# TaoSetJacobianDesignRoutine
Sets the function to compute the Jacobian of the constraint function with respect to the design variables.  Used only for PDE-constrained optimization. 
## Synopsis
```
#include "petsctao.h" 
PetscErrorCode TaoSetJacobianDesignRoutine(Tao tao, Mat J, PetscErrorCode (*func)(Tao, Vec, Mat, void *), void *ctx)
```
Logically collective on tao


## Input Parameters

- ***tao  -*** the Tao context
- ***J    -*** Matrix used for the jacobian
- ***func -*** Jacobian evaluation routine
- ***ctx  -*** [optional] user-defined context for private data for the
Jacobian evaluation routine (may be NULL)



## Calling sequence of func
```none
func(Tao tao,Vec x,Mat J,void *ctx);
```


- ***tao -*** the Tao  context
- ***x   -*** input vector
- ***J   -*** Jacobian matrix
- ***ctx -*** [optional] user-defined Jacobian context





## See Also
 `Tao`, `TaoComputeJacobianDesign()`, `TaoSetJacobianStateRoutine()`, `TaoSetStateDesignIS()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/interface/taosolver_hj.c.html#TaoSetJacobianDesignRoutine">src/tao/interface/taosolver_hj.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/elliptic.c.html">src/tao/pde_constrained/tutorials/elliptic.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/hyperbolic.c.html">src/tao/pde_constrained/tutorials/hyperbolic.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/parabolic.c.html">src/tao/pde_constrained/tutorials/parabolic.c.html</A><BR>


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


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