Matplotlib.artist.Artist.get_alpha() in Python

Last Updated : 10 May, 2020

Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. The Artist class contains Abstract base class for objects that render into a FigureCanvas. All visible elements in a figure are subclasses of Artist.

matplotlib.artist.Artist.get_alpha() method

The get_alpha() method in artist module of matplotlib library is used to get the alpha value used for blending.

Syntax: Artist.get_alpha(self)

Parameters: This method does not accepts any parameter.

Returns: This method return the alpha value used for blending.

Below examples illustrate the matplotlib.artist.Artist.get_alpha() function in matplotlib:

Example 1:

# Implementation of matplotlib function 
from matplotlib.artist import Artist   
import matplotlib  
import numpy as np  
import matplotlib.pyplot as plt  
    
  
np.random.seed(10**7)  
mu = 121 
sigma = 21
x = mu + sigma * np.random.randn(1000)  
     
num_bins = 100
fig, ax = plt.subplots()  
     
n, bins, patches = ax.hist(x, num_bins,  
                           density = 1,  
                           color ='green',  
                           alpha = 0.7)  
     
y = ((1 / (np.sqrt(2 * np.pi) * sigma)) *
     np.exp(-0.5 * (1 / sigma * (bins - mu))**2))  
    
ax.plot(bins, y, '--', color ='black')  
    
ax.set_xlabel('X-Axis')  
ax.set_ylabel('Y-Axis')  
    
w = Artist.get_alpha(ax)  
ax.set_title("Alpha Value : "+str(w))  
  
fig.suptitle('matplotlib.artist.Artist.get_alpha()\ 
function Example', fontweight ="bold")  
  
plt.show() 

Output:

Example 2:

# Implementation of matplotlib function 
from matplotlib.artist import Artist   
import matplotlib.pyplot as plt  
import numpy as np  
  
    
rx, ry = 3., 1.
  
value1 = rx * ry * np.pi  
value2 = np.arange(0, 3 * np.pi + 0.01, 0.2)  
value3 = np.column_stack([rx / value1 * np.cos(value2),  
                          ry / value1 * np.sin(value2)])  
     
x, y, s, c = np.random.rand(4, 99)  
s *= 10**2.
     
fig, ax = plt.subplots()  
ax.scatter(x, y, s, c, marker = value3)  
    
Artist.set_alpha(ax, 0.5)  
    
w = Artist.get_alpha(ax)  
ax.set_title("Alpha Value : "+str(w))  
  
fig.suptitle('matplotlib.artist.Artist.get_alpha()\ 
function Example', fontweight ="bold")  
  
plt.show() 