Python中的 Matplotlib.pyplot.axvspan()

Matplotlib是一个绘图库，用于在Python中创建静态、动画和交互式可视化。\ Pyplot是一个 Matplotlib 模块，它提供了一个类似于 MATLAB 的界面。 Matplotlib 旨在与 MATLAB 一样可用，具有使用Python的能力以及免费和开源的优势。

matplotlib.pyplot.axvspan()

此函数设置绘图轴上的垂直矩形

Syntax: matplotlib.pyplot.axvspan(xmin, xmax, ymin=0, ymax=1, **kwargs)

Parameters:
xmin :Number indicating the starting position of the vertical rectangle on X-axis
xmin :Number indicating the ending position of the vertical rectangle on X-axis
ymin :vertical rectangle starting position on y axis, it will take values between 0 and 1, 0 being bottom of the axis, 1 being top of the axis
ymax :vertical rectangle ending position on y axis, it will take values between 0 and 1, 0 being bottom of the axis, 1 being top of the axis
**kwargs :Other optional parameters to change the properties of the rectangle, like changing color etc.

示例 #1：

# Importing matplotlib.pyplot as plt
import matplotlib.pyplot as plt
  
# Initializing x and y
x =[1, 15, 27, 48, 50]
y =[1, 12, 22, 45, 67]
  
# Plotting the graph
plt.plot(x, y)
  
# Drawing rectangle starting 
# x = 5 and extending till x = 20
# With vertical span starting at 
# half the length of y-axis(ymin = 0.5)
# And extending till the top of 
# axis(ymax = 1)
plt.axvspan(5, 20, ymin = 0.5, ymax = 1)
plt.show()

输出：

示例 #2：

import matplotlib.pyplot as plt
  
  
x =[1, 15, 27, 48, 50]
y =[1, 12, 22, 45, 67]
  
plt.plot(x, y)
  
# Drawing rectangle starting 
# x = 5 and extending till x = 15
# With vertical span starting at
# 25 % the length of y-axis
# And extending till the 80 % of
# axis And also we are setting 
# the color of rectangle to yellow 
# and its edge color to blue
plt.axvspan(5, 15, ymin = 0.25,
            ymax = 0.80, ec ='blue', 
            color ='yellow')
  
plt.show()

输出 ：

示例#3：

import matplotlib.pyplot as plt
  
  
x =[1, 15, 27, 48, 50]
y =[1, 12, 22, 45, 67]
  
plt.plot(x, y)
  
# Setting alpha will make 
# the rectangle transparent
plt.axvspan(10, 30, ymin = 0.15, 
            ymax = 0.70, ec ='blue',
            color ='yellow',
            alpha = 0.5)
  
plt.show()

输出 ：