[Trilinos-Users] ML - mlguide example
Burkhard Doliwa
doliwa@temf.tu-darmstadt.de
Tue, 14 Sep 2004 21:13:00 +0200
Dear users,
I have built the ML package as a stand-alone tool and am now trying to
learn more about its capabilitites. Since good documentation of ML had
encouraged me, I tried out the mlguide.c example from the tutorial
(unfortunately I am no AMG expert). Well, the convergence rate was
impressive so I used - instead of 129 unknowns - 1000000. No
convergence. I then adjusted mlguide.c so that more than two levels were
initialized. Also I used the Krylov-CG solver instead of the Jacobi
smoother which also did not cause converge at large number of unknowns.
So my question to the experts would be whether it is possible by simple
means to make mlguide.c work at N=1000000 or larger (the overall
RELATIVE residuum should be smaller than 1e-8 or so). Other examples
using the AZTEC package (e.g., ml_exampled2s.c) work quite well, however
are too complex for a newbie.
Cheers,
Burkhard