error in the code

erroe in string(j,n)=string(k,n);

Index in position 1 exceeds array bounds. Index must not exceed 3.

  
    for k=1:Npop
        for j=1:dim
            busLocation(j,k)=busd(busLocation(j,k),1);
        end
        sdf= unique(busLocation(:,k)); 
        
        while length(sdf)<dim
            sdf=randi([2 length(busd(:,1))],dim,1);
            for j=1:dim
                sdf(j)=busd(sdf(j),1);
            end
            busLocation(:,k)=sdf;
            
            sdf= unique(busLocation(:,k));  
        end
    end
    ndif = [0.28; 0.35; 0.39; 0.35; 0.27; 0.34; 0.40; 0.34; 0.25; 0.32];
    for k = 1:Npop
        mdif(k)= ndif(k);
    end
    nsw=length(string);
    mpop = round(Npop/4);
    for j = 1:mpop  
        minman = min(mdif(:));
        for k = 1:Npop
            if mdif(k)== minman
                for n=1:nsw
                    string(j,n)=string(k,n);
                end
                mdif(k)= 1010; 
                break;
            end
        end
    end
    for j = 1:(Npop-mpop)
        for bits=1:nsw
            string(mpop +j,bits) = string(j,bits);
        end
    end  ; end

Answer 1

[Voss]

The first time this line is encountered:

string(j,n)=string(k,n);

k is 9, but string only has 3 rows. That's the reason for the error.

[qas abd]

Thank you for your response, even this gives an error

string(j,n)=string(j,n);

[Torsten]

But this error occurs in the last loop:

% select another 75% of new population 
    for j = 1:(Npop-mpop)
        for bits=1:nsw
            string(mpop +j,bits) = string(j,bits);
        end
    end 
    

Before entering this loop, "string" has size 3x10. But j runs up to 10-3 = 7 ...