Hi all, >> What about returning this value as the DISCRETE_L_INF norm instead? In >> particular since the FEMNormType enum offers this norm anyway. > > I think this might be confusing ... the DISCRETE_ versions are meant > to be for R^n vectors, and in this case of course you can get the > "exact" L_INF. I'd prefer adding a new enum called APPROXIMATE_L_INF > (or something similar). The user would know immediately that he was > getting an approximation to the true L-infty norm, and in the > documentation we could mention (as Derek said) that one can improve > the approximation by increasing the number of quadrature points.
But the L2, H1 etc errors in ExactSolution are computed using quadrature rules, so they are just approximations as well. As a result, it seems to me that the L_INF norm based on sampling at quadrature points is the natural counterpart for the Sobolev norms currently available in ExactSolution. Also, regarding the superconvergence issue, if we have superconvergence in the L_INF norm at the quadrature points, and we use that quadrature rule to compute the L2 error, then won't we just get the same superconvergence in the quadrature-based L2 error as well? - Dave ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
