# DMTSCheckJacobian
Check the Jacobian of the exact solution against the residual using the Taylor Test 
## Synopsis
```
#include "petscdmplex.h" 
#include "petscts.h" 
PetscErrorCode DMTSCheckJacobian(TS ts, DM dm, PetscReal t, Vec u, Vec u_t, PetscReal tol, PetscBool *isLinear, PetscReal *convRate)
```

## Input Parameters

- ***ts  -*** the TS object
- ***dm  -*** the DM
- ***t   -*** the time
- ***u   -*** a DM vector
- ***u_t -*** a DM vector
- ***tol -*** A tolerance for the check, or -1 to print the results instead



## Output Parameters

- ***isLinear -*** Flag indicaing that the function looks linear, or NULL
- ***convRate -*** The rate of convergence of the linear model, or NULL





## See Also
 [](chapter_ts), `DNTSCheckFromOptions()`, `DMTSCheckResidual()`, `DNSNESCheckFromOptions()`, `DMSNESCheckDiscretization()`, `DMSNESCheckResidual()`

## Level
developer

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


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