本文共 3674 字,大约阅读时间需要 12 分钟。
原文地址:http://blog.csdn.net/john_xyz/article/details/54754937
关于matplotlib如何设置图例的位置?如何将图例放在图外?以及如何在一幅图有多个子图的情况下,删除重复的图例?我用一个简单的例子说明一下。
import pandas as pdimport numpy as npimport matplotlib.pyplot as pltfig = plt.figure(1)ax1 = fig.add_subplot(2,2,1)ax2 = fig.add_subplot(2,2,2)ax3 = fig.add_subplot(2,2,3)ax4 = fig.add_subplot(2,2,4)df1 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df2 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df3 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df4 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df1.plot(ax = ax1, title = "df1", grid = 'on')df2.plot(ax = ax2, title = "df1", grid = 'on')df3.plot(ax = ax3, title = "df1", grid = 'on')df4.plot(ax = ax4, title = "df1", grid = 'on')plt.show() 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
运行结果如下
可以看出,随机生成了几个dataframe,在一个figure()中生成了四个子图,每个子图的图例都是dataframe.columns里的值,那么如何移除这些图例?
import pandas as pdimport numpy as npimport matplotlib.pyplot as pltfig = plt.figure(1)ax1 = fig.add_subplot(2,2,1)ax2 = fig.add_subplot(2,2,2)ax3 = fig.add_subplot(2,2,3)ax4 = fig.add_subplot(2,2,4)df1 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df2 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df3 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df4 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df1.plot(ax = ax1, title = "df1", grid = 'on')df2.plot(ax = ax2, title = "df1", grid = 'on')df3.plot(ax = ax3, title = "df1", grid = 'on')df4.plot(ax = ax4, title = "df1", grid = 'on')ax1.legend_.remove() ##移除子图ax1中的图例ax2.legend_.remove() ##移除子图ax2中的图例ax3.legend_.remove() ##移除子图ax3中的图例plt.show() 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
可以看出ax1,ax2,ax3中的图例都被移除了,但是上图还不是很美观?有没有什么办法将图例放到图外面呢?请看:
import pandas as pdimport numpy as npimport matplotlib.pyplot as pltfig = plt.figure(1)ax1 = fig.add_subplot(2,2,1)ax2 = fig.add_subplot(2,2,2)ax3 = fig.add_subplot(2,2,3)ax4 = fig.add_subplot(2,2,4)df1 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df2 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df3 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df4 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])df1.plot(ax = ax1, title = "df1", grid = 'on')df2.plot(ax = ax2, title = "df1", grid = 'on')df3.plot(ax = ax3, title = "df1", grid = 'on')df4.plot(ax = ax4, title = "df1", grid = 'on')ax1.legend_.remove()ax2.legend_.remove()ax3.legend_.remove()ax4.legend(loc=2, bbox_to_anchor=(1.05,1.0),borderaxespad = 0.) ##设置ax4中legend的位置,将其放在图外plt.show() 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
其中参数loc用于设置legend的位置
bbox_to_anchor用于在bbox_transform坐标(默认轴坐标)中为图例指定任意位置。
关于plt.legend更多的参数信息,详细见官方文档:
关于legend的官方教程:详细见:
关于pandas.DataFrame.plot更多的作图问题,详细见: