SciPy

scipy.stats.mstats.betai

scipy.stats.mstats.betai(a, b, x)[source]

Returns the incomplete beta function.

I_x(a,b) = 1/B(a,b)*(Integral(0,x) of t^(a-1)(1-t)^(b-1) dt)

where a,b>0 and B(a,b) = G(a)*G(b)/(G(a+b)) where G(a) is the gamma function of a.

The standard broadcasting rules apply to a, b, and x.

Parameters:

a : array_like or float > 0

b : array_like or float > 0

x : array_like or float

x will be clipped to be no greater than 1.0 .

Returns:

betai : ndarray

Incomplete beta function.