
When I try the following:
var binomial = new Binomial(0.0638, 3779);
binomial.CumulativeDistribution(250);
It will return Infinity
But when I try it in excel with =BINOM.DIST(250, 3779; 0.0638, TRUE) I will get 0.736156366002849
I've tried to write my own implementation, but I get the same result.
Only library I've found where this will work is
Extreme Optimization



Indeed, the current binomial CDF implementation could be better. In the meantime you can get the same result by using the special functions directly:
SpecialFunctions.BetaRegularized(3779250,250+1,1.00.0638) > 0.736156366003278



Update: fixed in mainline master, so using the binomial distribution as above should work properly in the next release.
Thanks,
Christoph

