1 #include <petsc/private/tsimpl.h> /*I "petscts.h" I*/ 2 3 typedef struct { 4 PetscBool always_accept; 5 PetscReal clip[2]; /* admissible decrease/increase factors */ 6 PetscReal safety; /* safety factor relative to target error */ 7 PetscReal reject_safety; /* extra safety factor if the last step was rejected */ 8 Vec X; 9 Vec Y; 10 Vec E; 11 } TSAdapt_GLEE; 12 13 #undef __FUNCT__ 14 #define __FUNCT__ "TSAdaptChoose_GLEE" 15 static PetscErrorCode TSAdaptChoose_GLEE(TSAdapt adapt,TS ts,PetscReal h,PetscInt *next_sc,PetscReal *next_h,PetscBool *accept,PetscReal *wlte,PetscReal *wltea,PetscReal *wlter) 16 { 17 TSAdapt_GLEE *glee = (TSAdapt_GLEE*)adapt->data; 18 TSType time_scheme; /* Type of time-integration scheme */ 19 PetscErrorCode ierr; 20 Vec X,Y,E; 21 PetscReal enorm,enorma,enormr,hfac_lte,h_lte,safety; 22 PetscInt order,stepno; 23 24 PetscFunctionBegin; 25 *next_sc = 0; /* Reuse the same order scheme */ 26 27 ierr = TSGetTimeStepNumber(ts,&stepno);CHKERRQ(ierr); 28 29 safety = glee->safety; 30 ierr = TSGetType(ts,&time_scheme);CHKERRQ(ierr); 31 if (!strcmp(time_scheme,TSGLEE)){ 32 /* the method is of GLEE type */ 33 ierr = TSGetSolution(ts,&X);CHKERRQ(ierr); 34 /* ierr = TSGetPreviousSolution(ts,&Y);CHKERRQ(ierr); 35 */ 36 if (!glee->E) {ierr = VecDuplicate(X,&glee->E);CHKERRQ(ierr);} 37 E = glee->E; 38 ierr = TSGetTimeError(ts,0,&E);CHKERRQ(ierr); 39 /* this should be called with Y */ 40 ierr = TSErrorWeightedENorm(ts,E,X,X,adapt->wnormtype,&enorm,&enorma,&enormr);CHKERRQ(ierr); 41 } else { 42 /* the method is NOT of GLEE type */ 43 ierr = TSGetSolution(ts,&X);CHKERRQ(ierr); 44 if (!glee->Y) {ierr = VecDuplicate(X,&glee->Y);CHKERRQ(ierr);} 45 Y = glee->Y; 46 order = adapt->candidates.order[0]; 47 ierr = TSEvaluateStep(ts,order-1,Y,NULL);CHKERRQ(ierr); 48 ierr = TSErrorWeightedNorm(ts,X,Y,adapt->wnormtype,&enorm,&enorma,&enormr);CHKERRQ(ierr); 49 } 50 51 if (enorm < 0) { 52 *accept = PETSC_TRUE; 53 *next_h = h; /* Reuse the old step */ 54 *wlte = -1; /* Weighted local truncation error was not evaluated */ 55 *wltea = -1; /* Weighted local truncation error was not evaluated */ 56 *wlter = -1; /* Weighted local truncation error was not evaluated */ 57 PetscFunctionReturn(0); 58 } 59 60 if (enorm > 1.) { 61 if (!*accept) safety *= glee->reject_safety; /* The last attempt also failed, shorten more aggressively */ 62 if (h < (1 + PETSC_SQRT_MACHINE_EPSILON)*adapt->dt_min) { 63 ierr = PetscInfo2(adapt,"Estimated scaled local truncation error %g, accepting because step size %g is at minimum\n",(double)enorm,(double)h);CHKERRQ(ierr); 64 *accept = PETSC_TRUE; 65 } else if (glee->always_accept) { 66 ierr = PetscInfo2(adapt,"Estimated scaled local truncation error %g, accepting step of size %g because always_accept is set\n",(double)enorm,(double)h);CHKERRQ(ierr); 67 *accept = PETSC_TRUE; 68 } else { 69 ierr = PetscInfo2(adapt,"Estimated scaled local truncation error %g, rejecting step of size %g\n",(double)enorm,(double)h);CHKERRQ(ierr); 70 *accept = PETSC_FALSE; 71 } 72 } else { 73 ierr = PetscInfo2(adapt,"Estimated scaled local truncation error %g, accepting step of size %g\n",(double)enorm,(double)h);CHKERRQ(ierr); 74 *accept = PETSC_TRUE; 75 } 76 77 /* The optimal new step based purely on local truncation error for this step. */ 78 if (enorm > 0) 79 hfac_lte = safety * PetscPowReal(enorm,((PetscReal)-1)/order); 80 else 81 hfac_lte = safety * PETSC_INFINITY; 82 h_lte = h * PetscClipInterval(hfac_lte,glee->clip[0],glee->clip[1]); 83 84 *next_h = PetscClipInterval(h_lte,adapt->dt_min,adapt->dt_max); 85 *wlte = enorm; 86 *wltea = enorma; 87 *wlter = enormr; 88 PetscFunctionReturn(0); 89 } 90 91 #undef __FUNCT__ 92 #define __FUNCT__ "TSAdaptReset_GLEE" 93 static PetscErrorCode TSAdaptReset_GLEE(TSAdapt adapt) 94 { 95 TSAdapt_GLEE *glee = (TSAdapt_GLEE*)adapt->data; 96 PetscErrorCode ierr; 97 98 PetscFunctionBegin; 99 ierr = VecDestroy(&glee->Y);CHKERRQ(ierr); 100 PetscFunctionReturn(0); 101 } 102 103 #undef __FUNCT__ 104 #define __FUNCT__ "TSAdaptDestroy_GLEE" 105 static PetscErrorCode TSAdaptDestroy_GLEE(TSAdapt adapt) 106 { 107 PetscErrorCode ierr; 108 109 PetscFunctionBegin; 110 ierr = TSAdaptReset_GLEE(adapt);CHKERRQ(ierr); 111 ierr = PetscFree(adapt->data);CHKERRQ(ierr); 112 PetscFunctionReturn(0); 113 } 114 115 #undef __FUNCT__ 116 #define __FUNCT__ "TSAdaptSetFromOptions_GLEE" 117 static PetscErrorCode TSAdaptSetFromOptions_GLEE(PetscOptionItems *PetscOptionsObject,TSAdapt adapt) 118 { 119 TSAdapt_GLEE *glee = (TSAdapt_GLEE*)adapt->data; 120 PetscErrorCode ierr; 121 PetscInt two; 122 PetscBool set; 123 124 PetscFunctionBegin; 125 ierr = PetscOptionsHead(PetscOptionsObject,"GLEE adaptive controller options");CHKERRQ(ierr); 126 two = 2; 127 ierr = PetscOptionsRealArray("-ts_adapt_glee_clip","Admissible decrease/increase in step size","",glee->clip,&two,&set);CHKERRQ(ierr); 128 if (set && (two != 2 || glee->clip[0] > glee->clip[1])) SETERRQ(PetscObjectComm((PetscObject)adapt),PETSC_ERR_ARG_OUTOFRANGE,"Must give exactly two values to -ts_adapt_glee_clip"); 129 ierr = PetscOptionsReal("-ts_adapt_glee_safety","Safety factor relative to target error","",glee->safety,&glee->safety,NULL);CHKERRQ(ierr); 130 ierr = PetscOptionsReal("-ts_adapt_glee_reject_safety","Extra safety factor to apply if the last step was rejected","",glee->reject_safety,&glee->reject_safety,NULL);CHKERRQ(ierr); 131 ierr = PetscOptionsBool("-ts_adapt_glee_always_accept","Always accept the step regardless of whether local truncation error meets goal","",glee->always_accept,&glee->always_accept,NULL);CHKERRQ(ierr); 132 ierr = PetscOptionsTail();CHKERRQ(ierr); 133 PetscFunctionReturn(0); 134 } 135 136 #undef __FUNCT__ 137 #define __FUNCT__ "TSAdaptView_GLEE" 138 static PetscErrorCode TSAdaptView_GLEE(TSAdapt adapt,PetscViewer viewer) 139 { 140 TSAdapt_GLEE *glee = (TSAdapt_GLEE*)adapt->data; 141 PetscErrorCode ierr; 142 PetscBool iascii; 143 144 PetscFunctionBegin; 145 ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); 146 if (iascii) { 147 if (glee->always_accept) {ierr = PetscViewerASCIIPrintf(viewer," GLEE: always accepting steps\n");CHKERRQ(ierr);} 148 ierr = PetscViewerASCIIPrintf(viewer," GLEE: clip fastest decrease %g, fastest increase %g\n",(double)glee->clip[0],(double)glee->clip[1]);CHKERRQ(ierr); 149 ierr = PetscViewerASCIIPrintf(viewer," GLEE: safety factor %g, extra factor after step rejection %g\n",(double)glee->safety,(double)glee->reject_safety);CHKERRQ(ierr); 150 } 151 PetscFunctionReturn(0); 152 } 153 154 #undef __FUNCT__ 155 #define __FUNCT__ "TSAdaptCreate_GLEE" 156 /*MC 157 TSADAPTGLEE - GLEE adaptive controller for time stepping 158 159 Level: intermediate 160 161 .seealso: TS, TSAdapt, TSSetAdapt() 162 M*/ 163 PETSC_EXTERN PetscErrorCode TSAdaptCreate_GLEE(TSAdapt adapt) 164 { 165 PetscErrorCode ierr; 166 TSAdapt_GLEE *a; 167 168 PetscFunctionBegin; 169 ierr = PetscNewLog(adapt,&a);CHKERRQ(ierr); 170 adapt->data = (void*)a; 171 adapt->ops->choose = TSAdaptChoose_GLEE; 172 adapt->ops->setfromoptions = TSAdaptSetFromOptions_GLEE; 173 adapt->ops->destroy = TSAdaptDestroy_GLEE; 174 adapt->ops->view = TSAdaptView_GLEE; 175 176 a->clip[0] = 0.1; 177 a->clip[1] = 10.; 178 a->safety = 0.9; 179 a->reject_safety = 0.5; 180 a->always_accept = PETSC_FALSE; 181 PetscFunctionReturn(0); 182 } 183