# DMShellSetMatrix
sets a template matrix associated with the DMShell 
## Synopsis
```
#include "petscdmshell.h"  
PetscErrorCode DMShellSetMatrix(DM dm, Mat J)
```
Collective


## Input Parameters

- ***dm -*** shell DM
- ***J -*** template matrix





## Developer Notes
To avoid circular references, if J is already associated to the same DM, then MatDuplicate(SHARE_NONZERO_PATTERN) is called, followed by removing the DM reference from the private template.


## See Also
 `DMCreateMatrix()`, `DMShellSetCreateMatrix()`, `DMShellSetContext()`, `DMShellGetContext()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/shell/dmshell.c.html#DMShellSetMatrix">src/dm/impls/shell/dmshell.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex73f90t.F90.html">src/snes/tutorials/ex73f90t.F90.html</A><BR>


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


[Index of all DM routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
