Concatenation Error: Using num2bin did not produce expected results

Hi everyone, I need someone to help check my code. I use randi function to get two real numbers out from a matrix, and then concatenate the two real numbers after using num2bin to convert to binary. The output of the randi function gave different results each time as expected, but when I concatenate using horzcat the results over several iteration are just same instead of being different. I need help!

    for d=1:(n-701)/100 % 5730 Iterations
       checkin_pts1=data_tokyo(randi(n),[1 2]);
       x1(d) = checkin_pts1(1,1);
       y1(d) = checkin_pts1(1,2);
       ch1= Initial_Pop(x1(d),y1(d));
  end

for t=1:(n-701)/100 % 5730 Iterations
     checkin_pts2=data_tokyo(randi(n),[1 2]);
     x2(t) = checkin_pts2(1,1);
     y2(t) = checkin_pts2(1,2);
     ch2= Initial_Pop(x2(t),y2(t));
end

    function single_chromo = Initial_Pop(val1,val2)

global chromo_length;global single_chromo;

global T;

%----------- Assign checkin values to known variable arrays  ------------  

      % Convert checkin values to binary
      %-------------------------------------------------------X
      q=quantizer([8 3]); 
      bx = num2bin(q,val1);

      %-------------------------------------------------------Y
      q=quantizer([8 3]); 
      by = num2bin(q,val2);

      chromo_length = horzcat(bx,by); % checkin_pts1, chekins_pts2
      single_chromo = chromo_length %(rangeval,:)  % Access individual xmosome 

end

[VicPeters]

solved, the precision of the quantizer determines the depth of accurancy.