.. _api-sankey_demo_links:

api example code: sankey_demo_links.py
======================================



.. plot:: /home/mandrake/rpm/BUILD/matplotlib-1.1.1/doc/mpl_examples/api/sankey_demo_links.py

::

    """Demonstrate/test the Sankey class by producing a long chain of connections.
    """
    import numpy as np
    import matplotlib.pyplot as plt
    
    from matplotlib.sankey import Sankey
    from itertools import cycle
    
    links_per_side = 6
    def side(sankey, n=1):
        """Generate a side chain.
        """
        prior = len(sankey.diagrams)
        colors = cycle(['orange', 'b', 'g', 'r', 'c', 'm', 'y'])
        for i in range(0, 2*n, 2):
            sankey.add(flows=[1, -1], orientations=[-1, -1],
                       patchlabel=str(prior+i), facecolor=colors.next(),
                       prior=prior+i-1, connect=(1, 0), alpha=0.5)
            sankey.add(flows=[1, -1], orientations=[1, 1],
                       patchlabel=str(prior+i+1), facecolor=colors.next(),
                       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()
    

Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)