scipy stats.halfgennorm() | Python

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scipy.stats.halfgennorm() is an upper half of a generalized normal continuous random variable. To complete its specificaitons, it is defined with a standard format and some shape parameters. The object object inherits from it a collection of generic methods and completes them with details specific.

Parameters :

-> α : scale
-> β : shape
-> μ : location

Code #1 : Creating Half-generalized normal continuous random variable

from scipy.stats import halfgennorm   
   
numargs = halfgennorm.numargs 
[a] = [0.7, ] * numargs 
rv = halfgennorm (a) 
   
print ("RV : \n", rv)  

Output:

RV : 
 scipy.stats._distn_infrastructure.rv_frozen object at 0x0000021FB55D8DD8

Code #2 : Half-generalized random variates and probability distribution

import numpy as np 
quantile = np.arange (0.01, 1, 0.1) 
    
# Random Variates 
R = halfgennorm .rvs(.2, scale = 2,  size = 10) 
print ("Random Variates : \n", R) 
   
# PDF 
R = halfgennorm .pdf(quantile, .2, loc = 0, scale = 1) 
print ("\nProbability Distribution : \n", R) 

Output:

Random Variates : 
 [1.41299459e+03 3.51301175e+04 1.79981484e+05 2.90925518e+02
 2.70178121e+05 1.31706797e+05 3.25898913e+01 1.62607410e+04
 2.02263946e+04 1.97078668e+04]

Probability Distribution : 
 [0.00559658 0.0043805  0.00400834 0.0037776  0.00360957 0.00347731
 0.00336825 0.00327549 0.00319482 0.00312348]

Code #3 : Graphical Representation.

import numpy as np 
import matplotlib.pyplot as plt 
   
distribution = np.linspace(0, np.minimum(rv.dist.b, 3)) 
print("Distribution : \n", distribution) 
   
plot = plt.plot(distribution, rv.pdf(distribution)) 

Output:

Distribution : 
 [0.         0.06122449 0.12244898 0.18367347 0.24489796 0.30612245
 0.36734694 0.42857143 0.48979592 0.55102041 0.6122449  0.67346939
 0.73469388 0.79591837 0.85714286 0.91836735 0.97959184 1.04081633
 1.10204082 1.16326531 1.2244898  1.28571429 1.34693878 1.40816327
 1.46938776 1.53061224 1.59183673 1.65306122 1.71428571 1.7755102
 1.83673469 1.89795918 1.95918367 2.02040816 2.08163265 2.14285714
 2.20408163 2.26530612 2.32653061 2.3877551  2.44897959 2.51020408
 2.57142857 2.63265306 2.69387755 2.75510204 2.81632653 2.87755102
 2.93877551 3.        ]

Code #4 : Varying Positional Arguments

import matplotlib.pyplot as plt 
import numpy as np 
   
x = np.linspace(0, 5, 100) 
   
# Varying positional arguments 
y1 = halfgennorm .pdf(x, 1, 3) 
y2 = halfgennorm .pdf(x, 1, 4) 
plt.plot(x, y1, "*", x, y2, "r--") 