title: Install old package using install.packages
body: <p>I get </p>
  
  <pre><code>package ‘rJava’ is not available (for R version 2.15.0) 
  Warning: unable to access index for repository http://cran.stat.ucla.edu/bin/macosx/leopard/contrib/2.15
  </code></pre>
  
  <p>when using <code>install.packages()</code> if the repository does not have a version of the given package for my version of R, 2.15.0--the latest Mac binary. Is there a way to get R to check in for older versions, e.g. rJava for R 2.14? </p>
  
  <p>I know that I could download the <code>tar.gz</code> file and then use <code>R CMD INSTALL</code> in terminal, but I was wondering if there was a way to do this using  <code>install.packages()</code>. Thank you.</p>