jintuifazone.m

黄金分割法

%单谷区间
%进退法求函数最小值区间
%宋斌
a0=5;
h0=0.01;
a1=a0;
h=h0;
y1=a1^4-4*a1^3-6*a1^2-16*a1+4;
a2=a1+h;
y2=a2^4-4*a2^3-6*a2^2-16*a2+4;
%while(1)
    if y2>y1
       h=-h;
        a3=a1;
        y3=y1;
       while(1)
            if y2>y3
                a1=a2;
                y1=y2;
                a2=a3;
                y2=y3;
                a3=a2+h;
                y3=a3^4-4*a3^3-6*a3^2-16*a3+4;
                if y3>y2
                    break
                end
            end
        end 
    end
%end
a1,a3