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The FORECAST Procedure

Getting Started: FORECAST Procedure

To use PROC FORECAST, specify the input and output data sets and the number of periods to forecast in the PROC FORECAST statement, and then list the variables to forecast in a VAR statement.

For example, suppose you have monthly data on the sales of some product in a data set named PAST, as shown in Figure 15.1, and you want to forecast sales for the next 10 months.

Figure 15.1 Example Data Set PAST
Obs date sales
1 JUL89 9.5161
2 AUG89 9.6994
3 SEP89 9.2644
4 OCT89 9.6837
5 NOV89 10.0784
6 DEC89 9.9005
7 JAN90 10.2375
8 FEB90 10.6940
9 MAR90 10.6290
10 APR90 11.0332
11 MAY90 11.0270
12 JUN90 11.4165
13 JUL90 11.2918
14 AUG90 11.3475
15 SEP90 11.2913
16 OCT90 11.3771
17 NOV90 11.5457
18 DEC90 11.6433
19 JAN91 11.9293
20 FEB91 11.9752
21 MAR91 11.9283
22 APR91 11.8985
23 MAY91 12.0419
24 JUN91 12.3537
25 JUL91 12.4546

The following statements forecast 10 observations for the variable SALES by using the default STEPAR method and write the results to the output data set PRED:

   proc forecast data=past lead=10 out=pred;
      var sales;
   run;

The following statements use the PRINT procedure to print the data set PRED:

   proc print data=pred;
   run;

The PROC PRINT listing of the forecast data set PRED is shown in Figure 15.2.

Figure 15.2 Forecast Data Set PRED
Obs _TYPE_ _LEAD_ sales
1 FORECAST 1 12.6205
2 FORECAST 2 12.7665
3 FORECAST 3 12.9020
4 FORECAST 4 13.0322
5 FORECAST 5 13.1595
6 FORECAST 6 13.2854
7 FORECAST 7 13.4105
8 FORECAST 8 13.5351
9 FORECAST 9 13.6596
10 FORECAST 10 13.7840

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