Matplotlib 不改变 x 比例以连续显示数据

Question

我尝试过类似以下的方法：

import matplotlib.pyplot as plt
import numpy as np
d= [1,2,3,4]
f = [1,2,3,4,5]
plt.ion()
fig = plt.figure()
fig.set_size_inches(10,5)
ax1 = fig.add_subplot(111)
line1, = ax1.plot(np.arange(len(d)),d,color='blue', label='first',marker=".")
line2, = ax1.plot(np.arange(len(f)),f,color='red', label='second',marker=".")
plt.show()

for i in range(20):
    d.append(i)
    f.append(i)
    line1.set_xdata(np.arange(len(d)))
    line2.set_xdata(np.arange(len(f)))
    line1.set_ydata(d)
    line2.set_ydata(f)

得到类似这样的错误：

>>> Exception in Tkinter callback
Traceback (most recent call last):ges\numpy\lib\stride_tricks.py", line 249, in broadcast_arrays
  File "C:\Python35\lib\site-packages\matplotlib\backends\tkagg.py", line 26, in blit
    dataptr, colormode, bboxptr)kages\numpy\lib\stride_tricks.py", line 184, in _broadcast_shape
_tkinter.TclError: this isn't a Tk application
ValueError: shape mismatch: objects cannot be broadcast to a single shape
During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Python35\lib\tkinter\__init__.py", line 1549, in __call__
    return self.func(*args)
  File "C:\Python35\lib\tkinter\__init__.py", line 596, in callit
    func(*args)
  File "C:\Python35\lib\site-packages\matplotlib\backends\_backend_tk.py", line 310, in idle_draw
    self.draw()
  File "C:\Python35\lib\site-packages\matplotlib\backends\backend_tkagg.py", line 13, in draw
    tkagg.blit(self._tkphoto, self.renderer._renderer, colormode=2)
  File "C:\Python35\lib\site-packages\matplotlib\backends\tkagg.py", line 34, in blit
    dataptr, colormode, bboxptr)
_tkinter.TclError: this isn't a Tk application

即使它没有改变 x 轴值。

我想像实时显示一样在同一个图表中显示这两个值。

数组有不同的大小。应用被称为重复的问题的解决方案后出现错误：

ValueError：形状不匹配：无法将对象广播到单个形状

我的查询与不同的数组大小和实时绘图有关。

Answer 1

我怀疑错误来自 for 循环太快，但我无法重现它。因此，让我们正确处理动画。通常你会想要设置一个延迟来感知情节的变化。为此使用plt.pause()。

要将绘图重新调整为新添加的数据，请使用.relim() 和.autoscale_view()。

最后，您可能希望在循环终止时保持绘图打开；这可以通过关闭交互模式并再次调用show 来完成。

import matplotlib
matplotlib.use("TkAgg")
import matplotlib.pyplot as plt
import numpy as np
d= [1,2,3,4]
f = [1,2,3,4,5]
plt.ion()
fig = plt.figure()
fig.set_size_inches(10,5)
ax1 = fig.add_subplot(111)
line1, = ax1.plot(np.arange(len(d)),d,color='blue', label='first',marker=".")
line2, = ax1.plot(np.arange(len(f)),f,color='red', label='second',marker=".")
plt.show()

for i in range(20):
    d.append(i)
    f.append(i)
    line1.set_xdata(np.arange(len(d)))
    line2.set_xdata(np.arange(len(f)))
    line1.set_ydata(d)
    line2.set_ydata(f)
    ax1.relim()
    ax1.autoscale_view()
    plt.pause(0.5)

# To keep the plot open after the animation has finished.  
plt.ioff()
plt.show()