You can use the Plots tab to create plots that graphically display results of the Thin-Plate Spline analysis. (See Figure 19.3.) The raw residuals are computed as , where indicates the variable that contains the predicted values of the response.
Creating a plot often adds one or more variables to the data table. The following plots are available:
creates a scatter plot of the X and Y variables, overlaid with a smoother.
creates a scatter plot of the Y variable versus the predicted values.
creates a scatter plot of the residuals versus the predicted values.
creates a scatter plot of the residuals versus the X variable.
creates a scatter plot of the GCV criterion versus the smoothing parameter value for a range of smoothing parameter values.
specifies the minimum value of the smoothing parameter to consider.
specifies the maximum value of the smoothing parameter to consider.
specifies the number of smoothing parameters to consider. The value in this field is combined with the values in the previous two fields to form a list of values for the LOGNLAMBDA= option.
Note: SAS/IML Studio adds a smoother to an existing scatter plot when both of the following conditions are satisfied:
The scatter plot is the active window when you select the analysis.
The scatter plot variables match the analysis variables.
Chapter 18: Data Smoothing: Loess, discusses how to display multiple smoothers in a single scatter plot and how to remove smoothers from a scatter plot.