Animation

November 6, 2022

Matplotlib provides two animation classes for animating a plot figure. The example below uses the ArtistAnimation class. The animation can be displayed just like any other Matplotlib figure and saved to file as various video formats.

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

fig, ax = plt.subplots(tight_layout=True)
ax.set_xlim(0, 2*np.pi)
ax.set_ylim(-1.1, 1.1)

xs = np.linspace(0, 2*np.pi, 128)
x = []
y = []
ims = []

for i in range(len(xs)):
    x.append(xs[i])
    y.append(np.sin(xs[i]))
    im, = ax.plot(x, y, '-ro', alpha=0.5)
    ims.append([im])

ani = ArtistAnimation(fig, ims, interval=40, repeat=False)

# Save animation to a movie file, requires the ffmpeg framework
ani.save('artistanim.mp4', fps=30)

plt.show()

This example creates a Matplotlib animation using the FuncAnimation class.

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

fig, ax = plt.subplots(tight_layout=True)
ax.set_xlim(0, 2*np.pi)
ax.set_ylim(-1.1, 1.1)
line, = ax.plot([], [], '-ro', alpha=0.5)

xs = np.linspace(0, 2*np.pi, 128)
x = []
y = []


def update(i):
    x.append(i)
    y.append(np.sin(i))
    line.set_data(x, y)
    return line,


ani = FuncAnimation(fig, update, frames=xs, interval=20, repeat=False, blit=True)

# Save animation to a movie file, requires the ffmpeg framework
ani.save('funcanim.mp4', fps=30)

# Uncomment to display animated figure
plt.show()

Both examples generate the animated line plot shown below.

🐍 Pythonic Programming
by Gavin Wiggins © 2022