:orphan:
# MatPartitioningSetFromOptions
Sets various partitioning options from the options database for the partitioning object 
## Synopsis
```
#include "petscmat.h" 
PetscErrorCode MatPartitioningSetFromOptions(MatPartitioning part)
```
Collective


## Input Parameter

- ***part -*** the partitioning context.



## Options Database Keys

- ***-mat_partitioning_type  <type> -*** (for instance, parmetis), use -help for a list of available methods
- ***-mat_partitioning_nparts -*** number of subgraphs





## Note
If the partitioner has not been set by the user it uses one of the installed partitioner such as ParMetis. If there are
no installed partitioners it does no repartioning.


## See Also
 [](ch_matrices), `Mat`, `MatPartitioning`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/partition/partition.c.html#MatPartitioningSetFromOptions">src/mat/partition/partition.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex64.c.html">src/ksp/ksp/tutorials/ex64.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/tutorials/ex11.c.html">src/mat/tutorials/ex11.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/tutorials/ex15.c.html">src/mat/tutorials/ex15.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/tutorials/ex15f.F90.html">src/mat/tutorials/ex15f.F90</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/tutorials/ex17.c.html">src/mat/tutorials/ex17.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/tutorials/ex17f.F90.html">src/mat/tutorials/ex17f.F90</A><BR>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/partition/impls/chaco/chaco.c.html#MatPartitioningSetFromOptions_Chaco">MatPartitioningSetFromOptions_Chaco in src/mat/partition/impls/chaco/chaco.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/partition/impls/hierarchical/hierarchical.c.html#MatPartitioningSetFromOptions_Hierarchical">MatPartitioningSetFromOptions_Hierarchical in src/mat/partition/impls/hierarchical/hierarchical.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/partition/impls/party/party.c.html#MatPartitioningSetFromOptions_Party">MatPartitioningSetFromOptions_Party in src/mat/partition/impls/party/party.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/partition/impls/pmetis/pmetis.c.html#MatPartitioningSetFromOptions_Parmetis">MatPartitioningSetFromOptions_Parmetis in src/mat/partition/impls/pmetis/pmetis.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/partition/impls/scotch/scotch.c.html#MatPartitioningSetFromOptions_PTScotch">MatPartitioningSetFromOptions_PTScotch in src/mat/partition/impls/scotch/scotch.c</A><BR>


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


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