.. _pylab_examples-legend_auto:

pylab_examples example code: legend_auto.py
===========================================



.. plot:: /home/mdboom/Work/builds/matplotlib/doc/mpl_examples/pylab_examples/legend_auto.py

::

    """
    This file was written to test matplotlib's autolegend placement
    algorithm, but shows lots of different ways to create legends so is
    useful as a general examples
    
    Thanks to John Gill and Phil ?? for help at the matplotlib sprint at
    pycon 2005 where the auto-legend support was written.
    """
    from pylab import *
    import sys
    
    rcParams['legend.loc'] = 'best'
    
    N = 100
    x = arange(N)
    
    def fig_1():
        figure(1)
        t = arange(0, 40.0 * pi, 0.1)
        l, = plot(t, 100*sin(t), 'r', label='sine')
        legend(framealpha=0.5)
    
    def fig_2():
        figure(2)
        plot(x, 'o', label='x=y')
        legend()
    
    def fig_3():
        figure(3)
        plot(x, -x, 'o', label='x= -y')
        legend()
    
    def fig_4():
        figure(4)
        plot(x, ones(len(x)), 'o', label='y=1')
        plot(x, -ones(len(x)), 'o', label='y=-1')
        legend()
    
    def fig_5():
        figure(5)
        n, bins, patches = hist(randn(1000), 40, normed=1)
        l, = plot(bins, normpdf(bins, 0.0, 1.0), 'r--', label='fit', linewidth=3)
        legend([l, patches[0]], ['fit', 'hist'])
    
    def fig_6():
        figure(6)
        plot(x, 50-x, 'o', label='y=1')
        plot(x, x-50, 'o', label='y=-1')
        legend()
    
    def fig_7():
        figure(7)
        xx = x - (N/2.0)
        plot(xx, (xx*xx)-1225, 'bo', label='$y=x^2$')
        plot(xx, 25*xx, 'go', label='$y=25x$')
        plot(xx, -25*xx, 'mo', label='$y=-25x$')
        legend()
    
    def fig_8():
        figure(8)
        b1 = bar(x, x, color='m')
        b2 = bar(x, x[::-1], color='g')
        legend([b1[0], b2[0]], ['up', 'down'])
    
    def fig_9():
        figure(9)
        b1 = bar(x, -x)
        b2 = bar(x, -x[::-1], color='r')
        legend([b1[0], b2[0]], ['down', 'up'])
    
    def fig_10():
        figure(10)
        b1 = bar(x, x, bottom=-100, color='m')
        b2 = bar(x, x[::-1], bottom=-100, color='g')
        b3 = bar(x, -x, bottom=100)
        b4 = bar(x, -x[::-1], bottom=100, color='r')
        legend([b1[0], b2[0], b3[0], b4[0]], ['bottom right', 'bottom left',
                                              'top left', 'top right'])
    
    if __name__ == '__main__':
        nfigs = 10
        figures = []
        for f in sys.argv[1:]:
            try:
                figures.append(int(f))
            except ValueError:
                pass
        if len(figures) == 0:
            figures = range(1, nfigs+1)
    
        for fig in figures:
            fn_name = "fig_%d" % fig
            fn = globals()[fn_name]
            fn()
    
        show()
    

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