文摘
In this paper, we propose a variant FR (VFR) formula and corresponding spectral-type conjugate gradient method (SVFR) such that the direction generated is always a descent direction for the objective function. We also extend to such that and have similar conclusions. Under appropriate conditions, we prove that the proposed method is globally convergent under not only Wolfe line search but also Armijo-type line search. Numerical experiments show the SVFR method performs well.