[R] Ratio of huge products

[R. Michael Weylandt]

Use logs?

Michael

On Thu, Dec 15, 2011 at 1:35 PM, Alberto Magni
<alberto.magni86 at gmail.com> wrote:
> Hello everybody,
>
> I have to compute something in this form:
>
> x = prod(a:b) / prod(c:d),    where: a < c and b < d and obviously: a
> < b and c < d
>
> I cannot make assumptions on the relative position of c,b and a,d.
>
> The problem is that a,b,c,d are large and the products are huge (R return Inf).
> Their ratio is less than 1 but significantly higher than 0: it is a
> non-tiny probability.
>
> I need to find a way to simplify this ratio.
> The only way to solve this that I see is to decompose into prime
> factors all the
> numbers in the numerator and the denominator and to remove the ones in common
>
> Do you know a better way to do this ?
>
> Thank you,
> Alberto
>
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