title: How to install sp (R package) from existing .gz file?
body: <p>I typed codes in R to download sp package, it says -- Package ‘sp’ is not available (for R version 3.0.1).</p>
  
  <p>I downloaded sp manually from <a href="http://cran.stat.ucla.edu/src/contrib/sp_1.0-9.tar.gz" rel="nofollow">http://cran.stat.ucla.edu/src/contrib/sp_1.0-9.tar.gz</a>. Questions is: how to unpack the tar.gz file? I work with RGui in windows 7.</p>
  
  <p>Thanks!!</p>