On Sat, Sep 6, 2008 at 10:57 AM, Kees, Christopher E <Christopher.E.Kees at usace.army.mil> wrote: > Hi, > > I'm interested in these types of Shur complement preconditioners as well. I > had stopped working with petsc-dev some time back because I wasn't using new > functionality. Would this be a good time to start working with petsc-dev in > order to start testing these? I'm primarily interested in stokes and > navier-stokes type systems but also have some other coupled systems that an > "operator-split" preconditioner should work well on.
Yes. We have introduced a whole new set of tools that work by mapping each field to an IS, like PCFieldSplit. > With regard to testing, I am also looking for a solid parallel direct solver > to verify everything from the nonlinear solver up. I have been using superlu > in serial and superlu_dist in parallel (through PETSc) but have noticed some > reduction in accuracy as I go to more processors with superlu_dist. This may > just be a bug in our code, but I thought if I get petsc-dev the new approach > to external direct solvers that Barry mentioned earlier might make it easier > to look at some other direct solvers. Several years ago I got better results > with spooles, but I'd be interested in any current recommendations. You can also try MUMPS with --download-mumps. Matt > Thanks, > Chris -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
