title: Multi-panel titles in R
body: <p>I have an ultra short question about R</p>
  
  <p>My aim is to assign a common title to a multi-panel plot generated using par, e.g.</p>
  
  <pre><code>par(mfrow=c(1,2))
  plot(rnorm(1000))
  plot(rnorm(1000))
  </code></pre>
  
  <p>So, something like "main" for the plot function, but extended to both plots. Is there a canonical way to do this?</p>
  
  <p>Thanks for any answer :-)</p>