Python 中，matplotlib绘图无法显示中文的问题

在python中，默认情况下是无法显示中文的，如下代码：

1. import matplotlib.pyplot as plt
2.  

3. # 定义文本框和箭头格式

4. decisionNode = dict(boxstyle = "sawtooth", fc = "0.8")

5. leafNode = dict(boxstyle = "round4", fc = "0.8")

6. arrow_args = dict(arrowstyle = "<-")

7.  

8. # 绘制带箭头的注解

9. def plotNode(nodeTxt, centerPt, parentPt, nodeType) :

10. createPlot.ax1.annotate(nodeTxt, xy = parentPt, xycoords = 'axes fraction', xytext = centerPt, textcoords = 'axes fraction', va = 'center', ha = 'center', bbox = nodeType, arrowprops = arrow_args)

11.  

12. def createPlot() :

13. fig = plt.figure(1, facecolor='white')

14. fig.clf()

15. createPlot.ax1 = plt.subplot(111, frameon = False)

16. plotNode(U'决策节点', (0.5, 0.1), (0.1, 0.5), decisionNode)

17. plotNode(U'叶节点', (0.8, 0.1), (0.3, 0.8), leafNode)

18. plt.show()

19.  

20. createPlot()

得到图像如下：

产生中文乱码的原因就是字体的默认设置中并没有中文字体，所以我们只要手动添加中文字体的名称就可以了

手动增加如下代码

1. from pylab import *

2. mpl.rcParams['font.sans-serif'] = ['SimHei']

源代码修改如下：

1. import matplotlib.pyplot as plt

2.  

3. from pylab import *

4. mpl.rcParams['font.sans-serif'] = ['SimHei']

5.  

6. # 定义文本框和箭头格式

7. decisionNode = dict(boxstyle = "sawtooth", fc = "0.8")

8. leafNode = dict(boxstyle = "round4", fc = "0.8")

9. arrow_args = dict(arrowstyle = "<-")

10.  

11. # 绘制带箭头的注解

12. def plotNode(nodeTxt, centerPt, parentPt, nodeType) :

13. createPlot.ax1.annotate(nodeTxt, xy = parentPt, xycoords = 'axes fraction', xytext = centerPt, textcoords = 'axes fraction', va = 'center', ha = 'center', bbox = nodeType, arrowprops = arrow_args)

14.  

15. def createPlot() :

16. fig = plt.figure(1, facecolor='white')

17. fig.clf()

18. createPlot.ax1 = plt.subplot(111, frameon = False)

19. plotNode(U'决策节点', (0.5, 0.1), (0.1, 0.5), decisionNode)

20. plotNode(U'叶节点', (0.8, 0.1), (0.3, 0.8), leafNode)

21. plt.show()

22. createPlot()

最终得到图像

成功！