我正在尝试使用Matplotlib展示行波动画（双色型）。该函数在下面介绍，并且可以正常工作，但是当我们将interval=...参数设置为小于默认值200时，会出现一个奇怪的错误。为什么以及如何删除它？谢谢。
anim = FuncAnimation(fig, update, frames=numpy.linspace(0, 60, 20*60),
init_func=init, blit = True, interval = 10)`
错误提示：
Exception in Tkinter callback
Traceback (most recent call last):
File "/usr/lib/python3.5/tkinter/__init__.py", line 1553, in __call__
return self.func(*args)
File "/usr/lib/python3.5/tkinter/__init__.py", line 599, in callit
func(*args)
File "/usr/lib/python3/dist-packages/matplotlib/backends/backend_tkagg.py", line 147, in _on_timer
TimerBase._on_timer(self)
File "/usr/lib/python3/dist-packages/matplotlib/backend_bases.py", line 1305, in _on_timer
ret = func(*args, **kwargs)
File "/usr/lib/python3/dist-packages/matplotlib/animation.py", line 1021, in _step
still_going = Animation._step(self, *args)
File "/usr/lib/python3/dist-packages/matplotlib/animation.py", line 827, in _step
self._draw_next_frame(framedata, self._blit)
File "/usr/lib/python3/dist-packages/matplotlib/animation.py", line 845, in _draw_next_frame
self._pre_draw(framedata, blit)
File "/usr/lib/python3/dist-packages/matplotlib/animation.py", line 858, in _pre_draw
self._blit_clear(self._drawn_artists, self._blit_cache)
File "/usr/lib/python3/dist-packages/matplotlib/animation.py", line 898, in _blit_clear
a.figure.canvas.restore_region(bg_cache[a])
KeyError: <matplotlib.axes._subplots.AxesSubplot object at 0xb1599eac>
导入：
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
import numpy
cos = numpy.cos; sin = numpy.sin;
主要功能：
def bichromatic_wave_anim():
amp = [1, 2]
mode = ['cos', 'cos']
phase_speed = [0.6, 0.8]
frq = [35, 38]
def func(x, amp, mode, frq, shift):
y = [ amp*getattr(numpy, mode)(frq*(i-shift)) \
for i in x ]
return y
N = 2000
xl = 0; xr = 10
dx = (xr-xl)/(N-1)
x = [ xl + i*(xr-xl)/(N-1) for i in range(N) ]
buoy_point = 2
fig, ax = plt.subplots(2, 1)
plot1, = ax[0].plot(x, func(x, amp[0], mode[0], frq[0], 0), \
'-', color = 'blue', lw = 1, \
animated = True)
plot2, = ax[0].plot(x, func(x, amp[1], mode[1], frq[1], 0), \
'-', color = 'red', lw = 1, \
animated = True)
bichromplot, = ax[1].plot(x, [ i+j for i,j in zip(func(x, amp[0], mode[0], frq[0], 0), func(x, amp[1], mode[1], frq[1], 0)) ], \
'-', color = 'purple', lw = 2, \
animated = True)
buoy, = ax[1].plot([buoy_point], func([buoy_point], amp[0], mode[0], frq[0], 0)[0] + \
func([buoy_point], amp[1], mode[1], frq[1], 0)[0], \
marker = 'o', markeredgecolor = (0,0,0,0), ms = 12, color = 'orange', \
animated = True)
def init():
ax[0].set_xlabel(r'$x$')
ax[1].set_xlabel(r'$x$')
ax[0].set_ylabel('Two monochromatic waves', \
)
ax[1].set_ylabel(r'A bichromatic wave: ${}\{}({}x) + {}\{}({}x)$'.format(amp[0], mode[0], frq[0], amp[1], mode[1], frq[1]),\
)
ax[0].legend(labels = [ r'${}\{}({}x)$'.format(i, j, k) for i, j, k in zip(amp, mode, frq) ])
return [plot1, plot2, bichromplot, buoy]
def update(frame):
y1 = func(x, amp[0], mode[0], frq[0], phase_speed[0]*frame)
y2 = func(x, amp[1], mode[1], frq[1], phase_speed[1]*frame)
ybichrom = [ i+j for i,j in zip(func(x, amp[0], mode[0], frq[0], phase_speed[0]*frame), func(x, amp[1], mode[1], frq[1], phase_speed[1]*frame)) ]
ybuoy = func([buoy_point], amp[0], mode[0], frq[0], phase_speed[0]*frame)[0] + \
func([buoy_point], amp[1], mode[1], frq[1], phase_speed[1]*frame)[0]
plot1.set_data(x, y1)
plot2.set_data(x, y2)
bichromplot.set_data(x, ybichrom)
buoy.set_data([buoy_point], ybuoy)
return [plot1, plot2, bichromplot, buoy]
anim = FuncAnimation(fig, update, frames=numpy.linspace(0, 60, 20*60),
init_func=init, blit = True, interval = 10) ## 'interval' can only be greater than 200 in order to remove the Error.
fig.tight_layout()
fig.show()
return anim
anim = bichromatic_wave_anim()