src/operator/sequence_last.cc

/*!
 * 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(
"Takes the last element of a sequence. Takes an n-dimensional tensor of "
"the form [max sequence length, batchsize, other dims] and returns a (n-1)-dimensional tensor "
"of the form [batchsize, other dims]. This operator takes an optional input tensor "
"sequence_length of positive ints of dimension [batchsize] when the "
"sequence_length option is set to true. This allows the operator to handle "
"variable-length sequences. If sequence_length is false, then each example "
"in the batch is assumed to have the max sequence length."
)
    .add_argument("data", "Symbol",
                  "n-dimensional input tensor of the form [max sequence "
                  "length, batchsize, other dims]")
    .add_argument("sequence_length", "Symbol",
                  "vector of sequence lengths of size batchsize")
    .add_arguments(SequenceLastParam::__FIELDS__());

}  // namespace op
}  // namespace mxnet