The LS conjugate gradient method was changed in this paper, in which the technique of nonmonotone line search is used.Under mild assumption, the global convergence of the method was proved.

• 对LS共轭梯度法做了某些变型，在非单调线搜索下，该方法保证每次迭带都会产生下降的方向，在较弱的条件下得到算法全局收敛性。