Python中的 Matplotlib.figure.Figure.legend()

Matplotlib是Python中的一个库，它是 NumPy 库的数值数学扩展。 figure 模块提供了顶级 Artist，即 Figure，其中包含所有绘图元素。该模块用于控制所有绘图元素的子图和顶级容器的默认间距。

matplotlib.figure.Figure.legend() 方法

matplotlib 库的legend() 方法图模块用于在图上放置图例。

Syntax: legend(self, *args, **kwargs)

Parameters: This method accept the following parameters that are discussed below:

• handles :This parameter is the list of Artists (lines, patches) to be added to the legend.
• labels :This parameter is the list of labels to show next to the artists.

Returns: This method returns the matplotlib.legend.Legend instance.

下面的示例说明了 matplotlib.figure 中的 matplotlib.figure.Figure.legend()函数：

示例 1：

# Implementation of matplotlib function 
import matplotlib.pyplot as plt 
    
fig, ax = plt.subplots() 
    
line1, = ax.plot([1, 2, 3], 
                 label ="Line 1", 
                 color ="black",  
                 linewidth = 4, 
                 linestyle =':') 
    
line2, = ax.plot([3, 2, 1],  
                 label ="Line 2", 
                 color ="green",  
                 linewidth = 4) 
    
    
first_legend = ax.legend(handles =[line1],  
                         loc ='upper center') 
    
ax.add_artist(first_legend) 
    
fig.legend(handles =[line2], loc ='lower center')
  
fig.suptitle("""matplotlib.figure.Figure.legend()
function Example\n\n""", fontweight ="bold") 
    
plt.show() 

输出：

示例 2：

# Implementation of matplotlib function
import numpy as np
np.random.seed(19680801)
import matplotlib.pyplot as plt
   
   
fig, ax = plt.subplots()
for color in [ 'tab:green', 'tab:blue', 'tab:orange']:
    n = 70
    x, y = np.random.rand(2, n)
    scale = 1000.0 * np.random.rand(n)
    ax.scatter(x, y, c = color, s = scale, label = color,
               alpha = 0.35)
   
fig.legend()
ax.grid(True)
  
fig.suptitle("""matplotlib.figure.Figure.legend()
function Example\n\n""", fontweight ="bold") 
    
plt.show() 

输出：