title: measure difference between two distribution
body: <p>I have a distance vector of a sample program. I am trying to quantify how similar they are. I was using Euclidean distance between sample groups (each value belongs to a bucket, we compare bucket by bucket), which works fine. But there are too many comparisons that needs to be done for large number of samples. </p>
  
  <p>I was wondering if there is a efficient way to build an index to compare the samples.  The samples look like this--</p>
  
  <pre><code>Sample:1 = {25 0 17 3 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0}
  Sample:2 = {25 1 16 2 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0}
  Sample:3 = {25 3 16 2 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0}
  </code></pre>