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<body class='hmmessage'><div dir='ltr'>Thanks Mat,<br><br> 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.<br><br>Best,<br><br><br> <br><br><div><hr id="stopSpelling">Date: Thu, 8 Aug 2013 14:03:53 -0500<br>Subject: Re: [petsc-users] implementation of multi-level grid in petsc<br>From: knepley@gmail.com<br>To: pengxwang@hotmail.com<br>CC: petsc-users@mcs.anl.gov<br><br><div dir="ltr">On Thu, Aug 8, 2013 at 1:29 PM, Roc Wang <span dir="ltr"><<a href="mailto:pengxwang@hotmail.com" target="_blank">pengxwang@hotmail.com</a>></span> wrote:<br><div class="ecxgmail_extra"><div class="ecxgmail_quote">
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<div><div dir="ltr">Hi,<br><br> 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?<br>
</div></div></blockquote><div><br></div><div>That is an experiment and does not work.</div><div> </div><blockquote class="ecxgmail_quote" style="border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex;">
<div><div dir="ltr"> 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?<br><br> 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.<br>
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</blockquote></div><br>No, that is not appropriate.</div><div class="ecxgmail_extra"><br></div><div class="ecxgmail_extra">It sounds like you want structured AMR. PETSc does not do this, and there are packages that do it.:</div>
<div class="ecxgmail_extra"><br></div><div class="ecxgmail_extra">a) Chombo</div><div class="ecxgmail_extra"><br></div><div class="ecxgmail_extra">b) SAMRAI</div><div class="ecxgmail_extra"><br></div><div class="ecxgmail_extra">which are both patch-based AMR. If you want octree-style AMR you could use p4est, but it would mean</div>
<div class="ecxgmail_extra">a lot of coding along the lines of <a href="http://arxiv.org/abs/1308.1472" target="_blank">http://arxiv.org/abs/1308.1472</a>, or Deal.II which is a complete package.</div><div class="ecxgmail_extra">I think Deal is the closest to using PETSc solvers.</div>
<div class="ecxgmail_extra"><br></div><div class="ecxgmail_extra"> Thanks,</div><div class="ecxgmail_extra"><br></div><div class="ecxgmail_extra"> Matt<br clear="all"><div><br></div>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener
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