title: Calculation of mutual information in R
body: <p>I am having problems interpreting the results of the <code>mi.plugin()</code> (or <code>mi.empirical()</code>) function from the entropy package.  As far as I understand, an MI=0 tells you that the two variables that you are comparing are completely independent; and as MI increases, the association between the two variables is increasingly non-random.</p>
  
  <p>Why, then, do I get a value of 0 when running the following in R (using the <code>{entropy}</code> package):</p>
  
  <p><code>mi.plugin( rbind( c(1, 2, 3), c(1, 2, 3) ) )</code></p>
  
  <p>when I'm comparing two vectors that are exactly the same?</p>
  
  <p>I assume my confusion is based on a theoretical misunderstanding on my part, can someone tell me where I've gone wrong?</p>
  
  <p>Thanks in advance.</p>