mx.nd.SequenceLast
¶
Description¶
Takes the last element of a sequence.
This function takes an n-dimensional input array of the form [max_sequence_length, batch_size, other_feature_dims] and returns a (n-1)-dimensional array of the form [batch_size, other_feature_dims].
Parameter sequence_length is used to handle variable-length sequences. sequence_length should be an input array of positive ints of dimension [batch_size]. To use this parameter, set use_sequence_length to True, otherwise each example in the batch is assumed to have the max sequence length.
Note
Alternatively, you can also use take operator.
Example:
x = [[[ 1., 2., 3.],
[ 4., 5., 6.],
[ 7., 8., 9.]],
[[ 10., 11., 12.],
[ 13., 14., 15.],
[ 16., 17., 18.]],
[[ 19., 20., 21.],
[ 22., 23., 24.],
[ 25., 26., 27.]]]
// returns last sequence when sequence_length parameter is not used
SequenceLast(x) = [[ 19., 20., 21.],
[ 22., 23., 24.],
[ 25., 26., 27.]]
// sequence_length is used
SequenceLast(x, sequence_length=[1,1,1], use_sequence_length=True) =
[[ 1., 2., 3.],
[ 4., 5., 6.],
[ 7., 8., 9.]]
// sequence_length is used
SequenceLast(x, sequence_length=[1,2,3], use_sequence_length=True) =
[[ 1., 2., 3.],
[ 13., 14., 15.],
[ 25., 26., 27.]]
Arguments¶
Argument |
Description |
---|---|
|
NDArray-or-Symbol n-dimensional input array of the form [max_sequence_length, batch_size, other_feature_dims] where n>2 |
|
NDArray-or-Symbol vector of sequence lengths of the form [batch_size] |
|
boolean, optional, default=0. If set to true, this layer takes in an extra input parameter sequence_length to specify variable length sequence |
|
int, optional, default=’0’. The sequence axis. Only values of 0 and 1 are currently supported. |
Value¶
out
The result mx.ndarray
Link to Source Code: http://github.com/apache/incubator-mxnet/blob/1.6.0/src/operator/sequence_last.cc#L106