Hi Matthew,

we did it with PetscSFCreateInverseSF !

It is working well without overlap, so we can go forward with this and compute the overlap afterward with DMPlexDistributeOverlap.

Thanks,

Eric

On 2021-07-20 10:39 p.m., Eric Chamberland wrote:

On 2021-07-14 6:42 p.m., Matthew Knepley wrote:

Ah, there was a confusion of intent. GlobalToNatural() is for people that want data transformed back into the original

order. I thought that was what you wanted. If you just want mesh points in the original order, we give you the

transformation as part of the output of DMPlexDistribute(). The migrationSF that is output maps the original point to

the distributed point. You run it backwards to get the original ordering.

  Thanks,

     Matt 

Hi,

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.

Is there a PETSc way to either:

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.

or

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)

If not, I can always build the communication myself...

Thanks,

Eric

-- 
Eric Chamberland, ing., M. Ing
Professionnel de recherche
GIREF/Université Laval
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