F distribution on the 41C

[Namir]

Thanks Dieter. I also found the code for ibeta in Numerical Recipes. I like your compact function hGamma (for multiples of 0.5) because it works well the Beta function with arguments that are multiples of 0.5 which is well suited to calculate the F CDF function.

I found a lot of interesting function in Numerical Recipes (3rd ed) in the chapter that discusses the Beta, incomplete Gamma, and so on. I was surprised to experiment with the book's implementation of function Gammaln and see that exp(Gammaln(x)) gives good results for Gamma(x) even small values of x. Until now, I had the impression that Gammaln was good only for large values of x.

Namir