title: matrix of hexbin plots with common bin/legend breaks
body: <p>Suppose I have a number of replications of bivariate experiments which I wish to display simultaneously in hexagonally binned plots, with common cell counts. Is there existing code to do this? Is there an easy way to modify the hexbin package to do this for me?</p>
  
  <p>For example:</p>
  
  <pre><code>library(hexbin)
  x &lt;- replicate(9, rnorm(10000), simplify=FALSE)
  y &lt;- replicate(9, rnorm(10000), simplify=FALSE)
  h &lt;- mapply(hexbin, x, y)
  par(mfrow=c(3,3))
  lapply(h, plot)
  </code></pre>
  
  <p>This code doesn't display a grid of hexbin plots with common cell counts, but I'd like it to.</p>