%% dot_product_timing

  x = rand ( n, 1 );
  y = rand ( n, 1 );

  tic;
  z = 0.0;
  for i = 1 : n
    z = z + x(i) * y(i);
  end
  t = toc;

  r = ( 2 * n ) / t;
  R = 2800000000;
  fprintf ( 1, '%d  %g  %g\n', n, r, R );
