Dear All,
I am having a problem with saving the output of an animation as a file. I
provide here two listing, first the small program which otherwise works
well, except while executing the last few lines to save the output produces
error which I also provide:
1. the program test.py :
from matplotlib import animation as anim
from matplotlib import pyplot as plt
import numpy as np
fig = plt.figure()
plt.axis([-1,1,-1,1])
abcissa, = plt.plot([],[], color='black')
graph, = plt.plot([], [], color='blue')
t, = plt.plot([],[], color='red')
def init():
''' set the basic graph and put slate clean for blit'''
x = np.arange(-1,1,0.01)# the x-values
y = np.sin(np.pi/2 * x)
abcissa.set_data(x, 0)
graph.set_data(x, y)
return abcissa, graph
def animate(i):
p = -1 + i*0.02
tx = [p-1,p+1]
ty = [np.sin(np.pi/2 * p) - np.pi/2 * np.cos(np.pi/2 *p),
np.sin(np.pi/2 * p) + np.pi/2 * np.cos(np.pi/2 *p)]
t.set_data(tx, ty)
return t,
ani = anim.FuncAnimation(fig, animate, init_func=init,
frames=100, interval=30, blit=True)
plt.show()
Writer = anim.writers['ffmpeg']
writer = Writer(fps=15, bitrate=1800)
ani.save('test.mp4', writer=writer)
2. Error output
ani.save('test.mp4', writer=writer)
File "/usr/lib/python3/dist-packages/matplotlib/animation.py", line 719,
in save
writer.grab_frame(**savefig_kwargs)
File "/usr/lib/python3/dist-packages/matplotlib/animation.py", line 205,
in grab_frame
dpi=self.dpi, **savefig_kwargs)
File "/usr/lib/python3/dist-packages/matplotlib/figure.py", line 1422, in
savefig
self.canvas.print_figure(*args, **kwargs)
File "/usr/lib/python3/dist-packages/matplotlib/backend_bases.py", line
2225, in print_figure
self.figure.dpi = origDPI
File "/usr/lib/python3/dist-packages/matplotlib/figure.py", line 385, in
_set_dpi
self.dpi_scale_trans.clear().scale(dpi, dpi)
File "/usr/lib/python3/dist-packages/matplotlib/transforms.py", line 1786,
in clear
self._mtx = np.identity(3)
File "/usr/lib/python3/dist-packages/numpy/core/numeric.py", line 2053, in
identity
from numpy import eye
File "<frozen importlib._bootstrap>", line 2280, in _handle_fromlist
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0:
invalid start byte
'
Exception in Tkinter callback
Traceback (most recent call last):
File "/usr/lib/python3.4/idlelib/run.py", line 121, in main
seq, request = rpc.request_queue.get(block=True, timeout=0.05)
File "/usr/lib/python3.4/queue.py", line 175, in get
raise Empty
queue.Empty
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/matplotlib/backends/tkagg.py", line
13, in blit
tk.call("PyAggImagePhoto", photoimage, id(aggimage), colormode,
id(bbox_array))
_tkinter.TclError: this isn't a Tk application
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/lib/python3.4/tkinter/__init__.py", line 1536, in __call__
return self.func(*args)
File "/usr/lib/python3.4/tkinter/__init__.py", line 585, in callit
func(*args)
File
"/usr/lib/python3/dist-packages/matplotlib/backends/backend_tkagg.py", line
363, in idle_draw
self.draw()
File
"/usr/lib/python3/dist-packages/matplotlib/backends/backend_tkagg.py", line
349, in draw
tkagg.blit(self._tkphoto, self.renderer._renderer, colormode=2)
File "/usr/lib/python3/dist-packages/matplotlib/backends/tkagg.py", line
20, in blit
tk.call("PyAggImagePhoto", photoimage, id(aggimage), colormode,
id(bbox_array))
_tkinter.TclError: this isn't a Tk application
Please can someone help me out of this problem.
With my regards,
partha
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