A note on exact calculation of the non central hypergeometric distribution

作者：Barrett Bruce^*

来源：Communications in Statistics - Theory and Methods, 2017, 46(13): 6737-6741.

DOI：10.1080/03610926.2015.1134573

• 2 x 2 tables
• conditional inference
• non central hypergeometric

Direct calculation of the non central hypergeometric (NH) distribution and its moments can present computational issues in both efficiency and accuracy. In response, several methods, both approximate and exact, for calculating the NH mean and variance have appeared in the literature. We add to this body ofwork, a straight-forward, exactmethod that is easily programed, efficient, and computationally stable. Specifically, by considering the logs of the values of the NH probability mass pmf) and then shifting the exponents so that, prior to normalization, the mode acquires a value of 1, concerns for overflow are eliminated.

• 出版日期2017