Python random.expovariate()

The random module is used to generate random numbers in Python. These numbers are not actually random, but rather pseudo-random. This means that these randomly generated numbers can be determined.

random.expovariate()

expovariate() is a built-in method of the random module. It returns a random floating-point number with an exponential distribution.

Syntax: Random.expovariate(lambda).

Parameters: lambda : A non-zero value

Returns: A random exponentially distributed floating-point number. If the argument is positive, the result ranges from 0 to positive infinity; if the argument is negative, the result ranges 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 numbers 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: