Version 3.0.3
# TODO:
# * Documentation -- this will need a new section of the User's Guide.
# Both for Animations and just timers.
# - Also need to update http://www.scipy.org/Cookbook/Matplotlib/Animations
# * Blit
# * Currently broken with Qt4 for widgets that don't start on screen
# * Still a few edge cases that aren't working correctly
# * Can this integrate better with existing matplotlib animation artist flag?
# - If animated removes from default draw(), perhaps we could use this to
# simplify initial draw.
# * Example
# * Frameless animation - pure procedural with no loop
# * Need example that uses something like inotify or subprocess
# * Complex syncing examples
# * Movies
# * Can blit be enabled for movies?
# * Need to consider event sources to allow clicking through multiple figures
import abc
import base64
import contextlib
from io import BytesIO
import itertools
import logging
import os
from pathlib import Path
import platform
import shutil
import subprocess
import sys
from tempfile import TemporaryDirectory
import uuid
import numpy as np
from matplotlib._animation_data import (DISPLAY_TEMPLATE, INCLUDED_FRAMES,
JS_INCLUDE)
from matplotlib import cbook, rcParams, rcParamsDefault, rc_context
_log = logging.getLogger(__name__)
# Process creation flag for subprocess to prevent it raising a terminal
# window. See for example:
# https://stackoverflow.com/questions/24130623/using-python-subprocess-popen-cant-prevent-exe-stopped-working-prompt
if platform.system() == 'Windows':
subprocess_creation_flags = CREATE_NO_WINDOW = 0x08000000
else:
# Apparently None won't work here
subprocess_creation_flags = 0
# Other potential writing methods:
# * http://pymedia.org/
# * libmng (produces swf) python wrappers: https://github.com/libming/libming
# * Wrap x264 API:
# (http://stackoverflow.com/questions/2940671/
# how-to-encode-series-of-images-into-h264-using-x264-api-c-c )
def adjusted_figsize(w, h, dpi, n):
'''Compute figure size so that pixels are a multiple of n
Parameters
----------
w, h : float
Size in inches
dpi : float
The dpi
n : int
The target multiple
Returns
-------
wnew, hnew : float
The new figure size in inches.
'''
# this maybe simplified if / when we adopt consistent rounding for
# pixel size across the whole library
def correct_roundoff(x, dpi, n):
if int(x*dpi) % n != 0:
if int(np.nextafter(x, np.inf)*dpi) % n == 0:
x = np.nextafter(x, np.inf)
elif int(np.nextafter(x, -np.inf)*dpi) % n == 0:
x = np.nextafter(x, -np.inf)
return x
wnew = int(w * dpi / n) * n / dpi
hnew = int(h * dpi / n) * n / dpi
return (correct_roundoff(wnew, dpi, n), correct_roundoff(hnew, dpi, n))
# A registry for available MovieWriter classes
[docs]class MovieWriterRegistry(object):
'''Registry of available writer classes by human readable name.'''
def __init__(self):
self.avail = dict()
self._registered = dict()
self._dirty = False
[docs] def register(self, name):
"""Decorator for registering a class under a name.
Example use::
@registry.register(name)
class Foo:
pass
"""
def wrapper(writerClass):
self._registered[name] = writerClass
if writerClass.isAvailable():
self.avail[name] = writerClass
return writerClass
return wrapper
[docs] def ensure_not_dirty(self):
"""If dirty, reasks the writers if they are available"""
if self._dirty:
self.reset_available_writers()
[docs] def reset_available_writers(self):
"""Reset the available state of all registered writers"""
self.avail = {}
for name, writerClass in self._registered.items():
if writerClass.isAvailable():
self.avail[name] = writerClass
self._dirty = False
[docs] def list(self):
'''Get a list of available MovieWriters.'''
self.ensure_not_dirty()
return list(self.avail)
[docs] def is_available(self, name):
'''Check if given writer is available by name.
Parameters
----------
name : str
Returns
-------
available : bool
'''
self.ensure_not_dirty()
return name in self.avail
def __getitem__(self, name):
self.ensure_not_dirty()
if not self.avail:
raise RuntimeError("No MovieWriters available!")
try:
return self.avail[name]
except KeyError:
raise RuntimeError(
'Requested MovieWriter ({}) not available'.format(name))
writers = MovieWriterRegistry()
[docs]class AbstractMovieWriter(abc.ABC):
'''
Abstract base class for writing movies. Fundamentally, what a MovieWriter
does is provide is a way to grab frames by calling grab_frame().
setup() is called to start the process and finish() is called afterwards.
This class is set up to provide for writing movie frame data to a pipe.
saving() is provided as a context manager to facilitate this process as::
with moviewriter.saving(fig, outfile='myfile.mp4', dpi=100):
# Iterate over frames
moviewriter.grab_frame(**savefig_kwargs)
The use of the context manager ensures that setup() and finish() are
performed as necessary.
An instance of a concrete subclass of this class can be given as the
``writer`` argument of `Animation.save()`.
'''
[docs] @abc.abstractmethod
def setup(self, fig, outfile, dpi=None):
'''
Perform setup for writing the movie file.
Parameters
----------
fig: `matplotlib.figure.Figure` instance
The figure object that contains the information for frames
outfile: string
The filename of the resulting movie file
dpi: int, optional
The DPI (or resolution) for the file. This controls the size
in pixels of the resulting movie file. Default is ``fig.dpi``.
'''
[docs] @abc.abstractmethod
def grab_frame(self, **savefig_kwargs):
'''
Grab the image information from the figure and save as a movie frame.
All keyword arguments in savefig_kwargs are passed on to the `savefig`
command that saves the figure.
'''
[docs] @contextlib.contextmanager
def saving(self, fig, outfile, dpi, *args, **kwargs):
'''
Context manager to facilitate writing the movie file.
``*args, **kw`` are any parameters that should be passed to `setup`.
'''
# This particular sequence is what contextlib.contextmanager wants
self.setup(fig, outfile, dpi, *args, **kwargs)
try:
yield self
finally:
self.finish()
[docs]class MovieWriter(AbstractMovieWriter):
'''Base class for writing movies.
This class is set up to provide for writing movie frame data to a pipe.
See examples for how to use these classes.
Attributes
----------
frame_format : str
The format used in writing frame data, defaults to 'rgba'
fig : `~matplotlib.figure.Figure`
The figure to capture data from.
This must be provided by the sub-classes.
'''
def __init__(self, fps=5, codec=None, bitrate=None, extra_args=None,
metadata=None):
'''MovieWriter
Parameters
----------
fps: int
Framerate for movie.
codec: string or None, optional
The codec to use. If ``None`` (the default) the ``animation.codec``
rcParam is used.
bitrate: int or None, optional
The bitrate for the saved movie file, which is one way to control
the output file size and quality. The default value is ``None``,
which uses the ``animation.bitrate`` rcParam. A value of -1
implies that the bitrate should be determined automatically by the
underlying utility.
extra_args: list of strings or None, optional
A list of extra string arguments to be passed to the underlying
movie utility. The default is ``None``, which passes the additional
arguments in the ``animation.extra_args`` rcParam.
metadata: Dict[str, str] or None
A dictionary of keys and values for metadata to include in the
output file. Some keys that may be of use include:
title, artist, genre, subject, copyright, srcform, comment.
'''
self.fps = fps
self.frame_format = 'rgba'
if codec is None:
self.codec = rcParams['animation.codec']
else:
self.codec = codec
if bitrate is None:
self.bitrate = rcParams['animation.bitrate']
else:
self.bitrate = bitrate
if extra_args is None:
self.extra_args = list(rcParams[self.args_key])
else:
self.extra_args = extra_args
if metadata is None:
self.metadata = dict()
else:
self.metadata = metadata
@property
def frame_size(self):
'''A tuple ``(width, height)`` in pixels of a movie frame.'''
w, h = self.fig.get_size_inches()
return int(w * self.dpi), int(h * self.dpi)
def _adjust_frame_size(self):
if self.codec == 'h264':
wo, ho = self.fig.get_size_inches()
w, h = adjusted_figsize(wo, ho, self.dpi, 2)
if not (wo, ho) == (w, h):
self.fig.set_size_inches(w, h, forward=True)
_log.info('figure size (inches) has been adjusted '
'from %s x %s to %s x %s', wo, ho, w, h)
else:
w, h = self.fig.get_size_inches()
_log.debug('frame size in pixels is %s x %s', *self.frame_size)
return w, h
[docs] def setup(self, fig, outfile, dpi=None):
'''
Perform setup for writing the movie file.
Parameters
----------
fig : matplotlib.figure.Figure
The figure object that contains the information for frames
outfile : string
The filename of the resulting movie file
dpi : int, optional
The DPI (or resolution) for the file. This controls the size
in pixels of the resulting movie file. Default is fig.dpi.
'''
self.outfile = outfile
self.fig = fig
if dpi is None:
dpi = self.fig.dpi
self.dpi = dpi
self._w, self._h = self._adjust_frame_size()
# Run here so that grab_frame() can write the data to a pipe. This
# eliminates the need for temp files.
self._run()
def _run(self):
# Uses subprocess to call the program for assembling frames into a
# movie file. *args* returns the sequence of command line arguments
# from a few configuration options.
command = self._args()
output = subprocess.PIPE
_log.info('MovieWriter.run: running command: %s', command)
self._proc = subprocess.Popen(command, shell=False,
stdout=output, stderr=output,
stdin=subprocess.PIPE,
creationflags=subprocess_creation_flags)
[docs] def grab_frame(self, **savefig_kwargs):
'''
Grab the image information from the figure and save as a movie frame.
All keyword arguments in savefig_kwargs are passed on to the `savefig`
command that saves the figure.
'''
_log.debug('MovieWriter.grab_frame: Grabbing frame.')
try:
# re-adjust the figure size in case it has been changed by the
# user. We must ensure that every frame is the same size or
# the movie will not save correctly.
self.fig.set_size_inches(self._w, self._h)
# Tell the figure to save its data to the sink, using the
# frame format and dpi.
self.fig.savefig(self._frame_sink(), format=self.frame_format,
dpi=self.dpi, **savefig_kwargs)
except (RuntimeError, IOError) as e:
out, err = self._proc.communicate()
_log.info('MovieWriter -- Error running proc:\n%s\n%s', out, err)
raise IOError('Error saving animation to file (cause: {0}) '
'Stdout: {1} StdError: {2}. It may help to re-run '
'with logging level set to '
'DEBUG.'.format(e, out, err))
def _frame_sink(self):
'''Returns the place to which frames should be written.'''
return self._proc.stdin
def _args(self):
'''Assemble list of utility-specific command-line arguments.'''
return NotImplementedError("args needs to be implemented by subclass.")
[docs] def cleanup(self):
'''Clean-up and collect the process used to write the movie file.'''
out, err = self._proc.communicate()
self._frame_sink().close()
_log.debug('MovieWriter -- Command stdout:\n%s', out)
_log.debug('MovieWriter -- Command stderr:\n%s', err)
[docs] @classmethod
def bin_path(cls):
'''
Returns the binary path to the commandline tool used by a specific
subclass. This is a class method so that the tool can be looked for
before making a particular MovieWriter subclass available.
'''
return str(rcParams[cls.exec_key])
[docs] @classmethod
def isAvailable(cls):
'''
Check to see if a MovieWriter subclass is actually available.
'''
return shutil.which(cls.bin_path()) is not None
[docs]class FileMovieWriter(MovieWriter):
'''`MovieWriter` for writing to individual files and stitching at the end.
This must be sub-classed to be useful.
'''
def __init__(self, *args, **kwargs):
MovieWriter.__init__(self, *args, **kwargs)
self.frame_format = rcParams['animation.frame_format']
[docs] def setup(self, fig, outfile, dpi=None, frame_prefix='_tmp',
clear_temp=True):
'''Perform setup for writing the movie file.
Parameters
----------
fig : matplotlib.figure.Figure
The figure to grab the rendered frames from.
outfile : str
The filename of the resulting movie file.
dpi : number, optional
The dpi of the output file. This, with the figure size,
controls the size in pixels of the resulting movie file.
Default is fig.dpi.
frame_prefix : str, optional
The filename prefix to use for temporary files. Defaults to
``'_tmp'``.
clear_temp : bool, optional
If the temporary files should be deleted after stitching
the final result. Setting this to ``False`` can be useful for
debugging. Defaults to ``True``.
'''
self.fig = fig
self.outfile = outfile
if dpi is None:
dpi = self.fig.dpi
self.dpi = dpi
self._adjust_frame_size()
self.clear_temp = clear_temp
self.temp_prefix = frame_prefix
self._frame_counter = 0 # used for generating sequential file names
self._temp_names = list()
self.fname_format_str = '%s%%07d.%s'
@property
def frame_format(self):
'''
Format (png, jpeg, etc.) to use for saving the frames, which can be
decided by the individual subclasses.
'''
return self._frame_format
@frame_format.setter
def frame_format(self, frame_format):
if frame_format in self.supported_formats:
self._frame_format = frame_format
else:
self._frame_format = self.supported_formats[0]
def _base_temp_name(self):
# Generates a template name (without number) given the frame format
# for extension and the prefix.
return self.fname_format_str % (self.temp_prefix, self.frame_format)
def _frame_sink(self):
# Creates a filename for saving using the basename and the current
# counter.
fname = self._base_temp_name() % self._frame_counter
# Save the filename so we can delete it later if necessary
self._temp_names.append(fname)
_log.debug('FileMovieWriter.frame_sink: saving frame %d to fname=%s',
self._frame_counter, fname)
self._frame_counter += 1 # Ensures each created name is 'unique'
# This file returned here will be closed once it's used by savefig()
# because it will no longer be referenced and will be gc-ed.
return open(fname, 'wb')
[docs] def grab_frame(self, **savefig_kwargs):
'''
Grab the image information from the figure and save as a movie frame.
All keyword arguments in savefig_kwargs are passed on to the `savefig`
command that saves the figure.
'''
# Overloaded to explicitly close temp file.
_log.debug('MovieWriter.grab_frame: Grabbing frame.')
try:
# Tell the figure to save its data to the sink, using the
# frame format and dpi.
with self._frame_sink() as myframesink:
self.fig.savefig(myframesink, format=self.frame_format,
dpi=self.dpi, **savefig_kwargs)
except RuntimeError:
out, err = self._proc.communicate()
_log.info('MovieWriter -- Error running proc:\n%s\n%s', out, err)
raise
[docs] def finish(self):
# Call run here now that all frame grabbing is done. All temp files
# are available to be assembled.
self._run()
MovieWriter.finish(self) # Will call clean-up
# Check error code for creating file here, since we just run
# the process here, rather than having an open pipe.
if self._proc.returncode:
try:
stdout = [s.decode() for s in self._proc._stdout_buff]
stderr = [s.decode() for s in self._proc._stderr_buff]
_log.info("MovieWriter.finish: stdout: %s", stdout)
_log.info("MovieWriter.finish: stderr: %s", stderr)
except Exception as e:
pass
raise RuntimeError('Error creating movie, return code: {}'
.format(self._proc.returncode))
[docs] def cleanup(self):
MovieWriter.cleanup(self)
# Delete temporary files
if self.clear_temp:
_log.debug('MovieWriter: clearing temporary fnames=%s',
self._temp_names)
for fname in self._temp_names:
os.remove(fname)
[docs]@writers.register('pillow')
class PillowWriter(MovieWriter):
[docs] @classmethod
def isAvailable(cls):
try:
import PIL
except ImportError:
return False
return True
def __init__(self, *args, **kwargs):
if kwargs.get("extra_args") is None:
kwargs["extra_args"] = ()
super().__init__(*args, **kwargs)
[docs] def setup(self, fig, outfile, dpi=None):
self._frames = []
self._outfile = outfile
self._dpi = dpi
self._fig = fig
[docs] def grab_frame(self, **savefig_kwargs):
from PIL import Image
buf = BytesIO()
self._fig.savefig(buf, **dict(savefig_kwargs, format="rgba"))
renderer = self._fig.canvas.get_renderer()
# Using frombuffer / getbuffer may be slightly more efficient, but
# Py3-only.
self._frames.append(Image.frombytes(
"RGBA",
(int(renderer.width), int(renderer.height)),
buf.getvalue()))
[docs] def finish(self):
self._frames[0].save(
self._outfile, save_all=True, append_images=self._frames[1:],
duration=int(1000 / self.fps))
# Base class of ffmpeg information. Has the config keys and the common set
# of arguments that controls the *output* side of things.
[docs]class FFMpegBase(object):
'''Mixin class for FFMpeg output.
To be useful this must be multiply-inherited from with a
`MovieWriterBase` sub-class.
'''
exec_key = 'animation.ffmpeg_path'
args_key = 'animation.ffmpeg_args'
@property
def output_args(self):
args = ['-vcodec', self.codec]
# For h264, the default format is yuv444p, which is not compatible
# with quicktime (and others). Specifying yuv420p fixes playback on
# iOS,as well as HTML5 video in firefox and safari (on both Win and
# OSX). Also fixes internet explorer. This is as of 2015/10/29.
if self.codec == 'h264' and '-pix_fmt' not in self.extra_args:
args.extend(['-pix_fmt', 'yuv420p'])
# The %dk adds 'k' as a suffix so that ffmpeg treats our bitrate as in
# kbps
if self.bitrate > 0:
args.extend(['-b', '%dk' % self.bitrate])
if self.extra_args:
args.extend(self.extra_args)
for k, v in self.metadata.items():
args.extend(['-metadata', '%s=%s' % (k, v)])
return args + ['-y', self.outfile]
[docs] @classmethod
def isAvailable(cls):
return (
super().isAvailable()
# Ubuntu 12.04 ships a broken ffmpeg binary which we shouldn't use.
# NOTE: when removed, remove the same method in AVConvBase.
and b'LibAv' not in subprocess.run(
[cls.bin_path()], creationflags=subprocess_creation_flags,
stdout=subprocess.DEVNULL, stderr=subprocess.PIPE).stderr)
# Combine FFMpeg options with pipe-based writing
[docs]@writers.register('ffmpeg')
class FFMpegWriter(FFMpegBase, MovieWriter):
'''Pipe-based ffmpeg writer.
Frames are streamed directly to ffmpeg via a pipe and written in a single
pass.
'''
def _args(self):
# Returns the command line parameters for subprocess to use
# ffmpeg to create a movie using a pipe.
args = [self.bin_path(), '-f', 'rawvideo', '-vcodec', 'rawvideo',
'-s', '%dx%d' % self.frame_size, '-pix_fmt', self.frame_format,
'-r', str(self.fps)]
# Logging is quieted because subprocess.PIPE has limited buffer size.
# If you have a lot of frames in your animation and set logging to
# DEBUG, you will have a buffer overrun.
if _log.getEffectiveLevel() > logging.DEBUG:
args += ['-loglevel', 'quiet']
args += ['-i', 'pipe:'] + self.output_args
return args
# Combine FFMpeg options with temp file-based writing
[docs]@writers.register('ffmpeg_file')
class FFMpegFileWriter(FFMpegBase, FileMovieWriter):
'''File-based ffmpeg writer.
Frames are written to temporary files on disk and then stitched
together at the end.
'''
supported_formats = ['png', 'jpeg', 'ppm', 'tiff', 'sgi', 'bmp',
'pbm', 'raw', 'rgba']
def _args(self):
# Returns the command line parameters for subprocess to use
# ffmpeg to create a movie using a collection of temp images
return [self.bin_path(), '-r', str(self.fps),
'-i', self._base_temp_name(),
'-vframes', str(self._frame_counter)] + self.output_args
# Base class of avconv information. AVConv has identical arguments to FFMpeg.
[docs]class AVConvBase(FFMpegBase):
'''Mixin class for avconv output.
To be useful this must be multiply-inherited from with a
`MovieWriterBase` sub-class.
'''
exec_key = 'animation.avconv_path'
args_key = 'animation.avconv_args'
# NOTE : should be removed when the same method is removed in FFMpegBase.
isAvailable = classmethod(MovieWriter.isAvailable.__func__)
# Combine AVConv options with pipe-based writing
[docs]@writers.register('avconv')
class AVConvWriter(AVConvBase, FFMpegWriter):
'''Pipe-based avconv writer.
Frames are streamed directly to avconv via a pipe and written in a single
pass.
'''
# Combine AVConv options with file-based writing
[docs]@writers.register('avconv_file')
class AVConvFileWriter(AVConvBase, FFMpegFileWriter):
'''File-based avconv writer.
Frames are written to temporary files on disk and then stitched
together at the end.
'''
# Base class for animated GIFs with convert utility
[docs]class ImageMagickBase(object):
'''Mixin class for ImageMagick output.
To be useful this must be multiply-inherited from with a
`MovieWriterBase` sub-class.
'''
exec_key = 'animation.convert_path'
args_key = 'animation.convert_args'
@property
def delay(self):
return 100. / self.fps
@property
def output_args(self):
return [self.outfile]
@classmethod
def _init_from_registry(cls):
if sys.platform != 'win32' or rcParams[cls.exec_key] != 'convert':
return
import winreg
for flag in (0, winreg.KEY_WOW64_32KEY, winreg.KEY_WOW64_64KEY):
try:
hkey = winreg.OpenKeyEx(winreg.HKEY_LOCAL_MACHINE,
r'Software\Imagemagick\Current',
0, winreg.KEY_QUERY_VALUE | flag)
binpath = winreg.QueryValueEx(hkey, 'BinPath')[0]
winreg.CloseKey(hkey)
break
except Exception:
binpath = ''
if binpath:
for exe in ('convert.exe', 'magick.exe'):
path = os.path.join(binpath, exe)
if os.path.exists(path):
binpath = path
break
else:
binpath = ''
rcParams[cls.exec_key] = rcParamsDefault[cls.exec_key] = binpath
[docs] @classmethod
def isAvailable(cls):
'''
Check to see if a ImageMagickWriter is actually available.
Done by first checking the windows registry (if applicable) and then
running the commandline tool.
'''
bin_path = cls.bin_path()
if bin_path == "convert":
cls._init_from_registry()
return super().isAvailable()
# Note: the base classes need to be in that order to get
# isAvailable() from ImageMagickBase called and not the
# one from MovieWriter. The latter is then called by the
# former.
[docs]@writers.register('imagemagick')
class ImageMagickWriter(ImageMagickBase, MovieWriter):
'''Pipe-based animated gif.
Frames are streamed directly to ImageMagick via a pipe and written
in a single pass.
'''
def _args(self):
return ([self.bin_path(),
'-size', '%ix%i' % self.frame_size, '-depth', '8',
'-delay', str(self.delay), '-loop', '0',
'%s:-' % self.frame_format]
+ self.output_args)
# Note: the base classes need to be in that order to get
# isAvailable() from ImageMagickBase called and not the
# one from MovieWriter. The latter is then called by the
# former.
[docs]@writers.register('imagemagick_file')
class ImageMagickFileWriter(ImageMagickBase, FileMovieWriter):
'''File-based animated gif writer.
Frames are written to temporary files on disk and then stitched
together at the end.
'''
supported_formats = ['png', 'jpeg', 'ppm', 'tiff', 'sgi', 'bmp',
'pbm', 'raw', 'rgba']
def _args(self):
return ([self.bin_path(), '-delay', str(self.delay), '-loop', '0',
'%s*.%s' % (self.temp_prefix, self.frame_format)]
+ self.output_args)
# Taken directly from jakevdp's JSAnimation package at
# http://github.com/jakevdp/JSAnimation
def _included_frames(frame_list, frame_format):
"""frame_list should be a list of filenames"""
return INCLUDED_FRAMES.format(Nframes=len(frame_list),
frame_dir=os.path.dirname(frame_list[0]),
frame_format=frame_format)
def _embedded_frames(frame_list, frame_format):
"""frame_list should be a list of base64-encoded png files"""
template = ' frames[{0}] = "data:image/{1};base64,{2}"\n'
return "\n" + "".join(
template.format(i, frame_format, frame_data.replace('\n', '\\\n'))
for i, frame_data in enumerate(frame_list))
@writers.register('html')
class HTMLWriter(FileMovieWriter):
supported_formats = ['png', 'jpeg', 'tiff', 'svg']
args_key = 'animation.html_args'
@classmethod
def isAvailable(cls):
return True
def __init__(self, fps=30, codec=None, bitrate=None, extra_args=None,
metadata=None, embed_frames=False, default_mode='loop',
embed_limit=None):
self.embed_frames = embed_frames
self.default_mode = default_mode.lower()
# Save embed limit, which is given in MB
if embed_limit is None:
self._bytes_limit = rcParams['animation.embed_limit']
else:
self._bytes_limit = embed_limit
# Convert from MB to bytes
self._bytes_limit *= 1024 * 1024
if self.default_mode not in ['loop', 'once', 'reflect']:
self.default_mode = 'loop'
_log.warning("unrecognized default_mode: using 'loop'")
super().__init__(fps, codec, bitrate, extra_args, metadata)
def setup(self, fig, outfile, dpi, frame_dir=None):
root, ext = os.path.splitext(outfile)
if ext not in ['.html', '.htm']:
raise ValueError("outfile must be *.htm or *.html")
self._saved_frames = []
self._total_bytes = 0
self._hit_limit = False
if not self.embed_frames:
if frame_dir is None:
frame_dir = root + '_frames'
if not os.path.exists(frame_dir):
os.makedirs(frame_dir)
frame_prefix = os.path.join(frame_dir, 'frame')
else:
frame_prefix = None
super().setup(fig, outfile, dpi, frame_prefix, clear_temp=False)
def grab_frame(self, **savefig_kwargs):
if self.embed_frames:
# Just stop processing if we hit the limit
if self._hit_limit:
return
f = BytesIO()
self.fig.savefig(f, format=self.frame_format,
dpi=self.dpi, **savefig_kwargs)
imgdata64 = base64.encodebytes(f.getvalue()).decode('ascii')
self._total_bytes += len(imgdata64)
if self._total_bytes >= self._bytes_limit:
_log.warning(
"Animation size has reached %s bytes, exceeding the limit "
"of %s. If you're sure you want a larger animation "
"embedded, set the animation.embed_limit rc parameter to "
"a larger value (in MB). This and further frames will be "
"dropped.", self._total_bytes, self._bytes_limit)
self._hit_limit = True
else:
self._saved_frames.append(imgdata64)
else:
return super().grab_frame(**savefig_kwargs)
def _run(self):
# make a duck-typed subprocess stand in
# this is called by the MovieWriter base class, but not used here.
class ProcessStandin(object):
returncode = 0
def communicate(self):
return '', ''
self._proc = ProcessStandin()
# save the frames to an html file
if self.embed_frames:
fill_frames = _embedded_frames(self._saved_frames,
self.frame_format)
Nframes = len(self._saved_frames)
else:
# temp names is filled by FileMovieWriter
fill_frames = _included_frames(self._temp_names,
self.frame_format)
Nframes = len(self._temp_names)
mode_dict = dict(once_checked='',
loop_checked='',
reflect_checked='')
mode_dict[self.default_mode + '_checked'] = 'checked'
interval = 1000 // self.fps
with open(self.outfile, 'w') as of:
of.write(JS_INCLUDE)
of.write(DISPLAY_TEMPLATE.format(id=uuid.uuid4().hex,
Nframes=Nframes,
fill_frames=fill_frames,
interval=interval,
**mode_dict))
[docs]class Animation(object):
'''This class wraps the creation of an animation using matplotlib.
It is only a base class which should be subclassed to provide
needed behavior.
This class is not typically used directly.
Parameters
----------
fig : matplotlib.figure.Figure
The figure object that is used to get draw, resize, and any
other needed events.
event_source : object, optional
A class that can run a callback when desired events
are generated, as well as be stopped and started.
Examples include timers (see :class:`TimedAnimation`) and file
system notifications.
blit : bool, optional
controls whether blitting is used to optimize drawing. Defaults
to ``False``.
See Also
--------
FuncAnimation, ArtistAnimation
'''
def __init__(self, fig, event_source=None, blit=False):
self._fig = fig
# Disables blitting for backends that don't support it. This
# allows users to request it if available, but still have a
# fallback that works if it is not.
self._blit = blit and fig.canvas.supports_blit
# These are the basics of the animation. The frame sequence represents
# information for each frame of the animation and depends on how the
# drawing is handled by the subclasses. The event source fires events
# that cause the frame sequence to be iterated.
self.frame_seq = self.new_frame_seq()
self.event_source = event_source
# Instead of starting the event source now, we connect to the figure's
# draw_event, so that we only start once the figure has been drawn.
self._first_draw_id = fig.canvas.mpl_connect('draw_event', self._start)
# Connect to the figure's close_event so that we don't continue to
# fire events and try to draw to a deleted figure.
self._close_id = self._fig.canvas.mpl_connect('close_event',
self._stop)
if self._blit:
self._setup_blit()
def _start(self, *args):
'''
Starts interactive animation. Adds the draw frame command to the GUI
handler, calls show to start the event loop.
'''
# First disconnect our draw event handler
self._fig.canvas.mpl_disconnect(self._first_draw_id)
self._first_draw_id = None # So we can check on save
# Now do any initial draw
self._init_draw()
# Add our callback for stepping the animation and
# actually start the event_source.
self.event_source.add_callback(self._step)
self.event_source.start()
def _stop(self, *args):
# On stop we disconnect all of our events.
if self._blit:
self._fig.canvas.mpl_disconnect(self._resize_id)
self._fig.canvas.mpl_disconnect(self._close_id)
self.event_source.remove_callback(self._step)
self.event_source = None
[docs] def save(self, filename, writer=None, fps=None, dpi=None, codec=None,
bitrate=None, extra_args=None, metadata=None, extra_anim=None,
savefig_kwargs=None):
"""
Save the animation as a movie file by drawing every frame.
Parameters
----------
filename : str
The output filename, e.g., :file:`mymovie.mp4`.
writer : :class:`MovieWriter` or str, optional
A `MovieWriter` instance to use or a key that identifies a
class to use, such as 'ffmpeg'. If ``None``, defaults to
:rc:`animation.writer` = 'ffmpeg'.
fps : number, optional
Frames per second in the movie. Defaults to ``None``, which will use
the animation's specified interval to set the frames per second.
dpi : number, optional
Controls the dots per inch for the movie frames. This combined with
the figure's size in inches controls the size of the movie. If
``None``, defaults to :rc:`savefig.dpi`.
codec : str, optional
The video codec to be used. Not all codecs are supported
by a given :class:`MovieWriter`. If ``None``, default to
:rc:`animation.codec` = 'h264'.
bitrate : number, optional
Specifies the number of bits used per second in the compressed
movie, in kilobits per second. A higher number means a higher
quality movie, but at the cost of increased file size. If ``None``,
defaults to :rc:`animation.bitrate` = -1.
extra_args : list, optional
List of extra string arguments to be passed to the underlying movie
utility. If ``None``, defaults to :rc:`animation.extra_args`.
metadata : Dict[str, str], optional
Dictionary of keys and values for metadata to include in
the output file. Some keys that may be of use include:
title, artist, genre, subject, copyright, srcform, comment.
extra_anim : list, optional
Additional `Animation` objects that should be included
in the saved movie file. These need to be from the same
`matplotlib.figure.Figure` instance. Also, animation frames will
just be simply combined, so there should be a 1:1 correspondence
between the frames from the different animations.
savefig_kwargs : dict, optional
Is a dictionary containing keyword arguments to be passed
on to the `savefig` command which is called repeatedly to
save the individual frames.
Notes
-----
*fps*, *codec*, *bitrate*, *extra_args* and *metadata* are used to
construct a `.MovieWriter` instance and can only be passed if
*writer* is a string. If they are passed as non-*None* and *writer*
is a `.MovieWriter`, a `RuntimeError` will be raised.
"""
# If the writer is None, use the rc param to find the name of the one
# to use
if writer is None:
writer = rcParams['animation.writer']
elif (not isinstance(writer, str) and
any(arg is not None
for arg in (fps, codec, bitrate, extra_args, metadata))):
raise RuntimeError('Passing in values for arguments '
'fps, codec, bitrate, extra_args, or metadata '
'is not supported when writer is an existing '
'MovieWriter instance. These should instead be '
'passed as arguments when creating the '
'MovieWriter instance.')
if savefig_kwargs is None:
savefig_kwargs = {}
# Need to disconnect the first draw callback, since we'll be doing
# draws. Otherwise, we'll end up starting the animation.
if self._first_draw_id is not None:
self._fig.canvas.mpl_disconnect(self._first_draw_id)
reconnect_first_draw = True
else:
reconnect_first_draw = False
if fps is None and hasattr(self, '_interval'):
# Convert interval in ms to frames per second
fps = 1000. / self._interval
# Re-use the savefig DPI for ours if none is given
if dpi is None:
dpi = rcParams['savefig.dpi']
if dpi == 'figure':
dpi = self._fig.dpi
if codec is None:
codec = rcParams['animation.codec']
if bitrate is None:
bitrate = rcParams['animation.bitrate']
all_anim = [self]
if extra_anim is not None:
all_anim.extend(anim
for anim
in extra_anim if anim._fig is self._fig)
# If we have the name of a writer, instantiate an instance of the
# registered class.
if isinstance(writer, str):
if writer in writers.avail:
writer = writers[writer](fps, codec, bitrate,
extra_args=extra_args,
metadata=metadata)
else:
_log.warning("MovieWriter {} unavailable. Trying to use {} "
"instead.".format(writer, writers.list()[0]))
try:
writer = writers[writers.list()[0]](fps, codec, bitrate,
extra_args=extra_args,
metadata=metadata)
except IndexError:
raise ValueError("Cannot save animation: no writers are "
"available. Please install ffmpeg to "
"save animations.")
_log.info('Animation.save using %s', type(writer))
if 'bbox_inches' in savefig_kwargs:
_log.warning("Warning: discarding the 'bbox_inches' argument in "
"'savefig_kwargs' as it may cause frame size "
"to vary, which is inappropriate for animation.")
savefig_kwargs.pop('bbox_inches')
# Create a new sequence of frames for saved data. This is different
# from new_frame_seq() to give the ability to save 'live' generated
# frame information to be saved later.
# TODO: Right now, after closing the figure, saving a movie won't work
# since GUI widgets are gone. Either need to remove extra code to
# allow for this non-existent use case or find a way to make it work.
with rc_context():
if rcParams['savefig.bbox'] == 'tight':
_log.info("Disabling savefig.bbox = 'tight', as it may cause "
"frame size to vary, which is inappropriate for "
"animation.")
rcParams['savefig.bbox'] = None
with writer.saving(self._fig, filename, dpi):
for anim in all_anim:
# Clear the initial frame
anim._init_draw()
for data in zip(*[a.new_saved_frame_seq() for a in all_anim]):
for anim, d in zip(all_anim, data):
# TODO: See if turning off blit is really necessary
anim._draw_next_frame(d, blit=False)
writer.grab_frame(**savefig_kwargs)
# Reconnect signal for first draw if necessary
if reconnect_first_draw:
self._first_draw_id = self._fig.canvas.mpl_connect('draw_event',
self._start)
def _step(self, *args):
'''
Handler for getting events. By default, gets the next frame in the
sequence and hands the data off to be drawn.
'''
# Returns True to indicate that the event source should continue to
# call _step, until the frame sequence reaches the end of iteration,
# at which point False will be returned.
try:
framedata = next(self.frame_seq)
self._draw_next_frame(framedata, self._blit)
return True
except StopIteration:
return False
[docs] def new_frame_seq(self):
"""Return a new sequence of frame information."""
# Default implementation is just an iterator over self._framedata
return iter(self._framedata)
[docs] def new_saved_frame_seq(self):
"""Return a new sequence of saved/cached frame information."""
# Default is the same as the regular frame sequence
return self.new_frame_seq()
def _draw_next_frame(self, framedata, blit):
# Breaks down the drawing of the next frame into steps of pre- and
# post- draw, as well as the drawing of the frame itself.
self._pre_draw(framedata, blit)
self._draw_frame(framedata)
self._post_draw(framedata, blit)
def _init_draw(self):
# Initial draw to clear the frame. Also used by the blitting code
# when a clean base is required.
pass
def _pre_draw(self, framedata, blit):
# Perform any cleaning or whatnot before the drawing of the frame.
# This default implementation allows blit to clear the frame.
if blit:
self._blit_clear(self._drawn_artists, self._blit_cache)
def _draw_frame(self, framedata):
# Performs actual drawing of the frame.
raise NotImplementedError('Needs to be implemented by subclasses to'
' actually make an animation.')
def _post_draw(self, framedata, blit):
# After the frame is rendered, this handles the actual flushing of
# the draw, which can be a direct draw_idle() or make use of the
# blitting.
if blit and self._drawn_artists:
self._blit_draw(self._drawn_artists, self._blit_cache)
else:
self._fig.canvas.draw_idle()
# The rest of the code in this class is to facilitate easy blitting
def _blit_draw(self, artists, bg_cache):
# Handles blitted drawing, which renders only the artists given instead
# of the entire figure.
updated_ax = []
for a in artists:
# If we haven't cached the background for this axes object, do
# so now. This might not always be reliable, but it's an attempt
# to automate the process.
if a.axes not in bg_cache:
bg_cache[a.axes] = a.figure.canvas.copy_from_bbox(a.axes.bbox)
a.axes.draw_artist(a)
updated_ax.append(a.axes)
# After rendering all the needed artists, blit each axes individually.
for ax in set(updated_ax):
ax.figure.canvas.blit(ax.bbox)
def _blit_clear(self, artists, bg_cache):
# Get a list of the axes that need clearing from the artists that
# have been drawn. Grab the appropriate saved background from the
# cache and restore.
axes = {a.axes for a in artists}
for a in axes:
if a in bg_cache:
a.figure.canvas.restore_region(bg_cache[a])
def _setup_blit(self):
# Setting up the blit requires: a cache of the background for the
# axes
self._blit_cache = dict()
self._drawn_artists = []
self._resize_id = self._fig.canvas.mpl_connect('resize_event',
self._handle_resize)
self._post_draw(None, self._blit)
def _handle_resize(self, *args):
# On resize, we need to disable the resize event handling so we don't
# get too many events. Also stop the animation events, so that
# we're paused. Reset the cache and re-init. Set up an event handler
# to catch once the draw has actually taken place.
self._fig.canvas.mpl_disconnect(self._resize_id)
self.event_source.stop()
self._blit_cache.clear()
self._init_draw()
self._resize_id = self._fig.canvas.mpl_connect('draw_event',
self._end_redraw)
def _end_redraw(self, evt):
# Now that the redraw has happened, do the post draw flushing and
# blit handling. Then re-enable all of the original events.
self._post_draw(None, False)
self.event_source.start()
self._fig.canvas.mpl_disconnect(self._resize_id)
self._resize_id = self._fig.canvas.mpl_connect('resize_event',
self._handle_resize)
[docs] def to_html5_video(self, embed_limit=None):
"""
Convert the animation to an HTML5 ``<video>`` tag.
This saves the animation as an h264 video, encoded in base64
directly into the HTML5 video tag. This respects the rc parameters
for the writer as well as the bitrate. This also makes use of the
``interval`` to control the speed, and uses the ``repeat``
parameter to decide whether to loop.
Parameters
----------
embed_limit : float, optional
Limit, in MB, of the returned animation. No animation is created
if the limit is exceeded.
Defaults to :rc:`animation.embed_limit` = 20.0.
Returns
-------
video_tag : str
An HTML5 video tag with the animation embedded as base64 encoded
h264 video.
If the *embed_limit* is exceeded, this returns the string
"Video too large to embed."
"""
VIDEO_TAG = r'''<video {size} {options}>
<source type="video/mp4" src="data:video/mp4;base64,{video}">
Your browser does not support the video tag.
</video>'''
# Cache the rendering of the video as HTML
if not hasattr(self, '_base64_video'):
# Save embed limit, which is given in MB
if embed_limit is None:
embed_limit = rcParams['animation.embed_limit']
# Convert from MB to bytes
embed_limit *= 1024 * 1024
# Can't open a NamedTemporaryFile twice on Windows, so use a
# TemporaryDirectory instead.
with TemporaryDirectory() as tmpdir:
path = Path(tmpdir, "temp.m4v")
# We create a writer manually so that we can get the
# appropriate size for the tag
Writer = writers[rcParams['animation.writer']]
writer = Writer(codec='h264',
bitrate=rcParams['animation.bitrate'],
fps=1000. / self._interval)
self.save(str(path), writer=writer)
# Now open and base64 encode.
vid64 = base64.encodebytes(path.read_bytes())
vid_len = len(vid64)
if vid_len >= embed_limit:
_log.warning(
"Animation movie is %s bytes, exceeding the limit of %s. "
"If you're sure you want a large animation embedded, set "
"the animation.embed_limit rc parameter to a larger value "
"(in MB).", vid_len, embed_limit)
else:
self._base64_video = vid64.decode('ascii')
self._video_size = 'width="{}" height="{}"'.format(
*writer.frame_size)
# If we exceeded the size, this attribute won't exist
if hasattr(self, '_base64_video'):
# Default HTML5 options are to autoplay and display video controls
options = ['controls', 'autoplay']
# If we're set to repeat, make it loop
if hasattr(self, 'repeat') and self.repeat:
options.append('loop')
return VIDEO_TAG.format(video=self._base64_video,
size=self._video_size,
options=' '.join(options))
else:
return 'Video too large to embed.'
[docs] def to_jshtml(self, fps=None, embed_frames=True, default_mode=None):
"""Generate HTML representation of the animation"""
if fps is None and hasattr(self, '_interval'):
# Convert interval in ms to frames per second
fps = 1000 / self._interval
# If we're not given a default mode, choose one base on the value of
# the repeat attribute
if default_mode is None:
default_mode = 'loop' if self.repeat else 'once'
if not hasattr(self, "_html_representation"):
# Can't open a NamedTemporaryFile twice on Windows, so use a
# TemporaryDirectory instead.
with TemporaryDirectory() as tmpdir:
path = Path(tmpdir, "temp.html")
writer = HTMLWriter(fps=fps,
embed_frames=embed_frames,
default_mode=default_mode)
self.save(str(path), writer=writer)
self._html_representation = path.read_text()
return self._html_representation
def _repr_html_(self):
'''IPython display hook for rendering.'''
fmt = rcParams['animation.html']
if fmt == 'html5':
return self.to_html5_video()
elif fmt == 'jshtml':
return self.to_jshtml()
[docs]class TimedAnimation(Animation):
''':class:`Animation` subclass for time-based animation.
A new frame is drawn every *interval* milliseconds.
Parameters
----------
fig : matplotlib.figure.Figure
The figure object that is used to get draw, resize, and any
other needed events.
interval : number, optional
Delay between frames in milliseconds. Defaults to 200.
repeat_delay : number, optional
If the animation in repeated, adds a delay in milliseconds
before repeating the animation. Defaults to ``None``.
repeat : bool, optional
Controls whether the animation should repeat when the sequence
of frames is completed. Defaults to ``True``.
blit : bool, optional
Controls whether blitting is used to optimize drawing. Defaults
to ``False``.
'''
def __init__(self, fig, interval=200, repeat_delay=None, repeat=True,
event_source=None, *args, **kwargs):
# Store the timing information
self._interval = interval
self._repeat_delay = repeat_delay
self.repeat = repeat
# If we're not given an event source, create a new timer. This permits
# sharing timers between animation objects for syncing animations.
if event_source is None:
event_source = fig.canvas.new_timer()
event_source.interval = self._interval
Animation.__init__(self, fig, event_source=event_source,
*args, **kwargs)
def _step(self, *args):
'''
Handler for getting events.
'''
# Extends the _step() method for the Animation class. If
# Animation._step signals that it reached the end and we want to
# repeat, we refresh the frame sequence and return True. If
# _repeat_delay is set, change the event_source's interval to our loop
# delay and set the callback to one which will then set the interval
# back.
still_going = Animation._step(self, *args)
if not still_going and self.repeat:
self._init_draw()
self.frame_seq = self.new_frame_seq()
if self._repeat_delay:
self.event_source.remove_callback(self._step)
self.event_source.add_callback(self._loop_delay)
self.event_source.interval = self._repeat_delay
return True
else:
return Animation._step(self, *args)
else:
return still_going
def _stop(self, *args):
# If we stop in the middle of a loop delay (which is relatively likely
# given the potential pause here, remove the loop_delay callback as
# well.
self.event_source.remove_callback(self._loop_delay)
Animation._stop(self)
def _loop_delay(self, *args):
# Reset the interval and change callbacks after the delay.
self.event_source.remove_callback(self._loop_delay)
self.event_source.interval = self._interval
self.event_source.add_callback(self._step)
Animation._step(self)
[docs]class ArtistAnimation(TimedAnimation):
'''Animation using a fixed set of `Artist` objects.
Before creating an instance, all plotting should have taken place
and the relevant artists saved.
Parameters
----------
fig : matplotlib.figure.Figure
The figure object that is used to get draw, resize, and any
other needed events.
artists : list
Each list entry a collection of artists that represent what
needs to be enabled on each frame. These will be disabled for
other frames.
interval : number, optional
Delay between frames in milliseconds. Defaults to 200.
repeat_delay : number, optional
If the animation in repeated, adds a delay in milliseconds
before repeating the animation. Defaults to ``None``.
repeat : bool, optional
Controls whether the animation should repeat when the sequence
of frames is completed. Defaults to ``True``.
blit : bool, optional
Controls whether blitting is used to optimize drawing. Defaults
to ``False``.
'''
def __init__(self, fig, artists, *args, **kwargs):
# Internal list of artists drawn in the most recent frame.
self._drawn_artists = []
# Use the list of artists as the framedata, which will be iterated
# over by the machinery.
self._framedata = artists
TimedAnimation.__init__(self, fig, *args, **kwargs)
def _init_draw(self):
# Make all the artists involved in *any* frame invisible
figs = set()
for f in self.new_frame_seq():
for artist in f:
artist.set_visible(False)
artist.set_animated(self._blit)
# Assemble a list of unique figures that need flushing
if artist.get_figure() not in figs:
figs.add(artist.get_figure())
# Flush the needed figures
for fig in figs:
fig.canvas.draw_idle()
def _pre_draw(self, framedata, blit):
'''
Clears artists from the last frame.
'''
if blit:
# Let blit handle clearing
self._blit_clear(self._drawn_artists, self._blit_cache)
else:
# Otherwise, make all the artists from the previous frame invisible
for artist in self._drawn_artists:
artist.set_visible(False)
def _draw_frame(self, artists):
# Save the artists that were passed in as framedata for the other
# steps (esp. blitting) to use.
self._drawn_artists = artists
# Make all the artists from the current frame visible
for artist in artists:
artist.set_visible(True)
[docs]class FuncAnimation(TimedAnimation):
"""
Makes an animation by repeatedly calling a function *func*.
Parameters
----------
fig : matplotlib.figure.Figure
The figure object that is used to get draw, resize, and any
other needed events.
func : callable
The function to call at each frame. The first argument will
be the next value in *frames*. Any additional positional
arguments can be supplied via the *fargs* parameter.
The required signature is::
def func(frame, *fargs) -> iterable_of_artists
If ``blit == True``, *func* must return an iterable of all artists
that were modified or created. This information is used by the blitting
algorithm to determine which parts of the figure have to be updated.
The return value is unused if ``blit == False`` and may be omitted in
that case.
frames : iterable, int, generator function, or None, optional
Source of data to pass *func* and each frame of the animation
- If an iterable, then simply use the values provided. If the
iterable has a length, it will override the *save_count* kwarg.
- If an integer, then equivalent to passing ``range(frames)``
- If a generator function, then must have the signature::
def gen_function() -> obj
- If *None*, then equivalent to passing ``itertools.count``.
In all of these cases, the values in *frames* is simply passed through
to the user-supplied *func* and thus can be of any type.
init_func : callable, optional
A function used to draw a clear frame. If not given, the
results of drawing from the first item in the frames sequence
will be used. This function will be called once before the
first frame.
The required signature is::
def init_func() -> iterable_of_artists
If ``blit == True``, *init_func* must return an iterable of artists
to be re-drawn. This information is used by the blitting
algorithm to determine which parts of the figure have to be updated.
The return value is unused if ``blit == False`` and may be omitted in
that case.
fargs : tuple or None, optional
Additional arguments to pass to each call to *func*.
save_count : int, optional
The number of values from *frames* to cache.
interval : number, optional
Delay between frames in milliseconds. Defaults to 200.
repeat_delay : number, optional
If the animation in repeated, adds a delay in milliseconds
before repeating the animation. Defaults to *None*.
repeat : bool, optional
Controls whether the animation should repeat when the sequence
of frames is completed. Defaults to *True*.
blit : bool, optional
Controls whether blitting is used to optimize drawing. Note: when using
blitting any animated artists will be drawn according to their zorder.
However, they will be drawn on top of any previous artists, regardless
of their zorder. Defaults to *False*.
"""
def __init__(self, fig, func, frames=None, init_func=None, fargs=None,
save_count=None, **kwargs):
if fargs:
self._args = fargs
else:
self._args = ()
self._func = func
# Amount of framedata to keep around for saving movies. This is only
# used if we don't know how many frames there will be: in the case
# of no generator or in the case of a callable.
self.save_count = save_count
# Set up a function that creates a new iterable when needed. If nothing
# is passed in for frames, just use itertools.count, which will just
# keep counting from 0. A callable passed in for frames is assumed to
# be a generator. An iterable will be used as is, and anything else
# will be treated as a number of frames.
if frames is None:
self._iter_gen = itertools.count
elif callable(frames):
self._iter_gen = frames
elif cbook.iterable(frames):
self._iter_gen = lambda: iter(frames)
if hasattr(frames, '__len__'):
self.save_count = len(frames)
else:
self._iter_gen = lambda: iter(range(frames))
self.save_count = frames
if self.save_count is None:
# If we're passed in and using the default, set save_count to 100.
self.save_count = 100
else:
# itertools.islice returns an error when passed a numpy int instead
# of a native python int (http://bugs.python.org/issue30537).
# As a workaround, convert save_count to a native python int.
self.save_count = int(self.save_count)
self._init_func = init_func
# Needs to be initialized so the draw functions work without checking
self._save_seq = []
TimedAnimation.__init__(self, fig, **kwargs)
# Need to reset the saved seq, since right now it will contain data
# for a single frame from init, which is not what we want.
self._save_seq = []
[docs] def new_frame_seq(self):
# Use the generating function to generate a new frame sequence
return self._iter_gen()
[docs] def new_saved_frame_seq(self):
# Generate an iterator for the sequence of saved data. If there are
# no saved frames, generate a new frame sequence and take the first
# save_count entries in it.
if self._save_seq:
# While iterating we are going to update _save_seq
# so make a copy to safely iterate over
self._old_saved_seq = list(self._save_seq)
return iter(self._old_saved_seq)
else:
if self.save_count is not None:
return itertools.islice(self.new_frame_seq(), self.save_count)
else:
frame_seq = self.new_frame_seq()
def gen():
try:
for _ in range(100):
yield next(frame_seq)
except StopIteration:
pass
else:
cbook.warn_deprecated(
"2.2", "FuncAnimation.save has truncated your "
"animation to 100 frames. In the future, no such "
"truncation will occur; please pass 'save_count' "
"accordingly.")
return gen()
def _init_draw(self):
# Initialize the drawing either using the given init_func or by
# calling the draw function with the first item of the frame sequence.
# For blitting, the init_func should return a sequence of modified
# artists.
if self._init_func is None:
self._draw_frame(next(self.new_frame_seq()))
else:
self._drawn_artists = self._init_func()
if self._blit:
if self._drawn_artists is None:
raise RuntimeError('The init_func must return a '
'sequence of Artist objects.')
for a in self._drawn_artists:
a.set_animated(self._blit)
self._save_seq = []
def _draw_frame(self, framedata):
# Save the data for potential saving of movies.
self._save_seq.append(framedata)
# Make sure to respect save_count (keep only the last save_count
# around)
self._save_seq = self._save_seq[-self.save_count:]
# Call the func with framedata and args. If blitting is desired,
# func needs to return a sequence of any artists that were modified.
self._drawn_artists = self._func(framedata, *self._args)
if self._blit:
if self._drawn_artists is None:
raise RuntimeError('The animation function must return a '
'sequence of Artist objects.')
self._drawn_artists = sorted(self._drawn_artists,
key=lambda x: x.get_zorder())
for a in self._drawn_artists:
a.set_animated(self._blit)