x_over2.m

用MATLAB实现遗传算法中的好多问题

% function [xnew,ynew]=x_over2(x,y)
% 将两个串做交叉
function [xnew,ynew]=x_over2(x,y)

for i=1:2,
   if i==2, x=y; end;
   L=length(x); 
   fo_ind=findstr(x,'{');
   if any(fo_ind)==1, 
      for j=1:length(fo_ind),
         for k=fo_ind(j):L,
            if x(k)=='(',
               x(k)='#';
            elseif x(k)==')',
               x(k)='$';
            elseif x(k)=='<',
               break,
            end
         end
      end

      mc_ind=findstr(x,'>');
      for j=1:length(mc_ind),
         for k=mc_ind(j):L,
            if x(k)=='(',
               x(k)='#';
            elseif x(k)==')',
               x(k)='$';
            elseif x(k)=='}' | x(k)=='<',
               break,
            end
         end
      end     
      
   end
   
   L = length(x);
   obr_ind = findstr(x,'(');
   cbr_ind = findstr(x,')');
 
   num_bra=length(obr_ind);
   r_num=ceil(rand(1)*num_bra + eps);
   start_point=obr_ind(r_num);
   
   if start_point > 1,
      if x(start_point-1)=='1' | x(start_point-1)=='2',
         xnew=x;
         ynew=y;
         
         % Unmask brackets
         xnew=strrep(xnew,'#','(');
         xnew=strrep(xnew,'$',')');
         ynew=strrep(ynew,'#','(');
         ynew=strrep(ynew,'$',')');
         return
      end
   end
      
   bo_count=0;
   bc_count=0;

   for j=start_point:L,
      if x(j) == '(',
         bo_count=bo_count+1;
      elseif x(j) == ')',
         bc_count=bc_count+1;
         if bc_count == bo_count;
            end_point = j;
            break;
         end
      end  
   end

  
   if i==1,     
      xstart=x(1:start_point-1);
      xcross=x(start_point:end_point);
      if end_point == L,
         xend=[]; 
      else
         xend=x(end_point+1:L);
      end
   else

      ystart=x(1:start_point-1);
      ycross=x(start_point:end_point);
      if end_point == L,
         yend=[]; 
      else
         yend=x(end_point+1:L);
      end
   end   

end

% 执行交叉

xnew=[xstart ycross xend];
ynew=[ystart xcross yend];      


xnew=strrep(xnew,'#','(');
xnew=strrep(xnew,'$',')');
ynew=strrep(ynew,'#','(');
ynew=strrep(ynew,'$',')');