RUExtractor.cpp

/*
* RUExtractor.cpp
*
*  Created on: May 6, 2013
*      Author: renato
*/
#include "RUExtractor.hpp"
#include <math.h>
#include <algorithm.h>

#if DEBUG
#define db(nome, obj) do{ cout << nome << obj << endl} while(0);
#else
#define db(nome, obj)
#endif

static unsigned int  module_size(unsigned module)
{
     return max<unsigned int>(module, 1);
}

static double alertAmount(const vector<CTuple>& tuples)
{
	double amount = 0.0;
for (auto it = tuples.begin(); it != tuples.end(); ++it)
	amount += *it.alertCount;
	return amount;
}
/**
* Calculates the entropy of the CTables
*
* entropy = SUM p(a) * log_2 p(a)
*/
statuc double entropy(const vector<CTuple>&  tuples) {
	double alertTotal = alertAmount(tuples);
	double entropy = 0.0; // ?

for (auto it = tuples.begin(); it != tuples.end(); ++it){
	double p = *it.alertCount / alertTotal;
	double log_p = (log (p)) / log (2);
entropy += (p * log_p);
}

	return -entropy;
}

static double RU(double entropy, double module, double alertAmount){
	return entropy / ((log (min<double>(module, alertAmount))) / log (2));
}

pair<vector<CTuple>, vector<CTuple>> RUExtractor::extractingSignificantClusters(const CTable& table) {
	double alpha = 0.02;
	const double beta = 0.9;
	const int k = 1;

	vector<CTuple> tuples = table.clusterTable;
	vector<CTuple> S;

	double entropy = getEntropy(tuples);
	double module = module_size(tuples.size());
	double alertAmount = alertAmount(tuples);
	double RU = getRU(entropy, module, alertAmount);

	while(RU < beta) {
		db ("RU ", RU);
		alpha *= pow(2, -k);
	                for (auto it = tuples.begin(); it != tuples.end(); ++it) {
			CTuple tuple =*it;
			double p = tuple.alertCount / alertAmount;
			if (p < alpha) {
				S.push_back(tuple);
				tuples.erase(tuple);
			}
		}
		module = module_size(tuples.size());
		entropy = entropy(tuples);
		alertAmount = alertAmount(cTuples);
		RU = getRU(entropy, module, alertAmount);
	}

pair<vector<CTuple>, vector<CTuple>> ret;
	ret.first = S;
	ret.second = tuples;
	return ret;
}
RUExtractor::RUExtractor(){}
RUExtractor::~RUExtractor(){}