I thought this had been solved some time ago, and was implemented in pari. Or is that only for real roots of real polynomials?
John On 9/25/07, cwitty <[EMAIL PROTECTED]> wrote: > > On Sep 25, 8:02 am, Bill Hart <[EMAIL PROTECTED]> wrote: > > Well that answered my next question, which is whether this method > > could be used for Qbar. > > The biggest obstacle to handling Qbar directly is that I haven't found > a good way of isolating the roots of a complex polynomial (that is, > finding the roots with a GUARANTEED error bound) and then refining a > root to arbitrary precision. (The other annoying part is that SAGE > does not yet have complex interval arithmetic.) > > And the third obstacle is that at the moment, I only care about real > numbers; so I'm not very motivated to work on the extension to > Qbar. :-) (Although I'd be happy to answer questions, if anybody else > wanted to work on it!) > > > Carl, what language is your code in. I would be interested in taking a > > look. > > The part I wrote is just Python (although it makes heavy use of the > rest of SAGE); it's in .../sage/rings/algebraic_real.py . > > > Bill. > > Carl > > > > > -- John Cremona --~--~---------~--~----~------------~-------~--~----~ 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/ -~----------~----~----~----~------~----~------~--~---
