Random walk example

random_walk.py

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation

fig = plt.figure()
ax = fig.add_subplot(111)
ax.set_xlim(-10, 10)
ax.set_aspect(1)

x = [0]
y = [0]
line, = ax.plot(x, y, '-o', color='0.8', markerfacecolor='0', marker='.')

def update(frame, x, y):
    # Choose a random direction
    d = np.random.random() * 2 * np.pi

    # Add a new step
    x.append(x[-1] + np.cos(d))
    y.append(y[-1] + np.sin(d))

    # Only show the last 500 steps
    if len(x) > 500:
        x.pop(0)
        y.pop(0)


    # Update the line
    line.set_xdata(x)
    line.set_ydata(y)

    ax.set_xlim(min(x), max(x))
    ax.set_ylim(min(y), max(y))

    return line,

ani = animation.FuncAnimation(fig, update, fargs=(x, y), interval=10)
plt.show()