Multiplying a Constant to All Elements in a NumPy Array

Numpy Array - Multiply a constant to all elements

Multiplying a constant to a NumPy array is as easy as multiplying two numbers.

To multiply a constant to each and every element of an array, use multiplication arithmetic operator *. Pass array and constant as operands to the multiplication operator as shown below.

output = arr * c

where

arr is a numpy array.
c is a constant.
output is the resulting numpy array.

Examples

1. Multiply each of the element in the array with 3

In the following python example, we will multiply a constant 3 to an array arr. The resulting array is stored in output.

Python Program

import numpy as np

#2D array
arr = (np.arange(8)*2).reshape(2,4)

#print array
print("The array\n", arr)

#multiplying a constant to all the elements of array
output = arr * 3

print("\nAfter multiplying a constant to all the elements of array\n", output)

Output

Summary