Actual source code: tsadapt.c
1: #include <petsc/private/tsimpl.h>
3: PetscClassId TSADAPT_CLASSID;
5: static PetscFunctionList TSAdaptList;
6: static PetscBool TSAdaptPackageInitialized;
7: static PetscBool TSAdaptRegisterAllCalled;
9: PETSC_EXTERN PetscErrorCode TSAdaptCreate_None(TSAdapt);
10: PETSC_EXTERN PetscErrorCode TSAdaptCreate_Basic(TSAdapt);
11: PETSC_EXTERN PetscErrorCode TSAdaptCreate_DSP(TSAdapt);
12: PETSC_EXTERN PetscErrorCode TSAdaptCreate_CFL(TSAdapt);
13: PETSC_EXTERN PetscErrorCode TSAdaptCreate_GLEE(TSAdapt);
14: PETSC_EXTERN PetscErrorCode TSAdaptCreate_History(TSAdapt);
16: /*@C
17: TSAdaptRegister - adds a TSAdapt implementation
19: Not Collective, No Fortran Support
21: Input Parameters:
22: + sname - name of user-defined adaptivity scheme
23: - function - routine to create method context
25: Level: advanced
27: Notes:
28: `TSAdaptRegister()` may be called multiple times to add several user-defined families.
30: Example Usage:
31: .vb
32: TSAdaptRegister("my_scheme", MySchemeCreate);
33: .ve
35: Then, your scheme can be chosen with the procedural interface via
36: .vb
37: TSAdaptSetType(ts, "my_scheme")
38: .ve
39: or at runtime via the option
40: .vb
41: -ts_adapt_type my_scheme
42: .ve
44: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdaptRegisterAll()`
45: @*/
46: PetscErrorCode TSAdaptRegister(const char sname[], PetscErrorCode (*function)(TSAdapt))
47: {
48: PetscFunctionBegin;
49: PetscCall(TSAdaptInitializePackage());
50: PetscCall(PetscFunctionListAdd(&TSAdaptList, sname, function));
51: PetscFunctionReturn(PETSC_SUCCESS);
52: }
54: /*@C
55: TSAdaptRegisterAll - Registers all of the adaptivity schemes in `TSAdapt`
57: Not Collective
59: Level: advanced
61: .seealso: [](ch_ts), `TSAdaptRegisterDestroy()`
62: @*/
63: PetscErrorCode TSAdaptRegisterAll(void)
64: {
65: PetscFunctionBegin;
66: if (TSAdaptRegisterAllCalled) PetscFunctionReturn(PETSC_SUCCESS);
67: TSAdaptRegisterAllCalled = PETSC_TRUE;
68: PetscCall(TSAdaptRegister(TSADAPTNONE, TSAdaptCreate_None));
69: PetscCall(TSAdaptRegister(TSADAPTBASIC, TSAdaptCreate_Basic));
70: PetscCall(TSAdaptRegister(TSADAPTDSP, TSAdaptCreate_DSP));
71: PetscCall(TSAdaptRegister(TSADAPTCFL, TSAdaptCreate_CFL));
72: PetscCall(TSAdaptRegister(TSADAPTGLEE, TSAdaptCreate_GLEE));
73: PetscCall(TSAdaptRegister(TSADAPTHISTORY, TSAdaptCreate_History));
74: PetscFunctionReturn(PETSC_SUCCESS);
75: }
77: /*@C
78: TSAdaptFinalizePackage - This function destroys everything in the `TS` package. It is
79: called from `PetscFinalize()`.
81: Level: developer
83: .seealso: [](ch_ts), `PetscFinalize()`
84: @*/
85: PetscErrorCode TSAdaptFinalizePackage(void)
86: {
87: PetscFunctionBegin;
88: PetscCall(PetscFunctionListDestroy(&TSAdaptList));
89: TSAdaptPackageInitialized = PETSC_FALSE;
90: TSAdaptRegisterAllCalled = PETSC_FALSE;
91: PetscFunctionReturn(PETSC_SUCCESS);
92: }
94: /*@C
95: TSAdaptInitializePackage - This function initializes everything in the `TSAdapt` package. It is
96: called from `TSInitializePackage()`.
98: Level: developer
100: .seealso: [](ch_ts), `PetscInitialize()`
101: @*/
102: PetscErrorCode TSAdaptInitializePackage(void)
103: {
104: PetscFunctionBegin;
105: if (TSAdaptPackageInitialized) PetscFunctionReturn(PETSC_SUCCESS);
106: TSAdaptPackageInitialized = PETSC_TRUE;
107: PetscCall(PetscClassIdRegister("TSAdapt", &TSADAPT_CLASSID));
108: PetscCall(TSAdaptRegisterAll());
109: PetscCall(PetscRegisterFinalize(TSAdaptFinalizePackage));
110: PetscFunctionReturn(PETSC_SUCCESS);
111: }
113: /*@
114: TSAdaptSetType - sets the approach used for the error adapter
116: Logicially Collective
118: Input Parameters:
119: + adapt - the `TS` adapter, most likely obtained with `TSGetAdapt()`
120: - type - one of the `TSAdaptType`
122: Options Database Key:
123: . -ts_adapt_type <basic or dsp or none> - to set the adapter type
125: Level: intermediate
127: .seealso: [](ch_ts), [](sec_ts_error_control), `TSGetAdapt()`, `TSAdaptDestroy()`, `TSAdaptType`, `TSAdaptGetType()`
128: @*/
129: PetscErrorCode TSAdaptSetType(TSAdapt adapt, TSAdaptType type)
130: {
131: PetscBool match;
132: PetscErrorCode (*r)(TSAdapt);
134: PetscFunctionBegin;
136: PetscAssertPointer(type, 2);
137: PetscCall(PetscObjectTypeCompare((PetscObject)adapt, type, &match));
138: if (match) PetscFunctionReturn(PETSC_SUCCESS);
139: PetscCall(PetscFunctionListFind(TSAdaptList, type, &r));
140: PetscCheck(r, PetscObjectComm((PetscObject)adapt), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown TSAdapt type \"%s\" given", type);
141: PetscTryTypeMethod(adapt, destroy);
142: PetscCall(PetscMemzero(adapt->ops, sizeof(struct _TSAdaptOps)));
143: PetscCall(PetscObjectChangeTypeName((PetscObject)adapt, type));
144: PetscCall((*r)(adapt));
145: PetscFunctionReturn(PETSC_SUCCESS);
146: }
148: /*@
149: TSAdaptGetType - gets the `TS` adapter method type (as a string).
151: Not Collective
153: Input Parameter:
154: . adapt - The `TS` adapter, most likely obtained with `TSGetAdapt()`
156: Output Parameter:
157: . type - The name of `TS` adapter method
159: Level: intermediate
161: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptType`, `TSAdaptSetType()`
162: @*/
163: PetscErrorCode TSAdaptGetType(TSAdapt adapt, TSAdaptType *type)
164: {
165: PetscFunctionBegin;
167: PetscAssertPointer(type, 2);
168: *type = ((PetscObject)adapt)->type_name;
169: PetscFunctionReturn(PETSC_SUCCESS);
170: }
172: PetscErrorCode TSAdaptSetOptionsPrefix(TSAdapt adapt, const char prefix[])
173: {
174: PetscFunctionBegin;
176: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)adapt, prefix));
177: PetscFunctionReturn(PETSC_SUCCESS);
178: }
180: /*@
181: TSAdaptLoad - Loads a TSAdapt that has been stored in binary with `TSAdaptView()`.
183: Collective
185: Input Parameters:
186: + adapt - the newly loaded `TSAdapt`, this needs to have been created with `TSAdaptCreate()` or
187: some related function before a call to `TSAdaptLoad()`.
188: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()` or
189: HDF5 file viewer, obtained from `PetscViewerHDF5Open()`
191: Level: intermediate
193: Note:
194: The type is determined by the data in the file, any type set into the `TSAdapt` before this call is ignored.
196: .seealso: [](ch_ts), `PetscViewerBinaryOpen()`, `TSAdaptView()`, `MatLoad()`, `VecLoad()`, `TSAdapt`
197: @*/
198: PetscErrorCode TSAdaptLoad(TSAdapt adapt, PetscViewer viewer)
199: {
200: PetscBool isbinary;
201: char type[256];
203: PetscFunctionBegin;
206: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
207: PetscCheck(isbinary, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen()");
209: PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
210: PetscCall(TSAdaptSetType(adapt, type));
211: PetscTryTypeMethod(adapt, load, viewer);
212: PetscFunctionReturn(PETSC_SUCCESS);
213: }
215: /*@
216: TSAdaptView - Prints the `TSAdapt` data structure.
218: Collective
220: Input Parameters:
221: + adapt - the `TSAdapt` context obtained from `TSGetAdapt()`
222: - viewer - visualization context
224: Options Database Key:
225: . -ts_view - calls `TSView()` at end of `TSStep()`
227: Level: advanced
229: Notes:
230: This is called by `TSView()` so rarely called directly.
232: The available visualization contexts include
233: + `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
234: - `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard
235: output where only the first processor opens
236: the file. All other processes send their
237: data to the first process to print.
239: The user can open an alternative visualization context with
240: `PetscViewerASCIIOpen()` - output to a specified file.
242: In the debugger you can do call `TSAdaptView`(adapt,0) to display the `TSAdapt`. (The same holds for any PETSc object viewer).
244: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSView()`, `PetscViewer`, `PetscViewerASCIIOpen()`
245: @*/
246: PetscErrorCode TSAdaptView(TSAdapt adapt, PetscViewer viewer)
247: {
248: PetscBool isascii, isbinary, isnone, isglee;
250: PetscFunctionBegin;
252: if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)adapt), &viewer));
254: PetscCheckSameComm(adapt, 1, viewer, 2);
255: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
256: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
257: if (isascii) {
258: PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)adapt, viewer));
259: PetscCall(PetscObjectTypeCompare((PetscObject)adapt, TSADAPTNONE, &isnone));
260: PetscCall(PetscObjectTypeCompare((PetscObject)adapt, TSADAPTGLEE, &isglee));
261: if (!isnone) {
262: if (adapt->always_accept) PetscCall(PetscViewerASCIIPrintf(viewer, " always accepting steps\n"));
263: PetscCall(PetscViewerASCIIPrintf(viewer, " safety factor %g\n", (double)adapt->safety));
264: PetscCall(PetscViewerASCIIPrintf(viewer, " extra safety factor after step rejection %g\n", (double)adapt->reject_safety));
265: PetscCall(PetscViewerASCIIPrintf(viewer, " clip fastest increase %g\n", (double)adapt->clip[1]));
266: PetscCall(PetscViewerASCIIPrintf(viewer, " clip fastest decrease %g\n", (double)adapt->clip[0]));
267: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum allowed timestep %g\n", (double)adapt->dt_max));
268: PetscCall(PetscViewerASCIIPrintf(viewer, " minimum allowed timestep %g\n", (double)adapt->dt_min));
269: PetscCall(PetscViewerASCIIPrintf(viewer, " maximum solution absolute value to be ignored %g\n", (double)adapt->ignore_max));
270: }
271: if (isglee) {
272: if (adapt->glee_use_local) {
273: PetscCall(PetscViewerASCIIPrintf(viewer, " GLEE uses local error control\n"));
274: } else {
275: PetscCall(PetscViewerASCIIPrintf(viewer, " GLEE uses global error control\n"));
276: }
277: }
278: PetscCall(PetscViewerASCIIPushTab(viewer));
279: PetscTryTypeMethod(adapt, view, viewer);
280: PetscCall(PetscViewerASCIIPopTab(viewer));
281: } else if (isbinary) {
282: char type[256];
284: /* need to save FILE_CLASS_ID for adapt class */
285: PetscCall(PetscStrncpy(type, ((PetscObject)adapt)->type_name, 256));
286: PetscCall(PetscViewerBinaryWrite(viewer, type, 256, PETSC_CHAR));
287: } else PetscTryTypeMethod(adapt, view, viewer);
288: PetscFunctionReturn(PETSC_SUCCESS);
289: }
291: /*@
292: TSAdaptReset - Resets a `TSAdapt` context to its defaults
294: Collective
296: Input Parameter:
297: . adapt - the `TSAdapt` context obtained from `TSGetAdapt()` or `TSAdaptCreate()`
299: Level: developer
301: .seealso: [](ch_ts), [](sec_ts_error_control), `TSGetAdapt()`, `TSAdapt`, `TSAdaptCreate()`, `TSAdaptDestroy()`
302: @*/
303: PetscErrorCode TSAdaptReset(TSAdapt adapt)
304: {
305: PetscFunctionBegin;
307: PetscTryTypeMethod(adapt, reset);
308: PetscFunctionReturn(PETSC_SUCCESS);
309: }
311: PetscErrorCode TSAdaptDestroy(TSAdapt *adapt)
312: {
313: PetscFunctionBegin;
314: if (!*adapt) PetscFunctionReturn(PETSC_SUCCESS);
316: if (--((PetscObject)*adapt)->refct > 0) {
317: *adapt = NULL;
318: PetscFunctionReturn(PETSC_SUCCESS);
319: }
321: PetscCall(TSAdaptReset(*adapt));
323: PetscTryTypeMethod(*adapt, destroy);
324: PetscCall(PetscViewerDestroy(&(*adapt)->monitor));
325: PetscCall(PetscHeaderDestroy(adapt));
326: PetscFunctionReturn(PETSC_SUCCESS);
327: }
329: /*@
330: TSAdaptSetMonitor - Monitor the choices made by the adaptive controller
332: Collective
334: Input Parameters:
335: + adapt - adaptive controller context
336: - flg - `PETSC_TRUE` to active a monitor, `PETSC_FALSE` to disable
338: Options Database Key:
339: . -ts_adapt_monitor - to turn on monitoring
341: Level: intermediate
343: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSGetAdapt()`, `TSAdaptChoose()`
344: @*/
345: PetscErrorCode TSAdaptSetMonitor(TSAdapt adapt, PetscBool flg)
346: {
347: PetscFunctionBegin;
350: if (flg) {
351: if (!adapt->monitor) PetscCall(PetscViewerASCIIOpen(PetscObjectComm((PetscObject)adapt), "stdout", &adapt->monitor));
352: } else {
353: PetscCall(PetscViewerDestroy(&adapt->monitor));
354: }
355: PetscFunctionReturn(PETSC_SUCCESS);
356: }
358: /*@C
359: TSAdaptSetCheckStage - Set a callback to check convergence for a stage
361: Logically Collective
363: Input Parameters:
364: + adapt - adaptive controller context
365: - func - stage check function
367: Calling sequence:
368: + adapt - adaptive controller context
369: . ts - time stepping context
370: . t - current time
371: . Y - current solution vector
372: - accept - pending choice of whether to accept, can be modified by this routine
374: Level: advanced
376: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSGetAdapt()`, `TSAdaptChoose()`
377: @*/
378: PetscErrorCode TSAdaptSetCheckStage(TSAdapt adapt, PetscErrorCode (*func)(TSAdapt adapt, TS ts, PetscReal t, Vec Y, PetscBool *accept))
379: {
380: PetscFunctionBegin;
382: adapt->checkstage = func;
383: PetscFunctionReturn(PETSC_SUCCESS);
384: }
386: /*@
387: TSAdaptSetAlwaysAccept - Set whether to always accept steps regardless of
388: any error or stability condition not meeting the prescribed goal.
390: Logically Collective
392: Input Parameters:
393: + adapt - time step adaptivity context, usually gotten with `TSGetAdapt()`
394: - flag - whether to always accept steps
396: Options Database Key:
397: . -ts_adapt_always_accept - to always accept steps
399: Level: intermediate
401: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSGetAdapt()`, `TSAdaptChoose()`
402: @*/
403: PetscErrorCode TSAdaptSetAlwaysAccept(TSAdapt adapt, PetscBool flag)
404: {
405: PetscFunctionBegin;
408: adapt->always_accept = flag;
409: PetscFunctionReturn(PETSC_SUCCESS);
410: }
412: /*@
413: TSAdaptSetSafety - Set safety factors for time step adaptor
415: Logically Collective
417: Input Parameters:
418: + adapt - adaptive controller context
419: . safety - safety factor relative to target error/stability goal
420: - reject_safety - extra safety factor to apply if the last step was rejected
422: Options Database Keys:
423: + -ts_adapt_safety <safety> - to set safety factor
424: - -ts_adapt_reject_safety <reject_safety> - to set reject safety factor
426: Level: intermediate
428: Note:
429: Use `PETSC_CURRENT` to keep the current value for either parameter
431: Fortran Note:
432: Use `PETSC_CURRENT_REAL`
434: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptGetSafety()`, `TSAdaptChoose()`
435: @*/
436: PetscErrorCode TSAdaptSetSafety(TSAdapt adapt, PetscReal safety, PetscReal reject_safety)
437: {
438: PetscFunctionBegin;
442: PetscCheck(safety == (PetscReal)PETSC_CURRENT || safety >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Safety factor %g must be non negative", (double)safety);
443: PetscCheck(safety == (PetscReal)PETSC_CURRENT || safety <= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Safety factor %g must be less than one", (double)safety);
444: PetscCheck(reject_safety == (PetscReal)PETSC_CURRENT || reject_safety >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Reject safety factor %g must be non negative", (double)reject_safety);
445: PetscCheck(reject_safety == (PetscReal)PETSC_CURRENT || reject_safety <= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Reject safety factor %g must be less than one", (double)reject_safety);
446: if (safety != (PetscReal)PETSC_CURRENT) adapt->safety = safety;
447: if (reject_safety != (PetscReal)PETSC_CURRENT) adapt->reject_safety = reject_safety;
448: PetscFunctionReturn(PETSC_SUCCESS);
449: }
451: /*@
452: TSAdaptGetSafety - Get safety factors for time step adapter
454: Not Collective
456: Input Parameter:
457: . adapt - adaptive controller context
459: Output Parameters:
460: + safety - safety factor relative to target error/stability goal
461: - reject_safety - extra safety factor to apply if the last step was rejected
463: Level: intermediate
465: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptSetSafety()`, `TSAdaptChoose()`
466: @*/
467: PetscErrorCode TSAdaptGetSafety(TSAdapt adapt, PetscReal *safety, PetscReal *reject_safety)
468: {
469: PetscFunctionBegin;
471: if (safety) PetscAssertPointer(safety, 2);
472: if (reject_safety) PetscAssertPointer(reject_safety, 3);
473: if (safety) *safety = adapt->safety;
474: if (reject_safety) *reject_safety = adapt->reject_safety;
475: PetscFunctionReturn(PETSC_SUCCESS);
476: }
478: /*@
479: TSAdaptSetMaxIgnore - Set error estimation threshold. Solution components below this threshold value will not be considered when computing error norms
480: for time step adaptivity (in absolute value). A negative value (default) of the threshold leads to considering all solution components.
482: Logically Collective
484: Input Parameters:
485: + adapt - adaptive controller context
486: - max_ignore - threshold for solution components that are ignored during error estimation
488: Options Database Key:
489: . -ts_adapt_max_ignore <max_ignore> - to set the threshold
491: Level: intermediate
493: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptGetMaxIgnore()`, `TSAdaptChoose()`
494: @*/
495: PetscErrorCode TSAdaptSetMaxIgnore(TSAdapt adapt, PetscReal max_ignore)
496: {
497: PetscFunctionBegin;
500: adapt->ignore_max = max_ignore;
501: PetscFunctionReturn(PETSC_SUCCESS);
502: }
504: /*@
505: TSAdaptGetMaxIgnore - Get error estimation threshold. Solution components below this threshold value will not be considered when computing error norms
506: for time step adaptivity (in absolute value).
508: Not Collective
510: Input Parameter:
511: . adapt - adaptive controller context
513: Output Parameter:
514: . max_ignore - threshold for solution components that are ignored during error estimation
516: Level: intermediate
518: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptSetMaxIgnore()`, `TSAdaptChoose()`
519: @*/
520: PetscErrorCode TSAdaptGetMaxIgnore(TSAdapt adapt, PetscReal *max_ignore)
521: {
522: PetscFunctionBegin;
524: PetscAssertPointer(max_ignore, 2);
525: *max_ignore = adapt->ignore_max;
526: PetscFunctionReturn(PETSC_SUCCESS);
527: }
529: /*@
530: TSAdaptSetClip - Sets the admissible decrease/increase factor in step size in the time step adapter
532: Logically collective
534: Input Parameters:
535: + adapt - adaptive controller context
536: . low - admissible decrease factor
537: - high - admissible increase factor
539: Options Database Key:
540: . -ts_adapt_clip <low>,<high> - to set admissible time step decrease and increase factors
542: Level: intermediate
544: Note:
545: Use `PETSC_CURRENT` to keep the current value for either parameter
547: Fortran Note:
548: Use `PETSC_CURRENT_REAL`
550: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptChoose()`, `TSAdaptGetClip()`, `TSAdaptSetScaleSolveFailed()`
551: @*/
552: PetscErrorCode TSAdaptSetClip(TSAdapt adapt, PetscReal low, PetscReal high)
553: {
554: PetscFunctionBegin;
558: PetscCheck(low == (PetscReal)PETSC_CURRENT || low >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Decrease factor %g must be non negative", (double)low);
559: PetscCheck(low == (PetscReal)PETSC_CURRENT || low <= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Decrease factor %g must be less than one", (double)low);
560: PetscCheck(high == (PetscReal)PETSC_CURRENT || high >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Increase factor %g must be greater than one", (double)high);
561: if (low != (PetscReal)PETSC_CURRENT) adapt->clip[0] = low;
562: if (high != (PetscReal)PETSC_CURRENT) adapt->clip[1] = high;
563: PetscFunctionReturn(PETSC_SUCCESS);
564: }
566: /*@
567: TSAdaptGetClip - Gets the admissible decrease/increase factor in step size in the time step adapter
569: Not Collective
571: Input Parameter:
572: . adapt - adaptive controller context
574: Output Parameters:
575: + low - optional, admissible decrease factor
576: - high - optional, admissible increase factor
578: Level: intermediate
580: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptChoose()`, `TSAdaptSetClip()`, `TSAdaptSetScaleSolveFailed()`
581: @*/
582: PetscErrorCode TSAdaptGetClip(TSAdapt adapt, PetscReal *low, PetscReal *high)
583: {
584: PetscFunctionBegin;
586: if (low) PetscAssertPointer(low, 2);
587: if (high) PetscAssertPointer(high, 3);
588: if (low) *low = adapt->clip[0];
589: if (high) *high = adapt->clip[1];
590: PetscFunctionReturn(PETSC_SUCCESS);
591: }
593: /*@
594: TSAdaptSetScaleSolveFailed - Scale step size by this factor if solve fails
596: Logically Collective
598: Input Parameters:
599: + adapt - adaptive controller context
600: - scale - scale
602: Options Database Key:
603: . -ts_adapt_scale_solve_failed <scale> - to set scale step by this factor if solve fails
605: Level: intermediate
607: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptChoose()`, `TSAdaptGetScaleSolveFailed()`, `TSAdaptGetClip()`
608: @*/
609: PetscErrorCode TSAdaptSetScaleSolveFailed(TSAdapt adapt, PetscReal scale)
610: {
611: PetscFunctionBegin;
614: PetscCheck(scale > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Scale factor %g must be positive", (double)scale);
615: PetscCheck(scale <= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Scale factor %g must be less than one", (double)scale);
616: adapt->scale_solve_failed = scale;
617: PetscFunctionReturn(PETSC_SUCCESS);
618: }
620: /*@
621: TSAdaptGetScaleSolveFailed - Gets the admissible decrease/increase factor in step size
623: Not Collective
625: Input Parameter:
626: . adapt - adaptive controller context
628: Output Parameter:
629: . scale - scale factor
631: Level: intermediate
633: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptChoose()`, `TSAdaptSetScaleSolveFailed()`, `TSAdaptSetClip()`
634: @*/
635: PetscErrorCode TSAdaptGetScaleSolveFailed(TSAdapt adapt, PetscReal *scale)
636: {
637: PetscFunctionBegin;
639: if (scale) PetscAssertPointer(scale, 2);
640: if (scale) *scale = adapt->scale_solve_failed;
641: PetscFunctionReturn(PETSC_SUCCESS);
642: }
644: /*@
645: TSAdaptSetStepLimits - Set the minimum and maximum step sizes to be considered by the time step controller
647: Logically Collective
649: Input Parameters:
650: + adapt - time step adaptivity context, usually gotten with `TSGetAdapt()`
651: . hmin - minimum time step
652: - hmax - maximum time step
654: Options Database Keys:
655: + -ts_adapt_dt_min <min> - to set minimum time step
656: - -ts_adapt_dt_max <max> - to set maximum time step
658: Level: intermediate
660: Note:
661: Use `PETSC_CURRENT` to keep the current value for either parameter
663: Fortran Note:
664: Use `PETSC_CURRENT_REAL`
666: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptGetStepLimits()`, `TSAdaptChoose()`
667: @*/
668: PetscErrorCode TSAdaptSetStepLimits(TSAdapt adapt, PetscReal hmin, PetscReal hmax)
669: {
670: PetscFunctionBegin;
674: PetscCheck(hmin == (PetscReal)PETSC_CURRENT || hmin >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Minimum time step %g must be non negative", (double)hmin);
675: PetscCheck(hmax == (PetscReal)PETSC_CURRENT || hmax >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Minimum time step %g must be non negative", (double)hmax);
676: if (hmin != (PetscReal)PETSC_CURRENT) adapt->dt_min = hmin;
677: if (hmax != (PetscReal)PETSC_CURRENT) adapt->dt_max = hmax;
678: hmin = adapt->dt_min;
679: hmax = adapt->dt_max;
680: PetscCheck(hmax > hmin, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Maximum time step %g must greater than minimum time step %g", (double)hmax, (double)hmin);
681: PetscFunctionReturn(PETSC_SUCCESS);
682: }
684: /*@
685: TSAdaptGetStepLimits - Get the minimum and maximum step sizes to be considered by the time step controller
687: Not Collective
689: Input Parameter:
690: . adapt - time step adaptivity context, usually gotten with `TSGetAdapt()`
692: Output Parameters:
693: + hmin - minimum time step
694: - hmax - maximum time step
696: Level: intermediate
698: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptSetStepLimits()`, `TSAdaptChoose()`
699: @*/
700: PetscErrorCode TSAdaptGetStepLimits(TSAdapt adapt, PetscReal *hmin, PetscReal *hmax)
701: {
702: PetscFunctionBegin;
704: if (hmin) PetscAssertPointer(hmin, 2);
705: if (hmax) PetscAssertPointer(hmax, 3);
706: if (hmin) *hmin = adapt->dt_min;
707: if (hmax) *hmax = adapt->dt_max;
708: PetscFunctionReturn(PETSC_SUCCESS);
709: }
711: /*@C
712: TSAdaptSetFromOptions - Sets various `TSAdapt` parameters from user options.
714: Collective
716: Input Parameters:
717: + adapt - the `TSAdapt` context
718: - PetscOptionsObject - object created by `PetscOptionsBegin()`
720: Options Database Keys:
721: + -ts_adapt_type <type> - algorithm to use for adaptivity
722: . -ts_adapt_always_accept - always accept steps regardless of error/stability goals
723: . -ts_adapt_safety <safety> - safety factor relative to target error/stability goal
724: . -ts_adapt_reject_safety <safety> - extra safety factor to apply if the last step was rejected
725: . -ts_adapt_clip <low,high> - admissible time step decrease and increase factors
726: . -ts_adapt_dt_min <min> - minimum timestep to use
727: . -ts_adapt_dt_max <max> - maximum timestep to use
728: . -ts_adapt_scale_solve_failed <scale> - scale timestep by this factor if a solve fails
729: . -ts_adapt_wnormtype <2 or infinity> - type of norm for computing error estimates
730: - -ts_adapt_time_step_increase_delay - number of timesteps to delay increasing the time step after it has been decreased due to failed solver
732: Level: advanced
734: Note:
735: This function is automatically called by `TSSetFromOptions()`
737: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSGetAdapt()`, `TSAdaptSetType()`, `TSAdaptSetAlwaysAccept()`, `TSAdaptSetSafety()`,
738: `TSAdaptSetClip()`, `TSAdaptSetScaleSolveFailed()`, `TSAdaptSetStepLimits()`, `TSAdaptSetMonitor()`
739: @*/
740: PetscErrorCode TSAdaptSetFromOptions(TSAdapt adapt, PetscOptionItems PetscOptionsObject)
741: {
742: char type[256] = TSADAPTBASIC;
743: PetscReal safety, reject_safety, clip[2], scale, hmin, hmax;
744: PetscBool set, flg;
745: PetscInt two;
747: PetscFunctionBegin;
749: /* This should use PetscOptionsBegin() if/when this becomes an object used outside of TS, but currently this
750: * function can only be called from inside TSSetFromOptions() */
751: PetscOptionsHeadBegin(PetscOptionsObject, "TS Adaptivity options");
752: PetscCall(PetscOptionsFList("-ts_adapt_type", "Algorithm to use for adaptivity", "TSAdaptSetType", TSAdaptList, ((PetscObject)adapt)->type_name ? ((PetscObject)adapt)->type_name : type, type, sizeof(type), &flg));
753: if (flg || !((PetscObject)adapt)->type_name) PetscCall(TSAdaptSetType(adapt, type));
755: PetscCall(PetscOptionsBool("-ts_adapt_always_accept", "Always accept the step", "TSAdaptSetAlwaysAccept", adapt->always_accept, &flg, &set));
756: if (set) PetscCall(TSAdaptSetAlwaysAccept(adapt, flg));
758: safety = adapt->safety;
759: reject_safety = adapt->reject_safety;
760: PetscCall(PetscOptionsReal("-ts_adapt_safety", "Safety factor relative to target error/stability goal", "TSAdaptSetSafety", safety, &safety, &set));
761: PetscCall(PetscOptionsReal("-ts_adapt_reject_safety", "Extra safety factor to apply if the last step was rejected", "TSAdaptSetSafety", reject_safety, &reject_safety, &flg));
762: if (set || flg) PetscCall(TSAdaptSetSafety(adapt, safety, reject_safety));
764: two = 2;
765: clip[0] = adapt->clip[0];
766: clip[1] = adapt->clip[1];
767: PetscCall(PetscOptionsRealArray("-ts_adapt_clip", "Admissible decrease/increase factor in step size", "TSAdaptSetClip", clip, &two, &set));
768: PetscCheck(!set || (two == 2), PetscObjectComm((PetscObject)adapt), PETSC_ERR_ARG_OUTOFRANGE, "Must give exactly two values to -ts_adapt_clip");
769: if (set) PetscCall(TSAdaptSetClip(adapt, clip[0], clip[1]));
771: hmin = adapt->dt_min;
772: hmax = adapt->dt_max;
773: PetscCall(PetscOptionsReal("-ts_adapt_dt_min", "Minimum time step considered", "TSAdaptSetStepLimits", hmin, &hmin, &set));
774: PetscCall(PetscOptionsReal("-ts_adapt_dt_max", "Maximum time step considered", "TSAdaptSetStepLimits", hmax, &hmax, &flg));
775: if (set || flg) PetscCall(TSAdaptSetStepLimits(adapt, hmin, hmax));
777: PetscCall(PetscOptionsReal("-ts_adapt_max_ignore", "Adaptor ignores (absolute) solution values smaller than this value", "", adapt->ignore_max, &adapt->ignore_max, &set));
778: PetscCall(PetscOptionsBool("-ts_adapt_glee_use_local", "GLEE adaptor uses local error estimation for step control", "", adapt->glee_use_local, &adapt->glee_use_local, &set));
780: PetscCall(PetscOptionsReal("-ts_adapt_scale_solve_failed", "Scale step by this factor if solve fails", "TSAdaptSetScaleSolveFailed", adapt->scale_solve_failed, &scale, &set));
781: if (set) PetscCall(TSAdaptSetScaleSolveFailed(adapt, scale));
783: PetscCall(PetscOptionsEnum("-ts_adapt_wnormtype", "Type of norm computed for error estimation", "", NormTypes, (PetscEnum)adapt->wnormtype, (PetscEnum *)&adapt->wnormtype, NULL));
784: PetscCheck(adapt->wnormtype == NORM_2 || adapt->wnormtype == NORM_INFINITY, PetscObjectComm((PetscObject)adapt), PETSC_ERR_SUP, "Only 2-norm and infinite norm supported");
786: PetscCall(PetscOptionsInt("-ts_adapt_time_step_increase_delay", "Number of timesteps to delay increasing the time step after it has been decreased due to failed solver", "TSAdaptSetTimeStepIncreaseDelay", adapt->timestepjustdecreased_delay, &adapt->timestepjustdecreased_delay, NULL));
788: PetscCall(PetscOptionsBool("-ts_adapt_monitor", "Print choices made by adaptive controller", "TSAdaptSetMonitor", adapt->monitor ? PETSC_TRUE : PETSC_FALSE, &flg, &set));
789: if (set) PetscCall(TSAdaptSetMonitor(adapt, flg));
791: PetscTryTypeMethod(adapt, setfromoptions, PetscOptionsObject);
792: PetscOptionsHeadEnd();
793: PetscFunctionReturn(PETSC_SUCCESS);
794: }
796: /*@
797: TSAdaptCandidatesClear - clear any previously set candidate schemes
799: Logically Collective
801: Input Parameter:
802: . adapt - adaptive controller
804: Level: developer
806: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptCreate()`, `TSAdaptCandidateAdd()`, `TSAdaptChoose()`
807: @*/
808: PetscErrorCode TSAdaptCandidatesClear(TSAdapt adapt)
809: {
810: PetscFunctionBegin;
812: PetscCall(PetscMemzero(&adapt->candidates, sizeof(adapt->candidates)));
813: PetscFunctionReturn(PETSC_SUCCESS);
814: }
816: /*@C
817: TSAdaptCandidateAdd - add a candidate scheme for the adaptive controller to select from
819: Logically Collective; No Fortran Support
821: Input Parameters:
822: + adapt - time step adaptivity context, obtained with `TSGetAdapt()` or `TSAdaptCreate()`
823: . name - name of the candidate scheme to add
824: . order - order of the candidate scheme
825: . stageorder - stage order of the candidate scheme
826: . ccfl - stability coefficient relative to explicit Euler, used for CFL constraints
827: . cost - relative measure of the amount of work required for the candidate scheme
828: - inuse - indicates that this scheme is the one currently in use, this flag can only be set for one scheme
830: Level: developer
832: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptCandidatesClear()`, `TSAdaptChoose()`
833: @*/
834: PetscErrorCode TSAdaptCandidateAdd(TSAdapt adapt, const char name[], PetscInt order, PetscInt stageorder, PetscReal ccfl, PetscReal cost, PetscBool inuse)
835: {
836: PetscInt c;
838: PetscFunctionBegin;
840: PetscCheck(order >= 1, PetscObjectComm((PetscObject)adapt), PETSC_ERR_ARG_OUTOFRANGE, "Classical order %" PetscInt_FMT " must be a positive integer", order);
841: if (inuse) {
842: PetscCheck(!adapt->candidates.inuse_set, PetscObjectComm((PetscObject)adapt), PETSC_ERR_ARG_WRONGSTATE, "Cannot set the inuse method twice, maybe forgot to call TSAdaptCandidatesClear()");
843: adapt->candidates.inuse_set = PETSC_TRUE;
844: }
845: /* first slot if this is the current scheme, otherwise the next available slot */
846: c = inuse ? 0 : !adapt->candidates.inuse_set + adapt->candidates.n;
848: adapt->candidates.name[c] = name;
849: adapt->candidates.order[c] = order;
850: adapt->candidates.stageorder[c] = stageorder;
851: adapt->candidates.ccfl[c] = ccfl;
852: adapt->candidates.cost[c] = cost;
853: adapt->candidates.n++;
854: PetscFunctionReturn(PETSC_SUCCESS);
855: }
857: /*@C
858: TSAdaptCandidatesGet - Get the list of candidate orders of accuracy and cost
860: Not Collective
862: Input Parameter:
863: . adapt - time step adaptivity context
865: Output Parameters:
866: + n - number of candidate schemes, always at least 1
867: . order - the order of each candidate scheme
868: . stageorder - the stage order of each candidate scheme
869: . ccfl - the CFL coefficient of each scheme
870: - cost - the relative cost of each scheme
872: Level: developer
874: Note:
875: The current scheme is always returned in the first slot
877: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptCandidatesClear()`, `TSAdaptCandidateAdd()`, `TSAdaptChoose()`
878: @*/
879: PetscErrorCode TSAdaptCandidatesGet(TSAdapt adapt, PetscInt *n, const PetscInt **order, const PetscInt **stageorder, const PetscReal **ccfl, const PetscReal **cost)
880: {
881: PetscFunctionBegin;
883: if (n) *n = adapt->candidates.n;
884: if (order) *order = adapt->candidates.order;
885: if (stageorder) *stageorder = adapt->candidates.stageorder;
886: if (ccfl) *ccfl = adapt->candidates.ccfl;
887: if (cost) *cost = adapt->candidates.cost;
888: PetscFunctionReturn(PETSC_SUCCESS);
889: }
891: /*@C
892: TSAdaptChoose - choose which method and step size to use for the next step
894: Collective
896: Input Parameters:
897: + adapt - adaptive controller
898: . ts - time stepper
899: - h - current step size
901: Output Parameters:
902: + next_sc - optional, scheme to use for the next step
903: . next_h - step size to use for the next step
904: - accept - `PETSC_TRUE` to accept the current step, `PETSC_FALSE` to repeat the current step with the new step size
906: Level: developer
908: Note:
909: The input value of parameter accept is retained from the last time step, so it will be `PETSC_FALSE` if the step is
910: being retried after an initial rejection.
912: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSAdaptCandidatesClear()`, `TSAdaptCandidateAdd()`
913: @*/
914: PetscErrorCode TSAdaptChoose(TSAdapt adapt, TS ts, PetscReal h, PetscInt *next_sc, PetscReal *next_h, PetscBool *accept)
915: {
916: PetscInt ncandidates = adapt->candidates.n;
917: PetscInt scheme = 0;
918: PetscReal wlte = -1.0;
919: PetscReal wltea = -1.0;
920: PetscReal wlter = -1.0;
922: PetscFunctionBegin;
925: if (next_sc) PetscAssertPointer(next_sc, 4);
926: PetscAssertPointer(next_h, 5);
927: PetscAssertPointer(accept, 6);
928: if (next_sc) *next_sc = 0;
930: /* Do not mess with adaptivity while handling events */
931: if (ts->event && ts->event->processing) {
932: *next_h = h;
933: *accept = PETSC_TRUE;
934: if (adapt->monitor) {
935: PetscCall(PetscViewerASCIIAddTab(adapt->monitor, ((PetscObject)adapt)->tablevel));
937: if (ts->event->iterctr == 0) {
938: /*
939: An event has been found, now finalising the event processing: performing the 1st and 2nd post-event steps.
940: Entering this if-branch means both these steps (set to either PETSC_DECIDE or numerical value) are managed
941: by the event handler. In this case the 1st post-event step is always accepted, without interference of TSAdapt.
942: Note: if the 2nd post-event step is not managed by the event handler (e.g. given 1st = numerical, 2nd = PETSC_DECIDE),
943: this if-branch is not entered, and TSAdapt may reject/adjust the proposed 1st post-event step.
944: */
945: PetscCall(PetscViewerASCIIPrintf(adapt->monitor, " TSAdapt does not interfere, step %3" PetscInt_FMT " accepted. Processing post-event steps: 1-st accepted just now, 2-nd yet to come\n", ts->steps));
946: } else PetscCall(PetscViewerASCIIPrintf(adapt->monitor, " TSAdapt does not interfere, step %3" PetscInt_FMT " accepted. Event handling in progress\n", ts->steps));
948: PetscCall(PetscViewerASCIISubtractTab(adapt->monitor, ((PetscObject)adapt)->tablevel));
949: }
950: PetscFunctionReturn(PETSC_SUCCESS);
951: }
953: PetscUseTypeMethod(adapt, choose, ts, h, &scheme, next_h, accept, &wlte, &wltea, &wlter);
954: PetscCheck(scheme >= 0 && (ncandidates <= 0 || scheme < ncandidates), PetscObjectComm((PetscObject)adapt), PETSC_ERR_ARG_OUTOFRANGE, "Chosen scheme %" PetscInt_FMT " not in valid range 0..%" PetscInt_FMT, scheme, ncandidates - 1);
955: PetscCheck(*next_h >= 0, PetscObjectComm((PetscObject)adapt), PETSC_ERR_ARG_OUTOFRANGE, "Computed step size %g must be positive", (double)*next_h);
956: if (next_sc) *next_sc = scheme;
958: if (*accept && ts->exact_final_time == TS_EXACTFINALTIME_MATCHSTEP) {
959: /* Increase/reduce step size if end time of next step is close to or overshoots max time */
960: PetscReal t = ts->ptime + ts->time_step, tend, tmax, h1, hmax;
961: PetscReal a = (PetscReal)(1.0 + adapt->matchstepfac[0]);
962: PetscReal b = adapt->matchstepfac[1];
964: /*
965: Logic in using 'dt_span_cached':
966: 1. It always overrides *next_h, except (any of):
967: a) the current step was rejected,
968: b) the adaptor proposed to decrease the next step,
969: c) the adaptor proposed *next_h > dt_span_cached.
970: 2. If *next_h was adjusted by eval_times points (or the final point):
971: -- when dt_span_cached is filled (>0), it keeps its value,
972: -- when dt_span_cached is clear (==0), it gets the unadjusted version of *next_h.
973: 3. If *next_h was not adjusted as in (2), dt_span_cached is cleared.
974: Note, if a combination (1.b || 1.c) && (3) takes place, this means that
975: dt_span_cached remains unused at the moment of clearing.
976: If (1.a) takes place, dt_span_cached keeps its value.
977: Also, dt_span_cached can be updated by the event handler, see tsevent.c.
978: */
979: if (h <= *next_h && *next_h <= adapt->dt_eval_times_cached) *next_h = adapt->dt_eval_times_cached; /* try employing the cache */
980: h1 = *next_h;
981: tend = t + h1;
983: if (ts->eval_times && ts->eval_times->time_point_idx < ts->eval_times->num_time_points) {
984: PetscCheck(ts->eval_times->worktol == 0, PetscObjectComm((PetscObject)adapt), PETSC_ERR_PLIB, "Unexpected state (tspan->worktol != 0) in TSAdaptChoose()");
985: ts->eval_times->worktol = ts->eval_times->reltol * h1 + ts->eval_times->abstol;
986: if (PetscIsCloseAtTol(t, ts->eval_times->time_points[ts->eval_times->time_point_idx], ts->eval_times->worktol, 0)) /* hit a span time point */
987: if (ts->eval_times->time_point_idx + 1 < ts->eval_times->num_time_points) tmax = ts->eval_times->time_points[ts->eval_times->time_point_idx + 1];
988: else tmax = ts->max_time; /* hit the last span time point */
989: else tmax = ts->eval_times->time_points[ts->eval_times->time_point_idx];
990: } else tmax = ts->max_time;
991: tmax = PetscMin(tmax, ts->max_time);
992: hmax = tmax - t;
994: if (t < tmax && tend > tmax) *next_h = hmax;
995: if (t < tmax && tend < tmax && h1 * b > hmax) *next_h = hmax / 2;
996: if (t < tmax && tend < tmax && h1 * a > hmax) *next_h = hmax;
997: if (ts->eval_times && h1 != *next_h && !adapt->dt_eval_times_cached) adapt->dt_eval_times_cached = h1; /* cache the step size if it is to be changed */
998: if (ts->eval_times && h1 == *next_h && adapt->dt_eval_times_cached) adapt->dt_eval_times_cached = 0; /* clear the cache if the step size is unchanged */
999: }
1000: if (adapt->monitor) {
1001: const char *sc_name = (scheme < ncandidates) ? adapt->candidates.name[scheme] : "";
1002: PetscCall(PetscViewerASCIIAddTab(adapt->monitor, ((PetscObject)adapt)->tablevel));
1003: if (wlte < 0) {
1004: PetscCall(PetscViewerASCIIPrintf(adapt->monitor, " TSAdapt %s %s %" PetscInt_FMT ":%s step %3" PetscInt_FMT " %s t=%-11g+%10.3e dt=%-10.3e\n", ((PetscObject)adapt)->type_name, ((PetscObject)ts)->type_name, scheme, sc_name, ts->steps, *accept ? "accepted" : "rejected",
1005: (double)ts->ptime, (double)h, (double)*next_h));
1006: } else {
1007: PetscCall(PetscViewerASCIIPrintf(adapt->monitor, " TSAdapt %s %s %" PetscInt_FMT ":%s step %3" PetscInt_FMT " %s t=%-11g+%10.3e dt=%-10.3e wlte=%5.3g wltea=%5.3g wlter=%5.3g\n", ((PetscObject)adapt)->type_name, ((PetscObject)ts)->type_name, scheme, sc_name, ts->steps, *accept ? "accepted" : "rejected",
1008: (double)ts->ptime, (double)h, (double)*next_h, (double)wlte, (double)wltea, (double)wlter));
1009: }
1010: PetscCall(PetscViewerASCIISubtractTab(adapt->monitor, ((PetscObject)adapt)->tablevel));
1011: }
1012: PetscFunctionReturn(PETSC_SUCCESS);
1013: }
1015: /*@
1016: TSAdaptSetTimeStepIncreaseDelay - The number of timesteps to wait after a decrease in the timestep due to failed solver
1017: before increasing the time step.
1019: Logicially Collective
1021: Input Parameters:
1022: + adapt - adaptive controller context
1023: - cnt - the number of timesteps
1025: Options Database Key:
1026: . -ts_adapt_time_step_increase_delay cnt - number of steps to delay the increase
1028: Level: advanced
1030: Notes:
1031: This is to prevent an adaptor from bouncing back and forth between two nearby timesteps. The default is 0.
1033: The successful use of this option is problem dependent
1035: Developer Notes:
1036: There is no theory to support this option
1038: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`
1039: @*/
1040: PetscErrorCode TSAdaptSetTimeStepIncreaseDelay(TSAdapt adapt, PetscInt cnt)
1041: {
1042: PetscFunctionBegin;
1043: adapt->timestepjustdecreased_delay = cnt;
1044: PetscFunctionReturn(PETSC_SUCCESS);
1045: }
1047: /*@
1048: TSAdaptCheckStage - checks whether to accept a stage, (e.g. reject and change time step size if nonlinear solve fails or solution vector is infeasible)
1050: Collective
1052: Input Parameters:
1053: + adapt - adaptive controller context
1054: . ts - time stepper
1055: . t - Current simulation time
1056: - Y - Current solution vector
1058: Output Parameter:
1059: . accept - `PETSC_TRUE` to accept the stage, `PETSC_FALSE` to reject
1061: Level: developer
1063: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`
1064: @*/
1065: PetscErrorCode TSAdaptCheckStage(TSAdapt adapt, TS ts, PetscReal t, Vec Y, PetscBool *accept)
1066: {
1067: SNESConvergedReason snesreason = SNES_CONVERGED_ITERATING;
1068: PetscBool func_accept, snes_div_func;
1070: PetscFunctionBegin;
1073: PetscAssertPointer(accept, 5);
1075: PetscCall(TSFunctionDomainError(ts, t, Y, &func_accept));
1076: if (ts->snes) PetscCall(SNESGetConvergedReason(ts->snes, &snesreason));
1077: snes_div_func = (PetscBool)(snesreason == SNES_DIVERGED_FUNCTION_DOMAIN);
1078: if (func_accept && snesreason < 0 && !snes_div_func) {
1079: *accept = PETSC_FALSE;
1080: PetscCall(PetscInfo(ts, "Step=%" PetscInt_FMT ", nonlinear solve failure: %s\n", ts->steps, SNESConvergedReasons[snesreason]));
1081: if (++ts->num_snes_failures >= ts->max_snes_failures && ts->max_snes_failures != PETSC_UNLIMITED) {
1082: ts->reason = TS_DIVERGED_NONLINEAR_SOLVE;
1083: PetscCall(PetscInfo(ts, "Step=%" PetscInt_FMT ", nonlinear solve failures %" PetscInt_FMT " greater than current TS allowed, stopping solve\n", ts->steps, ts->num_snes_failures));
1084: if (adapt->monitor) {
1085: PetscCall(PetscViewerASCIIAddTab(adapt->monitor, ((PetscObject)adapt)->tablevel));
1086: PetscCall(PetscViewerASCIIPrintf(adapt->monitor, " TSAdapt %s step %3" PetscInt_FMT " stage rejected t=%-11g+%10.3e, nonlinear solve failures %" PetscInt_FMT " greater than current TS allowed\n", ((PetscObject)adapt)->type_name, ts->steps,
1087: (double)ts->ptime, (double)ts->time_step, ts->num_snes_failures));
1088: PetscCall(PetscViewerASCIISubtractTab(adapt->monitor, ((PetscObject)adapt)->tablevel));
1089: }
1090: }
1091: } else {
1092: *accept = (PetscBool)(func_accept && !snes_div_func);
1093: if (*accept && adapt->checkstage) PetscCall((*adapt->checkstage)(adapt, ts, t, Y, accept));
1094: if (!*accept) {
1095: const char *user_func = !func_accept ? "TSSetFunctionDomainError()" : "TSAdaptSetCheckStage";
1096: const char *snes_err = "SNES invalid function domain";
1097: const char *err_msg = snes_div_func && func_accept ? snes_err : user_func;
1098: PetscCall(PetscInfo(ts, "Step=%" PetscInt_FMT ", solution rejected by %s\n", ts->steps, err_msg));
1099: if (adapt->monitor) {
1100: PetscCall(PetscViewerASCIIAddTab(adapt->monitor, ((PetscObject)adapt)->tablevel));
1101: PetscCall(PetscViewerASCIIPrintf(adapt->monitor, " TSAdapt %s step %3" PetscInt_FMT " stage rejected by %s\n", ((PetscObject)adapt)->type_name, ts->steps, err_msg));
1102: PetscCall(PetscViewerASCIISubtractTab(adapt->monitor, ((PetscObject)adapt)->tablevel));
1103: }
1104: }
1105: }
1107: if (!*accept && !ts->reason) {
1108: PetscReal dt, new_dt;
1109: PetscCall(TSGetTimeStep(ts, &dt));
1110: new_dt = dt * adapt->scale_solve_failed;
1111: PetscCall(TSSetTimeStep(ts, new_dt));
1112: adapt->timestepjustdecreased += adapt->timestepjustdecreased_delay;
1113: if (adapt->monitor) {
1114: PetscCall(PetscViewerASCIIAddTab(adapt->monitor, ((PetscObject)adapt)->tablevel));
1115: PetscCall(PetscViewerASCIIPrintf(adapt->monitor, " TSAdapt %s step %3" PetscInt_FMT " stage rejected (SNES reason %s) t=%-11g+%10.3e retrying with dt=%-10.3e\n", ((PetscObject)adapt)->type_name, ts->steps, SNESConvergedReasons[snesreason],
1116: (double)ts->ptime, (double)dt, (double)new_dt));
1117: PetscCall(PetscViewerASCIISubtractTab(adapt->monitor, ((PetscObject)adapt)->tablevel));
1118: }
1119: }
1120: PetscFunctionReturn(PETSC_SUCCESS);
1121: }
1123: /*@
1124: TSAdaptCreate - create an adaptive controller context for time stepping
1126: Collective
1128: Input Parameter:
1129: . comm - The communicator
1131: Output Parameter:
1132: . inadapt - new `TSAdapt` object
1134: Level: developer
1136: Note:
1137: `TSAdapt` creation is handled by `TS`, so users should not need to call this function.
1139: .seealso: [](ch_ts), [](sec_ts_error_control), `TSAdapt`, `TSGetAdapt()`, `TSAdaptSetType()`, `TSAdaptDestroy()`
1140: @*/
1141: PetscErrorCode TSAdaptCreate(MPI_Comm comm, TSAdapt *inadapt)
1142: {
1143: TSAdapt adapt;
1145: PetscFunctionBegin;
1146: PetscAssertPointer(inadapt, 2);
1147: PetscCall(TSAdaptInitializePackage());
1149: PetscCall(PetscHeaderCreate(adapt, TSADAPT_CLASSID, "TSAdapt", "Time stepping adaptivity", "TS", comm, TSAdaptDestroy, TSAdaptView));
1150: adapt->always_accept = PETSC_FALSE;
1151: adapt->safety = 0.9;
1152: adapt->reject_safety = 0.5;
1153: adapt->clip[0] = 0.1;
1154: adapt->clip[1] = 10.;
1155: adapt->dt_min = 1e-20;
1156: adapt->dt_max = 1e+20;
1157: adapt->ignore_max = -1.0;
1158: adapt->glee_use_local = PETSC_TRUE;
1159: adapt->scale_solve_failed = 0.25;
1160: /* these two safety factors are not public, and they are used only in the TS_EXACTFINALTIME_MATCHSTEP case
1161: to prevent from situations were unreasonably small time steps are taken in order to match the final time */
1162: adapt->matchstepfac[0] = 0.01; /* allow 1% step size increase in the last step */
1163: adapt->matchstepfac[1] = 2.0; /* halve last step if it is greater than what remains divided this factor */
1164: adapt->wnormtype = NORM_2;
1165: adapt->timestepjustdecreased_delay = 0;
1166: *inadapt = adapt;
1167: PetscFunctionReturn(PETSC_SUCCESS);
1168: }