title: Octave position of maximum value in column
body: <p>I want to find the argmax of the values in a matrix by column, e.g.:</p>
  
  <pre><code>1 2 3    2 3 3
  4 5 6 -&gt; 
  3 7 8 
  </code></pre>
  
  <p>I feel like I should just be able to map an argmax/posmax function over the columns, but I don't see a particularly intuitive way to do this in Octave.</p>