statsmodels.stats.weightstats.CompareMeans.tconfint_diff¶
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CompareMeans.
tconfint_diff
(alpha=0.05, alternative='two-sided', usevar='pooled')[source]¶ confidence interval for the difference in means
Parameters: 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: 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. Ifunequal
, then Welsh ttest with Satterthwait degrees of freedom is usedReturns: lower, upper : floats
lower and upper limits of the confidence interval
Notes
The result is independent of the user specified ddof.