watex.utils.cattarget#

watex.utils.cattarget(arr, /, func=None, labels=None, rename_labels=None, coerce=False, order='strict')[source]#

Categorize array to hold the given identifier labels.

Classifier numerical values according to the given label values. Labels are a list of integers where each integer is a group of unique identifier of a sample in the dataset.

Parameters:

  • arr (array-like |pandas.Series) – array or series containing numerical values. If a non-numerical values is given , an errors will raises.

  • func (Callable,) – Function to categorize the target y.

  • labels (int, list of int,) – if an integer value is given, it should be considered as the number of category to split ‘y’. For instance label=3 applied on the first ten number, the labels values should be [0, 1, 2]. If labels are given as a list, items must be self-contain in the target ‘y’.

  • rename_labels (list of str;) – list of string or values to replace the label integer identifier.

  • coerce (bool, default =False,) – force the new label names passed to rename_labels to appear in the target including or not some integer identifier class label. If coerce is True, the target array holds the dtype of new_array.

Returns:

arr – The category array with unique identifer labels

Return type:

Arraylike |pandas.Series

Examples

>>> from watex.utils.mlutils import cattarget
>>> def binfunc(v):
        if v < 3 : return 0
        else : return 1
>>> arr = np.arange (10 )
>>> arr
... array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> target = cattarget(arr, func =binfunc)
... array([0, 0, 0, 1, 1, 1, 1, 1, 1, 1], dtype=int64)
>>> cattarget(arr, labels =3 )
... array([0, 0, 0, 1, 1, 1, 2, 2, 2, 2])
>>> array([2, 2, 2, 2, 1, 1, 1, 0, 0, 0])
>>> cattarget(arr, labels =3 , order =None )
... array([0, 0, 0, 0, 1, 1, 1, 2, 2, 2])
>>> cattarget(arr[::-1], labels =3 , order =None )
... array([0, 0, 0, 1, 1, 1, 2, 2, 2, 2]) # reverse does not change
>>> cattarget(arr, labels =[0 , 2,  4]  )
... array([0, 0, 0, 2, 2, 4, 4, 4, 4, 4])