chisquare test for equality of median/location
This tests whether all groups have the same fraction of observations
above the median.
- Parameters:
- x : array_like
data values stacked for all groups
- groups : array_like
group labels or indicator
- Returns:
stat (float) – test statistic
pvalue (float) – pvalue from the chisquare distribution
others ???? – currently some test output, table and expected