Actual source code: snes.c
1: #include <petsc/private/snesimpl.h>
2: #include <petsc/private/linesearchimpl.h>
3: #include <petscdmshell.h>
4: #include <petscdraw.h>
5: #include <petscds.h>
6: #include <petscdmadaptor.h>
7: #include <petscconvest.h>
9: PetscBool SNESRegisterAllCalled = PETSC_FALSE;
10: PetscFunctionList SNESList = NULL;
12: /* Logging support */
13: PetscClassId SNES_CLASSID, DMSNES_CLASSID;
14: PetscLogEvent SNES_Solve, SNES_SetUp, SNES_FunctionEval, SNES_JacobianEval, SNES_NGSEval, SNES_NGSFuncEval, SNES_NewtonALEval, SNES_NPCSolve, SNES_ObjectiveEval;
16: /*@
17: SNESSetErrorIfNotConverged - Causes `SNESSolve()` to generate an error immediately if the solver has not converged.
19: Logically Collective
21: Input Parameters:
22: + snes - iterative context obtained from `SNESCreate()`
23: - flg - `PETSC_TRUE` indicates you want the error generated
25: Options Database Key:
26: . -snes_error_if_not_converged (true|false) - cause an immediate error condition and stop the program if the solver does not converge
28: Level: intermediate
30: Note:
31: Normally PETSc continues if a solver fails to converge, you can call `SNESGetConvergedReason()` after a `SNESSolve()`
32: to determine if it has converged. Otherwise the solution may be inaccurate or wrong
34: .seealso: [](ch_snes), `SNES`, `SNESGetErrorIfNotConverged()`, `KSPGetErrorIfNotConverged()`, `KSPSetErrorIfNotConverged()`
35: @*/
36: PetscErrorCode SNESSetErrorIfNotConverged(SNES snes, PetscBool flg)
37: {
38: PetscFunctionBegin;
41: snes->errorifnotconverged = flg;
42: PetscFunctionReturn(PETSC_SUCCESS);
43: }
45: /*@
46: SNESGetErrorIfNotConverged - Indicates if `SNESSolve()` will generate an error if the solver does not converge?
48: Not Collective
50: Input Parameter:
51: . snes - iterative context obtained from `SNESCreate()`
53: Output Parameter:
54: . flag - `PETSC_TRUE` if it will generate an error, else `PETSC_FALSE`
56: Level: intermediate
58: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetErrorIfNotConverged()`, `KSPGetErrorIfNotConverged()`, `KSPSetErrorIfNotConverged()`
59: @*/
60: PetscErrorCode SNESGetErrorIfNotConverged(SNES snes, PetscBool *flag)
61: {
62: PetscFunctionBegin;
64: PetscAssertPointer(flag, 2);
65: *flag = snes->errorifnotconverged;
66: PetscFunctionReturn(PETSC_SUCCESS);
67: }
69: /*@
70: SNESSetAlwaysComputesFinalResidual - tells the `SNES` to always compute the residual (nonlinear function value) at the final solution
72: Logically Collective
74: Input Parameters:
75: + snes - the shell `SNES`
76: - flg - `PETSC_TRUE` to always compute the residual
78: Level: advanced
80: Note:
81: Some solvers (such as smoothers in a `SNESFAS`) do not need the residual computed at the final solution so skip computing it
82: to save time.
84: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSolve()`, `SNESGetAlwaysComputesFinalResidual()`
85: @*/
86: PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES snes, PetscBool flg)
87: {
88: PetscFunctionBegin;
90: snes->alwayscomputesfinalresidual = flg;
91: PetscFunctionReturn(PETSC_SUCCESS);
92: }
94: /*@
95: SNESGetAlwaysComputesFinalResidual - checks if the `SNES` always computes the residual at the final solution
97: Logically Collective
99: Input Parameter:
100: . snes - the `SNES` context
102: Output Parameter:
103: . flg - `PETSC_TRUE` if the residual is computed
105: Level: advanced
107: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSolve()`, `SNESSetAlwaysComputesFinalResidual()`
108: @*/
109: PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES snes, PetscBool *flg)
110: {
111: PetscFunctionBegin;
113: *flg = snes->alwayscomputesfinalresidual;
114: PetscFunctionReturn(PETSC_SUCCESS);
115: }
117: /*@
118: SNESSetFunctionDomainError - tells `SNES` that the input vector, a proposed new solution, to your function you provided to `SNESSetFunction()` is not
119: in the function's domain. For example, a step with negative pressure.
121: Not Collective
123: Input Parameter:
124: . snes - the `SNES` context
126: Level: advanced
128: Notes:
129: This does not need to be called by all processes in the `SNES` MPI communicator.
131: A few solvers will try to cut the step size to avoid the domain error but for other solvers `SNESSolve()` stops iterating and
132: returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_DOMAIN`
134: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
135: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
137: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
139: You can call `SNESSetJacobianDomainError()` during a Jacobian computation to indicate the proposed solution is not in the domain.
141: Developer Note:
142: This value is used by `SNESCheckFunctionDomainError()` to determine if the `SNESConvergedReason` is set to `SNES_DIVERGED_FUNCTION_DOMAIN`
144: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetJacobianDomainError()`, `SNESVISetVariableBounds()`,
145: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`,
146: `SNES_DIVERGED_FUNCTION_DOMAIN`, `SNESSetObjectiveDomainError()`, `SNES_DIVERGED_OBJECTIVE_DOMAIN`
147: @*/
148: PetscErrorCode SNESSetFunctionDomainError(SNES snes)
149: {
150: PetscFunctionBegin;
152: snes->functiondomainerror = PETSC_TRUE;
153: PetscFunctionReturn(PETSC_SUCCESS);
154: }
156: /*@
157: SNESSetObjectiveDomainError - tells `SNES` that the input vector, a proposed new solution, to your function you provided to `SNESSetObjective()` is not
158: in the function's domain. For example, a step with negative pressure.
160: Not Collective
162: Input Parameter:
163: . snes - the `SNES` context
165: Level: advanced
167: Notes:
168: This does not need to be called by all processes in the `SNES` MPI communicator.
170: A few solvers will try to cut the step size to avoid the domain error but for other solvers `SNESSolve()` stops iterating and
171: returns with a `SNESConvergedReason` of `SNES_DIVERGED_OBJECTIVE_DOMAIN`
173: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
174: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
176: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
178: You can call `SNESSetJacobianDomainError()` during a Jacobian computation to indicate the proposed solution is not in the domain.
180: Developer Note:
181: This value is used by `SNESCheckObjectiveDomainError()` to determine if the `SNESConvergedReason` is set to `SNES_DIVERGED_OBJECTIVE_DOMAIN`
183: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetJacobianDomainError()`, `SNESVISetVariableBounds()`,
184: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`,
185: `SNES_DIVERGED_OBJECTIVE_DOMAIN`, `SNESSetFunctionDomainError()`, `SNES_DIVERGED_FUNCTION_DOMAIN`
186: @*/
187: PetscErrorCode SNESSetObjectiveDomainError(SNES snes)
188: {
189: PetscFunctionBegin;
191: snes->objectivedomainerror = PETSC_TRUE;
192: PetscFunctionReturn(PETSC_SUCCESS);
193: }
195: /*@
196: SNESSetJacobianDomainError - tells `SNES` that the function you provided to `SNESSetJacobian()` at the proposed step. For example there is a negative element transformation.
198: Logically Collective
200: Input Parameter:
201: . snes - the `SNES` context
203: Level: advanced
205: Notes:
206: If this is called the `SNESSolve()` stops iterating and returns with a `SNESConvergedReason` of `SNES_DIVERGED_JACOBIAN_DOMAIN`
208: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
210: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
211: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
213: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESVISetVariableBounds()`,
214: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
215: @*/
216: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
217: {
218: PetscFunctionBegin;
220: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates computeJacobian does not make sense");
221: snes->jacobiandomainerror = PETSC_TRUE;
222: PetscFunctionReturn(PETSC_SUCCESS);
223: }
225: /*@
226: SNESSetCheckJacobianDomainError - tells `SNESSolve()` whether to check if the user called `SNESSetJacobianDomainError()` to indicate a Jacobian domain error after
227: each Jacobian evaluation.
229: Logically Collective
231: Input Parameters:
232: + snes - the `SNES` context
233: - flg - indicates if or not to check Jacobian domain error after each Jacobian evaluation
235: Level: advanced
237: Notes:
238: By default, it checks for the Jacobian domain error in the debug mode, and does not check it in the optimized mode.
240: Checks require one extra parallel synchronization for each Jacobian evaluation
242: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESGetCheckJacobianDomainError()`
243: @*/
244: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
245: {
246: PetscFunctionBegin;
248: snes->checkjacdomainerror = flg;
249: PetscFunctionReturn(PETSC_SUCCESS);
250: }
252: /*@
253: SNESGetCheckJacobianDomainError - Get an indicator whether or not `SNES` is checking Jacobian domain errors after each Jacobian evaluation.
255: Logically Collective
257: Input Parameter:
258: . snes - the `SNES` context
260: Output Parameter:
261: . flg - `PETSC_FALSE` indicates that it is not checking Jacobian domain errors after each Jacobian evaluation
263: Level: advanced
265: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESSetCheckJacobianDomainError()`
266: @*/
267: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
268: {
269: PetscFunctionBegin;
271: PetscAssertPointer(flg, 2);
272: *flg = snes->checkjacdomainerror;
273: PetscFunctionReturn(PETSC_SUCCESS);
274: }
276: /*@
277: SNESLoad - Loads a `SNES` that has been stored in `PETSCVIEWERBINARY` with `SNESView()`.
279: Collective
281: Input Parameters:
282: + snes - the newly loaded `SNES`, this needs to have been created with `SNESCreate()` or
283: some related function before a call to `SNESLoad()`.
284: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()`
286: Level: intermediate
288: Note:
289: The `SNESType` is determined by the data in the file, any type set into the `SNES` before this call is ignored.
291: .seealso: [](ch_snes), `SNES`, `PetscViewer`, `SNESCreate()`, `SNESType`, `PetscViewerBinaryOpen()`, `SNESView()`, `MatLoad()`, `VecLoad()`
292: @*/
293: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
294: {
295: PetscBool isbinary;
296: PetscInt classid;
297: char type[256];
298: KSP ksp;
299: DM dm;
300: DMSNES dmsnes;
302: PetscFunctionBegin;
305: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
306: PetscCheck(isbinary, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen()");
308: PetscCall(PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT));
309: PetscCheck(classid == SNES_FILE_CLASSID, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Not SNES next in file");
310: PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
311: PetscCall(SNESSetType(snes, type));
312: PetscTryTypeMethod(snes, load, viewer);
313: PetscCall(SNESGetDM(snes, &dm));
314: PetscCall(DMGetDMSNES(dm, &dmsnes));
315: PetscCall(DMSNESLoad(dmsnes, viewer));
316: PetscCall(SNESGetKSP(snes, &ksp));
317: PetscCall(KSPLoad(ksp, viewer));
318: PetscFunctionReturn(PETSC_SUCCESS);
319: }
321: #include <petscdraw.h>
322: #if defined(PETSC_HAVE_SAWS)
323: #include <petscviewersaws.h>
324: #endif
326: /*@
327: SNESViewFromOptions - View a `SNES` based on values in the options database
329: Collective
331: Input Parameters:
332: + A - the `SNES` context
333: . obj - Optional object that provides the options prefix for the checks
334: - name - command line option
336: Options Database Key:
337: . -name [viewertype][:...] - option name and values. See `PetscObjectViewFromOptions()` for the possible arguments
339: Level: intermediate
341: .seealso: [](ch_snes), `SNES`, `SNESView`, `PetscObjectViewFromOptions()`, `SNESCreate()`
342: @*/
343: PetscErrorCode SNESViewFromOptions(SNES A, PetscObject obj, const char name[])
344: {
345: PetscFunctionBegin;
347: PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
348: PetscFunctionReturn(PETSC_SUCCESS);
349: }
351: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES, Vec, Mat, Mat, void *);
353: /*@
354: SNESView - Prints or visualizes the `SNES` data structure.
356: Collective
358: Input Parameters:
359: + snes - the `SNES` context
360: - viewer - the `PetscViewer`
362: Options Database Key:
363: . -snes_view - Calls `SNESView()` at end of `SNESSolve()`
365: Level: beginner
367: Notes:
368: The available visualization contexts include
369: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
370: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
371: output where only the first processor opens
372: the file. All other processors send their
373: data to the first processor to print.
375: The available formats include
376: + `PETSC_VIEWER_DEFAULT` - standard output (default)
377: - `PETSC_VIEWER_ASCII_INFO_DETAIL` - more verbose output for `SNESNASM`
379: The user can open an alternative visualization context with
380: `PetscViewerASCIIOpen()` - output to a specified file.
382: In the debugger you can do "call `SNESView`(snes,0)" to display the `SNES` solver. (The same holds for any PETSc object viewer).
384: .seealso: [](ch_snes), `SNES`, `SNESLoad()`, `SNESCreate()`, `PetscViewerASCIIOpen()`
385: @*/
386: PetscErrorCode SNESView(SNES snes, PetscViewer viewer)
387: {
388: SNESKSPEW *kctx;
389: KSP ksp;
390: SNESLineSearch linesearch;
391: PetscBool isascii, isstring, isbinary, isdraw;
392: DMSNES dmsnes;
393: #if defined(PETSC_HAVE_SAWS)
394: PetscBool issaws;
395: #endif
397: PetscFunctionBegin;
399: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &viewer));
401: PetscCheckSameComm(snes, 1, viewer, 2);
403: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
404: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
405: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
406: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
407: #if defined(PETSC_HAVE_SAWS)
408: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
409: #endif
410: if (isascii) {
411: SNESNormSchedule normschedule;
412: DM dm;
413: SNESJacobianFn *cJ;
414: void *ctx;
415: const char *pre = "";
417: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)snes, viewer));
418: if (!snes->setupcalled) PetscCall(PetscViewerASCIIPrintf(viewer, " SNES has not been set up so information may be incomplete\n"));
419: if (snes->ops->view) {
420: PetscCall(PetscViewerASCIIPushTab(viewer));
421: PetscUseTypeMethod(snes, view, viewer);
422: PetscCall(PetscViewerASCIIPopTab(viewer));
423: }
424: if (snes->max_funcs == PETSC_UNLIMITED) {
425: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=unlimited\n", snes->max_its));
426: } else {
427: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=%" PetscInt_FMT "\n", snes->max_its, snes->max_funcs));
428: }
429: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, solution=%g\n", (double)snes->rtol, (double)snes->abstol, (double)snes->stol));
430: if (snes->usesksp) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of linear solver iterations=%" PetscInt_FMT "\n", snes->linear_its));
431: PetscCall(PetscViewerASCIIPrintf(viewer, " total number of function evaluations=%" PetscInt_FMT "\n", snes->nfuncs));
432: PetscCall(SNESGetNormSchedule(snes, &normschedule));
433: if (normschedule > 0) PetscCall(PetscViewerASCIIPrintf(viewer, " norm schedule %s\n", SNESNormSchedules[normschedule]));
434: if (snes->gridsequence) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of grid sequence refinements=%" PetscInt_FMT "\n", snes->gridsequence));
435: if (snes->ksp_ewconv) {
436: kctx = (SNESKSPEW *)snes->kspconvctx;
437: if (kctx) {
438: PetscCall(PetscViewerASCIIPrintf(viewer, " Eisenstat-Walker computation of KSP relative tolerance (version %" PetscInt_FMT ")\n", kctx->version));
439: PetscCall(PetscViewerASCIIPrintf(viewer, " rtol_0=%g, rtol_max=%g, threshold=%g\n", (double)kctx->rtol_0, (double)kctx->rtol_max, (double)kctx->threshold));
440: PetscCall(PetscViewerASCIIPrintf(viewer, " gamma=%g, alpha=%g, alpha2=%g\n", (double)kctx->gamma, (double)kctx->alpha, (double)kctx->alpha2));
441: }
442: }
443: if (snes->lagpreconditioner == -1) {
444: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is never rebuilt\n"));
445: } else if (snes->lagpreconditioner > 1) {
446: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is rebuilt every %" PetscInt_FMT " new Jacobians\n", snes->lagpreconditioner));
447: }
448: if (snes->lagjacobian == -1) {
449: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is never rebuilt\n"));
450: } else if (snes->lagjacobian > 1) {
451: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is rebuilt every %" PetscInt_FMT " SNES iterations\n", snes->lagjacobian));
452: }
453: PetscCall(SNESGetDM(snes, &dm));
454: PetscCall(DMSNESGetJacobian(dm, &cJ, &ctx));
455: if (snes->mf_operator) {
456: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing\n"));
457: pre = "Preconditioning ";
458: }
459: if (cJ == SNESComputeJacobianDefault) {
460: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences one column at a time\n", pre));
461: } else if (cJ == SNESComputeJacobianDefaultColor) {
462: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences with coloring\n", pre));
463: /* it slightly breaks data encapsulation for access the DMDA information directly */
464: } else if (cJ == SNESComputeJacobian_DMDA) {
465: MatFDColoring fdcoloring;
466: PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
467: if (fdcoloring) {
468: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using colored finite differences on a DMDA\n", pre));
469: } else {
470: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using a DMDA local Jacobian\n", pre));
471: }
472: } else if (snes->mf && !snes->mf_operator) {
473: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing, no explicit Jacobian\n"));
474: }
475: } else if (isstring) {
476: const char *type;
477: PetscCall(SNESGetType(snes, &type));
478: PetscCall(PetscViewerStringSPrintf(viewer, " SNESType: %-7.7s", type));
479: PetscTryTypeMethod(snes, view, viewer);
480: } else if (isbinary) {
481: PetscInt classid = SNES_FILE_CLASSID;
482: MPI_Comm comm;
483: PetscMPIInt rank;
484: char type[256];
486: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
487: PetscCallMPI(MPI_Comm_rank(comm, &rank));
488: if (rank == 0) {
489: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
490: PetscCall(PetscStrncpy(type, ((PetscObject)snes)->type_name, sizeof(type)));
491: PetscCall(PetscViewerBinaryWrite(viewer, type, sizeof(type), PETSC_CHAR));
492: }
493: PetscTryTypeMethod(snes, view, viewer);
494: } else if (isdraw) {
495: PetscDraw draw;
496: char str[36];
497: PetscReal x, y, bottom, h;
499: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
500: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
501: PetscCall(PetscStrncpy(str, "SNES: ", sizeof(str)));
502: PetscCall(PetscStrlcat(str, ((PetscObject)snes)->type_name, sizeof(str)));
503: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_BLUE, PETSC_DRAW_BLACK, str, NULL, &h));
504: bottom = y - h;
505: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
506: PetscTryTypeMethod(snes, view, viewer);
507: #if defined(PETSC_HAVE_SAWS)
508: } else if (issaws) {
509: PetscMPIInt rank;
510: const char *name;
512: PetscCall(PetscObjectGetName((PetscObject)snes, &name));
513: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
514: if (!((PetscObject)snes)->amsmem && rank == 0) {
515: char dir[1024];
517: PetscCall(PetscObjectViewSAWs((PetscObject)snes, viewer));
518: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
519: PetscCallSAWs(SAWs_Register, (dir, &snes->iter, 1, SAWs_READ, SAWs_INT));
520: if (!snes->conv_hist) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, PETSC_DECIDE, PETSC_TRUE));
521: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/conv_hist", name));
522: PetscCallSAWs(SAWs_Register, (dir, snes->conv_hist, 10, SAWs_READ, SAWs_DOUBLE));
523: }
524: #endif
525: }
526: if (snes->linesearch) {
527: PetscCall(SNESGetLineSearch(snes, &linesearch));
528: PetscCall(PetscViewerASCIIPushTab(viewer));
529: PetscCall(SNESLineSearchView(linesearch, viewer));
530: PetscCall(PetscViewerASCIIPopTab(viewer));
531: }
532: if (snes->npc && snes->usesnpc) {
533: PetscCall(PetscViewerASCIIPushTab(viewer));
534: PetscCall(SNESView(snes->npc, viewer));
535: PetscCall(PetscViewerASCIIPopTab(viewer));
536: }
537: PetscCall(PetscViewerASCIIPushTab(viewer));
538: PetscCall(DMGetDMSNES(snes->dm, &dmsnes));
539: PetscCall(DMSNESView(dmsnes, viewer));
540: PetscCall(PetscViewerASCIIPopTab(viewer));
541: if (snes->usesksp) {
542: PetscCall(SNESGetKSP(snes, &ksp));
543: PetscCall(PetscViewerASCIIPushTab(viewer));
544: PetscCall(KSPView(ksp, viewer));
545: PetscCall(PetscViewerASCIIPopTab(viewer));
546: }
547: if (isdraw) {
548: PetscDraw draw;
549: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
550: PetscCall(PetscDrawPopCurrentPoint(draw));
551: }
552: PetscFunctionReturn(PETSC_SUCCESS);
553: }
555: /*
556: We retain a list of functions that also take SNES command
557: line options. These are called at the end SNESSetFromOptions()
558: */
559: #define MAXSETFROMOPTIONS 5
560: static PetscInt numberofsetfromoptions;
561: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
563: /*@C
564: SNESAddOptionsChecker - Adds an additional function to check for `SNES` options.
566: Not Collective
568: Input Parameter:
569: . snescheck - function that checks for options
571: Calling sequence of `snescheck`:
572: . snes - the `SNES` object for which it is checking options
574: Level: developer
576: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`
577: @*/
578: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES snes))
579: {
580: PetscFunctionBegin;
581: PetscCheck(numberofsetfromoptions < MAXSETFROMOPTIONS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %d allowed", MAXSETFROMOPTIONS);
582: othersetfromoptions[numberofsetfromoptions++] = snescheck;
583: PetscFunctionReturn(PETSC_SUCCESS);
584: }
586: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
587: {
588: Mat J;
589: MatNullSpace nullsp;
591: PetscFunctionBegin;
594: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
595: Mat A = snes->jacobian, B = snes->jacobian_pre;
596: PetscCall(MatCreateVecs(A ? A : B, NULL, &snes->vec_func));
597: }
599: PetscCheck(version == 1 || version == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator routines, only version 1 and 2");
600: if (version == 1) {
601: PetscCall(MatCreateSNESMF(snes, &J));
602: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
603: PetscCall(MatSetFromOptions(J));
604: /* TODO: the version 2 code should be merged into the MatCreateSNESMF() and MatCreateMFFD() infrastructure and then removed */
605: } else /* if (version == 2) */ {
606: PetscCheck(snes->vec_func, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "SNESSetFunction() must be called first");
607: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
608: PetscCall(MatCreateSNESMFMore(snes, snes->vec_func, &J));
609: #else
610: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "matrix-free operator routines (version 2)");
611: #endif
612: }
614: /* attach any user provided null space that was on Amat to the newly created matrix-free matrix */
615: if (snes->jacobian) {
616: PetscCall(MatGetNullSpace(snes->jacobian, &nullsp));
617: if (nullsp) PetscCall(MatSetNullSpace(J, nullsp));
618: }
620: PetscCall(PetscInfo(snes, "Setting default matrix-free operator routines (version %" PetscInt_FMT ")\n", version));
621: if (hasOperator) {
622: /* This version replaces the user provided Jacobian matrix with a
623: matrix-free version but still employs the user-provided matrix used for computing the preconditioner. */
624: PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
625: } else {
626: /* This version replaces both the user-provided Jacobian and the user-
627: provided preconditioner Jacobian with the default matrix-free version. */
628: if (snes->npcside == PC_LEFT && snes->npc) {
629: if (!snes->jacobian) PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
630: } else {
631: KSP ksp;
632: PC pc;
633: PetscBool match;
635: PetscCall(SNESSetJacobian(snes, J, J, MatMFFDComputeJacobian, NULL));
636: /* Force no preconditioner */
637: PetscCall(SNESGetKSP(snes, &ksp));
638: PetscCall(KSPGetPC(ksp, &pc));
639: PetscCall(PetscObjectTypeCompareAny((PetscObject)pc, &match, PCSHELL, PCH2OPUS, ""));
640: if (!match) {
641: PetscCall(PetscInfo(snes, "Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n"));
642: PetscCall(PCSetType(pc, PCNONE));
643: }
644: }
645: }
646: PetscCall(MatDestroy(&J));
647: PetscFunctionReturn(PETSC_SUCCESS);
648: }
650: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine, Mat Restrict, Vec Rscale, Mat Inject, DM dmcoarse, PetscCtx ctx)
651: {
652: SNES snes = (SNES)ctx;
653: Vec Xfine, Xfine_named = NULL, Xcoarse;
655: PetscFunctionBegin;
656: if (PetscLogPrintInfo) {
657: PetscInt finelevel, coarselevel, fineclevel, coarseclevel;
658: PetscCall(DMGetRefineLevel(dmfine, &finelevel));
659: PetscCall(DMGetCoarsenLevel(dmfine, &fineclevel));
660: PetscCall(DMGetRefineLevel(dmcoarse, &coarselevel));
661: PetscCall(DMGetCoarsenLevel(dmcoarse, &coarseclevel));
662: PetscCall(PetscInfo(dmfine, "Restricting SNES solution vector from level %" PetscInt_FMT "-%" PetscInt_FMT " to level %" PetscInt_FMT "-%" PetscInt_FMT "\n", finelevel, fineclevel, coarselevel, coarseclevel));
663: }
664: if (dmfine == snes->dm) Xfine = snes->vec_sol;
665: else {
666: PetscCall(DMGetNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
667: Xfine = Xfine_named;
668: }
669: PetscCall(DMGetNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
670: if (Inject) {
671: PetscCall(MatRestrict(Inject, Xfine, Xcoarse));
672: } else {
673: PetscCall(MatRestrict(Restrict, Xfine, Xcoarse));
674: PetscCall(VecPointwiseMult(Xcoarse, Xcoarse, Rscale));
675: }
676: PetscCall(DMRestoreNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
677: if (Xfine_named) PetscCall(DMRestoreNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
678: PetscFunctionReturn(PETSC_SUCCESS);
679: }
681: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm, DM dmc, PetscCtx ctx)
682: {
683: PetscFunctionBegin;
684: PetscCall(DMCoarsenHookAdd(dmc, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, ctx));
685: PetscFunctionReturn(PETSC_SUCCESS);
686: }
688: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
689: * safely call SNESGetDM() in their residual evaluation routine. */
690: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp, Mat A, Mat B, PetscCtx ctx)
691: {
692: SNES snes = (SNES)ctx;
693: DMSNES sdm;
694: Vec X, Xnamed = NULL;
695: DM dmsave;
696: void *ctxsave;
697: SNESJacobianFn *jac = NULL;
699: PetscFunctionBegin;
700: dmsave = snes->dm;
701: PetscCall(KSPGetDM(ksp, &snes->dm));
702: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
703: else {
704: PetscBool has;
706: /* We are on a coarser level, this vec was initialized using a DM restrict hook */
707: PetscCall(DMHasNamedGlobalVector(snes->dm, "SNESVecSol", &has));
708: PetscCheck(has, PetscObjectComm((PetscObject)snes->dm), PETSC_ERR_PLIB, "Missing SNESVecSol");
709: PetscCall(DMGetNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
710: X = Xnamed;
711: PetscCall(SNESGetJacobian(snes, NULL, NULL, &jac, &ctxsave));
712: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
713: if (jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, SNESComputeJacobianDefaultColor, NULL));
714: }
716: /* Compute the operators */
717: PetscCall(DMGetDMSNES(snes->dm, &sdm));
718: if (Xnamed && sdm->ops->computefunction) {
719: /* The SNES contract with the user is that ComputeFunction is always called before ComputeJacobian.
720: We make sure of this here. Disable affine shift since it is for the finest level */
721: Vec F, saverhs = snes->vec_rhs;
723: snes->vec_rhs = NULL;
724: PetscCall(DMGetGlobalVector(snes->dm, &F));
725: PetscCall(SNESComputeFunction(snes, X, F));
726: PetscCall(DMRestoreGlobalVector(snes->dm, &F));
727: snes->vec_rhs = saverhs;
728: snes->nfuncs--; /* Do not log coarser level evaluations */
729: }
730: /* Make sure KSP DM has the Jacobian computation routine */
731: if (!sdm->ops->computejacobian) PetscCall(DMCopyDMSNES(dmsave, snes->dm));
732: PetscCall(SNESComputeJacobian(snes, X, A, B)); /* cannot handle previous SNESSetJacobianDomainError() calls */
734: /* Put the previous context back */
735: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, jac, ctxsave));
737: if (Xnamed) PetscCall(DMRestoreNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
738: snes->dm = dmsave;
739: PetscFunctionReturn(PETSC_SUCCESS);
740: }
742: /*@
743: SNESSetUpMatrices - ensures that matrices are available for `SNES` Newton-like methods, this is called by `SNESSetUp_XXX()`
745: Collective
747: Input Parameter:
748: . snes - `SNES` object to configure
750: Level: developer
752: Note:
753: If the matrices do not yet exist it attempts to create them based on options previously set for the `SNES` such as `-snes_mf`
755: Developer Note:
756: The functionality of this routine overlaps in a confusing way with the functionality of `SNESSetUpMatrixFree_Private()` which is called by
757: `SNESSetUp()` but sometimes `SNESSetUpMatrices()` is called without `SNESSetUp()` being called. A refactorization to simplify the
758: logic that handles the matrix-free case is desirable.
760: .seealso: [](ch_snes), `SNES`, `SNESSetUp()`
761: @*/
762: PetscErrorCode SNESSetUpMatrices(SNES snes)
763: {
764: DM dm;
765: DMSNES sdm;
767: PetscFunctionBegin;
768: PetscCall(SNESGetDM(snes, &dm));
769: PetscCall(DMGetDMSNES(dm, &sdm));
770: if (!snes->jacobian && snes->mf && !snes->mf_operator && !snes->jacobian_pre) {
771: Mat J;
772: void *functx;
773: PetscCall(MatCreateSNESMF(snes, &J));
774: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
775: PetscCall(MatSetFromOptions(J));
776: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
777: PetscCall(SNESSetJacobian(snes, J, J, NULL, NULL));
778: PetscCall(MatDestroy(&J));
779: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
780: Mat J, B;
781: PetscCall(MatCreateSNESMF(snes, &J));
782: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
783: PetscCall(MatSetFromOptions(J));
784: PetscCall(DMCreateMatrix(snes->dm, &B));
785: /* sdm->computejacobian was already set to reach here */
786: PetscCall(SNESSetJacobian(snes, J, B, NULL, NULL));
787: PetscCall(MatDestroy(&J));
788: PetscCall(MatDestroy(&B));
789: } else if (!snes->jacobian_pre) {
790: PetscDS prob;
791: Mat J, B;
792: PetscBool hasPrec = PETSC_FALSE;
794: J = snes->jacobian;
795: PetscCall(DMGetDS(dm, &prob));
796: if (prob) PetscCall(PetscDSHasJacobianPreconditioner(prob, &hasPrec));
797: if (!J && hasPrec) PetscCall(DMCreateMatrix(snes->dm, &J));
798: else PetscCall(PetscObjectReference((PetscObject)J));
799: PetscCall(DMCreateMatrix(snes->dm, &B));
800: PetscCall(SNESSetJacobian(snes, J ? J : B, B, NULL, NULL));
801: PetscCall(MatDestroy(&J));
802: PetscCall(MatDestroy(&B));
803: }
804: {
805: KSP ksp;
806: PetscCall(SNESGetKSP(snes, &ksp));
807: PetscCall(KSPSetComputeOperators(ksp, KSPComputeOperators_SNES, snes));
808: PetscCall(DMCoarsenHookAdd(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
809: }
810: PetscFunctionReturn(PETSC_SUCCESS);
811: }
813: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode PetscMonitorPauseFinal_Internal(PetscInt, PetscCtx);
815: static PetscErrorCode SNESMonitorPauseFinal_Internal(SNES snes)
816: {
817: PetscFunctionBegin;
818: if (!snes->pauseFinal) PetscFunctionReturn(PETSC_SUCCESS);
819: PetscCall(PetscMonitorPauseFinal_Internal(snes->numbermonitors, snes->monitorcontext));
820: PetscFunctionReturn(PETSC_SUCCESS);
821: }
823: /*@C
824: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
826: Collective
828: Input Parameters:
829: + snes - `SNES` object you wish to monitor
830: . name - the monitor type one is seeking
831: . help - message indicating what monitoring is done
832: . manual - manual page for the monitor
833: . monitor - the monitor function, this must use a `PetscViewerFormat` as its context
834: - 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
836: Calling sequence of `monitor`:
837: + snes - the nonlinear solver context
838: . it - the current iteration
839: . r - the current function norm
840: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
842: Calling sequence of `monitorsetup`:
843: + snes - the nonlinear solver context
844: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
846: Options Database Key:
847: . -name - trigger the use of this monitor in `SNESSetFromOptions()`
849: Level: advanced
851: .seealso: [](ch_snes), `PetscOptionsCreateViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
852: `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`,
853: `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
854: `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
855: `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
856: `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
857: `PetscOptionsFList()`, `PetscOptionsEList()`
858: @*/
859: 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))
860: {
861: PetscViewer viewer;
862: PetscViewerFormat format;
863: PetscBool flg;
865: PetscFunctionBegin;
866: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, name, &viewer, &format, &flg));
867: if (flg) {
868: PetscViewerAndFormat *vf;
869: PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
870: PetscCall(PetscViewerDestroy(&viewer));
871: if (monitorsetup) PetscCall((*monitorsetup)(snes, vf));
872: PetscCall(SNESMonitorSet(snes, (PetscErrorCode (*)(SNES, PetscInt, PetscReal, PetscCtx))monitor, vf, (PetscCtxDestroyFn *)PetscViewerAndFormatDestroy));
873: }
874: PetscFunctionReturn(PETSC_SUCCESS);
875: }
877: PetscErrorCode SNESEWSetFromOptions_Private(SNESKSPEW *kctx, PetscBool print_api, MPI_Comm comm, const char *prefix)
878: {
879: const char *api = print_api ? "SNESKSPSetParametersEW" : NULL;
881: PetscFunctionBegin;
882: PetscOptionsBegin(comm, prefix, "Eisenstat and Walker type forcing options", "KSP");
883: PetscCall(PetscOptionsInt("-ksp_ew_version", "Version 1, 2 or 3", api, kctx->version, &kctx->version, NULL));
884: PetscCall(PetscOptionsReal("-ksp_ew_rtol0", "0 <= rtol0 < 1", api, kctx->rtol_0, &kctx->rtol_0, NULL));
885: kctx->rtol_max = PetscMax(kctx->rtol_0, kctx->rtol_max);
886: PetscCall(PetscOptionsReal("-ksp_ew_rtolmax", "0 <= rtolmax < 1", api, kctx->rtol_max, &kctx->rtol_max, NULL));
887: PetscCall(PetscOptionsReal("-ksp_ew_gamma", "0 <= gamma <= 1", api, kctx->gamma, &kctx->gamma, NULL));
888: PetscCall(PetscOptionsReal("-ksp_ew_alpha", "1 < alpha <= 2", api, kctx->alpha, &kctx->alpha, NULL));
889: PetscCall(PetscOptionsReal("-ksp_ew_alpha2", "alpha2", NULL, kctx->alpha2, &kctx->alpha2, NULL));
890: PetscCall(PetscOptionsReal("-ksp_ew_threshold", "0 < threshold < 1", api, kctx->threshold, &kctx->threshold, NULL));
891: PetscCall(PetscOptionsReal("-ksp_ew_v4_p1", "p1", NULL, kctx->v4_p1, &kctx->v4_p1, NULL));
892: PetscCall(PetscOptionsReal("-ksp_ew_v4_p2", "p2", NULL, kctx->v4_p2, &kctx->v4_p2, NULL));
893: PetscCall(PetscOptionsReal("-ksp_ew_v4_p3", "p3", NULL, kctx->v4_p3, &kctx->v4_p3, NULL));
894: PetscCall(PetscOptionsReal("-ksp_ew_v4_m1", "Scaling when rk-1 in [p2,p3)", NULL, kctx->v4_m1, &kctx->v4_m1, NULL));
895: PetscCall(PetscOptionsReal("-ksp_ew_v4_m2", "Scaling when rk-1 in [p3,+infty)", NULL, kctx->v4_m2, &kctx->v4_m2, NULL));
896: PetscCall(PetscOptionsReal("-ksp_ew_v4_m3", "Threshold for successive rtol (0.1 in Eq.7)", NULL, kctx->v4_m3, &kctx->v4_m3, NULL));
897: PetscCall(PetscOptionsReal("-ksp_ew_v4_m4", "Adaptation scaling (0.5 in Eq.7)", NULL, kctx->v4_m4, &kctx->v4_m4, NULL));
898: PetscOptionsEnd();
899: PetscFunctionReturn(PETSC_SUCCESS);
900: }
902: /*@
903: SNESSetFromOptions - Sets various `SNES` and `KSP` parameters from user options.
905: Collective
907: Input Parameter:
908: . snes - the `SNES` context
910: Options Database Keys:
911: + -snes_type type - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, `SNESType` for complete list
912: . -snes_rtol rtol - relative decrease in tolerance norm from initial
913: . -snes_atol abstol - absolute tolerance of residual norm
914: . -snes_stol stol - convergence tolerance in terms of the norm of the change in the solution between steps
915: . -snes_divergence_tolerance divtol - if the residual goes above divtol*rnorm0, exit with divergence
916: . -snes_max_it max_it - maximum number of iterations
917: . -snes_max_funcs max_funcs - maximum number of function evaluations
918: . -snes_force_iteration force - force `SNESSolve()` to take at least one iteration
919: . -snes_max_fail max_fail - maximum number of line search failures allowed before stopping, default is none
920: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
921: . -snes_lag_preconditioner lag - how often preconditioner is rebuilt (use -1 to never rebuild)
922: . -snes_lag_preconditioner_persists (true|false) - retains the -snes_lag_preconditioner information across multiple SNESSolve()
923: . -snes_lag_jacobian lag - how often Jacobian is rebuilt (use -1 to never rebuild)
924: . -snes_lag_jacobian_persists (true|false) - retains the -snes_lag_jacobian information across multiple SNESSolve()
925: . -snes_convergence_test (default|skip|correct_pressure) - convergence test in nonlinear solver. default `SNESConvergedDefault()`. skip `SNESConvergedSkip()` means continue
926: iterating until max_it or some other criterion is reached, saving expense of convergence test. correct_pressure
927: `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 [threshold] - compare the user provided Jacobian with one computed via finite differences to check for errors.
941: If a threshold is given, display only those entries whose difference is greater than the threshold.
942: - -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference between them
943: to help users detect the location of errors in the user provided Jacobian.
945: Options Database Keys for Eisenstat-Walker method:
946: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
947: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
948: . -snes_ksp_ew_rtol0 rtol0 - Sets rtol0
949: . -snes_ksp_ew_rtolmax rtolmax - Sets rtolmax
950: . -snes_ksp_ew_gamma gamma - Sets gamma
951: . -snes_ksp_ew_alpha alpha - Sets alpha
952: . -snes_ksp_ew_alpha2 alpha2 - Sets alpha2
953: - -snes_ksp_ew_threshold threshold - Sets threshold
955: Level: beginner
957: Notes:
958: To see all options, run your program with the -help option or consult the users manual
960: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
961: and computing explicitly with
962: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
964: .seealso: [](ch_snes), `SNESType`, `SNESSetOptionsPrefix()`, `SNESResetFromOptions()`, `SNES`, `SNESCreate()`, `MatCreateSNESMF()`, `MatFDColoring`
965: @*/
966: PetscErrorCode SNESSetFromOptions(SNES snes)
967: {
968: PetscBool flg, pcset, persist, set;
969: PetscInt i, indx, lag, grids, max_its, max_funcs;
970: const char *deft = SNESNEWTONLS;
971: const char *convtests[] = {"default", "skip", "correct_pressure"};
972: SNESKSPEW *kctx = NULL;
973: char type[256], monfilename[PETSC_MAX_PATH_LEN], ewprefix[256];
974: PCSide pcside;
975: const char *optionsprefix;
976: PetscReal rtol, abstol, stol;
978: PetscFunctionBegin;
980: PetscCall(SNESRegisterAll());
981: PetscObjectOptionsBegin((PetscObject)snes);
982: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
983: PetscCall(PetscOptionsFList("-snes_type", "Nonlinear solver method", "SNESSetType", SNESList, deft, type, 256, &flg));
984: if (flg) PetscCall(SNESSetType(snes, type));
985: else if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, deft));
987: abstol = snes->abstol;
988: rtol = snes->rtol;
989: stol = snes->stol;
990: max_its = snes->max_its;
991: max_funcs = snes->max_funcs;
992: PetscCall(PetscOptionsReal("-snes_rtol", "Stop if decrease in function norm less than", "SNESSetTolerances", snes->rtol, &rtol, NULL));
993: PetscCall(PetscOptionsReal("-snes_atol", "Stop if function norm less than", "SNESSetTolerances", snes->abstol, &abstol, NULL));
994: PetscCall(PetscOptionsReal("-snes_stol", "Stop if step length less than", "SNESSetTolerances", snes->stol, &stol, NULL));
995: PetscCall(PetscOptionsInt("-snes_max_it", "Maximum iterations", "SNESSetTolerances", snes->max_its, &max_its, NULL));
996: PetscCall(PetscOptionsInt("-snes_max_funcs", "Maximum function evaluations", "SNESSetTolerances", snes->max_funcs, &max_funcs, NULL));
997: PetscCall(SNESSetTolerances(snes, abstol, rtol, stol, max_its, max_funcs));
999: PetscCall(PetscOptionsReal("-snes_divergence_tolerance", "Stop if residual norm increases by this factor", "SNESSetDivergenceTolerance", snes->divtol, &snes->divtol, &flg));
1000: if (flg) PetscCall(SNESSetDivergenceTolerance(snes, snes->divtol));
1002: PetscCall(PetscOptionsInt("-snes_max_fail", "Maximum nonlinear step failures", "SNESSetMaxNonlinearStepFailures", snes->maxFailures, &snes->maxFailures, &flg));
1003: if (flg) PetscCall(SNESSetMaxNonlinearStepFailures(snes, snes->maxFailures));
1005: PetscCall(PetscOptionsInt("-snes_max_linear_solve_fail", "Maximum failures in linear solves allowed", "SNESSetMaxLinearSolveFailures", snes->maxLinearSolveFailures, &snes->maxLinearSolveFailures, &flg));
1006: if (flg) PetscCall(SNESSetMaxLinearSolveFailures(snes, snes->maxLinearSolveFailures));
1008: PetscCall(PetscOptionsBool("-snes_error_if_not_converged", "Generate error if solver does not converge", "SNESSetErrorIfNotConverged", snes->errorifnotconverged, &snes->errorifnotconverged, NULL));
1009: PetscCall(PetscOptionsBool("-snes_force_iteration", "Force SNESSolve() to take at least one iteration", "SNESSetForceIteration", snes->forceiteration, &snes->forceiteration, NULL));
1010: PetscCall(PetscOptionsBool("-snes_check_jacobian_domain_error", "Check Jacobian domain error after Jacobian evaluation", "SNESCheckJacobianDomainError", snes->checkjacdomainerror, &snes->checkjacdomainerror, NULL));
1012: PetscCall(PetscOptionsInt("-snes_lag_preconditioner", "How often to rebuild preconditioner", "SNESSetLagPreconditioner", snes->lagpreconditioner, &lag, &flg));
1013: if (flg) {
1014: 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");
1015: PetscCall(SNESSetLagPreconditioner(snes, lag));
1016: }
1017: PetscCall(PetscOptionsBool("-snes_lag_preconditioner_persists", "Preconditioner lagging through multiple SNES solves", "SNESSetLagPreconditionerPersists", snes->lagjac_persist, &persist, &flg));
1018: if (flg) PetscCall(SNESSetLagPreconditionerPersists(snes, persist));
1019: PetscCall(PetscOptionsInt("-snes_lag_jacobian", "How often to rebuild Jacobian", "SNESSetLagJacobian", snes->lagjacobian, &lag, &flg));
1020: if (flg) {
1021: 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");
1022: PetscCall(SNESSetLagJacobian(snes, lag));
1023: }
1024: PetscCall(PetscOptionsBool("-snes_lag_jacobian_persists", "Jacobian lagging through multiple SNES solves", "SNESSetLagJacobianPersists", snes->lagjac_persist, &persist, &flg));
1025: if (flg) PetscCall(SNESSetLagJacobianPersists(snes, persist));
1027: PetscCall(PetscOptionsInt("-snes_grid_sequence", "Use grid sequencing to generate initial guess", "SNESSetGridSequence", snes->gridsequence, &grids, &flg));
1028: if (flg) PetscCall(SNESSetGridSequence(snes, grids));
1030: PetscCall(PetscOptionsEList("-snes_convergence_test", "Convergence test", "SNESSetConvergenceTest", convtests, PETSC_STATIC_ARRAY_LENGTH(convtests), "default", &indx, &flg));
1031: if (flg) {
1032: switch (indx) {
1033: case 0:
1034: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedDefault, NULL, NULL));
1035: break;
1036: case 1:
1037: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedSkip, NULL, NULL));
1038: break;
1039: case 2:
1040: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedCorrectPressure, NULL, NULL));
1041: break;
1042: }
1043: }
1045: PetscCall(PetscOptionsEList("-snes_norm_schedule", "SNES Norm schedule", "SNESSetNormSchedule", SNESNormSchedules, 5, "function", &indx, &flg));
1046: if (flg) PetscCall(SNESSetNormSchedule(snes, (SNESNormSchedule)indx));
1048: PetscCall(PetscOptionsEList("-snes_function_type", "SNES Norm schedule", "SNESSetFunctionType", SNESFunctionTypes, 2, "unpreconditioned", &indx, &flg));
1049: if (flg) PetscCall(SNESSetFunctionType(snes, (SNESFunctionType)indx));
1051: kctx = (SNESKSPEW *)snes->kspconvctx;
1053: PetscCall(PetscOptionsBool("-snes_ksp_ew", "Use Eisentat-Walker linear system convergence test", "SNESKSPSetUseEW", snes->ksp_ewconv, &snes->ksp_ewconv, NULL));
1055: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1056: PetscCall(PetscSNPrintf(ewprefix, sizeof(ewprefix), "%s%s", optionsprefix ? optionsprefix : "", "snes_"));
1057: PetscCall(SNESEWSetFromOptions_Private(kctx, PETSC_TRUE, PetscObjectComm((PetscObject)snes), ewprefix));
1059: flg = PETSC_FALSE;
1060: PetscCall(PetscOptionsBool("-snes_monitor_cancel", "Remove all monitors", "SNESMonitorCancel", flg, &flg, &set));
1061: if (set && flg) PetscCall(SNESMonitorCancel(snes));
1063: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor", "Monitor norm of function", "SNESMonitorDefault", SNESMonitorDefault, SNESMonitorDefaultSetUp));
1064: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_short", "Monitor norm of function with fewer digits", "SNESMonitorDefaultShort", SNESMonitorDefaultShort, NULL));
1065: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_range", "Monitor range of elements of function", "SNESMonitorRange", SNESMonitorRange, NULL));
1067: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_ratio", "Monitor ratios of the norm of function for consecutive steps", "SNESMonitorRatio", SNESMonitorRatio, SNESMonitorRatioSetUp));
1068: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_field", "Monitor norm of function (split into fields)", "SNESMonitorDefaultField", SNESMonitorDefaultField, NULL));
1069: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution", "View solution at each iteration", "SNESMonitorSolution", SNESMonitorSolution, NULL));
1070: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution_update", "View correction at each iteration", "SNESMonitorSolutionUpdate", SNESMonitorSolutionUpdate, NULL));
1071: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_residual", "View residual at each iteration", "SNESMonitorResidual", SNESMonitorResidual, NULL));
1072: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_jacupdate_spectrum", "Print the change in the spectrum of the Jacobian", "SNESMonitorJacUpdateSpectrum", SNESMonitorJacUpdateSpectrum, NULL));
1073: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_fields", "Monitor norm of function per field", "SNESMonitorSet", SNESMonitorFields, NULL));
1074: PetscCall(PetscOptionsBool("-snes_monitor_pause_final", "Pauses all draw monitors at the final iterate", "SNESMonitorPauseFinal_Internal", PETSC_FALSE, &snes->pauseFinal, NULL));
1076: PetscCall(PetscOptionsString("-snes_monitor_python", "Use Python function", "SNESMonitorSet", NULL, monfilename, sizeof(monfilename), &flg));
1077: if (flg) PetscCall(PetscPythonMonitorSet((PetscObject)snes, monfilename));
1079: flg = PETSC_FALSE;
1080: PetscCall(PetscOptionsBool("-snes_monitor_lg_range", "Plot function range at each iteration", "SNESMonitorLGRange", flg, &flg, NULL));
1081: if (flg) {
1082: PetscViewer ctx;
1084: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &ctx));
1085: PetscCall(SNESMonitorSet(snes, SNESMonitorLGRange, ctx, (PetscCtxDestroyFn *)PetscViewerDestroy));
1086: }
1088: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
1089: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &snes->convergedreasonviewer, &snes->convergedreasonformat, NULL));
1090: flg = PETSC_FALSE;
1091: PetscCall(PetscOptionsBool("-snes_converged_reason_view_cancel", "Remove all converged reason viewers", "SNESConvergedReasonViewCancel", flg, &flg, &set));
1092: if (set && flg) PetscCall(SNESConvergedReasonViewCancel(snes));
1094: flg = PETSC_FALSE;
1095: PetscCall(PetscOptionsBool("-snes_fd", "Use finite differences (slow) to compute Jacobian", "SNESComputeJacobianDefault", flg, &flg, NULL));
1096: if (flg) {
1097: void *functx;
1098: DM dm;
1099: PetscCall(SNESGetDM(snes, &dm));
1100: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1101: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
1102: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefault, functx));
1103: PetscCall(PetscInfo(snes, "Setting default finite difference Jacobian matrix\n"));
1104: }
1106: flg = PETSC_FALSE;
1107: PetscCall(PetscOptionsBool("-snes_fd_function", "Use finite differences (slow) to compute function from user objective", "SNESObjectiveComputeFunctionDefaultFD", flg, &flg, NULL));
1108: if (flg) PetscCall(SNESSetFunction(snes, NULL, SNESObjectiveComputeFunctionDefaultFD, NULL));
1110: flg = PETSC_FALSE;
1111: PetscCall(PetscOptionsBool("-snes_fd_color", "Use finite differences with coloring to compute Jacobian", "SNESComputeJacobianDefaultColor", flg, &flg, NULL));
1112: if (flg) {
1113: DM dm;
1114: PetscCall(SNESGetDM(snes, &dm));
1115: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1116: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefaultColor, NULL));
1117: PetscCall(PetscInfo(snes, "Setting default finite difference coloring Jacobian matrix\n"));
1118: }
1120: flg = PETSC_FALSE;
1121: PetscCall(PetscOptionsBool("-snes_mf_operator", "Use a Matrix-Free Jacobian with user-provided matrix for computing the preconditioner", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf_operator, &flg));
1122: if (flg && snes->mf_operator) {
1123: snes->mf_operator = PETSC_TRUE;
1124: snes->mf = PETSC_TRUE;
1125: }
1126: flg = PETSC_FALSE;
1127: PetscCall(PetscOptionsBool("-snes_mf", "Use a Matrix-Free Jacobian with no matrix for computing the preconditioner", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf, &flg));
1128: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1129: PetscCall(PetscOptionsInt("-snes_mf_version", "Matrix-Free routines version 1 or 2", "None", snes->mf_version, &snes->mf_version, NULL));
1131: PetscCall(PetscOptionsName("-snes_test_function", "Compare hand-coded and finite difference functions", "None", &snes->testFunc));
1132: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &snes->testJac));
1134: flg = PETSC_FALSE;
1135: PetscCall(SNESGetNPCSide(snes, &pcside));
1136: PetscCall(PetscOptionsEnum("-snes_npc_side", "SNES nonlinear preconditioner side", "SNESSetNPCSide", PCSides, (PetscEnum)pcside, (PetscEnum *)&pcside, &flg));
1137: if (flg) PetscCall(SNESSetNPCSide(snes, pcside));
1139: #if defined(PETSC_HAVE_SAWS)
1140: /*
1141: Publish convergence information using SAWs
1142: */
1143: flg = PETSC_FALSE;
1144: PetscCall(PetscOptionsBool("-snes_monitor_saws", "Publish SNES progress using SAWs", "SNESMonitorSet", flg, &flg, NULL));
1145: if (flg) {
1146: PetscCtx ctx;
1147: PetscCall(SNESMonitorSAWsCreate(snes, &ctx));
1148: PetscCall(SNESMonitorSet(snes, SNESMonitorSAWs, ctx, SNESMonitorSAWsDestroy));
1149: }
1150: #endif
1151: #if defined(PETSC_HAVE_SAWS)
1152: {
1153: PetscBool set;
1154: flg = PETSC_FALSE;
1155: PetscCall(PetscOptionsBool("-snes_saws_block", "Block for SAWs at end of SNESSolve", "PetscObjectSAWsBlock", ((PetscObject)snes)->amspublishblock, &flg, &set));
1156: if (set) PetscCall(PetscObjectSAWsSetBlock((PetscObject)snes, flg));
1157: }
1158: #endif
1160: for (i = 0; i < numberofsetfromoptions; i++) PetscCall((*othersetfromoptions[i])(snes));
1162: PetscTryTypeMethod(snes, setfromoptions, PetscOptionsObject);
1164: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1165: PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)snes, PetscOptionsObject));
1166: PetscOptionsEnd();
1168: if (snes->linesearch) {
1169: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
1170: PetscCall(SNESLineSearchSetFromOptions(snes->linesearch));
1171: }
1173: if (snes->usesksp) {
1174: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
1175: PetscCall(KSPSetOperators(snes->ksp, snes->jacobian, snes->jacobian_pre));
1176: PetscCall(KSPSetFromOptions(snes->ksp));
1177: }
1179: /* if user has set the SNES NPC type via options database, create it. */
1180: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1181: PetscCall(PetscOptionsHasName(((PetscObject)snes)->options, optionsprefix, "-npc_snes_type", &pcset));
1182: if (pcset && (!snes->npc)) PetscCall(SNESGetNPC(snes, &snes->npc));
1183: if (snes->npc) PetscCall(SNESSetFromOptions(snes->npc));
1184: snes->setfromoptionscalled++;
1185: PetscFunctionReturn(PETSC_SUCCESS);
1186: }
1188: /*@
1189: SNESResetFromOptions - Sets various `SNES` and `KSP` parameters from user options ONLY if the `SNESSetFromOptions()` was previously called
1191: Collective
1193: Input Parameter:
1194: . snes - the `SNES` context
1196: Level: advanced
1198: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESSetOptionsPrefix()`
1199: @*/
1200: PetscErrorCode SNESResetFromOptions(SNES snes)
1201: {
1202: PetscFunctionBegin;
1203: if (snes->setfromoptionscalled) PetscCall(SNESSetFromOptions(snes));
1204: PetscFunctionReturn(PETSC_SUCCESS);
1205: }
1207: /*@C
1208: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1209: the nonlinear solvers.
1211: Logically Collective; No Fortran Support
1213: Input Parameters:
1214: + snes - the `SNES` context
1215: . compute - function to compute the context
1216: - destroy - function to destroy the context, see `PetscCtxDestroyFn` for the calling sequence
1218: Calling sequence of `compute`:
1219: + snes - the `SNES` context
1220: - ctx - context to be computed
1222: Level: intermediate
1224: Note:
1225: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1227: Use `SNESSetApplicationContext()` to see the context immediately
1229: .seealso: [](ch_snes), `SNESGetApplicationContext()`, `SNESSetApplicationContext()`, `PetscCtxDestroyFn`
1230: @*/
1231: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES snes, PetscCtxRt ctx), PetscCtxDestroyFn *destroy)
1232: {
1233: PetscFunctionBegin;
1235: snes->ops->ctxcompute = compute;
1236: snes->ops->ctxdestroy = destroy;
1237: PetscFunctionReturn(PETSC_SUCCESS);
1238: }
1240: /*@
1241: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1243: Logically Collective
1245: Input Parameters:
1246: + snes - the `SNES` context
1247: - ctx - the user context
1249: Level: intermediate
1251: Notes:
1252: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian computation, or other evaluation function
1253: with `SNESGetApplicationContext()`
1255: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1257: Fortran Note:
1258: This only works when `ctx` is a Fortran derived type (it cannot be a `PetscObject`), we recommend writing a Fortran interface definition for this
1259: function that tells the Fortran compiler the derived data type that is passed in as the `ctx` argument. See `SNESGetApplicationContext()` for
1260: an example.
1262: .seealso: [](ch_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1263: @*/
1264: PetscErrorCode SNESSetApplicationContext(SNES snes, PetscCtx ctx)
1265: {
1266: KSP ksp;
1268: PetscFunctionBegin;
1270: PetscCall(SNESGetKSP(snes, &ksp));
1271: PetscCall(KSPSetApplicationContext(ksp, ctx));
1272: snes->ctx = ctx;
1273: PetscFunctionReturn(PETSC_SUCCESS);
1274: }
1276: /*@
1277: SNESGetApplicationContext - Gets the user-defined context for the
1278: nonlinear solvers set with `SNESGetApplicationContext()` or `SNESSetComputeApplicationContext()`
1280: Not Collective
1282: Input Parameter:
1283: . snes - `SNES` context
1285: Output Parameter:
1286: . ctx - the application context
1288: Level: intermediate
1290: Fortran Notes:
1291: This only works when the context is a Fortran derived type or a `PetscObject`. Declare `ctx` with
1292: .vb
1293: type(tUsertype), pointer :: ctx
1294: .ve
1296: .seealso: [](ch_snes), `SNESSetApplicationContext()`, `SNESSetComputeApplicationContext()`
1297: @*/
1298: PetscErrorCode SNESGetApplicationContext(SNES snes, PetscCtxRt ctx)
1299: {
1300: PetscFunctionBegin;
1302: *(void **)ctx = snes->ctx;
1303: PetscFunctionReturn(PETSC_SUCCESS);
1304: }
1306: /*@
1307: SNESSetUseMatrixFree - indicates that `SNES` should use matrix-free finite difference matrix-vector products to apply the Jacobian.
1309: Logically Collective
1311: Input Parameters:
1312: + snes - `SNES` context
1313: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1314: - 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
1315: this option no matrix-element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1317: Options Database Keys:
1318: + -snes_mf_operator - use matrix-free only for the mat operator
1319: . -snes_mf - use matrix-free for both the mat and pmat operator
1320: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1321: - -snes_fd - compute the Jacobian via finite differences (slow)
1323: Level: intermediate
1325: Note:
1326: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
1327: and computing explicitly with
1328: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1330: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`, `MatFDColoring`
1331: @*/
1332: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1333: {
1334: PetscFunctionBegin;
1338: snes->mf = mf_operator ? PETSC_TRUE : mf;
1339: snes->mf_operator = mf_operator;
1340: PetscFunctionReturn(PETSC_SUCCESS);
1341: }
1343: /*@
1344: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1346: Not Collective, but the resulting flags will be the same on all MPI processes
1348: Input Parameter:
1349: . snes - `SNES` context
1351: Output Parameters:
1352: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1353: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1355: Level: intermediate
1357: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1358: @*/
1359: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1360: {
1361: PetscFunctionBegin;
1363: if (mf) *mf = snes->mf;
1364: if (mf_operator) *mf_operator = snes->mf_operator;
1365: PetscFunctionReturn(PETSC_SUCCESS);
1366: }
1368: /*@
1369: SNESGetIterationNumber - Gets the number of nonlinear iterations completed in the current or most recent `SNESSolve()`
1371: Not Collective
1373: Input Parameter:
1374: . snes - `SNES` context
1376: Output Parameter:
1377: . iter - iteration number
1379: Level: intermediate
1381: Notes:
1382: For example, during the computation of iteration 2 this would return 1.
1384: This is useful for using lagged Jacobians (where one does not recompute the
1385: Jacobian at each `SNES` iteration). For example, the code
1386: .vb
1387: ierr = SNESGetIterationNumber(snes,&it);
1388: if (!(it % 2)) {
1389: [compute Jacobian here]
1390: }
1391: .ve
1392: can be used in your function that computes the Jacobian to cause the Jacobian to be
1393: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1395: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1397: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`, `SNESSetMonitor()`
1398: @*/
1399: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1400: {
1401: PetscFunctionBegin;
1403: PetscAssertPointer(iter, 2);
1404: *iter = snes->iter;
1405: PetscFunctionReturn(PETSC_SUCCESS);
1406: }
1408: /*@
1409: SNESSetIterationNumber - Sets the current iteration number.
1411: Not Collective
1413: Input Parameters:
1414: + snes - `SNES` context
1415: - iter - iteration number
1417: Level: developer
1419: Note:
1420: This should only be called inside a `SNES` nonlinear solver.
1422: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1423: @*/
1424: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1425: {
1426: PetscFunctionBegin;
1428: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1429: snes->iter = iter;
1430: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1431: PetscFunctionReturn(PETSC_SUCCESS);
1432: }
1434: /*@
1435: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1436: taken by the nonlinear solver in the current or most recent `SNESSolve()` .
1438: Not Collective
1440: Input Parameter:
1441: . snes - `SNES` context
1443: Output Parameter:
1444: . nfails - number of unsuccessful steps attempted
1446: Level: intermediate
1448: Notes:
1449: A failed step is a step that was generated and taken but did not satisfy the requested step criteria. For example,
1450: the `SNESLineSearchApply()` could not generate a sufficient decrease in the function norm (in fact it may have produced an increase).
1452: Taken steps that produce a infinity or NaN in the function evaluation or generate a `SNESSetFunctionDomainError()`
1453: will always immediately terminate the `SNESSolve()` regardless of the value of `maxFails`.
1455: `SNESSetMaxNonlinearStepFailures()` determines how many unsuccessful steps are allowed before the `SNESSolve()` terminates
1457: This counter is reset to zero for each successive call to `SNESSolve()`.
1459: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1460: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1461: @*/
1462: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1463: {
1464: PetscFunctionBegin;
1466: PetscAssertPointer(nfails, 2);
1467: *nfails = snes->numFailures;
1468: PetscFunctionReturn(PETSC_SUCCESS);
1469: }
1471: /*@
1472: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1473: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1475: Not Collective
1477: Input Parameters:
1478: + snes - `SNES` context
1479: - maxFails - maximum of unsuccessful steps allowed, use `PETSC_UNLIMITED` to have no limit on the number of failures
1481: Options Database Key:
1482: . -snes_max_fail n - maximum number of unsuccessful steps allowed
1484: Level: intermediate
1486: Note:
1487: A failed step is a step that was generated and taken but did not satisfy the requested criteria. For example,
1488: the `SNESLineSearchApply()` could not generate a sufficient decrease in the function norm (in fact it may have produced an increase).
1490: Taken steps that produce a infinity or NaN in the function evaluation or generate a `SNESSetFunctionDomainError()`
1491: will always immediately terminate the `SNESSolve()` regardless of the value of `maxFails`.
1493: Developer Note:
1494: The options database key is wrong for this function name
1496: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1497: `SNESGetLinearSolveFailures()`, `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`, `SNESCheckLineSearchFailure()`
1498: @*/
1499: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1500: {
1501: PetscFunctionBegin;
1504: if (maxFails == PETSC_UNLIMITED) {
1505: snes->maxFailures = PETSC_INT_MAX;
1506: } else {
1507: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1508: snes->maxFailures = maxFails;
1509: }
1510: PetscFunctionReturn(PETSC_SUCCESS);
1511: }
1513: /*@
1514: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1515: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1517: Not Collective
1519: Input Parameter:
1520: . snes - `SNES` context
1522: Output Parameter:
1523: . maxFails - maximum of unsuccessful steps
1525: Level: intermediate
1527: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1528: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1529: @*/
1530: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1531: {
1532: PetscFunctionBegin;
1534: PetscAssertPointer(maxFails, 2);
1535: *maxFails = snes->maxFailures;
1536: PetscFunctionReturn(PETSC_SUCCESS);
1537: }
1539: /*@
1540: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1541: done by the `SNES` object in the current or most recent `SNESSolve()`
1543: Not Collective
1545: Input Parameter:
1546: . snes - `SNES` context
1548: Output Parameter:
1549: . nfuncs - number of evaluations
1551: Level: intermediate
1553: Note:
1554: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1556: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1557: @*/
1558: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1559: {
1560: PetscFunctionBegin;
1562: PetscAssertPointer(nfuncs, 2);
1563: *nfuncs = snes->nfuncs;
1564: PetscFunctionReturn(PETSC_SUCCESS);
1565: }
1567: /*@
1568: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1569: linear solvers in the current or most recent `SNESSolve()`
1571: Not Collective
1573: Input Parameter:
1574: . snes - `SNES` context
1576: Output Parameter:
1577: . nfails - number of failed solves
1579: Options Database Key:
1580: . -snes_max_linear_solve_fail num - The number of failures before the solve is terminated
1582: Level: intermediate
1584: Note:
1585: This counter is reset to zero for each successive call to `SNESSolve()`.
1587: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1588: @*/
1589: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1590: {
1591: PetscFunctionBegin;
1593: PetscAssertPointer(nfails, 2);
1594: *nfails = snes->numLinearSolveFailures;
1595: PetscFunctionReturn(PETSC_SUCCESS);
1596: }
1598: /*@
1599: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1600: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1602: Logically Collective
1604: Input Parameters:
1605: + snes - `SNES` context
1606: - maxFails - maximum allowed linear solve failures, use `PETSC_UNLIMITED` to have no limit on the number of failures
1608: Options Database Key:
1609: . -snes_max_linear_solve_fail num - The number of failures before the solve is terminated
1611: Level: intermediate
1613: Note:
1614: By default this is 0; that is `SNES` returns on the first failed linear solve
1616: Developer Note:
1617: The options database key is wrong for this function name
1619: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1620: @*/
1621: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1622: {
1623: PetscFunctionBegin;
1627: if (maxFails == PETSC_UNLIMITED) {
1628: snes->maxLinearSolveFailures = PETSC_INT_MAX;
1629: } else {
1630: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1631: snes->maxLinearSolveFailures = maxFails;
1632: }
1633: PetscFunctionReturn(PETSC_SUCCESS);
1634: }
1636: /*@
1637: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1638: are allowed before `SNES` returns as unsuccessful
1640: Not Collective
1642: Input Parameter:
1643: . snes - `SNES` context
1645: Output Parameter:
1646: . maxFails - maximum of unsuccessful solves allowed
1648: Level: intermediate
1650: Note:
1651: By default this is 1; that is `SNES` returns on the first failed linear solve
1653: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1654: @*/
1655: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1656: {
1657: PetscFunctionBegin;
1659: PetscAssertPointer(maxFails, 2);
1660: *maxFails = snes->maxLinearSolveFailures;
1661: PetscFunctionReturn(PETSC_SUCCESS);
1662: }
1664: /*@
1665: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1666: used by the nonlinear solver in the most recent `SNESSolve()`
1668: Not Collective
1670: Input Parameter:
1671: . snes - `SNES` context
1673: Output Parameter:
1674: . lits - number of linear iterations
1676: Level: intermediate
1678: Notes:
1679: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1681: 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
1682: then call `KSPGetIterationNumber()` after the failed solve.
1684: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1685: @*/
1686: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1687: {
1688: PetscFunctionBegin;
1690: PetscAssertPointer(lits, 2);
1691: *lits = snes->linear_its;
1692: PetscFunctionReturn(PETSC_SUCCESS);
1693: }
1695: /*@
1696: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1697: are reset every time `SNESSolve()` is called.
1699: Logically Collective
1701: Input Parameters:
1702: + snes - `SNES` context
1703: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1705: Level: developer
1707: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1708: @*/
1709: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1710: {
1711: PetscFunctionBegin;
1714: snes->counters_reset = reset;
1715: PetscFunctionReturn(PETSC_SUCCESS);
1716: }
1718: /*@
1719: SNESResetCounters - Reset counters for linear iterations and function evaluations.
1721: Logically Collective
1723: Input Parameters:
1724: . snes - `SNES` context
1726: Level: developer
1728: Note:
1729: It honors the flag set with `SNESSetCountersReset()`
1731: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1732: @*/
1733: PetscErrorCode SNESResetCounters(SNES snes)
1734: {
1735: PetscFunctionBegin;
1737: if (snes->counters_reset) {
1738: snes->nfuncs = 0;
1739: snes->linear_its = 0;
1740: snes->numFailures = 0;
1741: }
1742: PetscFunctionReturn(PETSC_SUCCESS);
1743: }
1745: /*@
1746: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1748: Not Collective, but the `SNES` and `KSP` objects must live on the same `MPI_Comm`
1750: Input Parameters:
1751: + snes - the `SNES` context
1752: - ksp - the `KSP` context
1754: Level: developer
1756: Notes:
1757: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1758: so this routine is rarely needed.
1760: The `KSP` object that is already in the `SNES` object has its reference count
1761: decreased by one when this is called.
1763: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`
1764: @*/
1765: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1766: {
1767: PetscFunctionBegin;
1770: PetscCheckSameComm(snes, 1, ksp, 2);
1771: PetscCall(PetscObjectReference((PetscObject)ksp));
1772: PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1773: snes->ksp = ksp;
1774: PetscFunctionReturn(PETSC_SUCCESS);
1775: }
1777: /*@
1778: SNESParametersInitialize - Sets all the parameters in `snes` to their default value (when `SNESCreate()` was called) if they
1779: currently contain default values
1781: Collective
1783: Input Parameter:
1784: . snes - the `SNES` object
1786: Level: developer
1788: Developer Note:
1789: This is called by all the `SNESCreate_XXX()` routines.
1791: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
1792: `PetscObjectParameterSetDefault()`
1793: @*/
1794: PetscErrorCode SNESParametersInitialize(SNES snes)
1795: {
1796: PetscObjectParameterSetDefault(snes, max_its, 50);
1797: PetscObjectParameterSetDefault(snes, max_funcs, 10000);
1798: PetscObjectParameterSetDefault(snes, rtol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1799: PetscObjectParameterSetDefault(snes, abstol, PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50);
1800: PetscObjectParameterSetDefault(snes, stol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1801: PetscObjectParameterSetDefault(snes, divtol, 1.e4);
1802: return PETSC_SUCCESS;
1803: }
1805: /*@
1806: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1808: Collective
1810: Input Parameter:
1811: . comm - MPI communicator
1813: Output Parameter:
1814: . outsnes - the new `SNES` context
1816: Options Database Keys:
1817: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no matrix to construct a preconditioner
1818: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided matrix as set by `SNESSetJacobian()`
1819: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1820: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1822: Level: beginner
1824: Developer Notes:
1825: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1826: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1827: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1828: in `SNESView()`.
1830: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1831: by help messages about meaningless `SNES` options.
1833: `SNES` always creates the `snes->kspconvctx` even though it is used by only one type. This should be fixed.
1835: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1836: @*/
1837: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1838: {
1839: SNES snes;
1840: SNESKSPEW *kctx;
1842: PetscFunctionBegin;
1843: PetscAssertPointer(outsnes, 2);
1844: PetscCall(SNESInitializePackage());
1846: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1847: snes->ops->converged = SNESConvergedDefault;
1848: snes->usesksp = PETSC_TRUE;
1849: snes->norm = 0.0;
1850: snes->xnorm = 0.0;
1851: snes->ynorm = 0.0;
1852: snes->normschedule = SNES_NORM_ALWAYS;
1853: snes->functype = SNES_FUNCTION_DEFAULT;
1854: snes->ttol = 0.0;
1856: snes->rnorm0 = 0;
1857: snes->nfuncs = 0;
1858: snes->numFailures = 0;
1859: snes->maxFailures = 1;
1860: snes->linear_its = 0;
1861: snes->lagjacobian = 1;
1862: snes->jac_iter = 0;
1863: snes->lagjac_persist = PETSC_FALSE;
1864: snes->lagpreconditioner = 1;
1865: snes->pre_iter = 0;
1866: snes->lagpre_persist = PETSC_FALSE;
1867: snes->numbermonitors = 0;
1868: snes->numberreasonviews = 0;
1869: snes->data = NULL;
1870: snes->setupcalled = PETSC_FALSE;
1871: snes->ksp_ewconv = PETSC_FALSE;
1872: snes->nwork = 0;
1873: snes->work = NULL;
1874: snes->nvwork = 0;
1875: snes->vwork = NULL;
1876: snes->conv_hist_len = 0;
1877: snes->conv_hist_max = 0;
1878: snes->conv_hist = NULL;
1879: snes->conv_hist_its = NULL;
1880: snes->conv_hist_reset = PETSC_TRUE;
1881: snes->counters_reset = PETSC_TRUE;
1882: snes->vec_func_init_set = PETSC_FALSE;
1883: snes->reason = SNES_CONVERGED_ITERATING;
1884: snes->npcside = PC_RIGHT;
1885: snes->setfromoptionscalled = 0;
1887: snes->mf = PETSC_FALSE;
1888: snes->mf_operator = PETSC_FALSE;
1889: snes->mf_version = 1;
1891: snes->numLinearSolveFailures = 0;
1892: snes->maxLinearSolveFailures = 1;
1894: snes->vizerotolerance = 1.e-8;
1895: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1897: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1898: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1900: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1901: PetscCall(PetscNew(&kctx));
1903: snes->kspconvctx = kctx;
1904: kctx->version = 2;
1905: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1906: this was too large for some test cases */
1907: kctx->rtol_last = 0.0;
1908: kctx->rtol_max = 0.9;
1909: kctx->gamma = 1.0;
1910: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1911: kctx->alpha2 = kctx->alpha;
1912: kctx->threshold = 0.1;
1913: kctx->lresid_last = 0.0;
1914: kctx->norm_last = 0.0;
1916: kctx->rk_last = 0.0;
1917: kctx->rk_last_2 = 0.0;
1918: kctx->rtol_last_2 = 0.0;
1919: kctx->v4_p1 = 0.1;
1920: kctx->v4_p2 = 0.4;
1921: kctx->v4_p3 = 0.7;
1922: kctx->v4_m1 = 0.8;
1923: kctx->v4_m2 = 0.5;
1924: kctx->v4_m3 = 0.1;
1925: kctx->v4_m4 = 0.5;
1927: PetscCall(SNESParametersInitialize(snes));
1928: *outsnes = snes;
1929: PetscFunctionReturn(PETSC_SUCCESS);
1930: }
1932: /*@C
1933: SNESSetFunction - Sets the function evaluation routine and function
1934: vector for use by the `SNES` routines in solving systems of nonlinear
1935: equations.
1937: Logically Collective
1939: Input Parameters:
1940: + snes - the `SNES` context
1941: . r - vector to store function values, may be `NULL`
1942: . f - function evaluation routine; for calling sequence see `SNESFunctionFn`
1943: - ctx - [optional] user-defined context for private data for the
1944: function evaluation routine (may be `NULL`)
1946: Level: beginner
1948: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunctionFn`
1949: @*/
1950: PetscErrorCode SNESSetFunction(SNES snes, Vec r, SNESFunctionFn *f, PetscCtx ctx)
1951: {
1952: DM dm;
1954: PetscFunctionBegin;
1956: if (r) {
1958: PetscCheckSameComm(snes, 1, r, 2);
1959: PetscCall(PetscObjectReference((PetscObject)r));
1960: PetscCall(VecDestroy(&snes->vec_func));
1961: snes->vec_func = r;
1962: }
1963: PetscCall(SNESGetDM(snes, &dm));
1964: PetscCall(DMSNESSetFunction(dm, f, ctx));
1965: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1966: PetscFunctionReturn(PETSC_SUCCESS);
1967: }
1969: /*@C
1970: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1972: Logically Collective
1974: Input Parameters:
1975: + snes - the `SNES` context
1976: - f - vector to store function value
1978: Level: developer
1980: Notes:
1981: This should not be modified during the solution procedure.
1983: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1985: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1986: @*/
1987: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1988: {
1989: Vec vec_func;
1991: PetscFunctionBegin;
1994: PetscCheckSameComm(snes, 1, f, 2);
1995: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1996: snes->vec_func_init_set = PETSC_FALSE;
1997: PetscFunctionReturn(PETSC_SUCCESS);
1998: }
1999: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
2000: PetscCall(VecCopy(f, vec_func));
2002: snes->vec_func_init_set = PETSC_TRUE;
2003: PetscFunctionReturn(PETSC_SUCCESS);
2004: }
2006: /*@
2007: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
2008: of the `SNES` method, when norms are computed in the solving process
2010: Logically Collective
2012: Input Parameters:
2013: + snes - the `SNES` context
2014: - normschedule - the frequency of norm computation
2016: Options Database Key:
2017: . -snes_norm_schedule (none|always|initialonly|finalonly|initialfinalonly) - set the schedule
2019: Level: advanced
2021: Notes:
2022: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
2023: of the nonlinear function and the taking of its norm at every iteration to
2024: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2025: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
2026: may either be monitored for convergence or not. As these are often used as nonlinear
2027: preconditioners, monitoring the norm of their error is not a useful enterprise within
2028: their solution.
2030: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
2031: @*/
2032: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
2033: {
2034: PetscFunctionBegin;
2036: snes->normschedule = normschedule;
2037: PetscFunctionReturn(PETSC_SUCCESS);
2038: }
2040: /*@
2041: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
2042: of the `SNES` method.
2044: Logically Collective
2046: Input Parameters:
2047: + snes - the `SNES` context
2048: - normschedule - the type of the norm used
2050: Level: advanced
2052: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2053: @*/
2054: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
2055: {
2056: PetscFunctionBegin;
2058: *normschedule = snes->normschedule;
2059: PetscFunctionReturn(PETSC_SUCCESS);
2060: }
2062: /*@
2063: SNESSetFunctionNorm - Sets the last computed residual norm.
2065: Logically Collective
2067: Input Parameters:
2068: + snes - the `SNES` context
2069: - norm - the value of the norm
2071: Level: developer
2073: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2074: @*/
2075: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
2076: {
2077: PetscFunctionBegin;
2079: snes->norm = norm;
2080: PetscFunctionReturn(PETSC_SUCCESS);
2081: }
2083: /*@
2084: SNESGetFunctionNorm - Gets the last computed norm of the residual
2086: Not Collective
2088: Input Parameter:
2089: . snes - the `SNES` context
2091: Output Parameter:
2092: . norm - the last computed residual norm
2094: Level: developer
2096: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2097: @*/
2098: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2099: {
2100: PetscFunctionBegin;
2102: PetscAssertPointer(norm, 2);
2103: *norm = snes->norm;
2104: PetscFunctionReturn(PETSC_SUCCESS);
2105: }
2107: /*@
2108: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2110: Not Collective
2112: Input Parameter:
2113: . snes - the `SNES` context
2115: Output Parameter:
2116: . ynorm - the last computed update norm
2118: Level: developer
2120: Note:
2121: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2123: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2124: @*/
2125: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2126: {
2127: PetscFunctionBegin;
2129: PetscAssertPointer(ynorm, 2);
2130: *ynorm = snes->ynorm;
2131: PetscFunctionReturn(PETSC_SUCCESS);
2132: }
2134: /*@
2135: SNESGetSolutionNorm - Gets the last computed norm of the solution
2137: Not Collective
2139: Input Parameter:
2140: . snes - the `SNES` context
2142: Output Parameter:
2143: . xnorm - the last computed solution norm
2145: Level: developer
2147: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2148: @*/
2149: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2150: {
2151: PetscFunctionBegin;
2153: PetscAssertPointer(xnorm, 2);
2154: *xnorm = snes->xnorm;
2155: PetscFunctionReturn(PETSC_SUCCESS);
2156: }
2158: /*@
2159: SNESSetFunctionType - Sets the `SNESFunctionType`
2160: of the `SNES` method.
2162: Logically Collective
2164: Input Parameters:
2165: + snes - the `SNES` context
2166: - type - the function type
2168: Level: developer
2170: Values of the function type\:
2171: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2172: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2173: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2175: Note:
2176: Different `SNESType`s use this value in different ways
2178: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2179: @*/
2180: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2181: {
2182: PetscFunctionBegin;
2184: snes->functype = type;
2185: PetscFunctionReturn(PETSC_SUCCESS);
2186: }
2188: /*@
2189: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2190: of the SNES method.
2192: Logically Collective
2194: Input Parameters:
2195: + snes - the `SNES` context
2196: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2198: Level: advanced
2200: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2201: @*/
2202: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2203: {
2204: PetscFunctionBegin;
2206: *type = snes->functype;
2207: PetscFunctionReturn(PETSC_SUCCESS);
2208: }
2210: /*@C
2211: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2212: use with composed nonlinear solvers.
2214: Input Parameters:
2215: + snes - the `SNES` context, usually of the `SNESType` `SNESNGS`
2216: . f - function evaluation routine to apply Gauss-Seidel, see `SNESNGSFn` for calling sequence
2217: - ctx - [optional] user-defined context for private data for the smoother evaluation routine (may be `NULL`)
2219: Level: intermediate
2221: Note:
2222: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2223: a problem appropriate update to the solution, particularly `SNESFAS`.
2225: .seealso: [](ch_snes), `SNESNGS`, `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`, `SNESNGSFn`
2226: @*/
2227: PetscErrorCode SNESSetNGS(SNES snes, SNESNGSFn *f, PetscCtx ctx)
2228: {
2229: DM dm;
2231: PetscFunctionBegin;
2233: PetscCall(SNESGetDM(snes, &dm));
2234: PetscCall(DMSNESSetNGS(dm, f, ctx));
2235: PetscFunctionReturn(PETSC_SUCCESS);
2236: }
2238: /*
2239: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2240: changed during the KSPSolve()
2241: */
2242: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, PetscCtx ctx)
2243: {
2244: DM dm;
2245: DMSNES sdm;
2247: PetscFunctionBegin;
2248: PetscCall(SNESGetDM(snes, &dm));
2249: PetscCall(DMGetDMSNES(dm, &sdm));
2250: /* A(x)*x - b(x) */
2251: if (sdm->ops->computepfunction) {
2252: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2253: PetscCall(VecScale(f, -1.0));
2254: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2255: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2256: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2257: PetscCall(MatMultAdd(snes->picard, x, f, f));
2258: } else {
2259: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2260: PetscCall(MatMult(snes->picard, x, f));
2261: }
2262: PetscFunctionReturn(PETSC_SUCCESS);
2263: }
2265: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, PetscCtx ctx)
2266: {
2267: DM dm;
2268: DMSNES sdm;
2270: PetscFunctionBegin;
2271: PetscCall(SNESGetDM(snes, &dm));
2272: PetscCall(DMGetDMSNES(dm, &sdm));
2273: /* A(x)*x - b(x) */
2274: if (sdm->ops->computepfunction) {
2275: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2276: PetscCall(VecScale(f, -1.0));
2277: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2278: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2279: } else {
2280: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2281: PetscCall(MatMult(snes->jacobian_pre, x, f));
2282: }
2283: PetscFunctionReturn(PETSC_SUCCESS);
2284: }
2286: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, PetscCtx ctx)
2287: {
2288: PetscFunctionBegin;
2289: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2290: /* must assembly if matrix-free to get the last SNES solution */
2291: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2292: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2293: PetscFunctionReturn(PETSC_SUCCESS);
2294: }
2296: /*@C
2297: SNESSetPicard - Use `SNES` to solve the system $A(x) x = bp(x) + b $ via a Picard type iteration (Picard linearization)
2299: Logically Collective
2301: Input Parameters:
2302: + snes - the `SNES` context
2303: . r - vector to store function values, may be `NULL`
2304: . bp - function evaluation routine, may be `NULL`, for the calling sequence see `SNESFunctionFn`
2305: . Amat - matrix with which $A(x) x - bp(x) - b$ is to be computed
2306: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2307: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFn`
2308: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2310: Level: intermediate
2312: Notes:
2313: It is often better to provide the nonlinear function $F()$ and some approximation to its Jacobian directly and use
2314: 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.
2316: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2318: Solves the equation $A(x) x = bp(x) - b$ via the defect correction algorithm $A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}$.
2319: When an exact solver is used this corresponds to the "classic" Picard $A(x^{n}) x^{n+1} = bp(x^{n}) + b$ iteration.
2321: Run with `-snes_mf_operator` to solve the system with Newton's method using $A(x^{n})$ to construct the preconditioner.
2323: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2324: the direct Picard iteration $A(x^n) x^{n+1} = bp(x^n) + b$
2326: 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
2327: 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
2328: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument \:-).
2330: 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
2331: $A(x^{n})$ is used to build the preconditioner
2333: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at a time) and thus represent Newton's method.
2335: 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
2336: 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
2337: 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`.
2338: See the comment in src/snes/tutorials/ex15.c.
2340: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`,
2341: `SNESFunctionFn`, `SNESJacobianFn`
2342: @*/
2343: PetscErrorCode SNESSetPicard(SNES snes, Vec r, SNESFunctionFn *bp, Mat Amat, Mat Pmat, SNESJacobianFn *J, PetscCtx ctx)
2344: {
2345: DM dm;
2347: PetscFunctionBegin;
2349: PetscCall(SNESGetDM(snes, &dm));
2350: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2351: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2352: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2353: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2354: PetscFunctionReturn(PETSC_SUCCESS);
2355: }
2357: /*@C
2358: SNESGetPicard - Returns the context for the Picard iteration
2360: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2362: Input Parameter:
2363: . snes - the `SNES` context
2365: Output Parameters:
2366: + r - the function (or `NULL`)
2367: . f - the function (or `NULL`); for calling sequence see `SNESFunctionFn`
2368: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2369: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2370: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFn`
2371: - ctx - the function context (or `NULL`)
2373: Level: advanced
2375: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunctionFn`, `SNESJacobianFn`
2376: @*/
2377: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, SNESFunctionFn **f, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, PetscCtxRt ctx)
2378: {
2379: DM dm;
2381: PetscFunctionBegin;
2383: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2384: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2385: PetscCall(SNESGetDM(snes, &dm));
2386: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2387: PetscFunctionReturn(PETSC_SUCCESS);
2388: }
2390: /*@C
2391: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2393: Logically Collective
2395: Input Parameters:
2396: + snes - the `SNES` context
2397: . func - function evaluation routine, see `SNESInitialGuessFn` for the calling sequence
2398: - ctx - [optional] user-defined context for private data for the
2399: function evaluation routine (may be `NULL`)
2401: Level: intermediate
2403: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESInitialGuessFn`
2404: @*/
2405: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, SNESInitialGuessFn *func, PetscCtx ctx)
2406: {
2407: PetscFunctionBegin;
2409: if (func) snes->ops->computeinitialguess = func;
2410: if (ctx) snes->initialguessP = ctx;
2411: PetscFunctionReturn(PETSC_SUCCESS);
2412: }
2414: /*@C
2415: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2416: it assumes a zero right-hand side.
2418: Logically Collective
2420: Input Parameter:
2421: . snes - the `SNES` context
2423: Output Parameter:
2424: . rhs - the right-hand side vector or `NULL` if there is no right-hand side vector
2426: Level: intermediate
2428: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2429: @*/
2430: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2431: {
2432: PetscFunctionBegin;
2434: PetscAssertPointer(rhs, 2);
2435: *rhs = snes->vec_rhs;
2436: PetscFunctionReturn(PETSC_SUCCESS);
2437: }
2439: /*@
2440: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2442: Collective
2444: Input Parameters:
2445: + snes - the `SNES` context
2446: - x - input vector
2448: Output Parameter:
2449: . f - function vector, as set by `SNESSetFunction()`
2451: Level: developer
2453: Notes:
2454: `SNESComputeFunction()` is typically used within nonlinear solvers
2455: implementations, so users would not generally call this routine themselves.
2457: When solving for $F(x) = b$, this routine computes $f = F(x) - b$.
2459: This function usually appears in the pattern.
2460: .vb
2461: SNESComputeFunction(snes, x, f);
2462: VecNorm(f, &fnorm);
2463: SNESCheckFunctionDomainError(snes, fnorm); or SNESLineSearchCheckFunctionDomainError(ls, fnorm);
2464: .ve
2465: to collectively handle the use of `SNESSetFunctionDomainError()` in the provided callback function.
2467: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`, `SNESSetFunctionDomainError()`
2468: @*/
2469: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec f)
2470: {
2471: DM dm;
2472: DMSNES sdm;
2474: PetscFunctionBegin;
2478: PetscCheckSameComm(snes, 1, x, 2);
2479: PetscCheckSameComm(snes, 1, f, 3);
2480: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2482: PetscCall(SNESGetDM(snes, &dm));
2483: PetscCall(DMGetDMSNES(dm, &sdm));
2484: 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().");
2485: if (sdm->ops->computefunction) {
2486: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, f, 0));
2487: PetscCall(VecLockReadPush(x));
2488: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2489: snes->functiondomainerror = PETSC_FALSE;
2490: {
2491: void *ctx;
2492: SNESFunctionFn *computefunction;
2493: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2494: PetscCallBack("SNES callback function", (*computefunction)(snes, x, f, ctx));
2495: }
2496: PetscCall(VecLockReadPop(x));
2497: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, f, 0));
2498: } else /* if (snes->vec_rhs) */ {
2499: PetscCall(MatMult(snes->jacobian, x, f));
2500: }
2501: if (snes->vec_rhs) PetscCall(VecAXPY(f, -1.0, snes->vec_rhs));
2502: snes->nfuncs++;
2503: /*
2504: domainerror might not be set on all processes; so we tag vector locally with infinity and the next inner product or norm will
2505: propagate the value to all processes
2506: */
2507: PetscCall(VecFlag(f, snes->functiondomainerror));
2508: PetscFunctionReturn(PETSC_SUCCESS);
2509: }
2511: /*@
2512: SNESComputeMFFunction - Calls the function that has been set with `DMSNESSetMFFunction()`.
2514: Collective
2516: Input Parameters:
2517: + snes - the `SNES` context
2518: - x - input vector
2520: Output Parameter:
2521: . y - output vector
2523: Level: developer
2525: Notes:
2526: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2527: so users would not generally call this routine themselves.
2529: Since this function is intended for use with finite differencing it does not subtract the right-hand side vector provided with `SNESSolve()`
2530: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2531: 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.
2533: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF()`, `DMSNESSetMFFunction()`
2534: @*/
2535: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2536: {
2537: DM dm;
2538: DMSNES sdm;
2540: PetscFunctionBegin;
2544: PetscCheckSameComm(snes, 1, x, 2);
2545: PetscCheckSameComm(snes, 1, y, 3);
2546: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2548: PetscCall(SNESGetDM(snes, &dm));
2549: PetscCall(DMGetDMSNES(dm, &sdm));
2550: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2551: PetscCall(VecLockReadPush(x));
2552: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2553: snes->functiondomainerror = PETSC_FALSE;
2554: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2555: PetscCall(VecLockReadPop(x));
2556: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2557: snes->nfuncs++;
2558: /*
2559: domainerror might not be set on all processes; so we tag vector locally with infinity and the next inner product or norm will
2560: propagate the value to all processes
2561: */
2562: PetscCall(VecFlag(y, snes->functiondomainerror));
2563: PetscFunctionReturn(PETSC_SUCCESS);
2564: }
2566: /*@
2567: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2569: Collective
2571: Input Parameters:
2572: + snes - the `SNES` context
2573: . x - input vector
2574: - b - rhs vector
2576: Output Parameter:
2577: . x - new solution vector
2579: Level: developer
2581: Note:
2582: `SNESComputeNGS()` is typically used within composed nonlinear solver
2583: implementations, so most users would not generally call this routine
2584: themselves.
2586: .seealso: [](ch_snes), `SNESNGSFn`, `SNESSetNGS()`, `SNESComputeFunction()`, `SNESNGS`
2587: @*/
2588: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2589: {
2590: DM dm;
2591: DMSNES sdm;
2593: PetscFunctionBegin;
2597: PetscCheckSameComm(snes, 1, x, 3);
2598: if (b) PetscCheckSameComm(snes, 1, b, 2);
2599: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2600: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2601: PetscCall(SNESGetDM(snes, &dm));
2602: PetscCall(DMGetDMSNES(dm, &sdm));
2603: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2604: if (b) PetscCall(VecLockReadPush(b));
2605: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2606: if (b) PetscCall(VecLockReadPop(b));
2607: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2608: PetscFunctionReturn(PETSC_SUCCESS);
2609: }
2611: static PetscErrorCode SNESComputeFunction_FD(SNES snes, Vec Xin, Vec G)
2612: {
2613: Vec X;
2614: PetscScalar *g;
2615: PetscReal f, f2;
2616: PetscInt low, high, N, i;
2617: PetscBool flg;
2618: PetscReal h = .5 * PETSC_SQRT_MACHINE_EPSILON;
2620: PetscFunctionBegin;
2621: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_fd_delta", &h, &flg));
2622: PetscCall(VecDuplicate(Xin, &X));
2623: PetscCall(VecCopy(Xin, X));
2624: PetscCall(VecGetSize(X, &N));
2625: PetscCall(VecGetOwnershipRange(X, &low, &high));
2626: PetscCall(VecSetOption(X, VEC_IGNORE_OFF_PROC_ENTRIES, PETSC_TRUE));
2627: PetscCall(VecGetArray(G, &g));
2628: for (i = 0; i < N; i++) {
2629: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2630: PetscCall(VecAssemblyBegin(X));
2631: PetscCall(VecAssemblyEnd(X));
2632: PetscCall(SNESComputeObjective(snes, X, &f));
2633: PetscCall(VecSetValue(X, i, 2.0 * h, ADD_VALUES));
2634: PetscCall(VecAssemblyBegin(X));
2635: PetscCall(VecAssemblyEnd(X));
2636: PetscCall(SNESComputeObjective(snes, X, &f2));
2637: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2638: PetscCall(VecAssemblyBegin(X));
2639: PetscCall(VecAssemblyEnd(X));
2640: if (i >= low && i < high) g[i - low] = (f2 - f) / (2.0 * h);
2641: }
2642: PetscCall(VecRestoreArray(G, &g));
2643: PetscCall(VecDestroy(&X));
2644: PetscFunctionReturn(PETSC_SUCCESS);
2645: }
2647: /*@
2648: SNESTestFunction - Computes the difference between the computed and finite-difference functions
2650: Collective
2652: Input Parameter:
2653: . snes - the `SNES` context
2655: Options Database Keys:
2656: + -snes_test_function - compare the user provided function with one compute via finite differences to check for errors.
2657: - -snes_test_function_view - display the user provided function, the finite difference function and the difference
2659: Level: developer
2661: .seealso: [](ch_snes), `SNESTestJacobian()`, `SNESSetFunction()`, `SNESComputeFunction()`
2662: @*/
2663: PetscErrorCode SNESTestFunction(SNES snes)
2664: {
2665: Vec x, g1, g2, g3;
2666: PetscBool complete_print = PETSC_FALSE;
2667: PetscReal hcnorm, fdnorm, hcmax, fdmax, diffmax, diffnorm;
2668: PetscScalar dot;
2669: MPI_Comm comm;
2670: PetscViewer viewer, mviewer;
2671: PetscViewerFormat format;
2672: PetscInt tabs;
2673: static PetscBool directionsprinted = PETSC_FALSE;
2674: SNESObjectiveFn *objective;
2676: PetscFunctionBegin;
2677: PetscCall(SNESGetObjective(snes, &objective, NULL));
2678: if (!objective) PetscFunctionReturn(PETSC_SUCCESS);
2680: PetscObjectOptionsBegin((PetscObject)snes);
2681: PetscCall(PetscOptionsViewer("-snes_test_function_view", "View difference between hand-coded and finite difference function element entries", "None", &mviewer, &format, &complete_print));
2682: PetscOptionsEnd();
2684: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2685: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2686: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2687: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2688: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Function -------------\n"));
2689: if (!complete_print && !directionsprinted) {
2690: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_function_view and optionally -snes_test_function <threshold> to show difference\n"));
2691: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference function entries greater than <threshold>.\n"));
2692: }
2693: if (!directionsprinted) {
2694: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Function, if (for double precision runs) ||F - Ffd||/||F|| is\n"));
2695: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Function is probably correct.\n"));
2696: directionsprinted = PETSC_TRUE;
2697: }
2698: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2700: PetscCall(SNESGetSolution(snes, &x));
2701: PetscCall(VecDuplicate(x, &g1));
2702: PetscCall(VecDuplicate(x, &g2));
2703: PetscCall(VecDuplicate(x, &g3));
2704: PetscCall(SNESComputeFunction(snes, x, g1)); /* does not handle use of SNESSetFunctionDomainError() correctly */
2705: PetscCall(SNESComputeFunction_FD(snes, x, g2));
2707: PetscCall(VecNorm(g2, NORM_2, &fdnorm));
2708: PetscCall(VecNorm(g1, NORM_2, &hcnorm));
2709: PetscCall(VecNorm(g2, NORM_INFINITY, &fdmax));
2710: PetscCall(VecNorm(g1, NORM_INFINITY, &hcmax));
2711: PetscCall(VecDot(g1, g2, &dot));
2712: PetscCall(VecCopy(g1, g3));
2713: PetscCall(VecAXPY(g3, -1.0, g2));
2714: PetscCall(VecNorm(g3, NORM_2, &diffnorm));
2715: PetscCall(VecNorm(g3, NORM_INFINITY, &diffmax));
2716: PetscCall(PetscViewerASCIIPrintf(viewer, " ||Ffd|| %g, ||F|| = %g, angle cosine = (Ffd'F)/||Ffd||||F|| = %g\n", (double)fdnorm, (double)hcnorm, (double)(PetscRealPart(dot) / (fdnorm * hcnorm))));
2717: PetscCall(PetscViewerASCIIPrintf(viewer, " 2-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffnorm / PetscMax(hcnorm, fdnorm)), (double)diffnorm));
2718: PetscCall(PetscViewerASCIIPrintf(viewer, " max-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffmax / PetscMax(hcmax, fdmax)), (double)diffmax));
2720: if (complete_print) {
2721: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded function ----------\n"));
2722: PetscCall(VecView(g1, mviewer));
2723: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference function ----------\n"));
2724: PetscCall(VecView(g2, mviewer));
2725: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference function ----------\n"));
2726: PetscCall(VecView(g3, mviewer));
2727: }
2728: PetscCall(VecDestroy(&g1));
2729: PetscCall(VecDestroy(&g2));
2730: PetscCall(VecDestroy(&g3));
2732: if (complete_print) {
2733: PetscCall(PetscViewerPopFormat(mviewer));
2734: PetscCall(PetscViewerDestroy(&mviewer));
2735: }
2736: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2737: PetscFunctionReturn(PETSC_SUCCESS);
2738: }
2740: /*@
2741: SNESTestJacobian - Computes the difference between the computed and finite-difference Jacobians
2743: Collective
2745: Input Parameter:
2746: . snes - the `SNES` context
2748: Output Parameters:
2749: + Jnorm - the Frobenius norm of the computed Jacobian, or `NULL`
2750: - diffNorm - the Frobenius norm of the difference of the computed and finite-difference Jacobians, or `NULL`
2752: Options Database Keys:
2753: + -snes_test_jacobian [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.
2754: - -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference
2756: Level: developer
2758: Note:
2759: Directions and norms are printed to stdout if `diffNorm` is `NULL`.
2761: .seealso: [](ch_snes), `SNESTestFunction()`, `SNESSetJacobian()`, `SNESComputeJacobian()`
2762: @*/
2763: PetscErrorCode SNESTestJacobian(SNES snes, PetscReal *Jnorm, PetscReal *diffNorm)
2764: {
2765: Mat A, B, C, D, jacobian;
2766: Vec x = snes->vec_sol, f;
2767: PetscReal nrm, gnorm;
2768: PetscReal threshold = 1.e-5;
2769: void *functx;
2770: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, flg, istranspose;
2771: PetscBool silent = diffNorm != PETSC_NULLPTR ? PETSC_TRUE : PETSC_FALSE;
2772: PetscViewer viewer, mviewer;
2773: MPI_Comm comm;
2774: PetscInt tabs;
2775: static PetscBool directionsprinted = PETSC_FALSE;
2776: PetscViewerFormat format;
2778: PetscFunctionBegin;
2779: PetscObjectOptionsBegin((PetscObject)snes);
2780: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2781: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2782: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2783: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2784: 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));
2785: PetscOptionsEnd();
2787: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2788: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2789: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2790: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2791: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2792: if (!complete_print && !silent && !directionsprinted) {
2793: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2794: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2795: }
2796: if (!directionsprinted && !silent) {
2797: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2798: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2799: directionsprinted = PETSC_TRUE;
2800: }
2801: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2803: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2804: if (!flg) jacobian = snes->jacobian;
2805: else jacobian = snes->jacobian_pre;
2807: if (!x) PetscCall(MatCreateVecs(jacobian, &x, NULL));
2808: else PetscCall(PetscObjectReference((PetscObject)x));
2809: PetscCall(VecDuplicate(x, &f));
2811: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2812: PetscCall(SNESComputeFunction(snes, x, f));
2813: PetscCall(VecDestroy(&f));
2814: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2815: while (jacobian) {
2816: Mat JT = NULL, Jsave = NULL;
2818: if (istranspose) {
2819: PetscCall(MatCreateTranspose(jacobian, &JT));
2820: Jsave = jacobian;
2821: jacobian = JT;
2822: }
2823: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2824: if (flg) {
2825: A = jacobian;
2826: PetscCall(PetscObjectReference((PetscObject)A));
2827: } else {
2828: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2829: }
2831: PetscCall(MatDuplicate(A, MAT_DO_NOT_COPY_VALUES, &B));
2832: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2834: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2835: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2837: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2838: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2839: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2840: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2841: PetscCall(MatDestroy(&D));
2842: if (!gnorm) gnorm = 1; /* just in case */
2843: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2844: if (complete_print) {
2845: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2846: PetscCall(MatView(A, mviewer));
2847: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2848: PetscCall(MatView(B, mviewer));
2849: }
2851: if (threshold_print || complete_print) {
2852: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2853: PetscScalar *cvals;
2854: const PetscInt *bcols;
2855: const PetscScalar *bvals;
2857: PetscCall(MatDuplicate(A, MAT_DO_NOT_COPY_VALUES, &C));
2858: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2860: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2861: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2863: for (row = Istart; row < Iend; row++) {
2864: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2865: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2866: for (j = 0, cncols = 0; j < bncols; j++) {
2867: if (PetscAbsScalar(bvals[j]) > threshold) {
2868: ccols[cncols] = bcols[j];
2869: cvals[cncols] = bvals[j];
2870: cncols += 1;
2871: }
2872: }
2873: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2874: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2875: PetscCall(PetscFree2(ccols, cvals));
2876: }
2877: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2878: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2879: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2880: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2881: PetscCall(MatDestroy(&C));
2882: }
2883: PetscCall(MatDestroy(&A));
2884: PetscCall(MatDestroy(&B));
2885: PetscCall(MatDestroy(&JT));
2886: if (Jsave) jacobian = Jsave;
2887: if (jacobian != snes->jacobian_pre) {
2888: jacobian = snes->jacobian_pre;
2889: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2890: } else jacobian = NULL;
2891: }
2892: PetscCall(VecDestroy(&x));
2893: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2894: PetscCall(PetscViewerDestroy(&mviewer));
2895: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2897: if (Jnorm) *Jnorm = gnorm;
2898: if (diffNorm) *diffNorm = nrm;
2899: PetscFunctionReturn(PETSC_SUCCESS);
2900: }
2902: /*@
2903: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2905: Collective
2907: Input Parameters:
2908: + snes - the `SNES` context
2909: - X - input vector
2911: Output Parameters:
2912: + A - Jacobian matrix
2913: - B - optional matrix for building the preconditioner, usually the same as `A`
2915: Options Database Keys:
2916: + -snes_lag_preconditioner lag - how often to rebuild preconditioner
2917: . -snes_lag_jacobian lag - how often to rebuild Jacobian
2918: . -snes_test_jacobian [threshold] - compare the user provided Jacobian with one compute via finite differences to check for errors.
2919: If a threshold is given, display only those entries whose difference is greater than the threshold.
2920: . -snes_test_jacobian_view [viewer] - 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
2921: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2922: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2923: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2924: . -snes_compare_operator - Make the comparison options above use the operator instead of the matrix used to construct the preconditioner
2925: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2926: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2927: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2928: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2929: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2930: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2931: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2933: Level: developer
2935: Note:
2936: Most users should not need to explicitly call this routine, as it
2937: is used internally within the nonlinear solvers.
2939: Developer Note:
2940: 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
2941: with the `SNESType` of test that has been removed.
2943: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
2944: `SNESSetJacobianDomainError()`, `SNESCheckJacobianDomainError()`, `SNESSetCheckJacobianDomainError()`
2945: @*/
2946: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2947: {
2948: PetscBool flag;
2949: DM dm;
2950: DMSNES sdm;
2951: KSP ksp;
2953: PetscFunctionBegin;
2956: PetscCheckSameComm(snes, 1, X, 2);
2957: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2958: PetscCall(SNESGetDM(snes, &dm));
2959: PetscCall(DMGetDMSNES(dm, &sdm));
2961: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2962: if (snes->lagjacobian == -2) {
2963: snes->lagjacobian = -1;
2965: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2966: } else if (snes->lagjacobian == -1) {
2967: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2968: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2969: if (flag) {
2970: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2971: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2972: }
2973: PetscFunctionReturn(PETSC_SUCCESS);
2974: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2975: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2976: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2977: if (flag) {
2978: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2979: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2980: }
2981: PetscFunctionReturn(PETSC_SUCCESS);
2982: }
2983: if (snes->npc && snes->npcside == PC_LEFT) {
2984: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2985: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2986: PetscFunctionReturn(PETSC_SUCCESS);
2987: }
2989: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2990: PetscCall(VecLockReadPush(X));
2991: {
2992: void *ctx;
2993: SNESJacobianFn *J;
2994: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
2995: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
2996: }
2997: PetscCall(VecLockReadPop(X));
2998: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
3000: /* attach latest linearization point to the matrix used to construct the preconditioner */
3001: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
3003: /* the next line ensures that snes->ksp exists */
3004: PetscCall(SNESGetKSP(snes, &ksp));
3005: if (snes->lagpreconditioner == -2) {
3006: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
3007: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
3008: snes->lagpreconditioner = -1;
3009: } else if (snes->lagpreconditioner == -1) {
3010: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
3011: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
3012: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
3013: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
3014: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
3015: } else {
3016: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
3017: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
3018: }
3020: /* monkey business to allow testing Jacobians in multilevel solvers.
3021: This is needed because the SNESTestXXX interface does not accept vectors and matrices */
3022: {
3023: Vec xsave = snes->vec_sol;
3024: Mat jacobiansave = snes->jacobian;
3025: Mat jacobian_presave = snes->jacobian_pre;
3027: snes->vec_sol = X;
3028: snes->jacobian = A;
3029: snes->jacobian_pre = B;
3030: if (snes->testFunc) PetscCall(SNESTestFunction(snes));
3031: if (snes->testJac) PetscCall(SNESTestJacobian(snes, NULL, NULL));
3033: snes->vec_sol = xsave;
3034: snes->jacobian = jacobiansave;
3035: snes->jacobian_pre = jacobian_presave;
3036: }
3038: {
3039: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
3040: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
3041: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
3042: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
3043: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
3044: if (flag || flag_draw || flag_contour) {
3045: Mat Bexp_mine = NULL, Bexp, FDexp;
3046: PetscViewer vdraw, vstdout;
3047: PetscBool flg;
3048: if (flag_operator) {
3049: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
3050: Bexp = Bexp_mine;
3051: } else {
3052: /* See if the matrix used to construct the preconditioner can be viewed and added directly */
3053: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
3054: if (flg) Bexp = B;
3055: else {
3056: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
3057: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
3058: Bexp = Bexp_mine;
3059: }
3060: }
3061: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
3062: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
3063: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3064: if (flag_draw || flag_contour) {
3065: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3066: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3067: } else vdraw = NULL;
3068: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
3069: if (flag) PetscCall(MatView(Bexp, vstdout));
3070: if (vdraw) PetscCall(MatView(Bexp, vdraw));
3071: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
3072: if (flag) PetscCall(MatView(FDexp, vstdout));
3073: if (vdraw) PetscCall(MatView(FDexp, vdraw));
3074: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
3075: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
3076: if (flag) PetscCall(MatView(FDexp, vstdout));
3077: if (vdraw) { /* Always use contour for the difference */
3078: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3079: PetscCall(MatView(FDexp, vdraw));
3080: PetscCall(PetscViewerPopFormat(vdraw));
3081: }
3082: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3083: PetscCall(PetscViewerDestroy(&vdraw));
3084: PetscCall(MatDestroy(&Bexp_mine));
3085: PetscCall(MatDestroy(&FDexp));
3086: }
3087: }
3088: {
3089: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
3090: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
3091: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
3092: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
3093: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
3094: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
3095: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
3096: if (flag_threshold) {
3097: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
3098: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
3099: }
3100: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
3101: Mat Bfd;
3102: PetscViewer vdraw, vstdout;
3103: MatColoring coloring;
3104: ISColoring iscoloring;
3105: MatFDColoring matfdcoloring;
3106: SNESFunctionFn *func;
3107: void *funcctx;
3108: PetscReal norm1, norm2, normmax;
3110: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
3111: PetscCall(MatColoringCreate(Bfd, &coloring));
3112: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
3113: PetscCall(MatColoringSetFromOptions(coloring));
3114: PetscCall(MatColoringApply(coloring, &iscoloring));
3115: PetscCall(MatColoringDestroy(&coloring));
3116: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
3117: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3118: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
3119: PetscCall(ISColoringDestroy(&iscoloring));
3121: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
3122: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
3123: PetscCall(MatFDColoringSetFunction(matfdcoloring, (MatFDColoringFn *)func, funcctx));
3124: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
3125: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
3126: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3127: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
3128: PetscCall(MatFDColoringDestroy(&matfdcoloring));
3130: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3131: if (flag_draw || flag_contour) {
3132: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3133: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3134: } else vdraw = NULL;
3135: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
3136: if (flag_display) PetscCall(MatView(B, vstdout));
3137: if (vdraw) PetscCall(MatView(B, vdraw));
3138: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
3139: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3140: if (vdraw) PetscCall(MatView(Bfd, vdraw));
3141: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
3142: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
3143: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
3144: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
3145: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
3146: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3147: if (vdraw) { /* Always use contour for the difference */
3148: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3149: PetscCall(MatView(Bfd, vdraw));
3150: PetscCall(PetscViewerPopFormat(vdraw));
3151: }
3152: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3154: if (flag_threshold) {
3155: PetscInt bs, rstart, rend, i;
3156: PetscCall(MatGetBlockSize(B, &bs));
3157: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
3158: for (i = rstart; i < rend; i++) {
3159: const PetscScalar *ba, *ca;
3160: const PetscInt *bj, *cj;
3161: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
3162: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
3163: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
3164: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
3165: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
3166: for (j = 0; j < bn; j++) {
3167: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3168: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
3169: maxentrycol = bj[j];
3170: maxentry = PetscRealPart(ba[j]);
3171: }
3172: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
3173: maxdiffcol = bj[j];
3174: maxdiff = PetscRealPart(ca[j]);
3175: }
3176: if (rdiff > maxrdiff) {
3177: maxrdiffcol = bj[j];
3178: maxrdiff = rdiff;
3179: }
3180: }
3181: if (maxrdiff > 1) {
3182: 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));
3183: for (j = 0; j < bn; j++) {
3184: PetscReal rdiff;
3185: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3186: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
3187: }
3188: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
3189: }
3190: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
3191: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
3192: }
3193: }
3194: PetscCall(PetscViewerDestroy(&vdraw));
3195: PetscCall(MatDestroy(&Bfd));
3196: }
3197: }
3198: PetscFunctionReturn(PETSC_SUCCESS);
3199: }
3201: /*@C
3202: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3203: location to store the matrix.
3205: Logically Collective
3207: Input Parameters:
3208: + snes - the `SNES` context
3209: . Amat - the matrix that defines the (approximate) Jacobian
3210: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3211: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFn` for details
3212: - ctx - [optional] user-defined context for private data for the
3213: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3215: Level: beginner
3217: Notes:
3218: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3219: each matrix.
3221: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3222: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3224: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3225: must be a `MatFDColoring`.
3227: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3228: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3230: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3231: `SNESSetPicard()`, `SNESJacobianFn`, `SNESFunctionFn`
3232: @*/
3233: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, SNESJacobianFn *J, PetscCtx ctx)
3234: {
3235: DM dm;
3237: PetscFunctionBegin;
3241: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3242: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3243: PetscCall(SNESGetDM(snes, &dm));
3244: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3245: if (Amat) {
3246: PetscCall(PetscObjectReference((PetscObject)Amat));
3247: PetscCall(MatDestroy(&snes->jacobian));
3249: snes->jacobian = Amat;
3250: }
3251: if (Pmat) {
3252: PetscCall(PetscObjectReference((PetscObject)Pmat));
3253: PetscCall(MatDestroy(&snes->jacobian_pre));
3255: snes->jacobian_pre = Pmat;
3256: }
3257: PetscFunctionReturn(PETSC_SUCCESS);
3258: }
3260: /*@C
3261: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3262: provided context for evaluating the Jacobian.
3264: Not Collective, but `Mat` object will be parallel if `SNES` is
3266: Input Parameter:
3267: . snes - the nonlinear solver context
3269: Output Parameters:
3270: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3271: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3272: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFn`
3273: - ctx - location to stash Jacobian ctx (or `NULL`)
3275: Level: advanced
3277: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFn`, `SNESGetFunction()`
3278: @*/
3279: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, PetscCtxRt ctx)
3280: {
3281: DM dm;
3283: PetscFunctionBegin;
3285: if (Amat) *Amat = snes->jacobian;
3286: if (Pmat) *Pmat = snes->jacobian_pre;
3287: PetscCall(SNESGetDM(snes, &dm));
3288: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3289: PetscFunctionReturn(PETSC_SUCCESS);
3290: }
3292: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3293: {
3294: DM dm;
3295: DMSNES sdm;
3297: PetscFunctionBegin;
3298: PetscCall(SNESGetDM(snes, &dm));
3299: PetscCall(DMGetDMSNES(dm, &sdm));
3300: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3301: DM dm;
3302: PetscBool isdense, ismf;
3304: PetscCall(SNESGetDM(snes, &dm));
3305: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3306: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3307: if (isdense) PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3308: else if (!ismf) PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3309: }
3310: PetscFunctionReturn(PETSC_SUCCESS);
3311: }
3313: /*@
3314: SNESSetUp - Sets up the internal data structures for the later use
3315: of a nonlinear solver `SNESSolve()`.
3317: Collective
3319: Input Parameter:
3320: . snes - the `SNES` context
3322: Level: advanced
3324: Note:
3325: For basic use of the `SNES` solvers the user does not need to explicitly call
3326: `SNESSetUp()`, since these actions will automatically occur during
3327: the call to `SNESSolve()`. However, if one wishes to control this
3328: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3329: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3331: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`, `SNESSetFromOptions()`
3332: @*/
3333: PetscErrorCode SNESSetUp(SNES snes)
3334: {
3335: DM dm;
3336: DMSNES sdm;
3337: SNESLineSearch linesearch, pclinesearch;
3338: void *lsprectx, *lspostctx;
3339: PetscBool mf_operator, mf;
3340: Vec f, fpc;
3341: void *funcctx;
3342: void *jacctx, *appctx;
3343: Mat j, jpre;
3344: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, PetscCtx);
3345: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, PetscCtx);
3346: SNESFunctionFn *func;
3347: SNESJacobianFn *jac;
3349: PetscFunctionBegin;
3351: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3352: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3354: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3356: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3358: PetscCall(SNESGetDM(snes, &dm));
3359: PetscCall(DMGetDMSNES(dm, &sdm));
3360: PetscCall(SNESSetDefaultComputeJacobian(snes));
3362: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3364: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3366: if (snes->linesearch) {
3367: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3368: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3369: }
3371: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3372: if (snes->npc && snes->npcside == PC_LEFT) {
3373: snes->mf = PETSC_TRUE;
3374: snes->mf_operator = PETSC_FALSE;
3375: }
3377: if (snes->npc) {
3378: /* copy the DM over */
3379: PetscCall(SNESGetDM(snes, &dm));
3380: PetscCall(SNESSetDM(snes->npc, dm));
3382: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3383: PetscCall(VecDuplicate(f, &fpc));
3384: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3385: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3386: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3387: PetscCall(SNESGetApplicationContext(snes, &appctx));
3388: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3389: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3390: PetscCall(VecDestroy(&fpc));
3392: /* copy the function pointers over */
3393: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3395: /* default to 1 iteration */
3396: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3397: if (snes->npcside == PC_RIGHT) {
3398: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3399: } else {
3400: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3401: }
3402: PetscCall(SNESSetFromOptions(snes->npc));
3404: /* copy the line search context over */
3405: if (snes->linesearch && snes->npc->linesearch) {
3406: PetscCall(SNESGetLineSearch(snes, &linesearch));
3407: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3408: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3409: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3410: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3411: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3412: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3413: }
3414: }
3415: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3416: if (snes->ops->ctxcompute && !snes->ctx) PetscCallBack("SNES callback compute application context", (*snes->ops->ctxcompute)(snes, &snes->ctx));
3418: snes->jac_iter = 0;
3419: snes->pre_iter = 0;
3421: PetscTryTypeMethod(snes, setup);
3423: PetscCall(SNESSetDefaultComputeJacobian(snes));
3425: if (snes->npc && snes->npcside == PC_LEFT) {
3426: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3427: if (snes->linesearch) {
3428: PetscCall(SNESGetLineSearch(snes, &linesearch));
3429: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3430: }
3431: }
3432: }
3433: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3434: snes->setupcalled = PETSC_TRUE;
3435: PetscFunctionReturn(PETSC_SUCCESS);
3436: }
3438: /*@
3439: SNESReset - Resets a `SNES` context to the state it was in before `SNESSetUp()` was called and removes any allocated `Vec` and `Mat` from its data structures
3441: Collective
3443: Input Parameter:
3444: . snes - the nonlinear iterative solver context obtained from `SNESCreate()`
3446: Level: intermediate
3448: Notes:
3449: Any options set on the `SNES` object, including those set with `SNESSetFromOptions()` remain.
3451: Call this if you wish to reuse a `SNES` but with different size vectors
3453: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3455: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3456: @*/
3457: PetscErrorCode SNESReset(SNES snes)
3458: {
3459: PetscFunctionBegin;
3461: if (snes->ops->ctxdestroy && snes->ctx) {
3462: PetscCallBack("SNES callback destroy application context", (*snes->ops->ctxdestroy)(&snes->ctx));
3463: snes->ctx = NULL;
3464: }
3465: if (snes->npc) PetscCall(SNESReset(snes->npc));
3467: PetscTryTypeMethod(snes, reset);
3468: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3470: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3472: PetscCall(VecDestroy(&snes->vec_rhs));
3473: PetscCall(VecDestroy(&snes->vec_sol));
3474: PetscCall(VecDestroy(&snes->vec_sol_update));
3475: PetscCall(VecDestroy(&snes->vec_func));
3476: PetscCall(MatDestroy(&snes->jacobian));
3477: PetscCall(MatDestroy(&snes->jacobian_pre));
3478: PetscCall(MatDestroy(&snes->picard));
3479: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3480: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3482: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3484: snes->nwork = snes->nvwork = 0;
3485: snes->setupcalled = PETSC_FALSE;
3486: PetscFunctionReturn(PETSC_SUCCESS);
3487: }
3489: /*@
3490: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()` also
3491: removes the default viewer.
3493: Collective
3495: Input Parameter:
3496: . snes - the nonlinear iterative solver context obtained from `SNESCreate()`
3498: Level: intermediate
3500: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3501: @*/
3502: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3503: {
3504: PetscInt i;
3506: PetscFunctionBegin;
3508: for (i = 0; i < snes->numberreasonviews; i++) {
3509: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3510: }
3511: snes->numberreasonviews = 0;
3512: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
3513: PetscFunctionReturn(PETSC_SUCCESS);
3514: }
3516: /*@
3517: SNESDestroy - Destroys the nonlinear solver context that was created
3518: with `SNESCreate()`.
3520: Collective
3522: Input Parameter:
3523: . snes - the `SNES` context
3525: Level: beginner
3527: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3528: @*/
3529: PetscErrorCode SNESDestroy(SNES *snes)
3530: {
3531: DM dm;
3533: PetscFunctionBegin;
3534: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3536: if (--((PetscObject)*snes)->refct > 0) {
3537: *snes = NULL;
3538: PetscFunctionReturn(PETSC_SUCCESS);
3539: }
3541: PetscCall(SNESReset(*snes));
3542: PetscCall(SNESDestroy(&(*snes)->npc));
3544: /* if memory was published with SAWs then destroy it */
3545: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3546: PetscTryTypeMethod(*snes, destroy);
3548: dm = (*snes)->dm;
3549: while (dm) {
3550: PetscCall(DMCoarsenHookRemove(dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3551: PetscCall(DMGetCoarseDM(dm, &dm));
3552: }
3554: PetscCall(DMDestroy(&(*snes)->dm));
3555: PetscCall(KSPDestroy(&(*snes)->ksp));
3556: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3558: PetscCall(PetscFree((*snes)->kspconvctx));
3559: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)(&(*snes)->cnvP));
3560: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3561: PetscCall(SNESMonitorCancel(*snes));
3562: PetscCall(SNESConvergedReasonViewCancel(*snes));
3563: PetscCall(PetscHeaderDestroy(snes));
3564: PetscFunctionReturn(PETSC_SUCCESS);
3565: }
3567: /* ----------- Routines to set solver parameters ---------- */
3569: /*@
3570: SNESSetLagPreconditioner - Sets when the preconditioner is rebuilt in the nonlinear solve `SNESSolve()`.
3572: Logically Collective
3574: Input Parameters:
3575: + snes - the `SNES` context
3576: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3577: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3579: Options Database Keys:
3580: + -snes_lag_jacobian_persists (true|false) - sets the persistence through multiple `SNESSolve()`
3581: . -snes_lag_jacobian (-2|1|2|...) - sets the lag
3582: . -snes_lag_preconditioner_persists (true|false) - sets the persistence through multiple `SNESSolve()`
3583: - -snes_lag_preconditioner (-2|1|2|...) - sets the lag
3585: Level: intermediate
3587: Notes:
3588: The default is 1
3590: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3592: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3594: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3595: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3596: @*/
3597: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3598: {
3599: PetscFunctionBegin;
3601: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3602: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3604: snes->lagpreconditioner = lag;
3605: PetscFunctionReturn(PETSC_SUCCESS);
3606: }
3608: /*@
3609: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3611: Logically Collective
3613: Input Parameters:
3614: + snes - the `SNES` context
3615: - steps - the number of refinements to do, defaults to 0
3617: Options Database Key:
3618: . -snes_grid_sequence steps - Use grid sequencing to generate initial guess
3620: Level: intermediate
3622: Notes:
3623: Once grid sequencing is turned on `SNESSolve()` will automatically perform the solve on each grid refinement.
3625: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3627: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3628: `SNESSetDM()`, `SNESSolve()`
3629: @*/
3630: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3631: {
3632: PetscFunctionBegin;
3635: snes->gridsequence = steps;
3636: PetscFunctionReturn(PETSC_SUCCESS);
3637: }
3639: /*@
3640: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3642: Logically Collective
3644: Input Parameter:
3645: . snes - the `SNES` context
3647: Output Parameter:
3648: . steps - the number of refinements to do, defaults to 0
3650: Level: intermediate
3652: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3653: @*/
3654: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3655: {
3656: PetscFunctionBegin;
3658: *steps = snes->gridsequence;
3659: PetscFunctionReturn(PETSC_SUCCESS);
3660: }
3662: /*@
3663: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3665: Not Collective
3667: Input Parameter:
3668: . snes - the `SNES` context
3670: Output Parameter:
3671: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3672: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3674: Level: intermediate
3676: Notes:
3677: The default is 1
3679: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3681: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3682: @*/
3683: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3684: {
3685: PetscFunctionBegin;
3687: *lag = snes->lagpreconditioner;
3688: PetscFunctionReturn(PETSC_SUCCESS);
3689: }
3691: /*@
3692: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3693: often the preconditioner is rebuilt.
3695: Logically Collective
3697: Input Parameters:
3698: + snes - the `SNES` context
3699: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3700: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3702: Options Database Keys:
3703: + -snes_lag_jacobian_persists (true|false) - sets the persistence through multiple SNES solves
3704: . -snes_lag_jacobian (-2|1|2|...) - sets the lag
3705: . -snes_lag_preconditioner_persists (true|false) - sets the persistence through multiple SNES solves
3706: - -snes_lag_preconditioner (-2|1|2|...) - sets the lag.
3708: Level: intermediate
3710: Notes:
3711: The default is 1
3713: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3715: 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
3716: at the next Newton step but never again (unless it is reset to another value)
3718: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3719: @*/
3720: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3721: {
3722: PetscFunctionBegin;
3724: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3725: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3727: snes->lagjacobian = lag;
3728: PetscFunctionReturn(PETSC_SUCCESS);
3729: }
3731: /*@
3732: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3734: Not Collective
3736: Input Parameter:
3737: . snes - the `SNES` context
3739: Output Parameter:
3740: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3741: the Jacobian is built etc.
3743: Level: intermediate
3745: Notes:
3746: The default is 1
3748: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3750: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3751: @*/
3752: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3753: {
3754: PetscFunctionBegin;
3756: *lag = snes->lagjacobian;
3757: PetscFunctionReturn(PETSC_SUCCESS);
3758: }
3760: /*@
3761: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3763: Logically collective
3765: Input Parameters:
3766: + snes - the `SNES` context
3767: - flg - jacobian lagging persists if true
3769: Options Database Keys:
3770: + -snes_lag_jacobian_persists (true|false) - sets the persistence through multiple SNES solves
3771: . -snes_lag_jacobian (-2|1|2|...) - sets the lag
3772: . -snes_lag_preconditioner_persists (true|false) - sets the persistence through multiple SNES solves
3773: - -snes_lag_preconditioner (-2|1|2|...) - sets the lag
3775: Level: advanced
3777: Notes:
3778: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3780: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3781: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3782: timesteps may present huge efficiency gains.
3784: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3785: @*/
3786: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3787: {
3788: PetscFunctionBegin;
3791: snes->lagjac_persist = flg;
3792: PetscFunctionReturn(PETSC_SUCCESS);
3793: }
3795: /*@
3796: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3798: Logically Collective
3800: Input Parameters:
3801: + snes - the `SNES` context
3802: - flg - preconditioner lagging persists if true
3804: Options Database Keys:
3805: + -snes_lag_jacobian_persists (true|false) - sets the persistence through multiple SNES solves
3806: . -snes_lag_jacobian (-2|1|2|...) - sets the lag
3807: . -snes_lag_preconditioner_persists (true|false) - sets the persistence through multiple SNES solves
3808: - -snes_lag_preconditioner (-2|1|2|...) - sets the lag
3810: Level: developer
3812: Notes:
3813: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3815: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3816: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3817: several timesteps may present huge efficiency gains.
3819: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3820: @*/
3821: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3822: {
3823: PetscFunctionBegin;
3826: snes->lagpre_persist = flg;
3827: PetscFunctionReturn(PETSC_SUCCESS);
3828: }
3830: /*@
3831: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3833: Logically Collective
3835: Input Parameters:
3836: + snes - the `SNES` context
3837: - force - `PETSC_TRUE` require at least one iteration
3839: Options Database Key:
3840: . -snes_force_iteration force - Sets forcing an iteration
3842: Level: intermediate
3844: Note:
3845: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3847: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetDivergenceTolerance()`
3848: @*/
3849: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3850: {
3851: PetscFunctionBegin;
3853: snes->forceiteration = force;
3854: PetscFunctionReturn(PETSC_SUCCESS);
3855: }
3857: /*@
3858: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3860: Logically Collective
3862: Input Parameter:
3863: . snes - the `SNES` context
3865: Output Parameter:
3866: . force - `PETSC_TRUE` requires at least one iteration.
3868: Level: intermediate
3870: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetDivergenceTolerance()`
3871: @*/
3872: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3873: {
3874: PetscFunctionBegin;
3876: *force = snes->forceiteration;
3877: PetscFunctionReturn(PETSC_SUCCESS);
3878: }
3880: /*@
3881: SNESSetTolerances - Sets various parameters used in `SNES` convergence tests.
3883: Logically Collective
3885: Input Parameters:
3886: + snes - the `SNES` context
3887: . abstol - the absolute convergence tolerance, $ F(x^n) \le abstol $
3888: . rtol - the relative convergence tolerance, $ F(x^n) \le reltol * F(x^0) $
3889: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3890: . maxit - the maximum number of iterations allowed in the solver, default 50.
3891: - maxf - the maximum number of function evaluations allowed in the solver (use `PETSC_UNLIMITED` indicates no limit), default 10,000
3893: Options Database Keys:
3894: + -snes_atol abstol - Sets `abstol`
3895: . -snes_rtol rtol - Sets `rtol`
3896: . -snes_stol stol - Sets `stol`
3897: . -snes_max_it maxit - Sets `maxit`
3898: - -snes_max_funcs maxf - Sets `maxf` (use `unlimited` to have no maximum)
3900: Level: intermediate
3902: Note:
3903: All parameters must be non-negative
3905: Use `PETSC_CURRENT` to retain the current value of any parameter and `PETSC_DETERMINE` to use the default value for the given `SNES`.
3906: The default value is the value in the object when its type is set.
3908: Use `PETSC_UNLIMITED` on `maxit` or `maxf` to indicate there is no bound on the number of iterations or number of function evaluations.
3910: Fortran Note:
3911: Use `PETSC_CURRENT_INTEGER`, `PETSC_CURRENT_REAL`, `PETSC_UNLIMITED_INTEGER`, `PETSC_DETERMINE_INTEGER`, or `PETSC_DETERMINE_REAL`
3913: .seealso: [](ch_snes), `SNESSolve()`, `SNES`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3914: @*/
3915: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3916: {
3917: PetscFunctionBegin;
3925: if (abstol == (PetscReal)PETSC_DETERMINE) {
3926: snes->abstol = snes->default_abstol;
3927: } else if (abstol != (PetscReal)PETSC_CURRENT) {
3928: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3929: snes->abstol = abstol;
3930: }
3932: if (rtol == (PetscReal)PETSC_DETERMINE) {
3933: snes->rtol = snes->default_rtol;
3934: } else if (rtol != (PetscReal)PETSC_CURRENT) {
3935: 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);
3936: snes->rtol = rtol;
3937: }
3939: if (stol == (PetscReal)PETSC_DETERMINE) {
3940: snes->stol = snes->default_stol;
3941: } else if (stol != (PetscReal)PETSC_CURRENT) {
3942: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3943: snes->stol = stol;
3944: }
3946: if (maxit == PETSC_DETERMINE) {
3947: snes->max_its = snes->default_max_its;
3948: } else if (maxit == PETSC_UNLIMITED) {
3949: snes->max_its = PETSC_INT_MAX;
3950: } else if (maxit != PETSC_CURRENT) {
3951: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3952: snes->max_its = maxit;
3953: }
3955: if (maxf == PETSC_DETERMINE) {
3956: snes->max_funcs = snes->default_max_funcs;
3957: } else if (maxf == PETSC_UNLIMITED || maxf == -1) {
3958: snes->max_funcs = PETSC_UNLIMITED;
3959: } else if (maxf != PETSC_CURRENT) {
3960: PetscCheck(maxf >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be nonnegative", maxf);
3961: snes->max_funcs = maxf;
3962: }
3963: PetscFunctionReturn(PETSC_SUCCESS);
3964: }
3966: /*@
3967: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3969: Logically Collective
3971: Input Parameters:
3972: + snes - the `SNES` context
3973: - divtol - the divergence tolerance. Use `PETSC_UNLIMITED` to deactivate the test. If the residual norm $ F(x^n) \ge divtol * F(x^0) $ the solver
3974: is stopped due to divergence.
3976: Options Database Key:
3977: . -snes_divergence_tolerance divtol - Sets `divtol`
3979: Level: intermediate
3981: Notes:
3982: Use `PETSC_DETERMINE` to use the default value from when the object's type was set.
3984: Fortran Note:
3985: Use ``PETSC_DETERMINE_REAL` or `PETSC_UNLIMITED_REAL`
3987: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance()`
3988: @*/
3989: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
3990: {
3991: PetscFunctionBegin;
3995: if (divtol == (PetscReal)PETSC_DETERMINE) {
3996: snes->divtol = snes->default_divtol;
3997: } else if (divtol == (PetscReal)PETSC_UNLIMITED || divtol == -1) {
3998: snes->divtol = PETSC_UNLIMITED;
3999: } else if (divtol != (PetscReal)PETSC_CURRENT) {
4000: PetscCheck(divtol >= 1.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Divergence tolerance %g must be greater than 1.0", (double)divtol);
4001: snes->divtol = divtol;
4002: }
4003: PetscFunctionReturn(PETSC_SUCCESS);
4004: }
4006: /*@
4007: SNESGetTolerances - Gets various parameters used in `SNES` convergence tests.
4009: Not Collective
4011: Input Parameter:
4012: . snes - the `SNES` context
4014: Output Parameters:
4015: + atol - the absolute convergence tolerance
4016: . rtol - the relative convergence tolerance
4017: . stol - convergence tolerance in terms of the norm of the change in the solution between steps
4018: . maxit - the maximum number of iterations allowed
4019: - maxf - the maximum number of function evaluations allowed, `PETSC_UNLIMITED` indicates no bound
4021: Level: intermediate
4023: Notes:
4024: See `SNESSetTolerances()` for details on the parameters.
4026: The user can specify `NULL` for any parameter that is not needed.
4028: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
4029: @*/
4030: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
4031: {
4032: PetscFunctionBegin;
4034: if (atol) *atol = snes->abstol;
4035: if (rtol) *rtol = snes->rtol;
4036: if (stol) *stol = snes->stol;
4037: if (maxit) *maxit = snes->max_its;
4038: if (maxf) *maxf = snes->max_funcs;
4039: PetscFunctionReturn(PETSC_SUCCESS);
4040: }
4042: /*@
4043: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
4045: Not Collective
4047: Input Parameters:
4048: + snes - the `SNES` context
4049: - divtol - divergence tolerance
4051: Level: intermediate
4053: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
4054: @*/
4055: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
4056: {
4057: PetscFunctionBegin;
4059: if (divtol) *divtol = snes->divtol;
4060: PetscFunctionReturn(PETSC_SUCCESS);
4061: }
4063: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
4065: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, PetscCtx monctx)
4066: {
4067: PetscDrawLG lg;
4068: PetscReal x, y, per;
4069: PetscViewer v = (PetscViewer)monctx;
4070: static PetscReal prev; /* should be in the context */
4071: PetscDraw draw;
4073: PetscFunctionBegin;
4075: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
4076: if (!n) PetscCall(PetscDrawLGReset(lg));
4077: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4078: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
4079: x = (PetscReal)n;
4080: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
4081: else y = -15.0;
4082: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4083: if (n < 20 || !(n % 5) || snes->reason) {
4084: PetscCall(PetscDrawLGDraw(lg));
4085: PetscCall(PetscDrawLGSave(lg));
4086: }
4088: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
4089: if (!n) PetscCall(PetscDrawLGReset(lg));
4090: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4091: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
4092: PetscCall(SNESMonitorRange_Private(snes, n, &per));
4093: x = (PetscReal)n;
4094: y = 100.0 * per;
4095: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4096: if (n < 20 || !(n % 5) || snes->reason) {
4097: PetscCall(PetscDrawLGDraw(lg));
4098: PetscCall(PetscDrawLGSave(lg));
4099: }
4101: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
4102: if (!n) {
4103: prev = rnorm;
4104: PetscCall(PetscDrawLGReset(lg));
4105: }
4106: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4107: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
4108: x = (PetscReal)n;
4109: y = (prev - rnorm) / prev;
4110: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4111: if (n < 20 || !(n % 5) || snes->reason) {
4112: PetscCall(PetscDrawLGDraw(lg));
4113: PetscCall(PetscDrawLGSave(lg));
4114: }
4116: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
4117: if (!n) PetscCall(PetscDrawLGReset(lg));
4118: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4119: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
4120: x = (PetscReal)n;
4121: y = (prev - rnorm) / (prev * per);
4122: if (n > 2) { /*skip initial crazy value */
4123: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4124: }
4125: if (n < 20 || !(n % 5) || snes->reason) {
4126: PetscCall(PetscDrawLGDraw(lg));
4127: PetscCall(PetscDrawLGSave(lg));
4128: }
4129: prev = rnorm;
4130: PetscFunctionReturn(PETSC_SUCCESS);
4131: }
4133: /*@
4134: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
4136: Collective
4138: Input Parameters:
4139: + snes - the `SNES` context
4140: . it - current iteration
4141: . xnorm - 2-norm of current iterate
4142: . snorm - 2-norm of current step
4143: - fnorm - 2-norm of function
4145: Level: developer
4147: Note:
4148: This routine is called by the `SNESSolve()` implementations.
4149: It does not typically need to be called by the user.
4151: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`
4152: @*/
4153: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
4154: {
4155: PetscFunctionBegin;
4156: if (!snes->reason) {
4157: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
4158: if (it == snes->max_its && !snes->reason) {
4159: if (snes->normschedule == SNES_NORM_ALWAYS) {
4160: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
4161: snes->reason = SNES_DIVERGED_MAX_IT;
4162: } else snes->reason = SNES_CONVERGED_ITS;
4163: }
4164: }
4165: PetscFunctionReturn(PETSC_SUCCESS);
4166: }
4168: /*@
4169: SNESMonitor - runs any `SNES` monitor routines provided with `SNESMonitor()` or the options database
4171: Collective
4173: Input Parameters:
4174: + snes - nonlinear solver context obtained from `SNESCreate()`
4175: . iter - current iteration number
4176: - rnorm - current relative norm of the residual
4178: Level: developer
4180: Note:
4181: This routine is called by the `SNESSolve()` implementations.
4182: It does not typically need to be called by the user.
4184: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
4185: @*/
4186: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
4187: {
4188: PetscInt i, n = snes->numbermonitors;
4190: PetscFunctionBegin;
4191: PetscCall(VecLockReadPush(snes->vec_sol));
4192: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
4193: PetscCall(VecLockReadPop(snes->vec_sol));
4194: PetscFunctionReturn(PETSC_SUCCESS);
4195: }
4197: /* ------------ Routines to set performance monitoring options ----------- */
4199: /*MC
4200: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
4202: Synopsis:
4203: #include <petscsnes.h>
4204: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, PetscCtx mctx)
4206: Collective
4208: Input Parameters:
4209: + snes - the `SNES` context
4210: . its - iteration number
4211: . norm - 2-norm function value (may be estimated)
4212: - mctx - [optional] monitoring context
4214: Level: advanced
4216: .seealso: [](ch_snes), `SNESMonitorSet()`, `PetscCtx`
4217: M*/
4219: /*@C
4220: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
4221: iteration of the `SNES` nonlinear solver to display the iteration's
4222: progress.
4224: Logically Collective
4226: Input Parameters:
4227: + snes - the `SNES` context
4228: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4229: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4230: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence
4232: Calling sequence of f:
4233: + snes - the `SNES` object
4234: . it - the current iteration
4235: . rnorm - norm of the residual
4236: - mctx - the optional monitor context
4238: Options Database Keys:
4239: + -snes_monitor - sets `SNESMonitorDefault()`
4240: . -snes_monitor draw::draw_lg - sets line graph monitor,
4241: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4242: the options database.
4244: Level: intermediate
4246: Note:
4247: Several different monitoring routines may be set by calling
4248: `SNESMonitorSet()` multiple times; all will be called in the
4249: order in which they were set.
4251: Fortran Note:
4252: Only a single monitor function can be set for each `SNES` object
4254: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`, `PetscCtxDestroyFn`
4255: @*/
4256: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES snes, PetscInt it, PetscReal rnorm, PetscCtx mctx), PetscCtx mctx, PetscCtxDestroyFn *monitordestroy)
4257: {
4258: PetscFunctionBegin;
4260: for (PetscInt i = 0; i < snes->numbermonitors; i++) {
4261: PetscBool identical;
4263: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))(PetscVoidFn *)f, mctx, monitordestroy, (PetscErrorCode (*)(void))(PetscVoidFn *)snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4264: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4265: }
4266: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4267: snes->monitor[snes->numbermonitors] = f;
4268: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4269: snes->monitorcontext[snes->numbermonitors++] = mctx;
4270: PetscFunctionReturn(PETSC_SUCCESS);
4271: }
4273: /*@
4274: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4276: Logically Collective
4278: Input Parameter:
4279: . snes - the `SNES` context
4281: Options Database Key:
4282: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4283: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4284: set via the options database
4286: Level: intermediate
4288: Note:
4289: There is no way to clear one specific monitor from a `SNES` object.
4291: .seealso: [](ch_snes), `SNES`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4292: @*/
4293: PetscErrorCode SNESMonitorCancel(SNES snes)
4294: {
4295: PetscInt i;
4297: PetscFunctionBegin;
4299: for (i = 0; i < snes->numbermonitors; i++) {
4300: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4301: }
4302: snes->numbermonitors = 0;
4303: PetscFunctionReturn(PETSC_SUCCESS);
4304: }
4306: /*@C
4307: SNESSetConvergenceTest - Sets the function that is to be used
4308: to test for convergence of the nonlinear iterative solution.
4310: Logically Collective
4312: Input Parameters:
4313: + snes - the `SNES` context
4314: . func - routine to test for convergence
4315: . ctx - [optional] context for private data for the convergence routine (may be `NULL`)
4316: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4318: Calling sequence of func:
4319: + snes - the `SNES` context
4320: . it - the current iteration number
4321: . xnorm - the norm of the new solution
4322: . snorm - the norm of the step
4323: . fnorm - the norm of the function value
4324: . reason - output, the reason convergence or divergence as declared
4325: - ctx - the optional convergence test context
4327: Level: advanced
4329: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`
4330: @*/
4331: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*func)(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm, SNESConvergedReason *reason, PetscCtx ctx), PetscCtx ctx, PetscCtxDestroyFn *destroy)
4332: {
4333: PetscFunctionBegin;
4335: if (!func) func = SNESConvergedSkip;
4336: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(&snes->cnvP));
4337: snes->ops->converged = func;
4338: snes->ops->convergeddestroy = destroy;
4339: snes->cnvP = ctx;
4340: PetscFunctionReturn(PETSC_SUCCESS);
4341: }
4343: /*@
4344: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped, which may be due to convergence, divergence, or stagnation
4346: Not Collective
4348: Input Parameter:
4349: . snes - the `SNES` context
4351: Output Parameter:
4352: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4354: Options Database Key:
4355: . -snes_converged_reason - prints the reason to standard out
4357: Level: intermediate
4359: Note:
4360: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4362: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4363: @*/
4364: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4365: {
4366: PetscFunctionBegin;
4368: PetscAssertPointer(reason, 2);
4369: *reason = snes->reason;
4370: PetscFunctionReturn(PETSC_SUCCESS);
4371: }
4373: /*@C
4374: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4376: Not Collective
4378: Input Parameter:
4379: . snes - the `SNES` context
4381: Output Parameter:
4382: . strreason - a human readable string that describes `SNES` converged reason
4384: Level: beginner
4386: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4387: @*/
4388: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4389: {
4390: PetscFunctionBegin;
4392: PetscAssertPointer(strreason, 2);
4393: *strreason = SNESConvergedReasons[snes->reason];
4394: PetscFunctionReturn(PETSC_SUCCESS);
4395: }
4397: /*@
4398: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4400: Not Collective
4402: Input Parameters:
4403: + snes - the `SNES` context
4404: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4405: manual pages for the individual convergence tests for complete lists
4407: Level: developer
4409: Developer Note:
4410: Called inside the various `SNESSolve()` implementations
4412: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4413: @*/
4414: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4415: {
4416: PetscFunctionBegin;
4418: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4419: snes->reason = reason;
4420: PetscFunctionReturn(PETSC_SUCCESS);
4421: }
4423: /*@
4424: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4426: Logically Collective
4428: Input Parameters:
4429: + snes - iterative context obtained from `SNESCreate()`
4430: . a - array to hold history, this array will contain the function norms computed at each step
4431: . its - integer array holds the number of linear iterations for each solve.
4432: . na - size of `a` and `its`
4433: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4434: else it continues storing new values for new nonlinear solves after the old ones
4436: Level: intermediate
4438: Notes:
4439: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' is `PETSC_DECIDE` (or, deprecated, `PETSC_DEFAULT`) then a
4440: default array of length 1,000 is allocated.
4442: This routine is useful, e.g., when running a code for purposes
4443: of accurate performance monitoring, when no I/O should be done
4444: during the section of code that is being timed.
4446: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4448: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4449: @*/
4450: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4451: {
4452: PetscFunctionBegin;
4454: if (a) PetscAssertPointer(a, 2);
4455: if (its) PetscAssertPointer(its, 3);
4456: if (!a) {
4457: if (na == PETSC_DECIDE) na = 1000;
4458: PetscCall(PetscCalloc2(na, &a, na, &its));
4459: snes->conv_hist_alloc = PETSC_TRUE;
4460: }
4461: snes->conv_hist = a;
4462: snes->conv_hist_its = its;
4463: snes->conv_hist_max = (size_t)na;
4464: snes->conv_hist_len = 0;
4465: snes->conv_hist_reset = reset;
4466: PetscFunctionReturn(PETSC_SUCCESS);
4467: }
4469: #if defined(PETSC_HAVE_MATLAB)
4470: #include <engine.h> /* MATLAB include file */
4471: #include <mex.h> /* MATLAB include file */
4473: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4474: {
4475: mxArray *mat;
4476: PetscInt i;
4477: PetscReal *ar;
4479: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4480: ar = (PetscReal *)mxGetData(mat);
4481: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4482: return mat;
4483: }
4484: #endif
4486: /*@C
4487: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4489: Not Collective
4491: Input Parameter:
4492: . snes - iterative context obtained from `SNESCreate()`
4494: Output Parameters:
4495: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4496: . its - integer array holds the number of linear iterations (or
4497: negative if not converged) for each solve.
4498: - na - size of `a` and `its`
4500: Level: intermediate
4502: Note:
4503: This routine is useful, e.g., when running a code for purposes
4504: of accurate performance monitoring, when no I/O should be done
4505: during the section of code that is being timed.
4507: Fortran Notes:
4508: Return the arrays with ``SNESRestoreConvergenceHistory()`
4510: Use the arguments
4511: .vb
4512: PetscReal, pointer :: a(:)
4513: PetscInt, pointer :: its(:)
4514: .ve
4516: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4517: @*/
4518: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4519: {
4520: PetscFunctionBegin;
4522: if (a) *a = snes->conv_hist;
4523: if (its) *its = snes->conv_hist_its;
4524: if (na) *na = (PetscInt)snes->conv_hist_len;
4525: PetscFunctionReturn(PETSC_SUCCESS);
4526: }
4528: /*@C
4529: SNESSetUpdate - Sets the general-purpose update function called
4530: at the beginning of every iteration of the nonlinear solve. Specifically
4531: it is called just before the Jacobian is "evaluated" and after the function
4532: evaluation.
4534: Logically Collective
4536: Input Parameters:
4537: + snes - The nonlinear solver context
4538: - func - The update function; for calling sequence see `SNESUpdateFn`
4540: Level: advanced
4542: Notes:
4543: 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
4544: to `SNESSetFunction()`, or `SNESSetPicard()`
4545: This is not used by most users, and it is intended to provide a general hook that is run
4546: right before the direction step is computed.
4548: Users are free to modify the current residual vector,
4549: the current linearization point, or any other vector associated to the specific solver used.
4550: If such modifications take place, it is the user responsibility to update all the relevant
4551: vectors. For example, if one is adjusting the model parameters at each Newton step their code may look like
4552: .vb
4553: PetscErrorCode update(SNES snes, PetscInt iteration)
4554: {
4555: PetscFunctionBeginUser;
4556: if (iteration > 0) {
4557: // update the model parameters here
4558: Vec x,f;
4559: PetscCall(SNESGetSolution(snes,&x));
4560: PetcCall(SNESGetFunction(snes,&f,NULL,NULL));
4561: PetscCall(SNESComputeFunction(snes,x,f));
4562: }
4563: PetscFunctionReturn(PETSC_SUCCESS);
4564: }
4565: .ve
4567: 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.
4569: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4570: `SNESMonitorSet()`
4571: @*/
4572: PetscErrorCode SNESSetUpdate(SNES snes, SNESUpdateFn *func)
4573: {
4574: PetscFunctionBegin;
4576: snes->ops->update = func;
4577: PetscFunctionReturn(PETSC_SUCCESS);
4578: }
4580: /*@
4581: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4583: Collective
4585: Input Parameters:
4586: + snes - iterative context obtained from `SNESCreate()`
4587: - viewer - the viewer to display the reason
4589: Options Database Keys:
4590: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4591: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4593: Level: beginner
4595: Note:
4596: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4597: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4599: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4600: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4601: `SNESConvergedReasonViewFromOptions()`,
4602: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4603: @*/
4604: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4605: {
4606: PetscViewerFormat format;
4607: PetscBool isAscii;
4609: PetscFunctionBegin;
4610: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4611: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4612: if (isAscii) {
4613: PetscCall(PetscViewerGetFormat(viewer, &format));
4614: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel + 1));
4615: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4616: DM dm;
4617: Vec u;
4618: PetscDS prob;
4619: PetscInt Nf, f;
4620: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4621: void **exactCtx;
4622: PetscReal error;
4624: PetscCall(SNESGetDM(snes, &dm));
4625: PetscCall(SNESGetSolution(snes, &u));
4626: PetscCall(DMGetDS(dm, &prob));
4627: PetscCall(PetscDSGetNumFields(prob, &Nf));
4628: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4629: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4630: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4631: PetscCall(PetscFree2(exactSol, exactCtx));
4632: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4633: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4634: }
4635: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4636: if (((PetscObject)snes)->prefix) {
4637: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4638: } else {
4639: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4640: }
4641: } else if (snes->reason <= 0) {
4642: if (((PetscObject)snes)->prefix) {
4643: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4644: } else {
4645: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4646: }
4647: }
4648: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel + 1));
4649: }
4650: PetscFunctionReturn(PETSC_SUCCESS);
4651: }
4653: /*@C
4654: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4655: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4657: Logically Collective
4659: Input Parameters:
4660: + snes - the `SNES` context
4661: . f - the `SNESConvergedReason` view function
4662: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4663: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence
4665: Calling sequence of `f`:
4666: + snes - the `SNES` context
4667: - vctx - [optional] context for private data for the function
4669: Options Database Keys:
4670: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4671: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4672: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4674: Level: intermediate
4676: Note:
4677: Several different converged reason view routines may be set by calling
4678: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4679: order in which they were set.
4681: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`,
4682: `PetscCtxDestroyFn`
4683: @*/
4684: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, PetscCtx vctx), PetscCtx vctx, PetscCtxDestroyFn *reasonviewdestroy)
4685: {
4686: PetscFunctionBegin;
4688: for (PetscInt i = 0; i < snes->numberreasonviews; i++) {
4689: PetscBool identical;
4691: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))(PetscVoidFn *)f, vctx, reasonviewdestroy, (PetscErrorCode (*)(void))(PetscVoidFn *)snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4692: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4693: }
4694: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4695: snes->reasonview[snes->numberreasonviews] = f;
4696: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4697: snes->reasonviewcontext[snes->numberreasonviews++] = vctx;
4698: PetscFunctionReturn(PETSC_SUCCESS);
4699: }
4701: /*@
4702: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4703: All the user-provided viewer routines set with `SNESConvergedReasonViewSet()` will be called, if they exist.
4705: Collective
4707: Input Parameter:
4708: . snes - the `SNES` object
4710: Level: advanced
4712: Note:
4713: This function has a different API and behavior than `PetscObjectViewFromOptions()`
4715: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4716: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4717: @*/
4718: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4719: {
4720: static PetscBool incall = PETSC_FALSE;
4722: PetscFunctionBegin;
4723: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4724: incall = PETSC_TRUE;
4726: /* All user-provided viewers are called first, if they exist. */
4727: for (PetscInt i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4729: /* Call PETSc default routine if users ask for it */
4730: if (snes->convergedreasonviewer) {
4731: PetscCall(PetscViewerPushFormat(snes->convergedreasonviewer, snes->convergedreasonformat));
4732: PetscCall(SNESConvergedReasonView(snes, snes->convergedreasonviewer));
4733: PetscCall(PetscViewerPopFormat(snes->convergedreasonviewer));
4734: }
4735: incall = PETSC_FALSE;
4736: PetscFunctionReturn(PETSC_SUCCESS);
4737: }
4739: /*@
4740: SNESSolve - Solves a nonlinear system $F(x) = b $ associated with a `SNES` object
4742: Collective
4744: Input Parameters:
4745: + snes - the `SNES` context
4746: . b - the constant part of the equation $F(x) = b$, or `NULL` to use zero.
4747: - x - the solution vector.
4749: Level: beginner
4751: Note:
4752: The user should initialize the vector, `x`, with the initial guess
4753: for the nonlinear solve prior to calling `SNESSolve()` .
4755: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4756: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4757: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`
4758: @*/
4759: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4760: {
4761: PetscBool flg;
4762: PetscInt grid;
4763: Vec xcreated = NULL;
4764: DM dm;
4766: PetscFunctionBegin;
4769: if (x) PetscCheckSameComm(snes, 1, x, 3);
4771: if (b) PetscCheckSameComm(snes, 1, b, 2);
4773: /* High level operations using the nonlinear solver */
4774: {
4775: PetscViewer viewer;
4776: PetscViewerFormat format;
4777: PetscInt num;
4778: PetscBool flg;
4779: static PetscBool incall = PETSC_FALSE;
4781: if (!incall) {
4782: /* Estimate the convergence rate of the discretization */
4783: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4784: if (flg) {
4785: PetscConvEst conv;
4786: DM dm;
4787: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4788: PetscInt Nf;
4790: incall = PETSC_TRUE;
4791: PetscCall(SNESGetDM(snes, &dm));
4792: PetscCall(DMGetNumFields(dm, &Nf));
4793: PetscCall(PetscCalloc1(Nf, &alpha));
4794: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4795: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4796: PetscCall(PetscConvEstSetFromOptions(conv));
4797: PetscCall(PetscConvEstSetUp(conv));
4798: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4799: PetscCall(PetscViewerPushFormat(viewer, format));
4800: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4801: PetscCall(PetscViewerPopFormat(viewer));
4802: PetscCall(PetscViewerDestroy(&viewer));
4803: PetscCall(PetscConvEstDestroy(&conv));
4804: PetscCall(PetscFree(alpha));
4805: incall = PETSC_FALSE;
4806: }
4807: /* Adaptively refine the initial grid */
4808: num = 1;
4809: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4810: if (flg) {
4811: DMAdaptor adaptor;
4813: incall = PETSC_TRUE;
4814: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4815: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4816: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4817: PetscCall(DMAdaptorSetFromOptions(adaptor));
4818: PetscCall(DMAdaptorSetUp(adaptor));
4819: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4820: PetscCall(DMAdaptorDestroy(&adaptor));
4821: incall = PETSC_FALSE;
4822: }
4823: /* Use grid sequencing to adapt */
4824: num = 0;
4825: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4826: if (num) {
4827: DMAdaptor adaptor;
4828: const char *prefix;
4830: incall = PETSC_TRUE;
4831: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4832: PetscCall(SNESGetOptionsPrefix(snes, &prefix));
4833: PetscCall(DMAdaptorSetOptionsPrefix(adaptor, prefix));
4834: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4835: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4836: PetscCall(DMAdaptorSetFromOptions(adaptor));
4837: PetscCall(DMAdaptorSetUp(adaptor));
4838: PetscCall(PetscObjectViewFromOptions((PetscObject)adaptor, NULL, "-snes_adapt_view"));
4839: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4840: PetscCall(DMAdaptorDestroy(&adaptor));
4841: incall = PETSC_FALSE;
4842: }
4843: }
4844: }
4845: if (!x) x = snes->vec_sol;
4846: if (!x) {
4847: PetscCall(SNESGetDM(snes, &dm));
4848: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4849: x = xcreated;
4850: }
4851: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4853: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4854: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4855: /* set solution vector */
4856: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4857: PetscCall(VecDestroy(&snes->vec_sol));
4858: snes->vec_sol = x;
4859: PetscCall(SNESGetDM(snes, &dm));
4861: /* set affine vector if provided */
4862: PetscCall(PetscObjectReference((PetscObject)b));
4863: PetscCall(VecDestroy(&snes->vec_rhs));
4864: snes->vec_rhs = b;
4866: 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");
4867: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4868: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right-hand side vector");
4869: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4870: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4871: PetscCall(SNESSetUp(snes));
4873: if (!grid) {
4874: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback compute initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4875: }
4877: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4878: PetscCall(SNESResetCounters(snes));
4879: snes->reason = SNES_CONVERGED_ITERATING;
4880: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4881: PetscUseTypeMethod(snes, solve);
4882: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4883: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4884: snes->functiondomainerror = PETSC_FALSE; /* clear the flag if it has been set */
4885: snes->objectivedomainerror = PETSC_FALSE; /* clear the flag if it has been set */
4886: snes->jacobiandomainerror = PETSC_FALSE; /* clear the flag if it has been set */
4888: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4889: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4891: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4892: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4893: /* Call converged reason views. This may involve user-provided viewers as well */
4894: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4896: if (snes->errorifnotconverged) {
4897: if (snes->reason < 0) PetscCall(SNESMonitorCancel(snes));
4898: PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4899: }
4900: if (snes->reason < 0) break;
4901: if (grid < snes->gridsequence) {
4902: DM fine;
4903: Vec xnew;
4904: Mat interp;
4906: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4907: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4908: PetscCall(DMGetCoordinatesLocalSetUp(fine));
4909: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4910: PetscCall(DMCreateGlobalVector(fine, &xnew));
4911: PetscCall(MatInterpolate(interp, x, xnew));
4912: PetscCall(DMInterpolate(snes->dm, interp, fine));
4913: PetscCall(MatDestroy(&interp));
4914: x = xnew;
4916: PetscCall(SNESReset(snes));
4917: PetscCall(SNESSetDM(snes, fine));
4918: PetscCall(SNESResetFromOptions(snes));
4919: PetscCall(DMDestroy(&fine));
4920: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4921: }
4922: }
4923: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4924: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4925: PetscCall(DMMonitor(snes->dm));
4926: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4928: PetscCall(VecDestroy(&xcreated));
4929: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4930: PetscFunctionReturn(PETSC_SUCCESS);
4931: }
4933: /* --------- Internal routines for SNES Package --------- */
4935: /*@
4936: SNESSetType - Sets the algorithm/method to be used to solve the nonlinear system with the given `SNES`
4938: Collective
4940: Input Parameters:
4941: + snes - the `SNES` context
4942: - type - a known method
4944: Options Database Key:
4945: . -snes_type type - Sets the method; see `SNESType`
4947: Level: intermediate
4949: Notes:
4950: See `SNESType` for available methods (for instance)
4951: + `SNESNEWTONLS` - Newton's method with line search
4952: (systems of nonlinear equations)
4953: - `SNESNEWTONTR` - Newton's method with trust region
4954: (systems of nonlinear equations)
4956: Normally, it is best to use the `SNESSetFromOptions()` command and then
4957: set the `SNES` solver type from the options database rather than by using
4958: this routine. Using the options database provides the user with
4959: maximum flexibility in evaluating the many nonlinear solvers.
4960: The `SNESSetType()` routine is provided for those situations where it
4961: is necessary to set the nonlinear solver independently of the command
4962: line or options database. This might be the case, for example, when
4963: the choice of solver changes during the execution of the program,
4964: and the user's application is taking responsibility for choosing the
4965: appropriate method.
4967: Developer Note:
4968: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4969: the constructor in that list and calls it to create the specific object.
4971: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4972: @*/
4973: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4974: {
4975: PetscBool match;
4976: PetscErrorCode (*r)(SNES);
4978: PetscFunctionBegin;
4980: PetscAssertPointer(type, 2);
4982: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4983: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4985: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4986: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4987: /* Destroy the previous private SNES context */
4988: PetscTryTypeMethod(snes, destroy);
4989: /* Reinitialize type-specific function pointers in SNESOps structure */
4990: snes->ops->reset = NULL;
4991: snes->ops->setup = NULL;
4992: snes->ops->solve = NULL;
4993: snes->ops->view = NULL;
4994: snes->ops->setfromoptions = NULL;
4995: snes->ops->destroy = NULL;
4997: /* It may happen the user has customized the line search before calling SNESSetType */
4998: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5000: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
5001: snes->setupcalled = PETSC_FALSE;
5003: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
5004: PetscCall((*r)(snes));
5005: PetscFunctionReturn(PETSC_SUCCESS);
5006: }
5008: /*@
5009: SNESGetType - Gets the `SNES` method type and name (as a string).
5011: Not Collective
5013: Input Parameter:
5014: . snes - nonlinear solver context
5016: Output Parameter:
5017: . type - `SNES` method (a character string)
5019: Level: intermediate
5021: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
5022: @*/
5023: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
5024: {
5025: PetscFunctionBegin;
5027: PetscAssertPointer(type, 2);
5028: *type = ((PetscObject)snes)->type_name;
5029: PetscFunctionReturn(PETSC_SUCCESS);
5030: }
5032: /*@
5033: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
5035: Logically Collective
5037: Input Parameters:
5038: + snes - the `SNES` context obtained from `SNESCreate()`
5039: - u - the solution vector
5041: Level: beginner
5043: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
5044: @*/
5045: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
5046: {
5047: DM dm;
5049: PetscFunctionBegin;
5052: PetscCall(PetscObjectReference((PetscObject)u));
5053: PetscCall(VecDestroy(&snes->vec_sol));
5055: snes->vec_sol = u;
5057: PetscCall(SNESGetDM(snes, &dm));
5058: PetscCall(DMShellSetGlobalVector(dm, u));
5059: PetscFunctionReturn(PETSC_SUCCESS);
5060: }
5062: /*@
5063: SNESGetSolution - Returns the vector where the approximate solution is
5064: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
5066: Not Collective, but `x` is parallel if `snes` is parallel
5068: Input Parameter:
5069: . snes - the `SNES` context
5071: Output Parameter:
5072: . x - the solution
5074: Level: intermediate
5076: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
5077: @*/
5078: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
5079: {
5080: PetscFunctionBegin;
5082: PetscAssertPointer(x, 2);
5083: *x = snes->vec_sol;
5084: PetscFunctionReturn(PETSC_SUCCESS);
5085: }
5087: /*@
5088: SNESGetSolutionUpdate - Returns the vector where the solution update is
5089: stored.
5091: Not Collective, but `x` is parallel if `snes` is parallel
5093: Input Parameter:
5094: . snes - the `SNES` context
5096: Output Parameter:
5097: . x - the solution update
5099: Level: advanced
5101: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
5102: @*/
5103: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
5104: {
5105: PetscFunctionBegin;
5107: PetscAssertPointer(x, 2);
5108: *x = snes->vec_sol_update;
5109: PetscFunctionReturn(PETSC_SUCCESS);
5110: }
5112: /*@C
5113: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
5115: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
5117: Input Parameter:
5118: . snes - the `SNES` context
5120: Output Parameters:
5121: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
5122: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunctionFn`
5123: - ctx - the function context (or `NULL` if you don't want it)
5125: Level: advanced
5127: Note:
5128: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
5130: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunctionFn`
5131: @*/
5132: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, SNESFunctionFn **f, PetscCtxRt ctx)
5133: {
5134: DM dm;
5136: PetscFunctionBegin;
5138: if (r) {
5139: if (!snes->vec_func) {
5140: if (snes->vec_rhs) {
5141: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
5142: } else if (snes->vec_sol) {
5143: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
5144: } else if (snes->dm) {
5145: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
5146: }
5147: }
5148: *r = snes->vec_func;
5149: }
5150: PetscCall(SNESGetDM(snes, &dm));
5151: PetscCall(DMSNESGetFunction(dm, f, ctx));
5152: PetscFunctionReturn(PETSC_SUCCESS);
5153: }
5155: /*@C
5156: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
5158: Input Parameter:
5159: . snes - the `SNES` context
5161: Output Parameters:
5162: + f - the function (or `NULL`) see `SNESNGSFn` for calling sequence
5163: - ctx - the function context (or `NULL`)
5165: Level: advanced
5167: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`, `SNESNGSFn`
5168: @*/
5169: PetscErrorCode SNESGetNGS(SNES snes, SNESNGSFn **f, PetscCtxRt ctx)
5170: {
5171: DM dm;
5173: PetscFunctionBegin;
5175: PetscCall(SNESGetDM(snes, &dm));
5176: PetscCall(DMSNESGetNGS(dm, f, ctx));
5177: PetscFunctionReturn(PETSC_SUCCESS);
5178: }
5180: /*@
5181: SNESSetOptionsPrefix - Sets the prefix used for searching for all
5182: `SNES` options in the database.
5184: Logically Collective
5186: Input Parameters:
5187: + snes - the `SNES` context
5188: - prefix - the prefix to prepend to all option names
5190: Level: advanced
5192: Note:
5193: A hyphen (-) must NOT be given at the beginning of the prefix name.
5194: The first character of all runtime options is AUTOMATICALLY the hyphen.
5196: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
5197: @*/
5198: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
5199: {
5200: PetscFunctionBegin;
5202: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
5203: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5204: if (snes->linesearch) {
5205: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5206: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
5207: }
5208: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
5209: PetscFunctionReturn(PETSC_SUCCESS);
5210: }
5212: /*@
5213: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5214: `SNES` options in the database.
5216: Logically Collective
5218: Input Parameters:
5219: + snes - the `SNES` context
5220: - prefix - the prefix to prepend to all option names
5222: Level: advanced
5224: Note:
5225: A hyphen (-) must NOT be given at the beginning of the prefix name.
5226: The first character of all runtime options is AUTOMATICALLY the hyphen.
5228: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5229: @*/
5230: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5231: {
5232: PetscFunctionBegin;
5234: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5235: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5236: if (snes->linesearch) {
5237: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5238: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5239: }
5240: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5241: PetscFunctionReturn(PETSC_SUCCESS);
5242: }
5244: /*@
5245: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5246: `SNES` options in the database.
5248: Not Collective
5250: Input Parameter:
5251: . snes - the `SNES` context
5253: Output Parameter:
5254: . prefix - pointer to the prefix string used
5256: Level: advanced
5258: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5259: @*/
5260: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5261: {
5262: PetscFunctionBegin;
5264: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5265: PetscFunctionReturn(PETSC_SUCCESS);
5266: }
5268: /*@C
5269: SNESRegister - Adds a method to the nonlinear solver package.
5271: Not Collective
5273: Input Parameters:
5274: + sname - name of a new user-defined solver
5275: - function - routine to create method context
5277: Level: advanced
5279: Note:
5280: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5282: Example Usage:
5283: .vb
5284: SNESRegister("my_solver", MySolverCreate);
5285: .ve
5287: Then, your solver can be chosen with the procedural interface via
5288: .vb
5289: SNESSetType(snes, "my_solver")
5290: .ve
5291: or at runtime via the option
5292: .vb
5293: -snes_type my_solver
5294: .ve
5296: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5297: @*/
5298: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5299: {
5300: PetscFunctionBegin;
5301: PetscCall(SNESInitializePackage());
5302: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5303: PetscFunctionReturn(PETSC_SUCCESS);
5304: }
5306: PetscErrorCode SNESTestLocalMin(SNES snes)
5307: {
5308: PetscInt N, i, j;
5309: Vec u, uh, fh;
5310: PetscScalar value;
5311: PetscReal norm;
5313: PetscFunctionBegin;
5314: PetscCall(SNESGetSolution(snes, &u));
5315: PetscCall(VecDuplicate(u, &uh));
5316: PetscCall(VecDuplicate(u, &fh));
5318: /* currently only works for sequential */
5319: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5320: PetscCall(VecGetSize(u, &N));
5321: for (i = 0; i < N; i++) {
5322: PetscCall(VecCopy(u, uh));
5323: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5324: for (j = -10; j < 11; j++) {
5325: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5326: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5327: PetscCall(SNESComputeFunction(snes, uh, fh));
5328: PetscCall(VecNorm(fh, NORM_2, &norm)); /* does not handle use of SNESSetFunctionDomainError() correctly */
5329: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5330: value = -value;
5331: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5332: }
5333: }
5334: PetscCall(VecDestroy(&uh));
5335: PetscCall(VecDestroy(&fh));
5336: PetscFunctionReturn(PETSC_SUCCESS);
5337: }
5339: /*@
5340: SNESGetLineSearch - Returns the line search associated with the `SNES`.
5342: Not Collective
5344: Input Parameter:
5345: . snes - iterative context obtained from `SNESCreate()`
5347: Output Parameter:
5348: . linesearch - linesearch context
5350: Level: beginner
5352: Notes:
5353: It creates a default line search instance which can be configured as needed in case it has not been already set with `SNESSetLineSearch()`.
5355: You can also use the options database keys `-snes_linesearch_*` to configure the line search. See `SNESLineSearchSetFromOptions()` for the possible options.
5357: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`, `SNESLineSearchSetFromOptions()`
5358: @*/
5359: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5360: {
5361: const char *optionsprefix;
5363: PetscFunctionBegin;
5365: PetscAssertPointer(linesearch, 2);
5366: if (!snes->linesearch) {
5367: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5368: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5369: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5370: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5371: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5372: }
5373: *linesearch = snes->linesearch;
5374: PetscFunctionReturn(PETSC_SUCCESS);
5375: }
5377: /*@
5378: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5379: computing relative tolerance for linear solvers within an inexact
5380: Newton method.
5382: Logically Collective
5384: Input Parameters:
5385: + snes - `SNES` context
5386: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5388: Options Database Keys:
5389: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5390: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5391: . -snes_ksp_ew_rtol0 rtol0 - Sets rtol0
5392: . -snes_ksp_ew_rtolmax rtolmax - Sets rtolmax
5393: . -snes_ksp_ew_gamma gamma - Sets gamma
5394: . -snes_ksp_ew_alpha alpha - Sets alpha
5395: . -snes_ksp_ew_alpha2 alpha2 - Sets alpha2
5396: - -snes_ksp_ew_threshold threshold - Sets threshold
5398: Level: advanced
5400: Note:
5401: The default is to use a constant relative tolerance for
5402: the inner linear solvers. Alternatively, one can use the
5403: Eisenstat-Walker method {cite}`ew96`, where the relative convergence tolerance
5404: is reset at each Newton iteration according progress of the nonlinear
5405: solver.
5407: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5408: @*/
5409: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5410: {
5411: PetscFunctionBegin;
5414: snes->ksp_ewconv = flag;
5415: PetscFunctionReturn(PETSC_SUCCESS);
5416: }
5418: /*@
5419: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5420: for computing relative tolerance for linear solvers within an
5421: inexact Newton method.
5423: Not Collective
5425: Input Parameter:
5426: . snes - `SNES` context
5428: Output Parameter:
5429: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5431: Level: advanced
5433: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5434: @*/
5435: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5436: {
5437: PetscFunctionBegin;
5439: PetscAssertPointer(flag, 2);
5440: *flag = snes->ksp_ewconv;
5441: PetscFunctionReturn(PETSC_SUCCESS);
5442: }
5444: /*@
5445: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5446: convergence criteria for the linear solvers within an inexact
5447: Newton method.
5449: Logically Collective
5451: Input Parameters:
5452: + snes - `SNES` context
5453: . version - version 1, 2 (default is 2), 3 or 4
5454: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5455: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5456: . gamma - multiplicative factor for version 2 rtol computation
5457: (0 <= gamma2 <= 1)
5458: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5459: . alpha2 - power for safeguard
5460: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5462: Level: advanced
5464: Notes:
5465: Version 3 was contributed by Luis Chacon, June 2006.
5467: Use `PETSC_CURRENT` to retain the default for any of the parameters.
5469: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5470: @*/
5471: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5472: {
5473: SNESKSPEW *kctx;
5475: PetscFunctionBegin;
5477: kctx = (SNESKSPEW *)snes->kspconvctx;
5478: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5487: if (version != PETSC_CURRENT) kctx->version = version;
5488: if (rtol_0 != (PetscReal)PETSC_CURRENT) kctx->rtol_0 = rtol_0;
5489: if (rtol_max != (PetscReal)PETSC_CURRENT) kctx->rtol_max = rtol_max;
5490: if (gamma != (PetscReal)PETSC_CURRENT) kctx->gamma = gamma;
5491: if (alpha != (PetscReal)PETSC_CURRENT) kctx->alpha = alpha;
5492: if (alpha2 != (PetscReal)PETSC_CURRENT) kctx->alpha2 = alpha2;
5493: if (threshold != (PetscReal)PETSC_CURRENT) kctx->threshold = threshold;
5495: 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);
5496: 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);
5497: 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);
5498: 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);
5499: 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);
5500: 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);
5501: PetscFunctionReturn(PETSC_SUCCESS);
5502: }
5504: /*@
5505: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5506: convergence criteria for the linear solvers within an inexact
5507: Newton method.
5509: Not Collective
5511: Input Parameter:
5512: . snes - `SNES` context
5514: Output Parameters:
5515: + version - version 1, 2 (default is 2), 3 or 4
5516: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5517: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5518: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5519: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5520: . alpha2 - power for safeguard
5521: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5523: Level: advanced
5525: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5526: @*/
5527: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5528: {
5529: SNESKSPEW *kctx;
5531: PetscFunctionBegin;
5533: kctx = (SNESKSPEW *)snes->kspconvctx;
5534: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5535: if (version) *version = kctx->version;
5536: if (rtol_0) *rtol_0 = kctx->rtol_0;
5537: if (rtol_max) *rtol_max = kctx->rtol_max;
5538: if (gamma) *gamma = kctx->gamma;
5539: if (alpha) *alpha = kctx->alpha;
5540: if (alpha2) *alpha2 = kctx->alpha2;
5541: if (threshold) *threshold = kctx->threshold;
5542: PetscFunctionReturn(PETSC_SUCCESS);
5543: }
5545: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, PetscCtx ctx)
5546: {
5547: SNES snes = (SNES)ctx;
5548: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5549: PetscReal rtol = PETSC_CURRENT, stol;
5551: PetscFunctionBegin;
5552: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5553: if (!snes->iter) {
5554: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5555: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5556: } else {
5557: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5558: if (kctx->version == 1) {
5559: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5560: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5561: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5562: } else if (kctx->version == 2) {
5563: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5564: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5565: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5566: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5567: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5568: /* safeguard: avoid sharp decrease of rtol */
5569: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5570: stol = PetscMax(rtol, stol);
5571: rtol = PetscMin(kctx->rtol_0, stol);
5572: /* safeguard: avoid oversolving */
5573: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5574: stol = PetscMax(rtol, stol);
5575: rtol = PetscMin(kctx->rtol_0, stol);
5576: } else /* if (kctx->version == 4) */ {
5577: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5578: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5579: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5580: PetscReal rk = ared / pred;
5581: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5582: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5583: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5584: else rtol = kctx->v4_m2 * kctx->rtol_last;
5586: 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;
5587: kctx->rtol_last_2 = kctx->rtol_last;
5588: kctx->rk_last_2 = kctx->rk_last;
5589: kctx->rk_last = rk;
5590: }
5591: }
5592: /* safeguard: avoid rtol greater than rtol_max */
5593: rtol = PetscMin(rtol, kctx->rtol_max);
5594: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_CURRENT, PETSC_CURRENT, PETSC_CURRENT));
5595: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5596: PetscFunctionReturn(PETSC_SUCCESS);
5597: }
5599: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, PetscCtx ctx)
5600: {
5601: SNES snes = (SNES)ctx;
5602: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5603: PCSide pcside;
5604: Vec lres;
5606: PetscFunctionBegin;
5607: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5608: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5609: kctx->norm_last = snes->norm;
5610: if (kctx->version == 1 || kctx->version == 4) {
5611: PC pc;
5612: PetscBool getRes;
5614: PetscCall(KSPGetPC(ksp, &pc));
5615: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5616: if (!getRes) {
5617: KSPNormType normtype;
5619: PetscCall(KSPGetNormType(ksp, &normtype));
5620: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5621: }
5622: PetscCall(KSPGetPCSide(ksp, &pcside));
5623: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5624: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5625: } else {
5626: /* KSP residual is preconditioned residual */
5627: /* compute true linear residual norm */
5628: Mat J;
5629: PetscCall(KSPGetOperators(ksp, &J, NULL));
5630: PetscCall(VecDuplicate(b, &lres));
5631: PetscCall(MatMult(J, x, lres));
5632: PetscCall(VecAYPX(lres, -1.0, b));
5633: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5634: PetscCall(VecDestroy(&lres));
5635: }
5636: }
5637: PetscFunctionReturn(PETSC_SUCCESS);
5638: }
5640: /*@
5641: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5643: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5645: Input Parameter:
5646: . snes - the `SNES` context
5648: Output Parameter:
5649: . ksp - the `KSP` context
5651: Level: beginner
5653: Notes:
5654: The user can then directly manipulate the `KSP` context to set various
5655: options, etc. Likewise, the user can then extract and manipulate the
5656: `PC` contexts as well.
5658: Some `SNESType`s do not use a `KSP` but a `KSP` is still returned by this function, changes to that `KSP` will have no effect.
5660: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5661: @*/
5662: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5663: {
5664: PetscFunctionBegin;
5666: PetscAssertPointer(ksp, 2);
5668: if (!snes->ksp) {
5669: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5670: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5672: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5673: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5675: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5676: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5677: }
5678: *ksp = snes->ksp;
5679: PetscFunctionReturn(PETSC_SUCCESS);
5680: }
5682: #include <petsc/private/dmimpl.h>
5683: /*@
5684: SNESSetDM - Sets the `DM` that may be used by some `SNES` nonlinear solvers or their underlying preconditioners
5686: Logically Collective
5688: Input Parameters:
5689: + snes - the nonlinear solver context
5690: - dm - the `DM`, cannot be `NULL`
5692: Level: intermediate
5694: Note:
5695: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5696: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5697: problems using the same function space.
5699: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5700: @*/
5701: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5702: {
5703: KSP ksp;
5704: DMSNES sdm;
5706: PetscFunctionBegin;
5709: PetscCall(PetscObjectReference((PetscObject)dm));
5710: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5711: if (snes->dm->dmsnes && !dm->dmsnes) {
5712: PetscCall(DMCopyDMSNES(snes->dm, dm));
5713: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5714: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5715: }
5716: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5717: PetscCall(DMDestroy(&snes->dm));
5718: }
5719: snes->dm = dm;
5720: snes->dmAuto = PETSC_FALSE;
5722: PetscCall(SNESGetKSP(snes, &ksp));
5723: PetscCall(KSPSetDM(ksp, dm));
5724: PetscCall(KSPSetDMActive(ksp, KSP_DMACTIVE_ALL, PETSC_FALSE));
5725: if (snes->npc) {
5726: PetscCall(SNESSetDM(snes->npc, snes->dm));
5727: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5728: }
5729: PetscFunctionReturn(PETSC_SUCCESS);
5730: }
5732: /*@
5733: SNESGetDM - Gets the `DM` that may be used by some `SNES` nonlinear solvers/preconditioners
5735: Not Collective but `dm` obtained is parallel on `snes`
5737: Input Parameter:
5738: . snes - the `SNES` context
5740: Output Parameter:
5741: . dm - the `DM`
5743: Level: intermediate
5745: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5746: @*/
5747: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5748: {
5749: PetscFunctionBegin;
5751: if (!snes->dm) {
5752: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5753: snes->dmAuto = PETSC_TRUE;
5754: }
5755: *dm = snes->dm;
5756: PetscFunctionReturn(PETSC_SUCCESS);
5757: }
5759: /*@
5760: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5762: Collective
5764: Input Parameters:
5765: + snes - iterative context obtained from `SNESCreate()`
5766: - npc - the `SNES` nonlinear preconditioner object
5768: Options Database Key:
5769: . -npc_snes_type type - set the type of the `SNES` to use as the nonlinear preconditioner
5771: Level: developer
5773: Notes:
5774: This is rarely used, rather use `SNESGetNPC()` to retrieve the preconditioner and configure it using the API.
5776: Only some `SNESType` can use a nonlinear preconditioner
5778: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5779: @*/
5780: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5781: {
5782: PetscFunctionBegin;
5785: PetscCheckSameComm(snes, 1, npc, 2);
5786: PetscCall(PetscObjectReference((PetscObject)npc));
5787: PetscCall(SNESDestroy(&snes->npc));
5788: snes->npc = npc;
5789: PetscFunctionReturn(PETSC_SUCCESS);
5790: }
5792: /*@
5793: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5795: Not Collective; but any changes to the obtained the `pc` object must be applied collectively
5797: Input Parameter:
5798: . snes - iterative context obtained from `SNESCreate()`
5800: Output Parameter:
5801: . pc - the `SNES` preconditioner context
5803: Options Database Key:
5804: . -npc_snes_type type - set the type of the `SNES` to use as the nonlinear preconditioner
5806: Level: advanced
5808: Notes:
5809: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created that will
5810: be used as the nonlinear preconditioner for the current `SNES`.
5812: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5813: `SNES`. These may be overwritten if needed.
5815: Use the options database prefixes `-npc_snes`, `-npc_ksp`, etc., to control the configuration of the nonlinear preconditioner
5817: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5818: @*/
5819: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5820: {
5821: const char *optionsprefix;
5823: PetscFunctionBegin;
5825: PetscAssertPointer(pc, 2);
5826: if (!snes->npc) {
5827: PetscCtx ctx;
5829: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5830: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5831: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5832: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5833: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5834: if (snes->ops->ctxcompute) {
5835: PetscCall(SNESSetComputeApplicationContext(snes, snes->ops->ctxcompute, snes->ops->ctxdestroy));
5836: } else {
5837: PetscCall(SNESGetApplicationContext(snes, &ctx));
5838: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5839: }
5840: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5841: }
5842: *pc = snes->npc;
5843: PetscFunctionReturn(PETSC_SUCCESS);
5844: }
5846: /*@
5847: SNESHasNPC - Returns whether a nonlinear preconditioner is associated with the given `SNES`
5849: Not Collective
5851: Input Parameter:
5852: . snes - iterative context obtained from `SNESCreate()`
5854: Output Parameter:
5855: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5857: Level: developer
5859: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5860: @*/
5861: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5862: {
5863: PetscFunctionBegin;
5865: PetscAssertPointer(has_npc, 2);
5866: *has_npc = snes->npc ? PETSC_TRUE : PETSC_FALSE;
5867: PetscFunctionReturn(PETSC_SUCCESS);
5868: }
5870: /*@
5871: SNESSetNPCSide - Sets the nonlinear preconditioning side used by the nonlinear preconditioner inside `SNES`.
5873: Logically Collective
5875: Input Parameter:
5876: . snes - iterative context obtained from `SNESCreate()`
5878: Output Parameter:
5879: . side - the preconditioning side, where side is one of
5880: .vb
5881: PC_LEFT - left preconditioning
5882: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5883: .ve
5885: Options Database Key:
5886: . -snes_npc_side (right|left) - nonlinear preconditioner side
5888: Level: intermediate
5890: Note:
5891: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5893: .seealso: [](ch_snes), `SNES`, `SNESGetNPC()`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5894: @*/
5895: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5896: {
5897: PetscFunctionBegin;
5900: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5901: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5902: snes->npcside = side;
5903: PetscFunctionReturn(PETSC_SUCCESS);
5904: }
5906: /*@
5907: SNESGetNPCSide - Gets the preconditioning side used by the nonlinear preconditioner inside `SNES`.
5909: Not Collective
5911: Input Parameter:
5912: . snes - iterative context obtained from `SNESCreate()`
5914: Output Parameter:
5915: . side - the preconditioning side, where side is one of
5916: .vb
5917: `PC_LEFT` - left preconditioning
5918: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5919: .ve
5921: Level: intermediate
5923: .seealso: [](ch_snes), `SNES`, `SNESGetNPC()`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5924: @*/
5925: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5926: {
5927: PetscFunctionBegin;
5929: PetscAssertPointer(side, 2);
5930: *side = snes->npcside;
5931: PetscFunctionReturn(PETSC_SUCCESS);
5932: }
5934: /*@
5935: SNESSetLineSearch - Sets the `SNESLineSearch` to be used for a given `SNES`
5937: Collective
5939: Input Parameters:
5940: + snes - iterative context obtained from `SNESCreate()`
5941: - linesearch - the linesearch object
5943: Level: developer
5945: Note:
5946: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
5947: to configure it using the API).
5949: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
5950: @*/
5951: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5952: {
5953: PetscFunctionBegin;
5956: PetscCheckSameComm(snes, 1, linesearch, 2);
5957: PetscCall(PetscObjectReference((PetscObject)linesearch));
5958: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5960: snes->linesearch = linesearch;
5961: PetscFunctionReturn(PETSC_SUCCESS);
5962: }