NumPy multiply()

Summary: in this tutorial, you’ll learn how to use the numpy multiply() function or the * operator to return the product of two equal-sized arrays, element-wise.

Introduction to the Numpy subtract function

The * operator or multiply() function returns the product of two equal-sized arrays by performing element-wise multiplication.

Let’s take some examples of using the * operator and multiply() function.

Using NumPy multiply() function and * operator to return the product of two 1D arrays

The following example uses the * operator to get the products of two 1-D arrays:

import numpy as np

a = np.array([1, 2])
b = np.array([3, 4])

c = a*b
print(c)
Code language: Python (python)

Output:

[3 8]Code language: Python (python)

How it works.

First, create two 1D arrays with two numbers in each:

a = np.array([1, 2])
b = np.array([3, 4])Code language: Python (python)

Second, get the product of two arrays a and b by using the * operator:

c = a * bCode language: Python (python)

The * operator returns the product of each element in array a with the corresponding element in array b:

[1*3, 2*4] = [3,8]Code language: Python (python)

Similarly, you can use the multiply() function to get the product between two 1D arrays as follows:

import numpy as np

a = np.array([1, 2])
b = np.array([3, 4])

c = np.multiply(a, b)
print(c)
Code language: Python (python)

Output:

[3 8]Code language: Python (python)

Using NumPy multiply() function and * operator to get the product of two 2D arrays

The following example uses the * operator to get the products of two 2D arrays:

import numpy as np

a = np.array([[1, 2], [3, 4]])
b = np.array([[5, 6], [7, 8]])

c = a*b
print(c)Code language: Python (python)

Output:

[[ 5 12]
 [21 32]]Code language: Python (python)

In this example, the * operator performs element-wise multiplication:

[[ 1*5  2*6]
 [3*7 4*8]]Code language: Python (python)

Likewise, you can use the multiply() function to find the products of two 2D arrays:

import numpy as np

a = np.array([[1, 2], [3, 4]])
b = np.array([[5, 6], [7, 8]])

c = np.multiply(a, b)
print(c)Code language: Python (python)

Output:

[[ 5 12]
 [21 32]]Code language: Python (python)

Summary

• Use the * operator or multiply() function to find the product of two equal-sized arrays.