/*
The ST (spectral transformation) interface routines related to the
KSP object associated to it.
*/
#include "src/st/stimpl.h" /*I "slepcst.h" I*/
#undef __FUNCT__
#define __FUNCT__ "STAssociatedKSPSolve"
/*
STAssociatedKSPSolve - Solves the linear system of equations associated
to the spectral transformation.
Input Parameters:
. st - the spectral transformation context
. b - right hand side vector
Output Parameter:
. x - computed solution
*/
PetscErrorCode STAssociatedKSPSolve(ST st,Vec b,Vec x)
{
PetscErrorCode ierr;
int its;
KSPConvergedReason reason;
PetscFunctionBegin;
PetscValidHeaderSpecific(st,ST_COOKIE,1);
PetscValidHeaderSpecific(b,VEC_COOKIE,2);
PetscValidHeaderSpecific(x,VEC_COOKIE,3);
if (!st->ksp) { SETERRQ(PETSC_ERR_SUP,"ST has no associated KSP"); }
ierr = KSPSolve(st->ksp,b,x);CHKERRQ(ierr);
ierr = KSPGetConvergedReason(st->ksp,&reason);CHKERRQ(ierr);
if (reason<0) { SETERRQ1(0,"Warning: KSP did not converge (%d)",reason); }
ierr = KSPGetIterationNumber(st->ksp,&its);CHKERRQ(ierr);
st->lineariterations += its;
PetscLogInfo(st,"ST: linear solve iterations=%d\n",its);
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "STAssociatedKSPSolveTranspose"
/*
STAssociatedKSPSolveTranspose - Solves the transpose of the linear
system of equations associated to the spectral transformation.
Input Parameters:
. st - the spectral transformation context
. b - right hand side vector
Output Parameter:
. x - computed solution
*/
PetscErrorCode STAssociatedKSPSolveTranspose(ST st,Vec b,Vec x)
{
PetscErrorCode ierr;
int its;
KSPConvergedReason reason;
PetscFunctionBegin;
PetscValidHeaderSpecific(st,ST_COOKIE,1);
PetscValidHeaderSpecific(b,VEC_COOKIE,2);
PetscValidHeaderSpecific(x,VEC_COOKIE,3);
if (!st->ksp) { SETERRQ(PETSC_ERR_SUP,"ST has no associated KSP"); }
ierr = KSPSolveTranspose(st->ksp,b,x);CHKERRQ(ierr);
ierr = KSPGetConvergedReason(st->ksp,&reason);CHKERRQ(ierr);
if (reason<0) { SETERRQ1(0,"Warning: KSP did not converge (%d)",reason); }
ierr = KSPGetIterationNumber(st->ksp,&its);CHKERRQ(ierr);
st->lineariterations += its;
PetscLogInfo(st,"ST: linear solve iterations=%d\n",its);
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "STSetKSP"
/*@
STSetKSP - Sets the KSP object associated with the spectral
transformation.
Not collective
Input Parameters:
+ st - the spectral transformation context
- ksp - the linear system context
Level: advanced
@*/
PetscErrorCode STSetKSP(ST st,KSP ksp)
{
PetscErrorCode ierr;
PetscFunctionBegin;
PetscValidHeaderSpecific(st,ST_COOKIE,1);
PetscValidHeaderSpecific(ksp,KSP_COOKIE,2);
PetscCheckSameComm(st,1,ksp,2);
if (st->ksp) {
ierr = KSPDestroy(st->ksp);CHKERRQ(ierr);
}
st->ksp = ksp;
PetscObjectReference((PetscObject)st->ksp);
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "STGetKSP"
/*@
STGetKSP - Gets the KSP object associated with the spectral
transformation.
Not collective
Input Parameter:
. st - the spectral transformation context
Output Parameter:
. ksp - the linear system context
Notes:
On output, the value of ksp can be PETSC_NULL if the combination of
eigenproblem type and selected transformation does not require to
solve a linear system of equations.
Level: intermediate
@*/
PetscErrorCode STGetKSP(ST st,KSP* ksp)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(st,ST_COOKIE,1);
if (!st->type_name) { SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Must call STSetType first"); }
if (ksp) *ksp = st->ksp;
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "STGetNumberLinearIterations"
/*@
STGetNumberLinearIterations - Gets the total number of linear iterations
used by the ST object.
Not Collective
Input Parameter:
. st - the spectral transformation context
Output Parameter:
. lits - number of linear iterations
Level: intermediate
.seealso: STResetNumberLinearIterations()
@*/
PetscErrorCode STGetNumberLinearIterations(ST st,int* lits)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(st,ST_COOKIE,1);
PetscValidIntPointer(lits,2);
*lits = st->lineariterations;
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "STResetNumberLinearIterations"
/*@
STResetNumberLinearIterations - Resets the counter for total number of
linear iterations used by the ST object.
Collective on ST
Input Parameter:
. st - the spectral transformation context
Level: intermediate
.seealso: STGetNumberLinearIterations()
@*/
PetscErrorCode STResetNumberLinearIterations(ST st)
{
PetscFunctionBegin;
PetscValidHeaderSpecific(st,ST_COOKIE,1);
st->lineariterations = 0;
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "STCheckNullSpace_Default"
PetscErrorCode STCheckNullSpace_Default(ST st,int n,Vec* V)
{
PetscErrorCode ierr;
int i,c;
PetscReal norm;
Vec *T,w;
Mat A;
PC pc;
MatNullSpace nullsp;
PetscFunctionBegin;
ierr = PetscMalloc(n*sizeof(Vec),&T);CHKERRQ(ierr);
ierr = KSPGetPC(st->ksp,&pc);CHKERRQ(ierr);
ierr = PCGetOperators(pc,&A,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
ierr = MatGetVecs(A,PETSC_NULL,&w);CHKERRQ(ierr);
c = 0;
for (i=0;i<n;i++) {
ierr = MatMult(A,V[i],w);CHKERRQ(ierr);
ierr = VecNorm(w,NORM_2,&norm);CHKERRQ(ierr);
if (norm < 1e-8) {
PetscLogInfo(st,"STCheckNullSpace: vector %i norm=%g\n",i,norm);
T[c] = V[i];
c++;
}
}
ierr = VecDestroy(w);CHKERRQ(ierr);
if (c>0) {
ierr = MatNullSpaceCreate(st->comm,PETSC_FALSE,c,T,&nullsp);CHKERRQ(ierr);
ierr = KSPSetNullSpace(st->ksp,nullsp);CHKERRQ(ierr);
ierr = MatNullSpaceDestroy(nullsp);CHKERRQ(ierr);
}
ierr = PetscFree(T);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
#undef __FUNCT__
#define __FUNCT__ "STCheckNullSpace"
/*@C
STCheckNullSpace - Given a set of vectors, this function test each of
them to be a nullspace vector of the coefficient matrix of the associated
KSP object. All these nullspace vectors are passed to the KSP object.
Collective on ST
Input Parameters:
+ st - the spectral transformation context
. n - number of vectors
- V - vectors to be checked
Note:
This function allows to handle singular pencils and to solve some problems
in which the nullspace is important (see the users guide for details).
Level: developer
.seealso: EPSAttachDeflationSpace()
@*/
PetscErrorCode STCheckNullSpace(ST st,int n,Vec* V)
{
PetscErrorCode ierr;
PetscFunctionBegin;
if (n>0 && st->checknullspace) {
ierr = (*st->checknullspace)(st,n,V);CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}