On Sat, Aug 23, 2008 at 1:00 PM, Fredrik Johansson <[EMAIL PROTECTED]> wrote: > > On Sat, Aug 23, 2008 at 9:57 PM, Nils Bruin <[EMAIL PROTECTED]> wrote: >> >> Would it break Python too much if comparison would simply throw an >> exception in these cases? > > Hardly, considering that this is what Python itself does: > >>>> 1+1j > 1-1j > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > TypeError: no ordering relation is defined for complex numbers > > Fredrik
Note by the way that this has consequences: >>> v = [1+1j , 1-1j] sage: v.sort() --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /Users/was/<ipython console> in <module>() TypeError: no ordering relation is defined for complex numbers However, these aren't too hard to deal with: >>> v.sort( lambda x,y: cmp(str(x),str(y)) ) >>> v [(1+1j), (1-1j)] So, for places in our code -- e.g., roots of polynomials -- where we want the result "sorted" for consistency of output, we could just have a bunch of "pseudo comparison" functions. William --~--~---------~--~----~------------~-------~--~----~ 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://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
