[petsc-users] Problems with preconditioners, which one?

[Jed Brown]

On Wed, 04 Aug 2010 08:53:16 -0400, Filippo Spiga <filippo.spiga at disco.unimib.it> wrote:
>   In my case that test is not useful, right?

Correct, if you have

  f(x) = A x - b

then -snes_type test doesn't check anything new.

> I didn't try UMFPACK and probably that external library is not compiled. 
> I will do that. But can I use "-pc_type lu,-pc_factor_mat_solver_package 
> umfpack" in a parallel execution?

You can use mumps and superlu_dist in parallel.  Or a domain
decomposition method with direct subdomain solves, but then my earlier
comment regarding being careful about the partition applies.

Jed