J Austral Math Soc Ser A 57 pp316--329, 1994.
(Received 14 June 1991; revised 21 February 1992)
The backfitting algorithm is an iterative procedure for fitting additive models in which, at each step, one component is estimated keeping the other components fixed, the algorithm proceeding component by component and iterating until convergence. Convergence of the algorithm has been studied by Buja, Hastie, and Tibshirani (1989). We give a simple, but more general, geometric proof of the convergence of the backfitting algorithm when the additive components are estimated by penalized least squares. Our treatment covers spline smoothers and structural time series models, and we give a full discussion of the degenerate case. Our proof is based on Halperin's (1962) generalization of von Neumann's altenating projection theorem.
1991 AMS Subject Classification: 62G05, 62J05, 65D07, 65D10
Last Modified: Wed Jun 14 10:48:51 2006