/*
    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.
*/

#include "../comparator_stdheaders.h"
#include "TfidfWeight.h"

namespace smartcomparator
{
	namespace weights
	{
		TfidfWeight::TfidfWeight(Matrices::SuperMatrixPtr m) : WeightFeature(m)
		{

			N = (double) m_pMatrix->NumberOfRows();
		}

		TfidfWeight::~TfidfWeight(void)
		{
		}

		void TfidfWeight::Weight(size_t rowindex, Matrices::CompressedVector *v, 
			std::set<size_t> &filteredIndices)
		{
			for(std::set<size_t>::iterator i = filteredIndices.begin(); i != filteredIndices.end();i++)
			{
				double  df_t = (double) (*m_pMatrix->GetColumnFeatures())[*i].GetNZ();
			
				double idf = log ( N / df_t );

				double tf_idf = ((*v)[*i])*idf;
				v->SetElement(*i, tf_idf);
			}
		}

		/*void TfidfWeight::Weight(size_t rowindex, Matrices::CompressedVector *v)
		{
			for(std::map<size_t,double>::iterator i = v->GetValues()->begin();
				i != v->GetValues()->end(); i++)
			{
			
				double  df_t = (double) (*m_pMatrix->GetColumnFeatures())[i->first].GetNZ();
				double idf = log ( N / df_t );

				double tf_idf = ((*v)[i->first])*idf;
				v->SetElement(i->first, tf_idf);
			}
		}*/

	}
}
