How to Multiply Array by Scalar in Python using NumPy

In Python, you can use the NumPy library to multiply an array by a scalar.

Because we are using a third-party library here, we can be sure that the code has been tested and is safe to use.

In this post, we'll learn how to use numpy to multiply all the elements in an array by a scalar.

Multiply an array by a scalar

First, let's start off importing the numpy library.

PYTHON
import numpy as np

Now, let's contine by creating an array in Python:

PYTHON
import numpy as np

array1 = np.array([1, 2, 3, 4, 5])

Now let's define n, as the number we want to multiply every element in the array by:

PYTHON
import numpy as np

array1 = np.array([1, 2, 3, 4, 5])

n = 5

To multiple every element, we can use the * operator, and then print it:

PYTHON
import numpy as np

array1 = np.array([1, 2, 3, 4, 5])

n = 5

print(array1 * n)

BASH
[5, 10, 15, 20, 25]

Alternatively, you can also use the multiply function from numpy to multiply every element in the array by a scalar:

PYTHON
import numpy as np

array1 = np.array([1, 2, 3, 4, 5])

n = 5

new_array = np.multiply(array1, n)

print(new_array)

BASH
[5, 10, 15, 20, 25]

In either case, you get the same result.

Conclusion

In this post, we looked at two different ways to multiply every element in an array by a scalar.

You can either use the * operator, or the multiply function from numpy.

Thanks for reading!

Resources

• NumPy

• Support Us