Preconditioned conjugate gradient methods for the solution of indefinite least squares problems

  • Authors:
  • Qiaohua Liu;Xianjuan Li

  • Affiliations:
  • Department of Mathematics, Shanghai University, Shanghai, China;Department of Mathematics, Shanghai University, Shanghai, China

  • Venue:
  • Calcolo: a quarterly on numerical analysis and theory of computation
  • Year:
  • 2011

Quantified Score

Hi-index 0.00

Visualization

Abstract

The conjugate gradient (CG) method is considered for solving the large and sparse indefinite least squares (ILS) problem min驴 x (b驴Ax) T J(b驴Ax) where J=diag驴(I p ,驴I q ) is a signature matrix. However the rate of convergence becomes slow for ill-conditioned problems. The QR-based preconditioner is found to be effective in accelerating the convergence. Numerical results show that the sparse Householder QR-based preconditioner is superior to the CG method especially for sparse and ill-conditioned problems.