desend.m

来自「最优化算法」· M 代码 · 共 34 行

format long %Scaled fixed point format, with 15 digits for double; 8 digits for single.
x=[0,0];
x=input('请输入初始值[x0,x1]=');
s=input('请输入初始精度s＝');
g=D_F(x);
g=g.';%转置为列向量；
k=1;
while(norm(g)>s) 
    s_k=-g;   r=min_F(x,s_k);   x=x+r.*s_k.';
    g=D_F(x);
    g=g.';
    fprintf('iteration step %d\n', k); 
    fprintf('The result is %8.5f\n', x); 
    fprintf('The daosu is %8.5f\n', g);
    k=k+1;
end
%axis normal;
%hold on;
%view([1,1,1]);
view(0,0);%视角
[x,y]=meshgrid(-50:1:100);
z=peaks(x,y);
c=ones(size(z));
for i=-50:100
    for j=-50:100
        p=[i,j];  z(i+51,j+51)=F(p);
%        plot3(i,j,z);
    end
end
surfc(x,y,z,c);
grid on;
%hold off;
%x=meshgrid(-50,1,100);