from __future__ import division
from visual import *


dx = 0.05
g = curve(x=arange(-10,10,dx), color=color.green)
scene.autoscale =0
wlth = 2.0
omega = pi
t = 0.05
dt = 0.005

#### traveling wave
while 1:
    rate(200)
    for pt in g.pos:
        pt[1]=2.5*cos(omega*t-2*pi*pt[0]/wlth)
    t = t+dt