遺傳算法Matlab實(shí)例講解課件

遺傳算法（GA）實(shí)例講解求函數(shù)f(x)=10*sin(5x)+7*cos(4x)，

x∈[0,10]的最大值：

1.函數(shù)最大值f(x)=10*sin(5x)+7*cos(4x)的最大值f1(x)=-f(x)

-10*sin(5x)-7*cos(4x)的最小值[x,fval]=fminbnd(‘-10*sin(5*x)-7*cos(4*x)’,0,10)x=1.5708fval=-17.0000x=7.8540fval=-17.0000f(x)=10*sin(5x)+7*cos(4x)，x∈[0,10]的最大值為：x1=1.5708x2=7.8540F(x1)=f(x2)=17.00002.主函數(shù)Matlab仿真主程序?qū)的值用一個(gè)10位的二值形式表示為二值問(wèn)題（編碼），一個(gè)10位的二值數(shù)提供的分辨率是(10-0)/(2^10-1)≈0.01。3.群體初始化

將x的值用一個(gè)10位的二值形式表示為二值問(wèn)題（編碼），一個(gè)10位的二值數(shù)提供的分辨率是每為(10-0)/(2^10-1)≈0.01。4.計(jì)算目標(biāo)函數(shù)值function[objvalue]=calobjvalue(pop)temp1=decodechrom(pop,1,10);x=temp1*10/1023;objvalue=10*sin(5*x)+7*cos(4*x);

end

5.計(jì)算個(gè)體適應(yīng)值functionfitvalue=calfitvalue(objvalue)globalCmin;Cmin=0;[px,py]=size(objvalue);fori=1:pxifobjvalue(i)+Cmin>0temp=Cmin+objvalue(i);elsetemp=0.0;endfitvalue(i)=temp;endfitvalue=fitvalue';

end

6.選擇function[newpop]=selection(pop,fitvalue)totalfit=sum(fitvalue);fitvalue=fitvalue/totalfit;fitvalue=cumsum(fitvalue);[px,py]=size(pop);ms=sort(rand(px,1));fitin=1;newin=1;whilenewin<=pxif(ms(newin))<fitvalue(fitin)newpop(newin)=pop(fitin);newin=newin+1;elsefitin=fitin+1;endendend7.

交叉function[newpop]=crossover(pop,pc)[px,py]=size(pop);newpop=ones(size(pop));fori=1:2:px-1if(rand<pc)cpoint=round(rand*py);newpop(i,:)=[pop(i,1:cpoint),pop(i+1,cpoint+1:py)];newpop(i+1,:)=[pop(i+1,1:cpoint),pop(i,cpoint+1:py)];elsenewpop(i,:)=pop(i);newpop(i+1,:)=pop(i+1);endendend

8.變異function[newpop]=mutation(pop,pm)[px,py]=size(pop);fori=1:pxif(rand<pm)mpoint=round(rand*py);ifmpoint<=0mpoint=1;endnewpop(i)=pop(i);ifany(newpop(i,mpoint)==0)newpop(i,mpoint)=1;elsenewpop(i,mpoint)=0;endelsenewpop(i)=pop(i);endend

end9.計(jì)算最大適應(yīng)值function[bestindividual,bestfit]=best(pop,fitvalue)[px,py]=size(pop);bestindivid