exm0572_1.m

matlab程序

shg     %使当前图形窗口位于前台
%exm0572_1.m
clear;clf;shg
x=-3:0.1:3;y=-2:0.1:4;
[X,Y]=meshgrid(x,y);
F=100*(Y-X.^2).^2+(1-X).^2;
contour3(X,Y,F,300),
xlabel('x'),ylabel('y'),axis([-3,3,-2,4,0,inf]),view([161,22])
colormap(summer)
hold on
x0=[-1.2,1];		%搜索的起点
options.Display='final';
ff=inline('100*(x(2)-x(1)^2)^2+(1-x(1))^2','x');  

[sx,sfval,sexit,soutput]=fminsearch(ff,x0)  

[ux,sfval,uexit,uoutput,grid,hess]=fminunc(ff,x0) 

text(x0(1),x0(2),4000,'\downarrow')
text(x0(1)+1,x0(2)+1.5,7000,'\fontname{隶书}\fontsize{16} 起点')
text(ux(1),ux(2),0,'\downarrow')
text(ux(1)+1,ux(2)+1.5,3000,'\fontname{隶书}\fontsize{16} 极小值点')

hold off