`numpy:roll`

source: /numpy/_core/numeric.py :1230

Signature

def roll ( a , shift , axis = None )

Summary

Roll array elements along a given axis.

Extended Summary

Elements that roll beyond the last position are re-introduced at the first.

Parameters

a : array_like: Input array.
shift : int or tuple of ints: The number of places by which elements are shifted. If a tuple, then axis must be a tuple of the same size, and each of the given axes is shifted by the corresponding number. If an int while axis is a tuple of ints, then the same value is used for all given axes.
axis : int or tuple of ints, optional: Axis or axes along which elements are shifted. By default, the array is flattened before shifting, after which the original shape is restored.

Returns

res : ndarray: Output array, with the same shape as a.

Notes

Supports rolling over multiple dimensions simultaneously.

Examples

import numpy as np
x = np.arange(10)
np.roll(x, 2)
np.roll(x, -2)

✓

x2 = np.reshape(x, (2, 5))
x2
np.roll(x2, 1)
np.roll(x2, -1)
np.roll(x2, 1, axis=0)
np.roll(x2, -1, axis=0)
np.roll(x2, 1, axis=1)
np.roll(x2, -1, axis=1)
np.roll(x2, (1, 1), axis=(1, 0))
np.roll(x2, (2, 1), axis=(1, 0))

✓

Aliases

numpy.roll