import matplotlib.pyplot as plt
import numpy as np
 
x= np.linspace(0,5*np.pi, 1000)
 
y1 = np.sin(x)
y2 = np.sin(2*x)
 
#plt.plot(x,y1)
#plt.plot(x,y2)
 
plt.fill(x,y1,'b',alpha=0.5)
plt.fill(x,y2,'r',alpha=0.3)
 
plt.fill_between(x,y1,y2,facecolor='green')
plt.grid(True)
 
plt.show()
 
#########################################################
plt.plot(x,y1,'b',alpha=0.5)
plt.plot(x,y2,'r',alpha=0.3)
#添加条件
#如果数据点比较少的情况下，会有缝隙出现，使用interpolate可以填充缝隙
plt.fill_between(x,y1,y2,where=y1>=y2,facecolor='green',interpolate=True)
plt.fill_between(x,y1,y2,where=y2>y1,facecolor='yellow',interpolate=True)
plt.grid(True)
 
plt.show()
###########################################################
 
n = 256
X = np.linspace(-np.pi, np.pi, n, endpoint=True)
Y = np.sin(2 * X)
 
 
plt.plot(X, Y + 1, color='blue', alpha=1.00)
plt.fill_between(X, 1, Y + 1, color='blue', alpha=.25)
 
plt.plot(X, Y - 1, color='blue', alpha=1.00)
plt.fill_between(X, -1, Y - 1, (Y - 1) > -1, color='blue', alpha=.25)
plt.fill_between(X, -1, Y - 1, (Y - 1)  -1, color='red', alpha=.25)
 
plt.xlim(-np.pi, np.pi)
plt.xticks(())
plt.ylim(-2.5, 2.5)
plt.yticks(())