| /********************************************************* |
| * |
| * 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. |
| * |
| ************************************************************/ |
| #ifndef SINGA_MODEL_LAYER_LRN_H_ |
| #define SINGA_MODEL_LAYER_LRN_H_ |
| #include "singa/model/layer.h" |
| #include <stack> |
| |
| namespace singa { |
| class LRN : public Layer { |
| public: |
| /// \copydoc Layer::layer_type() |
| // const std::string layer_type() const override { return "LRN"; } |
| |
| /// \copydoc Layer::Setup(const LayerConf&); |
| void Setup(const Shape& in_sample, const LayerConf& conf) override; |
| const Shape GetOutputSampleShape() const override { |
| CHECK(out_sample_shape_.size()) << "You may haven't call Setup()"; |
| return out_sample_shape_; |
| } |
| |
| /** |
| * Local Response Normalization edge |
| * |
| * @f$ b_i=a_i/x_i^beta @f$ |
| * @f$x_i=k+alpha*\sum_{j=max(0,i-n/2)}^{min(N,i+n/2)}(a_j)^2 @f$ |
| * n is size of local response area. |
| * @f$a_i@f$, the activation (after ReLU) of a neuron convolved with the i-th kernel. |
| * @f$b_i@f$, the neuron after normalization, N is the total num of kernels |
| */ |
| const Tensor Forward(int flag, const Tensor& input) |
| override; |
| |
| /// \copydoc Layer::Backward(int, const Tensor&, const Tensor&); |
| const std::pair<Tensor, vector<Tensor>> Backward( |
| int flag, const Tensor& grad) override; |
| |
| int local_size() const { return local_size_; } |
| float alpha() const { return alpha_; } |
| float beta() const { return beta_; } |
| float k() const { return k_; } |
| |
| protected: |
| //!< hyper-parameter: size local response (neighbor) area |
| int local_size_; |
| //!< other hyper-parameters |
| float alpha_, beta_, k_; |
| // store intermediate data, i.e., input tensor |
| std::stack<Tensor> buf_; |
| Shape out_sample_shape_; |
| |
| }; // class LRN |
| } // namespace |
| |
| #endif // SINGA_MODEL_LAYER_LRN_H_ |
| |