[petsc-users] parallel complex preconditioner needed

[Jed Brown]

On Mon, 19 Jul 2010 14:50:03 -0400, Craig Tanis <craig at tanistech.com> wrote:
> I'm looking for a parallel preconditioner for a complex linear system.
> For smaller serial runs, the built-in ILU has been great.
> 
> I've used hypre (euclid) on real matrices, but that suite is
> apparently only for reals.  What are my options for these big complex
> systems?

What problem are you solving?  Many of the direct solvers work with
complex scalars, the algebraic multigrid packages are currently lacking
in this regard.  If the problem is sufficiently small, you can use a
parallel direct solver, otherwise you'll need some sort of domain
decomposition method (e.g. -pc_type asm).  If ILU is working well for
you, direct subdomain solves are probably not important.  You may still
need a coarse level, there are many ways to do this, but they are
problem dependent.

Jed