title: Treemap in Protovis
body: <p>I liked the protovis library at <a href="http://vis.stanford.edu/protovis" rel="nofollow">http://vis.stanford.edu/protovis</a>. I am trying to use it to create a treemap. Is there a way in Protovis' treemap layout by which we can indicate maximum level to show. Basically, I have a deep tree with depth 5 but I want to show nodes upto 3 levels only. If a user navigates into a node at level 3 then show its children, if any. </p>
  
  <p>Any comments and help will be greatly appreciated.</p>
  
  <p>Thanks</p>