DIFF Subcommand (CASEPLOT command)

DIFF specifies the degree of differencing used to convert a nonstationary variable to a stationary one with a constant mean and variance before plotting.

  • You can specify any positive integer on DIFF.
  • If DIFF is specified without a value, the default is 1.
  • The number of values displayed decreases by 1 for each degree of differencing.

Example

CASEPLOT VARIABLES = TICKETS
  /DIFF=2.
  • In this example, TICKETS is differenced twice before plotting.