Python Scipy stats.f()用法及代碼示例

scipy.stats.f()是F連續隨機變量，使用標準格式和一些形狀參數定義以完成其規格。

代碼1：創建F個連續隨機變量

from scipy.stats import f    
  
numargs = f.numargs 
[a, b] = [0.6, ] * numargs 
rv = f(a, b) 
  
print ("RV : \n", rv) 

輸出：

RV : 
 <scipy.stats._distn_infrastructure.rv_frozen object at 0x0000018D566864A8>

代碼2：指數F隨機變量和概率分布。

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

輸出：

Random Variates : 
 [2.77609532e+00 2.55454726e-04 7.77303742e+01 2.61642158e+02
 3.39772973e-01 8.63437666e+02 3.24316832e+02 5.88915362e+06
 1.27105242e+03 7.30691909e-01]

Probability Distribution : 
 [0.00800042 0.06746857 0.10587056 0.13291306 0.15295841 0.16837285
 0.18056559 0.19043041 0.19856155 0.2053691 ]
 

代碼3：圖形表示。

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))

輸出：

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.        ]

代碼4：改變位置參數

import matplotlib.pyplot as plt 
import numpy as np 
  
x = np.linspace(0, 5, 100) 
  
# Varying positional arguments 
y1 = f  .pdf(x, 2, 6) 
y2 = f  .pdf(x, 1, 4) 
plt.plot(x, y1, "*", x, y2, "r--")

輸出：