畫面擷取

直接使用 MovieWriter 來擷取個別畫面並將其寫入檔案。這可避免任何事件迴圈整合，因此即使使用 Agg 後端也能運作。不建議在互動式設定中使用。

import numpy as np

import matplotlib

matplotlib.use("Agg")
import matplotlib.pyplot as plt

from matplotlib.animation import FFMpegWriter

# Fixing random state for reproducibility
np.random.seed(19680801)


metadata = dict(title='Movie Test', artist='Matplotlib',
                comment='Movie support!')
writer = FFMpegWriter(fps=15, metadata=metadata)

fig = plt.figure()
l, = plt.plot([], [], 'k-o')

plt.xlim(-5, 5)
plt.ylim(-5, 5)

x0, y0 = 0, 0

with writer.saving(fig, "writer_test.mp4", 100):
    for i in range(100):
        x0 += 0.1 * np.random.randn()
        y0 += 0.1 * np.random.randn()
        l.set_data([x0], [y0])
        writer.grab_frame()