The histogram overlay

histogram.py

#=============EXAMPLE===============
def compare(t, conditions, values):
    """Overlay histograms of values for two conditions."""
    t['count'] = 1
    e = t.pivot(conditions, values, 'count', sum)
    for label in e.column_labels[1:]:
        e[label] = e[label]/sum(e[label]) # Normalize each column of counts
    e.hist(counts=values, normed=True, overlay=True)

compare(couples, 'mar_status', 'age')

#=============ACTUAL===============
# sample the larger table to the smaller table size
# align