matplotlib之设置极坐标的方向

 #!/usr/bin/env python3
 #-*- coding:utf-8 -*-
 ############################
 #File Name: polar.py
 #Author: frank
 #Mail: frank0903@aliyun.com
 #Created Time:2018-05-22 22:08:01
 ############################
 import matplotlib.pyplot as plt
 import numpy as np
 import matplotlib as mpl

 #2. 怎样设置极坐标的方向
 plt.subplots_adjust(wspace=0.3)#控制两个subplot的间距，否则会有部分标签重叠
 ax1 = plt.subplot(121, polar=True)
 ax2 = plt.subplot(122, polar=True)
 #print(dir(ax))
 theta = np.arange(0, 2*np.pi, 0.1)
 ax1.set_theta_direction(-1)
 ax2.set_theta_direction('anticlockwise')
 ax1.plot(theta, theta/6,'o--')
 ax2.plot(theta, theta/6,'o--')
 plt.savefig('theta_direction.jpg')
 plt.show()

ax1 是顺时针方向的图

ax2 是逆时针方向的图

set_theta_direction(direction)

Set the direction in which theta increases.

clockwise, -1:
　　Theta increases in the clockwise direction
counterclockwise, anticlockwise, 1:
　　Theta increases in the counterclockwise direction

如果direction的值为1，表示逆时针方向，即默认theta增长方向；

如果direction的值为-1，表示顺时针方向。

同时direction也支持 ' clockwise'，'counterclockwise' ，'anticlockwise'

reference:https://matplotlib.org/api/projections_api.html?highlight=set_theta_direction#matplotlib.projections.polar.PolarAxes.set_theta_direction