<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">8. 11. 2017 v 15:59, Matthew Knepley <<a href="mailto:knepley@gmail.com" class="">knepley@gmail.com</a>>:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class="gmail_extra"><div class="gmail_quote">On Wed, Nov 8, 2017 at 9:14 AM, Vaclav Hapla <span dir="ltr" class=""><<a href="mailto:vaclav.hapla@erdw.ethz.ch" target="_blank" class="">vaclav.hapla@erdw.ethz.ch</a>></span> wrote:<br class=""><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" class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">8. 11. 2017 v 14:52, Jed Brown <<a href="mailto:jed@jedbrown.org" target="_blank" class="">jed@jedbrown.org</a>>:</div><div class=""><div class="gmail-h5"><br class="gmail-m_-5276602905406493153Apple-interchange-newline"><div class=""><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" class="">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" class="">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" class="">> 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" class=""><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" class=""><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" class="">On Wed, Nov 8, 2017 at 4:52 AM, Vaclav Hapla <<a href="mailto:vaclav.hapla@erdw.ethz.ch" target="_blank" class="">vaclav.hapla@erdw.ethz.ch</a>><br class="">wrote:<br class=""><br class=""><blockquote type="cite" class=""><br class=""><blockquote type="cite" class="">8. 11. 2017 v 9:06, Lisandro Dalcin <<a href="mailto:dalcinl@gmail.com" target="_blank" class="">dalcinl@gmail.com</a>>:<br class=""><br class="">On 8 November 2017 at 05:51, Smith, Barry F. <<a href="mailto:bsmith@mcs.anl.gov" target="_blank" class="">bsmith@mcs.anl.gov</a>> wrote:<br class=""><blockquote type="cite" class=""><br class=""><blockquote type="cite" class="">On Nov 7, 2017, at 1:33 AM, Lisandro Dalcin <<a href="mailto:dalcinl@gmail.com" target="_blank" class="">dalcinl@gmail.com</a>> wrote:<br class=""><br class="">The only concern I have about PetscPartitioner is that the API depends<br class="">on DM (PetscPartitionerPartition_<<wbr class="">TYPE> routines). Maybe<br class="">PetscPartitioner should eventually move to became more agnostic, and<br class="">that way it can be used to partition matrices and meshes.<br class=""></blockquote><br class=""> This is certainly a serious flaw if PetscPartitioner is intended as<br class=""></blockquote></blockquote>THE API to use for partitioning. If it is not intended as THE API for<br class="">partitioning then that is also a problem, because why have multiple APIs<br class="">for what is essentially one set of abstractions.<br class=""><blockquote type="cite" class=""><blockquote type="cite" class=""><br class=""></blockquote><br class="">Note however that things looks easy to refactor. I'll try to team up<br class="">with Matt to improve things.<br class=""></blockquote><br class="">Wait, now we are at the beginning again. I actually wanted to do some<br class="">refactoring of PetscPartitioner, starting with few cosmetic changes to make<br class="">it better settable from options. But Barry kept me back of any edits since<br class="">he think it's anti-systematic to keep two independent classes doing<br class="">essentially the same. And I agree with that to be honest. It's strange to<br class="">have two ParMetis, two Scotch and two whatever interfaces. The only thing I<br class="">don't like on MatPartitioning is its name as it's not just for Mat<br class="">Partitioning :-)<br class=""><br class="">There are from my point of view multiple issues with PetscPartitioner.<br class="">Let's look e.g. at PetscPartitionerPartition. It takes as arguments both<br class="">PetscPartitioner and DM. This DM must be in fact DMPlex which is not<br class="">checked so it will probably crash somewhere deep in the stack once the<br class="">first DMPlex specific line is reached. Then there are two output arguments<br class="">PetscSection partSection and IS *partition. The first must be created<br class="">beforehand while the second is created inside. And I guess they must keep<br class="">the same basic information just in two different forms.<br class=""><br class=""></blockquote><br class="">This is wrong.<br class=""></blockquote></div></div></div></blockquote><div class=""><br class=""></div><div class="">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 class="">design is actually not good :-)</div></div></div></blockquote><div class=""><br class=""></div><div class="">I meant "<span style="color:rgb(80,0,80)" class="">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 class="">each partition, and the IS stores the actual points being sent.</div></div></div></div></div></blockquote><div><br class=""></div><div>OK, now I see. And do you think the Section could be somehow computed from just the IS?</div><div><br class=""></div><div>Thanks</div><div><br class=""></div><div>Vaclav</div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="gmail_extra"><div class="gmail_quote"><div class=""><br class=""></div><div class=""> Matt</div><div class=""> </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" class=""><div class=""><span class="gmail-HOEnZb"><font color="#888888" class=""><div class="">Vaclav</div></font></span><span class="gmail-"><div class=""><br class=""></div><blockquote type="cite" class=""><div class=""><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" class=""><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" class="">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" class=""><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" class="">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" class=""><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" class="">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" class=""><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" class="">solution is not okay.</span></div></blockquote></span></div><br class=""></div></blockquote></div><br class=""><br clear="all" class=""><div class=""><br class=""></div>-- <br class=""><div class="gmail_signature"><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class="">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br class="">-- Norbert Wiener</div><div class=""><br class=""></div><div class=""><a href="http://www.caam.rice.edu/~mk51/" target="_blank" class="">https://www.cse.buffalo.edu/~knepley/</a><br class=""></div></div></div></div></div>
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