On Monday, August 27, 2007, at 06:37PM, "William Stein" <[EMAIL PROTECTED]> wrote: >On 8/27/07, Justin Walker <[EMAIL PROTECTED]> wrote: >> Hi, all, >> >> I do this, and get integers, but the types are rational: >> >> sage: b1=0 >> sage: b2=2 >> sage: s=(b1+b2)/2 >> sage: n=(b1-b2)/2 >> sage: s >> 1 >> sage: n >> -1 > >That s and n are rational is correct, since "/ is a constructor >for elements of the fraction field". If you want integers >you might do a floor div or explicit coercion:
This I get; I was just setting up for the problem below (I phrased my comment badly, perhaps). >> Then I do this: >> >> sage: xgcd(s,n) >> --------------------------------------------------------------------------- >> <type 'exceptions.AttributeError'> Traceback (most recent call last) >> >> /SandBox/Justin/sb/Sage/Code/<ipython console> in <module>() >> >> /SandBox/Justin/sb/sage-2.8/local/lib/python2.5/site-packages/sage/rings/arith.py >> in xgcd(a, b) >> 1122 if not isinstance(a, RingElement): >> 1123 a = integer_ring.ZZ(a) >> -> 1124 return a.xgcd(b) >> 1125 >> 1126 XGCD = xgcd >> >> <type 'exceptions.AttributeError'>: 'sage.rings.rational.Rational' object >> has no attribute 'xgcd' >> >> Is this expected? It seems, somehow, wrong :-} > >It's a bug. The fix is in the attached patch. Thanks for the quick turnaround! I'll try it out soon. Justin -- Justin C. Walker Director, Institute for the Enhancement of the Director's Income --- --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://sage.math.washington.edu/sage/ and http://sage.scipy.org/sage/ -~----------~----~----~----~------~----~------~--~---
