On Aug 8, 2013, at 3:32 PM, Roc Wang <pengxw...@hotmail.com> wrote: > Thanks Mat, > > I tried Chombo for implementing AMR but not tried SAMRAI yet. Chombo can > do AMR, but it seems the data structure is quite complicated for customizing > usage. What I want to do with petsc is to compose a simple "home-made" like > blocked multi-level grid, though it is not automatically adaptive. However, > I don't have too much experiences on petsc. As of now, I suppose to use DM to > manage the data for the big domain and all small sub-domains. I am not sure > whether it is a good idea. So, any suggestions are appreciated very much. > Thanks again. >
As Matt said, this is not what you want to do, most likely. Building AMR on DM/DA is a lot of work unless you have a simple application and have a clear idea of how to do it. Chombo is flexible but it is complex and takes time to get started. I'm not familiar wit SAMARI but I would guess it is like Chombo. Deall.II might be worth looking into. I'm not familiar. > Best, > > > > > Date: Thu, 8 Aug 2013 14:03:53 -0500 > Subject: Re: [petsc-users] implementation of multi-level grid in petsc > From: knep...@gmail.com > To: pengxw...@hotmail.com > CC: petsc-users@mcs.anl.gov > > On Thu, Aug 8, 2013 at 1:29 PM, Roc Wang <pengxw...@hotmail.com> wrote: > Hi, > > I am working on multi-level grid for Poisson equation. I need to refine > some sub-region in the computational domain. To this, I plan to build some > boxes (patches) based on the coarsest level. I am using DM to manage the > data. I found there is a new function DMPatachCreate() in the version 3.4. > Is this function the right one I should use for the refined region? If it is > not, which ones I should use? > > That is an experiment and does not work. > > My proposed approach is to start with code > dm/impls/patch/examples/tests/ex1.c. And then follow the code > /dm/examples/tutorials/ex65dm.c. Is this approach the right way to my goal? > > In addition, I need to use not only the nodes but also the cells > including nodes. Should I use DMMesh to create the cells? I noticed DMMesh > is mainly for unstructured grid, but I didn't find other class that > implements structured cells. Can anybody give me some suggestions on > multi-level grid or let me know which examples I should start with? Thanks. > > No, that is not appropriate. > > It sounds like you want structured AMR. PETSc does not do this, and there are > packages that do it.: > > a) Chombo > > b) SAMRAI > > which are both patch-based AMR. If you want octree-style AMR you could use > p4est, but it would mean > a lot of coding along the lines of http://arxiv.org/abs/1308.1472, or Deal.II > which is a complete package. > I think Deal is the closest to using PETSc solvers. > > Thanks, > > Matt > > -- > 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