# PCSetReusePreconditioner
reuse the current preconditioner even if the operator in the preconditioner has changed. 
## Synopsis
```
#include "petscksp.h" 
PetscErrorCode PCSetReusePreconditioner(PC pc, PetscBool flag)
```
Logically Collective


## Input Parameters

- ***pc -*** the preconditioner context
- ***flag -*** `PETSC_TRUE` do not compute a new preconditioner, `PETSC_FALSE` do compute a new preconditioner





## Note
Normally if a matrix inside a `PC` changes the `PC` automatically updates itself using information from the changed matrix. This option
prevents this.


## See Also
 `PC`, `PCGetOperators()`, `MatZeroEntries()`, `PCGetReusePreconditioner()`, `KSPSetReusePreconditioner()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/pc/interface/precon.c.html#PCSetReusePreconditioner">src/ksp/pc/interface/precon.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ksp/pc/interface/precon.c)


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