Variable Lists (RBF command)

The command line variable lists specify the dependent variables, any categorical predictors (also known as factors), and any scale predictors (also known as covariates).

Dependent Variables

  • A list of one or more dependent variables must be the first specification on the RBF command.
  • Each dependent variable may be followed by the measurement level specification, which contains, in parentheses, the MLEVEL keyword followed by an equals sign and then S for scale, O for ordinal, or N for nominal. RBF treats ordinal and nominal dependent variables equivalently as categorical.
  • If a measurement level is specified, then it temporarily overrides a dependent variable’s setting in the data dictionary.
  • If no measurement level is specified, then RBF defaults to the dictionary setting.
  • If a measurement level is not specified and no setting is recorded in the data dictionary, then a numeric variable is treated as scale and a string variable is treated as categorical.
  • Dependent variables can be numeric or string.
  • A string variable may be defined as ordinal or nominal only.

Predictor Variables

  • The names of the factors, if any, must be preceded by the keyword BY.
  • If the keyword BY is specified with no factors, then a warning is issued and BY is ignored.
  • The names of the covariates, if any, must be preceded by the keyword WITH.
  • If the keyword WITH is specified with no covariates, then a warning is issued and WITH is ignored.
  • If the dependent variable is specified within a factor list or a covariate list, then it is ignored in the list.
  • All variables specified within a factor or covariate list must be unique. If duplicate variables are specified within a list, then the duplicates are ignored.
  • If duplicate variables are specified across the factor and covariate lists, then an error is issued.
  • Factor variables can be numeric or string.
  • Covariates must be numeric.
  • At least one predictor must be specified.