如何在matplotlib（python）中标记一条线？
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How to label a line in matplotlib (python)?
提问by Sibbs Gambling
I followed the documentation but still failed to label a line.
我遵循了文档，但仍然未能标记一条线。
plt.plot([min(np.array(positions)[:,0]), max(np.array(positions)[:,0])], [0,0], color='k', label='East') # West-East
plt.plot([0,0], [min(np.array(positions)[:,1]), max(np.array(positions)[:,1])], color='k', label='North') # South-North
In the code snippet above, I am trying to plot out the North direction and the East direction.
在上面的代码片段中，我试图绘制出北向和东向。
positioncontains the points to be plotted.
position包含要绘制的点。
But I end up with 2 straight lines with NO labelsas follows:
但我最终得到 2 条没有标签的直线，如下所示：
Where went wrong?
哪里出错了？
采纳答案by shaunakde
The argument labelis used to set the sting that will be shown in the legend. For example consider the following snippet:
该参数label用于设置将在图例中显示的刺痛。例如，考虑以下代码段：
import matplotlib.pyplot as plt
plt.plot([1,2,3],'r-',label='Sample Label Red')
plt.plot([0.5,2,3.5],'b-',label='Sample Label Blue')
plt.legend()
plt.show()
This will plot 2 lines as shown:
这将绘制 2 条线，如图所示：
The arrow function supports labels. Do check this link: http://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.arrow
箭头函数支持标签。请检查此链接：http: //matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.arrow
