import sys
import random
import numpy as np
import matplotlib.pyplot as plt

N = 1					# number of walkers
ns = 10000				# number of steps to take

if len(sys.argv) > 1: N = int(sys.argv[1])
if len(sys.argv) > 2: ns = int(sys.argv[2])

np.random.seed(None)	# really random!
x = np.zeros(N)

xp = np.zeros((ns,N))
for i in range(ns):
    x += 2*np.random.randint(2, size=N) - 1
    xp[i,:] = x

for i in range(N):
    plt.plot(xp[:,i])

plt.show()