<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">The main reason to have this natural ordering is to read and write data, possibly with different numbers of procs.<div><br><div><div apple-content-edited="true">ALB</div><div apple-content-edited="true"><br></div><div><div>On Feb 17, 2014, at 6:21 PM, Jed Brown <<a href="mailto:jed@jedbrown.org">jed@jedbrown.org</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">Matthew Knepley <<a href="mailto:knepley@gmail.com">knepley@gmail.com</a>> writes:<br><br><blockquote type="cite">On Mon, Feb 17, 2014 at 5:14 PM, Jed Brown <<a href="mailto:jed@jedbrown.org">jed@jedbrown.org</a>> wrote:<br><br><blockquote type="cite">Andrés Alessandro León Baldelli <<a href="mailto:a.leon.baldelli@gmail.com">a.leon.baldelli@gmail.com</a>> writes:<br><br><blockquote type="cite">Hi all,<br>I am working with Blaise Bourdin on implementing a concept of "natural<br></blockquote>numbering" for unstructured meshes using DMplex.<br><blockquote type="cite">Such natural numbering can be, e.g., that of the mesh prior to parallel<br></blockquote>distribution.<br><blockquote type="cite">I have a working example in which I compute a field on the distributed<br></blockquote>DM and I scatter it back to the serial DM on rank0 but I would like to<br>create a more general interface. To this regard I ask your advice:<br><blockquote type="cite">1) Is it reasonable to add an SF within the DM typedef for this "natural<br></blockquote>to global" scatter?<br><br>Surely you don't want the (necessarily non-scalable) serial DM to be a<br>necessary part of this interface? What do you want to do with this<br>natural numbering? Just write output files?<br><br></blockquote><br>Jed, No, no, no. This is not an SF for a serial DM.<br></blockquote><br>I was responding to the question above. Yes, we need a genuine parallel<br>reader (naive partition) and a way to write back in that ordering. But<br>my question remains: do you want to do something other than IO with that<br>"natural" ordering?<br><br>Note that in the natural ordering, you likely have elements for which<br>you own zero of the vertices, and vice-versa, so it would be _really_<br>bad to compute on it.</div></blockquote></div><br></div></div></body></html>