title: How to control subgraphs' layout in dot?
body: <p>i have a <code>digraph</code> composed of many independant and simple <code>subgraphs</code> of various sizes. <code>dot</code> lays all these subgraphs horizontally, so i end up with a 40000x200 output file, e.g:</p>
  
  <pre><code>G1 G2 G3 G.....4 G5
  </code></pre>
  
  <p>How do i tell <code>dot</code> to layout these subgraphs in both dimensions to get something like:</p>
  
  <pre><code>G1 G2 G3
  G.....4
  G5
  </code></pre>
  
  <p>Thanks.</p>