Computational experience with numerical methods for nonnegative least-squares problems, Report 09/04, Dipartimento di Energetica S. Stecco, Università di Firenze, (submitted for publication

Abstract. We discuss the solution of large-scale box-constrained linear least-squares problems by two recent affine-scaling methods: a cyclic Barzilai-Borwein strategy and an Inexact Newton-like method where a preconditioning technique allows for an efficient computation of the steps. A robust globally and fast locally convergent method based on the combination of the two procedures is presented along with extensive numerical results. 1. Introduction. W