On Bayesian Curve Fitting Via Auxiliary Variables

Abstract

In this article we revisit the auxiliary variable method introduced in Smith and kohn (1996) for the fitting of P-th order spline regression models with an unknown number of knot points. We introduce modifications which allow the location of knot points to be random, and we further consider an extension of the method to handle models with non-Gaussian errors. We provide a new algorithm for the MCMC sampling of such models. Simulated data examples are used to compare the performance of our method with existing ones. Finally, we make a connection with some change-point problems, and show how they can be re-parameterised to the variable selection setting.