Surfaces of section (SOS) for the bar model. Left column: results for the analytic potential. Second and third columns: results for the HO method with N_p = 2 × 10⁵ and N_p = 10⁷, respectively. Fourth and fifth columns: results for the CylSP method with N_p = 2 × 10⁵ and N_p = 10⁷, respectively. From top to bottom: the rows correspond to E_J = −0.41, −0.39, −0.37, and −0.35, respectively. The red filled circle in each panel is the position of the x1 orbit.