title: Graphviz crossing edges
body: <p>I am trying to avoid the crossing of the lines between 20->40 and 30->70. Does anyone know how to do this? I am using single points to straighten out the edges but I would have expected the rendering engine to avoid these edges to overlap. Here is my dot code:</p>
  
  <pre><code>digraph {
  graph [splines="ortho", nodesep = "1", overlap = false];
  node [shape=rectangle, color=lightgrey, style=filled ];
  
  10
  20
  30
  40
  50
  60
  70
  80
  90
  
  
  node[shape=none, width=0, height=0 label=""];
  edge[dir=none];
  
  {rank=same;
  p1-&gt;10
  10-&gt;p2
  }
  
  p1-&gt;20
  p2-&gt;30
  
  
  {rank=same;
  p3-&gt;40
  40-&gt;p4
  }
  
  p3-&gt;50
  p4-&gt;60
  
  
  {rank=same;
  p5-&gt;70
  70-&gt;p6
  }
  
  p5-&gt;80
  p6-&gt;90
  
  
  20-&gt;40
  30-&gt;70
  }
  </code></pre>
  
  <p>I wanted to post an image, but stackoverflow does not allow me to do this... You can see what I mean when you copy the code into: <a href="http://stamm-wilbrandt.de/GraphvizFiddle/" rel="nofollow">http://stamm-wilbrandt.de/GraphvizFiddle/</a></p>
  
  <p>I really appreciate your help on this!</p>