On Fri, Dec 23, 2011 at 12:52, Dominik Szczerba <dominik at itis.ethz.ch>wrote:
> I am scaling my systems when dealing with small (microscopic) scales > in SI dimensions. > The best choice is to choose suitable units so that the system is intrinsically well-scaled. > This is because otherwise I have very small (near > epsilon) entries in the matrix and the solution fails or takes > significantly longer to converge. I used to do it by hand so far, if > there is a way to do it in Petsc - especially automatically detecting > the optimal scale - I am all ears. > You are best off doing it by hand, it is better to avoid -ksp_diagonal_scale when it's reasonable to do so. If you have trouble determining a reasonable scale at assembly time, it might make sense to use. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20111223/5f420f7a/attachment.htm>
