/*
    Copyright (C) 2012 Bartosz Broda, Jacek Bochenek, Łukasz Biłeńkij, 
    Damian Jaworski, Wojciech Mazur, Dominik Piasecki, Maciej Piasecki, 
    Radosław Ramocki
    
    This program is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at your option)
any later version.

    This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. 

    See the LICENSE and COPYING files for more details.
*/

#pragma once
#include "../comparator_stdheaders.h"
#include "FilterFeature.h"

namespace smartcomparator
{
	namespace filters
	{
		/**
		  * Retains max k nz features, removes features by entropy.
		  * Removal is made locally, i.e., for each row features might be different.
		  * \todo minimal entropy threshold is currently hardcoded to 0?
		  */
		class SMART_COMPARATOR_API NoiseKFilter  : public FilterFeature
		{
		public:
			NoiseKFilter(Matrices::FeatureVectorPtr cf, size_t k);
			NoiseKFilter(Matrices::FeatureVectorPtr cf, double retain_ratio);
			virtual ~NoiseKFilter(void);

			/**
			  * \return indices of features that passed the filtering process
			  */
			virtual void Filter(std::set<size_t> &out,const std::set<size_t> *nzind);

		protected:
			size_t m_stK;
		};

		/**
		  * * \todo minimal entropy threshold is currently hardcoded to 0?
		  */
		class NoiseKTFFilter  : public FilterFeature
		{
		public:
			/**
			  * Retains max k nz features, removes features by entropy + applies
			  * min_tf filter for column local term frequency
			  * \param cf column features
			  * \param k maximal number of features that will pass the filtering process
			  */
			NoiseKTFFilter(Matrices::FeatureVectorPtr cf, size_t k, size_t mintf = 2);
			/**
			  * \param cf column features
			  * \param retain_ration how many features will pass the filtering
			  */
			NoiseKTFFilter(Matrices::FeatureVectorPtr cf, double retain_ratio, size_t mintf = 2);
			virtual ~NoiseKTFFilter(void);

			/**
			  * \return indices of features that passed the filtering process
			  */
			virtual void Filter(std::set<size_t> &out,const std::set<size_t> *nzind);

		protected:
			size_t m_stK;
			size_t m_stMinTf;
		};
	}
}
