chainer.functions.get_item¶
-
chainer.functions.
get_item
(x, slices)[source]¶ Extract elements from array with specified shape, axes and offsets.
Parameters: - x (
Variable
ornumpy.ndarray
orcupy.ndarray
) – A variable to be sliced. - slices (int, slice, Ellipsis, None, integer array-like, boolean array-like or tuple of them) – An object to specify the selection of elements.
Returns: A
Variable
object which contains sliced array ofx
.Note
It only supports types that are supported by CUDA’s atomicAdd when an integer array is included in
slices
. The supported types arenumpy.float32
,numpy.int32
,numpy.uint32
,numpy.uint64
andnumpy.ulonglong
.Note
It does not support
slices
that contains multiple boolean arrays.Note
See NumPy documentation for details of indexing.
Example
>>> x = np.arange(12).reshape((2, 2, 3)) >>> x array([[[ 0, 1, 2], [ 3, 4, 5]], <BLANKLINE> [[ 6, 7, 8], [ 9, 10, 11]]]) >>> F.get_item(x, 0) variable([[0, 1, 2], [3, 4, 5]]) >>> F.get_item(x, (0, 0, slice(0, 2, 1))) # equals x[0, 0, 0:2:1] variable([0, 1]) >>> F.get_item(x, (Ellipsis, 2)) # equals x[..., 2] variable([[ 2, 5], [ 8, 11]]) >>> F.get_item(x, (1, np.newaxis, 1, 0)) # equals x[1, None, 1, 0] variable([9])
- x (