# MatCreateSubMatrixVirtual
Creates a virtual matrix `MATSUBMATRIX` that acts as a submatrix 
## Synopsis
```
#include "petscmat.h" 
PetscErrorCode MatCreateSubMatrixVirtual(Mat A, IS isrow, IS iscol, Mat *newmat)
```
Collective


## Input Parameters

- ***A -*** matrix that we will extract a submatrix of
- ***isrow -*** rows to be present in the submatrix
- ***iscol -*** columns to be present in the submatrix



## Output Parameters

- ***newmat -*** new matrix





## Note
Most will use `MatCreateSubMatrix()` which provides a more efficient representation if it is available.


## Developer Note
The `MatType` is `MATSUBMATRIX` but the routines associated have `SubMatrixVirtual` in them, the `MatType` should likely be changed


## See Also
 `MATSUBMATRIX`, `MATLOCALREF`, `MatCreateLocalRef()`, `MatCreateSubMatrix()`, `MatSubMatrixVirtualUpdate()`

## Level
developer

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


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


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