Shuffle functions for ndarrays.¶

Shuffle slices of ndarray along specific axis.¶

dlutils.shuffle.shuffle_ndarray(x, axis=0)[source]¶

Shuffle slices of ndarray along specific axis.

For example, given a 4-dimentional ndarray, which represents a batch of images in BCHW format, one could shuffle samples in that batch by applying shuffle_ndarray() with axis = 0.

Note

Function does not return anything. It shuffles ndarray inplace.

Parameters

x (array_like) – ndarray to shuffle.
axis (int, optional) – The axis over which to shuffle. Defaults to 0.

Example

>>> a = np.asarray([[1, 5], [0, 2], [0, 1]])
>>> a
array([[1, 5],
       [0, 2],
       [0, 1]])
>>> dlutils.shuffle.shuffle_ndarray(a, axis=0)
>>> a
array([[0, 2],
       [0, 1],
       [1, 5]])
>>> dlutils.shuffle.shuffle_ndarray(a, axis=1)
>>> a
array([[2, 0],
       [1, 0],
       [5, 1]])

Shuffle ndarrays in union.¶

dlutils.shuffle.shuffle_ndarrays_in_unison(arrays, axis=0)[source]¶

Shuffle slices of a list of ndarrays along specific axis with the same permutation for each of the arrays in the list.

Works similar to shuffle_ndarray(), but applys the same permutation to all arrays in the list

Note

Function does not return anything. It shuffles ndarray inplace. All arrays in the list should have the same shape.

Parameters

arrays (list[array_like]) – list of ndarrays to shuffle.
axis (int, optional) – The axis over which to shuffle. Defaults to 0.