`numpy:rot90`

source: /numpy/lib/_function_base_impl.py:178

Signature

def rot90(m, k = 1, axes = (0, 1))

Summary

Rotate an array by 90 degrees in the plane specified by axes.

Extended Summary

Rotation direction is from the first towards the second axis. This means for a 2D array with the default k and axes, the rotation will be counterclockwise.

Parameters

m : array_like: Array of two or more dimensions.
k : integer: Number of times the array is rotated by 90 degrees.
axes : (2,) array_like: The array is rotated in the plane defined by the axes. Axes must be different.

Returns

y : ndarray: A rotated view of m.

Notes

rot90(m, k=1, axes=(1,0)) is the reverse of rot90(m, k=1, axes=(0,1))

rot90(m, k=1, axes=(1,0)) is equivalent to rot90(m, k=-1, axes=(0,1))

Examples

import numpy as np
m = np.array([[1,2],[3,4]], int)
m
np.rot90(m)
np.rot90(m, 2)
m = np.arange(8).reshape((2,2,2))

✓

np.rot90(m, 1, (1,2))

✗

array([[[1, 3],
        [0, 2]],

       [[5, 7],
        [4, 6]]])

Aliases

numpy.rot90