#ifndef PATTERN_RECOGNITION_HPP
#define PATTERN_RECOGNITION_HPP





	template<typename Value_T=double>
	class roc_distribution
	{
	public:
		std::vector<  boost::numeric::ublas::c_vector<Value_T,3> > roc_data; //result

		Value_T sample_double;

		boost::accumulators::accumulator_set<
			Value_T 
			, boost::accumulators::stats<
				boost::accumulators::tag::p_square_cumulative_distribution
			>
		>acc_positive, acc_negative;



		roc_distribution():
			sample_double(0)
				,
			acc_positive(
				boost::accumulators::p_square_cumulative_distribution_num_cells = 30
				,boost::accumulators::sample = sample_double) //false_positive_rate
				,
			acc_negative(
				boost::accumulators::p_square_cumulative_distribution_num_cells = 30
				,boost::accumulators::sample = sample_double) //true_negative_rate
		{}

		
		void operator()(Value_T &val, bool positive_or_negative )
		{
			if(positive_or_negative)
			{
				acc_positive(val);//false_positive_rate
			}
			else
			{
				acc_negative(val);//true_negative_rate
			}
		}


		void get_result()
		{
			typedef boost::iterator_range< std::vector<std::pair<Value_T, Value_T> >::iterator > histogram_type;
			histogram_type histogram_positive = accumulators::p_square_cumulative_distribution(acc_positive);//false_positive_rate
			histogram_type histogram_negative = accumulators::p_square_cumulative_distribution(acc_negative);//true_negative_rate

			histogram_type::iterator
				hit_pos=histogram_positive.begin(),hit_neg=histogram_negative.begin();
			boost::numeric::ublas::c_vector<Value_T,3> tmp_vec;
			Value_T vp=0.0, vn=0.0;
			Value_T h;
			do
			{ 

				if( hit_pos != histogram_positive.end() && hit_neg != histogram_negative.end() ) 
				{
					if(   hit_pos->first < hit_neg->first  )
					{
						h=  hit_pos->first;
						vp= hit_pos->second;
						hit_pos++;						
					}else if(hit_neg->first < hit_pos->first   )
					{
						h=  hit_neg->first;
						vn= hit_neg->second;
						hit_neg++;
					}
				}else{
					if(	hit_neg != histogram_negative.end()	)
					{
						h=  hit_neg->first;
						vn= hit_neg->second;
						hit_neg++;						
					}else if(hit_pos != histogram_positive.end() )
					{
						h=  hit_pos->first;
						vp= hit_pos->second;
						hit_pos++;
					}
				}				
				tmp_vec[0]=h;
				tmp_vec[1]=1-vp;			//true_positive_rate
				tmp_vec[2]=1-vn;			//false_negative_rate
				roc_data.push_back(tmp_vec);
			}while( hit_pos != histogram_positive.end() || hit_neg != histogram_negative.end() );
		}
	};


#endif /* PATTERN_RECOGNITION_HPP */