title: Efficiently break an array every X number of values?
body: <p>I want to split an array into a group of values starting at the end and leaving the beginning as a remander array. Here's an example of the goal:</p>
  
  <pre><code>arr = [0,1,2,3,4,5,6,7,8,9,10,11]
  interval = 5
  #chop
  output = [[0,1],[2,3,4,5,6],[7,8,9,10,11]]
  </code></pre>
  
  <p>What's that most efficient way of doing this?</p>
  
  <p>Thanks for any help?</p>