On Jan 19, 1:43 pm, slabbe <sla...@gmail.com> wrote: > PROBLEM : > In a list of vectors, I want to know if there is a pair of equal > vectors. > > I have two solutions. The first to create an empty list L and append > the vectors one per one. If a vector is already in L before adding it, > then I found a pair of equal vectors. But looking if a vector belongs > to a list is apparently very slow on my computer :
The problem is that you're working in the symbolic ring, which is very slow. Do you need to? For instance, this particular example can be handled much more quickly in QQbar, the field of algebraic numbers: sage: v = vector((1, QQbar(0))) sage: w = vector((1, QQbar(sqrt(2)))) sage: time w in [v,v,v,v] CPU times: user 0.00 s, sys: 0.00 s, total: 0.00 s Wall time: 0.01 s False Carl Witty --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
