APPLY Subcommand (ACF command)

APPLY allows you to use a previously defined ACF model without having to repeat the specifications.

  • The only specification on APPLY is the name of a previous model in quotation marks. If a model name is not specified, the model specified on the previous ACF command is used.
  • To change one or more model specifications, specify the subcommands of only those portions you want to change after the APPLY subcommand.
  • If no series are specified on the ACF command, the series that were originally specified with the model being reapplied are used.
  • To change the series used with the model, enter new series names before or after the APPLY subcommand.

Example

ACF VARIABLES = TICKETS
  /LN
  /DIFF=1
  /SDIFF=1
  /PERIOD=12
  /MXAUTO=50.
ACF VARIABLES = ROUNDTRP
  /APPLY.
ACF APPLY
  /NOLOG.
ACF APPLY 'MOD_2'
  /PERIOD=6.
  • The first command requests a maximum of 50 autocorrelations for the series TICKETS after a natural log transformation, differencing, and one degree of seasonal differencing with a periodicity of 12 have been applied. This model is assigned the default name MOD_1.
  • The second command displays and plots the autocorrelation function for the series ROUNDTRP using the same model that was used for the series TICKETS. This model is assigned the name MOD_2.
  • The third command requests another autocorrelation function of the series ROUNDTRP using the same model but without the natural log transformation. Note that when APPLY is the first specification after the ACF command, the slash (/) before it is not necessary. This model is assigned the name MOD_3.
  • The fourth command reapplies MOD_2, autocorrelations for the series ROUNDTRP with the natural log and differencing specifications, but this time with a periodicity of 6. This model is assigned the name MOD_4. It differs from MOD_2 only in the periodicity.