我试图通过重现 this website 中的代码来保存动画图.然后我尝试从 another website 复制代码这很相似但得到了相同的消息错误“Invalid file object: <_io.BufferedReader name=76>”
import numpy as np
import matplotlib
matplotlib.use("Agg")
import matplotlib.pyplot as plt
import matplotlib.animation as animation
def update_line(num, data, line):
line.set_data(data[..., :num])
return line,
# Fixing random state for reproducibility
np.random.seed(19680801)
# Set up formatting for the movie files
Writer = animation.writers['ffmpeg']
writer = Writer(fps=15, metadata=dict(artist='Me'), bitrate=1800)
fig1 = plt.figure()
data = np.random.rand(2, 25)
l, = plt.plot([], [], 'r-')
plt.xlim(0, 1)
plt.ylim(0, 1)
plt.xlabel('x')
plt.title('test')
line_ani = animation.FuncAnimation(fig1, update_line, 25, fargs=(data, l),
interval=50, blit=True)
line_ani.save('lines.mp4', writer=writer)
fig2 = plt.figure()
x = np.arange(-9, 10)
y = np.arange(-9, 10).reshape(-1, 1)
base = np.hypot(x, y)
ims = []
for add in np.arange(15):
ims.append((plt.pcolor(x, y, base + add, norm=plt.Normalize(0, 30)),))
im_ani = animation.ArtistAnimation(fig2, ims, interval=50, repeat_delay=3000,
blit=True)
im_ani.save('im.mp4', writer=writer)
得到如下错误信息:
/anaconda3/lib/python3.6/site-packages/ipykernel_launcher.py:3: UserWarning:
This call to matplotlib.use() has no effect because the backend has already
been chosen; matplotlib.use() must be called *before* pylab, matplotlib.pyplot,
or matplotlib.backends is imported for the first time.
The backend was *originally* set to 'module://ipykernel.pylab.backend_inline' by the following code:
File "/anaconda3/lib/python3.6/runpy.py", line 193, in _run_module_as_main
"__main__", mod_spec)
File "/anaconda3/lib/python3.6/runpy.py", line 85, in _run_code
exec(code, run_globals)
File "/anaconda3/lib/python3.6/site-packages/ipykernel_launcher.py", line 16, in <module>
app.launch_new_instance()
File "/anaconda3/lib/python3.6/site-packages/traitlets/config/application.py", line 658, in launch_instance
app.start()
File "/anaconda3/lib/python3.6/site-packages/ipykernel/kernelapp.py", line 486, in start
self.io_loop.start()
File "/anaconda3/lib/python3.6/site-packages/tornado/platform/asyncio.py", line 127, in start
self.asyncio_loop.run_forever()
File "/anaconda3/lib/python3.6/asyncio/base_events.py", line 422, in run_forever
self._run_once()
File "/anaconda3/lib/python3.6/asyncio/base_events.py", line 1432, in _run_once
handle._run()
File "/anaconda3/lib/python3.6/asyncio/events.py", line 145, in _run
self._callback(*self._args)
File "/anaconda3/lib/python3.6/site-packages/tornado/platform/asyncio.py", line 117, in _handle_events
handler_func(fileobj, events)
File "/anaconda3/lib/python3.6/site-packages/tornado/stack_context.py", line 276, in null_wrapper
return fn(*args, **kwargs)
File "/anaconda3/lib/python3.6/site-packages/zmq/eventloop/zmqstream.py", line 450, in _handle_events
self._handle_recv()
File "/anaconda3/lib/python3.6/site-packages/zmq/eventloop/zmqstream.py", line 480, in _handle_recv
self._run_callback(callback, msg)
File "/anaconda3/lib/python3.6/site-packages/zmq/eventloop/zmqstream.py", line 432, in _run_callback
callback(*args, **kwargs)
File "/anaconda3/lib/python3.6/site-packages/tornado/stack_context.py", line 276, in null_wrapper
return fn(*args, **kwargs)
File "/anaconda3/lib/python3.6/site-packages/ipykernel/kernelbase.py", line 283, in dispatcher
return self.dispatch_shell(stream, msg)
File "/anaconda3/lib/python3.6/site-packages/ipykernel/kernelbase.py", line 233, in dispatch_shell
handler(stream, idents, msg)
File "/anaconda3/lib/python3.6/site-packages/ipykernel/kernelbase.py", line 399, in execute_request
user_expressions, allow_stdin)
File "/anaconda3/lib/python3.6/site-packages/ipykernel/ipkernel.py", line 208, in do_execute
res = shell.run_cell(code, store_history=store_history, silent=silent)
File "/anaconda3/lib/python3.6/site-packages/ipykernel/zmqshell.py", line 537, in run_cell
return super(ZMQInteractiveShell, self).run_cell(*args, **kwargs)
File "/anaconda3/lib/python3.6/site-packages/IPython/core/interactiveshell.py", line 2666, in run_cell
self.events.trigger('post_run_cell', result)
File "/anaconda3/lib/python3.6/site-packages/IPython/core/events.py", line 88, in trigger
func(*args, **kwargs)
File "/anaconda3/lib/python3.6/site-packages/ipykernel/pylab/backend_inline.py", line 160, in configure_once
activate_matplotlib(backend)
File "/anaconda3/lib/python3.6/site-packages/IPython/core/pylabtools.py", line 311, in activate_matplotlib
matplotlib.pyplot.switch_backend(backend)
File "/anaconda3/lib/python3.6/site-packages/matplotlib/pyplot.py", line 229, in switch_backend
matplotlib.use(newbackend, warn=False, force=True)
File "/anaconda3/lib/python3.6/site-packages/matplotlib/__init__.py", line 1305, in use
reload(sys.modules['matplotlib.backends'])
File "/anaconda3/lib/python3.6/importlib/__init__.py", line 166, in reload
_bootstrap._exec(spec, module)
File "/anaconda3/lib/python3.6/site-packages/matplotlib/backends/__init__.py", line 14, in <module>
line for line in traceback.format_stack()
This is separate from the ipykernel package so we can avoid doing imports until
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-3-97bf2a96714e> in <module>()
29 line_ani = animation.FuncAnimation(fig1, update_line, 25, fargs=(data, l),
30 interval=50, blit=True)
---> 31 line_ani.save('lines.mp4', writer=writer)
32
33 fig2 = plt.figure()
/anaconda3/lib/python3.6/site-packages/matplotlib/animation.py in save(self, filename, writer, fps, dpi, codec, bitrate, extra_args, metadata, extra_anim, savefig_kwargs)
1258 # TODO: See if turning off blit is really necessary
1259 anim._draw_next_frame(d, blit=False)
-> 1260 writer.grab_frame(**savefig_kwargs)
1261
1262 # Reconnect signal for first draw if necessary
/anaconda3/lib/python3.6/contextlib.py in __exit__(self, type, value, traceback)
97 value = type()
98 try:
---> 99 self.gen.throw(type, value, traceback)
100 except StopIteration as exc:
101 # Suppress StopIteration *unless* it's the same exception that
/anaconda3/lib/python3.6/site-packages/matplotlib/animation.py in saving(self, fig, outfile, dpi, *args, **kwargs)
235 yield self
236 finally:
--> 237 self.finish()
238
239
/anaconda3/lib/python3.6/site-packages/matplotlib/animation.py in finish(self)
367 def finish(self):
368 '''Finish any processing for writing the movie.'''
--> 369 self.cleanup()
370
371 def grab_frame(self, **savefig_kwargs):
/anaconda3/lib/python3.6/site-packages/matplotlib/animation.py in cleanup(self)
406 def cleanup(self):
407 '''Clean-up and collect the process used to write the movie file.'''
--> 408 out, err = self._proc.communicate()
409 self._frame_sink().close()
410 verbose.report('MovieWriter -- '
/anaconda3/lib/python3.6/subprocess.py in communicate(self, input, timeout)
841
842 try:
--> 843 stdout, stderr = self._communicate(input, endtime, timeout)
844 finally:
845 self._communication_started = True
/anaconda3/lib/python3.6/subprocess.py in _communicate(self, input, endtime, orig_timeout)
1503 selector.register(self.stdin, selectors.EVENT_WRITE)
1504 if self.stdout:
-> 1505 selector.register(self.stdout, selectors.EVENT_READ)
1506 if self.stderr:
1507 selector.register(self.stderr, selectors.EVENT_READ)
/anaconda3/lib/python3.6/selectors.py in register(self, fileobj, events, data)
349
350 def register(self, fileobj, events, data=None):
--> 351 key = super().register(fileobj, events, data)
352 poll_events = 0
353 if events & EVENT_READ:
/anaconda3/lib/python3.6/selectors.py in register(self, fileobj, events, data)
235 raise ValueError("Invalid events: {!r}".format(events))
236
--> 237 key = SelectorKey(fileobj, self._fileobj_lookup(fileobj), events, data)
238
239 if key.fd in self._fd_to_key:
/anaconda3/lib/python3.6/selectors.py in _fileobj_lookup(self, fileobj)
222 """
223 try:
--> 224 return _fileobj_to_fd(fileobj)
225 except ValueError:
226 # Do an exhaustive search.
/anaconda3/lib/python3.6/selectors.py in _fileobj_to_fd(fileobj)
37 except (AttributeError, TypeError, ValueError):
38 raise ValueError("Invalid file object: "
---> 39 "{!r}".format(fileobj)) from None
40 if fd < 0:
41 raise ValueError("Invalid file descriptor: {}".format(fd))
ValueError: Invalid file object: <_io.BufferedReader name=76>
我尝试运行其他在线可用的动画图形代码，但遇到了同样的错误。我更新了ffmpeg的版本但它没有帮助。我该怎么办？
最佳答案
在 OSX 中我通过以下方式解决了它:
1) 通过 brew 安装 ffmpeg
brew install ffmpeg
2) 也通过 brew 升级 ffmpeg
brew upgrade ffmpeg
3) 在“matplotlib”之后添加“ffmpeg”的路径:
# -*- coding: utf-8 -*-
"""
Created on Thu Oct 20 22:19:44 2018
@author: Irbin
"""
import numpy as np
import matplotlib
matplotlib.use("Agg")
import matplotlib.pyplot as plt
import matplotlib.animation as animation
plt.rcParams['animation.ffmpeg_path'] = '/usr/local/bin/ffmpeg' # Add the path of ffmpeg here!!
def update_line(num, data, line):
line.set_data(data[..., :num])
return line,
# Fixing random state for reproducibility
np.random.seed(19680801)
# Set up formatting for the movie files
Writer = animation.writers['ffmpeg']
writer = Writer(fps=15, metadata=dict(artist='Me'), bitrate=1800)
fig1 = plt.figure()
data = np.random.rand(2, 25)
l, = plt.plot([], [], 'r-')
plt.xlim(0, 1)
plt.ylim(0, 1)
plt.xlabel('x')
plt.title('test')
line_ani = animation.FuncAnimation(fig1, update_line, 25, fargs=(data, l),
interval=50, blit=True)
line_ani.save('lines.mp4', writer=writer)
fig2 = plt.figure()
x = np.arange(-9, 10)
y = np.arange(-9, 10).reshape(-1, 1)
base = np.hypot(x, y)
ims = []
for add in np.arange(15):
ims.append((plt.pcolor(x, y, base + add, norm=plt.Normalize(0, 30)),))
im_ani = animation.ArtistAnimation(fig2, ims, interval=50, repeat_delay=3000,
blit=True)
im_ani.save('im.mp4', writer=writer)
请注意，如果更改 .mp4 文件的输出目录，可能会出现错误。
关于python - 尝试在 Python 中使用 matplotlib 保存图形动画 - "Invalid file object: <_io.BufferedReader name=76>"，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/53198609/