numpy.
flip
Reverse the order of elements in an array along the given axis.
The shape of the array is preserved, but the elements are reordered.
New in version 1.12.0.
Input array.
Axis or axes along which to flip over. The default, axis=None, will flip over all of the axes of the input array. If axis is negative it counts from the last to the first axis.
If axis is a tuple of ints, flipping is performed on all of the axes specified in the tuple.
Changed in version 1.15.0: None and tuples of axes are supported
A view of m with the entries of axis reversed. Since a view is returned, this operation is done in constant time.
See also
flipud
Flip an array vertically (axis=0).
fliplr
Flip an array horizontally (axis=1).
Notes
flip(m, 0) is equivalent to flipud(m).
flip(m, 1) is equivalent to fliplr(m).
flip(m, n) corresponds to m[...,::-1,...] with ::-1 at position n.
m[...,::-1,...]
::-1
flip(m) corresponds to m[::-1,::-1,...,::-1] with ::-1 at all positions.
m[::-1,::-1,...,::-1]
flip(m, (0, 1)) corresponds to m[::-1,::-1,...] with ::-1 at position 0 and position 1.
m[::-1,::-1,...]
Examples
>>> A = np.arange(8).reshape((2,2,2)) >>> A array([[[0, 1], [2, 3]], [[4, 5], [6, 7]]]) >>> np.flip(A, 0) array([[[4, 5], [6, 7]], [[0, 1], [2, 3]]]) >>> np.flip(A, 1) array([[[2, 3], [0, 1]], [[6, 7], [4, 5]]]) >>> np.flip(A) array([[[7, 6], [5, 4]], [[3, 2], [1, 0]]]) >>> np.flip(A, (0, 2)) array([[[5, 4], [7, 6]], [[1, 0], [3, 2]]]) >>> A = np.random.randn(3,4,5) >>> np.all(np.flip(A,2) == A[:,:,::-1,...]) True