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: /*@C
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: `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: /*@C
71: KSPView - Prints the `KSP` data structure.
73: Collective
75: Input Parameters:
76: + ksp - the Krylov space context
77: - viewer - visualization context
79: Options Database Key:
80: . -ksp_view - print the `KSP` data structure at the end of each `KSPSolve()` call
82: Level: beginner
84: Notes:
85: The available visualization contexts include
86: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
87: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
88: output where only the first processor opens
89: the file. All other processors send their
90: data to the first processor to print.
92: The available formats include
93: + `PETSC_VIEWER_DEFAULT` - standard output (default)
94: - `PETSC_VIEWER_ASCII_INFO_DETAIL` - more verbose output for PCBJACOBI and PCASM
96: The user can open an alternative visualization context with
97: `PetscViewerASCIIOpen()` - output to a specified file.
99: In the debugger you can do call `KSPView(ksp,0)` to display the `KSP`. (The same holds for any PETSc object viewer).
101: .seealso: `KSP`, `PetscViewer`, `PCView()`, `PetscViewerASCIIOpen()`
102: @*/
103: PetscErrorCode KSPView(KSP ksp, PetscViewer viewer)
104: {
105: PetscBool iascii, isbinary, isdraw, isstring;
106: #if defined(PETSC_HAVE_SAWS)
107: PetscBool issaws;
108: #endif
110: PetscFunctionBegin;
112: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ksp), &viewer));
114: PetscCheckSameComm(ksp, 1, viewer, 2);
116: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
117: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
118: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
119: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
120: #if defined(PETSC_HAVE_SAWS)
121: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws));
122: #endif
123: if (iascii) {
124: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)ksp, viewer));
125: PetscCall(PetscViewerASCIIPushTab(viewer));
126: PetscTryTypeMethod(ksp, view, viewer);
127: PetscCall(PetscViewerASCIIPopTab(viewer));
128: if (ksp->guess_zero) {
129: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", initial guess is zero\n", ksp->max_it));
130: } else {
131: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", nonzero initial guess\n", ksp->max_it));
132: }
133: if (ksp->guess_knoll) PetscCall(PetscViewerASCIIPrintf(viewer, " using preconditioner applied to right hand side for initial guess\n"));
134: PetscCall(PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, divergence=%g\n", (double)ksp->rtol, (double)ksp->abstol, (double)ksp->divtol));
135: if (ksp->pc_side == PC_RIGHT) {
136: PetscCall(PetscViewerASCIIPrintf(viewer, " right preconditioning\n"));
137: } else if (ksp->pc_side == PC_SYMMETRIC) {
138: PetscCall(PetscViewerASCIIPrintf(viewer, " symmetric preconditioning\n"));
139: } else {
140: PetscCall(PetscViewerASCIIPrintf(viewer, " left preconditioning\n"));
141: }
142: if (ksp->guess) {
143: PetscCall(PetscViewerASCIIPushTab(viewer));
144: PetscCall(KSPGuessView(ksp->guess, viewer));
145: PetscCall(PetscViewerASCIIPopTab(viewer));
146: }
147: if (ksp->dscale) PetscCall(PetscViewerASCIIPrintf(viewer, " diagonally scaled system\n"));
148: PetscCall(PetscViewerASCIIPrintf(viewer, " using %s norm type for convergence test\n", KSPNormTypes[ksp->normtype]));
149: } else if (isbinary) {
150: PetscInt classid = KSP_FILE_CLASSID;
151: MPI_Comm comm;
152: PetscMPIInt rank;
153: char type[256];
155: PetscCall(PetscObjectGetComm((PetscObject)ksp, &comm));
156: PetscCallMPI(MPI_Comm_rank(comm, &rank));
157: if (rank == 0) {
158: PetscCall(PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT));
159: PetscCall(PetscStrncpy(type, ((PetscObject)ksp)->type_name, 256));
160: PetscCall(PetscViewerBinaryWrite(viewer, type, 256, PETSC_CHAR));
161: }
162: PetscTryTypeMethod(ksp, view, viewer);
163: } else if (isstring) {
164: const char *type;
165: PetscCall(KSPGetType(ksp, &type));
166: PetscCall(PetscViewerStringSPrintf(viewer, " KSPType: %-7.7s", type));
167: PetscTryTypeMethod(ksp, view, viewer);
168: } else if (isdraw) {
169: PetscDraw draw;
170: char str[36];
171: PetscReal x, y, bottom, h;
172: PetscBool flg;
174: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
175: PetscCall(PetscDrawGetCurrentPoint(draw, &x, &y));
176: PetscCall(PetscObjectTypeCompare((PetscObject)ksp, KSPPREONLY, &flg));
177: if (!flg) {
178: PetscCall(PetscStrncpy(str, "KSP: ", sizeof(str)));
179: PetscCall(PetscStrlcat(str, ((PetscObject)ksp)->type_name, sizeof(str)));
180: PetscCall(PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_RED, PETSC_DRAW_BLACK, str, NULL, &h));
181: bottom = y - h;
182: } else {
183: bottom = y;
184: }
185: PetscCall(PetscDrawPushCurrentPoint(draw, x, bottom));
186: #if defined(PETSC_HAVE_SAWS)
187: } else if (issaws) {
188: PetscMPIInt rank;
189: const char *name;
191: PetscCall(PetscObjectGetName((PetscObject)ksp, &name));
192: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
193: if (!((PetscObject)ksp)->amsmem && rank == 0) {
194: char dir[1024];
196: PetscCall(PetscObjectViewSAWs((PetscObject)ksp, viewer));
197: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name));
198: PetscCallSAWs(SAWs_Register, (dir, &ksp->its, 1, SAWs_READ, SAWs_INT));
199: if (!ksp->res_hist) PetscCall(KSPSetResidualHistory(ksp, NULL, PETSC_DECIDE, PETSC_TRUE));
200: PetscCall(PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/res_hist", name));
201: PetscCallSAWs(SAWs_Register, (dir, ksp->res_hist, 10, SAWs_READ, SAWs_DOUBLE));
202: }
203: #endif
204: } else PetscTryTypeMethod(ksp, view, viewer);
205: if (ksp->pc) PetscCall(PCView(ksp->pc, viewer));
206: if (isdraw) {
207: PetscDraw draw;
208: PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
209: PetscCall(PetscDrawPopCurrentPoint(draw));
210: }
211: PetscFunctionReturn(PETSC_SUCCESS);
212: }
214: /*@C
215: KSPViewFromOptions - View a `KSP` object based on values in the options database
217: Collective
219: Input Parameters:
220: + A - Krylov solver context
221: . obj - Optional object
222: - name - command line option
224: Level: intermediate
226: .seealso: `KSP`, `KSPView`, `PetscObjectViewFromOptions()`, `KSPCreate()`
227: @*/
228: PetscErrorCode KSPViewFromOptions(KSP A, PetscObject obj, const char name[])
229: {
230: PetscFunctionBegin;
232: PetscCall(PetscObjectViewFromOptions((PetscObject)A, obj, name));
233: PetscFunctionReturn(PETSC_SUCCESS);
234: }
236: /*@
237: KSPSetNormType - Sets the norm that is used for convergence testing.
239: Logically Collective
241: Input Parameters:
242: + ksp - Krylov solver context
243: - normtype - one of
244: .vb
245: KSP_NORM_NONE - skips computing the norm, this should generally only be used if you are using
246: the Krylov method as a smoother with a fixed small number of iterations.
247: Implicitly sets KSPConvergedSkip() as KSP convergence test.
248: Note that certain algorithms such as KSPGMRES ALWAYS require the norm calculation,
249: for these methods the norms are still computed, they are just not used in
250: the convergence test.
251: KSP_NORM_PRECONDITIONED - the default for left preconditioned solves, uses the l2 norm
252: of the preconditioned residual P^{-1}(b - A x)
253: KSP_NORM_UNPRECONDITIONED - uses the l2 norm of the true b - Ax residual.
254: KSP_NORM_NATURAL - supported by KSPCG, KSPCR, KSPCGNE, KSPCGS
255: .ve
257: Options Database Key:
258: . -ksp_norm_type <none,preconditioned,unpreconditioned,natural> - set `KSP` norm type
260: Level: advanced
262: Note:
263: Not all combinations of preconditioner side (see `KSPSetPCSide()`) and norm type are supported by all Krylov methods.
264: If only one is set, PETSc tries to automatically change the other to find a compatible pair. If no such combination
265: is supported, PETSc will generate an error.
267: Developer Note:
268: Supported combinations of norm and preconditioner side are set using `KSPSetSupportedNorm()`.
270: .seealso: `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSPConvergedSkip()`, `KSPSetCheckNormIteration()`, `KSPSetPCSide()`, `KSPGetPCSide()`, `KSPNormType`
271: @*/
272: PetscErrorCode KSPSetNormType(KSP ksp, KSPNormType normtype)
273: {
274: PetscFunctionBegin;
277: ksp->normtype = ksp->normtype_set = normtype;
278: PetscFunctionReturn(PETSC_SUCCESS);
279: }
281: /*@
282: KSPSetCheckNormIteration - Sets the first iteration at which the norm of the residual will be
283: computed and used in the convergence test.
285: Logically Collective
287: Input Parameters:
288: + ksp - Krylov solver context
289: - it - use -1 to check at all iterations
291: Notes:
292: Currently only works with `KSPCG`, `KSPBCGS` and `KSPIBCGS`
294: Use `KSPSetNormType`(ksp,`KSP_NORM_NONE`) to never check the norm
296: On steps where the norm is not computed, the previous norm is still in the variable, so if you run with, for example,
297: -ksp_monitor the residual norm will appear to be unchanged for several iterations (though it is not really unchanged).
298: Level: advanced
300: .seealso: `KSP`, `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSPConvergedSkip()`, `KSPSetNormType()`
301: @*/
302: PetscErrorCode KSPSetCheckNormIteration(KSP ksp, PetscInt it)
303: {
304: PetscFunctionBegin;
307: ksp->chknorm = it;
308: PetscFunctionReturn(PETSC_SUCCESS);
309: }
311: /*@
312: KSPSetLagNorm - Lags the residual norm calculation so that it is computed as part of the `MPI_Allreduce()` for
313: computing the inner products for the next iteration. This can reduce communication costs at the expense of doing
314: one additional iteration.
316: Logically Collective
318: Input Parameters:
319: + ksp - Krylov solver context
320: - flg - `PETSC_TRUE` or `PETSC_FALSE`
322: Options Database Key:
323: . -ksp_lag_norm - lag the calculated residual norm
325: Level: advanced
327: Notes:
328: Currently only works with `KSPIBCGS`.
330: Use `KSPSetNormType`(ksp,`KSP_NORM_NONE`) to never check the norm
332: If you lag the norm and run with, for example, -ksp_monitor, the residual norm reported will be the lagged one.
334: .seealso: `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSPConvergedSkip()`, `KSPSetNormType()`, `KSPSetCheckNormIteration()`
335: @*/
336: PetscErrorCode KSPSetLagNorm(KSP ksp, PetscBool flg)
337: {
338: PetscFunctionBegin;
341: ksp->lagnorm = flg;
342: PetscFunctionReturn(PETSC_SUCCESS);
343: }
345: /*@
346: KSPSetSupportedNorm - Sets a norm and preconditioner side supported by a `KSP`
348: Logically Collective
350: Input Parameters:
351: + ksp - Krylov method
352: . normtype - supported norm type
353: . pcside - preconditioner side that can be used with this norm
354: - priority - positive integer preference for this combination; larger values have higher priority
356: Level: developer
358: Note:
359: This function should be called from the implementation files `KSPCreate_XXX()` to declare
360: which norms and preconditioner sides are supported. Users should not need to call this
361: function.
363: .seealso: `KSP`, `KSPNormType`, `PCSide`, `KSPSetNormType()`, `KSPSetPCSide()`
364: @*/
365: PetscErrorCode KSPSetSupportedNorm(KSP ksp, KSPNormType normtype, PCSide pcside, PetscInt priority)
366: {
367: PetscFunctionBegin;
369: ksp->normsupporttable[normtype][pcside] = priority;
370: PetscFunctionReturn(PETSC_SUCCESS);
371: }
373: PetscErrorCode KSPNormSupportTableReset_Private(KSP ksp)
374: {
375: PetscFunctionBegin;
376: PetscCall(PetscMemzero(ksp->normsupporttable, sizeof(ksp->normsupporttable)));
377: ksp->pc_side = ksp->pc_side_set;
378: ksp->normtype = ksp->normtype_set;
379: PetscFunctionReturn(PETSC_SUCCESS);
380: }
382: PetscErrorCode KSPSetUpNorms_Private(KSP ksp, PetscBool errorifnotsupported, KSPNormType *normtype, PCSide *pcside)
383: {
384: PetscInt i, j, best, ibest = 0, jbest = 0;
386: PetscFunctionBegin;
387: best = 0;
388: for (i = 0; i < KSP_NORM_MAX; i++) {
389: for (j = 0; j < PC_SIDE_MAX; j++) {
390: if ((ksp->normtype == KSP_NORM_DEFAULT || ksp->normtype == i) && (ksp->pc_side == PC_SIDE_DEFAULT || ksp->pc_side == j) && (ksp->normsupporttable[i][j] > best)) {
391: best = ksp->normsupporttable[i][j];
392: ibest = i;
393: jbest = j;
394: }
395: }
396: }
397: if (best < 1 && errorifnotsupported) {
398: 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);
399: 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]);
400: 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]);
401: 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]);
402: }
403: if (normtype) *normtype = (KSPNormType)ibest;
404: if (pcside) *pcside = (PCSide)jbest;
405: PetscFunctionReturn(PETSC_SUCCESS);
406: }
408: /*@
409: KSPGetNormType - Gets the norm that is used for convergence testing.
411: Not Collective
413: Input Parameter:
414: . ksp - Krylov solver context
416: Output Parameter:
417: . normtype - norm that is used for convergence testing
419: Level: advanced
421: .seealso: `KSPNormType`, `KSPSetNormType()`, `KSPConvergedSkip()`
422: @*/
423: PetscErrorCode KSPGetNormType(KSP ksp, KSPNormType *normtype)
424: {
425: PetscFunctionBegin;
428: PetscCall(KSPSetUpNorms_Private(ksp, PETSC_TRUE, &ksp->normtype, &ksp->pc_side));
429: *normtype = ksp->normtype;
430: PetscFunctionReturn(PETSC_SUCCESS);
431: }
433: #if defined(PETSC_HAVE_SAWS)
434: #include <petscviewersaws.h>
435: #endif
437: /*@
438: KSPSetOperators - Sets the matrix associated with the linear system
439: and a (possibly) different one from which the preconditioner will be built
441: Collective
443: Input Parameters:
444: + ksp - the `KSP` context
445: . Amat - the matrix that defines the linear system
446: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
448: Level: beginner
450: Notes:
451: If you know the operator Amat has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
452: space to `Amat` and the `KSP` solvers will automatically use that null space as needed during the solution process.
454: All future calls to `KSPSetOperators()` must use the same size matrices!
456: Passing a `NULL` for `Amat` or `Pmat` removes the matrix that is currently used.
458: If you wish to replace either `Amat` or `Pmat` but leave the other one untouched then
459: first call `KSPGetOperators()` to get the one you wish to keep, call `PetscObjectReference()`
460: on it and then pass it back in in your call to `KSPSetOperators()`.
462: Developer Notes:
463: If the operators have NOT been set with `KSPSetOperators()` then the operators
464: are created in the `PC` and returned to the user. In this case, if both operators
465: mat and pmat are requested, two DIFFERENT operators will be returned. If
466: only one is requested both operators in the `PC` will be the same (i.e. as
467: if one had called `KSPSetOperators()` with the same argument for both `Mat`s).
468: The user must set the sizes of the returned matrices and their type etc just
469: as if the user created them with `MatCreate()`. For example,
471: .vb
472: KSPGetOperators(ksp/pc,&mat,NULL); is equivalent to
473: set size, type, etc of mat
475: MatCreate(comm,&mat);
476: KSP/PCSetOperators(ksp/pc,mat,mat);
477: PetscObjectDereference((PetscObject)mat);
478: set size, type, etc of mat
480: and
482: KSP/PCGetOperators(ksp/pc,&mat,&pmat); is equivalent to
483: set size, type, etc of mat and pmat
485: MatCreate(comm,&mat);
486: MatCreate(comm,&pmat);
487: KSP/PCSetOperators(ksp/pc,mat,pmat);
488: PetscObjectDereference((PetscObject)mat);
489: PetscObjectDereference((PetscObject)pmat);
490: set size, type, etc of mat and pmat
491: .ve
493: The rationale for this support is so that when creating a `TS`, `SNES`, or `KSP` the hierarchy
494: of underlying objects (i.e. `SNES`, `KSP`, `PC`, `Mat`) and their lifespans can be completely
495: managed by the top most level object (i.e. the `TS`, `SNES`, or `KSP`). Another way to look
496: at this is when you create a `SNES` you do not NEED to create a `KSP` and attach it to
497: the `SNES` object (the `SNES` object manages it for you). Similarly when you create a `KSP`
498: you do not need to attach a `PC` to it (the `KSP` object manages the `PC` object for you).
499: Thus, why should YOU have to create the `Mat` and attach it to the `SNES`/`KSP`/`PC`, when
500: it can be created for you?
502: .seealso: `KSP`, `Mat`, `KSPSolve()`, `KSPGetPC()`, `PCGetOperators()`, `PCSetOperators()`, `KSPGetOperators()`, `KSPSetComputeOperators()`, `KSPSetComputeInitialGuess()`, `KSPSetComputeRHS()`
503: @*/
504: PetscErrorCode KSPSetOperators(KSP ksp, Mat Amat, Mat Pmat)
505: {
506: PetscFunctionBegin;
510: if (Amat) PetscCheckSameComm(ksp, 1, Amat, 2);
511: if (Pmat) PetscCheckSameComm(ksp, 1, Pmat, 3);
512: if (!ksp->pc) PetscCall(KSPGetPC(ksp, &ksp->pc));
513: PetscCall(PCSetOperators(ksp->pc, Amat, Pmat));
514: if (ksp->setupstage == KSP_SETUP_NEWRHS) ksp->setupstage = KSP_SETUP_NEWMATRIX; /* so that next solve call will call PCSetUp() on new matrix */
515: PetscFunctionReturn(PETSC_SUCCESS);
516: }
518: /*@
519: KSPGetOperators - Gets the matrix associated with the linear system
520: and a (possibly) different one used to construct the preconditioner.
522: Collective
524: Input Parameter:
525: . ksp - the `KSP` context
527: Output Parameters:
528: + Amat - the matrix that defines the linear system
529: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.
531: Level: intermediate
533: Note:
534: DOES NOT increase the reference counts of the matrix, so you should NOT destroy them.
536: .seealso: `KSP`, `KSPSolve()`, `KSPGetPC()`, `PCGetOperators()`, `PCSetOperators()`, `KSPSetOperators()`, `KSPGetOperatorsSet()`
537: @*/
538: PetscErrorCode KSPGetOperators(KSP ksp, Mat *Amat, Mat *Pmat)
539: {
540: PetscFunctionBegin;
542: if (!ksp->pc) PetscCall(KSPGetPC(ksp, &ksp->pc));
543: PetscCall(PCGetOperators(ksp->pc, Amat, Pmat));
544: PetscFunctionReturn(PETSC_SUCCESS);
545: }
547: /*@C
548: KSPGetOperatorsSet - Determines if the matrix associated with the linear system and
549: possibly a different one associated with the preconditioner have been set in the `KSP`.
551: Not Collective, though the results on all processes should be the same
553: Input Parameter:
554: . pc - the `KSP` context
556: Output Parameters:
557: + mat - the matrix associated with the linear system was set
558: - pmat - matrix associated with the preconditioner was set, usually the same as `mat`
560: Level: intermediate
562: Note:
563: This routine exists because if you call `KSPGetOperators()` on a `KSP` that does not yet have operators they are
564: automatically created in the call.
566: .seealso: `KSP`, `PCSetOperators()`, `KSPGetOperators()`, `KSPSetOperators()`, `PCGetOperators()`, `PCGetOperatorsSet()`
567: @*/
568: PetscErrorCode KSPGetOperatorsSet(KSP ksp, PetscBool *mat, PetscBool *pmat)
569: {
570: PetscFunctionBegin;
572: if (!ksp->pc) PetscCall(KSPGetPC(ksp, &ksp->pc));
573: PetscCall(PCGetOperatorsSet(ksp->pc, mat, pmat));
574: PetscFunctionReturn(PETSC_SUCCESS);
575: }
577: /*@C
578: KSPSetPreSolve - Sets a function that is called at the beginning of each `KSPSolve()`
580: Logically Collective
582: Input Parameters:
583: + ksp - the solver object
584: . presolve - the function to call before the solve
585: - prectx - any context needed by the function
587: Calling sequence of `presolve`:
588: $ PetscErrorCode func(KSP ksp, Vec rhs, Vec x, void *ctx)
589: + ksp - the `KSP` context
590: . rhs - the right-hand side vector
591: . x - the solution vector
592: - ctx - optional user-provided context
594: Level: developer
596: .seealso: `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPSetPostSolve()`, `PCEISENSTAT`
597: @*/
598: PetscErrorCode KSPSetPreSolve(KSP ksp, PetscErrorCode (*presolve)(KSP, Vec, Vec, void *), void *prectx)
599: {
600: PetscFunctionBegin;
602: ksp->presolve = presolve;
603: ksp->prectx = prectx;
604: PetscFunctionReturn(PETSC_SUCCESS);
605: }
607: /*@C
608: KSPSetPostSolve - Sets a function that is called at the end of each `KSPSolve()` (whether it converges or not)
610: Logically Collective
612: Input Parameters:
613: + ksp - the solver object
614: . postsolve - the function to call after the solve
615: - postctx - any context needed by the function
617: Calling sequence of `postsolve`:
618: $ PetscErrorCode func(KSP ksp, Vec rhs, Vec x, void *ctx)
619: + ksp - the `KSP` context
620: . rhs - the right-hand side vector
621: . x - the solution vector
622: - ctx - optional user-provided context
624: Level: developer
626: .seealso: `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPSetPreSolve()`, `PCEISENSTAT`
627: @*/
628: PetscErrorCode KSPSetPostSolve(KSP ksp, PetscErrorCode (*postsolve)(KSP, Vec, Vec, void *), void *postctx)
629: {
630: PetscFunctionBegin;
632: ksp->postsolve = postsolve;
633: ksp->postctx = postctx;
634: PetscFunctionReturn(PETSC_SUCCESS);
635: }
637: /*@
638: KSPCreate - Creates the `KSP` context.
640: Collective
642: Input Parameter:
643: . comm - MPI communicator
645: Output Parameter:
646: . ksp - location to put the `KSP` context
648: Level: beginner
650: Note:
651: The default `KSPType` is `KSPGMRES` with a restart of 30, using modified Gram-Schmidt orthogonalization.
653: .seealso: [](ch_ksp), `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPGMRES`, `KSPType`
654: @*/
655: PetscErrorCode KSPCreate(MPI_Comm comm, KSP *inksp)
656: {
657: KSP ksp;
658: void *ctx;
660: PetscFunctionBegin;
662: *inksp = NULL;
663: PetscCall(KSPInitializePackage());
665: PetscCall(PetscHeaderCreate(ksp, KSP_CLASSID, "KSP", "Krylov Method", "KSP", comm, KSPDestroy, KSPView));
667: ksp->max_it = 10000;
668: ksp->pc_side = ksp->pc_side_set = PC_SIDE_DEFAULT;
669: ksp->rtol = 1.e-5;
670: #if defined(PETSC_USE_REAL_SINGLE)
671: ksp->abstol = 1.e-25;
672: #else
673: ksp->abstol = 1.e-50;
674: #endif
675: ksp->divtol = 1.e4;
677: ksp->chknorm = -1;
678: ksp->normtype = ksp->normtype_set = KSP_NORM_DEFAULT;
679: ksp->rnorm = 0.0;
680: ksp->its = 0;
681: ksp->guess_zero = PETSC_TRUE;
682: ksp->calc_sings = PETSC_FALSE;
683: ksp->res_hist = NULL;
684: ksp->res_hist_alloc = NULL;
685: ksp->res_hist_len = 0;
686: ksp->res_hist_max = 0;
687: ksp->res_hist_reset = PETSC_TRUE;
688: ksp->err_hist = NULL;
689: ksp->err_hist_alloc = NULL;
690: ksp->err_hist_len = 0;
691: ksp->err_hist_max = 0;
692: ksp->err_hist_reset = PETSC_TRUE;
693: ksp->numbermonitors = 0;
694: ksp->numberreasonviews = 0;
695: ksp->setfromoptionscalled = 0;
696: ksp->nmax = PETSC_DECIDE;
698: PetscCall(KSPConvergedDefaultCreate(&ctx));
699: PetscCall(KSPSetConvergenceTest(ksp, KSPConvergedDefault, ctx, KSPConvergedDefaultDestroy));
700: ksp->ops->buildsolution = KSPBuildSolutionDefault;
701: ksp->ops->buildresidual = KSPBuildResidualDefault;
703: ksp->vec_sol = NULL;
704: ksp->vec_rhs = NULL;
705: ksp->pc = NULL;
706: ksp->data = NULL;
707: ksp->nwork = 0;
708: ksp->work = NULL;
709: ksp->reason = KSP_CONVERGED_ITERATING;
710: ksp->setupstage = KSP_SETUP_NEW;
712: PetscCall(KSPNormSupportTableReset_Private(ksp));
714: *inksp = ksp;
715: PetscFunctionReturn(PETSC_SUCCESS);
716: }
718: /*@C
719: KSPSetType - Builds the `KSP` datastructure for a particular `KSPType`
721: Logically Collective
723: Input Parameters:
724: + ksp - the Krylov space context
725: - type - a known method
727: Options Database Key:
728: . -ksp_type <method> - Sets the method; use `-help` for a list of available methods (for instance, cg or gmres)
730: Level: intermediate
732: Notes:
733: See "petsc/include/petscksp.h" for available methods (for instance, `KSPCG` or `KSPGMRES`).
735: Normally, it is best to use the `KSPSetFromOptions()` command and
736: then set the `KSP` type from the options database rather than by using
737: this routine. Using the options database provides the user with
738: maximum flexibility in evaluating the many different Krylov methods.
739: The `KSPSetType()` routine is provided for those situations where it
740: is necessary to set the iterative solver independently of the command
741: line or options database. This might be the case, for example, when
742: the choice of iterative solver changes during the execution of the
743: program, and the user's application is taking responsibility for
744: choosing the appropriate method. In other words, this routine is
745: not for beginners.
747: Developer Note:
748: `KSPRegister()` is used to add Krylov types to `KSPList` from which they are accessed by `KSPSetType()`.
750: .seealso: [](ch_ksp), `PCSetType()`, `KSPType`, `KSPRegister()`, `KSPCreate()`, `KSP`
751: @*/
752: PetscErrorCode KSPSetType(KSP ksp, KSPType type)
753: {
754: PetscBool match;
755: PetscErrorCode (*r)(KSP);
757: PetscFunctionBegin;
761: PetscCall(PetscObjectTypeCompare((PetscObject)ksp, type, &match));
762: if (match) PetscFunctionReturn(PETSC_SUCCESS);
764: PetscCall(PetscFunctionListFind(KSPList, type, &r));
765: PetscCheck(r, PetscObjectComm((PetscObject)ksp), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unable to find requested KSP type %s", type);
766: /* Destroy the previous private KSP context */
767: PetscTryTypeMethod(ksp, destroy);
768: ksp->ops->destroy = NULL;
770: /* Reinitialize function pointers in KSPOps structure */
771: PetscCall(PetscMemzero(ksp->ops, sizeof(struct _KSPOps)));
772: ksp->ops->buildsolution = KSPBuildSolutionDefault;
773: ksp->ops->buildresidual = KSPBuildResidualDefault;
774: PetscCall(KSPNormSupportTableReset_Private(ksp));
775: ksp->converged_neg_curve = PETSC_FALSE; // restore default
776: ksp->setupnewmatrix = PETSC_FALSE; // restore default (setup not called in case of new matrix)
777: /* Call the KSPCreate_XXX routine for this particular Krylov solver */
778: ksp->setupstage = KSP_SETUP_NEW;
779: PetscCall((*r)(ksp));
780: PetscCall(PetscObjectChangeTypeName((PetscObject)ksp, type));
781: PetscFunctionReturn(PETSC_SUCCESS);
782: }
784: /*@C
785: KSPGetType - Gets the `KSP` type as a string from the KSP object.
787: Not Collective
789: Input Parameter:
790: . ksp - Krylov context
792: Output Parameter:
793: . name - name of the `KSP` method
795: Level: intermediate
797: .seealso: [](ch_ksp), `KSPType`, `KSP`, `KSPSetType()`
798: @*/
799: PetscErrorCode KSPGetType(KSP ksp, KSPType *type)
800: {
801: PetscFunctionBegin;
804: *type = ((PetscObject)ksp)->type_name;
805: PetscFunctionReturn(PETSC_SUCCESS);
806: }
808: /*@C
809: KSPRegister - Adds a method, `KSPType`, to the Krylov subspace solver package.
811: Not Collective
813: Input Parameters:
814: + sname - name of a new user-defined solver
815: - function - routine to create method
817: Level: advanced
819: Note:
820: `KSPRegister()` may be called multiple times to add several user-defined solvers.
822: Sample usage:
823: .vb
824: KSPRegister("my_solver", MySolverCreate);
825: .ve
827: Then, your solver can be chosen with the procedural interface via
828: $ ` KSPSetType`(ksp, "my_solver")
829: or at runtime via the option
830: $ -ksp_type my_solver
832: .seealso: [](ch_ksp), `KSP`, `KSPType`, `KSPSetType`, `KSPRegisterAll()`
833: @*/
834: PetscErrorCode KSPRegister(const char sname[], PetscErrorCode (*function)(KSP))
835: {
836: PetscFunctionBegin;
837: PetscCall(KSPInitializePackage());
838: PetscCall(PetscFunctionListAdd(&KSPList, sname, function));
839: PetscFunctionReturn(PETSC_SUCCESS);
840: }
842: PetscErrorCode KSPMonitorMakeKey_Internal(const char name[], PetscViewerType vtype, PetscViewerFormat format, char key[])
843: {
844: PetscFunctionBegin;
845: PetscCall(PetscStrncpy(key, name, PETSC_MAX_PATH_LEN));
846: PetscCall(PetscStrlcat(key, ":", PETSC_MAX_PATH_LEN));
847: PetscCall(PetscStrlcat(key, vtype, PETSC_MAX_PATH_LEN));
848: PetscCall(PetscStrlcat(key, ":", PETSC_MAX_PATH_LEN));
849: PetscCall(PetscStrlcat(key, PetscViewerFormats[format], PETSC_MAX_PATH_LEN));
850: PetscFunctionReturn(PETSC_SUCCESS);
851: }
853: /*@C
854: KSPMonitorRegister - Registers a Krylov subspace solver monitor routine that may be accessed with `KSPMonitorSetFromOptions()`
856: Not Collective
858: Input Parameters:
859: + name - name of a new monitor routine
860: . vtype - A `PetscViewerType` for the output
861: . format - A `PetscViewerFormat` for the output
862: . monitor - Monitor routine
863: . create - Creation routine, or `NULL`
864: - destroy - Destruction routine, or `NULL`
866: Level: advanced
868: Note:
869: `KSPMonitorRegister()` may be called multiple times to add several user-defined monitors.
871: Sample usage:
872: .vb
873: KSPMonitorRegister("my_monitor", PETSCVIEWERASCII, PETSC_VIEWER_ASCII_INFO_DETAIL, MyMonitor, NULL, NULL);
874: .ve
876: Then, your monitor can be chosen with the procedural interface via
877: $ KSPMonitorSetFromOptions(ksp, "-ksp_monitor_my_monitor", "my_monitor", NULL)
878: or at runtime via the option
879: $ -ksp_monitor_my_monitor
881: .seealso: [](ch_ksp), `KSP`, `KSPMonitorSet()`, `KSPMonitorRegisterAll()`, `KSPMonitorSetFromOptions()`
882: @*/
883: PetscErrorCode KSPMonitorRegister(const char name[], PetscViewerType vtype, PetscViewerFormat format, PetscErrorCode (*monitor)(KSP, PetscInt, PetscReal, PetscViewerAndFormat *), PetscErrorCode (*create)(PetscViewer, PetscViewerFormat, void *, PetscViewerAndFormat **), PetscErrorCode (*destroy)(PetscViewerAndFormat **))
884: {
885: char key[PETSC_MAX_PATH_LEN];
887: PetscFunctionBegin;
888: PetscCall(KSPInitializePackage());
889: PetscCall(KSPMonitorMakeKey_Internal(name, vtype, format, key));
890: PetscCall(PetscFunctionListAdd(&KSPMonitorList, key, monitor));
891: if (create) PetscCall(PetscFunctionListAdd(&KSPMonitorCreateList, key, create));
892: if (destroy) PetscCall(PetscFunctionListAdd(&KSPMonitorDestroyList, key, destroy));
893: PetscFunctionReturn(PETSC_SUCCESS);
894: }