简单的二元遗传matlab算法.doc

老师： 这是简单的y=x1^2+x2^2,其中x1,x2在[-10，10] %产生初始种群pop，共a个个体，每个个体编码长度为b function [pop1,pop2]=initate(a,b) pop1=round(rand(a,b)); pop2=round(rand(a,b)); %通过number函数将个体编码转化为十进制并落在区间内 function [x1,x2]=number(pop1,pop2) [a,b]=size(pop1); pop11=zeros(a,b); pop22=zeros(a,b); for i=1:b pop11(:,i)=pop1(:,i).*2^(b-i); pop22(:,i)=pop2(:,i).*2^(b-i); end pop11=sum(pop11,2); pop22=sum(pop22,2); x1=(pop11.*20)./2^b-10; x2=(pop22.*20)./2^b-10; %计算个体适应值 function fit=fitness(x1,x2) fit=x1.^2+x2.^2; %通过选择/交叉/变异产生新的种群 function [newpop1,newpop2]=new(pop1,pop2,pm,pc) [a,b]=size(pop1); newpop1=pop1; newpop2=pop2; [x1,x2]=number(pop1,pop2); fit=fitness(x1,x2); fitvalue=fit/sum(fit); pw=fitvalue(1); ps=sort(rand(a)); new=1; for i=1:a if ps(i)pw newpop1(i)=pop1(new); newpop2(i)=pop2(new); else new=new+1; pw=pw+fitvalue(new); end end for i=1:a if randpc point1=round(rand*(b-1)+1); newpop1(i,1:point1)=pop1(a-i+1,1:point1); newpop1(a-i+1,1:point1)=pop1(i,1:point1); end if randpc point2=round(rand*(b-1)+1); newpop2(i,1:point2)=pop2(a-i+1,1:point2); newpop2(a-i+1,1:point2)=pop2(i,1:point2); end end for i=1:a if randpm point1=round(rand*(b-1)+1); newpop1(i,point1)=1-pop1(i,point1); end if randpm point2=round(rand*(b-1)+1); newpop2(i,point2)=1-pop2(i,point2); end end %主函数 clear a=30; b=15; pc=0.6; pm=0.0001; [pop1,pop2]=initate(a,b); [x1,x2]=number(pop1,pop2); fit=fitness(x1,x2); [yy,xx]=min(fit); besty=yy; bestx1=x1(xx); bestx2=x2(xx); for N=1:200 [newpop1,newpop2]=new(pop1,pop2,pm,pc); [x1,x2]=number(newpop1,newpop2); fit=fitness(x1,x2); [yy,xx]=min(fit); if bestyyy besty=yy; bestx1=x1(xx); bestx2=x2(xx); end pop1=newpop1; pop2=newpop2; end [x1,x2]=number(pop1,pop2); bestx1=x1(xx) bestx2=x2(xx) besty