scipy.stats.kruskal

scipy.stats.kruskal(*args)

Compute the Kruskal-Wallis H-test for independent samples

The Kruskal-Wallis H-test tests the null hypothesis that the population median of all of the groups are equal. It is a non-parametric version of ANOVA. The test works on 2 or more independent samples, which may have different sizes. Note that rejecting the null hypothesis does not indicate which of the groups differs. Post-hoc comparisons between groups are required to determine which groups are different.

Parameters:sample2, ... (sample1,) -- Two or more arrays with the sample measurements can be given as arguments. Returns:

• H-statistic (float) -- The Kruskal-Wallis H statistic, corrected for ties
• p-value (float) -- The p-value for the test using the assumption that H has a chi square distribution

Notes

Due to the assumption that H has a chi square distribution, the number of samples in each group must not be too small. A typical rule is that each sample must have at least 5 measurements.

References

[1]	http://en.wikipedia.org/wiki/Kruskal-Wallis_one-way_analysis_of_variance