/*
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/* 
 * File:   Rbm.hpp
 * Author: jens
 *
 * Created on 21. Oktober 2019, 21:28
 */

#ifndef RBM_HPP
#define RBM_HPP

#include <armadillo>
#include "noise.h"

class Rbm
{
public:
	
	struct Params
	{
		Params()
		: m_weightInit(0.01)
		, m_weightDecay(0.0)
		, m_learningRate(0.1)
		, m_momentum(0.5)
		, m_doRaoBlackwell(true)
		, m_gibbsDoSampleVisible(false)
		, m_gibbsDoSampleHidden(false)
		, m_doSampleBatch(false)
		, m_numGibbs(1)
		{
		}

		double m_weightInit;
		double m_weightDecay;
		double m_learningRate;
		double m_momentum;
		bool m_doRaoBlackwell;
		bool m_gibbsDoSampleVisible;
		bool m_gibbsDoSampleHidden;
		bool m_doSampleBatch;
		size_t m_numGibbs;
	};

	struct Status
	{
		size_t epoch;
		size_t trainingSizeRemain;
		double progress;
		double err;
		double err_total;
		double L1;
		double L2;
	};

	class IListener
	{
	public:

		IListener() {}
		virtual ~IListener() {}
		virtual bool onProgress(const Status &status)
		{
			return true;
		}
	};

	Rbm(const Params& params, arma::mat &w, arma::mat &bv, arma::mat &bh);
	Rbm(const Rbm& orig);
	virtual ~Rbm();

	void train(arma::mat const &batch, size_t numEpochs, size_t sizeMiniBatch, IListener *pListener);
	
	arma::mat toHiddenState(const arma::mat &visible);
	arma::mat toVisibleState(const arma::mat &hidden);
	arma::mat toHiddenProbs(const arma::mat &visible);
	arma::mat toVisibleProbs(const arma::mat &hidden);
	arma::mat& weights();
	arma::mat& bias_visible();
	arma::mat& bias_hidden();
	
private:
	noise_gen_t m_noise;
	const Params &m_params;
	arma::mat &m_w;
	arma::mat &m_bh;
	arma::mat &m_bv;
	arma::mat sample(arma::mat const &src);
	static arma::mat probsLogistic(arma::mat const &src);
	void uniform(arma::mat &srcDst, double mu=0.0, double stdDev=1.0);
};

#endif /* RBM_HPP */