function[x,val,k] dampnm(fun,gfun,hesse,x0)

功能：用阻尼牛顿法求解无约束问题：min f(x)

输入：x0是初始点，fun,gfun,hesse分别是目标函数值，梯度，hesse矩阵的函数

输出：x,val分别是近似最优点和最优值，k是迭代次数-The function/x, val, k　 dampnm (fun, gfun, Hesse, x0)

　function: with damped Newton method for solving unconstrained problem: min f (x)

　input: x0 is the initial point, fun, gfun, Hesse is the objective function value respectively, gradient, Hesse matrix function

　output: x, val is approximate optimal point and the optimal value respectively, k is the number of iterations