On Mon, Jan 13, 2014 at 2:27 PM, Rémi Lacroix <[email protected]> wrote:
> Le 13/01/2014 19:00, Matthew Knepley a écrit : > > On Mon, Jan 13, 2014 at 9:47 AM, Rémi Lacroix <[email protected]>wrote: > >> 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? >> > > We do not have this particular composition in our interface. However, > you could accomplish this using PetscSF. > > Thanks, > > Matt > > > Thanks for the quick answer. > > So basically I need to have a look at the underlying mechanism of > VecScatter and implement something similar for IS. How complex would it be > in practice? > Using the PetscSF interface instead of VecScatter should not be too hard. Matt > > Rémi > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
