DescrStatsW.zconfint_mean(alpha=0.05, alternative='two-sided')[source]

two-sided confidence interval for weighted mean of data

Confidence interval is based on normal distribution. If the data is 2d, then these are separate confidence intervals for each column.


alpha : float

significance level for the confidence interval, coverage is 1-alpha

alternative : string

This specifies the alternative hypothesis for the test that corresponds to the confidence interval. The alternative hypothesis, H1, has to be one of the following

‘two-sided’: H1: mean not equal to value (default) ‘larger’ : H1: mean larger than value ‘smaller’ : H1: mean smaller than value


lower, upper : floats or ndarrays

lower and upper bound of confidence interval


In a previous version, statsmodels 0.4, alpha was the confidence level, e.g. 0.95