[petsc-users] PetscFE questions

[Julian Andrej]

Hi,

i have general question about PetscFE. When i want to assemble certain
parts of physics separately, how can i do that? I basically want to
assemble matrices/vectors from the weak forms on the same DM (and
avoid copying the DM) and use them afterwards. Is there a convenient
way for doing that?

The "workflow" i'm approaching is something like:

- Setup the DM
- Setup discretization (spaces and quadrature) for each weak form i
want to compute
- Compute just the weak form i want right now for a specific
discretization and field.

The reason is i need certain parts of the "complete" Jacobian for
computations of eigenproblems and like to avoid computing those more
often than needed.

Regards
Julian