Computes the (normalized) probability mass function, the cumulative distribution function and mid-p percentiles of a beta-binomial distribution in a numerically stable way (log space).
bb_distribution(a, b, n)A list with elements x (support 0:n), Px (pmf), cum (cdf) and perc (mid-p percentiles, i.e. P(X < x) + 0.5 * P(X = x)).
Alpha parameter (> 0).
Beta parameter (> 0).
Number of trials / maximum score.