title: Fit ARIMA model
body: <p>I have a zoo time series object, <code>vels</code>:</p>
  
  <pre><code>2011-05-01 00:00:00 7.52
  2011-05-01 00:10:00 7.69
  2011-05-01 00:20:00 7.67
  2011-05-01 00:30:00 7.52
  2011-05-01 00:40:00 7.38
  2011-05-01 00:50:00 7.56
  2011-05-01 01:00:00 7.41
  2011-05-01 01:10:00 7.11
  2011-05-01 01:20:00 7.23
  2011-05-01 01:30:00 7.31
  </code></pre>
  
  <p>I would like to fit an Arima model but I don't know how to find the orders automatically.</p>
  
  <p>PS: I have read that I must use <code>arima.sim</code> but I think you have to enter orders too in that function.               </p>