title: How to run R on a server without X11, and avoid broken dependencies
body: <p>I'm running R 2.9 on a large EC2 Ubuntu instance, loaded with RAM, but without a terminal.  When I load a library that has display dependencies, such as the sqldf package, I receive the following error:</p>
  
  <pre><code>library(sqldf)
  ...
  Loading required package: tcltk
  Loading Tcl/Tk interface ... Error in fun(...) : couldn't connect to display "localhost:11.0"
  Error : .onLoad failed in 'loadNamespace' for 'tcltk'
  Error: package 'tcltk' could not be loaded
  </code></pre>
  
  <p>This seems to be a general problem, and I'm wondering how others have solved it.  Installing an X11 server is not a desirable solution.</p>