[petsc-users] Time integrated adjoints

[Barry Smith]

  Hong and Emil,

    You will need to answer this.


> On Apr 15, 2015, at 6:24 AM, Dave Makhija <makhijad at colorado.edu> wrote:
> 
> Barry,
> 
> Is the method exact if I have a time dependent mass matrix (dF/dU_t changes each time step)? I'm not sure it's possible if TSSetIJacobian expects a function which computes the combination of dF/dU and a*dF/dU_t. But, perhaps there is something I'm missing.
> 
> Otherwise, it looks very comprehensive. I like how you added the "cost integrand". If I recall correctly, the Trilinos package Rythmos is missing this.
> 
> Thanks!
> 
> Dave
> 
> On Tue, Apr 14, 2015 at 8:30 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:
> 
> > On Apr 14, 2015, at 1:06 AM, Dave Makhija <makhijad at colorado.edu> wrote:
> >
> > Hello,
> >
> > I'm evaluating my options for computing time dependent adjoints. I did not think PETSc supported this, but I see "TSAdjointSolve" in the development branch. That would be fantastic news if you plan to support time integrated adjoints!
> >
> > What features are envisioned and when is the targeted release date?
> 
>   Dave,
> 
>    We currently have discrete adjoint computations for explicit RK methods and for implicit theta methods (backward Euler and Crank-Nicholson). The development copy of the users manual has some discussion (http://www.mcs.anl.gov/petsc/petsc-master/docs/manual.pdf page 135) and there are several examples.   I urge you to try them out now in master and stay in contact with us to insure we provide what you need as we are actively developing them.
> We plan a release for early June.
> 
>   Barry
> 
> >
> > Thanks!
> >
> > Dave
> 
>