On Tue, May 7, 2019 at 11:38 AM GIRET Jean-Christophe via petsc-users < petsc-users@mcs.anl.gov> wrote:
> Dear PETSc users, > > > > I would like to use Petsc4Py for a project extension, which consists > mainly of: > > - Storing data and matrices on several rank/nodes which could > not fit on a single node. > > - Performing some linear algebra in a parallel fashion (solving > sparse linear system for instance) > > - Exchanging those data structures (parallel vectors) between > non-overlapping MPI communicators, created for instance by splitting > MPI_COMM_WORLD. > > > > While the two first items seems to be well addressed by PETSc, I am > wondering about the last one. > > > > Is it possible to access the data of a vector, defined on a communicator > from another, non-overlapping communicator? From what I have seen from the > documentation and the several threads on the user mailing-list, I would say > no. But maybe I am missing something? If not, is it possible to transfer a > vector defined on a given communicator on a communicator which is a subset > of the previous one? > If you are sending to a subset of processes then VecGetSubVec + Jed's tricks might work. https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Vec/VecGetSubVector.html > > > Best regards, > > Jean-Christophe > > > > >
