On Sun, Dec 2, 2012 at 9:09 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
> >> block diagonal part of A11 actually means A11, correct? Otherwise what > blocks???? > Yeah, DIAG just meens to use the diagonal block (A11) directly, rather than to build some approximation to the Schur complement. > > > > Processor diagonal. This is not ASM where what we select is > > automatically process diagonal. > > I don't see this at all. It seems to me we actually use A11 to form the > preconditioner, of course if we use bjacobi as the preconditioner then it > becomes the diagonal blocks of A11, but if we use, for example LU then we > are using all of A11 in forming the preconditioner of S. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20121202/19edfd5a/attachment.html>
