# KSPSetDiagonalScaleFix#

Tells KSP to diagonally scale the system back after solving.

## Synopsis#

#include "petscksp.h"
#include "petscmat.h"
PetscErrorCode KSPSetDiagonalScaleFix(KSP ksp, PetscBool fix)


Logically Collective

## Input Parameters#

• ksp - the KSP context

• fix - PETSC_TRUE to scale back after the system solve, PETSC_FALSE to not rescale (default)

## Notes#

Must be called after KSPSetDiagonalScale()

Using this will slow things down, because it rescales the matrix before and after each linear solve. This is intended mainly for testing to allow one to easily get back the original system to make sure the solution computed is accurate enough.

KSP: Linear System Solvers, KSPGetDiagonalScale(), KSPSetDiagonalScale(), KSPGetDiagonalScaleFix(), KSP