On Fri, Dec 3, 2010 at 19:29, Vijay S. Mahadevan <vijay.m at gmail.com> wrote:
> Jed and Dave, thanks for the explanation. Now I do understand that the > MG PC is generic if I have restriction/prolongation operators for > every level. But I do not have the fine grid operator on hand > explicitly (only a shell matrix with MatMult) and technically all my > coarser grid operators will also be matrix-free. I was originally > planning to hand these shell matrices to petsc as the coarse > operators but can petsc do this by itself with only access to the fine > grid operator ? > PETSc cannot magically create intermediate-level shell operators. If you want to do everything matrix-free, then you have to provide everything that needs to be "smart": restriction/interpolation, smoothers, and residuals. Jed -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20101203/7dca7977/attachment.htm>
