The KEEPEVENT statement specifies which event variables in the data file are to be included in the OUTEVENT= data set. As a result, the KEEPEVENT statement is valid only for data files containing event-oriented time series data. All the BY variables, the time ID variable DATE, and the event-grouping variable EVENT are always included in the OUTEVENT= data set. These variables cannot be referenced in the KEEPEVENT statement. If any of these variables are referenced, a warning message is given and the reference is ignored.

The variable list can contain variable names or name range specifications. See Variable Lists for details.

Only one KEEPEVENT or one DROPEVENT statement can be used. KEEPEVENT and DROPEVENT are mutually exclusive.

You can also use the KEEP= data set option to control which event variables to include in the OUTEVENT= data set. However, the KEEPEVENT statement differs from the KEEP= data set option in several respects:

• The KEEPEVENT statement selection is applied before variables are read from the data file, while the KEEP= data set option selection is applied after variables are read and as they are written to the OUTEVENT= data set. Therefore, using the KEEPEVENT statement instead of the KEEP= data set option is much more efficient.

• If the KEEPEVENT statement causes no event variables to be selected, then no observations are output to the OUTEVENT= data set.