title: Incompatible packages in R
body: <p>Working with time series in R, I find out that unfortunately, two packages seem to be incompatible with each other. These are forecast and TSA.</p>
  
  <p>The first snippet shows forecast working as it should.</p>
  
  <pre><code>require(forecast)
  test&lt;-ts(rnorm(100), frequency=12, start=c(2000,1))
  mod&lt;-arima(test, order=c(1,1,2))
  mod2&lt;-forecast.Arima(mod, h=12)
  </code></pre>
  
  <p>This MRE shows my problem:</p>
  
  <pre><code>require(forecast)
  require(TSA)
  test&lt;-ts(rnorm(100), frequency=12, start=c(2000,1))
  mod&lt;-arima(test, order=c(1,1,2))
  mod2&lt;-forecast.Arima(mod, h=12)
  </code></pre>
  
  <p>This is the error:</p>
  
  <pre><code> Error in ts(x) : 'ts' object must have one or more observations
  </code></pre>
  
  <p>What can be done in order to make both work (as I seem to need both), or what other packages could I use to work around this problem? I prioritize having forecast work over TSA.</p>