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 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()`
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 and
171: returns with a `SNESConvergedReason` of `SNES_DIVERGED_FUNCTION_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 `SNESCheckFunctionDomainError()` to determine if the `SNESConvergedReason` is set to `SNES_DIVERGED_FUNCTION_DOMAIN`
183: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetJacobianDomainError()`, `SNESVISetVariableBounds()`,
184: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`,
185: `SNES_DIVERGED_FUNCTION_DOMAIN`, `SNESSetFunctionDomainError()`
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_FUNCTION_DOMAIN`
208: You should always call `SNESGetConvergedReason()` after each `SNESSolve()` and verify if the iteration converged (positive result) or diverged (negative result).
210: You can direct `SNES` to avoid certain steps by using `SNESVISetVariableBounds()`, `SNESVISetComputeVariableBounds()` or
211: `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`
213: .seealso: [](ch_snes), `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESVISetVariableBounds()`,
214: `SNESVISetComputeVariableBounds()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESConvergedReason`, `SNESGetConvergedReason()`
215: @*/
216: PetscErrorCode SNESSetJacobianDomainError(SNES snes)
217: {
218: PetscFunctionBegin;
220: PetscCheck(!snes->errorifnotconverged, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "User code indicates computeJacobian does not make sense");
221: snes->jacobiandomainerror = PETSC_TRUE;
222: PetscFunctionReturn(PETSC_SUCCESS);
223: }
225: /*@
226: SNESSetCheckJacobianDomainError - tells `SNESSolve()` whether to check if the user called `SNESSetJacobianDomainError()` to indicate a Jacobian domain error after
227: each Jacobian evaluation.
229: Logically Collective
231: Input Parameters:
232: + snes - the `SNES` context
233: - flg - indicates if or not to check Jacobian domain error after each Jacobian evaluation
235: Level: advanced
237: Notes:
238: By default, it checks for the Jacobian domain error in the debug mode, and does not check it in the optimized mode.
240: Checks require one extra parallel synchronization for each Jacobian evaluation
242: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESGetCheckJacobianDomainError()`
243: @*/
244: PetscErrorCode SNESSetCheckJacobianDomainError(SNES snes, PetscBool flg)
245: {
246: PetscFunctionBegin;
248: snes->checkjacdomainerror = flg;
249: PetscFunctionReturn(PETSC_SUCCESS);
250: }
252: /*@
253: SNESGetCheckJacobianDomainError - Get an indicator whether or not `SNES` is checking Jacobian domain errors after each Jacobian evaluation.
255: Logically Collective
257: Input Parameter:
258: . snes - the `SNES` context
260: Output Parameter:
261: . flg - `PETSC_FALSE` indicates that it is not checking Jacobian domain errors after each Jacobian evaluation
263: Level: advanced
265: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSetFunction()`, `SNESFunctionFn`, `SNESSetFunctionDomainError()`, `SNESSetCheckJacobianDomainError()`
266: @*/
267: PetscErrorCode SNESGetCheckJacobianDomainError(SNES snes, PetscBool *flg)
268: {
269: PetscFunctionBegin;
271: PetscAssertPointer(flg, 2);
272: *flg = snes->checkjacdomainerror;
273: PetscFunctionReturn(PETSC_SUCCESS);
274: }
276: /*@
277: SNESLoad - Loads a `SNES` that has been stored in `PETSCVIEWERBINARY` with `SNESView()`.
279: Collective
281: Input Parameters:
282: + snes - the newly loaded `SNES`, this needs to have been created with `SNESCreate()` or
283: some related function before a call to `SNESLoad()`.
284: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()`
286: Level: intermediate
288: Note:
289: The `SNESType` is determined by the data in the file, any type set into the `SNES` before this call is ignored.
291: .seealso: [](ch_snes), `SNES`, `PetscViewer`, `SNESCreate()`, `SNESType`, `PetscViewerBinaryOpen()`, `SNESView()`, `MatLoad()`, `VecLoad()`
292: @*/
293: PetscErrorCode SNESLoad(SNES snes, PetscViewer viewer)
294: {
295: PetscBool isbinary;
296: PetscInt classid;
297: char type[256];
298: KSP ksp;
299: DM dm;
300: DMSNES dmsnes;
302: PetscFunctionBegin;
305: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
306: PetscCheck(isbinary, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen()");
308: PetscCall(PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT));
309: PetscCheck(classid == SNES_FILE_CLASSID, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Not SNES next in file");
310: PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
311: PetscCall(SNESSetType(snes, type));
312: PetscTryTypeMethod(snes, load, viewer);
313: PetscCall(SNESGetDM(snes, &dm));
314: PetscCall(DMGetDMSNES(dm, &dmsnes));
315: PetscCall(DMSNESLoad(dmsnes, viewer));
316: PetscCall(SNESGetKSP(snes, &ksp));
317: PetscCall(KSPLoad(ksp, viewer));
318: PetscFunctionReturn(PETSC_SUCCESS);
319: }
321: #include <petscdraw.h>
322: #if defined(PETSC_HAVE_SAWS)
323: #include <petscviewersaws.h>
324: #endif
326: /*@
327: SNESViewFromOptions - View a `SNES` based on values in the options database
329: Collective
331: Input Parameters:
332: + A - the `SNES` context
333: . obj - Optional object that provides the options prefix for the checks
334: - name - command line option
336: Level: intermediate
338: .seealso: [](ch_snes), `SNES`, `SNESView`, `PetscObjectViewFromOptions()`, `SNESCreate()`
339: @*/
340: PetscErrorCode SNESViewFromOptions(SNES A, PetscObject obj, const char name[])
341: {
342: PetscFunctionBegin;
344: PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
345: PetscFunctionReturn(PETSC_SUCCESS);
346: }
348: PETSC_EXTERN PetscErrorCode SNESComputeJacobian_DMDA(SNES, Vec, Mat, Mat, void *);
350: /*@
351: SNESView - Prints or visualizes the `SNES` data structure.
353: Collective
355: Input Parameters:
356: + snes - the `SNES` context
357: - viewer - the `PetscViewer`
359: Options Database Key:
360: . -snes_view - Calls `SNESView()` at end of `SNESSolve()`
362: Level: beginner
364: Notes:
365: The available visualization contexts include
366: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
367: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
368: output where only the first processor opens
369: the file. All other processors send their
370: data to the first processor to print.
372: The available formats include
373: + `PETSC_VIEWER_DEFAULT` - standard output (default)
374: - `PETSC_VIEWER_ASCII_INFO_DETAIL` - more verbose output for `SNESNASM`
376: The user can open an alternative visualization context with
377: `PetscViewerASCIIOpen()` - output to a specified file.
379: In the debugger you can do "call `SNESView`(snes,0)" to display the `SNES` solver. (The same holds for any PETSc object viewer).
381: .seealso: [](ch_snes), `SNES`, `SNESLoad()`, `SNESCreate()`, `PetscViewerASCIIOpen()`
382: @*/
383: PetscErrorCode SNESView(SNES snes, PetscViewer viewer)
384: {
385: SNESKSPEW *kctx;
386: KSP ksp;
387: SNESLineSearch linesearch;
388: PetscBool isascii, isstring, isbinary, isdraw;
389: DMSNES dmsnes;
390: #if defined(PETSC_HAVE_SAWS)
391: PetscBool issaws;
392: #endif
394: PetscFunctionBegin;
396: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &viewer));
398: PetscCheckSameComm(snes, 1, viewer, 2);
400: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
401: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
402: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
403: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
404: #if defined(PETSC_HAVE_SAWS)
405: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
406: #endif
407: if (isascii) {
408: SNESNormSchedule normschedule;
409: DM dm;
410: SNESJacobianFn *cJ;
411: void *ctx;
412: const char *pre = "";
414: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)snes, viewer));
415: if (!snes->setupcalled) PetscCall(PetscViewerASCIIPrintf(viewer, " SNES has not been set up so information may be incomplete\n"));
416: if (snes->ops->view) {
417: PetscCall(PetscViewerASCIIPushTab(viewer));
418: PetscUseTypeMethod(snes, view, viewer);
419: PetscCall(PetscViewerASCIIPopTab(viewer));
420: }
421: if (snes->max_funcs == PETSC_UNLIMITED) {
422: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=unlimited\n", snes->max_its));
423: } else {
424: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", maximum function evaluations=%" PetscInt_FMT "\n", snes->max_its, snes->max_funcs));
425: }
426: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, solution=%g\n", (double)snes->rtol, (double)snes->abstol, (double)snes->stol));
427: if (snes->usesksp) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of linear solver iterations=%" PetscInt_FMT "\n", snes->linear_its));
428: PetscCall(PetscViewerASCIIPrintf(viewer, " total number of function evaluations=%" PetscInt_FMT "\n", snes->nfuncs));
429: PetscCall(SNESGetNormSchedule(snes, &normschedule));
430: if (normschedule > 0) PetscCall(PetscViewerASCIIPrintf(viewer, " norm schedule %s\n", SNESNormSchedules[normschedule]));
431: if (snes->gridsequence) PetscCall(PetscViewerASCIIPrintf(viewer, " total number of grid sequence refinements=%" PetscInt_FMT "\n", snes->gridsequence));
432: if (snes->ksp_ewconv) {
433: kctx = (SNESKSPEW *)snes->kspconvctx;
434: if (kctx) {
435: PetscCall(PetscViewerASCIIPrintf(viewer, " Eisenstat-Walker computation of KSP relative tolerance (version %" PetscInt_FMT ")\n", kctx->version));
436: PetscCall(PetscViewerASCIIPrintf(viewer, " rtol_0=%g, rtol_max=%g, threshold=%g\n", (double)kctx->rtol_0, (double)kctx->rtol_max, (double)kctx->threshold));
437: PetscCall(PetscViewerASCIIPrintf(viewer, " gamma=%g, alpha=%g, alpha2=%g\n", (double)kctx->gamma, (double)kctx->alpha, (double)kctx->alpha2));
438: }
439: }
440: if (snes->lagpreconditioner == -1) {
441: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is never rebuilt\n"));
442: } else if (snes->lagpreconditioner > 1) {
443: PetscCall(PetscViewerASCIIPrintf(viewer, " Preconditioned is rebuilt every %" PetscInt_FMT " new Jacobians\n", snes->lagpreconditioner));
444: }
445: if (snes->lagjacobian == -1) {
446: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is never rebuilt\n"));
447: } else if (snes->lagjacobian > 1) {
448: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is rebuilt every %" PetscInt_FMT " SNES iterations\n", snes->lagjacobian));
449: }
450: PetscCall(SNESGetDM(snes, &dm));
451: PetscCall(DMSNESGetJacobian(dm, &cJ, &ctx));
452: if (snes->mf_operator) {
453: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing\n"));
454: pre = "Preconditioning ";
455: }
456: if (cJ == SNESComputeJacobianDefault) {
457: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences one column at a time\n", pre));
458: } else if (cJ == SNESComputeJacobianDefaultColor) {
459: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using finite differences with coloring\n", pre));
460: /* it slightly breaks data encapsulation for access the DMDA information directly */
461: } else if (cJ == SNESComputeJacobian_DMDA) {
462: MatFDColoring fdcoloring;
463: PetscCall(PetscObjectQuery((PetscObject)dm, "DMDASNES_FDCOLORING", (PetscObject *)&fdcoloring));
464: if (fdcoloring) {
465: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using colored finite differences on a DMDA\n", pre));
466: } else {
467: PetscCall(PetscViewerASCIIPrintf(viewer, " %sJacobian is built using a DMDA local Jacobian\n", pre));
468: }
469: } else if (snes->mf && !snes->mf_operator) {
470: PetscCall(PetscViewerASCIIPrintf(viewer, " Jacobian is applied matrix-free with differencing, no explicit Jacobian\n"));
471: }
472: } else if (isstring) {
473: const char *type;
474: PetscCall(SNESGetType(snes, &type));
475: PetscCall(PetscViewerStringSPrintf(viewer, " SNESType: %-7.7s", type));
476: PetscTryTypeMethod(snes, view, viewer);
477: } else if (isbinary) {
478: PetscInt classid = SNES_FILE_CLASSID;
479: MPI_Comm comm;
480: PetscMPIInt rank;
481: char type[256];
483: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
484: PetscCallMPI(MPI_Comm_rank(comm, &rank));
485: if (rank == 0) {
486: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
487: PetscCall(PetscStrncpy(type, ((PetscObject)snes)->type_name, sizeof(type)));
488: PetscCall(PetscViewerBinaryWrite(viewer, type, sizeof(type), PETSC_CHAR));
489: }
490: PetscTryTypeMethod(snes, view, viewer);
491: } else if (isdraw) {
492: PetscDraw draw;
493: char str[36];
494: PetscReal x, y, bottom, h;
496: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
497: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
498: PetscCall(PetscStrncpy(str, "SNES: ", sizeof(str)));
499: PetscCall(PetscStrlcat(str, ((PetscObject)snes)->type_name, sizeof(str)));
500: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_BLUE, PETSC_DRAW_BLACK, str, NULL, &h));
501: bottom = y - h;
502: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
503: PetscTryTypeMethod(snes, view, viewer);
504: #if defined(PETSC_HAVE_SAWS)
505: } else if (issaws) {
506: PetscMPIInt rank;
507: const char *name;
509: PetscCall(PetscObjectGetName((PetscObject)snes, &name));
510: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
511: if (!((PetscObject)snes)->amsmem && rank == 0) {
512: char dir[1024];
514: PetscCall(PetscObjectViewSAWs((PetscObject)snes, viewer));
515: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
516: PetscCallSAWs(SAWs_Register, (dir, &snes->iter, 1, SAWs_READ, SAWs_INT));
517: if (!snes->conv_hist) PetscCall(SNESSetConvergenceHistory(snes, NULL, NULL, PETSC_DECIDE, PETSC_TRUE));
518: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/conv_hist", name));
519: PetscCallSAWs(SAWs_Register, (dir, snes->conv_hist, 10, SAWs_READ, SAWs_DOUBLE));
520: }
521: #endif
522: }
523: if (snes->linesearch) {
524: PetscCall(SNESGetLineSearch(snes, &linesearch));
525: PetscCall(PetscViewerASCIIPushTab(viewer));
526: PetscCall(SNESLineSearchView(linesearch, viewer));
527: PetscCall(PetscViewerASCIIPopTab(viewer));
528: }
529: if (snes->npc && snes->usesnpc) {
530: PetscCall(PetscViewerASCIIPushTab(viewer));
531: PetscCall(SNESView(snes->npc, viewer));
532: PetscCall(PetscViewerASCIIPopTab(viewer));
533: }
534: PetscCall(PetscViewerASCIIPushTab(viewer));
535: PetscCall(DMGetDMSNES(snes->dm, &dmsnes));
536: PetscCall(DMSNESView(dmsnes, viewer));
537: PetscCall(PetscViewerASCIIPopTab(viewer));
538: if (snes->usesksp) {
539: PetscCall(SNESGetKSP(snes, &ksp));
540: PetscCall(PetscViewerASCIIPushTab(viewer));
541: PetscCall(KSPView(ksp, viewer));
542: PetscCall(PetscViewerASCIIPopTab(viewer));
543: }
544: if (isdraw) {
545: PetscDraw draw;
546: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
547: PetscCall(PetscDrawPopCurrentPoint(draw));
548: }
549: PetscFunctionReturn(PETSC_SUCCESS);
550: }
552: /*
553: We retain a list of functions that also take SNES command
554: line options. These are called at the end SNESSetFromOptions()
555: */
556: #define MAXSETFROMOPTIONS 5
557: static PetscInt numberofsetfromoptions;
558: static PetscErrorCode (*othersetfromoptions[MAXSETFROMOPTIONS])(SNES);
560: /*@C
561: SNESAddOptionsChecker - Adds an additional function to check for `SNES` options.
563: Not Collective
565: Input Parameter:
566: . snescheck - function that checks for options
568: Calling sequence of `snescheck`:
569: . snes - the `SNES` object for which it is checking options
571: Level: developer
573: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`
574: @*/
575: PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*snescheck)(SNES snes))
576: {
577: PetscFunctionBegin;
578: PetscCheck(numberofsetfromoptions < MAXSETFROMOPTIONS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many options checkers, only %d allowed", MAXSETFROMOPTIONS);
579: othersetfromoptions[numberofsetfromoptions++] = snescheck;
580: PetscFunctionReturn(PETSC_SUCCESS);
581: }
583: static PetscErrorCode SNESSetUpMatrixFree_Private(SNES snes, PetscBool hasOperator, PetscInt version)
584: {
585: Mat J;
586: MatNullSpace nullsp;
588: PetscFunctionBegin;
591: if (!snes->vec_func && (snes->jacobian || snes->jacobian_pre)) {
592: Mat A = snes->jacobian, B = snes->jacobian_pre;
593: PetscCall(MatCreateVecs(A ? A : B, NULL, &snes->vec_func));
594: }
596: PetscCheck(version == 1 || version == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "matrix-free operator routines, only version 1 and 2");
597: if (version == 1) {
598: PetscCall(MatCreateSNESMF(snes, &J));
599: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
600: PetscCall(MatSetFromOptions(J));
601: /* TODO: the version 2 code should be merged into the MatCreateSNESMF() and MatCreateMFFD() infrastructure and then removed */
602: } else /* if (version == 2) */ {
603: PetscCheck(snes->vec_func, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "SNESSetFunction() must be called first");
604: #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_REAL_SINGLE) && !defined(PETSC_USE_REAL___FLOAT128) && !defined(PETSC_USE_REAL___FP16)
605: PetscCall(MatCreateSNESMFMore(snes, snes->vec_func, &J));
606: #else
607: SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "matrix-free operator routines (version 2)");
608: #endif
609: }
611: /* attach any user provided null space that was on Amat to the newly created matrix-free matrix */
612: if (snes->jacobian) {
613: PetscCall(MatGetNullSpace(snes->jacobian, &nullsp));
614: if (nullsp) PetscCall(MatSetNullSpace(J, nullsp));
615: }
617: PetscCall(PetscInfo(snes, "Setting default matrix-free operator routines (version %" PetscInt_FMT ")\n", version));
618: if (hasOperator) {
619: /* This version replaces the user provided Jacobian matrix with a
620: matrix-free version but still employs the user-provided matrix used for computing the preconditioner. */
621: PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
622: } else {
623: /* This version replaces both the user-provided Jacobian and the user-
624: provided preconditioner Jacobian with the default matrix-free version. */
625: if (snes->npcside == PC_LEFT && snes->npc) {
626: if (!snes->jacobian) PetscCall(SNESSetJacobian(snes, J, NULL, NULL, NULL));
627: } else {
628: KSP ksp;
629: PC pc;
630: PetscBool match;
632: PetscCall(SNESSetJacobian(snes, J, J, MatMFFDComputeJacobian, NULL));
633: /* Force no preconditioner */
634: PetscCall(SNESGetKSP(snes, &ksp));
635: PetscCall(KSPGetPC(ksp, &pc));
636: PetscCall(PetscObjectTypeCompareAny((PetscObject)pc, &match, PCSHELL, PCH2OPUS, ""));
637: if (!match) {
638: PetscCall(PetscInfo(snes, "Setting default matrix-free preconditioner routines\nThat is no preconditioner is being used\n"));
639: PetscCall(PCSetType(pc, PCNONE));
640: }
641: }
642: }
643: PetscCall(MatDestroy(&J));
644: PetscFunctionReturn(PETSC_SUCCESS);
645: }
647: static PetscErrorCode DMRestrictHook_SNESVecSol(DM dmfine, Mat Restrict, Vec Rscale, Mat Inject, DM dmcoarse, void *ctx)
648: {
649: SNES snes = (SNES)ctx;
650: Vec Xfine, Xfine_named = NULL, Xcoarse;
652: PetscFunctionBegin;
653: if (PetscLogPrintInfo) {
654: PetscInt finelevel, coarselevel, fineclevel, coarseclevel;
655: PetscCall(DMGetRefineLevel(dmfine, &finelevel));
656: PetscCall(DMGetCoarsenLevel(dmfine, &fineclevel));
657: PetscCall(DMGetRefineLevel(dmcoarse, &coarselevel));
658: PetscCall(DMGetCoarsenLevel(dmcoarse, &coarseclevel));
659: PetscCall(PetscInfo(dmfine, "Restricting SNES solution vector from level %" PetscInt_FMT "-%" PetscInt_FMT " to level %" PetscInt_FMT "-%" PetscInt_FMT "\n", finelevel, fineclevel, coarselevel, coarseclevel));
660: }
661: if (dmfine == snes->dm) Xfine = snes->vec_sol;
662: else {
663: PetscCall(DMGetNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
664: Xfine = Xfine_named;
665: }
666: PetscCall(DMGetNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
667: if (Inject) {
668: PetscCall(MatRestrict(Inject, Xfine, Xcoarse));
669: } else {
670: PetscCall(MatRestrict(Restrict, Xfine, Xcoarse));
671: PetscCall(VecPointwiseMult(Xcoarse, Xcoarse, Rscale));
672: }
673: PetscCall(DMRestoreNamedGlobalVector(dmcoarse, "SNESVecSol", &Xcoarse));
674: if (Xfine_named) PetscCall(DMRestoreNamedGlobalVector(dmfine, "SNESVecSol", &Xfine_named));
675: PetscFunctionReturn(PETSC_SUCCESS);
676: }
678: static PetscErrorCode DMCoarsenHook_SNESVecSol(DM dm, DM dmc, void *ctx)
679: {
680: PetscFunctionBegin;
681: PetscCall(DMCoarsenHookAdd(dmc, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, ctx));
682: PetscFunctionReturn(PETSC_SUCCESS);
683: }
685: /* This may be called to rediscretize the operator on levels of linear multigrid. The DM shuffle is so the user can
686: * safely call SNESGetDM() in their residual evaluation routine. */
687: static PetscErrorCode KSPComputeOperators_SNES(KSP ksp, Mat A, Mat B, void *ctx)
688: {
689: SNES snes = (SNES)ctx;
690: DMSNES sdm;
691: Vec X, Xnamed = NULL;
692: DM dmsave;
693: void *ctxsave;
694: SNESJacobianFn *jac = NULL;
696: PetscFunctionBegin;
697: dmsave = snes->dm;
698: PetscCall(KSPGetDM(ksp, &snes->dm));
699: if (dmsave == snes->dm) X = snes->vec_sol; /* We are on the finest level */
700: else {
701: PetscBool has;
703: /* We are on a coarser level, this vec was initialized using a DM restrict hook */
704: PetscCall(DMHasNamedGlobalVector(snes->dm, "SNESVecSol", &has));
705: PetscCheck(has, PetscObjectComm((PetscObject)snes->dm), PETSC_ERR_PLIB, "Missing SNESVecSol");
706: PetscCall(DMGetNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
707: X = Xnamed;
708: PetscCall(SNESGetJacobian(snes, NULL, NULL, &jac, &ctxsave));
709: /* If the DM's don't match up, the MatFDColoring context needed for the jacobian won't match up either -- fixit. */
710: if (jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, SNESComputeJacobianDefaultColor, NULL));
711: }
713: /* Compute the operators */
714: PetscCall(DMGetDMSNES(snes->dm, &sdm));
715: if (Xnamed && sdm->ops->computefunction) {
716: /* The SNES contract with the user is that ComputeFunction is always called before ComputeJacobian.
717: We make sure of this here. Disable affine shift since it is for the finest level */
718: Vec F, saverhs = snes->vec_rhs;
720: snes->vec_rhs = NULL;
721: PetscCall(DMGetGlobalVector(snes->dm, &F));
722: PetscCall(SNESComputeFunction(snes, X, F));
723: PetscCall(DMRestoreGlobalVector(snes->dm, &F));
724: snes->vec_rhs = saverhs;
725: snes->nfuncs--; /* Do not log coarser level evaluations */
726: }
727: /* Make sure KSP DM has the Jacobian computation routine */
728: if (!sdm->ops->computejacobian) PetscCall(DMCopyDMSNES(dmsave, snes->dm));
729: PetscCall(SNESComputeJacobian(snes, X, A, B)); /* cannot handle previous SNESSetJacobianDomainError() calls */
731: /* Put the previous context back */
732: if (snes->dm != dmsave && jac == SNESComputeJacobianDefaultColor) PetscCall(SNESSetJacobian(snes, NULL, NULL, jac, ctxsave));
734: if (Xnamed) PetscCall(DMRestoreNamedGlobalVector(snes->dm, "SNESVecSol", &Xnamed));
735: snes->dm = dmsave;
736: PetscFunctionReturn(PETSC_SUCCESS);
737: }
739: /*@
740: SNESSetUpMatrices - ensures that matrices are available for `SNES` Newton-like methods, this is called by `SNESSetUp_XXX()`
742: Collective
744: Input Parameter:
745: . snes - `SNES` object to configure
747: Level: developer
749: Note:
750: If the matrices do not yet exist it attempts to create them based on options previously set for the `SNES` such as `-snes_mf`
752: Developer Note:
753: The functionality of this routine overlaps in a confusing way with the functionality of `SNESSetUpMatrixFree_Private()` which is called by
754: `SNESSetUp()` but sometimes `SNESSetUpMatrices()` is called without `SNESSetUp()` being called. A refactorization to simplify the
755: logic that handles the matrix-free case is desirable.
757: .seealso: [](ch_snes), `SNES`, `SNESSetUp()`
758: @*/
759: PetscErrorCode SNESSetUpMatrices(SNES snes)
760: {
761: DM dm;
762: DMSNES sdm;
764: PetscFunctionBegin;
765: PetscCall(SNESGetDM(snes, &dm));
766: PetscCall(DMGetDMSNES(dm, &sdm));
767: if (!snes->jacobian && snes->mf && !snes->mf_operator && !snes->jacobian_pre) {
768: Mat J;
769: void *functx;
770: PetscCall(MatCreateSNESMF(snes, &J));
771: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
772: PetscCall(MatSetFromOptions(J));
773: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
774: PetscCall(SNESSetJacobian(snes, J, J, NULL, NULL));
775: PetscCall(MatDestroy(&J));
776: } else if (snes->mf_operator && !snes->jacobian_pre && !snes->jacobian) {
777: Mat J, B;
778: PetscCall(MatCreateSNESMF(snes, &J));
779: PetscCall(MatMFFDSetOptionsPrefix(J, ((PetscObject)snes)->prefix));
780: PetscCall(MatSetFromOptions(J));
781: PetscCall(DMCreateMatrix(snes->dm, &B));
782: /* sdm->computejacobian was already set to reach here */
783: PetscCall(SNESSetJacobian(snes, J, B, NULL, NULL));
784: PetscCall(MatDestroy(&J));
785: PetscCall(MatDestroy(&B));
786: } else if (!snes->jacobian_pre) {
787: PetscDS prob;
788: Mat J, B;
789: PetscBool hasPrec = PETSC_FALSE;
791: J = snes->jacobian;
792: PetscCall(DMGetDS(dm, &prob));
793: if (prob) PetscCall(PetscDSHasJacobianPreconditioner(prob, &hasPrec));
794: if (J) PetscCall(PetscObjectReference((PetscObject)J));
795: else if (hasPrec) PetscCall(DMCreateMatrix(snes->dm, &J));
796: PetscCall(DMCreateMatrix(snes->dm, &B));
797: PetscCall(SNESSetJacobian(snes, J ? J : B, B, NULL, NULL));
798: PetscCall(MatDestroy(&J));
799: PetscCall(MatDestroy(&B));
800: }
801: {
802: KSP ksp;
803: PetscCall(SNESGetKSP(snes, &ksp));
804: PetscCall(KSPSetComputeOperators(ksp, KSPComputeOperators_SNES, snes));
805: PetscCall(DMCoarsenHookAdd(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
806: }
807: PetscFunctionReturn(PETSC_SUCCESS);
808: }
810: PETSC_SINGLE_LIBRARY_INTERN PetscErrorCode PetscMonitorPauseFinal_Internal(PetscInt, void *);
812: static PetscErrorCode SNESMonitorPauseFinal_Internal(SNES snes)
813: {
814: PetscFunctionBegin;
815: if (!snes->pauseFinal) PetscFunctionReturn(PETSC_SUCCESS);
816: PetscCall(PetscMonitorPauseFinal_Internal(snes->numbermonitors, snes->monitorcontext));
817: PetscFunctionReturn(PETSC_SUCCESS);
818: }
820: /*@C
821: SNESMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user
823: Collective
825: Input Parameters:
826: + snes - `SNES` object you wish to monitor
827: . name - the monitor type one is seeking
828: . help - message indicating what monitoring is done
829: . manual - manual page for the monitor
830: . monitor - the monitor function, this must use a `PetscViewerFormat` as its context
831: - 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
833: Calling sequence of `monitor`:
834: + snes - the nonlinear solver context
835: . it - the current iteration
836: . r - the current function norm
837: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
839: Calling sequence of `monitorsetup`:
840: + snes - the nonlinear solver context
841: - vf - a `PetscViewerAndFormat` struct that contains the `PetscViewer` and `PetscViewerFormat` to use
843: Options Database Key:
844: . -name - trigger the use of this monitor in `SNESSetFromOptions()`
846: Level: advanced
848: .seealso: [](ch_snes), `PetscOptionsCreateViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
849: `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`
850: `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
851: `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
852: `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
853: `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
854: `PetscOptionsFList()`, `PetscOptionsEList()`
855: @*/
856: 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))
857: {
858: PetscViewer viewer;
859: PetscViewerFormat format;
860: PetscBool flg;
862: PetscFunctionBegin;
863: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, name, &viewer, &format, &flg));
864: if (flg) {
865: PetscViewerAndFormat *vf;
866: PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
867: PetscCall(PetscViewerDestroy(&viewer));
868: if (monitorsetup) PetscCall((*monitorsetup)(snes, vf));
869: PetscCall(SNESMonitorSet(snes, (PetscErrorCode (*)(SNES, PetscInt, PetscReal, void *))monitor, vf, (PetscCtxDestroyFn *)PetscViewerAndFormatDestroy));
870: }
871: PetscFunctionReturn(PETSC_SUCCESS);
872: }
874: PetscErrorCode SNESEWSetFromOptions_Private(SNESKSPEW *kctx, PetscBool print_api, MPI_Comm comm, const char *prefix)
875: {
876: const char *api = print_api ? "SNESKSPSetParametersEW" : NULL;
878: PetscFunctionBegin;
879: PetscOptionsBegin(comm, prefix, "Eisenstat and Walker type forcing options", "KSP");
880: PetscCall(PetscOptionsInt("-ksp_ew_version", "Version 1, 2 or 3", api, kctx->version, &kctx->version, NULL));
881: PetscCall(PetscOptionsReal("-ksp_ew_rtol0", "0 <= rtol0 < 1", api, kctx->rtol_0, &kctx->rtol_0, NULL));
882: kctx->rtol_max = PetscMax(kctx->rtol_0, kctx->rtol_max);
883: PetscCall(PetscOptionsReal("-ksp_ew_rtolmax", "0 <= rtolmax < 1", api, kctx->rtol_max, &kctx->rtol_max, NULL));
884: PetscCall(PetscOptionsReal("-ksp_ew_gamma", "0 <= gamma <= 1", api, kctx->gamma, &kctx->gamma, NULL));
885: PetscCall(PetscOptionsReal("-ksp_ew_alpha", "1 < alpha <= 2", api, kctx->alpha, &kctx->alpha, NULL));
886: PetscCall(PetscOptionsReal("-ksp_ew_alpha2", "alpha2", NULL, kctx->alpha2, &kctx->alpha2, NULL));
887: PetscCall(PetscOptionsReal("-ksp_ew_threshold", "0 < threshold < 1", api, kctx->threshold, &kctx->threshold, NULL));
888: PetscCall(PetscOptionsReal("-ksp_ew_v4_p1", "p1", NULL, kctx->v4_p1, &kctx->v4_p1, NULL));
889: PetscCall(PetscOptionsReal("-ksp_ew_v4_p2", "p2", NULL, kctx->v4_p2, &kctx->v4_p2, NULL));
890: PetscCall(PetscOptionsReal("-ksp_ew_v4_p3", "p3", NULL, kctx->v4_p3, &kctx->v4_p3, NULL));
891: PetscCall(PetscOptionsReal("-ksp_ew_v4_m1", "Scaling when rk-1 in [p2,p3)", NULL, kctx->v4_m1, &kctx->v4_m1, NULL));
892: PetscCall(PetscOptionsReal("-ksp_ew_v4_m2", "Scaling when rk-1 in [p3,+infty)", NULL, kctx->v4_m2, &kctx->v4_m2, NULL));
893: PetscCall(PetscOptionsReal("-ksp_ew_v4_m3", "Threshold for successive rtol (0.1 in Eq.7)", NULL, kctx->v4_m3, &kctx->v4_m3, NULL));
894: PetscCall(PetscOptionsReal("-ksp_ew_v4_m4", "Adaptation scaling (0.5 in Eq.7)", NULL, kctx->v4_m4, &kctx->v4_m4, NULL));
895: PetscOptionsEnd();
896: PetscFunctionReturn(PETSC_SUCCESS);
897: }
899: /*@
900: SNESSetFromOptions - Sets various `SNES` and `KSP` parameters from user options.
902: Collective
904: Input Parameter:
905: . snes - the `SNES` context
907: Options Database Keys:
908: + -snes_type <type> - newtonls, newtontr, ngmres, ncg, nrichardson, qn, vi, fas, `SNESType` for complete list
909: . -snes_rtol <rtol> - relative decrease in tolerance norm from initial
910: . -snes_atol <abstol> - absolute tolerance of residual norm
911: . -snes_stol <stol> - convergence tolerance in terms of the norm of the change in the solution between steps
912: . -snes_divergence_tolerance <divtol> - if the residual goes above divtol*rnorm0, exit with divergence
913: . -snes_max_it <max_it> - maximum number of iterations
914: . -snes_max_funcs <max_funcs> - maximum number of function evaluations
915: . -snes_force_iteration <force> - force `SNESSolve()` to take at least one iteration
916: . -snes_max_fail <max_fail> - maximum number of line search failures allowed before stopping, default is none
917: . -snes_max_linear_solve_fail - number of linear solver failures before SNESSolve() stops
918: . -snes_lag_preconditioner <lag> - how often preconditioner is rebuilt (use -1 to never rebuild)
919: . -snes_lag_preconditioner_persists <true,false> - retains the -snes_lag_preconditioner information across multiple SNESSolve()
920: . -snes_lag_jacobian <lag> - how often Jacobian is rebuilt (use -1 to never rebuild)
921: . -snes_lag_jacobian_persists <true,false> - retains the -snes_lag_jacobian information across multiple SNESSolve()
922: . -snes_convergence_test <default,skip,correct_pressure> - convergence test in nonlinear solver. default `SNESConvergedDefault()`. skip `SNESConvergedSkip()` means continue iterating until max_it or some other criterion is reached, saving expense of convergence test. correct_pressure `SNESConvergedCorrectPressure()` has special handling of a pressure null space.
923: . -snes_monitor [ascii][:filename][:viewer format] - prints residual norm at each iteration. if no filename given prints to stdout
924: . -snes_monitor_solution [ascii binary draw][:filename][:viewer format] - plots solution at each iteration
925: . -snes_monitor_residual [ascii binary draw][:filename][:viewer format] - plots residual (not its norm) at each iteration
926: . -snes_monitor_solution_update [ascii binary draw][:filename][:viewer format] - plots update to solution at each iteration
927: . -snes_monitor_lg_residualnorm - plots residual norm at each iteration
928: . -snes_monitor_lg_range - plots residual norm at each iteration
929: . -snes_monitor_pause_final - Pauses all monitor drawing after the solver ends
930: . -snes_fd - use finite differences to compute Jacobian; very slow, only for testing
931: . -snes_fd_color - use finite differences with coloring to compute Jacobian
932: . -snes_mf_ksp_monitor - if using matrix-free multiply then print h at each `KSP` iteration
933: . -snes_converged_reason - print the reason for convergence/divergence after each solve
934: . -npc_snes_type <type> - the `SNES` type to use as a nonlinear preconditioner
935: . -snes_test_jacobian <optional threshold> - compare the user provided Jacobian with one computed via finite differences to check for errors. If a threshold is given, display only those entries whose difference is greater than the threshold.
936: - -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference between them to help users detect the location of errors in the user provided Jacobian.
938: Options Database Keys for Eisenstat-Walker method:
939: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
940: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
941: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
942: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
943: . -snes_ksp_ew_gamma <gamma> - Sets gamma
944: . -snes_ksp_ew_alpha <alpha> - Sets alpha
945: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
946: - -snes_ksp_ew_threshold <threshold> - Sets threshold
948: Level: beginner
950: Notes:
951: To see all options, run your program with the -help option or consult the users manual
953: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
954: and computing explicitly with
955: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
957: .seealso: [](ch_snes), `SNESType`, `SNESSetOptionsPrefix()`, `SNESResetFromOptions()`, `SNES`, `SNESCreate()`, `MatCreateSNESMF()`, `MatFDColoring`
958: @*/
959: PetscErrorCode SNESSetFromOptions(SNES snes)
960: {
961: PetscBool flg, pcset, persist, set;
962: PetscInt i, indx, lag, grids, max_its, max_funcs;
963: const char *deft = SNESNEWTONLS;
964: const char *convtests[] = {"default", "skip", "correct_pressure"};
965: SNESKSPEW *kctx = NULL;
966: char type[256], monfilename[PETSC_MAX_PATH_LEN], ewprefix[256];
967: PCSide pcside;
968: const char *optionsprefix;
969: PetscReal rtol, abstol, stol;
971: PetscFunctionBegin;
973: PetscCall(SNESRegisterAll());
974: PetscObjectOptionsBegin((PetscObject)snes);
975: if (((PetscObject)snes)->type_name) deft = ((PetscObject)snes)->type_name;
976: PetscCall(PetscOptionsFList("-snes_type", "Nonlinear solver method", "SNESSetType", SNESList, deft, type, 256, &flg));
977: if (flg) {
978: PetscCall(SNESSetType(snes, type));
979: } else if (!((PetscObject)snes)->type_name) {
980: PetscCall(SNESSetType(snes, deft));
981: }
983: abstol = snes->abstol;
984: rtol = snes->rtol;
985: stol = snes->stol;
986: max_its = snes->max_its;
987: max_funcs = snes->max_funcs;
988: PetscCall(PetscOptionsReal("-snes_rtol", "Stop if decrease in function norm less than", "SNESSetTolerances", snes->rtol, &rtol, NULL));
989: PetscCall(PetscOptionsReal("-snes_atol", "Stop if function norm less than", "SNESSetTolerances", snes->abstol, &abstol, NULL));
990: PetscCall(PetscOptionsReal("-snes_stol", "Stop if step length less than", "SNESSetTolerances", snes->stol, &stol, NULL));
991: PetscCall(PetscOptionsInt("-snes_max_it", "Maximum iterations", "SNESSetTolerances", snes->max_its, &max_its, NULL));
992: PetscCall(PetscOptionsInt("-snes_max_funcs", "Maximum function evaluations", "SNESSetTolerances", snes->max_funcs, &max_funcs, NULL));
993: PetscCall(SNESSetTolerances(snes, abstol, rtol, stol, max_its, max_funcs));
995: PetscCall(PetscOptionsReal("-snes_divergence_tolerance", "Stop if residual norm increases by this factor", "SNESSetDivergenceTolerance", snes->divtol, &snes->divtol, &flg));
996: if (flg) PetscCall(SNESSetDivergenceTolerance(snes, snes->divtol));
998: PetscCall(PetscOptionsInt("-snes_max_fail", "Maximum nonlinear step failures", "SNESSetMaxNonlinearStepFailures", snes->maxFailures, &snes->maxFailures, &flg));
999: if (flg) PetscCall(SNESSetMaxNonlinearStepFailures(snes, snes->maxFailures));
1001: PetscCall(PetscOptionsInt("-snes_max_linear_solve_fail", "Maximum failures in linear solves allowed", "SNESSetMaxLinearSolveFailures", snes->maxLinearSolveFailures, &snes->maxLinearSolveFailures, &flg));
1002: if (flg) PetscCall(SNESSetMaxLinearSolveFailures(snes, snes->maxLinearSolveFailures));
1004: PetscCall(PetscOptionsBool("-snes_error_if_not_converged", "Generate error if solver does not converge", "SNESSetErrorIfNotConverged", snes->errorifnotconverged, &snes->errorifnotconverged, NULL));
1005: PetscCall(PetscOptionsBool("-snes_force_iteration", "Force SNESSolve() to take at least one iteration", "SNESSetForceIteration", snes->forceiteration, &snes->forceiteration, NULL));
1006: PetscCall(PetscOptionsBool("-snes_check_jacobian_domain_error", "Check Jacobian domain error after Jacobian evaluation", "SNESCheckJacobianDomainError", snes->checkjacdomainerror, &snes->checkjacdomainerror, NULL));
1008: PetscCall(PetscOptionsInt("-snes_lag_preconditioner", "How often to rebuild preconditioner", "SNESSetLagPreconditioner", snes->lagpreconditioner, &lag, &flg));
1009: if (flg) {
1010: 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");
1011: PetscCall(SNESSetLagPreconditioner(snes, lag));
1012: }
1013: PetscCall(PetscOptionsBool("-snes_lag_preconditioner_persists", "Preconditioner lagging through multiple SNES solves", "SNESSetLagPreconditionerPersists", snes->lagjac_persist, &persist, &flg));
1014: if (flg) PetscCall(SNESSetLagPreconditionerPersists(snes, persist));
1015: PetscCall(PetscOptionsInt("-snes_lag_jacobian", "How often to rebuild Jacobian", "SNESSetLagJacobian", snes->lagjacobian, &lag, &flg));
1016: if (flg) {
1017: 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");
1018: PetscCall(SNESSetLagJacobian(snes, lag));
1019: }
1020: PetscCall(PetscOptionsBool("-snes_lag_jacobian_persists", "Jacobian lagging through multiple SNES solves", "SNESSetLagJacobianPersists", snes->lagjac_persist, &persist, &flg));
1021: if (flg) PetscCall(SNESSetLagJacobianPersists(snes, persist));
1023: PetscCall(PetscOptionsInt("-snes_grid_sequence", "Use grid sequencing to generate initial guess", "SNESSetGridSequence", snes->gridsequence, &grids, &flg));
1024: if (flg) PetscCall(SNESSetGridSequence(snes, grids));
1026: PetscCall(PetscOptionsEList("-snes_convergence_test", "Convergence test", "SNESSetConvergenceTest", convtests, PETSC_STATIC_ARRAY_LENGTH(convtests), "default", &indx, &flg));
1027: if (flg) {
1028: switch (indx) {
1029: case 0:
1030: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedDefault, NULL, NULL));
1031: break;
1032: case 1:
1033: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedSkip, NULL, NULL));
1034: break;
1035: case 2:
1036: PetscCall(SNESSetConvergenceTest(snes, SNESConvergedCorrectPressure, NULL, NULL));
1037: break;
1038: }
1039: }
1041: PetscCall(PetscOptionsEList("-snes_norm_schedule", "SNES Norm schedule", "SNESSetNormSchedule", SNESNormSchedules, 5, "function", &indx, &flg));
1042: if (flg) PetscCall(SNESSetNormSchedule(snes, (SNESNormSchedule)indx));
1044: PetscCall(PetscOptionsEList("-snes_function_type", "SNES Norm schedule", "SNESSetFunctionType", SNESFunctionTypes, 2, "unpreconditioned", &indx, &flg));
1045: if (flg) PetscCall(SNESSetFunctionType(snes, (SNESFunctionType)indx));
1047: kctx = (SNESKSPEW *)snes->kspconvctx;
1049: PetscCall(PetscOptionsBool("-snes_ksp_ew", "Use Eisentat-Walker linear system convergence test", "SNESKSPSetUseEW", snes->ksp_ewconv, &snes->ksp_ewconv, NULL));
1051: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1052: PetscCall(PetscSNPrintf(ewprefix, sizeof(ewprefix), "%s%s", optionsprefix ? optionsprefix : "", "snes_"));
1053: PetscCall(SNESEWSetFromOptions_Private(kctx, PETSC_TRUE, PetscObjectComm((PetscObject)snes), ewprefix));
1055: flg = PETSC_FALSE;
1056: PetscCall(PetscOptionsBool("-snes_monitor_cancel", "Remove all monitors", "SNESMonitorCancel", flg, &flg, &set));
1057: if (set && flg) PetscCall(SNESMonitorCancel(snes));
1059: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor", "Monitor norm of function", "SNESMonitorDefault", SNESMonitorDefault, SNESMonitorDefaultSetUp));
1060: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_short", "Monitor norm of function with fewer digits", "SNESMonitorDefaultShort", SNESMonitorDefaultShort, NULL));
1061: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_range", "Monitor range of elements of function", "SNESMonitorRange", SNESMonitorRange, NULL));
1063: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_ratio", "Monitor ratios of the norm of function for consecutive steps", "SNESMonitorRatio", SNESMonitorRatio, SNESMonitorRatioSetUp));
1064: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_field", "Monitor norm of function (split into fields)", "SNESMonitorDefaultField", SNESMonitorDefaultField, NULL));
1065: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution", "View solution at each iteration", "SNESMonitorSolution", SNESMonitorSolution, NULL));
1066: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_solution_update", "View correction at each iteration", "SNESMonitorSolutionUpdate", SNESMonitorSolutionUpdate, NULL));
1067: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_residual", "View residual at each iteration", "SNESMonitorResidual", SNESMonitorResidual, NULL));
1068: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_jacupdate_spectrum", "Print the change in the spectrum of the Jacobian", "SNESMonitorJacUpdateSpectrum", SNESMonitorJacUpdateSpectrum, NULL));
1069: PetscCall(SNESMonitorSetFromOptions(snes, "-snes_monitor_fields", "Monitor norm of function per field", "SNESMonitorSet", SNESMonitorFields, NULL));
1070: PetscCall(PetscOptionsBool("-snes_monitor_pause_final", "Pauses all draw monitors at the final iterate", "SNESMonitorPauseFinal_Internal", PETSC_FALSE, &snes->pauseFinal, NULL));
1072: PetscCall(PetscOptionsString("-snes_monitor_python", "Use Python function", "SNESMonitorSet", NULL, monfilename, sizeof(monfilename), &flg));
1073: if (flg) PetscCall(PetscPythonMonitorSet((PetscObject)snes, monfilename));
1075: flg = PETSC_FALSE;
1076: PetscCall(PetscOptionsBool("-snes_monitor_lg_range", "Plot function range at each iteration", "SNESMonitorLGRange", flg, &flg, NULL));
1077: if (flg) {
1078: PetscViewer ctx;
1080: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, NULL, PETSC_DECIDE, PETSC_DECIDE, 400, 300, &ctx));
1081: PetscCall(SNESMonitorSet(snes, SNESMonitorLGRange, ctx, (PetscCtxDestroyFn *)PetscViewerDestroy));
1082: }
1084: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
1085: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_converged_reason", &snes->convergedreasonviewer, &snes->convergedreasonformat, NULL));
1086: flg = PETSC_FALSE;
1087: PetscCall(PetscOptionsBool("-snes_converged_reason_view_cancel", "Remove all converged reason viewers", "SNESConvergedReasonViewCancel", flg, &flg, &set));
1088: if (set && flg) PetscCall(SNESConvergedReasonViewCancel(snes));
1090: flg = PETSC_FALSE;
1091: PetscCall(PetscOptionsBool("-snes_fd", "Use finite differences (slow) to compute Jacobian", "SNESComputeJacobianDefault", flg, &flg, NULL));
1092: if (flg) {
1093: void *functx;
1094: DM dm;
1095: PetscCall(SNESGetDM(snes, &dm));
1096: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1097: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
1098: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefault, functx));
1099: PetscCall(PetscInfo(snes, "Setting default finite difference Jacobian matrix\n"));
1100: }
1102: flg = PETSC_FALSE;
1103: PetscCall(PetscOptionsBool("-snes_fd_function", "Use finite differences (slow) to compute function from user objective", "SNESObjectiveComputeFunctionDefaultFD", flg, &flg, NULL));
1104: if (flg) PetscCall(SNESSetFunction(snes, NULL, SNESObjectiveComputeFunctionDefaultFD, NULL));
1106: flg = PETSC_FALSE;
1107: PetscCall(PetscOptionsBool("-snes_fd_color", "Use finite differences with coloring to compute Jacobian", "SNESComputeJacobianDefaultColor", flg, &flg, NULL));
1108: if (flg) {
1109: DM dm;
1110: PetscCall(SNESGetDM(snes, &dm));
1111: PetscCall(DMSNESUnsetJacobianContext_Internal(dm));
1112: PetscCall(SNESSetJacobian(snes, snes->jacobian, snes->jacobian_pre, SNESComputeJacobianDefaultColor, NULL));
1113: PetscCall(PetscInfo(snes, "Setting default finite difference coloring Jacobian matrix\n"));
1114: }
1116: flg = PETSC_FALSE;
1117: 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));
1118: if (flg && snes->mf_operator) {
1119: snes->mf_operator = PETSC_TRUE;
1120: snes->mf = PETSC_TRUE;
1121: }
1122: flg = PETSC_FALSE;
1123: PetscCall(PetscOptionsBool("-snes_mf", "Use a Matrix-Free Jacobian with no matrix for computing the preconditioner", "SNESSetUseMatrixFree", PETSC_FALSE, &snes->mf, &flg));
1124: if (!flg && snes->mf_operator) snes->mf = PETSC_TRUE;
1125: PetscCall(PetscOptionsInt("-snes_mf_version", "Matrix-Free routines version 1 or 2", "None", snes->mf_version, &snes->mf_version, NULL));
1127: PetscCall(PetscOptionsName("-snes_test_function", "Compare hand-coded and finite difference functions", "None", &snes->testFunc));
1128: PetscCall(PetscOptionsName("-snes_test_jacobian", "Compare hand-coded and finite difference Jacobians", "None", &snes->testJac));
1130: flg = PETSC_FALSE;
1131: PetscCall(SNESGetNPCSide(snes, &pcside));
1132: PetscCall(PetscOptionsEnum("-snes_npc_side", "SNES nonlinear preconditioner side", "SNESSetNPCSide", PCSides, (PetscEnum)pcside, (PetscEnum *)&pcside, &flg));
1133: if (flg) PetscCall(SNESSetNPCSide(snes, pcside));
1135: #if defined(PETSC_HAVE_SAWS)
1136: /*
1137: Publish convergence information using SAWs
1138: */
1139: flg = PETSC_FALSE;
1140: PetscCall(PetscOptionsBool("-snes_monitor_saws", "Publish SNES progress using SAWs", "SNESMonitorSet", flg, &flg, NULL));
1141: if (flg) {
1142: void *ctx;
1143: PetscCall(SNESMonitorSAWsCreate(snes, &ctx));
1144: PetscCall(SNESMonitorSet(snes, SNESMonitorSAWs, ctx, SNESMonitorSAWsDestroy));
1145: }
1146: #endif
1147: #if defined(PETSC_HAVE_SAWS)
1148: {
1149: PetscBool set;
1150: flg = PETSC_FALSE;
1151: PetscCall(PetscOptionsBool("-snes_saws_block", "Block for SAWs at end of SNESSolve", "PetscObjectSAWsBlock", ((PetscObject)snes)->amspublishblock, &flg, &set));
1152: if (set) PetscCall(PetscObjectSAWsSetBlock((PetscObject)snes, flg));
1153: }
1154: #endif
1156: for (i = 0; i < numberofsetfromoptions; i++) PetscCall((*othersetfromoptions[i])(snes));
1158: PetscTryTypeMethod(snes, setfromoptions, PetscOptionsObject);
1160: /* process any options handlers added with PetscObjectAddOptionsHandler() */
1161: PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)snes, PetscOptionsObject));
1162: PetscOptionsEnd();
1164: if (snes->linesearch) {
1165: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
1166: PetscCall(SNESLineSearchSetFromOptions(snes->linesearch));
1167: }
1169: if (snes->usesksp) {
1170: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
1171: PetscCall(KSPSetOperators(snes->ksp, snes->jacobian, snes->jacobian_pre));
1172: PetscCall(KSPSetFromOptions(snes->ksp));
1173: }
1175: /* if user has set the SNES NPC type via options database, create it. */
1176: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
1177: PetscCall(PetscOptionsHasName(((PetscObject)snes)->options, optionsprefix, "-npc_snes_type", &pcset));
1178: if (pcset && (!snes->npc)) PetscCall(SNESGetNPC(snes, &snes->npc));
1179: if (snes->npc) PetscCall(SNESSetFromOptions(snes->npc));
1180: snes->setfromoptionscalled++;
1181: PetscFunctionReturn(PETSC_SUCCESS);
1182: }
1184: /*@
1185: SNESResetFromOptions - Sets various `SNES` and `KSP` parameters from user options ONLY if the `SNESSetFromOptions()` was previously called
1187: Collective
1189: Input Parameter:
1190: . snes - the `SNES` context
1192: Level: advanced
1194: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESSetOptionsPrefix()`
1195: @*/
1196: PetscErrorCode SNESResetFromOptions(SNES snes)
1197: {
1198: PetscFunctionBegin;
1199: if (snes->setfromoptionscalled) PetscCall(SNESSetFromOptions(snes));
1200: PetscFunctionReturn(PETSC_SUCCESS);
1201: }
1203: /*@C
1204: SNESSetComputeApplicationContext - Sets an optional function to compute a user-defined context for
1205: the nonlinear solvers.
1207: Logically Collective; No Fortran Support
1209: Input Parameters:
1210: + snes - the `SNES` context
1211: . compute - function to compute the context
1212: - destroy - function to destroy the context, see `PetscCtxDestroyFn` for the calling sequence
1214: Calling sequence of `compute`:
1215: + snes - the `SNES` context
1216: - ctx - context to be computed
1218: Level: intermediate
1220: Note:
1221: This routine is useful if you are performing grid sequencing or using `SNESFAS` and need the appropriate context generated for each level.
1223: Use `SNESSetApplicationContext()` to see the context immediately
1225: .seealso: [](ch_snes), `SNESGetApplicationContext()`, `SNESSetApplicationContext()`, `PetscCtxDestroyFn`
1226: @*/
1227: PetscErrorCode SNESSetComputeApplicationContext(SNES snes, PetscErrorCode (*compute)(SNES snes, void **ctx), PetscCtxDestroyFn *destroy)
1228: {
1229: PetscFunctionBegin;
1231: snes->ops->usercompute = compute;
1232: snes->ops->ctxdestroy = destroy;
1233: PetscFunctionReturn(PETSC_SUCCESS);
1234: }
1236: /*@
1237: SNESSetApplicationContext - Sets the optional user-defined context for the nonlinear solvers.
1239: Logically Collective
1241: Input Parameters:
1242: + snes - the `SNES` context
1243: - ctx - the user context
1245: Level: intermediate
1247: Notes:
1248: Users can provide a context when constructing the `SNES` options and then access it inside their function, Jacobian computation, or other evaluation function
1249: with `SNESGetApplicationContext()`
1251: To provide a function that computes the context for you use `SNESSetComputeApplicationContext()`
1253: Fortran Note:
1254: This only works when `ctx` is a Fortran derived type (it cannot be a `PetscObject`), we recommend writing a Fortran interface definition for this
1255: function that tells the Fortran compiler the derived data type that is passed in as the `ctx` argument. See `SNESGetApplicationContext()` for
1256: an example.
1258: .seealso: [](ch_snes), `SNES`, `SNESSetComputeApplicationContext()`, `SNESGetApplicationContext()`
1259: @*/
1260: PetscErrorCode SNESSetApplicationContext(SNES snes, void *ctx)
1261: {
1262: KSP ksp;
1264: PetscFunctionBegin;
1266: PetscCall(SNESGetKSP(snes, &ksp));
1267: PetscCall(KSPSetApplicationContext(ksp, ctx));
1268: snes->ctx = ctx;
1269: PetscFunctionReturn(PETSC_SUCCESS);
1270: }
1272: /*@
1273: SNESGetApplicationContext - Gets the user-defined context for the
1274: nonlinear solvers set with `SNESGetApplicationContext()` or `SNESSetComputeApplicationContext()`
1276: Not Collective
1278: Input Parameter:
1279: . snes - `SNES` context
1281: Output Parameter:
1282: . ctx - user context
1284: Level: intermediate
1286: Fortran Notes:
1287: This only works when the context is a Fortran derived type (it cannot be a `PetscObject`) and you **must** write a Fortran interface definition for this
1288: function that tells the Fortran compiler the derived data type that is returned as the `ctx` argument. For example,
1289: .vb
1290: Interface SNESGetApplicationContext
1291: Subroutine SNESGetApplicationContext(snes,ctx,ierr)
1292: #include <petsc/finclude/petscsnes.h>
1293: use petscsnes
1294: SNES snes
1295: type(tUsertype), pointer :: ctx
1296: PetscErrorCode ierr
1297: End Subroutine
1298: End Interface SNESGetApplicationContext
1299: .ve
1301: The prototype for `ctx` must be
1302: .vb
1303: type(tUsertype), pointer :: ctx
1304: .ve
1306: .seealso: [](ch_snes), `SNESSetApplicationContext()`, `SNESSetComputeApplicationContext()`
1307: @*/
1308: PetscErrorCode SNESGetApplicationContext(SNES snes, PeCtx ctx)
1309: {
1310: PetscFunctionBegin;
1312: *(void **)ctx = snes->ctx;
1313: PetscFunctionReturn(PETSC_SUCCESS);
1314: }
1316: /*@
1317: SNESSetUseMatrixFree - indicates that `SNES` should use matrix-free finite difference matrix-vector products to apply the Jacobian.
1319: Logically Collective
1321: Input Parameters:
1322: + snes - `SNES` context
1323: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1324: - 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
1325: this option no matrix-element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1327: Options Database Keys:
1328: + -snes_mf_operator - use matrix-free only for the mat operator
1329: . -snes_mf - use matrix-free for both the mat and pmat operator
1330: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1331: - -snes_fd - compute the Jacobian via finite differences (slow)
1333: Level: intermediate
1335: Note:
1336: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
1337: and computing explicitly with
1338: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1340: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`, `MatFDColoring`
1341: @*/
1342: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1343: {
1344: PetscFunctionBegin;
1348: snes->mf = mf_operator ? PETSC_TRUE : mf;
1349: snes->mf_operator = mf_operator;
1350: PetscFunctionReturn(PETSC_SUCCESS);
1351: }
1353: /*@
1354: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1356: Not Collective, but the resulting flags will be the same on all MPI processes
1358: Input Parameter:
1359: . snes - `SNES` context
1361: Output Parameters:
1362: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1363: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1365: Level: intermediate
1367: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1368: @*/
1369: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1370: {
1371: PetscFunctionBegin;
1373: if (mf) *mf = snes->mf;
1374: if (mf_operator) *mf_operator = snes->mf_operator;
1375: PetscFunctionReturn(PETSC_SUCCESS);
1376: }
1378: /*@
1379: SNESGetIterationNumber - Gets the number of nonlinear iterations completed in the current or most recent `SNESSolve()`
1381: Not Collective
1383: Input Parameter:
1384: . snes - `SNES` context
1386: Output Parameter:
1387: . iter - iteration number
1389: Level: intermediate
1391: Notes:
1392: For example, during the computation of iteration 2 this would return 1.
1394: This is useful for using lagged Jacobians (where one does not recompute the
1395: Jacobian at each `SNES` iteration). For example, the code
1396: .vb
1397: ierr = SNESGetIterationNumber(snes,&it);
1398: if (!(it % 2)) {
1399: [compute Jacobian here]
1400: }
1401: .ve
1402: can be used in your function that computes the Jacobian to cause the Jacobian to be
1403: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1405: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1407: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`, `SNESSetMonitor()`
1408: @*/
1409: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1410: {
1411: PetscFunctionBegin;
1413: PetscAssertPointer(iter, 2);
1414: *iter = snes->iter;
1415: PetscFunctionReturn(PETSC_SUCCESS);
1416: }
1418: /*@
1419: SNESSetIterationNumber - Sets the current iteration number.
1421: Not Collective
1423: Input Parameters:
1424: + snes - `SNES` context
1425: - iter - iteration number
1427: Level: developer
1429: Note:
1430: This should only be called inside a `SNES` nonlinear solver.
1432: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1433: @*/
1434: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1435: {
1436: PetscFunctionBegin;
1438: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1439: snes->iter = iter;
1440: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1441: PetscFunctionReturn(PETSC_SUCCESS);
1442: }
1444: /*@
1445: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1446: taken by the nonlinear solver in the current or most recent `SNESSolve()` .
1448: Not Collective
1450: Input Parameter:
1451: . snes - `SNES` context
1453: Output Parameter:
1454: . nfails - number of unsuccessful steps attempted
1456: Level: intermediate
1458: Notes:
1459: A failed step is a step that was generated and taken but did not satisfy the requested step criteria. For example,
1460: the `SNESLineSearchApply()` could not generate a sufficient decrease in the function norm (in fact it may have produced an increase).
1462: Taken steps that produce a infinity or NaN in the function evaluation or generate a `SNESSetFunctionDomainError()`
1463: will always immediately terminate the `SNESSolve()` regardless of the value of `maxFails`.
1465: `SNESSetMaxNonlinearStepFailures()` determines how many unsuccessful steps are allowed before the `SNESSolve()` terminates
1467: This counter is reset to zero for each successive call to `SNESSolve()`.
1469: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1470: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1471: @*/
1472: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1473: {
1474: PetscFunctionBegin;
1476: PetscAssertPointer(nfails, 2);
1477: *nfails = snes->numFailures;
1478: PetscFunctionReturn(PETSC_SUCCESS);
1479: }
1481: /*@
1482: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1483: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1485: Not Collective
1487: Input Parameters:
1488: + snes - `SNES` context
1489: - maxFails - maximum of unsuccessful steps allowed, use `PETSC_UNLIMITED` to have no limit on the number of failures
1491: Options Database Key:
1492: . -snes_max_fail <n> - maximum number of unsuccessful steps allowed
1494: Level: intermediate
1496: Note:
1497: A failed step is a step that was generated and taken but did not satisfy the requested criteria. For example,
1498: the `SNESLineSearchApply()` could not generate a sufficient decrease in the function norm (in fact it may have produced an increase).
1500: Taken steps that produce a infinity or NaN in the function evaluation or generate a `SNESSetFunctionDomainError()`
1501: will always immediately terminate the `SNESSolve()` regardless of the value of `maxFails`.
1503: Developer Note:
1504: The options database key is wrong for this function name
1506: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1507: `SNESGetLinearSolveFailures()`, `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`, `SNESCheckLineSearchFailure()`
1508: @*/
1509: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1510: {
1511: PetscFunctionBegin;
1514: if (maxFails == PETSC_UNLIMITED) {
1515: snes->maxFailures = PETSC_INT_MAX;
1516: } else {
1517: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1518: snes->maxFailures = maxFails;
1519: }
1520: PetscFunctionReturn(PETSC_SUCCESS);
1521: }
1523: /*@
1524: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1525: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1527: Not Collective
1529: Input Parameter:
1530: . snes - `SNES` context
1532: Output Parameter:
1533: . maxFails - maximum of unsuccessful steps
1535: Level: intermediate
1537: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1538: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1539: @*/
1540: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1541: {
1542: PetscFunctionBegin;
1544: PetscAssertPointer(maxFails, 2);
1545: *maxFails = snes->maxFailures;
1546: PetscFunctionReturn(PETSC_SUCCESS);
1547: }
1549: /*@
1550: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1551: done by the `SNES` object in the current or most recent `SNESSolve()`
1553: Not Collective
1555: Input Parameter:
1556: . snes - `SNES` context
1558: Output Parameter:
1559: . nfuncs - number of evaluations
1561: Level: intermediate
1563: Note:
1564: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1566: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1567: @*/
1568: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1569: {
1570: PetscFunctionBegin;
1572: PetscAssertPointer(nfuncs, 2);
1573: *nfuncs = snes->nfuncs;
1574: PetscFunctionReturn(PETSC_SUCCESS);
1575: }
1577: /*@
1578: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1579: linear solvers in the current or most recent `SNESSolve()`
1581: Not Collective
1583: Input Parameter:
1584: . snes - `SNES` context
1586: Output Parameter:
1587: . nfails - number of failed solves
1589: Options Database Key:
1590: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1592: Level: intermediate
1594: Note:
1595: This counter is reset to zero for each successive call to `SNESSolve()`.
1597: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1598: @*/
1599: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1600: {
1601: PetscFunctionBegin;
1603: PetscAssertPointer(nfails, 2);
1604: *nfails = snes->numLinearSolveFailures;
1605: PetscFunctionReturn(PETSC_SUCCESS);
1606: }
1608: /*@
1609: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1610: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1612: Logically Collective
1614: Input Parameters:
1615: + snes - `SNES` context
1616: - maxFails - maximum allowed linear solve failures, use `PETSC_UNLIMITED` to have no limit on the number of failures
1618: Options Database Key:
1619: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1621: Level: intermediate
1623: Note:
1624: By default this is 0; that is `SNES` returns on the first failed linear solve
1626: Developer Note:
1627: The options database key is wrong for this function name
1629: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1630: @*/
1631: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1632: {
1633: PetscFunctionBegin;
1637: if (maxFails == PETSC_UNLIMITED) {
1638: snes->maxLinearSolveFailures = PETSC_INT_MAX;
1639: } else {
1640: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1641: snes->maxLinearSolveFailures = maxFails;
1642: }
1643: PetscFunctionReturn(PETSC_SUCCESS);
1644: }
1646: /*@
1647: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1648: are allowed before `SNES` returns as unsuccessful
1650: Not Collective
1652: Input Parameter:
1653: . snes - `SNES` context
1655: Output Parameter:
1656: . maxFails - maximum of unsuccessful solves allowed
1658: Level: intermediate
1660: Note:
1661: By default this is 1; that is `SNES` returns on the first failed linear solve
1663: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1664: @*/
1665: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1666: {
1667: PetscFunctionBegin;
1669: PetscAssertPointer(maxFails, 2);
1670: *maxFails = snes->maxLinearSolveFailures;
1671: PetscFunctionReturn(PETSC_SUCCESS);
1672: }
1674: /*@
1675: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1676: used by the nonlinear solver in the most recent `SNESSolve()`
1678: Not Collective
1680: Input Parameter:
1681: . snes - `SNES` context
1683: Output Parameter:
1684: . lits - number of linear iterations
1686: Level: intermediate
1688: Notes:
1689: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1691: 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
1692: then call `KSPGetIterationNumber()` after the failed solve.
1694: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1695: @*/
1696: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1697: {
1698: PetscFunctionBegin;
1700: PetscAssertPointer(lits, 2);
1701: *lits = snes->linear_its;
1702: PetscFunctionReturn(PETSC_SUCCESS);
1703: }
1705: /*@
1706: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1707: are reset every time `SNESSolve()` is called.
1709: Logically Collective
1711: Input Parameters:
1712: + snes - `SNES` context
1713: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1715: Level: developer
1717: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1718: @*/
1719: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1720: {
1721: PetscFunctionBegin;
1724: snes->counters_reset = reset;
1725: PetscFunctionReturn(PETSC_SUCCESS);
1726: }
1728: /*@
1729: SNESResetCounters - Reset counters for linear iterations and function evaluations.
1731: Logically Collective
1733: Input Parameters:
1734: . snes - `SNES` context
1736: Level: developer
1738: Note:
1739: It honors the flag set with `SNESSetCountersReset()`
1741: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1742: @*/
1743: PetscErrorCode SNESResetCounters(SNES snes)
1744: {
1745: PetscFunctionBegin;
1747: if (snes->counters_reset) {
1748: snes->nfuncs = 0;
1749: snes->linear_its = 0;
1750: snes->numFailures = 0;
1751: }
1752: PetscFunctionReturn(PETSC_SUCCESS);
1753: }
1755: /*@
1756: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1758: Not Collective, but the `SNES` and `KSP` objects must live on the same `MPI_Comm`
1760: Input Parameters:
1761: + snes - the `SNES` context
1762: - ksp - the `KSP` context
1764: Level: developer
1766: Notes:
1767: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1768: so this routine is rarely needed.
1770: The `KSP` object that is already in the `SNES` object has its reference count
1771: decreased by one when this is called.
1773: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`
1774: @*/
1775: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1776: {
1777: PetscFunctionBegin;
1780: PetscCheckSameComm(snes, 1, ksp, 2);
1781: PetscCall(PetscObjectReference((PetscObject)ksp));
1782: if (snes->ksp) PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1783: snes->ksp = ksp;
1784: PetscFunctionReturn(PETSC_SUCCESS);
1785: }
1787: /*@
1788: SNESParametersInitialize - Sets all the parameters in `snes` to their default value (when `SNESCreate()` was called) if they
1789: currently contain default values
1791: Collective
1793: Input Parameter:
1794: . snes - the `SNES` object
1796: Level: developer
1798: Developer Note:
1799: This is called by all the `SNESCreate_XXX()` routines.
1801: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
1802: `PetscObjectParameterSetDefault()`
1803: @*/
1804: PetscErrorCode SNESParametersInitialize(SNES snes)
1805: {
1806: PetscObjectParameterSetDefault(snes, max_its, 50);
1807: PetscObjectParameterSetDefault(snes, max_funcs, 10000);
1808: PetscObjectParameterSetDefault(snes, rtol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1809: PetscObjectParameterSetDefault(snes, abstol, PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50);
1810: PetscObjectParameterSetDefault(snes, stol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1811: PetscObjectParameterSetDefault(snes, divtol, 1.e4);
1812: return PETSC_SUCCESS;
1813: }
1815: /*@
1816: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1818: Collective
1820: Input Parameter:
1821: . comm - MPI communicator
1823: Output Parameter:
1824: . outsnes - the new `SNES` context
1826: Options Database Keys:
1827: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no matrix to construct a preconditioner
1828: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided matrix as set by `SNESSetJacobian()`
1829: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1830: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1832: Level: beginner
1834: Developer Notes:
1835: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1836: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1837: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1838: in `SNESView()`.
1840: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1841: by help messages about meaningless `SNES` options.
1843: `SNES` always creates the `snes->kspconvctx` even though it is used by only one type. This should be fixed.
1845: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1846: @*/
1847: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1848: {
1849: SNES snes;
1850: SNESKSPEW *kctx;
1852: PetscFunctionBegin;
1853: PetscAssertPointer(outsnes, 2);
1854: PetscCall(SNESInitializePackage());
1856: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1857: snes->ops->converged = SNESConvergedDefault;
1858: snes->usesksp = PETSC_TRUE;
1859: snes->norm = 0.0;
1860: snes->xnorm = 0.0;
1861: snes->ynorm = 0.0;
1862: snes->normschedule = SNES_NORM_ALWAYS;
1863: snes->functype = SNES_FUNCTION_DEFAULT;
1864: snes->ttol = 0.0;
1866: snes->rnorm0 = 0;
1867: snes->nfuncs = 0;
1868: snes->numFailures = 0;
1869: snes->maxFailures = 1;
1870: snes->linear_its = 0;
1871: snes->lagjacobian = 1;
1872: snes->jac_iter = 0;
1873: snes->lagjac_persist = PETSC_FALSE;
1874: snes->lagpreconditioner = 1;
1875: snes->pre_iter = 0;
1876: snes->lagpre_persist = PETSC_FALSE;
1877: snes->numbermonitors = 0;
1878: snes->numberreasonviews = 0;
1879: snes->data = NULL;
1880: snes->setupcalled = PETSC_FALSE;
1881: snes->ksp_ewconv = PETSC_FALSE;
1882: snes->nwork = 0;
1883: snes->work = NULL;
1884: snes->nvwork = 0;
1885: snes->vwork = NULL;
1886: snes->conv_hist_len = 0;
1887: snes->conv_hist_max = 0;
1888: snes->conv_hist = NULL;
1889: snes->conv_hist_its = NULL;
1890: snes->conv_hist_reset = PETSC_TRUE;
1891: snes->counters_reset = PETSC_TRUE;
1892: snes->vec_func_init_set = PETSC_FALSE;
1893: snes->reason = SNES_CONVERGED_ITERATING;
1894: snes->npcside = PC_RIGHT;
1895: snes->setfromoptionscalled = 0;
1897: snes->mf = PETSC_FALSE;
1898: snes->mf_operator = PETSC_FALSE;
1899: snes->mf_version = 1;
1901: snes->numLinearSolveFailures = 0;
1902: snes->maxLinearSolveFailures = 1;
1904: snes->vizerotolerance = 1.e-8;
1905: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1907: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1908: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1910: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1911: PetscCall(PetscNew(&kctx));
1913: snes->kspconvctx = kctx;
1914: kctx->version = 2;
1915: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1916: this was too large for some test cases */
1917: kctx->rtol_last = 0.0;
1918: kctx->rtol_max = 0.9;
1919: kctx->gamma = 1.0;
1920: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1921: kctx->alpha2 = kctx->alpha;
1922: kctx->threshold = 0.1;
1923: kctx->lresid_last = 0.0;
1924: kctx->norm_last = 0.0;
1926: kctx->rk_last = 0.0;
1927: kctx->rk_last_2 = 0.0;
1928: kctx->rtol_last_2 = 0.0;
1929: kctx->v4_p1 = 0.1;
1930: kctx->v4_p2 = 0.4;
1931: kctx->v4_p3 = 0.7;
1932: kctx->v4_m1 = 0.8;
1933: kctx->v4_m2 = 0.5;
1934: kctx->v4_m3 = 0.1;
1935: kctx->v4_m4 = 0.5;
1937: PetscCall(SNESParametersInitialize(snes));
1938: *outsnes = snes;
1939: PetscFunctionReturn(PETSC_SUCCESS);
1940: }
1942: /*@C
1943: SNESSetFunction - Sets the function evaluation routine and function
1944: vector for use by the `SNES` routines in solving systems of nonlinear
1945: equations.
1947: Logically Collective
1949: Input Parameters:
1950: + snes - the `SNES` context
1951: . r - vector to store function values, may be `NULL`
1952: . f - function evaluation routine; for calling sequence see `SNESFunctionFn`
1953: - ctx - [optional] user-defined context for private data for the
1954: function evaluation routine (may be `NULL`)
1956: Level: beginner
1958: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunctionFn`
1959: @*/
1960: PetscErrorCode SNESSetFunction(SNES snes, Vec r, SNESFunctionFn *f, void *ctx)
1961: {
1962: DM dm;
1964: PetscFunctionBegin;
1966: if (r) {
1968: PetscCheckSameComm(snes, 1, r, 2);
1969: PetscCall(PetscObjectReference((PetscObject)r));
1970: PetscCall(VecDestroy(&snes->vec_func));
1971: snes->vec_func = r;
1972: }
1973: PetscCall(SNESGetDM(snes, &dm));
1974: PetscCall(DMSNESSetFunction(dm, f, ctx));
1975: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1976: PetscFunctionReturn(PETSC_SUCCESS);
1977: }
1979: /*@C
1980: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1982: Logically Collective
1984: Input Parameters:
1985: + snes - the `SNES` context
1986: - f - vector to store function value
1988: Level: developer
1990: Notes:
1991: This should not be modified during the solution procedure.
1993: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1995: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1996: @*/
1997: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1998: {
1999: Vec vec_func;
2001: PetscFunctionBegin;
2004: PetscCheckSameComm(snes, 1, f, 2);
2005: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
2006: snes->vec_func_init_set = PETSC_FALSE;
2007: PetscFunctionReturn(PETSC_SUCCESS);
2008: }
2009: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
2010: PetscCall(VecCopy(f, vec_func));
2012: snes->vec_func_init_set = PETSC_TRUE;
2013: PetscFunctionReturn(PETSC_SUCCESS);
2014: }
2016: /*@
2017: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
2018: of the `SNES` method, when norms are computed in the solving process
2020: Logically Collective
2022: Input Parameters:
2023: + snes - the `SNES` context
2024: - normschedule - the frequency of norm computation
2026: Options Database Key:
2027: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
2029: Level: advanced
2031: Notes:
2032: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
2033: of the nonlinear function and the taking of its norm at every iteration to
2034: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2035: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
2036: may either be monitored for convergence or not. As these are often used as nonlinear
2037: preconditioners, monitoring the norm of their error is not a useful enterprise within
2038: their solution.
2040: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
2041: @*/
2042: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
2043: {
2044: PetscFunctionBegin;
2046: snes->normschedule = normschedule;
2047: PetscFunctionReturn(PETSC_SUCCESS);
2048: }
2050: /*@
2051: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
2052: of the `SNES` method.
2054: Logically Collective
2056: Input Parameters:
2057: + snes - the `SNES` context
2058: - normschedule - the type of the norm used
2060: Level: advanced
2062: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2063: @*/
2064: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
2065: {
2066: PetscFunctionBegin;
2068: *normschedule = snes->normschedule;
2069: PetscFunctionReturn(PETSC_SUCCESS);
2070: }
2072: /*@
2073: SNESSetFunctionNorm - Sets the last computed residual norm.
2075: Logically Collective
2077: Input Parameters:
2078: + snes - the `SNES` context
2079: - norm - the value of the norm
2081: Level: developer
2083: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2084: @*/
2085: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
2086: {
2087: PetscFunctionBegin;
2089: snes->norm = norm;
2090: PetscFunctionReturn(PETSC_SUCCESS);
2091: }
2093: /*@
2094: SNESGetFunctionNorm - Gets the last computed norm of the residual
2096: Not Collective
2098: Input Parameter:
2099: . snes - the `SNES` context
2101: Output Parameter:
2102: . norm - the last computed residual norm
2104: Level: developer
2106: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2107: @*/
2108: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2109: {
2110: PetscFunctionBegin;
2112: PetscAssertPointer(norm, 2);
2113: *norm = snes->norm;
2114: PetscFunctionReturn(PETSC_SUCCESS);
2115: }
2117: /*@
2118: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2120: Not Collective
2122: Input Parameter:
2123: . snes - the `SNES` context
2125: Output Parameter:
2126: . ynorm - the last computed update norm
2128: Level: developer
2130: Note:
2131: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2133: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2134: @*/
2135: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2136: {
2137: PetscFunctionBegin;
2139: PetscAssertPointer(ynorm, 2);
2140: *ynorm = snes->ynorm;
2141: PetscFunctionReturn(PETSC_SUCCESS);
2142: }
2144: /*@
2145: SNESGetSolutionNorm - Gets the last computed norm of the solution
2147: Not Collective
2149: Input Parameter:
2150: . snes - the `SNES` context
2152: Output Parameter:
2153: . xnorm - the last computed solution norm
2155: Level: developer
2157: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2158: @*/
2159: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2160: {
2161: PetscFunctionBegin;
2163: PetscAssertPointer(xnorm, 2);
2164: *xnorm = snes->xnorm;
2165: PetscFunctionReturn(PETSC_SUCCESS);
2166: }
2168: /*@
2169: SNESSetFunctionType - Sets the `SNESFunctionType`
2170: of the `SNES` method.
2172: Logically Collective
2174: Input Parameters:
2175: + snes - the `SNES` context
2176: - type - the function type
2178: Level: developer
2180: Values of the function type\:
2181: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2182: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2183: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2185: Note:
2186: Different `SNESType`s use this value in different ways
2188: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2189: @*/
2190: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2191: {
2192: PetscFunctionBegin;
2194: snes->functype = type;
2195: PetscFunctionReturn(PETSC_SUCCESS);
2196: }
2198: /*@
2199: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2200: of the SNES method.
2202: Logically Collective
2204: Input Parameters:
2205: + snes - the `SNES` context
2206: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2208: Level: advanced
2210: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2211: @*/
2212: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2213: {
2214: PetscFunctionBegin;
2216: *type = snes->functype;
2217: PetscFunctionReturn(PETSC_SUCCESS);
2218: }
2220: /*@C
2221: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2222: use with composed nonlinear solvers.
2224: Input Parameters:
2225: + snes - the `SNES` context, usually of the `SNESType` `SNESNGS`
2226: . f - function evaluation routine to apply Gauss-Seidel, see `SNESNGSFn` for calling sequence
2227: - ctx - [optional] user-defined context for private data for the smoother evaluation routine (may be `NULL`)
2229: Level: intermediate
2231: Note:
2232: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2233: a problem appropriate update to the solution, particularly `SNESFAS`.
2235: .seealso: [](ch_snes), `SNESNGS`, `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`, `SNESNGSFn`
2236: @*/
2237: PetscErrorCode SNESSetNGS(SNES snes, SNESNGSFn *f, void *ctx)
2238: {
2239: DM dm;
2241: PetscFunctionBegin;
2243: PetscCall(SNESGetDM(snes, &dm));
2244: PetscCall(DMSNESSetNGS(dm, f, ctx));
2245: PetscFunctionReturn(PETSC_SUCCESS);
2246: }
2248: /*
2249: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2250: changed during the KSPSolve()
2251: */
2252: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, void *ctx)
2253: {
2254: DM dm;
2255: DMSNES sdm;
2257: PetscFunctionBegin;
2258: PetscCall(SNESGetDM(snes, &dm));
2259: PetscCall(DMGetDMSNES(dm, &sdm));
2260: /* A(x)*x - b(x) */
2261: if (sdm->ops->computepfunction) {
2262: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2263: PetscCall(VecScale(f, -1.0));
2264: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2265: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2266: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2267: PetscCall(MatMultAdd(snes->picard, x, f, f));
2268: } else {
2269: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2270: PetscCall(MatMult(snes->picard, x, f));
2271: }
2272: PetscFunctionReturn(PETSC_SUCCESS);
2273: }
2275: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, void *ctx)
2276: {
2277: DM dm;
2278: DMSNES sdm;
2280: PetscFunctionBegin;
2281: PetscCall(SNESGetDM(snes, &dm));
2282: PetscCall(DMGetDMSNES(dm, &sdm));
2283: /* A(x)*x - b(x) */
2284: if (sdm->ops->computepfunction) {
2285: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2286: PetscCall(VecScale(f, -1.0));
2287: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2288: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2289: } else {
2290: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2291: PetscCall(MatMult(snes->jacobian_pre, x, f));
2292: }
2293: PetscFunctionReturn(PETSC_SUCCESS);
2294: }
2296: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, void *ctx)
2297: {
2298: PetscFunctionBegin;
2299: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2300: /* must assembly if matrix-free to get the last SNES solution */
2301: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2302: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2303: PetscFunctionReturn(PETSC_SUCCESS);
2304: }
2306: /*@C
2307: SNESSetPicard - Use `SNES` to solve the system $A(x) x = bp(x) + b $ via a Picard type iteration (Picard linearization)
2309: Logically Collective
2311: Input Parameters:
2312: + snes - the `SNES` context
2313: . r - vector to store function values, may be `NULL`
2314: . bp - function evaluation routine, may be `NULL`, for the calling sequence see `SNESFunctionFn`
2315: . Amat - matrix with which $A(x) x - bp(x) - b$ is to be computed
2316: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2317: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFn`
2318: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2320: Level: intermediate
2322: Notes:
2323: It is often better to provide the nonlinear function $F()$ and some approximation to its Jacobian directly and use
2324: 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.
2326: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2328: Solves the equation $A(x) x = bp(x) - b$ via the defect correction algorithm $A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}$.
2329: When an exact solver is used this corresponds to the "classic" Picard $A(x^{n}) x^{n+1} = bp(x^{n}) + b$ iteration.
2331: Run with `-snes_mf_operator` to solve the system with Newton's method using $A(x^{n})$ to construct the preconditioner.
2333: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2334: the direct Picard iteration $A(x^n) x^{n+1} = bp(x^n) + b$
2336: 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
2337: 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
2338: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument \:-).
2340: 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
2341: $A(x^{n})$ is used to build the preconditioner
2343: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at a time) and thus represent Newton's method.
2345: 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
2346: 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
2347: 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`.
2348: See the comment in src/snes/tutorials/ex15.c.
2350: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`,
2351: `SNESFunctionFn`, `SNESJacobianFn`
2352: @*/
2353: PetscErrorCode SNESSetPicard(SNES snes, Vec r, SNESFunctionFn *bp, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
2354: {
2355: DM dm;
2357: PetscFunctionBegin;
2359: PetscCall(SNESGetDM(snes, &dm));
2360: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2361: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2362: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2363: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2364: PetscFunctionReturn(PETSC_SUCCESS);
2365: }
2367: /*@C
2368: SNESGetPicard - Returns the context for the Picard iteration
2370: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2372: Input Parameter:
2373: . snes - the `SNES` context
2375: Output Parameters:
2376: + r - the function (or `NULL`)
2377: . f - the function (or `NULL`); for calling sequence see `SNESFunctionFn`
2378: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2379: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2380: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFn`
2381: - ctx - the function context (or `NULL`)
2383: Level: advanced
2385: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunctionFn`, `SNESJacobianFn`
2386: @*/
2387: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, SNESFunctionFn **f, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
2388: {
2389: DM dm;
2391: PetscFunctionBegin;
2393: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2394: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2395: PetscCall(SNESGetDM(snes, &dm));
2396: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2397: PetscFunctionReturn(PETSC_SUCCESS);
2398: }
2400: /*@C
2401: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2403: Logically Collective
2405: Input Parameters:
2406: + snes - the `SNES` context
2407: . func - function evaluation routine, see `SNESInitialGuessFn` for the calling sequence
2408: - ctx - [optional] user-defined context for private data for the
2409: function evaluation routine (may be `NULL`)
2411: Level: intermediate
2413: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESInitialGuessFn`
2414: @*/
2415: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, SNESInitialGuessFn *func, void *ctx)
2416: {
2417: PetscFunctionBegin;
2419: if (func) snes->ops->computeinitialguess = func;
2420: if (ctx) snes->initialguessP = ctx;
2421: PetscFunctionReturn(PETSC_SUCCESS);
2422: }
2424: /*@C
2425: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2426: it assumes a zero right-hand side.
2428: Logically Collective
2430: Input Parameter:
2431: . snes - the `SNES` context
2433: Output Parameter:
2434: . rhs - the right-hand side vector or `NULL` if there is no right-hand side vector
2436: Level: intermediate
2438: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2439: @*/
2440: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2441: {
2442: PetscFunctionBegin;
2444: PetscAssertPointer(rhs, 2);
2445: *rhs = snes->vec_rhs;
2446: PetscFunctionReturn(PETSC_SUCCESS);
2447: }
2449: /*@
2450: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2452: Collective
2454: Input Parameters:
2455: + snes - the `SNES` context
2456: - x - input vector
2458: Output Parameter:
2459: . f - function vector, as set by `SNESSetFunction()`
2461: Level: developer
2463: Notes:
2464: `SNESComputeFunction()` is typically used within nonlinear solvers
2465: implementations, so users would not generally call this routine themselves.
2467: When solving for $F(x) = b$, this routine computes $f = F(x) - b$.
2469: This function usually appears in the pattern.
2470: .vb
2471: SNESComputeFunction(snes, x, f);
2472: VecNorm(f, &fnorm);
2473: SNESCheckFunctionDomainError(snes, fnorm); or SNESLineSearchCheckFunctionDomainError(ls, fnorm);
2474: .ve
2475: to collectively handle the use of `SNESSetFunctionDomainError()` in the provided callback function.
2477: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`, `SNESSetFunctionDomainError()`
2478: @*/
2479: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec f)
2480: {
2481: DM dm;
2482: DMSNES sdm;
2484: PetscFunctionBegin;
2488: PetscCheckSameComm(snes, 1, x, 2);
2489: PetscCheckSameComm(snes, 1, f, 3);
2490: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2492: PetscCall(SNESGetDM(snes, &dm));
2493: PetscCall(DMGetDMSNES(dm, &sdm));
2494: 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().");
2495: if (sdm->ops->computefunction) {
2496: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, f, 0));
2497: PetscCall(VecLockReadPush(x));
2498: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2499: snes->functiondomainerror = PETSC_FALSE;
2500: {
2501: void *ctx;
2502: SNESFunctionFn *computefunction;
2503: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2504: PetscCallBack("SNES callback function", (*computefunction)(snes, x, f, ctx));
2505: }
2506: PetscCall(VecLockReadPop(x));
2507: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, f, 0));
2508: } else /* if (snes->vec_rhs) */ {
2509: PetscCall(MatMult(snes->jacobian, x, f));
2510: }
2511: if (snes->vec_rhs) PetscCall(VecAXPY(f, -1.0, snes->vec_rhs));
2512: snes->nfuncs++;
2513: /*
2514: domainerror might not be set on all processes; so we tag vector locally with infinity and the next inner product or norm will
2515: propagate the value to all processes
2516: */
2517: PetscCall(VecFlag(f, snes->functiondomainerror));
2518: PetscFunctionReturn(PETSC_SUCCESS);
2519: }
2521: /*@
2522: SNESComputeMFFunction - Calls the function that has been set with `DMSNESSetMFFunction()`.
2524: Collective
2526: Input Parameters:
2527: + snes - the `SNES` context
2528: - x - input vector
2530: Output Parameter:
2531: . y - output vector
2533: Level: developer
2535: Notes:
2536: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2537: so users would not generally call this routine themselves.
2539: Since this function is intended for use with finite differencing it does not subtract the right-hand side vector provided with `SNESSolve()`
2540: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2541: 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.
2543: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF()`, `DMSNESSetMFFunction()`
2544: @*/
2545: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2546: {
2547: DM dm;
2548: DMSNES sdm;
2550: PetscFunctionBegin;
2554: PetscCheckSameComm(snes, 1, x, 2);
2555: PetscCheckSameComm(snes, 1, y, 3);
2556: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2558: PetscCall(SNESGetDM(snes, &dm));
2559: PetscCall(DMGetDMSNES(dm, &sdm));
2560: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2561: PetscCall(VecLockReadPush(x));
2562: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2563: snes->functiondomainerror = PETSC_FALSE;
2564: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2565: PetscCall(VecLockReadPop(x));
2566: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2567: snes->nfuncs++;
2568: /*
2569: domainerror might not be set on all processes; so we tag vector locally with infinity and the next inner product or norm will
2570: propagate the value to all processes
2571: */
2572: PetscCall(VecFlag(y, snes->functiondomainerror));
2573: PetscFunctionReturn(PETSC_SUCCESS);
2574: }
2576: /*@
2577: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2579: Collective
2581: Input Parameters:
2582: + snes - the `SNES` context
2583: . x - input vector
2584: - b - rhs vector
2586: Output Parameter:
2587: . x - new solution vector
2589: Level: developer
2591: Note:
2592: `SNESComputeNGS()` is typically used within composed nonlinear solver
2593: implementations, so most users would not generally call this routine
2594: themselves.
2596: .seealso: [](ch_snes), `SNESNGSFn`, `SNESSetNGS()`, `SNESComputeFunction()`, `SNESNGS`
2597: @*/
2598: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2599: {
2600: DM dm;
2601: DMSNES sdm;
2603: PetscFunctionBegin;
2607: PetscCheckSameComm(snes, 1, x, 3);
2608: if (b) PetscCheckSameComm(snes, 1, b, 2);
2609: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2610: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2611: PetscCall(SNESGetDM(snes, &dm));
2612: PetscCall(DMGetDMSNES(dm, &sdm));
2613: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2614: if (b) PetscCall(VecLockReadPush(b));
2615: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2616: if (b) PetscCall(VecLockReadPop(b));
2617: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2618: PetscFunctionReturn(PETSC_SUCCESS);
2619: }
2621: static PetscErrorCode SNESComputeFunction_FD(SNES snes, Vec Xin, Vec G)
2622: {
2623: Vec X;
2624: PetscScalar *g;
2625: PetscReal f, f2;
2626: PetscInt low, high, N, i;
2627: PetscBool flg;
2628: PetscReal h = .5 * PETSC_SQRT_MACHINE_EPSILON;
2630: PetscFunctionBegin;
2631: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_fd_delta", &h, &flg));
2632: PetscCall(VecDuplicate(Xin, &X));
2633: PetscCall(VecCopy(Xin, X));
2634: PetscCall(VecGetSize(X, &N));
2635: PetscCall(VecGetOwnershipRange(X, &low, &high));
2636: PetscCall(VecSetOption(X, VEC_IGNORE_OFF_PROC_ENTRIES, PETSC_TRUE));
2637: PetscCall(VecGetArray(G, &g));
2638: for (i = 0; i < N; i++) {
2639: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2640: PetscCall(VecAssemblyBegin(X));
2641: PetscCall(VecAssemblyEnd(X));
2642: PetscCall(SNESComputeObjective(snes, X, &f));
2643: PetscCall(VecSetValue(X, i, 2.0 * h, ADD_VALUES));
2644: PetscCall(VecAssemblyBegin(X));
2645: PetscCall(VecAssemblyEnd(X));
2646: PetscCall(SNESComputeObjective(snes, X, &f2));
2647: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2648: PetscCall(VecAssemblyBegin(X));
2649: PetscCall(VecAssemblyEnd(X));
2650: if (i >= low && i < high) g[i - low] = (f2 - f) / (2.0 * h);
2651: }
2652: PetscCall(VecRestoreArray(G, &g));
2653: PetscCall(VecDestroy(&X));
2654: PetscFunctionReturn(PETSC_SUCCESS);
2655: }
2657: /*@
2658: SNESTestFunction - Computes the difference between the computed and finite-difference functions
2660: Collective
2662: Input Parameter:
2663: . snes - the `SNES` context
2665: Options Database Keys:
2666: + -snes_test_function - compare the user provided function with one compute via finite differences to check for errors.
2667: - -snes_test_function_view - display the user provided function, the finite difference function and the difference
2669: Level: developer
2671: .seealso: [](ch_snes), `SNESTestJacobian()`, `SNESSetFunction()`, `SNESComputeFunction()`
2672: @*/
2673: PetscErrorCode SNESTestFunction(SNES snes)
2674: {
2675: Vec x, g1, g2, g3;
2676: PetscBool complete_print = PETSC_FALSE;
2677: PetscReal hcnorm, fdnorm, hcmax, fdmax, diffmax, diffnorm;
2678: PetscScalar dot;
2679: MPI_Comm comm;
2680: PetscViewer viewer, mviewer;
2681: PetscViewerFormat format;
2682: PetscInt tabs;
2683: static PetscBool directionsprinted = PETSC_FALSE;
2684: SNESObjectiveFn *objective;
2686: PetscFunctionBegin;
2687: PetscCall(SNESGetObjective(snes, &objective, NULL));
2688: if (!objective) PetscFunctionReturn(PETSC_SUCCESS);
2690: PetscObjectOptionsBegin((PetscObject)snes);
2691: PetscCall(PetscOptionsViewer("-snes_test_function_view", "View difference between hand-coded and finite difference function element entries", "None", &mviewer, &format, &complete_print));
2692: PetscOptionsEnd();
2694: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2695: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2696: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2697: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2698: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Function -------------\n"));
2699: if (!complete_print && !directionsprinted) {
2700: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_function_view and optionally -snes_test_function <threshold> to show difference\n"));
2701: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference function entries greater than <threshold>.\n"));
2702: }
2703: if (!directionsprinted) {
2704: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Function, if (for double precision runs) ||F - Ffd||/||F|| is\n"));
2705: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Function is probably correct.\n"));
2706: directionsprinted = PETSC_TRUE;
2707: }
2708: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2710: PetscCall(SNESGetSolution(snes, &x));
2711: PetscCall(VecDuplicate(x, &g1));
2712: PetscCall(VecDuplicate(x, &g2));
2713: PetscCall(VecDuplicate(x, &g3));
2714: PetscCall(SNESComputeFunction(snes, x, g1)); /* does not handle use of SNESSetFunctionDomainError() corrrectly */
2715: PetscCall(SNESComputeFunction_FD(snes, x, g2));
2717: PetscCall(VecNorm(g2, NORM_2, &fdnorm));
2718: PetscCall(VecNorm(g1, NORM_2, &hcnorm));
2719: PetscCall(VecNorm(g2, NORM_INFINITY, &fdmax));
2720: PetscCall(VecNorm(g1, NORM_INFINITY, &hcmax));
2721: PetscCall(VecDot(g1, g2, &dot));
2722: PetscCall(VecCopy(g1, g3));
2723: PetscCall(VecAXPY(g3, -1.0, g2));
2724: PetscCall(VecNorm(g3, NORM_2, &diffnorm));
2725: PetscCall(VecNorm(g3, NORM_INFINITY, &diffmax));
2726: PetscCall(PetscViewerASCIIPrintf(viewer, " ||Ffd|| %g, ||F|| = %g, angle cosine = (Ffd'F)/||Ffd||||F|| = %g\n", (double)fdnorm, (double)hcnorm, (double)(PetscRealPart(dot) / (fdnorm * hcnorm))));
2727: PetscCall(PetscViewerASCIIPrintf(viewer, " 2-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffnorm / PetscMax(hcnorm, fdnorm)), (double)diffnorm));
2728: PetscCall(PetscViewerASCIIPrintf(viewer, " max-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffmax / PetscMax(hcmax, fdmax)), (double)diffmax));
2730: if (complete_print) {
2731: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded function ----------\n"));
2732: PetscCall(VecView(g1, mviewer));
2733: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference function ----------\n"));
2734: PetscCall(VecView(g2, mviewer));
2735: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference function ----------\n"));
2736: PetscCall(VecView(g3, mviewer));
2737: }
2738: PetscCall(VecDestroy(&g1));
2739: PetscCall(VecDestroy(&g2));
2740: PetscCall(VecDestroy(&g3));
2742: if (complete_print) {
2743: PetscCall(PetscViewerPopFormat(mviewer));
2744: PetscCall(PetscViewerDestroy(&mviewer));
2745: }
2746: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2747: PetscFunctionReturn(PETSC_SUCCESS);
2748: }
2750: /*@
2751: SNESTestJacobian - Computes the difference between the computed and finite-difference Jacobians
2753: Collective
2755: Input Parameter:
2756: . snes - the `SNES` context
2758: Output Parameters:
2759: + Jnorm - the Frobenius norm of the computed Jacobian, or `NULL`
2760: - diffNorm - the Frobenius norm of the difference of the computed and finite-difference Jacobians, or `NULL`
2762: Options Database Keys:
2763: + -snes_test_jacobian <optional threshold> - compare the user provided Jacobian with one compute via finite differences to check for errors. If a threshold is given, display only those entries whose difference is greater than the threshold.
2764: - -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference
2766: Level: developer
2768: Note:
2769: Directions and norms are printed to stdout if `diffNorm` is `NULL`.
2771: .seealso: [](ch_snes), `SNESTestFunction()`, `SNESSetJacobian()`, `SNESComputeJacobian()`
2772: @*/
2773: PetscErrorCode SNESTestJacobian(SNES snes, PetscReal *Jnorm, PetscReal *diffNorm)
2774: {
2775: Mat A, B, C, D, jacobian;
2776: Vec x = snes->vec_sol, f;
2777: PetscReal nrm, gnorm;
2778: PetscReal threshold = 1.e-5;
2779: MatType mattype;
2780: PetscInt m, n, M, N;
2781: void *functx;
2782: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, flg, istranspose;
2783: PetscBool silent = diffNorm != PETSC_NULLPTR ? PETSC_TRUE : PETSC_FALSE;
2784: PetscViewer viewer, mviewer;
2785: MPI_Comm comm;
2786: PetscInt tabs;
2787: static PetscBool directionsprinted = PETSC_FALSE;
2788: PetscViewerFormat format;
2790: PetscFunctionBegin;
2791: PetscObjectOptionsBegin((PetscObject)snes);
2792: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2793: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2794: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2795: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2796: 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));
2797: PetscOptionsEnd();
2799: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2800: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2801: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2802: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2803: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2804: if (!complete_print && !silent && !directionsprinted) {
2805: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2806: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2807: }
2808: if (!directionsprinted && !silent) {
2809: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2810: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2811: directionsprinted = PETSC_TRUE;
2812: }
2813: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2815: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2816: if (!flg) jacobian = snes->jacobian;
2817: else jacobian = snes->jacobian_pre;
2819: if (!x) PetscCall(MatCreateVecs(jacobian, &x, NULL));
2820: else PetscCall(PetscObjectReference((PetscObject)x));
2821: PetscCall(VecDuplicate(x, &f));
2823: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2824: PetscCall(SNESComputeFunction(snes, x, f));
2825: PetscCall(VecDestroy(&f));
2826: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2827: while (jacobian) {
2828: Mat JT = NULL, Jsave = NULL;
2830: if (istranspose) {
2831: PetscCall(MatCreateTranspose(jacobian, &JT));
2832: Jsave = jacobian;
2833: jacobian = JT;
2834: }
2835: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2836: if (flg) {
2837: A = jacobian;
2838: PetscCall(PetscObjectReference((PetscObject)A));
2839: } else {
2840: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2841: }
2843: PetscCall(MatGetType(A, &mattype));
2844: PetscCall(MatGetSize(A, &M, &N));
2845: PetscCall(MatGetLocalSize(A, &m, &n));
2846: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2847: PetscCall(MatSetType(B, mattype));
2848: PetscCall(MatSetSizes(B, m, n, M, N));
2849: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2850: PetscCall(MatSetUp(B));
2851: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2853: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2854: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2856: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2857: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2858: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2859: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2860: PetscCall(MatDestroy(&D));
2861: if (!gnorm) gnorm = 1; /* just in case */
2862: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2863: if (complete_print) {
2864: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2865: PetscCall(MatView(A, mviewer));
2866: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2867: PetscCall(MatView(B, mviewer));
2868: }
2870: if (threshold_print || complete_print) {
2871: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2872: PetscScalar *cvals;
2873: const PetscInt *bcols;
2874: const PetscScalar *bvals;
2876: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2877: PetscCall(MatSetType(C, mattype));
2878: PetscCall(MatSetSizes(C, m, n, M, N));
2879: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2880: PetscCall(MatSetUp(C));
2881: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2883: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2884: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2886: for (row = Istart; row < Iend; row++) {
2887: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2888: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2889: for (j = 0, cncols = 0; j < bncols; j++) {
2890: if (PetscAbsScalar(bvals[j]) > threshold) {
2891: ccols[cncols] = bcols[j];
2892: cvals[cncols] = bvals[j];
2893: cncols += 1;
2894: }
2895: }
2896: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2897: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2898: PetscCall(PetscFree2(ccols, cvals));
2899: }
2900: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2901: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2902: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2903: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2904: PetscCall(MatDestroy(&C));
2905: }
2906: PetscCall(MatDestroy(&A));
2907: PetscCall(MatDestroy(&B));
2908: PetscCall(MatDestroy(&JT));
2909: if (Jsave) jacobian = Jsave;
2910: if (jacobian != snes->jacobian_pre) {
2911: jacobian = snes->jacobian_pre;
2912: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2913: } else jacobian = NULL;
2914: }
2915: PetscCall(VecDestroy(&x));
2916: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2917: if (mviewer) PetscCall(PetscViewerDestroy(&mviewer));
2918: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2920: if (Jnorm) *Jnorm = gnorm;
2921: if (diffNorm) *diffNorm = nrm;
2922: PetscFunctionReturn(PETSC_SUCCESS);
2923: }
2925: /*@
2926: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2928: Collective
2930: Input Parameters:
2931: + snes - the `SNES` context
2932: - X - input vector
2934: Output Parameters:
2935: + A - Jacobian matrix
2936: - B - optional matrix for building the preconditioner, usually the same as `A`
2938: Options Database Keys:
2939: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2940: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2941: . -snes_test_jacobian <optional threshold> - compare the user provided Jacobian with one compute via finite differences to check for errors. If a threshold is given, display only those entries whose difference is greater than the threshold.
2942: . -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference between them to help users detect the location of errors in the user provided Jacobian
2943: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2944: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2945: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2946: . -snes_compare_operator - Make the comparison options above use the operator instead of the matrix used to construct the preconditioner
2947: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2948: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2949: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2950: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2951: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2952: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2953: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2955: Level: developer
2957: Note:
2958: Most users should not need to explicitly call this routine, as it
2959: is used internally within the nonlinear solvers.
2961: Developer Note:
2962: 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
2963: with the `SNESType` of test that has been removed.
2965: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
2966: `SNESSetJacobianDomainError()`, `SNESCheckJacobianDomainError()`, `SNESSetCheckJacobianDomainError()`
2967: @*/
2968: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2969: {
2970: PetscBool flag;
2971: DM dm;
2972: DMSNES sdm;
2973: KSP ksp;
2975: PetscFunctionBegin;
2978: PetscCheckSameComm(snes, 1, X, 2);
2979: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2980: PetscCall(SNESGetDM(snes, &dm));
2981: PetscCall(DMGetDMSNES(dm, &sdm));
2983: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2984: if (snes->lagjacobian == -2) {
2985: snes->lagjacobian = -1;
2987: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2988: } else if (snes->lagjacobian == -1) {
2989: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2990: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2991: if (flag) {
2992: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2993: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2994: }
2995: PetscFunctionReturn(PETSC_SUCCESS);
2996: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2997: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2998: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2999: if (flag) {
3000: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
3001: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
3002: }
3003: PetscFunctionReturn(PETSC_SUCCESS);
3004: }
3005: if (snes->npc && snes->npcside == PC_LEFT) {
3006: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
3007: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
3008: PetscFunctionReturn(PETSC_SUCCESS);
3009: }
3011: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
3012: PetscCall(VecLockReadPush(X));
3013: {
3014: void *ctx;
3015: SNESJacobianFn *J;
3016: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
3017: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
3018: }
3019: PetscCall(VecLockReadPop(X));
3020: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
3022: /* attach latest linearization point to the matrix used to construct the preconditioner */
3023: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
3025: /* the next line ensures that snes->ksp exists */
3026: PetscCall(SNESGetKSP(snes, &ksp));
3027: if (snes->lagpreconditioner == -2) {
3028: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
3029: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
3030: snes->lagpreconditioner = -1;
3031: } else if (snes->lagpreconditioner == -1) {
3032: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
3033: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
3034: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
3035: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
3036: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
3037: } else {
3038: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
3039: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
3040: }
3042: /* monkey business to allow testing Jacobians in multilevel solvers.
3043: This is needed because the SNESTestXXX interface does not accept vectors and matrices */
3044: {
3045: Vec xsave = snes->vec_sol;
3046: Mat jacobiansave = snes->jacobian;
3047: Mat jacobian_presave = snes->jacobian_pre;
3049: snes->vec_sol = X;
3050: snes->jacobian = A;
3051: snes->jacobian_pre = B;
3052: if (snes->testFunc) PetscCall(SNESTestFunction(snes));
3053: if (snes->testJac) PetscCall(SNESTestJacobian(snes, NULL, NULL));
3055: snes->vec_sol = xsave;
3056: snes->jacobian = jacobiansave;
3057: snes->jacobian_pre = jacobian_presave;
3058: }
3060: {
3061: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
3062: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
3063: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
3064: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
3065: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
3066: if (flag || flag_draw || flag_contour) {
3067: Mat Bexp_mine = NULL, Bexp, FDexp;
3068: PetscViewer vdraw, vstdout;
3069: PetscBool flg;
3070: if (flag_operator) {
3071: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
3072: Bexp = Bexp_mine;
3073: } else {
3074: /* See if the matrix used to construct the preconditioner can be viewed and added directly */
3075: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
3076: if (flg) Bexp = B;
3077: else {
3078: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
3079: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
3080: Bexp = Bexp_mine;
3081: }
3082: }
3083: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
3084: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
3085: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3086: if (flag_draw || flag_contour) {
3087: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3088: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3089: } else vdraw = NULL;
3090: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
3091: if (flag) PetscCall(MatView(Bexp, vstdout));
3092: if (vdraw) PetscCall(MatView(Bexp, vdraw));
3093: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
3094: if (flag) PetscCall(MatView(FDexp, vstdout));
3095: if (vdraw) PetscCall(MatView(FDexp, vdraw));
3096: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
3097: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
3098: if (flag) PetscCall(MatView(FDexp, vstdout));
3099: if (vdraw) { /* Always use contour for the difference */
3100: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3101: PetscCall(MatView(FDexp, vdraw));
3102: PetscCall(PetscViewerPopFormat(vdraw));
3103: }
3104: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3105: PetscCall(PetscViewerDestroy(&vdraw));
3106: PetscCall(MatDestroy(&Bexp_mine));
3107: PetscCall(MatDestroy(&FDexp));
3108: }
3109: }
3110: {
3111: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
3112: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
3113: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
3114: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
3115: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
3116: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
3117: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
3118: if (flag_threshold) {
3119: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
3120: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
3121: }
3122: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
3123: Mat Bfd;
3124: PetscViewer vdraw, vstdout;
3125: MatColoring coloring;
3126: ISColoring iscoloring;
3127: MatFDColoring matfdcoloring;
3128: SNESFunctionFn *func;
3129: void *funcctx;
3130: PetscReal norm1, norm2, normmax;
3132: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
3133: PetscCall(MatColoringCreate(Bfd, &coloring));
3134: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
3135: PetscCall(MatColoringSetFromOptions(coloring));
3136: PetscCall(MatColoringApply(coloring, &iscoloring));
3137: PetscCall(MatColoringDestroy(&coloring));
3138: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
3139: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3140: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
3141: PetscCall(ISColoringDestroy(&iscoloring));
3143: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
3144: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
3145: PetscCall(MatFDColoringSetFunction(matfdcoloring, (MatFDColoringFn *)func, funcctx));
3146: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
3147: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
3148: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3149: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
3150: PetscCall(MatFDColoringDestroy(&matfdcoloring));
3152: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3153: if (flag_draw || flag_contour) {
3154: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3155: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3156: } else vdraw = NULL;
3157: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
3158: if (flag_display) PetscCall(MatView(B, vstdout));
3159: if (vdraw) PetscCall(MatView(B, vdraw));
3160: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
3161: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3162: if (vdraw) PetscCall(MatView(Bfd, vdraw));
3163: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
3164: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
3165: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
3166: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
3167: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
3168: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3169: if (vdraw) { /* Always use contour for the difference */
3170: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3171: PetscCall(MatView(Bfd, vdraw));
3172: PetscCall(PetscViewerPopFormat(vdraw));
3173: }
3174: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3176: if (flag_threshold) {
3177: PetscInt bs, rstart, rend, i;
3178: PetscCall(MatGetBlockSize(B, &bs));
3179: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
3180: for (i = rstart; i < rend; i++) {
3181: const PetscScalar *ba, *ca;
3182: const PetscInt *bj, *cj;
3183: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
3184: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
3185: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
3186: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
3187: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
3188: for (j = 0; j < bn; j++) {
3189: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3190: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
3191: maxentrycol = bj[j];
3192: maxentry = PetscRealPart(ba[j]);
3193: }
3194: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
3195: maxdiffcol = bj[j];
3196: maxdiff = PetscRealPart(ca[j]);
3197: }
3198: if (rdiff > maxrdiff) {
3199: maxrdiffcol = bj[j];
3200: maxrdiff = rdiff;
3201: }
3202: }
3203: if (maxrdiff > 1) {
3204: 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));
3205: for (j = 0; j < bn; j++) {
3206: PetscReal rdiff;
3207: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3208: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
3209: }
3210: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
3211: }
3212: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
3213: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
3214: }
3215: }
3216: PetscCall(PetscViewerDestroy(&vdraw));
3217: PetscCall(MatDestroy(&Bfd));
3218: }
3219: }
3220: PetscFunctionReturn(PETSC_SUCCESS);
3221: }
3223: /*@C
3224: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3225: location to store the matrix.
3227: Logically Collective
3229: Input Parameters:
3230: + snes - the `SNES` context
3231: . Amat - the matrix that defines the (approximate) Jacobian
3232: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3233: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFn` for details
3234: - ctx - [optional] user-defined context for private data for the
3235: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3237: Level: beginner
3239: Notes:
3240: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3241: each matrix.
3243: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3244: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3246: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3247: must be a `MatFDColoring`.
3249: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3250: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3252: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3253: `SNESSetPicard()`, `SNESJacobianFn`, `SNESFunctionFn`
3254: @*/
3255: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, SNESJacobianFn *J, void *ctx)
3256: {
3257: DM dm;
3259: PetscFunctionBegin;
3263: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3264: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3265: PetscCall(SNESGetDM(snes, &dm));
3266: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3267: if (Amat) {
3268: PetscCall(PetscObjectReference((PetscObject)Amat));
3269: PetscCall(MatDestroy(&snes->jacobian));
3271: snes->jacobian = Amat;
3272: }
3273: if (Pmat) {
3274: PetscCall(PetscObjectReference((PetscObject)Pmat));
3275: PetscCall(MatDestroy(&snes->jacobian_pre));
3277: snes->jacobian_pre = Pmat;
3278: }
3279: PetscFunctionReturn(PETSC_SUCCESS);
3280: }
3282: /*@C
3283: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3284: provided context for evaluating the Jacobian.
3286: Not Collective, but `Mat` object will be parallel if `SNES` is
3288: Input Parameter:
3289: . snes - the nonlinear solver context
3291: Output Parameters:
3292: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3293: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3294: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFn`
3295: - ctx - location to stash Jacobian ctx (or `NULL`)
3297: Level: advanced
3299: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFn`, `SNESGetFunction()`
3300: @*/
3301: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, void **ctx)
3302: {
3303: DM dm;
3305: PetscFunctionBegin;
3307: if (Amat) *Amat = snes->jacobian;
3308: if (Pmat) *Pmat = snes->jacobian_pre;
3309: PetscCall(SNESGetDM(snes, &dm));
3310: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3311: PetscFunctionReturn(PETSC_SUCCESS);
3312: }
3314: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3315: {
3316: DM dm;
3317: DMSNES sdm;
3319: PetscFunctionBegin;
3320: PetscCall(SNESGetDM(snes, &dm));
3321: PetscCall(DMGetDMSNES(dm, &sdm));
3322: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3323: DM dm;
3324: PetscBool isdense, ismf;
3326: PetscCall(SNESGetDM(snes, &dm));
3327: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3328: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3329: if (isdense) {
3330: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3331: } else if (!ismf) {
3332: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3333: }
3334: }
3335: PetscFunctionReturn(PETSC_SUCCESS);
3336: }
3338: /*@
3339: SNESSetUp - Sets up the internal data structures for the later use
3340: of a nonlinear solver `SNESSolve()`.
3342: Collective
3344: Input Parameter:
3345: . snes - the `SNES` context
3347: Level: advanced
3349: Note:
3350: For basic use of the `SNES` solvers the user does not need to explicitly call
3351: `SNESSetUp()`, since these actions will automatically occur during
3352: the call to `SNESSolve()`. However, if one wishes to control this
3353: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3354: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3356: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`, `SNESSetFromOptions()`
3357: @*/
3358: PetscErrorCode SNESSetUp(SNES snes)
3359: {
3360: DM dm;
3361: DMSNES sdm;
3362: SNESLineSearch linesearch, pclinesearch;
3363: void *lsprectx, *lspostctx;
3364: PetscBool mf_operator, mf;
3365: Vec f, fpc;
3366: void *funcctx;
3367: void *jacctx, *appctx;
3368: Mat j, jpre;
3369: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, void *);
3370: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *);
3371: SNESFunctionFn *func;
3372: SNESJacobianFn *jac;
3374: PetscFunctionBegin;
3376: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3377: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3379: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3381: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3383: PetscCall(SNESGetDM(snes, &dm));
3384: PetscCall(DMGetDMSNES(dm, &sdm));
3385: PetscCall(SNESSetDefaultComputeJacobian(snes));
3387: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3389: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3391: if (snes->linesearch) {
3392: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3393: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3394: }
3396: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3397: if (snes->npc && snes->npcside == PC_LEFT) {
3398: snes->mf = PETSC_TRUE;
3399: snes->mf_operator = PETSC_FALSE;
3400: }
3402: if (snes->npc) {
3403: /* copy the DM over */
3404: PetscCall(SNESGetDM(snes, &dm));
3405: PetscCall(SNESSetDM(snes->npc, dm));
3407: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3408: PetscCall(VecDuplicate(f, &fpc));
3409: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3410: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3411: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3412: PetscCall(SNESGetApplicationContext(snes, &appctx));
3413: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3414: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3415: PetscCall(VecDestroy(&fpc));
3417: /* copy the function pointers over */
3418: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3420: /* default to 1 iteration */
3421: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3422: if (snes->npcside == PC_RIGHT) {
3423: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3424: } else {
3425: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3426: }
3427: PetscCall(SNESSetFromOptions(snes->npc));
3429: /* copy the line search context over */
3430: if (snes->linesearch && snes->npc->linesearch) {
3431: PetscCall(SNESGetLineSearch(snes, &linesearch));
3432: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3433: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3434: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3435: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3436: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3437: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3438: }
3439: }
3440: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3441: if (snes->ops->usercompute && !snes->ctx) PetscCallBack("SNES callback compute application context", (*snes->ops->usercompute)(snes, &snes->ctx));
3443: snes->jac_iter = 0;
3444: snes->pre_iter = 0;
3446: PetscTryTypeMethod(snes, setup);
3448: PetscCall(SNESSetDefaultComputeJacobian(snes));
3450: if (snes->npc && snes->npcside == PC_LEFT) {
3451: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3452: if (snes->linesearch) {
3453: PetscCall(SNESGetLineSearch(snes, &linesearch));
3454: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3455: }
3456: }
3457: }
3458: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3459: snes->setupcalled = PETSC_TRUE;
3460: PetscFunctionReturn(PETSC_SUCCESS);
3461: }
3463: /*@
3464: 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
3466: Collective
3468: Input Parameter:
3469: . snes - the nonlinear iterative solver context obtained from `SNESCreate()`
3471: Level: intermediate
3473: Notes:
3474: Any options set on the `SNES` object, including those set with `SNESSetFromOptions()` remain.
3476: Call this if you wish to reuse a `SNES` but with different size vectors
3478: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3480: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3481: @*/
3482: PetscErrorCode SNESReset(SNES snes)
3483: {
3484: PetscFunctionBegin;
3486: if (snes->ops->ctxdestroy && snes->ctx) {
3487: PetscCallBack("SNES callback destroy application context", (*snes->ops->ctxdestroy)(&snes->ctx));
3488: snes->ctx = NULL;
3489: }
3490: if (snes->npc) PetscCall(SNESReset(snes->npc));
3492: PetscTryTypeMethod(snes, reset);
3493: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3495: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3497: PetscCall(VecDestroy(&snes->vec_rhs));
3498: PetscCall(VecDestroy(&snes->vec_sol));
3499: PetscCall(VecDestroy(&snes->vec_sol_update));
3500: PetscCall(VecDestroy(&snes->vec_func));
3501: PetscCall(MatDestroy(&snes->jacobian));
3502: PetscCall(MatDestroy(&snes->jacobian_pre));
3503: PetscCall(MatDestroy(&snes->picard));
3504: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3505: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3507: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3509: snes->nwork = snes->nvwork = 0;
3510: snes->setupcalled = PETSC_FALSE;
3511: PetscFunctionReturn(PETSC_SUCCESS);
3512: }
3514: /*@
3515: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()` also
3516: removes the default viewer.
3518: Collective
3520: Input Parameter:
3521: . snes - the nonlinear iterative solver context obtained from `SNESCreate()`
3523: Level: intermediate
3525: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3526: @*/
3527: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3528: {
3529: PetscInt i;
3531: PetscFunctionBegin;
3533: for (i = 0; i < snes->numberreasonviews; i++) {
3534: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3535: }
3536: snes->numberreasonviews = 0;
3537: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
3538: PetscFunctionReturn(PETSC_SUCCESS);
3539: }
3541: /*@
3542: SNESDestroy - Destroys the nonlinear solver context that was created
3543: with `SNESCreate()`.
3545: Collective
3547: Input Parameter:
3548: . snes - the `SNES` context
3550: Level: beginner
3552: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3553: @*/
3554: PetscErrorCode SNESDestroy(SNES *snes)
3555: {
3556: DM dm;
3558: PetscFunctionBegin;
3559: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3561: if (--((PetscObject)*snes)->refct > 0) {
3562: *snes = NULL;
3563: PetscFunctionReturn(PETSC_SUCCESS);
3564: }
3566: PetscCall(SNESReset(*snes));
3567: PetscCall(SNESDestroy(&(*snes)->npc));
3569: /* if memory was published with SAWs then destroy it */
3570: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3571: PetscTryTypeMethod(*snes, destroy);
3573: dm = (*snes)->dm;
3574: while (dm) {
3575: PetscCall(DMCoarsenHookRemove(dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3576: PetscCall(DMGetCoarseDM(dm, &dm));
3577: }
3579: PetscCall(DMDestroy(&(*snes)->dm));
3580: PetscCall(KSPDestroy(&(*snes)->ksp));
3581: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3583: PetscCall(PetscFree((*snes)->kspconvctx));
3584: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)(&(*snes)->cnvP));
3585: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3586: PetscCall(SNESMonitorCancel(*snes));
3587: PetscCall(SNESConvergedReasonViewCancel(*snes));
3588: PetscCall(PetscHeaderDestroy(snes));
3589: PetscFunctionReturn(PETSC_SUCCESS);
3590: }
3592: /* ----------- Routines to set solver parameters ---------- */
3594: /*@
3595: SNESSetLagPreconditioner - Sets when the preconditioner is rebuilt in the nonlinear solve `SNESSolve()`.
3597: Logically Collective
3599: Input Parameters:
3600: + snes - the `SNES` context
3601: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3602: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3604: Options Database Keys:
3605: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3606: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3607: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3608: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3610: Level: intermediate
3612: Notes:
3613: The default is 1
3615: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3617: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3619: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3620: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3621: @*/
3622: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3623: {
3624: PetscFunctionBegin;
3626: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3627: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3629: snes->lagpreconditioner = lag;
3630: PetscFunctionReturn(PETSC_SUCCESS);
3631: }
3633: /*@
3634: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3636: Logically Collective
3638: Input Parameters:
3639: + snes - the `SNES` context
3640: - steps - the number of refinements to do, defaults to 0
3642: Options Database Key:
3643: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3645: Level: intermediate
3647: Notes:
3648: Once grid sequencing is turned on `SNESSolve()` will automatically perform the solve on each grid refinement.
3650: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3652: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3653: `SNESSetDM()`, `SNESSolve()`
3654: @*/
3655: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3656: {
3657: PetscFunctionBegin;
3660: snes->gridsequence = steps;
3661: PetscFunctionReturn(PETSC_SUCCESS);
3662: }
3664: /*@
3665: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3667: Logically Collective
3669: Input Parameter:
3670: . snes - the `SNES` context
3672: Output Parameter:
3673: . steps - the number of refinements to do, defaults to 0
3675: Level: intermediate
3677: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3678: @*/
3679: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3680: {
3681: PetscFunctionBegin;
3683: *steps = snes->gridsequence;
3684: PetscFunctionReturn(PETSC_SUCCESS);
3685: }
3687: /*@
3688: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3690: Not Collective
3692: Input Parameter:
3693: . snes - the `SNES` context
3695: Output Parameter:
3696: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3697: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3699: Level: intermediate
3701: Notes:
3702: The default is 1
3704: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3706: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3707: @*/
3708: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3709: {
3710: PetscFunctionBegin;
3712: *lag = snes->lagpreconditioner;
3713: PetscFunctionReturn(PETSC_SUCCESS);
3714: }
3716: /*@
3717: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3718: often the preconditioner is rebuilt.
3720: Logically Collective
3722: Input Parameters:
3723: + snes - the `SNES` context
3724: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3725: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3727: Options Database Keys:
3728: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3729: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3730: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3731: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3733: Level: intermediate
3735: Notes:
3736: The default is 1
3738: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3740: 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
3741: at the next Newton step but never again (unless it is reset to another value)
3743: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3744: @*/
3745: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3746: {
3747: PetscFunctionBegin;
3749: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3750: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3752: snes->lagjacobian = lag;
3753: PetscFunctionReturn(PETSC_SUCCESS);
3754: }
3756: /*@
3757: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3759: Not Collective
3761: Input Parameter:
3762: . snes - the `SNES` context
3764: Output Parameter:
3765: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3766: the Jacobian is built etc.
3768: Level: intermediate
3770: Notes:
3771: The default is 1
3773: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3775: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3777: @*/
3778: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3779: {
3780: PetscFunctionBegin;
3782: *lag = snes->lagjacobian;
3783: PetscFunctionReturn(PETSC_SUCCESS);
3784: }
3786: /*@
3787: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3789: Logically collective
3791: Input Parameters:
3792: + snes - the `SNES` context
3793: - flg - jacobian lagging persists if true
3795: Options Database Keys:
3796: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3797: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3798: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3799: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3801: Level: advanced
3803: Notes:
3804: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3806: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3807: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3808: timesteps may present huge efficiency gains.
3810: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3811: @*/
3812: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3813: {
3814: PetscFunctionBegin;
3817: snes->lagjac_persist = flg;
3818: PetscFunctionReturn(PETSC_SUCCESS);
3819: }
3821: /*@
3822: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3824: Logically Collective
3826: Input Parameters:
3827: + snes - the `SNES` context
3828: - flg - preconditioner lagging persists if true
3830: Options Database Keys:
3831: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3832: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3833: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3834: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3836: Level: developer
3838: Notes:
3839: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3841: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3842: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3843: several timesteps may present huge efficiency gains.
3845: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3846: @*/
3847: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3848: {
3849: PetscFunctionBegin;
3852: snes->lagpre_persist = flg;
3853: PetscFunctionReturn(PETSC_SUCCESS);
3854: }
3856: /*@
3857: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3859: Logically Collective
3861: Input Parameters:
3862: + snes - the `SNES` context
3863: - force - `PETSC_TRUE` require at least one iteration
3865: Options Database Key:
3866: . -snes_force_iteration <force> - Sets forcing an iteration
3868: Level: intermediate
3870: Note:
3871: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3873: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetDivergenceTolerance()`
3874: @*/
3875: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3876: {
3877: PetscFunctionBegin;
3879: snes->forceiteration = force;
3880: PetscFunctionReturn(PETSC_SUCCESS);
3881: }
3883: /*@
3884: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3886: Logically Collective
3888: Input Parameter:
3889: . snes - the `SNES` context
3891: Output Parameter:
3892: . force - `PETSC_TRUE` requires at least one iteration.
3894: Level: intermediate
3896: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetDivergenceTolerance()`
3897: @*/
3898: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3899: {
3900: PetscFunctionBegin;
3902: *force = snes->forceiteration;
3903: PetscFunctionReturn(PETSC_SUCCESS);
3904: }
3906: /*@
3907: SNESSetTolerances - Sets various parameters used in `SNES` convergence tests.
3909: Logically Collective
3911: Input Parameters:
3912: + snes - the `SNES` context
3913: . abstol - the absolute convergence tolerance, $ F(x^n) \le abstol $
3914: . rtol - the relative convergence tolerance, $ F(x^n) \le reltol * F(x^0) $
3915: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3916: . maxit - the maximum number of iterations allowed in the solver, default 50.
3917: - maxf - the maximum number of function evaluations allowed in the solver (use `PETSC_UNLIMITED` indicates no limit), default 10,000
3919: Options Database Keys:
3920: + -snes_atol <abstol> - Sets `abstol`
3921: . -snes_rtol <rtol> - Sets `rtol`
3922: . -snes_stol <stol> - Sets `stol`
3923: . -snes_max_it <maxit> - Sets `maxit`
3924: - -snes_max_funcs <maxf> - Sets `maxf` (use `unlimited` to have no maximum)
3926: Level: intermediate
3928: Note:
3929: All parameters must be non-negative
3931: Use `PETSC_CURRENT` to retain the current value of any parameter and `PETSC_DETERMINE` to use the default value for the given `SNES`.
3932: The default value is the value in the object when its type is set.
3934: Use `PETSC_UNLIMITED` on `maxit` or `maxf` to indicate there is no bound on the number of iterations or number of function evaluations.
3936: Fortran Note:
3937: Use `PETSC_CURRENT_INTEGER`, `PETSC_CURRENT_REAL`, `PETSC_UNLIMITED_INTEGER`, `PETSC_DETERMINE_INTEGER`, or `PETSC_DETERMINE_REAL`
3939: .seealso: [](ch_snes), `SNESSolve()`, `SNES`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3940: @*/
3941: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3942: {
3943: PetscFunctionBegin;
3951: if (abstol == (PetscReal)PETSC_DETERMINE) {
3952: snes->abstol = snes->default_abstol;
3953: } else if (abstol != (PetscReal)PETSC_CURRENT) {
3954: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3955: snes->abstol = abstol;
3956: }
3958: if (rtol == (PetscReal)PETSC_DETERMINE) {
3959: snes->rtol = snes->default_rtol;
3960: } else if (rtol != (PetscReal)PETSC_CURRENT) {
3961: 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);
3962: snes->rtol = rtol;
3963: }
3965: if (stol == (PetscReal)PETSC_DETERMINE) {
3966: snes->stol = snes->default_stol;
3967: } else if (stol != (PetscReal)PETSC_CURRENT) {
3968: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3969: snes->stol = stol;
3970: }
3972: if (maxit == PETSC_DETERMINE) {
3973: snes->max_its = snes->default_max_its;
3974: } else if (maxit == PETSC_UNLIMITED) {
3975: snes->max_its = PETSC_INT_MAX;
3976: } else if (maxit != PETSC_CURRENT) {
3977: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3978: snes->max_its = maxit;
3979: }
3981: if (maxf == PETSC_DETERMINE) {
3982: snes->max_funcs = snes->default_max_funcs;
3983: } else if (maxf == PETSC_UNLIMITED || maxf == -1) {
3984: snes->max_funcs = PETSC_UNLIMITED;
3985: } else if (maxf != PETSC_CURRENT) {
3986: PetscCheck(maxf >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be nonnegative", maxf);
3987: snes->max_funcs = maxf;
3988: }
3989: PetscFunctionReturn(PETSC_SUCCESS);
3990: }
3992: /*@
3993: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3995: Logically Collective
3997: Input Parameters:
3998: + snes - the `SNES` context
3999: - 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
4000: is stopped due to divergence.
4002: Options Database Key:
4003: . -snes_divergence_tolerance <divtol> - Sets `divtol`
4005: Level: intermediate
4007: Notes:
4008: Use `PETSC_DETERMINE` to use the default value from when the object's type was set.
4010: Fortran Note:
4011: Use ``PETSC_DETERMINE_REAL` or `PETSC_UNLIMITED_REAL`
4013: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance()`
4014: @*/
4015: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
4016: {
4017: PetscFunctionBegin;
4021: if (divtol == (PetscReal)PETSC_DETERMINE) {
4022: snes->divtol = snes->default_divtol;
4023: } else if (divtol == (PetscReal)PETSC_UNLIMITED || divtol == -1) {
4024: snes->divtol = PETSC_UNLIMITED;
4025: } else if (divtol != (PetscReal)PETSC_CURRENT) {
4026: PetscCheck(divtol >= 1.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Divergence tolerance %g must be greater than 1.0", (double)divtol);
4027: snes->divtol = divtol;
4028: }
4029: PetscFunctionReturn(PETSC_SUCCESS);
4030: }
4032: /*@
4033: SNESGetTolerances - Gets various parameters used in `SNES` convergence tests.
4035: Not Collective
4037: Input Parameter:
4038: . snes - the `SNES` context
4040: Output Parameters:
4041: + atol - the absolute convergence tolerance
4042: . rtol - the relative convergence tolerance
4043: . stol - convergence tolerance in terms of the norm of the change in the solution between steps
4044: . maxit - the maximum number of iterations allowed
4045: - maxf - the maximum number of function evaluations allowed, `PETSC_UNLIMITED` indicates no bound
4047: Level: intermediate
4049: Notes:
4050: See `SNESSetTolerances()` for details on the parameters.
4052: The user can specify `NULL` for any parameter that is not needed.
4054: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
4055: @*/
4056: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
4057: {
4058: PetscFunctionBegin;
4060: if (atol) *atol = snes->abstol;
4061: if (rtol) *rtol = snes->rtol;
4062: if (stol) *stol = snes->stol;
4063: if (maxit) *maxit = snes->max_its;
4064: if (maxf) *maxf = snes->max_funcs;
4065: PetscFunctionReturn(PETSC_SUCCESS);
4066: }
4068: /*@
4069: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
4071: Not Collective
4073: Input Parameters:
4074: + snes - the `SNES` context
4075: - divtol - divergence tolerance
4077: Level: intermediate
4079: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
4080: @*/
4081: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
4082: {
4083: PetscFunctionBegin;
4085: if (divtol) *divtol = snes->divtol;
4086: PetscFunctionReturn(PETSC_SUCCESS);
4087: }
4089: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
4091: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, void *monctx)
4092: {
4093: PetscDrawLG lg;
4094: PetscReal x, y, per;
4095: PetscViewer v = (PetscViewer)monctx;
4096: static PetscReal prev; /* should be in the context */
4097: PetscDraw draw;
4099: PetscFunctionBegin;
4101: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
4102: if (!n) PetscCall(PetscDrawLGReset(lg));
4103: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4104: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
4105: x = (PetscReal)n;
4106: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
4107: else y = -15.0;
4108: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4109: if (n < 20 || !(n % 5) || snes->reason) {
4110: PetscCall(PetscDrawLGDraw(lg));
4111: PetscCall(PetscDrawLGSave(lg));
4112: }
4114: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
4115: if (!n) PetscCall(PetscDrawLGReset(lg));
4116: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4117: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
4118: PetscCall(SNESMonitorRange_Private(snes, n, &per));
4119: x = (PetscReal)n;
4120: y = 100.0 * per;
4121: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4122: if (n < 20 || !(n % 5) || snes->reason) {
4123: PetscCall(PetscDrawLGDraw(lg));
4124: PetscCall(PetscDrawLGSave(lg));
4125: }
4127: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
4128: if (!n) {
4129: prev = rnorm;
4130: PetscCall(PetscDrawLGReset(lg));
4131: }
4132: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4133: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
4134: x = (PetscReal)n;
4135: y = (prev - rnorm) / prev;
4136: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4137: if (n < 20 || !(n % 5) || snes->reason) {
4138: PetscCall(PetscDrawLGDraw(lg));
4139: PetscCall(PetscDrawLGSave(lg));
4140: }
4142: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
4143: if (!n) PetscCall(PetscDrawLGReset(lg));
4144: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4145: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
4146: x = (PetscReal)n;
4147: y = (prev - rnorm) / (prev * per);
4148: if (n > 2) { /*skip initial crazy value */
4149: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4150: }
4151: if (n < 20 || !(n % 5) || snes->reason) {
4152: PetscCall(PetscDrawLGDraw(lg));
4153: PetscCall(PetscDrawLGSave(lg));
4154: }
4155: prev = rnorm;
4156: PetscFunctionReturn(PETSC_SUCCESS);
4157: }
4159: /*@
4160: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
4162: Collective
4164: Input Parameters:
4165: + snes - the `SNES` context
4166: . it - current iteration
4167: . xnorm - 2-norm of current iterate
4168: . snorm - 2-norm of current step
4169: - fnorm - 2-norm of function
4171: Level: developer
4173: Note:
4174: This routine is called by the `SNESSolve()` implementations.
4175: It does not typically need to be called by the user.
4177: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`
4178: @*/
4179: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
4180: {
4181: PetscFunctionBegin;
4182: if (!snes->reason) {
4183: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
4184: if (it == snes->max_its && !snes->reason) {
4185: if (snes->normschedule == SNES_NORM_ALWAYS) {
4186: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
4187: snes->reason = SNES_DIVERGED_MAX_IT;
4188: } else snes->reason = SNES_CONVERGED_ITS;
4189: }
4190: }
4191: PetscFunctionReturn(PETSC_SUCCESS);
4192: }
4194: /*@
4195: SNESMonitor - runs any `SNES` monitor routines provided with `SNESMonitor()` or the options database
4197: Collective
4199: Input Parameters:
4200: + snes - nonlinear solver context obtained from `SNESCreate()`
4201: . iter - current iteration number
4202: - rnorm - current relative norm of the residual
4204: Level: developer
4206: Note:
4207: This routine is called by the `SNESSolve()` implementations.
4208: It does not typically need to be called by the user.
4210: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
4211: @*/
4212: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
4213: {
4214: PetscInt i, n = snes->numbermonitors;
4216: PetscFunctionBegin;
4217: PetscCall(VecLockReadPush(snes->vec_sol));
4218: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
4219: PetscCall(VecLockReadPop(snes->vec_sol));
4220: PetscFunctionReturn(PETSC_SUCCESS);
4221: }
4223: /* ------------ Routines to set performance monitoring options ----------- */
4225: /*MC
4226: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
4228: Synopsis:
4229: #include <petscsnes.h>
4230: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, void *mctx)
4232: Collective
4234: Input Parameters:
4235: + snes - the `SNES` context
4236: . its - iteration number
4237: . norm - 2-norm function value (may be estimated)
4238: - mctx - [optional] monitoring context
4240: Level: advanced
4242: .seealso: [](ch_snes), `SNESMonitorSet()`
4243: M*/
4245: /*@C
4246: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
4247: iteration of the `SNES` nonlinear solver to display the iteration's
4248: progress.
4250: Logically Collective
4252: Input Parameters:
4253: + snes - the `SNES` context
4254: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4255: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4256: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence
4258: Options Database Keys:
4259: + -snes_monitor - sets `SNESMonitorDefault()`
4260: . -snes_monitor draw::draw_lg - sets line graph monitor,
4261: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4262: the options database.
4264: Level: intermediate
4266: Note:
4267: Several different monitoring routines may be set by calling
4268: `SNESMonitorSet()` multiple times; all will be called in the
4269: order in which they were set.
4271: Fortran Note:
4272: Only a single monitor function can be set for each `SNES` object
4274: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`, `PetscCtxDestroyFn`
4275: @*/
4276: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES, PetscInt, PetscReal, void *), void *mctx, PetscCtxDestroyFn *monitordestroy)
4277: {
4278: PetscFunctionBegin;
4280: for (PetscInt i = 0; i < snes->numbermonitors; i++) {
4281: PetscBool identical;
4283: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))(PetscVoidFn *)f, mctx, monitordestroy, (PetscErrorCode (*)(void))(PetscVoidFn *)snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4284: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4285: }
4286: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4287: snes->monitor[snes->numbermonitors] = f;
4288: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4289: snes->monitorcontext[snes->numbermonitors++] = mctx;
4290: PetscFunctionReturn(PETSC_SUCCESS);
4291: }
4293: /*@
4294: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4296: Logically Collective
4298: Input Parameter:
4299: . snes - the `SNES` context
4301: Options Database Key:
4302: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4303: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4304: set via the options database
4306: Level: intermediate
4308: Note:
4309: There is no way to clear one specific monitor from a `SNES` object.
4311: .seealso: [](ch_snes), `SNES`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4312: @*/
4313: PetscErrorCode SNESMonitorCancel(SNES snes)
4314: {
4315: PetscInt i;
4317: PetscFunctionBegin;
4319: for (i = 0; i < snes->numbermonitors; i++) {
4320: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4321: }
4322: snes->numbermonitors = 0;
4323: PetscFunctionReturn(PETSC_SUCCESS);
4324: }
4326: /*MC
4327: SNESConvergenceTestFunction - functional form used for testing of convergence of nonlinear solver
4329: Synopsis:
4330: #include <petscsnes.h>
4331: PetscErrorCode SNESConvergenceTest(SNES snes, PetscInt it, PetscReal xnorm, PetscReal gnorm, PetscReal f, SNESConvergedReason *reason, void *cctx)
4333: Collective
4335: Input Parameters:
4336: + snes - the `SNES` context
4337: . it - current iteration (0 is the first and is before any Newton step)
4338: . xnorm - 2-norm of current iterate
4339: . gnorm - 2-norm of current step
4340: . f - 2-norm of function
4341: - cctx - [optional] convergence context
4343: Output Parameter:
4344: . reason - reason for convergence/divergence, only needs to be set when convergence or divergence is detected
4346: Level: intermediate
4348: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`
4349: M*/
4351: /*@C
4352: SNESSetConvergenceTest - Sets the function that is to be used
4353: to test for convergence of the nonlinear iterative solution.
4355: Logically Collective
4357: Input Parameters:
4358: + snes - the `SNES` context
4359: . SNESConvergenceTestFunction - routine to test for convergence
4360: . cctx - [optional] context for private data for the convergence routine (may be `NULL`)
4361: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4363: Level: advanced
4365: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`, `SNESConvergenceTestFunction`
4366: @*/
4367: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*SNESConvergenceTestFunction)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *cctx, PetscCtxDestroyFn *destroy)
4368: {
4369: PetscFunctionBegin;
4371: if (!SNESConvergenceTestFunction) SNESConvergenceTestFunction = SNESConvergedSkip;
4372: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(&snes->cnvP));
4373: snes->ops->converged = SNESConvergenceTestFunction;
4374: snes->ops->convergeddestroy = destroy;
4375: snes->cnvP = cctx;
4376: PetscFunctionReturn(PETSC_SUCCESS);
4377: }
4379: /*@
4380: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped, which may be due to convergence, divergence, or stagnation
4382: Not Collective
4384: Input Parameter:
4385: . snes - the `SNES` context
4387: Output Parameter:
4388: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4390: Options Database Key:
4391: . -snes_converged_reason - prints the reason to standard out
4393: Level: intermediate
4395: Note:
4396: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4398: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4399: @*/
4400: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4401: {
4402: PetscFunctionBegin;
4404: PetscAssertPointer(reason, 2);
4405: *reason = snes->reason;
4406: PetscFunctionReturn(PETSC_SUCCESS);
4407: }
4409: /*@C
4410: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4412: Not Collective
4414: Input Parameter:
4415: . snes - the `SNES` context
4417: Output Parameter:
4418: . strreason - a human readable string that describes `SNES` converged reason
4420: Level: beginner
4422: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4423: @*/
4424: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4425: {
4426: PetscFunctionBegin;
4428: PetscAssertPointer(strreason, 2);
4429: *strreason = SNESConvergedReasons[snes->reason];
4430: PetscFunctionReturn(PETSC_SUCCESS);
4431: }
4433: /*@
4434: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4436: Not Collective
4438: Input Parameters:
4439: + snes - the `SNES` context
4440: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4441: manual pages for the individual convergence tests for complete lists
4443: Level: developer
4445: Developer Note:
4446: Called inside the various `SNESSolve()` implementations
4448: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4449: @*/
4450: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4451: {
4452: PetscFunctionBegin;
4454: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4455: snes->reason = reason;
4456: PetscFunctionReturn(PETSC_SUCCESS);
4457: }
4459: /*@
4460: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4462: Logically Collective
4464: Input Parameters:
4465: + snes - iterative context obtained from `SNESCreate()`
4466: . a - array to hold history, this array will contain the function norms computed at each step
4467: . its - integer array holds the number of linear iterations for each solve.
4468: . na - size of `a` and `its`
4469: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4470: else it continues storing new values for new nonlinear solves after the old ones
4472: Level: intermediate
4474: Notes:
4475: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' is `PETSC_DECIDE` (or, deprecated, `PETSC_DEFAULT`) then a
4476: default array of length 1,000 is allocated.
4478: This routine is useful, e.g., when running a code for purposes
4479: of accurate performance monitoring, when no I/O should be done
4480: during the section of code that is being timed.
4482: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4484: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4485: @*/
4486: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4487: {
4488: PetscFunctionBegin;
4490: if (a) PetscAssertPointer(a, 2);
4491: if (its) PetscAssertPointer(its, 3);
4492: if (!a) {
4493: if (na == PETSC_DECIDE) na = 1000;
4494: PetscCall(PetscCalloc2(na, &a, na, &its));
4495: snes->conv_hist_alloc = PETSC_TRUE;
4496: }
4497: snes->conv_hist = a;
4498: snes->conv_hist_its = its;
4499: snes->conv_hist_max = (size_t)na;
4500: snes->conv_hist_len = 0;
4501: snes->conv_hist_reset = reset;
4502: PetscFunctionReturn(PETSC_SUCCESS);
4503: }
4505: #if defined(PETSC_HAVE_MATLAB)
4506: #include <engine.h> /* MATLAB include file */
4507: #include <mex.h> /* MATLAB include file */
4509: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4510: {
4511: mxArray *mat;
4512: PetscInt i;
4513: PetscReal *ar;
4515: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4516: ar = (PetscReal *)mxGetData(mat);
4517: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4518: return mat;
4519: }
4520: #endif
4522: /*@C
4523: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4525: Not Collective
4527: Input Parameter:
4528: . snes - iterative context obtained from `SNESCreate()`
4530: Output Parameters:
4531: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4532: . its - integer array holds the number of linear iterations (or
4533: negative if not converged) for each solve.
4534: - na - size of `a` and `its`
4536: Level: intermediate
4538: Note:
4539: This routine is useful, e.g., when running a code for purposes
4540: of accurate performance monitoring, when no I/O should be done
4541: during the section of code that is being timed.
4543: Fortran Notes:
4544: Return the arrays with ``SNESRestoreConvergenceHistory()`
4546: Use the arguments
4547: .vb
4548: PetscReal, pointer :: a(:)
4549: PetscInt, pointer :: its(:)
4550: .ve
4552: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4553: @*/
4554: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4555: {
4556: PetscFunctionBegin;
4558: if (a) *a = snes->conv_hist;
4559: if (its) *its = snes->conv_hist_its;
4560: if (na) *na = (PetscInt)snes->conv_hist_len;
4561: PetscFunctionReturn(PETSC_SUCCESS);
4562: }
4564: /*@C
4565: SNESSetUpdate - Sets the general-purpose update function called
4566: at the beginning of every iteration of the nonlinear solve. Specifically
4567: it is called just before the Jacobian is "evaluated" and after the function
4568: evaluation.
4570: Logically Collective
4572: Input Parameters:
4573: + snes - The nonlinear solver context
4574: - func - The update function; for calling sequence see `SNESUpdateFn`
4576: Level: advanced
4578: Notes:
4579: 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
4580: to `SNESSetFunction()`, or `SNESSetPicard()`
4581: This is not used by most users, and it is intended to provide a general hook that is run
4582: right before the direction step is computed.
4584: Users are free to modify the current residual vector,
4585: the current linearization point, or any other vector associated to the specific solver used.
4586: If such modifications take place, it is the user responsibility to update all the relevant
4587: vectors. For example, if one is adjusting the model parameters at each Newton step their code may look like
4588: .vb
4589: PetscErrorCode update(SNES snes, PetscInt iteration)
4590: {
4591: PetscFunctionBeginUser;
4592: if (iteration > 0) {
4593: // update the model parameters here
4594: Vec x,f;
4595: PetscCall(SNESGetSolution(snes,&x));
4596: PetcCall(SNESGetFunction(snes,&f,NULL,NULL));
4597: PetscCall(SNESComputeFunction(snes,x,f));
4598: }
4599: PetscFunctionReturn(PETSC_SUCCESS);
4600: }
4601: .ve
4603: 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.
4605: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4606: `SNESMonitorSet()`
4607: @*/
4608: PetscErrorCode SNESSetUpdate(SNES snes, SNESUpdateFn *func)
4609: {
4610: PetscFunctionBegin;
4612: snes->ops->update = func;
4613: PetscFunctionReturn(PETSC_SUCCESS);
4614: }
4616: /*@
4617: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4619: Collective
4621: Input Parameters:
4622: + snes - iterative context obtained from `SNESCreate()`
4623: - viewer - the viewer to display the reason
4625: Options Database Keys:
4626: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4627: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4629: Level: beginner
4631: Note:
4632: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4633: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4635: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4636: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4637: `SNESConvergedReasonViewFromOptions()`,
4638: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4639: @*/
4640: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4641: {
4642: PetscViewerFormat format;
4643: PetscBool isAscii;
4645: PetscFunctionBegin;
4646: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4647: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4648: if (isAscii) {
4649: PetscCall(PetscViewerGetFormat(viewer, &format));
4650: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel + 1));
4651: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4652: DM dm;
4653: Vec u;
4654: PetscDS prob;
4655: PetscInt Nf, f;
4656: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4657: void **exactCtx;
4658: PetscReal error;
4660: PetscCall(SNESGetDM(snes, &dm));
4661: PetscCall(SNESGetSolution(snes, &u));
4662: PetscCall(DMGetDS(dm, &prob));
4663: PetscCall(PetscDSGetNumFields(prob, &Nf));
4664: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4665: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4666: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4667: PetscCall(PetscFree2(exactSol, exactCtx));
4668: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4669: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4670: }
4671: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4672: if (((PetscObject)snes)->prefix) {
4673: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4674: } else {
4675: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4676: }
4677: } else if (snes->reason <= 0) {
4678: if (((PetscObject)snes)->prefix) {
4679: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4680: } else {
4681: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4682: }
4683: }
4684: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel + 1));
4685: }
4686: PetscFunctionReturn(PETSC_SUCCESS);
4687: }
4689: /*@C
4690: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4691: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4693: Logically Collective
4695: Input Parameters:
4696: + snes - the `SNES` context
4697: . f - the `SNESConvergedReason` view function
4698: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4699: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence
4701: Calling sequence of `f`:
4702: + snes - the `SNES` context
4703: - vctx - [optional] context for private data for the function
4705: Options Database Keys:
4706: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4707: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4708: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4710: Level: intermediate
4712: Note:
4713: Several different converged reason view routines may be set by calling
4714: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4715: order in which they were set.
4717: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`,
4718: `PetscCtxDestroyFn`
4719: @*/
4720: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, void *vctx), void *vctx, PetscCtxDestroyFn *reasonviewdestroy)
4721: {
4722: PetscFunctionBegin;
4724: for (PetscInt i = 0; i < snes->numberreasonviews; i++) {
4725: PetscBool identical;
4727: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))(PetscVoidFn *)f, vctx, reasonviewdestroy, (PetscErrorCode (*)(void))(PetscVoidFn *)snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4728: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4729: }
4730: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4731: snes->reasonview[snes->numberreasonviews] = f;
4732: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4733: snes->reasonviewcontext[snes->numberreasonviews++] = vctx;
4734: PetscFunctionReturn(PETSC_SUCCESS);
4735: }
4737: /*@
4738: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4739: All the user-provided viewer routines set with `SNESConvergedReasonViewSet()` will be called, if they exist.
4741: Collective
4743: Input Parameter:
4744: . snes - the `SNES` object
4746: Level: advanced
4748: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4749: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4750: @*/
4751: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4752: {
4753: static PetscBool incall = PETSC_FALSE;
4755: PetscFunctionBegin;
4756: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4757: incall = PETSC_TRUE;
4759: /* All user-provided viewers are called first, if they exist. */
4760: for (PetscInt i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4762: /* Call PETSc default routine if users ask for it */
4763: if (snes->convergedreasonviewer) {
4764: PetscCall(PetscViewerPushFormat(snes->convergedreasonviewer, snes->convergedreasonformat));
4765: PetscCall(SNESConvergedReasonView(snes, snes->convergedreasonviewer));
4766: PetscCall(PetscViewerPopFormat(snes->convergedreasonviewer));
4767: }
4768: incall = PETSC_FALSE;
4769: PetscFunctionReturn(PETSC_SUCCESS);
4770: }
4772: /*@
4773: SNESSolve - Solves a nonlinear system $F(x) = b $ associated with a `SNES` object
4775: Collective
4777: Input Parameters:
4778: + snes - the `SNES` context
4779: . b - the constant part of the equation $F(x) = b$, or `NULL` to use zero.
4780: - x - the solution vector.
4782: Level: beginner
4784: Note:
4785: The user should initialize the vector, `x`, with the initial guess
4786: for the nonlinear solve prior to calling `SNESSolve()` .
4788: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4789: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4790: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`
4791: @*/
4792: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4793: {
4794: PetscBool flg;
4795: PetscInt grid;
4796: Vec xcreated = NULL;
4797: DM dm;
4799: PetscFunctionBegin;
4802: if (x) PetscCheckSameComm(snes, 1, x, 3);
4804: if (b) PetscCheckSameComm(snes, 1, b, 2);
4806: /* High level operations using the nonlinear solver */
4807: {
4808: PetscViewer viewer;
4809: PetscViewerFormat format;
4810: PetscInt num;
4811: PetscBool flg;
4812: static PetscBool incall = PETSC_FALSE;
4814: if (!incall) {
4815: /* Estimate the convergence rate of the discretization */
4816: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4817: if (flg) {
4818: PetscConvEst conv;
4819: DM dm;
4820: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4821: PetscInt Nf;
4823: incall = PETSC_TRUE;
4824: PetscCall(SNESGetDM(snes, &dm));
4825: PetscCall(DMGetNumFields(dm, &Nf));
4826: PetscCall(PetscCalloc1(Nf, &alpha));
4827: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4828: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4829: PetscCall(PetscConvEstSetFromOptions(conv));
4830: PetscCall(PetscConvEstSetUp(conv));
4831: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4832: PetscCall(PetscViewerPushFormat(viewer, format));
4833: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4834: PetscCall(PetscViewerPopFormat(viewer));
4835: PetscCall(PetscViewerDestroy(&viewer));
4836: PetscCall(PetscConvEstDestroy(&conv));
4837: PetscCall(PetscFree(alpha));
4838: incall = PETSC_FALSE;
4839: }
4840: /* Adaptively refine the initial grid */
4841: num = 1;
4842: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4843: if (flg) {
4844: DMAdaptor adaptor;
4846: incall = PETSC_TRUE;
4847: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4848: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4849: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4850: PetscCall(DMAdaptorSetFromOptions(adaptor));
4851: PetscCall(DMAdaptorSetUp(adaptor));
4852: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4853: PetscCall(DMAdaptorDestroy(&adaptor));
4854: incall = PETSC_FALSE;
4855: }
4856: /* Use grid sequencing to adapt */
4857: num = 0;
4858: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4859: if (num) {
4860: DMAdaptor adaptor;
4861: const char *prefix;
4863: incall = PETSC_TRUE;
4864: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4865: PetscCall(SNESGetOptionsPrefix(snes, &prefix));
4866: PetscCall(DMAdaptorSetOptionsPrefix(adaptor, prefix));
4867: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4868: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4869: PetscCall(DMAdaptorSetFromOptions(adaptor));
4870: PetscCall(DMAdaptorSetUp(adaptor));
4871: PetscCall(PetscObjectViewFromOptions((PetscObject)adaptor, NULL, "-snes_adapt_view"));
4872: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4873: PetscCall(DMAdaptorDestroy(&adaptor));
4874: incall = PETSC_FALSE;
4875: }
4876: }
4877: }
4878: if (!x) x = snes->vec_sol;
4879: if (!x) {
4880: PetscCall(SNESGetDM(snes, &dm));
4881: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4882: x = xcreated;
4883: }
4884: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4886: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4887: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4888: /* set solution vector */
4889: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4890: PetscCall(VecDestroy(&snes->vec_sol));
4891: snes->vec_sol = x;
4892: PetscCall(SNESGetDM(snes, &dm));
4894: /* set affine vector if provided */
4895: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4896: PetscCall(VecDestroy(&snes->vec_rhs));
4897: snes->vec_rhs = b;
4899: 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");
4900: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4901: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right-hand side vector");
4902: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4903: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4904: PetscCall(SNESSetUp(snes));
4906: if (!grid) {
4907: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback compute initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4908: }
4910: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4911: PetscCall(SNESResetCounters(snes));
4912: snes->reason = SNES_CONVERGED_ITERATING;
4913: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4914: PetscUseTypeMethod(snes, solve);
4915: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4916: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4917: snes->functiondomainerror = PETSC_FALSE; /* clear the flag if it has been set */
4918: snes->objectivedomainerror = PETSC_FALSE; /* clear the flag if it has been set */
4919: snes->jacobiandomainerror = PETSC_FALSE; /* clear the flag if it has been set */
4921: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4922: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4924: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4925: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4926: /* Call converged reason views. This may involve user-provided viewers as well */
4927: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4929: if (snes->errorifnotconverged) {
4930: if (snes->reason < 0) PetscCall(SNESMonitorCancel(snes));
4931: PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4932: }
4933: if (snes->reason < 0) break;
4934: if (grid < snes->gridsequence) {
4935: DM fine;
4936: Vec xnew;
4937: Mat interp;
4939: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4940: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4941: PetscCall(DMGetCoordinatesLocalSetUp(fine));
4942: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4943: PetscCall(DMCreateGlobalVector(fine, &xnew));
4944: PetscCall(MatInterpolate(interp, x, xnew));
4945: PetscCall(DMInterpolate(snes->dm, interp, fine));
4946: PetscCall(MatDestroy(&interp));
4947: x = xnew;
4949: PetscCall(SNESReset(snes));
4950: PetscCall(SNESSetDM(snes, fine));
4951: PetscCall(SNESResetFromOptions(snes));
4952: PetscCall(DMDestroy(&fine));
4953: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4954: }
4955: }
4956: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4957: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4958: PetscCall(DMMonitor(snes->dm));
4959: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4961: PetscCall(VecDestroy(&xcreated));
4962: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4963: PetscFunctionReturn(PETSC_SUCCESS);
4964: }
4966: /* --------- Internal routines for SNES Package --------- */
4968: /*@
4969: SNESSetType - Sets the algorithm/method to be used to solve the nonlinear system with the given `SNES`
4971: Collective
4973: Input Parameters:
4974: + snes - the `SNES` context
4975: - type - a known method
4977: Options Database Key:
4978: . -snes_type <type> - Sets the method; use -help for a list
4979: of available methods (for instance, newtonls or newtontr)
4981: Level: intermediate
4983: Notes:
4984: See `SNESType` for available methods (for instance)
4985: + `SNESNEWTONLS` - Newton's method with line search
4986: (systems of nonlinear equations)
4987: - `SNESNEWTONTR` - Newton's method with trust region
4988: (systems of nonlinear equations)
4990: Normally, it is best to use the `SNESSetFromOptions()` command and then
4991: set the `SNES` solver type from the options database rather than by using
4992: this routine. Using the options database provides the user with
4993: maximum flexibility in evaluating the many nonlinear solvers.
4994: The `SNESSetType()` routine is provided for those situations where it
4995: is necessary to set the nonlinear solver independently of the command
4996: line or options database. This might be the case, for example, when
4997: the choice of solver changes during the execution of the program,
4998: and the user's application is taking responsibility for choosing the
4999: appropriate method.
5001: Developer Note:
5002: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
5003: the constructor in that list and calls it to create the specific object.
5005: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
5006: @*/
5007: PetscErrorCode SNESSetType(SNES snes, SNESType type)
5008: {
5009: PetscBool match;
5010: PetscErrorCode (*r)(SNES);
5012: PetscFunctionBegin;
5014: PetscAssertPointer(type, 2);
5016: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
5017: if (match) PetscFunctionReturn(PETSC_SUCCESS);
5019: PetscCall(PetscFunctionListFind(SNESList, type, &r));
5020: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
5021: /* Destroy the previous private SNES context */
5022: PetscTryTypeMethod(snes, destroy);
5023: /* Reinitialize type-specific function pointers in SNESOps structure */
5024: snes->ops->reset = NULL;
5025: snes->ops->setup = NULL;
5026: snes->ops->solve = NULL;
5027: snes->ops->view = NULL;
5028: snes->ops->setfromoptions = NULL;
5029: snes->ops->destroy = NULL;
5031: /* It may happen the user has customized the line search before calling SNESSetType */
5032: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5034: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
5035: snes->setupcalled = PETSC_FALSE;
5037: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
5038: PetscCall((*r)(snes));
5039: PetscFunctionReturn(PETSC_SUCCESS);
5040: }
5042: /*@
5043: SNESGetType - Gets the `SNES` method type and name (as a string).
5045: Not Collective
5047: Input Parameter:
5048: . snes - nonlinear solver context
5050: Output Parameter:
5051: . type - `SNES` method (a character string)
5053: Level: intermediate
5055: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
5056: @*/
5057: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
5058: {
5059: PetscFunctionBegin;
5061: PetscAssertPointer(type, 2);
5062: *type = ((PetscObject)snes)->type_name;
5063: PetscFunctionReturn(PETSC_SUCCESS);
5064: }
5066: /*@
5067: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
5069: Logically Collective
5071: Input Parameters:
5072: + snes - the `SNES` context obtained from `SNESCreate()`
5073: - u - the solution vector
5075: Level: beginner
5077: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
5078: @*/
5079: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
5080: {
5081: DM dm;
5083: PetscFunctionBegin;
5086: PetscCall(PetscObjectReference((PetscObject)u));
5087: PetscCall(VecDestroy(&snes->vec_sol));
5089: snes->vec_sol = u;
5091: PetscCall(SNESGetDM(snes, &dm));
5092: PetscCall(DMShellSetGlobalVector(dm, u));
5093: PetscFunctionReturn(PETSC_SUCCESS);
5094: }
5096: /*@
5097: SNESGetSolution - Returns the vector where the approximate solution is
5098: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
5100: Not Collective, but `x` is parallel if `snes` is parallel
5102: Input Parameter:
5103: . snes - the `SNES` context
5105: Output Parameter:
5106: . x - the solution
5108: Level: intermediate
5110: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
5111: @*/
5112: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
5113: {
5114: PetscFunctionBegin;
5116: PetscAssertPointer(x, 2);
5117: *x = snes->vec_sol;
5118: PetscFunctionReturn(PETSC_SUCCESS);
5119: }
5121: /*@
5122: SNESGetSolutionUpdate - Returns the vector where the solution update is
5123: stored.
5125: Not Collective, but `x` is parallel if `snes` is parallel
5127: Input Parameter:
5128: . snes - the `SNES` context
5130: Output Parameter:
5131: . x - the solution update
5133: Level: advanced
5135: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
5136: @*/
5137: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
5138: {
5139: PetscFunctionBegin;
5141: PetscAssertPointer(x, 2);
5142: *x = snes->vec_sol_update;
5143: PetscFunctionReturn(PETSC_SUCCESS);
5144: }
5146: /*@C
5147: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
5149: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
5151: Input Parameter:
5152: . snes - the `SNES` context
5154: Output Parameters:
5155: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
5156: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunctionFn`
5157: - ctx - the function context (or `NULL` if you don't want it)
5159: Level: advanced
5161: Note:
5162: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
5164: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunctionFn`
5165: @*/
5166: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, SNESFunctionFn **f, void **ctx)
5167: {
5168: DM dm;
5170: PetscFunctionBegin;
5172: if (r) {
5173: if (!snes->vec_func) {
5174: if (snes->vec_rhs) {
5175: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
5176: } else if (snes->vec_sol) {
5177: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
5178: } else if (snes->dm) {
5179: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
5180: }
5181: }
5182: *r = snes->vec_func;
5183: }
5184: PetscCall(SNESGetDM(snes, &dm));
5185: PetscCall(DMSNESGetFunction(dm, f, ctx));
5186: PetscFunctionReturn(PETSC_SUCCESS);
5187: }
5189: /*@C
5190: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
5192: Input Parameter:
5193: . snes - the `SNES` context
5195: Output Parameters:
5196: + f - the function (or `NULL`) see `SNESNGSFn` for calling sequence
5197: - ctx - the function context (or `NULL`)
5199: Level: advanced
5201: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`, `SNESNGSFn`
5202: @*/
5203: PetscErrorCode SNESGetNGS(SNES snes, SNESNGSFn **f, void **ctx)
5204: {
5205: DM dm;
5207: PetscFunctionBegin;
5209: PetscCall(SNESGetDM(snes, &dm));
5210: PetscCall(DMSNESGetNGS(dm, f, ctx));
5211: PetscFunctionReturn(PETSC_SUCCESS);
5212: }
5214: /*@
5215: SNESSetOptionsPrefix - Sets the prefix used for searching for all
5216: `SNES` options in the database.
5218: Logically Collective
5220: Input Parameters:
5221: + snes - the `SNES` context
5222: - prefix - the prefix to prepend to all option names
5224: Level: advanced
5226: Note:
5227: A hyphen (-) must NOT be given at the beginning of the prefix name.
5228: The first character of all runtime options is AUTOMATICALLY the hyphen.
5230: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
5231: @*/
5232: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
5233: {
5234: PetscFunctionBegin;
5236: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
5237: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5238: if (snes->linesearch) {
5239: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5240: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
5241: }
5242: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
5243: PetscFunctionReturn(PETSC_SUCCESS);
5244: }
5246: /*@
5247: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5248: `SNES` options in the database.
5250: Logically Collective
5252: Input Parameters:
5253: + snes - the `SNES` context
5254: - prefix - the prefix to prepend to all option names
5256: Level: advanced
5258: Note:
5259: A hyphen (-) must NOT be given at the beginning of the prefix name.
5260: The first character of all runtime options is AUTOMATICALLY the hyphen.
5262: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5263: @*/
5264: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5265: {
5266: PetscFunctionBegin;
5268: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5269: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5270: if (snes->linesearch) {
5271: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5272: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5273: }
5274: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5275: PetscFunctionReturn(PETSC_SUCCESS);
5276: }
5278: /*@
5279: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5280: `SNES` options in the database.
5282: Not Collective
5284: Input Parameter:
5285: . snes - the `SNES` context
5287: Output Parameter:
5288: . prefix - pointer to the prefix string used
5290: Level: advanced
5292: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5293: @*/
5294: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5295: {
5296: PetscFunctionBegin;
5298: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5299: PetscFunctionReturn(PETSC_SUCCESS);
5300: }
5302: /*@C
5303: SNESRegister - Adds a method to the nonlinear solver package.
5305: Not Collective
5307: Input Parameters:
5308: + sname - name of a new user-defined solver
5309: - function - routine to create method context
5311: Level: advanced
5313: Note:
5314: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5316: Example Usage:
5317: .vb
5318: SNESRegister("my_solver", MySolverCreate);
5319: .ve
5321: Then, your solver can be chosen with the procedural interface via
5322: .vb
5323: SNESSetType(snes, "my_solver")
5324: .ve
5325: or at runtime via the option
5326: .vb
5327: -snes_type my_solver
5328: .ve
5330: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5331: @*/
5332: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5333: {
5334: PetscFunctionBegin;
5335: PetscCall(SNESInitializePackage());
5336: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5337: PetscFunctionReturn(PETSC_SUCCESS);
5338: }
5340: PetscErrorCode SNESTestLocalMin(SNES snes)
5341: {
5342: PetscInt N, i, j;
5343: Vec u, uh, fh;
5344: PetscScalar value;
5345: PetscReal norm;
5347: PetscFunctionBegin;
5348: PetscCall(SNESGetSolution(snes, &u));
5349: PetscCall(VecDuplicate(u, &uh));
5350: PetscCall(VecDuplicate(u, &fh));
5352: /* currently only works for sequential */
5353: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5354: PetscCall(VecGetSize(u, &N));
5355: for (i = 0; i < N; i++) {
5356: PetscCall(VecCopy(u, uh));
5357: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5358: for (j = -10; j < 11; j++) {
5359: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5360: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5361: PetscCall(SNESComputeFunction(snes, uh, fh));
5362: PetscCall(VecNorm(fh, NORM_2, &norm)); /* does not handle use of SNESSetFunctionDomainError() correctly */
5363: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5364: value = -value;
5365: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5366: }
5367: }
5368: PetscCall(VecDestroy(&uh));
5369: PetscCall(VecDestroy(&fh));
5370: PetscFunctionReturn(PETSC_SUCCESS);
5371: }
5373: /*@
5374: SNESGetLineSearch - Returns the line search associated with the `SNES`.
5376: Not Collective
5378: Input Parameter:
5379: . snes - iterative context obtained from `SNESCreate()`
5381: Output Parameter:
5382: . linesearch - linesearch context
5384: Level: beginner
5386: Notes:
5387: It creates a default line search instance which can be configured as needed in case it has not been already set with `SNESSetLineSearch()`.
5389: You can also use the options database keys `-snes_linesearch_*` to configure the line search. See `SNESLineSearchSetFromOptions()` for the possible options.
5391: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`, `SNESLineSearchSetFromOptions()`
5392: @*/
5393: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5394: {
5395: const char *optionsprefix;
5397: PetscFunctionBegin;
5399: PetscAssertPointer(linesearch, 2);
5400: if (!snes->linesearch) {
5401: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5402: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5403: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5404: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5405: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5406: }
5407: *linesearch = snes->linesearch;
5408: PetscFunctionReturn(PETSC_SUCCESS);
5409: }
5411: /*@
5412: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5413: computing relative tolerance for linear solvers within an inexact
5414: Newton method.
5416: Logically Collective
5418: Input Parameters:
5419: + snes - `SNES` context
5420: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5422: Options Database Keys:
5423: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5424: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5425: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5426: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5427: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5428: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5429: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5430: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5432: Level: advanced
5434: Note:
5435: The default is to use a constant relative tolerance for
5436: the inner linear solvers. Alternatively, one can use the
5437: Eisenstat-Walker method {cite}`ew96`, where the relative convergence tolerance
5438: is reset at each Newton iteration according progress of the nonlinear
5439: solver.
5441: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5442: @*/
5443: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5444: {
5445: PetscFunctionBegin;
5448: snes->ksp_ewconv = flag;
5449: PetscFunctionReturn(PETSC_SUCCESS);
5450: }
5452: /*@
5453: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5454: for computing relative tolerance for linear solvers within an
5455: inexact Newton method.
5457: Not Collective
5459: Input Parameter:
5460: . snes - `SNES` context
5462: Output Parameter:
5463: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5465: Level: advanced
5467: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5468: @*/
5469: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5470: {
5471: PetscFunctionBegin;
5473: PetscAssertPointer(flag, 2);
5474: *flag = snes->ksp_ewconv;
5475: PetscFunctionReturn(PETSC_SUCCESS);
5476: }
5478: /*@
5479: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5480: convergence criteria for the linear solvers within an inexact
5481: Newton method.
5483: Logically Collective
5485: Input Parameters:
5486: + snes - `SNES` context
5487: . version - version 1, 2 (default is 2), 3 or 4
5488: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5489: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5490: . gamma - multiplicative factor for version 2 rtol computation
5491: (0 <= gamma2 <= 1)
5492: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5493: . alpha2 - power for safeguard
5494: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5496: Level: advanced
5498: Notes:
5499: Version 3 was contributed by Luis Chacon, June 2006.
5501: Use `PETSC_CURRENT` to retain the default for any of the parameters.
5503: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5504: @*/
5505: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5506: {
5507: SNESKSPEW *kctx;
5509: PetscFunctionBegin;
5511: kctx = (SNESKSPEW *)snes->kspconvctx;
5512: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5521: if (version != PETSC_CURRENT) kctx->version = version;
5522: if (rtol_0 != (PetscReal)PETSC_CURRENT) kctx->rtol_0 = rtol_0;
5523: if (rtol_max != (PetscReal)PETSC_CURRENT) kctx->rtol_max = rtol_max;
5524: if (gamma != (PetscReal)PETSC_CURRENT) kctx->gamma = gamma;
5525: if (alpha != (PetscReal)PETSC_CURRENT) kctx->alpha = alpha;
5526: if (alpha2 != (PetscReal)PETSC_CURRENT) kctx->alpha2 = alpha2;
5527: if (threshold != (PetscReal)PETSC_CURRENT) kctx->threshold = threshold;
5529: 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);
5530: 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);
5531: 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);
5532: 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);
5533: 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);
5534: 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);
5535: PetscFunctionReturn(PETSC_SUCCESS);
5536: }
5538: /*@
5539: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5540: convergence criteria for the linear solvers within an inexact
5541: Newton method.
5543: Not Collective
5545: Input Parameter:
5546: . snes - `SNES` context
5548: Output Parameters:
5549: + version - version 1, 2 (default is 2), 3 or 4
5550: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5551: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5552: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5553: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5554: . alpha2 - power for safeguard
5555: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5557: Level: advanced
5559: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5560: @*/
5561: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5562: {
5563: SNESKSPEW *kctx;
5565: PetscFunctionBegin;
5567: kctx = (SNESKSPEW *)snes->kspconvctx;
5568: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5569: if (version) *version = kctx->version;
5570: if (rtol_0) *rtol_0 = kctx->rtol_0;
5571: if (rtol_max) *rtol_max = kctx->rtol_max;
5572: if (gamma) *gamma = kctx->gamma;
5573: if (alpha) *alpha = kctx->alpha;
5574: if (alpha2) *alpha2 = kctx->alpha2;
5575: if (threshold) *threshold = kctx->threshold;
5576: PetscFunctionReturn(PETSC_SUCCESS);
5577: }
5579: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5580: {
5581: SNES snes = (SNES)ctx;
5582: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5583: PetscReal rtol = PETSC_CURRENT, stol;
5585: PetscFunctionBegin;
5586: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5587: if (!snes->iter) {
5588: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5589: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5590: } else {
5591: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5592: if (kctx->version == 1) {
5593: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5594: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5595: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5596: } else if (kctx->version == 2) {
5597: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5598: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5599: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5600: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5601: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5602: /* safeguard: avoid sharp decrease of rtol */
5603: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5604: stol = PetscMax(rtol, stol);
5605: rtol = PetscMin(kctx->rtol_0, stol);
5606: /* safeguard: avoid oversolving */
5607: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5608: stol = PetscMax(rtol, stol);
5609: rtol = PetscMin(kctx->rtol_0, stol);
5610: } else /* if (kctx->version == 4) */ {
5611: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5612: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5613: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5614: PetscReal rk = ared / pred;
5615: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5616: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5617: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5618: else rtol = kctx->v4_m2 * kctx->rtol_last;
5620: 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;
5621: kctx->rtol_last_2 = kctx->rtol_last;
5622: kctx->rk_last_2 = kctx->rk_last;
5623: kctx->rk_last = rk;
5624: }
5625: }
5626: /* safeguard: avoid rtol greater than rtol_max */
5627: rtol = PetscMin(rtol, kctx->rtol_max);
5628: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_CURRENT, PETSC_CURRENT, PETSC_CURRENT));
5629: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5630: PetscFunctionReturn(PETSC_SUCCESS);
5631: }
5633: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, void *ctx)
5634: {
5635: SNES snes = (SNES)ctx;
5636: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5637: PCSide pcside;
5638: Vec lres;
5640: PetscFunctionBegin;
5641: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5642: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5643: kctx->norm_last = snes->norm;
5644: if (kctx->version == 1 || kctx->version == 4) {
5645: PC pc;
5646: PetscBool getRes;
5648: PetscCall(KSPGetPC(ksp, &pc));
5649: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5650: if (!getRes) {
5651: KSPNormType normtype;
5653: PetscCall(KSPGetNormType(ksp, &normtype));
5654: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5655: }
5656: PetscCall(KSPGetPCSide(ksp, &pcside));
5657: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5658: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5659: } else {
5660: /* KSP residual is preconditioned residual */
5661: /* compute true linear residual norm */
5662: Mat J;
5663: PetscCall(KSPGetOperators(ksp, &J, NULL));
5664: PetscCall(VecDuplicate(b, &lres));
5665: PetscCall(MatMult(J, x, lres));
5666: PetscCall(VecAYPX(lres, -1.0, b));
5667: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5668: PetscCall(VecDestroy(&lres));
5669: }
5670: }
5671: PetscFunctionReturn(PETSC_SUCCESS);
5672: }
5674: /*@
5675: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5677: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5679: Input Parameter:
5680: . snes - the `SNES` context
5682: Output Parameter:
5683: . ksp - the `KSP` context
5685: Level: beginner
5687: Notes:
5688: The user can then directly manipulate the `KSP` context to set various
5689: options, etc. Likewise, the user can then extract and manipulate the
5690: `PC` contexts as well.
5692: 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.
5694: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5695: @*/
5696: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5697: {
5698: PetscFunctionBegin;
5700: PetscAssertPointer(ksp, 2);
5702: if (!snes->ksp) {
5703: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5704: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5706: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5707: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5709: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5710: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5711: }
5712: *ksp = snes->ksp;
5713: PetscFunctionReturn(PETSC_SUCCESS);
5714: }
5716: #include <petsc/private/dmimpl.h>
5717: /*@
5718: SNESSetDM - Sets the `DM` that may be used by some `SNES` nonlinear solvers or their underlying preconditioners
5720: Logically Collective
5722: Input Parameters:
5723: + snes - the nonlinear solver context
5724: - dm - the `DM`, cannot be `NULL`
5726: Level: intermediate
5728: Note:
5729: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5730: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5731: problems using the same function space.
5733: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5734: @*/
5735: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5736: {
5737: KSP ksp;
5738: DMSNES sdm;
5740: PetscFunctionBegin;
5743: PetscCall(PetscObjectReference((PetscObject)dm));
5744: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5745: if (snes->dm->dmsnes && !dm->dmsnes) {
5746: PetscCall(DMCopyDMSNES(snes->dm, dm));
5747: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5748: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5749: }
5750: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5751: PetscCall(DMDestroy(&snes->dm));
5752: }
5753: snes->dm = dm;
5754: snes->dmAuto = PETSC_FALSE;
5756: PetscCall(SNESGetKSP(snes, &ksp));
5757: PetscCall(KSPSetDM(ksp, dm));
5758: PetscCall(KSPSetDMActive(ksp, PETSC_FALSE));
5759: if (snes->npc) {
5760: PetscCall(SNESSetDM(snes->npc, snes->dm));
5761: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5762: }
5763: PetscFunctionReturn(PETSC_SUCCESS);
5764: }
5766: /*@
5767: SNESGetDM - Gets the `DM` that may be used by some `SNES` nonlinear solvers/preconditioners
5769: Not Collective but `dm` obtained is parallel on `snes`
5771: Input Parameter:
5772: . snes - the `SNES` context
5774: Output Parameter:
5775: . dm - the `DM`
5777: Level: intermediate
5779: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5780: @*/
5781: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5782: {
5783: PetscFunctionBegin;
5785: if (!snes->dm) {
5786: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5787: snes->dmAuto = PETSC_TRUE;
5788: }
5789: *dm = snes->dm;
5790: PetscFunctionReturn(PETSC_SUCCESS);
5791: }
5793: /*@
5794: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5796: Collective
5798: Input Parameters:
5799: + snes - iterative context obtained from `SNESCreate()`
5800: - npc - the `SNES` nonlinear preconditioner object
5802: Options Database Key:
5803: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5805: Level: developer
5807: Notes:
5808: This is rarely used, rather use `SNESGetNPC()` to retrieve the preconditioner and configure it using the API.
5810: Only some `SNESType` can use a nonlinear preconditioner
5812: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5813: @*/
5814: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5815: {
5816: PetscFunctionBegin;
5819: PetscCheckSameComm(snes, 1, npc, 2);
5820: PetscCall(PetscObjectReference((PetscObject)npc));
5821: PetscCall(SNESDestroy(&snes->npc));
5822: snes->npc = npc;
5823: PetscFunctionReturn(PETSC_SUCCESS);
5824: }
5826: /*@
5827: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5829: Not Collective; but any changes to the obtained the `pc` object must be applied collectively
5831: Input Parameter:
5832: . snes - iterative context obtained from `SNESCreate()`
5834: Output Parameter:
5835: . pc - the `SNES` preconditioner context
5837: Options Database Key:
5838: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5840: Level: advanced
5842: Notes:
5843: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created that will
5844: be used as the nonlinear preconditioner for the current `SNES`.
5846: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5847: `SNES`. These may be overwritten if needed.
5849: Use the options database prefixes `-npc_snes`, `-npc_ksp`, etc., to control the configuration of the nonlinear preconditioner
5851: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5852: @*/
5853: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5854: {
5855: const char *optionsprefix;
5857: PetscFunctionBegin;
5859: PetscAssertPointer(pc, 2);
5860: if (!snes->npc) {
5861: void *ctx;
5863: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5864: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5865: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5866: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5867: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5868: if (snes->ops->usercompute) {
5869: PetscCall(SNESSetComputeApplicationContext(snes, snes->ops->usercompute, snes->ops->ctxdestroy));
5870: } else {
5871: PetscCall(SNESGetApplicationContext(snes, &ctx));
5872: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5873: }
5874: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5875: }
5876: *pc = snes->npc;
5877: PetscFunctionReturn(PETSC_SUCCESS);
5878: }
5880: /*@
5881: SNESHasNPC - Returns whether a nonlinear preconditioner is associated with the given `SNES`
5883: Not Collective
5885: Input Parameter:
5886: . snes - iterative context obtained from `SNESCreate()`
5888: Output Parameter:
5889: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5891: Level: developer
5893: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5894: @*/
5895: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5896: {
5897: PetscFunctionBegin;
5899: PetscAssertPointer(has_npc, 2);
5900: *has_npc = snes->npc ? PETSC_TRUE : PETSC_FALSE;
5901: PetscFunctionReturn(PETSC_SUCCESS);
5902: }
5904: /*@
5905: SNESSetNPCSide - Sets the nonlinear preconditioning side used by the nonlinear preconditioner inside `SNES`.
5907: Logically Collective
5909: Input Parameter:
5910: . snes - iterative context obtained from `SNESCreate()`
5912: Output Parameter:
5913: . side - the preconditioning side, where side is one of
5914: .vb
5915: PC_LEFT - left preconditioning
5916: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5917: .ve
5919: Options Database Key:
5920: . -snes_npc_side <right,left> - nonlinear preconditioner side
5922: Level: intermediate
5924: Note:
5925: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5927: .seealso: [](ch_snes), `SNES`, `SNESGetNPC()`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5928: @*/
5929: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5930: {
5931: PetscFunctionBegin;
5934: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5935: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5936: snes->npcside = side;
5937: PetscFunctionReturn(PETSC_SUCCESS);
5938: }
5940: /*@
5941: SNESGetNPCSide - Gets the preconditioning side used by the nonlinear preconditioner inside `SNES`.
5943: Not Collective
5945: Input Parameter:
5946: . snes - iterative context obtained from `SNESCreate()`
5948: Output Parameter:
5949: . side - the preconditioning side, where side is one of
5950: .vb
5951: `PC_LEFT` - left preconditioning
5952: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5953: .ve
5955: Level: intermediate
5957: .seealso: [](ch_snes), `SNES`, `SNESGetNPC()`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5958: @*/
5959: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5960: {
5961: PetscFunctionBegin;
5963: PetscAssertPointer(side, 2);
5964: *side = snes->npcside;
5965: PetscFunctionReturn(PETSC_SUCCESS);
5966: }
5968: /*@
5969: SNESSetLineSearch - Sets the `SNESLineSearch` to be used for a given `SNES`
5971: Collective
5973: Input Parameters:
5974: + snes - iterative context obtained from `SNESCreate()`
5975: - linesearch - the linesearch object
5977: Level: developer
5979: Note:
5980: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
5981: to configure it using the API).
5983: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
5984: @*/
5985: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5986: {
5987: PetscFunctionBegin;
5990: PetscCheckSameComm(snes, 1, linesearch, 2);
5991: PetscCall(PetscObjectReference((PetscObject)linesearch));
5992: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5994: snes->linesearch = linesearch;
5995: PetscFunctionReturn(PETSC_SUCCESS);
5996: }