statsmodels.stats.weightstats.ttest_ind(x1, x2, alternative='two-sided', usevar='pooled', weights=(None, None), value=0)[source]

ttest independent sample

convenience function that uses the classes and throws away the intermediate results, compared to scipy stats: drops axis option, adds alternative, usevar, and weights option

  • 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 Welsh ttest with Satterthwait degrees of freedom is used
  • weights (tuple of None or ndarrays) – Case weights for the two samples. For details on weights see DescrStatsW
  • value (float) – difference between the means under the Null hypothesis.

  • tstat (float) – test statisic
  • pvalue (float) – pvalue of the t-test
  • df (int or float) – degrees of freedom used in the t-test