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

    Click :ref:`here <sphx_glr_download_packages_statistics_auto_examples_plot_paired_boxplots.py>` to download the full example code
.. rst-class:: sphx-glr-example-title

.. _sphx_glr_packages_statistics_auto_examples_plot_paired_boxplots.py:


Boxplots and paired differences
=================================================

Plot boxplots for FSIQ, PIQ, and the paired difference between the two:
while the spread (error bars) for FSIQ and PIQ are very large, there is a
systematic (common) effect due to the subjects. This effect is cancelled
out in the difference and the spread of the difference ("paired" by
subject) is much smaller than the spread of the individual measures.





.. rst-class:: sphx-glr-horizontal


    *

      .. image:: /packages/statistics/auto_examples/images/sphx_glr_plot_paired_boxplots_001.png
            :class: sphx-glr-multi-img

    *

      .. image:: /packages/statistics/auto_examples/images/sphx_glr_plot_paired_boxplots_002.png
            :class: sphx-glr-multi-img





.. code-block:: python


    import pandas

    import matplotlib.pyplot as plt

    data = pandas.read_csv('brain_size.csv', sep=';', na_values='.')

    # Box plot of FSIQ and PIQ (different measures od IQ)
    plt.figure(figsize=(4, 3))
    data.boxplot(column=['FSIQ', 'PIQ'])

    # Boxplot of the difference
    plt.figure(figsize=(4, 3))
    plt.boxplot(data['FSIQ'] - data['PIQ'])
    plt.xticks((1, ), ('FSIQ - PIQ', ))

    plt.show()

**Total running time of the script:** ( 0 minutes  0.053 seconds)


.. _sphx_glr_download_packages_statistics_auto_examples_plot_paired_boxplots.py:


.. only :: html

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



  .. container:: sphx-glr-download

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



  .. container:: sphx-glr-download

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


.. only:: html

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

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