src/operator/numpy/random/np_choice_op.cc

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/*!
 * \file np_choice_op.cc
 * \brief Operator for random subset sampling
 */

#include "./np_choice_op.h"
#include <algorithm>

namespace mxnet {
namespace op {

template <>
void _sort<cpu>(float* key, int64_t* data, index_t length) {
  std::sort(data, data + length, [key](int64_t const& i, int64_t const& j) -> bool {
    return key[i] > key[j];
  });
}

DMLC_REGISTER_PARAMETER(NumpyChoiceParam);

NNVM_REGISTER_OP(_npi_choice)
    .describe("random choice")
    .set_num_inputs([](const nnvm::NodeAttrs& attrs) {
      int num_input                 = 0;
      const NumpyChoiceParam& param = nnvm::get<NumpyChoiceParam>(attrs.parsed);
      if (param.weighted)
        num_input += 1;
      if (!param.a.has_value())
        num_input += 1;
      return num_input;
    })
    .set_num_outputs(1)
    .set_attr<nnvm::FListInputNames>("FListInputNames",
                                     [](const NodeAttrs& attrs) {
                                       int num_input = 0;
                                       const NumpyChoiceParam& param =
                                           nnvm::get<NumpyChoiceParam>(attrs.parsed);
                                       if (param.weighted)
                                         num_input += 1;
                                       if (!param.a.has_value())
                                         num_input += 1;
                                       if (num_input == 0)
                                         return std::vector<std::string>();
                                       if (num_input == 1)
                                         return std::vector<std::string>{"input1"};
                                       return std::vector<std::string>{"input1", "input2"};
                                     })
    .set_attr_parser(ParamParser<NumpyChoiceParam>)
    .set_attr<mxnet::FInferShape>("FInferShape", NumpyChoiceOpShape)
    .set_attr<nnvm::FInferType>("FInferType", NumpyChoiceOpType)
    .set_attr<FResourceRequest>("FResourceRequest",
                                [](const nnvm::NodeAttrs& attrs) {
                                  return std::vector<ResourceRequest>{ResourceRequest::kRandom,
                                                                      ResourceRequest::kTempSpace};
                                })
    .set_attr<FCompute>("FCompute<cpu>", NumpyChoiceForward<cpu>)
    .set_attr<nnvm::FGradient>("FGradient", MakeZeroGradNodes)
    .add_argument("input1", "NDArray-or-Symbol", "Source input")
    .add_argument("input2", "NDArray-or-Symbol", "Source input")
    .add_arguments(NumpyChoiceParam::__FIELDS__());

}  // namespace op
}  // namespace mxnet