# MatGetRowMaxAbs
Gets the maximum value (in absolute value) of each row of the matrix 
## Synopsis
```
#include "petscmat.h" 
PetscErrorCode MatGetRowMaxAbs(Mat mat, Vec v, PetscInt idx[])
```
Logically Collective


## Input Parameter

- ***mat -*** the matrix



## Output Parameters

- ***v -*** the vector for storing the maximums
- ***idx -*** the indices of the column found for each row (or `NULL` if not needed)





## Notes
if a row is completely empty or has only 0.0 values then the idx[] value for that
row is 0 (the first column).

This code is only implemented for a couple of matrix formats.


## See Also
 `Mat`, `MatGetDiagonal()`, `MatCreateSubMatrices()`, `MatCreateSubMatrix()`, `MatGetRowMax()`, `MatGetRowMin()`, `MatGetRowMinAbs()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/interface/matrix.c.html#MatGetRowMaxAbs">src/mat/interface/matrix.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex72.c.html">src/ksp/ksp/tutorials/ex72.c.html</A><BR>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/mpiaij.c.html#MatGetRowMaxAbs_MPIAIJ">MatGetRowMaxAbs_MPIAIJ in src/mat/impls/aij/mpi/mpiaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/aij.c.html#MatGetRowMaxAbs_SeqAIJ">MatGetRowMaxAbs_SeqAIJ in src/mat/impls/aij/seq/aij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/baij/mpi/mpibaij.c.html#MatGetRowMaxAbs_MPIBAIJ">MatGetRowMaxAbs_MPIBAIJ in src/mat/impls/baij/mpi/mpibaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/baij/seq/baij.c.html#MatGetRowMaxAbs_SeqBAIJ">MatGetRowMaxAbs_SeqBAIJ in src/mat/impls/baij/seq/baij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/dense/seq/dense.c.html#MatGetRowMaxAbs_SeqDense">MatGetRowMaxAbs_SeqDense in src/mat/impls/dense/seq/dense.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/sbaij/mpi/mpisbaij.c.html#MatGetRowMaxAbs_MPISBAIJ">MatGetRowMaxAbs_MPISBAIJ in src/mat/impls/sbaij/mpi/mpisbaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/sbaij/seq/sbaij2.c.html#MatGetRowMaxAbs_SeqSBAIJ">MatGetRowMaxAbs_SeqSBAIJ in src/mat/impls/sbaij/seq/sbaij2.c</A><BR>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/mat/interface/matrix.c)


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