On Thu, Dec 29, 2011 at 11:51, Dave Nystrom <Dave.Nystrom at tachyonlogic.com>wrote:
> Both although the most challenging problem right now is one for a Hall > matrix > system that is block banded with 2x2 blocks. > What is the null space of this operator. > Right now, I am just inputting > the matrix into a petsc seqaij matrix. I guess I need to put it into a > petsc > block matrix but have not yet attempted to do that. I'm not sure how much > work is involved - I need to read the section in the users manual on that. > > Anyway, I have 5 scalar systems and on vector system with 2x2 blocks. I am > interested in applying gamg to all of them to see how well it works. > PCGAMG currently takes coordinates for a nodal basis, from which it generates a null space (making assumptions about the equations). I have it on my list to update so that you can call MatSetNearNullSpace() and have PCGAMG use this null space. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20111229/f4f875a6/attachment.html>
