Group by function

[king-michael]

Idea

Need of a group by function

Solutions

Works always

def groupby(X, y):
    y = np.asarray(y)
    X = np.asarray(X)
    y_uniques = np.unique(y)
    return [(yi, X[y==yi]) for yi in y_uniques]

Works for ascending data

def groupby(X, y):
    uniq, index = np.unique(y, return_index = True)
    group = np.split(X, index[1:])
    return uniq, group

ToDo

• benchmark
• clean up
• implentation