.. only:: html

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

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

    .. _sphx_glr_gallery_lines_bars_and_markers_scatter_hist.py:


============================
Scatter plot with histograms
============================

Show the marginal distributions of a scatter as histograms at the sides of
the plot.

For a nice alignment of the main axes with the marginals, two options are shown
below.

* the axes positions are defined in terms of rectangles in figure coordinates
* the axes positions are defined via a gridspec

An alternative method to produce a similar figure using the ``axes_grid1``
toolkit is shown in the
:doc:`/gallery/axes_grid1/scatter_hist_locatable_axes` example.

Let us first define a function that takes x and y data as input, as well
as three axes, the main axes for the scatter, and two marginal axes. It will
then create the scatter and histograms inside the provided axes.


.. code-block:: default


    import numpy as np
    import matplotlib.pyplot as plt

    # Fixing random state for reproducibility
    np.random.seed(19680801)

    # some random data
    x = np.random.randn(1000)
    y = np.random.randn(1000)


    def scatter_hist(x, y, ax, ax_histx, ax_histy):
        # no labels
        ax_histx.tick_params(axis="x", labelbottom=False)
        ax_histy.tick_params(axis="y", labelleft=False)

        # the scatter plot:
        ax.scatter(x, y)

        # now determine nice limits by hand:
        binwidth = 0.25
        xymax = max(np.max(np.abs(x)), np.max(np.abs(y)))
        lim = (int(xymax/binwidth) + 1) * binwidth

        bins = np.arange(-lim, lim + binwidth, binwidth)
        ax_histx.hist(x, bins=bins)
        ax_histy.hist(y, bins=bins, orientation='horizontal')









Axes in figure coordinates
--------------------------

To define the axes positions, `.Figure.add_axes` is provided with a rectangle
``[left, bottom, width, height]`` in figure coordinates. The marginal axes
share one dimension with the main axes.


.. code-block:: default


    # definitions for the axes
    left, width = 0.1, 0.65
    bottom, height = 0.1, 0.65
    spacing = 0.005


    rect_scatter = [left, bottom, width, height]
    rect_histx = [left, bottom + height + spacing, width, 0.2]
    rect_histy = [left + width + spacing, bottom, 0.2, height]

    # start with a square Figure
    fig = plt.figure(figsize=(8, 8))

    ax = fig.add_axes(rect_scatter)
    ax_histx = fig.add_axes(rect_histx, sharex=ax)
    ax_histy = fig.add_axes(rect_histy, sharey=ax)

    # use the previously defined function
    scatter_hist(x, y, ax, ax_histx, ax_histy)

    plt.show()





.. image:: /gallery/lines_bars_and_markers/images/sphx_glr_scatter_hist_001.png
    :alt: scatter hist
    :class: sphx-glr-single-img





Using a gridspec
----------------

We may equally define a gridspec with unequal width- and height-ratios to
achieve desired layout. Also see the :doc:`/tutorials/intermediate/gridspec`
tutorial.


.. code-block:: default


    # start with a square Figure
    fig = plt.figure(figsize=(8, 8))

    # Add a gridspec with two rows and two columns and a ratio of 2 to 7 between
    # the size of the marginal axes and the main axes in both directions.
    # Also adjust the subplot parameters for a square plot.
    gs = fig.add_gridspec(2, 2,  width_ratios=(7, 2), height_ratios=(2, 7),
                          left=0.1, right=0.9, bottom=0.1, top=0.9,
                          wspace=0.05, hspace=0.05)

    ax = fig.add_subplot(gs[1, 0])
    ax_histx = fig.add_subplot(gs[0, 0], sharex=ax)
    ax_histy = fig.add_subplot(gs[1, 1], sharey=ax)

    # use the previously defined function
    scatter_hist(x, y, ax, ax_histx, ax_histy)

    plt.show()





.. image:: /gallery/lines_bars_and_markers/images/sphx_glr_scatter_hist_002.png
    :alt: scatter hist
    :class: sphx-glr-single-img





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

References
""""""""""

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


.. code-block:: default


    import matplotlib
    matplotlib.figure.Figure.add_axes
    matplotlib.figure.Figure.add_subplot
    matplotlib.figure.Figure.add_gridspec
    matplotlib.axes.Axes.scatter
    matplotlib.axes.Axes.hist




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

 Out:

 .. code-block:: none


    <function Axes.hist at 0x7f79f2798430>




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

   **Total running time of the script:** ( 0 minutes  1.536 seconds)


.. _sphx_glr_download_gallery_lines_bars_and_markers_scatter_hist.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: scatter_hist.py <scatter_hist.py>`



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

     :download:`Download Jupyter notebook: scatter_hist.ipynb <scatter_hist.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>`_