title: Total of multiple columns using datatables footer callback
body: <p>I am trying to implement a datatable with multiple columns containing numerical values.</p>
  <p>I would like to show the sum of each column in the table footer.</p>
  <p>I got some inspiration from <a href="https://datatables.net/examples/advanced_init/footer_callback.html" rel="nofollow noreferrer">here</a>.</p>
  <p><a href="http://live.datatables.net/vepedopa/16/" rel="nofollow noreferrer">LIVE JS BIN DEMO</a></p>