:orphan:
# TSAdjointSetForward
Trigger the tangent linear solver and initialize the forward sensitivities
## Synopsis
```
#include "petscts.h"
PetscErrorCode TSAdjointSetForward(TS ts, Mat didp)
```
Logically Collective
## 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
[](ch_ts), `TSAdjointSolve()`, `TSSetCostHessianProducts()`, `TSAdjointResetForward()`
## Level
intermediate
## Location
src/ts/interface/sensitivity/tssen.c
## Examples
src/ts/tutorials/ex20opt_ic.c
src/ts/tutorials/ex20opt_p.c
---
[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](/manualpages/index.md)
[Index of all manual pages](/manualpages/singleindex.md)