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

.. only:: html

    .. meta::
        :keywords: codex

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

        :ref:`Go to the end <sphx_glr_download_gallery_lines_bars_and_markers_horizontal_barchart_distribution.py>`
        to download the full example code

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

.. _sphx_glr_gallery_lines_bars_and_markers_horizontal_barchart_distribution.py:


=============================================
Discrete distribution as horizontal bar chart
=============================================

Stacked bar charts can be used to visualize discrete distributions.

This example visualizes the result of a survey in which people could rate
their agreement to questions on a five-element scale.

The horizontal stacking is achieved by calling `~.Axes.barh()` for each
category and passing the starting point as the cumulative sum of the
already drawn bars via the parameter ``left``.

.. GENERATED FROM PYTHON SOURCE LINES 15-71

.. code-block:: Python


    import matplotlib.pyplot as plt
    import numpy as np

    category_names = ['Strongly disagree', 'Disagree',
                      'Neither agree nor disagree', 'Agree', 'Strongly agree']
    results = {
        'Question 1': [10, 15, 17, 32, 26],
        'Question 2': [26, 22, 29, 10, 13],
        'Question 3': [35, 37, 7, 2, 19],
        'Question 4': [32, 11, 9, 15, 33],
        'Question 5': [21, 29, 5, 5, 40],
        'Question 6': [8, 19, 5, 30, 38]
    }


    def survey(results, category_names):
        """
        Parameters
        ----------
        results : dict
            A mapping from question labels to a list of answers per category.
            It is assumed all lists contain the same number of entries and that
            it matches the length of *category_names*.
        category_names : list of str
            The category labels.
        """
        labels = list(results.keys())
        data = np.array(list(results.values()))
        data_cum = data.cumsum(axis=1)
        category_colors = plt.colormaps['RdYlGn'](
            np.linspace(0.15, 0.85, data.shape[1]))

        fig, ax = plt.subplots(figsize=(9.2, 5))
        ax.invert_yaxis()
        ax.xaxis.set_visible(False)
        ax.set_xlim(0, np.sum(data, axis=1).max())

        for i, (colname, color) in enumerate(zip(category_names, category_colors)):
            widths = data[:, i]
            starts = data_cum[:, i] - widths
            rects = ax.barh(labels, widths, left=starts, height=0.5,
                            label=colname, color=color)

            r, g, b, _ = color
            text_color = 'white' if r * g * b < 0.5 else 'darkgrey'
            ax.bar_label(rects, label_type='center', color=text_color)
        ax.legend(ncols=len(category_names), bbox_to_anchor=(0, 1),
                  loc='lower left', fontsize='small')

        return fig, ax


    survey(results, category_names)
    plt.show()




.. image-sg:: /gallery/lines_bars_and_markers/images/sphx_glr_horizontal_barchart_distribution_001.png
   :alt: horizontal barchart distribution
   :srcset: /gallery/lines_bars_and_markers/images/sphx_glr_horizontal_barchart_distribution_001.png, /gallery/lines_bars_and_markers/images/sphx_glr_horizontal_barchart_distribution_001_2_00x.png 2.00x
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 72-80

.. admonition:: References

   The use of the following functions, methods, classes and modules is shown
   in this example:

   - `matplotlib.axes.Axes.barh` / `matplotlib.pyplot.barh`
   - `matplotlib.axes.Axes.bar_label` / `matplotlib.pyplot.bar_label`
   - `matplotlib.axes.Axes.legend` / `matplotlib.pyplot.legend`


.. _sphx_glr_download_gallery_lines_bars_and_markers_horizontal_barchart_distribution.py:

.. only:: html

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

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

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

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

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


.. only:: html

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

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