On Fri, Dec 23, 2011 at 10:48, Mark F. Adams <mark.adams at columbia.edu>wrote:
> There is the implementation in Prometheus that uses my C++ linked lists > and hash tables. I would like to implement this with STLs. I also hack > into MPIAIJ matrices to provide a primitive of applying G-S on an index set > of local vertices, required for the algorithm. This should be rethought. > I would guess that it would take about a week or two to move this into > PETSc. > > The complex communication required make this code work much better with > large subdomains, so it is getting less attractive in a flat MPI mode, as > it is currently written. If I do this I would like to think about doing it > in the next programming model of PETSc (pthreads?). Anyway, this would > take enough work that I'd like to think a bit about its design and even the > algorithm in a non flat MPI model. > > Note, I see the win with G-S over Cheby in highly unsymmetric (convection, > hyperbolic) problems where Cheby is not very good. > Can we mix with Eisenstat to apply multiple cycles? I know the theory doesn't argue for it, but G-S with Cheby sometimes wins over everything else I've tried. Is there any hope of doing nonlinear G-S where the user can provide something moderately simple? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20111223/eca72b8d/attachment.html>