:orphan:
# TSRHSJacobianSetReuse
restore RHS Jacobian before re-evaluating.  Without this flag, `TS` will change the sign and shift the RHS Jacobian for a finite-time-step implicit solve, in which case the user function will need to recompute the entire Jacobian.  The reuse flag must be set if the evaluation function will assume that the matrix entries have not been changed by the `TS`. 
## Synopsis
```
#include "petscts.h"  
PetscErrorCode TSRHSJacobianSetReuse(TS ts, PetscBool reuse)
```
Logically Collective


## Input Parameters

- ***ts -*** `TS` context obtained from `TSCreate()`
- ***reuse -*** `PETSC_TRUE` if the RHS Jacobian





## See Also
 [](ch_ts), `TS`, `TSSetRHSJacobian()`, `TSComputeRHSJacobianConstant()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/interface/ts.c.html#TSRHSJacobianSetReuse">src/ts/interface/ts.c</A>


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