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<div class="moz-cite-prefix">On 2021-07-14 6:42 p.m., Matthew
Knepley wrote:<br>
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cite="mid:CAMYG4GkfZyvrc+jNOhLbqqG=qyb6v7ViY2_4mOyaqT_=U2FTpg@mail.gmail.com">
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<div>Ah, there was a confusion of intent. GlobalToNatural() is
for people that want data transformed back into the original</div>
<div>order. I thought that was what you wanted. If you just
want mesh points in the original order, we give you the</div>
<div>transformation as part of the output of
DMPlexDistribute(). The migrationSF that is output maps the
original point to</div>
<div>the distributed point. You run it backwards to get the
original ordering.</div>
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<div> Thanks,</div>
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<div> Matt </div>
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<p>Hi,</p>
<p>that seems to work better! However, if I understand well the
migrationSF is giving information on the originating process where
the elements have been migrated from.</p>
<p>Is there a PETSc way to either:</p>
<p>1) send back the information to the originating process (somewhat
"inverting" the migrationSF) ? So I can retrieve the
"partitioning array" (just like the "part" parameter in
ParMETIS_V3_PartMeshKway) on the sender process.<br>
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<p>or<br>
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<p>2) Have the pre-migrationSF: I mean I would like to extract the
"where are the elements going to be sent?" (again like "part"
parameter)</p>
<p>If not, I can always build the communication myself...<br>
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<p>Thanks,</p>
<p>Eric</p>
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