#16769: Conversion RR -> QQ wrong for exact integers
------------------------------------+------------------------
Reporter: jdemeyer | Owner:
Type: defect | Status: new
Priority: major | Milestone: sage-6.3
Component: basic arithmetic | Resolution:
Keywords: | Merged in:
Authors: | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
Dependencies: | Stopgaps:
------------------------------------+------------------------
Description changed by jdemeyer:
Old description:
> This real number can be exactly represented by the integer (and also
> rational) `2^54`, so this is off by one:
> {{{
> sage: QQ(RR(2^54))
> 18014398509481983
> }}}
>
> The underlying function called by `QQ()` is `simplest_rational`:
> {{{
> sage: RR(2^54).simplest_rational()
> 18014398509481983
> }}}
New description:
This real number can be exactly represented by the integer (and also
rational) `2^54`, so this is off by one:
{{{
sage: QQ(RR(2^54))
18014398509481983
}}}
The underlying function called by `QQ()` is `simplest_rational`:
{{{
sage: RR(2^54).simplest_rational()
18014398509481983
}}}
It must be said that this result agrees with the definition of "simplest
rational", so perhaps the definition is wrong.
--
--
Ticket URL: <http://trac.sagemath.org/ticket/16769#comment:1>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
