sga_mutation.m

多种群的链式智能体遗传算法

% 2.6 变异
% 变异(mutation)，基因的突变普遍存在于生物的进化过程中。变异是指父代中的每个个体的每一位都以概率 pm 翻转，即由“1”变为“0”，
% 或由“0”变为“1”。遗传算法的变异特性可以使求解过程随机地搜索到解可能存在的整个空间，因此可以在一定程度上求得全局最优解。
%遗传算法子程序
%Name: mutation.m
%变异
function [newpop]=sga_mutation(popsize,chromlength,pop,pm)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% popsize=10;
% pop=[1023,980,2133,726,1946,657,1702,1224,1522,807;
%      2025,2565,1773,2340,2354,1144,2061,240,1573,825]
% chromlength=12;
% pm=0.7;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


 pop1=pop(1,:);                %将种群矩阵拆分
 pop1;
 pop2=pop(2,:);
 pop2;
 
 pop1=dec2bin(pop1,chromlength);  %%各自转为二进制
 pop1;
 pop2=dec2bin(pop2,chromlength);
 pop2;
 
newpop1=pop1;
newpop2=pop2;
for i=1:popsize;

   if(rand<pm) %产生一随机数与变异概率比较
     mpoint=round(rand*chromlength);
%      mpoint
     if mpoint<=0
        mpoint=1;
     end

    if newpop1(i,mpoint)=='0'
       newpop1(i,mpoint)='1';
    else
       newpop1(i,mpoint)='0';
    end
   end  
   
    if(rand<pm) %产生一随机数与变异概率比较
     mpoint=round(rand*chromlength);
%      mpoint
     if mpoint<=0
        mpoint=1;
     end  
     
     if newpop2(i,mpoint)=='0'
        newpop2(i,mpoint)='1';
     else
        newpop2(i,mpoint)='0';
     end
    end

end

newpop1=bin2dec(newpop1);
newpop2=bin2dec(newpop2);



for i=1:popsize
    if newpop1(i)>=12000
%         pop_init=randperm(20000); 
%         newpop1(i)=newpop1(i)-3095;  
        newpop1(i)=rand;
    end
    
    if newpop2(i)>=12000
%         newpop2(i)=newpop2(i)-3095;       
%         pop_init=randperm(20000); 
        newpop2(i)=rand;       
    end
    
end

newpop(1,:)=newpop1';
newpop(2,:)=newpop2';
newpop;