Comments on: How to calculate binomial probabilities http://www.johndcook.com/blog/2008/04/24/how-to-calculate-binomial-probabilities/ The blog of John D. Cook Fri, 19 Mar 2010 19:25:59 -0400 http://wordpress.org/?v=2.8.4 hourly 1 By: robin http://www.johndcook.com/blog/2008/04/24/how-to-calculate-binomial-probabilities/comment-page-1/#comment-7872 robin Wed, 15 Oct 2008 16:33:20 +0000 http://www.johndcook.com/blog/2008/04/24/how-to-calculate-binomial-probabilities/#comment-7872 Nice article. I have used the gammln trick before but it is nice to have it written out explicitly for the binomial. jimcp, I am not one to miss giving a sucker good jibe, but if you can find a set of programs that encompasses the full range of functionality I require (choose from parser X add to Parser Y and subtract the marketing lingo) to get my job done please enlighten me, otherwise you might want to study some numerical proofs. Nice article. I have used the gammln trick before but it is nice to have it written out explicitly for the binomial.

jimcp, I am not one to miss giving a sucker good jibe, but if you can find a set of programs that encompasses the full range of functionality I require (choose from parser X add to Parser Y and subtract the marketing lingo) to get my job done please enlighten me, otherwise you might want to study some numerical proofs.

]]> By: Jan http://www.johndcook.com/blog/2008/04/24/how-to-calculate-binomial-probabilities/comment-page-1/#comment-7769 Jan Tue, 14 Oct 2008 09:17:15 +0000 http://www.johndcook.com/blog/2008/04/24/how-to-calculate-binomial-probabilities/#comment-7769 John, thanks a lot for that suggestion! It helped me to fit multiplicity distributions in high-energy physics proton-proton collisions (n goes up to 250). Cheers, Jan John, thanks a lot for that suggestion! It helped me to fit multiplicity distributions in high-energy physics proton-proton collisions (n goes up to 250).
Cheers, Jan

]]> By: jimcp http://www.johndcook.com/blog/2008/04/24/how-to-calculate-binomial-probabilities/comment-page-1/#comment-245 jimcp Fri, 25 Apr 2008 09:05:23 +0000 http://www.johndcook.com/blog/2008/04/24/how-to-calculate-binomial-probabilities/#comment-245 Choose the tools first before doing the job. The job you describe asks for software designed to handle math. The tool I count on is Mathematica. Imho, the dream of a mathematician. ( SAGE is an open source alternative and even speaks to Mathematica ) Mathematica can be called from Java, I am sure, probably C++ as well, but of this I am not sure. Choose the tools first before doing the job. The job you describe asks for software designed to handle math. The tool I count on is Mathematica. Imho, the dream of a mathematician. ( SAGE is an open source alternative and even speaks to Mathematica ) Mathematica can be called from Java, I am sure, probably C++ as well, but of this I am not sure.

]]> By: Thomas Guest http://www.johndcook.com/blog/2008/04/24/how-to-calculate-binomial-probabilities/comment-page-1/#comment-244 Thomas Guest Fri, 25 Apr 2008 07:46:15 +0000 http://www.johndcook.com/blog/2008/04/24/how-to-calculate-binomial-probabilities/#comment-244 Another interesting article John, especially the warning about gamma. I tried "man gamma" on a Redhat linux close to hand to get the details. HISTORY 4.2BSD had a gamma() that computed ln(|Gamma(|x|)|), leaving the sign of Gamma(|x|) in the external integer signgam. In 4.3BSD the name was changed to lgamma(), and the man page promises "At some time in the future the name gamma will be rehabilitated and used for the Gamma function" This did indeed happen in 4.4BSD, where gamma() computes the Gamma func- tion (with no effect on signgam). However, this came too late, and we now have tgamma(), the "true gamma" function. CONFORMING TO 4.2BSD. Compatible with previous mistakes. Another interesting article John, especially the warning about gamma. I tried “man gamma” on a Redhat linux close to hand to get the details.

HISTORY
4.2BSD had a gamma() that computed ln(|Gamma(|x|)|), leaving the sign of
Gamma(|x|) in the external integer signgam. In 4.3BSD the name was
changed to lgamma(), and the man page promises

“At some time in the future the name gamma will be rehabilitated and
used for the Gamma function”

This did indeed happen in 4.4BSD, where gamma() computes the Gamma func-
tion (with no effect on signgam). However, this came too late, and we now
have tgamma(), the “true gamma” function.

CONFORMING TO
4.2BSD. Compatible with previous mistakes.

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