Ben, Thanks for the clarification. Now I get what Roy was suggesting. I think the libmesh 'Mesh' and 'Elem' data structures already have enough base routines to help me started on creating a geometric multigrid algorithm.
Another question that I have in mind is whether I would need to create multiple equations systems in order to maintain different Mesh levels. I understand from your answers that this might not be necessary entirely. And so would I then create a new System with new dofs attached to the current level ? In that case, I would have an active System for every active level of the mesh. Is this what you had in mind ? > -----Original Message----- > From: Benjamin Kirk [mailto:[EMAIL PROTECTED] > Sent: Wednesday, November 12, 2008 9:59 PM > To: Vijay M > Cc: [email protected] > Subject: Re: [Libmesh-users] Multigrid techniques with libmesh > > >>> For example when I have an unstructured grid, and when I coarsen > >>> uniformly twice and refine uniformly twice, would I get the exact > >>> same mesh?! > > One issue is we cannot coarsen below the initial, level-0 mesh. > > So if you start with a mesh, uniformly refine twice, and then uniformly > coarsen two times you will get back to the initial mesh. I think there > was > a little confusion - you first asked 'coarsen twice then refine twice' but > then mentioned > > > I refine it once, all new elements get the > > level_1 flag and become active while the original elements still are in > > memory but inactive. And now if I coarsen the mesh uniformly, then the > > level_1 elements become inactive and level_0 elements become active. > > the latter of which is certainly true. > > What's more, if you have a mesh and uniformly refine it N times, you will > have N+1 total levels in the mesh, and you can access each level directly > with a 'level element iterator.' we just usually use active local ones, > especially in the examples. > > -Ben > > ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
