title: How do I cut seconds into minute intervals?
body: <p>My data is arranged as below:</p>
  <pre><code>Data &lt;- data.frame(Seconds = c(4, 33, 46, 64, 78, 94, 100, 123, 150, 166, 183),
                     Margin = c(0, -1, 0, 1, 1, 2, 2, 3, 3, 4, 4))
  </code></pre>
  <p>I wish to get the <code>Margin</code> at the 1, 2 and 3 minute mark. My anticipated output would therefore look like:</p>
  <pre><code>MinuteData &lt;- data.frame(Minutes = c(1, 2, 3),
                           Margin = c(0, 2, 4))
  </code></pre>
  <p>How would I go about doing this?</p>