.. _pylab_examples-barchart_demo2:

pylab_examples example code: barchart_demo2.py
==============================================



.. plot:: /media/TOSHI/temp/numpy_scipy_matplotlib/matplotlib/matplotlib-1.1.1~rc2/doc/mpl_examples/pylab_examples/barchart_demo2.py

::

    """
    Thanks Josh Hemann for the example
    
    This examples comes from an application in which grade school gym
    teachers wanted to be able to show parents how their child did across
    a handful of fitness tests, and importantly, relative to how other
    children did. To extract the plotting code for demo purposes, we'll
    just make up some data for little Johnny Doe...
    
    """
    import numpy as np
    import matplotlib.pyplot as plt
    import pylab
    from matplotlib.patches import Polygon
    from matplotlib.ticker import MaxNLocator
    
    
    
    student = 'Johnny Doe'
    grade = 2
    gender = 'boy'
    cohortSize = 62 #The number of other 2nd grade boys
    
    numTests = 5
    testNames = ['Pacer Test', 'Flexed Arm\n Hang', 'Mile Run', 'Agility',
                'Push Ups']
    testMeta = ['laps', 'sec', 'min:sec', 'sec', '']
    scores = ['7', '48', '12:52', '17', '14']
    rankings = np.round(np.random.uniform(0, 1, numTests)*100, 0)
    
    fig = plt.figure(figsize=(9,7))
    ax1 = fig.add_subplot(111)
    plt.subplots_adjust(left=0.115, right=0.88)
    fig.canvas.set_window_title('Eldorado K-8 Fitness Chart')
    pos = np.arange(numTests)+0.5    #Center bars on the Y-axis ticks
    rects = ax1.barh(pos, rankings, align='center', height=0.5, color='m')
    
    ax1.axis([0,100,0,5])
    pylab.yticks(pos, testNames)
    ax1.set_title('Johnny Doe')
    plt.text(50, -0.5, 'Cohort Size: ' + str(cohortSize),
            horizontalalignment='center', size='small')
    
    # Set the right-hand Y-axis ticks and labels and set X-axis tick marks at the
    # deciles
    ax2 = ax1.twinx()
    ax2.plot([100,100], [0, 5], 'white', alpha=0.1)
    ax2.xaxis.set_major_locator(MaxNLocator(11))
    xticks = pylab.setp(ax2, xticklabels=['0','10','20','30','40','50','60',
    '70',
                                         '80','90','100'])
    ax2.xaxis.grid(True, linestyle='--', which='major', color='grey',
    alpha=0.25)
    #Plot a solid vertical gridline to highlight the median position
    plt.plot([50,50], [0, 5], 'grey', alpha=0.25)
    
    # Build up the score labels for the right Y-axis by first appending a carriage
    # return to each string and then tacking on the appropriate meta information
    # (i.e., 'laps' vs 'seconds'). We want the labels centered on the ticks, so if
    # there is no meta info (like for pushups) then don't add the carriage return to
    # the string
    
    def withnew(i, scr):
        if testMeta[i] != '' : return '%s\n'%scr
        else: return scr
    scoreLabels = [withnew(i, scr) for i,scr in enumerate(scores)]
    scoreLabels = [i+j for i,j in zip(scoreLabels, testMeta)]
    pylab.yticks(pos, scoreLabels)
    ax2.set_ylabel('Test Scores')
    #Make list of numerical suffixes corresponding to position in a list
    #           0     1     2     3     4     5     6     7     8     9
    suffixes =['th', 'st', 'nd', 'rd', 'th', 'th', 'th', 'th', 'th', 'th']
    ax2.set_xlabel('Percentile Ranking Across ' + str(grade) + suffixes[grade] \
                  + ' Grade ' + gender.title() + 's')
    
    # Lastly, write in the ranking inside each bar to aid in interpretation
    for rect in rects:
       # Rectangle widths are already integer-valued but are floating
       # type, so it helps to remove the trailing decimal point and 0 by
       # converting width to int type
       width = int(rect.get_width())
    
       # Figure out what the last digit (width modulo 10) so we can add
       # the appropriate numerical suffix (e.g. 1st, 2nd, 3rd, etc)
       lastDigit = width % 10
       # Note that 11, 12, and 13 are special cases
       if (width == 11) or (width == 12) or (width == 13):
           suffix = 'th'
       else:
           suffix = suffixes[lastDigit]
    
       rankStr = str(width) + suffix
       if (width < 5): # The bars aren't wide enough to print the ranking inside
           xloc = width + 1 # Shift the text to the right side of the right edge
           clr = 'black' # Black against white background
           align = 'left'
       else:
           xloc = 0.98*width # Shift the text to the left side of the right edge
           clr = 'white' # White on magenta
           align = 'right'
    
       yloc = rect.get_y()+rect.get_height()/2.0 #Center the text vertically in the bar
       ax1.text(xloc, yloc, rankStr, horizontalalignment=align,
                verticalalignment='center', color=clr, weight='bold')
    
    plt.show()
    
    

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