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:
s = (b1+b2)//2
or
s = ZZ((b1+b2)/2)
> 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.
William
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5891.patch
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