%%%*****用遺傳算法求函數(shù)最大值（雙輸入單輸出）****%%%%%
clc;
clear;
x1min=-3.0;?%輸入變量1的變化范圍
x1max=12.1;???????
x2min=4.1;??%輸入變量2的變化范圍
x2max=5.8;??????????????????????????????????????
pb=0.001;??%變異概率

N=20;????%初始種群數(shù)目＝20
s1=ceil（log2（1000*（x1max-x1min）））;?%計(jì)算二進(jìn)制串的長度
s2=ceil（log2（1000*（x2max-x2min）））;?
s=s1+s2;????%%種群的位數(shù)

zq=randi（Ns）;?%產(chǎn)生初始種群，庫函數(shù)和for循環(huán)均可
%?for?i=1:N
%?????for?j=1:s
%?????????r=rand（1）;
%?????????if?r>0.5
%?????????zq（ij）=1;
%?????????else?zq（ij）=0;
%?????????end
%?????end
%?end

%%*****用于二進(jìn)制轉(zhuǎn)化為十進(jìn)制****
for?i=1:s1
????zhuanhuan（i1）?=?2^（s1-i）;
end
for?i=s1+1:s
????zhuanhuan（i1）?=?2^（s-i）;
end

for?k=1:500?%遺傳算法的次數(shù)
????%%********將二進(jìn)制轉(zhuǎn)換成十進(jìn)制
????for??i=1:N
????????j1（i）=zq（i1:s1）*zhuanhuan（1:s1）;
????????j2（i）=zq（is1+1:s）*zhuanhuan（s1+1:s）;
????end?
????%%****轉(zhuǎn)化為目標(biāo)函數(shù)值
????x1=x1min+j1*（x1max-x1min）/（2^s1-1）;
????x2=x2min+j2*（x2max-x2min）/（2^s2-1）;
????%%****計(jì)算適配值?
????f=21.5+x1.*sin（4*pi*x1）+x2.*sin（20*pi*x2）;
????%%%******依次得到最大值，平均值
????f_max（k）=max（f）;
????f_sum=sum（f）;
????f_avr（k）=sum（f）/N;
????%%******復(fù)制********?
????g=f/f_sum;??%計(jì)算選擇概率
??