title: graphViz: how to assign multiple color to nodes
body: <p>I want to assign multiple color to a node in graphViz. the optimal solution would be a circular node with a pie chart format.</p>
  
  <p>I know one way which is to use HTML tag. the following is a simple example:</p>
  
  <pre><code>graph G{
      1--2;
      1[shape=none,margin=0,label=&lt; 
      &lt;table BORDER="0" CELLBORDER="1" CELLSPACING="0" CELLPADDING="4"&gt; 
          &lt;tr&gt;
              &lt;td bgcolor="red"&gt;&lt;/td&gt;
              &lt;td bgcolor="blue"&gt;&lt;/td&gt;
          &lt;/tr&gt;   
       &lt;/table&gt;         &gt;];
      2[shape=circle,style=filled,fillcolor=yellow];
      3[shape=circle,style=filled,fillcolor=yellow];
  }
  </code></pre>
  
  <p><strong>However</strong>, there are some problems:</p>
  
  <ol>
  <li><p>the node 1 has no label (I want it to have label "1" )</p></li>
  <li><p>the edge connecting the node 1 to node 2 is not completely attached to node 1. In other words, there is a space between node 1 and the edge connecting it to node 2.</p></li>
  <li><p>node 1 is rectangular. how can I have a circular node?</p></li>
  </ol>
  
  <p>If there is no way to overcome these problems, would you please suggest any other graph visualization software?</p>