matplotlib bar plot errbar
Question: in the official example,we can use bar function like this:

    
    
    #!/usr/bin/env python
    # a stacked bar plot with errorbars
    import numpy as np
    import matplotlib.pyplot as plt
    
    
    N = 5
    menMeans   = (20, 35, 30, 35, 27)
    womenMeans = (25, 32, 34, 20, 25)
    menStd     = (2, 3, 4, 1, 2)
    womenStd   = (3, 5, 2, 3, 3)
    ind = np.arange(N)    # the x locations for the groups
    width = 0.35       # the width of the bars: can also be len(x) sequence
    
    p1 = plt.bar(ind, menMeans,   width, color='r', yerr=womenStd,align='center')
    p2 = plt.bar(ind, womenMeans, width, color='y',bottom=menMeans, yerr=menStd,align='center')
    
    plt.ylabel('Scores')
    plt.title('Scores by group and gender')
    plt.xticks(ind, ('G1', 'G2', 'G3', 'G4', 'G5') )
    plt.yticks(np.arange(0,81,10))
    plt.legend( (p1[0], p2[0]), ('Men', 'Women') )
    
    plt.show()
    

What I don't understand is that, **why the womenStd is used as the menMeans's
yerr, and the menStd is used as womenMeans's yerr.**

Could you please explain that for me? Thanks very much.


Answer: It could very plausibly be a typo. It doesn't appear to be important to the
example at all, which exists to illustrate matplotlib functionality.

