PERIOD Subcommand (CASEPLOT command)

PERIOD indicates the length of the period to be used by the SDIFF subcommand.

  • The specification on PERIOD indicates how many observations are in one period or season and can be any positive integer.
  • PERIOD is ignored if it is used without the SDIFF subcommand.
  • If PERIOD is not specified, the periodicity established on TSET PERIOD is in effect. If TSET PERIOD is not specified either, the periodicity established on the DATE command is used. If periodicity is not established anywhere, the SDIFF subcommand will not be executed.

Example

CASEPLOT VARIABLES = TICKETS
  /SDIFF=1
  /PERIOD=12.
  • This command applies one degree of seasonal differencing with 12 observations per season to TICKETS before plotting.