Sure, go for it!
On 3/2/07, Robert Bradshaw <[EMAIL PROTECTED]> wrote:
>
> It's always bugged me that the default distribution for integers (and
> rationals) is just a uniform distribution over some small range. What
> if instead we chose the distribution ZZ.random_element() = floor(1/r)
> where r is uniformly distributed in (-1,1). Then P(n) = 1 / (2 |n| (|
> n| + 1)) for all n in Z-{0}. This gives mostly small numbers with the
> occasional large ones thrown in at ever decreasing probabilities.
>
> A random rational could then be the ratio of two such integers.
>
> - Robert
>
>
> On Mar 2, 2007, at 9:57 AM, William Stein wrote:
>
> > On 3/1/07, didier deshommes <[EMAIL PROTECTED]> wrote:
> >> On 2/25/07, Craig Citro <[EMAIL PROTECTED]> wrote:
> >>> Hey all,
> >>>
> >>> So I tried to generate a random polynomial today, and ran into
> >>> some trouble.
> >>> Here's what I did:
> >>>
> >>> sage: R.<x> = ZZ['x']
> >>> sage: R.random_element(3)
> >>> <sage crashes>
> >>
> >> That is a nice edge case. I would say that or you just return 0
> >> everytime. Other rings seem to do that:
> >> {{{
> >> sage: RR.random_element(0)
> >> 0.000000000000000
> >> sage: QQ.random_element(0)
> >> 0
> >> sage: RDF.random_element(0)
> >> 0.143951483848
> >> }}}
> >
> >>> I traced back the problem, and it's not clear what the right fix
> >>> is. So
> >>> R.random_element makes a list of the appropriate length and calls
> >>> ZZ.random_element(0) to fill it up. In the comments, it clearly
> >>> explains why
> >
> > I've fixed this for sage > 2.2. The patch is attached in case you're
> > interested.
> >
> > >
> > <3251.patch>
>
>
> >
>
--
William Stein
Associate Professor of Mathematics
University of Washington
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