scikit_posthocs.posthoc_nemenyi¶
- scikit_posthocs.posthoc_nemenyi(a: Union[list, ndarray, DataFrame], val_col: Optional[str] = None, group_col: Optional[str] = None, dist: str = 'chi', sort: bool = True) DataFrame¶
Post hoc pairwise test for multiple comparisons of mean rank sums (Nemenyi’s test). May be used after Kruskal-Wallis one-way analysis of variance by ranks to do pairwise comparisons 1.
- Parameters
a (array_like or pandas DataFrame object) – An array, any object exposing the array interface or a pandas DataFrame. Array must be two-dimensional. Second dimension may vary, i.e. groups may have different lengths.
val_col (str, optional) – Name of a DataFrame column that contains dependent variable values (test or response variable). Values should have a non-nominal scale. Must be specified if a is a pandas DataFrame object.
group_col (str, optional) – Name of a DataFrame column that contains independent variable values (grouping or predictor variable). Values should have a nominal scale (categorical). Must be specified if a is a pandas DataFrame object.
dist (str, optional) – Method for determining the p value. The default distribution is “chi” (chi-squared), else “tukey” (studentized range).
sort (bool, optional) – Specifies whether to sort DataFrame by group_col or not. Recommended unless you sort your data manually.
- Returns
result – P values.
- Return type
pandas.DataFrame
Notes
A tie correction will be employed according to Glantz (2012).
References
- 1
Lothar Sachs (1997), Angewandte Statistik. Berlin: Springer. Pages: 395-397, 662-664.
Examples
>>> x = [[1,2,3,5,1], [12,31,54, np.nan], [10,12,6,74,11]] >>> sp.posthoc_nemenyi(x)