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 PetscDefined(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: Vec u;
391: SNESLineSearch linesearch;
392: PetscBool isascii, isstring, isbinary, isdraw;
393: DMSNES dmsnes;
394: #if PetscDefined(HAVE_SAWS)
395: PetscBool issaws;
396: #endif
398: PetscFunctionBegin;
400: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &viewer));
402: PetscCheckSameComm(snes, 1, viewer, 2);
404: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
405: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
406: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
407: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
408: #if PetscDefined(HAVE_SAWS)
409: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
410: #endif
411: if (isascii) {
412: SNESNormSchedule normschedule;
413: DM dm;
414: SNESJacobianFn *cJ;
415: void *ctx;
416: const char *pre = "";
418: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)snes, viewer));
419: if (!snes->setupcalled) PetscCall(PetscViewerASCIIPrintf(viewer, " SNES has not been set up so information may be incomplete\n"));
420: if (snes->ops->view) {
421: PetscCall(PetscViewerASCIIPushTab(viewer));
422: PetscUseTypeMethod(snes, view, viewer);
423: PetscCall(PetscViewerASCIIPopTab(viewer));
424: }
425: if (snes->max_funcs == PETSC_UNLIMITED) {
426: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=unlimited\n", snes->max_its));
427: } else {
428: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=%" PetscInt_FMT "\n", snes->max_its, snes->max_funcs));
429: }
430: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, solution=%g\n", (double)snes->rtol, (double)snes->abstol, (double)snes->stol));
431: if (snes->usesksp) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of linear solver iterations=%" PetscInt_FMT "\n", snes->linear_its));
432: PetscCall(PetscViewerASCIIPrintf(viewer, " total number of function evaluations=%" PetscInt_FMT "\n", snes->nfuncs));
433: PetscCall(SNESGetNormSchedule(snes, &normschedule));
434: if (normschedule > 0) PetscCall(PetscViewerASCIIPrintf(viewer, " norm schedule %s\n", SNESNormSchedules[normschedule]));
435: if (snes->gridsequence) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of grid sequence refinements=%" PetscInt_FMT "\n", snes->gridsequence));
436: if (snes->ksp_ewconv) {
437: kctx = (SNESKSPEW *)snes->kspconvctx;
438: if (kctx) {
439: PetscCall(PetscViewerASCIIPrintf(viewer, " Eisenstat-Walker computation of KSP relative tolerance (version %" PetscInt_FMT ")\n", kctx->version));
440: PetscCall(PetscViewerASCIIPrintf(viewer, " rtol_0=%g, rtol_max=%g, threshold=%g\n", (double)kctx->rtol_0, (double)kctx->rtol_max, (double)kctx->threshold));
441: PetscCall(PetscViewerASCIIPrintf(viewer, " gamma=%g, alpha=%g, alpha2=%g\n", (double)kctx->gamma, (double)kctx->alpha, (double)kctx->alpha2));
442: }
443: }
444: if (snes->lagpreconditioner == -1) {
445: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is never rebuilt\n"));
446: } else if (snes->lagpreconditioner > 1) {
447: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is rebuilt every %" PetscInt_FMT " new Jacobians\n", snes->lagpreconditioner));
448: }
449: if (snes->lagjacobian == -1) {
450: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is never rebuilt\n"));
451: } else if (snes->lagjacobian > 1) {
452: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is rebuilt every %" PetscInt_FMT " SNES iterations\n", snes->lagjacobian));
453: }
454: PetscCall(SNESGetDM(snes, &dm));
455: PetscCall(DMSNESGetJacobian(dm, &cJ, &ctx));
456: if (snes->mf_operator) {
457: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing\n"));
458: pre = "Preconditioning ";
459: }
460: if (cJ == SNESComputeJacobianDefault) {
461: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences one column at a time\n", pre));
462: } else if (cJ == SNESComputeJacobianDefaultColor) {
463: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences with coloring\n", pre));
464: /* it slightly breaks data encapsulation for access the DMDA information directly */
465: } else if (cJ == SNESComputeJacobian_DMDA) {
466: MatFDColoring fdcoloring;
467: PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
468: if (fdcoloring) {
469: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using colored finite differences on a DMDA\n", pre));
470: } else {
471: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using a DMDA local Jacobian\n", pre));
472: }
473: } else if (snes->mf && !snes->mf_operator) {
474: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing, no explicit Jacobian\n"));
475: }
476: } else if (isstring) {
477: const char *type;
478: PetscCall(SNESGetType(snes, &type));
479: PetscCall(PetscViewerStringSPrintf(viewer, " SNESType: %-7.7s", type));
480: PetscTryTypeMethod(snes, view, viewer);
481: } else if (isbinary) {
482: PetscInt classid = SNES_FILE_CLASSID;
483: MPI_Comm comm;
484: PetscMPIInt rank;
485: char type[256];
487: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
488: PetscCallMPI(MPI_Comm_rank(comm, &rank));
489: if (rank == 0) {
490: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
491: PetscCall(PetscStrncpy(type, ((PetscObject)snes)->type_name, sizeof(type)));
492: PetscCall(PetscViewerBinaryWrite(viewer, type, sizeof(type), PETSC_CHAR));
493: }
494: PetscTryTypeMethod(snes, view, viewer);
495: } else if (isdraw) {
496: PetscDraw draw;
497: char str[36];
498: PetscReal x, y, bottom, h;
500: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
501: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
502: PetscCall(PetscStrncpy(str, "SNES: ", sizeof(str)));
503: PetscCall(PetscStrlcat(str, ((PetscObject)snes)->type_name, sizeof(str)));
504: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_BLUE, PETSC_DRAW_BLACK, str, NULL, &h));
505: bottom = y - h;
506: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
507: PetscTryTypeMethod(snes, view, viewer);
508: #if PetscDefined(HAVE_SAWS)
509: } else if (issaws) {
510: PetscMPIInt rank;
511: const char *name;
513: PetscCall(PetscObjectGetName((PetscObject)snes, &name));
514: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
515: if (!((PetscObject)snes)->amsmem && rank == 0) {
516: char dir[1024];
518: PetscCall(PetscObjectViewSAWs((PetscObject)snes, viewer));
519: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
520: PetscCallSAWs(SAWs_Register, (dir, &snes->iter, 1, SAWs_READ, SAWs_INT));
521: if (!snes->conv_hist) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, PETSC_DECIDE, PETSC_TRUE));
522: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/conv_hist", name));
523: PetscCallSAWs(SAWs_Register, (dir, snes->conv_hist, 10, SAWs_READ, SAWs_DOUBLE));
524: }
525: #endif
526: }
527: if (snes->linesearch) {
528: PetscCall(SNESGetLineSearch(snes, &linesearch));
529: PetscCall(PetscViewerASCIIPushTab(viewer));
530: PetscCall(SNESLineSearchView(linesearch, viewer));
531: PetscCall(PetscViewerASCIIPopTab(viewer));
532: }
533: if (snes->npc && snes->usesnpc) {
534: PetscCall(PetscViewerASCIIPushTab(viewer));
535: PetscCall(SNESView(snes->npc, viewer));
536: PetscCall(PetscViewerASCIIPopTab(viewer));
537: }
538: PetscCall(PetscViewerASCIIPushTab(viewer));
539: PetscCall(DMGetDMSNES(snes->dm, &dmsnes));
540: PetscCall(DMSNESView(dmsnes, viewer));
541: PetscCall(PetscViewerASCIIPopTab(viewer));
542: if (snes->usesksp) {
543: PetscCall(SNESGetKSP(snes, &ksp));
544: PetscCall(PetscViewerASCIIPushTab(viewer));
545: PetscCall(KSPView(ksp, viewer));
546: PetscCall(PetscViewerASCIIPopTab(viewer));
547: } else {
548: PetscViewerFormat format;
550: PetscCall(SNESGetSolution(snes, &u));
551: PetscCall(PetscViewerGetFormat(viewer, &format));
552: if (u && isascii) {
553: if (format != PETSC_VIEWER_ASCII_INFO_DETAIL) PetscCall(PetscViewerPushFormat(viewer, PETSC_VIEWER_ASCII_INFO));
554: PetscCall(PetscViewerASCIIPrintf(viewer, "solution vector:\n"));
555: PetscCall(PetscViewerASCIIPushTab(viewer));
556: PetscCall(VecView(u, viewer));
557: PetscCall(PetscViewerASCIIPopTab(viewer));
558: if (format != PETSC_VIEWER_ASCII_INFO_DETAIL) PetscCall(PetscViewerPopFormat(viewer));
559: }
560: }
561: if (isdraw) {
562: PetscDraw draw;
563: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
564: PetscCall(PetscDrawPopCurrentPoint(draw));
565: }
566: PetscFunctionReturn(PETSC_SUCCESS);
567: }
569: /*
570: We retain a list of functions that also take SNES command
571: line options. These are called at the end SNESSetFromOptions()
572: */
573: #define MAXSETFROMOPTIONS 5
574: static PetscInt numberofsetfromoptions;
575: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
577: /*@C
578: SNESAddOptionsChecker - Adds an additional function to check for `SNES` options.
580: Not Collective
582: Input Parameter:
583: . snescheck - function that checks for options
585: Calling sequence of `snescheck`:
586: . snes - the `SNES` object for which it is checking options
588: Level: developer
590: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`
591: @*/
592: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES snes))
593: {
594: PetscFunctionBegin;
595: PetscCheck(numberofsetfromoptions < MAXSETFROMOPTIONS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %d allowed", MAXSETFROMOPTIONS);
596: othersetfromoptions[numberofsetfromoptions++] = snescheck;
597: PetscFunctionReturn(PETSC_SUCCESS);
598: }
600: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
601: {
602: Mat J;
603: MatNullSpace nullsp;
605: PetscFunctionBegin;
608: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
609: Mat A = snes->jacobian, B = snes->jacobian_pre;
610: PetscCall(MatCreateVecs(A ? A : B, NULL, &snes->vec_func));
611: }
613: PetscCheck(version == 1 || version == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator routines, only version 1 and 2");
614: if (version == 1) {
615: PetscCall(MatCreateSNESMF(snes, &J));
616: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
617: PetscCall(MatSetFromOptions(J));
618: /* TODO: the version 2 code should be merged into the MatCreateSNESMF() and MatCreateMFFD() infrastructure and then removed */
619: } else /* if (version == 2) */ {
620: PetscCheck(snes->vec_func, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "SNESSetFunction() must be called first");
621: #if !PetscDefined(USE_COMPLEX) && !PetscDefined(USE_REAL_SINGLE) && !PetscDefined(USE_REAL___FLOAT128) && !PetscDefined(USE_REAL___FP16)
622: PetscCall(MatCreateSNESMFMore(snes, snes->vec_func, &J));
623: #else
624: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "matrix-free operator routines (version 2)");
625: #endif
626: }
628: /* attach any user provided null space that was on Amat to the newly created matrix-free matrix */
629: if (snes->jacobian) {
630: PetscCall(MatGetNullSpace(snes->jacobian, &nullsp));
631: if (nullsp) PetscCall(MatSetNullSpace(J, nullsp));
632: }
634: PetscCall(PetscInfo(snes, "Setting default matrix-free operator routines (version %" PetscInt_FMT ")\n", version));
635: if (hasOperator) {
636: /* This version replaces the user provided Jacobian matrix with a
637: matrix-free version but still employs the user-provided matrix used for computing the preconditioner. */
638: PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
639: } else {
640: /* This version replaces both the user-provided Jacobian and the user-
641: provided preconditioner Jacobian with the default matrix-free version. */
642: if (snes->npcside == PC_LEFT && snes->npc) {
643: if (!snes->jacobian) PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
644: } else {
645: KSP ksp;
646: PC pc;
647: PetscBool match;
649: PetscCall(SNESSetJacobian(snes, J, J, MatMFFDComputeJacobian, NULL));
650: /* Force no preconditioner */
651: PetscCall(SNESGetKSP(snes, &ksp));
652: PetscCall(KSPGetPC(ksp, &pc));
653: PetscCall(PetscObjectTypeCompareAny((PetscObject)pc, &match, PCSHELL, PCH2OPUS, ""));
654: if (!match) {
655: PetscCall(PetscInfo(snes, "Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n"));
656: PetscCall(PCSetType(pc, PCNONE));
657: }
658: }
659: }
660: PetscCall(MatDestroy(&J));
661: PetscFunctionReturn(PETSC_SUCCESS);
662: }
664: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine, Mat Restrict, Vec Rscale, Mat Inject, DM dmcoarse, PetscCtx ctx)
665: {
666: SNES snes = (SNES)ctx;
667: Vec Xfine, Xfine_named = NULL, Xcoarse;
669: PetscFunctionBegin;
670: if (PetscLogPrintInfo) {
671: PetscInt finelevel, coarselevel, fineclevel, coarseclevel;
672: PetscCall(DMGetRefineLevel(dmfine, &finelevel));
673: PetscCall(DMGetCoarsenLevel(dmfine, &fineclevel));
674: PetscCall(DMGetRefineLevel(dmcoarse, &coarselevel));
675: PetscCall(DMGetCoarsenLevel(dmcoarse, &coarseclevel));
676: PetscCall(PetscInfo(dmfine, "Restricting SNES solution vector from level %" PetscInt_FMT "-%" PetscInt_FMT " to level %" PetscInt_FMT "-%" PetscInt_FMT "\n", finelevel, fineclevel, coarselevel, coarseclevel));
677: }
678: if (dmfine == snes->dm) Xfine = snes->vec_sol;
679: else {
680: PetscCall(DMGetNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
681: Xfine = Xfine_named;
682: }
683: PetscCall(DMGetNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
684: if (Inject) {
685: PetscCall(MatRestrict(Inject, Xfine, Xcoarse));
686: } else {
687: PetscCall(MatRestrict(Restrict, Xfine, Xcoarse));
688: PetscCall(VecPointwiseMult(Xcoarse, Xcoarse, Rscale));
689: }
690: PetscCall(DMRestoreNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
691: if (Xfine_named) PetscCall(DMRestoreNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
692: PetscFunctionReturn(PETSC_SUCCESS);
693: }
695: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm, DM dmc, PetscCtx ctx)
696: {
697: PetscFunctionBegin;
698: PetscCall(DMCoarsenHookAdd(dmc, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, ctx));
699: PetscFunctionReturn(PETSC_SUCCESS);
700: }
702: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
703: * safely call SNESGetDM() in their residual evaluation routine. */
704: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp, Mat A, Mat B, PetscCtx ctx)
705: {
706: SNES snes = (SNES)ctx;
707: DMSNES sdm;
708: Vec X, Xnamed = NULL;
709: DM dmsave;
710: void *ctxsave;
711: SNESJacobianFn *jac = NULL;
713: PetscFunctionBegin;
714: dmsave = snes->dm;
715: PetscCall(KSPGetDM(ksp, &snes->dm));
716: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
717: else {
718: PetscBool has;
720: /* We are on a coarser level, this vec was initialized using a DM restrict hook */
721: PetscCall(DMHasNamedGlobalVector(snes->dm, "SNESVecSol", &has));
722: PetscCheck(has, PetscObjectComm((PetscObject)snes->dm), PETSC_ERR_PLIB, "Missing SNESVecSol");
723: PetscCall(DMGetNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
724: X = Xnamed;
725: PetscCall(SNESGetJacobian(snes, NULL, NULL, &jac, &ctxsave));
726: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
727: if (jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, SNESComputeJacobianDefaultColor, NULL));
728: }
730: /* Compute the operators */
731: PetscCall(DMGetDMSNES(snes->dm, &sdm));
732: if (Xnamed && sdm->ops->computefunction) {
733: /* The SNES contract with the user is that ComputeFunction is always called before ComputeJacobian.
734: We make sure of this here. Disable affine shift since it is for the finest level */
735: Vec F, saverhs = snes->vec_rhs;
737: snes->vec_rhs = NULL;
738: PetscCall(DMGetGlobalVector(snes->dm, &F));
739: PetscCall(SNESComputeFunction(snes, X, F));
740: PetscCall(DMRestoreGlobalVector(snes->dm, &F));
741: snes->vec_rhs = saverhs;
742: snes->nfuncs--; /* Do not log coarser level evaluations */
743: }
744: /* Make sure KSP DM has the Jacobian computation routine */
745: if (!sdm->ops->computejacobian) PetscCall(DMCopyDMSNES(dmsave, snes->dm));
746: PetscCall(SNESComputeJacobian(snes, X, A, B)); /* cannot handle previous SNESSetJacobianDomainError() calls */
748: /* Put the previous context back */
749: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, jac, ctxsave));
751: if (Xnamed) PetscCall(DMRestoreNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
752: snes->dm = dmsave;
753: PetscFunctionReturn(PETSC_SUCCESS);
754: }
756: /*@
757: SNESSetUpMatrices - ensures that matrices are available for `SNES` Newton-like methods, this is called by `SNESSetUp_XXX()`
759: Collective
761: Input Parameter:
762: . snes - `SNES` object to configure
764: Level: developer
766: Note:
767: If the matrices do not yet exist it attempts to create them based on options previously set for the `SNES` such as `-snes_mf`
769: Developer Note:
770: The functionality of this routine overlaps in a confusing way with the functionality of `SNESSetUpMatrixFree_Private()` which is called by
771: `SNESSetUp()` but sometimes `SNESSetUpMatrices()` is called without `SNESSetUp()` being called. A refactorization to simplify the
772: logic that handles the matrix-free case is desirable.
774: .seealso: [](ch_snes), `SNES`, `SNESSetUp()`
775: @*/
776: PetscErrorCode SNESSetUpMatrices(SNES snes)
777: {
778: DM dm;
779: DMSNES sdm;
781: PetscFunctionBegin;
782: PetscCall(SNESGetDM(snes, &dm));
783: PetscCall(DMGetDMSNES(dm, &sdm));
784: if (!snes->jacobian && snes->mf && !snes->mf_operator && !snes->jacobian_pre) {
785: Mat J;
786: void *functx;
787: PetscCall(MatCreateSNESMF(snes, &J));
788: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
789: PetscCall(MatSetFromOptions(J));
790: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
791: PetscCall(SNESSetJacobian(snes, J, J, NULL, NULL));
792: PetscCall(MatDestroy(&J));
793: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
794: Mat J, B;
795: PetscCall(MatCreateSNESMF(snes, &J));
796: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
797: PetscCall(MatSetFromOptions(J));
798: PetscCall(DMCreateMatrix(snes->dm, &B));
799: /* sdm->computejacobian was already set to reach here */
800: PetscCall(SNESSetJacobian(snes, J, B, NULL, NULL));
801: PetscCall(MatDestroy(&J));
802: PetscCall(MatDestroy(&B));
803: } else if (!snes->jacobian_pre) {
804: PetscDS prob;
805: Mat J, B;
806: PetscBool hasPrec = PETSC_FALSE;
808: J = snes->jacobian;
809: PetscCall(DMGetDS(dm, &prob));
810: if (prob) PetscCall(PetscDSHasJacobianPreconditioner(prob, &hasPrec));
811: if (!J && hasPrec) PetscCall(DMCreateMatrix(snes->dm, &J));
812: else PetscCall(PetscObjectReference((PetscObject)J));
813: PetscCall(DMCreateMatrix(snes->dm, &B));
814: PetscCall(SNESSetJacobian(snes, J ? J : B, B, NULL, NULL));
815: PetscCall(MatDestroy(&J));
816: PetscCall(MatDestroy(&B));
817: }
818: {
819: KSP ksp;
820: PetscCall(SNESGetKSP(snes, &ksp));
821: PetscCall(KSPSetComputeOperators(ksp, KSPComputeOperators_SNES, snes));
822: PetscCall(DMCoarsenHookAdd(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
823: }
824: PetscFunctionReturn(PETSC_SUCCESS);
825: }
827: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode PetscMonitorPauseFinal_Internal(PetscInt, PetscCtx);
829: static PetscErrorCode SNESMonitorPauseFinal_Internal(SNES snes)
830: {
831: PetscFunctionBegin;
832: if (!snes->pauseFinal) PetscFunctionReturn(PETSC_SUCCESS);
833: PetscCall(PetscMonitorPauseFinal_Internal(snes->numbermonitors, snes->monitorcontext));
834: PetscFunctionReturn(PETSC_SUCCESS);
835: }
837: /*@C
838: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
840: Collective
842: Input Parameters:
843: + snes - `SNES` object you wish to monitor
844: . name - the monitor type one is seeking
845: . help - message indicating what monitoring is done
846: . manual - manual page for the monitor
847: . monitor - the monitor function, this must use a `PetscViewerFormat` as its context
848: - 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
850: Calling sequence of `monitor`:
851: + snes - the nonlinear solver context
852: . it - the current iteration
853: . r - the current function norm
854: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
856: Calling sequence of `monitorsetup`:
857: + snes - the nonlinear solver context
858: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
860: Options Database Key:
861: . -name - trigger the use of this monitor in `SNESSetFromOptions()`
863: Level: advanced
865: .seealso: [](ch_snes), `PetscOptionsCreateViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
866: `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`,
867: `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
868: `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
869: `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
870: `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
871: `PetscOptionsFList()`, `PetscOptionsEList()`
872: @*/
873: 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))
874: {
875: PetscViewer viewer;
876: PetscViewerFormat format;
877: PetscBool flg;
879: PetscFunctionBegin;
880: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, name, &viewer, &format, &flg));
881: if (flg) {
882: PetscViewerAndFormat *vf;
883: PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
884: PetscCall(PetscViewerDestroy(&viewer));
885: if (monitorsetup) PetscCall((*monitorsetup)(snes, vf));
886: PetscCall(SNESMonitorSet(snes, (PetscErrorCode (*)(SNES, PetscInt, PetscReal, PetscCtx))monitor, vf, (PetscCtxDestroyFn *)PetscViewerAndFormatDestroy));
887: }
888: PetscFunctionReturn(PETSC_SUCCESS);
889: }
891: PetscErrorCode SNESEWSetFromOptions_Private(SNESKSPEW *kctx, PetscBool print_api, MPI_Comm comm, const char *prefix)
892: {
893: const char *api = print_api ? "SNESKSPSetParametersEW" : NULL;
895: PetscFunctionBegin;
896: PetscOptionsBegin(comm, prefix, "Eisenstat and Walker type forcing options", "KSP");
897: PetscCall(PetscOptionsInt("-ksp_ew_version", "Version 1, 2 or 3", api, kctx->version, &kctx->version, NULL));
898: PetscCall(PetscOptionsReal("-ksp_ew_rtol0", "0 <= rtol0 < 1", api, kctx->rtol_0, &kctx->rtol_0, NULL));
899: kctx->rtol_max = PetscMax(kctx->rtol_0, kctx->rtol_max);
900: PetscCall(PetscOptionsReal("-ksp_ew_rtolmax", "0 <= rtolmax < 1", api, kctx->rtol_max, &kctx->rtol_max, NULL));
901: PetscCall(PetscOptionsReal("-ksp_ew_gamma", "0 <= gamma <= 1", api, kctx->gamma, &kctx->gamma, NULL));
902: PetscCall(PetscOptionsReal("-ksp_ew_alpha", "1 < alpha <= 2", api, kctx->alpha, &kctx->alpha, NULL));
903: PetscCall(PetscOptionsReal("-ksp_ew_alpha2", "alpha2", NULL, kctx->alpha2, &kctx->alpha2, NULL));
904: PetscCall(PetscOptionsReal("-ksp_ew_threshold", "0 < threshold < 1", api, kctx->threshold, &kctx->threshold, NULL));
905: PetscCall(PetscOptionsReal("-ksp_ew_v4_p1", "p1", NULL, kctx->v4_p1, &kctx->v4_p1, NULL));
906: PetscCall(PetscOptionsReal("-ksp_ew_v4_p2", "p2", NULL, kctx->v4_p2, &kctx->v4_p2, NULL));
907: PetscCall(PetscOptionsReal("-ksp_ew_v4_p3", "p3", NULL, kctx->v4_p3, &kctx->v4_p3, NULL));
908: PetscCall(PetscOptionsReal("-ksp_ew_v4_m1", "Scaling when rk-1 in [p2,p3)", NULL, kctx->v4_m1, &kctx->v4_m1, NULL));
909: PetscCall(PetscOptionsReal("-ksp_ew_v4_m2", "Scaling when rk-1 in [p3,+infty)", NULL, kctx->v4_m2, &kctx->v4_m2, NULL));
910: PetscCall(PetscOptionsReal("-ksp_ew_v4_m3", "Threshold for successive rtol (0.1 in Eq.7)", NULL, kctx->v4_m3, &kctx->v4_m3, NULL));
911: PetscCall(PetscOptionsReal("-ksp_ew_v4_m4", "Adaptation scaling (0.5 in Eq.7)", NULL, kctx->v4_m4, &kctx->v4_m4, NULL));
912: PetscOptionsEnd();
913: PetscFunctionReturn(PETSC_SUCCESS);
914: }
916: /*@
917: SNESSetFromOptions - Sets various `SNES` and `KSP` parameters from user options.
919: Collective
921: Input Parameter:
922: . snes - the `SNES` context
924: Options Database Keys:
925: + -snes_type type - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, `SNESType` for complete list
926: . -snes_rtol rtol - relative decrease in tolerance norm from initial
927: . -snes_atol abstol - absolute tolerance of residual norm
928: . -snes_stol stol - convergence tolerance in terms of the norm of the change in the solution between steps
929: . -snes_divergence_tolerance divtol - if the residual goes above divtol*rnorm0, exit with divergence
930: . -snes_max_it max_it - maximum number of iterations
931: . -snes_max_funcs max_funcs - maximum number of function evaluations
932: . -snes_force_iteration force - force `SNESSolve()` to take at least one iteration
933: . -snes_max_fail max_fail - maximum number of line search failures allowed before stopping, default is none
934: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
935: . -snes_lag_preconditioner lag - how often preconditioner is rebuilt (use -1 to never rebuild)
936: . -snes_lag_preconditioner_persists (true|false) - retains the -snes_lag_preconditioner information across multiple SNESSolve()
937: . -snes_lag_jacobian lag - how often Jacobian is rebuilt (use -1 to never rebuild)
938: . -snes_lag_jacobian_persists (true|false) - retains the -snes_lag_jacobian information across multiple SNESSolve()
939: . -snes_convergence_test (default|skip|correct_pressure) - convergence test in nonlinear solver. default `SNESConvergedDefault()`. skip `SNESConvergedSkip()` means continue
940: iterating until max_it or some other criterion is reached, saving expense of convergence test. correct_pressure
941: `SNESConvergedCorrectPressure()` has special handling of a pressure null space.
942: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
943: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
944: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
945: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
946: . -snes_monitor draw::draw_lg - plots residual norm at each iteration
947: . -snes_monitor_lg_range - plots function range at each iteration
948: . -snes_monitor_pause_final - Pauses all monitor drawing after the solver ends
949: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
950: . -snes_fd_color - use finite differences with coloring to compute Jacobian
951: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each `KSP` iteration
952: . -snes_converged_reason - print the reason for convergence/divergence after each solve
953: . -npc_snes_type type - the `SNES` type to use as a nonlinear preconditioner
954: . -snes_test_jacobian [threshold] - compare the user provided Jacobian with one computed via finite differences to check for errors.
955: If a threshold is given, display only those entries whose difference is greater than the threshold.
956: - -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference between them
957: to help users detect the location of errors in the user provided Jacobian.
959: Options Database Keys for Eisenstat-Walker method:
960: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
961: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
962: . -snes_ksp_ew_rtol0 rtol0 - Sets rtol0
963: . -snes_ksp_ew_rtolmax rtolmax - Sets rtolmax
964: . -snes_ksp_ew_gamma gamma - Sets gamma
965: . -snes_ksp_ew_alpha alpha - Sets alpha
966: . -snes_ksp_ew_alpha2 alpha2 - Sets alpha2
967: - -snes_ksp_ew_threshold threshold - Sets threshold
969: Level: beginner
971: Notes:
972: To see all options, run your program with the -help option or consult the users manual
974: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
975: and computing explicitly with
976: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
978: .seealso: [](ch_snes), `SNESType`, `SNESSetOptionsPrefix()`, `SNESResetFromOptions()`, `SNES`, `SNESCreate()`, `MatCreateSNESMF()`, `MatFDColoring`
979: @*/
980: PetscErrorCode SNESSetFromOptions(SNES snes)
981: {
982: PetscBool flg, pcset, persist, set;
983: PetscInt i, indx, lag, grids, max_its, max_funcs;
984: const char *deft = SNESNEWTONLS;
985: const char *convtests[] = {"default", "skip", "correct_pressure"};
986: SNESKSPEW *kctx = NULL;
987: char type[256], monfilename[PETSC_MAX_PATH_LEN], ewprefix[256];
988: PCSide pcside;
989: const char *optionsprefix;
990: PetscReal rtol, abstol, stol;
992: PetscFunctionBegin;
994: PetscCall(SNESRegisterAll());
995: PetscObjectOptionsBegin((PetscObject)snes);
996: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
997: PetscCall(PetscOptionsFList("-snes_type", "Nonlinear solver method", "SNESSetType", SNESList, deft, type, 256, &flg));
998: if (flg) PetscCall(SNESSetType(snes, type));
999: else if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, deft));
1001: abstol = snes->abstol;
1002: rtol = snes->rtol;
1003: stol = snes->stol;
1004: max_its = snes->max_its;
1005: max_funcs = snes->max_funcs;
1006: PetscCall(PetscOptionsReal("-snes_rtol", "Stop if decrease in function norm less than", "SNESSetTolerances", snes->rtol, &rtol, NULL));
1007: PetscCall(PetscOptionsReal("-snes_atol", "Stop if function norm less than", "SNESSetTolerances", snes->abstol, &abstol, NULL));
1008: PetscCall(PetscOptionsReal("-snes_stol", "Stop if step length less than", "SNESSetTolerances", snes->stol, &stol, NULL));
1009: PetscCall(PetscOptionsInt("-snes_max_it", "Maximum iterations", "SNESSetTolerances", snes->max_its, &max_its, NULL));
1010: PetscCall(PetscOptionsInt("-snes_max_funcs", "Maximum function evaluations", "SNESSetTolerances", snes->max_funcs, &max_funcs, NULL));
1011: PetscCall(SNESSetTolerances(snes, abstol, rtol, stol, max_its, max_funcs));
1013: PetscCall(PetscOptionsReal("-snes_divergence_tolerance", "Stop if residual norm increases by this factor", "SNESSetDivergenceTolerance", snes->divtol, &snes->divtol, &flg));
1014: if (flg) PetscCall(SNESSetDivergenceTolerance(snes, snes->divtol));
1016: PetscCall(PetscOptionsInt("-snes_max_fail", "Maximum nonlinear step failures", "SNESSetMaxNonlinearStepFailures", snes->maxFailures, &snes->maxFailures, &flg));
1017: if (flg) PetscCall(SNESSetMaxNonlinearStepFailures(snes, snes->maxFailures));
1019: PetscCall(PetscOptionsInt("-snes_max_linear_solve_fail", "Maximum failures in linear solves allowed", "SNESSetMaxLinearSolveFailures", snes->maxLinearSolveFailures, &snes->maxLinearSolveFailures, &flg));
1020: if (flg) PetscCall(SNESSetMaxLinearSolveFailures(snes, snes->maxLinearSolveFailures));
1022: PetscCall(PetscOptionsBool("-snes_error_if_not_converged", "Generate error if solver does not converge", "SNESSetErrorIfNotConverged", snes->errorifnotconverged, &snes->errorifnotconverged, NULL));
1023: PetscCall(PetscOptionsBool("-snes_force_iteration", "Force SNESSolve() to take at least one iteration", "SNESSetForceIteration", snes->forceiteration, &snes->forceiteration, NULL));
1024: PetscCall(PetscOptionsBool("-snes_check_jacobian_domain_error", "Check Jacobian domain error after Jacobian evaluation", "SNESCheckJacobianDomainError", snes->checkjacdomainerror, &snes->checkjacdomainerror, NULL));
1026: PetscCall(PetscOptionsInt("-snes_lag_preconditioner", "How often to rebuild preconditioner", "SNESSetLagPreconditioner", snes->lagpreconditioner, &lag, &flg));
1027: if (flg) {
1028: 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");
1029: PetscCall(SNESSetLagPreconditioner(snes, lag));
1030: }
1031: PetscCall(PetscOptionsBool("-snes_lag_preconditioner_persists", "Preconditioner lagging through multiple SNES solves", "SNESSetLagPreconditionerPersists", snes->lagjac_persist, &persist, &flg));
1032: if (flg) PetscCall(SNESSetLagPreconditionerPersists(snes, persist));
1033: PetscCall(PetscOptionsInt("-snes_lag_jacobian", "How often to rebuild Jacobian", "SNESSetLagJacobian", snes->lagjacobian, &lag, &flg));
1034: if (flg) {
1035: 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");
1036: PetscCall(SNESSetLagJacobian(snes, lag));
1037: }
1038: PetscCall(PetscOptionsBool("-snes_lag_jacobian_persists", "Jacobian lagging through multiple SNES solves", "SNESSetLagJacobianPersists", snes->lagjac_persist, &persist, &flg));
1039: if (flg) PetscCall(SNESSetLagJacobianPersists(snes, persist));
1041: PetscCall(PetscOptionsInt("-snes_grid_sequence", "Use grid sequencing to generate initial guess", "SNESSetGridSequence", snes->gridsequence, &grids, &flg));
1042: if (flg) PetscCall(SNESSetGridSequence(snes, grids));
1044: PetscCall(PetscOptionsEList("-snes_convergence_test", "Convergence test", "SNESSetConvergenceTest", convtests, PETSC_STATIC_ARRAY_LENGTH(convtests), "default", &indx, &flg));
1045: if (flg) {
1046: switch (indx) {
1047: case 0:
1048: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedDefault, NULL, NULL));
1049: break;
1050: case 1:
1051: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedSkip, NULL, NULL));
1052: break;
1053: case 2:
1054: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedCorrectPressure, NULL, NULL));
1055: break;
1056: }
1057: }
1059: PetscCall(PetscOptionsEList("-snes_norm_schedule", "SNES Norm schedule", "SNESSetNormSchedule", SNESNormSchedules, 5, "function", &indx, &flg));
1060: if (flg) PetscCall(SNESSetNormSchedule(snes, (SNESNormSchedule)indx));
1062: PetscCall(PetscOptionsEList("-snes_function_type", "SNES Norm schedule", "SNESSetFunctionType", SNESFunctionTypes, 2, "unpreconditioned", &indx, &flg));
1063: if (flg) PetscCall(SNESSetFunctionType(snes, (SNESFunctionType)indx));
1065: kctx = (SNESKSPEW *)snes->kspconvctx;
1067: PetscCall(PetscOptionsBool("-snes_ksp_ew", "Use Eisentat-Walker linear system convergence test", "SNESKSPSetUseEW", snes->ksp_ewconv, &snes->ksp_ewconv, NULL));
1069: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1070: PetscCall(PetscSNPrintf(ewprefix, sizeof(ewprefix), "%s%s", optionsprefix ? optionsprefix : "", "snes_"));
1071: PetscCall(SNESEWSetFromOptions_Private(kctx, PETSC_TRUE, PetscObjectComm((PetscObject)snes), ewprefix));
1073: flg = PETSC_FALSE;
1074: PetscCall(PetscOptionsBool("-snes_monitor_cancel", "Remove all monitors", "SNESMonitorCancel", flg, &flg, &set));
1075: if (set && flg) PetscCall(SNESMonitorCancel(snes));
1077: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor", "Monitor norm of function", "SNESMonitorDefault", SNESMonitorDefault, SNESMonitorDefaultSetUp));
1078: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_short", "Monitor norm of function with fewer digits", "SNESMonitorDefaultShort", SNESMonitorDefaultShort, NULL));
1079: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_range", "Monitor range of elements of function", "SNESMonitorRange", SNESMonitorRange, NULL));
1081: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_ratio", "Monitor ratios of the norm of function for consecutive steps", "SNESMonitorRatio", SNESMonitorRatio, SNESMonitorRatioSetUp));
1082: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_field", "Monitor norm of function (split into fields)", "SNESMonitorDefaultField", SNESMonitorDefaultField, NULL));
1083: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution", "View solution at each iteration", "SNESMonitorSolution", SNESMonitorSolution, NULL));
1084: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution_update", "View correction at each iteration", "SNESMonitorSolutionUpdate", SNESMonitorSolutionUpdate, NULL));
1085: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_residual", "View residual at each iteration", "SNESMonitorResidual", SNESMonitorResidual, NULL));
1086: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_jacupdate_spectrum", "Print the change in the spectrum of the Jacobian", "SNESMonitorJacUpdateSpectrum", SNESMonitorJacUpdateSpectrum, NULL));
1087: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_fields", "Monitor norm of function per field", "SNESMonitorSet", SNESMonitorFields, NULL));
1088: PetscCall(PetscOptionsBool("-snes_monitor_pause_final", "Pauses all draw monitors at the final iterate", "SNESMonitorPauseFinal_Internal", PETSC_FALSE, &snes->pauseFinal, NULL));
1090: PetscCall(PetscOptionsString("-snes_monitor_python", "Use Python function", "SNESMonitorSet", NULL, monfilename, sizeof(monfilename), &flg));
1091: if (flg) PetscCall(PetscPythonMonitorSet((PetscObject)snes, monfilename));
1093: flg = PETSC_FALSE;
1094: PetscCall(PetscOptionsBool("-snes_monitor_lg_range", "Plot function range at each iteration", "SNESMonitorLGRange", flg, &flg, NULL));
1095: if (flg) {
1096: PetscViewer ctx;
1098: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &ctx));
1099: PetscCall(SNESMonitorSet(snes, SNESMonitorLGRange, ctx, (PetscCtxDestroyFn *)PetscViewerDestroy));
1100: }
1102: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
1103: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &snes->convergedreasonviewer, &snes->convergedreasonformat, NULL));
1104: flg = PETSC_FALSE;
1105: PetscCall(PetscOptionsBool("-snes_converged_reason_view_cancel", "Remove all converged reason viewers", "SNESConvergedReasonViewCancel", flg, &flg, &set));
1106: if (set && flg) PetscCall(SNESConvergedReasonViewCancel(snes));
1108: flg = PETSC_FALSE;
1109: PetscCall(PetscOptionsBool("-snes_fd", "Use finite differences (slow) to compute Jacobian", "SNESComputeJacobianDefault", flg, &flg, NULL));
1110: if (flg) {
1111: void *functx;
1112: DM dm;
1113: PetscCall(SNESGetDM(snes, &dm));
1114: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1115: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
1116: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefault, functx));
1117: PetscCall(PetscInfo(snes, "Setting default finite difference Jacobian matrix\n"));
1118: }
1120: flg = PETSC_FALSE;
1121: PetscCall(PetscOptionsBool("-snes_fd_function", "Use finite differences (slow) to compute function from user objective", "SNESObjectiveComputeFunctionDefaultFD", flg, &flg, NULL));
1122: if (flg) PetscCall(SNESSetFunction(snes, NULL, SNESObjectiveComputeFunctionDefaultFD, NULL));
1124: flg = PETSC_FALSE;
1125: PetscCall(PetscOptionsBool("-snes_fd_color", "Use finite differences with coloring to compute Jacobian", "SNESComputeJacobianDefaultColor", flg, &flg, NULL));
1126: if (flg) {
1127: DM dm;
1128: PetscCall(SNESGetDM(snes, &dm));
1129: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1130: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefaultColor, NULL));
1131: PetscCall(PetscInfo(snes, "Setting default finite difference coloring Jacobian matrix\n"));
1132: }
1134: flg = PETSC_FALSE;
1135: 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));
1136: if (flg && snes->mf_operator) {
1137: snes->mf_operator = PETSC_TRUE;
1138: snes->mf = PETSC_TRUE;
1139: }
1140: flg = PETSC_FALSE;
1141: PetscCall(PetscOptionsBool("-snes_mf", "Use a Matrix-Free Jacobian with no matrix for computing the preconditioner", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf, &flg));
1142: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1143: PetscCall(PetscOptionsInt("-snes_mf_version", "Matrix-Free routines version 1 or 2", "None", snes->mf_version, &snes->mf_version, NULL));
1145: PetscCall(PetscOptionsName("-snes_test_function", "Compare hand-coded and finite difference functions", "None", &snes->testFunc));
1146: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &snes->testJac));
1148: flg = PETSC_FALSE;
1149: PetscCall(SNESGetNPCSide(snes, &pcside));
1150: PetscCall(PetscOptionsEnum("-snes_npc_side", "SNES nonlinear preconditioner side", "SNESSetNPCSide", PCSides, (PetscEnum)pcside, (PetscEnum *)&pcside, &flg));
1151: if (flg) PetscCall(SNESSetNPCSide(snes, pcside));
1153: #if PetscDefined(HAVE_SAWS)
1154: /*
1155: Publish convergence information using SAWs
1156: */
1157: flg = PETSC_FALSE;
1158: PetscCall(PetscOptionsBool("-snes_monitor_saws", "Publish SNES progress using SAWs", "SNESMonitorSet", flg, &flg, NULL));
1159: if (flg) {
1160: PetscCtx ctx;
1161: PetscCall(SNESMonitorSAWsCreate(snes, &ctx));
1162: PetscCall(SNESMonitorSet(snes, SNESMonitorSAWs, ctx, SNESMonitorSAWsDestroy));
1163: }
1164: #endif
1165: #if PetscDefined(HAVE_SAWS)
1166: {
1167: PetscBool set;
1168: flg = PETSC_FALSE;
1169: PetscCall(PetscOptionsBool("-snes_saws_block", "Block for SAWs at end of SNESSolve", "PetscObjectSAWsBlock", ((PetscObject)snes)->amspublishblock, &flg, &set));
1170: if (set) PetscCall(PetscObjectSAWsSetBlock((PetscObject)snes, flg));
1171: }
1172: #endif
1174: for (i = 0; i < numberofsetfromoptions; i++) PetscCall((*othersetfromoptions[i])(snes));
1176: PetscTryTypeMethod(snes, setfromoptions, PetscOptionsObject);
1178: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1179: PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)snes, PetscOptionsObject));
1180: PetscOptionsEnd();
1182: if (snes->linesearch) {
1183: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
1184: PetscCall(SNESLineSearchSetFromOptions(snes->linesearch));
1185: }
1187: if (snes->usesksp) {
1188: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
1189: PetscCall(KSPSetOperators(snes->ksp, snes->jacobian, snes->jacobian_pre));
1190: PetscCall(KSPSetFromOptions(snes->ksp));
1191: }
1193: /* if user has set the SNES NPC type via options database, create it. */
1194: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1195: PetscCall(PetscOptionsHasName(((PetscObject)snes)->options, optionsprefix, "-npc_snes_type", &pcset));
1196: if (pcset && !snes->npc) PetscCall(SNESGetNPC(snes, &snes->npc));
1197: if (snes->npc) PetscCall(SNESSetFromOptions(snes->npc));
1198: snes->setfromoptionscalled++;
1199: PetscFunctionReturn(PETSC_SUCCESS);
1200: }
1202: /*@
1203: SNESResetFromOptions - Sets various `SNES` and `KSP` parameters from user options ONLY if the `SNESSetFromOptions()` was previously called
1205: Collective
1207: Input Parameter:
1208: . snes - the `SNES` context
1210: Level: advanced
1212: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESSetOptionsPrefix()`
1213: @*/
1214: PetscErrorCode SNESResetFromOptions(SNES snes)
1215: {
1216: PetscFunctionBegin;
1217: if (snes->setfromoptionscalled) PetscCall(SNESSetFromOptions(snes));
1218: PetscFunctionReturn(PETSC_SUCCESS);
1219: }
1221: /*@C
1222: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1223: the nonlinear solvers.
1225: Logically Collective; No Fortran Support
1227: Input Parameters:
1228: + snes - the `SNES` context
1229: . compute - function to compute the context
1230: - destroy - function to destroy the context, see `PetscCtxDestroyFn` for the calling sequence
1232: Calling sequence of `compute`:
1233: + snes - the `SNES` context
1234: - ctx - context to be computed
1236: Level: intermediate
1238: Note:
1239: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1241: Use `SNESSetApplicationContext()` to see the context immediately
1243: .seealso: [](ch_snes), `SNESGetApplicationContext()`, `SNESSetApplicationContext()`, `PetscCtxDestroyFn`
1244: @*/
1245: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES snes, PetscCtxRt ctx), PetscCtxDestroyFn *destroy)
1246: {
1247: PetscFunctionBegin;
1249: snes->ops->ctxcompute = compute;
1250: snes->ops->ctxdestroy = destroy;
1251: PetscFunctionReturn(PETSC_SUCCESS);
1252: }
1254: /*@
1255: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1257: Logically Collective
1259: Input Parameters:
1260: + snes - the `SNES` context
1261: - ctx - the application context
1263: Level: intermediate
1265: Notes:
1266: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian computation, or other evaluation function
1267: with `SNESGetApplicationContext()`
1269: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1271: Fortran Note:
1272: This only works when `ctx` is a Fortran derived type (it cannot be a `PetscObject`), we recommend writing a Fortran interface definition for this
1273: function that tells the Fortran compiler the derived data type that is passed in as the `ctx` argument. See `SNESGetApplicationContext()` for
1274: an example.
1276: .seealso: [](ch_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1277: @*/
1278: PetscErrorCode SNESSetApplicationContext(SNES snes, PetscCtx ctx)
1279: {
1280: KSP ksp;
1282: PetscFunctionBegin;
1284: PetscCall(SNESGetKSP(snes, &ksp));
1285: PetscCall(KSPSetApplicationContext(ksp, ctx));
1286: snes->ctx = ctx;
1287: PetscFunctionReturn(PETSC_SUCCESS);
1288: }
1290: /*@
1291: SNESGetApplicationContext - Gets the user-defined context for the
1292: nonlinear solvers set with `SNESGetApplicationContext()` or `SNESSetComputeApplicationContext()`
1294: Not Collective
1296: Input Parameter:
1297: . snes - `SNES` context
1299: Output Parameter:
1300: . ctx - the application context
1302: Level: intermediate
1304: Fortran Notes:
1305: This only works when the context is a Fortran derived type or a `PetscObject`. Declare `ctx` with
1306: .vb
1307: type(tUsertype), pointer :: ctx
1308: .ve
1310: .seealso: [](ch_snes), `SNESSetApplicationContext()`, `SNESSetComputeApplicationContext()`
1311: @*/
1312: PetscErrorCode SNESGetApplicationContext(SNES snes, PetscCtxRt ctx)
1313: {
1314: PetscFunctionBegin;
1316: *(void **)ctx = snes->ctx;
1317: PetscFunctionReturn(PETSC_SUCCESS);
1318: }
1320: /*@
1321: SNESSetUseMatrixFree - indicates that `SNES` should use matrix-free finite difference matrix-vector products to apply the Jacobian.
1323: Logically Collective
1325: Input Parameters:
1326: + snes - `SNES` context
1327: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1328: - 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
1329: this option no matrix-element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1331: Options Database Keys:
1332: + -snes_mf_operator - use matrix-free only for the mat operator
1333: . -snes_mf - use matrix-free for both the mat and pmat operator
1334: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1335: - -snes_fd - compute the Jacobian via finite differences (slow)
1337: Level: intermediate
1339: Note:
1340: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
1341: and computing explicitly with
1342: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1344: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`, `MatFDColoring`
1345: @*/
1346: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1347: {
1348: PetscFunctionBegin;
1352: snes->mf = mf_operator ? PETSC_TRUE : mf;
1353: snes->mf_operator = mf_operator;
1354: PetscFunctionReturn(PETSC_SUCCESS);
1355: }
1357: /*@
1358: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1360: Not Collective, but the resulting flags will be the same on all MPI processes
1362: Input Parameter:
1363: . snes - `SNES` context
1365: Output Parameters:
1366: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1367: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1369: Level: intermediate
1371: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1372: @*/
1373: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1374: {
1375: PetscFunctionBegin;
1377: if (mf) *mf = snes->mf;
1378: if (mf_operator) *mf_operator = snes->mf_operator;
1379: PetscFunctionReturn(PETSC_SUCCESS);
1380: }
1382: /*@
1383: SNESGetIterationNumber - Gets the number of nonlinear iterations completed in the current or most recent `SNESSolve()`
1385: Not Collective
1387: Input Parameter:
1388: . snes - `SNES` context
1390: Output Parameter:
1391: . iter - iteration number
1393: Level: intermediate
1395: Notes:
1396: For example, during the computation of iteration 2 this would return 1.
1398: This is useful for using lagged Jacobians (where one does not recompute the
1399: Jacobian at each `SNES` iteration). For example, the code
1400: .vb
1401: ierr = SNESGetIterationNumber(snes,&it);
1402: if (!(it % 2)) {
1403: [compute Jacobian here]
1404: }
1405: .ve
1406: can be used in your function that computes the Jacobian to cause the Jacobian to be
1407: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1409: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1411: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`, `SNESSetMonitor()`
1412: @*/
1413: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1414: {
1415: PetscFunctionBegin;
1417: PetscAssertPointer(iter, 2);
1418: *iter = snes->iter;
1419: PetscFunctionReturn(PETSC_SUCCESS);
1420: }
1422: /*@
1423: SNESSetIterationNumber - Sets the current iteration number.
1425: Not Collective
1427: Input Parameters:
1428: + snes - `SNES` context
1429: - iter - iteration number
1431: Level: developer
1433: Note:
1434: This should only be called inside a `SNES` nonlinear solver.
1436: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1437: @*/
1438: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1439: {
1440: PetscFunctionBegin;
1442: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1443: snes->iter = iter;
1444: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1445: PetscFunctionReturn(PETSC_SUCCESS);
1446: }
1448: /*@
1449: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1450: taken by the nonlinear solver in the current or most recent `SNESSolve()` .
1452: Not Collective
1454: Input Parameter:
1455: . snes - `SNES` context
1457: Output Parameter:
1458: . nfails - number of unsuccessful steps attempted
1460: Level: intermediate
1462: Notes:
1463: A failed step is a step that was generated and taken but did not satisfy the requested step criteria. For example,
1464: the `SNESLineSearchApply()` could not generate a sufficient decrease in the function norm (in fact it may have produced an increase).
1466: Taken steps that produce a infinity or NaN in the function evaluation or generate a `SNESSetFunctionDomainError()`
1467: will always immediately terminate the `SNESSolve()` regardless of the value of `maxFails`.
1469: `SNESSetMaxNonlinearStepFailures()` determines how many unsuccessful steps are allowed before the `SNESSolve()` terminates
1471: This counter is reset to zero for each successive call to `SNESSolve()`.
1473: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1474: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1475: @*/
1476: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1477: {
1478: PetscFunctionBegin;
1480: PetscAssertPointer(nfails, 2);
1481: *nfails = snes->numFailures;
1482: PetscFunctionReturn(PETSC_SUCCESS);
1483: }
1485: /*@
1486: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1487: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1489: Not Collective
1491: Input Parameters:
1492: + snes - `SNES` context
1493: - maxFails - maximum of unsuccessful steps allowed, use `PETSC_UNLIMITED` to have no limit on the number of failures
1495: Options Database Key:
1496: . -snes_max_fail n - maximum number of unsuccessful steps allowed
1498: Level: intermediate
1500: Note:
1501: A failed step is a step that was generated and taken but did not satisfy the requested criteria. For example,
1502: the `SNESLineSearchApply()` could not generate a sufficient decrease in the function norm (in fact it may have produced an increase).
1504: Taken steps that produce a infinity or NaN in the function evaluation or generate a `SNESSetFunctionDomainError()`
1505: will always immediately terminate the `SNESSolve()` regardless of the value of `maxFails`.
1507: Developer Note:
1508: The options database key is wrong for this function name
1510: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1511: `SNESGetLinearSolveFailures()`, `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`, `SNESCheckLineSearchFailure()`
1512: @*/
1513: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1514: {
1515: PetscFunctionBegin;
1518: if (maxFails == PETSC_UNLIMITED) {
1519: snes->maxFailures = PETSC_INT_MAX;
1520: } else {
1521: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1522: snes->maxFailures = maxFails;
1523: }
1524: PetscFunctionReturn(PETSC_SUCCESS);
1525: }
1527: /*@
1528: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1529: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1531: Not Collective
1533: Input Parameter:
1534: . snes - `SNES` context
1536: Output Parameter:
1537: . maxFails - maximum of unsuccessful steps
1539: Level: intermediate
1541: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1542: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1543: @*/
1544: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1545: {
1546: PetscFunctionBegin;
1548: PetscAssertPointer(maxFails, 2);
1549: *maxFails = snes->maxFailures;
1550: PetscFunctionReturn(PETSC_SUCCESS);
1551: }
1553: /*@
1554: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1555: done by the `SNES` object in the current or most recent `SNESSolve()`
1557: Not Collective
1559: Input Parameter:
1560: . snes - `SNES` context
1562: Output Parameter:
1563: . nfuncs - number of evaluations
1565: Level: intermediate
1567: Note:
1568: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1570: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1571: @*/
1572: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1573: {
1574: PetscFunctionBegin;
1576: PetscAssertPointer(nfuncs, 2);
1577: *nfuncs = snes->nfuncs;
1578: PetscFunctionReturn(PETSC_SUCCESS);
1579: }
1581: /*@
1582: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1583: linear solvers in the current or most recent `SNESSolve()`
1585: Not Collective
1587: Input Parameter:
1588: . snes - `SNES` context
1590: Output Parameter:
1591: . nfails - number of failed solves
1593: Options Database Key:
1594: . -snes_max_linear_solve_fail num - The number of failures before the solve is terminated
1596: Level: intermediate
1598: Note:
1599: This counter is reset to zero for each successive call to `SNESSolve()`.
1601: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1602: @*/
1603: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1604: {
1605: PetscFunctionBegin;
1607: PetscAssertPointer(nfails, 2);
1608: *nfails = snes->numLinearSolveFailures;
1609: PetscFunctionReturn(PETSC_SUCCESS);
1610: }
1612: /*@
1613: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1614: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1616: Logically Collective
1618: Input Parameters:
1619: + snes - `SNES` context
1620: - maxFails - maximum allowed linear solve failures, use `PETSC_UNLIMITED` to have no limit on the number of failures
1622: Options Database Key:
1623: . -snes_max_linear_solve_fail num - The number of failures before the solve is terminated
1625: Level: intermediate
1627: Note:
1628: By default this is 0; that is `SNES` returns on the first failed linear solve
1630: Developer Note:
1631: The options database key is wrong for this function name
1633: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1634: @*/
1635: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1636: {
1637: PetscFunctionBegin;
1641: if (maxFails == PETSC_UNLIMITED) {
1642: snes->maxLinearSolveFailures = PETSC_INT_MAX;
1643: } else {
1644: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1645: snes->maxLinearSolveFailures = maxFails;
1646: }
1647: PetscFunctionReturn(PETSC_SUCCESS);
1648: }
1650: /*@
1651: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1652: are allowed before `SNES` returns as unsuccessful
1654: Not Collective
1656: Input Parameter:
1657: . snes - `SNES` context
1659: Output Parameter:
1660: . maxFails - maximum of unsuccessful solves allowed
1662: Level: intermediate
1664: Note:
1665: By default this is 1; that is `SNES` returns on the first failed linear solve
1667: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1668: @*/
1669: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1670: {
1671: PetscFunctionBegin;
1673: PetscAssertPointer(maxFails, 2);
1674: *maxFails = snes->maxLinearSolveFailures;
1675: PetscFunctionReturn(PETSC_SUCCESS);
1676: }
1678: /*@
1679: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1680: used by the nonlinear solver in the most recent `SNESSolve()`
1682: Not Collective
1684: Input Parameter:
1685: . snes - `SNES` context
1687: Output Parameter:
1688: . lits - number of linear iterations
1690: Level: intermediate
1692: Notes:
1693: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1695: 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
1696: then call `KSPGetIterationNumber()` after the failed solve.
1698: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1699: @*/
1700: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1701: {
1702: PetscFunctionBegin;
1704: PetscAssertPointer(lits, 2);
1705: *lits = snes->linear_its;
1706: PetscFunctionReturn(PETSC_SUCCESS);
1707: }
1709: /*@
1710: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1711: are reset every time `SNESSolve()` is called.
1713: Logically Collective
1715: Input Parameters:
1716: + snes - `SNES` context
1717: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1719: Level: developer
1721: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1722: @*/
1723: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1724: {
1725: PetscFunctionBegin;
1728: snes->counters_reset = reset;
1729: PetscFunctionReturn(PETSC_SUCCESS);
1730: }
1732: /*@
1733: SNESResetCounters - Reset counters for linear iterations and function evaluations.
1735: Logically Collective
1737: Input Parameters:
1738: . snes - `SNES` context
1740: Level: developer
1742: Note:
1743: It honors the flag set with `SNESSetCountersReset()`
1745: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1746: @*/
1747: PetscErrorCode SNESResetCounters(SNES snes)
1748: {
1749: PetscFunctionBegin;
1751: if (snes->counters_reset) {
1752: snes->nfuncs = 0;
1753: snes->linear_its = 0;
1754: snes->numFailures = 0;
1755: }
1756: PetscFunctionReturn(PETSC_SUCCESS);
1757: }
1759: /*@
1760: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1762: Not Collective, but the `SNES` and `KSP` objects must live on the same `MPI_Comm`
1764: Input Parameters:
1765: + snes - the `SNES` context
1766: - ksp - the `KSP` context
1768: Level: developer
1770: Notes:
1771: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1772: so this routine is rarely needed.
1774: The `KSP` object that is already in the `SNES` object has its reference count
1775: decreased by one when this is called.
1777: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`
1778: @*/
1779: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1780: {
1781: PetscFunctionBegin;
1784: PetscCheckSameComm(snes, 1, ksp, 2);
1785: PetscCall(PetscObjectReference((PetscObject)ksp));
1786: PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1787: snes->ksp = ksp;
1788: PetscFunctionReturn(PETSC_SUCCESS);
1789: }
1791: /*@
1792: SNESParametersInitialize - Sets the base defaults for parameters in `snes`, updating a parameter's current value when it matches its previously recorded default.
1794: Logically collective
1796: Input Parameter:
1797: . snes - the `SNES` object
1799: Level: developer
1801: Notes:
1803: The base defaults are the non-type-specific values established when the `SNES` is created. A `SNESType` constructor may subsequently replace them with type-specific defaults.
1805: Developer Notes:
1807: `SNESCreate()` calls this routine to establish the base defaults. `SNESSetType()` calls it before constructing a new `SNESType`, so the recorded defaults associated with the previous type are replaced before the new type installs its own defaults.
1809: Default tracking is based on value equality, not on whether a setter was called. Consequently, an explicitly assigned value that equals the recorded default may be updated when the type changes.
1811: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
1812: `PetscObjectParameterSetDefault()`
1813: @*/
1814: PetscErrorCode SNESParametersInitialize(SNES snes)
1815: {
1816: PetscObjectParameterSetDefault(snes, max_its, 50);
1817: PetscObjectParameterSetDefault(snes, max_funcs, 10000);
1818: PetscObjectParameterSetDefault(snes, rtol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1819: PetscObjectParameterSetDefault(snes, abstol, PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50);
1820: PetscObjectParameterSetDefault(snes, stol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1821: PetscObjectParameterSetDefault(snes, divtol, 1.e4);
1822: return PETSC_SUCCESS;
1823: }
1825: /*@
1826: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1828: Collective
1830: Input Parameter:
1831: . comm - MPI communicator
1833: Output Parameter:
1834: . outsnes - the new `SNES` context
1836: Options Database Keys:
1837: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no matrix to construct a preconditioner
1838: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided matrix as set by `SNESSetJacobian()`
1839: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1840: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1842: Level: beginner
1844: Developer Notes:
1845: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1846: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1847: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1848: in `SNESView()`.
1850: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1851: by help messages about meaningless `SNES` options.
1853: `SNES` always creates the `snes->kspconvctx` even though it is used by only one type. This should be fixed.
1855: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1856: @*/
1857: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1858: {
1859: SNES snes;
1860: SNESKSPEW *kctx;
1862: PetscFunctionBegin;
1863: PetscAssertPointer(outsnes, 2);
1864: PetscCall(SNESInitializePackage());
1866: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1867: snes->ops->converged = SNESConvergedDefault;
1868: snes->usesksp = PETSC_TRUE;
1869: snes->norm = 0.0;
1870: snes->xnorm = 0.0;
1871: snes->ynorm = 0.0;
1872: snes->normschedule = SNES_NORM_ALWAYS;
1873: snes->functype = SNES_FUNCTION_DEFAULT;
1874: snes->ttol = 0.0;
1876: snes->rnorm0 = 0;
1877: snes->nfuncs = 0;
1878: snes->numFailures = 0;
1879: snes->maxFailures = 1;
1880: snes->linear_its = 0;
1881: snes->lagjacobian = 1;
1882: snes->jac_iter = 0;
1883: snes->lagjac_persist = PETSC_FALSE;
1884: snes->lagpreconditioner = 1;
1885: snes->pre_iter = 0;
1886: snes->lagpre_persist = PETSC_FALSE;
1887: snes->numbermonitors = 0;
1888: snes->numberreasonviews = 0;
1889: snes->data = NULL;
1890: snes->setupcalled = PETSC_FALSE;
1891: snes->ksp_ewconv = PETSC_FALSE;
1892: snes->nwork = 0;
1893: snes->work = NULL;
1894: snes->nvwork = 0;
1895: snes->vwork = NULL;
1896: snes->conv_hist_len = 0;
1897: snes->conv_hist_max = 0;
1898: snes->conv_hist = NULL;
1899: snes->conv_hist_its = NULL;
1900: snes->conv_hist_reset = PETSC_TRUE;
1901: snes->counters_reset = PETSC_TRUE;
1902: snes->vec_func_init_set = PETSC_FALSE;
1903: snes->reason = SNES_CONVERGED_ITERATING;
1904: snes->npcside = PC_RIGHT;
1905: snes->setfromoptionscalled = 0;
1907: snes->mf = PETSC_FALSE;
1908: snes->mf_operator = PETSC_FALSE;
1909: snes->mf_version = 1;
1911: snes->numLinearSolveFailures = 0;
1912: snes->maxLinearSolveFailures = 1;
1914: snes->vizerotolerance = 1.e-8;
1915: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1917: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1918: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1920: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1921: PetscCall(PetscNew(&kctx));
1923: snes->kspconvctx = kctx;
1924: kctx->version = 2;
1925: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1926: this was too large for some test cases */
1927: kctx->rtol_last = 0.0;
1928: kctx->rtol_max = 0.9;
1929: kctx->gamma = 1.0;
1930: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1931: kctx->alpha2 = kctx->alpha;
1932: kctx->threshold = 0.1;
1933: kctx->lresid_last = 0.0;
1934: kctx->norm_last = 0.0;
1936: kctx->rk_last = 0.0;
1937: kctx->rk_last_2 = 0.0;
1938: kctx->rtol_last_2 = 0.0;
1939: kctx->v4_p1 = 0.1;
1940: kctx->v4_p2 = 0.4;
1941: kctx->v4_p3 = 0.7;
1942: kctx->v4_m1 = 0.8;
1943: kctx->v4_m2 = 0.5;
1944: kctx->v4_m3 = 0.1;
1945: kctx->v4_m4 = 0.5;
1947: PetscCall(SNESParametersInitialize(snes));
1948: *outsnes = snes;
1949: PetscFunctionReturn(PETSC_SUCCESS);
1950: }
1952: /*@C
1953: SNESSetFunction - Sets the function evaluation routine and function
1954: vector for use by the `SNES` routines in solving systems of nonlinear
1955: equations.
1957: Logically Collective
1959: Input Parameters:
1960: + snes - the `SNES` context
1961: . r - vector to store function values, may be `NULL`
1962: . f - function evaluation routine; for calling sequence see `SNESFunctionFn`
1963: - ctx - [optional] user-defined context for private data for the
1964: function evaluation routine (may be `NULL`)
1966: Level: beginner
1968: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunctionFn`
1969: @*/
1970: PetscErrorCode SNESSetFunction(SNES snes, Vec r, SNESFunctionFn *f, PetscCtx ctx)
1971: {
1972: DM dm;
1974: PetscFunctionBegin;
1976: if (r) {
1978: PetscCheckSameComm(snes, 1, r, 2);
1979: PetscCall(PetscObjectReference((PetscObject)r));
1980: PetscCall(VecDestroy(&snes->vec_func));
1981: snes->vec_func = r;
1982: }
1983: /* update DMSNES
1984: We support incremental information; so update the function context only if r is not specified
1985: (which allows to disable the callbacks when both f and ctx are NULL),
1986: or, if r is specified, when at least one of f and ctx is not NULL */
1987: PetscCall(SNESGetDM(snes, &dm));
1988: if (!r || f || ctx) PetscCall(DMSNESSetFunction(dm, f, ctx));
1989: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1990: PetscFunctionReturn(PETSC_SUCCESS);
1991: }
1993: /*@C
1994: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1996: Logically Collective
1998: Input Parameters:
1999: + snes - the `SNES` context
2000: - f - vector to store function value
2002: Level: developer
2004: Notes:
2005: This should not be modified during the solution procedure.
2007: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
2009: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
2010: @*/
2011: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
2012: {
2013: Vec vec_func;
2015: PetscFunctionBegin;
2018: PetscCheckSameComm(snes, 1, f, 2);
2019: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
2020: snes->vec_func_init_set = PETSC_FALSE;
2021: PetscFunctionReturn(PETSC_SUCCESS);
2022: }
2023: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
2024: PetscCall(VecCopy(f, vec_func));
2026: snes->vec_func_init_set = PETSC_TRUE;
2027: PetscFunctionReturn(PETSC_SUCCESS);
2028: }
2030: /*@
2031: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
2032: of the `SNES` method, when norms are computed in the solving process
2034: Logically Collective
2036: Input Parameters:
2037: + snes - the `SNES` context
2038: - normschedule - the frequency of norm computation
2040: Options Database Key:
2041: . -snes_norm_schedule (none|always|initialonly|finalonly|initialfinalonly) - set the schedule
2043: Level: advanced
2045: Notes:
2046: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
2047: of the nonlinear function and the taking of its norm at every iteration to
2048: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2049: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
2050: may either be monitored for convergence or not. As these are often used as nonlinear
2051: preconditioners, monitoring the norm of their error is not a useful enterprise within
2052: their solution.
2054: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
2055: @*/
2056: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
2057: {
2058: PetscFunctionBegin;
2061: snes->normschedule = normschedule;
2062: PetscFunctionReturn(PETSC_SUCCESS);
2063: }
2065: /*@
2066: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
2067: of the `SNES` method.
2069: Logically Collective
2071: Input Parameters:
2072: + snes - the `SNES` context
2073: - normschedule - the type of the norm used
2075: Level: advanced
2077: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2078: @*/
2079: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
2080: {
2081: PetscFunctionBegin;
2083: *normschedule = snes->normschedule;
2084: PetscFunctionReturn(PETSC_SUCCESS);
2085: }
2087: /*@
2088: SNESSetFunctionNorm - Sets the last computed residual norm.
2090: Logically Collective
2092: Input Parameters:
2093: + snes - the `SNES` context
2094: - norm - the value of the norm
2096: Level: developer
2098: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2099: @*/
2100: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
2101: {
2102: PetscFunctionBegin;
2104: snes->norm = norm;
2105: PetscFunctionReturn(PETSC_SUCCESS);
2106: }
2108: /*@
2109: SNESGetFunctionNorm - Gets the last computed norm of the residual
2111: Not Collective
2113: Input Parameter:
2114: . snes - the `SNES` context
2116: Output Parameter:
2117: . norm - the last computed residual norm
2119: Level: developer
2121: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2122: @*/
2123: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2124: {
2125: PetscFunctionBegin;
2127: PetscAssertPointer(norm, 2);
2128: *norm = snes->norm;
2129: PetscFunctionReturn(PETSC_SUCCESS);
2130: }
2132: /*@
2133: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2135: Not Collective
2137: Input Parameter:
2138: . snes - the `SNES` context
2140: Output Parameter:
2141: . ynorm - the last computed update norm
2143: Level: developer
2145: Note:
2146: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2148: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2149: @*/
2150: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2151: {
2152: PetscFunctionBegin;
2154: PetscAssertPointer(ynorm, 2);
2155: *ynorm = snes->ynorm;
2156: PetscFunctionReturn(PETSC_SUCCESS);
2157: }
2159: /*@
2160: SNESGetSolutionNorm - Gets the last computed norm of the solution
2162: Not Collective
2164: Input Parameter:
2165: . snes - the `SNES` context
2167: Output Parameter:
2168: . xnorm - the last computed solution norm
2170: Level: developer
2172: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2173: @*/
2174: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2175: {
2176: PetscFunctionBegin;
2178: PetscAssertPointer(xnorm, 2);
2179: *xnorm = snes->xnorm;
2180: PetscFunctionReturn(PETSC_SUCCESS);
2181: }
2183: /*@
2184: SNESSetFunctionType - Sets the `SNESFunctionType`
2185: of the `SNES` method.
2187: Logically Collective
2189: Input Parameters:
2190: + snes - the `SNES` context
2191: - type - the function type
2193: Level: developer
2195: Values of the function type\:
2196: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2197: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2198: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2200: Note:
2201: Different `SNESType`s use this value in different ways
2203: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2204: @*/
2205: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2206: {
2207: PetscFunctionBegin;
2209: snes->functype = type;
2210: PetscFunctionReturn(PETSC_SUCCESS);
2211: }
2213: /*@
2214: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2215: of the SNES method.
2217: Logically Collective
2219: Input Parameters:
2220: + snes - the `SNES` context
2221: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2223: Level: advanced
2225: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2226: @*/
2227: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2228: {
2229: PetscFunctionBegin;
2231: *type = snes->functype;
2232: PetscFunctionReturn(PETSC_SUCCESS);
2233: }
2235: /*@C
2236: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2237: use with composed nonlinear solvers.
2239: Input Parameters:
2240: + snes - the `SNES` context, usually of the `SNESType` `SNESNGS`
2241: . f - function evaluation routine to apply Gauss-Seidel, see `SNESNGSFn` for calling sequence
2242: - ctx - [optional] user-defined context for private data for the smoother evaluation routine (may be `NULL`)
2244: Level: intermediate
2246: Note:
2247: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2248: a problem appropriate update to the solution, particularly `SNESFAS`.
2250: .seealso: [](ch_snes), `SNESNGS`, `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`, `SNESNGSFn`
2251: @*/
2252: PetscErrorCode SNESSetNGS(SNES snes, SNESNGSFn *f, PetscCtx ctx)
2253: {
2254: DM dm;
2256: PetscFunctionBegin;
2258: PetscCall(SNESGetDM(snes, &dm));
2259: PetscCall(DMSNESSetNGS(dm, f, ctx));
2260: PetscFunctionReturn(PETSC_SUCCESS);
2261: }
2263: /*@C
2264: SNESPicardComputeMFFunction - Matrix-free residual $A(x) x - b(x)$ used by `SNESSetPicard()` when the operator is applied through `-snes_mf_operator`
2266: Collective
2268: Input Parameters:
2269: + snes - the `SNES` context
2270: . x - the current iterate
2271: - ctx - unused application context; the Picard callbacks are retrieved from the attached `DMSNES`
2273: Output Parameter:
2274: . f - the residual vector
2276: Level: developer
2278: Note:
2279: Uses a duplicate of `snes->jacobian_pre` because `snes->jacobian_pre` cannot be changed during the `KSPSolve()`.
2281: .seealso: [](ch_snes), `SNES`, `SNESSetPicard()`, `SNESPicardComputeFunction()`, `SNESPicardComputeJacobian()`
2282: @*/
2283: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, PetscCtx ctx)
2284: {
2285: DM dm;
2286: DMSNES sdm;
2288: PetscFunctionBegin;
2289: PetscCall(SNESGetDM(snes, &dm));
2290: PetscCall(DMGetDMSNES(dm, &sdm));
2291: /* A(x)*x - b(x) */
2292: if (sdm->ops->computepfunction) {
2293: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2294: PetscCall(VecScale(f, -1.0));
2295: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2296: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2297: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2298: PetscCall(MatMultAdd(snes->picard, x, f, f));
2299: } else {
2300: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2301: PetscCall(MatMult(snes->picard, x, f));
2302: }
2303: PetscFunctionReturn(PETSC_SUCCESS);
2304: }
2306: /*@C
2307: SNESPicardComputeFunction - Compute the residual $A(x) x - b(x)$ using the callbacks registered by `SNESSetPicard()`
2309: Collective
2311: Input Parameters:
2312: + snes - the `SNES` context
2313: . x - the current iterate
2314: - ctx - unused application context; the Picard callbacks are retrieved from the attached `DMSNES`
2316: Output Parameter:
2317: . f - the residual vector
2319: Level: developer
2321: .seealso: [](ch_snes), `SNES`, `SNESSetPicard()`, `SNESPicardComputeMFFunction()`, `SNESPicardComputeJacobian()`
2322: @*/
2323: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, PetscCtx ctx)
2324: {
2325: DM dm;
2326: DMSNES sdm;
2328: PetscFunctionBegin;
2329: PetscCall(SNESGetDM(snes, &dm));
2330: PetscCall(DMGetDMSNES(dm, &sdm));
2331: /* A(x)*x - b(x) */
2332: if (sdm->ops->computepfunction) {
2333: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2334: PetscCall(VecScale(f, -1.0));
2335: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2336: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2337: } else {
2338: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2339: PetscCall(MatMult(snes->jacobian_pre, x, f));
2340: }
2341: PetscFunctionReturn(PETSC_SUCCESS);
2342: }
2344: /*@C
2345: SNESPicardComputeJacobian - Trivial Jacobian assembly callback used by `SNESSetPicard()`; the Picard operator is filled in by `SNESPicardComputeFunction()`
2347: Collective
2349: Input Parameters:
2350: + snes - the `SNES` context
2351: . x1 - the current iterate (unused)
2352: . J - the Jacobian matrix to assemble
2353: . B - the preconditioning matrix (unused)
2354: - ctx - unused application context
2356: Level: developer
2358: Note:
2359: Only calls `MatAssemblyBegin()`/`MatAssemblyEnd()` on `J`, because the Picard iteration reuses the operator already assembled by `SNESPicardComputeFunction()`.
2361: .seealso: [](ch_snes), `SNES`, `SNESSetPicard()`, `SNESPicardComputeFunction()`, `SNESPicardComputeMFFunction()`
2362: @*/
2363: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, PetscCtx ctx)
2364: {
2365: PetscFunctionBegin;
2366: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2367: /* must assembly if matrix-free to get the last SNES solution */
2368: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2369: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2370: PetscFunctionReturn(PETSC_SUCCESS);
2371: }
2373: /*@C
2374: SNESSetPicard - Use `SNES` to solve the system $A(x) x = bp(x) + b $ via a Picard type iteration (Picard linearization)
2376: Logically Collective
2378: Input Parameters:
2379: + snes - the `SNES` context
2380: . r - vector to store function values, may be `NULL`
2381: . bp - function evaluation routine, may be `NULL`, for the calling sequence see `SNESFunctionFn`
2382: . Amat - matrix with which $A(x) x - bp(x) - b$ is to be computed
2383: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2384: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFn`
2385: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2387: Level: intermediate
2389: Notes:
2390: It is often better to provide the nonlinear function $F()$ and some approximation to its Jacobian directly and use
2391: 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.
2393: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2395: Solves the equation $A(x) x = bp(x) - b$ via the defect correction algorithm $A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}$.
2396: When an exact solver is used this corresponds to the "classic" Picard $A(x^{n}) x^{n+1} = bp(x^{n}) + b$ iteration.
2398: Run with `-snes_mf_operator` to solve the system with Newton's method using $A(x^{n})$ to construct the preconditioner.
2400: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2401: the direct Picard iteration $A(x^n) x^{n+1} = bp(x^n) + b$
2403: 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
2404: 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
2405: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument \:-).
2407: 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
2408: $A(x^{n})$ is used to build the preconditioner
2410: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at a time) and thus represent Newton's method.
2412: 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
2413: 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
2414: 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`.
2415: See the comment in src/snes/tutorials/ex15.c.
2417: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`,
2418: `SNESFunctionFn`, `SNESJacobianFn`
2419: @*/
2420: PetscErrorCode SNESSetPicard(SNES snes, Vec r, SNESFunctionFn *bp, Mat Amat, Mat Pmat, SNESJacobianFn *J, PetscCtx ctx)
2421: {
2422: DM dm;
2424: PetscFunctionBegin;
2426: PetscCall(SNESGetDM(snes, &dm));
2427: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2428: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2429: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2430: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2431: PetscFunctionReturn(PETSC_SUCCESS);
2432: }
2434: /*@C
2435: SNESGetPicard - Returns the context for the Picard iteration
2437: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2439: Input Parameter:
2440: . snes - the `SNES` context
2442: Output Parameters:
2443: + r - the function (or `NULL`)
2444: . f - the function (or `NULL`); for calling sequence see `SNESFunctionFn`
2445: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2446: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2447: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFn`
2448: - ctx - the function context (or `NULL`)
2450: Level: advanced
2452: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunctionFn`, `SNESJacobianFn`
2453: @*/
2454: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, SNESFunctionFn **f, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, PetscCtxRt ctx)
2455: {
2456: DM dm;
2458: PetscFunctionBegin;
2460: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2461: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2462: PetscCall(SNESGetDM(snes, &dm));
2463: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2464: PetscFunctionReturn(PETSC_SUCCESS);
2465: }
2467: /*@C
2468: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2470: Logically Collective
2472: Input Parameters:
2473: + snes - the `SNES` context
2474: . func - function evaluation routine, see `SNESInitialGuessFn` for the calling sequence
2475: - ctx - [optional] user-defined context for private data for the
2476: function evaluation routine (may be `NULL`)
2478: Level: intermediate
2480: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESInitialGuessFn`
2481: @*/
2482: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, SNESInitialGuessFn *func, PetscCtx ctx)
2483: {
2484: PetscFunctionBegin;
2486: if (func) snes->ops->computeinitialguess = func;
2487: if (ctx) snes->initialguessP = ctx;
2488: PetscFunctionReturn(PETSC_SUCCESS);
2489: }
2491: /*@C
2492: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2493: it assumes a zero right-hand side.
2495: Logically Collective
2497: Input Parameter:
2498: . snes - the `SNES` context
2500: Output Parameter:
2501: . rhs - the right-hand side vector or `NULL` if there is no right-hand side vector
2503: Level: intermediate
2505: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2506: @*/
2507: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2508: {
2509: PetscFunctionBegin;
2511: PetscAssertPointer(rhs, 2);
2512: *rhs = snes->vec_rhs;
2513: PetscFunctionReturn(PETSC_SUCCESS);
2514: }
2516: /*@
2517: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2519: Collective
2521: Input Parameters:
2522: + snes - the `SNES` context
2523: - x - input vector
2525: Output Parameter:
2526: . f - function vector, as set by `SNESSetFunction()`
2528: Level: developer
2530: Notes:
2531: `SNESComputeFunction()` is typically used within nonlinear solvers
2532: implementations, so users would not generally call this routine themselves.
2534: When solving for $F(x) = b$, this routine computes $f = F(x) - b$.
2536: This function usually appears in the pattern.
2537: .vb
2538: SNESComputeFunction(snes, x, f);
2539: VecNorm(f, &fnorm);
2540: SNESCheckFunctionDomainError(snes, fnorm); or SNESLineSearchCheckFunctionDomainError(ls, fnorm);
2541: .ve
2542: to collectively handle the use of `SNESSetFunctionDomainError()` in the provided callback function.
2544: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`, `SNESSetFunctionDomainError()`
2545: @*/
2546: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec f)
2547: {
2548: DM dm;
2549: DMSNES sdm;
2551: PetscFunctionBegin;
2555: PetscCheckSameComm(snes, 1, x, 2);
2556: PetscCheckSameComm(snes, 1, f, 3);
2557: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2559: PetscCall(SNESGetDM(snes, &dm));
2560: PetscCall(DMGetDMSNES(dm, &sdm));
2561: 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().");
2562: if (sdm->ops->computefunction) {
2563: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, f, 0));
2564: PetscCall(VecLockReadPush(x));
2565: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2566: snes->functiondomainerror = PETSC_FALSE;
2567: {
2568: void *ctx;
2569: SNESFunctionFn *computefunction;
2570: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2571: PetscCallBack("SNES callback function", (*computefunction)(snes, x, f, ctx));
2572: }
2573: PetscCall(VecLockReadPop(x));
2574: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, f, 0));
2575: } else /* if (snes->vec_rhs) */ {
2576: PetscCall(MatMult(snes->jacobian, x, f));
2577: }
2578: if (snes->vec_rhs) PetscCall(VecAXPY(f, -1.0, snes->vec_rhs));
2579: snes->nfuncs++;
2580: /*
2581: domainerror might not be set on all processes; so we tag vector locally with infinity and the next inner product or norm will
2582: propagate the value to all processes
2583: */
2584: PetscCall(VecFlag(f, snes->functiondomainerror));
2585: PetscFunctionReturn(PETSC_SUCCESS);
2586: }
2588: /*@
2589: SNESComputeMFFunction - Calls the function that has been set with `DMSNESSetMFFunction()`.
2591: Collective
2593: Input Parameters:
2594: + snes - the `SNES` context
2595: - x - input vector
2597: Output Parameter:
2598: . y - output vector
2600: Level: developer
2602: Notes:
2603: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2604: so users would not generally call this routine themselves.
2606: Since this function is intended for use with finite differencing it does not subtract the right-hand side vector provided with `SNESSolve()`
2607: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2608: 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.
2610: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF()`, `DMSNESSetMFFunction()`
2611: @*/
2612: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2613: {
2614: DM dm;
2615: DMSNES sdm;
2617: PetscFunctionBegin;
2621: PetscCheckSameComm(snes, 1, x, 2);
2622: PetscCheckSameComm(snes, 1, y, 3);
2623: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2625: PetscCall(SNESGetDM(snes, &dm));
2626: PetscCall(DMGetDMSNES(dm, &sdm));
2627: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2628: PetscCall(VecLockReadPush(x));
2629: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2630: snes->functiondomainerror = PETSC_FALSE;
2631: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2632: PetscCall(VecLockReadPop(x));
2633: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2634: snes->nfuncs++;
2635: /*
2636: domainerror might not be set on all processes; so we tag vector locally with infinity and the next inner product or norm will
2637: propagate the value to all processes
2638: */
2639: PetscCall(VecFlag(y, snes->functiondomainerror));
2640: PetscFunctionReturn(PETSC_SUCCESS);
2641: }
2643: /*@
2644: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2646: Collective
2648: Input Parameters:
2649: + snes - the `SNES` context
2650: . x - input vector
2651: - b - rhs vector
2653: Output Parameter:
2654: . x - new solution vector
2656: Level: developer
2658: Note:
2659: `SNESComputeNGS()` is typically used within composed nonlinear solver
2660: implementations, so most users would not generally call this routine
2661: themselves.
2663: .seealso: [](ch_snes), `SNESNGSFn`, `SNESSetNGS()`, `SNESComputeFunction()`, `SNESNGS`
2664: @*/
2665: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2666: {
2667: DM dm;
2668: DMSNES sdm;
2670: PetscFunctionBegin;
2674: PetscCheckSameComm(snes, 1, x, 3);
2675: if (b) PetscCheckSameComm(snes, 1, b, 2);
2676: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2677: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2678: PetscCall(SNESGetDM(snes, &dm));
2679: PetscCall(DMGetDMSNES(dm, &sdm));
2680: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2681: if (b) PetscCall(VecLockReadPush(b));
2682: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2683: if (b) PetscCall(VecLockReadPop(b));
2684: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2685: PetscFunctionReturn(PETSC_SUCCESS);
2686: }
2688: static PetscErrorCode SNESComputeFunction_FD(SNES snes, Vec Xin, Vec G)
2689: {
2690: Vec X;
2691: PetscScalar *g;
2692: PetscReal f, f2;
2693: PetscInt low, high, N, i;
2694: PetscBool flg;
2695: PetscReal h = .5 * PETSC_SQRT_MACHINE_EPSILON;
2697: PetscFunctionBegin;
2698: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_fd_delta", &h, &flg));
2699: PetscCall(VecDuplicate(Xin, &X));
2700: PetscCall(VecCopy(Xin, X));
2701: PetscCall(VecGetSize(X, &N));
2702: PetscCall(VecGetOwnershipRange(X, &low, &high));
2703: PetscCall(VecSetOption(X, VEC_IGNORE_OFF_PROC_ENTRIES, PETSC_TRUE));
2704: PetscCall(VecGetArray(G, &g));
2705: for (i = 0; i < N; i++) {
2706: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2707: PetscCall(VecAssemblyBegin(X));
2708: PetscCall(VecAssemblyEnd(X));
2709: PetscCall(SNESComputeObjective(snes, X, &f));
2710: PetscCall(VecSetValue(X, i, 2.0 * h, ADD_VALUES));
2711: PetscCall(VecAssemblyBegin(X));
2712: PetscCall(VecAssemblyEnd(X));
2713: PetscCall(SNESComputeObjective(snes, X, &f2));
2714: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2715: PetscCall(VecAssemblyBegin(X));
2716: PetscCall(VecAssemblyEnd(X));
2717: if (i >= low && i < high) g[i - low] = (f2 - f) / (2.0 * h);
2718: }
2719: PetscCall(VecRestoreArray(G, &g));
2720: PetscCall(VecDestroy(&X));
2721: PetscFunctionReturn(PETSC_SUCCESS);
2722: }
2724: /*@
2725: SNESTestFunction - Computes the difference between the computed and finite-difference functions
2727: Collective
2729: Input Parameter:
2730: . snes - the `SNES` context
2732: Options Database Keys:
2733: + -snes_test_function - compare the user provided function with one compute via finite differences to check for errors.
2734: - -snes_test_function_view - display the user provided function, the finite difference function and the difference
2736: Level: developer
2738: .seealso: [](ch_snes), `SNESTestJacobian()`, `SNESSetFunction()`, `SNESComputeFunction()`
2739: @*/
2740: PetscErrorCode SNESTestFunction(SNES snes)
2741: {
2742: Vec x, g1, g2, g3;
2743: PetscBool complete_print = PETSC_FALSE;
2744: PetscReal hcnorm, fdnorm, hcmax, fdmax, diffmax, diffnorm;
2745: PetscScalar dot;
2746: MPI_Comm comm;
2747: PetscViewer viewer, mviewer;
2748: PetscViewerFormat format;
2749: PetscInt tabs;
2750: static PetscBool directionsprinted = PETSC_FALSE;
2751: SNESObjectiveFn *objective;
2753: PetscFunctionBegin;
2754: PetscCall(SNESGetObjective(snes, &objective, NULL));
2755: if (!objective) PetscFunctionReturn(PETSC_SUCCESS);
2757: PetscObjectOptionsBegin((PetscObject)snes);
2758: PetscCall(PetscOptionsViewer("-snes_test_function_view", "View difference between hand-coded and finite difference function element entries", "None", &mviewer, &format, &complete_print));
2759: PetscOptionsEnd();
2761: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2762: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2763: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2764: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2765: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Function -------------\n"));
2766: if (!complete_print && !directionsprinted) {
2767: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_function_view and optionally -snes_test_function <threshold> to show difference\n"));
2768: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference function entries greater than <threshold>.\n"));
2769: }
2770: if (!directionsprinted) {
2771: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Function, if (for double precision runs) ||F - Ffd||/||F|| is\n"));
2772: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Function is probably correct.\n"));
2773: directionsprinted = PETSC_TRUE;
2774: }
2775: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2777: PetscCall(SNESGetSolution(snes, &x));
2778: PetscCall(VecDuplicate(x, &g1));
2779: PetscCall(VecDuplicate(x, &g2));
2780: PetscCall(VecDuplicate(x, &g3));
2781: PetscCall(SNESComputeFunction(snes, x, g1)); /* does not handle use of SNESSetFunctionDomainError() correctly */
2782: PetscCall(SNESComputeFunction_FD(snes, x, g2));
2784: PetscCall(VecNorm(g2, NORM_2, &fdnorm));
2785: PetscCall(VecNorm(g1, NORM_2, &hcnorm));
2786: PetscCall(VecNorm(g2, NORM_INFINITY, &fdmax));
2787: PetscCall(VecNorm(g1, NORM_INFINITY, &hcmax));
2788: PetscCall(VecDot(g1, g2, &dot));
2789: PetscCall(VecCopy(g1, g3));
2790: PetscCall(VecAXPY(g3, -1.0, g2));
2791: PetscCall(VecNorm(g3, NORM_2, &diffnorm));
2792: PetscCall(VecNorm(g3, NORM_INFINITY, &diffmax));
2793: PetscCall(PetscViewerASCIIPrintf(viewer, " ||Ffd|| %g, ||F|| = %g, angle cosine = (Ffd'F)/||Ffd||||F|| = %g\n", (double)fdnorm, (double)hcnorm, (double)(PetscRealPart(dot) / (fdnorm * hcnorm))));
2794: PetscCall(PetscViewerASCIIPrintf(viewer, " 2-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffnorm / PetscMax(hcnorm, fdnorm)), (double)diffnorm));
2795: PetscCall(PetscViewerASCIIPrintf(viewer, " max-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffmax / PetscMax(hcmax, fdmax)), (double)diffmax));
2797: if (complete_print) {
2798: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded function ----------\n"));
2799: PetscCall(VecView(g1, mviewer));
2800: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference function ----------\n"));
2801: PetscCall(VecView(g2, mviewer));
2802: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference function ----------\n"));
2803: PetscCall(VecView(g3, mviewer));
2804: }
2805: PetscCall(VecDestroy(&g1));
2806: PetscCall(VecDestroy(&g2));
2807: PetscCall(VecDestroy(&g3));
2809: if (complete_print) {
2810: PetscCall(PetscViewerPopFormat(mviewer));
2811: PetscCall(PetscViewerDestroy(&mviewer));
2812: }
2813: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2814: PetscFunctionReturn(PETSC_SUCCESS);
2815: }
2817: /*@
2818: SNESTestJacobian - Computes the difference between the computed and finite-difference Jacobians
2820: Collective
2822: Input Parameter:
2823: . snes - the `SNES` context
2825: Output Parameters:
2826: + Jnorm - the Frobenius norm of the computed Jacobian, or `NULL`
2827: - diffNorm - the Frobenius norm of the difference of the computed and finite-difference Jacobians, or `NULL`
2829: Options Database Keys:
2830: + -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.
2831: - -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference
2833: Level: developer
2835: Note:
2836: Directions and norms are printed to stdout if `diffNorm` is `NULL`.
2838: .seealso: [](ch_snes), `SNESTestFunction()`, `SNESSetJacobian()`, `SNESComputeJacobian()`
2839: @*/
2840: PetscErrorCode SNESTestJacobian(SNES snes, PetscReal *Jnorm, PetscReal *diffNorm)
2841: {
2842: Mat A, B, C, D, jacobian;
2843: Vec x = snes->vec_sol, f;
2844: PetscReal nrm, gnorm;
2845: PetscReal threshold = 1.e-5;
2846: void *functx;
2847: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, flg, istranspose;
2848: PetscBool silent = diffNorm != PETSC_NULLPTR ? PETSC_TRUE : PETSC_FALSE;
2849: PetscViewer viewer, mviewer;
2850: MPI_Comm comm;
2851: PetscInt tabs;
2852: static PetscBool directionsprinted = PETSC_FALSE;
2853: PetscViewerFormat format;
2855: PetscFunctionBegin;
2856: PetscObjectOptionsBegin((PetscObject)snes);
2857: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2858: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2859: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2860: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2861: 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));
2862: PetscOptionsEnd();
2864: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2865: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2866: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2867: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2868: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2869: if (!complete_print && !silent && !directionsprinted) {
2870: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2871: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2872: }
2873: if (!directionsprinted && !silent) {
2874: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2875: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2876: directionsprinted = PETSC_TRUE;
2877: }
2878: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2880: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2881: if (!flg) jacobian = snes->jacobian;
2882: else jacobian = snes->jacobian_pre;
2884: if (!x) PetscCall(MatCreateVecs(jacobian, &x, NULL));
2885: else PetscCall(PetscObjectReference((PetscObject)x));
2886: PetscCall(VecDuplicate(x, &f));
2888: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2889: PetscCall(SNESComputeFunction(snes, x, f));
2890: PetscCall(VecDestroy(&f));
2891: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2892: while (jacobian) {
2893: Mat JT = NULL, Jsave = NULL;
2895: if (istranspose) {
2896: PetscCall(MatCreateTranspose(jacobian, &JT));
2897: Jsave = jacobian;
2898: jacobian = JT;
2899: }
2900: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2901: if (flg) {
2902: A = jacobian;
2903: PetscCall(PetscObjectReference((PetscObject)A));
2904: } else {
2905: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2906: }
2908: PetscCall(MatDuplicate(A, MAT_DO_NOT_COPY_VALUES, &B));
2909: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2911: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2912: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2914: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2915: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2916: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2917: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2918: PetscCall(MatDestroy(&D));
2919: if (!gnorm) gnorm = 1; /* just in case */
2920: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2921: if (complete_print) {
2922: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2923: PetscCall(MatView(A, mviewer));
2924: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2925: PetscCall(MatView(B, mviewer));
2926: }
2928: if (threshold_print || complete_print) {
2929: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2930: PetscScalar *cvals;
2931: const PetscInt *bcols;
2932: const PetscScalar *bvals;
2934: PetscCall(MatDuplicate(A, MAT_DO_NOT_COPY_VALUES, &C));
2935: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2937: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2938: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2940: for (row = Istart; row < Iend; row++) {
2941: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2942: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2943: for (j = 0, cncols = 0; j < bncols; j++) {
2944: if (PetscAbsScalar(bvals[j]) > threshold) {
2945: ccols[cncols] = bcols[j];
2946: cvals[cncols] = bvals[j];
2947: cncols += 1;
2948: }
2949: }
2950: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2951: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2952: PetscCall(PetscFree2(ccols, cvals));
2953: }
2954: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2955: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2956: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2957: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2958: PetscCall(MatDestroy(&C));
2959: }
2960: PetscCall(MatDestroy(&A));
2961: PetscCall(MatDestroy(&B));
2962: PetscCall(MatDestroy(&JT));
2963: if (Jsave) jacobian = Jsave;
2964: if (jacobian != snes->jacobian_pre) {
2965: jacobian = snes->jacobian_pre;
2966: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2967: } else jacobian = NULL;
2968: }
2969: PetscCall(VecDestroy(&x));
2970: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2971: PetscCall(PetscViewerDestroy(&mviewer));
2972: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2974: if (Jnorm) *Jnorm = gnorm;
2975: if (diffNorm) *diffNorm = nrm;
2976: PetscFunctionReturn(PETSC_SUCCESS);
2977: }
2979: /*@
2980: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2982: Collective
2984: Input Parameters:
2985: + snes - the `SNES` context
2986: - X - input vector
2988: Output Parameters:
2989: + A - Jacobian matrix
2990: - B - optional matrix for building the preconditioner, usually the same as `A`
2992: Options Database Keys:
2993: + -snes_lag_preconditioner lag - how often to rebuild preconditioner
2994: . -snes_lag_jacobian lag - how often to rebuild Jacobian
2995: . -snes_test_jacobian [threshold] - compare the user provided Jacobian with one compute via finite differences to check for errors.
2996: If a threshold is given, display only those entries whose difference is greater than the threshold.
2997: . -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
2998: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2999: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
3000: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
3001: . -snes_compare_operator - Make the comparison options above use the operator instead of the matrix used to construct the preconditioner
3002: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
3003: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
3004: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
3005: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
3006: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
3007: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
3008: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
3010: Level: developer
3012: Note:
3013: Most users should not need to explicitly call this routine, as it
3014: is used internally within the nonlinear solvers.
3016: Developer Note:
3017: 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
3018: with the `SNESType` of test that has been removed.
3020: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
3021: `SNESSetJacobianDomainError()`, `SNESCheckJacobianDomainError()`, `SNESSetCheckJacobianDomainError()`
3022: @*/
3023: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
3024: {
3025: PetscBool flag;
3026: DM dm;
3027: DMSNES sdm;
3028: KSP ksp;
3030: PetscFunctionBegin;
3033: PetscCheckSameComm(snes, 1, X, 2);
3034: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
3035: PetscCall(SNESGetDM(snes, &dm));
3036: PetscCall(DMGetDMSNES(dm, &sdm));
3038: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
3039: if (snes->lagjacobian == -2) {
3040: snes->lagjacobian = -1;
3042: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
3043: } else if (snes->lagjacobian == -1) {
3044: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
3045: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
3046: if (flag) {
3047: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
3048: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
3049: }
3050: PetscFunctionReturn(PETSC_SUCCESS);
3051: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
3052: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
3053: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
3054: if (flag) {
3055: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
3056: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
3057: }
3058: PetscFunctionReturn(PETSC_SUCCESS);
3059: }
3060: if (snes->npc && snes->npcside == PC_LEFT) {
3061: /* SNESASPIN uses SNESNASM as the nonlinear preconditioner. When SNESNASM
3062: is done solving the sub-systems it calls the user-provided Jacobian function
3063: (corresponding to the unpreconditioned residual) retrieved through the DM.
3064: Consequently it would be redundant to call the Jacobian function here. In
3065: the future we may move the outer Jacobian function call out of SNESNASM
3066: in which case no special casing will be required here. */
3067: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESASPIN, &flag));
3068: if (flag) {
3069: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
3070: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
3071: PetscFunctionReturn(PETSC_SUCCESS);
3072: }
3073: }
3075: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
3076: PetscCall(VecLockReadPush(X));
3077: {
3078: void *ctx;
3079: SNESJacobianFn *J;
3080: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
3081: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
3082: }
3083: PetscCall(VecLockReadPop(X));
3084: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
3086: /* attach latest linearization point to the matrix used to construct the preconditioner */
3087: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
3089: /* the next line ensures that snes->ksp exists */
3090: PetscCall(SNESGetKSP(snes, &ksp));
3091: if (snes->lagpreconditioner == -2) {
3092: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
3093: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
3094: snes->lagpreconditioner = -1;
3095: } else if (snes->lagpreconditioner == -1) {
3096: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
3097: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
3098: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
3099: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
3100: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
3101: } else {
3102: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
3103: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
3104: }
3106: /* monkey business to allow testing Jacobians in multilevel solvers.
3107: This is needed because the SNESTestXXX interface does not accept vectors and matrices */
3108: {
3109: Vec xsave = snes->vec_sol;
3110: Mat jacobiansave = snes->jacobian;
3111: Mat jacobian_presave = snes->jacobian_pre;
3113: snes->vec_sol = X;
3114: snes->jacobian = A;
3115: snes->jacobian_pre = B;
3116: if (snes->testFunc) PetscCall(SNESTestFunction(snes));
3117: if (snes->testJac) PetscCall(SNESTestJacobian(snes, NULL, NULL));
3119: snes->vec_sol = xsave;
3120: snes->jacobian = jacobiansave;
3121: snes->jacobian_pre = jacobian_presave;
3122: }
3124: {
3125: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
3126: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
3127: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
3128: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
3129: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
3130: if (flag || flag_draw || flag_contour) {
3131: Mat Bexp_mine = NULL, Bexp, FDexp;
3132: PetscViewer vdraw, vstdout;
3133: PetscBool flg;
3134: if (flag_operator) {
3135: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
3136: Bexp = Bexp_mine;
3137: } else {
3138: /* See if the matrix used to construct the preconditioner can be viewed and added directly */
3139: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
3140: if (flg) Bexp = B;
3141: else {
3142: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
3143: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
3144: Bexp = Bexp_mine;
3145: }
3146: }
3147: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
3148: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
3149: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3150: if (flag_draw || flag_contour) {
3151: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3152: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3153: } else vdraw = NULL;
3154: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
3155: if (flag) PetscCall(MatView(Bexp, vstdout));
3156: if (vdraw) PetscCall(MatView(Bexp, vdraw));
3157: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
3158: if (flag) PetscCall(MatView(FDexp, vstdout));
3159: if (vdraw) PetscCall(MatView(FDexp, vdraw));
3160: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
3161: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
3162: if (flag) PetscCall(MatView(FDexp, vstdout));
3163: if (vdraw) { /* Always use contour for the difference */
3164: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3165: PetscCall(MatView(FDexp, vdraw));
3166: PetscCall(PetscViewerPopFormat(vdraw));
3167: }
3168: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3169: PetscCall(PetscViewerDestroy(&vdraw));
3170: PetscCall(MatDestroy(&Bexp_mine));
3171: PetscCall(MatDestroy(&FDexp));
3172: }
3173: }
3174: {
3175: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
3176: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
3177: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
3178: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
3179: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
3180: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
3181: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
3182: if (flag_threshold) {
3183: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
3184: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
3185: }
3186: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
3187: Mat Bfd;
3188: PetscViewer vdraw, vstdout;
3189: MatColoring coloring;
3190: ISColoring iscoloring;
3191: MatFDColoring matfdcoloring;
3192: SNESFunctionFn *func;
3193: void *funcctx;
3194: PetscReal norm1, norm2, normmax;
3196: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
3197: PetscCall(MatColoringCreate(Bfd, &coloring));
3198: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
3199: PetscCall(MatColoringSetFromOptions(coloring));
3200: PetscCall(MatColoringApply(coloring, &iscoloring));
3201: PetscCall(MatColoringDestroy(&coloring));
3202: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
3203: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3204: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
3205: PetscCall(ISColoringDestroy(&iscoloring));
3207: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
3208: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
3209: PetscCall(MatFDColoringSetFunction(matfdcoloring, (MatFDColoringFn *)func, funcctx));
3210: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
3211: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
3212: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3213: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
3214: PetscCall(MatFDColoringDestroy(&matfdcoloring));
3216: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3217: if (flag_draw || flag_contour) {
3218: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3219: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3220: } else vdraw = NULL;
3221: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
3222: if (flag_display) PetscCall(MatView(B, vstdout));
3223: if (vdraw) PetscCall(MatView(B, vdraw));
3224: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
3225: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3226: if (vdraw) PetscCall(MatView(Bfd, vdraw));
3227: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
3228: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
3229: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
3230: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
3231: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
3232: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3233: if (vdraw) { /* Always use contour for the difference */
3234: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3235: PetscCall(MatView(Bfd, vdraw));
3236: PetscCall(PetscViewerPopFormat(vdraw));
3237: }
3238: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3240: if (flag_threshold) {
3241: PetscInt bs, rstart, rend, i;
3242: PetscCall(MatGetBlockSize(B, &bs));
3243: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
3244: for (i = rstart; i < rend; i++) {
3245: const PetscScalar *ba, *ca;
3246: const PetscInt *bj, *cj;
3247: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
3248: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
3249: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
3250: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
3251: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
3252: for (j = 0; j < bn; j++) {
3253: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3254: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
3255: maxentrycol = bj[j];
3256: maxentry = PetscRealPart(ba[j]);
3257: }
3258: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
3259: maxdiffcol = bj[j];
3260: maxdiff = PetscRealPart(ca[j]);
3261: }
3262: if (rdiff > maxrdiff) {
3263: maxrdiffcol = bj[j];
3264: maxrdiff = rdiff;
3265: }
3266: }
3267: if (maxrdiff > 1) {
3268: 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));
3269: for (j = 0; j < bn; j++) {
3270: PetscReal rdiff;
3271: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3272: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
3273: }
3274: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
3275: }
3276: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
3277: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
3278: }
3279: }
3280: PetscCall(PetscViewerDestroy(&vdraw));
3281: PetscCall(MatDestroy(&Bfd));
3282: }
3283: }
3284: PetscFunctionReturn(PETSC_SUCCESS);
3285: }
3287: /*@C
3288: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3289: location to store the matrix.
3291: Logically Collective
3293: Input Parameters:
3294: + snes - the `SNES` context
3295: . Amat - the matrix that defines the (approximate) Jacobian
3296: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3297: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFn` for details
3298: - ctx - [optional] user-defined context for private data for the
3299: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3301: Level: beginner
3303: Notes:
3304: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3305: each matrix.
3307: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3308: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3310: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3311: must be a `MatFDColoring`.
3313: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3314: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3316: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3317: `SNESSetPicard()`, `SNESJacobianFn`, `SNESFunctionFn`
3318: @*/
3319: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, SNESJacobianFn *J, PetscCtx ctx)
3320: {
3321: DM dm;
3323: PetscFunctionBegin;
3327: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3328: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3329: /* update DMSNES
3330: We support incremental information; so update the function context only if both Amat and Pmat are not specified
3331: (which allows to disable the callbacks when both J and ctx are NULL),
3332: or, if any of the mats is specified, when at least one of J and ctx is not NULL */
3333: PetscCall(SNESGetDM(snes, &dm));
3334: if ((!Amat && !Pmat) || J || ctx) PetscCall(DMSNESSetJacobian(dm, J, ctx));
3335: if (Amat) {
3336: PetscCall(PetscObjectReference((PetscObject)Amat));
3337: PetscCall(MatDestroy(&snes->jacobian));
3339: snes->jacobian = Amat;
3340: }
3341: if (Pmat) {
3342: PetscCall(PetscObjectReference((PetscObject)Pmat));
3343: PetscCall(MatDestroy(&snes->jacobian_pre));
3345: snes->jacobian_pre = Pmat;
3346: }
3347: PetscFunctionReturn(PETSC_SUCCESS);
3348: }
3350: /*@C
3351: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3352: provided context for evaluating the Jacobian.
3354: Not Collective, but `Mat` object will be parallel if `SNES` is
3356: Input Parameter:
3357: . snes - the nonlinear solver context
3359: Output Parameters:
3360: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3361: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3362: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFn`
3363: - ctx - location to stash Jacobian ctx (or `NULL`)
3365: Level: advanced
3367: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFn`, `SNESGetFunction()`
3368: @*/
3369: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, PetscCtxRt ctx)
3370: {
3371: DM dm;
3373: PetscFunctionBegin;
3375: if (Amat) *Amat = snes->jacobian;
3376: if (Pmat) *Pmat = snes->jacobian_pre;
3377: PetscCall(SNESGetDM(snes, &dm));
3378: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3379: PetscFunctionReturn(PETSC_SUCCESS);
3380: }
3382: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3383: {
3384: DM dm;
3385: DMSNES sdm;
3387: PetscFunctionBegin;
3388: PetscCall(SNESGetDM(snes, &dm));
3389: PetscCall(DMGetDMSNES(dm, &sdm));
3390: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3391: DM dm;
3392: PetscBool isdense, ismf;
3394: PetscCall(SNESGetDM(snes, &dm));
3395: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3396: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3397: if (isdense) PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3398: else if (!ismf) PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3399: }
3400: PetscFunctionReturn(PETSC_SUCCESS);
3401: }
3403: /*@
3404: SNESSetUp - Sets up the internal data structures for the later use
3405: of a nonlinear solver `SNESSolve()`.
3407: Collective
3409: Input Parameter:
3410: . snes - the `SNES` context
3412: Level: advanced
3414: Note:
3415: For basic use of the `SNES` solvers the user does not need to explicitly call
3416: `SNESSetUp()`, since these actions will automatically occur during
3417: the call to `SNESSolve()`. However, if one wishes to control this
3418: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3419: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3421: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`, `SNESSetFromOptions()`
3422: @*/
3423: PetscErrorCode SNESSetUp(SNES snes)
3424: {
3425: DM dm;
3426: DMSNES sdm;
3427: SNESLineSearch linesearch, pclinesearch;
3428: void *lsprectx, *lspostctx;
3429: PetscBool mf_operator, mf;
3430: Vec f, fpc;
3431: void *funcctx;
3432: void *jacctx, *appctx;
3433: Mat j, jpre;
3434: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, PetscCtx);
3435: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, PetscCtx);
3436: SNESFunctionFn *func;
3437: SNESJacobianFn *jac;
3439: PetscFunctionBegin;
3441: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3442: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3444: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3446: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3448: PetscCall(SNESGetDM(snes, &dm));
3449: PetscCall(DMGetDMSNES(dm, &sdm));
3450: PetscCall(SNESSetDefaultComputeJacobian(snes));
3452: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3454: if (snes->usesksp && !snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3456: if (snes->linesearch) {
3457: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3458: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3459: }
3461: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3462: if (snes->npc && snes->npcside == PC_LEFT) {
3463: snes->mf = PETSC_TRUE;
3464: snes->mf_operator = PETSC_FALSE;
3465: }
3466: if (snes->ops->ctxcompute && !snes->ctx) PetscCallBack("SNES callback compute application context", (*snes->ops->ctxcompute)(snes, &snes->ctx));
3467: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3469: if (snes->npc) {
3470: SNESNormSchedule npc_norm_schedule;
3472: /* copy the DM over and the functions if NPC DM is not present */
3473: if (!snes->npc->dm) {
3474: PetscCall(SNESGetDM(snes, &dm));
3475: PetscCall(SNESSetDM(snes->npc, dm));
3477: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3478: PetscCall(VecDuplicate(f, &fpc));
3479: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3480: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3481: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3482: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3483: PetscCall(VecDestroy(&fpc));
3485: /* copy the function pointers over */
3486: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3488: /* Propagate app context if not present */
3489: PetscCall(SNESGetApplicationContext(snes->npc, &appctx));
3490: if (!appctx && !snes->npc->ops->ctxcompute) {
3491: if (snes->ops->ctxcompute) {
3492: PetscCall(SNESSetComputeApplicationContext(snes->npc, snes->ops->ctxcompute, snes->ops->ctxdestroy));
3493: } else {
3494: PetscCall(SNESGetApplicationContext(snes, &appctx));
3495: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3496: }
3497: }
3498: }
3500: /* Set default norm schedule for NPC if not yet set */
3501: PetscCall(SNESGetNormSchedule(snes->npc, &npc_norm_schedule));
3502: if (npc_norm_schedule == SNES_NORM_DEFAULT) {
3503: if (snes->npcside == PC_RIGHT) PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3504: else if (snes->npcside == PC_LEFT) PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3505: }
3507: PetscCall(SNESSetFromOptions(snes->npc));
3509: /* copy the line search context over */
3510: if (snes->dm == snes->npc->dm && snes->linesearch && snes->npc->linesearch) {
3511: PetscCall(SNESGetLineSearch(snes, &linesearch));
3512: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3513: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3514: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3515: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3516: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3517: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3518: }
3519: }
3521: snes->jac_iter = 0;
3522: snes->pre_iter = 0;
3524: PetscTryTypeMethod(snes, setup);
3526: PetscCall(SNESSetDefaultComputeJacobian(snes));
3528: if (snes->npc && snes->npcside == PC_LEFT) {
3529: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3530: if (snes->linesearch) {
3531: PetscCall(SNESGetLineSearch(snes, &linesearch));
3532: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3533: }
3534: }
3535: }
3536: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3537: snes->setupcalled = PETSC_TRUE;
3538: PetscFunctionReturn(PETSC_SUCCESS);
3539: }
3541: /*@
3542: 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
3544: Collective
3546: Input Parameter:
3547: . snes - the nonlinear iterative solver context obtained from `SNESCreate()`
3549: Level: intermediate
3551: Notes:
3552: Any options set on the `SNES` object, including those set with `SNESSetFromOptions()` remain.
3554: Call this if you wish to reuse a `SNES` but with different size vectors
3556: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3558: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3559: @*/
3560: PetscErrorCode SNESReset(SNES snes)
3561: {
3562: PetscFunctionBegin;
3564: if (snes->ops->ctxdestroy && snes->ctx) {
3565: PetscCallBack("SNES callback destroy application context", (*snes->ops->ctxdestroy)(&snes->ctx));
3566: snes->ctx = NULL;
3567: }
3568: if (snes->npc) PetscCall(SNESReset(snes->npc));
3570: PetscTryTypeMethod(snes, reset);
3571: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3573: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3575: PetscCall(VecDestroy(&snes->vec_rhs));
3576: PetscCall(VecDestroy(&snes->vec_sol));
3577: PetscCall(VecDestroy(&snes->vec_sol_update));
3578: PetscCall(VecDestroy(&snes->vec_func));
3579: PetscCall(MatDestroy(&snes->jacobian));
3580: PetscCall(MatDestroy(&snes->jacobian_pre));
3581: PetscCall(MatDestroy(&snes->picard));
3582: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3583: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3585: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3587: snes->nwork = snes->nvwork = 0;
3588: snes->setupcalled = PETSC_FALSE;
3589: PetscFunctionReturn(PETSC_SUCCESS);
3590: }
3592: /*@
3593: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()` also
3594: removes the default viewer.
3596: Collective
3598: Input Parameter:
3599: . snes - the nonlinear iterative solver context obtained from `SNESCreate()`
3601: Level: intermediate
3603: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3604: @*/
3605: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3606: {
3607: PetscFunctionBegin;
3609: for (PetscInt i = 0; i < snes->numberreasonviews; i++) {
3610: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3611: }
3612: snes->numberreasonviews = 0;
3613: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
3614: PetscFunctionReturn(PETSC_SUCCESS);
3615: }
3617: /*@
3618: SNESDestroy - Destroys the nonlinear solver context that was created
3619: with `SNESCreate()`.
3621: Collective
3623: Input Parameter:
3624: . snes - the `SNES` context
3626: Level: beginner
3628: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3629: @*/
3630: PetscErrorCode SNESDestroy(SNES *snes)
3631: {
3632: DM dm;
3634: PetscFunctionBegin;
3635: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3637: if (--((PetscObject)*snes)->refct > 0) {
3638: *snes = NULL;
3639: PetscFunctionReturn(PETSC_SUCCESS);
3640: }
3642: PetscCall(SNESReset(*snes));
3643: PetscCall(SNESDestroy(&(*snes)->npc));
3645: /* if memory was published with SAWs then destroy it */
3646: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3647: PetscTryTypeMethod(*snes, destroy);
3649: dm = (*snes)->dm;
3650: while (dm) {
3651: PetscCall(DMCoarsenHookRemove(dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3652: PetscCall(DMGetCoarseDM(dm, &dm));
3653: }
3655: PetscCall(DMDestroy(&(*snes)->dm));
3656: PetscCall(KSPDestroy(&(*snes)->ksp));
3657: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3659: PetscCall(PetscFree((*snes)->kspconvctx));
3660: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)(&(*snes)->cnvP));
3661: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3662: PetscCall(SNESMonitorCancel(*snes));
3663: PetscCall(SNESConvergedReasonViewCancel(*snes));
3664: PetscCall(PetscHeaderDestroy(snes));
3665: PetscFunctionReturn(PETSC_SUCCESS);
3666: }
3668: /* ----------- Routines to set solver parameters ---------- */
3670: /*@
3671: SNESSetLagPreconditioner - Sets when the preconditioner is rebuilt in the nonlinear solve `SNESSolve()`.
3673: Logically Collective
3675: Input Parameters:
3676: + snes - the `SNES` context
3677: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3678: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3680: Options Database Keys:
3681: + -snes_lag_jacobian_persists (true|false) - sets the persistence through multiple `SNESSolve()`
3682: . -snes_lag_jacobian (-2|1|2|...) - sets the lag
3683: . -snes_lag_preconditioner_persists (true|false) - sets the persistence through multiple `SNESSolve()`
3684: - -snes_lag_preconditioner (-2|1|2|...) - sets the lag
3686: Level: intermediate
3688: Notes:
3689: The default is 1
3691: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3693: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3695: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3696: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3697: @*/
3698: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3699: {
3700: PetscFunctionBegin;
3703: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3704: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3705: snes->lagpreconditioner = lag;
3706: PetscFunctionReturn(PETSC_SUCCESS);
3707: }
3709: /*@
3710: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3712: Logically Collective
3714: Input Parameters:
3715: + snes - the `SNES` context
3716: - steps - the number of refinements to do, defaults to 0
3718: Options Database Key:
3719: . -snes_grid_sequence steps - Use grid sequencing to generate initial guess
3721: Level: intermediate
3723: Notes:
3724: Once grid sequencing is turned on `SNESSolve()` will automatically perform the solve on each grid refinement.
3726: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3728: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3729: `SNESSetDM()`, `SNESSolve()`
3730: @*/
3731: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3732: {
3733: PetscFunctionBegin;
3736: snes->gridsequence = steps;
3737: PetscFunctionReturn(PETSC_SUCCESS);
3738: }
3740: /*@
3741: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3743: Logically Collective
3745: Input Parameter:
3746: . snes - the `SNES` context
3748: Output Parameter:
3749: . steps - the number of refinements to do, defaults to 0
3751: Level: intermediate
3753: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3754: @*/
3755: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3756: {
3757: PetscFunctionBegin;
3759: *steps = snes->gridsequence;
3760: PetscFunctionReturn(PETSC_SUCCESS);
3761: }
3763: /*@
3764: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3766: Not Collective
3768: Input Parameter:
3769: . snes - the `SNES` context
3771: Output Parameter:
3772: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3773: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3775: Level: intermediate
3777: Notes:
3778: The default is 1
3780: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3782: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3783: @*/
3784: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3785: {
3786: PetscFunctionBegin;
3788: *lag = snes->lagpreconditioner;
3789: PetscFunctionReturn(PETSC_SUCCESS);
3790: }
3792: /*@
3793: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3794: often the preconditioner is rebuilt.
3796: Logically Collective
3798: Input Parameters:
3799: + snes - the `SNES` context
3800: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3801: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3803: Options Database Keys:
3804: + -snes_lag_jacobian_persists (true|false) - sets the persistence through multiple SNES solves
3805: . -snes_lag_jacobian (-2|1|2|...) - sets the lag
3806: . -snes_lag_preconditioner_persists (true|false) - sets the persistence through multiple SNES solves
3807: - -snes_lag_preconditioner (-2|1|2|...) - sets the lag.
3809: Level: intermediate
3811: Notes:
3812: The default is 1
3814: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3816: 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
3817: at the next Newton step but never again (unless it is reset to another value)
3819: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3820: @*/
3821: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3822: {
3823: PetscFunctionBegin;
3825: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3826: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3828: snes->lagjacobian = lag;
3829: PetscFunctionReturn(PETSC_SUCCESS);
3830: }
3832: /*@
3833: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3835: Not Collective
3837: Input Parameter:
3838: . snes - the `SNES` context
3840: Output Parameter:
3841: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3842: the Jacobian is built etc.
3844: Level: intermediate
3846: Notes:
3847: The default is 1
3849: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3851: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3852: @*/
3853: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3854: {
3855: PetscFunctionBegin;
3857: *lag = snes->lagjacobian;
3858: PetscFunctionReturn(PETSC_SUCCESS);
3859: }
3861: /*@
3862: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3864: Logically collective
3866: Input Parameters:
3867: + snes - the `SNES` context
3868: - flg - jacobian lagging persists if true
3870: Options Database Keys:
3871: + -snes_lag_jacobian_persists (true|false) - sets the persistence through multiple SNES solves
3872: . -snes_lag_jacobian (-2|1|2|...) - sets the lag
3873: . -snes_lag_preconditioner_persists (true|false) - sets the persistence through multiple SNES solves
3874: - -snes_lag_preconditioner (-2|1|2|...) - sets the lag
3876: Level: advanced
3878: Notes:
3879: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3881: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3882: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3883: timesteps may present huge efficiency gains.
3885: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3886: @*/
3887: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3888: {
3889: PetscFunctionBegin;
3892: snes->lagjac_persist = flg;
3893: PetscFunctionReturn(PETSC_SUCCESS);
3894: }
3896: /*@
3897: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3899: Logically Collective
3901: Input Parameters:
3902: + snes - the `SNES` context
3903: - flg - preconditioner lagging persists if true
3905: Options Database Keys:
3906: + -snes_lag_jacobian_persists (true|false) - sets the persistence through multiple SNES solves
3907: . -snes_lag_jacobian (-2|1|2|...) - sets the lag
3908: . -snes_lag_preconditioner_persists (true|false) - sets the persistence through multiple SNES solves
3909: - -snes_lag_preconditioner (-2|1|2|...) - sets the lag
3911: Level: developer
3913: Notes:
3914: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3916: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3917: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3918: several timesteps may present huge efficiency gains.
3920: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3921: @*/
3922: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3923: {
3924: PetscFunctionBegin;
3927: snes->lagpre_persist = flg;
3928: PetscFunctionReturn(PETSC_SUCCESS);
3929: }
3931: /*@
3932: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3934: Logically Collective
3936: Input Parameters:
3937: + snes - the `SNES` context
3938: - force - `PETSC_TRUE` require at least one iteration
3940: Options Database Key:
3941: . -snes_force_iteration force - Sets forcing an iteration
3943: Level: intermediate
3945: Note:
3946: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3948: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetDivergenceTolerance()`
3949: @*/
3950: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3951: {
3952: PetscFunctionBegin;
3954: snes->forceiteration = force;
3955: PetscFunctionReturn(PETSC_SUCCESS);
3956: }
3958: /*@
3959: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3961: Logically Collective
3963: Input Parameter:
3964: . snes - the `SNES` context
3966: Output Parameter:
3967: . force - `PETSC_TRUE` requires at least one iteration.
3969: Level: intermediate
3971: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetDivergenceTolerance()`
3972: @*/
3973: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3974: {
3975: PetscFunctionBegin;
3977: *force = snes->forceiteration;
3978: PetscFunctionReturn(PETSC_SUCCESS);
3979: }
3981: /*@
3982: SNESSetTolerances - Sets various parameters used in `SNES` convergence tests.
3984: Logically Collective
3986: Input Parameters:
3987: + snes - the `SNES` context
3988: . abstol - the absolute convergence tolerance, $ F(x^n) \le abstol $
3989: . rtol - the relative convergence tolerance, $ F(x^n) \le reltol * F(x^0) $
3990: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3991: . maxit - the maximum number of iterations allowed in the solver, default 50.
3992: - maxf - the maximum number of function evaluations allowed in the solver (use `PETSC_UNLIMITED` indicates no limit), default 10,000
3994: Options Database Keys:
3995: + -snes_atol abstol - Sets `abstol`
3996: . -snes_rtol rtol - Sets `rtol`
3997: . -snes_stol stol - Sets `stol`
3998: . -snes_max_it maxit - Sets `maxit`
3999: - -snes_max_funcs maxf - Sets `maxf` (use `unlimited` to have no maximum)
4001: Level: intermediate
4003: Note:
4004: All parameters must be non-negative
4006: Use `PETSC_CURRENT` to retain the current value of any parameter and `PETSC_DETERMINE` to use the default value for the given `SNES`.
4007: The default value is the value in the object when its type is set.
4009: Use `PETSC_UNLIMITED` on `maxit` or `maxf` to indicate there is no bound on the number of iterations or number of function evaluations.
4011: Fortran Note:
4012: Use `PETSC_CURRENT_INTEGER`, `PETSC_CURRENT_REAL`, `PETSC_UNLIMITED_INTEGER`, `PETSC_DETERMINE_INTEGER`, or `PETSC_DETERMINE_REAL`
4014: .seealso: [](ch_snes), `SNESSolve()`, `SNES`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
4015: @*/
4016: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
4017: {
4018: PetscFunctionBegin;
4026: if (abstol == (PetscReal)PETSC_DETERMINE) {
4027: snes->abstol = snes->default_abstol;
4028: } else if (abstol != (PetscReal)PETSC_CURRENT) {
4029: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
4030: snes->abstol = abstol;
4031: }
4033: if (rtol == (PetscReal)PETSC_DETERMINE) {
4034: snes->rtol = snes->default_rtol;
4035: } else if (rtol != (PetscReal)PETSC_CURRENT) {
4036: 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);
4037: snes->rtol = rtol;
4038: }
4040: if (stol == (PetscReal)PETSC_DETERMINE) {
4041: snes->stol = snes->default_stol;
4042: } else if (stol != (PetscReal)PETSC_CURRENT) {
4043: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
4044: snes->stol = stol;
4045: }
4047: if (maxit == PETSC_DETERMINE) {
4048: snes->max_its = snes->default_max_its;
4049: } else if (maxit == PETSC_UNLIMITED) {
4050: snes->max_its = PETSC_INT_MAX;
4051: } else if (maxit != PETSC_CURRENT) {
4052: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
4053: snes->max_its = maxit;
4054: }
4056: if (maxf == PETSC_DETERMINE) {
4057: snes->max_funcs = snes->default_max_funcs;
4058: } else if (maxf == PETSC_UNLIMITED || maxf == -1) {
4059: snes->max_funcs = PETSC_UNLIMITED;
4060: } else if (maxf != PETSC_CURRENT) {
4061: PetscCheck(maxf >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be nonnegative", maxf);
4062: snes->max_funcs = maxf;
4063: }
4064: PetscFunctionReturn(PETSC_SUCCESS);
4065: }
4067: /*@
4068: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
4070: Logically Collective
4072: Input Parameters:
4073: + snes - the `SNES` context
4074: - 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
4075: is stopped due to divergence.
4077: Options Database Key:
4078: . -snes_divergence_tolerance divtol - Sets `divtol`
4080: Level: intermediate
4082: Notes:
4083: Use `PETSC_DETERMINE` to use the default value from when the object's type was set.
4085: Fortran Note:
4086: Use ``PETSC_DETERMINE_REAL` or `PETSC_UNLIMITED_REAL`
4088: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance()`
4089: @*/
4090: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
4091: {
4092: PetscFunctionBegin;
4096: if (divtol == (PetscReal)PETSC_DETERMINE) {
4097: snes->divtol = snes->default_divtol;
4098: } else if (divtol == (PetscReal)PETSC_UNLIMITED || divtol == -1) {
4099: snes->divtol = PETSC_UNLIMITED;
4100: } else if (divtol != (PetscReal)PETSC_CURRENT) {
4101: PetscCheck(divtol >= 1.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Divergence tolerance %g must be greater than 1.0", (double)divtol);
4102: snes->divtol = divtol;
4103: }
4104: PetscFunctionReturn(PETSC_SUCCESS);
4105: }
4107: /*@
4108: SNESGetTolerances - Gets various parameters used in `SNES` convergence tests.
4110: Not Collective
4112: Input Parameter:
4113: . snes - the `SNES` context
4115: Output Parameters:
4116: + atol - the absolute convergence tolerance
4117: . rtol - the relative convergence tolerance
4118: . stol - convergence tolerance in terms of the norm of the change in the solution between steps
4119: . maxit - the maximum number of iterations allowed
4120: - maxf - the maximum number of function evaluations allowed, `PETSC_UNLIMITED` indicates no bound
4122: Level: intermediate
4124: Notes:
4125: See `SNESSetTolerances()` for details on the parameters.
4127: The user can specify `NULL` for any parameter that is not needed.
4129: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
4130: @*/
4131: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
4132: {
4133: PetscFunctionBegin;
4135: if (atol) *atol = snes->abstol;
4136: if (rtol) *rtol = snes->rtol;
4137: if (stol) *stol = snes->stol;
4138: if (maxit) *maxit = snes->max_its;
4139: if (maxf) *maxf = snes->max_funcs;
4140: PetscFunctionReturn(PETSC_SUCCESS);
4141: }
4143: /*@
4144: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
4146: Not Collective
4148: Input Parameters:
4149: + snes - the `SNES` context
4150: - divtol - divergence tolerance
4152: Level: intermediate
4154: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
4155: @*/
4156: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
4157: {
4158: PetscFunctionBegin;
4160: if (divtol) *divtol = snes->divtol;
4161: PetscFunctionReturn(PETSC_SUCCESS);
4162: }
4164: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
4166: /*@C
4167: SNESMonitorLGRange - Line-graph monitor that plots the residual norm together with residual-range statistics for a `SNESSolve()`
4169: Collective
4171: Input Parameters:
4172: + snes - the `SNES` context
4173: . n - the iteration number
4174: . rnorm - the 2-norm of the residual
4175: - monctx - a `PetscViewer` of type `PETSCVIEWERDRAW` set up with `PetscViewerMonitorLGSetUp()`
4177: Level: intermediate
4179: Note:
4180: Plots four line graphs in the viewer: the residual norm (log scale), the fraction of residual entries larger than 20% of the maximum entry, the relative decrease `(prev - rnorm)/prev`, and their product.
4182: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`, `SNESMonitorDefault()`, `PetscViewerDrawGetDrawLG()`, `PetscDrawLG`
4183: @*/
4184: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, PetscCtx monctx)
4185: {
4186: PetscDrawLG lg;
4187: PetscReal x, y, per;
4188: PetscViewer v = (PetscViewer)monctx;
4189: static PetscReal prev; /* should be in the context */
4190: PetscDraw draw;
4192: PetscFunctionBegin;
4194: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
4195: if (!n) PetscCall(PetscDrawLGReset(lg));
4196: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4197: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
4198: x = (PetscReal)n;
4199: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
4200: else y = -15.0;
4201: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4202: if (n < 20 || !(n % 5) || snes->reason) {
4203: PetscCall(PetscDrawLGDraw(lg));
4204: PetscCall(PetscDrawLGSave(lg));
4205: }
4207: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
4208: if (!n) PetscCall(PetscDrawLGReset(lg));
4209: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4210: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
4211: PetscCall(SNESMonitorRange_Private(snes, n, &per));
4212: x = (PetscReal)n;
4213: y = 100.0 * per;
4214: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4215: if (n < 20 || !(n % 5) || snes->reason) {
4216: PetscCall(PetscDrawLGDraw(lg));
4217: PetscCall(PetscDrawLGSave(lg));
4218: }
4220: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
4221: if (!n) {
4222: prev = rnorm;
4223: PetscCall(PetscDrawLGReset(lg));
4224: }
4225: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4226: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
4227: x = (PetscReal)n;
4228: y = (prev - rnorm) / prev;
4229: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4230: if (n < 20 || !(n % 5) || snes->reason) {
4231: PetscCall(PetscDrawLGDraw(lg));
4232: PetscCall(PetscDrawLGSave(lg));
4233: }
4235: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
4236: if (!n) PetscCall(PetscDrawLGReset(lg));
4237: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4238: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
4239: x = (PetscReal)n;
4240: y = (prev - rnorm) / (prev * per);
4241: if (n > 2) { /*skip initial crazy value */
4242: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4243: }
4244: if (n < 20 || !(n % 5) || snes->reason) {
4245: PetscCall(PetscDrawLGDraw(lg));
4246: PetscCall(PetscDrawLGSave(lg));
4247: }
4248: prev = rnorm;
4249: PetscFunctionReturn(PETSC_SUCCESS);
4250: }
4252: /*@
4253: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
4255: Collective
4257: Input Parameters:
4258: + snes - the `SNES` context
4259: . it - current iteration
4260: . xnorm - 2-norm of current iterate
4261: . snorm - 2-norm of current step
4262: - fnorm - 2-norm of function
4264: Level: developer
4266: Note:
4267: This routine is called by the `SNESSolve()` implementations.
4268: It does not typically need to be called by the user.
4270: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`
4271: @*/
4272: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
4273: {
4274: PetscFunctionBegin;
4275: if (!snes->reason) {
4276: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
4277: if (it == snes->max_its && !snes->reason) {
4278: if (snes->normschedule == SNES_NORM_ALWAYS) {
4279: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
4280: snes->reason = SNES_DIVERGED_MAX_IT;
4281: } else snes->reason = SNES_CONVERGED_ITS;
4282: }
4283: }
4284: PetscFunctionReturn(PETSC_SUCCESS);
4285: }
4287: /*@
4288: SNESMonitor - runs any `SNES` monitor routines provided with `SNESMonitor()` or the options database
4290: Collective
4292: Input Parameters:
4293: + snes - nonlinear solver context obtained from `SNESCreate()`
4294: . iter - current iteration number
4295: - rnorm - current relative norm of the residual
4297: Level: developer
4299: Note:
4300: This routine is called by the `SNESSolve()` implementations.
4301: It does not typically need to be called by the user.
4303: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
4304: @*/
4305: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
4306: {
4307: PetscInt i, n = snes->numbermonitors;
4309: PetscFunctionBegin;
4310: PetscCall(VecLockReadPush(snes->vec_sol));
4311: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
4312: PetscCall(VecLockReadPop(snes->vec_sol));
4313: PetscFunctionReturn(PETSC_SUCCESS);
4314: }
4316: /* ------------ Routines to set performance monitoring options ----------- */
4318: /*MC
4319: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
4321: Synopsis:
4322: #include <petscsnes.h>
4323: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, PetscCtx mctx)
4325: Collective
4327: Input Parameters:
4328: + snes - the `SNES` context
4329: . its - iteration number
4330: . norm - 2-norm function value (may be estimated)
4331: - mctx - [optional] monitoring context
4333: Level: advanced
4335: .seealso: [](ch_snes), `SNESMonitorSet()`, `PetscCtx`
4336: M*/
4338: /*@C
4339: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
4340: iteration of the `SNES` nonlinear solver to display the iteration's
4341: progress.
4343: Logically Collective
4345: Input Parameters:
4346: + snes - the `SNES` context
4347: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4348: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4349: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence
4351: Calling sequence of f:
4352: + snes - the `SNES` object
4353: . it - the current iteration
4354: . rnorm - norm of the residual
4355: - mctx - the optional monitor context
4357: Options Database Keys:
4358: + -snes_monitor - sets `SNESMonitorDefault()`
4359: . -snes_monitor draw::draw_lg - sets line graph monitor
4360: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4361: the options database.
4363: Level: intermediate
4365: Note:
4366: Several different monitoring routines may be set by calling
4367: `SNESMonitorSet()` multiple times; all will be called in the
4368: order in which they were set.
4370: Fortran Note:
4371: Only a single monitor function can be set for each `SNES` object
4373: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`, `PetscCtxDestroyFn`
4374: @*/
4375: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES snes, PetscInt it, PetscReal rnorm, PetscCtx mctx), PetscCtx mctx, PetscCtxDestroyFn *monitordestroy)
4376: {
4377: PetscFunctionBegin;
4379: for (PetscInt i = 0; i < snes->numbermonitors; i++) {
4380: PetscBool identical;
4382: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))(PetscVoidFn *)f, mctx, monitordestroy, (PetscErrorCode (*)(void))(PetscVoidFn *)snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4383: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4384: }
4385: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4386: snes->monitor[snes->numbermonitors] = f;
4387: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4388: snes->monitorcontext[snes->numbermonitors++] = mctx;
4389: PetscFunctionReturn(PETSC_SUCCESS);
4390: }
4392: /*@
4393: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4395: Logically Collective
4397: Input Parameter:
4398: . snes - the `SNES` context
4400: Options Database Key:
4401: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4402: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4403: set via the options database
4405: Level: intermediate
4407: Note:
4408: There is no way to clear one specific monitor from a `SNES` object.
4410: .seealso: [](ch_snes), `SNES`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4411: @*/
4412: PetscErrorCode SNESMonitorCancel(SNES snes)
4413: {
4414: PetscFunctionBegin;
4416: for (PetscInt i = 0; i < snes->numbermonitors; i++) {
4417: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4418: }
4419: snes->numbermonitors = 0;
4420: PetscFunctionReturn(PETSC_SUCCESS);
4421: }
4423: /*@C
4424: SNESSetConvergenceTest - Sets the function that is to be used
4425: to test for convergence of the nonlinear iterative solution.
4427: Logically Collective
4429: Input Parameters:
4430: + snes - the `SNES` context
4431: . func - routine to test for convergence
4432: . ctx - [optional] context for private data for the convergence routine (may be `NULL`)
4433: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4435: Calling sequence of func:
4436: + snes - the `SNES` context
4437: . it - the current iteration number
4438: . xnorm - the norm of the new solution
4439: . snorm - the norm of the step
4440: . fnorm - the norm of the function value
4441: . reason - output, the reason convergence or divergence as declared
4442: - ctx - the optional convergence test context
4444: Level: advanced
4446: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`
4447: @*/
4448: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*func)(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm, SNESConvergedReason *reason, PetscCtx ctx), PetscCtx ctx, PetscCtxDestroyFn *destroy)
4449: {
4450: PetscFunctionBegin;
4452: if (!func) func = SNESConvergedSkip;
4453: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(&snes->cnvP));
4454: snes->ops->converged = func;
4455: snes->ops->convergeddestroy = destroy;
4456: snes->cnvP = ctx;
4457: PetscFunctionReturn(PETSC_SUCCESS);
4458: }
4460: /*@
4461: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped, which may be due to convergence, divergence, or stagnation
4463: Not Collective
4465: Input Parameter:
4466: . snes - the `SNES` context
4468: Output Parameter:
4469: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4471: Options Database Key:
4472: . -snes_converged_reason - prints the reason to standard out
4474: Level: intermediate
4476: Note:
4477: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4479: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4480: @*/
4481: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4482: {
4483: PetscFunctionBegin;
4485: PetscAssertPointer(reason, 2);
4486: *reason = snes->reason;
4487: PetscFunctionReturn(PETSC_SUCCESS);
4488: }
4490: /*@C
4491: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4493: Not Collective
4495: Input Parameter:
4496: . snes - the `SNES` context
4498: Output Parameter:
4499: . strreason - a human readable string that describes `SNES` converged reason
4501: Level: beginner
4503: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4504: @*/
4505: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char *strreason[])
4506: {
4507: PetscFunctionBegin;
4509: PetscAssertPointer(strreason, 2);
4510: *strreason = SNESConvergedReasons[snes->reason];
4511: PetscFunctionReturn(PETSC_SUCCESS);
4512: }
4514: /*@
4515: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4517: Not Collective
4519: Input Parameters:
4520: + snes - the `SNES` context
4521: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4522: manual pages for the individual convergence tests for complete lists
4524: Level: developer
4526: Developer Note:
4527: Called inside the various `SNESSolve()` implementations
4529: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4530: @*/
4531: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4532: {
4533: PetscFunctionBegin;
4535: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4536: snes->reason = reason;
4537: PetscFunctionReturn(PETSC_SUCCESS);
4538: }
4540: /*@
4541: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4543: Logically Collective
4545: Input Parameters:
4546: + snes - iterative context obtained from `SNESCreate()`
4547: . a - array to hold history, this array will contain the function norms computed at each step
4548: . its - integer array holds the number of linear iterations for each solve.
4549: . na - size of `a` and `its`
4550: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4551: else it continues storing new values for new nonlinear solves after the old ones
4553: Level: intermediate
4555: Notes:
4556: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' is `PETSC_DECIDE` (or, deprecated, `PETSC_DEFAULT`) then a
4557: default array of length 1,000 is allocated.
4559: This routine is useful, e.g., when running a code for purposes
4560: of accurate performance monitoring, when no I/O should be done
4561: during the section of code that is being timed.
4563: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4565: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4566: @*/
4567: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4568: {
4569: PetscFunctionBegin;
4571: if (a) PetscAssertPointer(a, 2);
4572: if (its) PetscAssertPointer(its, 3);
4573: if (!a) {
4574: if (na == PETSC_DECIDE) na = 1000;
4575: PetscCall(PetscCalloc2(na, &a, na, &its));
4576: snes->conv_hist_alloc = PETSC_TRUE;
4577: }
4578: snes->conv_hist = a;
4579: snes->conv_hist_its = its;
4580: snes->conv_hist_max = (size_t)na;
4581: snes->conv_hist_len = 0;
4582: snes->conv_hist_reset = reset;
4583: PetscFunctionReturn(PETSC_SUCCESS);
4584: }
4586: #if PetscDefined(HAVE_MATLAB)
4587: #include <engine.h> /* MATLAB include file */
4588: #include <mex.h> /* MATLAB include file */
4590: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4591: {
4592: mxArray *mat;
4593: PetscReal *ar;
4595: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4596: ar = (PetscReal *)mxGetData(mat);
4597: for (PetscInt i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4598: return mat;
4599: }
4600: #endif
4602: /*@C
4603: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4605: Not Collective
4607: Input Parameter:
4608: . snes - iterative context obtained from `SNESCreate()`
4610: Output Parameters:
4611: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4612: . its - integer array holds the number of linear iterations (or
4613: negative if not converged) for each solve.
4614: - na - size of `a` and `its`
4616: Level: intermediate
4618: Note:
4619: This routine is useful, e.g., when running a code for purposes
4620: of accurate performance monitoring, when no I/O should be done
4621: during the section of code that is being timed.
4623: Fortran Notes:
4624: Return the arrays with ``SNESRestoreConvergenceHistory()`
4626: Use the arguments
4627: .vb
4628: PetscReal, pointer :: a(:)
4629: PetscInt, pointer :: its(:)
4630: .ve
4632: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4633: @*/
4634: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4635: {
4636: PetscFunctionBegin;
4638: if (a) *a = snes->conv_hist;
4639: if (its) *its = snes->conv_hist_its;
4640: if (na) *na = (PetscInt)snes->conv_hist_len;
4641: PetscFunctionReturn(PETSC_SUCCESS);
4642: }
4644: /*@C
4645: SNESSetUpdate - Sets the general-purpose update function called
4646: at the beginning of every iteration of the nonlinear solve. Specifically
4647: it is called just before the Jacobian is "evaluated" and after the function
4648: evaluation.
4650: Logically Collective
4652: Input Parameters:
4653: + snes - The nonlinear solver context
4654: - func - The update function; for calling sequence see `SNESUpdateFn`
4656: Level: advanced
4658: Notes:
4659: 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
4660: to `SNESSetFunction()`, or `SNESSetPicard()`
4661: This is not used by most users, and it is intended to provide a general hook that is run
4662: right before the direction step is computed.
4664: Users are free to modify the current residual vector,
4665: the current linearization point, or any other vector associated to the specific solver used.
4666: If such modifications take place, it is the user responsibility to update all the relevant
4667: vectors. For example, if one is adjusting the model parameters at each Newton step their code may look like
4668: .vb
4669: PetscErrorCode update(SNES snes, PetscInt iteration)
4670: {
4671: PetscFunctionBeginUser;
4672: if (iteration > 0) {
4673: // update the model parameters here
4674: Vec x,f;
4675: PetscCall(SNESGetSolution(snes,&x));
4676: PetcCall(SNESGetFunction(snes,&f,NULL,NULL));
4677: PetscCall(SNESComputeFunction(snes,x,f));
4678: }
4679: PetscFunctionReturn(PETSC_SUCCESS);
4680: }
4681: .ve
4683: 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.
4685: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4686: `SNESMonitorSet()`
4687: @*/
4688: PetscErrorCode SNESSetUpdate(SNES snes, SNESUpdateFn *func)
4689: {
4690: PetscFunctionBegin;
4692: snes->ops->update = func;
4693: PetscFunctionReturn(PETSC_SUCCESS);
4694: }
4696: /*@
4697: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4699: Collective
4701: Input Parameters:
4702: + snes - iterative context obtained from `SNESCreate()`
4703: - viewer - the viewer to display the reason
4705: Options Database Keys:
4706: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4707: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4709: Level: beginner
4711: Note:
4712: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4713: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4715: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4716: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4717: `SNESConvergedReasonViewFromOptions()`,
4718: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4719: @*/
4720: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4721: {
4722: PetscViewerFormat format;
4723: PetscBool isAscii;
4725: PetscFunctionBegin;
4726: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4727: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4728: if (isAscii) {
4729: PetscCall(PetscViewerGetFormat(viewer, &format));
4730: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel + 1));
4731: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4732: DM dm;
4733: Vec u;
4734: PetscDS prob;
4735: PetscInt Nf;
4736: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4737: void **exactCtx;
4738: PetscReal error;
4740: PetscCall(SNESGetDM(snes, &dm));
4741: PetscCall(SNESGetSolution(snes, &u));
4742: PetscCall(DMGetDS(dm, &prob));
4743: PetscCall(PetscDSGetNumFields(prob, &Nf));
4744: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4745: for (PetscInt f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4746: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4747: PetscCall(PetscFree2(exactSol, exactCtx));
4748: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4749: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4750: }
4751: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4752: if (((PetscObject)snes)->prefix) {
4753: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4754: } else {
4755: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4756: }
4757: } else if (snes->reason <= 0) {
4758: if (((PetscObject)snes)->prefix) {
4759: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4760: } else {
4761: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4762: }
4763: }
4764: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel + 1));
4765: }
4766: PetscFunctionReturn(PETSC_SUCCESS);
4767: }
4769: /*@C
4770: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4771: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4773: Logically Collective
4775: Input Parameters:
4776: + snes - the `SNES` context
4777: . f - the `SNESConvergedReason` view function
4778: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4779: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence
4781: Calling sequence of `f`:
4782: + snes - the `SNES` context
4783: - vctx - [optional] context for private data for the function
4785: Options Database Keys:
4786: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4787: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4788: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4790: Level: intermediate
4792: Note:
4793: Several different converged reason view routines may be set by calling
4794: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4795: order in which they were set.
4797: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`,
4798: `PetscCtxDestroyFn`
4799: @*/
4800: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, PetscCtx vctx), PetscCtx vctx, PetscCtxDestroyFn *reasonviewdestroy)
4801: {
4802: PetscFunctionBegin;
4804: for (PetscInt i = 0; i < snes->numberreasonviews; i++) {
4805: PetscBool identical;
4807: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))(PetscVoidFn *)f, vctx, reasonviewdestroy, (PetscErrorCode (*)(void))(PetscVoidFn *)snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4808: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4809: }
4810: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4811: snes->reasonview[snes->numberreasonviews] = f;
4812: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4813: snes->reasonviewcontext[snes->numberreasonviews++] = vctx;
4814: PetscFunctionReturn(PETSC_SUCCESS);
4815: }
4817: /*@
4818: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4819: All the user-provided viewer routines set with `SNESConvergedReasonViewSet()` will be called, if they exist.
4821: Collective
4823: Input Parameter:
4824: . snes - the `SNES` object
4826: Level: advanced
4828: Note:
4829: This function has a different API and behavior than `PetscObjectViewFromOptions()`
4831: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4832: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4833: @*/
4834: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4835: {
4836: static PetscBool incall = PETSC_FALSE;
4838: PetscFunctionBegin;
4839: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4840: incall = PETSC_TRUE;
4842: /* All user-provided viewers are called first, if they exist. */
4843: for (PetscInt i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4845: /* Call PETSc default routine if users ask for it */
4846: if (snes->convergedreasonviewer) {
4847: PetscCall(PetscViewerPushFormat(snes->convergedreasonviewer, snes->convergedreasonformat));
4848: PetscCall(SNESConvergedReasonView(snes, snes->convergedreasonviewer));
4849: PetscCall(PetscViewerPopFormat(snes->convergedreasonviewer));
4850: }
4851: incall = PETSC_FALSE;
4852: PetscFunctionReturn(PETSC_SUCCESS);
4853: }
4855: /*@
4856: SNESSolve - Solves a nonlinear system $F(x) = b $ associated with a `SNES` object
4858: Collective
4860: Input Parameters:
4861: + snes - the `SNES` context
4862: . b - the constant part of the equation $F(x) = b$, or `NULL` to use zero.
4863: - x - the solution vector.
4865: Level: beginner
4867: Note:
4868: The user should initialize the vector, `x`, with the initial guess
4869: for the nonlinear solve prior to calling `SNESSolve()` .
4871: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4872: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4873: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`
4874: @*/
4875: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4876: {
4877: PetscBool flg;
4878: Vec xcreated = NULL;
4879: DM dm;
4881: PetscFunctionBegin;
4884: if (x) PetscCheckSameComm(snes, 1, x, 3);
4886: if (b) PetscCheckSameComm(snes, 1, b, 2);
4888: /* High level operations using the nonlinear solver */
4889: {
4890: PetscViewer viewer;
4891: PetscViewerFormat format;
4892: PetscInt num;
4893: PetscBool flg;
4894: static PetscBool incall = PETSC_FALSE;
4896: if (!incall) {
4897: /* Estimate the convergence rate of the discretization */
4898: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4899: if (flg) {
4900: PetscConvEst conv;
4901: DM dm;
4902: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4903: PetscInt Nf;
4905: incall = PETSC_TRUE;
4906: PetscCall(SNESGetDM(snes, &dm));
4907: PetscCall(DMGetNumFields(dm, &Nf));
4908: PetscCall(PetscCalloc1(Nf, &alpha));
4909: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4910: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4911: PetscCall(PetscConvEstSetFromOptions(conv));
4912: PetscCall(PetscConvEstSetUp(conv));
4913: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4914: PetscCall(PetscViewerPushFormat(viewer, format));
4915: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4916: PetscCall(PetscViewerPopFormat(viewer));
4917: PetscCall(PetscViewerDestroy(&viewer));
4918: PetscCall(PetscConvEstDestroy(&conv));
4919: PetscCall(PetscFree(alpha));
4920: incall = PETSC_FALSE;
4921: }
4922: /* Adaptively refine the initial grid */
4923: num = 1;
4924: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4925: if (flg) {
4926: DMAdaptor adaptor;
4928: incall = PETSC_TRUE;
4929: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4930: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4931: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4932: PetscCall(DMAdaptorSetFromOptions(adaptor));
4933: PetscCall(DMAdaptorSetUp(adaptor));
4934: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4935: PetscCall(DMAdaptorDestroy(&adaptor));
4936: incall = PETSC_FALSE;
4937: }
4938: /* Use grid sequencing to adapt */
4939: num = 0;
4940: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4941: if (num) {
4942: DMAdaptor adaptor;
4943: const char *prefix;
4945: incall = PETSC_TRUE;
4946: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4947: PetscCall(SNESGetOptionsPrefix(snes, &prefix));
4948: PetscCall(DMAdaptorSetOptionsPrefix(adaptor, prefix));
4949: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4950: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4951: PetscCall(DMAdaptorSetFromOptions(adaptor));
4952: PetscCall(DMAdaptorSetUp(adaptor));
4953: PetscCall(PetscObjectViewFromOptions((PetscObject)adaptor, NULL, "-snes_adapt_view"));
4954: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4955: PetscCall(DMAdaptorDestroy(&adaptor));
4956: incall = PETSC_FALSE;
4957: }
4958: }
4959: }
4960: if (!x) x = snes->vec_sol;
4961: if (!x) {
4962: PetscCall(SNESGetDM(snes, &dm));
4963: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4964: x = xcreated;
4965: }
4966: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4968: for (PetscInt grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4969: for (PetscInt grid = 0; grid < snes->gridsequence + 1; grid++) {
4970: /* set solution vector */
4971: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4972: PetscCall(VecDestroy(&snes->vec_sol));
4973: snes->vec_sol = x;
4974: PetscCall(SNESGetDM(snes, &dm));
4976: /* set affine vector if provided */
4977: PetscCall(PetscObjectReference((PetscObject)b));
4978: PetscCall(VecDestroy(&snes->vec_rhs));
4979: snes->vec_rhs = b;
4981: 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");
4982: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4983: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right-hand side vector");
4984: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4985: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4986: PetscCall(SNESSetUp(snes));
4988: if (!grid) {
4989: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback compute initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4990: }
4992: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4993: PetscCall(SNESResetCounters(snes));
4994: snes->reason = SNES_CONVERGED_ITERATING;
4995: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4996: PetscUseTypeMethod(snes, solve);
4997: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4998: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4999: snes->functiondomainerror = PETSC_FALSE; /* clear the flag if it has been set */
5000: snes->objectivedomainerror = PETSC_FALSE; /* clear the flag if it has been set */
5001: snes->jacobiandomainerror = PETSC_FALSE; /* clear the flag if it has been set */
5003: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
5004: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
5006: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
5007: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
5008: /* Call converged reason views. This may involve user-provided viewers as well */
5009: PetscCall(SNESConvergedReasonViewFromOptions(snes));
5011: if (snes->errorifnotconverged) {
5012: if (snes->reason < 0) PetscCall(SNESMonitorCancel(snes));
5013: PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
5014: }
5015: if (snes->reason < 0) break;
5016: if (grid < snes->gridsequence) {
5017: DM fine;
5018: Vec xnew;
5019: Mat interp;
5021: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
5022: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
5023: PetscCall(DMGetCoordinatesLocalSetUp(fine));
5024: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
5025: PetscCall(DMCreateGlobalVector(fine, &xnew));
5026: PetscCall(MatInterpolate(interp, x, xnew));
5027: PetscCall(DMInterpolate(snes->dm, interp, fine));
5028: PetscCall(MatDestroy(&interp));
5029: x = xnew;
5031: PetscCall(SNESReset(snes));
5032: PetscCall(SNESSetDM(snes, fine));
5033: PetscCall(SNESResetFromOptions(snes));
5034: PetscCall(DMDestroy(&fine));
5035: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
5036: }
5037: }
5038: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
5039: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
5040: PetscCall(DMMonitor(snes->dm));
5041: PetscCall(SNESMonitorPauseFinal_Internal(snes));
5043: PetscCall(VecDestroy(&xcreated));
5044: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
5045: PetscFunctionReturn(PETSC_SUCCESS);
5046: }
5048: /* --------- Internal routines for SNES Package --------- */
5050: /*@
5051: SNESSetType - Sets the algorithm/method to be used to solve the nonlinear system with the given `SNES`
5053: Collective
5055: Input Parameters:
5056: + snes - the `SNES` context
5057: - type - a known method
5059: Options Database Key:
5060: . -snes_type type - Sets the method; see `SNESType`
5062: Level: intermediate
5064: Notes:
5065: See `SNESType` for available methods (for instance)
5066: + `SNESNEWTONLS` - Newton's method with line search
5067: (systems of nonlinear equations)
5068: - `SNESNEWTONTR` - Newton's method with trust region
5069: (systems of nonlinear equations)
5071: Normally, it is best to use the `SNESSetFromOptions()` command and then
5072: set the `SNES` solver type from the options database rather than by using
5073: this routine. Using the options database provides the user with
5074: maximum flexibility in evaluating the many nonlinear solvers.
5075: The `SNESSetType()` routine is provided for those situations where it
5076: is necessary to set the nonlinear solver independently of the command
5077: line or options database. This might be the case, for example, when
5078: the choice of solver changes during the execution of the program,
5079: and the user's application is taking responsibility for choosing the
5080: appropriate method.
5082: Developer Note:
5083: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
5084: the constructor in that list and calls it to create the specific object.
5086: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
5087: @*/
5088: PetscErrorCode SNESSetType(SNES snes, SNESType type)
5089: {
5090: PetscBool match;
5091: PetscErrorCode (*r)(SNES);
5093: PetscFunctionBegin;
5095: PetscAssertPointer(type, 2);
5097: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
5098: if (match) PetscFunctionReturn(PETSC_SUCCESS);
5100: PetscCall(PetscFunctionListFind(SNESList, type, &r));
5101: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
5102: /* Destroy the previous private SNES context */
5103: PetscTryTypeMethod(snes, destroy);
5104: /* Reinitialize type-specific function pointers in SNESOps structure */
5105: snes->ops->reset = NULL;
5106: snes->ops->setup = NULL;
5107: snes->ops->solve = NULL;
5108: snes->ops->view = NULL;
5109: snes->ops->setfromoptions = NULL;
5110: snes->ops->destroy = NULL;
5112: /* It may happen the user has customized the line search before calling SNESSetType */
5113: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5115: /* Reinitialize default parameters */
5116: PetscCall(SNESParametersInitialize(snes));
5118: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
5119: snes->setupcalled = PETSC_FALSE;
5120: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
5121: PetscCall((*r)(snes));
5122: PetscFunctionReturn(PETSC_SUCCESS);
5123: }
5125: /*@
5126: SNESGetType - Gets the `SNES` method type and name (as a string).
5128: Not Collective
5130: Input Parameter:
5131: . snes - nonlinear solver context
5133: Output Parameter:
5134: . type - `SNES` method (a character string)
5136: Level: intermediate
5138: Note:
5139: `type` should not be retained for later use as it will be an invalid pointer if the `SNESType` of `snes` is changed.
5141: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`, `PetscObjectTypeCompare()`, `PetscObjectTypeCompareAny()`
5142: @*/
5143: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
5144: {
5145: PetscFunctionBegin;
5147: PetscAssertPointer(type, 2);
5148: *type = ((PetscObject)snes)->type_name;
5149: PetscFunctionReturn(PETSC_SUCCESS);
5150: }
5152: /*@
5153: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
5155: Logically Collective
5157: Input Parameters:
5158: + snes - the `SNES` context obtained from `SNESCreate()`
5159: - u - the solution vector
5161: Level: beginner
5163: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
5164: @*/
5165: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
5166: {
5167: DM dm;
5169: PetscFunctionBegin;
5172: PetscCall(PetscObjectReference((PetscObject)u));
5173: PetscCall(VecDestroy(&snes->vec_sol));
5175: snes->vec_sol = u;
5177: PetscCall(SNESGetDM(snes, &dm));
5178: PetscCall(DMShellSetGlobalVector(dm, u));
5179: PetscFunctionReturn(PETSC_SUCCESS);
5180: }
5182: /*@
5183: SNESGetSolution - Returns the vector where the approximate solution is
5184: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
5186: Not Collective, but `x` is parallel if `snes` is parallel
5188: Input Parameter:
5189: . snes - the `SNES` context
5191: Output Parameter:
5192: . x - the solution
5194: Level: intermediate
5196: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
5197: @*/
5198: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
5199: {
5200: PetscFunctionBegin;
5202: PetscAssertPointer(x, 2);
5203: *x = snes->vec_sol;
5204: PetscFunctionReturn(PETSC_SUCCESS);
5205: }
5207: /*@
5208: SNESGetSolutionUpdate - Returns the vector where the solution update is
5209: stored.
5211: Not Collective, but `x` is parallel if `snes` is parallel
5213: Input Parameter:
5214: . snes - the `SNES` context
5216: Output Parameter:
5217: . x - the solution update
5219: Level: advanced
5221: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
5222: @*/
5223: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
5224: {
5225: PetscFunctionBegin;
5227: PetscAssertPointer(x, 2);
5228: *x = snes->vec_sol_update;
5229: PetscFunctionReturn(PETSC_SUCCESS);
5230: }
5232: /*@C
5233: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
5235: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
5237: Input Parameter:
5238: . snes - the `SNES` context
5240: Output Parameters:
5241: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
5242: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunctionFn`
5243: - ctx - the function context (or `NULL` if you don't want it)
5245: Level: advanced
5247: Note:
5248: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
5250: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunctionFn`
5251: @*/
5252: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, SNESFunctionFn **f, PetscCtxRt ctx)
5253: {
5254: DM dm;
5256: PetscFunctionBegin;
5258: if (r) {
5259: if (!snes->vec_func) {
5260: if (snes->vec_rhs) {
5261: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
5262: } else if (snes->vec_sol) {
5263: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
5264: } else if (snes->dm) {
5265: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
5266: }
5267: }
5268: *r = snes->vec_func;
5269: }
5270: PetscCall(SNESGetDM(snes, &dm));
5271: PetscCall(DMSNESGetFunction(dm, f, ctx));
5272: PetscFunctionReturn(PETSC_SUCCESS);
5273: }
5275: /*@C
5276: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
5278: Input Parameter:
5279: . snes - the `SNES` context
5281: Output Parameters:
5282: + f - the function (or `NULL`) see `SNESNGSFn` for calling sequence
5283: - ctx - the function context (or `NULL`)
5285: Level: advanced
5287: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`, `SNESNGSFn`
5288: @*/
5289: PetscErrorCode SNESGetNGS(SNES snes, SNESNGSFn **f, PetscCtxRt ctx)
5290: {
5291: DM dm;
5293: PetscFunctionBegin;
5295: PetscCall(SNESGetDM(snes, &dm));
5296: PetscCall(DMSNESGetNGS(dm, f, ctx));
5297: PetscFunctionReturn(PETSC_SUCCESS);
5298: }
5300: /*@
5301: SNESSetOptionsPrefix - Sets the prefix used for searching for all
5302: `SNES` options in the database.
5304: Logically Collective
5306: Input Parameters:
5307: + snes - the `SNES` context
5308: - prefix - the prefix to prepend to all option names
5310: Level: advanced
5312: Note:
5313: A hyphen (-) must NOT be given at the beginning of the prefix name.
5314: The first character of all runtime options is AUTOMATICALLY the hyphen.
5316: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
5317: @*/
5318: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
5319: {
5320: PetscFunctionBegin;
5322: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
5323: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5324: if (snes->linesearch) {
5325: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5326: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
5327: }
5328: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
5329: PetscFunctionReturn(PETSC_SUCCESS);
5330: }
5332: /*@
5333: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5334: `SNES` options in the database.
5336: Logically Collective
5338: Input Parameters:
5339: + snes - the `SNES` context
5340: - prefix - the prefix to prepend to all option names
5342: Level: advanced
5344: Note:
5345: A hyphen (-) must NOT be given at the beginning of the prefix name.
5346: The first character of all runtime options is AUTOMATICALLY the hyphen.
5348: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5349: @*/
5350: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5351: {
5352: PetscFunctionBegin;
5354: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5355: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5356: if (snes->linesearch) {
5357: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5358: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5359: }
5360: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5361: PetscFunctionReturn(PETSC_SUCCESS);
5362: }
5364: /*@
5365: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5366: `SNES` options in the database.
5368: Not Collective
5370: Input Parameter:
5371: . snes - the `SNES` context
5373: Output Parameter:
5374: . prefix - pointer to the prefix string used
5376: Level: advanced
5378: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5379: @*/
5380: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5381: {
5382: PetscFunctionBegin;
5384: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5385: PetscFunctionReturn(PETSC_SUCCESS);
5386: }
5388: /*@C
5389: SNESRegister - Adds a method to the nonlinear solver package.
5391: Not Collective
5393: Input Parameters:
5394: + sname - name of a new user-defined solver
5395: - function - routine to create method context
5397: Level: advanced
5399: Note:
5400: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5402: Example Usage:
5403: .vb
5404: SNESRegister("my_solver", MySolverCreate);
5405: .ve
5407: Then, your solver can be chosen with the procedural interface via
5408: .vb
5409: SNESSetType(snes, "my_solver")
5410: .ve
5411: or at runtime via the option
5412: .vb
5413: -snes_type my_solver
5414: .ve
5416: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5417: @*/
5418: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5419: {
5420: PetscFunctionBegin;
5421: PetscCall(SNESInitializePackage());
5422: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5423: PetscFunctionReturn(PETSC_SUCCESS);
5424: }
5426: /*@
5427: SNESTestLocalMin - Diagnostic that probes each entry of the current `SNES` solution to check whether the residual norm has a local minimum along the coordinate directions
5429: Collective
5431: Input Parameter:
5432: . snes - the `SNES` context
5434: Level: developer
5436: Note:
5437: Currently intended for serial runs. For each degree of freedom it perturbs the solution by increasing amounts and prints the resulting `SNESComputeFunction()` residual norms so the user can inspect local behavior.
5439: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESComputeFunction()`
5440: @*/
5441: PetscErrorCode SNESTestLocalMin(SNES snes)
5442: {
5443: PetscInt N, i, j;
5444: Vec u, uh, fh;
5445: PetscScalar value;
5446: PetscReal norm;
5448: PetscFunctionBegin;
5449: PetscCall(SNESGetSolution(snes, &u));
5450: PetscCall(VecDuplicate(u, &uh));
5451: PetscCall(VecDuplicate(u, &fh));
5453: /* currently only works for sequential */
5454: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5455: PetscCall(VecGetSize(u, &N));
5456: for (i = 0; i < N; i++) {
5457: PetscCall(VecCopy(u, uh));
5458: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5459: for (j = -10; j < 11; j++) {
5460: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5461: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5462: PetscCall(SNESComputeFunction(snes, uh, fh));
5463: PetscCall(VecNorm(fh, NORM_2, &norm)); /* does not handle use of SNESSetFunctionDomainError() correctly */
5464: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5465: value = -value;
5466: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5467: }
5468: }
5469: PetscCall(VecDestroy(&uh));
5470: PetscCall(VecDestroy(&fh));
5471: PetscFunctionReturn(PETSC_SUCCESS);
5472: }
5474: /*@
5475: SNESGetLineSearch - Returns the line search associated with the `SNES`.
5477: Not Collective
5479: Input Parameter:
5480: . snes - iterative context obtained from `SNESCreate()`
5482: Output Parameter:
5483: . linesearch - linesearch context
5485: Level: beginner
5487: Notes:
5488: It creates a default line search instance which can be configured as needed in case it has not been already set with `SNESSetLineSearch()`.
5490: You can also use the options database keys `-snes_linesearch_*` to configure the line search. See `SNESLineSearchSetFromOptions()` for the possible options.
5492: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`, `SNESLineSearchSetFromOptions()`
5493: @*/
5494: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5495: {
5496: const char *optionsprefix;
5498: PetscFunctionBegin;
5500: PetscAssertPointer(linesearch, 2);
5501: if (!snes->linesearch) {
5502: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5503: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5504: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5505: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5506: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5507: }
5508: *linesearch = snes->linesearch;
5509: PetscFunctionReturn(PETSC_SUCCESS);
5510: }
5512: /*@
5513: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5514: computing relative tolerance for linear solvers within an inexact
5515: Newton method.
5517: Logically Collective
5519: Input Parameters:
5520: + snes - `SNES` context
5521: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5523: Options Database Keys:
5524: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5525: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5526: . -snes_ksp_ew_rtol0 rtol0 - Sets rtol0
5527: . -snes_ksp_ew_rtolmax rtolmax - Sets rtolmax
5528: . -snes_ksp_ew_gamma gamma - Sets gamma
5529: . -snes_ksp_ew_alpha alpha - Sets alpha
5530: . -snes_ksp_ew_alpha2 alpha2 - Sets alpha2
5531: - -snes_ksp_ew_threshold threshold - Sets threshold
5533: Level: advanced
5535: Note:
5536: The default is to use a constant relative tolerance for
5537: the inner linear solvers. Alternatively, one can use the
5538: Eisenstat-Walker method {cite}`ew96`, where the relative convergence tolerance
5539: is reset at each Newton iteration according progress of the nonlinear
5540: solver.
5542: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5543: @*/
5544: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5545: {
5546: PetscFunctionBegin;
5549: snes->ksp_ewconv = flag;
5550: PetscFunctionReturn(PETSC_SUCCESS);
5551: }
5553: /*@
5554: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5555: for computing relative tolerance for linear solvers within an
5556: inexact Newton method.
5558: Not Collective
5560: Input Parameter:
5561: . snes - `SNES` context
5563: Output Parameter:
5564: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5566: Level: advanced
5568: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5569: @*/
5570: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5571: {
5572: PetscFunctionBegin;
5574: PetscAssertPointer(flag, 2);
5575: *flag = snes->ksp_ewconv;
5576: PetscFunctionReturn(PETSC_SUCCESS);
5577: }
5579: /*@
5580: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5581: convergence criteria for the linear solvers within an inexact
5582: Newton method.
5584: Logically Collective
5586: Input Parameters:
5587: + snes - `SNES` context
5588: . version - version 1, 2 (default is 2), 3 or 4
5589: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5590: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5591: . gamma - multiplicative factor for version 2 rtol computation
5592: (0 <= gamma2 <= 1)
5593: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5594: . alpha2 - power for safeguard
5595: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5597: Level: advanced
5599: Notes:
5600: Version 3 was contributed by Luis Chacon, June 2006.
5602: Use `PETSC_CURRENT` to retain the default for any of the parameters.
5604: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5605: @*/
5606: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5607: {
5608: SNESKSPEW *kctx;
5610: PetscFunctionBegin;
5612: kctx = (SNESKSPEW *)snes->kspconvctx;
5613: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5622: if (version != PETSC_CURRENT) kctx->version = version;
5623: if (rtol_0 != (PetscReal)PETSC_CURRENT) kctx->rtol_0 = rtol_0;
5624: if (rtol_max != (PetscReal)PETSC_CURRENT) kctx->rtol_max = rtol_max;
5625: if (gamma != (PetscReal)PETSC_CURRENT) kctx->gamma = gamma;
5626: if (alpha != (PetscReal)PETSC_CURRENT) kctx->alpha = alpha;
5627: if (alpha2 != (PetscReal)PETSC_CURRENT) kctx->alpha2 = alpha2;
5628: if (threshold != (PetscReal)PETSC_CURRENT) kctx->threshold = threshold;
5630: 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);
5631: 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);
5632: 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);
5633: 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);
5634: 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);
5635: 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);
5636: PetscFunctionReturn(PETSC_SUCCESS);
5637: }
5639: /*@
5640: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5641: convergence criteria for the linear solvers within an inexact
5642: Newton method.
5644: Not Collective
5646: Input Parameter:
5647: . snes - `SNES` context
5649: Output Parameters:
5650: + version - version 1, 2 (default is 2), 3 or 4
5651: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5652: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5653: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5654: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5655: . alpha2 - power for safeguard
5656: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5658: Level: advanced
5660: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5661: @*/
5662: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5663: {
5664: SNESKSPEW *kctx;
5666: PetscFunctionBegin;
5668: kctx = (SNESKSPEW *)snes->kspconvctx;
5669: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5670: if (version) *version = kctx->version;
5671: if (rtol_0) *rtol_0 = kctx->rtol_0;
5672: if (rtol_max) *rtol_max = kctx->rtol_max;
5673: if (gamma) *gamma = kctx->gamma;
5674: if (alpha) *alpha = kctx->alpha;
5675: if (alpha2) *alpha2 = kctx->alpha2;
5676: if (threshold) *threshold = kctx->threshold;
5677: PetscFunctionReturn(PETSC_SUCCESS);
5678: }
5680: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, PetscCtx ctx)
5681: {
5682: SNES snes = (SNES)ctx;
5683: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5684: PetscReal rtol = PETSC_CURRENT, stol;
5686: PetscFunctionBegin;
5687: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5688: if (!snes->iter) {
5689: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5690: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5691: } else {
5692: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5693: if (kctx->version == 1) {
5694: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5695: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5696: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5697: } else if (kctx->version == 2) {
5698: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5699: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5700: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5701: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5702: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5703: /* safeguard: avoid sharp decrease of rtol */
5704: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5705: stol = PetscMax(rtol, stol);
5706: rtol = PetscMin(kctx->rtol_0, stol);
5707: /* safeguard: avoid oversolving */
5708: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5709: stol = PetscMax(rtol, stol);
5710: rtol = PetscMin(kctx->rtol_0, stol);
5711: } else /* if (kctx->version == 4) */ {
5712: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5713: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5714: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5715: PetscReal rk = ared / pred;
5716: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5717: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5718: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5719: else rtol = kctx->v4_m2 * kctx->rtol_last;
5721: 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;
5722: kctx->rtol_last_2 = kctx->rtol_last;
5723: kctx->rk_last_2 = kctx->rk_last;
5724: kctx->rk_last = rk;
5725: }
5726: }
5727: /* safeguard: avoid rtol greater than rtol_max */
5728: rtol = PetscMin(rtol, kctx->rtol_max);
5729: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_CURRENT, PETSC_CURRENT, PETSC_CURRENT));
5730: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5731: PetscFunctionReturn(PETSC_SUCCESS);
5732: }
5734: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, PetscCtx ctx)
5735: {
5736: SNES snes = (SNES)ctx;
5737: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5738: PCSide pcside;
5739: Vec lres;
5741: PetscFunctionBegin;
5742: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5743: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5744: kctx->norm_last = snes->norm;
5745: if (kctx->version == 1 || kctx->version == 4) {
5746: PC pc;
5747: PetscBool getRes;
5749: PetscCall(KSPGetPC(ksp, &pc));
5750: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5751: if (!getRes) {
5752: KSPNormType normtype;
5754: PetscCall(KSPGetNormType(ksp, &normtype));
5755: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5756: }
5757: PetscCall(KSPGetPCSide(ksp, &pcside));
5758: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5759: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5760: } else {
5761: /* KSP residual is preconditioned residual */
5762: /* compute true linear residual norm */
5763: Mat J;
5764: PetscCall(KSPGetOperators(ksp, &J, NULL));
5765: PetscCall(VecDuplicate(b, &lres));
5766: PetscCall(MatMult(J, x, lres));
5767: PetscCall(VecAYPX(lres, -1.0, b));
5768: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5769: PetscCall(VecDestroy(&lres));
5770: }
5771: }
5772: PetscFunctionReturn(PETSC_SUCCESS);
5773: }
5775: #include <petsc/private/kspimpl.h>
5776: /*@
5777: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5779: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5781: Input Parameter:
5782: . snes - the `SNES` context
5784: Output Parameter:
5785: . ksp - the `KSP` context
5787: Level: beginner
5789: Notes:
5790: The user can then directly manipulate the `KSP` context to set various
5791: options, etc. Likewise, the user can then extract and manipulate the
5792: `PC` contexts as well.
5794: 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.
5796: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5797: @*/
5798: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5799: {
5800: PetscFunctionBegin;
5802: PetscAssertPointer(ksp, 2);
5804: if (!snes->ksp) {
5805: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5806: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5808: snes->ksp->presolve_ew = KSPPreSolve_SNESEW;
5809: snes->ksp->prectx_ew = snes;
5810: snes->ksp->postsolve_ew = KSPPostSolve_SNESEW;
5811: snes->ksp->postctx_ew = snes;
5813: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5814: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5815: }
5816: *ksp = snes->ksp;
5817: PetscFunctionReturn(PETSC_SUCCESS);
5818: }
5820: #include <petsc/private/dmimpl.h>
5821: /*@
5822: SNESSetDM - Sets the `DM` that may be used by some `SNES` nonlinear solvers or their underlying preconditioners
5824: Logically Collective
5826: Input Parameters:
5827: + snes - the nonlinear solver context
5828: - dm - the `DM`, cannot be `NULL`
5830: Level: intermediate
5832: Note:
5833: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5834: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5835: problems using the same function space.
5837: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5838: @*/
5839: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5840: {
5841: KSP ksp;
5842: DMSNES sdm;
5843: DM odm;
5845: PetscFunctionBegin;
5848: PetscCall(PetscObjectReference((PetscObject)dm));
5849: odm = snes->dm;
5850: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5851: if (snes->dm->dmsnes && !dm->dmsnes) {
5852: PetscCall(DMCopyDMSNES(snes->dm, dm));
5853: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5854: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5855: }
5856: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5857: PetscCall(DMDestroy(&snes->dm));
5858: }
5859: snes->dm = dm;
5860: snes->dmAuto = PETSC_FALSE;
5862: PetscCall(SNESGetKSP(snes, &ksp));
5863: PetscCall(KSPSetDM(ksp, dm));
5864: PetscCall(KSPSetDMActive(ksp, KSP_DMACTIVE_ALL, PETSC_FALSE));
5865: /* Propagate DM to NPC if npc does not have one yet or
5866: if it has the same DM SNES had before (like for gridsequencing) */
5867: if (snes->npc && (!snes->npc->dm || snes->npc->dm == odm)) PetscCall(SNESSetDM(snes->npc, snes->dm));
5868: PetscFunctionReturn(PETSC_SUCCESS);
5869: }
5871: /*@
5872: SNESGetDM - Gets the `DM` that may be used by some `SNES` nonlinear solvers/preconditioners
5874: Not Collective but `dm` obtained is parallel on `snes`
5876: Input Parameter:
5877: . snes - the `SNES` context
5879: Output Parameter:
5880: . dm - the `DM`
5882: Level: intermediate
5884: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5885: @*/
5886: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5887: {
5888: PetscFunctionBegin;
5890: if (!snes->dm) {
5891: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5892: snes->dmAuto = PETSC_TRUE;
5893: }
5894: *dm = snes->dm;
5895: PetscFunctionReturn(PETSC_SUCCESS);
5896: }
5898: /*@
5899: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5901: Collective
5903: Input Parameters:
5904: + snes - iterative context obtained from `SNESCreate()`
5905: - npc - the `SNES` nonlinear preconditioner object
5907: Level: developer
5909: Notes:
5910: This is rarely used, rather use `SNESGetNPC()` to retrieve the preconditioner and configure it using the API.
5912: Only some `SNESType` can use a nonlinear preconditioner
5914: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5915: @*/
5916: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5917: {
5918: PetscFunctionBegin;
5921: PetscCheckSameComm(snes, 1, npc, 2);
5922: PetscCall(PetscObjectReference((PetscObject)npc));
5923: PetscCall(SNESDestroy(&snes->npc));
5924: snes->npc = npc;
5925: PetscFunctionReturn(PETSC_SUCCESS);
5926: }
5928: /*@
5929: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5931: Collective the first time it is called if the `SNES` has no NPC set.
5933: Input Parameter:
5934: . snes - iterative context obtained from `SNESCreate()`
5936: Output Parameter:
5937: . npc - the `SNES` preconditioner context
5939: Options Database Key:
5940: . -npc_snes_type type - set the type of the `SNES` to use as the nonlinear preconditioner
5942: Level: advanced
5944: Notes:
5945: If a `SNES` was previously set with `SNESSetNPC()` then that object is returned, otherwise a new `SNES` object is created that will
5946: be used as the nonlinear preconditioner for the current `SNES` if no nonlinear preconditioner is present.
5948: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5949: `SNES`. These may be overwritten if needed by calling `SNESSetDM()` on the nonlinear preconditioner followed by `SNESSetFunction()`
5950: and `SNESSetJacobian()`.
5952: The default preconditioner uses the options database prefixes `-npc_snes`, `-npc_ksp`, etc., to control the configuration.
5954: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5955: @*/
5956: PetscErrorCode SNESGetNPC(SNES snes, SNES *npc)
5957: {
5958: const char *optionsprefix;
5960: PetscFunctionBegin;
5962: PetscAssertPointer(npc, 2);
5963: if (!snes->npc) {
5964: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5965: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5966: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5967: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5968: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5969: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5970: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_DEFAULT));
5972: /* default to 1 iteration */
5973: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
5974: }
5975: *npc = snes->npc;
5976: PetscFunctionReturn(PETSC_SUCCESS);
5977: }
5979: /*@
5980: SNESHasNPC - Returns whether a nonlinear preconditioner is associated with the given `SNES`
5982: Not Collective
5984: Input Parameter:
5985: . snes - iterative context obtained from `SNESCreate()`
5987: Output Parameter:
5988: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5990: Level: developer
5992: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5993: @*/
5994: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5995: {
5996: PetscFunctionBegin;
5998: PetscAssertPointer(has_npc, 2);
5999: *has_npc = snes->npc ? PETSC_TRUE : PETSC_FALSE;
6000: PetscFunctionReturn(PETSC_SUCCESS);
6001: }
6003: /*@
6004: SNESSetNPCSide - Sets the nonlinear preconditioning side used by the nonlinear preconditioner inside `SNES`.
6006: Logically Collective
6008: Input Parameter:
6009: . snes - iterative context obtained from `SNESCreate()`
6011: Output Parameter:
6012: . side - the preconditioning side, where side is one of
6013: .vb
6014: PC_LEFT - left preconditioning
6015: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
6016: .ve
6018: Options Database Key:
6019: . -snes_npc_side (right|left) - nonlinear preconditioner side
6021: Level: intermediate
6023: Note:
6024: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
6026: .seealso: [](ch_snes), `SNES`, `SNESGetNPC()`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
6027: @*/
6028: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
6029: {
6030: PetscFunctionBegin;
6033: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
6034: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
6035: snes->npcside = side;
6036: PetscFunctionReturn(PETSC_SUCCESS);
6037: }
6039: /*@
6040: SNESGetNPCSide - Gets the preconditioning side used by the nonlinear preconditioner inside `SNES`.
6042: Not Collective
6044: Input Parameter:
6045: . snes - iterative context obtained from `SNESCreate()`
6047: Output Parameter:
6048: . side - the preconditioning side, where side is one of
6049: .vb
6050: `PC_LEFT` - left preconditioning
6051: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
6052: .ve
6054: Level: intermediate
6056: .seealso: [](ch_snes), `SNES`, `SNESGetNPC()`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
6057: @*/
6058: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
6059: {
6060: PetscFunctionBegin;
6062: PetscAssertPointer(side, 2);
6063: *side = snes->npcside;
6064: PetscFunctionReturn(PETSC_SUCCESS);
6065: }
6067: /*@
6068: SNESSetLineSearch - Sets the `SNESLineSearch` to be used for a given `SNES`
6070: Collective
6072: Input Parameters:
6073: + snes - iterative context obtained from `SNESCreate()`
6074: - linesearch - the linesearch object
6076: Level: developer
6078: Note:
6079: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
6080: to configure it using the API).
6082: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
6083: @*/
6084: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
6085: {
6086: PetscFunctionBegin;
6089: PetscCheckSameComm(snes, 1, linesearch, 2);
6090: PetscCall(PetscObjectReference((PetscObject)linesearch));
6091: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
6093: snes->linesearch = linesearch;
6094: PetscFunctionReturn(PETSC_SUCCESS);
6095: }