在 Python/Matplotlib 中动画“增长”线图
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/28074461/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Animating "growing" line plot in Python/Matplotlib
提问by Blink
I want to produce a set of frames that can be used to animate a plot of a growing line. In the past, I have always used plt.draw() and set_ydata() to redraw the y-data as it changed over time. This time, I wish to draw a "growing" line, moving across the graph with time. Because of this, set_ydata doesn't work (xdata is changing length). For example,
我想生成一组可用于为不断增长的线图制作动画的帧。过去，我一直使用 plt.draw() 和 set_ydata() 来重绘 y 数据，因为它会随着时间的推移而变化。这一次，我想画一条“增长”线，随着时间在图形上移动。因此， set_ydata 不起作用（xdata 正在改变长度）。例如，
import numpy as np
import matplotlib.pyplot as plt
x = np.linspace(0, 10, 100)
y = np.sin(x)
plt.figure()
for n in range(len(x)):
plt.plot(x[:n], y[:n], color='k')
plt.axis([0, 10, 0, 1])
plt.savefig('Frame%03d.png' %n)
While this works, it becomes very slow as it scales. Is there a faster way to do this?
虽然这有效，但随着它的扩展，它变得非常缓慢。有没有更快的方法来做到这一点？
采纳答案by Joe Kington
A couple of notes:
一些注意事项：
First off, the reason that things become progressively slower is that you're drawing more and more and more overlapping lines in the same position.
首先，事情变得越来越慢的原因是您在同一位置绘制了越来越多的重叠线。
A quick fix is to clear the plot each time:
一个快速的解决方法是每次都清除绘图：
import numpy as np
import matplotlib.pyplot as plt
x = np.linspace(0, 10, 100)
y = np.sin(x)
plt.figure()
for n in range(len(x)):
plt.cla()
plt.plot(x[:n], y[:n], color='k')
plt.axis([0, 10, 0, 1])
plt.savefig('Frame%03d.png' %n)
Better yet, however, update both the x and y data at the same time:
然而，更好的是，同时更新 x 和 y 数据：
import numpy as np
import matplotlib.pyplot as plt
x = np.linspace(0, 10, 100)
y = np.sin(x)
fig, ax = plt.subplots()
line, = ax.plot(x, y, color='k')
for n in range(len(x)):
line.set_data(x[:n], y[:n])
ax.axis([0, 10, 0, 1])
fig.canvas.draw()
fig.savefig('Frame%03d.png' %n)
And if you'd like to use the animation module (side note: blit=Truemay not work properly on some backends (e.g. OSX), so try blit=Falseif you have issues):
如果你想使用动画模块（旁注：blit=True在某些后端（例如 OSX）上可能无法正常工作，所以blit=False如果你有问题，请尝试）：
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
x = np.linspace(0, 10, 100)
y = np.sin(x)
fig, ax = plt.subplots()
line, = ax.plot(x, y, color='k')
def update(num, x, y, line):
line.set_data(x[:num], y[:num])
line.axes.axis([0, 10, 0, 1])
return line,
ani = animation.FuncAnimation(fig, update, len(x), fargs=[x, y, line],
interval=25, blit=True)
ani.save('test.gif')
plt.show()
