# MatScaleSystem

Scale a vector solution and right hand side to match the scaling of a scaled matrix.

### Synopsis

    #include "petscmat.h"
    PetscErrorCode PETSCMAT_DLLEXPORT MatScaleSystem(Mat mat,Vec x,Vec b)

Collective on Mat

### Input Parameter

| mat | - the matrix
| x | - solution vector (or PETSC_NULL)
| b | - right hand side vector (or PETSC_NULL)

### Notes

For AIJ, BAIJ, and BDiag matrix formats, the matrices are not internally scaled, so this does nothing. For MPIROWBS it permutes and diagonally scales.

The KSP methods automatically call this routine when required (via PCPreSolve()) so it is rarely used directly.

### See Also

MatUseScaledForm(), MatUnScaleSystem()

Level:Developer
Location:src/mat/interface/matrix.c
Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages