PERIOD Subcommand (PPLOT command)
PERIOD indicates
the length of the period to be used by the SDIFF subcommand.
- The specification on
PERIODindicates how many observations are in one period or season. You can specify any positive integer onPERIOD. - The
PERIODsubcommand is ignored if it is used without theSDIFFsubcommand. - If
PERIODis not specified, the periodicity that is established onTSET PERIODis in effect. IfTSET PERIODis not specified either, the periodicity that is established on theDATEcommand is used. If periodicity was not established anywhere, theSDIFFsubcommand will not be executed.
Example
PPLOT VARIABLES = TICKETS
/SDIFF=1
/PERIOD=12.
- This command applies 1 degree of seasonal differencing with 12 observations per season to the variable TICKETS.