Actual source code: itcreate.c
1: /*
2: The basic KSP routines, Create, View etc. are here.
3: */
4: #include <petsc/private/kspimpl.h>
6: /* Logging support */
7: PetscClassId KSP_CLASSID;
8: PetscClassId DMKSP_CLASSID;
9: PetscClassId KSPGUESS_CLASSID;
10: PetscLogEvent KSP_GMRESOrthogonalization, KSP_SetUp, KSP_Solve, KSP_SolveTranspose, KSP_MatSolve, KSP_MatSolveTranspose;
12: /*
13: Contains the list of registered KSP routines
14: */
15: PetscFunctionList KSPList = NULL;
16: PetscBool KSPRegisterAllCalled = PETSC_FALSE;
18: /*
19: Contains the list of registered KSP monitors
20: */
21: PetscFunctionList KSPMonitorList = NULL;
22: PetscFunctionList KSPMonitorCreateList = NULL;
23: PetscFunctionList KSPMonitorDestroyList = NULL;
24: PetscBool KSPMonitorRegisterAllCalled = PETSC_FALSE;
26: /*@
27: KSPLoad - Loads a `KSP` that has been stored in a `PETSCVIEWERBINARY` with `KSPView()`.
29: Collective
31: Input Parameters:
32: + newdm - the newly loaded `KSP`, this needs to have been created with `KSPCreate()` or
33: some related function before a call to `KSPLoad()`.
34: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()`
36: Level: intermediate
38: Note:
39: The type is determined by the data in the file, any type set into the `KSP` before this call is ignored.
41: .seealso: [](ch_ksp), `KSP`, `PetscViewerBinaryOpen()`, `KSPView()`, `MatLoad()`, `VecLoad()`
42: @*/
43: PetscErrorCode KSPLoad(KSP newdm, PetscViewer viewer)
44: {
45: PetscBool isbinary;
46: PetscInt classid;
47: char type[256];
48: PC pc;
50: PetscFunctionBegin;
53: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
54: PetscCheck(isbinary, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen()");
56: PetscCall(PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT));
57: PetscCheck(classid == KSP_FILE_CLASSID, PetscObjectComm((PetscObject)newdm), PETSC_ERR_ARG_WRONG, "Not KSP next in file");
58: PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
59: PetscCall(KSPSetType(newdm, type));
60: PetscTryTypeMethod(newdm, load, viewer);
61: PetscCall(KSPGetPC(newdm, &pc));
62: PetscCall(PCLoad(pc, viewer));
63: PetscFunctionReturn(PETSC_SUCCESS);
64: }
66: #include <petscdraw.h>
67: #if defined(PETSC_HAVE_SAWS)
68: #include <petscviewersaws.h>
69: #endif
70: /*@
71: KSPView - Prints the various parameters currently set in the `KSP` object. For example, the convergence tolerances and `KSPType`.
72: Also views the `PC` and `Mat` contained by the `KSP` with `PCView()` and `MatView()`.
74: Collective
76: Input Parameters:
77: + ksp - the Krylov space context
78: - viewer - visualization context
80: Options Database Key:
81: . -ksp_view - print the `KSP` data structure at the end of each `KSPSolve()` call
83: Level: beginner
85: Notes:
86: The available visualization contexts include
87: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
88: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
89: output where only the first processor opens
90: the file. All other processors send their
91: data to the first processor to print.
93: The available formats include
94: + `PETSC_VIEWER_DEFAULT` - standard output (default)
95: - `PETSC_VIEWER_ASCII_INFO_DETAIL` - more verbose output for `PCBJACOBI` and `PCASM`
97: The user can open an alternative visualization context with
98: `PetscViewerASCIIOpen()` - output to a specified file.
100: Use `KSPViewFromOptions()` to allow the user to select many different `PetscViewerType` and formats from the options database.
102: In the debugger you can do call `KSPView(ksp,0)` to display the `KSP`. (The same holds for any PETSc object viewer).
104: .seealso: [](ch_ksp), `KSP`, `PetscViewer`, `PCView()`, `PetscViewerASCIIOpen()`, `KSPViewFromOptions()`
105: @*/
106: PetscErrorCode KSPView(KSP ksp, PetscViewer viewer)
107: {
108: PetscBool isascii, isbinary, isdraw, isstring;
109: #if defined(PETSC_HAVE_SAWS)
110: PetscBool issaws;
111: #endif
113: PetscFunctionBegin;
115: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ksp), &viewer));
117: PetscCheckSameComm(ksp, 1, viewer, 2);
119: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
120: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
121: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
122: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
123: #if defined(PETSC_HAVE_SAWS)
124: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
125: #endif
126: if (isascii) {
127: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)ksp, viewer));
128: PetscCall(PetscViewerASCIIPushTab(viewer));
129: PetscTryTypeMethod(ksp, view, viewer);
130: PetscCall(PetscViewerASCIIPopTab(viewer));
131: if (ksp->guess_zero) {
132: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", initial guess is zero\n", ksp->max_it));
133: } else {
134: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", nonzero initial guess\n", ksp->max_it));
135: }
136: if (ksp->min_it) PetscCall(PetscViewerASCIIPrintf(viewer, " minimum iterations=%" PetscInt_FMT "\n", ksp->min_it));
137: if (ksp->guess_knoll) PetscCall(PetscViewerASCIIPrintf(viewer, " using preconditioner applied to right-hand side for initial guess\n"));
138: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, divergence=%g\n", (double)ksp->rtol, (double)ksp->abstol, (double)ksp->divtol));
139: if (ksp->pc_side == PC_RIGHT) {
140: PetscCall(PetscViewerASCIIPrintf(viewer, " right preconditioning\n"));
141: } else if (ksp->pc_side == PC_SYMMETRIC) {
142: PetscCall(PetscViewerASCIIPrintf(viewer, " symmetric preconditioning\n"));
143: } else {
144: PetscCall(PetscViewerASCIIPrintf(viewer, " left preconditioning\n"));
145: }
146: if (ksp->guess) {
147: PetscCall(PetscViewerASCIIPushTab(viewer));
148: PetscCall(KSPGuessView(ksp->guess, viewer));
149: PetscCall(PetscViewerASCIIPopTab(viewer));
150: }
151: if (ksp->dscale) PetscCall(PetscViewerASCIIPrintf(viewer, " diagonally scaled system\n"));
152: if (ksp->converged == KSPConvergedSkip || ksp->normtype == KSP_NORM_NONE) PetscCall(PetscViewerASCIIPrintf(viewer, " not checking for convergence\n"));
153: else PetscCall(PetscViewerASCIIPrintf(viewer, " using %s norm type for convergence test\n", KSPNormTypes[ksp->normtype]));
154: } else if (isbinary) {
155: PetscInt classid = KSP_FILE_CLASSID;
156: MPI_Comm comm;
157: PetscMPIInt rank;
158: char type[256];
160: PetscCall(PetscObjectGetComm((PetscObject)ksp, &comm));
161: PetscCallMPI(MPI_Comm_rank(comm, &rank));
162: if (rank == 0) {
163: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
164: PetscCall(PetscStrncpy(type, ((PetscObject)ksp)->type_name, 256));
165: PetscCall(PetscViewerBinaryWrite(viewer, type, 256, PETSC_CHAR));
166: }
167: PetscTryTypeMethod(ksp, view, viewer);
168: } else if (isstring) {
169: const char *type;
170: PetscCall(KSPGetType(ksp, &type));
171: PetscCall(PetscViewerStringSPrintf(viewer, " KSPType: %-7.7s", type));
172: PetscTryTypeMethod(ksp, view, viewer);
173: } else if (isdraw) {
174: PetscDraw draw;
175: char str[36];
176: PetscReal x, y, bottom, h;
177: PetscBool flg;
179: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
180: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
181: PetscCall(PetscObjectTypeCompare((PetscObject)ksp, KSPPREONLY, &flg));
182: if (!flg) {
183: PetscCall(PetscStrncpy(str, "KSP: ", sizeof(str)));
184: PetscCall(PetscStrlcat(str, ((PetscObject)ksp)->type_name, sizeof(str)));
185: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_RED, PETSC_DRAW_BLACK, str, NULL, &h));
186: bottom = y - h;
187: } else {
188: bottom = y;
189: }
190: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
191: #if defined(PETSC_HAVE_SAWS)
192: } else if (issaws) {
193: PetscMPIInt rank;
194: const char *name;
196: PetscCall(PetscObjectGetName((PetscObject)ksp, &name));
197: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
198: if (!((PetscObject)ksp)->amsmem && rank == 0) {
199: char dir[1024];
201: PetscCall(PetscObjectViewSAWs((PetscObject)ksp, viewer));
202: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
203: PetscCallSAWs(SAWs_Register, (dir, &ksp->its, 1, SAWs_READ, SAWs_INT));
204: if (!ksp->res_hist) PetscCall(KSPSetResidualHistory(ksp, NULL, PETSC_DECIDE, PETSC_TRUE));
205: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/res_hist", name));
206: PetscCallSAWs(SAWs_Register, (dir, ksp->res_hist, 10, SAWs_READ, SAWs_DOUBLE));
207: }
208: #endif
209: } else PetscTryTypeMethod(ksp, view, viewer);
210: if (ksp->pc) PetscCall(PCView(ksp->pc, viewer));
211: if (isdraw) {
212: PetscDraw draw;
213: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
214: PetscCall(PetscDrawPopCurrentPoint(draw));
215: }
216: PetscFunctionReturn(PETSC_SUCCESS);
217: }
219: /*@
220: KSPViewFromOptions - View (print) a `KSP` object based on values in the options database. Also views the `PC` and `Mat` contained by the `KSP`
221: with `PCView()` and `MatView()`.
223: Collective
225: Input Parameters:
226: + A - Krylov solver context
227: . obj - Optional object that provides the options prefix used to query the options database
228: - name - command line option
230: Level: intermediate
232: .seealso: [](ch_ksp), `KSP`, `KSPView()`, `PetscObjectViewFromOptions()`, `KSPCreate()`
233: @*/
234: PetscErrorCode KSPViewFromOptions(KSP A, PetscObject obj, const char name[])
235: {
236: PetscFunctionBegin;
238: PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
239: PetscFunctionReturn(PETSC_SUCCESS);
240: }
242: /*@
243: KSPSetNormType - Sets the type of residual norm that is used for convergence testing in `KSPSolve()` for the given `KSP` context
245: Logically Collective
247: Input Parameters:
248: + ksp - Krylov solver context
249: - normtype - one of
250: .vb
251: KSP_NORM_NONE - skips computing the norm, this should generally only be used if you are using
252: the Krylov method as a smoother with a fixed small number of iterations.
253: Implicitly sets `KSPConvergedSkip()` as the `KSP` convergence test.
254: Note that certain algorithms such as `KSPGMRES` ALWAYS require the norm calculation,
255: for these methods the norms are still computed, they are just not used in
256: the convergence test.
257: KSP_NORM_PRECONDITIONED - the default for left-preconditioned solves, uses the 2-norm
258: of the preconditioned residual $B^{-1}(b - A x)$.
259: KSP_NORM_UNPRECONDITIONED - uses the 2-norm of the true $b - Ax$ residual.
260: KSP_NORM_NATURAL - uses the $A$ norm of the true $b - Ax$ residual; supported by `KSPCG`, `KSPCR`, `KSPCGNE`, `KSPCGS`
261: .ve
263: Options Database Key:
264: . -ksp_norm_type (none|preconditioned|unpreconditioned|natural) - set `KSP` norm type
266: Level: advanced
268: Notes:
269: The norm is always of the equations residual $\| b - A x^n \|$ (or an approximation to that norm), they are never a norm of the error in the equation.
271: Not all combinations of preconditioner side (see `KSPSetPCSide()`) and norm types are supported by all Krylov methods.
272: If only one is set, PETSc tries to automatically change the other to find a compatible pair. If no such combination
273: is supported, PETSc will generate an error.
275: Developer Note:
276: Supported combinations of norm and preconditioner side are set using `KSPSetSupportedNorm()` for each `KSPType`.
278: .seealso: [](ch_ksp), `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSPConvergedSkip()`, `KSPSetCheckNormIteration()`, `KSPSetPCSide()`, `KSPGetPCSide()`, `KSPNormType`
279: @*/
280: PetscErrorCode KSPSetNormType(KSP ksp, KSPNormType normtype)
281: {
282: PetscFunctionBegin;
285: ksp->normtype = ksp->normtype_set = normtype;
286: PetscFunctionReturn(PETSC_SUCCESS);
287: }
289: /*@
290: KSPSetCheckNormIteration - Sets the first iteration at which the norm of the residual will be
291: computed and used in the convergence test of `KSPSolve()` for the given `KSP` context
293: Logically Collective
295: Input Parameters:
296: + ksp - Krylov solver context
297: - it - use -1 to check at all iterations
299: Level: advanced
301: Notes:
302: Currently only works with `KSPCG`, `KSPBCGS` and `KSPIBCGS`
304: Use `KSPSetNormType`(ksp,`KSP_NORM_NONE`) to never check the norm
306: On steps where the norm is not computed, the previous norm is still in the variable, so if you run with, for example,
307: `-ksp_monitor` the residual norm will appear to be unchanged for several iterations (though it is not really unchanged).
309: Certain methods such as `KSPGMRES` always compute the residual norm, this routine will not change that computation, but it will
310: prevent the computed norm from being checked.
312: .seealso: [](ch_ksp), `KSP`, `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSPConvergedSkip()`, `KSPSetNormType()`, `KSPSetLagNorm()`
313: @*/
314: PetscErrorCode KSPSetCheckNormIteration(KSP ksp, PetscInt it)
315: {
316: PetscFunctionBegin;
319: ksp->chknorm = it;
320: PetscFunctionReturn(PETSC_SUCCESS);
321: }
323: /*@
324: KSPSetLagNorm - Lags the residual norm calculation so that it is computed as part of the `MPI_Allreduce()` used for
325: computing the inner products needed for the next iteration.
327: Logically Collective
329: Input Parameters:
330: + ksp - Krylov solver context
331: - flg - `PETSC_TRUE` or `PETSC_FALSE`
333: Options Database Key:
334: . -ksp_lag_norm - lag the calculated residual norm
336: Level: advanced
338: Notes:
339: Currently only works with `KSPIBCGS`.
341: This can reduce communication costs at the expense of doing
342: one additional iteration because the norm used in the convergence test of `KSPSolve()` is one iteration behind the actual
343: current residual norm (which has not yet been computed due to the lag).
345: Use `KSPSetNormType`(ksp,`KSP_NORM_NONE`) to never check the norm
347: If you lag the norm and run with, for example, `-ksp_monitor`, the residual norm reported will be the lagged one.
349: `KSPSetCheckNormIteration()` is an alternative way of avoiding the expense of computing the residual norm at each iteration.
351: .seealso: [](ch_ksp), `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSPConvergedSkip()`, `KSPSetNormType()`, `KSPSetCheckNormIteration()`
352: @*/
353: PetscErrorCode KSPSetLagNorm(KSP ksp, PetscBool flg)
354: {
355: PetscFunctionBegin;
358: ksp->lagnorm = flg;
359: PetscFunctionReturn(PETSC_SUCCESS);
360: }
362: /*@
363: KSPSetSupportedNorm - Sets a norm and preconditioner side supported by a `KSPType`
365: Logically Collective
367: Input Parameters:
368: + ksp - Krylov method
369: . normtype - supported norm type of the type `KSPNormType`
370: . pcside - preconditioner side, of the type `PCSide` that can be used with this `KSPNormType`
371: - priority - positive integer preference for this combination; larger values have higher priority
373: Level: developer
375: Notes:
376: This function should be called from the implementation files `KSPCreate_XXX()` to declare
377: which norms and preconditioner sides are supported. Users should not call this
378: function.
380: This function can be called multiple times for each combination of `KSPNormType` and `PCSide`
381: the `KSPType` supports
383: .seealso: [](ch_ksp), `KSP`, `KSPNormType`, `PCSide`, `KSPSetNormType()`, `KSPSetPCSide()`
384: @*/
385: PetscErrorCode KSPSetSupportedNorm(KSP ksp, KSPNormType normtype, PCSide pcside, PetscInt priority)
386: {
387: PetscFunctionBegin;
389: ksp->normsupporttable[normtype][pcside] = priority;
390: PetscFunctionReturn(PETSC_SUCCESS);
391: }
393: static PetscErrorCode KSPNormSupportTableReset_Private(KSP ksp)
394: {
395: PetscFunctionBegin;
396: PetscCall(PetscMemzero(ksp->normsupporttable, sizeof(ksp->normsupporttable)));
397: ksp->pc_side = ksp->pc_side_set;
398: ksp->normtype = ksp->normtype_set;
399: PetscFunctionReturn(PETSC_SUCCESS);
400: }
402: PetscErrorCode KSPSetUpNorms_Private(KSP ksp, PetscBool errorifnotsupported, KSPNormType *normtype, PCSide *pcside)
403: {
404: PetscInt i, j, best, ibest = 0, jbest = 0;
406: PetscFunctionBegin;
407: best = 0;
408: for (i = 0; i < KSP_NORM_MAX; i++) {
409: for (j = 0; j < PC_SIDE_MAX; j++) {
410: if ((ksp->normtype == KSP_NORM_DEFAULT || ksp->normtype == i) && (ksp->pc_side == PC_SIDE_DEFAULT || ksp->pc_side == j) && ksp->normsupporttable[i][j] > best) {
411: best = ksp->normsupporttable[i][j];
412: ibest = i;
413: jbest = j;
414: }
415: }
416: }
417: if (best < 1 && errorifnotsupported) {
418: PetscCheck(ksp->normtype != KSP_NORM_DEFAULT || ksp->pc_side != PC_SIDE_DEFAULT, PetscObjectComm((PetscObject)ksp), PETSC_ERR_PLIB, "The %s KSP implementation did not call KSPSetSupportedNorm()", ((PetscObject)ksp)->type_name);
419: PetscCheck(ksp->normtype != KSP_NORM_DEFAULT, PetscObjectComm((PetscObject)ksp), PETSC_ERR_SUP, "KSP %s does not support preconditioner side %s", ((PetscObject)ksp)->type_name, PCSides[ksp->pc_side]);
420: PetscCheck(ksp->pc_side != PC_SIDE_DEFAULT, PetscObjectComm((PetscObject)ksp), PETSC_ERR_SUP, "KSP %s does not support norm type %s", ((PetscObject)ksp)->type_name, KSPNormTypes[ksp->normtype]);
421: SETERRQ(PetscObjectComm((PetscObject)ksp), PETSC_ERR_SUP, "KSP %s does not support norm type %s with preconditioner side %s", ((PetscObject)ksp)->type_name, KSPNormTypes[ksp->normtype], PCSides[ksp->pc_side]);
422: }
423: if (normtype) *normtype = (KSPNormType)ibest;
424: if (pcside) *pcside = (PCSide)jbest;
425: PetscFunctionReturn(PETSC_SUCCESS);
426: }
428: /*@
429: KSPGetNormType - Gets the `KSPNormType` that is used for convergence testing during `KSPSolve()` for this `KSP` context
431: Not Collective
433: Input Parameter:
434: . ksp - Krylov solver context
436: Output Parameter:
437: . normtype - the `KSPNormType` that is used for convergence testing
439: Level: advanced
441: .seealso: [](ch_ksp), `KSPNormType`, `KSPSetNormType()`, `KSPConvergedSkip()`
442: @*/
443: PetscErrorCode KSPGetNormType(KSP ksp, KSPNormType *normtype)
444: {
445: PetscFunctionBegin;
447: PetscAssertPointer(normtype, 2);
448: PetscCall(KSPSetUpNorms_Private(ksp, PETSC_TRUE, &ksp->normtype, &ksp->pc_side));
449: *normtype = ksp->normtype;
450: PetscFunctionReturn(PETSC_SUCCESS);
451: }
453: #if defined(PETSC_HAVE_SAWS)
454: #include <petscviewersaws.h>
455: #endif
457: /*@
458: KSPSetOperators - Sets the matrix associated with the linear system
459: and a (possibly) different one from which the preconditioner will be built into the `KSP` context. The matrix will then be used during `KSPSolve()`
461: Collective
463: Input Parameters:
464: + ksp - the `KSP` context
465: . Amat - the matrix that defines the linear system
466: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
468: Level: beginner
470: Notes:
471: .vb
472: KSPSetOperators(ksp, Amat, Pmat);
473: .ve
474: is the same as
475: .vb
476: KSPGetPC(ksp, &pc);
477: PCSetOperators(pc, Amat, Pmat);
478: .ve
479: and is equivalent to
480: .vb
481: PCCreate(PetscObjectComm((PetscObject)ksp), &pc);
482: PCSetOperators(pc, Amat, Pmat);
483: KSPSetPC(ksp, pc);
484: .ve
486: If you know the operator `Amat` has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
487: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
489: All future calls to `KSPSetOperators()` must use the same size matrices, unless `KSPReset()` is called!
491: Passing a `NULL` for `Amat` or `Pmat` removes the matrix that is currently being used from the `KSP` context.
493: If you wish to replace either `Amat` or `Pmat` but leave the other one untouched then
494: first call `KSPGetOperators()` to get the one you wish to keep, call `PetscObjectReference()`
495: on it and then pass it back in your call to `KSPSetOperators()`.
497: Developer Notes:
498: If the operators have NOT been set with `KSPSetOperators()` then the operators
499: are created in the `PC` and returned to the user. In this case, if both operators
500: mat and pmat are requested, two DIFFERENT operators will be returned. If
501: only one is requested both operators in the `PC` will be the same (i.e. as
502: if one had called `KSPSetOperators()` with the same argument for both `Mat`s).
503: The user must set the sizes of the returned matrices and their type etc just
504: as if the user created them with `MatCreate()`. For example,
506: .vb
507: KSPGetOperators(ksp/pc,&mat,NULL); is equivalent to
508: set size, type, etc of mat
510: MatCreate(comm,&mat);
511: KSP/PCSetOperators(ksp/pc,mat,mat);
512: PetscObjectDereference((PetscObject)mat);
513: set size, type, etc of mat
515: and
517: KSP/PCGetOperators(ksp/pc,&mat,&pmat); is equivalent to
518: set size, type, etc of mat and pmat
520: MatCreate(comm,&mat);
521: MatCreate(comm,&pmat);
522: KSP/PCSetOperators(ksp/pc,mat,pmat);
523: PetscObjectDereference((PetscObject)mat);
524: PetscObjectDereference((PetscObject)pmat);
525: set size, type, etc of mat and pmat
526: .ve
528: The rationale for this support is so that when creating a `TS`, `SNES`, or `KSP` the hierarchy
529: of underlying objects (i.e. `SNES`, `KSP`, `PC`, `Mat`) and their lifespans can be completely
530: managed by the top most level object (i.e. the `TS`, `SNES`, or `KSP`). Another way to look
531: at this is when you create a `SNES` you do not NEED to create a `KSP` and attach it to
532: the `SNES` object (the `SNES` object manages it for you). Similarly when you create a `KSP`
533: you do not need to attach a `PC` to it (the `KSP` object manages the `PC` object for you).
534: Thus, why should YOU have to create the `Mat` and attach it to the `SNES`/`KSP`/`PC`, when
535: it can be created for you?
537: .seealso: [](ch_ksp), `KSP`, `Mat`, `KSPSolve()`, `KSPGetPC()`, `PCGetOperators()`, `PCSetOperators()`, `KSPGetOperators()`, `KSPSetComputeOperators()`, `KSPSetComputeInitialGuess()`, `KSPSetComputeRHS()`
538: @*/
539: PetscErrorCode KSPSetOperators(KSP ksp, Mat Amat, Mat Pmat)
540: {
541: PetscFunctionBegin;
545: if (Amat) PetscCheckSameComm(ksp, 1, Amat, 2);
546: if (Pmat) PetscCheckSameComm(ksp, 1, Pmat, 3);
547: if (!ksp->pc) PetscCall(KSPGetPC(ksp, &ksp->pc));
548: PetscCall(PCSetOperators(ksp->pc, Amat, Pmat));
549: if (ksp->setupstage == KSP_SETUP_NEWRHS) ksp->setupstage = KSP_SETUP_NEWMATRIX; /* so that next solve call will call PCSetUp() on new matrix */
550: PetscFunctionReturn(PETSC_SUCCESS);
551: }
553: /*@
554: KSPGetOperators - Gets the matrix associated with the linear system
555: and a (possibly) different one used to construct the preconditioner from the `KSP` context
557: Collective
559: Input Parameter:
560: . ksp - the `KSP` context
562: Output Parameters:
563: + Amat - the matrix that defines the linear system
564: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
566: Level: intermediate
568: Notes:
569: If `KSPSetOperators()` has not been called then the `KSP` object will attempt to automatically create the matrix `Amat` and return it
571: Use `KSPGetOperatorsSet()` to determine if matrices have been provided.
573: DOES NOT increase the reference counts of the matrix, so you should NOT destroy them.
575: .seealso: [](ch_ksp), `KSP`, `KSPSolve()`, `KSPGetPC()`, `PCSetOperators()`, `KSPSetOperators()`, `KSPGetOperatorsSet()`
576: @*/
577: PetscErrorCode KSPGetOperators(KSP ksp, Mat *Amat, Mat *Pmat)
578: {
579: PetscFunctionBegin;
581: if (!ksp->pc) PetscCall(KSPGetPC(ksp, &ksp->pc));
582: PetscCall(PCGetOperators(ksp->pc, Amat, Pmat));
583: PetscFunctionReturn(PETSC_SUCCESS);
584: }
586: /*@
587: KSPGetOperatorsSet - Determines if the matrix associated with the linear system and
588: possibly a different one from which the preconditioner will be built have been set in the `KSP` with `KSPSetOperators()`
590: Not Collective, though the results on all processes will be the same
592: Input Parameter:
593: . ksp - the `KSP` context
595: Output Parameters:
596: + mat - the matrix associated with the linear system was set
597: - pmat - matrix from which the preconditioner will be built, usually the same as `mat` was set
599: Level: intermediate
601: Note:
602: This routine exists because if you call `KSPGetOperators()` on a `KSP` that does not yet have operators they are
603: automatically created in the call.
605: .seealso: [](ch_ksp), `KSP`, `PCSetOperators()`, `KSPGetOperators()`, `KSPSetOperators()`, `PCGetOperators()`, `PCGetOperatorsSet()`
606: @*/
607: PetscErrorCode KSPGetOperatorsSet(KSP ksp, PetscBool *mat, PetscBool *pmat)
608: {
609: PetscFunctionBegin;
611: if (!ksp->pc) PetscCall(KSPGetPC(ksp, &ksp->pc));
612: PetscCall(PCGetOperatorsSet(ksp->pc, mat, pmat));
613: PetscFunctionReturn(PETSC_SUCCESS);
614: }
616: /*@C
617: KSPSetPreSolve - Sets a function that is called at the beginning of each `KSPSolve()`. Used in conjunction with `KSPSetPostSolve()`.
619: Logically Collective
621: Input Parameters:
622: + ksp - the solver object
623: . presolve - the function to call before the solve, see` KSPPSolveFn`
624: - ctx - an optional context needed by the function
626: Level: developer
628: Notes:
629: The function provided here `presolve` is used to modify the right hand side, and possibly the matrix, of the linear system to be solved.
630: The function provided with `KSPSetPostSolve()` then modifies the resulting solution of that linear system to obtain the correct solution
631: to the initial linear system.
633: The functions `PCPreSolve()` and `PCPostSolve()` provide a similar functionality and are used, for example with `PCEISENSTAT`.
635: .seealso: [](ch_ksp), `KSPPSolveFn`, `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPSetPostSolve()`, `PCEISENSTAT`, `PCPreSolve()`, `PCPostSolve()`
636: @*/
637: PetscErrorCode KSPSetPreSolve(KSP ksp, KSPPSolveFn *presolve, PetscCtx ctx)
638: {
639: PetscFunctionBegin;
641: ksp->presolve = presolve;
642: ksp->prectx = ctx;
643: PetscFunctionReturn(PETSC_SUCCESS);
644: }
646: /*@C
647: KSPSetPostSolve - Sets a function that is called at the end of each `KSPSolve()` (whether it converges or not). Used in conjunction with `KSPSetPreSolve()`.
649: Logically Collective
651: Input Parameters:
652: + ksp - the solver object
653: . postsolve - the function to call after the solve, see` KSPPSolveFn`
654: - ctx - an optional context needed by the function
656: Level: developer
658: .seealso: [](ch_ksp), `KSPPSolveFn`, `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPSetPreSolve()`, `PCEISENSTAT`
659: @*/
660: PetscErrorCode KSPSetPostSolve(KSP ksp, KSPPSolveFn *postsolve, PetscCtx ctx)
661: {
662: PetscFunctionBegin;
664: ksp->postsolve = postsolve;
665: ksp->postctx = ctx;
666: PetscFunctionReturn(PETSC_SUCCESS);
667: }
669: /*@
670: KSPSetNestLevel - sets the amount of nesting the `KSP` has. That is the number of levels of `KSP` above this `KSP` in a linear solve.
672: Collective
674: Input Parameters:
675: + ksp - the `KSP`
676: - level - the nest level
678: Level: developer
680: Note:
681: For example, the `KSP` in each block of a `KSPBJACOBI` has a level of 1, while the outer `KSP` has a level of 0.
683: .seealso: [](ch_ksp), `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPGMRES`, `KSPType`, `KSPGetNestLevel()`, `PCSetKSPNestLevel()`, `PCGetKSPNestLevel()`
684: @*/
685: PetscErrorCode KSPSetNestLevel(KSP ksp, PetscInt level)
686: {
687: PetscFunctionBegin;
690: ksp->nestlevel = level;
691: PetscFunctionReturn(PETSC_SUCCESS);
692: }
694: /*@
695: KSPGetNestLevel - gets the amount of nesting the `KSP` has
697: Not Collective
699: Input Parameter:
700: . ksp - the `KSP`
702: Output Parameter:
703: . level - the nest level
705: Level: developer
707: .seealso: [](ch_ksp), `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPGMRES`, `KSPType`, `KSPSetNestLevel()`, `PCSetKSPNestLevel()`, `PCGetKSPNestLevel()`
708: @*/
709: PetscErrorCode KSPGetNestLevel(KSP ksp, PetscInt *level)
710: {
711: PetscFunctionBegin;
713: PetscAssertPointer(level, 2);
714: *level = ksp->nestlevel;
715: PetscFunctionReturn(PETSC_SUCCESS);
716: }
718: /*@
719: KSPCreate - Creates the `KSP` context. This `KSP` context is used in PETSc to solve linear systems with `KSPSolve()`
721: Collective
723: Input Parameter:
724: . comm - MPI communicator
726: Output Parameter:
727: . inksp - location to put the `KSP` context
729: Level: beginner
731: Note:
732: The default `KSPType` is `KSPGMRES` with a restart of 30, using modified Gram-Schmidt orthogonalization. The `KSPType` may be
733: changed with `KSPSetType()`
735: .seealso: [](ch_ksp), `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPGMRES`, `KSPType`, `KSPSetType()`
736: @*/
737: PetscErrorCode KSPCreate(MPI_Comm comm, KSP *inksp)
738: {
739: KSP ksp;
740: PetscCtx ctx;
742: PetscFunctionBegin;
743: PetscAssertPointer(inksp, 2);
744: PetscCall(KSPInitializePackage());
746: PetscCall(PetscHeaderCreate(ksp, KSP_CLASSID, "KSP", "Krylov Method", "KSP", comm, KSPDestroy, KSPView));
747: ksp->default_max_it = ksp->max_it = 10000;
748: ksp->pc_side = ksp->pc_side_set = PC_SIDE_DEFAULT;
750: ksp->default_rtol = ksp->rtol = 1.e-5;
751: ksp->default_abstol = ksp->abstol = PetscDefined(USE_REAL_SINGLE) ? 1.e-25 : 1.e-50;
752: ksp->default_divtol = ksp->divtol = 1.e4;
754: ksp->chknorm = -1;
755: ksp->normtype = ksp->normtype_set = KSP_NORM_DEFAULT;
756: ksp->rnorm = 0.0;
757: ksp->its = 0;
758: ksp->guess_zero = PETSC_TRUE;
759: ksp->calc_sings = PETSC_FALSE;
760: ksp->res_hist = NULL;
761: ksp->res_hist_alloc = NULL;
762: ksp->res_hist_len = 0;
763: ksp->res_hist_max = 0;
764: ksp->res_hist_reset = PETSC_TRUE;
765: ksp->err_hist = NULL;
766: ksp->err_hist_alloc = NULL;
767: ksp->err_hist_len = 0;
768: ksp->err_hist_max = 0;
769: ksp->err_hist_reset = PETSC_TRUE;
770: ksp->numbermonitors = 0;
771: ksp->numberreasonviews = 0;
772: ksp->setfromoptionscalled = 0;
773: ksp->nmax = PETSC_DECIDE;
775: PetscCall(KSPConvergedDefaultCreate(&ctx));
776: PetscCall(KSPSetConvergenceTest(ksp, KSPConvergedDefault, ctx, KSPConvergedDefaultDestroy));
777: ksp->ops->buildsolution = KSPBuildSolutionDefault;
778: ksp->ops->buildresidual = KSPBuildResidualDefault;
780: ksp->vec_sol = NULL;
781: ksp->vec_rhs = NULL;
782: ksp->pc = NULL;
783: ksp->data = NULL;
784: ksp->nwork = 0;
785: ksp->work = NULL;
786: ksp->reason = KSP_CONVERGED_ITERATING;
787: ksp->setupstage = KSP_SETUP_NEW;
789: PetscCall(KSPNormSupportTableReset_Private(ksp));
791: *inksp = ksp;
792: PetscFunctionReturn(PETSC_SUCCESS);
793: }
795: /*@
796: KSPSetType - Sets the algorithm/method to be used to solve the linear system with the given `KSP`
798: Logically Collective
800: Input Parameters:
801: + ksp - the Krylov space context
802: - type - a known method
804: Options Database Key:
805: . -ksp_type type - Sets the method; see `KSPType`
807: Level: intermediate
809: Notes:
810: See `KSPType` for available methods (for instance, `KSPCG` or `KSPGMRES`).
812: Normally, it is best to use the `KSPSetFromOptions()` command and
813: then set the `KSP` type from the options database rather than by using
814: this routine. Using the options database provides the user with
815: maximum flexibility in evaluating the many different Krylov methods.
816: The `KSPSetType()` routine is provided for those situations where it
817: is necessary to set the iterative solver independently of the command
818: line or options database. This might be the case, for example, when
819: the choice of iterative solver changes during the execution of the
820: program, and the user's application is taking responsibility for
821: choosing the appropriate method. In other words, this routine is
822: not for beginners.
824: Developer Note:
825: `KSPRegister()` is used to add Krylov types to `KSPList` from which they are accessed by `KSPSetType()`.
827: .seealso: [](ch_ksp), `PCSetType()`, `KSPType`, `KSPRegister()`, `KSPCreate()`, `KSP`
828: @*/
829: PetscErrorCode KSPSetType(KSP ksp, KSPType type)
830: {
831: PetscBool match;
832: PetscErrorCode (*r)(KSP);
834: PetscFunctionBegin;
836: PetscAssertPointer(type, 2);
838: PetscCall(PetscObjectTypeCompare((PetscObject)ksp, type, &match));
839: if (match) PetscFunctionReturn(PETSC_SUCCESS);
841: PetscCall(PetscFunctionListFind(KSPList, type, &r));
842: PetscCheck(r, PetscObjectComm((PetscObject)ksp), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested KSP type %s", type);
843: /* Destroy the previous private KSP context */
844: PetscTryTypeMethod(ksp, destroy);
846: /* Reinitialize function pointers in KSPOps structure */
847: PetscCall(PetscMemzero(ksp->ops, sizeof(struct _KSPOps)));
848: ksp->ops->buildsolution = KSPBuildSolutionDefault;
849: ksp->ops->buildresidual = KSPBuildResidualDefault;
850: PetscCall(KSPNormSupportTableReset_Private(ksp));
851: ksp->converged_neg_curve = PETSC_FALSE; // restore default
852: ksp->setupnewmatrix = PETSC_FALSE; // restore default (setup not called in case of new matrix)
853: /* Call the KSPCreate_XXX routine for this particular Krylov solver */
854: ksp->setupstage = KSP_SETUP_NEW;
855: ksp->guess_not_read = PETSC_FALSE; // restore default
856: PetscCall((*r)(ksp));
857: PetscCall(PetscObjectChangeTypeName((PetscObject)ksp, type));
858: PetscFunctionReturn(PETSC_SUCCESS);
859: }
861: /*@
862: KSPGetType - Gets the `KSP` type as a string from the `KSP` object.
864: Not Collective
866: Input Parameter:
867: . ksp - Krylov context
869: Output Parameter:
870: . type - name of the `KSP` method
872: Level: intermediate
874: .seealso: [](ch_ksp), `KSPType`, `KSP`, `KSPSetType()`
875: @*/
876: PetscErrorCode KSPGetType(KSP ksp, KSPType *type)
877: {
878: PetscFunctionBegin;
880: PetscAssertPointer(type, 2);
881: *type = ((PetscObject)ksp)->type_name;
882: PetscFunctionReturn(PETSC_SUCCESS);
883: }
885: /*@C
886: KSPRegister - Adds a method, `KSPType`, to the Krylov subspace solver package.
888: Not Collective, No Fortran Support
890: Input Parameters:
891: + sname - name of a new user-defined solver
892: - function - routine to create method
894: Level: advanced
896: Note:
897: `KSPRegister()` may be called multiple times to add several user-defined solvers.
899: Example Usage:
900: .vb
901: KSPRegister("my_solver", MySolverCreate);
902: .ve
904: Then, your solver can be chosen with the procedural interface via
905: .vb
906: KSPSetType(ksp, "my_solver")
907: .ve
908: or at runtime via the option `-ksp_type my_solver`
910: .seealso: [](ch_ksp), `KSP`, `KSPType`, `KSPSetType`, `KSPRegisterAll()`
911: @*/
912: PetscErrorCode KSPRegister(const char sname[], PetscErrorCode (*function)(KSP))
913: {
914: PetscFunctionBegin;
915: PetscCall(KSPInitializePackage());
916: PetscCall(PetscFunctionListAdd(&KSPList, sname, function));
917: PetscFunctionReturn(PETSC_SUCCESS);
918: }
920: PetscErrorCode KSPMonitorMakeKey_Internal(const char name[], PetscViewerType vtype, PetscViewerFormat format, char key[])
921: {
922: PetscFunctionBegin;
923: PetscCall(PetscStrncpy(key, name, PETSC_MAX_PATH_LEN));
924: PetscCall(PetscStrlcat(key, ":", PETSC_MAX_PATH_LEN));
925: PetscCall(PetscStrlcat(key, vtype, PETSC_MAX_PATH_LEN));
926: PetscCall(PetscStrlcat(key, ":", PETSC_MAX_PATH_LEN));
927: PetscCall(PetscStrlcat(key, PetscViewerFormats[format], PETSC_MAX_PATH_LEN));
928: PetscFunctionReturn(PETSC_SUCCESS);
929: }
931: /*@C
932: KSPMonitorRegister - Registers a Krylov subspace solver monitor routine that may be accessed with `KSPMonitorSetFromOptions()`
934: Not Collective
936: Input Parameters:
937: + name - name of a new monitor type
938: . vtype - A `PetscViewerType` for the output
939: . format - A `PetscViewerFormat` for the output
940: . monitor - Monitor routine, see `KSPMonitorRegisterFn`
941: . create - Creation routine, or `NULL`
942: - destroy - Destruction routine, or `NULL`
944: Level: advanced
946: Notes:
947: `KSPMonitorRegister()` may be called multiple times to add several user-defined monitors.
949: The calling sequence for the given function matches the calling sequence used by `KSPMonitorFn` functions passed to `KSPMonitorSet()` with the additional
950: requirement that its final argument be a `PetscViewerAndFormat`.
952: Example Usage:
953: .vb
954: KSPMonitorRegister("my_monitor", PETSCVIEWERASCII, PETSC_VIEWER_ASCII_INFO_DETAIL, MyMonitor, NULL, NULL);
955: .ve
957: Then, your monitor can be chosen with the procedural interface via
958: .vb
959: KSPMonitorSetFromOptions(ksp, "-ksp_monitor_my_monitor", "my_monitor", NULL)
960: .ve
961: or at runtime via the option `-ksp_monitor_my_monitor`
963: .seealso: [](ch_ksp), `KSP`, `KSPMonitorSet()`, `KSPMonitorRegisterAll()`, `KSPMonitorSetFromOptions()`
964: @*/
965: PetscErrorCode KSPMonitorRegister(const char name[], PetscViewerType vtype, PetscViewerFormat format, KSPMonitorRegisterFn *monitor, KSPMonitorRegisterCreateFn *create, KSPMonitorRegisterDestroyFn *destroy)
966: {
967: char key[PETSC_MAX_PATH_LEN];
969: PetscFunctionBegin;
970: PetscCall(KSPInitializePackage());
971: PetscCall(KSPMonitorMakeKey_Internal(name, vtype, format, key));
972: PetscCall(PetscFunctionListAdd(&KSPMonitorList, key, monitor));
973: if (create) PetscCall(PetscFunctionListAdd(&KSPMonitorCreateList, key, create));
974: if (destroy) PetscCall(PetscFunctionListAdd(&KSPMonitorDestroyList, key, destroy));
975: PetscFunctionReturn(PETSC_SUCCESS);
976: }