PetscErrorCode StokesSetupPC(Stokes* s, KSP ksp) {
KSP* subksp;
PC pc;
PetscInt n = 1;
PetscErrorCode ierr;
PetscFunctionBeginUser;
ierr = KSPGetPC(ksp, &pc);
CHKERRQ(ierr);
ierr = PCFieldSplitSetIS(pc, "0", s->isg[0]);
CHKERRQ(ierr);
ierr = PCFieldSplitSetIS(pc, "1", s->isg[1]);
CHKERRQ(ierr);
if (s->userPC) {
ierr = PCFieldSplitSetSchurPre(pc, PC_FIELDSPLIT_SCHUR_PRE_USER, s->myS);
CHKERRQ(ierr);
}
if (s->userKSP) {
ierr = PCSetUp(pc);
CHKERRQ(ierr);
ierr = PCFieldSplitGetSubKSP(pc, &n, &subksp);
CHKERRQ(ierr);
ierr = KSPSetOperators(subksp[1], s->myS, s->myS);
CHKERRQ(ierr);
ierr = PetscFree(subksp);
CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
PETSC_EXTERN void PETSC_STDCALL pcfieldsplitsetschurpre_(PC pc,PCFieldSplitSchurPreType *ptype,Mat pre, int *__ierr ){
*__ierr = PCFieldSplitSetSchurPre(
(PC)PetscToPointer((pc) ),*ptype,
(Mat)PetscToPointer((pre) ));
}