from visual import *
scene.autoscale = 0
c = curve(radius=0.1)
n=40
scene.center=(n/2,0,0)
scene.range = 0.6 * n

slinkieposition = []
slinkievelocity = []
for i in range(n):
    slinkieposition.append(vector(i,0,0))
    slinkievelocity.append(vector(0,2.*sin(i/(n-1.0)*2.*3.1415926535),0))

dt = 0.05
k = 1.0
mass=1.0

while 1:
    rate(20)
    for i in range(n):
        slinkieposition[i] += dt * slinkievelocity[i]
    slinkieposition[0] = vector(0,0,0)
    slinkieposition[n-1] = vector(n-1,0,0)
    for i in range(1,n-1):
        force = k * (slinkieposition[i-1] - slinkieposition[i]
                     + slinkieposition[i+1] - slinkieposition[i])
        slinkievelocity[i] += force/mass
    c.pos = slinkieposition