On Thu, Dec 4, 2008 at 10:51 PM, Jan Groenewald <[EMAIL PROTECTED]> wrote: > > Hi, > > On Thu, Dec 04, 2008 at 02:47:22AM -0800, Mike Hansen wrote: >> I don't have a whole lot of time, but I put some improvements up at >> http://sagenb.org:8000/home/pub/94/ and included some timings there. >> h6.eigenvalues() took 0.11 seconds to run on my machine. It looks >> like everything you're doing can be done with exact arithmetic so that >> you don't have to use CDF. Most of the matrices are over QQ, and the >> ones that are complex are over QQ[sqrt(-1)]. > > Thanks, this is great. This way the h6.eigenvalues took less than 1 second, > and h6.eigenvectors_right took 18 seconds. > > I don't understand why complex floats are so much slower than rationals: > 18 seconds versus 4+ hours (unfinished)! In the end the eigenvalues are > real (floats).
A lot of Sage developers (like me) care about trying to make Sage the fastest program in the world for lots linear algebra over QQ, since it is very important to our research. The same isn't try for arbitrary precision floating point complex numbers, at present. William > > regards, > Jan > > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
