stats.py 文件源码

def r2p(r,n):
    """
Given a value of the Pearson r coefficient, this method gives the
corresponding p-value of the null hypothesis (i.e. no correlation).

Code copied from scipy.stats.pearsonr source.

Usage:

>>> p=r2p(r,n)

where 'r' is the Pearson coefficient and n is the number of data
points.

:returns: p-value of the null hypothesis.
    """
    df = n-2
    if abs(r) == 1.0:
        prob = 0.0
    else:
        t_squared = r*r * (df / ((1.0 - r) * (1.0 + r)))
        prob = scipy.stats.betai(0.5*df, 0.5, df / (df + t_squared))

    return prob