print 'approaching brownian motion through limit of scaled random walk'
import numpy as np
mu, sigma = 0, 1
nmax = 1000;
s = np.random.normal(mu, sigma, nmax)
ss = np.cumsum(s)
import matplotlib.pyplot as plt
@interact
def f( n=(1..nmax) ):
P = points([(i/n, 1/sqrt(n)*ss[i+1] ) for i in range(0, n)])
P.set_axes_range(0, 1, -2, 2)
show(P)