1af0996ceSBarry Smith #include <petsc/private/tsimpl.h> /*I "petscts.h" I*/ 28d59e960SJed Brown 38d59e960SJed Brown typedef struct { 4*1566a47fSLisandro Dalcin PetscReal safety; /* safety factor relative to target CFL constraint */ 58d59e960SJed Brown PetscBool always_accept; 68d59e960SJed Brown } TSAdapt_CFL; 78d59e960SJed Brown 88d59e960SJed Brown #undef __FUNCT__ 98d59e960SJed Brown #define __FUNCT__ "TSAdaptChoose_CFL" 100b99f514SJed Brown static PetscErrorCode TSAdaptChoose_CFL(TSAdapt adapt,TS ts,PetscReal h,PetscInt *next_sc,PetscReal *next_h,PetscBool *accept,PetscReal *wlte) 118d59e960SJed Brown { 128d59e960SJed Brown TSAdapt_CFL *cfl = (TSAdapt_CFL*)adapt->data; 138d59e960SJed Brown PetscErrorCode ierr; 14*1566a47fSLisandro Dalcin PetscReal hcfl,cfltimestep,ccfl; 15*1566a47fSLisandro Dalcin PetscInt ncandidates; 16*1566a47fSLisandro Dalcin const PetscReal *ccflarray; 178d59e960SJed Brown 188d59e960SJed Brown PetscFunctionBegin; 19*1566a47fSLisandro Dalcin ierr = TSGetCFLTime(ts,&cfltimestep);CHKERRQ(ierr); 20*1566a47fSLisandro Dalcin ierr = TSAdaptCandidatesGet(adapt,&ncandidates,NULL,NULL,&ccflarray,NULL);CHKERRQ(ierr); 21*1566a47fSLisandro Dalcin ccfl = (ncandidates > 0) ? ccflarray[0] : 1.0; 228d59e960SJed Brown 23*1566a47fSLisandro Dalcin /* Determine whether the step is accepted of rejected */ 24*1566a47fSLisandro Dalcin *accept = PETSC_TRUE; 25*1566a47fSLisandro Dalcin if (h > cfltimestep * ccfl) { 268d59e960SJed Brown if (cfl->always_accept) { 27*1566a47fSLisandro Dalcin ierr = PetscInfo3(adapt,"Step length %g with scheme of CFL coefficient %g did not satisfy user-provided CFL constraint %g, proceeding anyway\n",(double)h,(double)ccfl,(double)cfltimestep);CHKERRQ(ierr); 288d59e960SJed Brown } else { 29*1566a47fSLisandro Dalcin ierr = PetscInfo3(adapt,"Step length %g with scheme of CFL coefficient %g did not satisfy user-provided CFL constraint %g, step REJECTED\n",(double)h,(double)ccfl,(double)cfltimestep);CHKERRQ(ierr); 308d59e960SJed Brown *accept = PETSC_FALSE; 318d59e960SJed Brown } 328d59e960SJed Brown } 338d59e960SJed Brown 34*1566a47fSLisandro Dalcin /* The optimal new step based purely on CFL constraint for this step. */ 35*1566a47fSLisandro Dalcin hcfl = cfl->safety * cfltimestep * ccfl; 36*1566a47fSLisandro Dalcin if (hcfl < adapt->dt_min) { 37*1566a47fSLisandro Dalcin ierr = PetscInfo4(adapt,"Cannot satisfy CFL constraint %g (with %g safety) at minimum time step %g with method coefficient %g, proceding anyway\n",(double)cfltimestep,(double)cfl->safety,(double)adapt->dt_min,(double)ccfl);CHKERRQ(ierr); 38*1566a47fSLisandro Dalcin } 39*1566a47fSLisandro Dalcin 408d59e960SJed Brown *next_sc = 0; 418d59e960SJed Brown *next_h = PetscClipInterval(hcfl,adapt->dt_min,adapt->dt_max); 420b99f514SJed Brown *wlte = -1; /* Weighted local truncation error was not evaluated */ 438d59e960SJed Brown PetscFunctionReturn(0); 448d59e960SJed Brown } 458d59e960SJed Brown 468d59e960SJed Brown #undef __FUNCT__ 478d59e960SJed Brown #define __FUNCT__ "TSAdaptDestroy_CFL" 488d59e960SJed Brown static PetscErrorCode TSAdaptDestroy_CFL(TSAdapt adapt) 498d59e960SJed Brown { 508d59e960SJed Brown PetscErrorCode ierr; 518d59e960SJed Brown 528d59e960SJed Brown PetscFunctionBegin; 538d59e960SJed Brown ierr = PetscFree(adapt->data);CHKERRQ(ierr); 548d59e960SJed Brown PetscFunctionReturn(0); 558d59e960SJed Brown } 568d59e960SJed Brown 578d59e960SJed Brown #undef __FUNCT__ 588d59e960SJed Brown #define __FUNCT__ "TSAdaptSetFromOptions_CFL" 594416b707SBarry Smith static PetscErrorCode TSAdaptSetFromOptions_CFL(PetscOptionItems *PetscOptionsObject,TSAdapt adapt) 608d59e960SJed Brown { 618d59e960SJed Brown TSAdapt_CFL *cfl = (TSAdapt_CFL*)adapt->data; 628d59e960SJed Brown PetscErrorCode ierr; 638d59e960SJed Brown 648d59e960SJed Brown PetscFunctionBegin; 65e55864a3SBarry Smith ierr = PetscOptionsHead(PetscOptionsObject,"CFL adaptive controller options");CHKERRQ(ierr); 66*1566a47fSLisandro Dalcin ierr = PetscOptionsReal("-ts_adapt_cfl_safety","Safety factor relative to target CFL constraint","",cfl->safety,&cfl->safety,NULL);CHKERRQ(ierr); 67*1566a47fSLisandro Dalcin ierr = PetscOptionsBool("-ts_adapt_cfl_always_accept","Always accept the step regardless of whether CFL constraint meets goal","",cfl->always_accept,&cfl->always_accept,NULL);CHKERRQ(ierr); 688d59e960SJed Brown ierr = PetscOptionsTail();CHKERRQ(ierr); 698d59e960SJed Brown PetscFunctionReturn(0); 708d59e960SJed Brown } 718d59e960SJed Brown 728d59e960SJed Brown #undef __FUNCT__ 738d59e960SJed Brown #define __FUNCT__ "TSAdaptCreate_CFL" 748d59e960SJed Brown /*MC 758d59e960SJed Brown TSADAPTCFL - CFL adaptive controller for time stepping 768d59e960SJed Brown 778d59e960SJed Brown Level: intermediate 788d59e960SJed Brown 798d59e960SJed Brown .seealso: TS, TSAdapt, TSSetAdapt() 808d59e960SJed Brown M*/ 818cc058d9SJed Brown PETSC_EXTERN PetscErrorCode TSAdaptCreate_CFL(TSAdapt adapt) 828d59e960SJed Brown { 838d59e960SJed Brown PetscErrorCode ierr; 848d59e960SJed Brown TSAdapt_CFL *a; 858d59e960SJed Brown 868d59e960SJed Brown PetscFunctionBegin; 87b00a9115SJed Brown ierr = PetscNewLog(adapt,&a);CHKERRQ(ierr); 888d59e960SJed Brown adapt->data = (void*)a; 89*1566a47fSLisandro Dalcin 908d59e960SJed Brown adapt->ops->choose = TSAdaptChoose_CFL; 918d59e960SJed Brown adapt->ops->setfromoptions = TSAdaptSetFromOptions_CFL; 928d59e960SJed Brown adapt->ops->destroy = TSAdaptDestroy_CFL; 938d59e960SJed Brown 948d59e960SJed Brown a->safety = 0.9; 958d59e960SJed Brown a->always_accept = PETSC_FALSE; 968d59e960SJed Brown PetscFunctionReturn(0); 978d59e960SJed Brown } 98