Re: [petsc-users] question about VecScatter from one global vector to another

How big are the scatters? If they are not large, say 100,000 or less then just gather the send and receive indices to one process and pass them all on that process while all other processes pass 0 indices (it doesn't matter from what process the indices are list in the VecScatterCreate()).

Re: [petsc-users] question about VecScatter from one global vector to another

Yes, it makes perfect sense. The issue is that the global size of my ISs are the same, but it’s the local size that is different (because of different DMDAs) Is there an easy way to put both IS’s on the same parallel layout. ISCopy doesn’t work in that case. Randy > On Feb 19, 2016, at

Re: [petsc-users] question about VecScatter from one global vector to another

On Fri, Feb 19, 2016 at 6:33 PM, Randall Mackie wrote: > I am trying to do a VecScatter of a subset of elements from a global > vector on one DMDA to a global vector on a different DMDA (different sized > DMDAs). > > I thought what made sense was to create a parallel IS

[petsc-users] question about VecScatter from one global vector to another

I am trying to do a VecScatter of a subset of elements from a global vector on one DMDA to a global vector on a different DMDA (different sized DMDAs). I thought what made sense was to create a parallel IS using the local to global mapping obtained from the two DMDAs so that the local portion