title: Ranking two dimensions of data
body: <p>I have a set of data in two dimensions, like so:</p>
  
  <pre><code>      A     B     C
  
   A    -     9     4
  
   B    24    -     13
  
   C    3     12    -
  </code></pre>
  
  <p>It represents relationships between two entities. I would like to return a list of those values ranked, such as:  </p>
  
  <pre>
  AB:4
  AC:5
  BA:1
  BC:2
  CA:6
  CB:3</pre>
  
  <p>Any thoughts on the best way to approach this?</p>