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, PetscCtx 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, PetscCtx 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, PetscCtx 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, PetscCtx);
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, PetscCtx))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: PetscCtx 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, PetscCtxRt ctx), PetscCtxDestroyFn *destroy)
1228: {
1229: PetscFunctionBegin;
1231: snes->ops->ctxcompute = 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, PetscCtx 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 - the application context
1284: Level: intermediate
1286: Fortran Notes:
1287: This only works when the context is a Fortran derived type or a `PetscObject`. Declare `ctx` with
1288: .vb
1289: type(tUsertype), pointer :: ctx
1290: .ve
1292: .seealso: [](ch_snes), `SNESSetApplicationContext()`, `SNESSetComputeApplicationContext()`
1293: @*/
1294: PetscErrorCode SNESGetApplicationContext(SNES snes, PetscCtxRt ctx)
1295: {
1296: PetscFunctionBegin;
1298: *(void **)ctx = snes->ctx;
1299: PetscFunctionReturn(PETSC_SUCCESS);
1300: }
1302: /*@
1303: SNESSetUseMatrixFree - indicates that `SNES` should use matrix-free finite difference matrix-vector products to apply the Jacobian.
1305: Logically Collective
1307: Input Parameters:
1308: + snes - `SNES` context
1309: . mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1310: - 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
1311: this option no matrix-element based preconditioners can be used in the linear solve since the matrix won't be explicitly available
1313: Options Database Keys:
1314: + -snes_mf_operator - use matrix-free only for the mat operator
1315: . -snes_mf - use matrix-free for both the mat and pmat operator
1316: . -snes_fd_color - compute the Jacobian via coloring and finite differences.
1317: - -snes_fd - compute the Jacobian via finite differences (slow)
1319: Level: intermediate
1321: Note:
1322: `SNES` supports three approaches for computing (approximate) Jacobians: user provided via `SNESSetJacobian()`, matrix-free using `MatCreateSNESMF()`,
1323: and computing explicitly with
1324: finite differences and coloring using `MatFDColoring`. It is also possible to use automatic differentiation and the `MatFDColoring` object.
1326: .seealso: [](ch_snes), `SNES`, `SNESGetUseMatrixFree()`, `MatCreateSNESMF()`, `SNESComputeJacobianDefaultColor()`, `MatFDColoring`
1327: @*/
1328: PetscErrorCode SNESSetUseMatrixFree(SNES snes, PetscBool mf_operator, PetscBool mf)
1329: {
1330: PetscFunctionBegin;
1334: snes->mf = mf_operator ? PETSC_TRUE : mf;
1335: snes->mf_operator = mf_operator;
1336: PetscFunctionReturn(PETSC_SUCCESS);
1337: }
1339: /*@
1340: SNESGetUseMatrixFree - indicates if the `SNES` uses matrix-free finite difference matrix vector products to apply the Jacobian.
1342: Not Collective, but the resulting flags will be the same on all MPI processes
1344: Input Parameter:
1345: . snes - `SNES` context
1347: Output Parameters:
1348: + mf_operator - use matrix-free only for the Amat used by `SNESSetJacobian()`, this means the user provided Pmat will continue to be used
1349: - mf - use matrix-free for both the Amat and Pmat used by `SNESSetJacobian()`, both the Amat and Pmat set in `SNESSetJacobian()` will be ignored
1351: Level: intermediate
1353: .seealso: [](ch_snes), `SNES`, `SNESSetUseMatrixFree()`, `MatCreateSNESMF()`
1354: @*/
1355: PetscErrorCode SNESGetUseMatrixFree(SNES snes, PetscBool *mf_operator, PetscBool *mf)
1356: {
1357: PetscFunctionBegin;
1359: if (mf) *mf = snes->mf;
1360: if (mf_operator) *mf_operator = snes->mf_operator;
1361: PetscFunctionReturn(PETSC_SUCCESS);
1362: }
1364: /*@
1365: SNESGetIterationNumber - Gets the number of nonlinear iterations completed in the current or most recent `SNESSolve()`
1367: Not Collective
1369: Input Parameter:
1370: . snes - `SNES` context
1372: Output Parameter:
1373: . iter - iteration number
1375: Level: intermediate
1377: Notes:
1378: For example, during the computation of iteration 2 this would return 1.
1380: This is useful for using lagged Jacobians (where one does not recompute the
1381: Jacobian at each `SNES` iteration). For example, the code
1382: .vb
1383: ierr = SNESGetIterationNumber(snes,&it);
1384: if (!(it % 2)) {
1385: [compute Jacobian here]
1386: }
1387: .ve
1388: can be used in your function that computes the Jacobian to cause the Jacobian to be
1389: recomputed every second `SNES` iteration. See also `SNESSetLagJacobian()`
1391: After the `SNES` solve is complete this will return the number of nonlinear iterations used.
1393: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetLagJacobian()`, `SNESGetLinearSolveIterations()`, `SNESSetMonitor()`
1394: @*/
1395: PetscErrorCode SNESGetIterationNumber(SNES snes, PetscInt *iter)
1396: {
1397: PetscFunctionBegin;
1399: PetscAssertPointer(iter, 2);
1400: *iter = snes->iter;
1401: PetscFunctionReturn(PETSC_SUCCESS);
1402: }
1404: /*@
1405: SNESSetIterationNumber - Sets the current iteration number.
1407: Not Collective
1409: Input Parameters:
1410: + snes - `SNES` context
1411: - iter - iteration number
1413: Level: developer
1415: Note:
1416: This should only be called inside a `SNES` nonlinear solver.
1418: .seealso: [](ch_snes), `SNESGetLinearSolveIterations()`
1419: @*/
1420: PetscErrorCode SNESSetIterationNumber(SNES snes, PetscInt iter)
1421: {
1422: PetscFunctionBegin;
1424: PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
1425: snes->iter = iter;
1426: PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
1427: PetscFunctionReturn(PETSC_SUCCESS);
1428: }
1430: /*@
1431: SNESGetNonlinearStepFailures - Gets the number of unsuccessful steps
1432: taken by the nonlinear solver in the current or most recent `SNESSolve()` .
1434: Not Collective
1436: Input Parameter:
1437: . snes - `SNES` context
1439: Output Parameter:
1440: . nfails - number of unsuccessful steps attempted
1442: Level: intermediate
1444: Notes:
1445: A failed step is a step that was generated and taken but did not satisfy the requested step criteria. For example,
1446: the `SNESLineSearchApply()` could not generate a sufficient decrease in the function norm (in fact it may have produced an increase).
1448: Taken steps that produce a infinity or NaN in the function evaluation or generate a `SNESSetFunctionDomainError()`
1449: will always immediately terminate the `SNESSolve()` regardless of the value of `maxFails`.
1451: `SNESSetMaxNonlinearStepFailures()` determines how many unsuccessful steps are allowed before the `SNESSolve()` terminates
1453: This counter is reset to zero for each successive call to `SNESSolve()`.
1455: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1456: `SNESSetMaxNonlinearStepFailures()`, `SNESGetMaxNonlinearStepFailures()`
1457: @*/
1458: PetscErrorCode SNESGetNonlinearStepFailures(SNES snes, PetscInt *nfails)
1459: {
1460: PetscFunctionBegin;
1462: PetscAssertPointer(nfails, 2);
1463: *nfails = snes->numFailures;
1464: PetscFunctionReturn(PETSC_SUCCESS);
1465: }
1467: /*@
1468: SNESSetMaxNonlinearStepFailures - Sets the maximum number of unsuccessful steps
1469: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1471: Not Collective
1473: Input Parameters:
1474: + snes - `SNES` context
1475: - maxFails - maximum of unsuccessful steps allowed, use `PETSC_UNLIMITED` to have no limit on the number of failures
1477: Options Database Key:
1478: . -snes_max_fail <n> - maximum number of unsuccessful steps allowed
1480: Level: intermediate
1482: Note:
1483: A failed step is a step that was generated and taken but did not satisfy the requested criteria. For example,
1484: the `SNESLineSearchApply()` could not generate a sufficient decrease in the function norm (in fact it may have produced an increase).
1486: Taken steps that produce a infinity or NaN in the function evaluation or generate a `SNESSetFunctionDomainError()`
1487: will always immediately terminate the `SNESSolve()` regardless of the value of `maxFails`.
1489: Developer Note:
1490: The options database key is wrong for this function name
1492: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1493: `SNESGetLinearSolveFailures()`, `SNESGetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`, `SNESCheckLineSearchFailure()`
1494: @*/
1495: PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES snes, PetscInt maxFails)
1496: {
1497: PetscFunctionBegin;
1500: if (maxFails == PETSC_UNLIMITED) {
1501: snes->maxFailures = PETSC_INT_MAX;
1502: } else {
1503: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1504: snes->maxFailures = maxFails;
1505: }
1506: PetscFunctionReturn(PETSC_SUCCESS);
1507: }
1509: /*@
1510: SNESGetMaxNonlinearStepFailures - Gets the maximum number of unsuccessful steps
1511: attempted by the nonlinear solver before it gives up and returns unconverged or generates an error
1513: Not Collective
1515: Input Parameter:
1516: . snes - `SNES` context
1518: Output Parameter:
1519: . maxFails - maximum of unsuccessful steps
1521: Level: intermediate
1523: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`,
1524: `SNESSetMaxNonlinearStepFailures()`, `SNESGetNonlinearStepFailures()`
1525: @*/
1526: PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES snes, PetscInt *maxFails)
1527: {
1528: PetscFunctionBegin;
1530: PetscAssertPointer(maxFails, 2);
1531: *maxFails = snes->maxFailures;
1532: PetscFunctionReturn(PETSC_SUCCESS);
1533: }
1535: /*@
1536: SNESGetNumberFunctionEvals - Gets the number of user provided function evaluations
1537: done by the `SNES` object in the current or most recent `SNESSolve()`
1539: Not Collective
1541: Input Parameter:
1542: . snes - `SNES` context
1544: Output Parameter:
1545: . nfuncs - number of evaluations
1547: Level: intermediate
1549: Note:
1550: Reset every time `SNESSolve()` is called unless `SNESSetCountersReset()` is used.
1552: .seealso: [](ch_snes), `SNES`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`, `SNESGetLinearSolveFailures()`, `SNESSetCountersReset()`
1553: @*/
1554: PetscErrorCode SNESGetNumberFunctionEvals(SNES snes, PetscInt *nfuncs)
1555: {
1556: PetscFunctionBegin;
1558: PetscAssertPointer(nfuncs, 2);
1559: *nfuncs = snes->nfuncs;
1560: PetscFunctionReturn(PETSC_SUCCESS);
1561: }
1563: /*@
1564: SNESGetLinearSolveFailures - Gets the number of failed (non-converged)
1565: linear solvers in the current or most recent `SNESSolve()`
1567: Not Collective
1569: Input Parameter:
1570: . snes - `SNES` context
1572: Output Parameter:
1573: . nfails - number of failed solves
1575: Options Database Key:
1576: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1578: Level: intermediate
1580: Note:
1581: This counter is reset to zero for each successive call to `SNESSolve()`.
1583: .seealso: [](ch_snes), `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`
1584: @*/
1585: PetscErrorCode SNESGetLinearSolveFailures(SNES snes, PetscInt *nfails)
1586: {
1587: PetscFunctionBegin;
1589: PetscAssertPointer(nfails, 2);
1590: *nfails = snes->numLinearSolveFailures;
1591: PetscFunctionReturn(PETSC_SUCCESS);
1592: }
1594: /*@
1595: SNESSetMaxLinearSolveFailures - the number of failed linear solve attempts
1596: allowed before `SNES` returns with a diverged reason of `SNES_DIVERGED_LINEAR_SOLVE`
1598: Logically Collective
1600: Input Parameters:
1601: + snes - `SNES` context
1602: - maxFails - maximum allowed linear solve failures, use `PETSC_UNLIMITED` to have no limit on the number of failures
1604: Options Database Key:
1605: . -snes_max_linear_solve_fail <num> - The number of failures before the solve is terminated
1607: Level: intermediate
1609: Note:
1610: By default this is 0; that is `SNES` returns on the first failed linear solve
1612: Developer Note:
1613: The options database key is wrong for this function name
1615: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESGetLinearSolveIterations()`
1616: @*/
1617: PetscErrorCode SNESSetMaxLinearSolveFailures(SNES snes, PetscInt maxFails)
1618: {
1619: PetscFunctionBegin;
1623: if (maxFails == PETSC_UNLIMITED) {
1624: snes->maxLinearSolveFailures = PETSC_INT_MAX;
1625: } else {
1626: PetscCheck(maxFails >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Cannot have a negative maximum number of failures");
1627: snes->maxLinearSolveFailures = maxFails;
1628: }
1629: PetscFunctionReturn(PETSC_SUCCESS);
1630: }
1632: /*@
1633: SNESGetMaxLinearSolveFailures - gets the maximum number of linear solve failures that
1634: are allowed before `SNES` returns as unsuccessful
1636: Not Collective
1638: Input Parameter:
1639: . snes - `SNES` context
1641: Output Parameter:
1642: . maxFails - maximum of unsuccessful solves allowed
1644: Level: intermediate
1646: Note:
1647: By default this is 1; that is `SNES` returns on the first failed linear solve
1649: .seealso: [](ch_snes), `SNESSetErrorIfNotConverged()`, `SNESGetLinearSolveFailures()`, `SNESGetLinearSolveIterations()`, `SNESSetMaxLinearSolveFailures()`,
1650: @*/
1651: PetscErrorCode SNESGetMaxLinearSolveFailures(SNES snes, PetscInt *maxFails)
1652: {
1653: PetscFunctionBegin;
1655: PetscAssertPointer(maxFails, 2);
1656: *maxFails = snes->maxLinearSolveFailures;
1657: PetscFunctionReturn(PETSC_SUCCESS);
1658: }
1660: /*@
1661: SNESGetLinearSolveIterations - Gets the total number of linear iterations
1662: used by the nonlinear solver in the most recent `SNESSolve()`
1664: Not Collective
1666: Input Parameter:
1667: . snes - `SNES` context
1669: Output Parameter:
1670: . lits - number of linear iterations
1672: Level: intermediate
1674: Notes:
1675: This counter is reset to zero for each successive call to `SNESSolve()` unless `SNESSetCountersReset()` is used.
1677: 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
1678: then call `KSPGetIterationNumber()` after the failed solve.
1680: .seealso: [](ch_snes), `SNES`, `SNESGetIterationNumber()`, `SNESGetLinearSolveFailures()`, `SNESGetMaxLinearSolveFailures()`, `SNESSetCountersReset()`
1681: @*/
1682: PetscErrorCode SNESGetLinearSolveIterations(SNES snes, PetscInt *lits)
1683: {
1684: PetscFunctionBegin;
1686: PetscAssertPointer(lits, 2);
1687: *lits = snes->linear_its;
1688: PetscFunctionReturn(PETSC_SUCCESS);
1689: }
1691: /*@
1692: SNESSetCountersReset - Sets whether or not the counters for linear iterations and function evaluations
1693: are reset every time `SNESSolve()` is called.
1695: Logically Collective
1697: Input Parameters:
1698: + snes - `SNES` context
1699: - reset - whether to reset the counters or not, defaults to `PETSC_TRUE`
1701: Level: developer
1703: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1704: @*/
1705: PetscErrorCode SNESSetCountersReset(SNES snes, PetscBool reset)
1706: {
1707: PetscFunctionBegin;
1710: snes->counters_reset = reset;
1711: PetscFunctionReturn(PETSC_SUCCESS);
1712: }
1714: /*@
1715: SNESResetCounters - Reset counters for linear iterations and function evaluations.
1717: Logically Collective
1719: Input Parameters:
1720: . snes - `SNES` context
1722: Level: developer
1724: Note:
1725: It honors the flag set with `SNESSetCountersReset()`
1727: .seealso: [](ch_snes), `SNESGetNumberFunctionEvals()`, `SNESGetLinearSolveIterations()`, `SNESGetNPC()`
1728: @*/
1729: PetscErrorCode SNESResetCounters(SNES snes)
1730: {
1731: PetscFunctionBegin;
1733: if (snes->counters_reset) {
1734: snes->nfuncs = 0;
1735: snes->linear_its = 0;
1736: snes->numFailures = 0;
1737: }
1738: PetscFunctionReturn(PETSC_SUCCESS);
1739: }
1741: /*@
1742: SNESSetKSP - Sets a `KSP` context for the `SNES` object to use
1744: Not Collective, but the `SNES` and `KSP` objects must live on the same `MPI_Comm`
1746: Input Parameters:
1747: + snes - the `SNES` context
1748: - ksp - the `KSP` context
1750: Level: developer
1752: Notes:
1753: The `SNES` object already has its `KSP` object, you can obtain with `SNESGetKSP()`
1754: so this routine is rarely needed.
1756: The `KSP` object that is already in the `SNES` object has its reference count
1757: decreased by one when this is called.
1759: .seealso: [](ch_snes), `SNES`, `KSP`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`
1760: @*/
1761: PetscErrorCode SNESSetKSP(SNES snes, KSP ksp)
1762: {
1763: PetscFunctionBegin;
1766: PetscCheckSameComm(snes, 1, ksp, 2);
1767: PetscCall(PetscObjectReference((PetscObject)ksp));
1768: if (snes->ksp) PetscCall(PetscObjectDereference((PetscObject)snes->ksp));
1769: snes->ksp = ksp;
1770: PetscFunctionReturn(PETSC_SUCCESS);
1771: }
1773: /*@
1774: SNESParametersInitialize - Sets all the parameters in `snes` to their default value (when `SNESCreate()` was called) if they
1775: currently contain default values
1777: Collective
1779: Input Parameter:
1780: . snes - the `SNES` object
1782: Level: developer
1784: Developer Note:
1785: This is called by all the `SNESCreate_XXX()` routines.
1787: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
1788: `PetscObjectParameterSetDefault()`
1789: @*/
1790: PetscErrorCode SNESParametersInitialize(SNES snes)
1791: {
1792: PetscObjectParameterSetDefault(snes, max_its, 50);
1793: PetscObjectParameterSetDefault(snes, max_funcs, 10000);
1794: PetscObjectParameterSetDefault(snes, rtol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1795: PetscObjectParameterSetDefault(snes, abstol, PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50);
1796: PetscObjectParameterSetDefault(snes, stol, PetscDefined(USE_REAL_SINGLE) ? 1.e-5 : 1.e-8);
1797: PetscObjectParameterSetDefault(snes, divtol, 1.e4);
1798: return PETSC_SUCCESS;
1799: }
1801: /*@
1802: SNESCreate - Creates a nonlinear solver context used to manage a set of nonlinear solves
1804: Collective
1806: Input Parameter:
1807: . comm - MPI communicator
1809: Output Parameter:
1810: . outsnes - the new `SNES` context
1812: Options Database Keys:
1813: + -snes_mf - Activates default matrix-free Jacobian-vector products, and no matrix to construct a preconditioner
1814: . -snes_mf_operator - Activates default matrix-free Jacobian-vector products, and a user-provided matrix as set by `SNESSetJacobian()`
1815: . -snes_fd_coloring - uses a relative fast computation of the Jacobian using finite differences and a graph coloring
1816: - -snes_fd - Uses (slow!) finite differences to compute Jacobian
1818: Level: beginner
1820: Developer Notes:
1821: `SNES` always creates a `KSP` object even though many `SNES` methods do not use it. This is
1822: unfortunate and should be fixed at some point. The flag snes->usesksp indicates if the
1823: particular method does use `KSP` and regulates if the information about the `KSP` is printed
1824: in `SNESView()`.
1826: `TSSetFromOptions()` does call `SNESSetFromOptions()` which can lead to users being confused
1827: by help messages about meaningless `SNES` options.
1829: `SNES` always creates the `snes->kspconvctx` even though it is used by only one type. This should be fixed.
1831: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESDestroy()`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`
1832: @*/
1833: PetscErrorCode SNESCreate(MPI_Comm comm, SNES *outsnes)
1834: {
1835: SNES snes;
1836: SNESKSPEW *kctx;
1838: PetscFunctionBegin;
1839: PetscAssertPointer(outsnes, 2);
1840: PetscCall(SNESInitializePackage());
1842: PetscCall(PetscHeaderCreate(snes, SNES_CLASSID, "SNES", "Nonlinear solver", "SNES", comm, SNESDestroy, SNESView));
1843: snes->ops->converged = SNESConvergedDefault;
1844: snes->usesksp = PETSC_TRUE;
1845: snes->norm = 0.0;
1846: snes->xnorm = 0.0;
1847: snes->ynorm = 0.0;
1848: snes->normschedule = SNES_NORM_ALWAYS;
1849: snes->functype = SNES_FUNCTION_DEFAULT;
1850: snes->ttol = 0.0;
1852: snes->rnorm0 = 0;
1853: snes->nfuncs = 0;
1854: snes->numFailures = 0;
1855: snes->maxFailures = 1;
1856: snes->linear_its = 0;
1857: snes->lagjacobian = 1;
1858: snes->jac_iter = 0;
1859: snes->lagjac_persist = PETSC_FALSE;
1860: snes->lagpreconditioner = 1;
1861: snes->pre_iter = 0;
1862: snes->lagpre_persist = PETSC_FALSE;
1863: snes->numbermonitors = 0;
1864: snes->numberreasonviews = 0;
1865: snes->data = NULL;
1866: snes->setupcalled = PETSC_FALSE;
1867: snes->ksp_ewconv = PETSC_FALSE;
1868: snes->nwork = 0;
1869: snes->work = NULL;
1870: snes->nvwork = 0;
1871: snes->vwork = NULL;
1872: snes->conv_hist_len = 0;
1873: snes->conv_hist_max = 0;
1874: snes->conv_hist = NULL;
1875: snes->conv_hist_its = NULL;
1876: snes->conv_hist_reset = PETSC_TRUE;
1877: snes->counters_reset = PETSC_TRUE;
1878: snes->vec_func_init_set = PETSC_FALSE;
1879: snes->reason = SNES_CONVERGED_ITERATING;
1880: snes->npcside = PC_RIGHT;
1881: snes->setfromoptionscalled = 0;
1883: snes->mf = PETSC_FALSE;
1884: snes->mf_operator = PETSC_FALSE;
1885: snes->mf_version = 1;
1887: snes->numLinearSolveFailures = 0;
1888: snes->maxLinearSolveFailures = 1;
1890: snes->vizerotolerance = 1.e-8;
1891: snes->checkjacdomainerror = PetscDefined(USE_DEBUG) ? PETSC_TRUE : PETSC_FALSE;
1893: /* Set this to true if the implementation of SNESSolve_XXX does compute the residual at the final solution. */
1894: snes->alwayscomputesfinalresidual = PETSC_FALSE;
1896: /* Create context to compute Eisenstat-Walker relative tolerance for KSP */
1897: PetscCall(PetscNew(&kctx));
1899: snes->kspconvctx = kctx;
1900: kctx->version = 2;
1901: kctx->rtol_0 = 0.3; /* Eisenstat and Walker suggest rtol_0=.5, but
1902: this was too large for some test cases */
1903: kctx->rtol_last = 0.0;
1904: kctx->rtol_max = 0.9;
1905: kctx->gamma = 1.0;
1906: kctx->alpha = 0.5 * (1.0 + PetscSqrtReal(5.0));
1907: kctx->alpha2 = kctx->alpha;
1908: kctx->threshold = 0.1;
1909: kctx->lresid_last = 0.0;
1910: kctx->norm_last = 0.0;
1912: kctx->rk_last = 0.0;
1913: kctx->rk_last_2 = 0.0;
1914: kctx->rtol_last_2 = 0.0;
1915: kctx->v4_p1 = 0.1;
1916: kctx->v4_p2 = 0.4;
1917: kctx->v4_p3 = 0.7;
1918: kctx->v4_m1 = 0.8;
1919: kctx->v4_m2 = 0.5;
1920: kctx->v4_m3 = 0.1;
1921: kctx->v4_m4 = 0.5;
1923: PetscCall(SNESParametersInitialize(snes));
1924: *outsnes = snes;
1925: PetscFunctionReturn(PETSC_SUCCESS);
1926: }
1928: /*@C
1929: SNESSetFunction - Sets the function evaluation routine and function
1930: vector for use by the `SNES` routines in solving systems of nonlinear
1931: equations.
1933: Logically Collective
1935: Input Parameters:
1936: + snes - the `SNES` context
1937: . r - vector to store function values, may be `NULL`
1938: . f - function evaluation routine; for calling sequence see `SNESFunctionFn`
1939: - ctx - [optional] user-defined context for private data for the
1940: function evaluation routine (may be `NULL`)
1942: Level: beginner
1944: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetPicard()`, `SNESFunctionFn`
1945: @*/
1946: PetscErrorCode SNESSetFunction(SNES snes, Vec r, SNESFunctionFn *f, PetscCtx ctx)
1947: {
1948: DM dm;
1950: PetscFunctionBegin;
1952: if (r) {
1954: PetscCheckSameComm(snes, 1, r, 2);
1955: PetscCall(PetscObjectReference((PetscObject)r));
1956: PetscCall(VecDestroy(&snes->vec_func));
1957: snes->vec_func = r;
1958: }
1959: PetscCall(SNESGetDM(snes, &dm));
1960: PetscCall(DMSNESSetFunction(dm, f, ctx));
1961: if (f == SNESPicardComputeFunction) PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
1962: PetscFunctionReturn(PETSC_SUCCESS);
1963: }
1965: /*@C
1966: SNESSetInitialFunction - Set an already computed function evaluation at the initial guess to be reused by `SNESSolve()`.
1968: Logically Collective
1970: Input Parameters:
1971: + snes - the `SNES` context
1972: - f - vector to store function value
1974: Level: developer
1976: Notes:
1977: This should not be modified during the solution procedure.
1979: This is used extensively in the `SNESFAS` hierarchy and in nonlinear preconditioning.
1981: .seealso: [](ch_snes), `SNES`, `SNESFAS`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetInitialFunctionNorm()`
1982: @*/
1983: PetscErrorCode SNESSetInitialFunction(SNES snes, Vec f)
1984: {
1985: Vec vec_func;
1987: PetscFunctionBegin;
1990: PetscCheckSameComm(snes, 1, f, 2);
1991: if (snes->npcside == PC_LEFT && snes->functype == SNES_FUNCTION_PRECONDITIONED) {
1992: snes->vec_func_init_set = PETSC_FALSE;
1993: PetscFunctionReturn(PETSC_SUCCESS);
1994: }
1995: PetscCall(SNESGetFunction(snes, &vec_func, NULL, NULL));
1996: PetscCall(VecCopy(f, vec_func));
1998: snes->vec_func_init_set = PETSC_TRUE;
1999: PetscFunctionReturn(PETSC_SUCCESS);
2000: }
2002: /*@
2003: SNESSetNormSchedule - Sets the `SNESNormSchedule` used in convergence and monitoring
2004: of the `SNES` method, when norms are computed in the solving process
2006: Logically Collective
2008: Input Parameters:
2009: + snes - the `SNES` context
2010: - normschedule - the frequency of norm computation
2012: Options Database Key:
2013: . -snes_norm_schedule <none, always, initialonly, finalonly, initialfinalonly> - set the schedule
2015: Level: advanced
2017: Notes:
2018: Only certain `SNES` methods support certain `SNESNormSchedules`. Most require evaluation
2019: of the nonlinear function and the taking of its norm at every iteration to
2020: even ensure convergence at all. However, methods such as custom Gauss-Seidel methods
2021: `SNESNGS` and the like do not require the norm of the function to be computed, and therefore
2022: may either be monitored for convergence or not. As these are often used as nonlinear
2023: preconditioners, monitoring the norm of their error is not a useful enterprise within
2024: their solution.
2026: .seealso: [](ch_snes), `SNESNormSchedule`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`
2027: @*/
2028: PetscErrorCode SNESSetNormSchedule(SNES snes, SNESNormSchedule normschedule)
2029: {
2030: PetscFunctionBegin;
2032: snes->normschedule = normschedule;
2033: PetscFunctionReturn(PETSC_SUCCESS);
2034: }
2036: /*@
2037: SNESGetNormSchedule - Gets the `SNESNormSchedule` used in convergence and monitoring
2038: of the `SNES` method.
2040: Logically Collective
2042: Input Parameters:
2043: + snes - the `SNES` context
2044: - normschedule - the type of the norm used
2046: Level: advanced
2048: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2049: @*/
2050: PetscErrorCode SNESGetNormSchedule(SNES snes, SNESNormSchedule *normschedule)
2051: {
2052: PetscFunctionBegin;
2054: *normschedule = snes->normschedule;
2055: PetscFunctionReturn(PETSC_SUCCESS);
2056: }
2058: /*@
2059: SNESSetFunctionNorm - Sets the last computed residual norm.
2061: Logically Collective
2063: Input Parameters:
2064: + snes - the `SNES` context
2065: - norm - the value of the norm
2067: Level: developer
2069: .seealso: [](ch_snes), `SNES`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2070: @*/
2071: PetscErrorCode SNESSetFunctionNorm(SNES snes, PetscReal norm)
2072: {
2073: PetscFunctionBegin;
2075: snes->norm = norm;
2076: PetscFunctionReturn(PETSC_SUCCESS);
2077: }
2079: /*@
2080: SNESGetFunctionNorm - Gets the last computed norm of the residual
2082: Not Collective
2084: Input Parameter:
2085: . snes - the `SNES` context
2087: Output Parameter:
2088: . norm - the last computed residual norm
2090: Level: developer
2092: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2093: @*/
2094: PetscErrorCode SNESGetFunctionNorm(SNES snes, PetscReal *norm)
2095: {
2096: PetscFunctionBegin;
2098: PetscAssertPointer(norm, 2);
2099: *norm = snes->norm;
2100: PetscFunctionReturn(PETSC_SUCCESS);
2101: }
2103: /*@
2104: SNESGetUpdateNorm - Gets the last computed norm of the solution update
2106: Not Collective
2108: Input Parameter:
2109: . snes - the `SNES` context
2111: Output Parameter:
2112: . ynorm - the last computed update norm
2114: Level: developer
2116: Note:
2117: The new solution is the current solution plus the update, so this norm is an indication of the size of the update
2119: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`
2120: @*/
2121: PetscErrorCode SNESGetUpdateNorm(SNES snes, PetscReal *ynorm)
2122: {
2123: PetscFunctionBegin;
2125: PetscAssertPointer(ynorm, 2);
2126: *ynorm = snes->ynorm;
2127: PetscFunctionReturn(PETSC_SUCCESS);
2128: }
2130: /*@
2131: SNESGetSolutionNorm - Gets the last computed norm of the solution
2133: Not Collective
2135: Input Parameter:
2136: . snes - the `SNES` context
2138: Output Parameter:
2139: . xnorm - the last computed solution norm
2141: Level: developer
2143: .seealso: [](ch_snes), `SNES`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `SNESGetFunctionNorm()`, `SNESGetUpdateNorm()`
2144: @*/
2145: PetscErrorCode SNESGetSolutionNorm(SNES snes, PetscReal *xnorm)
2146: {
2147: PetscFunctionBegin;
2149: PetscAssertPointer(xnorm, 2);
2150: *xnorm = snes->xnorm;
2151: PetscFunctionReturn(PETSC_SUCCESS);
2152: }
2154: /*@
2155: SNESSetFunctionType - Sets the `SNESFunctionType`
2156: of the `SNES` method.
2158: Logically Collective
2160: Input Parameters:
2161: + snes - the `SNES` context
2162: - type - the function type
2164: Level: developer
2166: Values of the function type\:
2167: + `SNES_FUNCTION_DEFAULT` - the default for the given `SNESType`
2168: . `SNES_FUNCTION_UNPRECONDITIONED` - an unpreconditioned function evaluation (this is the function provided with `SNESSetFunction()`
2169: - `SNES_FUNCTION_PRECONDITIONED` - a transformation of the function provided with `SNESSetFunction()`
2171: Note:
2172: Different `SNESType`s use this value in different ways
2174: .seealso: [](ch_snes), `SNES`, `SNESFunctionType`, `SNESGetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2175: @*/
2176: PetscErrorCode SNESSetFunctionType(SNES snes, SNESFunctionType type)
2177: {
2178: PetscFunctionBegin;
2180: snes->functype = type;
2181: PetscFunctionReturn(PETSC_SUCCESS);
2182: }
2184: /*@
2185: SNESGetFunctionType - Gets the `SNESFunctionType` used in convergence and monitoring set with `SNESSetFunctionType()`
2186: of the SNES method.
2188: Logically Collective
2190: Input Parameters:
2191: + snes - the `SNES` context
2192: - type - the type of the function evaluation, see `SNESSetFunctionType()`
2194: Level: advanced
2196: .seealso: [](ch_snes), `SNESSetFunctionType()`, `SNESFunctionType`, `SNESSetNormSchedule()`, `SNESComputeFunction()`, `VecNorm()`, `SNESSetFunction()`, `SNESSetInitialFunction()`, `SNESNormSchedule`
2197: @*/
2198: PetscErrorCode SNESGetFunctionType(SNES snes, SNESFunctionType *type)
2199: {
2200: PetscFunctionBegin;
2202: *type = snes->functype;
2203: PetscFunctionReturn(PETSC_SUCCESS);
2204: }
2206: /*@C
2207: SNESSetNGS - Sets the user nonlinear Gauss-Seidel routine for
2208: use with composed nonlinear solvers.
2210: Input Parameters:
2211: + snes - the `SNES` context, usually of the `SNESType` `SNESNGS`
2212: . f - function evaluation routine to apply Gauss-Seidel, see `SNESNGSFn` for calling sequence
2213: - ctx - [optional] user-defined context for private data for the smoother evaluation routine (may be `NULL`)
2215: Level: intermediate
2217: Note:
2218: The `SNESNGS` routines are used by the composed nonlinear solver to generate
2219: a problem appropriate update to the solution, particularly `SNESFAS`.
2221: .seealso: [](ch_snes), `SNESNGS`, `SNESGetNGS()`, `SNESNCG`, `SNESGetFunction()`, `SNESComputeNGS()`, `SNESNGSFn`
2222: @*/
2223: PetscErrorCode SNESSetNGS(SNES snes, SNESNGSFn *f, PetscCtx ctx)
2224: {
2225: DM dm;
2227: PetscFunctionBegin;
2229: PetscCall(SNESGetDM(snes, &dm));
2230: PetscCall(DMSNESSetNGS(dm, f, ctx));
2231: PetscFunctionReturn(PETSC_SUCCESS);
2232: }
2234: /*
2235: This is used for -snes_mf_operator; it uses a duplicate of snes->jacobian_pre because snes->jacobian_pre cannot be
2236: changed during the KSPSolve()
2237: */
2238: PetscErrorCode SNESPicardComputeMFFunction(SNES snes, Vec x, Vec f, PetscCtx ctx)
2239: {
2240: DM dm;
2241: DMSNES sdm;
2243: PetscFunctionBegin;
2244: PetscCall(SNESGetDM(snes, &dm));
2245: PetscCall(DMGetDMSNES(dm, &sdm));
2246: /* A(x)*x - b(x) */
2247: if (sdm->ops->computepfunction) {
2248: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2249: PetscCall(VecScale(f, -1.0));
2250: /* Cannot share nonzero pattern because of the possible use of SNESComputeJacobianDefault() */
2251: if (!snes->picard) PetscCall(MatDuplicate(snes->jacobian_pre, MAT_DO_NOT_COPY_VALUES, &snes->picard));
2252: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2253: PetscCall(MatMultAdd(snes->picard, x, f, f));
2254: } else {
2255: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->picard, snes->picard, sdm->pctx));
2256: PetscCall(MatMult(snes->picard, x, f));
2257: }
2258: PetscFunctionReturn(PETSC_SUCCESS);
2259: }
2261: PetscErrorCode SNESPicardComputeFunction(SNES snes, Vec x, Vec f, PetscCtx ctx)
2262: {
2263: DM dm;
2264: DMSNES sdm;
2266: PetscFunctionBegin;
2267: PetscCall(SNESGetDM(snes, &dm));
2268: PetscCall(DMGetDMSNES(dm, &sdm));
2269: /* A(x)*x - b(x) */
2270: if (sdm->ops->computepfunction) {
2271: PetscCallBack("SNES Picard callback function", (*sdm->ops->computepfunction)(snes, x, f, sdm->pctx));
2272: PetscCall(VecScale(f, -1.0));
2273: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2274: PetscCall(MatMultAdd(snes->jacobian_pre, x, f, f));
2275: } else {
2276: PetscCallBack("SNES Picard callback Jacobian", (*sdm->ops->computepjacobian)(snes, x, snes->jacobian, snes->jacobian_pre, sdm->pctx));
2277: PetscCall(MatMult(snes->jacobian_pre, x, f));
2278: }
2279: PetscFunctionReturn(PETSC_SUCCESS);
2280: }
2282: PetscErrorCode SNESPicardComputeJacobian(SNES snes, Vec x1, Mat J, Mat B, PetscCtx ctx)
2283: {
2284: PetscFunctionBegin;
2285: /* the jacobian matrix should be pre-filled in SNESPicardComputeFunction */
2286: /* must assembly if matrix-free to get the last SNES solution */
2287: PetscCall(MatAssemblyBegin(J, MAT_FINAL_ASSEMBLY));
2288: PetscCall(MatAssemblyEnd(J, MAT_FINAL_ASSEMBLY));
2289: PetscFunctionReturn(PETSC_SUCCESS);
2290: }
2292: /*@C
2293: SNESSetPicard - Use `SNES` to solve the system $A(x) x = bp(x) + b $ via a Picard type iteration (Picard linearization)
2295: Logically Collective
2297: Input Parameters:
2298: + snes - the `SNES` context
2299: . r - vector to store function values, may be `NULL`
2300: . bp - function evaluation routine, may be `NULL`, for the calling sequence see `SNESFunctionFn`
2301: . Amat - matrix with which $A(x) x - bp(x) - b$ is to be computed
2302: . Pmat - matrix from which preconditioner is computed (usually the same as `Amat`)
2303: . J - function to compute matrix values, for the calling sequence see `SNESJacobianFn`
2304: - ctx - [optional] user-defined context for private data for the function evaluation routine (may be `NULL`)
2306: Level: intermediate
2308: Notes:
2309: It is often better to provide the nonlinear function $F()$ and some approximation to its Jacobian directly and use
2310: 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.
2312: One can call `SNESSetPicard()` or `SNESSetFunction()` (and possibly `SNESSetJacobian()`) but cannot call both
2314: Solves the equation $A(x) x = bp(x) - b$ via the defect correction algorithm $A(x^{n}) (x^{n+1} - x^{n}) = bp(x^{n}) + b - A(x^{n})x^{n}$.
2315: When an exact solver is used this corresponds to the "classic" Picard $A(x^{n}) x^{n+1} = bp(x^{n}) + b$ iteration.
2317: Run with `-snes_mf_operator` to solve the system with Newton's method using $A(x^{n})$ to construct the preconditioner.
2319: We implement the defect correction form of the Picard iteration because it converges much more generally when inexact linear solvers are used then
2320: the direct Picard iteration $A(x^n) x^{n+1} = bp(x^n) + b$
2322: 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
2323: 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
2324: different please contact us at petsc-dev@mcs.anl.gov and we'll have an entirely new argument \:-).
2326: 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
2327: $A(x^{n})$ is used to build the preconditioner
2329: When used with `-snes_fd` this will compute the true Jacobian (very slowly one column at a time) and thus represent Newton's method.
2331: 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
2332: 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
2333: 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`.
2334: See the comment in src/snes/tutorials/ex15.c.
2336: .seealso: [](ch_snes), `SNES`, `SNESGetFunction()`, `SNESSetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESGetPicard()`, `SNESLineSearchPreCheckPicard()`,
2337: `SNESFunctionFn`, `SNESJacobianFn`
2338: @*/
2339: PetscErrorCode SNESSetPicard(SNES snes, Vec r, SNESFunctionFn *bp, Mat Amat, Mat Pmat, SNESJacobianFn *J, PetscCtx ctx)
2340: {
2341: DM dm;
2343: PetscFunctionBegin;
2345: PetscCall(SNESGetDM(snes, &dm));
2346: PetscCall(DMSNESSetPicard(dm, bp, J, ctx));
2347: PetscCall(DMSNESSetMFFunction(dm, SNESPicardComputeMFFunction, ctx));
2348: PetscCall(SNESSetFunction(snes, r, SNESPicardComputeFunction, ctx));
2349: PetscCall(SNESSetJacobian(snes, Amat, Pmat, SNESPicardComputeJacobian, ctx));
2350: PetscFunctionReturn(PETSC_SUCCESS);
2351: }
2353: /*@C
2354: SNESGetPicard - Returns the context for the Picard iteration
2356: Not Collective, but `Vec` is parallel if `SNES` is parallel. Collective if `Vec` is requested, but has not been created yet.
2358: Input Parameter:
2359: . snes - the `SNES` context
2361: Output Parameters:
2362: + r - the function (or `NULL`)
2363: . f - the function (or `NULL`); for calling sequence see `SNESFunctionFn`
2364: . Amat - the matrix used to defined the operation A(x) x - b(x) (or `NULL`)
2365: . Pmat - the matrix from which the preconditioner will be constructed (or `NULL`)
2366: . J - the function for matrix evaluation (or `NULL`); for calling sequence see `SNESJacobianFn`
2367: - ctx - the function context (or `NULL`)
2369: Level: advanced
2371: .seealso: [](ch_snes), `SNESSetFunction()`, `SNESSetPicard()`, `SNESGetFunction()`, `SNESGetJacobian()`, `SNESGetDM()`, `SNESFunctionFn`, `SNESJacobianFn`
2372: @*/
2373: PetscErrorCode SNESGetPicard(SNES snes, Vec *r, SNESFunctionFn **f, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, PetscCtxRt ctx)
2374: {
2375: DM dm;
2377: PetscFunctionBegin;
2379: PetscCall(SNESGetFunction(snes, r, NULL, NULL));
2380: PetscCall(SNESGetJacobian(snes, Amat, Pmat, NULL, NULL));
2381: PetscCall(SNESGetDM(snes, &dm));
2382: PetscCall(DMSNESGetPicard(dm, f, J, ctx));
2383: PetscFunctionReturn(PETSC_SUCCESS);
2384: }
2386: /*@C
2387: SNESSetComputeInitialGuess - Sets a routine used to compute an initial guess for the nonlinear problem
2389: Logically Collective
2391: Input Parameters:
2392: + snes - the `SNES` context
2393: . func - function evaluation routine, see `SNESInitialGuessFn` for the calling sequence
2394: - ctx - [optional] user-defined context for private data for the
2395: function evaluation routine (may be `NULL`)
2397: Level: intermediate
2399: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESInitialGuessFn`
2400: @*/
2401: PetscErrorCode SNESSetComputeInitialGuess(SNES snes, SNESInitialGuessFn *func, PetscCtx ctx)
2402: {
2403: PetscFunctionBegin;
2405: if (func) snes->ops->computeinitialguess = func;
2406: if (ctx) snes->initialguessP = ctx;
2407: PetscFunctionReturn(PETSC_SUCCESS);
2408: }
2410: /*@C
2411: SNESGetRhs - Gets the vector for solving F(x) = `rhs`. If `rhs` is not set
2412: it assumes a zero right-hand side.
2414: Logically Collective
2416: Input Parameter:
2417: . snes - the `SNES` context
2419: Output Parameter:
2420: . rhs - the right-hand side vector or `NULL` if there is no right-hand side vector
2422: Level: intermediate
2424: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`, `SNESComputeFunction()`, `SNESSetJacobian()`, `SNESSetFunction()`
2425: @*/
2426: PetscErrorCode SNESGetRhs(SNES snes, Vec *rhs)
2427: {
2428: PetscFunctionBegin;
2430: PetscAssertPointer(rhs, 2);
2431: *rhs = snes->vec_rhs;
2432: PetscFunctionReturn(PETSC_SUCCESS);
2433: }
2435: /*@
2436: SNESComputeFunction - Calls the function that has been set with `SNESSetFunction()`.
2438: Collective
2440: Input Parameters:
2441: + snes - the `SNES` context
2442: - x - input vector
2444: Output Parameter:
2445: . f - function vector, as set by `SNESSetFunction()`
2447: Level: developer
2449: Notes:
2450: `SNESComputeFunction()` is typically used within nonlinear solvers
2451: implementations, so users would not generally call this routine themselves.
2453: When solving for $F(x) = b$, this routine computes $f = F(x) - b$.
2455: This function usually appears in the pattern.
2456: .vb
2457: SNESComputeFunction(snes, x, f);
2458: VecNorm(f, &fnorm);
2459: SNESCheckFunctionDomainError(snes, fnorm); or SNESLineSearchCheckFunctionDomainError(ls, fnorm);
2460: .ve
2461: to collectively handle the use of `SNESSetFunctionDomainError()` in the provided callback function.
2463: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeMFFunction()`, `SNESSetFunctionDomainError()`
2464: @*/
2465: PetscErrorCode SNESComputeFunction(SNES snes, Vec x, Vec f)
2466: {
2467: DM dm;
2468: DMSNES sdm;
2470: PetscFunctionBegin;
2474: PetscCheckSameComm(snes, 1, x, 2);
2475: PetscCheckSameComm(snes, 1, f, 3);
2476: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2478: PetscCall(SNESGetDM(snes, &dm));
2479: PetscCall(DMGetDMSNES(dm, &sdm));
2480: 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().");
2481: if (sdm->ops->computefunction) {
2482: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, f, 0));
2483: PetscCall(VecLockReadPush(x));
2484: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2485: snes->functiondomainerror = PETSC_FALSE;
2486: {
2487: void *ctx;
2488: SNESFunctionFn *computefunction;
2489: PetscCall(DMSNESGetFunction(dm, &computefunction, &ctx));
2490: PetscCallBack("SNES callback function", (*computefunction)(snes, x, f, ctx));
2491: }
2492: PetscCall(VecLockReadPop(x));
2493: if (sdm->ops->computefunction != SNESObjectiveComputeFunctionDefaultFD) PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, f, 0));
2494: } else /* if (snes->vec_rhs) */ {
2495: PetscCall(MatMult(snes->jacobian, x, f));
2496: }
2497: if (snes->vec_rhs) PetscCall(VecAXPY(f, -1.0, snes->vec_rhs));
2498: snes->nfuncs++;
2499: /*
2500: domainerror might not be set on all processes; so we tag vector locally with infinity and the next inner product or norm will
2501: propagate the value to all processes
2502: */
2503: PetscCall(VecFlag(f, snes->functiondomainerror));
2504: PetscFunctionReturn(PETSC_SUCCESS);
2505: }
2507: /*@
2508: SNESComputeMFFunction - Calls the function that has been set with `DMSNESSetMFFunction()`.
2510: Collective
2512: Input Parameters:
2513: + snes - the `SNES` context
2514: - x - input vector
2516: Output Parameter:
2517: . y - output vector
2519: Level: developer
2521: Notes:
2522: `SNESComputeMFFunction()` is used within the matrix-vector products called by the matrix created with `MatCreateSNESMF()`
2523: so users would not generally call this routine themselves.
2525: Since this function is intended for use with finite differencing it does not subtract the right-hand side vector provided with `SNESSolve()`
2526: while `SNESComputeFunction()` does. As such, this routine cannot be used with `MatMFFDSetBase()` with a provided F function value even if it applies the
2527: 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.
2529: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESComputeFunction()`, `MatCreateSNESMF()`, `DMSNESSetMFFunction()`
2530: @*/
2531: PetscErrorCode SNESComputeMFFunction(SNES snes, Vec x, Vec y)
2532: {
2533: DM dm;
2534: DMSNES sdm;
2536: PetscFunctionBegin;
2540: PetscCheckSameComm(snes, 1, x, 2);
2541: PetscCheckSameComm(snes, 1, y, 3);
2542: PetscCall(VecValidValues_Internal(x, 2, PETSC_TRUE));
2544: PetscCall(SNESGetDM(snes, &dm));
2545: PetscCall(DMGetDMSNES(dm, &sdm));
2546: PetscCall(PetscLogEventBegin(SNES_FunctionEval, snes, x, y, 0));
2547: PetscCall(VecLockReadPush(x));
2548: /* ensure domainerror is false prior to computefunction evaluation (may not have been reset) */
2549: snes->functiondomainerror = PETSC_FALSE;
2550: PetscCallBack("SNES callback function", (*sdm->ops->computemffunction)(snes, x, y, sdm->mffunctionctx));
2551: PetscCall(VecLockReadPop(x));
2552: PetscCall(PetscLogEventEnd(SNES_FunctionEval, snes, x, y, 0));
2553: snes->nfuncs++;
2554: /*
2555: domainerror might not be set on all processes; so we tag vector locally with infinity and the next inner product or norm will
2556: propagate the value to all processes
2557: */
2558: PetscCall(VecFlag(y, snes->functiondomainerror));
2559: PetscFunctionReturn(PETSC_SUCCESS);
2560: }
2562: /*@
2563: SNESComputeNGS - Calls the Gauss-Seidel function that has been set with `SNESSetNGS()`.
2565: Collective
2567: Input Parameters:
2568: + snes - the `SNES` context
2569: . x - input vector
2570: - b - rhs vector
2572: Output Parameter:
2573: . x - new solution vector
2575: Level: developer
2577: Note:
2578: `SNESComputeNGS()` is typically used within composed nonlinear solver
2579: implementations, so most users would not generally call this routine
2580: themselves.
2582: .seealso: [](ch_snes), `SNESNGSFn`, `SNESSetNGS()`, `SNESComputeFunction()`, `SNESNGS`
2583: @*/
2584: PetscErrorCode SNESComputeNGS(SNES snes, Vec b, Vec x)
2585: {
2586: DM dm;
2587: DMSNES sdm;
2589: PetscFunctionBegin;
2593: PetscCheckSameComm(snes, 1, x, 3);
2594: if (b) PetscCheckSameComm(snes, 1, b, 2);
2595: if (b) PetscCall(VecValidValues_Internal(b, 2, PETSC_TRUE));
2596: PetscCall(PetscLogEventBegin(SNES_NGSEval, snes, x, b, 0));
2597: PetscCall(SNESGetDM(snes, &dm));
2598: PetscCall(DMGetDMSNES(dm, &sdm));
2599: PetscCheck(sdm->ops->computegs, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call SNESSetNGS() before SNESComputeNGS(), likely called from SNESSolve().");
2600: if (b) PetscCall(VecLockReadPush(b));
2601: PetscCallBack("SNES callback NGS", (*sdm->ops->computegs)(snes, x, b, sdm->gsctx));
2602: if (b) PetscCall(VecLockReadPop(b));
2603: PetscCall(PetscLogEventEnd(SNES_NGSEval, snes, x, b, 0));
2604: PetscFunctionReturn(PETSC_SUCCESS);
2605: }
2607: static PetscErrorCode SNESComputeFunction_FD(SNES snes, Vec Xin, Vec G)
2608: {
2609: Vec X;
2610: PetscScalar *g;
2611: PetscReal f, f2;
2612: PetscInt low, high, N, i;
2613: PetscBool flg;
2614: PetscReal h = .5 * PETSC_SQRT_MACHINE_EPSILON;
2616: PetscFunctionBegin;
2617: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_fd_delta", &h, &flg));
2618: PetscCall(VecDuplicate(Xin, &X));
2619: PetscCall(VecCopy(Xin, X));
2620: PetscCall(VecGetSize(X, &N));
2621: PetscCall(VecGetOwnershipRange(X, &low, &high));
2622: PetscCall(VecSetOption(X, VEC_IGNORE_OFF_PROC_ENTRIES, PETSC_TRUE));
2623: PetscCall(VecGetArray(G, &g));
2624: for (i = 0; i < N; i++) {
2625: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2626: PetscCall(VecAssemblyBegin(X));
2627: PetscCall(VecAssemblyEnd(X));
2628: PetscCall(SNESComputeObjective(snes, X, &f));
2629: PetscCall(VecSetValue(X, i, 2.0 * h, ADD_VALUES));
2630: PetscCall(VecAssemblyBegin(X));
2631: PetscCall(VecAssemblyEnd(X));
2632: PetscCall(SNESComputeObjective(snes, X, &f2));
2633: PetscCall(VecSetValue(X, i, -h, ADD_VALUES));
2634: PetscCall(VecAssemblyBegin(X));
2635: PetscCall(VecAssemblyEnd(X));
2636: if (i >= low && i < high) g[i - low] = (f2 - f) / (2.0 * h);
2637: }
2638: PetscCall(VecRestoreArray(G, &g));
2639: PetscCall(VecDestroy(&X));
2640: PetscFunctionReturn(PETSC_SUCCESS);
2641: }
2643: /*@
2644: SNESTestFunction - Computes the difference between the computed and finite-difference functions
2646: Collective
2648: Input Parameter:
2649: . snes - the `SNES` context
2651: Options Database Keys:
2652: + -snes_test_function - compare the user provided function with one compute via finite differences to check for errors.
2653: - -snes_test_function_view - display the user provided function, the finite difference function and the difference
2655: Level: developer
2657: .seealso: [](ch_snes), `SNESTestJacobian()`, `SNESSetFunction()`, `SNESComputeFunction()`
2658: @*/
2659: PetscErrorCode SNESTestFunction(SNES snes)
2660: {
2661: Vec x, g1, g2, g3;
2662: PetscBool complete_print = PETSC_FALSE;
2663: PetscReal hcnorm, fdnorm, hcmax, fdmax, diffmax, diffnorm;
2664: PetscScalar dot;
2665: MPI_Comm comm;
2666: PetscViewer viewer, mviewer;
2667: PetscViewerFormat format;
2668: PetscInt tabs;
2669: static PetscBool directionsprinted = PETSC_FALSE;
2670: SNESObjectiveFn *objective;
2672: PetscFunctionBegin;
2673: PetscCall(SNESGetObjective(snes, &objective, NULL));
2674: if (!objective) PetscFunctionReturn(PETSC_SUCCESS);
2676: PetscObjectOptionsBegin((PetscObject)snes);
2677: PetscCall(PetscOptionsViewer("-snes_test_function_view", "View difference between hand-coded and finite difference function element entries", "None", &mviewer, &format, &complete_print));
2678: PetscOptionsEnd();
2680: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2681: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2682: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2683: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2684: PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Function -------------\n"));
2685: if (!complete_print && !directionsprinted) {
2686: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_function_view and optionally -snes_test_function <threshold> to show difference\n"));
2687: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference function entries greater than <threshold>.\n"));
2688: }
2689: if (!directionsprinted) {
2690: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Function, if (for double precision runs) ||F - Ffd||/||F|| is\n"));
2691: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Function is probably correct.\n"));
2692: directionsprinted = PETSC_TRUE;
2693: }
2694: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2696: PetscCall(SNESGetSolution(snes, &x));
2697: PetscCall(VecDuplicate(x, &g1));
2698: PetscCall(VecDuplicate(x, &g2));
2699: PetscCall(VecDuplicate(x, &g3));
2700: PetscCall(SNESComputeFunction(snes, x, g1)); /* does not handle use of SNESSetFunctionDomainError() corrrectly */
2701: PetscCall(SNESComputeFunction_FD(snes, x, g2));
2703: PetscCall(VecNorm(g2, NORM_2, &fdnorm));
2704: PetscCall(VecNorm(g1, NORM_2, &hcnorm));
2705: PetscCall(VecNorm(g2, NORM_INFINITY, &fdmax));
2706: PetscCall(VecNorm(g1, NORM_INFINITY, &hcmax));
2707: PetscCall(VecDot(g1, g2, &dot));
2708: PetscCall(VecCopy(g1, g3));
2709: PetscCall(VecAXPY(g3, -1.0, g2));
2710: PetscCall(VecNorm(g3, NORM_2, &diffnorm));
2711: PetscCall(VecNorm(g3, NORM_INFINITY, &diffmax));
2712: PetscCall(PetscViewerASCIIPrintf(viewer, " ||Ffd|| %g, ||F|| = %g, angle cosine = (Ffd'F)/||Ffd||||F|| = %g\n", (double)fdnorm, (double)hcnorm, (double)(PetscRealPart(dot) / (fdnorm * hcnorm))));
2713: PetscCall(PetscViewerASCIIPrintf(viewer, " 2-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffnorm / PetscMax(hcnorm, fdnorm)), (double)diffnorm));
2714: PetscCall(PetscViewerASCIIPrintf(viewer, " max-norm ||F - Ffd||/||F|| = %g, ||F - Ffd|| = %g\n", (double)(diffmax / PetscMax(hcmax, fdmax)), (double)diffmax));
2716: if (complete_print) {
2717: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded function ----------\n"));
2718: PetscCall(VecView(g1, mviewer));
2719: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference function ----------\n"));
2720: PetscCall(VecView(g2, mviewer));
2721: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference function ----------\n"));
2722: PetscCall(VecView(g3, mviewer));
2723: }
2724: PetscCall(VecDestroy(&g1));
2725: PetscCall(VecDestroy(&g2));
2726: PetscCall(VecDestroy(&g3));
2728: if (complete_print) {
2729: PetscCall(PetscViewerPopFormat(mviewer));
2730: PetscCall(PetscViewerDestroy(&mviewer));
2731: }
2732: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2733: PetscFunctionReturn(PETSC_SUCCESS);
2734: }
2736: /*@
2737: SNESTestJacobian - Computes the difference between the computed and finite-difference Jacobians
2739: Collective
2741: Input Parameter:
2742: . snes - the `SNES` context
2744: Output Parameters:
2745: + Jnorm - the Frobenius norm of the computed Jacobian, or `NULL`
2746: - diffNorm - the Frobenius norm of the difference of the computed and finite-difference Jacobians, or `NULL`
2748: Options Database Keys:
2749: + -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.
2750: - -snes_test_jacobian_view - display the user provided Jacobian, the finite difference Jacobian and the difference
2752: Level: developer
2754: Note:
2755: Directions and norms are printed to stdout if `diffNorm` is `NULL`.
2757: .seealso: [](ch_snes), `SNESTestFunction()`, `SNESSetJacobian()`, `SNESComputeJacobian()`
2758: @*/
2759: PetscErrorCode SNESTestJacobian(SNES snes, PetscReal *Jnorm, PetscReal *diffNorm)
2760: {
2761: Mat A, B, C, D, jacobian;
2762: Vec x = snes->vec_sol, f;
2763: PetscReal nrm, gnorm;
2764: PetscReal threshold = 1.e-5;
2765: MatType mattype;
2766: PetscInt m, n, M, N;
2767: void *functx;
2768: PetscBool complete_print = PETSC_FALSE, threshold_print = PETSC_FALSE, flg, istranspose;
2769: PetscBool silent = diffNorm != PETSC_NULLPTR ? PETSC_TRUE : PETSC_FALSE;
2770: PetscViewer viewer, mviewer;
2771: MPI_Comm comm;
2772: PetscInt tabs;
2773: static PetscBool directionsprinted = PETSC_FALSE;
2774: PetscViewerFormat format;
2776: PetscFunctionBegin;
2777: PetscObjectOptionsBegin((PetscObject)snes);
2778: PetscCall(PetscOptionsReal("-snes_test_jacobian", "Threshold for element difference between hand-coded and finite difference being meaningful", "None", threshold, &threshold, NULL));
2779: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display", "-snes_test_jacobian_view", "3.13", NULL));
2780: PetscCall(PetscOptionsViewer("-snes_test_jacobian_view", "View difference between hand-coded and finite difference Jacobians element entries", "None", &mviewer, &format, &complete_print));
2781: PetscCall(PetscOptionsDeprecated("-snes_test_jacobian_display_threshold", "-snes_test_jacobian", "3.13", "-snes_test_jacobian accepts an optional threshold (since v3.10)"));
2782: 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));
2783: PetscOptionsEnd();
2785: PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
2786: PetscCall(PetscViewerASCIIGetStdout(comm, &viewer));
2787: PetscCall(PetscViewerASCIIGetTab(viewer, &tabs));
2788: PetscCall(PetscViewerASCIISetTab(viewer, ((PetscObject)snes)->tablevel));
2789: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian -------------\n"));
2790: if (!complete_print && !silent && !directionsprinted) {
2791: PetscCall(PetscViewerASCIIPrintf(viewer, " Run with -snes_test_jacobian_view and optionally -snes_test_jacobian <threshold> to show difference\n"));
2792: PetscCall(PetscViewerASCIIPrintf(viewer, " of hand-coded and finite difference Jacobian entries greater than <threshold>.\n"));
2793: }
2794: if (!directionsprinted && !silent) {
2795: PetscCall(PetscViewerASCIIPrintf(viewer, " Testing hand-coded Jacobian, if (for double precision runs) ||J - Jfd||_F/||J||_F is\n"));
2796: PetscCall(PetscViewerASCIIPrintf(viewer, " O(1.e-8), the hand-coded Jacobian is probably correct.\n"));
2797: directionsprinted = PETSC_TRUE;
2798: }
2799: if (complete_print) PetscCall(PetscViewerPushFormat(mviewer, format));
2801: PetscCall(PetscObjectTypeCompare((PetscObject)snes->jacobian, MATMFFD, &flg));
2802: if (!flg) jacobian = snes->jacobian;
2803: else jacobian = snes->jacobian_pre;
2805: if (!x) PetscCall(MatCreateVecs(jacobian, &x, NULL));
2806: else PetscCall(PetscObjectReference((PetscObject)x));
2807: PetscCall(VecDuplicate(x, &f));
2809: /* evaluate the function at this point because SNESComputeJacobianDefault() assumes that the function has been evaluated and put into snes->vec_func */
2810: PetscCall(SNESComputeFunction(snes, x, f));
2811: PetscCall(VecDestroy(&f));
2812: PetscCall(PetscObjectTypeCompare((PetscObject)snes, SNESKSPTRANSPOSEONLY, &istranspose));
2813: while (jacobian) {
2814: Mat JT = NULL, Jsave = NULL;
2816: if (istranspose) {
2817: PetscCall(MatCreateTranspose(jacobian, &JT));
2818: Jsave = jacobian;
2819: jacobian = JT;
2820: }
2821: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)jacobian, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
2822: if (flg) {
2823: A = jacobian;
2824: PetscCall(PetscObjectReference((PetscObject)A));
2825: } else {
2826: PetscCall(MatComputeOperator(jacobian, MATAIJ, &A));
2827: }
2829: PetscCall(MatGetType(A, &mattype));
2830: PetscCall(MatGetSize(A, &M, &N));
2831: PetscCall(MatGetLocalSize(A, &m, &n));
2832: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
2833: PetscCall(MatSetType(B, mattype));
2834: PetscCall(MatSetSizes(B, m, n, M, N));
2835: PetscCall(MatSetBlockSizesFromMats(B, A, A));
2836: PetscCall(MatSetUp(B));
2837: PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2839: PetscCall(SNESGetFunction(snes, NULL, NULL, &functx));
2840: PetscCall(SNESComputeJacobianDefault(snes, x, B, B, functx));
2842: PetscCall(MatDuplicate(B, MAT_COPY_VALUES, &D));
2843: PetscCall(MatAYPX(D, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2844: PetscCall(MatNorm(D, NORM_FROBENIUS, &nrm));
2845: PetscCall(MatNorm(A, NORM_FROBENIUS, &gnorm));
2846: PetscCall(MatDestroy(&D));
2847: if (!gnorm) gnorm = 1; /* just in case */
2848: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ||J - Jfd||_F/||J||_F = %g, ||J - Jfd||_F = %g\n", (double)(nrm / gnorm), (double)nrm));
2849: if (complete_print) {
2850: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded Jacobian ----------\n"));
2851: PetscCall(MatView(A, mviewer));
2852: PetscCall(PetscViewerASCIIPrintf(viewer, " Finite difference Jacobian ----------\n"));
2853: PetscCall(MatView(B, mviewer));
2854: }
2856: if (threshold_print || complete_print) {
2857: PetscInt Istart, Iend, *ccols, bncols, cncols, j, row;
2858: PetscScalar *cvals;
2859: const PetscInt *bcols;
2860: const PetscScalar *bvals;
2862: PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2863: PetscCall(MatSetType(C, mattype));
2864: PetscCall(MatSetSizes(C, m, n, M, N));
2865: PetscCall(MatSetBlockSizesFromMats(C, A, A));
2866: PetscCall(MatSetUp(C));
2867: PetscCall(MatSetOption(C, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
2869: PetscCall(MatAYPX(B, -1.0, A, DIFFERENT_NONZERO_PATTERN));
2870: PetscCall(MatGetOwnershipRange(B, &Istart, &Iend));
2872: for (row = Istart; row < Iend; row++) {
2873: PetscCall(MatGetRow(B, row, &bncols, &bcols, &bvals));
2874: PetscCall(PetscMalloc2(bncols, &ccols, bncols, &cvals));
2875: for (j = 0, cncols = 0; j < bncols; j++) {
2876: if (PetscAbsScalar(bvals[j]) > threshold) {
2877: ccols[cncols] = bcols[j];
2878: cvals[cncols] = bvals[j];
2879: cncols += 1;
2880: }
2881: }
2882: if (cncols) PetscCall(MatSetValues(C, 1, &row, cncols, ccols, cvals, INSERT_VALUES));
2883: PetscCall(MatRestoreRow(B, row, &bncols, &bcols, &bvals));
2884: PetscCall(PetscFree2(ccols, cvals));
2885: }
2886: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2887: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2888: PetscCall(PetscViewerASCIIPrintf(viewer, " Hand-coded minus finite-difference Jacobian with tolerance %g ----------\n", (double)threshold));
2889: PetscCall(MatView(C, complete_print ? mviewer : viewer));
2890: PetscCall(MatDestroy(&C));
2891: }
2892: PetscCall(MatDestroy(&A));
2893: PetscCall(MatDestroy(&B));
2894: PetscCall(MatDestroy(&JT));
2895: if (Jsave) jacobian = Jsave;
2896: if (jacobian != snes->jacobian_pre) {
2897: jacobian = snes->jacobian_pre;
2898: if (!silent) PetscCall(PetscViewerASCIIPrintf(viewer, " ---------- Testing Jacobian for preconditioner -------------\n"));
2899: } else jacobian = NULL;
2900: }
2901: PetscCall(VecDestroy(&x));
2902: if (complete_print) PetscCall(PetscViewerPopFormat(mviewer));
2903: if (mviewer) PetscCall(PetscViewerDestroy(&mviewer));
2904: PetscCall(PetscViewerASCIISetTab(viewer, tabs));
2906: if (Jnorm) *Jnorm = gnorm;
2907: if (diffNorm) *diffNorm = nrm;
2908: PetscFunctionReturn(PETSC_SUCCESS);
2909: }
2911: /*@
2912: SNESComputeJacobian - Computes the Jacobian matrix that has been set with `SNESSetJacobian()`.
2914: Collective
2916: Input Parameters:
2917: + snes - the `SNES` context
2918: - X - input vector
2920: Output Parameters:
2921: + A - Jacobian matrix
2922: - B - optional matrix for building the preconditioner, usually the same as `A`
2924: Options Database Keys:
2925: + -snes_lag_preconditioner <lag> - how often to rebuild preconditioner
2926: . -snes_lag_jacobian <lag> - how often to rebuild Jacobian
2927: . -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.
2928: . -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
2929: . -snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences
2930: . -snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result
2931: . -snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result
2932: . -snes_compare_operator - Make the comparison options above use the operator instead of the matrix used to construct the preconditioner
2933: . -snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference
2934: . -snes_compare_coloring_display - Compute the finite difference Jacobian using coloring and display verbose differences
2935: . -snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold
2936: . -snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2937: . -snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by `-snes_compare_coloring_threshold`
2938: . -snes_compare_coloring_draw - Compute the finite difference Jacobian using coloring and draw differences
2939: - -snes_compare_coloring_draw_contour - Compute the finite difference Jacobian using coloring and show contours of matrices and differences
2941: Level: developer
2943: Note:
2944: Most users should not need to explicitly call this routine, as it
2945: is used internally within the nonlinear solvers.
2947: Developer Note:
2948: 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
2949: with the `SNESType` of test that has been removed.
2951: .seealso: [](ch_snes), `SNESSetJacobian()`, `KSPSetOperators()`, `MatStructure`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobian()`,
2952: `SNESSetJacobianDomainError()`, `SNESCheckJacobianDomainError()`, `SNESSetCheckJacobianDomainError()`
2953: @*/
2954: PetscErrorCode SNESComputeJacobian(SNES snes, Vec X, Mat A, Mat B)
2955: {
2956: PetscBool flag;
2957: DM dm;
2958: DMSNES sdm;
2959: KSP ksp;
2961: PetscFunctionBegin;
2964: PetscCheckSameComm(snes, 1, X, 2);
2965: PetscCall(VecValidValues_Internal(X, 2, PETSC_TRUE));
2966: PetscCall(SNESGetDM(snes, &dm));
2967: PetscCall(DMGetDMSNES(dm, &sdm));
2969: /* make sure that MatAssemblyBegin/End() is called on A matrix if it is matrix-free */
2970: if (snes->lagjacobian == -2) {
2971: snes->lagjacobian = -1;
2973: PetscCall(PetscInfo(snes, "Recomputing Jacobian/preconditioner because lag is -2 (means compute Jacobian, but then never again) \n"));
2974: } else if (snes->lagjacobian == -1) {
2975: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is -1\n"));
2976: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2977: if (flag) {
2978: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2979: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2980: }
2981: PetscFunctionReturn(PETSC_SUCCESS);
2982: } else if (snes->lagjacobian > 1 && (snes->iter + snes->jac_iter) % snes->lagjacobian) {
2983: PetscCall(PetscInfo(snes, "Reusing Jacobian/preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagjacobian, snes->iter));
2984: PetscCall(PetscObjectTypeCompare((PetscObject)A, MATMFFD, &flag));
2985: if (flag) {
2986: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2987: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2988: }
2989: PetscFunctionReturn(PETSC_SUCCESS);
2990: }
2991: if (snes->npc && snes->npcside == PC_LEFT) {
2992: PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2993: PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2994: PetscFunctionReturn(PETSC_SUCCESS);
2995: }
2997: PetscCall(PetscLogEventBegin(SNES_JacobianEval, snes, X, A, B));
2998: PetscCall(VecLockReadPush(X));
2999: {
3000: void *ctx;
3001: SNESJacobianFn *J;
3002: PetscCall(DMSNESGetJacobian(dm, &J, &ctx));
3003: PetscCallBack("SNES callback Jacobian", (*J)(snes, X, A, B, ctx));
3004: }
3005: PetscCall(VecLockReadPop(X));
3006: PetscCall(PetscLogEventEnd(SNES_JacobianEval, snes, X, A, B));
3008: /* attach latest linearization point to the matrix used to construct the preconditioner */
3009: PetscCall(PetscObjectCompose((PetscObject)B, "__SNES_latest_X", (PetscObject)X));
3011: /* the next line ensures that snes->ksp exists */
3012: PetscCall(SNESGetKSP(snes, &ksp));
3013: if (snes->lagpreconditioner == -2) {
3014: PetscCall(PetscInfo(snes, "Rebuilding preconditioner exactly once since lag is -2\n"));
3015: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
3016: snes->lagpreconditioner = -1;
3017: } else if (snes->lagpreconditioner == -1) {
3018: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is -1\n"));
3019: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
3020: } else if (snes->lagpreconditioner > 1 && (snes->iter + snes->pre_iter) % snes->lagpreconditioner) {
3021: PetscCall(PetscInfo(snes, "Reusing preconditioner because lag is %" PetscInt_FMT " and SNES iteration is %" PetscInt_FMT "\n", snes->lagpreconditioner, snes->iter));
3022: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_TRUE));
3023: } else {
3024: PetscCall(PetscInfo(snes, "Rebuilding preconditioner\n"));
3025: PetscCall(KSPSetReusePreconditioner(snes->ksp, PETSC_FALSE));
3026: }
3028: /* monkey business to allow testing Jacobians in multilevel solvers.
3029: This is needed because the SNESTestXXX interface does not accept vectors and matrices */
3030: {
3031: Vec xsave = snes->vec_sol;
3032: Mat jacobiansave = snes->jacobian;
3033: Mat jacobian_presave = snes->jacobian_pre;
3035: snes->vec_sol = X;
3036: snes->jacobian = A;
3037: snes->jacobian_pre = B;
3038: if (snes->testFunc) PetscCall(SNESTestFunction(snes));
3039: if (snes->testJac) PetscCall(SNESTestJacobian(snes, NULL, NULL));
3041: snes->vec_sol = xsave;
3042: snes->jacobian = jacobiansave;
3043: snes->jacobian_pre = jacobian_presave;
3044: }
3046: {
3047: PetscBool flag = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_operator = PETSC_FALSE;
3048: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit", NULL, NULL, &flag));
3049: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw", NULL, NULL, &flag_draw));
3050: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_explicit_draw_contour", NULL, NULL, &flag_contour));
3051: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_operator", NULL, NULL, &flag_operator));
3052: if (flag || flag_draw || flag_contour) {
3053: Mat Bexp_mine = NULL, Bexp, FDexp;
3054: PetscViewer vdraw, vstdout;
3055: PetscBool flg;
3056: if (flag_operator) {
3057: PetscCall(MatComputeOperator(A, MATAIJ, &Bexp_mine));
3058: Bexp = Bexp_mine;
3059: } else {
3060: /* See if the matrix used to construct the preconditioner can be viewed and added directly */
3061: PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)B, &flg, MATSEQAIJ, MATMPIAIJ, MATSEQDENSE, MATMPIDENSE, MATSEQBAIJ, MATMPIBAIJ, MATSEQSBAIJ, MATMPISBAIJ, ""));
3062: if (flg) Bexp = B;
3063: else {
3064: /* If the "preconditioning" matrix is itself MATSHELL or some other type without direct support */
3065: PetscCall(MatComputeOperator(B, MATAIJ, &Bexp_mine));
3066: Bexp = Bexp_mine;
3067: }
3068: }
3069: PetscCall(MatConvert(Bexp, MATSAME, MAT_INITIAL_MATRIX, &FDexp));
3070: PetscCall(SNESComputeJacobianDefault(snes, X, FDexp, FDexp, NULL));
3071: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3072: if (flag_draw || flag_contour) {
3073: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Explicit Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3074: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3075: } else vdraw = NULL;
3076: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit %s\n", flag_operator ? "Jacobian" : "preconditioning Jacobian"));
3077: if (flag) PetscCall(MatView(Bexp, vstdout));
3078: if (vdraw) PetscCall(MatView(Bexp, vdraw));
3079: PetscCall(PetscViewerASCIIPrintf(vstdout, "Finite difference Jacobian\n"));
3080: if (flag) PetscCall(MatView(FDexp, vstdout));
3081: if (vdraw) PetscCall(MatView(FDexp, vdraw));
3082: PetscCall(MatAYPX(FDexp, -1.0, Bexp, SAME_NONZERO_PATTERN));
3083: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian\n"));
3084: if (flag) PetscCall(MatView(FDexp, vstdout));
3085: if (vdraw) { /* Always use contour for the difference */
3086: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3087: PetscCall(MatView(FDexp, vdraw));
3088: PetscCall(PetscViewerPopFormat(vdraw));
3089: }
3090: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3091: PetscCall(PetscViewerDestroy(&vdraw));
3092: PetscCall(MatDestroy(&Bexp_mine));
3093: PetscCall(MatDestroy(&FDexp));
3094: }
3095: }
3096: {
3097: PetscBool flag = PETSC_FALSE, flag_display = PETSC_FALSE, flag_draw = PETSC_FALSE, flag_contour = PETSC_FALSE, flag_threshold = PETSC_FALSE;
3098: PetscReal threshold_atol = PETSC_SQRT_MACHINE_EPSILON, threshold_rtol = 10 * PETSC_SQRT_MACHINE_EPSILON;
3099: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring", NULL, NULL, &flag));
3100: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_display", NULL, NULL, &flag_display));
3101: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw", NULL, NULL, &flag_draw));
3102: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_draw_contour", NULL, NULL, &flag_contour));
3103: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold", NULL, NULL, &flag_threshold));
3104: if (flag_threshold) {
3105: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_rtol", &threshold_rtol, NULL));
3106: PetscCall(PetscOptionsGetReal(((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_compare_coloring_threshold_atol", &threshold_atol, NULL));
3107: }
3108: if (flag || flag_display || flag_draw || flag_contour || flag_threshold) {
3109: Mat Bfd;
3110: PetscViewer vdraw, vstdout;
3111: MatColoring coloring;
3112: ISColoring iscoloring;
3113: MatFDColoring matfdcoloring;
3114: SNESFunctionFn *func;
3115: void *funcctx;
3116: PetscReal norm1, norm2, normmax;
3118: PetscCall(MatDuplicate(B, MAT_DO_NOT_COPY_VALUES, &Bfd));
3119: PetscCall(MatColoringCreate(Bfd, &coloring));
3120: PetscCall(MatColoringSetType(coloring, MATCOLORINGSL));
3121: PetscCall(MatColoringSetFromOptions(coloring));
3122: PetscCall(MatColoringApply(coloring, &iscoloring));
3123: PetscCall(MatColoringDestroy(&coloring));
3124: PetscCall(MatFDColoringCreate(Bfd, iscoloring, &matfdcoloring));
3125: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3126: PetscCall(MatFDColoringSetUp(Bfd, iscoloring, matfdcoloring));
3127: PetscCall(ISColoringDestroy(&iscoloring));
3129: /* This method of getting the function is currently unreliable since it doesn't work for DM local functions. */
3130: PetscCall(SNESGetFunction(snes, NULL, &func, &funcctx));
3131: PetscCall(MatFDColoringSetFunction(matfdcoloring, (MatFDColoringFn *)func, funcctx));
3132: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)matfdcoloring, ((PetscObject)snes)->prefix));
3133: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)matfdcoloring, "coloring_"));
3134: PetscCall(MatFDColoringSetFromOptions(matfdcoloring));
3135: PetscCall(MatFDColoringApply(Bfd, matfdcoloring, X, snes));
3136: PetscCall(MatFDColoringDestroy(&matfdcoloring));
3138: PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)snes), &vstdout));
3139: if (flag_draw || flag_contour) {
3140: PetscCall(PetscViewerDrawOpen(PetscObjectComm((PetscObject)snes), NULL, "Colored Jacobians", PETSC_DECIDE, PETSC_DECIDE, 300, 300, &vdraw));
3141: if (flag_contour) PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3142: } else vdraw = NULL;
3143: PetscCall(PetscViewerASCIIPrintf(vstdout, "Explicit preconditioning Jacobian\n"));
3144: if (flag_display) PetscCall(MatView(B, vstdout));
3145: if (vdraw) PetscCall(MatView(B, vdraw));
3146: PetscCall(PetscViewerASCIIPrintf(vstdout, "Colored Finite difference Jacobian\n"));
3147: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3148: if (vdraw) PetscCall(MatView(Bfd, vdraw));
3149: PetscCall(MatAYPX(Bfd, -1.0, B, SAME_NONZERO_PATTERN));
3150: PetscCall(MatNorm(Bfd, NORM_1, &norm1));
3151: PetscCall(MatNorm(Bfd, NORM_FROBENIUS, &norm2));
3152: PetscCall(MatNorm(Bfd, NORM_MAX, &normmax));
3153: PetscCall(PetscViewerASCIIPrintf(vstdout, "User-provided matrix minus finite difference Jacobian, norm1=%g normFrob=%g normmax=%g\n", (double)norm1, (double)norm2, (double)normmax));
3154: if (flag_display) PetscCall(MatView(Bfd, vstdout));
3155: if (vdraw) { /* Always use contour for the difference */
3156: PetscCall(PetscViewerPushFormat(vdraw, PETSC_VIEWER_DRAW_CONTOUR));
3157: PetscCall(MatView(Bfd, vdraw));
3158: PetscCall(PetscViewerPopFormat(vdraw));
3159: }
3160: if (flag_contour) PetscCall(PetscViewerPopFormat(vdraw));
3162: if (flag_threshold) {
3163: PetscInt bs, rstart, rend, i;
3164: PetscCall(MatGetBlockSize(B, &bs));
3165: PetscCall(MatGetOwnershipRange(B, &rstart, &rend));
3166: for (i = rstart; i < rend; i++) {
3167: const PetscScalar *ba, *ca;
3168: const PetscInt *bj, *cj;
3169: PetscInt bn, cn, j, maxentrycol = -1, maxdiffcol = -1, maxrdiffcol = -1;
3170: PetscReal maxentry = 0, maxdiff = 0, maxrdiff = 0;
3171: PetscCall(MatGetRow(B, i, &bn, &bj, &ba));
3172: PetscCall(MatGetRow(Bfd, i, &cn, &cj, &ca));
3173: PetscCheck(bn == cn, ((PetscObject)A)->comm, PETSC_ERR_PLIB, "Unexpected different nonzero pattern in -snes_compare_coloring_threshold");
3174: for (j = 0; j < bn; j++) {
3175: PetscReal rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3176: if (PetscAbsScalar(ba[j]) > PetscAbs(maxentry)) {
3177: maxentrycol = bj[j];
3178: maxentry = PetscRealPart(ba[j]);
3179: }
3180: if (PetscAbsScalar(ca[j]) > PetscAbs(maxdiff)) {
3181: maxdiffcol = bj[j];
3182: maxdiff = PetscRealPart(ca[j]);
3183: }
3184: if (rdiff > maxrdiff) {
3185: maxrdiffcol = bj[j];
3186: maxrdiff = rdiff;
3187: }
3188: }
3189: if (maxrdiff > 1) {
3190: 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));
3191: for (j = 0; j < bn; j++) {
3192: PetscReal rdiff;
3193: rdiff = PetscAbsScalar(ca[j]) / (threshold_atol + threshold_rtol * PetscAbsScalar(ba[j]));
3194: if (rdiff > 1) PetscCall(PetscViewerASCIIPrintf(vstdout, " (%" PetscInt_FMT ",%g:%g)", bj[j], (double)PetscRealPart(ba[j]), (double)PetscRealPart(ca[j])));
3195: }
3196: PetscCall(PetscViewerASCIIPrintf(vstdout, "\n"));
3197: }
3198: PetscCall(MatRestoreRow(B, i, &bn, &bj, &ba));
3199: PetscCall(MatRestoreRow(Bfd, i, &cn, &cj, &ca));
3200: }
3201: }
3202: PetscCall(PetscViewerDestroy(&vdraw));
3203: PetscCall(MatDestroy(&Bfd));
3204: }
3205: }
3206: PetscFunctionReturn(PETSC_SUCCESS);
3207: }
3209: /*@C
3210: SNESSetJacobian - Sets the function to compute Jacobian as well as the
3211: location to store the matrix.
3213: Logically Collective
3215: Input Parameters:
3216: + snes - the `SNES` context
3217: . Amat - the matrix that defines the (approximate) Jacobian
3218: . Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
3219: . J - Jacobian evaluation routine (if `NULL` then `SNES` retains any previously set value), see `SNESJacobianFn` for details
3220: - ctx - [optional] user-defined context for private data for the
3221: Jacobian evaluation routine (may be `NULL`) (if `NULL` then `SNES` retains any previously set value)
3223: Level: beginner
3225: Notes:
3226: If the `Amat` matrix and `Pmat` matrix are different you must call `MatAssemblyBegin()`/`MatAssemblyEnd()` on
3227: each matrix.
3229: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
3230: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
3232: If using `SNESComputeJacobianDefaultColor()` to assemble a Jacobian, the `ctx` argument
3233: must be a `MatFDColoring`.
3235: Other defect-correction schemes can be used by computing a different matrix in place of the Jacobian. One common
3236: example is to use the "Picard linearization" which only differentiates through the highest order parts of each term using `SNESSetPicard()`
3238: .seealso: [](ch_snes), `SNES`, `KSPSetOperators()`, `SNESSetFunction()`, `MatMFFDComputeJacobian()`, `SNESComputeJacobianDefaultColor()`, `MatStructure`,
3239: `SNESSetPicard()`, `SNESJacobianFn`, `SNESFunctionFn`
3240: @*/
3241: PetscErrorCode SNESSetJacobian(SNES snes, Mat Amat, Mat Pmat, SNESJacobianFn *J, PetscCtx ctx)
3242: {
3243: DM dm;
3245: PetscFunctionBegin;
3249: if (Amat) PetscCheckSameComm(snes, 1, Amat, 2);
3250: if (Pmat) PetscCheckSameComm(snes, 1, Pmat, 3);
3251: PetscCall(SNESGetDM(snes, &dm));
3252: PetscCall(DMSNESSetJacobian(dm, J, ctx));
3253: if (Amat) {
3254: PetscCall(PetscObjectReference((PetscObject)Amat));
3255: PetscCall(MatDestroy(&snes->jacobian));
3257: snes->jacobian = Amat;
3258: }
3259: if (Pmat) {
3260: PetscCall(PetscObjectReference((PetscObject)Pmat));
3261: PetscCall(MatDestroy(&snes->jacobian_pre));
3263: snes->jacobian_pre = Pmat;
3264: }
3265: PetscFunctionReturn(PETSC_SUCCESS);
3266: }
3268: /*@C
3269: SNESGetJacobian - Returns the Jacobian matrix and optionally the user
3270: provided context for evaluating the Jacobian.
3272: Not Collective, but `Mat` object will be parallel if `SNES` is
3274: Input Parameter:
3275: . snes - the nonlinear solver context
3277: Output Parameters:
3278: + Amat - location to stash (approximate) Jacobian matrix (or `NULL`)
3279: . Pmat - location to stash matrix used to compute the preconditioner (or `NULL`)
3280: . J - location to put Jacobian function (or `NULL`), for calling sequence see `SNESJacobianFn`
3281: - ctx - location to stash Jacobian ctx (or `NULL`)
3283: Level: advanced
3285: .seealso: [](ch_snes), `SNES`, `Mat`, `SNESSetJacobian()`, `SNESComputeJacobian()`, `SNESJacobianFn`, `SNESGetFunction()`
3286: @*/
3287: PetscErrorCode SNESGetJacobian(SNES snes, Mat *Amat, Mat *Pmat, SNESJacobianFn **J, PetscCtxRt ctx)
3288: {
3289: DM dm;
3291: PetscFunctionBegin;
3293: if (Amat) *Amat = snes->jacobian;
3294: if (Pmat) *Pmat = snes->jacobian_pre;
3295: PetscCall(SNESGetDM(snes, &dm));
3296: PetscCall(DMSNESGetJacobian(dm, J, ctx));
3297: PetscFunctionReturn(PETSC_SUCCESS);
3298: }
3300: static PetscErrorCode SNESSetDefaultComputeJacobian(SNES snes)
3301: {
3302: DM dm;
3303: DMSNES sdm;
3305: PetscFunctionBegin;
3306: PetscCall(SNESGetDM(snes, &dm));
3307: PetscCall(DMGetDMSNES(dm, &sdm));
3308: if (!sdm->ops->computejacobian && snes->jacobian_pre) {
3309: DM dm;
3310: PetscBool isdense, ismf;
3312: PetscCall(SNESGetDM(snes, &dm));
3313: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &isdense, MATSEQDENSE, MATMPIDENSE, MATDENSE, NULL));
3314: PetscCall(PetscObjectTypeCompareAny((PetscObject)snes->jacobian_pre, &ismf, MATMFFD, MATSHELL, NULL));
3315: if (isdense) {
3316: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefault, NULL));
3317: } else if (!ismf) {
3318: PetscCall(DMSNESSetJacobian(dm, SNESComputeJacobianDefaultColor, NULL));
3319: }
3320: }
3321: PetscFunctionReturn(PETSC_SUCCESS);
3322: }
3324: /*@
3325: SNESSetUp - Sets up the internal data structures for the later use
3326: of a nonlinear solver `SNESSolve()`.
3328: Collective
3330: Input Parameter:
3331: . snes - the `SNES` context
3333: Level: advanced
3335: Note:
3336: For basic use of the `SNES` solvers the user does not need to explicitly call
3337: `SNESSetUp()`, since these actions will automatically occur during
3338: the call to `SNESSolve()`. However, if one wishes to control this
3339: phase separately, `SNESSetUp()` should be called after `SNESCreate()`
3340: and optional routines of the form SNESSetXXX(), but before `SNESSolve()`.
3342: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`, `SNESDestroy()`, `SNESSetFromOptions()`
3343: @*/
3344: PetscErrorCode SNESSetUp(SNES snes)
3345: {
3346: DM dm;
3347: DMSNES sdm;
3348: SNESLineSearch linesearch, pclinesearch;
3349: void *lsprectx, *lspostctx;
3350: PetscBool mf_operator, mf;
3351: Vec f, fpc;
3352: void *funcctx;
3353: void *jacctx, *appctx;
3354: Mat j, jpre;
3355: PetscErrorCode (*precheck)(SNESLineSearch, Vec, Vec, PetscBool *, PetscCtx);
3356: PetscErrorCode (*postcheck)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, PetscCtx);
3357: SNESFunctionFn *func;
3358: SNESJacobianFn *jac;
3360: PetscFunctionBegin;
3362: if (snes->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
3363: PetscCall(PetscLogEventBegin(SNES_SetUp, snes, 0, 0, 0));
3365: if (!((PetscObject)snes)->type_name) PetscCall(SNESSetType(snes, SNESNEWTONLS));
3367: PetscCall(SNESGetFunction(snes, &snes->vec_func, NULL, NULL));
3369: PetscCall(SNESGetDM(snes, &dm));
3370: PetscCall(DMGetDMSNES(dm, &sdm));
3371: PetscCall(SNESSetDefaultComputeJacobian(snes));
3373: if (!snes->vec_func) PetscCall(DMCreateGlobalVector(dm, &snes->vec_func));
3375: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
3377: if (snes->linesearch) {
3378: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
3379: PetscCall(SNESLineSearchSetFunction(snes->linesearch, SNESComputeFunction));
3380: }
3382: PetscCall(SNESGetUseMatrixFree(snes, &mf_operator, &mf));
3383: if (snes->npc && snes->npcside == PC_LEFT) {
3384: snes->mf = PETSC_TRUE;
3385: snes->mf_operator = PETSC_FALSE;
3386: }
3388: if (snes->npc) {
3389: /* copy the DM over */
3390: PetscCall(SNESGetDM(snes, &dm));
3391: PetscCall(SNESSetDM(snes->npc, dm));
3393: PetscCall(SNESGetFunction(snes, &f, &func, &funcctx));
3394: PetscCall(VecDuplicate(f, &fpc));
3395: PetscCall(SNESSetFunction(snes->npc, fpc, func, funcctx));
3396: PetscCall(SNESGetJacobian(snes, &j, &jpre, &jac, &jacctx));
3397: PetscCall(SNESSetJacobian(snes->npc, j, jpre, jac, jacctx));
3398: PetscCall(SNESGetApplicationContext(snes, &appctx));
3399: PetscCall(SNESSetApplicationContext(snes->npc, appctx));
3400: PetscCall(SNESSetUseMatrixFree(snes->npc, mf_operator, mf));
3401: PetscCall(VecDestroy(&fpc));
3403: /* copy the function pointers over */
3404: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)snes, (PetscObject)snes->npc));
3406: /* default to 1 iteration */
3407: PetscCall(SNESSetTolerances(snes->npc, 0.0, 0.0, 0.0, 1, snes->npc->max_funcs));
3408: if (snes->npcside == PC_RIGHT) {
3409: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_FINAL_ONLY));
3410: } else {
3411: PetscCall(SNESSetNormSchedule(snes->npc, SNES_NORM_NONE));
3412: }
3413: PetscCall(SNESSetFromOptions(snes->npc));
3415: /* copy the line search context over */
3416: if (snes->linesearch && snes->npc->linesearch) {
3417: PetscCall(SNESGetLineSearch(snes, &linesearch));
3418: PetscCall(SNESGetLineSearch(snes->npc, &pclinesearch));
3419: PetscCall(SNESLineSearchGetPreCheck(linesearch, &precheck, &lsprectx));
3420: PetscCall(SNESLineSearchGetPostCheck(linesearch, &postcheck, &lspostctx));
3421: PetscCall(SNESLineSearchSetPreCheck(pclinesearch, precheck, lsprectx));
3422: PetscCall(SNESLineSearchSetPostCheck(pclinesearch, postcheck, lspostctx));
3423: PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)linesearch, (PetscObject)pclinesearch));
3424: }
3425: }
3426: if (snes->mf) PetscCall(SNESSetUpMatrixFree_Private(snes, snes->mf_operator, snes->mf_version));
3427: if (snes->ops->ctxcompute && !snes->ctx) PetscCallBack("SNES callback compute application context", (*snes->ops->ctxcompute)(snes, &snes->ctx));
3429: snes->jac_iter = 0;
3430: snes->pre_iter = 0;
3432: PetscTryTypeMethod(snes, setup);
3434: PetscCall(SNESSetDefaultComputeJacobian(snes));
3436: if (snes->npc && snes->npcside == PC_LEFT) {
3437: if (snes->functype == SNES_FUNCTION_PRECONDITIONED) {
3438: if (snes->linesearch) {
3439: PetscCall(SNESGetLineSearch(snes, &linesearch));
3440: PetscCall(SNESLineSearchSetFunction(linesearch, SNESComputeFunctionDefaultNPC));
3441: }
3442: }
3443: }
3444: PetscCall(PetscLogEventEnd(SNES_SetUp, snes, 0, 0, 0));
3445: snes->setupcalled = PETSC_TRUE;
3446: PetscFunctionReturn(PETSC_SUCCESS);
3447: }
3449: /*@
3450: 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
3452: Collective
3454: Input Parameter:
3455: . snes - the nonlinear iterative solver context obtained from `SNESCreate()`
3457: Level: intermediate
3459: Notes:
3460: Any options set on the `SNES` object, including those set with `SNESSetFromOptions()` remain.
3462: Call this if you wish to reuse a `SNES` but with different size vectors
3464: Also calls the application context destroy routine set with `SNESSetComputeApplicationContext()`
3466: .seealso: [](ch_snes), `SNES`, `SNESDestroy()`, `SNESCreate()`, `SNESSetUp()`, `SNESSolve()`
3467: @*/
3468: PetscErrorCode SNESReset(SNES snes)
3469: {
3470: PetscFunctionBegin;
3472: if (snes->ops->ctxdestroy && snes->ctx) {
3473: PetscCallBack("SNES callback destroy application context", (*snes->ops->ctxdestroy)(&snes->ctx));
3474: snes->ctx = NULL;
3475: }
3476: if (snes->npc) PetscCall(SNESReset(snes->npc));
3478: PetscTryTypeMethod(snes, reset);
3479: if (snes->ksp) PetscCall(KSPReset(snes->ksp));
3481: if (snes->linesearch) PetscCall(SNESLineSearchReset(snes->linesearch));
3483: PetscCall(VecDestroy(&snes->vec_rhs));
3484: PetscCall(VecDestroy(&snes->vec_sol));
3485: PetscCall(VecDestroy(&snes->vec_sol_update));
3486: PetscCall(VecDestroy(&snes->vec_func));
3487: PetscCall(MatDestroy(&snes->jacobian));
3488: PetscCall(MatDestroy(&snes->jacobian_pre));
3489: PetscCall(MatDestroy(&snes->picard));
3490: PetscCall(VecDestroyVecs(snes->nwork, &snes->work));
3491: PetscCall(VecDestroyVecs(snes->nvwork, &snes->vwork));
3493: snes->alwayscomputesfinalresidual = PETSC_FALSE;
3495: snes->nwork = snes->nvwork = 0;
3496: snes->setupcalled = PETSC_FALSE;
3497: PetscFunctionReturn(PETSC_SUCCESS);
3498: }
3500: /*@
3501: SNESConvergedReasonViewCancel - Clears all the reason view functions for a `SNES` object provided with `SNESConvergedReasonViewSet()` also
3502: removes the default viewer.
3504: Collective
3506: Input Parameter:
3507: . snes - the nonlinear iterative solver context obtained from `SNESCreate()`
3509: Level: intermediate
3511: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESReset()`, `SNESConvergedReasonViewSet()`
3512: @*/
3513: PetscErrorCode SNESConvergedReasonViewCancel(SNES snes)
3514: {
3515: PetscInt i;
3517: PetscFunctionBegin;
3519: for (i = 0; i < snes->numberreasonviews; i++) {
3520: if (snes->reasonviewdestroy[i]) PetscCall((*snes->reasonviewdestroy[i])(&snes->reasonviewcontext[i]));
3521: }
3522: snes->numberreasonviews = 0;
3523: PetscCall(PetscViewerDestroy(&snes->convergedreasonviewer));
3524: PetscFunctionReturn(PETSC_SUCCESS);
3525: }
3527: /*@
3528: SNESDestroy - Destroys the nonlinear solver context that was created
3529: with `SNESCreate()`.
3531: Collective
3533: Input Parameter:
3534: . snes - the `SNES` context
3536: Level: beginner
3538: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESSolve()`
3539: @*/
3540: PetscErrorCode SNESDestroy(SNES *snes)
3541: {
3542: DM dm;
3544: PetscFunctionBegin;
3545: if (!*snes) PetscFunctionReturn(PETSC_SUCCESS);
3547: if (--((PetscObject)*snes)->refct > 0) {
3548: *snes = NULL;
3549: PetscFunctionReturn(PETSC_SUCCESS);
3550: }
3552: PetscCall(SNESReset(*snes));
3553: PetscCall(SNESDestroy(&(*snes)->npc));
3555: /* if memory was published with SAWs then destroy it */
3556: PetscCall(PetscObjectSAWsViewOff((PetscObject)*snes));
3557: PetscTryTypeMethod(*snes, destroy);
3559: dm = (*snes)->dm;
3560: while (dm) {
3561: PetscCall(DMCoarsenHookRemove(dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, *snes));
3562: PetscCall(DMGetCoarseDM(dm, &dm));
3563: }
3565: PetscCall(DMDestroy(&(*snes)->dm));
3566: PetscCall(KSPDestroy(&(*snes)->ksp));
3567: PetscCall(SNESLineSearchDestroy(&(*snes)->linesearch));
3569: PetscCall(PetscFree((*snes)->kspconvctx));
3570: if ((*snes)->ops->convergeddestroy) PetscCall((*(*snes)->ops->convergeddestroy)(&(*snes)->cnvP));
3571: if ((*snes)->conv_hist_alloc) PetscCall(PetscFree2((*snes)->conv_hist, (*snes)->conv_hist_its));
3572: PetscCall(SNESMonitorCancel(*snes));
3573: PetscCall(SNESConvergedReasonViewCancel(*snes));
3574: PetscCall(PetscHeaderDestroy(snes));
3575: PetscFunctionReturn(PETSC_SUCCESS);
3576: }
3578: /* ----------- Routines to set solver parameters ---------- */
3580: /*@
3581: SNESSetLagPreconditioner - Sets when the preconditioner is rebuilt in the nonlinear solve `SNESSolve()`.
3583: Logically Collective
3585: Input Parameters:
3586: + snes - the `SNES` context
3587: - lag - 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3588: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3590: Options Database Keys:
3591: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3592: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3593: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple `SNESSolve()`
3594: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3596: Level: intermediate
3598: Notes:
3599: The default is 1
3601: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagPreconditionerPersists()` was called
3603: `SNESSetLagPreconditionerPersists()` allows using the same uniform lagging (for example every second linear solve) across multiple nonlinear solves.
3605: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetLagPreconditionerPersists()`,
3606: `SNESSetLagJacobianPersists()`, `SNES`, `SNESSolve()`
3607: @*/
3608: PetscErrorCode SNESSetLagPreconditioner(SNES snes, PetscInt lag)
3609: {
3610: PetscFunctionBegin;
3612: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3613: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3615: snes->lagpreconditioner = lag;
3616: PetscFunctionReturn(PETSC_SUCCESS);
3617: }
3619: /*@
3620: SNESSetGridSequence - sets the number of steps of grid sequencing that `SNES` will do
3622: Logically Collective
3624: Input Parameters:
3625: + snes - the `SNES` context
3626: - steps - the number of refinements to do, defaults to 0
3628: Options Database Key:
3629: . -snes_grid_sequence <steps> - Use grid sequencing to generate initial guess
3631: Level: intermediate
3633: Notes:
3634: Once grid sequencing is turned on `SNESSolve()` will automatically perform the solve on each grid refinement.
3636: Use `SNESGetSolution()` to extract the fine grid solution after grid sequencing.
3638: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetGridSequence()`,
3639: `SNESSetDM()`, `SNESSolve()`
3640: @*/
3641: PetscErrorCode SNESSetGridSequence(SNES snes, PetscInt steps)
3642: {
3643: PetscFunctionBegin;
3646: snes->gridsequence = steps;
3647: PetscFunctionReturn(PETSC_SUCCESS);
3648: }
3650: /*@
3651: SNESGetGridSequence - gets the number of steps of grid sequencing that `SNES` will do
3653: Logically Collective
3655: Input Parameter:
3656: . snes - the `SNES` context
3658: Output Parameter:
3659: . steps - the number of refinements to do, defaults to 0
3661: Level: intermediate
3663: .seealso: [](ch_snes), `SNESGetLagPreconditioner()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESSetGridSequence()`
3664: @*/
3665: PetscErrorCode SNESGetGridSequence(SNES snes, PetscInt *steps)
3666: {
3667: PetscFunctionBegin;
3669: *steps = snes->gridsequence;
3670: PetscFunctionReturn(PETSC_SUCCESS);
3671: }
3673: /*@
3674: SNESGetLagPreconditioner - Return how often the preconditioner is rebuilt
3676: Not Collective
3678: Input Parameter:
3679: . snes - the `SNES` context
3681: Output Parameter:
3682: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3683: the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that
3685: Level: intermediate
3687: Notes:
3688: The default is 1
3690: The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3692: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3693: @*/
3694: PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)
3695: {
3696: PetscFunctionBegin;
3698: *lag = snes->lagpreconditioner;
3699: PetscFunctionReturn(PETSC_SUCCESS);
3700: }
3702: /*@
3703: SNESSetLagJacobian - Set when the Jacobian is rebuilt in the nonlinear solve. See `SNESSetLagPreconditioner()` for determining how
3704: often the preconditioner is rebuilt.
3706: Logically Collective
3708: Input Parameters:
3709: + snes - the `SNES` context
3710: - lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3711: the Jacobian is built etc. -2 means rebuild at next chance but then never again
3713: Options Database Keys:
3714: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3715: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3716: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3717: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag.
3719: Level: intermediate
3721: Notes:
3722: The default is 1
3724: The Jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1
3726: 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
3727: at the next Newton step but never again (unless it is reset to another value)
3729: .seealso: [](ch_snes), `SNES`, `SNESGetLagPreconditioner()`, `SNESSetLagPreconditioner()`, `SNESGetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3730: @*/
3731: PetscErrorCode SNESSetLagJacobian(SNES snes, PetscInt lag)
3732: {
3733: PetscFunctionBegin;
3735: PetscCheck(lag >= -2, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag must be -2, -1, 1 or greater");
3736: PetscCheck(lag, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Lag cannot be 0");
3738: snes->lagjacobian = lag;
3739: PetscFunctionReturn(PETSC_SUCCESS);
3740: }
3742: /*@
3743: SNESGetLagJacobian - Get how often the Jacobian is rebuilt. See `SNESGetLagPreconditioner()` to determine when the preconditioner is rebuilt
3745: Not Collective
3747: Input Parameter:
3748: . snes - the `SNES` context
3750: Output Parameter:
3751: . lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time
3752: the Jacobian is built etc.
3754: Level: intermediate
3756: Notes:
3757: The default is 1
3759: The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or `SNESSetLagJacobianPersists()` was called.
3761: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobian()`, `SNESSetLagPreconditioner()`, `SNESGetLagPreconditioner()`, `SNESSetLagJacobianPersists()`, `SNESSetLagPreconditionerPersists()`
3763: @*/
3764: PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
3765: {
3766: PetscFunctionBegin;
3768: *lag = snes->lagjacobian;
3769: PetscFunctionReturn(PETSC_SUCCESS);
3770: }
3772: /*@
3773: SNESSetLagJacobianPersists - Set whether or not the Jacobian lagging persists through multiple nonlinear solves
3775: Logically collective
3777: Input Parameters:
3778: + snes - the `SNES` context
3779: - flg - jacobian lagging persists if true
3781: Options Database Keys:
3782: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3783: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3784: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3785: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3787: Level: advanced
3789: Notes:
3790: Normally when `SNESSetLagJacobian()` is used, the Jacobian is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3792: This is useful both for nonlinear preconditioning, where it's appropriate to have the Jacobian be stale by
3793: several solves, and for implicit time-stepping, where Jacobian lagging in the inner nonlinear solve over several
3794: timesteps may present huge efficiency gains.
3796: .seealso: [](ch_snes), `SNES`, `SNESSetLagPreconditionerPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`
3797: @*/
3798: PetscErrorCode SNESSetLagJacobianPersists(SNES snes, PetscBool flg)
3799: {
3800: PetscFunctionBegin;
3803: snes->lagjac_persist = flg;
3804: PetscFunctionReturn(PETSC_SUCCESS);
3805: }
3807: /*@
3808: SNESSetLagPreconditionerPersists - Set whether or not the preconditioner lagging persists through multiple nonlinear solves
3810: Logically Collective
3812: Input Parameters:
3813: + snes - the `SNES` context
3814: - flg - preconditioner lagging persists if true
3816: Options Database Keys:
3817: + -snes_lag_jacobian_persists <true,false> - sets the persistence through multiple SNES solves
3818: . -snes_lag_jacobian <-2,1,2,...> - sets the lag
3819: . -snes_lag_preconditioner_persists <true,false> - sets the persistence through multiple SNES solves
3820: - -snes_lag_preconditioner <-2,1,2,...> - sets the lag
3822: Level: developer
3824: Notes:
3825: Normally when `SNESSetLagPreconditioner()` is used, the preconditioner is always rebuilt at the beginning of each new nonlinear solve, this removes that behavior
3827: This is useful both for nonlinear preconditioning, where it's appropriate to have the preconditioner be stale
3828: by several solves, and for implicit time-stepping, where preconditioner lagging in the inner nonlinear solve over
3829: several timesteps may present huge efficiency gains.
3831: .seealso: [](ch_snes), `SNES`, `SNESSetLagJacobianPersists()`, `SNESSetLagJacobian()`, `SNESGetLagJacobian()`, `SNESGetNPC()`, `SNESSetLagPreconditioner()`
3832: @*/
3833: PetscErrorCode SNESSetLagPreconditionerPersists(SNES snes, PetscBool flg)
3834: {
3835: PetscFunctionBegin;
3838: snes->lagpre_persist = flg;
3839: PetscFunctionReturn(PETSC_SUCCESS);
3840: }
3842: /*@
3843: SNESSetForceIteration - force `SNESSolve()` to take at least one iteration regardless of the initial residual norm
3845: Logically Collective
3847: Input Parameters:
3848: + snes - the `SNES` context
3849: - force - `PETSC_TRUE` require at least one iteration
3851: Options Database Key:
3852: . -snes_force_iteration <force> - Sets forcing an iteration
3854: Level: intermediate
3856: Note:
3857: This is used sometimes with `TS` to prevent `TS` from detecting a false steady state solution
3859: .seealso: [](ch_snes), `SNES`, `TS`, `SNESSetDivergenceTolerance()`
3860: @*/
3861: PetscErrorCode SNESSetForceIteration(SNES snes, PetscBool force)
3862: {
3863: PetscFunctionBegin;
3865: snes->forceiteration = force;
3866: PetscFunctionReturn(PETSC_SUCCESS);
3867: }
3869: /*@
3870: SNESGetForceIteration - Check whether or not `SNESSolve()` take at least one iteration regardless of the initial residual norm
3872: Logically Collective
3874: Input Parameter:
3875: . snes - the `SNES` context
3877: Output Parameter:
3878: . force - `PETSC_TRUE` requires at least one iteration.
3880: Level: intermediate
3882: .seealso: [](ch_snes), `SNES`, `SNESSetForceIteration()`, `SNESSetDivergenceTolerance()`
3883: @*/
3884: PetscErrorCode SNESGetForceIteration(SNES snes, PetscBool *force)
3885: {
3886: PetscFunctionBegin;
3888: *force = snes->forceiteration;
3889: PetscFunctionReturn(PETSC_SUCCESS);
3890: }
3892: /*@
3893: SNESSetTolerances - Sets various parameters used in `SNES` convergence tests.
3895: Logically Collective
3897: Input Parameters:
3898: + snes - the `SNES` context
3899: . abstol - the absolute convergence tolerance, $ F(x^n) \le abstol $
3900: . rtol - the relative convergence tolerance, $ F(x^n) \le reltol * F(x^0) $
3901: . stol - convergence tolerance in terms of the norm of the change in the solution between steps, || delta x || < stol*|| x ||
3902: . maxit - the maximum number of iterations allowed in the solver, default 50.
3903: - maxf - the maximum number of function evaluations allowed in the solver (use `PETSC_UNLIMITED` indicates no limit), default 10,000
3905: Options Database Keys:
3906: + -snes_atol <abstol> - Sets `abstol`
3907: . -snes_rtol <rtol> - Sets `rtol`
3908: . -snes_stol <stol> - Sets `stol`
3909: . -snes_max_it <maxit> - Sets `maxit`
3910: - -snes_max_funcs <maxf> - Sets `maxf` (use `unlimited` to have no maximum)
3912: Level: intermediate
3914: Note:
3915: All parameters must be non-negative
3917: Use `PETSC_CURRENT` to retain the current value of any parameter and `PETSC_DETERMINE` to use the default value for the given `SNES`.
3918: The default value is the value in the object when its type is set.
3920: Use `PETSC_UNLIMITED` on `maxit` or `maxf` to indicate there is no bound on the number of iterations or number of function evaluations.
3922: Fortran Note:
3923: Use `PETSC_CURRENT_INTEGER`, `PETSC_CURRENT_REAL`, `PETSC_UNLIMITED_INTEGER`, `PETSC_DETERMINE_INTEGER`, or `PETSC_DETERMINE_REAL`
3925: .seealso: [](ch_snes), `SNESSolve()`, `SNES`, `SNESSetDivergenceTolerance()`, `SNESSetForceIteration()`
3926: @*/
3927: PetscErrorCode SNESSetTolerances(SNES snes, PetscReal abstol, PetscReal rtol, PetscReal stol, PetscInt maxit, PetscInt maxf)
3928: {
3929: PetscFunctionBegin;
3937: if (abstol == (PetscReal)PETSC_DETERMINE) {
3938: snes->abstol = snes->default_abstol;
3939: } else if (abstol != (PetscReal)PETSC_CURRENT) {
3940: PetscCheck(abstol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Absolute tolerance %g must be non-negative", (double)abstol);
3941: snes->abstol = abstol;
3942: }
3944: if (rtol == (PetscReal)PETSC_DETERMINE) {
3945: snes->rtol = snes->default_rtol;
3946: } else if (rtol != (PetscReal)PETSC_CURRENT) {
3947: 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);
3948: snes->rtol = rtol;
3949: }
3951: if (stol == (PetscReal)PETSC_DETERMINE) {
3952: snes->stol = snes->default_stol;
3953: } else if (stol != (PetscReal)PETSC_CURRENT) {
3954: PetscCheck(stol >= 0.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Step tolerance %g must be non-negative", (double)stol);
3955: snes->stol = stol;
3956: }
3958: if (maxit == PETSC_DETERMINE) {
3959: snes->max_its = snes->default_max_its;
3960: } else if (maxit == PETSC_UNLIMITED) {
3961: snes->max_its = PETSC_INT_MAX;
3962: } else if (maxit != PETSC_CURRENT) {
3963: PetscCheck(maxit >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of iterations %" PetscInt_FMT " must be non-negative", maxit);
3964: snes->max_its = maxit;
3965: }
3967: if (maxf == PETSC_DETERMINE) {
3968: snes->max_funcs = snes->default_max_funcs;
3969: } else if (maxf == PETSC_UNLIMITED || maxf == -1) {
3970: snes->max_funcs = PETSC_UNLIMITED;
3971: } else if (maxf != PETSC_CURRENT) {
3972: PetscCheck(maxf >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Maximum number of function evaluations %" PetscInt_FMT " must be nonnegative", maxf);
3973: snes->max_funcs = maxf;
3974: }
3975: PetscFunctionReturn(PETSC_SUCCESS);
3976: }
3978: /*@
3979: SNESSetDivergenceTolerance - Sets the divergence tolerance used for the `SNES` divergence test.
3981: Logically Collective
3983: Input Parameters:
3984: + snes - the `SNES` context
3985: - 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
3986: is stopped due to divergence.
3988: Options Database Key:
3989: . -snes_divergence_tolerance <divtol> - Sets `divtol`
3991: Level: intermediate
3993: Notes:
3994: Use `PETSC_DETERMINE` to use the default value from when the object's type was set.
3996: Fortran Note:
3997: Use ``PETSC_DETERMINE_REAL` or `PETSC_UNLIMITED_REAL`
3999: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetTolerances()`, `SNESGetDivergenceTolerance()`
4000: @*/
4001: PetscErrorCode SNESSetDivergenceTolerance(SNES snes, PetscReal divtol)
4002: {
4003: PetscFunctionBegin;
4007: if (divtol == (PetscReal)PETSC_DETERMINE) {
4008: snes->divtol = snes->default_divtol;
4009: } else if (divtol == (PetscReal)PETSC_UNLIMITED || divtol == -1) {
4010: snes->divtol = PETSC_UNLIMITED;
4011: } else if (divtol != (PetscReal)PETSC_CURRENT) {
4012: PetscCheck(divtol >= 1.0, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "Divergence tolerance %g must be greater than 1.0", (double)divtol);
4013: snes->divtol = divtol;
4014: }
4015: PetscFunctionReturn(PETSC_SUCCESS);
4016: }
4018: /*@
4019: SNESGetTolerances - Gets various parameters used in `SNES` convergence tests.
4021: Not Collective
4023: Input Parameter:
4024: . snes - the `SNES` context
4026: Output Parameters:
4027: + atol - the absolute convergence tolerance
4028: . rtol - the relative convergence tolerance
4029: . stol - convergence tolerance in terms of the norm of the change in the solution between steps
4030: . maxit - the maximum number of iterations allowed
4031: - maxf - the maximum number of function evaluations allowed, `PETSC_UNLIMITED` indicates no bound
4033: Level: intermediate
4035: Notes:
4036: See `SNESSetTolerances()` for details on the parameters.
4038: The user can specify `NULL` for any parameter that is not needed.
4040: .seealso: [](ch_snes), `SNES`, `SNESSetTolerances()`
4041: @*/
4042: PetscErrorCode SNESGetTolerances(SNES snes, PetscReal *atol, PetscReal *rtol, PetscReal *stol, PetscInt *maxit, PetscInt *maxf)
4043: {
4044: PetscFunctionBegin;
4046: if (atol) *atol = snes->abstol;
4047: if (rtol) *rtol = snes->rtol;
4048: if (stol) *stol = snes->stol;
4049: if (maxit) *maxit = snes->max_its;
4050: if (maxf) *maxf = snes->max_funcs;
4051: PetscFunctionReturn(PETSC_SUCCESS);
4052: }
4054: /*@
4055: SNESGetDivergenceTolerance - Gets divergence tolerance used in divergence test.
4057: Not Collective
4059: Input Parameters:
4060: + snes - the `SNES` context
4061: - divtol - divergence tolerance
4063: Level: intermediate
4065: .seealso: [](ch_snes), `SNES`, `SNESSetDivergenceTolerance()`
4066: @*/
4067: PetscErrorCode SNESGetDivergenceTolerance(SNES snes, PetscReal *divtol)
4068: {
4069: PetscFunctionBegin;
4071: if (divtol) *divtol = snes->divtol;
4072: PetscFunctionReturn(PETSC_SUCCESS);
4073: }
4075: PETSC_INTERN PetscErrorCode SNESMonitorRange_Private(SNES, PetscInt, PetscReal *);
4077: PetscErrorCode SNESMonitorLGRange(SNES snes, PetscInt n, PetscReal rnorm, PetscCtx monctx)
4078: {
4079: PetscDrawLG lg;
4080: PetscReal x, y, per;
4081: PetscViewer v = (PetscViewer)monctx;
4082: static PetscReal prev; /* should be in the context */
4083: PetscDraw draw;
4085: PetscFunctionBegin;
4087: PetscCall(PetscViewerDrawGetDrawLG(v, 0, &lg));
4088: if (!n) PetscCall(PetscDrawLGReset(lg));
4089: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4090: PetscCall(PetscDrawSetTitle(draw, "Residual norm"));
4091: x = (PetscReal)n;
4092: if (rnorm > 0.0) y = PetscLog10Real(rnorm);
4093: else y = -15.0;
4094: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4095: if (n < 20 || !(n % 5) || snes->reason) {
4096: PetscCall(PetscDrawLGDraw(lg));
4097: PetscCall(PetscDrawLGSave(lg));
4098: }
4100: PetscCall(PetscViewerDrawGetDrawLG(v, 1, &lg));
4101: if (!n) PetscCall(PetscDrawLGReset(lg));
4102: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4103: PetscCall(PetscDrawSetTitle(draw, "% elements > .2*max element"));
4104: PetscCall(SNESMonitorRange_Private(snes, n, &per));
4105: x = (PetscReal)n;
4106: y = 100.0 * per;
4107: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4108: if (n < 20 || !(n % 5) || snes->reason) {
4109: PetscCall(PetscDrawLGDraw(lg));
4110: PetscCall(PetscDrawLGSave(lg));
4111: }
4113: PetscCall(PetscViewerDrawGetDrawLG(v, 2, &lg));
4114: if (!n) {
4115: prev = rnorm;
4116: PetscCall(PetscDrawLGReset(lg));
4117: }
4118: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4119: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm"));
4120: x = (PetscReal)n;
4121: y = (prev - rnorm) / prev;
4122: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4123: if (n < 20 || !(n % 5) || snes->reason) {
4124: PetscCall(PetscDrawLGDraw(lg));
4125: PetscCall(PetscDrawLGSave(lg));
4126: }
4128: PetscCall(PetscViewerDrawGetDrawLG(v, 3, &lg));
4129: if (!n) PetscCall(PetscDrawLGReset(lg));
4130: PetscCall(PetscDrawLGGetDraw(lg, &draw));
4131: PetscCall(PetscDrawSetTitle(draw, "(norm -oldnorm)/oldnorm*(% > .2 max)"));
4132: x = (PetscReal)n;
4133: y = (prev - rnorm) / (prev * per);
4134: if (n > 2) { /*skip initial crazy value */
4135: PetscCall(PetscDrawLGAddPoint(lg, &x, &y));
4136: }
4137: if (n < 20 || !(n % 5) || snes->reason) {
4138: PetscCall(PetscDrawLGDraw(lg));
4139: PetscCall(PetscDrawLGSave(lg));
4140: }
4141: prev = rnorm;
4142: PetscFunctionReturn(PETSC_SUCCESS);
4143: }
4145: /*@
4146: SNESConverged - Run the convergence test and update the `SNESConvergedReason`.
4148: Collective
4150: Input Parameters:
4151: + snes - the `SNES` context
4152: . it - current iteration
4153: . xnorm - 2-norm of current iterate
4154: . snorm - 2-norm of current step
4155: - fnorm - 2-norm of function
4157: Level: developer
4159: Note:
4160: This routine is called by the `SNESSolve()` implementations.
4161: It does not typically need to be called by the user.
4163: .seealso: [](ch_snes), `SNES`, `SNESSolve`, `SNESSetConvergenceTest()`
4164: @*/
4165: PetscErrorCode SNESConverged(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm)
4166: {
4167: PetscFunctionBegin;
4168: if (!snes->reason) {
4169: if (snes->normschedule == SNES_NORM_ALWAYS) PetscUseTypeMethod(snes, converged, it, xnorm, snorm, fnorm, &snes->reason, snes->cnvP);
4170: if (it == snes->max_its && !snes->reason) {
4171: if (snes->normschedule == SNES_NORM_ALWAYS) {
4172: PetscCall(PetscInfo(snes, "Maximum number of iterations has been reached: %" PetscInt_FMT "\n", snes->max_its));
4173: snes->reason = SNES_DIVERGED_MAX_IT;
4174: } else snes->reason = SNES_CONVERGED_ITS;
4175: }
4176: }
4177: PetscFunctionReturn(PETSC_SUCCESS);
4178: }
4180: /*@
4181: SNESMonitor - runs any `SNES` monitor routines provided with `SNESMonitor()` or the options database
4183: Collective
4185: Input Parameters:
4186: + snes - nonlinear solver context obtained from `SNESCreate()`
4187: . iter - current iteration number
4188: - rnorm - current relative norm of the residual
4190: Level: developer
4192: Note:
4193: This routine is called by the `SNESSolve()` implementations.
4194: It does not typically need to be called by the user.
4196: .seealso: [](ch_snes), `SNES`, `SNESMonitorSet()`
4197: @*/
4198: PetscErrorCode SNESMonitor(SNES snes, PetscInt iter, PetscReal rnorm)
4199: {
4200: PetscInt i, n = snes->numbermonitors;
4202: PetscFunctionBegin;
4203: PetscCall(VecLockReadPush(snes->vec_sol));
4204: for (i = 0; i < n; i++) PetscCall((*snes->monitor[i])(snes, iter, rnorm, snes->monitorcontext[i]));
4205: PetscCall(VecLockReadPop(snes->vec_sol));
4206: PetscFunctionReturn(PETSC_SUCCESS);
4207: }
4209: /* ------------ Routines to set performance monitoring options ----------- */
4211: /*MC
4212: SNESMonitorFunction - functional form passed to `SNESMonitorSet()` to monitor convergence of nonlinear solver
4214: Synopsis:
4215: #include <petscsnes.h>
4216: PetscErrorCode SNESMonitorFunction(SNES snes, PetscInt its, PetscReal norm, PetscCtx mctx)
4218: Collective
4220: Input Parameters:
4221: + snes - the `SNES` context
4222: . its - iteration number
4223: . norm - 2-norm function value (may be estimated)
4224: - mctx - [optional] monitoring context
4226: Level: advanced
4228: .seealso: [](ch_snes), `SNESMonitorSet()`, `PetscCtx`
4229: M*/
4231: /*@C
4232: SNESMonitorSet - Sets an ADDITIONAL function that is to be used at every
4233: iteration of the `SNES` nonlinear solver to display the iteration's
4234: progress.
4236: Logically Collective
4238: Input Parameters:
4239: + snes - the `SNES` context
4240: . f - the monitor function, for the calling sequence see `SNESMonitorFunction`
4241: . mctx - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
4242: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence
4244: Calling sequence of f:
4245: + snes - the `SNES` object
4246: . it - the current iteration
4247: . rnorm - norm of the residual
4248: - mctx - the optional monitor context
4250: Options Database Keys:
4251: + -snes_monitor - sets `SNESMonitorDefault()`
4252: . -snes_monitor draw::draw_lg - sets line graph monitor,
4253: - -snes_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `SNESMonitorSet()`, but does not cancel those set via
4254: the options database.
4256: Level: intermediate
4258: Note:
4259: Several different monitoring routines may be set by calling
4260: `SNESMonitorSet()` multiple times; all will be called in the
4261: order in which they were set.
4263: Fortran Note:
4264: Only a single monitor function can be set for each `SNES` object
4266: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESMonitorDefault()`, `SNESMonitorCancel()`, `SNESMonitorFunction`, `PetscCtxDestroyFn`
4267: @*/
4268: PetscErrorCode SNESMonitorSet(SNES snes, PetscErrorCode (*f)(SNES snes, PetscInt it, PetscReal rnorm, PetscCtx mctx), PetscCtx mctx, PetscCtxDestroyFn *monitordestroy)
4269: {
4270: PetscFunctionBegin;
4272: for (PetscInt i = 0; i < snes->numbermonitors; i++) {
4273: PetscBool identical;
4275: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))(PetscVoidFn *)f, mctx, monitordestroy, (PetscErrorCode (*)(void))(PetscVoidFn *)snes->monitor[i], snes->monitorcontext[i], snes->monitordestroy[i], &identical));
4276: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4277: }
4278: PetscCheck(snes->numbermonitors < MAXSNESMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
4279: snes->monitor[snes->numbermonitors] = f;
4280: snes->monitordestroy[snes->numbermonitors] = monitordestroy;
4281: snes->monitorcontext[snes->numbermonitors++] = mctx;
4282: PetscFunctionReturn(PETSC_SUCCESS);
4283: }
4285: /*@
4286: SNESMonitorCancel - Clears all the monitor functions for a `SNES` object.
4288: Logically Collective
4290: Input Parameter:
4291: . snes - the `SNES` context
4293: Options Database Key:
4294: . -snes_monitor_cancel - cancels all monitors that have been hardwired
4295: into a code by calls to `SNESMonitorSet()`, but does not cancel those
4296: set via the options database
4298: Level: intermediate
4300: Note:
4301: There is no way to clear one specific monitor from a `SNES` object.
4303: .seealso: [](ch_snes), `SNES`, `SNESMonitorDefault()`, `SNESMonitorSet()`
4304: @*/
4305: PetscErrorCode SNESMonitorCancel(SNES snes)
4306: {
4307: PetscInt i;
4309: PetscFunctionBegin;
4311: for (i = 0; i < snes->numbermonitors; i++) {
4312: if (snes->monitordestroy[i]) PetscCall((*snes->monitordestroy[i])(&snes->monitorcontext[i]));
4313: }
4314: snes->numbermonitors = 0;
4315: PetscFunctionReturn(PETSC_SUCCESS);
4316: }
4318: /*@C
4319: SNESSetConvergenceTest - Sets the function that is to be used
4320: to test for convergence of the nonlinear iterative solution.
4322: Logically Collective
4324: Input Parameters:
4325: + snes - the `SNES` context
4326: . func - routine to test for convergence
4327: . ctx - [optional] context for private data for the convergence routine (may be `NULL`)
4328: - destroy - [optional] destructor for the context (may be `NULL`; `PETSC_NULL_FUNCTION` in Fortran)
4330: Calling sequence of func:
4331: + snes - the `SNES` context
4332: . it - the current iteration number
4333: . xnorm - the norm of the new solution
4334: . snorm - the norm of the step
4335: . fnorm - the norm of the function value
4336: . reason - output, the reason convergence or divergence as declared
4337: - ctx - the optional convergence test context
4339: Level: advanced
4341: .seealso: [](ch_snes), `SNES`, `SNESConvergedDefault()`, `SNESConvergedSkip()`
4342: @*/
4343: PetscErrorCode SNESSetConvergenceTest(SNES snes, PetscErrorCode (*func)(SNES snes, PetscInt it, PetscReal xnorm, PetscReal snorm, PetscReal fnorm, SNESConvergedReason *reason, PetscCtx ctx), PetscCtx ctx, PetscCtxDestroyFn *destroy)
4344: {
4345: PetscFunctionBegin;
4347: if (!func) func = SNESConvergedSkip;
4348: if (snes->ops->convergeddestroy) PetscCall((*snes->ops->convergeddestroy)(&snes->cnvP));
4349: snes->ops->converged = func;
4350: snes->ops->convergeddestroy = destroy;
4351: snes->cnvP = ctx;
4352: PetscFunctionReturn(PETSC_SUCCESS);
4353: }
4355: /*@
4356: SNESGetConvergedReason - Gets the reason the `SNES` iteration was stopped, which may be due to convergence, divergence, or stagnation
4358: Not Collective
4360: Input Parameter:
4361: . snes - the `SNES` context
4363: Output Parameter:
4364: . reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` for the individual convergence tests for complete lists
4366: Options Database Key:
4367: . -snes_converged_reason - prints the reason to standard out
4369: Level: intermediate
4371: Note:
4372: Should only be called after the call the `SNESSolve()` is complete, if it is called earlier it returns the value `SNES__CONVERGED_ITERATING`.
4374: .seealso: [](ch_snes), `SNESSolve()`, `SNESSetConvergenceTest()`, `SNESSetConvergedReason()`, `SNESConvergedReason`, `SNESGetConvergedReasonString()`
4375: @*/
4376: PetscErrorCode SNESGetConvergedReason(SNES snes, SNESConvergedReason *reason)
4377: {
4378: PetscFunctionBegin;
4380: PetscAssertPointer(reason, 2);
4381: *reason = snes->reason;
4382: PetscFunctionReturn(PETSC_SUCCESS);
4383: }
4385: /*@C
4386: SNESGetConvergedReasonString - Return a human readable string for `SNESConvergedReason`
4388: Not Collective
4390: Input Parameter:
4391: . snes - the `SNES` context
4393: Output Parameter:
4394: . strreason - a human readable string that describes `SNES` converged reason
4396: Level: beginner
4398: .seealso: [](ch_snes), `SNES`, `SNESGetConvergedReason()`
4399: @*/
4400: PetscErrorCode SNESGetConvergedReasonString(SNES snes, const char **strreason)
4401: {
4402: PetscFunctionBegin;
4404: PetscAssertPointer(strreason, 2);
4405: *strreason = SNESConvergedReasons[snes->reason];
4406: PetscFunctionReturn(PETSC_SUCCESS);
4407: }
4409: /*@
4410: SNESSetConvergedReason - Sets the reason the `SNES` iteration was stopped.
4412: Not Collective
4414: Input Parameters:
4415: + snes - the `SNES` context
4416: - reason - negative value indicates diverged, positive value converged, see `SNESConvergedReason` or the
4417: manual pages for the individual convergence tests for complete lists
4419: Level: developer
4421: Developer Note:
4422: Called inside the various `SNESSolve()` implementations
4424: .seealso: [](ch_snes), `SNESGetConvergedReason()`, `SNESSetConvergenceTest()`, `SNESConvergedReason`
4425: @*/
4426: PetscErrorCode SNESSetConvergedReason(SNES snes, SNESConvergedReason reason)
4427: {
4428: PetscFunctionBegin;
4430: PetscCheck(!snes->errorifnotconverged || reason > 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_PLIB, "SNES code should have previously errored due to negative reason");
4431: snes->reason = reason;
4432: PetscFunctionReturn(PETSC_SUCCESS);
4433: }
4435: /*@
4436: SNESSetConvergenceHistory - Sets the arrays used to hold the convergence history.
4438: Logically Collective
4440: Input Parameters:
4441: + snes - iterative context obtained from `SNESCreate()`
4442: . a - array to hold history, this array will contain the function norms computed at each step
4443: . its - integer array holds the number of linear iterations for each solve.
4444: . na - size of `a` and `its`
4445: - reset - `PETSC_TRUE` indicates each new nonlinear solve resets the history counter to zero,
4446: else it continues storing new values for new nonlinear solves after the old ones
4448: Level: intermediate
4450: Notes:
4451: If 'a' and 'its' are `NULL` then space is allocated for the history. If 'na' is `PETSC_DECIDE` (or, deprecated, `PETSC_DEFAULT`) then a
4452: default array of length 1,000 is allocated.
4454: This routine is useful, e.g., when running a code for purposes
4455: of accurate performance monitoring, when no I/O should be done
4456: during the section of code that is being timed.
4458: If the arrays run out of space after a number of iterations then the later values are not saved in the history
4460: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergenceHistory()`
4461: @*/
4462: PetscErrorCode SNESSetConvergenceHistory(SNES snes, PetscReal a[], PetscInt its[], PetscInt na, PetscBool reset)
4463: {
4464: PetscFunctionBegin;
4466: if (a) PetscAssertPointer(a, 2);
4467: if (its) PetscAssertPointer(its, 3);
4468: if (!a) {
4469: if (na == PETSC_DECIDE) na = 1000;
4470: PetscCall(PetscCalloc2(na, &a, na, &its));
4471: snes->conv_hist_alloc = PETSC_TRUE;
4472: }
4473: snes->conv_hist = a;
4474: snes->conv_hist_its = its;
4475: snes->conv_hist_max = (size_t)na;
4476: snes->conv_hist_len = 0;
4477: snes->conv_hist_reset = reset;
4478: PetscFunctionReturn(PETSC_SUCCESS);
4479: }
4481: #if defined(PETSC_HAVE_MATLAB)
4482: #include <engine.h> /* MATLAB include file */
4483: #include <mex.h> /* MATLAB include file */
4485: PETSC_EXTERN mxArray *SNESGetConvergenceHistoryMatlab(SNES snes)
4486: {
4487: mxArray *mat;
4488: PetscInt i;
4489: PetscReal *ar;
4491: mat = mxCreateDoubleMatrix(snes->conv_hist_len, 1, mxREAL);
4492: ar = (PetscReal *)mxGetData(mat);
4493: for (i = 0; i < snes->conv_hist_len; i++) ar[i] = snes->conv_hist[i];
4494: return mat;
4495: }
4496: #endif
4498: /*@C
4499: SNESGetConvergenceHistory - Gets the arrays used to hold the convergence history.
4501: Not Collective
4503: Input Parameter:
4504: . snes - iterative context obtained from `SNESCreate()`
4506: Output Parameters:
4507: + a - array to hold history, usually was set with `SNESSetConvergenceHistory()`
4508: . its - integer array holds the number of linear iterations (or
4509: negative if not converged) for each solve.
4510: - na - size of `a` and `its`
4512: Level: intermediate
4514: Note:
4515: This routine is useful, e.g., when running a code for purposes
4516: of accurate performance monitoring, when no I/O should be done
4517: during the section of code that is being timed.
4519: Fortran Notes:
4520: Return the arrays with ``SNESRestoreConvergenceHistory()`
4522: Use the arguments
4523: .vb
4524: PetscReal, pointer :: a(:)
4525: PetscInt, pointer :: its(:)
4526: .ve
4528: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetConvergenceHistory()`
4529: @*/
4530: PetscErrorCode SNESGetConvergenceHistory(SNES snes, PetscReal *a[], PetscInt *its[], PetscInt *na)
4531: {
4532: PetscFunctionBegin;
4534: if (a) *a = snes->conv_hist;
4535: if (its) *its = snes->conv_hist_its;
4536: if (na) *na = (PetscInt)snes->conv_hist_len;
4537: PetscFunctionReturn(PETSC_SUCCESS);
4538: }
4540: /*@C
4541: SNESSetUpdate - Sets the general-purpose update function called
4542: at the beginning of every iteration of the nonlinear solve. Specifically
4543: it is called just before the Jacobian is "evaluated" and after the function
4544: evaluation.
4546: Logically Collective
4548: Input Parameters:
4549: + snes - The nonlinear solver context
4550: - func - The update function; for calling sequence see `SNESUpdateFn`
4552: Level: advanced
4554: Notes:
4555: 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
4556: to `SNESSetFunction()`, or `SNESSetPicard()`
4557: This is not used by most users, and it is intended to provide a general hook that is run
4558: right before the direction step is computed.
4560: Users are free to modify the current residual vector,
4561: the current linearization point, or any other vector associated to the specific solver used.
4562: If such modifications take place, it is the user responsibility to update all the relevant
4563: vectors. For example, if one is adjusting the model parameters at each Newton step their code may look like
4564: .vb
4565: PetscErrorCode update(SNES snes, PetscInt iteration)
4566: {
4567: PetscFunctionBeginUser;
4568: if (iteration > 0) {
4569: // update the model parameters here
4570: Vec x,f;
4571: PetscCall(SNESGetSolution(snes,&x));
4572: PetcCall(SNESGetFunction(snes,&f,NULL,NULL));
4573: PetscCall(SNESComputeFunction(snes,x,f));
4574: }
4575: PetscFunctionReturn(PETSC_SUCCESS);
4576: }
4577: .ve
4579: 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.
4581: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetJacobian()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchSetPostCheck()`, `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRSetPostCheck()`,
4582: `SNESMonitorSet()`
4583: @*/
4584: PetscErrorCode SNESSetUpdate(SNES snes, SNESUpdateFn *func)
4585: {
4586: PetscFunctionBegin;
4588: snes->ops->update = func;
4589: PetscFunctionReturn(PETSC_SUCCESS);
4590: }
4592: /*@
4593: SNESConvergedReasonView - Displays the reason a `SNES` solve converged or diverged to a viewer
4595: Collective
4597: Input Parameters:
4598: + snes - iterative context obtained from `SNESCreate()`
4599: - viewer - the viewer to display the reason
4601: Options Database Keys:
4602: + -snes_converged_reason - print reason for converged or diverged, also prints number of iterations
4603: - -snes_converged_reason ::failed - only print reason and number of iterations when diverged
4605: Level: beginner
4607: Note:
4608: To change the format of the output call `PetscViewerPushFormat`(viewer,format) before this call. Use `PETSC_VIEWER_DEFAULT` for the default,
4609: use `PETSC_VIEWER_FAILED` to only display a reason if it fails.
4611: .seealso: [](ch_snes), `SNESConvergedReason`, `PetscViewer`, `SNES`,
4612: `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`, `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`,
4613: `SNESConvergedReasonViewFromOptions()`,
4614: `PetscViewerPushFormat()`, `PetscViewerPopFormat()`
4615: @*/
4616: PetscErrorCode SNESConvergedReasonView(SNES snes, PetscViewer viewer)
4617: {
4618: PetscViewerFormat format;
4619: PetscBool isAscii;
4621: PetscFunctionBegin;
4622: if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes));
4623: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isAscii));
4624: if (isAscii) {
4625: PetscCall(PetscViewerGetFormat(viewer, &format));
4626: PetscCall(PetscViewerASCIIAddTab(viewer, ((PetscObject)snes)->tablevel + 1));
4627: if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
4628: DM dm;
4629: Vec u;
4630: PetscDS prob;
4631: PetscInt Nf, f;
4632: PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
4633: void **exactCtx;
4634: PetscReal error;
4636: PetscCall(SNESGetDM(snes, &dm));
4637: PetscCall(SNESGetSolution(snes, &u));
4638: PetscCall(DMGetDS(dm, &prob));
4639: PetscCall(PetscDSGetNumFields(prob, &Nf));
4640: PetscCall(PetscMalloc2(Nf, &exactSol, Nf, &exactCtx));
4641: for (f = 0; f < Nf; ++f) PetscCall(PetscDSGetExactSolution(prob, f, &exactSol[f], &exactCtx[f]));
4642: PetscCall(DMComputeL2Diff(dm, 0.0, exactSol, exactCtx, u, &error));
4643: PetscCall(PetscFree2(exactSol, exactCtx));
4644: if (error < 1.0e-11) PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: < 1.0e-11\n"));
4645: else PetscCall(PetscViewerASCIIPrintf(viewer, "L_2 Error: %g\n", (double)error));
4646: }
4647: if (snes->reason > 0 && format != PETSC_VIEWER_FAILED) {
4648: if (((PetscObject)snes)->prefix) {
4649: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve converged due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4650: } else {
4651: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve converged due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4652: }
4653: } else if (snes->reason <= 0) {
4654: if (((PetscObject)snes)->prefix) {
4655: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear %s solve did not converge due to %s iterations %" PetscInt_FMT "\n", ((PetscObject)snes)->prefix, SNESConvergedReasons[snes->reason], snes->iter));
4656: } else {
4657: PetscCall(PetscViewerASCIIPrintf(viewer, "Nonlinear solve did not converge due to %s iterations %" PetscInt_FMT "\n", SNESConvergedReasons[snes->reason], snes->iter));
4658: }
4659: }
4660: PetscCall(PetscViewerASCIISubtractTab(viewer, ((PetscObject)snes)->tablevel + 1));
4661: }
4662: PetscFunctionReturn(PETSC_SUCCESS);
4663: }
4665: /*@C
4666: SNESConvergedReasonViewSet - Sets an ADDITIONAL function that is to be used at the
4667: end of the nonlinear solver to display the convergence reason of the nonlinear solver.
4669: Logically Collective
4671: Input Parameters:
4672: + snes - the `SNES` context
4673: . f - the `SNESConvergedReason` view function
4674: . vctx - [optional] user-defined context for private data for the `SNESConvergedReason` view function (use `NULL` if no context is desired)
4675: - reasonviewdestroy - [optional] routine that frees the context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence
4677: Calling sequence of `f`:
4678: + snes - the `SNES` context
4679: - vctx - [optional] context for private data for the function
4681: Options Database Keys:
4682: + -snes_converged_reason - sets a default `SNESConvergedReasonView()`
4683: - -snes_converged_reason_view_cancel - cancels all converged reason viewers that have been hardwired into a code by
4684: calls to `SNESConvergedReasonViewSet()`, but does not cancel those set via the options database.
4686: Level: intermediate
4688: Note:
4689: Several different converged reason view routines may be set by calling
4690: `SNESConvergedReasonViewSet()` multiple times; all will be called in the
4691: order in which they were set.
4693: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESConvergedReason`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`, `SNESConvergedReasonViewCancel()`,
4694: `PetscCtxDestroyFn`
4695: @*/
4696: PetscErrorCode SNESConvergedReasonViewSet(SNES snes, PetscErrorCode (*f)(SNES snes, PetscCtx vctx), PetscCtx vctx, PetscCtxDestroyFn *reasonviewdestroy)
4697: {
4698: PetscFunctionBegin;
4700: for (PetscInt i = 0; i < snes->numberreasonviews; i++) {
4701: PetscBool identical;
4703: PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))(PetscVoidFn *)f, vctx, reasonviewdestroy, (PetscErrorCode (*)(void))(PetscVoidFn *)snes->reasonview[i], snes->reasonviewcontext[i], snes->reasonviewdestroy[i], &identical));
4704: if (identical) PetscFunctionReturn(PETSC_SUCCESS);
4705: }
4706: PetscCheck(snes->numberreasonviews < MAXSNESREASONVIEWS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many SNES reasonview set");
4707: snes->reasonview[snes->numberreasonviews] = f;
4708: snes->reasonviewdestroy[snes->numberreasonviews] = reasonviewdestroy;
4709: snes->reasonviewcontext[snes->numberreasonviews++] = vctx;
4710: PetscFunctionReturn(PETSC_SUCCESS);
4711: }
4713: /*@
4714: SNESConvergedReasonViewFromOptions - Processes command line options to determine if/how a `SNESConvergedReason` is to be viewed at the end of `SNESSolve()`
4715: All the user-provided viewer routines set with `SNESConvergedReasonViewSet()` will be called, if they exist.
4717: Collective
4719: Input Parameter:
4720: . snes - the `SNES` object
4722: Level: advanced
4724: .seealso: [](ch_snes), `SNES`, `SNESConvergedReason`, `SNESConvergedReasonViewSet()`, `SNESCreate()`, `SNESSetUp()`, `SNESDestroy()`,
4725: `SNESSetTolerances()`, `SNESConvergedDefault()`, `SNESGetConvergedReason()`, `SNESConvergedReasonView()`
4726: @*/
4727: PetscErrorCode SNESConvergedReasonViewFromOptions(SNES snes)
4728: {
4729: static PetscBool incall = PETSC_FALSE;
4731: PetscFunctionBegin;
4732: if (incall) PetscFunctionReturn(PETSC_SUCCESS);
4733: incall = PETSC_TRUE;
4735: /* All user-provided viewers are called first, if they exist. */
4736: for (PetscInt i = 0; i < snes->numberreasonviews; i++) PetscCall((*snes->reasonview[i])(snes, snes->reasonviewcontext[i]));
4738: /* Call PETSc default routine if users ask for it */
4739: if (snes->convergedreasonviewer) {
4740: PetscCall(PetscViewerPushFormat(snes->convergedreasonviewer, snes->convergedreasonformat));
4741: PetscCall(SNESConvergedReasonView(snes, snes->convergedreasonviewer));
4742: PetscCall(PetscViewerPopFormat(snes->convergedreasonviewer));
4743: }
4744: incall = PETSC_FALSE;
4745: PetscFunctionReturn(PETSC_SUCCESS);
4746: }
4748: /*@
4749: SNESSolve - Solves a nonlinear system $F(x) = b $ associated with a `SNES` object
4751: Collective
4753: Input Parameters:
4754: + snes - the `SNES` context
4755: . b - the constant part of the equation $F(x) = b$, or `NULL` to use zero.
4756: - x - the solution vector.
4758: Level: beginner
4760: Note:
4761: The user should initialize the vector, `x`, with the initial guess
4762: for the nonlinear solve prior to calling `SNESSolve()` .
4764: .seealso: [](ch_snes), `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFunction()`, `SNESSetJacobian()`, `SNESSetGridSequence()`, `SNESGetSolution()`,
4765: `SNESNewtonTRSetPreCheck()`, `SNESNewtonTRGetPreCheck()`, `SNESNewtonTRSetPostCheck()`, `SNESNewtonTRGetPostCheck()`,
4766: `SNESLineSearchSetPostCheck()`, `SNESLineSearchGetPostCheck()`, `SNESLineSearchSetPreCheck()`, `SNESLineSearchGetPreCheck()`
4767: @*/
4768: PetscErrorCode SNESSolve(SNES snes, Vec b, Vec x)
4769: {
4770: PetscBool flg;
4771: PetscInt grid;
4772: Vec xcreated = NULL;
4773: DM dm;
4775: PetscFunctionBegin;
4778: if (x) PetscCheckSameComm(snes, 1, x, 3);
4780: if (b) PetscCheckSameComm(snes, 1, b, 2);
4782: /* High level operations using the nonlinear solver */
4783: {
4784: PetscViewer viewer;
4785: PetscViewerFormat format;
4786: PetscInt num;
4787: PetscBool flg;
4788: static PetscBool incall = PETSC_FALSE;
4790: if (!incall) {
4791: /* Estimate the convergence rate of the discretization */
4792: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_convergence_estimate", &viewer, &format, &flg));
4793: if (flg) {
4794: PetscConvEst conv;
4795: DM dm;
4796: PetscReal *alpha; /* Convergence rate of the solution error for each field in the L_2 norm */
4797: PetscInt Nf;
4799: incall = PETSC_TRUE;
4800: PetscCall(SNESGetDM(snes, &dm));
4801: PetscCall(DMGetNumFields(dm, &Nf));
4802: PetscCall(PetscCalloc1(Nf, &alpha));
4803: PetscCall(PetscConvEstCreate(PetscObjectComm((PetscObject)snes), &conv));
4804: PetscCall(PetscConvEstSetSolver(conv, (PetscObject)snes));
4805: PetscCall(PetscConvEstSetFromOptions(conv));
4806: PetscCall(PetscConvEstSetUp(conv));
4807: PetscCall(PetscConvEstGetConvRate(conv, alpha));
4808: PetscCall(PetscViewerPushFormat(viewer, format));
4809: PetscCall(PetscConvEstRateView(conv, alpha, viewer));
4810: PetscCall(PetscViewerPopFormat(viewer));
4811: PetscCall(PetscViewerDestroy(&viewer));
4812: PetscCall(PetscConvEstDestroy(&conv));
4813: PetscCall(PetscFree(alpha));
4814: incall = PETSC_FALSE;
4815: }
4816: /* Adaptively refine the initial grid */
4817: num = 1;
4818: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_initial", &num, &flg));
4819: if (flg) {
4820: DMAdaptor adaptor;
4822: incall = PETSC_TRUE;
4823: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4824: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4825: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4826: PetscCall(DMAdaptorSetFromOptions(adaptor));
4827: PetscCall(DMAdaptorSetUp(adaptor));
4828: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_INITIAL, &dm, &x));
4829: PetscCall(DMAdaptorDestroy(&adaptor));
4830: incall = PETSC_FALSE;
4831: }
4832: /* Use grid sequencing to adapt */
4833: num = 0;
4834: PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)snes)->prefix, "-snes_adapt_sequence", &num, NULL));
4835: if (num) {
4836: DMAdaptor adaptor;
4837: const char *prefix;
4839: incall = PETSC_TRUE;
4840: PetscCall(DMAdaptorCreate(PetscObjectComm((PetscObject)snes), &adaptor));
4841: PetscCall(SNESGetOptionsPrefix(snes, &prefix));
4842: PetscCall(DMAdaptorSetOptionsPrefix(adaptor, prefix));
4843: PetscCall(DMAdaptorSetSolver(adaptor, snes));
4844: PetscCall(DMAdaptorSetSequenceLength(adaptor, num));
4845: PetscCall(DMAdaptorSetFromOptions(adaptor));
4846: PetscCall(DMAdaptorSetUp(adaptor));
4847: PetscCall(PetscObjectViewFromOptions((PetscObject)adaptor, NULL, "-snes_adapt_view"));
4848: PetscCall(DMAdaptorAdapt(adaptor, x, DM_ADAPTATION_SEQUENTIAL, &dm, &x));
4849: PetscCall(DMAdaptorDestroy(&adaptor));
4850: incall = PETSC_FALSE;
4851: }
4852: }
4853: }
4854: if (!x) x = snes->vec_sol;
4855: if (!x) {
4856: PetscCall(SNESGetDM(snes, &dm));
4857: PetscCall(DMCreateGlobalVector(dm, &xcreated));
4858: x = xcreated;
4859: }
4860: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view_pre"));
4862: for (grid = 0; grid < snes->gridsequence; grid++) PetscCall(PetscViewerASCIIPushTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4863: for (grid = 0; grid < snes->gridsequence + 1; grid++) {
4864: /* set solution vector */
4865: if (!grid) PetscCall(PetscObjectReference((PetscObject)x));
4866: PetscCall(VecDestroy(&snes->vec_sol));
4867: snes->vec_sol = x;
4868: PetscCall(SNESGetDM(snes, &dm));
4870: /* set affine vector if provided */
4871: if (b) PetscCall(PetscObjectReference((PetscObject)b));
4872: PetscCall(VecDestroy(&snes->vec_rhs));
4873: snes->vec_rhs = b;
4875: 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");
4876: PetscCheck(snes->vec_func != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be function vector");
4877: PetscCheck(snes->vec_rhs != snes->vec_sol, PETSC_COMM_SELF, PETSC_ERR_ARG_IDN, "Solution vector cannot be right-hand side vector");
4878: if (!snes->vec_sol_update /* && snes->vec_sol */) PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_sol_update));
4879: PetscCall(DMShellSetGlobalVector(dm, snes->vec_sol));
4880: PetscCall(SNESSetUp(snes));
4882: if (!grid) {
4883: if (snes->ops->computeinitialguess) PetscCallBack("SNES callback compute initial guess", (*snes->ops->computeinitialguess)(snes, snes->vec_sol, snes->initialguessP));
4884: }
4886: if (snes->conv_hist_reset) snes->conv_hist_len = 0;
4887: PetscCall(SNESResetCounters(snes));
4888: snes->reason = SNES_CONVERGED_ITERATING;
4889: PetscCall(PetscLogEventBegin(SNES_Solve, snes, 0, 0, 0));
4890: PetscUseTypeMethod(snes, solve);
4891: PetscCall(PetscLogEventEnd(SNES_Solve, snes, 0, 0, 0));
4892: PetscCheck(snes->reason, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal error, solver %s returned without setting converged reason", ((PetscObject)snes)->type_name);
4893: snes->functiondomainerror = PETSC_FALSE; /* clear the flag if it has been set */
4894: snes->objectivedomainerror = PETSC_FALSE; /* clear the flag if it has been set */
4895: snes->jacobiandomainerror = PETSC_FALSE; /* clear the flag if it has been set */
4897: if (snes->lagjac_persist) snes->jac_iter += snes->iter;
4898: if (snes->lagpre_persist) snes->pre_iter += snes->iter;
4900: PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)snes), ((PetscObject)snes)->options, ((PetscObject)snes)->prefix, "-snes_test_local_min", NULL, NULL, &flg));
4901: if (flg && !PetscPreLoadingOn) PetscCall(SNESTestLocalMin(snes));
4902: /* Call converged reason views. This may involve user-provided viewers as well */
4903: PetscCall(SNESConvergedReasonViewFromOptions(snes));
4905: if (snes->errorifnotconverged) {
4906: if (snes->reason < 0) PetscCall(SNESMonitorCancel(snes));
4907: PetscCheck(snes->reason >= 0, PetscObjectComm((PetscObject)snes), PETSC_ERR_NOT_CONVERGED, "SNESSolve has not converged");
4908: }
4909: if (snes->reason < 0) break;
4910: if (grid < snes->gridsequence) {
4911: DM fine;
4912: Vec xnew;
4913: Mat interp;
4915: PetscCall(DMRefine(snes->dm, PetscObjectComm((PetscObject)snes), &fine));
4916: PetscCheck(fine, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_INCOMP, "DMRefine() did not perform any refinement, cannot continue grid sequencing");
4917: PetscCall(DMGetCoordinatesLocalSetUp(fine));
4918: PetscCall(DMCreateInterpolation(snes->dm, fine, &interp, NULL));
4919: PetscCall(DMCreateGlobalVector(fine, &xnew));
4920: PetscCall(MatInterpolate(interp, x, xnew));
4921: PetscCall(DMInterpolate(snes->dm, interp, fine));
4922: PetscCall(MatDestroy(&interp));
4923: x = xnew;
4925: PetscCall(SNESReset(snes));
4926: PetscCall(SNESSetDM(snes, fine));
4927: PetscCall(SNESResetFromOptions(snes));
4928: PetscCall(DMDestroy(&fine));
4929: PetscCall(PetscViewerASCIIPopTab(PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)snes))));
4930: }
4931: }
4932: PetscCall(SNESViewFromOptions(snes, NULL, "-snes_view"));
4933: PetscCall(VecViewFromOptions(snes->vec_sol, (PetscObject)snes, "-snes_view_solution"));
4934: PetscCall(DMMonitor(snes->dm));
4935: PetscCall(SNESMonitorPauseFinal_Internal(snes));
4937: PetscCall(VecDestroy(&xcreated));
4938: PetscCall(PetscObjectSAWsBlock((PetscObject)snes));
4939: PetscFunctionReturn(PETSC_SUCCESS);
4940: }
4942: /* --------- Internal routines for SNES Package --------- */
4944: /*@
4945: SNESSetType - Sets the algorithm/method to be used to solve the nonlinear system with the given `SNES`
4947: Collective
4949: Input Parameters:
4950: + snes - the `SNES` context
4951: - type - a known method
4953: Options Database Key:
4954: . -snes_type <type> - Sets the method; use -help for a list
4955: of available methods (for instance, newtonls or newtontr)
4957: Level: intermediate
4959: Notes:
4960: See `SNESType` for available methods (for instance)
4961: + `SNESNEWTONLS` - Newton's method with line search
4962: (systems of nonlinear equations)
4963: - `SNESNEWTONTR` - Newton's method with trust region
4964: (systems of nonlinear equations)
4966: Normally, it is best to use the `SNESSetFromOptions()` command and then
4967: set the `SNES` solver type from the options database rather than by using
4968: this routine. Using the options database provides the user with
4969: maximum flexibility in evaluating the many nonlinear solvers.
4970: The `SNESSetType()` routine is provided for those situations where it
4971: is necessary to set the nonlinear solver independently of the command
4972: line or options database. This might be the case, for example, when
4973: the choice of solver changes during the execution of the program,
4974: and the user's application is taking responsibility for choosing the
4975: appropriate method.
4977: Developer Note:
4978: `SNESRegister()` adds a constructor for a new `SNESType` to `SNESList`, `SNESSetType()` locates
4979: the constructor in that list and calls it to create the specific object.
4981: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESType`, `SNESCreate()`, `SNESDestroy()`, `SNESGetType()`, `SNESSetFromOptions()`
4982: @*/
4983: PetscErrorCode SNESSetType(SNES snes, SNESType type)
4984: {
4985: PetscBool match;
4986: PetscErrorCode (*r)(SNES);
4988: PetscFunctionBegin;
4990: PetscAssertPointer(type, 2);
4992: PetscCall(PetscObjectTypeCompare((PetscObject)snes, type, &match));
4993: if (match) PetscFunctionReturn(PETSC_SUCCESS);
4995: PetscCall(PetscFunctionListFind(SNESList, type, &r));
4996: PetscCheck(r, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested SNES type %s", type);
4997: /* Destroy the previous private SNES context */
4998: PetscTryTypeMethod(snes, destroy);
4999: /* Reinitialize type-specific function pointers in SNESOps structure */
5000: snes->ops->reset = NULL;
5001: snes->ops->setup = NULL;
5002: snes->ops->solve = NULL;
5003: snes->ops->view = NULL;
5004: snes->ops->setfromoptions = NULL;
5005: snes->ops->destroy = NULL;
5007: /* It may happen the user has customized the line search before calling SNESSetType */
5008: if (((PetscObject)snes)->type_name) PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5010: /* Call the SNESCreate_XXX routine for this particular Nonlinear solver */
5011: snes->setupcalled = PETSC_FALSE;
5013: PetscCall(PetscObjectChangeTypeName((PetscObject)snes, type));
5014: PetscCall((*r)(snes));
5015: PetscFunctionReturn(PETSC_SUCCESS);
5016: }
5018: /*@
5019: SNESGetType - Gets the `SNES` method type and name (as a string).
5021: Not Collective
5023: Input Parameter:
5024: . snes - nonlinear solver context
5026: Output Parameter:
5027: . type - `SNES` method (a character string)
5029: Level: intermediate
5031: .seealso: [](ch_snes), `SNESSetType()`, `SNESType`, `SNESSetFromOptions()`, `SNES`
5032: @*/
5033: PetscErrorCode SNESGetType(SNES snes, SNESType *type)
5034: {
5035: PetscFunctionBegin;
5037: PetscAssertPointer(type, 2);
5038: *type = ((PetscObject)snes)->type_name;
5039: PetscFunctionReturn(PETSC_SUCCESS);
5040: }
5042: /*@
5043: SNESSetSolution - Sets the solution vector for use by the `SNES` routines.
5045: Logically Collective
5047: Input Parameters:
5048: + snes - the `SNES` context obtained from `SNESCreate()`
5049: - u - the solution vector
5051: Level: beginner
5053: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetSolution()`, `Vec`
5054: @*/
5055: PetscErrorCode SNESSetSolution(SNES snes, Vec u)
5056: {
5057: DM dm;
5059: PetscFunctionBegin;
5062: PetscCall(PetscObjectReference((PetscObject)u));
5063: PetscCall(VecDestroy(&snes->vec_sol));
5065: snes->vec_sol = u;
5067: PetscCall(SNESGetDM(snes, &dm));
5068: PetscCall(DMShellSetGlobalVector(dm, u));
5069: PetscFunctionReturn(PETSC_SUCCESS);
5070: }
5072: /*@
5073: SNESGetSolution - Returns the vector where the approximate solution is
5074: stored. This is the fine grid solution when using `SNESSetGridSequence()`.
5076: Not Collective, but `x` is parallel if `snes` is parallel
5078: Input Parameter:
5079: . snes - the `SNES` context
5081: Output Parameter:
5082: . x - the solution
5084: Level: intermediate
5086: .seealso: [](ch_snes), `SNESSetSolution()`, `SNESSolve()`, `SNES`, `SNESGetSolutionUpdate()`, `SNESGetFunction()`
5087: @*/
5088: PetscErrorCode SNESGetSolution(SNES snes, Vec *x)
5089: {
5090: PetscFunctionBegin;
5092: PetscAssertPointer(x, 2);
5093: *x = snes->vec_sol;
5094: PetscFunctionReturn(PETSC_SUCCESS);
5095: }
5097: /*@
5098: SNESGetSolutionUpdate - Returns the vector where the solution update is
5099: stored.
5101: Not Collective, but `x` is parallel if `snes` is parallel
5103: Input Parameter:
5104: . snes - the `SNES` context
5106: Output Parameter:
5107: . x - the solution update
5109: Level: advanced
5111: .seealso: [](ch_snes), `SNES`, `SNESGetSolution()`, `SNESGetFunction()`
5112: @*/
5113: PetscErrorCode SNESGetSolutionUpdate(SNES snes, Vec *x)
5114: {
5115: PetscFunctionBegin;
5117: PetscAssertPointer(x, 2);
5118: *x = snes->vec_sol_update;
5119: PetscFunctionReturn(PETSC_SUCCESS);
5120: }
5122: /*@C
5123: SNESGetFunction - Returns the function that defines the nonlinear system set with `SNESSetFunction()`
5125: Not Collective, but `r` is parallel if `snes` is parallel. Collective if `r` is requested, but has not been created yet.
5127: Input Parameter:
5128: . snes - the `SNES` context
5130: Output Parameters:
5131: + r - the vector that is used to store residuals (or `NULL` if you don't want it)
5132: . f - the function (or `NULL` if you don't want it); for calling sequence see `SNESFunctionFn`
5133: - ctx - the function context (or `NULL` if you don't want it)
5135: Level: advanced
5137: Note:
5138: The vector `r` DOES NOT, in general, contain the current value of the `SNES` nonlinear function
5140: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESSetFunction()`, `SNESGetSolution()`, `SNESFunctionFn`
5141: @*/
5142: PetscErrorCode SNESGetFunction(SNES snes, Vec *r, SNESFunctionFn **f, PetscCtxRt ctx)
5143: {
5144: DM dm;
5146: PetscFunctionBegin;
5148: if (r) {
5149: if (!snes->vec_func) {
5150: if (snes->vec_rhs) {
5151: PetscCall(VecDuplicate(snes->vec_rhs, &snes->vec_func));
5152: } else if (snes->vec_sol) {
5153: PetscCall(VecDuplicate(snes->vec_sol, &snes->vec_func));
5154: } else if (snes->dm) {
5155: PetscCall(DMCreateGlobalVector(snes->dm, &snes->vec_func));
5156: }
5157: }
5158: *r = snes->vec_func;
5159: }
5160: PetscCall(SNESGetDM(snes, &dm));
5161: PetscCall(DMSNESGetFunction(dm, f, ctx));
5162: PetscFunctionReturn(PETSC_SUCCESS);
5163: }
5165: /*@C
5166: SNESGetNGS - Returns the function and context set with `SNESSetNGS()`
5168: Input Parameter:
5169: . snes - the `SNES` context
5171: Output Parameters:
5172: + f - the function (or `NULL`) see `SNESNGSFn` for calling sequence
5173: - ctx - the function context (or `NULL`)
5175: Level: advanced
5177: .seealso: [](ch_snes), `SNESSetNGS()`, `SNESGetFunction()`, `SNESNGSFn`
5178: @*/
5179: PetscErrorCode SNESGetNGS(SNES snes, SNESNGSFn **f, PetscCtxRt ctx)
5180: {
5181: DM dm;
5183: PetscFunctionBegin;
5185: PetscCall(SNESGetDM(snes, &dm));
5186: PetscCall(DMSNESGetNGS(dm, f, ctx));
5187: PetscFunctionReturn(PETSC_SUCCESS);
5188: }
5190: /*@
5191: SNESSetOptionsPrefix - Sets the prefix used for searching for all
5192: `SNES` options in the database.
5194: Logically Collective
5196: Input Parameters:
5197: + snes - the `SNES` context
5198: - prefix - the prefix to prepend to all option names
5200: Level: advanced
5202: Note:
5203: A hyphen (-) must NOT be given at the beginning of the prefix name.
5204: The first character of all runtime options is AUTOMATICALLY the hyphen.
5206: .seealso: [](ch_snes), `SNES`, `SNESSetFromOptions()`, `SNESAppendOptionsPrefix()`
5207: @*/
5208: PetscErrorCode SNESSetOptionsPrefix(SNES snes, const char prefix[])
5209: {
5210: PetscFunctionBegin;
5212: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes, prefix));
5213: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5214: if (snes->linesearch) {
5215: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5216: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)snes->linesearch, prefix));
5217: }
5218: PetscCall(KSPSetOptionsPrefix(snes->ksp, prefix));
5219: PetscFunctionReturn(PETSC_SUCCESS);
5220: }
5222: /*@
5223: SNESAppendOptionsPrefix - Appends to the prefix used for searching for all
5224: `SNES` options in the database.
5226: Logically Collective
5228: Input Parameters:
5229: + snes - the `SNES` context
5230: - prefix - the prefix to prepend to all option names
5232: Level: advanced
5234: Note:
5235: A hyphen (-) must NOT be given at the beginning of the prefix name.
5236: The first character of all runtime options is AUTOMATICALLY the hyphen.
5238: .seealso: [](ch_snes), `SNESGetOptionsPrefix()`, `SNESSetOptionsPrefix()`
5239: @*/
5240: PetscErrorCode SNESAppendOptionsPrefix(SNES snes, const char prefix[])
5241: {
5242: PetscFunctionBegin;
5244: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes, prefix));
5245: if (!snes->ksp) PetscCall(SNESGetKSP(snes, &snes->ksp));
5246: if (snes->linesearch) {
5247: PetscCall(SNESGetLineSearch(snes, &snes->linesearch));
5248: PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)snes->linesearch, prefix));
5249: }
5250: PetscCall(KSPAppendOptionsPrefix(snes->ksp, prefix));
5251: PetscFunctionReturn(PETSC_SUCCESS);
5252: }
5254: /*@
5255: SNESGetOptionsPrefix - Gets the prefix used for searching for all
5256: `SNES` options in the database.
5258: Not Collective
5260: Input Parameter:
5261: . snes - the `SNES` context
5263: Output Parameter:
5264: . prefix - pointer to the prefix string used
5266: Level: advanced
5268: .seealso: [](ch_snes), `SNES`, `SNESSetOptionsPrefix()`, `SNESAppendOptionsPrefix()`
5269: @*/
5270: PetscErrorCode SNESGetOptionsPrefix(SNES snes, const char *prefix[])
5271: {
5272: PetscFunctionBegin;
5274: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, prefix));
5275: PetscFunctionReturn(PETSC_SUCCESS);
5276: }
5278: /*@C
5279: SNESRegister - Adds a method to the nonlinear solver package.
5281: Not Collective
5283: Input Parameters:
5284: + sname - name of a new user-defined solver
5285: - function - routine to create method context
5287: Level: advanced
5289: Note:
5290: `SNESRegister()` may be called multiple times to add several user-defined solvers.
5292: Example Usage:
5293: .vb
5294: SNESRegister("my_solver", MySolverCreate);
5295: .ve
5297: Then, your solver can be chosen with the procedural interface via
5298: .vb
5299: SNESSetType(snes, "my_solver")
5300: .ve
5301: or at runtime via the option
5302: .vb
5303: -snes_type my_solver
5304: .ve
5306: .seealso: [](ch_snes), `SNESRegisterAll()`, `SNESRegisterDestroy()`
5307: @*/
5308: PetscErrorCode SNESRegister(const char sname[], PetscErrorCode (*function)(SNES))
5309: {
5310: PetscFunctionBegin;
5311: PetscCall(SNESInitializePackage());
5312: PetscCall(PetscFunctionListAdd(&SNESList, sname, function));
5313: PetscFunctionReturn(PETSC_SUCCESS);
5314: }
5316: PetscErrorCode SNESTestLocalMin(SNES snes)
5317: {
5318: PetscInt N, i, j;
5319: Vec u, uh, fh;
5320: PetscScalar value;
5321: PetscReal norm;
5323: PetscFunctionBegin;
5324: PetscCall(SNESGetSolution(snes, &u));
5325: PetscCall(VecDuplicate(u, &uh));
5326: PetscCall(VecDuplicate(u, &fh));
5328: /* currently only works for sequential */
5329: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "Testing FormFunction() for local min\n"));
5330: PetscCall(VecGetSize(u, &N));
5331: for (i = 0; i < N; i++) {
5332: PetscCall(VecCopy(u, uh));
5333: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), "i = %" PetscInt_FMT "\n", i));
5334: for (j = -10; j < 11; j++) {
5335: value = PetscSign(j) * PetscExpReal(PetscAbs(j) - 10.0);
5336: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5337: PetscCall(SNESComputeFunction(snes, uh, fh));
5338: PetscCall(VecNorm(fh, NORM_2, &norm)); /* does not handle use of SNESSetFunctionDomainError() correctly */
5339: PetscCall(PetscPrintf(PetscObjectComm((PetscObject)snes), " j norm %" PetscInt_FMT " %18.16e\n", j, (double)norm));
5340: value = -value;
5341: PetscCall(VecSetValue(uh, i, value, ADD_VALUES));
5342: }
5343: }
5344: PetscCall(VecDestroy(&uh));
5345: PetscCall(VecDestroy(&fh));
5346: PetscFunctionReturn(PETSC_SUCCESS);
5347: }
5349: /*@
5350: SNESGetLineSearch - Returns the line search associated with the `SNES`.
5352: Not Collective
5354: Input Parameter:
5355: . snes - iterative context obtained from `SNESCreate()`
5357: Output Parameter:
5358: . linesearch - linesearch context
5360: Level: beginner
5362: Notes:
5363: It creates a default line search instance which can be configured as needed in case it has not been already set with `SNESSetLineSearch()`.
5365: You can also use the options database keys `-snes_linesearch_*` to configure the line search. See `SNESLineSearchSetFromOptions()` for the possible options.
5367: .seealso: [](ch_snes), `SNESLineSearch`, `SNESSetLineSearch()`, `SNESLineSearchCreate()`, `SNESLineSearchSetFromOptions()`
5368: @*/
5369: PetscErrorCode SNESGetLineSearch(SNES snes, SNESLineSearch *linesearch)
5370: {
5371: const char *optionsprefix;
5373: PetscFunctionBegin;
5375: PetscAssertPointer(linesearch, 2);
5376: if (!snes->linesearch) {
5377: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5378: PetscCall(SNESLineSearchCreate(PetscObjectComm((PetscObject)snes), &snes->linesearch));
5379: PetscCall(SNESLineSearchSetSNES(snes->linesearch, snes));
5380: PetscCall(SNESLineSearchAppendOptionsPrefix(snes->linesearch, optionsprefix));
5381: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->linesearch, (PetscObject)snes, 1));
5382: }
5383: *linesearch = snes->linesearch;
5384: PetscFunctionReturn(PETSC_SUCCESS);
5385: }
5387: /*@
5388: SNESKSPSetUseEW - Sets `SNES` to the use Eisenstat-Walker method for
5389: computing relative tolerance for linear solvers within an inexact
5390: Newton method.
5392: Logically Collective
5394: Input Parameters:
5395: + snes - `SNES` context
5396: - flag - `PETSC_TRUE` or `PETSC_FALSE`
5398: Options Database Keys:
5399: + -snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence
5400: . -snes_ksp_ew_version ver - version of Eisenstat-Walker method
5401: . -snes_ksp_ew_rtol0 <rtol0> - Sets rtol0
5402: . -snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax
5403: . -snes_ksp_ew_gamma <gamma> - Sets gamma
5404: . -snes_ksp_ew_alpha <alpha> - Sets alpha
5405: . -snes_ksp_ew_alpha2 <alpha2> - Sets alpha2
5406: - -snes_ksp_ew_threshold <threshold> - Sets threshold
5408: Level: advanced
5410: Note:
5411: The default is to use a constant relative tolerance for
5412: the inner linear solvers. Alternatively, one can use the
5413: Eisenstat-Walker method {cite}`ew96`, where the relative convergence tolerance
5414: is reset at each Newton iteration according progress of the nonlinear
5415: solver.
5417: .seealso: [](ch_snes), `KSP`, `SNES`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5418: @*/
5419: PetscErrorCode SNESKSPSetUseEW(SNES snes, PetscBool flag)
5420: {
5421: PetscFunctionBegin;
5424: snes->ksp_ewconv = flag;
5425: PetscFunctionReturn(PETSC_SUCCESS);
5426: }
5428: /*@
5429: SNESKSPGetUseEW - Gets if `SNES` is using Eisenstat-Walker method
5430: for computing relative tolerance for linear solvers within an
5431: inexact Newton method.
5433: Not Collective
5435: Input Parameter:
5436: . snes - `SNES` context
5438: Output Parameter:
5439: . flag - `PETSC_TRUE` or `PETSC_FALSE`
5441: Level: advanced
5443: .seealso: [](ch_snes), `SNESKSPSetUseEW()`, `SNESKSPGetParametersEW()`, `SNESKSPSetParametersEW()`
5444: @*/
5445: PetscErrorCode SNESKSPGetUseEW(SNES snes, PetscBool *flag)
5446: {
5447: PetscFunctionBegin;
5449: PetscAssertPointer(flag, 2);
5450: *flag = snes->ksp_ewconv;
5451: PetscFunctionReturn(PETSC_SUCCESS);
5452: }
5454: /*@
5455: SNESKSPSetParametersEW - Sets parameters for Eisenstat-Walker
5456: convergence criteria for the linear solvers within an inexact
5457: Newton method.
5459: Logically Collective
5461: Input Parameters:
5462: + snes - `SNES` context
5463: . version - version 1, 2 (default is 2), 3 or 4
5464: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5465: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5466: . gamma - multiplicative factor for version 2 rtol computation
5467: (0 <= gamma2 <= 1)
5468: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5469: . alpha2 - power for safeguard
5470: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5472: Level: advanced
5474: Notes:
5475: Version 3 was contributed by Luis Chacon, June 2006.
5477: Use `PETSC_CURRENT` to retain the default for any of the parameters.
5479: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPGetParametersEW()`
5480: @*/
5481: PetscErrorCode SNESKSPSetParametersEW(SNES snes, PetscInt version, PetscReal rtol_0, PetscReal rtol_max, PetscReal gamma, PetscReal alpha, PetscReal alpha2, PetscReal threshold)
5482: {
5483: SNESKSPEW *kctx;
5485: PetscFunctionBegin;
5487: kctx = (SNESKSPEW *)snes->kspconvctx;
5488: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5497: if (version != PETSC_CURRENT) kctx->version = version;
5498: if (rtol_0 != (PetscReal)PETSC_CURRENT) kctx->rtol_0 = rtol_0;
5499: if (rtol_max != (PetscReal)PETSC_CURRENT) kctx->rtol_max = rtol_max;
5500: if (gamma != (PetscReal)PETSC_CURRENT) kctx->gamma = gamma;
5501: if (alpha != (PetscReal)PETSC_CURRENT) kctx->alpha = alpha;
5502: if (alpha2 != (PetscReal)PETSC_CURRENT) kctx->alpha2 = alpha2;
5503: if (threshold != (PetscReal)PETSC_CURRENT) kctx->threshold = threshold;
5505: 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);
5506: 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);
5507: 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);
5508: 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);
5509: 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);
5510: 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);
5511: PetscFunctionReturn(PETSC_SUCCESS);
5512: }
5514: /*@
5515: SNESKSPGetParametersEW - Gets parameters for Eisenstat-Walker
5516: convergence criteria for the linear solvers within an inexact
5517: Newton method.
5519: Not Collective
5521: Input Parameter:
5522: . snes - `SNES` context
5524: Output Parameters:
5525: + version - version 1, 2 (default is 2), 3 or 4
5526: . rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
5527: . rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
5528: . gamma - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
5529: . alpha - power for version 2 rtol computation (1 < alpha <= 2)
5530: . alpha2 - power for safeguard
5531: - threshold - threshold for imposing safeguard (0 < threshold < 1)
5533: Level: advanced
5535: .seealso: [](ch_snes), `SNES`, `SNESKSPSetUseEW()`, `SNESKSPGetUseEW()`, `SNESKSPSetParametersEW()`
5536: @*/
5537: PetscErrorCode SNESKSPGetParametersEW(SNES snes, PetscInt *version, PetscReal *rtol_0, PetscReal *rtol_max, PetscReal *gamma, PetscReal *alpha, PetscReal *alpha2, PetscReal *threshold)
5538: {
5539: SNESKSPEW *kctx;
5541: PetscFunctionBegin;
5543: kctx = (SNESKSPEW *)snes->kspconvctx;
5544: PetscCheck(kctx, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "No Eisenstat-Walker context existing");
5545: if (version) *version = kctx->version;
5546: if (rtol_0) *rtol_0 = kctx->rtol_0;
5547: if (rtol_max) *rtol_max = kctx->rtol_max;
5548: if (gamma) *gamma = kctx->gamma;
5549: if (alpha) *alpha = kctx->alpha;
5550: if (alpha2) *alpha2 = kctx->alpha2;
5551: if (threshold) *threshold = kctx->threshold;
5552: PetscFunctionReturn(PETSC_SUCCESS);
5553: }
5555: PetscErrorCode KSPPreSolve_SNESEW(KSP ksp, Vec b, Vec x, PetscCtx ctx)
5556: {
5557: SNES snes = (SNES)ctx;
5558: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5559: PetscReal rtol = PETSC_CURRENT, stol;
5561: PetscFunctionBegin;
5562: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5563: if (!snes->iter) {
5564: rtol = kctx->rtol_0; /* first time in, so use the original user rtol */
5565: PetscCall(VecNorm(snes->vec_func, NORM_2, &kctx->norm_first));
5566: } else {
5567: PetscCheck(kctx->version >= 1 && kctx->version <= 4, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Only versions 1-4 are supported: %" PetscInt_FMT, kctx->version);
5568: if (kctx->version == 1) {
5569: rtol = PetscAbsReal(snes->norm - kctx->lresid_last) / kctx->norm_last;
5570: stol = PetscPowReal(kctx->rtol_last, kctx->alpha2);
5571: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5572: } else if (kctx->version == 2) {
5573: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5574: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5575: if (stol > kctx->threshold) rtol = PetscMax(rtol, stol);
5576: } else if (kctx->version == 3) { /* contributed by Luis Chacon, June 2006. */
5577: rtol = kctx->gamma * PetscPowReal(snes->norm / kctx->norm_last, kctx->alpha);
5578: /* safeguard: avoid sharp decrease of rtol */
5579: stol = kctx->gamma * PetscPowReal(kctx->rtol_last, kctx->alpha);
5580: stol = PetscMax(rtol, stol);
5581: rtol = PetscMin(kctx->rtol_0, stol);
5582: /* safeguard: avoid oversolving */
5583: stol = kctx->gamma * (kctx->norm_first * snes->rtol) / snes->norm;
5584: stol = PetscMax(rtol, stol);
5585: rtol = PetscMin(kctx->rtol_0, stol);
5586: } else /* if (kctx->version == 4) */ {
5587: /* H.-B. An et al. Journal of Computational and Applied Mathematics 200 (2007) 47-60 */
5588: PetscReal ared = PetscAbsReal(kctx->norm_last - snes->norm);
5589: PetscReal pred = PetscAbsReal(kctx->norm_last - kctx->lresid_last);
5590: PetscReal rk = ared / pred;
5591: if (rk < kctx->v4_p1) rtol = 1. - 2. * kctx->v4_p1;
5592: else if (rk < kctx->v4_p2) rtol = kctx->rtol_last;
5593: else if (rk < kctx->v4_p3) rtol = kctx->v4_m1 * kctx->rtol_last;
5594: else rtol = kctx->v4_m2 * kctx->rtol_last;
5596: 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;
5597: kctx->rtol_last_2 = kctx->rtol_last;
5598: kctx->rk_last_2 = kctx->rk_last;
5599: kctx->rk_last = rk;
5600: }
5601: }
5602: /* safeguard: avoid rtol greater than rtol_max */
5603: rtol = PetscMin(rtol, kctx->rtol_max);
5604: PetscCall(KSPSetTolerances(ksp, rtol, PETSC_CURRENT, PETSC_CURRENT, PETSC_CURRENT));
5605: PetscCall(PetscInfo(snes, "iter %" PetscInt_FMT ", Eisenstat-Walker (version %" PetscInt_FMT ") KSP rtol=%g\n", snes->iter, kctx->version, (double)rtol));
5606: PetscFunctionReturn(PETSC_SUCCESS);
5607: }
5609: PetscErrorCode KSPPostSolve_SNESEW(KSP ksp, Vec b, Vec x, PetscCtx ctx)
5610: {
5611: SNES snes = (SNES)ctx;
5612: SNESKSPEW *kctx = (SNESKSPEW *)snes->kspconvctx;
5613: PCSide pcside;
5614: Vec lres;
5616: PetscFunctionBegin;
5617: if (!snes->ksp_ewconv) PetscFunctionReturn(PETSC_SUCCESS);
5618: PetscCall(KSPGetTolerances(ksp, &kctx->rtol_last, NULL, NULL, NULL));
5619: kctx->norm_last = snes->norm;
5620: if (kctx->version == 1 || kctx->version == 4) {
5621: PC pc;
5622: PetscBool getRes;
5624: PetscCall(KSPGetPC(ksp, &pc));
5625: PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCNONE, &getRes));
5626: if (!getRes) {
5627: KSPNormType normtype;
5629: PetscCall(KSPGetNormType(ksp, &normtype));
5630: getRes = (PetscBool)(normtype == KSP_NORM_UNPRECONDITIONED);
5631: }
5632: PetscCall(KSPGetPCSide(ksp, &pcside));
5633: if (pcside == PC_RIGHT || getRes) { /* KSP residual is true linear residual */
5634: PetscCall(KSPGetResidualNorm(ksp, &kctx->lresid_last));
5635: } else {
5636: /* KSP residual is preconditioned residual */
5637: /* compute true linear residual norm */
5638: Mat J;
5639: PetscCall(KSPGetOperators(ksp, &J, NULL));
5640: PetscCall(VecDuplicate(b, &lres));
5641: PetscCall(MatMult(J, x, lres));
5642: PetscCall(VecAYPX(lres, -1.0, b));
5643: PetscCall(VecNorm(lres, NORM_2, &kctx->lresid_last));
5644: PetscCall(VecDestroy(&lres));
5645: }
5646: }
5647: PetscFunctionReturn(PETSC_SUCCESS);
5648: }
5650: /*@
5651: SNESGetKSP - Returns the `KSP` context for a `SNES` solver.
5653: Not Collective, but if `snes` is parallel, then `ksp` is parallel
5655: Input Parameter:
5656: . snes - the `SNES` context
5658: Output Parameter:
5659: . ksp - the `KSP` context
5661: Level: beginner
5663: Notes:
5664: The user can then directly manipulate the `KSP` context to set various
5665: options, etc. Likewise, the user can then extract and manipulate the
5666: `PC` contexts as well.
5668: 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.
5670: .seealso: [](ch_snes), `SNES`, `KSP`, `PC`, `KSPGetPC()`, `SNESCreate()`, `KSPCreate()`, `SNESSetKSP()`
5671: @*/
5672: PetscErrorCode SNESGetKSP(SNES snes, KSP *ksp)
5673: {
5674: PetscFunctionBegin;
5676: PetscAssertPointer(ksp, 2);
5678: if (!snes->ksp) {
5679: PetscCall(KSPCreate(PetscObjectComm((PetscObject)snes), &snes->ksp));
5680: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->ksp, (PetscObject)snes, 1));
5682: PetscCall(KSPSetPreSolve(snes->ksp, KSPPreSolve_SNESEW, snes));
5683: PetscCall(KSPSetPostSolve(snes->ksp, KSPPostSolve_SNESEW, snes));
5685: PetscCall(KSPMonitorSetFromOptions(snes->ksp, "-snes_monitor_ksp", "snes_preconditioned_residual", snes));
5686: PetscCall(PetscObjectSetOptions((PetscObject)snes->ksp, ((PetscObject)snes)->options));
5687: }
5688: *ksp = snes->ksp;
5689: PetscFunctionReturn(PETSC_SUCCESS);
5690: }
5692: #include <petsc/private/dmimpl.h>
5693: /*@
5694: SNESSetDM - Sets the `DM` that may be used by some `SNES` nonlinear solvers or their underlying preconditioners
5696: Logically Collective
5698: Input Parameters:
5699: + snes - the nonlinear solver context
5700: - dm - the `DM`, cannot be `NULL`
5702: Level: intermediate
5704: Note:
5705: A `DM` can only be used for solving one problem at a time because information about the problem is stored on the `DM`,
5706: even when not using interfaces like `DMSNESSetFunction()`. Use `DMClone()` to get a distinct `DM` when solving different
5707: problems using the same function space.
5709: .seealso: [](ch_snes), `DM`, `SNES`, `SNESGetDM()`, `KSPSetDM()`, `KSPGetDM()`
5710: @*/
5711: PetscErrorCode SNESSetDM(SNES snes, DM dm)
5712: {
5713: KSP ksp;
5714: DMSNES sdm;
5716: PetscFunctionBegin;
5719: PetscCall(PetscObjectReference((PetscObject)dm));
5720: if (snes->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
5721: if (snes->dm->dmsnes && !dm->dmsnes) {
5722: PetscCall(DMCopyDMSNES(snes->dm, dm));
5723: PetscCall(DMGetDMSNES(snes->dm, &sdm));
5724: if (sdm->originaldm == snes->dm) sdm->originaldm = dm; /* Grant write privileges to the replacement DM */
5725: }
5726: PetscCall(DMCoarsenHookRemove(snes->dm, DMCoarsenHook_SNESVecSol, DMRestrictHook_SNESVecSol, snes));
5727: PetscCall(DMDestroy(&snes->dm));
5728: }
5729: snes->dm = dm;
5730: snes->dmAuto = PETSC_FALSE;
5732: PetscCall(SNESGetKSP(snes, &ksp));
5733: PetscCall(KSPSetDM(ksp, dm));
5734: PetscCall(KSPSetDMActive(ksp, KSP_DMACTIVE_ALL, PETSC_FALSE));
5735: if (snes->npc) {
5736: PetscCall(SNESSetDM(snes->npc, snes->dm));
5737: PetscCall(SNESSetNPCSide(snes, snes->npcside));
5738: }
5739: PetscFunctionReturn(PETSC_SUCCESS);
5740: }
5742: /*@
5743: SNESGetDM - Gets the `DM` that may be used by some `SNES` nonlinear solvers/preconditioners
5745: Not Collective but `dm` obtained is parallel on `snes`
5747: Input Parameter:
5748: . snes - the `SNES` context
5750: Output Parameter:
5751: . dm - the `DM`
5753: Level: intermediate
5755: .seealso: [](ch_snes), `DM`, `SNES`, `SNESSetDM()`, `KSPSetDM()`, `KSPGetDM()`
5756: @*/
5757: PetscErrorCode SNESGetDM(SNES snes, DM *dm)
5758: {
5759: PetscFunctionBegin;
5761: if (!snes->dm) {
5762: PetscCall(DMShellCreate(PetscObjectComm((PetscObject)snes), &snes->dm));
5763: snes->dmAuto = PETSC_TRUE;
5764: }
5765: *dm = snes->dm;
5766: PetscFunctionReturn(PETSC_SUCCESS);
5767: }
5769: /*@
5770: SNESSetNPC - Sets the nonlinear preconditioner to be used.
5772: Collective
5774: Input Parameters:
5775: + snes - iterative context obtained from `SNESCreate()`
5776: - npc - the `SNES` nonlinear preconditioner object
5778: Options Database Key:
5779: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5781: Level: developer
5783: Notes:
5784: This is rarely used, rather use `SNESGetNPC()` to retrieve the preconditioner and configure it using the API.
5786: Only some `SNESType` can use a nonlinear preconditioner
5788: .seealso: [](ch_snes), `SNES`, `SNESNGS`, `SNESFAS`, `SNESGetNPC()`, `SNESHasNPC()`
5789: @*/
5790: PetscErrorCode SNESSetNPC(SNES snes, SNES npc)
5791: {
5792: PetscFunctionBegin;
5795: PetscCheckSameComm(snes, 1, npc, 2);
5796: PetscCall(PetscObjectReference((PetscObject)npc));
5797: PetscCall(SNESDestroy(&snes->npc));
5798: snes->npc = npc;
5799: PetscFunctionReturn(PETSC_SUCCESS);
5800: }
5802: /*@
5803: SNESGetNPC - Gets a nonlinear preconditioning solver SNES` to be used to precondition the original nonlinear solver.
5805: Not Collective; but any changes to the obtained the `pc` object must be applied collectively
5807: Input Parameter:
5808: . snes - iterative context obtained from `SNESCreate()`
5810: Output Parameter:
5811: . pc - the `SNES` preconditioner context
5813: Options Database Key:
5814: . -npc_snes_type <type> - set the type of the `SNES` to use as the nonlinear preconditioner
5816: Level: advanced
5818: Notes:
5819: If a `SNES` was previously set with `SNESSetNPC()` then that value is returned, otherwise a new `SNES` object is created that will
5820: be used as the nonlinear preconditioner for the current `SNES`.
5822: The (preconditioner) `SNES` returned automatically inherits the same nonlinear function and Jacobian supplied to the original
5823: `SNES`. These may be overwritten if needed.
5825: Use the options database prefixes `-npc_snes`, `-npc_ksp`, etc., to control the configuration of the nonlinear preconditioner
5827: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESHasNPC()`, `SNES`, `SNESCreate()`
5828: @*/
5829: PetscErrorCode SNESGetNPC(SNES snes, SNES *pc)
5830: {
5831: const char *optionsprefix;
5833: PetscFunctionBegin;
5835: PetscAssertPointer(pc, 2);
5836: if (!snes->npc) {
5837: PetscCtx ctx;
5839: PetscCall(SNESCreate(PetscObjectComm((PetscObject)snes), &snes->npc));
5840: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes->npc, (PetscObject)snes, 1));
5841: PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
5842: PetscCall(SNESSetOptionsPrefix(snes->npc, optionsprefix));
5843: PetscCall(SNESAppendOptionsPrefix(snes->npc, "npc_"));
5844: if (snes->ops->ctxcompute) {
5845: PetscCall(SNESSetComputeApplicationContext(snes, snes->ops->ctxcompute, snes->ops->ctxdestroy));
5846: } else {
5847: PetscCall(SNESGetApplicationContext(snes, &ctx));
5848: PetscCall(SNESSetApplicationContext(snes->npc, ctx));
5849: }
5850: PetscCall(SNESSetCountersReset(snes->npc, PETSC_FALSE));
5851: }
5852: *pc = snes->npc;
5853: PetscFunctionReturn(PETSC_SUCCESS);
5854: }
5856: /*@
5857: SNESHasNPC - Returns whether a nonlinear preconditioner is associated with the given `SNES`
5859: Not Collective
5861: Input Parameter:
5862: . snes - iterative context obtained from `SNESCreate()`
5864: Output Parameter:
5865: . has_npc - whether the `SNES` has a nonlinear preconditioner or not
5867: Level: developer
5869: .seealso: [](ch_snes), `SNESSetNPC()`, `SNESGetNPC()`
5870: @*/
5871: PetscErrorCode SNESHasNPC(SNES snes, PetscBool *has_npc)
5872: {
5873: PetscFunctionBegin;
5875: PetscAssertPointer(has_npc, 2);
5876: *has_npc = snes->npc ? PETSC_TRUE : PETSC_FALSE;
5877: PetscFunctionReturn(PETSC_SUCCESS);
5878: }
5880: /*@
5881: SNESSetNPCSide - Sets the nonlinear preconditioning side used by the nonlinear preconditioner inside `SNES`.
5883: Logically Collective
5885: Input Parameter:
5886: . snes - iterative context obtained from `SNESCreate()`
5888: Output Parameter:
5889: . side - the preconditioning side, where side is one of
5890: .vb
5891: PC_LEFT - left preconditioning
5892: PC_RIGHT - right preconditioning (default for most nonlinear solvers)
5893: .ve
5895: Options Database Key:
5896: . -snes_npc_side <right,left> - nonlinear preconditioner side
5898: Level: intermediate
5900: Note:
5901: `SNESNRICHARDSON` and `SNESNCG` only support left preconditioning.
5903: .seealso: [](ch_snes), `SNES`, `SNESGetNPC()`, `SNESNRICHARDSON`, `SNESNCG`, `SNESType`, `SNESGetNPCSide()`, `KSPSetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5904: @*/
5905: PetscErrorCode SNESSetNPCSide(SNES snes, PCSide side)
5906: {
5907: PetscFunctionBegin;
5910: if (side == PC_SIDE_DEFAULT) side = PC_RIGHT;
5911: PetscCheck((side == PC_LEFT) || (side == PC_RIGHT), PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONG, "Only PC_LEFT and PC_RIGHT are supported");
5912: snes->npcside = side;
5913: PetscFunctionReturn(PETSC_SUCCESS);
5914: }
5916: /*@
5917: SNESGetNPCSide - Gets the preconditioning side used by the nonlinear preconditioner inside `SNES`.
5919: Not Collective
5921: Input Parameter:
5922: . snes - iterative context obtained from `SNESCreate()`
5924: Output Parameter:
5925: . side - the preconditioning side, where side is one of
5926: .vb
5927: `PC_LEFT` - left preconditioning
5928: `PC_RIGHT` - right preconditioning (default for most nonlinear solvers)
5929: .ve
5931: Level: intermediate
5933: .seealso: [](ch_snes), `SNES`, `SNESGetNPC()`, `SNESSetNPCSide()`, `KSPGetPCSide()`, `PC_LEFT`, `PC_RIGHT`, `PCSide`
5934: @*/
5935: PetscErrorCode SNESGetNPCSide(SNES snes, PCSide *side)
5936: {
5937: PetscFunctionBegin;
5939: PetscAssertPointer(side, 2);
5940: *side = snes->npcside;
5941: PetscFunctionReturn(PETSC_SUCCESS);
5942: }
5944: /*@
5945: SNESSetLineSearch - Sets the `SNESLineSearch` to be used for a given `SNES`
5947: Collective
5949: Input Parameters:
5950: + snes - iterative context obtained from `SNESCreate()`
5951: - linesearch - the linesearch object
5953: Level: developer
5955: Note:
5956: This is almost never used, rather one uses `SNESGetLineSearch()` to retrieve the line search and set options on it
5957: to configure it using the API).
5959: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`, `SNESGetLineSearch()`
5960: @*/
5961: PetscErrorCode SNESSetLineSearch(SNES snes, SNESLineSearch linesearch)
5962: {
5963: PetscFunctionBegin;
5966: PetscCheckSameComm(snes, 1, linesearch, 2);
5967: PetscCall(PetscObjectReference((PetscObject)linesearch));
5968: PetscCall(SNESLineSearchDestroy(&snes->linesearch));
5970: snes->linesearch = linesearch;
5971: PetscFunctionReturn(PETSC_SUCCESS);
5972: }