

.. _sphx_glr_gallery_api_sankey_links.py:


======================================
Long chain of connections using Sankey
======================================

Demonstrate/test the Sankey class by producing a long chain of connections.




.. image:: /gallery/api/images/sphx_glr_sankey_links_001.png
    :align: center





.. code-block:: python


    from itertools import cycle

    import matplotlib.pyplot as plt
    from matplotlib.sankey import Sankey

    links_per_side = 6


    def side(sankey, n=1):
        """Generate a side chain."""
        prior = len(sankey.diagrams)
        for i in range(0, 2*n, 2):
            sankey.add(flows=[1, -1], orientations=[-1, -1],
                       patchlabel=str(prior + i),
                       prior=prior + i - 1, connect=(1, 0), alpha=0.5)
            sankey.add(flows=[1, -1], orientations=[1, 1],
                       patchlabel=str(prior + i + 1),
                       prior=prior + i, connect=(1, 0), alpha=0.5)


    def corner(sankey):
        """Generate a corner link."""
        prior = len(sankey.diagrams)
        sankey.add(flows=[1, -1], orientations=[0, 1],
                   patchlabel=str(prior), facecolor='k',
                   prior=prior - 1, connect=(1, 0), alpha=0.5)


    fig = plt.figure()
    ax = fig.add_subplot(1, 1, 1, xticks=[], yticks=[],
                         title="Why would you want to do this?\n(But you could.)")
    sankey = Sankey(ax=ax, unit=None)
    sankey.add(flows=[1, -1], orientations=[0, 1],
               patchlabel="0", facecolor='k',
               rotation=45)
    side(sankey, n=links_per_side)
    corner(sankey)
    side(sankey, n=links_per_side)
    corner(sankey)
    side(sankey, n=links_per_side)
    corner(sankey)
    side(sankey, n=links_per_side)
    sankey.finish()
    # Notice:
    # 1. The alignment doesn't drift significantly (if at all; with 16007
    #    subdiagrams there is still closure).
    # 2. The first diagram is rotated 45 deg, so all other diagrams are rotated
    #    accordingly.

    plt.show()

**Total running time of the script:** ( 0 minutes  0.181 seconds)



.. only :: html

 .. container:: sphx-glr-footer


  .. container:: sphx-glr-download

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



  .. container:: sphx-glr-download

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


.. only:: html

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

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