From 0cca0fcf1152b6d2a7c9068934aa2505491ca856 Mon Sep 17 00:00:00 2001 From: hedaoyuan Date: Tue, 1 Aug 2017 11:35:17 +0800 Subject: [PATCH] Add SliceProjection. --- paddle/gserver/layers/SliceProjection.cpp | 96 +++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 paddle/gserver/layers/SliceProjection.cpp diff --git a/paddle/gserver/layers/SliceProjection.cpp b/paddle/gserver/layers/SliceProjection.cpp new file mode 100644 index 0000000000..a361d19bde --- /dev/null +++ b/paddle/gserver/layers/SliceProjection.cpp @@ -0,0 +1,96 @@ +/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve. + +Licensed 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 "Projection.h" + +namespace paddle { + +/** + * SliceProjection can slice the input value into multiple parts, + * and then select some of them to merge into a new output. + * + * First, calculate the slices that need to be merged into the output. + * slices = input.slices().for_output() + * + * Second, merge each slice into the output. + * for(auto slice: slices) { + * out.addAtOffset(slice, offset); + * } + * + * Input slices as output: s0, s1, ...: + * ----------------------- + * |///| |//////| | + * |/s0| |//s1//| | + * |///| |//////| | + * ----------------------- + * Output, merge s0, s1, ... into one output: + * ---------------- + * |///|//////| | + * |/s0|//s1//|...| + * |///|//////| | + * ---------------- + * + * The config file api is slice_projection. + */ +class SliceProjection : public Projection { +public: + SliceProjection(const ProjectionConfig& config, + const ParameterPtr& parameter, + bool useGpu); + virtual void forward(); + virtual void backward(const UpdateCallback& callback); + +protected: + std::vector> slices_; +}; + +REGISTER_PROJECTION(slice, SliceProjection); + +/** + * Constructed function. + * @note SliceProjection should not have any parameter. + */ +SliceProjection::SliceProjection(const ProjectionConfig& config, + const ParameterPtr& parameter, + bool useGpu) + : Projection(config, parameter, useGpu) { + CHECK(!parameter) << "'slice' projection should not have any parameter"; + + slices_.reserve(config.slices_size()); + for (const auto& slice : config.slices()) { + slices_.push_back(std::make_pair(slice.start(), slice.end())); + } +} + +void SliceProjection::forward() { + size_t offset = 0; + for (auto& slice : slices_) { + auto slice_out = in_->value->subColMatrix(slice.first, slice.second); + out_->value->addAtOffset(*slice_out, offset); + offset += slice_out->getWidth(); + } +} + +void SliceProjection::backward(const UpdateCallback& callback) { + if (in_->grad) { + size_t offset = 0; + for (auto& slice : slices_) { + auto slice_out = in_->grad->subColMatrix(slice.first, slice.second); + slice_out->addAtOffset(*out_->grad, config_.offset()); + offset += slice_out->getWidth(); + } + } +} + +} // namespace paddle -- GitLab