title: Overlapping ggplot2 histograms with different variables
body: <p>If I had 2 different variables to plot as histograms, how would I do it? Take an example of this:</p>
  
  <pre><code>data1 &lt;- rnorm(100)
  data2 &lt;- rnorm(130)
  </code></pre>
  
  <p>If I want histograms of data1 and data2 in the same plot, is there a way of doing it?</p>