使用子类 FuncAnimation 的动画播放器时出现播放错误

Question

Python3.9，MacOS11.6.1

我正在实现几年前在上发布的动画示例，其中包含一个不错的播放控制台。然而，当动画结束时，再次按下播放按钮将抛出越界索引错误。我如何修改代码，为了完整起见，我在下面包含了这些代码，以便在动画结束时按下播放按钮时什么也不会发生，或者更好的是，动画从头开始。

import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
import mpl_toolkits.axes_grid1
import matplotlib.widgets

class Player(FuncAnimation):
    def __init__(self, fig, func, frames=None, init_func=None, fargs=None,
                 save_count=None, mini=0, maxi=100, pos=(0.125, 0.92), **kwargs):
        self.i = 0
        self.min=mini
        self.max=maxi
        self.runs = True
        self.forwards = True
        self.fig = fig
        self.func = func
        self.setup(pos)
        FuncAnimation.__init__(self,self.fig, self.func, frames=self.play(), 
                                           init_func=init_func, fargs=fargs,
                                           save_count=save_count, **kwargs )    

    def play(self):
        while self.runs:
            self.i = self.i+self.forwards-(not self.forwards)
            if self.i > self.min and self.i < self.max:
                yield self.i
            else:
                self.stop()
                yield self.i

    def start(self):
        self.runs=True
        self.event_source.start()

    def stop(self, event=None):
        self.runs = False
        self.event_source.stop()

    def forward(self, event=None):
        self.forwards = True
        self.start()
    def backward(self, event=None):
        self.forwards = False
        self.start()
    def oneforward(self, event=None):
        self.forwards = True
        self.onestep()
    def onebackward(self, event=None):
        self.forwards = False
        self.onestep()

    def onestep(self):
        if self.i > self.min and self.i < self.max:
            self.i = self.i+self.forwards-(not self.forwards)
        elif self.i == self.min and self.forwards:
            self.i+=1
        elif self.i == self.max and not self.forwards:
            self.i-=1
        self.func(self.i)
        self.fig.canvas.draw_idle()

    def setup(self, pos):
        playerax = self.fig.add_axes([pos[0],pos[1], 0.22, 0.04])
        divider = mpl_toolkits.axes_grid1.make_axes_locatable(playerax)
        bax = divider.append_axes("right", size="80%", pad=0.05)
        sax = divider.append_axes("right", size="80%", pad=0.05)
        fax = divider.append_axes("right", size="80%", pad=0.05)
        ofax = divider.append_axes("right", size="100%", pad=0.05)
        self.button_oneback = matplotlib.widgets.Button(playerax, label=u'$\u29CF$')
        self.button_back = matplotlib.widgets.Button(bax, label=u'$\u25C0$')
        self.button_stop = matplotlib.widgets.Button(sax, label=u'$\u25A0$')
        self.button_forward = matplotlib.widgets.Button(fax, label=u'$\u25B6$')
        self.button_oneforward = matplotlib.widgets.Button(ofax, label=u'$\u29D0$')
        self.button_oneback.on_clicked(self.onebackward)
        self.button_back.on_clicked(self.backward)
        self.button_stop.on_clicked(self.stop)
        self.button_forward.on_clicked(self.forward)
        self.button_oneforward.on_clicked(self.oneforward)

### using this class is as easy as using FuncAnimation:            

fig, ax = plt.subplots()
x = np.linspace(0,6*np.pi, num=100)
y = np.sin(x)

ax.plot(x,y)
point, = ax.plot([],[], marker="o", color="crimson", ms=15)

def update(i):
    point.set_data(x[i],y[i])

ani = Player(fig, update, maxi=len(y)-1)

plt.show()

Answer 1

一种方法是在 start 函数中添加 if 条件，以检查 self.i 值是否达到 self.max。如果是这样，您可以将 self.i 值重置为零，然后让动画重新开始。下面是执行此操作的代码：

def start(self):
    if self.i==self.max:
        self.i=0
    self.runs=True
    self.event_source.start()

使用子类 FuncAnimation 的动画播放器时出现播放错误

Playback error results when using an animation player that subclasses FuncAnimation

python

animation

matplotlib