This statement applies to the following SAS/STAT procedures: GENMOD, LOGISTIC, ORTHOREG, and PLM. It also applies to the RELIABILITY procedure in SAS/QC software.
The EFFECTPLOT statement produces a display (effect plot) of a complex fitted model and provides options for changing and enhancing the display. One simple effect plot is the display for a linear regression of the response Y on a single predictor X: the regression line is drawn with the predicted response on the Y axis and the covariate on the X axis. The regression line can be enhanced by displaying the observations and adding confidence and prediction limits. When your model is more complicated—with more continuous and categorical covariates, nestings and interactions, and link functions—the effect plots display the behavior of some covariates over their ranges while holding other covariates at some fixed values; this can enable easier interpretation and explanation of the resulting model.
By default, a single plot is produced based on the type of response variable and the number of continuous and classification covariates in the model. You can also specify options to do the following:
select the variables to display in the plots
produce multiple plots based on the following: the levels of classification covariates; the minimum, maximum, mean, or middle (midrange) value of continuous covariates; and specified values of the covariates
specify different fixed values for continuous and classification covariates that are not displayed in the plot
panel and unpanel plots
select variables to slice or group by
display (or remove from display) observations and confidence limits