title: Creating a wordcloud with matplotlib
body: <p>Im trying to create a <a href="http://upload.wikimedia.org/wikipedia/en/thumb/a/a5/TagCloudCloud.png/800px-TagCloudCloud.png" rel="nofollow">wordcloud</a> with Matplotlib.  Essentially I am able to put text at arbitrary locations in my grid, but need to work out a way of preventing them from colliding.  In relation to this I am stuck on two questions:</p>
  
  <ol>
  <li><p>What is the unit of fontsize? </p></li>
  <li><p>How do I transfer the "fontsize" of the text to units in my figure, so I can mark them as used?  That is, how do I know how much space each letter will take up in my grid?  Ideally I would not have to mark out a whole rectangle around each word, but only the pixels they actually use as available for other words.</p></li>
  </ol>