BackPropagationAlgorithm.h

#ifndef BACKPROPAGATIONALGORITHM_H
#define BACKPROPAGATIONALGORITHM_H

#include "NeuralNetConfig.h"

#include "NeuralNet.h"

#include <vector>

//namespace nnet added 15/08/06 by Mark Grimes (mark.grimes@bristol.ac.uk) for the LCFI vertex package
namespace nnet
{

class
#ifndef __CINT__
NEURALNETDLL
#endif
BackPropagationAlgorithm
{
public:
        BackPropagationAlgorithm(NeuralNet &theNetwork,const double learningRate=0.5,const double momentumConstant=0.5);
        ~BackPropagationAlgorithm(void);
        void setLearningRate(const double newLearningRate)
        { _learningRate = newLearningRate;}
        void setMomentumConstant(const double newMomentumConstant)
        { _momentumConstant = newMomentumConstant;}
        double train(const std::vector<double> &inputValues,const std::vector<double> &desiredOutput);

protected:
        std::vector<double> layerOutput(const int layer) const;
        void calculateLayerOutputs();
        void calculateDerivativeOutputs();
        void calculateErrorSignals();
        void calculateDeltaWeights();
        double error();

private:
        typedef std::vector<std::vector<double> > NetMatrix;

private:
        NeuralNet &_theNetwork;
        double _learningRate;
        const std::vector<double> *_inputs,*_target;
        NetMatrix _neuronErrorSignals;
        NetMatrix _neuronOutputs;
        NetMatrix _neuronDerivativeOutputs;
        std::vector<double> _momentumWeights;
        double _momentumConstant;
};

}//namespace nnet
#endif