[petsc-users] Example for adaptive high-order FEM in PETSc

[Jed Brown]

Mark Adams via petsc-users <petsc-users at mcs.anl.gov> writes:

>> The following is still unclear and I would appreciate some guidance:
>>
>> — A implicit DG solve of the inviscid Euler equations would require
>> Jacobian contributions from the Riemann Solver at element interfaces. I do
>> not see the ability to define Jacobian contribution in
>> PetscDSSetRiemannSolver. What would be the best approach to do this?
>>
>
> See
> https://www.mcs.anl.gov/petsc/petsc-current/src/ts/examples/tutorials/ex11.c.html
>
> The Riemann solver computes the flux and the Jacobian is assembled in PETSc.

If you run this example with an implicit integrator, it uses FD coloring
to compute the Jacobian.  Manav wants an analytic Jacobian.  I was
hoping Matt could answer this; I haven't used Plex in that way.