# TSAdjointSetForward
Trigger the tangent linear solver and initialize the forward sensitivities 
## Synopsis
```
#include "petscts.h"  
PetscErrorCode TSAdjointSetForward(TS ts, Mat didp)
```
Logically Collective on TS


## Input Parameters

- ***ts -*** the TS context obtained from TSCreate()
- ***didp -*** the derivative of initial values w.r.t. parameters




Notes: When computing sensitivies w.r.t. initial condition, set didp to NULL so that the solver will take it as an identity matrix mathematically. TSAdjoint does not reset the tangent linear solver automatically, TSAdjointResetForward() should be called to reset the tangent linear solver.


## See Also
 `TSSetCostHessianProducts()`, `TSAdjointResetForward()`

## Level
intermediate

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

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex20opt_ic.c.html">src/ts/tutorials/ex20opt_ic.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ts/tutorials/ex20opt_p.c.html">src/ts/tutorials/ex20opt_p.c.html</A><BR>


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


[Index of all Sensitivity routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
