title: Splitting boxplots onto multiple pages
body: <p>Say I have some data</p>
  
  <pre><code>tmp = data.frame(ID = replicate(25, paste(sample(LETTERS, 7, replace = T), 
                                            collapse = "")),
                   Score = rnorm(1000))
  </code></pre>
  
  <p>I wish to create boxplots of these data using ggplot, but I want to split the boxplots over multiple pages. I then need to extend this to split on a random number. So for example if I had, say, 66 unique IDs and therefore 66 boxplots and I wanted the first 42 to be on one graphics window and the next 24 to be on the next window. </p>
  
  <p>I know that if I create a ggplot object then I can get the structure of that object, but I am just not sure where I should subset it, or if sub-setting would work in this case.</p>
  
  <pre><code>p = ggplot(tmp, aes(ID, Score)) + geom_boxplot() + coord_flip()
  str(p)
  </code></pre>