ValueError：无法在 Python 中将序列复制到 MatplotLib 动画中的数组轴

Question

我正在读取一个不断更新的data.txt 文件，并正在计算传入数据流的滚动标准偏差。我将其存储在std 中。我的滚动标准差的窗口大小为 100。

我收到一个错误：

ValueError: cannot copy sequence with size 78 to array axis with dimension 1

其中大小对应于std 数组中的项目数。 （当然，每次我点击 Run 时，这个值都会增加）。

我想知道为什么我会收到此 ValueError，并且正在寻找任何修复它的建议！当我只是为ax1.plot(xar, yar) 评分时，动画效果很好。但是一旦我尝试绘制ax1.plot(xar, std)，问题就出现了。

data.txt 中的数据如下：

[0.0, 0.0078125, 0.015625][0.0, 0.0078125, 0.015625][0.0, 0.0078125, 0.015625][0.0, 0.0078125, 0.015625][0.0, 0.0078125, 0.015625][0.0, 0.0078125, 0.015625][0.0244140625, 0.0322265625, 0.9609375][0.0244140625, 0.0322265625, 0.9609375][0.0244140625, 0.0322265625, 0.9609375][0.0244140625, 0.0322265625, 0.9609375][0.0244140625, 0.0322265625, 0.9609375][0.0244140625, 0.0322265625, 0.9609375][0.0244140625, 0.0322265625, 0.9609375][0.0244140625, 0.0322265625, 0.9609375][0.0244140625, 0.0322265625, 0.9609375][0.0263671875, 0.0341796875, 1.0341796875][0.0263671875, 0.0341796875, 1.0341796875][0.0263671875, 0.0341796875, 1.0341796875][0.0263671875, 0.0341796875, 1.0341796875][0.0263671875, 0.0341796875, 1.0341796875][0.0263671875, 0.0341796875, 1.0341796875][0.0263671875, 0.0341796875, 1.0341796875][0.0263671875, 0.0341796875, 1.0341796875][0.0244140625, 0.0341796875, 1.0048828125][0.0244140625, 0.0341796875, 1.0048828125][0.0244140625, 0.0341796875, 1.0048828125][0.0244140625, 0.0341796875, 1.0048828125][0.0244140625, 0.0341796875, 1.0048828125][0.0244140625, 0.0341796875, 1.0048828125][0.0244140625, 0.0341796875, 1.0048828125][0.0244140625, 0.0341796875, 1.0048828125][0.0244140625, 0.0341796875, 1.0048828125][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.033203125, 1.009765625][0.025390625, 0.033203125, 1.009765625][0.025390625, 0.033203125, 1.009765625][0.025390625, 0.033203125, 1.009765625][0.025390625, 0.033203125, 1.009765625][0.025390625, 0.033203125, 1.009765625][0.025390625, 0.033203125, 1.009765625][0.025390625, 0.033203125, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.0263671875, 0.0341796875, 1.009765625][0.0263671875, 0.0341796875, 1.009765625][0.0263671875, 0.0341796875, 1.009765625][0.0263671875, 0.0341796875, 1.009765625][0.0263671875, 0.0341796875, 1.009765625][0.0263671875, 0.0341796875, 1.009765625][0.0263671875, 0.0341796875, 1.009765625][0.0263671875, 0.0341796875, 1.009765625][0.0263671875, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.0107421875][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625][0.025390625, 0.0341796875, 1.009765625]

我目前的代码如下：

fig = plt.figure()
ax1 = fig.add_subplot(1,1,1)

def animate(i):
    data = pd.read_csv("C:\\Users\\Desktop\\data.txt", sep="\[|\]\[|\]",engine = 'python', header = None)
    data = data.iloc[0]
    data = data.astype(str).apply(lambda x: x.split(',')[-1]).astype(float)
    data.pop(0)
    xar = []
    yar = []
    std = []
    for j in range(len(data)):
        xar.append(j)
    for k in range(len(data)):
        yar.append(data.iloc[k])
    yar = pd.DataFrame(yar)
    std.append(pd.rolling_std(yar, 100))
    ax1.clear()
    ax1.plot(xar,std)
ani = animation.FuncAnimation(fig, animate, interval=.01)
plt.show()

Answer 1

您的错误原因是您std成为数据框的（一个元素的）列表。 pd.rolling_std() 已经为您提供了一个数据框，然后您将其附加到您的列表中。如果直接赋值，效果会更好：

std = pd.rolling_std(yar, 100)

但是，当运行pd.rolling_std() 时，会给出弃用警告。因此，该行应该是：

std = yar.rolling(window=100,center=False).std()

此外，对于生成xar 和yar 的方式，还可以进行一些简化。 xar 只是一个范围，yar 包含 data 的所有元素，允许您编写：

import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.animation as animation

def animate(i):
    data = pd.read_csv("C:\\Users\\Desktop\\data.txt", sep="\[|\]\[|\]",engine = 'python', header = None)
    data = data.iloc[0]
    data = data.astype(str).apply(lambda x: x.split(',')[-1]).astype(float)
    data.pop(0)
    xar = range(len(data))
    yar = pd.DataFrame(data)
    std = yar.rolling(window=100,center=False).std()
    ax1.clear()
    ax1.plot(xar,std)

fig = plt.figure()
ax1 = fig.add_subplot(1,1,1)
ani = animation.FuncAnimation(fig, animate, interval=.01)
plt.show()

其中animate() 已有所简化。