haojin2 commented on a change in pull request #10780: [MXNET-375] Lp Pooling and Global Lp Pooling URL: https://github.com/apache/incubator-mxnet/pull/10780#discussion_r187247799
########## File path: src/operator/nn/pool_utils.h ########## @@ -0,0 +1,115 @@ +/* + * 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 MXNET_OPERATOR_NN_POOL_UTILS_H_ +#define MXNET_OPERATOR_NN_POOL_UTILS_H_ + +#include "../mshadow_op.h" + +namespace mxnet { +namespace op { + +template<typename DType, int p> +struct a_to_p { + static MSHADOW_XINLINE DType Map(DType a) { + return mshadow_op::power::Map(a, DType(p)); + } +}; + +template<typename DType> +struct a_to_p<DType, 1> { + static MSHADOW_XINLINE DType Map(DType a) { + return a; + } +}; + +template<typename DType> +struct a_to_p<DType, 2> { + static MSHADOW_XINLINE DType Map(DType a) { + return a*a; + } +}; + +template<typename DType> +struct a_to_p<DType, 3> { + static MSHADOW_XINLINE DType Map(DType a) { + return a*a*a; + } +}; + +template<typename DType, int p> +struct a_root_p { + static MSHADOW_XINLINE DType Map(DType a) { + return mshadow_op::power::Map(a, DType(1.0 / p)); + } +}; + +template<typename DType> +struct a_root_p<DType, 1> { + static MSHADOW_XINLINE DType Map(DType a) { + return a; + } +}; + +template<typename DType> +struct a_root_p<DType, 2> { + static MSHADOW_XINLINE DType Map(DType a) { + return mshadow_op::square_root::Map(a); + } +}; + +template<typename DType> +struct a_root_p<DType, 3> { + static MSHADOW_XINLINE DType Map(DType a) { + return mshadow_op::cube_root::Map(a); + } +}; + +template<typename DType, int p> +struct lp_grad { + static MSHADOW_XINLINE DType Map(DType grad, DType in_data, DType out_data) { + return grad * mshadow_op::power::Map(in_data / out_data, DType(p - 1)); + } +}; + +template<typename DType> +struct lp_grad<DType, 1> { + static MSHADOW_XINLINE DType Map(DType grad, DType in_data, DType out_data) { + return grad; + } +}; + +template<typename DType> +struct lp_grad<DType, 2> { + static MSHADOW_XINLINE DType Map(DType grad, DType in_data, DType out_data) { + return grad * in_data / out_data; + } +}; + +template<typename DType> +struct lp_grad<DType, 3> { + static MSHADOW_XINLINE DType Map(DType grad, DType in_data, DType out_data) { + return grad * in_data * in_data / out_data / out_data; Review comment: Do you mean something like ```return grad * in_data * in_data / (out_data * out_data)```? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
