Random Permutations
Random Permutations of Elements
A permutation refers to an arrangement of elements. e.g. [3, 2, 1] is a permutation of [1, 2, 3] and vice-versa.
The NumPy Random module provides two methods for this: shuffle() and permutation().
Shuffling Arrays
Shuffle means changing arrangement of elements in-place. i.e. in the array itself.
Example
Randomly shuffle elements of following array:
12345678
from numpy import randomimport numpy as np arr = np.array([1, 2, 3, 4, 5]) random.shuffle(arr) print(arr)
The shuffle() method makes changes to the original array.
Generating Permutation of Arrays
Example
Generate a random permutation of elements of following array:
123456
from numpy import randomimport numpy as np arr = np.array([1, 2, 3, 4, 5]) print(random.permutation(arr))
The permutation() method returns a re-arranged array (and leaves the original array un-changed).
