# TSComputeRHSFunctionLinear
Evaluate the right hand side via the user-provided Jacobian, for linear problems Udot = A U only 
## Synopsis
```
#include "petscts.h"  
PetscErrorCode TSComputeRHSFunctionLinear(TS ts, PetscReal t, Vec U, Vec F, void *ctx)
```
Collective


## Input Parameters

- ***ts -*** time stepping context
- ***t -*** time at which to evaluate
- ***U -*** state at which to evaluate
- ***ctx -*** context



## Output Parameter

- ***F -*** right hand side





## Note
This function is intended to be passed to `TSSetRHSFunction()` to evaluate the right hand side for linear problems.
The matrix (and optionally the evaluation context) should be passed to `TSSetRHSJacobian()`.


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

## Level
intermediate

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

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex3.c.html">src/ts/tutorials/ex3.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex4.c.html">src/ts/tutorials/ex4.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex5.c.html">src/ts/tutorials/ex5.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex6.c.html">src/ts/tutorials/ex6.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex74.c.html">src/ts/tutorials/ex74.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/unconstrained/tutorials/spectraladjointassimilation.c.html">src/tao/unconstrained/tutorials/spectraladjointassimilation.c.html</A><BR>


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