[EDIT]: My problem is solved analytically. I'm just not able to color each peak and find the speed of each.
I would like to graphing the position of the maximum of the three peaks (solitons) that form after take off the signal Cos [2 Pi x /20] on the KdV equation environment. Subsequently I wanted coloring each in different colors shifting in the plane (x, t).
My first question is whether I'm doing it right, to solve a dissipative KdV. Also, my goal is calculate the speed(t) for each peak.
Attached, the introduction and my status.