PetscErrorCode KSPInitialResidual(KSP ksp,Vec vsoln,Vec vt1,Vec vt2,Vec vres,Vec vb)
{
Mat Amat,Pmat;
PetscErrorCode ierr;
PetscFunctionBegin;
PetscValidHeaderSpecific(ksp,KSP_CLASSID,1);
PetscValidHeaderSpecific(vsoln,VEC_CLASSID,2);
PetscValidHeaderSpecific(vres,VEC_CLASSID,5);
PetscValidHeaderSpecific(vb,VEC_CLASSID,6);
if (!ksp->pc) {ierr = KSPGetPC(ksp,&ksp->pc);CHKERRQ(ierr);}
ierr = PCGetOperators(ksp->pc,&Amat,&Pmat);CHKERRQ(ierr);
if (!ksp->guess_zero) {
/* skip right scaling since current guess already has it */
ierr = KSP_MatMult(ksp,Amat,vsoln,vt1);CHKERRQ(ierr);
ierr = VecCopy(vb,vt2);CHKERRQ(ierr);
ierr = VecAXPY(vt2,-1.0,vt1);CHKERRQ(ierr);
ierr = (ksp->pc_side == PC_RIGHT) ? (VecCopy(vt2,vres)) : (KSP_PCApply(ksp,vt2,vres));CHKERRQ(ierr);
ierr = PCDiagonalScaleLeft(ksp->pc,vres,vres);CHKERRQ(ierr);
} else {
ierr = VecCopy(vb,vt2);CHKERRQ(ierr);
if (ksp->pc_side == PC_RIGHT) {
ierr = PCDiagonalScaleLeft(ksp->pc,vb,vres);CHKERRQ(ierr);
} else if (ksp->pc_side == PC_LEFT) {
ierr = KSP_PCApply(ksp,vb,vres);CHKERRQ(ierr);
ierr = PCDiagonalScaleLeft(ksp->pc,vres,vres);CHKERRQ(ierr);
} else if (ksp->pc_side == PC_SYMMETRIC) {
ierr = PCApplySymmetricLeft(ksp->pc, vb, vres);CHKERRQ(ierr);
} else SETERRQ1(PetscObjectComm((PetscObject)ksp),PETSC_ERR_SUP, "Invalid preconditioning side %d", (int)ksp->pc_side);
}
PetscFunctionReturn(0);
}
PETSC_EXTERN void PETSC_STDCALL pcdiagonalscaleleft_(PC pc,Vec in,Vec out, int *__ierr ){
*__ierr = PCDiagonalScaleLeft(
(PC)PetscToPointer((pc) ),
(Vec)PetscToPointer((in) ),
(Vec)PetscToPointer((out) ));
}
