matplotlib.axes.axes.fill_between

matplotlib.axes.axes.fill_between()函数，matplotlib库的Axes模块中的ax.fill_between()函数用于填充两条水平曲线之间的区域。

语法:

Axes.fill_between(self, x, y1, y2=0, where=None, interpolate=False, step=None, *, data=None, **kwargs)

参数:该方法接受如下参数说明:

• x:该参数包含用于定义曲线的数据点的横坐标。
• y1:该参数包含用于定义第一条曲线的数据点的y坐标
• y2:该参数包含用于定义第二条曲线的数据点的y坐标。它是可选的，默认值为0。
• where:该参数为可选参数。并用于排除一些水平区域的填充。
• interpolate:可选参数。它是错误条的线宽，默认值为NONE。
• step:可选参数。用于确定填充是否为阶跃函数。

返回一个包含绘制多边形的PolyCollection。

下面的例子演示了matplotlib.axes.axes.fill_between()函数在matplotlib.axes中的作用:

示例1

# Implementation of matplotlib function
      
import numpy as np
import matplotlib.pyplot as plt
  
x = np.arange(-5, 5, 0.01)
y1 = -3 * x*x + 10 * x + 10
y2 = 3 * x*x + x
  
fig, ax = plt.subplots()
ax.plot(x, y1, x, y2, color ='black')
ax.fill_between(x, y1, y2, where = y2 >y1, 
                facecolor ='green', alpha = 0.8)
  
ax.fill_between(x, y1, y2, where = y2 <= y1,
                facecolor ='black', alpha = 0.8)
  
ax.set_title('matplotlib.axes.Axes.fill_between Example1')
plt.show()

输出:

示例2

# Implementation of matplotlib function
      
import numpy as np
import matplotlib.pyplot as plt
  
x = np.arange(0.0, 2, 0.01)
y1 = np.sin(2 * np.pi * x)
y2 = 0.8 * np.sin(4 * np.pi * x)
  
fig, (ax1, ax2, ax3, ax4) = plt.subplots(4, 1,
                                         sharex = True,
                                         figsize =(6, 6))
  
ax1.fill_between(x, y1, facecolor ='green')
ax1.set_title('Fill_Between y1 and 0')
  
ax2.fill_between(x, y1, 1, facecolor ='green')
ax2.set_title('Fill_Between y1 and 1')
  
ax3.fill_between(x, y1, y2, facecolor ='green')
ax3.set_title('Fill_Between y1 and y2')
ax3.set_xlabel('x')
fig.tight_layout()
  
ax4.fill_between(x, y1, y2, where = y2 <= y1,
                 facecolor ='green')
  
ax4.set_title('Fill_Between y1 and y2 with condition y2 <= y1 ' )
ax4.set_xlabel('x')
fig.tight_layout()
  
plt.show()

输出: