/*
This file implements a wrapper to the TRLAN package
*/
#include "src/eps/impls/trlan/trlanp.h"
/* Nasty global variable to access EPS data from TRLan_ */
static EPS globaleps;
#undef __FUNCT__
#define __FUNCT__ "EPSSetUp_TRLAN"
static int EPSSetUp_TRLAN(EPS eps)
{
int ierr, n;
EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
PetscFunctionBegin;
#if defined(PETSC_USE_COMPLEX)
SETERRQ(PETSC_ERR_SUP,"Requested method is not available for complex problems");
#endif
if (!eps->ishermitian)
SETERRQ(PETSC_ERR_SUP,"Requested method is only available for Hermitian problems");
if (eps->isgeneralized)
SETERRQ(PETSC_ERR_SUP,"Requested method is not available for generalized problems");
tr->restart = 0;
ierr = VecGetLocalSize(eps->vec_initial,&n); CHKERRQ(ierr);
tr->maxlan = eps->nev+PetscMin(eps->nev,6);
if (tr->maxlan+1-eps->ncv<=0) tr->lwork = tr->maxlan*(tr->maxlan+10);
else tr->lwork = n*(tr->maxlan+1-eps->ncv) + tr->maxlan*(tr->maxlan+10);
ierr = PetscMalloc(tr->lwork*sizeof(PetscReal),&tr->work);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "EPSSetDefaults_TRLAN"
static int EPSSetDefaults_TRLAN(EPS eps)
{
int ierr, N;
PetscFunctionBegin;
ierr = VecGetSize(eps->vec_initial,&N);CHKERRQ(ierr);
if (eps->ncv) {
if (eps->ncv<eps->nev) SETERRQ(1,"The value of ncv must be at least nev");
}
else eps->ncv = eps->nev;
if (!eps->max_it) eps->max_it = PetscMax(100,N);
if (!eps->tol) eps->tol = 1.e-7;
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "MatMult_TRLAN"
static int MatMult_TRLAN(int *n,int *m,PetscReal *xin,int *ldx,PetscReal *yout,int *ldy)
{
Vec x,y;
int i,ierr;
PetscFunctionBegin;
ierr = VecCreateMPIWithArray(globaleps->comm,*n,PETSC_DECIDE,PETSC_NULL,&x);CHKERRQ(ierr);
ierr = VecCreateMPIWithArray(globaleps->comm,*n,PETSC_DECIDE,PETSC_NULL,&y);CHKERRQ(ierr);
for (i=0;i<*m;i++) {
ierr = VecPlaceArray(x,(PetscScalar*)xin+i*(*ldx));CHKERRQ(ierr);
ierr = VecPlaceArray(y,(PetscScalar*)yout+i*(*ldy));CHKERRQ(ierr);
ierr = STApply(globaleps->OP,x,y);CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "EPSSolve_TRLAN"
static int EPSSolve_TRLAN(EPS eps,int *its)
{
int ipar[32], i, n, lohi, stat, ierr;
EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
PetscScalar *pV;
PetscFunctionBegin;
ierr = VecGetLocalSize(eps->vec_initial,&n); CHKERRQ(ierr);
lohi = 0;
if (eps->which==EPS_LARGEST_MAGNITUDE) lohi = 1;
else if (eps->which==EPS_SMALLEST_MAGNITUDE) lohi = -1;
globaleps = eps;
ipar[0] = 0; /* stat: error flag */
ipar[1] = lohi; /* smallest (lohi<0) or largest eigenvalues (lohi>0) */
ipar[2] = eps->nev; /* number of desired eigenpairs */
ipar[3] = 0; /* number of eigenpairs already converged */
ipar[4] = tr->maxlan; /* maximum Lanczos basis size */
ipar[5] = tr->restart; /* restarting scheme */
ipar[6] = eps->max_it; /* maximum number of MATVECs */
ipar[7] = MPI_Comm_c2f(eps->comm); /* communicator */
ipar[8] = 0; /* verboseness */
ipar[9] = 99; /* Fortran IO unit number used to write log messages */
ipar[10] = 1; /* use supplied starting vector */
ipar[11] = 0; /* checkpointing flag */
ipar[12] = 98; /* Fortran IO unit number used to write checkpoint files */
ipar[13] = 0; /* number of flops per matvec per PE (not used) */
tr->work[0] = eps->tol; /* relative tolerance on residual norms */
for (i=0;i<eps->ncv;i++) eps->eigr[i]=0.0;
ierr = VecCopy(eps->vec_initial,eps->V[0]);CHKERRQ(ierr);
ierr = VecGetArray(eps->V[0],&pV);CHKERRQ(ierr);
TRLan_ ( MatMult_TRLAN, ipar, &n, &eps->ncv, eps->eigr, pV, &n, tr->work, &tr->lwork );
ierr = VecRestoreArray( eps->V[0], &pV );CHKERRQ(ierr);
stat = ipar[0];
eps->nconv = ipar[3];
eps->its = ipar[25];
*its = eps->its;
eps->reason = EPS_CONVERGED_TOL;
for (i=0;i<eps->nconv;i++) eps->eigi[i]=0.0;
if (stat!=0) { SETERRQ1(PETSC_ERR_LIB,"Error in TRLAN (code=%d)",stat);}
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "EPSDestroy_TRLAN"
/*
EPSDestroy_TRLAN - Destroys the context variable for TRLAN.
Input Parameter:
. eps - the iterative context
*/
int EPSDestroy_TRLAN(EPS eps)
{
EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
int ierr;
PetscFunctionBegin;
PetscValidHeaderSpecific(eps,EPS_COOKIE);
if (tr->work) { ierr = PetscFree(tr->work);CHKERRQ(ierr); }
if (eps->data) { ierr = PetscFree(eps->data);CHKERRQ(ierr); }
PetscFunctionReturn(0);
}
EXTERN_C_BEGIN
#undef __FUNCT__
#define __FUNCT__ "EPSCreate_TRLAN"
int EPSCreate_TRLAN(EPS eps)
{
EPS_TRLAN *trlan;
int ierr;
PetscFunctionBegin;
ierr = PetscNew(EPS_TRLAN,&trlan);CHKERRQ(ierr);
PetscMemzero(trlan,sizeof(EPS_TRLAN));
PetscLogObjectMemory(eps,sizeof(EPS_TRLAN));
eps->data = (void *) trlan;
eps->ops->setup = EPSSetUp_TRLAN;
eps->ops->setdefaults = EPSSetDefaults_TRLAN;
eps->ops->solve = EPSSolve_TRLAN;
eps->ops->destroy = EPSDestroy_TRLAN;
eps->ops->view = 0;
PetscFunctionReturn(0);
}
EXTERN_C_END