title: binning geom_boxplot in ggplot2 in R?
body: <p>I want to use geom_boxplot to make boxplots that correlate two variables: for each bin of x values, plot the distribution (as boxplot) of y values for that bin. I tried:</p>
  
  <pre><code>ggplot(cars) + geom_boxplot(aes(x=dist, y=speed))
  </code></pre>
  
  <p>but this creates basically one large bin of x values. How can I make it so for each bin of <code>dist</code>, there's a boxplot representing the corresponding <code>speed</code> values?</p>