A modified nonlinear Polak–Ribière–Polyak conjugate gradient method with sufficient descent property

In this paper, a small and necessary revision on an assumption condition of Aminifard and Babaie-Kafaki (Calcolo, 2019. https://doi.org/10.1007/s10092-019-0312-9) is made. By a little modification, a new conjugate gradient method is proposed, in which the search directions satisfy the sufficient descent condition with the strong Wolfe line search. The main difference between two algorithms is that the proposed method is globally convergent without boundedness assumption on the steplength. Comparative numerical results demonstrating efficiency of the proposed method are reported.