% 2.6 變異
% 
%遺傳算法子程序
%Name: mutation.m
%變異
function [newpop]=sga_mutation(popsize,chromlength,pop,pm,up_range)
%函數說明
%入口參數：pop         當前處理的種群,
%          popsize     種群大小,
%          chromlength 基因位長度,
%          up_range    自變量的相對上限,
%出口參數：newpop      準子代
%功能說明：變異(mutation)，基因的突變普遍存在于生物的進化過程中。變異是指父代中的每個個體的每一位都以概率 pm 翻轉，即由“1”變為“0”，
%          或由“0”變為“1”。遺傳算法的變異特性可以使求解過程隨機地搜索到解可能存在的整個空間，因此可以在一定程度上求得全局最優解。

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%調試用語句
% 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,:);                %將種群矩陣拆分
 pop1;
 pop2=pop(2,:);
 pop2;
 
 pop1=dec2bin(pop1,chromlength);  %%各自轉為二進制
 pop1;
 pop2=dec2bin(pop2,chromlength);
 pop2;
 
newpop1=pop1;
newpop2=pop2;
for i=1:popsize;

   if(rand<pm) %產生一隨機數與變異概率比較
     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) %產生一隨機數與變異概率比較
     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);


%如果產生的個體超過了相對定義域  則隨機產生替換
for i=1:popsize
    if newpop1(i)>=up_range
        newpop1(i)=rand;
    end
    
    if newpop2(i)>=up_range
        newpop2(i)=rand;       
    end
    
end

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