[x1,x2]=meshgrid(-10:.1:10);
figure(1);mesh(x1,x2,shubert(x1,x2));            %畫出Shubert函數(shù)圖像
%定義遺傳算法參數(shù)
NIND=40;               %個(gè)體數(shù)目(Number of individuals)
MAXGEN=50;             %最大遺傳代數(shù)(Maximum number of generations)
NVAR=2;                %變量數(shù)目
PRECI=25;              %變量的二進(jìn)制位數(shù)(Precision of variables)
GGAP=0.9;              %代溝(Generation gap)
%建立區(qū)域描述器(Build field descriptor)
FieldD=[rep([PRECI],[1,NVAR]);rep([-10;10],[1,NVAR]);rep([1;0;1;1],[1,NVAR])];
Chrom=crtbp(NIND, NVAR*PRECI);                         %創(chuàng)建初始種群
gen=0;                                                 
trace=zeros(MAXGEN, 2);                                %遺傳算法性能跟蹤初始值
x=bs2rv(Chrom, FieldD);                                %初始種群十進(jìn)制轉(zhuǎn)換
ObjV=Shubert(x(:,1),x(:,2));                           %計(jì)算初始種群的目標(biāo)函數(shù)值
while gen<MAXGEN
    FitnV=ranking(ObjV);                               %分配適應(yīng)度值(Assign fitness values)
    SelCh=select('sus',Chrom,FitnV,GGAP);              %選擇
    SelCh=recombin('xovsp',SelCh,0.7);                 %重組
    SelCh=mut(SelCh);                                  %變異
    x=bs2rv(SelCh,FieldD);                             %子代十進(jìn)制轉(zhuǎn)換
    ObjVSel=Shubert(x(:,1),x(:,2));
    [Chrom ObjV]=reins(Chrom,SelCh,1,1,ObjV,ObjVSel);  %重插入
    gen=gen+1;
    [Y, I]=min(ObjV);
    Y,bs2rv(Chrom(I,:),FieldD)                         %輸出每一次的最優(yōu)解及其對(duì)應(yīng)的自變量值
    trace(gen,1)=min(ObjV);                            %遺傳算法性能跟蹤
    trace(gen,2)=sum(ObjV)/length(ObjV);
    if(gen==50)                                        %迭代數(shù)為50時(shí)畫出目標(biāo)函數(shù)值分布圖
        figure(2);
        plot(ObjV);hold on;
        plot(ObjV,'b*');grid;
    end
end
figure(3);clf;
plot(trace(:,1));hold on;
plot(trace(:,2),'-.');grid
legend('解的變化','種群均值的變化')