1.5: Random Numbers

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Random numbers are part of the NumPy package. For example, if we want to create 5 random numbers in \((0,1)\), we use the following.

import numpy as np
print(np.random.rand(5))

output: [0.99332819 0.98682806 0.32328937 0.70417298 0.59908967]

Using the same function above, together with the matplotlib package, we can create a histogram of 100000 real numbers (with 50 bins) with the following code to see the distribution.

import numpy as np
import matplotlib.pyplot as plt

y = np.random.rand(10**5)
plt.hist(y, 50);
plt.show()

output:

If, instead, we wanted a normal distribution, we can use the randn function.

import numpy as np
import matplotlib.pyplot as plt

y = np.random.randn(10**5)
plt.hist(y, 50);
plt.show()

output:

Random Package

For a bit more flexibility with random numbers, we can use Python's random package. This allows us to use, for example, the randint function to give us a random integer between two numbers, inclusive. We do so here:

import random
x=random.randint(1,5)
print(x)

output: 3