# coding:utf-8

"""

@Function:

使用contour,contourf

使用隐函数绘图

@author: Minux

@date: 2017-12-21

"""

import numpy as np

import matplotlib.pyplot as plt

import matplotlib.cm as cm

plt.rcParams["axes.unicode_minus"] = False

def implicit_function():

x, y = np.ogrid[-1.5:1.5:200j, -1.5:1.5:200j]

f = (x**2 + y**2)**4 - (x**2 - y**2)**2

fig = plt.figure()

plt.figure(figsize = (9, 4))

plt.subplot(121)

extent = [np.min(x), np.max(x), np.min(y), np.max(y)]

# 绘制出f=0和f=0.1

cs = plt.contour(f, extent = extent, levels = [0, 0.1],

color=["b", "r"], linestyles = ["solid", "dashed"],

linewidths = [2, 2])

plt.subplot(122)

for c in cs.collections:

data = c.get_paths()[0].vertices

plt.plot(data[:,0], data[:,1], color = c.get_color()[0], linewidth = c.get_linewidth()[0])

plt.show()

if __name__ == "__main__":

implicit_function()