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:
  • x2 (x1,) – two independent samples, see notes for 2-D case
  • alternative (string) – 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 (string, 'pooled' or 'unequal') – If pooled, then the standard deviation of the samples is assumed to be the same. If unequal, then the standard deviations of the samples may be different.
  • value (float) – difference between the means under the Null hypothesis.
Returns:

  • tstat (float) – test statisic
  • pvalue (float) – pvalue of the z-test