title: Is it possible to define the version of a package in R install.packages?
body: <p>I know that you can download old packages and install them with </p>
  
  <pre><code>R CMD INSTALL package-version.tar.gz
  </code></pre>
  
  <p>I wonder if you can tell <code>install.packages()</code> to install a specific version from a repository, saving you from having to locate the tar.gz first. I have neither found this option in the help entry for install.packages nor googling for it. If this option does not exist, is there any reason for that?. I can only think that not all repos have all versions so you are forced to find the version first and download it. </p>
  
  <p>There is an <a href="https://stackoverflow.com/questions/11175414/install-old-package-using-install-packages">equivalent question</a> already in SO but the problem and answer is more about repository problems, so at the end they never answered this question directly.</p>