[R] Ratio of huge products
R. Michael Weylandt
michael.weylandt at gmail.com
Thu Dec 15 19:57:34 CET 2011
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,
> R-help at r-project.org mailing list
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
More information about the R-help