%多變量尋優的共軛梯度
%允許迭代的最大次數M,變量數N，

n=4;        %變量數
x0=[-3;-1;-3;-1];
x1=x0;      %代表k次迭代點

M=2000;
e=0.0001;

df0=dfm(x0);

s0=-df0;
s=s0;

ndf0=norm(df0);
ndf1=ndf0;

tic

for i=1:M

    if ndf1<e
        break;
    end

    for j=1:n

    a=fpart618(x1,s);     %采用618法進行單變量尋優
    x2=x1+a*s;            %代表k＋1次迭代點

    x0=x1;
    x1=x2;

    df0=dfm(x0);
    df1=dfm(x1);

    ndf0=ndf1;
    ndf1=norm(df1);

    s0=s;
    s=-df1+s0*ndf1^2/ndf0^2;            %搜索方向

    end

    s=-df1;

end

i
x1
fm(x1)
toc