.. only:: html

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

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

    .. _sphx_glr_gallery_statistics_histogram_features.py:


==============================================
Some features of the histogram (hist) function
==============================================

In addition to the basic histogram, this demo shows a few optional features:

* Setting the number of data bins.
* The *density* parameter, which normalizes bin heights so that the integral of
  the histogram is 1. The resulting histogram is an approximation of the
  probability density function.
* Setting the face color of the bars.
* Setting the opacity (alpha value).

Selecting different bin counts and sizes can significantly affect the shape
of a histogram. The Astropy docs have a great section_ on how to select these
parameters.

.. _section: http://docs.astropy.org/en/stable/visualization/histogram.html


.. code-block:: default


    import matplotlib
    import numpy as np
    import matplotlib.pyplot as plt

    np.random.seed(19680801)

    # example data
    mu = 100  # mean of distribution
    sigma = 15  # standard deviation of distribution
    x = mu + sigma * np.random.randn(437)

    num_bins = 50

    fig, ax = plt.subplots()

    # the histogram of the data
    n, bins, patches = ax.hist(x, num_bins, density=True)

    # add a 'best fit' line
    y = ((1 / (np.sqrt(2 * np.pi) * sigma)) *
         np.exp(-0.5 * (1 / sigma * (bins - mu))**2))
    ax.plot(bins, y, '--')
    ax.set_xlabel('Smarts')
    ax.set_ylabel('Probability density')
    ax.set_title(r'Histogram of IQ: $\mu=100$, $\sigma=15$')

    # Tweak spacing to prevent clipping of ylabel
    fig.tight_layout()
    plt.show()




.. image:: /gallery/statistics/images/sphx_glr_histogram_features_001.png
    :alt: Histogram of IQ: $\mu=100$, $\sigma=15$
    :class: sphx-glr-single-img





------------

References
""""""""""

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


.. code-block:: default


    matplotlib.axes.Axes.hist
    matplotlib.axes.Axes.set_title
    matplotlib.axes.Axes.set_xlabel
    matplotlib.axes.Axes.set_ylabel




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

 Out:

 .. code-block:: none


    <function Axes.set_ylabel at 0x7f280fea3af0>




.. _sphx_glr_download_gallery_statistics_histogram_features.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: histogram_features.py <histogram_features.py>`



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

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


.. only:: html

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

    Keywords: matplotlib code example, codex, python plot, pyplot
    `Gallery generated by Sphinx-Gallery
    <https://sphinx-gallery.readthedocs.io>`_