<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Tue, Oct 17, 2017 at 2:51 PM, Hittinger, Jeffrey A. F. <span dir="ltr"><<a href="mailto:hittinger1@llnl.gov" target="_blank">hittinger1@llnl.gov</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<p class="MsoNormal">Bummer.<u></u><u></u></p>
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<p class="MsoNormal">Matt - Never is a very strong word. Don’t underestimate the power of mappings and/or AMR. Also, sparse grid techniques haven’t (yet) proven to be particularly useful for kinetic problems.</p></div></div></blockquote><div><br></div><div>None of the above is wrong, but I really meant "regular grids in high dimension". DMDA will never do AMR or sparse grids since its designed</div><div>to be the simplest thing possible. For AMR we are using p4est, and that could definitely work in higher dimensions. I have read the Irene Gamba</div><div>stuff on Boltzmann Transport using higher-D regular grids, but its just tremendously expensive, and they really play up spectral convergence,</div><div>which relies on regularity which is often not there in practical problems.</div><div><br></div><div> Thanks,</div><div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div bgcolor="white" lang="EN-US"><div class="gmail-m_8795958808222375419WordSection1"><p class="MsoNormal"> </p><p class="MsoNormal"><u></u></p>
<p class="MsoNormal">Thanks for the quick response.<u></u><u></u></p>
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<p class="MsoNormal">j-<u></u><u></u></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black">-.-- -.-- --..<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black">Jeffrey A. F. Hittinger<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black">Center for Applied Scientific Computing<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black">Lawrence Livermore National Laboratory<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black">Office: <a href="tel:(925)%20422-0993" value="+19254220993" target="_blank">(925) 422-0993</a><u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black">FAX: <a href="tel:(925)%20423-2993" value="+19254232993" target="_blank">(925) 423-2993</a></span><u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in"><b><span style="font-size:12pt;color:black">From:
</span></b><span style="font-size:12pt;color:black">Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>><br>
<b>Date: </b>Tuesday, October 17, 2017 at 11:42 AM<br>
<b>To: </b>Barry Smith <<a href="mailto:bsmith@mcs.anl.gov" target="_blank">bsmith@mcs.anl.gov</a>><br>
<b>Cc: </b>Undisclosed recipients <<a href="mailto:hittinger1@llnl.gov" target="_blank">hittinger1@llnl.gov</a>>, "<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>" <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>><br>
<b>Subject: </b>Re: [petsc-users] High-dimensional DMDA<u></u><u></u></span></p>
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<p class="MsoNormal" style="margin-left:0.5in">On Tue, Oct 17, 2017 at 2:32 PM, Barry Smith <<a href="mailto:bsmith@mcs.anl.gov" target="_blank">bsmith@mcs.anl.gov</a>> wrote:<u></u><u></u></p>
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No and it is highly unlikely to appear (the 3d code is already too complicated and we tried to write a dimension independent version but that failed)<br>
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But note that by using a dof argument > 1 one can handle some "4d" problems so long as one does no parallelize in the 4th dimension.<u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in">History: We did have a version for arbitrary dimension called ADDA written by a student of David Keyes, that exists<u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in">in the bowels of Git. We are unlikely to replicate it because regular grids in high dimension never seem like the right<u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in">thing to do.<u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in"> Thanks,<u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in"> Matt<u></u><u></u></p>
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<span class="gmail-m_8795958808222375419hoenzb"> Barry</span></span><u></u><u></u></p>
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> On Oct 17, 2017, at 1:15 PM, Hittinger, Jeffrey A. F. <<a href="mailto:hittinger1@llnl.gov" target="_blank">hittinger1@llnl.gov</a>> wrote:<br>
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> Quick question: is there a version of the DMDA structured grid interface that supports dimensions higher than 3?<br>
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> j-<br>
> -.-- -.-- --..<br>
> Jeffrey A. F. Hittinger<br>
> Center for Applied Scientific Computing<br>
> Lawrence Livermore National Laboratory<br>
> Office: <a href="tel:%28925%29%20422-0993" target="_blank">(925) 422-0993</a><br>
> FAX: <a href="tel:%28925%29%20423-2993" target="_blank">(925) 423-2993</a><u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in">-- <u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in">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<u></u><u></u></p>
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<p class="MsoNormal" style="margin-left:0.5in"><a href="http://www.caam.rice.edu/~mk51/" target="_blank">https://www.cse.buffalo.edu/~<wbr>knepley/</a><u></u><u></u></p>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div>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</div><div><br></div><div><a href="http://www.caam.rice.edu/~mk51/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br></div></div></div></div></div>
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