On Thu, Jul 14, 2016 at 6:27 PM, Mark Adams <[email protected]> wrote: > >> >> Notice that there are 7 orders of magnitude between the apparent residual >> (using the preconditioner), and the actual residual, Ax - b. >> You are using Hypre, and this generally means the Hypre coarse grid >> operator is crap. Please >> >> > Huh?, this data looks fine, both the true and preconditioned residual stay > separated by about 9 orders of magnitude. This just tells you that the norm > of A (or is it A^-1) is 10^9. Am I misunderstanding this? >
This is why Barry and I asked for a comparsion with MUMPS. If you are right, and its just the condition number, the LU will not be any more accurate. Matt -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
