Jed Thanks i will pursue it through MATELEMENTAL.
Ross > On 12 Dec 2013, at 18:21, Jed Brown <[email protected]> wrote: > > Ross Brodie <[email protected]> writes: > >> I have considered using libElemental for the dense part (to make use >> of the grid cyclic layout) and PETSc for the sparse part of the PCG >> matvec product but I am not sure it is wise to mix packages. > > The PETSc interface to Elemental can do this. In principle, you don't > have to deal with the cyclic ordering, but you should assemble the rows > and columns returned by MatGetOwnershipIS(). > >> On a different note could you clarify the terminology for the >> sequential vector VECSEQ. Does it mean: (i) It is an independent >> uniprocessor object such that the data storage is not distributed and >> if you change an element on one process the change is NOT reflected on >> other processes, > > Yes, and only makes sense on a communicator of size 1 (effectively > PETSC_COMM_SELF).
