title: What is the computational complexity of arima() function in R?
body: <p>If my time series has <code>n</code> members and I want to fit <code>ARIMA(1,0,1)</code> model, what will be the complexity in big <code>O</code> notation?</p>
  
  <p>In the following example I need to know the complexity of second line of code:</p>
  
  <pre><code>series &lt;- arima.sim(list(order=c(1,0,1), ar=.9, ma=-.5), n=1000)
  result &lt;- arima(series, order=c(1,0,1))
  </code></pre>
  
  <p>Thanks.</p>