- scipy.special.bdtrik(y, n, p) = <ufunc 'bdtrik'>¶
Inverse function to bdtr with respect to k.
Finds the number of successes k such that the sum of the terms 0 through k of the Binomial probability density for n events with probability p is equal to the given cumulative probability y.
y : array_like
Cumulative probability (probability of k or fewer successes in n events).
n : array_like
Number of events (float).
p : array_like
Success probability (float).
k : ndarray
The number of successes k such that bdtr(k, n, p) = y.
Formula 26.5.24 of [R374] is used to reduce the binomial distribution to the cumulative incomplete beta distribution.
Computation of k involves a seach for a value that produces the desired value of y. The search relies on the monotinicity of y with k.
Wrapper for the CDFLIB [R375] Fortran routine cdfbin.
[R374] (1, 2) Milton Abramowitz and Irene A. Stegun, eds. Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables. New York: Dover, 1972. [R375] (1, 2) Barry Brown, James Lovato, and Kathy Russell, CDFLIB: Library of Fortran Routines for Cumulative Distribution Functions, Inverses, and Other Parameters.