random module is used to generate random numbers in Python. Not actually random, rather this is used to generate pseudo-random numbers. That implies that these randomly generated numbers can be determined.
random.expovariate()
expovariate() is an inbuilt method of the random module. It is used to return a random floating point number with exponential distribution.
Syntax : random.expovariate(lambda)
Parameters :
lambda : a non zero valueReturns : a random exponential distribution floating number
if the parameter is positive, the results range from 0 to positive infinity
if the parameter is negative, the results range from 0 to negative infinity
Example 1:
# import the random module import random # determining the values of the parameter lambda = 1.5 # using the expovariate() method print(random.expovariate(lambda)) |
Output :
0.22759592233982198
Example 2: We can generate the number multiple times and plot a graph to observe the exponential distribution.
# import the required libraries import random import matplotlib.pyplot as plt # store the random numbers in a # list nums = [] alpha = 3 for i in range(100): temp = random.paretovariate(alpha) nums.append(temp) # plotting a graph plt.plot(nums) plt.show() |
Output :
Example 3: We can create a histogram to observe the density of the exponential distribution.
# import the required libraries import random import matplotlib.pyplot as plt # store the random numbers in a list nums = [] lambda = 1.5 for i in range(10000): temp = random.expovariate(lambda) nums.append(temp) # plotting a graph plt.hist(nums, bins = 200) plt.show() |
Output :
