| /** |
| * 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. |
| */ |
| |
| #include "singa/model/layer.h" |
| #include "./dropout.h" |
| namespace singa { |
| |
| RegisterLayerClass(singa_dropout, Dropout); |
| RegisterLayerClass(singacpp_dropout, Dropout); |
| RegisterLayerClass(singacuda_dropout, Dropout); |
| RegisterLayerClass(singacl_dropout, Dropout); |
| void Dropout::Setup(const Shape& in_sample, const LayerConf& conf) { |
| Layer::Setup(in_sample, conf); |
| dropout_ratio_ = conf.dropout_conf().dropout_ratio(); |
| out_sample_shape_= in_sample; |
| } |
| |
| const Tensor Dropout::Forward(int flag, const Tensor& input) { |
| Tensor out; |
| if (flag & kTrain) { |
| mask_.ResetLike(input); |
| // set mask_[i] = 1 with prob 1-dropout_rato_ |
| Bernoulli(1.0f - dropout_ratio_, &mask_); |
| mask_ *= 1.0f / (1.0f - dropout_ratio_); |
| out = input * mask_; |
| } else { |
| out = input; |
| } |
| return out; |
| } |
| |
| const std::pair<Tensor, vector<Tensor>> Dropout::Backward(int flag, |
| const Tensor& grad) { |
| vector<Tensor> param_grad; |
| Tensor input_grad; |
| if (flag & kTrain) { |
| // note mask is already scaled by 1/(1-dropout_ratio_) |
| input_grad = grad * mask_; |
| } else { |
| LOG(ERROR) << "Do not call backward for evaluation phase"; |
| } |
| return std::make_pair(input_grad, param_grad); |
| } |
| |
| void Dropout::ToDevice(std::shared_ptr<Device> device) { |
| Layer::ToDevice(device); |
| mask_.ToDevice(device); |
| } |
| |
| } // namespace singa |