title: What is the purpose of using unclass() function? and why the error ""the column indexes must be at most 2 if postive,not 3,4,5,6,7,8,9,10" appears
body: <p>What is the purpose of using unclass() function in r ? I can't get it right.<br>
  Can you demisifiy it with this code below? </p>
  
  <pre><code>unclass(tele%&gt;%mutate(dec=ntile(rev_Range,n=10))%&gt;%count(dec)%&gt;%unname())[[2]]
  </code></pre>