Why is the saved video from FuncAnimation a superpositions of plots?
Regards, I would like to ask about Python's FuncAnimation .
In the full code, I was trying to animate bar plots (for integral illustration). The animated output from
ani = FuncAnimation(fig, update, frames=Iter, init_func = init, blit=True);
plt.show(ani);
looks fine.
But the output video from
ani.save("example_new.mp4", fps = 5)
gives a slightly different version from the animation showed in Python. The output gives a video of 'superposition version' compared to the animation. Unlike the animation : in the video, at each frame, the previous plots kept showing together with the current one.
Here is the full code :
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
fig, ax = plt.subplots()
Num = 20
p = plt.bar([0], [0], 1, color = 'b')
Iter = tuple(range(2, Num+1))
xx = list(np.linspace(0, 2, 200)); yy = list(map(lambda x : x**2,xx));
def init():
ax.set_xlim(0, 2)
ax.set_ylim(0, 4)
return (p)
def update(frame):
w = 2/frame;
X = list(np.linspace(0, 2-w, frame+1));
Y = list(map(lambda x: x**2, X));
X = list(map(lambda x: x + w/2,X));
C = (0, 0, frame/Num);
L = plt.plot(xx , yy, 'y', animated=True)[0]
p = plt.bar(X, Y, w, color = C, animated=True)
P = list(p[:]); P.append(L)
return P
ani = FuncAnimation(fig, update, frames=Iter, init_func = init, interval = 0.25, blit=True)
ani.save("examplenew.mp4", fps = 5)
plt.show(ani)
Any constructive inputs on this would be appreciated. Thanks. Regards, Arief.
When saving the animation, no blitting is used. You can turn off blitting, ie blit=False and see the animation the same way as it is saved.
What is happening is that in each iteration a new plot is added without the last one being removed. You basically have two options:
ax.clear() (then remember to set the axes limits again) plot : Matplotlib Live Update Graph bar : Dynamically updating a bar plot in matplotlib 上一篇: Netbeans无法启动德比服务器