A note on the optimal parameters of USSOR method for solving linear least squares problems

Abstract

For solving  rank deficient linear least squares problems,   unsymmetric successive overrelaxation  (USSOR) type methods are investigated by some researchers recently. In this note, we continue to study the USSOR method for solving  rank deficient linear least squares problems and obtain  the optimal iteration parameters and the corresponding optimal convergence factors. Numerical experiments are given to examine the feasibility and effectiveness of the USSOR method with optimal parameters.