:orphan:
# DMPlexTSComputeIJacobianFEM
Form the Jacobian `Jac` from the local input `locX` using pointwise functions specified by the user 
## Synopsis
```
#include "petscdmplex.h" 
#include "petscts.h" 
PetscErrorCode DMPlexTSComputeIJacobianFEM(DM dm, PetscReal time, Vec locX, Vec locX_t, PetscReal X_tShift, Mat Jac, Mat JacP, void *user)
```

## Input Parameters

- ***dm -*** The mesh
- ***t -*** The time
- ***locX  -*** Local solution
- ***locX_t -*** Local solution time derivative, or `NULL`
- ***X_tShift -*** The multiplicative parameter for dF/du_t
- ***user -*** The user context



## Output Parameters

- ***Jac -*** the Jacobian
- ***JacP -*** an additional approximation for the Jacobian to be used to compute the preconditioner (often is `Jac`)





## See Also
 [](ch_ts), `TS`, `DM`, `DMPlexTSComputeIFunctionFEM()`, `DMPlexTSComputeRHSFunctionFEM()`

## Level
developer

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/utils/dmplexts.c.html#DMPlexTSComputeIJacobianFEM">src/ts/utils/dmplexts.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex18.c.html">src/ts/tutorials/ex18.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex45.c.html">src/ts/tutorials/ex45.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex46.c.html">src/ts/tutorials/ex46.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex47.c.html">src/ts/tutorials/ex47.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex48.c.html">src/ts/tutorials/ex48.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex53.c.html">src/ts/tutorials/ex53.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex76.c.html">src/ts/tutorials/ex76.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex77.c.html">src/ts/tutorials/ex77.c</A><BR>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ts/utils/dmplexts.c)


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