Question

我通过调用：

使用matplotlib动画

plot = animation.FuncAnimation(fig, update, frames=data_gen(a), init_func=init, interval=10, blit=True)

这里，“a”是data_gen函数的初始值，如下所示：

data_gen(x)
    old_x = x
    while True:
        new_x = func(old_x)
        old_x = new_x
        yield new_x

此代码的目的是让data_gen在每次更新动画图时为new_x生成一个新值。

但是......这恰巧发生了：

animation.py在FuncAnimation类的 init （）方法中抛出错误。

此代码中出现问题：

elif iterable(frames):
    self._iter_gen = lambda: iter(frames)
    self.save_count = len(frames)

错误是“TypeError：类型'生成器'的对象没有len（）”

看起来data_gen是可迭代的，但它没有len（）。

以下是FuncAnimation类中 init （）方法的更多代码：

    # 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 isinstance(frames, collections.Callable):
        self._iter_gen = frames
    elif iterable(frames):
        self._iter_gen = lambda: iter(frames)
        self.save_count = len(frames)
    else:
        self._iter_gen = lambda: iter(list(range(frames)))
        self.save_count = frames

我不确定为什么我的data_gen不是collections.Callable。如果是，则len（帧）永远不会发生。

对于我应该做些什么的任何建议都将不胜感激！

Answer 1

解决方案是A）预先生成所有数据并将其推送到列表中（如果你的帧数确实有限），即data_list = list(data_gen) B）从我的分支机构安装来源解决了这个问题：PR #2634或C）猴子补丁matplotlib，它只是在运行时使用固定代码替换安装中的错误代码

C）是最有趣的;）

# copied directly from the proposed fix
def monkey_patch_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 six.callable(frames):
        self._iter_gen = frames
    elif iterable(frames):
        self._iter_gen = lambda: iter(frames)
        if hasattr(frames, '__len__'):
            self.save_count = len(frames)
    else:
        self._iter_gen = lambda: xrange(frames).__iter__()
        self.save_count = frames

    # If we're passed in and using the default, set it to 100.
    if self.save_count is None:
        self.save_count = 100

    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 = []

我们现在有一个函数monkey_patch_init，它是（我声称的）固定代码。我们现在只用这个函数替换bug __init__函数：

matplotlib.animation.FuncAnimation.__init__ = monkey_patch_init

，你的动画应该有用。

ani = animation.FuncAnimation(fig, update, frames=data_gen(a), init_func=init, interval=10, blit=True)

作为旁注，请勿使用plot作为变量名称。很多人将pyplot批量导入其名称空间（例如ipython --pylab），其中plot - > matplotlib.pyplot.plot - ＆gt; plt.gca().plot因此它使得代码更容易让某人感到困惑。

matplotlib动画FuncAnimation帧参数

1 个答案: