.. _pylab_examples-histogram_demo_extended:

pylab_examples example code: histogram_demo_extended.py
=======================================================



.. plot:: /home/mandrake/rpm/BUILD/matplotlib-0.99.3/doc/mpl_examples/pylab_examples/histogram_demo_extended.py

::

    #!/usr/bin/env python
    import pylab as P
    
    #
    # The hist() function now has a lot more options
    #
    
    #
    # first create a single histogram
    #
    mu, sigma = 200, 25
    x = mu + sigma*P.randn(10000)
    
    # the histogram of the data with histtype='step'
    n, bins, patches = P.hist(x, 50, normed=1, histtype='stepfilled')
    P.setp(patches, 'facecolor', 'g', 'alpha', 0.75)
    
    # add a line showing the expected distribution
    y = P.normpdf( bins, mu, sigma)
    l = P.plot(bins, y, 'k--', linewidth=1.5)
    
    
    #
    # create a histogram by providing the bin edges (unequally spaced)
    #
    P.figure()
    
    bins = [100,125,150,160,170,180,190,200,210,220,230,240,250,275,300]
    # the histogram of the data with histtype='step'
    n, bins, patches = P.hist(x, bins, normed=1, histtype='bar', rwidth=0.8)
    
    #
    # now we create a cumulative histogram of the data
    #
    P.figure()
    
    n, bins, patches = P.hist(x, 50, normed=1, histtype='step', cumulative=True)
    
    # add a line showing the expected distribution
    y = P.normpdf( bins, mu, sigma).cumsum()
    y /= y[-1]
    l = P.plot(bins, y, 'k--', linewidth=1.5)
    
    # create a second data-set with a smaller standard deviation
    sigma2 = 15.
    x = mu + sigma2*P.randn(10000)
    
    n, bins, patches = P.hist(x, bins=bins, normed=1, histtype='step', cumulative=True)
    
    # add a line showing the expected distribution
    y = P.normpdf( bins, mu, sigma2).cumsum()
    y /= y[-1]
    l = P.plot(bins, y, 'r--', linewidth=1.5)
    
    # finally overplot a reverted cumulative histogram
    n, bins, patches = P.hist(x, bins=bins, normed=1,
        histtype='step', cumulative=-1)
    
    
    P.grid(True)
    P.ylim(0, 1.05)
    
    
    #
    # histogram has the ability to plot multiple data in parallel ...
    #
    P.figure()
    
    # create a new data-set
    x = mu + sigma*P.randn(1000,3)
    
    n, bins, patches = P.hist(x, 10, normed=1, histtype='bar')
    
    #
    # ... or we can stack the data
    #
    P.figure()
    
    n, bins, patches = P.hist(x, 10, normed=1, histtype='barstacked')
    
    #
    # finally: make a multiple-histogram of data-sets with different length
    #
    x0 = mu + sigma*P.randn(10000)
    x1 = mu + sigma*P.randn(7000)
    x2 = mu + sigma*P.randn(3000)
    
    P.figure()
    
    n, bins, patches = P.hist( [x0,x1,x2], 10, histtype='bar')
    
    P.show()
    

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