two questions on GMP & C float

[Sylvain Pion]

Marc Glisse a écrit :
> On Sat, 16 May 2009, Sylvain Pion wrote:
> 
>>> That is quite a different issue though. These 0s are useful.
>>
>> I think it's the only issue here.  Maybe I was just reading between the
>> lines of the OP's mail, because I know the issue.
> 
> I read his question as asking whether .5 would give the mpq 1/2 or 
> possibly 2^52/2^53, but I may have misunderstood.

OK.

> Not quite related: a function to find the smallest fraction in some 
> float interval could be useful, but I am not sure where it would fit 
> best (gmp tries to handle float and double as little as possible, mpfi 
> is more about conversions that widen an interval, etc).

(I guess you mean a fraction with the smallest denominator?)

Would it be possible that this "smallest" fraction is always representable
by a quotient of floats?  In which case you would only need floats
in the interface.

-- 
Sylvain Pion
INRIA Sophia-Antipolis
Geometrica Project-Team
CGAL, http://cgal.org/