title: How to install a package not located on CRAN repository?
body: <p>I am trying to use Google Trends data and have come across a few packages that are not on CRAN (<a href="http://anotherrblog.blogspot.de/2013/06/introducing-gtrendsr.html">GTrends</a>, <a href="http://www.omegahat.org/RGoogleTrends/">RGoogleTrends</a>).</p>
  
  <p>I like what I have seen from the RGoogleTrends package <a href="http://thelogcabin.wordpress.com/2011/08/01/google-trends-r-and-the-nfl/">at this blog</a>, and wanted to give it a try. The RGoogleTrends package is located here: <a href="http://www.omegahat.org/RGoogleTrends/">http://www.omegahat.org/RGoogleTrends/</a></p>
  
  <p>First of all, I am using a Windows OS and there is an uption in my R console: </p>
  
  <pre><code>&gt;Packages&gt;Install package(s) from local zip drives ...
  </code></pre>
  
  <p>This results in the following:</p>
  
  <pre><code>&gt; utils:::menuInstallLocal()
  Error in read.dcf(file.path(pkgname, "DESCRIPTION"), c("Package", "Type")) : 
    cannot open the connection
  In addition: Warning messages:
  1: In unzip(zipname, exdir = dest) : error 1 in extracting from zip file
  2: In read.dcf(file.path(pkgname, "DESCRIPTION"), c("Package", "Type")) :
    cannot open compressed file 'RGoogleTrends_0.2-1.tar.gz/DESCRIPTION', probable reason 'No such file or directory'
  </code></pre>
  
  <p>I'm guessing this has to do with the fact that the file is as a <code>.gz</code> and not a <code>.zip</code> file.</p>
  
  <p>So, I unzipped the <code>.gz</code> file outside of R and then zipped it into a <code>.zip</code> file (there's got to be a better way). Now I can install the <code>.zip</code> file, but when I try and load it with <code>library</code>, the following error occurs: </p>
  
  <pre><code>&gt; library(RGoogleTrends)
  Error in library(RGoogleTrends) : 
    ‘RGoogleTrends’ is not a valid installed package
  </code></pre>
  
  <p>What am I doing wrong here? </p>