interface does not accept vectors and matrices */
2900: {
2901: Vec xsave = snes->vec_sol;
2902: Mat jacobiansave = snes->jacobian;
2903: Mat jacobian_presave = snes->jacobian_pre;
2905: snes->vec_sol = X;
2906: snes->jacobian = A;
2907: snes->jacobian_pre = B;
2908: PetscCall(SNESTestFunction(snes));
2909: PetscCall(SNESTestJacobian(snes));
2911: snes->vec_sol = xsave;
2912: snes->jacobian = jacobiansave;
2913: snes->jacobian_pre = jacobian_presave;
2914: }
2916: {
2917: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
2918: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
2919: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
2920: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
2921: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
2922: if (flag || flag_draw || flag_contour) {
2923: Mat Bexp_mine = NULL, Bexp, FDexp;
2924: PetscViewer vdraw, vstdout;
2925: PetscBool flg;
2926: if (flag_operator) {
2927: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
2928: Bexp = Bexp_mine;
2929: } else {
2930: /* See if the preconditioning matrix can be viewed and added directly */
2931: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPIBAIJ, ""));
2932: if (flg) Bexp = B;
2933: else {
2934: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
2935: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
2936: Bexp = Bexp_mine;
2937: }
2938: }
2939: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
2940: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
2941: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
2942: if (flag_draw || flag_contour) {
2943: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
2944: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2945: } else vdraw = NULL;
2946: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
2947: if (flag) PetscCall(MatView(Bexp, vstdout));
2948: if (vdraw) PetscCall(MatView(Bexp, vdraw));
2949: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
2950: if (flag) PetscCall(MatView(FDexp, vstdout));
2951: if (vdraw) PetscCall(MatView(FDexp, vdraw));
2952: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
2953: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
2954: if (flag) PetscCall(MatView(FDexp, vstdout));
2955: if (vdraw) { /* Always use contour for the difference */
2956: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
2957: PetscCall(MatView(FDexp, vdraw));
2958: PetscCall(PetscViewerPopFormat(vdraw));
2959: }
2960: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
2961: PetscCall(PetscViewerDestroy(&vdraw));
2962: PetscCall(MatDestroy(&Bexp_mine));
2963: PetscCall(MatDestroy(&FDexp));
2964: }
2965: }
2966: {
2967: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
2968: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
2969: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
2970: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
2971: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
2972: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
2973: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
2974: if (flag_threshold) {
2975: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
2976: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
2977: }
2978: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
2979: Mat Bfd;
2980: PetscViewer vdraw, vstdout;
2981: MatColoring coloring;
2982: ISColoring iscoloring;
2983: MatFDColoring matfdcoloring;
2984: SNESFunctionFn *func;
2985: void *funcctx;
2986: PetscReal norm1, norm2, normmax;
2988: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
2989: PetscCall(MatColoringCreate(Bfd, &coloring));
2990: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
2991: PetscCall(MatColoringSetFromOptions(coloring));
2992: PetscCall(MatColoringApply(coloring, &iscoloring));
2993: PetscCall(MatColoringDestroy(&coloring));
2994: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
2995: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
2996: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
2997: PetscCall(ISColoringDestroy(&iscoloring));
2999: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
3000: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
3001: PetscCall(MatFDColoringSetFunction(matfdcoloring, (PetscErrorCode(*)(void))func, funcctx));
3002: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
3003: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
3004: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3005: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
3006: PetscCall(MatFDColoringDestroy(&matfdcoloring));
3008: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3009: if (flag_draw || flag_contour) {
3010: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3011: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3012: } else vdraw = NULL;
3013: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
3014: if (flag_display) PetscCall(MatView(B, vstdout));
3015: if (vdraw) PetscCall(MatView(B, vdraw));
3016: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
3017: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3018: if (vdraw) PetscCall(MatView(Bfd, vdraw));
3019: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
3020: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
3021: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
3022: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
3023: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
3024: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3025: if (vdraw) { /* Always use contour for the difference */
3026: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3027: PetscCall(MatView(Bfd, vdraw));
3028: PetscCall(PetscViewerPopFormat(vdraw));
3029: }
3030: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3032: if (flag_threshold) {
3033: PetscInt bs, rstart, rend, i;
3034: PetscCall(MatGetBlockSize(B, &bs));
3035: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
3036: for (i = rstart; i < rend; i++) {
3037: const PetscScalar *ba, *ca;
3038: const PetscInt *bj, *cj;
3039: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
3040: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
3041: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
3042: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
3043: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
3044: for (j = 0; j < bn; j++) {
3045: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3046: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
3047: maxentrycol = bj[j];
3048: maxentry = PetscRealPart(ba[j]);
3049: }
3050: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
3051: maxdiffcol = bj[j];
3052: maxdiff = PetscRealPart(ca[j]);
3053: }
3054: if (rdiff > maxrdiff) {
3055: maxrdiffcol = bj[j];
3056: maxrdiff = rdiff;
3057: }
3058: }
3059: if (maxrdiff > 1) {
3060: 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));
3061: for (j = 0; j < bn; j++) {
3062: PetscReal rdiff;
3063: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3064: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
3065: }
3066: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
3067: }
3068: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
3069: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
3070: }
3071: }
3072: PetscCall(PetscViewerDestroy(&vdraw));
3073: PetscCall(MatDestroy(&Bfd));
3074: }
3075: }
3076: PetscFunctionReturn(PETSC_SUCCESS);
3077: }
3079: /*@C
3080: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3081: location to store the matrix.
3083: Logically Collective
3085: Input Parameters:
3086: + snes - the `SNES` context
3087: . Amat - the matrix that defines the (approximate) Jacobian
3088: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3089: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFn` for details
3090: - ctx - [optional] user-defined context for private data for the
3091: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3093: Level: beginner
3095: Notes:
3096: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3097: each matrix.
3099: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3100: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3102: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3103: must be a `MatFDColoring`.
3105: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3106: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3108: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3109: `SNESSetPicard()`, `SNESJacobianFn`, `SNESFunctionFn`
3110: @*/
3111: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
3112: {
3113: DM dm;
3115: PetscFunctionBegin;
3119: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3120: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3121: PetscCall(SNESGetDM(snes, &dm));
3122: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3123: if (Amat) {
3124: PetscCall(PetscObjectReference((PetscObject)Amat));
3125: PetscCall(MatDestroy(&snes->jacobian));
3127: snes->jacobian = Amat;
3128: }
3129: if (Pmat) {
3130: PetscCall(PetscObjectReference((PetscObject)Pmat));
3131: PetscCall(MatDestroy(&snes->jacobian_pre));
3133: snes->jacobian_pre = Pmat;
3134: }
3135: PetscFunctionReturn(PETSC_SUCCESS);
3136: }
3138: /*@C
3139: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3140: provided context for evaluating the Jacobian.
3142: Not Collective, but `Mat` object will be parallel if `SNES` is
3144: Input Parameter:
3145: . snes - the nonlinear solver context
3147: Output Parameters:
3148: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3149: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3150: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFn`
3151: - ctx - location to stash Jacobian ctx (or `NULL`)
3153: Level: advanced
3155: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFn`, `SNESGetFunction()`
3156: @*/
3157: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
3158: {
3159: DM dm;
3161: PetscFunctionBegin;
3163: if (Amat) *Amat = snes->jacobian;
3164: if (Pmat) *Pmat = snes->jacobian_pre;
3165: PetscCall(SNESGetDM(snes, &dm));
3166: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3167: PetscFunctionReturn(PETSC_SUCCESS);
3168: }
3170: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3171: {
3172: DM dm;
3173: DMSNES sdm;
3175: PetscFunctionBegin;
3176: PetscCall(SNESGetDM(snes, &dm));
3177: PetscCall(DMGetDMSNES(dm, &sdm));
3178: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3179: DM dm;
3180: PetscBool isdense, ismf;
3182: PetscCall(SNESGetDM(snes, &dm));
3183: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3184: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3185: if (isdense) {
3186: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3187: } else if (!ismf) {
3188: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3189: }
3190: }
3191: PetscFunctionReturn(PETSC_SUCCESS);
3192: }
3194: /*@
3195: SNESSetUp - Sets up the internal data structures for the later use
3196: of a nonlinear solver.
3198: Collective
3200: Input Parameter:
3201: . snes - the `SNES` context
3203: Level: advanced
3205: Note:
3206: For basic use of the `SNES` solvers the user need not explicitly call
3207: `SNESSetUp()`, since these actions will automatically occur during
3208: the call to `SNESSolve()`. However, if one wishes to control this
3209: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3210: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3212: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`
3213: @*/
3214: PetscErrorCode SNESSetUp(SNES snes)
3215: {
3216: DM dm;
3217: DMSNES sdm;
3218: SNESLineSearch linesearch, pclinesearch;
3219: void *lsprectx, *lspostctx;
3220: PetscBool mf_operator, mf;
3221: Vec f, fpc;
3222: void *funcctx;
3223: void *jacctx, *appctx;
3224: Mat j, jpre;
3225: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3226: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3227: SNESFunctionFn *func;
3228: SNESJacobianFn *jac;
3230: PetscFunctionBegin;
3232: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3233: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3235: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3237: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3239: PetscCall(SNESGetDM(snes, &dm));
3240: PetscCall(DMGetDMSNES(dm, &sdm));
3241: PetscCall(SNESSetDefaultComputeJacobian(snes));
3243: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3245: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3247: if (snes->linesearch) {
3248: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3249: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3250: }
3252: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3253: if (snes->npc && snes->npcside == PC_LEFT) {
3254: snes->mf = PETSC_TRUE;
3255: snes->mf_operator = PETSC_FALSE;
3256: }
3258: if (snes->npc) {
3259: /* copy the DM over */
3260: PetscCall(SNESGetDM(snes, &dm));
3261: PetscCall(SNESSetDM(snes->npc, dm));
3263: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3264: PetscCall(VecDuplicate(f, &fpc));
3265: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3266: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3267: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3268: PetscCall(SNESGetApplicationContext(snes, &appctx));
3269: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3270: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3271: PetscCall(VecDestroy(&fpc));
3273: /* copy the function pointers over */
3274: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3276: /* default to 1 iteration */
3277: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3278: if (snes->npcside == PC_RIGHT) {
3279: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3280: } else {
3281: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3282: }
3283: PetscCall(SNESSetFromOptions(snes->npc));
3285: /* copy the line search context over */
3286: if (snes->linesearch && snes->npc->linesearch) {
3287: PetscCall(SNESGetLineSearch(snes, &linesearch));
3288: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3289: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3290: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3291: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3292: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3293: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3294: }
3295: }
3296: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3297: if (snes->ops->usercompute && !snes->user) PetscCallBack("SNES callback compute application context", (*snes->ops->usercompute)(snes, (void **)&snes->user));
3299: snes->jac_iter = 0;
3300: snes->pre_iter = 0;
3302: PetscTryTypeMethod(snes, setup);
3304: PetscCall(SNESSetDefaultComputeJacobian(snes));
3306: if (snes->npc && snes->npcside == PC_LEFT) {
3307: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3308: if (snes->linesearch) {
3309: PetscCall(SNESGetLineSearch(snes, &linesearch));
3310: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3311: }
3312: }
3313: }
3314: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3315: snes->setupcalled = PETSC_TRUE;
3316: PetscFunctionReturn(PETSC_SUCCESS);
3317: }
3319: /*@
3320: SNESReset - Resets a `SNES` context to the snessetupcalled = 0 state and removes any allocated `Vec`s and `Mat`s
3322: Collective
3324: Input Parameter:
3325: . snes - iterative context obtained from `SNESCreate()`
3327: Level: intermediate
3329: Notes:
3330: Call this if you wish to reuse a `SNES` but with different size vectors
3332: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3334: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3335: @*/
3336: PetscErrorCode SNESReset(SNES snes)
3337: {
3338: PetscFunctionBegin;
3340: if (snes->ops->userdestroy && snes->user) {
3341: PetscCallBack("SNES callback destroy application context", (*snes->ops->userdestroy)((void **)&snes->user));
3342: snes->user = NULL;
3343: }
3344: if (snes->npc) PetscCall(SNESReset(snes->npc));
3346: PetscTryTypeMethod(snes, reset);
3347: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3349: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3351: PetscCall(VecDestroy(&snes->vec_rhs));
3352: PetscCall(VecDestroy(&snes->vec_sol));
3353: PetscCall(VecDestroy(&snes->vec_sol_update));
3354: PetscCall(VecDestroy(&snes->vec_func));
3355: PetscCall(MatDestroy(&snes->jacobian));
3356: PetscCall(MatDestroy(&snes->jacobian_pre));
3357: PetscCall(MatDestroy(&snes->picard));
3358: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3359: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3361: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3363: snes->nwork = snes->nvwork = 0;
3364: snes->setupcalled = PETSC_FALSE;
3365: PetscFunctionReturn(PETSC_SUCCESS);
3366: }
3368: /*@
3369: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()`
3371: Collective
3373: Input Parameter:
3374: . snes - iterative context obtained from `SNESCreate()`
3376: Level: intermediate
3378: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3379: @*/
3380: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3381: {
3382: PetscInt i;
3384: PetscFunctionBegin;
3386: for (i = 0; i < snes->numberreasonviews; i++) {
3387: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3388: }
3389: snes->numberreasonviews = 0;
3390: PetscFunctionReturn(PETSC_SUCCESS);
3391: }
3393: /*@C
3394: SNESDestroy - Destroys the nonlinear solver context that was created
3395: with `SNESCreate()`.
3397: Collective
3399: Input Parameter:
3400: . snes - the `SNES` context
3402: Level: beginner
3404: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3405: @*/
3406: PetscErrorCode SNESDestroy(SNES *snes)
3407: {
3408: PetscFunctionBegin;
3409: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3411: if (--((PetscObject)*snes)->refct > 0) {
3412: *snes = NULL;
3413: PetscFunctionReturn(PETSC_SUCCESS);
3414: }
3416: PetscCall(SNESReset(*snes));
3417: PetscCall(SNESDestroy(&(*snes)->npc));
3419: /* if memory was published with SAWs then destroy it */
3420: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3421: PetscTryTypeMethod(*snes, destroy);
3423: if ((*snes)->dm) PetscCall(DMCoarsenHookRemove((*snes)->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3424: PetscCall(DMDestroy(&(*snes)->dm));
3425: PetscCall(KSPDestroy(&(*snes)->ksp));
3426: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3428: PetscCall(PetscFree((*snes)->kspconvctx));
3429: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)((*snes)->cnvP));
3430: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3431: PetscCall(SNESMonitorCancel(*snes));
3432: PetscCall(SNESConvergedReasonViewCancel(*snes));
3433: PetscCall(PetscHeaderDestroy(snes));
3434: PetscFunctionReturn(PETSC_SUCCESS);
3435: }
3437: /* ----------- Routines to set solver parameters ---------- */
3439: /*@
3440: SNESSetLagPreconditioner - Determines when the preconditioner is rebuilt in the nonlinear solve.
3442: Logically Collective
3444: Input Parameters:
3445: + snes - the `SNES` context
3446: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3447: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3449: Options Database Keys:
3450: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3451: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3452: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3453: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3455: Level: intermediate
3457: Notes:
3458: The default is 1
3460: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3462: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3464: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3465: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3466: @*/
3467: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3468: {
3469: PetscFunctionBegin;
3471: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3472: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3474: snes->lagpreconditioner = lag;
3475: PetscFunctionReturn(PETSC_SUCCESS);
3476: }
3478: /*@
3479: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3481: Logically Collective
3483: Input Parameters:
3484: + snes - the `SNES` context
3485: - steps - the number of refinements to do, defaults to 0
3487: Options Database Key:
3488: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3490: Level: intermediate
3492: Note:
3493: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3495: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3496: `SNESetDM()`
3497: @*/
3498: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3499: {
3500: PetscFunctionBegin;
3503: snes->gridsequence = steps;
3504: PetscFunctionReturn(PETSC_SUCCESS);
3505: }
3507: /*@
3508: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3510: Logically Collective
3512: Input Parameter:
3513: . snes - the `SNES` context
3515: Output Parameter:
3516: . steps - the number of refinements to do, defaults to 0
3518: Level: intermediate
3520: .seealso: [](ch_snes), `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3521: @*/
3522: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3523: {
3524: PetscFunctionBegin;
3526: *steps = snes->gridsequence;
3527: PetscFunctionReturn(PETSC_SUCCESS);
3528: }
3530: /*@
3531: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3533: Not Collective
3535: Input Parameter:
3536: . snes - the `SNES` context
3538: Output Parameter:
3539: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3540: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3542: Level: intermediate
3544: Notes:
3545: The default is 1
3547: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3549: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3550: @*/
3551: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3552: {
3553: PetscFunctionBegin;
3555: *lag = snes->lagpreconditioner;
3556: PetscFunctionReturn(PETSC_SUCCESS);
3557: }
3559: /*@
3560: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3561: often the preconditioner is rebuilt.
3563: Logically Collective
3565: Input Parameters:
3566: + snes - the `SNES` context
3567: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3568: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3570: Options Database Keys:
3571: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3572: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3573: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3574: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3576: Level: intermediate
3578: Notes:
3579: The default is 1
3581: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3583: 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
3584: at the next Newton step but never again (unless it is reset to another value)
3586: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3587: @*/
3588: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3589: {
3590: PetscFunctionBegin;
3592: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3593: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3595: snes->lagjacobian = lag;
3596: PetscFunctionReturn(PETSC_SUCCESS);
3597: }
3599: /*@
3600: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3602: Not Collective
3604: Input Parameter:
3605: . snes - the `SNES` context
3607: Output Parameter:
3608: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3609: the Jacobian is built etc.
3611: Level: intermediate
3613: Notes:
3614: The default is 1
3616: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3618: .seealso: [](ch_snes), `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3620: @*/
3621: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3622: {
3623: PetscFunctionBegin;
3625: *lag = snes->lagjacobian;
3626: PetscFunctionReturn(PETSC_SUCCESS);
3627: }
3629: /*@
3630: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3632: Logically collective
3634: Input Parameters:
3635: + snes - the `SNES` context
3636: - flg - jacobian lagging persists if true
3638: Options Database Keys:
3639: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3640: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3641: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3642: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3644: Level: advanced
3646: Notes:
3647: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3649: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3650: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3651: timesteps may present huge efficiency gains.
3653: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3654: @*/
3655: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3656: {
3657: PetscFunctionBegin;
3660: snes->lagjac_persist = flg;
3661: PetscFunctionReturn(PETSC_SUCCESS);
3662: }
3664: /*@
3665: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3667: Logically Collective
3669: Input Parameters:
3670: + snes - the `SNES` context
3671: - flg - preconditioner lagging persists if true
3673: Options Database Keys:
3674: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3675: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3676: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3677: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3679: Level: developer
3681: Notes:
3682: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3684: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3685: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3686: several timesteps may present huge efficiency gains.
3688: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3689: @*/
3690: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3691: {
3692: PetscFunctionBegin;
3695: snes->lagpre_persist = flg;
3696: PetscFunctionReturn(PETSC_SUCCESS);
3697: }
3699: /*@
3700: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3702: Logically Collective
3704: Input Parameters:
3705: + snes - the `SNES` context
3706: - force - `PETSC_TRUE` require at least one iteration
3708: Options Database Key:
3709: . -snes_force_iteration <force> - Sets forcing an iteration
3711: Level: intermediate
3713: Note:
3714: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3716: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3717: @*/
3718: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3719: {
3720: PetscFunctionBegin;
3722: snes->forceiteration = force;
3723: PetscFunctionReturn(PETSC_SUCCESS);
3724: }
3726: /*@
3727: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3729: Logically Collective
3731: Input Parameter:
3732: . snes - the `SNES` context
3734: Output Parameter:
3735: . force - `PETSC_TRUE` requires at least one iteration.
3737: Level: intermediate
3739: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`
3740: @*/
3741: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3742: {
3743: PetscFunctionBegin;
3745: *force = snes->forceiteration;
3746: PetscFunctionReturn(PETSC_SUCCESS);
3747: }
3749: /*@
3750: SNESSetTolerances - Sets `SNES` various parameters used in convergence tests.
3752: Logically Collective
3754: Input Parameters:
3755: + snes - the `SNES` context
3756: . abstol - absolute convergence tolerance
3757: . rtol - relative convergence tolerance
3758: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3759: . maxit - maximum number of iterations, default 50.
3760: - maxf - maximum number of function evaluations (-1 indicates no limit), default 1000
3762: Options Database Keys:
3763: + -snes_atol <abstol> - Sets abstol
3764: . -snes_rtol <rtol> - Sets rtol
3765: . -snes_stol <stol> - Sets stol
3766: . -snes_max_it <maxit> - Sets maxit
3767: - -snes_max_funcs <maxf> - Sets maxf
3769: Level: intermediate
3771: .seealso: [](ch_snes), `SNESSolve()`, `SNES`, `SNESSetTrustRegionTolerance()`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3772: @*/
3773: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3774: {
3775: PetscFunctionBegin;
3783: if (abstol != (PetscReal)PETSC_DEFAULT) {
3784: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3785: snes->abstol = abstol;
3786: }
3787: if (rtol != (PetscReal)PETSC_DEFAULT) {
3788: 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);
3789: snes->rtol = rtol;
3790: }
3791: if (stol != (PetscReal)PETSC_DEFAULT) {
3792: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3793: snes->stol = stol;
3794: }
3795: if (maxit != PETSC_DEFAULT) {
3796: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3797: snes->max_its = maxit;
3798: }
3799: if (maxf != PETSC_DEFAULT) {
3800: PetscCheck(maxf >= -1, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be -1 or nonnegative", maxf);
3801: snes->max_funcs = maxf;
3802: }
3803: snes->tolerancesset = PETSC_TRUE;
3804: PetscFunctionReturn(PETSC_SUCCESS);
3805: }
3807: /*@
3808: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3810: Logically Collective
3812: Input Parameters:
3813: + snes - the `SNES` context
3814: - divtol - the divergence tolerance. Use -1 to deactivate the test, default is 1e4
3816: Options Database Key:
3817: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3819: Level: intermediate
3821: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance`
3822: @*/
3823: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3824: {
3825: PetscFunctionBegin;
3829: if (divtol != (PetscReal)PETSC_DEFAULT) {
3830: snes->divtol = divtol;
3831: } else {
3832: snes->divtol = 1.0e4;
3833: }
3834: PetscFunctionReturn(PETSC_SUCCESS);
3835: }
3837: /*@
3838: SNESGetTolerances - Gets various parameters used in convergence tests.
3840: Not Collective
3842: Input Parameters:
3843: + snes - the `SNES` context
3844: . atol - absolute convergence tolerance
3845: . rtol - relative convergence tolerance
3846: . stol - convergence tolerance in terms of the norm
3847: of the change in the solution between steps
3848: . maxit - maximum number of iterations
3849: - maxf - maximum number of function evaluations
3851: Level: intermediate
3853: Note:
3854: The user can specify `NULL` for any parameter that is not needed.
3856: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
3857: @*/
3858: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
3859: {
3860: PetscFunctionBegin;
3862: if (atol) *atol = snes->abstol;
3863: if (rtol) *rtol = snes->rtol;
3864: if (stol) *stol = snes->stol;
3865: if (maxit) *maxit = snes->max_its;
3866: if (maxf) *maxf = snes->max_funcs;
3867: PetscFunctionReturn(PETSC_SUCCESS);
3868: }
3870: /*@
3871: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
3873: Not Collective
3875: Input Parameters:
3876: + snes - the `SNES` context
3877: - divtol - divergence tolerance
3879: Level: intermediate
3881: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
3882: @*/
3883: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
3884: {
3885: PetscFunctionBegin;
3887: if (divtol) *divtol = snes->divtol;
3888: PetscFunctionReturn(PETSC_SUCCESS);
3889: }
3891: /*@
3892: SNESSetTrustRegionTolerance - Sets the trust region parameter tolerance.
3894: Logically Collective
3896: Input Parameters:
3897: + snes - the `SNES` context
3898: - tol - tolerance
3900: Options Database Key:
3901: . -snes_tr_tol <tol> - Sets tol
3903: Level: intermediate
3905: Developer Note:
3906: Should be SNESTrustRegionSetTolerance()
3908: .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`, `SNESSetTolerances()`
3909: @*/
3910: PetscErrorCode SNESSetTrustRegionTolerance(SNES snes, PetscReal tol)
3911: {
3912: PetscFunctionBegin;
3915: snes->deltatol = tol;
3916: PetscFunctionReturn(PETSC_SUCCESS);
3917: }
3919: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
3921: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
3922: {
3923: PetscDrawLG lg;
3924: PetscReal x, y, per;
3925: PetscViewer v = (PetscViewer)monctx;
3926: static PetscReal prev; /* should be in the context */
3927: PetscDraw draw;
3929: PetscFunctionBegin;
3931: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
3932: if (!n) PetscCall(PetscDrawLGReset(lg));
3933: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3934: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
3935: x = (PetscReal)n;
3936: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
3937: else y = -15.0;
3938: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3939: if (n < 20 || !(n % 5) || snes->reason) {
3940: PetscCall(PetscDrawLGDraw(lg));
3941: PetscCall(PetscDrawLGSave(lg));
3942: }
3944: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
3945: if (!n) PetscCall(PetscDrawLGReset(lg));
3946: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3947: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
3948: PetscCall(SNESMonitorRange_Private(snes, n, &per));
3949: x = (PetscReal)n;
3950: y = 100.0 * per;
3951: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3952: if (n < 20 || !(n % 5) || snes->reason) {
3953: PetscCall(PetscDrawLGDraw(lg));
3954: PetscCall(PetscDrawLGSave(lg));
3955: }
3957: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
3958: if (!n) {
3959: prev = rnorm;
3960: PetscCall(PetscDrawLGReset(lg));
3961: }
3962: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3963: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
3964: x = (PetscReal)n;
3965: y = (prev - rnorm) / prev;
3966: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3967: if (n < 20 || !(n % 5) || snes->reason) {
3968: PetscCall(PetscDrawLGDraw(lg));
3969: PetscCall(PetscDrawLGSave(lg));
3970: }
3972: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
3973: if (!n) PetscCall(PetscDrawLGReset(lg));
3974: PetscCall(PetscDrawLGGetDraw(lg, &draw));
3975: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
3976: x = (PetscReal)n;
3977: y = (prev - rnorm) / (prev * per);
3978: if (n > 2) { /*skip initial crazy value */
3979: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
3980: }
3981: if (n < 20 || !(n % 5) || snes->reason) {
3982: PetscCall(PetscDrawLGDraw(lg));
3983: PetscCall(PetscDrawLGSave(lg));
3984: }
3985: prev = rnorm;
3986: PetscFunctionReturn(PETSC_SUCCESS);
3987: }
3989: /*@
3990: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
3992: Collective
3994: Input Parameters:
3995: + snes - the `SNES` context
3996: . it - current iteration
3997: . xnorm - 2-norm of current iterate
3998: . snorm - 2-norm of current step
3999: - fnorm - 2-norm of function
4001: Level: developer
4003: Note:
4004: This routine is called by the `SNESSolve()` implementations.
4005: It does not typically need to be called by the user.
4007: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4008: @*/
4009: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
4010: {
4011: PetscFunctionBegin;
4012: if (!snes->reason) {
4013: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
4014: if (it == snes->max_its && !snes->reason) {
4015: if (snes->normschedule == SNES_NORM_ALWAYS) {
4016: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
4017: snes->reason = SNES_DIVERGED_MAX_IT;
4018: } else snes->reason = SNES_CONVERGED_ITS;
4019: }
4020: }
4021: PetscFunctionReturn(PETSC_SUCCESS);
4022: }
4024: /*@
4025: SNESMonitor - runs the user provided monitor routines, if they exist
4027: Collective
4029: Input Parameters:
4030: + snes - nonlinear solver context obtained from `SNESCreate()`
4031: . iter - iteration number
4032: - rnorm - relative norm of the residual
4034: Level: developer
4036: Note:
4037: This routine is called by the `SNESSolve()` implementations.
4038: It does not typically need to be called by the user.
4040: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
4041: @*/
4042: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
4043: {
4044: PetscInt i, n = snes->numbermonitors;
4046: PetscFunctionBegin;
4047: if (n > 0) SNESCheckFunctionNorm(snes, rnorm);
4048: PetscCall(VecLockReadPush(snes->vec_sol));
4049: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
4050: PetscCall(VecLockReadPop(snes->vec_sol));
4051: PetscFunctionReturn(PETSC_SUCCESS);
4052: }
4054: /* ------------ Routines to set performance monitoring options ----------- */
4056: /*MC
4057: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
4059: Synopsis:
4060: #include <petscsnes.h>
4061: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, void *mctx)
4063: Collective
4065: Input Parameters:
4066: + snes - the `SNES` context
4067: . its - iteration number
4068: . norm - 2-norm function value (may be estimated)
4069: - mctx - [optional] monitoring context
4071: Level: advanced
4073: .seealso: [](ch_snes), `SNESMonitorSet()`, `SNESMonitorSet()`, `SNESMonitorGet()`
4074: M*/
4076: /*@C
4077: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
4078: iteration of the nonlinear solver to display the iteration's
4079: progress.
4081: Logically Collective
4083: Input Parameters:
4084: + snes - the `SNES` context
4085: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4086: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4087: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`)
4089: Options Database Keys:
4090: + -snes_monitor - sets `SNESMonitorDefault()`
4091: . -snes_monitor draw::draw_lg - sets line graph monitor,
4092: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4093: the options database.
4095: Level: intermediate
4097: Note:
4098: Several different monitoring routines may be set by calling
4099: `SNESMonitorSet()` multiple times; all will be called in the
4100: order in which they were set.
4102: Fortran Note:
4103: Only a single monitor function can be set for each `SNES` object
4105: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`
4106: @*/
4107: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscErrorCode (*monitordestroy)(void **))
4108: {
4109: PetscInt i;
4110: PetscBool identical;
4112: PetscFunctionBegin;
4114: for (i = 0; i < snes->numbermonitors; i++) {
4115: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, mctx, monitordestroy, (PetscErrorCode(*)(void))snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4116: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4117: }
4118: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4119: snes->monitor[snes->numbermonitors] = f;
4120: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4121: snes->monitorcontext[snes->numbermonitors++] = (void *)mctx;
4122: PetscFunctionReturn(PETSC_SUCCESS);
4123: }
4125: /*@
4126: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4128: Logically Collective
4130: Input Parameter:
4131: . snes - the `SNES` context
4133: Options Database Key:
4134: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4135: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4136: set via the options database
4138: Level: intermediate
4140: Note:
4141: There is no way to clear one specific monitor from a `SNES` object.
4143: .seealso: [](ch_snes), `SNES`, `SNESMonitorGet()`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4144: @*/
4145: PetscErrorCode SNESMonitorCancel(SNES snes)
4146: {
4147: PetscInt i;
4149: PetscFunctionBegin;
4151: for (i = 0; i < snes->numbermonitors; i++) {
4152: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4153: }
4154: snes->numbermonitors = 0;
4155: PetscFunctionReturn(PETSC_SUCCESS);
4156: }
4158: /*MC
4159: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4161: Synopsis:
4162: #include <petscsnes.h>
4163: PetscErrorCode SNESConvergenceTest(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *cctx)
4165: Collective
4167: Input Parameters:
4168: + snes - the `SNES` context
4169: . it - current iteration (0 is the first and is before any Newton step)
4170: . xnorm - 2-norm of current iterate
4171: . gnorm - 2-norm of current step
4172: . f - 2-norm of function
4173: - cctx - [optional] convergence context
4175: Output Parameter:
4176: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4178: Level: intermediate
4180: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`, `SNESGetConvergenceTest()`
4181: M*/
4183: /*@C
4184: SNESSetConvergenceTest - Sets the function that is to be used
4185: to test for convergence of the nonlinear iterative solution.
4187: Logically Collective
4189: Input Parameters:
4190: + snes - the `SNES` context
4191: . SNESConvergenceTestFunction - routine to test for convergence
4192: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4193: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4195: Level: advanced
4197: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4198: @*/
4199: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscErrorCode (*destroy)(void *))
4200: {
4201: PetscFunctionBegin;
4203: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4204: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(snes->cnvP));
4205: snes->ops->converged = SNESConvergenceTestFunction;
4206: snes->ops->convergeddestroy = destroy;
4207: snes->cnvP = cctx;
4208: PetscFunctionReturn(PETSC_SUCCESS);
4209: }
4211: /*@
4212: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped.
4214: Not Collective
4216: Input Parameter:
4217: . snes - the `SNES` context
4219: Output Parameter:
4220: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4222: Options Database Key:
4223: . -snes_converged_reason - prints the reason to standard out
4225: Level: intermediate
4227: Note:
4228: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4230: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4231: @*/
4232: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4233: {
4234: PetscFunctionBegin;
4236: PetscAssertPointer(reason, 2);
4237: *reason = snes->reason;
4238: PetscFunctionReturn(PETSC_SUCCESS);
4239: }
4241: /*@C
4242: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4244: Not Collective
4246: Input Parameter:
4247: . snes - the `SNES` context
4249: Output Parameter:
4250: . strreason - a human readable string that describes `SNES` converged reason
4252: Level: beginner
4254: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4255: @*/
4256: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4257: {
4258: PetscFunctionBegin;
4260: PetscAssertPointer(strreason, 2);
4261: *strreason = SNESConvergedReasons[snes->reason];
4262: PetscFunctionReturn(PETSC_SUCCESS);
4263: }
4265: /*@
4266: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4268: Not Collective
4270: Input Parameters:
4271: + snes - the `SNES` context
4272: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4273: manual pages for the individual convergence tests for complete lists
4275: Level: developer
4277: Developer Note:
4278: Called inside the various `SNESSolve()` implementations
4280: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4281: @*/
4282: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4283: {
4284: PetscFunctionBegin;
4286: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4287: snes->reason = reason;
4288: PetscFunctionReturn(PETSC_SUCCESS);
4289: }
4291: /*@
4292: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4294: Logically Collective
4296: Input Parameters:
4297: + snes - iterative context obtained from `SNESCreate()`
4298: . a - array to hold history, this array will contain the function norms computed at each step
4299: . its - integer array holds the number of linear iterations for each solve.
4300: . na - size of `a` and `its`
4301: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4302: else it continues storing new values for new nonlinear solves after the old ones
4304: Level: intermediate
4306: Notes:
4307: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' `PETSC_DECIDE` or `PETSC_DEFAULT` then a
4308: default array of length 10000 is allocated.
4310: This routine is useful, e.g., when running a code for purposes
4311: of accurate performance monitoring, when no I/O should be done
4312: during the section of code that is being timed.
4314: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4316: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4317: @*/
4318: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4319: {
4320: PetscFunctionBegin;
4322: if (a) PetscAssertPointer(a, 2);
4323: if (its) PetscAssertPointer(its, 3);
4324: if (!a) {
4325: if (na == PETSC_DECIDE || na == PETSC_DEFAULT) na = 1000;
4326: PetscCall(PetscCalloc2(na, &a, na, &its));
4327: snes->conv_hist_alloc = PETSC_TRUE;
4328: }
4329: snes->conv_hist = a;
4330: snes->conv_hist_its = its;
4331: snes->conv_hist_max = (size_t)na;
4332: snes->conv_hist_len = 0;
4333: snes->conv_hist_reset = reset;
4334: PetscFunctionReturn(PETSC_SUCCESS);
4335: }
4337: #if defined(PETSC_HAVE_MATLAB)
4338: #include <engine.h> /* MATLAB include file */
4339: #include <mex.h> /* MATLAB include file */
4341: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4342: {
4343: mxArray *mat;
4344: PetscInt i;
4345: PetscReal *ar;
4347: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4348: ar = (PetscReal *)mxGetData(mat);
4349: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4350: return mat;
4351: }
4352: #endif
4354: /*@C
4355: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4357: Not Collective
4359: Input Parameter:
4360: . snes - iterative context obtained from `SNESCreate()`
4362: Output Parameters:
4363: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4364: . its - integer array holds the number of linear iterations (or
4365: negative if not converged) for each solve.
4366: - na - size of `a` and `its`
4368: Level: intermediate
4370: Note:
4371: This routine is useful, e.g., when running a code for purposes
4372: of accurate performance monitoring, when no I/O should be done
4373: during the section of code that is being timed.
4375: Fortran Note:
4376: The calling sequence for this routine in Fortran is
4377: .vb
4378: call SNESGetConvergenceHistory(SNES snes, integer na, integer ierr)
4379: .ve
4381: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4382: @*/
4383: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4384: {
4385: PetscFunctionBegin;
4387: if (a) *a = snes->conv_hist;
4388: if (its) *its = snes->conv_hist_its;
4389: if (na) *na = (PetscInt)snes->conv_hist_len;
4390: PetscFunctionReturn(PETSC_SUCCESS);
4391: }
4393: /*@C
4394: SNESSetUpdate - Sets the general-purpose update function called
4395: at the beginning of every iteration of the nonlinear solve. Specifically
4396: it is called just before the Jacobian is "evaluated".
4398: Logically Collective
4400: Input Parameters:
4401: + snes - The nonlinear solver context
4402: - func - The function
4404: Calling sequence of `func`:
4405: + snes - the nonlinear solver context
4406: - step - The current step of the iteration
4408: Level: advanced
4410: Notes:
4411: 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
4412: to `SNESSetFunction()`, or `SNESSetPicard()`
4413: This is not used by most users.
4415: 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.
4417: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4418: `SNESMonitorSet()`, `SNESSetDivergenceTest()`
4419: @*/
4420: PetscErrorCode SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES snes, PetscInt step))
4421: {
4422: PetscFunctionBegin;
4424: snes->ops->update = func;
4425: PetscFunctionReturn(PETSC_SUCCESS);
4426: }
4428: /*@C
4429: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4431: Collective
4433: Input Parameters:
4434: + snes - iterative context obtained from `SNESCreate()`
4435: - viewer - the viewer to display the reason
4437: Options Database Keys:
4438: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4439: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4441: Level: beginner
4443: Note:
4444: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4445: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4447: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4448: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4449: `SNESConvergedReasonViewFromOptions()`,
4450: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4451: @*/
4452: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4453: {
4454: PetscViewerFormat format;
4455: PetscBool isAscii;
4457: PetscFunctionBegin;
4458: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4459: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4460: if (isAscii) {
4461: PetscCall(PetscViewerGetFormat(viewer, &format));
4462: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel));
4463: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4464: DM dm;
4465: Vec u;
4466: PetscDS prob;
4467: PetscInt Nf, f;
4468: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4469: void **exactCtx;
4470: PetscReal error;
4472: PetscCall(SNESGetDM(snes, &dm));
4473: PetscCall(SNESGetSolution(snes, &u));
4474: PetscCall(DMGetDS(dm, &prob));
4475: PetscCall(PetscDSGetNumFields(prob, &Nf));
4476: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4477: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4478: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4479: PetscCall(PetscFree2(exactSol, exactCtx));
4480: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4481: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4482: }
4483: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4484: if (((PetscObject)snes)->prefix) {
4485: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4486: } else {
4487: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4488: }
4489: } else if (snes->reason <= 0) {
4490: if (((PetscObject)snes)->prefix) {
4491: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4492: } else {
4493: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4494: }
4495: }
4496: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel));
4497: }
4498: PetscFunctionReturn(PETSC_SUCCESS);
4499: }
4501: /*@C
4502: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4503: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4505: Logically Collective
4507: Input Parameters:
4508: + snes - the `SNES` context
4509: . f - the `SNESConvergedReason` view function
4510: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4511: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`)
4513: Calling sequence of `f`:
4514: + snes - the `SNES` context
4515: - vctx - [optional] user-defined context for private data for the function
4517: Calling sequence of `reasonviewerdestroy`:
4518: . vctx - [optional] user-defined context for private data for the function
4520: Options Database Keys:
4521: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4522: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4523: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4525: Level: intermediate
4527: Note:
4528: Several different converged reason view routines may be set by calling
4529: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4530: order in which they were set.
4532: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`
4533: @*/
4534: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, void *vctx), void *vctx, PetscErrorCode (*reasonviewdestroy)(void **vctx))
4535: {
4536: PetscInt i;
4537: PetscBool identical;
4539: PetscFunctionBegin;
4541: for (i = 0; i < snes->numberreasonviews; i++) {
4542: PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))f, vctx, reasonviewdestroy, (PetscErrorCode(*)(void))snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4543: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4544: }
4545: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4546: snes->reasonview[snes->numberreasonviews] = f;
4547: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4548: snes->reasonviewcontext[snes->numberreasonviews++] = (void *)vctx;
4549: PetscFunctionReturn(PETSC_SUCCESS);
4550: }
4552: /*@
4553: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4554: All the user-provided convergedReasonView routines will be involved as well, if they exist.
4556: Collective
4558: Input Parameter:
4559: . snes - the `SNES` object
4561: Level: advanced
4563: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4564: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4565: @*/
4566: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4567: {
4568: PetscViewer viewer;
4569: PetscBool flg;
4570: static PetscBool incall = PETSC_FALSE;
4571: PetscViewerFormat format;
4572: PetscInt i;
4574: PetscFunctionBegin;
4575: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4576: incall = PETSC_TRUE;
4578: /* All user-provided viewers are called first, if they exist. */
4579: for (i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4581: /* Call PETSc default routine if users ask for it */
4582: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &viewer, &format, &flg));
4583: if (flg) {
4584: PetscCall(PetscViewerPushFormat(viewer, format));
4585: PetscCall(SNESConvergedReasonView(snes, viewer));
4586: PetscCall(PetscViewerPopFormat(viewer));
4587: PetscCall(PetscOptionsRestoreViewer(&viewer));
4588: }
4589: incall = PETSC_FALSE;
4590: PetscFunctionReturn(PETSC_SUCCESS);
4591: }
4593: /*@
4594: SNESSolve - Solves a nonlinear system F(x) = b.
4596: Collective
4598: Input Parameters:
4599: + snes - the `SNES` context
4600: . b - the constant part of the equation F(x) = b, or `NULL` to use zero.
4601: - x - the solution vector.
4603: Level: beginner
4605: Note:
4606: The user should initialize the vector, `x`, with the initial guess
4607: for the nonlinear solve prior to calling `SNESSolve()` or use `SNESSetInitialSolution()`. In particular,
4608: to employ an initial guess of zero, the user should explicitly set
4609: this vector to zero by calling `VecSet()`.
4611: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4612: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4613: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`, `SNESSetInitialSolution()`
4614: @*/
4615: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4616: {
4617: PetscBool flg;
4618: PetscInt grid;
4619: Vec xcreated = NULL;
4620: DM dm;
4622: PetscFunctionBegin;
4625: if (x) PetscCheckSameComm(snes, 1, x, 3);
4627: if (b) PetscCheckSameComm(snes, 1, b, 2);
4629: /* High level operations using the nonlinear solver */
4630: {
4631: PetscViewer viewer;
4632: PetscViewerFormat format;
4633: PetscInt num;
4634: PetscBool flg;
4635: static PetscBool incall = PETSC_FALSE;
4637: if (!incall) {
4638: /* Estimate the convergence rate of the discretization */
4639: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4640: if (flg) {
4641: PetscConvEst conv;
4642: DM dm;
4643: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4644: PetscInt Nf;
4646: incall = PETSC_TRUE;
4647: PetscCall(SNESGetDM(snes, &dm));
4648: PetscCall(DMGetNumFields(dm, &Nf));
4649: PetscCall(PetscCalloc1(Nf, &alpha));
4650: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4651: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4652: PetscCall(PetscConvEstSetFromOptions(conv));
4653: PetscCall(PetscConvEstSetUp(conv));
4654: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4655: PetscCall(PetscViewerPushFormat(viewer, format));
4656: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4657: PetscCall(PetscViewerPopFormat(viewer));
4658: PetscCall(PetscOptionsRestoreViewer(&viewer));
4659: PetscCall(PetscConvEstDestroy(&conv));
4660: PetscCall(PetscFree(alpha));
4661: incall = PETSC_FALSE;
4662: }
4663: /* Adaptively refine the initial grid */
4664: num = 1;
4665: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4666: if (flg) {
4667: DMAdaptor adaptor;
4669: incall = PETSC_TRUE;
4670: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4671: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4672: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4673: PetscCall(DMAdaptorSetFromOptions(adaptor));
4674: PetscCall(DMAdaptorSetUp(adaptor));
4675: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4676: PetscCall(DMAdaptorDestroy(&adaptor));
4677: incall = PETSC_FALSE;
4678: }
4679: /* Use grid sequencing to adapt */
4680: num = 0;
4681: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4682: if (num) {
4683: DMAdaptor adaptor;
4685: incall = PETSC_TRUE;
4686: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4687: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4688: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4689: PetscCall(DMAdaptorSetFromOptions(adaptor));
4690: PetscCall(DMAdaptorSetUp(adaptor));
4691: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4692: PetscCall(DMAdaptorDestroy(&adaptor));
4693: incall = PETSC_FALSE;
4694: }
4695: }
4696: }
4697: if (!x) x = snes->vec_sol;
4698: if (!x) {
4699: PetscCall(SNESGetDM(snes, &dm));
4700: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4701: x = xcreated;
4702: }
4703: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4705: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4706: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4707: /* set solution vector */
4708: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4709: PetscCall(VecDestroy(&snes->vec_sol));
4710: snes->vec_sol = x;
4711: PetscCall(SNESGetDM(snes, &dm));
4713: /* set affine vector if provided */
4714: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4715: PetscCall(VecDestroy(&snes->vec_rhs));
4716: snes->vec_rhs = b;
4718: 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");
4719: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4720: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right-hand side vector");
4721: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4722: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4723: PetscCall(SNESSetUp(snes));
4725: if (!grid) {
4726: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback compute initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4727: }
4729: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4730: if (snes->counters_reset) {
4731: snes->nfuncs = 0;
4732: snes->linear_its = 0;
4733: snes->numFailures = 0;
4734: }
4736: snes->reason = SNES_CONVERGED_ITERATING;
4737: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4738: PetscUseTypeMethod(snes, solve);
4739: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4740: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4741: snes->domainerror = PETSC_FALSE; /* clear the flag if it has been set */
4743: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4744: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4746: PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4747: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4748: /* Call converged reason views. This may involve user-provided viewers as well */
4749: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4751: if (snes->errorifnotconverged) PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4752: if (snes->reason < 0) break;
4753: if (grid < snes->gridsequence) {
4754: DM fine;
4755: Vec xnew;
4756: Mat interp;
4758: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4759: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4760: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4761: PetscCall(DMCreateGlobalVector(fine, &xnew));
4762: PetscCall(MatInterpolate(interp, x, xnew));
4763: PetscCall(DMInterpolate(snes->dm, interp, fine));
4764: PetscCall(MatDestroy(&interp));
4765: x = xnew;
4767: PetscCall(SNESReset(snes));
4768: PetscCall(SNESSetDM(snes, fine));
4769: PetscCall(SNESResetFromOptions(snes));
4770: PetscCall(DMDestroy(&fine));
4771: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4772: }
4773: }
4774: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4775: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4776: PetscCall(DMMonitor(snes->dm));
4777: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4779: PetscCall(VecDestroy(&xcreated));
4780: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4781: PetscFunctionReturn(PETSC_SUCCESS);
4782: }
4784: /* --------- Internal routines for SNES Package --------- */
4786: /*@C
4787: SNESSetType - Sets the method for the nonlinear solver.
4789: Collective
4791: Input Parameters:
4792: + snes - the `SNES` context
4793: - type - a known method
4795: Options Database Key:
4796: . -snes_type <type> - Sets the method; use -help for a list
4797: of available methods (for instance, newtonls or newtontr)
4799: Level: intermediate
4801: Notes:
4802: See "petsc/include/petscsnes.h" for available methods (for instance)
4803: + `SNESNEWTONLS` - Newton's method with line search
4804: (systems of nonlinear equations)
4805: - `SNESNEWTONTR` - Newton's method with trust region
4806: (systems of nonlinear equations)
4808: Normally, it is best to use the `SNESSetFromOptions()` command and then
4809: set the `SNES` solver type from the options database rather than by using
4810: this routine. Using the options database provides the user with
4811: maximum flexibility in evaluating the many nonlinear solvers.
4812: The `SNESSetType()` routine is provided for those situations where it
4813: is necessary to set the nonlinear solver independently of the command
4814: line or options database. This might be the case, for example, when
4815: the choice of solver changes during the execution of the program,
4816: and the user's application is taking responsibility for choosing the
4817: appropriate method.
4819: Developer Note:
4820: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4821: the constructor in that list and calls it to create the specific object.
4823: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4824: @*/
4825: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4826: {
4827: PetscBool match;
4828: PetscErrorCode (*r)(SNES);
4830: PetscFunctionBegin;
4832: PetscAssertPointer(type, 2);
4834: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4835: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4837: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4838: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4839: /* Destroy the previous private SNES context */
4840: PetscTryTypeMethod(snes, destroy);
4841: /* Reinitialize function pointers in SNESOps structure */
4842: snes->ops->setup = NULL;
4843: snes->ops->solve = NULL;
4844: snes->ops->view = NULL;
4845: snes->ops->setfromoptions = NULL;
4846: snes->ops->destroy = NULL;
4848: /* It may happen the user has customized the line search before calling SNESSetType */
4849: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
4851: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
4852: snes->setupcalled = PETSC_FALSE;
4854: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
4855: PetscCall((*r)(snes));
4856: PetscFunctionReturn(PETSC_SUCCESS);
4857: }
4859: /*@C
4860: SNESGetType - Gets the `SNES` method type and name (as a string).
4862: Not Collective
4864: Input Parameter:
4865: . snes - nonlinear solver context
4867: Output Parameter:
4868: . type - `SNES` method (a character string)
4870: Level: intermediate
4872: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
4873: @*/
4874: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
4875: {
4876: PetscFunctionBegin;
4878: PetscAssertPointer(type, 2);
4879: *type = ((PetscObject)snes)->type_name;
4880: PetscFunctionReturn(PETSC_SUCCESS);
4881: }
4883: /*@
4884: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
4886: Logically Collective
4888: Input Parameters:
4889: + snes - the `SNES` context obtained from `SNESCreate()`
4890: - u - the solution vector
4892: Level: beginner
4894: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
4895: @*/
4896: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
4897: {
4898: DM dm;
4900: PetscFunctionBegin;
4903: PetscCall(PetscObjectReference((PetscObject)u));
4904: PetscCall(VecDestroy(&snes->vec_sol));
4906: snes->vec_sol = u;
4908: PetscCall(SNESGetDM(snes, &dm));
4909: PetscCall(DMShellSetGlobalVector(dm, u));
4910: PetscFunctionReturn(PETSC_SUCCESS);
4911: }
4913: /*@
4914: SNESGetSolution - Returns the vector where the approximate solution is
4915: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
4917: Not Collective, but `x` is parallel if `snes` is parallel
4919: Input Parameter:
4920: . snes - the `SNES` context
4922: Output Parameter:
4923: . x - the solution
4925: Level: intermediate
4927: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
4928: @*/
4929: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
4930: {
4931: PetscFunctionBegin;
4933: PetscAssertPointer(x, 2);
4934: *x = snes->vec_sol;
4935: PetscFunctionReturn(PETSC_SUCCESS);
4936: }
4938: /*@
4939: SNESGetSolutionUpdate - Returns the vector where the solution update is
4940: stored.
4942: Not Collective, but `x` is parallel if `snes` is parallel
4944: Input Parameter:
4945: . snes - the `SNES` context
4947: Output Parameter:
4948: . x - the solution update
4950: Level: advanced
4952: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
4953: @*/
4954: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
4955: {
4956: PetscFunctionBegin;
4958: PetscAssertPointer(x, 2);
4959: *x = snes->vec_sol_update;
4960: PetscFunctionReturn(PETSC_SUCCESS);
4961: }
4963: /*@C
4964: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
4966: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
4968: Input Parameter:
4969: . snes - the `SNES` context
4971: Output Parameters:
4972: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
4973: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunctionFn`
4974: - ctx - the function context (or `NULL` if you don't want it)
4976: Level: advanced
4978: Note:
4979: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
4981: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunctionFn`
4982: @*/
4983: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, SNESFunctionFn **f, void **ctx)
4984: {
4985: DM dm;
4987: PetscFunctionBegin;
4989: if (r) {
4990: if (!snes->vec_func) {
4991: if (snes->vec_rhs) {
4992: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
4993: } else if (snes->vec_sol) {
4994: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
4995: } else if (snes->dm) {
4996: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
4997: }
4998: }
4999: *r = snes->vec_func;
5000: }
5001: PetscCall(SNESGetDM(snes, &dm));
5002: PetscCall(DMSNESGetFunction(dm, f, ctx));
5003: PetscFunctionReturn(PETSC_SUCCESS);
5004: }
5006: /*@C
5007: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
5009: Input Parameter:
5010: . snes - the `SNES` context
5012: Output Parameters:
5013: + f - the function (or `NULL`) see `SNESNGSFn` for calling sequence
5014: - ctx - the function context (or `NULL`)
5016: Level: advanced
5018: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`, `SNESNGSFn`
5019: @*/
5020: PetscErrorCode SNESGetNGS(SNES snes, SNESNGSFn **f, void **ctx)
5021: {
5022: DM dm;
5024: PetscFunctionBegin;
5026: PetscCall(SNESGetDM(snes, &dm));
5027: PetscCall(DMSNESGetNGS(dm, f, ctx));
5028: PetscFunctionReturn(PETSC_SUCCESS);
5029: }
5031: /*@C
5032: SNESSetOptionsPrefix - Sets the prefix used for searching for all
5033: `SNES` options in the database.
5035: Logically Collective
5037: Input Parameters:
5038: + snes - the `SNES` context
5039: - prefix - the prefix to prepend to all option names
5041: Level: advanced
5043: Note:
5044: A hyphen (-) must NOT be given at the beginning of the prefix name.
5045: The first character of all runtime options is AUTOMATICALLY the hyphen.
5047: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
5048: @*/
5049: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
5050: {
5051: PetscFunctionBegin;
5053: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
5054: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5055: if (snes->linesearch) {
5056: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5057: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
5058: }
5059: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
5060: PetscFunctionReturn(PETSC_SUCCESS);
5061: }
5063: /*@C
5064: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5065: `SNES` options in the database.
5067: Logically Collective
5069: Input Parameters:
5070: + snes - the `SNES` context
5071: - prefix - the prefix to prepend to all option names
5073: Level: advanced
5075: Note:
5076: A hyphen (-) must NOT be given at the beginning of the prefix name.
5077: The first character of all runtime options is AUTOMATICALLY the hyphen.
5079: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5080: @*/
5081: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5082: {
5083: PetscFunctionBegin;
5085: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5086: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5087: if (snes->linesearch) {
5088: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5089: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5090: }
5091: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5092: PetscFunctionReturn(PETSC_SUCCESS);
5093: }
5095: /*@C
5096: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5097: `SNES` options in the database.
5099: Not Collective
5101: Input Parameter:
5102: . snes - the `SNES` context
5104: Output Parameter:
5105: . prefix - pointer to the prefix string used
5107: Level: advanced
5109: Fortran Note:
5110: The user should pass in a string 'prefix' of
5111: sufficient length to hold the prefix.
5113: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5114: @*/
5115: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5116: {
5117: PetscFunctionBegin;
5119: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5120: PetscFunctionReturn(PETSC_SUCCESS);
5121: }
5123: /*@C
5124: SNESRegister - Adds a method to the nonlinear solver package.
5126: Not Collective
5128: Input Parameters:
5129: + sname - name of a new user-defined solver
5130: - function - routine to create method context
5132: Level: advanced
5134: Note:
5135: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5137: Example Usage:
5138: .vb
5139: SNESRegister("my_solver", MySolverCreate);
5140: .ve
5142: Then, your solver can be chosen with the procedural interface via
5143: $ SNESSetType(snes, "my_solver")
5144: or at runtime via the option
5145: $ -snes_type my_solver
5147: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5148: @*/
5149: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5150: {
5151: PetscFunctionBegin;
5152: PetscCall(SNESInitializePackage());
5153: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5154: PetscFunctionReturn(PETSC_SUCCESS);
5155: }
5157: PetscErrorCode SNESTestLocalMin(SNES snes)
5158: {
5159: PetscInt N, i, j;
5160: Vec u, uh, fh;
5161: PetscScalar value;
5162: PetscReal norm;
5164: PetscFunctionBegin;
5165: PetscCall(SNESGetSolution(snes, &u));
5166: PetscCall(VecDuplicate(u, &uh));
5167: PetscCall(VecDuplicate(u, &fh));
5169: /* currently only works for sequential */
5170: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5171: PetscCall(VecGetSize(u, &N));
5172: for (i = 0; i < N; i++) {
5173: PetscCall(VecCopy(u, uh));
5174: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5175: for (j = -10; j < 11; j++) {
5176: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5177: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5178: PetscCall(SNESComputeFunction(snes, uh, fh));
5179: PetscCall(VecNorm(fh, NORM_2, &norm));
5180: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5181: value = -value;
5182: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5183: }
5184: }
5185: PetscCall(VecDestroy(&uh));
5186: PetscCall(VecDestroy(&fh));
5187: PetscFunctionReturn(PETSC_SUCCESS);
5188: }
5190: /*@
5191: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5192: computing relative tolerance for linear solvers within an inexact
5193: Newton method.
5195: Logically Collective
5197: Input Parameters:
5198: + snes - `SNES` context
5199: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5201: Options Database Keys:
5202: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5203: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5204: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5205: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5206: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5207: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5208: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5209: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5211: Level: advanced
5213: Note:
5214: The default is to use a constant relative tolerance for
5215: the inner linear solvers. Alternatively, one can use the
5216: Eisenstat-Walker method {cite}`ew96`, where the relative convergence tolerance
5217: is reset at each Newton iteration according progress of the nonlinear
5218: solver.
5220: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5221: @*/
5222: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5223: {
5224: PetscFunctionBegin;
5227: snes->ksp_ewconv = flag;
5228: PetscFunctionReturn(PETSC_SUCCESS);
5229: }
5231: /*@
5232: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5233: for computing relative tolerance for linear solvers within an
5234: inexact Newton method.
5236: Not Collective
5238: Input Parameter:
5239: . snes - `SNES` context
5241: Output Parameter:
5242: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5244: Level: advanced
5246: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5247: @*/
5248: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5249: {
5250: PetscFunctionBegin;
5252: PetscAssertPointer(flag, 2);
5253: *flag = snes->ksp_ewconv;
5254: PetscFunctionReturn(PETSC_SUCCESS);
5255: }
5257: /*@
5258: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5259: convergence criteria for the linear solvers within an inexact
5260: Newton method.
5262: Logically Collective
5264: Input Parameters:
5265: + snes - `SNES` context
5266: . version - version 1, 2 (default is 2), 3 or 4
5267: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5268: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5269: . gamma - multiplicative factor for version 2 rtol computation
5270: (0 <= gamma2 <= 1)
5271: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5272: . alpha2 - power for safeguard
5273: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5275: Level: advanced
5277: Notes:
5278: Version 3 was contributed by Luis Chacon, June 2006.
5280: Use `PETSC_DEFAULT` to retain the default for any of the parameters.
5282: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5283: @*/
5284: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5285: {
5286: SNESKSPEW *kctx;
5288: PetscFunctionBegin;
5290: kctx = (SNESKSPEW *)snes->kspconvctx;
5291: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5300: if (version != PETSC_DEFAULT) kctx->version = version;
5301: if (rtol_0 != (PetscReal)PETSC_DEFAULT) kctx->rtol_0 = rtol_0;
5302: if (rtol_max != (PetscReal)PETSC_DEFAULT) kctx->rtol_max = rtol_max;
5303: if (gamma != (PetscReal)PETSC_DEFAULT) kctx->gamma = gamma;
5304: if (alpha != (PetscReal)PETSC_DEFAULT) kctx->alpha = alpha;
5305: if (alpha2 != (PetscReal)PETSC_DEFAULT) kctx->alpha2 = alpha2;
5306: if (threshold != (PetscReal)PETSC_DEFAULT) kctx->threshold = threshold;
5308: 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);
5309: 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);
5310: 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);
5311: 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);
5312: 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);
5313: 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);
5314: PetscFunctionReturn(PETSC_SUCCESS);
5315: }
5317: /*@
5318: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5319: convergence criteria for the linear solvers within an inexact
5320: Newton method.
5322: Not Collective
5324: Input Parameter:
5325: . snes - `SNES` context
5327: Output Parameters:
5328: + version - version 1, 2 (default is 2), 3 or 4
5329: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5330: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5331: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5332: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5333: . alpha2 - power for safeguard
5334: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5336: Level: advanced
5338: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5339: @*/
5340: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5341: {
5342: SNESKSPEW *kctx;
5344: PetscFunctionBegin;
5346: kctx = (SNESKSPEW *)snes->kspconvctx;
5347: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5348: if (version) *version = kctx->version;
5349: if (rtol_0) *rtol_0 = kctx->rtol_0;
5350: if (rtol_max) *rtol_max = kctx->rtol_max;
5351: if (gamma) *gamma = kctx->gamma;
5352: if (alpha) *alpha = kctx->alpha;
5353: if (alpha2) *alpha2 = kctx->alpha2;
5354: if (threshold) *threshold = kctx->threshold;
5355: PetscFunctionReturn(PETSC_SUCCESS);
5356: }
5358: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5359: {
5360: SNES snes = (SNES)ctx;
5361: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5362: PetscReal rtol = PETSC_DEFAULT, stol;
5364: PetscFunctionBegin;
5365: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5366: if (!snes->iter) {
5367: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5368: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5369: } else {
5370: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5371: if (kctx->version == 1) {
5372: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5373: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5374: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5375: } else if (kctx->version == 2) {
5376: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5377: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5378: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5379: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5380: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5381: /* safeguard: avoid sharp decrease of rtol */
5382: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5383: stol = PetscMax(rtol, stol);
5384: rtol = PetscMin(kctx->rtol_0, stol);
5385: /* safeguard: avoid oversolving */
5386: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5387: stol = PetscMax(rtol, stol);
5388: rtol = PetscMin(kctx->rtol_0, stol);
5389: } else /* if (kctx->version == 4) */ {
5390: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5391: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5392: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5393: PetscReal rk = ared / pred;
5394: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5395: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5396: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5397: else rtol = kctx->v4_m2 * kctx->rtol_last;
5399: 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;
5400: kctx->rtol_last_2 = kctx->rtol_last;
5401: kctx->rk_last_2 = kctx->rk_last;
5402: kctx->rk_last = rk;
5403: }
5404: }
5405: /* safeguard: avoid rtol greater than rtol_max */
5406: rtol = PetscMin(rtol, kctx->rtol_max);
5407: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_DEFAULT, PETSC_DEFAULT, PETSC_DEFAULT));
5408: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5409: PetscFunctionReturn(PETSC_SUCCESS);
5410: }
5412: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5413: {
5414: SNES snes = (SNES)ctx;
5415: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5416: PCSide pcside;
5417: Vec lres;
5419: PetscFunctionBegin;
5420: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5421: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5422: kctx->norm_last = snes->norm;
5423: if (kctx->version == 1 || kctx->version == 4) {
5424: PC pc;
5425: PetscBool getRes;
5427: PetscCall(KSPGetPC(ksp, &pc));
5428: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5429: if (!getRes) {
5430: KSPNormType normtype;
5432: PetscCall(KSPGetNormType(ksp, &normtype));
5433: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5434: }
5435: PetscCall(KSPGetPCSide(ksp, &pcside));
5436: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5437: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5438: } else {
5439: /* KSP residual is preconditioned residual */
5440: /* compute true linear residual norm */
5441: Mat J;
5442: PetscCall(KSPGetOperators(ksp, &J, NULL));
5443: PetscCall(VecDuplicate(b, &lres));
5444: PetscCall(MatMult(J, x, lres));
5445: PetscCall(VecAYPX(lres, -1.0, b));
5446: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5447: PetscCall(VecDestroy(&lres));
5448: }
5449: }
5450: PetscFunctionReturn(PETSC_SUCCESS);
5451: }
5453: /*@
5454: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5456: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5458: Input Parameter:
5459: . snes - the `SNES` context
5461: Output Parameter:
5462: . ksp - the `KSP` context
5464: Level: beginner
5466: Notes:
5467: The user can then directly manipulate the `KSP` context to set various
5468: options, etc. Likewise, the user can then extract and manipulate the
5469: `PC` contexts as well.
5471: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function
5473: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5474: @*/
5475: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5476: {
5477: PetscFunctionBegin;
5479: PetscAssertPointer(ksp, 2);
5481: if (!snes->ksp) {
5482: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5483: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5485: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5486: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5488: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5489: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5490: }
5491: *ksp = snes->ksp;
5492: PetscFunctionReturn(PETSC_SUCCESS);
5493: }
5495: #include <petsc/private/dmimpl.h>
5496: /*@
5497: SNESSetDM - Sets the `DM` that may be used by some nonlinear solvers or their underlying preconditioners
5499: Logically Collective
5501: Input Parameters:
5502: + snes - the nonlinear solver context
5503: - dm - the `DM`, cannot be `NULL`
5505: Level: intermediate
5507: Note:
5508: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5509: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5510: problems using the same function space.
5512: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5513: @*/
5514: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5515: {
5516: KSP ksp;
5517: DMSNES sdm;
5519: PetscFunctionBegin;
5522: PetscCall(PetscObjectReference((PetscObject)dm));
5523: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5524: if (snes->dm->dmsnes && !dm->dmsnes) {
5525: PetscCall(DMCopyDMSNES(snes->dm, dm));
5526: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5527: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5528: }
5529: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5530: PetscCall(DMDestroy(&snes->dm));
5531: }
5532: snes->dm = dm;
5533: snes->dmAuto = PETSC_FALSE;
5535: PetscCall(SNESGetKSP(snes, &ksp));
5536: PetscCall(KSPSetDM(ksp, dm));
5537: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5538: if (snes->npc) {
5539: PetscCall(SNESSetDM(snes->npc, snes->dm));
5540: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5541: }
5542: PetscFunctionReturn(PETSC_SUCCESS);
5543: }
5545: /*@
5546: SNESGetDM - Gets the `DM` that may be used by some solvers/preconditioners
5548: Not Collective but dm obtained is parallel on snes
5550: Input Parameter:
5551: . snes - the `SNES` context
5553: Output Parameter:
5554: . dm - the `DM`
5556: Level: intermediate
5558: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5559: @*/
5560: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5561: {
5562: PetscFunctionBegin;
5564: if (!snes->dm) {
5565: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5566: snes->dmAuto = PETSC_TRUE;
5567: }
5568: *dm = snes->dm;
5569: PetscFunctionReturn(PETSC_SUCCESS);
5570: }
5572: /*@
5573: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5575: Collective
5577: Input Parameters:
5578: + snes - iterative context obtained from `SNESCreate()`
5579: - npc - the nonlinear preconditioner object
5581: Level: developer
5583: Notes:
5584: Use `SNESGetNPC()` to retrieve the preconditioner context (for example,
5585: to configure it using the API).
5587: Only some `SNESType` can use a nonlinear preconditioner
5589: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5590: @*/
5591: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5592: {
5593: PetscFunctionBegin;
5596: PetscCheckSameComm(snes, 1, npc, 2);
5597: PetscCall(PetscObjectReference((PetscObject)npc));
5598: PetscCall(SNESDestroy(&snes->npc));
5599: snes->npc = npc;
5600: PetscFunctionReturn(PETSC_SUCCESS);
5601: }
5603: /*@
5604: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5606: Not Collective; but any changes to the obtained the npc object must be applied collectively
5608: Input Parameter:
5609: . snes - iterative context obtained from `SNESCreate()`
5611: Output Parameter:
5612: . pc - preconditioner context
5614: Options Database Key:
5615: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5617: Level: developer
5619: Notes:
5620: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created.
5622: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5623: `SNES`
5625: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5626: @*/
5627: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5628: {
5629: const char *optionsprefix;
5631: PetscFunctionBegin;
5633: PetscAssertPointer(pc, 2);
5634: if (!snes->npc) {
5635: void *ctx;
5637: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5638: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5639: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5640: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5641: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5642: if (snes->ops->usercompute) {
5643: PetscCall(SNESSetComputeApplicationContext(snes, snes->ops->usercompute, snes->ops->userdestroy));
5644: } else {
5645: PetscCall(SNESGetApplicationContext(snes, &ctx));
5646: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5647: }
5648: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5649: }
5650: *pc = snes->npc;
5651: PetscFunctionReturn(PETSC_SUCCESS);
5652: }
5654: /*@
5655: SNESHasNPC - Returns whether a nonlinear preconditioner exists
5657: Not Collective
5659: Input Parameter:
5660: . snes - iterative context obtained from `SNESCreate()`
5662: Output Parameter:
5663: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5665: Level: developer
5667: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5668: @*/
5669: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5670: {
5671: PetscFunctionBegin;
5673: *has_npc = (PetscBool)(snes->npc ? PETSC_TRUE : PETSC_FALSE);
5674: PetscFunctionReturn(PETSC_SUCCESS);
5675: }
5677: /*@
5678: SNESSetNPCSide - Sets the nonlinear preconditioning side.
5680: Logically Collective
5682: Input Parameter:
5683: . snes - iterative context obtained from `SNESCreate()`
5685: Output Parameter:
5686: . side - the preconditioning side, where side is one of
5687: .vb
5688: PC_LEFT - left preconditioning
5689: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5690: .ve
5692: Options Database Key:
5693: . -snes_npc_side <right,left> - nonlinear preconditioner side
5695: Level: intermediate
5697: Note:
5698: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5700: .seealso: [](ch_snes), `SNES`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5701: @*/
5702: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5703: {
5704: PetscFunctionBegin;
5707: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5708: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5709: snes->npcside = side;
5710: PetscFunctionReturn(PETSC_SUCCESS);
5711: }
5713: /*@
5714: SNESGetNPCSide - Gets the preconditioning side.
5716: Not Collective
5718: Input Parameter:
5719: . snes - iterative context obtained from `SNESCreate()`
5721: Output Parameter:
5722: . side - the preconditioning side, where side is one of
5723: .vb
5724: `PC_LEFT` - left preconditioning
5725: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5726: .ve
5728: Level: intermediate
5730: .seealso: [](ch_snes), `SNES`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5731: @*/
5732: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5733: {
5734: PetscFunctionBegin;
5736: PetscAssertPointer(side, 2);
5737: *side = snes->npcside;
5738: PetscFunctionReturn(PETSC_SUCCESS);
5739: }
5741: /*@
5742: SNESSetLineSearch - Sets the linesearch to be used for `SNES`
5744: Collective
5746: Input Parameters:
5747: + snes - iterative context obtained from `SNESCreate()`
5748: - linesearch - the linesearch object
5750: Level: developer
5752: Note:
5753: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
5754: to configure it using the API).
5756: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
5757: @*/
5758: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5759: {
5760: PetscFunctionBegin;
5763: PetscCheckSameComm(snes, 1, linesearch, 2);
5764: PetscCall(PetscObjectReference((PetscObject)linesearch));
5765: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5767: snes->linesearch = linesearch;
5768: PetscFunctionReturn(PETSC_SUCCESS);
5769: }
5771: /*@
5772: SNESGetLineSearch - Returns the line search context possibly set with `SNESSetLineSearch()`
5773: or creates a default line search instance associated with the `SNES` and returns it.
5775: Not Collective
5777: Input Parameter:
5778: . snes - iterative context obtained from `SNESCreate()`
5780: Output Parameter:
5781: . linesearch - linesearch context
5783: Level: beginner
5785: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`
5786: @*/
5787: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5788: {
5789: const char *optionsprefix;
5791: PetscFunctionBegin;
5793: PetscAssertPointer(linesearch, 2);
5794: if (!snes->linesearch) {
5795: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5796: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5797: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5798: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5799: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5800: }
5801: *linesearch = snes->linesearch;
5802: PetscFunctionReturn(PETSC_SUCCESS);
5803: }