<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Wed, Nov 8, 2017 at 9:14 AM, Vaclav Hapla <span dir="ltr"><<a href="mailto:vaclav.hapla@erdw.ethz.ch" target="_blank">vaclav.hapla@erdw.ethz.ch</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"><div style="word-wrap:break-word"><br><div><blockquote type="cite"><div>8. 11. 2017 v 14:52, Jed Brown <<a href="mailto:jed@jedbrown.org" target="_blank">jed@jedbrown.org</a>>:</div><div><div class="gmail-h5"><br class="gmail-m_-5276602905406493153Apple-interchange-newline"><div><span style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline">Matthew Knepley <</span><a href="mailto:knepley@gmail.com" style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank">knepley@gmail.com</a><span style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline">> writes:</span><br style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><br style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><blockquote type="cite" style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px">On Wed, Nov 8, 2017 at 4:52 AM, Vaclav Hapla <<a href="mailto:vaclav.hapla@erdw.ethz.ch" target="_blank">vaclav.hapla@erdw.ethz.ch</a>><br>wrote:<br><br><blockquote type="cite"><br><blockquote type="cite">8. 11. 2017 v 9:06, Lisandro Dalcin <<a href="mailto:dalcinl@gmail.com" target="_blank">dalcinl@gmail.com</a>>:<br><br>On 8 November 2017 at 05:51, Smith, Barry F. <<a href="mailto:bsmith@mcs.anl.gov" target="_blank">bsmith@mcs.anl.gov</a>> wrote:<br><blockquote type="cite"><br><blockquote type="cite">On Nov 7, 2017, at 1:33 AM, Lisandro Dalcin <<a href="mailto:dalcinl@gmail.com" target="_blank">dalcinl@gmail.com</a>> wrote:<br><br>The only concern I have about PetscPartitioner is that the API depends<br>on DM (PetscPartitionerPartition_<<wbr>TYPE> routines). Maybe<br>PetscPartitioner should eventually move to became more agnostic, and<br>that way it can be used to partition matrices and meshes.<br></blockquote><br> This is certainly a serious flaw if PetscPartitioner is intended as<br></blockquote></blockquote>THE API to use for partitioning. If it is not intended as THE API for<br>partitioning then that is also a problem, because why have multiple APIs<br>for what is essentially one set of abstractions.<br><blockquote type="cite"><blockquote type="cite"><br></blockquote><br>Note however that things looks easy to refactor. I'll try to team up<br>with Matt to improve things.<br></blockquote><br>Wait, now we are at the beginning again. I actually wanted to do some<br>refactoring of PetscPartitioner, starting with few cosmetic changes to make<br>it better settable from options. But Barry kept me back of any edits since<br>he think it's anti-systematic to keep two independent classes doing<br>essentially the same. And I agree with that to be honest. It's strange to<br>have two ParMetis, two Scotch and two whatever interfaces. The only thing I<br>don't like on MatPartitioning is its name as it's not just for Mat<br>Partitioning :-)<br><br>There are from my point of view multiple issues with PetscPartitioner.<br>Let's look e.g. at PetscPartitionerPartition. It takes as arguments both<br>PetscPartitioner and DM. This DM must be in fact DMPlex which is not<br>checked so it will probably crash somewhere deep in the stack once the<br>first DMPlex specific line is reached. Then there are two output arguments<br>PetscSection partSection and IS *partition. The first must be created<br>beforehand while the second is created inside. And I guess they must keep<br>the same basic information just in two different forms.<br><br></blockquote><br>This is wrong.<br></blockquote></div></div></div></blockquote><div><br></div><div>Matt, do you mean what I wrote above is not true (then I'm going to prove that it's true), or the opposite that the PetscPartitionerPartition <wbr>design is actually not good :-)</div></div></div></blockquote><div><br></div><div>I meant "<span style="color:rgb(80,0,80)">they must keep </span>the same basic information just in two different forms" is wrong (I had to leave for work). The Section gives offsets for</div><div>each partition, and the IS stores the actual points being sent.</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 style="word-wrap:break-word"><div><span class="gmail-HOEnZb"><font color="#888888"><div>Vaclav</div></font></span><span class="gmail-"><div><br></div><blockquote type="cite"><div><br style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><span style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline">Dude, this isn't how we interaction here. If there is a technical</span><br style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><span style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline">reason why what Vaclav, Lisandro, and Barry want to do cannot work, you</span><br style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><span style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline">should explain that. Just casting doubt without working toward a</span><br style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><span style="font-family:Menlo-Regular;font-size:11px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline">solution is not okay.</span></div></blockquote></span></div><br></div></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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