pandas 在 matplotlib 子图中添加一行
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add a line to matplotlib subplots
提问by Nabla
I would like to do a subplot of two figures with matplotlib and add a horizontal line in both. This is probably basic, but I don't know how to specify that one of the lines should be drawn in the first figure, they both end up in the last one. e.g.
我想用 matplotlib 绘制两个图形的子图，并在两者中添加一条水平线。这可能是基本的，但我不知道如何指定应在第一个图中绘制其中一条线，它们最终都在最后一个图中。例如
import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
%matplotlib inline
s1= pd.Series(np.random.rand(10))
s2= pd.Series(np.random.rand(10))
fig, axes = plt.subplots(nrows=2,ncols=1)
f1= s1.plot(ax=axes[0])
l1=plt.axhline(0.5,color='black',ls='--')
l1.set_label('l1')
f2= s1.plot(ax=axes[1])
l2=plt.axhline(0.7,color='red',ls='--')
l2.set_label('l2')
plt.legend()
axhline does not have "ax" as an argument, as the pandas plot function does. So this would work:
axhline 没有“ax”作为参数，就像 pandas plot 函数那样。所以这会起作用：
l1=plt.axhline(0.5,color='black',ls='--',ax=axes[0])
I read the examplesin matplotlib and I tried with this other option that does not work either (probably for good reasons)
我阅读了matplotlib 中的示例，并尝试了另一个不起作用的选项（可能有充分的理由）
axes[0].plt.axhline(0.5,color='black',ls='--')
How should I do to draw lines in subplots? Ideally with a legend Thanks!
我应该如何在子图中画线？最好有传说 谢谢！
采纳答案by Nabla
with the help of @Nick Becker I answered my own "syntax" question.
在@Nick Becker 的帮助下，我回答了我自己的“语法”问题。
import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
%matplotlib inline
s1= pd.Series(np.random.rand(10))
s2= pd.Series(np.random.randn(10))
fig, axes = plt.subplots(nrows=2,ncols=1)
f1= s1.plot(ax=axes[0],label='s1')
l1=axes[0].axhline(0.5,color='black',ls='--')
l1.set_label('l1')
axes[0].legend(loc='best')
f2= s1.plot(ax=axes[1],label='s2')
l2=axes[1].axhline(0.5,color='black',ls='--')
l2.set_label('l2')
axes[1].legend(loc='best')
