Actual source code: adaptglee.c
1: #include <petsc/private/tsimpl.h>
2: #include <petscdm.h>
4: typedef struct {
5: Vec Y;
6: } TSAdapt_GLEE;
8: static PetscErrorCode TSAdaptChoose_GLEE(TSAdapt adapt, TS ts, PetscReal h, PetscInt *next_sc, PetscReal *next_h, PetscBool *accept, PetscReal *wlte, PetscReal *wltea, PetscReal *wlter)
9: {
10: TSAdapt_GLEE *glee = (TSAdapt_GLEE *)adapt->data;
11: Vec X, Y, E;
12: PetscReal enorm, enorma, enormr, hfac_lte, hfac_ltea, hfac_lter, h_lte, safety;
13: PetscInt order;
14: PetscBool bGTEMethod;
16: PetscFunctionBegin;
17: *next_sc = 0; /* Reuse the same order scheme */
18: safety = adapt->safety;
19: PetscCall(PetscObjectTypeCompare((PetscObject)ts, TSGLEE, &bGTEMethod));
20: order = adapt->candidates.order[0];
22: if (bGTEMethod) { /* the method is of GLEE type */
23: DM dm;
25: PetscCall(TSGetSolution(ts, &X));
26: if (!glee->Y && adapt->glee_use_local) PetscCall(VecDuplicate(X, &glee->Y)); /*create vector to store previous step global error*/
27: PetscCall(TSGetDM(ts, &dm));
28: PetscCall(DMGetGlobalVector(dm, &E));
29: PetscCall(TSGetTimeError(ts, 0, &E));
31: if (adapt->glee_use_local) PetscCall(VecAXPY(E, -1.0, glee->Y)); /* local error = current error - previous step error */
33: /* this should be called with the solution at the beginning of the step too*/
34: PetscCall(TSErrorWeightedENorm(ts, E, X, X, adapt->wnormtype, &enorm, &enorma, &enormr));
35: PetscCall(DMRestoreGlobalVector(dm, &E));
36: } else {
37: /* the method is NOT of GLEE type; use the stantard basic augmented by separate atol and rtol */
38: PetscCall(TSGetSolution(ts, &X));
39: if (!glee->Y) PetscCall(VecDuplicate(X, &glee->Y));
40: Y = glee->Y;
41: PetscCall(TSEvaluateStep(ts, order - 1, Y, NULL));
42: PetscCall(TSErrorWeightedNorm(ts, X, Y, adapt->wnormtype, &enorm, &enorma, &enormr));
43: }
45: if (enorm < 0) {
46: *accept = PETSC_TRUE;
47: *next_h = h; /* Reuse the old step */
48: *wlte = -1; /* Weighted error was not evaluated */
49: *wltea = -1; /* Weighted absolute error was not evaluated */
50: *wlter = -1; /* Weighted relative error was not evaluated */
51: PetscFunctionReturn(PETSC_SUCCESS);
52: }
54: if (enorm > 1. || enorma > 1. || enormr > 1.) {
55: if (!*accept) safety *= adapt->reject_safety; /* The last attempt also failed, shorten more aggressively */
56: if (h < (1 + PETSC_SQRT_MACHINE_EPSILON) * adapt->dt_min) {
57: PetscCall(PetscInfo(adapt, "Estimated scaled truncation error [combined, absolute, relative]] [%g, %g, %g], accepting because step size %g is at minimum\n", (double)enorm, (double)enorma, (double)enormr, (double)h));
58: *accept = PETSC_TRUE;
59: } else if (adapt->always_accept) {
60: PetscCall(PetscInfo(adapt, "Estimated scaled truncation error [combined, absolute, relative]] [%g, %g, %g], accepting step of size %g because always_accept is set\n", (double)enorm, (double)enorma, (double)enormr, (double)h));
61: *accept = PETSC_TRUE;
62: } else {
63: PetscCall(PetscInfo(adapt, "Estimated scaled truncation error [combined, absolute, relative]] [%g, %g, %g], rejecting step of size %g\n", (double)enorm, (double)enorma, (double)enormr, (double)h));
64: *accept = PETSC_FALSE;
65: }
66: } else {
67: PetscCall(PetscInfo(adapt, "Estimated scaled truncation error [combined, absolute, relative] [%g, %g, %g], accepting step of size %g\n", (double)enorm, (double)enorma, (double)enormr, (double)h));
68: *accept = PETSC_TRUE;
69: }
71: if (bGTEMethod) {
72: if (*accept == PETSC_TRUE && adapt->glee_use_local) {
73: /* If step is accepted, then overwrite previous step error with the current error to be used on the next step */
74: /* WARNING: if the adapters are composable, then the accept test will not be reliable*/
75: PetscCall(TSGetTimeError(ts, 0, &glee->Y));
76: }
78: /* The optimal new step based on the current global truncation error. */
79: if (enorm > 0) {
80: /* factor based on the absolute tolerance */
81: hfac_ltea = safety * PetscPowReal(1. / enorma, ((PetscReal)1) / (order + 1));
82: /* factor based on the relative tolerance */
83: hfac_lter = safety * PetscPowReal(1. / enormr, ((PetscReal)1) / (order + 1));
84: /* pick the minimum time step among the relative and absolute tolerances */
85: hfac_lte = PetscMin(hfac_ltea, hfac_lter);
86: } else {
87: hfac_lte = safety * PETSC_INFINITY;
88: }
89: h_lte = h * PetscClipInterval(hfac_lte, adapt->clip[0], adapt->clip[1]);
90: *next_h = PetscClipInterval(h_lte, adapt->dt_min, adapt->dt_max);
91: } else {
92: /* The optimal new step based purely on local truncation error for this step. */
93: if (enorm > 0) {
94: /* factor based on the absolute tolerance */
95: hfac_ltea = safety * PetscPowReal(enorma, ((PetscReal)-1) / order);
96: /* factor based on the relative tolerance */
97: hfac_lter = safety * PetscPowReal(enormr, ((PetscReal)-1) / order);
98: /* pick the minimum time step among the relative and absolute tolerances */
99: hfac_lte = PetscMin(hfac_ltea, hfac_lter);
100: } else {
101: hfac_lte = safety * PETSC_INFINITY;
102: }
103: h_lte = h * PetscClipInterval(hfac_lte, adapt->clip[0], adapt->clip[1]);
104: *next_h = PetscClipInterval(h_lte, adapt->dt_min, adapt->dt_max);
105: }
106: *wlte = enorm;
107: *wltea = enorma;
108: *wlter = enormr;
109: PetscFunctionReturn(PETSC_SUCCESS);
110: }
112: static PetscErrorCode TSAdaptReset_GLEE(TSAdapt adapt)
113: {
114: TSAdapt_GLEE *glee = (TSAdapt_GLEE *)adapt->data;
116: PetscFunctionBegin;
117: PetscCall(VecDestroy(&glee->Y));
118: PetscFunctionReturn(PETSC_SUCCESS);
119: }
121: static PetscErrorCode TSAdaptDestroy_GLEE(TSAdapt adapt)
122: {
123: PetscFunctionBegin;
124: PetscCall(TSAdaptReset_GLEE(adapt));
125: PetscCall(PetscFree(adapt->data));
126: PetscFunctionReturn(PETSC_SUCCESS);
127: }
129: /*MC
130: TSADAPTGLEE - GLEE adaptive controller for time stepping
132: Level: intermediate
134: .seealso: [](ch_ts), [](sec_ts_error_control), `TS`, `TSAdapt`, `TSGetAdapt()`, `TSAdaptType`
135: M*/
136: PETSC_EXTERN PetscErrorCode TSAdaptCreate_GLEE(TSAdapt adapt)
137: {
138: TSAdapt_GLEE *glee;
140: PetscFunctionBegin;
141: PetscCall(PetscNew(&glee));
142: adapt->data = (void *)glee;
143: adapt->ops->choose = TSAdaptChoose_GLEE;
144: adapt->ops->reset = TSAdaptReset_GLEE;
145: adapt->ops->destroy = TSAdaptDestroy_GLEE;
146: PetscFunctionReturn(PETSC_SUCCESS);
147: }