title: Setting a relative frequency in a matplotlib histogram
body: <p>I have data as a list of floats and I want to plot it as a histogram. Hist() function does the job perfectly for plotting the absolute histogram. However, I cannot figure out how to represent it in a relative frequency format - I would like to have it as a fraction or ideally as a percentage on the y-axis.</p>
  
  <p>Here is the code:</p>
  
  <pre><code>fig = plt.figure()
  ax = fig.add_subplot(111)
  n, bins, patches = ax.hist(mydata, bins=100, normed=1, cumulative=0)
  ax.set_xlabel('Bins', size=20)
  ax.set_ylabel('Frequency', size=20)
  ax.legend
  
  plt.show()
  </code></pre>
  
  <p>I thought normed=1 argument would do it, but it gives fractions that are too high and sometimes are greater than 1. They also seem to depend on the bin size, as if they are not normalized by the bin size or something. Nevertheless, when I set cumulative=1, it nicely sums up to 1. So, where is the catch? By the way, when I feed the same data into Origin and plot it, it gives me perfectly correct fractions. Thank you!</p>