# MatH2OpusGetIndexMap
Access reordering index set. 
## Synopsis
```
PetscErrorCode MatH2OpusGetIndexMap(Mat A, IS *indexmap)
```

## Input Parameters

- ***A -*** the matrix



## Output Parameter

- ***indexmap -*** the index set for the reordering





## See Also
 `MatCreate()`, `MATH2OPUS`, `MatCreateH2OpusFromMat()`, `MatCreateH2OpusFromKernel()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/h2opus/cuda/math2opus.cu.html#MatH2OpusGetIndexMap">src/mat/impls/h2opus/cuda/math2opus.cu</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/mat/impls/h2opus/cuda/math2opus.cu)


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