'''

henon_animation.py

Animating 20000 iterations of the Henon function

'''

import matplotlib.pyplot as plt

from matplotlib import animation

def transform(p):

x,y = p

x1 = y + 1.0 - 1.4*x**2

y1 = 0.3*x

return x1, y1

def update_points(i, x, y, plot):

plot.set_data(x[:i], y[:i])

return plot,

if __name__ == '__main__':

p = (0, 0)

x = [p[0]]

y = [p[1]]

for i in range(10000):

p = transform(p)

x.append(p[0])

y.append(p[1])

fig = plt.gcf()

ax = plt.axes(xlim = (min(x), max(x)),

ylim = (min(y), max(y)))

plot = plt.plot([], [], 'o')[0]

anim = animation.FuncAnimation(fig, update_points,

fargs=(x, y, plot),

frames = len(x),

interval = 25)

plt.title('Henon Function Animation')

plt.show()