title: Time series plot range
body: <p>Hi am ploting a xts object: 
  <img src="https://i.stack.imgur.com/OGSQG.png" alt="enter image description here"></p>
  
  <p>And I would like to extend the xlim til 30-february because I want to add the prediction from an Arima model:</p>
  
  <pre><code>par(mfrow=c(1,1))
  pred &lt;- predict(try2, n.ahead = 1,se.fit=T)
  lim_sup &lt;- pred$pred + 1.96 * pred$se
  lim_inf &lt;- pred$pred - 1.96 * pred$se
  plot(heat["1996-02-01 00:00/1996-02-16 04:00"],type="l",main="Cross Validation")
  points(exp(pred$pred),col="blue",lwd=2)
  points(exp(lim_sup),lwd=2,col="green")
  points(exp(lim_inf),lwd=2,col="green")
  </code></pre>
  
  <p>But I can not see any lines in the plot. Could you give me some recommendation?</p>
  
  <p>The heat time series looks like this</p>
  
  <pre><code>                     HC.f
  1996-02-01 00:00:00 1437.000
  1996-02-01 01:00:00 1441.600
  1996-02-01 02:00:00 1489.300
  1996-02-01 03:00:00 1501.300
  1996-02-01 04:00:00 1568.400
  1996-02-01 05:00:00 1629.400
  </code></pre>
  
  <p>While the predictions for one hour step:</p>
  
  <pre><code>pred$pred
  Time Series:
  Start = 3002 
  End  = 3002 
  Frequency = 1 
  [1] 7.480588
  </code></pre>