geneticweaklearner.cpp

WeakLearner,弱分类器

			<< m_LearningSet->NbrOfSamples() 
			<< " all"
			<< ")"
			<< std::endl;

		oStrLog<< setprecision( 5 )
			<< setw( 7 )
			<< left
			<< cur_error << " "
			<< setprecision( 5 )
			<< setw( 7 )
			<< left
			<< m_bestwc.second << " "
			<< setfill(' ')
			<< setw( 4 )
			<< nbr_generation_no_improvement << " "
			<< setw( 4 )
			<< cur_bestwc->GetTruePositive() << " "
			<< setw( 4 )
			<< m_LearningSet->NbrOfPositiveSamples()<< " "
			<< setw( 4 )
			<< cur_bestwc->GetTrueNegative() << " " 
			<< setw( 4 )
			<< m_LearningSet->NbrOfNegativeSamples() << " "
			<< setw( 4 )
			<< cur_bestwc->GetTrueNegative() + cur_bestwc->GetTruePositive() << " "
			<< setw( 4 )
			<< m_LearningSet->NbrOfSamples() << " "
			<< std::endl;

		// Update the number Of Generations With No improvments
		// compare this Weak Classifier to the previous, if it is better then swap
		if( cur_error < m_bestwc.second )
		{
			// Store this new Weak Classifier
			m_bestwc.second = cur_error;
			if(m_bestwc.first != NULL){
				delete m_bestwc.first;
				m_bestwc.first = NULL;
			}

			m_bestwc.first = cur_bestwc;
			cur_bestwc = NULL;

			// Reset Counter to Zero
			nbr_generation_no_improvement = 0;
		}else{
			// Delete the Temporary Cur Best Weak Classifier
            delete cur_bestwc;
			cur_bestwc = NULL;
			nbr_generation_no_improvement++;
		}

		// IF STOP CONDITION IS TRUE THEN BREAK
		// THE STOP CONDITION COULD BE THE TRACITIONAL ONE AS BELOW
		// OR BASED ON THE MAS ALLOWED ITERATIONS WITHOUT IMPROVEMENT
		// IF ERROR IS ZERO THEN THIS IS THE PERFECT CLASSIFIER
		if( nbr_generation_no_improvement >= m_max_generation ){
			break;
		}

		// SELECT BEST RANKING : A PERCENTAGE, A FIXED NUMBER, A SCORE ?

		unsigned winner_to_keep = m_population.size() * m_winner_to_keep / 100;
		unsigned looser_to_keep = (m_population.size() - winner_to_keep) * m_looser_to_keep / 100;
		unsigned to_keep = winner_to_keep + looser_to_keep;

		// DO MUTATE
		for(int index = 1; index < winner_to_keep; index++)
		{
			for(int m=0; m < m_nb_mutation; m++)
			{
				WeakClassifier *mut= NULL;
				
				//mut = m_population[ index ]->Mutate();

				mut = myInterface->Mutate( *(m_population[index]) );

				if( mut != NULL)
				{
					// Test The Mutate Result
					double err = 0.0;
					//std::cout << "[in]" <<std::endl;
					TestWeakClassifier(mut, m_LearningSet);
					//std::cout << "[out]" <<std::endl;

					err = mut->GetError();

					// If The error is less than the actual one
					if( err < m_population[ index ]->GetError() )
					{
						// then replace the curent Weak Classifier with the Mutate Result
						WeakClassifier *tmp = m_population[ index ];
						m_population[ index ] = mut;
						mut = tmp;
					}

					delete mut;
				}
			}
		}

		// SHUFFLE LOOSERS
		std::random_shuffle(m_population.begin() + winner_to_keep, m_population.end());

		for( it = (m_population.begin()+ winner_to_keep); it != (m_population.begin()+ to_keep) ;it++)
		{
			WeakClassifier *wc = (*it);
			WeakClassifier *randWC= NULL;

			// Randomize the Weak Classifier
			//randWC = wc->Randomize();
			randWC = myInterface->Randomize( *wc );
			if( randWC != NULL)
			{
				// then replace the curent Weak Classifier with the Mutate Result
				WeakClassifier *tmp = *it;
				*it = randWC;
				randWC = tmp;
				delete randWC;
			}

		}

		for( it = (m_population.begin()+ to_keep); it != m_population.end() ;it++)
		{
			WeakClassifier *wc = (*it);
			WeakClassifier *randWC= NULL;

			// Randomize the Weak Classifier
			randWC = m_RandomGenerator->GetNewRandomWeakClassifier();

			if( randWC != NULL)
			{
				// then replace the curent Weak Classifier with the Mutate Result
				WeakClassifier *tmp = *it;
				*it = randWC;
				randWC = tmp;
				delete randWC;
			}

		}

		// INC GENERATION
		generation++;
	}

	m_StringLog = oStrLog.str();
}

void GeneticWeakLearner::InitializePopulation( void )
{
	// Clean Population
	for(int i=0; i < m_population.size(); i++)
	{
		delete m_population[i];
		m_population[i] = NULL;
	}
	m_population.clear();

	m_RandomGenerator->Init();

	// RANDOM GENERATION OF WEAK CLASSIFIERS
	for(int i=0; i < m_nb_indiv; i++)
	{
		m_population.push_back( m_RandomGenerator->GetNewRandomWeakClassifier() );
	}
}

void
GeneticWeakLearner::Reset(void)
{
	assert( m_LearningSet != NULL);
	assert( m_RandomGenerator != NULL);
	assert( m_interface != NULL);

	if( m_bestwc.first != NULL)
		delete m_bestwc.first;

	m_bestwc.first = NULL;
	m_bestwc.second=  1.0;

	m_StringLog.clear();

	InitializePopulation();
}

IClassifier *
GeneticWeakLearner::GetResult(void)
{
	return m_bestwc.first;
}

double
GeneticWeakLearner::GetResultError(void) const
{
	return m_bestwc.second;
}

ILearningSet *
GeneticWeakLearner::GetLearningSet(void)
{
	return m_LearningSet;
}

void
GeneticWeakLearner::SetLearningSet(ILearningSet *learningSet)
{
	assert( learningSet != NULL );
	m_LearningSet = learningSet;
}

void
GeneticWeakLearner::SetRandomWeakClassifierGenerator(IRandomWeakClassifierGenerator *randomGen)
{
	m_RandomGenerator = randomGen;
}

IRandomWeakClassifierGenerator *
GeneticWeakLearner::GetRandomWeakClassifierGenerator(void)
{
	return m_RandomGenerator;
}

const WeakLearnerInterface *
GeneticWeakLearner::GetWeakLearnerInterface(void)
{
	return m_interface;
}

void 
GeneticWeakLearner::SetWeakLearnerInterface(const WeakLearnerInterface *wli)
{
	m_interface = wli;
}

const std::string &
GeneticWeakLearner::GetWeakLearnerLog() const
{
	return m_StringLog;
}

const std::string &
GeneticWeakLearner::GetLearnerLog() const
{
	return m_StringLog;
}

void 
GeneticWeakLearner::SetOptions(const modules::options::ModuleOptions &options)
{
	const modules::options::GeneticWeakLearnerOptions &opts = static_cast<const GeneticWeakLearnerOptions &>(options);

	// get attributes
	int nb_indiv		=  opts.GetNbrIndiv();
	int winner_to_keep  =  opts.GetWinnerToKeep();
	int looser_to_keep  =  opts.GetLooserToKeep();
	int max_generation  =  opts.GetMaxGeneration();
	int nb_mutation	    =  opts.GetNbrMutation();

	// set the attributes
	m_nb_indiv		  =  GA_DEFAULT_NBR_INDIV      ;
	m_winner_to_keep  =  GA_DEFAULT_WINNER_TO_KEEP ;
	m_looser_to_keep  =  GA_DEFAULT_LOOSER_TO_KEEP ;
	m_max_generation  =  GA_DEFAULT_MAX_GENERATION ;
	m_nb_mutation	  =  GA_DEFAULT_NBR_MUTATION   ;

	m_population.reserve( m_nb_indiv ) ;

	m_StringLog.clear();
}