02-08-2013 02:44 PM
hi ..I'm trying to fit a Forecast Model using Proc Forecast. I would like to translate the Estimates into equation. Could anyone help me to code the equation and how Forecast Values in the output are calculated.
Attached is the data and forecast values (got using Method=Expo Trend=2 lead=3).
02-11-2013 06:40 PM
Never mind my earlier response - I guess you are running something like this (otherwise please do mind my earlier response :smileylaugh:
proc forecast data=have method=expo trend=2 outall outest=est lead=3;
You will find plenty of details of how the EXPO method of the FORECAST procedure works, here: http://support.sas.com/documentation/cdl/en/etsug/63939/HTML/default/viewer.htm#etsug_forecast_sect0...
(scroll down to EXPO Method). In particular you will find how to interpret the values of the OUTEST data set.
May I also suggest to have a look at the ESM procedure instead - for your data set the code will look similar to this (I'm proposing to consider a DAMPTREND model, but you can change that of course):
proc esm data=have out=outesm lead=3 outest=est2 plot=forecasts back=3;
id time interval=obs;
forecast actual / method=damptrend;
which results in:
Note that in this case the parameters listed in the OUTEST data set are easier to read: