numpy.rot90#

numpy.rot90(m, k=1, axes=(0, 1))[原始碼]#

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

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:

marray_like: Array of two or more dimensions.
kinteger: 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:

yndarray: A rotated view of m.

也參考

flip: Reverse the order of elements in an array along the given axis.
fliplr: Flip an array horizontally.
flipud: Flip an array vertically.

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
array([[1, 2],
       [3, 4]])
>>> np.rot90(m)
array([[2, 4],
       [1, 3]])
>>> np.rot90(m, 2)
array([[4, 3],
       [2, 1]])
>>> m = np.arange(8).reshape((2,2,2))
>>> np.rot90(m, 1, (1,2))
array([[[1, 3],
        [0, 2]],
       [[5, 7],
        [4, 6]]])