:orphan:
# MatIsShell
Inquires if a matrix is derived from `MATSHELL` 
## Synopsis
```
#include "petscmat.h" 
PetscErrorCode MatIsShell(Mat mat, PetscBool *flg)
```

## Input Parameter

- ***mat -*** the matrix



## Output Parameter

- ***flg -*** the boolean value





## Developer Note
In the future, we should allow the object type name to be changed still using the `MATSHELL` data structure for other matrices
(i.e. `MATTRANSPOSEVIRTUAL`, `MATSCHURCOMPLEMENT` etc)


## See Also
 [](ch_matrices), `Mat`, `MATSHELL`, `MATMFFD`, `MatCreateShell()`, `MATTRANSPOSEVIRTUAL`, `MATSCHURCOMPLEMENT`

## Level
developer

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/shell/shell.c.html#MatIsShell">src/mat/impls/shell/shell.c</A>


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


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