python matplotlib动画中的停止/启动/暂停

stop / start / pause in python matplotlib animation

提问by Jaco Vermaak

I'm using FuncAnimation in matplotlib's animation module for some basic animation. This function perpetually loops through the animation. Is there a way by which I can pause and restart the animation by, say, mouse clicks?

我在 matplotlib 的动画模块中使用 FuncAnimation 来制作一些基本动画。此函数会永久循环播放动画。有没有办法让我可以通过鼠标点击来暂停和重新启动动画？

采纳答案by unutbu

Here is a FuncAnimation examplewhich I modified to pause on mouse clicks. Since the animation is driven by a generator function, simData, when the global variable pauseis True, yielding the same data makes the animation appear paused.

这是一个 FuncAnimation 示例，我将其修改为在鼠标点击时暂停。由于动画是由生成器函数驱动的simData，当全局变量pause为 True 时，产生相同的数据会使动画出现暂停。

The value of pausedis toggled by setting up an event callback:

paused通过设置事件回调来切换的值：

def onClick(event):
    global pause
    pause ^= True
fig.canvas.mpl_connect('button_press_event', onClick)

---

---

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

pause = False
def simData():
    t_max = 10.0
    dt = 0.05
    x = 0.0
    t = 0.0
    while t < t_max:
        if not pause:
            x = np.sin(np.pi*t)
            t = t + dt
        yield x, t

def onClick(event):
    global pause
    pause ^= True

def simPoints(simData):
    x, t = simData[0], simData[1]
    time_text.set_text(time_template%(t))
    line.set_data(t, x)
    return line, time_text

fig = plt.figure()
ax = fig.add_subplot(111)
line, = ax.plot([], [], 'bo', ms=10)
ax.set_ylim(-1, 1)
ax.set_xlim(0, 10)

time_template = 'Time = %.1f s'
time_text = ax.text(0.05, 0.9, '', transform=ax.transAxes)
fig.canvas.mpl_connect('button_press_event', onClick)
ani = animation.FuncAnimation(fig, simPoints, simData, blit=False, interval=10,
    repeat=True)
plt.show()

回答by fred

This works...

这工作...

anim = animation.FuncAnimation(fig, animfunc[,..other args])

#pause
anim.event_source.stop()

#unpause
anim.event_source.start()

回答by woodenflute

Combining both the answers from @fred and @unutbu here, we can add an onClick function after creating the animation:

在这里结合@fred 和@unutbu 的回答，我们可以在创建动画后添加一个 onClick 函数：

import matplotlib.pyplot as plt
import matplotlib.animation as animation

fig = plt.figure()

def run_animation():
    anim_running = True

    def onClick(event):
        nonlocal anim_running
        if anim_running:
            anim.event_source.stop()
            anim_running = False
        else:
            anim.event_source.start()
            anim_running = True

    def animFunc( ...args... ):
        # Animation update function here

    fig.canvas.mpl_connect('button_press_event', onClick)

    anim = animation.FuncAnimation(fig, animFunc[,...other args])

run_animation()

Now we can simply stop or start the animation with clicks.

现在我们可以简单地通过点击停止或开始动画。

回答by Peter9192

I landed on this page trying to implement the same functionality, pausing matplotlibs animation. The other answers are great, but in addition I wanted to be able to manually loop through the frames using the arrow keys. For anyone looking for the same functionality, here's my implementation:

我登陆这个页面试图实现相同的功能，暂停 matplotlibs 动画。其他答案很好，但除此之外，我还希望能够使用箭头键手动循环浏览帧。对于任何寻找相同功能的人，这是我的实现：

import matplotlib.pyplot as plt
import matplotlib.animation as ani

fig, ax = plt.subplots()
txt = fig.text(0.5,0.5,'0')

def update_time():
    t = 0
    t_max = 10
    while t<t_max:
        t += anim.direction
        yield t

def update_plot(t):
    txt.set_text('%s'%t)
    return txt

def on_press(event):
    if event.key.isspace():
        if anim.running:
            anim.event_source.stop()
        else:
            anim.event_source.start()
        anim.running ^= True
    elif event.key == 'left':
        anim.direction = -1
    elif event.key == 'right':
        anim.direction = +1

    # Manually update the plot
    if event.key in ['left','right']:
        t = anim.frame_seq.next()
        update_plot(t)
        plt.draw()

fig.canvas.mpl_connect('key_press_event', on_press)
anim = ani.FuncAnimation(fig, update_plot, frames=update_time,
                         interval=1000, repeat=True)
anim.running = True
anim.direction = +1
plt.show()

Some notes:

一些注意事项：

• To be able to modify the values of runningand direction, I assigned them to anim. It avoids using nonlocal (not avaible in Python2.7) or global (not desirable since I'm running this code within another function). Not sure whether this is good practice, but I found it quite elegant.
• For the manual update, I'm accessing anim's generator object that FuncAnimation uses to update the plot. This ensures that when I resume the animation, it starts from the active frame rather than from where it was originally paused.

• 为了能够修改的值running和direction，我分配他们anim。它避免使用非本地（Python2.7 中不可用）或全局（不可取，因为我在另一个函数中运行此代码）。不确定这是否是好的做法，但我发现它非常优雅。
• 对于手动更新，我正在访问animFuncAnimation 用来更新绘图的生成器对象。这确保当我恢复动画时，它从活动帧开始，而不是从最初暂停的位置开始。