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

.. only:: html

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

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

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

.. _sphx_glr_gallery_plot_Sign_Test.py:


Sign test
=========================================
In this tutorial we demonstrate how to check equal size of two samples using the sign test. To do so, we provide an example
in which we check if Heung-Min Son shoots with both feet the same number of times. 

.. GENERATED FROM PYTHON SOURCE LINES 7-20

.. code-block:: default

    import pandas as pd
    import numpy as np
    import json
    # plotting
    import matplotlib.pyplot as plt
    #opening data
    import os
    import pathlib
    import warnings

    pd.options.mode.chained_assignment = None
    warnings.filterwarnings('ignore')








.. GENERATED FROM PYTHON SOURCE LINES 21-26

Opening the dataset
----------------------------

First we open the data. For this example we will use WyScout data from 2017/18 Premier League season.  To meet file size requirements of Github, we have to open it from different files,
but you can open the file locally from the directory you saved it in. Also, we open the file containing all players in WyScout database.

.. GENERATED FROM PYTHON SOURCE LINES 26-43

.. code-block:: default


    #open event data
    train = pd.DataFrame()
    for i in range(13):
        file_name = 'events_England_' + str(i+1) + '.json'
        path = os.path.join(str(pathlib.Path().resolve()), 'data', 'Wyscout', file_name)
        with open(path) as f:
            data = json.load(f)
        train = pd.concat([train, pd.DataFrame(data)])
    
        path = os.path.join(str(pathlib.Path().resolve()),"data", 'Wyscout', 'players.json')

    #open dataset with players
    with open(path) as f:
        players = json.load(f)
    player_df = pd.DataFrame(players)








.. GENERATED FROM PYTHON SOURCE LINES 44-50

Preparing the dataset
----------------------------

First, we filter the events to only keep shots. Then, we check for Son's id in the player database. As the next step,
we keep shots made by him. Then, we look for the shots made with his left (ones with *id* = 401) and right (ones with *id* = 401) foot.
In the end, we create a list with ones for shots with his left foot and -1 for shots with his right foot.

.. GENERATED FROM PYTHON SOURCE LINES 50-67

.. code-block:: default


    #take shots only
    shots = train.loc[train['subEventName'] == 'Shot'] 
    #look for son's id
    son_id = player_df.loc[player_df["shortName"] == "Son Heung-Min"]["wyId"].iloc[0]
    #get son's shot
    son_shots = shots.loc[shots["playerId"] == son_id]

    #left leg shots
    lefty_shots = son_shots.loc[son_shots.apply (lambda x:{'id':401} in x.tags, axis = 1)]
    #right leg shots
    righty_shots = son_shots.loc[son_shots.apply (lambda x:{'id':402} in x.tags, axis = 1)]

    #create list with ones for left foot shots and -1 for right foot shots   
    l = [1] * len(lefty_shots) 
    l.extend([-1] * len(righty_shots))








.. GENERATED FROM PYTHON SOURCE LINES 68-74

Testing the hypothesis
----------------------------

Now we can test the hypothesis that Heung-Min Son is indeed ambidextrous. To do so, a `sign test <https://en.wikipedia.org/wiki/Sign_test>`_ is used.
We set the significance level at 0.05. After conducting the hypothesis, there's no reason to reject the null hypothesis. Therefore, we claim that
Son shoots with his right and left foot the same number of times.

.. GENERATED FROM PYTHON SOURCE LINES 74-85

.. code-block:: default


    from statsmodels.stats.descriptivestats import sign_test
    test = sign_test(l, mu0 = 0)
    pvalue = test[1]

    if pvalue < 0.05:
        print("P-value amounts to", str(pvalue)[:5], "- We reject null hypothesis - Heung-Min Son is not ambidextrous")
    else:
        print("P-value amounts to", str(pvalue)[:5], " - We do not reject null hypothesis - Heung-Min Son is ambidextrous")






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

 .. code-block:: none

    P-value amounts to 0.142  - We do not reject null hypothesis - Heung-Min Son is ambidextrous





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

   **Total running time of the script:** ( 0 minutes  9.498 seconds)


.. _sphx_glr_download_gallery_plot_Sign_Test.py:

.. only:: html

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


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

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

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

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


.. only:: html

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

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