| /*! |
| * Copyright (c) 2015 by Contributors |
| * \file sequence_last.cc |
| * \brief |
| * \author Sebastian Bodenstein |
| */ |
| #include "./sequence_last-inl.h" |
| |
| namespace mxnet { |
| namespace op { |
| template <> |
| Operator *CreateOp<cpu>(SequenceLastParam param, int dtype) { |
| Operator *op = NULL; |
| MSHADOW_REAL_TYPE_SWITCH(dtype, DType, |
| { op = new SequenceLastOp<cpu, DType>(param); }) |
| return op; |
| } |
| |
| // DO_BIND_DISPATCH comes from operator_common.h |
| Operator *SequenceLastProp::CreateOperatorEx(Context ctx, |
| std::vector<TShape> *in_shape, |
| std::vector<int> *in_type) const { |
| std::vector<TShape> out_shape, aux_shape; |
| std::vector<int> out_type, aux_type; |
| CHECK(InferType(in_type, &out_type, &aux_type)); |
| CHECK(InferShape(in_shape, &out_shape, &aux_shape)); |
| DO_BIND_DISPATCH(CreateOp, param_, (*in_type)[0]); |
| } |
| |
| DMLC_REGISTER_PARAMETER(SequenceLastParam); |
| |
| MXNET_REGISTER_OP_PROPERTY(SequenceLast, SequenceLastProp) |
| .describe(R"code(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 y is used |
| SequenceLast(x, y=[1,1,1], use_sequence_length=True) = |
| [[ 1., 2., 3.], |
| [ 4., 5., 6.], |
| [ 7., 8., 9.]] |
| |
| // sequence_length y is used |
| SequenceLast(x, y=[1,2,3], use_sequence_length=True) = |
| [[ 1., 2., 3.], |
| [ 13., 14., 15.], |
| [ 25., 26., 27.]] |
| |
| )code" ADD_FILELINE) |
| .add_argument("data", "NDArray-or-Symbol", |
| "n-dimensional input array of the form [max_sequence_length," |
| " batch_size, other_feature_dims] where n>2") |
| .add_argument("sequence_length", "NDArray-or-Symbol", |
| "vector of sequence lengths of the form [batch_size]") |
| .add_arguments(SequenceLastParam::__FIELDS__()); |
| |
| } // namespace op |
| } // namespace mxnet |