title: splitting or removing graphs after arrangeGrob
body: <p>I created a graph with <code>ggplot</code> and later I used <code>arrangeGrob</code> to combine those graphs. Is there a way to remove parts a graph from this combined plot? Or maybe extract?</p>
  
  <p>Here is a minimal example:</p>
  
  <pre><code>library(ggplot2)
  library(gridExtra)
  df &lt;- data.frame(x=rnorm(20), y=rnorm(20), y2=rnorm(20))
  g1 &lt;- ggplot(df, aes(x, y)) + geom_point()
  g2 &lt;- ggplot(df, aes(x, y2)) + geom_point()
  g &lt;- arrangeGrob(g1,g2, widths=c(3.5,7.5), ncol=2)
  print(g)
  </code></pre>
  
  <p>I would like to remove one of the two plots.</p>