On Fri, Dec 3, 2010 at 06:02, Vijay S. Mahadevan <vijay.m at gmail.com> wrote:
> I was wondering whether the MG preconditioner object is generic enough > to work out of the box like say ILU or SOR. To elaborate on this, if > I can provide the number of levels, restriction and prolongation > operators for each level and the system operators along with vectors > allocated for solution and rhs, would it work as a preconditioner for > my given problem and a prescribed rhs at the finest level of PCMG. Or > does it need some knowledge of the fine and coarser meshes to perform > the MG operations correctly ? > PCMG is purely algebraic so it does not need knowledge about the mesh, just interpolation/restriction. However, if you want to use non-Galerkin coarse operators, then you will need a coarse mesh (this is something that DMMG facilitates). Look at section 4.4.7 of the users manual for explanation of using PCMG. There don't seem to be any well-documented examples using PCMG directly, but you might want to look at src/ksp/examples/tests/ex19.c or src/snes/examples/tests/ex11.c. Jed -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20101203/b269f33c/attachment.htm>
