Perturbations are added to these main effects, then used to create the interactions. The default value is 100. The default is f8.4. Any valid SPSS numeric format may be specified. The new dataset contains niter cases and the variable names used in the regression.
Notes Use lower case only.
If interactions are included then the first four characters of variable names should be unique to avoid problems when creating names for the interactions. If the perturb macro is too limited for your model, e.g. because of complex nonlinear functions or higher order interactions, it can be used to generate a template which can be adapted to the model at hand. This will print the syntax generated by the macro to the output, which can be modified to specify the desired model. This problem seems to occur because of a combination of macro and matrix syntax errors, e.g. when matrix tries to read a variable that doesn't exist due to a mistake in macro syntax. Conditioning diagnostics, collinearity and weak data in regression.