statsmodels.stats.weightstats.CompareMeans.ztest_ind¶
-
CompareMeans.ztest_ind(alternative=
'two-sided', usevar='pooled', value=0)[source]¶ z-test for the null hypothesis of identical means
- Parameters:¶
- x1 : array_like, 1-D or 2-D
first of the two independent samples, see notes for 2-D case
- x2 : array_like, 1-D or 2-D
second of the two independent samples, see notes for 2-D case
- alternative : str¶
The alternative hypothesis, H1, has to be one of the following ‘two-sided’: H1: difference in means not equal to value (default) ‘larger’ : H1: difference in means larger than value ‘smaller’ : H1: difference in means smaller than value
- usevar : str, 'pooled' or 'unequal'¶
If
pooled, then the standard deviation of the samples is assumed to be the same. Ifunequal, then the standard deviations of the samples may be different.- value : float¶
difference between the means under the Null hypothesis.
- Returns:¶
tstat (float) – test statistic
pvalue (float) – pvalue of the z-test