numpy.flipud#

numpy.flipud(m)[source]#

Reverse the order of elements along axis 0 (up/down).

For a 2-D array, this flips the entries in each column in the up/down direction. Rows are preserved, but appear in a different order than before.

Parameters:

marray_like: Input array.

Returns:

outarray_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.
flip: Flip array in one or more dimensions.
rot90: Rotate array counterclockwise.

Notes

Equivalent to m[::-1, ...] or np.flip(m, axis=0). Requires the array to be at least 1-D.

Examples

>>> import numpy as np
>>> 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.]])

>>> rng = np.random.default_rng()
>>> A = rng.normal(size=(2,3,5))
>>> np.all(np.flipud(A) == A[::-1,...])
True

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