I would like to know how i could use Gretl to make forecasts using AR modeling under the following conditions:

1. the observations used for making the forecasts are both positively and negatively biased.
2.Both the positive and negative values of bias have ranges of values from (28.1 to 1389) and (-57 to -250)

I seem to get some result by :

1. importing the time series data
2.conduct AR modeling with AR-4 and MA-4
3. add to data set the fitted values (by picking add to data set ->fitted values from model data  menu)
4. do Ar modeling on the new data set (options AR-4 and MA-4)

I would appreciate any feedback.

Deepak Muricken

Deepak Muricken
Renewable Resource Engineer I
Business Performance & Planning, SaskPower

Phone      :   (306)566-3136
Fax           :   (306)566-2916
Email       :   dmuricken@saskpower.com