FUNCTIONS Subcommand (DISCRIMINANT command)

By default, DISCRIMINANT computes all possible functions. This is either the number of groups minus 1 or the number of predictor variables, whichever is less. Use FUNCTIONS to set more restrictive criteria for the extraction of functions.

FUNCTIONS has three parameters:

n. Maximum number of functions. The default is the number of groups minus 1 or the number of predictor variables, whichever is less.

n. Cumulative percentage of the sum of the eigenvalues. The default is 100.

n. Significance level of function. The default is 1.0.

  • The parameters must always be specified in sequential order (n 1, n 2, n 3). To specify n 2, you must explicitly specify the default for n 1. Similarly, to specify n 3, you must specify the defaults for n 1 and n 2.
  • If more than one restriction is specified, the program stops extracting functions when any one of the restrictions is met.
  • When multiple FUNCTIONS subcommands are specified, the program uses the last; however, if n 2 or n 3 are omitted on the last FUNCTIONS subcommand, the corresponding specifications on the previous FUNCTIONS subcommands will remain in effect.

Example

DISCRIMINANT  GROUPS=CLASS(1,5)
  /VARIABLES = SCORE1 TO SCORE20
  /FUNCTIONS=4,100,.80.
  • The first two parameters on the FUNCTIONS subcommand are defaults: the default for n 1 is 4 (the number of groups minus 1), and the default for n 2 is 100.
  • The third parameter tells DISCRIMINANT to use fewer than four discriminant functions if the significance level of a function is greater than 0.80.