title: frequency trail in matplotlib
body: <p>I'm looking into outliers detection. Brendan Gregg has a really nice <a href="http://dtrace.org/blogs/brendan/2013/07/01/detecting-outliers/" rel="nofollow noreferrer">article</a> and I'm especially intrigued by his visualizations. One of the methods he uses are <a href="http://dtrace.org/blogs/brendan/2013/06/19/frequency-trails/" rel="nofollow noreferrer">frequency trails</a>.</p>
  
  <p><img src="https://i.stack.imgur.com/JDbHn.jpg" alt="frequency trails"></p>
  
  <p>I'm trying to reproduce this in matplotlib using <a href="http://matplotlib.org/examples/mplot3d/polys3d_demo.html" rel="nofollow noreferrer">this</a> example. Which looks like this:</p>
  
  <p><img src="https://i.stack.imgur.com/3I0vd.png" alt="polys3d_demo"></p>
  
  <p>And the plot is based on this answer: <a href="https://stackoverflow.com/a/4152016/948369">https://stackoverflow.com/a/4152016/948369</a></p>
  
  <p>Now my issue is, like described by Brendan, that I have a continuous line that masks the outlier (I simplified the input values so you can still see them):</p>
  
  <p><img src="https://i.stack.imgur.com/ek8nG.png" alt="masked outlier"></p>
  
  <p>Any help on making the line "non-continuous" for non existent values?</p>