.. _pylab_examples-spine_placement_demo:

pylab_examples example code: spine_placement_demo.py
====================================================



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

::

    import sys
    import matplotlib.pyplot as plt
    import numpy as np
    from matplotlib.pyplot import show
    
    fig = plt.figure()
    x = np.linspace(0,2*np.pi,100)
    y = 2*np.sin(x)
    ax = fig.add_subplot(1,2,1)
    ax.set_title('dropped spines')
    ax.plot(x,y)
    for loc, spine in ax.spines.items():
        if loc in ['left','bottom']:
            spine.set_position(('outward',10)) # outward by 10 points
        elif loc in ['right','top']:
            spine.set_color('none') # don't draw spine
        else:
            raise ValueError('unknown spine location: %s'%loc)
    
    # turn off ticks where there is no spine
    ax.xaxis.set_ticks_position('bottom')
    ax.yaxis.set_ticks_position('left')
    
    ax = fig.add_subplot(1,2,2,sharex=ax)
    ax.plot(x,y)
    ax.set_title('normal spines')
    
    # ----------------------------------------------------
    
    fig = plt.figure()
    x = np.linspace(-np.pi,np.pi,100)
    y = 2*np.sin(x)
    
    ax = fig.add_subplot(2,2,1)
    ax.set_title('centered spines')
    ax.plot(x,y)
    ax.spines['left'].set_position('center')
    ax.spines['right'].set_color('none')
    ax.spines['bottom'].set_position('center')
    ax.spines['top'].set_color('none')
    ax.spines['left'].set_smart_bounds(True)
    ax.spines['bottom'].set_smart_bounds(True)
    ax.xaxis.set_ticks_position('bottom')
    ax.yaxis.set_ticks_position('left')
    
    ax = fig.add_subplot(2,2,2)
    ax.set_title('zeroed spines')
    ax.plot(x,y)
    ax.spines['left'].set_position('zero')
    ax.spines['right'].set_color('none')
    ax.spines['bottom'].set_position('zero')
    ax.spines['top'].set_color('none')
    ax.spines['left'].set_smart_bounds(True)
    ax.spines['bottom'].set_smart_bounds(True)
    ax.xaxis.set_ticks_position('bottom')
    ax.yaxis.set_ticks_position('left')
    
    ax = fig.add_subplot(2,2,3)
    ax.set_title('spines at axes (0.6, 0.1)')
    ax.plot(x,y)
    ax.spines['left'].set_position(('axes',0.6))
    ax.spines['right'].set_color('none')
    ax.spines['bottom'].set_position(('axes',0.1))
    ax.spines['top'].set_color('none')
    ax.spines['left'].set_smart_bounds(True)
    ax.spines['bottom'].set_smart_bounds(True)
    ax.xaxis.set_ticks_position('bottom')
    ax.yaxis.set_ticks_position('left')
    
    ax = fig.add_subplot(2,2,4)
    ax.set_title('spines at data (1,2)')
    ax.plot(x,y)
    ax.spines['left'].set_position(('data',1))
    ax.spines['right'].set_color('none')
    ax.spines['bottom'].set_position(('data',2))
    ax.spines['top'].set_color('none')
    ax.spines['left'].set_smart_bounds(True)
    ax.spines['bottom'].set_smart_bounds(True)
    ax.xaxis.set_ticks_position('bottom')
    ax.yaxis.set_ticks_position('left')
    # ----------------------------------------------------
    
    def adjust_spines(ax,spines):
        for loc, spine in ax.spines.items():
            if loc in spines:
                spine.set_position(('outward',10)) # outward by 10 points
                spine.set_smart_bounds(True)
            else:
                spine.set_color('none') # don't draw spine
    
        # turn off ticks where there is no spine
        if 'left' in spines:
            ax.yaxis.set_ticks_position('left')
        else:
            # no yaxis ticks
            ax.yaxis.set_ticks([])
    
        if 'bottom' in spines:
            ax.xaxis.set_ticks_position('bottom')
        else:
            # no xaxis ticks
            ax.xaxis.set_ticks([])
    
    fig = plt.figure()
    
    x = np.linspace(0,2*np.pi,100)
    y = 2*np.sin(x)
    
    ax = fig.add_subplot(2,2,1)
    ax.plot(x,y)
    adjust_spines(ax,['left'])
    
    ax = fig.add_subplot(2,2,2)
    ax.plot(x,y)
    adjust_spines(ax,[])
    
    ax = fig.add_subplot(2,2,3)
    ax.plot(x,y)
    adjust_spines(ax,['left','bottom'])
    
    ax = fig.add_subplot(2,2,4)
    ax.plot(x,y)
    adjust_spines(ax,['bottom'])
    
    # ----------------------------------------------------
    
    fig = plt.figure()
    
    x = np.linspace(0,2*np.pi,50)
    y = np.sin(x)
    y2 = y + 0.1*np.random.normal( size=x.shape )
    
    # plot data
    ax = fig.add_subplot(1,1,1)
    line1,=ax.plot(x,y,'--')
    line2,=ax.plot(x,y2,'bo')
    
    # adjust the spines
    adjust_spines(ax,['left','bottom'])
    
    # set ticks and tick labels
    #   x
    ax.set_xlim((0,2*np.pi))
    ax.set_xticks([0,np.pi,2*np.pi])
    if sys.version_info[0] < 3:
        pichr = unichr(0x03C0)
    else:
        pichr = chr(0x03C0)
    ax.set_xticklabels(['0',pichr,'2 '+pichr])
    
    #   y
    ax.set_yticks([-1,0,1])
    
    # disable clipping of data points by axes range
    for artist in (line1,line2):
        artist.set_clip_on(False)
    
    # adjust spine to be within ticks
    ax.spines['left'].set_bounds( -1, 1 )
    
    show()
    

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