Barry, sorry if I'm coming off stubborn or something, but I think I'm not following your reasoning.
NO. > > If you are using LU to construct a preconditioner then you ARE providing > the Jacobian explicitly (as a sparse) matrix. Each time the preconditioner > is built this sparse matrix is factored. What do you mean by "providing the jacobian explicity (as a sparse) matrix"? I thought that there was no explicit jacobian matrix, but only a MATMFFD context. Rafael -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20090323/5ddb1f21/attachment.htm>
