Matplotlib FuncAnimation only draws one frame

Question

I am trying to do an animation using the FuncAnimation module, but my code only produces one frame and then stops. It seems like it doesn\'t realize what it nee

Answer 1

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

x = np.linspace(0,2*np.pi,100)

fig = plt.figure()  
sub = fig.add_subplot(111, xlim=(x[0], x[-1]), ylim=(-1, 1))
PLOT, = sub.plot([],[])

def animate(i):
    PLOT.set_data(x[:i], np.sin(x[:i]))
    # print("test")
    return PLOT,

ani = animation.FuncAnimation(fig, animate, frames=len(x), interval=10, blit=True)
plt.show()

You need to keep a reference to the animation object around, otherwise it gets garbage collected and it's timer goes away.

There is an open issue to attach a hard-ref to the animation to the underlying Figure object.

As written, your code well only plot a single point which won't be visible, I changed it a bit to draw up to current index