[petsc-users] Equivalent of VecScatter for index sets

[Rémi Lacroix]

Hello,

I would like to permute an index set with another index set, just like 
you can do for vectors using VecScatter.

I have two index sets IS1 and IS2 which share the same size but have 
different parallel layouts. I often need to permute vectors/matrices 
using those two index sets (as in first permute with IS1 then permute 
the result with IS2). Since I don't use the intermediate result, I would 
like to permute IS1 with IS2 to get a new index set so that I can 
permute directly my vectors/matrices with it. Is that possible using Petsc?

I'm not sure I am clear so feel free to ask for clarifications if need be.

Best regards,

-- 
Rémi Lacroix
Équipe ALPINES
Inria Paris-Rocquencourt / Laboratoire Jacques Louis Lions, UPMC