4.7.7.1.2.3.1.12. statsmodels.tools.grouputils.Grouping.transform_slices

Grouping.transform_slices(array, function, level=0, **kwargs)

Apply function to each group. Similar to transform_array but does not coerce array to a DataFrame and back and only works on a 1D or 2D numpy array. function is called function(group, group_idx, **kwargs).