GofChisquarePower.power(effect_size, nobs, alpha, n_bins, ddof=0)[source]

Calculate the power of a chisquare test for one sample

Only two-sided alternative is implemented


effect_size : float

standardized effect size, according to Cohen’s definition. see statsmodels.stats.gof.chisquare_effectsize

nobs : int or float

sample size, number of observations.

alpha : float in interval (0,1)

significance level, e.g. 0.05, is the probability of a type I error, that is wrong rejections if the Null Hypothesis is true.

n_bins : int

number of bins or cells in the distribution.


power : float

Power of the test, e.g. 0.8, is one minus the probability of a type II error. Power is the probability that the test correctly rejects the Null Hypothesis if the Alternative Hypothesis is true.