Ejemplo n.º 1
0
    void FilterBoostLearner::run(const nor_utils::Args& args)
    {
        // load the arguments
        this->getArgs(args);

        time_t startTime, currentTime;
        time(&startTime);

        // get the registered weak learner (type from name)
        BaseLearner* pWeakHypothesisSource = 
            BaseLearner::RegisteredLearners().getLearner(_baseLearnerName);
        // initialize learning options; normally it's done in the strong loop
        // also, here we do it for Product learners, so input data can be created
        pWeakHypothesisSource->initLearningOptions(args);

        BaseLearner* pConstantWeakHypothesisSource = 
            BaseLearner::RegisteredLearners().getLearner("ConstantLearner");

        // get the training input data, and load it

        InputData* pTrainingData = pWeakHypothesisSource->createInputData();
        pTrainingData->initOptions(args);
        pTrainingData->load(_trainFileName, IT_TRAIN, _verbose);

        const int numClasses = pTrainingData->getNumClasses();
        const int numExamples = pTrainingData->getNumExamples();
                
        //initialize the margins variable
        _margins.resize( numExamples );
        for( int i=0; i<numExamples; i++ )
        {
            _margins[i].resize( numClasses );
            fill( _margins[i].begin(), _margins[i].end(), 0.0 );
        }


        // get the testing input data, and load it
        InputData* pTestData = NULL;
        if ( !_testFileName.empty() )
        {
            pTestData = pWeakHypothesisSource->createInputData();
            pTestData->initOptions(args);
            pTestData->load(_testFileName, IT_TEST, _verbose);
        }

        // The output information object
        OutputInfo* pOutInfo = NULL;


        if ( !_outputInfoFile.empty() ) 
        {
            // Baseline: constant classifier - goes into 0th iteration

            BaseLearner* pConstantWeakHypothesis = pConstantWeakHypothesisSource->create() ;
            pConstantWeakHypothesis->initLearningOptions(args);
            pConstantWeakHypothesis->setTrainingData(pTrainingData);
            AlphaReal constantEnergy = pConstantWeakHypothesis->run();

            pOutInfo = new OutputInfo(args);
            pOutInfo->initialize(pTrainingData);

            updateMargins( pTrainingData, pConstantWeakHypothesis );

            if (pTestData)
                pOutInfo->initialize(pTestData);
            pOutInfo->outputHeader(pTrainingData->getClassMap() );

            pOutInfo->outputIteration(-1);
            pOutInfo->outputCustom(pTrainingData, pConstantWeakHypothesis);

            if (pTestData)
            {
                pOutInfo->separator();
                pOutInfo->outputCustom(pTestData, pConstantWeakHypothesis);
            }
                        
            pOutInfo->outputCurrentTime();

            pOutInfo->endLine();
            pOutInfo->initialize(pTrainingData);
                        
            if (pTestData)
                pOutInfo->initialize(pTestData);
        }
        // reload the previously found weak learners if -resume is set. 
        // otherwise just return 0
        int startingIteration = resumeWeakLearners(pTrainingData);


        Serialization ss(_shypFileName, _isShypCompressed );
        ss.writeHeader(_baseLearnerName); // this must go after resumeProcess has been called

        // perform the resuming if necessary. If not it will just return
        resumeProcess(ss, pTrainingData, pTestData, pOutInfo);

        if (_verbose == 1)
            cout << "Learning in progress..." << endl;
                                
        ///////////////////////////////////////////////////////////////////////
        // Starting the AdaBoost main loop
        ///////////////////////////////////////////////////////////////////////
        for (int t = startingIteration; t < _numIterations; ++t)
        {                       
            if (_verbose > 1)
                cout << "------- WORKING ON ITERATION " << (t+1) << " -------" << endl;
                
            // create the weak learner
            BaseLearner* pWeakHypothesis;
            BaseLearner* pConstantWeakHypothesis;
            pWeakHypothesis = pWeakHypothesisSource->create();
            pWeakHypothesis->initLearningOptions(args);
            //pTrainingData->clearIndexSet();
            pWeakHypothesis->setTrainingData(pTrainingData);
            AlphaReal edge, energy=0.0;
                        
            // create the constant learner
            pConstantWeakHypothesis = pConstantWeakHypothesisSource->create() ;
            pConstantWeakHypothesis->initLearningOptions(args);
            pConstantWeakHypothesis->setTrainingData(pTrainingData);
            AlphaReal constantEdge = -numeric_limits<AlphaReal>::max();
                        
            int currentNumberOfUsedData = static_cast<int>(_Cn * log(t+3.0));
                        
            if ( _onlineWeakLearning )
            {
                //check whether the weak learner is a ScalarLeaerner
                try {
                    StochasticLearner* pStochasticLearner = dynamic_cast<StochasticLearner*>(pWeakHypothesis);
                    StochasticLearner* pStochasticConstantWeakHypothesis = dynamic_cast<StochasticLearner*> (pConstantWeakHypothesis);
                                        
                    pStochasticLearner->initLearning();
                    pStochasticConstantWeakHypothesis->initLearning();                                                                              
                                        
                    if (_verbose>1)
                        cout << "Number of random instances: \t" << currentNumberOfUsedData << endl;
                                        
                    // set the weights
                    setWeightToMargins(pTrainingData);
                                        
                    //learning
                    for (int i=0; i<currentNumberOfUsedData; ++i )
                    {
                        int randomIndex = (rand() % pTrainingData->getNumExamples());   
                        //int randomIndex = getRandomIndex();
                        pStochasticLearner->update(randomIndex);
                        pStochasticConstantWeakHypothesis->update(randomIndex);
                    }                                       
                    pStochasticLearner->finishLearning();           
                    pStochasticConstantWeakHypothesis->finishLearning();
                }
                catch (bad_cast& e) {
                    cerr << "The weak learner must be a StochasticLearner!!!" << endl;
                    exit(-1);
                }                                                                                               
            }
            else
            {
                filter( pTrainingData, currentNumberOfUsedData );
                if ( pTrainingData->getNumExamples() < 2 ) 
                {
                    filter( pTrainingData, currentNumberOfUsedData, false );
                }
                                
                if (_verbose > 1)
                {
                    cout << "--> Size of training data = " << pTrainingData->getNumExamples() << endl;
                }
                                
                energy = pWeakHypothesis->run();                                                                
                pConstantWeakHypothesis->run(); 
            }                       

            //estimate edge
            filter( pTrainingData, currentNumberOfUsedData, false );
            edge = pWeakHypothesis->getEdge(true) / 2.0;                                            
            constantEdge = pConstantWeakHypothesis->getEdge() / 2.0;
                        
                        
            if ( constantEdge > edge )
            {
                delete pWeakHypothesis;
                pWeakHypothesis = pConstantWeakHypothesis;
                edge = constantEdge;
            } else {
                delete pConstantWeakHypothesis;
            }
                                                                        
            // calculate alpha
            AlphaReal alpha = 0.0;
            alpha = 0.5 * log( ( 1 + edge ) / ( 1 - edge ) );
            pWeakHypothesis->setAlpha( alpha );
            _sumAlpha += alpha;
                        
            if (_verbose > 1)
                cout << "Weak learner: " << pWeakHypothesis->getName()<< endl;
            // Output the step-by-step information
            pTrainingData->clearIndexSet();
            printOutputInfo(pOutInfo, t, pTrainingData, pTestData, pWeakHypothesis);

            // Updates the weights and returns the edge
            //AlphaReal gamma = updateWeights(pTrainingData, pWeakHypothesis);

            if (_verbose > 1)
            {
                cout << setprecision(5)
                     << "--> Alpha = " << pWeakHypothesis->getAlpha() << endl
                     << "--> Edge  = " << edge << endl
                     << "--> Energy  = " << energy << endl
                    //            << "--> ConstantEnergy  = " << constantEnergy << endl
                    //            << "--> difference  = " << (energy - constantEnergy) << endl
                    ;
            }

            // update the margins
            //saveMargins();
            updateMargins( pTrainingData, pWeakHypothesis );
                        
            // append the current weak learner to strong hypothesis file,
            // that is, serialize it.
            ss.appendHypothesis(t, pWeakHypothesis);

            // Add it to the internal list of weak hypotheses
            _foundHypotheses.push_back(pWeakHypothesis); 

            // check if the time limit has been reached
            if (_maxTime > 0)
            {
                time( &currentTime );
                float diff = difftime(currentTime, startTime); // difftime is in seconds
                diff /= 60; // = minutes

                if (diff > _maxTime)
                {
                    if (_verbose > 0)
                        cout << "Time limit of " << _maxTime 
                             << " minutes has been reached!" << endl;
                    break;     
                }
            } // check for maxtime
            delete pWeakHypothesis;
        }  // loop on iterations
        /////////////////////////////////////////////////////////

        // write the footer of the strong hypothesis file
        ss.writeFooter();

        // Free the two input data objects
        if (pTrainingData)
            delete pTrainingData;
        if (pTestData)
            delete pTestData;

        if (pOutInfo)
            delete pOutInfo;

        if (_verbose > 0)
            cout << "Learning completed." << endl;
    }
Ejemplo n.º 2
0
	void AdaBoostMHLearner::run(const nor_utils::Args& args)
	{
		// load the arguments
		this->getArgs(args);

		// get the registered weak learner (type from name)
		BaseLearner* pWeakHypothesisSource = 
			BaseLearner::RegisteredLearners().getLearner(_baseLearnerName);
		// initialize learning options; normally it's done in the strong loop
		// also, here we do it for Product learners, so input data can be created
		pWeakHypothesisSource->initLearningOptions(args);

		BaseLearner* pConstantWeakHypothesisSource = 
			BaseLearner::RegisteredLearners().getLearner("ConstantLearner");

		// get the training input data, and load it

		InputData* pTrainingData = pWeakHypothesisSource->createInputData();
		pTrainingData->initOptions(args);
		pTrainingData->load(_trainFileName, IT_TRAIN, _verbose);
		
		// get the testing input data, and load it
		InputData* pTestData = NULL;
		if ( !_testFileName.empty() )
		{
			pTestData = pWeakHypothesisSource->createInputData();
			pTestData->initOptions(args);
			pTestData->load(_testFileName, IT_TEST, _verbose);
		}

		// The output information object
		OutputInfo* pOutInfo = NULL;


		if ( !_outputInfoFile.empty() ) 
		{
			// Baseline: constant classifier - goes into 0th iteration

			BaseLearner* pConstantWeakHypothesis = pConstantWeakHypothesisSource->create() ;
			pConstantWeakHypothesis->initLearningOptions(args);
			pConstantWeakHypothesis->setTrainingData(pTrainingData);
			AlphaReal constantEnergy = pConstantWeakHypothesis->run();

			//pOutInfo = new OutputInfo(_outputInfoFile);
            pOutInfo = new OutputInfo(args);
			pOutInfo->initialize(pTrainingData);

			if (pTestData)
				pOutInfo->initialize(pTestData);
			pOutInfo->outputHeader(pTrainingData->getClassMap());

			pOutInfo->outputIteration(-1);
            pOutInfo->outputCustom(pTrainingData, pConstantWeakHypothesis);
            
			if (pTestData != NULL)
            {
                pOutInfo->separator();
                pOutInfo->outputCustom(pTestData, pConstantWeakHypothesis);   
            }

			pOutInfo->outputCurrentTime();

			pOutInfo->endLine(); 
			pOutInfo->initialize(pTrainingData);

			if (pTestData)
				pOutInfo->initialize(pTestData);
		}
		//cout << "Before serialization" << endl;
		// reload the previously found weak learners if -resume is set. 
		// otherwise just return 0
		int startingIteration = resumeWeakLearners(pTrainingData);


		Serialization ss(_shypFileName, _isShypCompressed );
		ss.writeHeader(_baseLearnerName); // this must go after resumeProcess has been called

		// perform the resuming if necessary. If not it will just return
		resumeProcess(ss, pTrainingData, pTestData, pOutInfo);

		if (_verbose == 1)
			cout << "Learning in progress..." << endl;

		//I put here the starting time, but it may take very long time to load the saved model
		time_t startTime, currentTime;
		time(&startTime);

		///////////////////////////////////////////////////////////////////////
		// Starting the AdaBoost main loop
		///////////////////////////////////////////////////////////////////////
		for (int t = startingIteration; t < _numIterations; ++t)
		{
			if (_verbose > 1)
				cout << "------- WORKING ON ITERATION " << (t+1) << " -------" << endl;

			BaseLearner* pWeakHypothesis = pWeakHypothesisSource->create();
			pWeakHypothesis->initLearningOptions(args);
			//pTrainingData->clearIndexSet();

			pWeakHypothesis->setTrainingData(pTrainingData);
			
			AlphaReal energy = pWeakHypothesis->run();
			
			//float gamma = pWeakHypothesis->getEdge();
			//cout << gamma << endl;

			if ( (_withConstantLearner) || ( energy != energy ) ) // check constant learner if user wants it (if energi is nan, then we chose constant learner
			{
				BaseLearner* pConstantWeakHypothesis = pConstantWeakHypothesisSource->create() ;
				pConstantWeakHypothesis->initLearningOptions(args);
				pConstantWeakHypothesis->setTrainingData(pTrainingData);
				AlphaReal constantEnergy = pConstantWeakHypothesis->run();

				if ( (constantEnergy <= energy) || ( energy != energy ) ) {
					delete pWeakHypothesis;
					pWeakHypothesis = pConstantWeakHypothesis;
				}
			}

			if (_verbose > 1)
				cout << "Weak learner: " << pWeakHypothesis->getName()<< endl;
			// Output the step-by-step information
			printOutputInfo(pOutInfo, t, pTrainingData, pTestData, pWeakHypothesis);

			// Updates the weights and returns the edge
			AlphaReal gamma = updateWeights(pTrainingData, pWeakHypothesis);

			if (_verbose > 1)
			{
				cout << setprecision(5)
					<< "--> Alpha = " << pWeakHypothesis->getAlpha() << endl
					<< "--> Edge  = " << gamma << endl
					<< "--> Energy  = " << energy << endl
					//            << "--> ConstantEnergy  = " << constantEnergy << endl
					//            << "--> difference  = " << (energy - constantEnergy) << endl
					;
			}

			// If gamma <= theta the algorithm must stop.
			// If theta == 0 and gamma is 0, it means that the weak learner is no better than chance
			// and no further training is possible.
			if (gamma <= _theta)
			{
				if (_verbose > 0)
				{
					cout << "Can't train any further: edge = " << gamma 
						<< " (with and edge offset (theta)=" << _theta << ")" << endl;
				}

				//          delete pWeakHypothesis;
				//          break; 
			}

			// append the current weak learner to strong hypothesis file,
			// that is, serialize it.
			ss.appendHypothesis(t, pWeakHypothesis);

			// Add it to the internal list of weak hypotheses
			_foundHypotheses.push_back(pWeakHypothesis); 

			// check if the time limit has been reached
			if (_maxTime > 0)
			{
				time( &currentTime );
				float diff = difftime(currentTime, startTime); // difftime is in seconds
				diff /= 60; // = minutes

				if (diff > _maxTime)
				{
					if (_verbose > 0)
						cout << "Time limit of " << _maxTime 
						<< " minutes has been reached!" << endl;
					break;     
				}
			} // check for maxtime
			delete pWeakHypothesis;
		}  // loop on iterations
		/////////////////////////////////////////////////////////

		// write the footer of the strong hypothesis file
		ss.writeFooter();

		// write the weights of the instances if the name of weights file isn't empty
		printOutWeights( pTrainingData );


		// Free the two input data objects
		if (pTrainingData)
			delete pTrainingData;
		if (pTestData)
			delete pTestData;

		if (pOutInfo)
			delete pOutInfo;

		if (_verbose > 0)
			cout << "Learning completed." << endl;
	}