On Fri, Dec 3, 2010 at 20:20, Vijay S. Mahadevan <vijay.m at gmail.com> wrote:
> This is fine and I am more than happy to hand these to Petsc. I do > have the restriction/prolongation matrices explicitly but only the > operators are matrix-free for now. So if I start off with a > matrix-free PC operator, how exactly do I provide the shell matrix > operators for all the other levels ? > PCMGSetResidual, PCMGGetSmoother and set it to whatever type you want (maybe your custom one). > I do not see any routine to enable this and my conclusion is that > petsc does find it using the fine grid operator at hand using R^T*A*R > transformation. > Galerkin coarse operators really need to be formed (not applied as a product) to make sense. PCMG calls MatPtAP(), Galerkin coarse operators will not work unless this is implemented. You want to provide the matrix yourself. Jed -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20101203/187882f6/attachment.htm>
