numpy.random.mtrand.RandomState.permutation

method

RandomState.permutation(x)

Randomly permute a sequence, or return a permuted range.

If x is a multi-dimensional array, it is only shuffled along its first index.

Parameters:

x : int or array_like

If x is an integer, randomly permute np.arange(x). If x is an array, make a copy and shuffle the elements randomly.

Returns:

out : ndarray

Permuted sequence or array range.

Examples

>>> np.random.permutation(10)
array([1, 7, 4, 3, 0, 9, 2, 5, 8, 6]) # random

>>> np.random.permutation([1, 4, 9, 12, 15])
array([15,  1,  9,  4, 12]) # random

>>> arr = np.arange(9).reshape((3, 3))
>>> np.random.permutation(arr)
array([[6, 7, 8], # random
       [0, 1, 2],
       [3, 4, 5]])