newton.m

优化设计中的一维搜索方法

function [fx,fy,iter]=Newton(func,Ini,limt)
if or(Ini<limt(1),Ini>limt(2))
    error('error input of Initial val!');
end
x = Ini;
dif1 = subs(diff(func));
dif2 = subs(diff(func,2));
iter = 0;
while abs(dif1)>10^10*eps
    d = -dif1/dif2;
    x = x+d;
    if or(x<limt(1),x>limt(2))
        error('wrong iterate direction!');
    end
    dif1 = subs(diff(func));
    dif2 = subs(diff(func,2));
    iter = iter+1;
end
fx = x;
fy = subs(func);