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On Mon, May 13, 2024 at 10: 04 PM Adrian Croucher <a. croucher@ auckland. ac. nz> wrote: On 14/05/24 1: 44 pm, Matthew Knepley wrote: I wish GMsh was clearer about what is optional: https: //gmsh. info/doc/texinfo/gmsh. html#MSH-file-format They
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<div dir="ltr"><div dir="ltr">On Mon, May 13, 2024 at 10:04 PM Adrian Croucher <<a href="mailto:a.croucher@auckland.ac.nz" target="_blank">a.croucher@auckland.ac.nz</a>> wrote:<br></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><u></u>
<div>
<p>On 14/05/24 1:44 pm, Matthew Knepley wrote:</p>
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_quote">I wish GMsh was clearer about what is
optional: <a href="https://urldefense.us/v3/__https://gmsh.info/doc/texinfo/gmsh.html*MSH-file-format__;Iw!!G_uCfscf7eWS!YJN5how37EbmfjwDvfPAsVSCQdWejJn8symxZ83hj94omk6Mh9imh2qOrFqZbsZRM_3W3G5YIn5lZK2KzQlj$" target="_blank">https://gmsh.info/doc/texinfo/gmsh.html#MSH-file-format</a>
<div>They do talk about it, but not exhaustively. GMsh always
writes and $Entities block from what I can tell.</div>
<div>I can make it optional, it just might take until after
the PETSc Meeting.</div>
</div>
</div>
</blockquote>
<p>Looks like $Entities are optional:</p>
<p><a href="https://urldefense.us/v3/__https://gitlab.onelab.info/gmsh/gmsh/-/commit/b5feba2af57181ffa946d3f0c494b014603c6efa__;!!G_uCfscf7eWS!YJN5how37EbmfjwDvfPAsVSCQdWejJn8symxZ83hj94omk6Mh9imh2qOrFqZbsZRM_3W3G5YIn5lZMbTrLlQ$" target="_blank">https://gitlab.onelab.info/gmsh/gmsh/-/commit/b5feba2af57181ffa946d3f0c494b014603c6efa</a><br>
</p>
<p>I can also load a GMSH 4.1 file without $Entities into GMSH
itself and it doesn't complain, suggesting that they are indeed
optional.</p>
<p></p></div></blockquote><div>Yes, but they are not careful to specify when a file can be inconsistent. For instance, omitting the $Entities, but then specifying entity numbers in the $Nodes block. I think they also thought this was inconsistent, but then got user complaints. The minimal example they show does exactly this.</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div><p>If the $Entities aren't strictly needed for anything in DMPlex
(which I'm guessing they aren't, as the GMSH file format 2.2
doesn't even have them) then it would be useful not to require
them.</p></div></blockquote><div>I put in some code for this: <a href="https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/merge_requests/7546__;!!G_uCfscf7eWS!YJN5how37EbmfjwDvfPAsVSCQdWejJn8symxZ83hj94omk6Mh9imh2qOrFqZbsZRM_3W3G5YIn5lZHVFZ3e3$">https://gitlab.com/petsc/petsc/-/merge_requests/7546</a></div><div><br></div><div>It just ignores entity numbers when there is no section.</div><div><br></div><div> Thanks,</div><div><br></div><div> Matt</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div>
<p>- Adrian<br>
</p>
<pre cols="72">--
Dr Adrian Croucher
Senior Research Fellow
Department of Engineering Science
Waipapa Taumata Rau / University of Auckland, New Zealand
email: <a href="mailto:a.croucher@auckland.ac.nz" target="_blank">a.croucher@auckland.ac.nz</a>
tel: +64 (0)9 923 4611</pre>
</div>
</blockquote></div><br clear="all"><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><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="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!YJN5how37EbmfjwDvfPAsVSCQdWejJn8symxZ83hj94omk6Mh9imh2qOrFqZbsZRM_3W3G5YIn5lZFz1kNMU$" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br></div></div></div></div></div></div></div></div>