Example 13.3 Specifying the Forecasting Model

This example illustrates how the ESM procedure can be used to specify different models for different series. Internet data from the previous example are used for this illustration.

This example, forecasts the BOATS variable by using the seasonal exponential smoothing model (SEASONAL), the CARS variable by using the Winters (multiplicative) model (MULTWINTERS), and the PLANES variable by using the Log Winters (additive) model. The following ESM procedure statements forecast each of the transactional data series based on these requirements:

   proc esm data=websites out=nextweek lead=7;
      id time interval=dtday accumulate=total;
      forecast boats   / model=seasonal;
      forecast cars    / model=multwinters;
      forecast planes  / model=addwinters transform=log;
   run;