# MatSetOptionsPrefixFactor
Sets the prefix used for searching for all matrix factor options in the database for for matrices created with `MatGetFactor()` 
## Synopsis
```
#include "petscmat.h" 
PetscErrorCode MatSetOptionsPrefixFactor(Mat A, const char prefix[])
```
Logically Collective


## Input Parameters

- ***A -*** the matrix
- ***prefix -*** the prefix to prepend to all option names for the factored matrix





## Notes
A hyphen (-) must NOT be given at the beginning of the prefix name.
The first character of all runtime options is AUTOMATICALLY the hyphen.

Normally the prefix is automatically passed in from the `PC` calling the factorization. To set
it directly when not using `KSP`/`PC` use  `MatSetOptionsPrefixFactor()`


## See Also
 `Mat`,   [Matrix Factorization](sec_matfactor), `MatGetFactor()`, `MatSetFromOptions()`, `MatSetOptionsPrefix()`, `MatAppendOptionsPrefixFactor()`

## Level
developer

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/interface/matrix.c.html#MatSetOptionsPrefixFactor">src/mat/interface/matrix.c</A>


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