The Thin-Plate Spline analysis is intended for scatter plot smoothing. The Thin-Plate Spline analysis uses a penalized least squares method to fit a nonparametric regression model. You can use the generalized cross validation (GCV) function to select the amount of smoothing.
You can run the Thin-Plate Spline analysis by selecting Analysis Data Smoothing Thin-Plate Spline from the main menu. The computation of the fitted spline function, confidence limits, and related statistics is implemented by calling the TPSPLINE procedure in SAS/STAT software. See the TPSPLINE procedure documentation in the SAS/STAT User's Guide for additional details.