title: Installing older version of R package
body: <p>I am trying to use Rpy2 and ggplot2 but I get an error. After some searching for the error online, I found that the error occurs because there are changes in the ggplot2 package that are not yet reflected in Rpy2 (for example, see <a href="https://bitbucket.org/lgautier/rpy2/issue/100/import-rpy2robjectslibggplot2-causes" rel="noreferrer">this post</a> (Edit: Link is now dead)). </p>
  
  <p>So I now need to install an older version of ggplot2. Here is pseudo-code for what I want:</p>
  
  <pre><code>install.packages("ggplot2", version='0.9.1')
  </code></pre>
  
  <p>But <a href="https://stackoverflow.com/questions/12670162/is-it-possible-to-define-the-version-of-a-package-in-r-install-packages"><code>install.packages</code> does not have a <code>version</code> argument</a>. How do I do it?</p>