versions/1.6.0/api/r/docs/_sources/api/mx.nd.SequenceLast.rst

``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                                                |
+========================================+============================================================+
| ``data``                               | NDArray-or-Symbol                                          |
|                                        | n-dimensional input array of the form                      |
|                                        | [max_sequence_length, batch_size, other_feature_dims]      |
|                                        | where                                                      |
|                                        | n>2                                                        |
+----------------------------------------+------------------------------------------------------------+
| ``sequence.length``                    | NDArray-or-Symbol                                          |
|                                        | vector of sequence lengths of the form [batch_size]        |
+----------------------------------------+------------------------------------------------------------+
| ``use.sequence.length``                | boolean, optional, default=0.                              |
|                                        |                                                            |
|                                        | If set to true, this layer takes in an extra input         |
|                                        | parameter `sequence_length` to specify variable length     |
|                                        | sequence                                                   |
+----------------------------------------+------------------------------------------------------------+
| ``axis``                               | 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