R help - Apr 2013 - Questions about out-of-sample forecast using random walk

Hi there,



I'm a bit confused about which command should I use when performing an
out-of-sample forecast using random walk. I have som time sereis data from
1957Q1 to 2011Q4, I want to use a fraction of data from 1960Q1 to 1984Q4 to
forecast data from 1985Q1 onwards using random walk model and evaluate the
forecasting performance based on the true data I have. I used rwf command from
'forecast' package to do this. However, the results I obtained is all
around the value of 1984Q4, which is quite different from the true data that
shows an increasing trend with time. Could you me give some suggestions on which
command should I choose to perform the random walk forecast and get the Mean
Squared Forecast Error and Mean Absolute Error of the forecast? It would be
really helpful if you can reply as soon as possible since I'm urgently need
this. Thanks a lot.



Kind Regards,



Lavender

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