# MatSNESMFGetReuseBase
Determines if the base vector is to be used for differencing even if the function provided to `SNESSetFunction()` is not the same as that provided to `MatMFFDSetFunction()`. 
## Synopsis
```
#include "petscsnes.h" 
#include "petscdm.h"   
PetscErrorCode MatSNESMFGetReuseBase(Mat J, PetscBool *use)
```
Logically Collective on J


## Input Parameter

- ***J -*** the `MATMFFD` matrix



## Output Parameter

- ***use -*** if true always reuse the base vector instead of recomputing f(u) even if the function in the `MATMFFD` is
not `SNESComputeFunction()`





## Note
See `MatSNESMFSetReuseBase()`


## See Also
 `MatSNESMFSetReuseBase()`, `MatCreateSNESMF()`, `MatSNESMFSetReuseBase()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/mf/snesmfj.c.html#MatSNESMFGetReuseBase">src/snes/mf/snesmfj.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/snes/mf/snesmfj.c)


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