| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| #ifndef ANDROID_FRAMEWORKS_ML_NN_COMMON_ACTIVATION_FUNCTOR_H |
| #define ANDROID_FRAMEWORKS_ML_NN_COMMON_ACTIVATION_FUNCTOR_H |
| |
| #include <android/log.h> |
| |
| #include <algorithm> |
| #include <cmath> |
| |
| enum ActivationFn { |
| kActivationNone = 0, |
| kActivationRelu, |
| kActivationRelu1, |
| kActivationRelu6, |
| kActivationTanh, |
| kActivationSignBit, |
| kActivationSigmoid, |
| }; |
| |
| class ActivationFunctor { |
| public: |
| explicit ActivationFunctor(ActivationFn act) : act_(act) {} |
| |
| float operator()(float a) const { |
| switch (act_) { |
| case kActivationNone: |
| return a; |
| case kActivationRelu: |
| return a < 0.f ? 0.f : a; |
| case kActivationRelu6: |
| return std::max(0.f, std::min(a, 6.f)); |
| case kActivationTanh: |
| return std::tanh(a); |
| case kActivationSigmoid: |
| return 1.0f / (1.0f + std::exp(-a)); |
| default: |
| __android_log_print(ANDROID_LOG_ERROR, "NN API", |
| "Invalid enum value for activation function: 0x%0X", act_); |
| abort(); |
| } |
| } |
| |
| private: |
| ActivationFn act_; |
| }; |
| |
| #endif // ANDROID_FRAMEWORKS_ML_NN_COMMON_ACTIVATION_FUNCTOR_H |