用Powell法编程求解无约束优化问题.doc

用Powell法编程求解无约束优化问题题目：用Powell法编程求解无约束优化问题min ， 要求：（1）程序流程图?????（2）源程序清单?????（3）运行结果求解过程：流程图....程序清单源程序由以下几个部分组成：（1）??????目标函数程序清单：建立函数f（）以f.m存盘%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%函数名：f（），参数2个%函数作用：带入参数，求解目标函数f（）%可以更改目标函数为任意二维函数，结果由m返回%作者：WYH???学号：xxxxxxxx%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%function m=f(x1,x2)m=x1^2+x2^2-x1*x2-10*x1-4*x2+60; %目标函数（2）??????关于α的目标函数清单：建立函数y（）以y.m存盘%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%函数名：y（），参数5个%函数作用：带入参数，求解关于α的一元函数y（α），根据原目标函数更改此函数，%其中原目标函数变量X1＝x1+alpha*d1，X2＝x2+alpha*d2结果由m返回%作者：WYH???学号：xxxxxxxx%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%function m=y(x1,x2,d1,d2,alpha)m=(x1+alpha*d1)^2+(x2+alpha*d2)^2-(x1+alpha*d1)*(x2+alpha*d2)-10*(x1+alpha*d1)-4*(x2+alpha*d2)+60; %含α的目标函数，其形式与原目标函数f（x）＝x1^2+x2^2-x1*x2-10*x1-4*x2+60一致（3）?????? 外推法求解一元函数最小值区间：建立函数section（）以sextion.m存盘%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%函数名：section（），参数4个%函数作用：利用外推法求解关于α的函数y（α）的极小点α*所在的区间【a，b】，%结果由a、b返回%作者：WYH???学号：xxxxxxxx%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%function [a,b]=section(x1,x2,d1,d2)x11=x1; %给出起始点坐标x1，x2和有哪些信誉好的足球投注网站方向d1，d2x22=x2;d11=d1;d22=d2;h0=1;???%初始化h=h0;alpha1=0;y1=y(x11,x22,d11,d22,alpha1); %代入α1求解y1alpha2=h;y2=y(x11,x22,d11,d22,alpha2);t=0;if y2y1??? h=-h;alpha3=alpha1;y3=y1;t=1; %如果y2y1，则改变有哪些信誉好的足球投注网站方向endwhile(1)??? if t==1????????alpha1=alpha2;y1=y2; %实现交换????????alpha2=alpha3;y2=y3;??? else t=1;??? end??? alpha3=alpha2+h;y3=y(x11,x22,d11,d22,alpha3);??? if y3y2????????h=2*h; %改变有哪些信誉好的足球投注网站步长，将其加倍??? else ????????break;??? endendif alpha1alpha3??? tem=alpha1;alpha1=alpha3;alpha3=tem; %比较大小，保证输出区间为【a，b】??? a=alpha1;b=alpha3;else a=alpha1;b=alpha3;end（1）??????黄金分割法求解区间已知的一元函数最小值：建立函数ALPHA（）以ALPHA.m存盘%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%函数名：ALPHA（），参数6个%函数作用：利用黄金分割法求解关于α的函数y（α）的极小点α*，已知α所在的%区间【A，B】，结果由α返回%作者：WYH???学号：xxxxxxxx%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%function alpha=ALPHA(x1,x2,d1,d2,A,B)x11=x1;x22=x2;???%给出起始点坐标x1，x2和有哪些信誉好的足球投注网站方向d1，d2d