title: Plotting a histogram given bin endpoints and values
body: <p>Say I have an array of bin edges, and an array of bin values. (basically the output of <code>plt.hist</code>). For instance:</p>
  
  <pre><code>bins = np.array([1, 2, 3, 4, 5])
  vals = np.array([2, 5, 5, 2])
  </code></pre>
  
  <p>How do I plot this as a histogram?</p>
  
  <p>Edit: for clarity, I mean vals to be the "height" of each bin, where len(vals) + 1 = len(bins)</p>