35 lines
1.1 KiB
C++
35 lines
1.1 KiB
C++
#pragma once
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#include <cmath>
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#include "./StreamingActivationFunction.h"
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#include "../../sse_mathfun.h"
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namespace NeuralNetwork {
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namespace ActivationFunction {
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/**
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* @author Tomas Cernik (Tom.Cernik@gmail.com)
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* @brief Class for computing sigmoid
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*/
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class Sigmoid: public StreamingActivationFunction {
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public:
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Sigmoid(const float lambdaP = -0.5): lambda(lambdaP) {}
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inline virtual float derivatedOutput(const float&,const float &output) override { return lambda*output*(1.0f-output); }
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inline virtual float operator()(const float &x) override { return 1.0f / (1.0f +exp(lambda*x) ); };
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inline virtual __m128 operator()(const __m128 &x) override {
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// exp_ps is extremly slow!
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return _mm_div_ps(_mm_set1_ps(1.0),_mm_add_ps(exp_ps(_mm_mul_ps(_mm_set1_ps(lambda),x)),_mm_set1_ps(1.0)));
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}
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virtual ActivationFunction* clone() const override {
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return new Sigmoid(lambda);
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}
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virtual std::string stringify() const override {
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return "{ \"class\": \"NeuralNetwork::ActivationFunction::Sigmoid\", \"lamba\" : "+std::to_string(lambda)+"}";
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}
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protected:
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float lambda;
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};
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}
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} |