PETSC_EXTERN PetscErrorCode PetscDLLibraryRegister_tao(void)
{
PetscErrorCode ierr;
PetscFunctionBegin;
ierr = TaoInitializePackage();CHKERRQ(ierr);
ierr = TaoLineSearchInitializePackage();CHKERRQ(ierr);
PetscFunctionReturn(0);
}
PetscErrorCode TaoLineSearchCreate(MPI_Comm comm, TaoLineSearch *newls)
{
PetscErrorCode ierr;
TaoLineSearch ls;
PetscFunctionBegin;
PetscValidPointer(newls,2);
*newls = NULL;
#ifndef PETSC_USE_DYNAMIC_LIBRARIES
ierr = TaoLineSearchInitializePackage();CHKERRQ(ierr);
#endif
ierr = PetscHeaderCreate(ls,_p_TaoLineSearch,struct _TaoLineSearchOps,TAOLINESEARCH_CLASSID,"TaoLineSearch",0,0,comm,TaoLineSearchDestroy,TaoLineSearchView);CHKERRQ(ierr);
ls->bounded = 0;
ls->max_funcs=30;
ls->ftol = 0.0001;
ls->gtol = 0.9;
#if defined(PETSC_USE_REAL_SINGLE)
ls->rtol = 1.0e-5;
#else
ls->rtol = 1.0e-10;
#endif
ls->stepmin=1.0e-20;
ls->stepmax=1.0e+20;
ls->step=1.0;
ls->nfeval=0;
ls->ngeval=0;
ls->nfgeval=0;
ls->ops->computeobjective=0;
ls->ops->computegradient=0;
ls->ops->computeobjectiveandgradient=0;
ls->ops->computeobjectiveandgts=0;
ls->ops->setup=0;
ls->ops->apply=0;
ls->ops->view=0;
ls->ops->setfromoptions=0;
ls->ops->reset=0;
ls->ops->destroy=0;
ls->setupcalled=PETSC_FALSE;
ls->usetaoroutines=PETSC_FALSE;
*newls = ls;
PetscFunctionReturn(0);
}
/*@
TaoLineSearchSetFromOptions - Sets various TaoLineSearch parameters from user
options.
Collective on TaoLineSearch
Input Paremeter:
. ls - the TaoLineSearch context
Options Database Keys:
+ -tao_ls_type <type> - The algorithm that TAO uses (more-thuente, gpcg, unit)
. -tao_ls_ftol <tol> - tolerance for sufficient decrease
. -tao_ls_gtol <tol> - tolerance for curvature condition
. -tao_ls_rtol <tol> - relative tolerance for acceptable step
. -tao_ls_stepmin <step> - minimum steplength allowed
. -tao_ls_stepmax <step> - maximum steplength allowed
. -tao_ls_max_funcs <n> - maximum number of function evaluations allowed
- -tao_ls_view - display line-search results to standard output
Level: beginner
@*/
PetscErrorCode TaoLineSearchSetFromOptions(TaoLineSearch ls)
{
PetscErrorCode ierr;
const char *default_type=TAOLINESEARCHMT;
char type[256];
PetscBool flg;
PetscFunctionBegin;
PetscValidHeaderSpecific(ls,TAOLINESEARCH_CLASSID,1);
ierr = PetscObjectOptionsBegin((PetscObject)ls);CHKERRQ(ierr);
if (!TaoLineSearchInitialized) {
ierr = TaoLineSearchInitializePackage();CHKERRQ(ierr);
}
if (((PetscObject)ls)->type_name) {
default_type = ((PetscObject)ls)->type_name;
}
/* Check for type from options */
ierr = PetscOptionsFList("-tao_ls_type","Tao Line Search type","TaoLineSearchSetType",TaoLineSearchList,default_type,type,256,&flg);CHKERRQ(ierr);
if (flg) {
ierr = TaoLineSearchSetType(ls,type);CHKERRQ(ierr);
} else if (!((PetscObject)ls)->type_name) {
ierr = TaoLineSearchSetType(ls,default_type);
}
ierr = PetscOptionsInt("-tao_ls_max_funcs","max function evals in line search","",ls->max_funcs,&ls->max_funcs,0);CHKERRQ(ierr);
ierr = PetscOptionsReal("-tao_ls_ftol","tol for sufficient decrease","",ls->ftol,&ls->ftol,0);CHKERRQ(ierr);
ierr = PetscOptionsReal("-tao_ls_gtol","tol for curvature condition","",ls->gtol,&ls->gtol,0);CHKERRQ(ierr);
ierr = PetscOptionsReal("-tao_ls_rtol","relative tol for acceptable step","",ls->rtol,&ls->rtol,0);CHKERRQ(ierr);
ierr = PetscOptionsReal("-tao_ls_stepmin","lower bound for step","",ls->stepmin,&ls->stepmin,0);CHKERRQ(ierr);
ierr = PetscOptionsReal("-tao_ls_stepmax","upper bound for step","",ls->stepmax,&ls->stepmax,0);CHKERRQ(ierr);
ierr = PetscOptionsBool("-tao_ls_view","view TaoLineSearch info after each line search has completed","TaoLineSearchView",PETSC_FALSE,&ls->viewls,NULL);CHKERRQ(ierr);
if (ls->ops->setfromoptions) {
ierr = (*ls->ops->setfromoptions)(ls);CHKERRQ(ierr);
}
ierr = PetscOptionsEnd();CHKERRQ(ierr);
PetscFunctionReturn(0);
}