scipy stats.halfgennorm() | Python

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--")

Output: