“…In a corresponding simulation using a collocation method with quartic spline elements [9], the L 2 -error norm at t = 20 is less than 0.6463 × 10 −3 and the quantity I 1 does not change from the analytic, I 2 varies by less than 0.043%, and I 3 varies by less than 0.005%. Second, we model the motion of a single solitary wave with the three different amplitudes 0.3, 0.09, and 0.03 and compare with results given in [6,7,9] at times t = 40, 80; see Tables 3-7, using the region 0 ≤ x ≤ [9] x = 0.03, t = 0.2 40 1.199992 0.292159 0.057599 0.0795 Least-square [7] x = 0.03, t = 0.03 40 1.1967 0.2860 0.0570 3.475 Least-square [7] x = 0.03, t = 0.03 80 1.1964 0.2858 0.0569 7.444 Petrov-Galerkin [6] x = 0.03, t = 0.05 80 1.1910 0.2855 0.0558 3.849 Table 4 Error norms for a single solitary wave: Table 3 where the L 2 -error norm is less than 0.0038 × 10 −3 and the constants of motion vary little from the analytic value: I 1 varies by less than 0.002%, I 2 and I 3 are conserved during the experiment. In a corresponding simulation using a collocation method with quartic spline elements [9], the L 2 -error norm is less than 0.0796 × 10 −3 and the quantity I 1 changes by less than 0.0007%, I 2 by less than 1.5%, and I 3 varies by less than 0.002%, and using a least-squares method with linear spline elements [7] the L 2 -error norm is less than 3.476 × 10 −3 and the quantity I 1 changes by less than 0.28%, I 2 by less than 0.7%, and I 3 varies by less than 1.1%.…”