[petsc-users] PetscFE and TS

[Julian Andrej]

Hello,

i'm using PetscFE in combination with SNES and a hand written backward
euler solver right now and like to hand that over to TS. I have been
fiddling quite a while getting TS to work with PetscFE and have
encountered a few unclarities.

I have looked at examples which are outdated i guess
(src/ts/examples/tutorials/ex32.c) and i am confused on how i have to
formulate the discretization of the jacobian and the residual. It
seems obvious to use the DMTSSetIFunctionLocal and
DMTSSetIJacobianLocal functions because there are prepared wrappers
from DMPlexTSComputeIFunctionFEM and DMPlexTSComputeIJacobianFEM.

I need a Mass matrix for my problem, is that formed from the function
space information or do i have to form it myself? Is there any working
example which uses PetscFE and TS to form the DMTSSetIFunctionLocal
and DMTSSetIJacobianLocal? (grepping the tree tells me "no"
unfortunately).

Regards
Julian