%P199-8

%x=linspace(-100,100,101);
%y=x;
function f=fun_value(x,y)
for i=1:length(x)
    f(i)=0.5-((sin((x(i)^2+y(i)^2)^0.5))^2-0.5)/((1.0+0.001*(x(i)^2+y(i)^2))^2);%21.5+x(i)*sin(4*pi*x(i))+y(i)*sin(20*pi*y(i));
end
%mesh(x,y,f)
%fprintf('函數最大值：')
%max(max(f))