.. _api-span_regions:

api example code: span_regions.py
=================================



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

::

    """
    Illustrate some helper functions for shading regions where a logical
    mask is True
    
    See :meth:`matplotlib.collections.BrokenBarHCollection.span_where`
    """
    import numpy as np
    import matplotlib.pyplot as plt
    import matplotlib.collections as collections
    
    
    t = np.arange(0.0, 2, 0.01)
    s1 = np.sin(2*np.pi*t)
    s2 = 1.2*np.sin(4*np.pi*t)
    
    
    fig = plt.figure()
    ax = fig.add_subplot(111)
    ax.set_title('using span_where')
    ax.plot(t, s1, color='black')
    ax.axhline(0, color='black', lw=2)
    
    collection = collections.BrokenBarHCollection.span_where(
           t, ymin=0, ymax=1, where=s1>0, facecolor='green', alpha=0.5)
    ax.add_collection(collection)
    
    collection = collections.BrokenBarHCollection.span_where(
           t, ymin=-1, ymax=0, where=s1<0, facecolor='red', alpha=0.5)
    ax.add_collection(collection)
    
    
    
    plt.show()
    
    
    
    
    
    

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