title: Graphviz - Squished on page and rank not respected
body: <p>[enter image description here][1]I'm just learning GraphViz and I'm struggling with some Basic issues. I have two subgraphs that should be able to show basic nodes and links between, see code:</p>
  
  <pre><code>digraph G {
  graph [rankdir="TB", splines=ortho, nodesep=2, ranksep=2.5, fontsize=18, fontname="Verdana"];
  node [shape=record, height=3, width=3];
  rankdir = TB;
  
  
  subgraph cluster_0 {    
      node [style=filled, color=lightgrey, fontsize=18, fontname="Verdana"];
      label = "DMZ 1";
      PWI -&gt; PWE -&gt; PWI
  }
  
  subgraph cluster_1 {
      node [style=filled, color=lightgrey, fontsize=18, fontname="Verdana"];
      label = "Trusted Zone EBC" ;
      PR1 -&gt; PWI [headlabel="test text", labeldistance=2.5] 
      PWI -&gt; PR1  
      PR1 -&gt; PWE  
      PWE -&gt; PR1  
      PWI -&gt; PWE -&gt; PWI  
      PFI -&gt; PWE  
      PFI -&gt; PWI  
      PWE -&gt; PFI  
      PWI -&gt; PFI  
      PBW -&gt; PWI  
      PBW -&gt; PWE  
      PWI -&gt; PBW  
      PWE -&gt; PBW  
      PSM -&gt; PWE  
      PSM -&gt; PWI  
      PWE -&gt; PSM  
      PWI -&gt; PSM  
      {rank = same; PR1; PFI; PSM; PBW}
      {rank = same; PWI}
      {rank = same; PWE}
  }
  </code></pre>
  
  <p>}</p>
  
  <p>Which leads to the below.. Am I hitting the edges of [enter image description here][2]a "canvas" if so, can I increase it? And why are the ranks not being respected where the top rank is being shown on the same as the lowest rank, as well as the middle rank being above them?</p>
  
  <p>Thanks!</p>
  
  <p><a href="https://i.stack.imgur.com/meU6p.png" rel="nofollow noreferrer">https://i.stack.imgur.com/meU6p.png</a></p>