翻转矩阵flipud和fliplr函数

numpy.flipud

numpy.flipud(m)[source]

Flip array in the up/down direction.

Flip the entries in each column in the up/down direction. Rows are preserved, but appear in a different order than before.

Parameters:  

m : array_like

Input array.

Returns:  

out : array_like

A view of m with the rows reversed. Since a view is returned, this operation is \mathcal O(1).

See also

fliplr

Flip array in the left/right direction.

rot90

Rotate array counterclockwise.

Notes

Equivalent to m[::-1,...]. Does not require the array to be two-dimensional.

Examples

>>> A = np.diag([1.0, 2, 3])

>>> A

array([[ 1.,  0.,  0.],

[ 0.,  2.,  0.],

[ 0.,  0.,  3.]])

>>> np.flipud(A)

array([[ 0.,  0.,  3.],

[ 0.,  2.,  0.],

[ 1.,  0.,  0.]])

>>> A = np.random.randn(2,3,5)

>>> np.all(np.flipud(A) == A[::-1,...])

True

>>> np.flipud([1,2])

array([2, 1])