在IPython Notebook中Matplotlib动画无法工作（空白图）

Question

在IPython Notebook中Matplotlib动画无法工作（空白图）

26

我尝试了多个动画示例代码，但无法使它们正常工作。这是我从Matplotlib文档中尝试的一个基本示例：

"""
A simple example of an animated plot
"""
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation

fig, ax = plt.subplots()

x = np.arange(0, 2*np.pi, 0.01)        # x-array
line, = ax.plot(x, np.sin(x))

def animate(i):
    line.set_ydata(np.sin(x+i/10.0))  # update the data
    return line,

#Init only required for blitting to give a clean slate.
def init():
    line.set_ydata(np.ma.array(x, mask=True))
    return line,

ani = animation.FuncAnimation(fig, animate, np.arange(1, 200), init_func=init,
    interval=25, blit=True)
plt.show()

当我在IPython笔记本上执行上述代码时，只会看到生成的一个空白图。我已经尝试从多个服务器（包括Wakari）上运行此代码，在多台机器上使用多个浏览器（Chrome、Firefox、IE）都是如此。我可以很好地将动画保存为mp4文件，并在播放时看起来很棒。任何帮助都将不胜感激！

- Mark Ebersole

1

不使用内联图形运行它。 - tacaswell

5个回答

12

根据这个答案，你可以通过启用`nbagg`后端并输入命令`%matplotlib nbagg`在IPython笔记本中实现动画（以及完整的交互支持）。

- Adrian Martin

5

我之前和你一样遇到了完全相同的问题。由于我是一个完全的新手，所以tcaswell的答案对我来说有点晦涩难懂。也许你已经理解了他的意思或者找到了自己的解决方案。如果你还没有找到解决方法，我会在这里提供一个。我谷歌了“matplotlib inline figures”并找到了this这个网站，它提到你需要启用matplotlib模式。不幸的是，仅使用%maplotlib并没有任何帮助。然后我在IPython控制台上随便输入了%matplotlib qt，现在它就可以正常工作了，尽管绘图出现在一个单独的窗口中。

- Grinning Kroot

这对我有用。是的，在一个单独的窗口中。我希望有一个直接保存动漫为视频文件的选项，而不是PNG。 - Bhanu Chander

2

我也遇到了这个问题，发现需要理解matplotlib后端的概念，如何启用特定的后端以及哪些后端适用于FuncAnimation。我编写了一个 ipython笔记本来解释细节，并汇总了哪些后端适用于Mac、Windows和wakari.io 上的 FuncAnimation。该笔记本还总结了哪些后端适用于ipython interact()小部件，以及基本matplotlib绘图的情况下绘图出现的位置（内联或次级窗口）。代码和说明包括在内，所以您可以重现任何结果。

底线是，无法使使用FuncAnimation创建的动画内联显示在ipython笔记本中。但是，您可以在单独的窗口中将其显示出来。事实证明，我需要为我本学期教授的本科课程创建可视化效果，虽然我更希望动画能够内联显示，但至少我能够创建一些有用的可视化效果，在课堂上展示。

- alwaysCurious

0

当动画结束时，在Jupyter中没有内联视频也会发生这种情况。

HTML(ani.to_html5_video())

如果不在笔记本单元格的最末尾，输出将被抑制。

您可以按以下方式使用它

out = HTML(ani.to_html5_video())

只需在新单元格中键入 out` 即可在线获取视频。

- theo olsthoorn

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- ImportanceOfBeingErnest · Accepted Answer

总结一下你有以下选项：

Using display in a loop Use IPython.display.display(fig) to display a figure in the output. Using a loop you would want to clear the output before a new figure is shown. Note that this technique gives in general not so smooth resluts. I would hence advice to use any of the below.

import matplotlib.pyplot as plt
import matplotlib.animation
import numpy as np
from IPython.display import display, clear_output

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

fig, ax = plt.subplots()
l, = ax.plot([0,2*np.pi],[-1,1])

animate = lambda i: l.set_data(t[:i], x[:i])

for i in range(len(x)):
animate(i)
clear_output(wait=True)
display(fig)

plt.show()

%matplotlib notebook Use IPython magic %matplotlib notebook to set the backend to the notebook backend. This will keep the figure alive instead of displaying a static png file and can hence also show animations.
Complete example:

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

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

fig, ax = plt.subplots()
l, = ax.plot([0,2*np.pi],[-1,1])

animate = lambda i: l.set_data(t[:i], x[:i])

ani = matplotlib.animation.FuncAnimation(fig, animate, frames=len(t))

plt.show()

%matplotlib tk Use IPython magic %matplotlib tk to set the backend to the tk backend. This will open the figure in a new plotting window, which is interactive and can thus also show animations.
Complete example:

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

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

fig, ax = plt.subplots()
l, = ax.plot([0,2*np.pi],[-1,1])

animate = lambda i: l.set_data(t[:i], x[:i])

ani = matplotlib.animation.FuncAnimation(fig, animate, frames=len(t))

plt.show()

Convert animation to mp4 video:

from IPython.display import HTML
HTML(ani.to_html5_video())

or use plt.rcParams["animation.html"] = "html5" at the beginning of the notebook. This will require to have ffmpeg video codecs available to convert to HTML5 video. The video is then shown inline. This is therefore compatible with %matplotlib inline backend. Complete example:

%matplotlib inline
import matplotlib.pyplot as plt
plt.rcParams["animation.html"] = "html5"
import matplotlib.animation
import numpy as np

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

fig, ax = plt.subplots()
l, = ax.plot([0,2*np.pi],[-1,1])

animate = lambda i: l.set_data(t[:i], x[:i])

ani = matplotlib.animation.FuncAnimation(fig, animate, frames=len(t))
ani

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

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

fig, ax = plt.subplots()
l, = ax.plot([0,2*np.pi],[-1,1])

animate = lambda i: l.set_data(t[:i], x[:i])

ani = matplotlib.animation.FuncAnimation(fig, animate, frames=len(t))

from IPython.display import HTML
HTML(ani.to_html5_video())

Convert animation to JavaScript:

from IPython.display import HTML
HTML(ani.to_jshtml())

or use plt.rcParams["animation.html"] = "jshtml" at the beginning of the notebook. This will display the animation as HTML with JavaScript. This highly compatible with most new browsers and also with the %matplotlib inline backend. It is available in matplotlib 2.1 or higher.
Complete example:

%matplotlib inline
import matplotlib.pyplot as plt
plt.rcParams["animation.html"] = "jshtml"
import matplotlib.animation
import numpy as np

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

fig, ax = plt.subplots()
l, = ax.plot([0,2*np.pi],[-1,1])

animate = lambda i: l.set_data(t[:i], x[:i])

ani = matplotlib.animation.FuncAnimation(fig, animate, frames=len(t))
ani

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

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

fig, ax = plt.subplots()
l, = ax.plot([0,2*np.pi],[-1,1])

animate = lambda i: l.set_data(t[:i], x[:i])

ani = matplotlib.animation.FuncAnimation(fig, animate, frames=len(t))

from IPython.display import HTML
HTML(ani.to_jshtml())