.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "_examples/scikits/plot_data_skfold_test.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        Click :ref:`here <sphx_glr_download__examples_scikits_plot_data_skfold_test.py>`
        to download the full example code

.. rst-class:: sphx-glr-example-title

.. _sphx_glr__examples_scikits_plot_data_skfold_test.py:


01. Test Skfold
===============

Demonstrate that ``StratifiedKFold`` is deterministic and
always returns the same splits. The way to change the splits
is by changing the random state.

.. GENERATED FROM PYTHON SOURCE LINES 9-101




.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none


    Example I:
    0 == 1 : True
    1 == 2 : True
    2 == 3 : True
    3 == 4 : True

    Example II:
    0 == 1 : True
    1 == 2 : True
    2 == 3 : True
    3 == 4 : True






|

.. code-block:: default
   :lineno-start: 9

    # General
    import numpy as np
    import pandas as pd

    # Specific
    from sklearn.model_selection import StratifiedKFold


    # ---------------------------------------------------
    #
    # ---------------------------------------------------
    def repeated_splits(X, y, n_loops=2, n_splits=5):
        """This method creates several times the
           splits using the same function. Then
           it is used to check that the splitting
           is always consistent.
        """
        # Record for comparison
        records = []

        # Split
        for i in range(n_loops):
            # Create dataframe
            dataframe = pd.DataFrame()
            # Create splitter
            skf = StratifiedKFold(n_splits=n_splits)
            # Loop
            for j, (train, test) in enumerate(skf.split(X, y)):
                dataframe['fold_{0}'.format(j)] = \
                    np.concatenate((train, test))
            # Append
            records.append(dataframe)

        # Return
        return records


    # ---------------------------------------------------
    # Artificial example
    # ---------------------------------------------------
    # Size
    n = 2000
    n_splits = 5
    n_loops = 5

    # Create dataset
    X = np.random.randint(10, size=(n, 7))
    y = (np.random.rand(n) > 0.1).astype(int)

    # Create splits
    records = repeated_splits(X, y, n_loops=n_loops,
                                    n_splits=n_splits)

    # Compare if all records are equal
    print("\nExample I:")
    for i in range(len(records)-1):
        print('{0} == {1} : {2}'.format(i, i+1, \
            records[i].equals(records[i+1])))



    # ---------------------------------------------------
    # Real example
    # ---------------------------------------------------
    # Libraries
    from sklearn.datasets import load_iris

    # Load data
    bunch = load_iris(as_frame=True)

    # Label conversion
    lblmap = dict(enumerate(bunch.target_names))

    # Dataframe
    df = bunch.data
    df['target'] = bunch.target
    df['label'] = df.target.map(lblmap)

    # Get X, and y
    X = df.to_numpy()
    y = df.label.to_numpy()

    # Create splits
    records = repeated_splits(X, y, n_loops=n_loops,
                                    n_splits=n_splits)

    # Compare if all records are equal
    print("\nExample II:")
    for i in range(len(records)-1):
        print('{0} == {1} : {2}'.format(i, i+1, \
            records[i].equals(records[i+1])))



.. rst-class:: sphx-glr-timing

   **Total running time of the script:** ( 0 minutes  0.032 seconds)


.. _sphx_glr_download__examples_scikits_plot_data_skfold_test.py:


.. only :: html

 .. container:: sphx-glr-footer
    :class: sphx-glr-footer-example



  .. container:: sphx-glr-download sphx-glr-download-python

     :download:`Download Python source code: plot_data_skfold_test.py <plot_data_skfold_test.py>`



  .. container:: sphx-glr-download sphx-glr-download-jupyter

     :download:`Download Jupyter notebook: plot_data_skfold_test.ipynb <plot_data_skfold_test.ipynb>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_