implement row echelon form;

ref.m

function o = myref(A)
  row = length(A(:, 1));
  
  for i=1:1:row
      current_row = A(i, :);
      for j=i+1:1:row
        compare_row = A(j, :);
        f = current_row(1, i);
        s = compare_row(1, i);
        mult_row = current_row * (s / f);
        A(j, :) = compare_row - mult_row;
      end
  end 
  o = A;
end