On Fri, May 28, 2010 at 1:02 PM, Yujie <recrusader at gmail.com> wrote:
> Dear PETSc Developers, > > I got the following information from VecScatterCreate() manpage. > " > PetscErrorCode VecScatterCreate(Vec xin,IS ix,Vec yin,IS iy,VecScatter > *newctx) > > Collective on Vec > > Input Parameters > xin - a vector that defines the shape (parallel data layout of > the > vector) of vectors from which we scatter > yin - a vector that defines the shape (parallel data layout of > the > vector) of vectors to which we scatter > ix - the indices of xin to scatter (if PETSC_NULL scatters all > values) > iy - the indices of yin to hold results (if PETSC_NULL fills > entire > vector yin) > " > My question is about "ix". If xin and yin are parallel Vec, how about ix? > > Is "ix" an IS only containing local index set or a parallel IS > containing all the index set on all the processors (each local index > set on its processor)? Thanks a lot. > ix contains some indices for that process. The indices can be different on each process. We take the union. Matt > Regards, > Yujie > -- 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20100528/aecc7fac/attachment.htm>
