LOG Subcommand (PROBIT command)

LOG specifies the base of the logarithmic transformation of the predictor variables or suppresses the default log transformation.

  • LOG applies to all predictors.
  • To transform only selected predictors, use COMPUTE commands before the Probit procedure. Then specify NONE on the LOG subcommand.
  • If LOG is omitted, a logarithm base of 10 is used.
  • If LOG is used without a specification, the natural logarithm base e (2.718) is used.
  • If you have a control group in your data and specify NONE on the LOG subcommand, the control group is included in the analysis. See the topic NATRES Subcommand (PROBIT command) for more information.

You can specify one of the following on LOG:

value. Logarithm base to be applied to all predictors.

NONE. No transformation of the predictors.

Example

PROBIT R OF N BY ROOT (1,2) WITH X
  /LOG = 2.
  • LOG specifies a base-2 logarithmic transformation.