title: repeated forecasts gives same values
body: <p>I have a monthly dataset of performance (in terms of %) of different sectors in a company in the form</p>
  
  <pre><code>   Date    |Sector  |Value
  2016-01-01 |Sect 1  |-20
  2016-02-01 |Sect 1  |10
  2016-01-01 |Sect 2  |23
  2016-02-01 |Sect 1  |10 
  </code></pre>
  
  <p>the data has 20 Sectors and monthly data till June 2018. Now I want to forecast Value for the next month. I used the below code:</p>
  
  <pre><code>combine_ts &lt;- function(data, h=1, frequency= 12, start= c(2016,5), 
  end=c(2018,6)) 
  {
    results &lt;- list()
    sectgrowthsub &lt;- data[!duplicated(sectgrowthdf2[,2]),]
    sectgrowthts &lt;- ts(sectgrowthsub[,3], frequency = frequency, start = start, 
    end = end)
  
  
    for (i in 1:(nrow(sectgrowthsub))) {    
    results[[i]] &lt;- data.frame(Date = 
    format(as.Date(time(forecast(auto.arima(sectgrowthts), h)$mean)), "%b-%y"),
                           SectorName = rep(sectgrowthsub[,2], h),
                           PointEstimate = forecast(auto.arima(sectgrowthts), 
                           h=h)$mean[i])
  
      }
  
  return(data.table::rbindlist(results)) 
  }
  fore &lt;- combine_ts(sectgrowthsub) 
  </code></pre>
  
  <p>The problem in this case is that Value forecast is the same for all the Sectors.
  Help is much appreciated </p>