On Wed, Jul 14, 2021 at 1:18 PM Eric Chamberland <Eric.Chamberland@giref.ulaval.ca> wrote:
Hi,

I want to use DMPlexDistribute from PETSc for computing overlapping and
play with the different partitioners supported.

However, after calling DMPlexDistribute, I noticed the elements are
renumbered and then the original number is lost.

What would be the best way to keep track of the element renumbering?

a) Adding an optional parameter to let the user retrieve a vector or
"IS" giving the old number?

b) Adding a DMLabel (seems a wrong good solution)

c) Other idea?

Of course, I don't want to loose performances with the need of this
"mapping"...

You need to call

  https://petsc.org/release/docs/manualpages/DM/DMSetUseNatural.html

before call DMPlexDistribute(). Then you can call

  https://petsc.org/release/docs/manualpages/DMPLEX/DMPlexGlobalToNaturalBegin.html

to map back to the original numbering if you want. This is the same thing that DMDA is doing.

  Thanks,

     Matt
 
Thanks,

Eric

--
Eric Chamberland, ing., M. Ing
Professionnel de recherche
GIREF/Université Laval
(418) 656-2131 poste 41 22 42



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What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
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