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;
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;
52: PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary);
55: PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT);
57: PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR);
58: KSPSetType(newdm, type);
59: PetscTryTypeMethod(newdm, load, viewer);
60: KSPGetPC(newdm, &pc);
61: PCLoad(pc, viewer);
62: return 0;
63: }
65: #include <petscdraw.h>
66: #if defined(PETSC_HAVE_SAWS)
67: #include <petscviewersaws.h>
68: #endif
69: /*@C
70: KSPView - Prints the `KSP` data structure.
72: Collective
74: Input Parameters:
75: + ksp - the Krylov space context
76: - viewer - visualization context
78: Options Database Keys:
79: . -ksp_view - print the `KSP` data structure at the end of each `KSPSolve()` call
81: Notes:
82: The available visualization contexts include
83: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
84: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
85: output where only the first processor opens
86: the file. All other processors send their
87: data to the first processor to print.
89: The available formats include
90: + `PETSC_VIEWER_DEFAULT` - standard output (default)
91: - `PETSC_VIEWER_ASCII_INFO_DETAIL` - more verbose output for PCBJACOBI and PCASM
93: The user can open an alternative visualization context with
94: `PetscViewerASCIIOpen()` - output to a specified file.
96: In the debugger you can do call `KSPView(ksp,0)` to display the `KSP`. (The same holds for any PETSc object viewer).
98: Level: beginner
100: .seealso: `KSP`, `PetscViewer`, `PCView()`, `PetscViewerASCIIOpen()`
101: @*/
102: PetscErrorCode KSPView(KSP ksp, PetscViewer viewer)
103: {
104: PetscBool iascii, isbinary, isdraw, isstring;
105: #if defined(PETSC_HAVE_SAWS)
106: PetscBool issaws;
107: #endif
110: if (!viewer) PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ksp), &viewer);
114: PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii);
115: PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary);
116: PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw);
117: PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring);
118: #if defined(PETSC_HAVE_SAWS)
119: PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSAWS, &issaws);
120: #endif
121: if (iascii) {
122: PetscObjectPrintClassNamePrefixType((PetscObject)ksp, viewer);
123: PetscViewerASCIIPushTab(viewer);
124: PetscTryTypeMethod(ksp, view, viewer);
125: PetscViewerASCIIPopTab(viewer);
126: if (ksp->guess_zero) {
127: PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", initial guess is zero\n", ksp->max_it);
128: } else {
129: PetscViewerASCIIPrintf(viewer, " maximum iterations=%" PetscInt_FMT ", nonzero initial guess\n", ksp->max_it);
130: }
131: if (ksp->guess_knoll) PetscViewerASCIIPrintf(viewer, " using preconditioner applied to right hand side for initial guess\n");
132: PetscViewerASCIIPrintf(viewer, " tolerances: relative=%g, absolute=%g, divergence=%g\n", (double)ksp->rtol, (double)ksp->abstol, (double)ksp->divtol);
133: if (ksp->pc_side == PC_RIGHT) {
134: PetscViewerASCIIPrintf(viewer, " right preconditioning\n");
135: } else if (ksp->pc_side == PC_SYMMETRIC) {
136: PetscViewerASCIIPrintf(viewer, " symmetric preconditioning\n");
137: } else {
138: PetscViewerASCIIPrintf(viewer, " left preconditioning\n");
139: }
140: if (ksp->guess) {
141: PetscViewerASCIIPushTab(viewer);
142: KSPGuessView(ksp->guess, viewer);
143: PetscViewerASCIIPopTab(viewer);
144: }
145: if (ksp->dscale) PetscViewerASCIIPrintf(viewer, " diagonally scaled system\n");
146: PetscViewerASCIIPrintf(viewer, " using %s norm type for convergence test\n", KSPNormTypes[ksp->normtype]);
147: } else if (isbinary) {
148: PetscInt classid = KSP_FILE_CLASSID;
149: MPI_Comm comm;
150: PetscMPIInt rank;
151: char type[256];
153: PetscObjectGetComm((PetscObject)ksp, &comm);
154: MPI_Comm_rank(comm, &rank);
155: if (rank == 0) {
156: PetscViewerBinaryWrite(viewer, &classid, 1, PETSC_INT);
157: PetscStrncpy(type, ((PetscObject)ksp)->type_name, 256);
158: PetscViewerBinaryWrite(viewer, type, 256, PETSC_CHAR);
159: }
160: PetscTryTypeMethod(ksp, view, viewer);
161: } else if (isstring) {
162: const char *type;
163: KSPGetType(ksp, &type);
164: PetscViewerStringSPrintf(viewer, " KSPType: %-7.7s", type);
165: PetscTryTypeMethod(ksp, view, viewer);
166: } else if (isdraw) {
167: PetscDraw draw;
168: char str[36];
169: PetscReal x, y, bottom, h;
170: PetscBool flg;
172: PetscViewerDrawGetDraw(viewer, 0, &draw);
173: PetscDrawGetCurrentPoint(draw, &x, &y);
174: PetscObjectTypeCompare((PetscObject)ksp, KSPPREONLY, &flg);
175: if (!flg) {
176: PetscStrncpy(str, "KSP: ", sizeof(str));
177: PetscStrlcat(str, ((PetscObject)ksp)->type_name, sizeof(str));
178: PetscDrawStringBoxed(draw, x, y, PETSC_DRAW_RED, PETSC_DRAW_BLACK, str, NULL, &h);
179: bottom = y - h;
180: } else {
181: bottom = y;
182: }
183: PetscDrawPushCurrentPoint(draw, x, bottom);
184: #if defined(PETSC_HAVE_SAWS)
185: } else if (issaws) {
186: PetscMPIInt rank;
187: const char *name;
189: PetscObjectGetName((PetscObject)ksp, &name);
190: MPI_Comm_rank(PETSC_COMM_WORLD, &rank);
191: if (!((PetscObject)ksp)->amsmem && rank == 0) {
192: char dir[1024];
194: PetscObjectViewSAWs((PetscObject)ksp, viewer);
195: PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/its", name);
196: SAWs_Register, (dir, &ksp->its, 1, SAWs_READ, SAWs_INT);
197: if (!ksp->res_hist) KSPSetResidualHistory(ksp, NULL, PETSC_DECIDE, PETSC_TRUE);
198: PetscSNPrintf(dir, 1024, "/PETSc/Objects/%s/res_hist", name);
199: SAWs_Register, (dir, ksp->res_hist, 10, SAWs_READ, SAWs_DOUBLE);
200: }
201: #endif
202: } else PetscTryTypeMethod(ksp, view, viewer);
203: if (ksp->pc) PCView(ksp->pc, viewer);
204: if (isdraw) {
205: PetscDraw draw;
206: PetscViewerDrawGetDraw(viewer, 0, &draw);
207: PetscDrawPopCurrentPoint(draw);
208: }
209: return 0;
210: }
212: /*@C
213: KSPViewFromOptions - View a `KSP` object based on values in the options database
215: Collective
217: Input Parameters:
218: + A - Krylov solver context
219: . obj - Optional object
220: - name - command line option
222: Level: intermediate
224: .seealso: `KSP`, `KSPView`, `PetscObjectViewFromOptions()`, `KSPCreate()`
225: @*/
226: PetscErrorCode KSPViewFromOptions(KSP A, PetscObject obj, const char name[])
227: {
229: PetscObjectViewFromOptions((PetscObject)A, obj, name);
230: return 0;
231: }
233: /*@
234: KSPSetNormType - Sets the norm that is used for convergence testing.
236: Logically Collective
238: Input Parameters:
239: + ksp - Krylov solver context
240: - normtype - one of
241: .vb
242: KSP_NORM_NONE - skips computing the norm, this should generally only be used if you are using
243: the Krylov method as a smoother with a fixed small number of iterations.
244: Implicitly sets KSPConvergedSkip() as KSP convergence test.
245: Note that certain algorithms such as KSPGMRES ALWAYS require the norm calculation,
246: for these methods the norms are still computed, they are just not used in
247: the convergence test.
248: KSP_NORM_PRECONDITIONED - the default for left preconditioned solves, uses the l2 norm
249: of the preconditioned residual P^{-1}(b - A x)
250: KSP_NORM_UNPRECONDITIONED - uses the l2 norm of the true b - Ax residual.
251: KSP_NORM_NATURAL - supported by KSPCG, KSPCR, KSPCGNE, KSPCGS
252: .ve
254: Options Database Key:
255: . -ksp_norm_type <none,preconditioned,unpreconditioned,natural> - set `KSP` norm type
257: Level: advanced
259: Note:
260: Not all combinations of preconditioner side (see `KSPSetPCSide()`) and norm type are supported by all Krylov methods.
261: If only one is set, PETSc tries to automatically change the other to find a compatible pair. If no such combination
262: is supported, PETSc will generate an error.
264: Developer Note:
265: Supported combinations of norm and preconditioner side are set using `KSPSetSupportedNorm()`.
267: .seealso: `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSPConvergedSkip()`, `KSPSetCheckNormIteration()`, `KSPSetPCSide()`, `KSPGetPCSide()`, `KSPNormType`
268: @*/
269: PetscErrorCode KSPSetNormType(KSP ksp, KSPNormType normtype)
270: {
273: ksp->normtype = ksp->normtype_set = normtype;
274: return 0;
275: }
277: /*@
278: KSPSetCheckNormIteration - Sets the first iteration at which the norm of the residual will be
279: computed and used in the convergence test.
281: Logically Collective
283: Input Parameters:
284: + ksp - Krylov solver context
285: - it - use -1 to check at all iterations
287: Notes:
288: Currently only works with `KSPCG`, `KSPBCGS` and `KSPIBCGS`
290: Use `KSPSetNormType`(ksp,`KSP_NORM_NONE`) to never check the norm
292: On steps where the norm is not computed, the previous norm is still in the variable, so if you run with, for example,
293: -ksp_monitor the residual norm will appear to be unchanged for several iterations (though it is not really unchanged).
294: Level: advanced
296: .seealso: `KSP`, `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSPConvergedSkip()`, `KSPSetNormType()`
297: @*/
298: PetscErrorCode KSPSetCheckNormIteration(KSP ksp, PetscInt it)
299: {
302: ksp->chknorm = it;
303: return 0;
304: }
306: /*@
307: KSPSetLagNorm - Lags the residual norm calculation so that it is computed as part of the `MPI_Allreduce()` for
308: computing the inner products for the next iteration. This can reduce communication costs at the expense of doing
309: one additional iteration.
311: Logically Collective
313: Input Parameters:
314: + ksp - Krylov solver context
315: - flg - `PETSC_TRUE` or `PETSC_FALSE`
317: Options Database Keys:
318: . -ksp_lag_norm - lag the calculated residual norm
320: Level: advanced
322: Notes:
323: Currently only works with `KSPIBCGS`.
325: Use `KSPSetNormType`(ksp,`KSP_NORM_NONE`) to never check the norm
327: If you lag the norm and run with, for example, -ksp_monitor, the residual norm reported will be the lagged one.
329: .seealso: `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSPConvergedSkip()`, `KSPSetNormType()`, `KSPSetCheckNormIteration()`
330: @*/
331: PetscErrorCode KSPSetLagNorm(KSP ksp, PetscBool flg)
332: {
335: ksp->lagnorm = flg;
336: return 0;
337: }
339: /*@
340: KSPSetSupportedNorm - Sets a norm and preconditioner side supported by a `KSP`
342: Logically Collective
344: Input Parameters:
345: + ksp - Krylov method
346: . normtype - supported norm type
347: . pcside - preconditioner side that can be used with this norm
348: - priority - positive integer preference for this combination; larger values have higher priority
350: Level: developer
352: Note:
353: This function should be called from the implementation files `KSPCreate_XXX()` to declare
354: which norms and preconditioner sides are supported. Users should not need to call this
355: function.
357: .seealso: `KSP`, `KSPNormType`, `PCSide`, `KSPSetNormType()`, `KSPSetPCSide()`
358: @*/
359: PetscErrorCode KSPSetSupportedNorm(KSP ksp, KSPNormType normtype, PCSide pcside, PetscInt priority)
360: {
362: ksp->normsupporttable[normtype][pcside] = priority;
363: return 0;
364: }
366: PetscErrorCode KSPNormSupportTableReset_Private(KSP ksp)
367: {
368: PetscMemzero(ksp->normsupporttable, sizeof(ksp->normsupporttable));
369: ksp->pc_side = ksp->pc_side_set;
370: ksp->normtype = ksp->normtype_set;
371: return 0;
372: }
374: PetscErrorCode KSPSetUpNorms_Private(KSP ksp, PetscBool errorifnotsupported, KSPNormType *normtype, PCSide *pcside)
375: {
376: PetscInt i, j, best, ibest = 0, jbest = 0;
378: best = 0;
379: for (i = 0; i < KSP_NORM_MAX; i++) {
380: for (j = 0; j < PC_SIDE_MAX; j++) {
381: if ((ksp->normtype == KSP_NORM_DEFAULT || ksp->normtype == i) && (ksp->pc_side == PC_SIDE_DEFAULT || ksp->pc_side == j) && (ksp->normsupporttable[i][j] > best)) {
382: best = ksp->normsupporttable[i][j];
383: ibest = i;
384: jbest = j;
385: }
386: }
387: }
388: if (best < 1 && errorifnotsupported) {
392: 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]);
393: }
394: if (normtype) *normtype = (KSPNormType)ibest;
395: if (pcside) *pcside = (PCSide)jbest;
396: return 0;
397: }
399: /*@
400: KSPGetNormType - Gets the norm that is used for convergence testing.
402: Not Collective
404: Input Parameter:
405: . ksp - Krylov solver context
407: Output Parameter:
408: . normtype - norm that is used for convergence testing
410: Level: advanced
412: .seealso: `KSPNormType`, `KSPSetNormType()`, `KSPConvergedSkip()`
413: @*/
414: PetscErrorCode KSPGetNormType(KSP ksp, KSPNormType *normtype)
415: {
418: KSPSetUpNorms_Private(ksp, PETSC_TRUE, &ksp->normtype, &ksp->pc_side);
419: *normtype = ksp->normtype;
420: return 0;
421: }
423: #if defined(PETSC_HAVE_SAWS)
424: #include <petscviewersaws.h>
425: #endif
427: /*@
428: KSPSetOperators - Sets the matrix associated with the linear system
429: and a (possibly) different one from which the preconditioner will be built
431: Collective
433: Input Parameters:
434: + ksp - the `KSP` context
435: . Amat - the matrix that defines the linear system
436: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
438: Level: beginner
440: Notes:
441: If you know the operator Amat has a null space you can use `MatSetNullSpace()` and `MatSetTransposeNullSpace()` to supply the null
442: space to Amat and the `KSP` solvers will automatically use that null space as needed during the solution process.
444: All future calls to `KSPSetOperators()` must use the same size matrices!
446: Passing a NULL for Amat or Pmat removes the matrix that is currently used.
448: If you wish to replace either Amat or Pmat but leave the other one untouched then
449: first call KSPGetOperators() to get the one you wish to keep, call `PetscObjectReference()`
450: on it and then pass it back in in your call to `KSPSetOperators()`.
452: Developer Notes:
453: If the operators have NOT been set with `KSPSetOperators()` then the operators
454: are created in the `PC` and returned to the user. In this case, if both operators
455: mat and pmat are requested, two DIFFERENT operators will be returned. If
456: only one is requested both operators in the PC will be the same (i.e. as
457: if one had called `KSPSetOperators()` with the same argument for both `Mat`s).
458: The user must set the sizes of the returned matrices and their type etc just
459: as if the user created them with `MatCreate()`. For example,
461: .vb
462: KSPGetOperators(ksp/pc,&mat,NULL); is equivalent to
463: set size, type, etc of mat
465: MatCreate(comm,&mat);
466: KSP/PCSetOperators(ksp/pc,mat,mat);
467: PetscObjectDereference((PetscObject)mat);
468: set size, type, etc of mat
470: and
472: KSP/PCGetOperators(ksp/pc,&mat,&pmat); is equivalent to
473: set size, type, etc of mat and pmat
475: MatCreate(comm,&mat);
476: MatCreate(comm,&pmat);
477: KSP/PCSetOperators(ksp/pc,mat,pmat);
478: PetscObjectDereference((PetscObject)mat);
479: PetscObjectDereference((PetscObject)pmat);
480: set size, type, etc of mat and pmat
481: .ve
483: The rationale for this support is so that when creating a `TS`, `SNES`, or `KSP` the hierarchy
484: of underlying objects (i.e. `SNES`, `KSP`, `PC`, `Mat`) and their livespans can be completely
485: managed by the top most level object (i.e. the `TS`, `SNES`, or `KSP`). Another way to look
486: at this is when you create a `SNES` you do not NEED to create a `KSP` and attach it to
487: the `SNES` object (the `SNES` object manages it for you). Similarly when you create a `KSP`
488: you do not need to attach a `PC` to it (the `KSP` object manages the `PC` object for you).
489: Thus, why should YOU have to create the `Mat` and attach it to the `SNES`/`KSP`/`PC`, when
490: it can be created for you?
492: .seealso: `KSP`, `Mat`, `KSPSolve()`, `KSPGetPC()`, `PCGetOperators()`, `PCSetOperators()`, `KSPGetOperators()`, `KSPSetComputeOperators()`, `KSPSetComputeInitialGuess()`, `KSPSetComputeRHS()`
493: @*/
494: PetscErrorCode KSPSetOperators(KSP ksp, Mat Amat, Mat Pmat)
495: {
501: if (!ksp->pc) KSPGetPC(ksp, &ksp->pc);
502: PCSetOperators(ksp->pc, Amat, Pmat);
503: if (ksp->setupstage == KSP_SETUP_NEWRHS) ksp->setupstage = KSP_SETUP_NEWMATRIX; /* so that next solve call will call PCSetUp() on new matrix */
504: return 0;
505: }
507: /*@
508: KSPGetOperators - Gets the matrix associated with the linear system
509: and a (possibly) different one used to construct the preconditioner.
511: Collective
513: Input Parameter:
514: . ksp - the `KSP` context
516: Output Parameters:
517: + Amat - the matrix that defines the linear system
518: - Pmat - the matrix to be used in constructing the preconditioner, usually the same as Amat.
520: Level: intermediate
522: Note:
523: DOES NOT increase the reference counts of the matrix, so you should NOT destroy them.
525: .seealso: `KSP`, `KSPSolve()`, `KSPGetPC()`, `PCGetOperators()`, `PCSetOperators()`, `KSPSetOperators()`, `KSPGetOperatorsSet()`
526: @*/
527: PetscErrorCode KSPGetOperators(KSP ksp, Mat *Amat, Mat *Pmat)
528: {
530: if (!ksp->pc) KSPGetPC(ksp, &ksp->pc);
531: PCGetOperators(ksp->pc, Amat, Pmat);
532: return 0;
533: }
535: /*@C
536: KSPGetOperatorsSet - Determines if the matrix associated with the linear system and
537: possibly a different one associated with the preconditioner have been set in the `KSP`.
539: Not collective, though the results on all processes should be the same
541: Input Parameter:
542: . pc - the `KSP` context
544: Output Parameters:
545: + mat - the matrix associated with the linear system was set
546: - pmat - matrix associated with the preconditioner was set, usually the same
548: Level: intermediate
550: Note:
551: This routine exists because if you call `KSPGetOperators()` on a `KSP` that does not yet have operators they are
552: automatically created in the call.
554: .seealso: `KSP`, `PCSetOperators()`, `KSPGetOperators()`, `KSPSetOperators()`, `PCGetOperators()`, `PCGetOperatorsSet()`
555: @*/
556: PetscErrorCode KSPGetOperatorsSet(KSP ksp, PetscBool *mat, PetscBool *pmat)
557: {
559: if (!ksp->pc) KSPGetPC(ksp, &ksp->pc);
560: PCGetOperatorsSet(ksp->pc, mat, pmat);
561: return 0;
562: }
564: /*@C
565: KSPSetPreSolve - Sets a function that is called at the beginning of each `KSPSolve()`
567: Logically Collective
569: Input Parameters:
570: + ksp - the solver object
571: . presolve - the function to call before the solve
572: - prectx - any context needed by the function
574: Calling sequence of presolve:
575: $ func(KSP ksp,Vec rhs,Vec x,void *ctx)
577: + ksp - the `KSP` context
578: . rhs - the right-hand side vector
579: . x - the solution vector
580: - ctx - optional user-provided context
582: Level: developer
584: .seealso: `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPSetPostSolve()`, `PCEISENSTAT`
585: @*/
586: PetscErrorCode KSPSetPreSolve(KSP ksp, PetscErrorCode (*presolve)(KSP, Vec, Vec, void *), void *prectx)
587: {
589: ksp->presolve = presolve;
590: ksp->prectx = prectx;
591: return 0;
592: }
594: /*@C
595: KSPSetPostSolve - Sets a function that is called at the end of each `KSPSolve()` (whether it converges or not)
597: Logically Collective
599: Input Parameters:
600: + ksp - the solver object
601: . postsolve - the function to call after the solve
602: - postctx - any context needed by the function
604: Calling sequence of postsolve:
605: $ func(KSP ksp,Vec rhs,Vec x,void *ctx)
607: + ksp - the `KSP` context
608: . rhs - the right-hand side vector
609: . x - the solution vector
610: - ctx - optional user-provided context
612: Level: developer
614: .seealso: `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPSetPreSolve()`, `PCEISENSTAT`
615: @*/
616: PetscErrorCode KSPSetPostSolve(KSP ksp, PetscErrorCode (*postsolve)(KSP, Vec, Vec, void *), void *postctx)
617: {
619: ksp->postsolve = postsolve;
620: ksp->postctx = postctx;
621: return 0;
622: }
624: /*@
625: KSPCreate - Creates the `KSP` context.
627: Collective
629: Input Parameter:
630: . comm - MPI communicator
632: Output Parameter:
633: . ksp - location to put the `KSP` context
635: Note:
636: The default `KSPType` is `KSPGMRES` with a restart of 30, using modified Gram-Schmidt orthogonalization.
638: Level: beginner
640: .seealso: [](chapter_ksp), `KSPSetUp()`, `KSPSolve()`, `KSPDestroy()`, `KSP`, `KSPGMRES`, `KSPType`
641: @*/
642: PetscErrorCode KSPCreate(MPI_Comm comm, KSP *inksp)
643: {
644: KSP ksp;
645: void *ctx;
648: *inksp = NULL;
649: KSPInitializePackage();
651: PetscHeaderCreate(ksp, KSP_CLASSID, "KSP", "Krylov Method", "KSP", comm, KSPDestroy, KSPView);
653: ksp->max_it = 10000;
654: ksp->pc_side = ksp->pc_side_set = PC_SIDE_DEFAULT;
655: ksp->rtol = 1.e-5;
656: #if defined(PETSC_USE_REAL_SINGLE)
657: ksp->abstol = 1.e-25;
658: #else
659: ksp->abstol = 1.e-50;
660: #endif
661: ksp->divtol = 1.e4;
663: ksp->chknorm = -1;
664: ksp->normtype = ksp->normtype_set = KSP_NORM_DEFAULT;
665: ksp->rnorm = 0.0;
666: ksp->its = 0;
667: ksp->guess_zero = PETSC_TRUE;
668: ksp->calc_sings = PETSC_FALSE;
669: ksp->res_hist = NULL;
670: ksp->res_hist_alloc = NULL;
671: ksp->res_hist_len = 0;
672: ksp->res_hist_max = 0;
673: ksp->res_hist_reset = PETSC_TRUE;
674: ksp->err_hist = NULL;
675: ksp->err_hist_alloc = NULL;
676: ksp->err_hist_len = 0;
677: ksp->err_hist_max = 0;
678: ksp->err_hist_reset = PETSC_TRUE;
679: ksp->numbermonitors = 0;
680: ksp->numberreasonviews = 0;
681: ksp->setfromoptionscalled = 0;
682: ksp->nmax = PETSC_DECIDE;
684: KSPConvergedDefaultCreate(&ctx);
685: KSPSetConvergenceTest(ksp, KSPConvergedDefault, ctx, KSPConvergedDefaultDestroy);
686: ksp->ops->buildsolution = KSPBuildSolutionDefault;
687: ksp->ops->buildresidual = KSPBuildResidualDefault;
689: ksp->vec_sol = NULL;
690: ksp->vec_rhs = NULL;
691: ksp->pc = NULL;
692: ksp->data = NULL;
693: ksp->nwork = 0;
694: ksp->work = NULL;
695: ksp->reason = KSP_CONVERGED_ITERATING;
696: ksp->setupstage = KSP_SETUP_NEW;
698: KSPNormSupportTableReset_Private(ksp);
700: *inksp = ksp;
701: return 0;
702: }
704: /*@C
705: KSPSetType - Builds the `KSP` datastructure for a particular `KSPType`
707: Logically Collective
709: Input Parameters:
710: + ksp - the Krylov space context
711: - type - a known method
713: Options Database Key:
714: . -ksp_type <method> - Sets the method; use -help for a list of available methods (for instance, cg or gmres)
716: Notes:
717: See "petsc/include/petscksp.h" for available methods (for instance, `KSPCG` or `KSPGMRES`).
719: Normally, it is best to use the `KSPSetFromOptions()` command and
720: then set the `KSP` type from the options database rather than by using
721: this routine. Using the options database provides the user with
722: maximum flexibility in evaluating the many different Krylov methods.
723: The `KSPSetType()` routine is provided for those situations where it
724: is necessary to set the iterative solver independently of the command
725: line or options database. This might be the case, for example, when
726: the choice of iterative solver changes during the execution of the
727: program, and the user's application is taking responsibility for
728: choosing the appropriate method. In other words, this routine is
729: not for beginners.
731: Level: intermediate
733: Developer Note:
734: `KSPRegister()` is used to add Krylov types to `KSPList` from which they are accessed by `KSPSetType()`.
736: .seealso: [](chapter_ksp), `PCSetType()`, `KSPType`, `KSPRegister()`, `KSPCreate()`, `KSP`
737: @*/
738: PetscErrorCode KSPSetType(KSP ksp, KSPType type)
739: {
740: PetscBool match;
741: PetscErrorCode (*r)(KSP);
746: PetscObjectTypeCompare((PetscObject)ksp, type, &match);
747: if (match) return 0;
749: PetscFunctionListFind(KSPList, type, &r);
751: /* Destroy the previous private KSP context */
752: PetscTryTypeMethod(ksp, destroy);
753: ksp->ops->destroy = NULL;
755: /* Reinitialize function pointers in KSPOps structure */
756: PetscMemzero(ksp->ops, sizeof(struct _KSPOps));
757: ksp->ops->buildsolution = KSPBuildSolutionDefault;
758: ksp->ops->buildresidual = KSPBuildResidualDefault;
759: KSPNormSupportTableReset_Private(ksp);
760: ksp->setupnewmatrix = PETSC_FALSE; // restore default (setup not called in case of new matrix)
761: /* Call the KSPCreate_XXX routine for this particular Krylov solver */
762: ksp->setupstage = KSP_SETUP_NEW;
763: (*r)(ksp);
764: PetscObjectChangeTypeName((PetscObject)ksp, type);
765: return 0;
766: }
768: /*@C
769: KSPGetType - Gets the `KSP` type as a string from the KSP object.
771: Not Collective
773: Input Parameter:
774: . ksp - Krylov context
776: Output Parameter:
777: . name - name of the `KSP` method
779: Level: intermediate
781: .seealso: [](chapter_ksp), `KSPType`, `KSP`, `KSPSetType()`
782: @*/
783: PetscErrorCode KSPGetType(KSP ksp, KSPType *type)
784: {
787: *type = ((PetscObject)ksp)->type_name;
788: return 0;
789: }
791: /*@C
792: KSPRegister - Adds a method, `KSPType`, to the Krylov subspace solver package.
794: Not Collective
796: Input Parameters:
797: + name_solver - name of a new user-defined solver
798: - routine_create - routine to create method context
800: Level: advanced
802: Note:
803: `KSPRegister()` may be called multiple times to add several user-defined solvers.
805: Sample usage:
806: .vb
807: KSPRegister("my_solver",MySolverCreate);
808: .ve
810: Then, your solver can be chosen with the procedural interface via
811: $ ` KSPSetType`(ksp,"my_solver")
812: or at runtime via the option
813: $ -ksp_type my_solver
815: .seealso: [](chapter_ksp), `KSP`, `KSPType`, `KSPSetType`, `KSPRegisterAll()`
816: @*/
817: PetscErrorCode KSPRegister(const char sname[], PetscErrorCode (*function)(KSP))
818: {
819: KSPInitializePackage();
820: PetscFunctionListAdd(&KSPList, sname, function);
821: return 0;
822: }
824: PetscErrorCode KSPMonitorMakeKey_Internal(const char name[], PetscViewerType vtype, PetscViewerFormat format, char key[])
825: {
826: PetscStrncpy(key, name, PETSC_MAX_PATH_LEN);
827: PetscStrlcat(key, ":", PETSC_MAX_PATH_LEN);
828: PetscStrlcat(key, vtype, PETSC_MAX_PATH_LEN);
829: PetscStrlcat(key, ":", PETSC_MAX_PATH_LEN);
830: PetscStrlcat(key, PetscViewerFormats[format], PETSC_MAX_PATH_LEN);
831: return 0;
832: }
834: /*@C
835: KSPMonitorRegister - Registers a Krylov subspace solver monitor routine that may be accessed with `KSPMonitorSetFromOptions()`
837: Not Collective
839: Input Parameters:
840: + name - name of a new monitor routine
841: . vtype - A `PetscViewerType` for the output
842: . format - A `PetscViewerFormat` for the output
843: . monitor - Monitor routine
844: . create - Creation routine, or NULL
845: - destroy - Destruction routine, or NULL
847: Level: advanced
849: Note:
850: `KSPMonitorRegister()` may be called multiple times to add several user-defined monitors.
852: Sample usage:
853: .vb
854: KSPMonitorRegister("my_monitor",PETSCVIEWERASCII,PETSC_VIEWER_ASCII_INFO_DETAIL,MyMonitor,NULL,NULL);
855: .ve
857: Then, your monitor can be chosen with the procedural interface via
858: $ KSPMonitorSetFromOptions(ksp,"-ksp_monitor_my_monitor","my_monitor",NULL)
859: or at runtime via the option
860: $ -ksp_monitor_my_monitor
862: .seealso: [](chapter_ksp), `KSP`, `KSPMonitorSet()`, `KSPMonitorRegisterAll()`, `KSPMonitorSetFromOptions()`
863: @*/
864: PetscErrorCode KSPMonitorRegister(const char name[], PetscViewerType vtype, PetscViewerFormat format, PetscErrorCode (*monitor)(KSP, PetscInt, PetscReal, PetscViewerAndFormat *), PetscErrorCode (*create)(PetscViewer, PetscViewerFormat, void *, PetscViewerAndFormat **), PetscErrorCode (*destroy)(PetscViewerAndFormat **))
865: {
866: char key[PETSC_MAX_PATH_LEN];
868: KSPInitializePackage();
869: KSPMonitorMakeKey_Internal(name, vtype, format, key);
870: PetscFunctionListAdd(&KSPMonitorList, key, monitor);
871: if (create) PetscFunctionListAdd(&KSPMonitorCreateList, key, create);
872: if (destroy) PetscFunctionListAdd(&KSPMonitorDestroyList, key, destroy);
873: return 0;
874: }