How to permute in Numpy?

Posted on By Pythoneo

Let’s learn how to permute in Numpy. We will use Python Numpy permutation method.
Numpy permute array

There are two different use cases of permutations in Python you should bew aware of.

Permutation of random generated array

In NumPy, you can use the random.permutation() method to permute the elements of an array.

The random.permutation() method takes an integer as an argument, which specifies the number of elements in the array. The method returns a new array with the elements permuted.

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For example, the following code creates an array with 10 elements and then permutes the elements:

import numpy as np

for i in range(5):
    my_array = np.random.permutation(10)
    print(f"My generated permuted array: \n {my_array}")

Numpy random permute

Python returned five different arrays 10 items each.

Permutation of existing array

The random.permutation() method can also be used to permute the elements of an existing array. For example, the following code creates an array and then permutes the elements of the array five times:

import numpy as np

my_array = np.array([1, 3, 5, 7, 9])

for i in range(5):
    permuted_array = np.random.permutation(my_array)
    print(f"My permuted array: \n {permuted_array}")

Numpy permute array

Your array has been permuted five times.

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How to Permute a 2D Array

The `random.permutation()` method can also be used to permute the elements of a 2D array. For example, the following code creates a 2D array and then permutes the elements of the array:

import numpy as np

my_array = np.arange(10).reshape(2, 5)

permuted_array = np.random.permutation(my_array)

print(permuted_array)

The `random.permutation()` method can also be used to permute the rows or columns of a 2D array. To permute the rows, you can use the `axis=0` argument. To permute the columns, you can use the `axis=1` argument. For example, the following code permutes the rows of the array:

permuted_array = np.random.permutation(my_array, axis=0)

print(permuted_array)

The following code permutes the columns of the array:

permuted_array = np.random.permutation(my_array, axis=1)

print(permuted_array)
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