STAT 425 Week 08 - Regression Splines

Regression splines provide a flexible family of curves that can be fit to data using ordinary least squares linear model methods, yet closely model arbitrary smooth response curves. We study how B-spline and natural cubic spline basis functions allow us to do this. We also discuss how to use k-fold cross-validation to select the optimal number of knots or degrees of freedom for the basis. As an illustration the methods are applied to birth rate data from 1917 to 2003.