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() andpermutation().
Shuffling Arrays
Shuffle means changing arrangement of elements in-place. i.e. in the array itself.
Example
Randomly shuffle elements of following array:
from numpy import random
import numpy as np
arr = np.array([1, 2, 3, 4, 5])
random.shuffle(arr)
print(arr)
Try it Yourself »import numpy as np
arr = np.array([1, 2, 3, 4, 5])
random.shuffle(arr)
print(arr)
Theshuffle() method makes changes to the original array.
Generating Permutation of Arrays
Example
Generate a random permutation of elements of following array:
from numpy import random
import numpy as np
arr = np.array([1, 2, 3, 4, 5])
print(random.permutation(arr))
Try it Yourself »import numpy as np
arr = np.array([1, 2, 3, 4, 5])
print(random.permutation(arr))
Thepermutation() methodreturns a re-arranged array (and leaves the original array un-changed).
