Fig. 9.

Ratio between errors given by the 2D prediction and by the 1D prediction. Ratio of the absolute difference between the 2-dimensional approach and the analytic one (numerator, see Fig. 7) over the absolute difference between the 1-dimensional approach and the analytic one (denominator, see Fig. 8), that is, $|{\rho }_{2D}-\rho |/|{\rho }_{1D}-\rho |$