Yes, lets get this back on the list. On Wed, Jun 10, 2015 at 12:01 PM, Young, Matthew, Adam <[email protected]> wrote:
> Ah, oops - I was looking at the v 3.5 manual. I am certainly interested > in algorithmic details if there are relevant papers. My main interest right > now is determining if this method is appropriate for my problem. > Jed mentioned that this will not work well out of the box, as I recall. It looks like very high anisotropy. There are heuristics in GAMG to deal with anisotropy, but I would not trust them on unstructured grids. You would want to play with '-pc_gamg_threshold x', x in [0 - 0.1]. My advisor used SuperLU on a sequential version of this problem years ago, > but SuperLU_dist appears to not scale well. > > yep, > Before any of that, though: Would you rather I redirect this to the > petsc-users list? I emailed you directly because I worried that the > discussion of my problem physics was detracting from PETSc-specific > conversation but maybe this is a conversation better had with the entire > PETSc group. > > You might look in the appendix of the "Multigrid" book by Trottenberg, et al. They have a listing of lots of physics problems and way to deal with them, with multigrid. Maybe they have something like your problem. Mark > --Matt > > -------------------------------------------------------------- > Matthew Young > Graduate Student > Boston University Dept. of Astronomy > -------------------------------------------------------------- > > ------------------------------ > *From:* Mark Adams [[email protected]] > *Sent:* Wednesday, June 10, 2015 10:33 AM > *To:* Young, Matthew, Adam > *Subject:* Re: GAMG > > The manual has material on this. Let me know if you want more detail, > algorithmic, etc. > Mark > > On Wed, Jun 10, 2015 at 10:15 AM, Young, Matthew, Adam <[email protected]> wrote: > >> Hi Mark, >> >> We recently had a brief discussion (along with Matt Knepley and Jed >> Brown) on the petsc-users list about a problem I'm working on for my >> thesis research. Since I'd like to explore what GAMG has to offer, I was >> wondering if you can direct me to an introduction of sorts if such a >> document exists. >> >> Best, >> Matt >> >> -------------------------------------------------------------- >> Matthew Young >> Graduate Student >> Boston University Dept. of Astronomy >> -------------------------------------------------------------- >> >> >
