> > Thanks, that was fast! If I may ask, what was the problem? Must've > > been something not particularly exciting... > > Robert Miller implemented root finding for RDF polynomials right > before SAGE-2.8.3, and he messed up. Basically SAGE represents > polynomials as list with one "endian-ness", and numpy uses > the other. So I just reverse the list before passing it into numpy.
Actually, I just moved already-broken code: http://www.sagemath.org/hg/sage-main/diff/7085de591817/sage/rings/polynomial/polynomial_element.pyx (at the bottom...). What I implemented was factoring of RDF polynomials. > > Double precision is more than sufficient for my purposes--even floats > > (!) are fine, I just need fast and reasonably accurate. Using numpy, reasonably accurate means up to only a few places, not the full double precision. This leads to badness when you try to factor anything. If it finds that 1.0000112451357 is a root of (x-1)^3, you will likely get a quadratic irreducible as a factor... > What polynomials are you evaluating? If they are double precision, > I wonder if making a special GSL-based polynomial class will help > a lot? The root finding is much much more accurate, and no doubt faster too. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
