/*@
KSPSetDM - Sets the DM that may be used by some preconditioners
Logically Collective on KSP
Input Parameters:
+ ksp - the preconditioner context
- dm - the dm, cannot be NULL
Notes: If this is used then the KSP will attempt to use the DM to create the matrix and use the routine
set with DMKSPSetComputeOperators(). Use KSPSetDMActive(ksp,PETSC_FALSE) to instead use the matrix
you've provided with KSPSetOperators().
Level: intermediate
.seealso: KSPGetDM(), KSPSetDMActive(), KSPSetComputeOperators(), KSPSetComputeRHS(), KSPSetComputeInitialGuess(), DMKSPSetComputeOperators(), DMKSPSetComputeRHS(), DMKSPSetComputeInitialGuess()
@*/
PetscErrorCode KSPSetDM(KSP ksp,DM dm)
{
PetscErrorCode ierr;
PC pc;
PetscFunctionBegin;
PetscValidHeaderSpecific(ksp,KSP_CLASSID,1);
PetscValidHeaderSpecific(dm,DM_CLASSID,2);
ierr = PetscObjectReference((PetscObject)dm);
CHKERRQ(ierr);
if (ksp->dm) { /* Move the DMSNES context over to the new DM unless the new DM already has one */
if (ksp->dm->dmksp && !dm->dmksp) {
DMKSP kdm;
ierr = DMCopyDMKSP(ksp->dm,dm);
CHKERRQ(ierr);
ierr = DMGetDMKSP(ksp->dm,&kdm);
CHKERRQ(ierr);
if (kdm->originaldm == ksp->dm) kdm->originaldm = dm; /* Grant write privileges to the replacement DM */
}
ierr = DMDestroy(&ksp->dm);
CHKERRQ(ierr);
}
ksp->dm = dm;
ksp->dmAuto = PETSC_FALSE;
ierr = KSPGetPC(ksp,&pc);
CHKERRQ(ierr);
ierr = PCSetDM(pc,dm);
CHKERRQ(ierr);
ksp->dmActive = PETSC_TRUE;
PetscFunctionReturn(0);
}
/* Attaches the DMKSP to the coarse level.
* Under what conditions should we copy versus duplicate?
*/
static PetscErrorCode DMRefineHook_DMKSP(DM dm,DM dmc,void *ctx)
{
PetscErrorCode ierr;
PetscFunctionBegin;
ierr = DMCopyDMKSP(dm,dmc);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
