title: How can I implement QT (quality threshold) clustering in Perl?
body: <p>I am having trouble with a QT clustering implementation that I want to implement in Perl.</p>
  
  <p><a href="https://i.stack.imgur.com/w27I9.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/w27I9.png" alt="Algorithm"></a>
  </p>
  
  <p>The line beginning with "identify set", the third from the end, is the part I can't figure out.</p>
  
  <p>The full paper is available <a href="http://ifile.it/56l4s2u" rel="nofollow noreferrer">here</a>.</p>