title: Cannot allocate vector in R despite being in 64-bit version
body: <p>I am trying to do a dcast in R to generate a matrix as seen in <a href="https://stackoverflow.com/questions/8888516/how-to-create-vector-matrix-of-movie-ratings-using-r-project">another question I asked</a></p>
  
  <p>However, I am getting an error:</p>
  
  <blockquote>
    <p>Error: cannot allocate vector of size 2.8Gb.</p>
  </blockquote>
  
  <p>My desktop has 8GB of RAM and I am running ubuntu 11.10 64-bit version. Am I perhaps using the wrong version of R? How would I know, is there a way to determine it while running R? I surely must have the necessary space to allocate this vector.</p>