# MatCompositeSetType
Indicates if the matrix is defined as the sum of a set of matrices or the product. 
## Synopsis
```
#include "petscmat.h" 
PetscErrorCode MatCompositeSetType(Mat mat, MatCompositeType type)
```
Logically Collective


## Input Parameters

- ***mat -*** the composite matrix





## See Also
 `Mat`, `MatDestroy()`, `MatMult()`, `MatCompositeAddMat()`, `MatCreateComposite()`, `MatCompositeGetType()`, `MATCOMPOSITE`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/composite/mcomposite.c.html#MatCompositeSetType">src/mat/impls/composite/mcomposite.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/tutorials/ex9.c.html">src/mat/tutorials/ex9.c.html</A><BR>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/composite/mcomposite.c.html#MatCompositeSetType_Composite">MatCompositeSetType_Composite in src/mat/impls/composite/mcomposite.c</A><BR>


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


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