title: R, Python: install packages on rpy2
body: <p>I'm using <code>R</code> in my Python script through the <code>rpy2</code> library and I need a <a href="http://dirichletreg.r-forge.r-project.org" rel="noreferrer">package</a> that is not in the default installation of R.  How can I install it?</p>
  
  <pre><code>install.packages("DirichletReg", repos="http://r-forge.r-project.org")
  </code></pre>
  
  <p>won't work.</p>
  
  <p>On Python:</p>
  
  <pre><code>&gt;&gt;&gt; install.packages("DirichletReg", repos="http://r-forge.r-project.org") 
  Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  NameError: name 'install' is not defined
  </code></pre>
  
  <p>And from R:</p>
  
  <pre><code>&gt; install.packages("DirichletReg", repos="http://r-forge.r-project.org")
  Installing package(s) into ‘/usr/local/lib/R/site-library’
  (as ‘lib’ is unspecified)
  Warning message:
  In getDependencies(pkgs, dependencies, available, lib) :
    package ‘DirichletReg’ is not available (for R version 2.14.1)
  </code></pre>