主要问题：如函数为f(X)=x1*x1*x1*x1+x2*x2时，算得的结果有问题，初步估计是因为迭代公式中出现了求梯度的模的分量造成的，有待继续改进，不过用BFGS算法C语言程序算时，上述问题没有发生，所以才说BFGS算法是无约束优化中最稳定的算法之一了-Main issues: If function f (X) = x1* x1* x1* x1+ x2* x2, the result of a problem considered, the preliminary estimate is that there has been seeking iterative formula weight gradient caused by mold, to be continue to improve, but with the BFGS algorithm in C program calculation, the above problem does not occur, so it is said BFGS algorithm for unconstrained optimization algorithms in one of the most stable