title: MPLCONFIGDIR error in matplotlib
body: <p>When I try to import matplotlib.pyplot I get the following error:</p>
  
  <pre><code>RuntimeError("'%s' is not a writable dir; you must set %s/.matplotlib to be a writable dir.  You can also set environment variable MPLCONFIGDIR to any writable directory where you want matplotlib data stored "% (h, h))
  </code></pre>
  
  <p>I do have a .matplotlib directory in my home directory which is owned by me and has write permissions on. So why is it telling me it is "not a writable dir" and how do I fix this?</p>