title: R: Selectively display nodes when plotting an igraph
body: <p>How can I plot a selection of igraph nodes?</p>
  
  <p>I have an existing graph, but it is too complex.  I want to be able to 'zoom in' on a subset of the nodes.</p>
  
  <p>I am able to delete a subset of edges, but I can't figure out how to 'turn off' the isolated nodes.</p>
  
  <p>When using the <em>network</em> package, the  <code>displayisolates=FALSE</code> parameter does this;  it does not display these isolated nodes.</p>
  
  <p>The layout algorithm should also ignore the 'turned off' edges.</p>
  
  <p>For example:</p>
  
  <pre><code>g1 &lt;- graph( c( 0,1, 1,2, 2,2, 2,3 ) )
  g2 &lt;- delete.edges(g1, E(g1, c(0,1)))
  plot(g2)
  </code></pre>
  
  <p>When plotting g2, I want to not display node 0.</p>
  
  <p>Thanks</p>