1:  #include <petsc/private/tsimpl.h>

  3: typedef struct {
  4:   Vec E,Y;
  5: } TSAdapt_GLEE;

  7: static PetscErrorCode TSAdaptChoose_GLEE(TSAdapt adapt,TS ts,PetscReal h,PetscInt *next_sc,PetscReal *next_h,PetscBool *accept,PetscReal *wlte,PetscReal *wltea,PetscReal *wlter)
  8: {
  9:   TSAdapt_GLEE  *glee = (TSAdapt_GLEE*)adapt->data;
 10:   TSType         time_scheme;      /* Type of time-integration scheme        */
 12:   Vec            X,Y,E;
 13:   PetscReal      enorm,enorma,enormr,hfac_lte,hfac_ltea,hfac_lter,h_lte,safety;
 14:   PetscInt       order;
 15:   PetscBool      bGTEMethod=PETSC_FALSE;


 19:   *next_sc = 0; /* Reuse the same order scheme */
 20:   safety = adapt->safety;
 21:   TSGetType(ts,&time_scheme);
 22:   if (!strcmp(time_scheme,TSGLEE)) bGTEMethod=PETSC_TRUE;
 23:   order = adapt->candidates.order[0];

 25:   if (bGTEMethod){/* the method is of GLEE type */
 26:     TSGetSolution(ts,&X);
 27:     if (!glee->E) {VecDuplicate(X,&glee->E);}
 28:     E    = glee->E;
 29:     TSGetTimeError(ts,0,&E);
 30:     /* this should be called with Y (the solution at the beginning of the step)*/
 31:     TSErrorWeightedENorm(ts,E,X,X,adapt->wnormtype,&enorm,&enorma,&enormr);
 32:   } else {
 33:     /* the method is NOT of GLEE type; use the stantard basic augmented by separate atol and rtol */
 34:     TSGetSolution(ts,&X);
 35:     if (!glee->Y) {VecDuplicate(X,&glee->Y);}
 36:     Y     = glee->Y;
 37:     TSEvaluateStep(ts,order-1,Y,NULL);
 38:     TSErrorWeightedNorm(ts,X,Y,adapt->wnormtype,&enorm,&enorma,&enormr);
 39:   }

 41:   if (enorm < 0) {
 42:     *accept  = PETSC_TRUE;
 43:     *next_h  = h;            /* Reuse the old step */
 44:     *wlte    = -1;           /* Weighted error was not evaluated */
 45:     *wltea   = -1;           /* Weighted absolute error was not evaluated */
 46:     *wlter   = -1;           /* Weighted relative error was not evaluated */
 47:     return(0);
 48:   }

 50:   if (enorm > 1. || enorma > 1. || enormr > 1.) {
 51:     if (!*accept) safety *= adapt->reject_safety; /* The last attempt also failed, shorten more aggressively */
 52:     if (h < (1 + PETSC_SQRT_MACHINE_EPSILON)*adapt->dt_min) {
 53:       PetscInfo4(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);
 54:       *accept = PETSC_TRUE;
 55:     } else if (adapt->always_accept) {
 56:       PetscInfo4(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);
 57:       *accept = PETSC_TRUE;
 58:     } else {
 59:       PetscInfo4(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);
 60:       *accept = PETSC_FALSE;
 61:     }
 62:   } else {
 63:     PetscInfo4(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);
 64:     *accept = PETSC_TRUE;
 65:   }

 67:   if (bGTEMethod){
 68:     /* The optimal new step based on the current global truncation error. */
 69:     if (enorm > 0) {
 70:       /* factor based on the absolute tolerance */
 71:       hfac_ltea = safety * PetscPowReal(1./enorma,((PetscReal)1)/order);
 72:       /* factor based on the relative tolerance */
 73:       hfac_lter = safety * PetscPowReal(1./enormr,((PetscReal)1)/order);
 74:       /* pick the minimum time step among the relative and absolute tolerances */
 75:       hfac_lte  = PetscMin(hfac_ltea,hfac_lter);
 76:     } else {
 77:       hfac_lte = safety * PETSC_INFINITY;
 78:     }
 79:     h_lte = h * PetscClipInterval(hfac_lte,adapt->clip[0],adapt->clip[1]);
 80:     *next_h = PetscClipInterval(h_lte,adapt->dt_min,adapt->dt_max);
 81:   } else {
 82:     /* The optimal new step based purely on local truncation error for this step. */
 83:     if (enorm > 0) {
 84:       /* factor based on the absolute tolerance */
 85:       hfac_ltea = safety * PetscPowReal(enorma,((PetscReal)-1)/order);
 86:       /* factor based on the relative tolerance */
 87:       hfac_lter = safety * PetscPowReal(enormr,((PetscReal)-1)/order);
 88:       /* pick the minimum time step among the relative and absolute tolerances */
 89:       hfac_lte  = PetscMin(hfac_ltea,hfac_lter);
 90:     } else {
 91:       hfac_lte = safety * PETSC_INFINITY;
 92:     }
 93:     h_lte = h * PetscClipInterval(hfac_lte,adapt->clip[0],adapt->clip[1]);
 94:     *next_h = PetscClipInterval(h_lte,adapt->dt_min,adapt->dt_max);
 95:   }
 96:   *wlte   = enorm;
 97:   *wltea  = enorma;
 98:   *wlter  = enormr;
 99:   return(0);
100: }

102: static PetscErrorCode TSAdaptReset_GLEE(TSAdapt adapt)
103: {
104:   TSAdapt_GLEE  *glee = (TSAdapt_GLEE*)adapt->data;

108:   VecDestroy(&glee->Y);
109:   VecDestroy(&glee->E);
110:   return(0);
111: }

113: static PetscErrorCode TSAdaptDestroy_GLEE(TSAdapt adapt)
114: {

118:   TSAdaptReset_GLEE(adapt);
119:   PetscFree(adapt->data);
120:   return(0);
121: }

123: /*MC
124:    TSADAPTGLEE - GLEE adaptive controller for time stepping

126:    Level: intermediate

128: .seealso: TS, TSAdapt, TSGetAdapt()
129: M*/
130: PETSC_EXTERN PetscErrorCode TSAdaptCreate_GLEE(TSAdapt adapt)
131: {
133:   TSAdapt_GLEE  *glee;

136:   PetscNewLog(adapt,&glee);
137:   adapt->data         = (void*)glee;
138:   adapt->ops->choose  = TSAdaptChoose_GLEE;
139:   adapt->ops->reset   = TSAdaptReset_GLEE;
140:   adapt->ops->destroy = TSAdaptDestroy_GLEE;
141:   return(0);
142: }