numpy.flip#
- numpy.flip(m,axis=None)[source]#
Reverse the order of elements in an array along the given axis.
The shape of the array is preserved, but the elements are reordered.
- Parameters:
- marray_like
Input array.
- axisNone or int or tuple of ints, optional
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 axesspecified in the tuple.
- Returns:
- outarray_like
A view ofm with the entries of axis reversed. Since a view isreturned, this operation is done in constant time.
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::-1at position n.flip(m) corresponds to
m[::-1,::-1,...,::-1]with::-1at allpositions.flip(m, (0, 1)) corresponds to
m[::-1,::-1,...]with::-1atposition 0 and position 1.Examples
>>>importnumpyasnp>>>A=np.arange(8).reshape((2,2,2))>>>Aarray([[[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]]])>>>rng=np.random.default_rng()>>>A=rng.normal(size=(3,4,5))>>>np.all(np.flip(A,2)==A[:,:,::-1,...])True