Specifying the PLOTS=SURFACE option in the PROC RSREG statement displays contour plots for all pairs of factors in the model (see Example 75.1), while specifying the PLOTS=SURFACE(3D) option displays a three-dimensional surface as shown in Figure 75.4.

You can also generate predicted values for a grid of points with the PREDICT option (see the section Getting Started: RSREG Procedure for an example) and then use these values to create a contour plot or a three-dimensional plot of the response surface over a two-dimensional grid. Any two factor variables can be chosen to form the grid for the plot. Several plots can be generated by using different pairs of factor variables.