chainer.functions.select_item¶
-
chainer.functions.
select_item
(x, t)[source]¶ Select elements stored in given indices.
This function returns
t.choose(x.T)
, that meansy[i] == x[i, t[i]]
for alli
.- Parameters
x (
Variable
or N-dimensional array) – Variable storing arrays. A two-dimensional float array.t (
Variable
or N-dimensional array) – Variable storing index numbers. A one-dimensional int array. Length of thet
should be equal tox.shape[0]
.
- Returns
Variable that holds
t
-th element ofx
.- Return type
Example
>>> x = np.array([[0, 1, 2], [3, 4, 5]], np.float32) >>> t = np.array([0, 2], np.int32) >>> y = F.select_item(x, t) >>> y.shape (2,) >>> y.array array([0., 5.], dtype=float32)