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 = 0.0
dt = 0.005
#### add traveling waves
while 1:
    for pt in g.pos:
        pt[1]=2.5*cos(omega*t-2*pi*pt[0]/wlth)+2.5*cos(omega*t+2*pi*pt[0]/wlth)
    t = t+dt

#### or product of cosines
##while 1:
##    for pt in g.pos:
##        pt[1]=5*cos(2*pi*pt[0]/wlth)*cos(omega*t)
##    t = t+dt