It turns out that the bug underlying this has already been fixed in ticket 5434 which has been merged in 3.4.rc1, so this problem will not arise once 3.4 has been released.
2009/3/7 John Cremona <john.crem...@gmail.com>: > It is now ticket number 5451: see > http://trac.sagemath.org/sage_trac/ticket/5451 > > John Cremona > > 2009/3/7 John Cremona <john.crem...@gmail.com>: >> I am hoping that someone who has worked on that code, such as Martin >> Albrecht, might reply as might know what is going on. It should not >> be too hard to fix. >> >> I could not find a relevant trac ticket so am opening one now. >> >> John Cremona >> >> 2009/3/7 Alex Lara <lrodr...@gmail.com>: >>> >>> Just as I thought. So there is nothing I can do but work with sage >>> 3.1.1, right? >>> >>> Those polynomials arised as coefficients of some polynomials in F_q(t) >>> [T] and inside a sum command: >>> >>> sum ( (do something with H_j(T)) for j in bla bla) >>> >>> The routine which gave the error was successfully used many times >>> before. >>> >>> Thanks John. >>> >>> ---Alex >>> >>> On 7 mar, 05:50, John Cremona <john.crem...@gmail.com> wrote: >>>> That is definitely a bug. Doing it step by step works: >>>> >>>> sage: fd=f.denominator(); gd=g.denominator() >>>> sage: fn=f.numerator(); gn=g.numerator() >>>> sage: fn*gd+fd*gn >>>> 2*t^18 + t^11 + t^10 + 2*t^2 >>>> sage: hn = fn*gd+fd*gn >>>> sage: hd = fd*gd >>>> sage: hn.gcd(hd) >>>> t^3 + 2*t^2 >>>> sage: hn/hd >>>> (2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 + 2*t^10 + 2*t^9 + t^7 + >>>> t^6 + t^5 + t^4 + t^3 + t^2 + t + 1)/(t^17 + t^9 + t) >>>> >>>> sage 3.4.alpha0 gives the same thing. >>>> >>>> John Cremona >>>> >>>> 2009/3/7 Alex Lara <lrodr...@gmail.com>: >>>> >>>> >>>> >>>> > Hi guys, >>>> >>>> > I recently upgrade sage from 3.2.3 to 3.3. I'm also have sage 3.1.1 >>>> > The thing is that the following commands give different results: >>>> >>>> > F.<theta>=FiniteField(9) >>>> > A.<t> = PolynomialRing(F) >>>> > K.<t> = FractionField(A) >>>> > f= 2/(t^2+2*t); g =t^9/(t^18 + t^10 + t^2);f+g >>>> >>>> > In 3.1.1 gives the right answer (I guess) but in 3.2.3 give an error: >>>> >>>> > ZeroDivisionError Traceback (most recent call >>>> > last) >>>> > ... >>>> > ZeroDivisionError: division by zero in finite field. >>>> >>>> > I don't know how those commands work in 3.2.3. >>>> >>>> > I had a problem with sage 3.2.3, but Craig Citro helped me. Sage 3.2.3 >>>> > couldn't open objects created in sage 3.1.1. This objects contain >>>> > polynomials p(T) in F_q(t)[T]. Perhaps these problems are related. >>>> >>>> > Any idea of how to fix that? >>>> >>>> >>> >>> >>> >> > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
