nltk.choose()¶

nltk.choose(n, k)[source]¶

This function is a fast way to calculate binomial coefficients, commonly known as nCk, i.e. the number of combinations of n things taken k at a time. (https://en.wikipedia.org/wiki/Binomial_coefficient).

This is the scipy.special.comb() with long integer computation but this approximation is faster, see https://github.com/nltk/nltk/issues/1181

>>> choose(4, 2)
6
>>> choose(6, 2)
15

Parameters:	n (int) – The number of things. r (int) – The number of times a thing is taken.