:orphan: # TSComputeI2Jacobian Evaluates the Jacobian of the DAE ## Synopsis ``` #include "petscts.h" PetscErrorCode TSComputeI2Jacobian(TS ts, PetscReal t, Vec U, Vec V, Vec A, PetscReal shiftV, PetscReal shiftA, Mat J, Mat P) ``` Collective ## Input Parameters - ***ts -*** the `TS` context - ***t -*** current timestep - ***U -*** state vector - ***V -*** time derivative of state vector - ***A -*** second time derivative of state vector - ***shiftV -*** shift to apply, see note below - ***shiftA -*** shift to apply, see note below ## Output Parameters - ***J -*** Jacobian matrix - ***P -*** optional preconditioning matrix ## Notes If F(t,U,V,A)=0 is the DAE, the required Jacobian is dF/dU + shiftV*dF/dV + shiftA*dF/dA Most users should not need to explicitly call this routine, as it is used internally within the nonlinear solvers. ## See Also [](ch_ts), `TS`, `TSSetI2Jacobian()` ## Level developer ## Location src/ts/interface/ts.c --- [Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/ts/interface/ts.c) [Index of all TS routines](index.md) [Table of Contents for all manual pages](/manualpages/index.md) [Index of all manual pages](/manualpages/singleindex.md)