title: SVM rank works only on tiny datasets
body: <p>I am using <a href="http://www.cs.cornell.edu/people/tj/svm_light/svm_rank.html" rel="nofollow">svm-rank</a>.</p>
  
  <p>When running <code>svm_rank_learn</code> on a tiny dataset:</p>
  
  <blockquote>
    <p>Training set properties: 3 features, 12 rankings, 596 examples</p>
  </blockquote>
  
  <p>The run finishes in a few seconds and I get a valid model. But when I use a bit <a href="https://www.dropbox.com/s/zgjwvrcal556tiz/train.dat?dl=0" rel="nofollow">larger dataset</a>:</p>
  
  <blockquote>
    <p>Training set properties: 3 features, 30 rankings, 1580 examples</p>
  </blockquote>
  
  <p>The run is stuck for hours on iteration 29.
  This is very strange since the documentation states that svm-rank "scales linearly in the number of rankings (i.e. queries)".</p>
  
  <p>What is wrong with my dataset or format?</p>