On 30/10/2012 1:44 PM, Matthew Knepley wrote: > On Tue, Oct 30, 2012 at 7:41 AM, TAY wee-beng <zonexo at gmail.com > <mailto:zonexo at gmail.com>> wrote: > > On 28/10/2012 2:17 PM, Jed Brown wrote: >> >> Algebraic multigrid can be used directly, -pc_type gamg >> -pc_gamg_agg_nsmooths 1. Geometric either required that you use >> the PCMG interface to set interpolation (and provide a coarse >> operator for non-Galerkin) or use a DM that provides coarsening >> capability. >> >> What kind of problem are you solving? >> > > Hi, > > May I know if there is an example which explains using the > geometric MG, either using PCMG or DM? > > > SNES ex5 and ex19 both use MG. > > Matt Are there examples which uses ksp and geometric MG? I want to solve a Poisson eqn which has been discretized to give a sys of linear eqns.
I also found this thread : http://lists.mcs.anl.gov/pipermail/petsc-users/2012-August/015073.html Is it using geometric MG to solve a sys of linear eqns? > > Yours sincerely, > > TAY wee-beng > > >> On Oct 28, 2012 6:09 AM, "w_ang_temp" <w_ang_temp at 163.com >> <mailto:w_ang_temp at 163.com>> wrote: >> >> Hello, >> I want to use the multigrid as a preconditioner. The >> introduction about it in the manual is little. >> So are there some typical examples or details about >> multigrid? Is it used just like other preconditioners >> like jacobi, sor, which can be simply used in the cammand >> line options? >> Thanks. >> Jim >> >> > > > > > -- > 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20121030/3441df46/attachment.html>
