Esempio n. 1
0
void KNN::train(Examples& exs){

	TRACE_V(TAG,"train");
    
    //Maybe we didnt calculate this before...
    stats->calculateIDF();
 
    for(int i = 0; i < exs.getNumberOfNumericalAttibutes(); i++){
        maxv[i] = numeric_limits<double>::min();
        minv[i] = numeric_limits<double>::max();
    }
    
	for(ExampleIterator e = exs.getBegin(); e != exs.getEnd(); e++){
   
        vector<string> textTokens = (e)->getTextTokens();
        vector<int> textFrequencyTokens = (e)->getTextFrequency();
		string exampleClass = (e)->getClass();
        string eId = (e)->getId();
        double docSize = 0.0;

//      cout<<" Tokens categoricos  =  " << tokens.size() << endl;
		for(unsigned int i = 3; i < textTokens.size(); i++){
			int tf = textFrequencyTokens[i-3];
			string termId = textTokens[i];
            
            double tfidf = tf * stats->getIDF(termId);

            docSize += (tfidf * tfidf);

            docWeighted dw(eId, tfidf);
            termDocWset[termId].insert(dw);
		}
        
        vector<double> numTokens = (e)->getNumericalTokens();
       
        for(unsigned int i = 0; i < numTokens.size(); i++){
            if(greaterThan(numTokens[i], maxv[i])){
                maxv[i] = numTokens[i];
            }
            if(lesserThan(numTokens[i], minv[i])){
                minv[i] = numTokens[i];
            }
        }

        exNumTrain[eId] = numTokens;
        exCatTrain[eId] = (e)->getCategoricalTokens();
        
        docTrainSizes[eId] = docSize;
    }

}
Esempio n. 2
0
void KNN::test(Examples& exs){

    TRACE_V(TAG,"test");

    //Statistics:
    map<string,unsigned long long> classHits;
    map<string,unsigned long long> classMiss;
    map<string,unsigned long long> mappedDocs;
    map<string,unsigned long long> docsPerClass;
    
    int numExamples = 0;
    for(ExampleIterator it = exs.getBegin(); it != exs.getEnd(); it++){
        numExamples++;
        if(numExamples % 100 == 0)
            cout<<"Evaluated: " << numExamples<<endl;

        Example ex = *it;


        vector<string> textTokens = ex.getTextTokens();	
        vector<int>    textFreqTokens = ex.getTextFrequency();	
        vector<double> numTokens = ex.getNumericalTokens();
        vector<string> catTokens = ex.getCategoricalTokens();

        string eId = ex.getId();
        string classId = ex.getClass();
        
        map<string, double> examplesTestSize;
        //credibility to each class
        if((usingKNNOptimize && !valuesSaved )  || !usingKNNOptimize){
            for(unsigned int i = 3; i < textTokens.size(); i++){
                string termId = textTokens[i];
                int tf = textFreqTokens[i-3];

                for(set<string>::iterator classIt = stats->getClasses().begin(); classIt != stats->getClasses().end(); classIt++) {
                    double tfidf = tf * getContentCredibility(termId, *classIt);
                    examplesTestSize[*classIt] += (tfidf * tfidf);
                }
            }
        }
        map<string, double> similarity;

        if(usingKNNOptimize && valuesSaved){
            similarity = saveValues[eId];
        }
        else{
            for(unsigned int i = 3; i < textTokens.size();i++){
                string termId = textTokens[i];
                int tf = textFreqTokens[1-3];

                for(set<docWeighted, docWeightedCmp>::iterator termIt = termDocWset[termId].begin(); termIt != termDocWset[termId].end(); termIt++){
                    string trainClass = stats-> getTrainClass(termIt->docId);

                    double trainDocSize = docTrainSizes[termIt->docId];
                    double trainTermWeight = termIt->weight;
                    double testTermWeight = tf * getContentCredibility(termId, trainClass);
                    
                    similarity[termIt->docId] +=  ( - ( trainTermWeight / sqrt(trainDocSize)  * testTermWeight / sqrt(examplesTestSize[trainClass]) ));
//                    cout<<"sim = " << similarity[termIt->docId] <<endl;
                }
            }

            //numerical KNN
            for(map<string, vector<double> >::iterator trainIt  = exNumTrain.begin(); trainIt != exNumTrain.end(); trainIt++){
                double dist = 0.0;

                for(unsigned int i = 0; i < numTokens.size(); i++){
                    double a = minMaxNorm(numTokens[i],i);
                    double b = minMaxNorm(exNumTrain[trainIt->first][i],i);
                    double val = (a-b)*(a-b);
                    //double val = (numTokens[i] - exNumTrain[trainIt->first][i]) * ( numTokens[i] - exNumTrain[trainIt->first][i]);
                    //                    cout<<numTokens[i] << " - " <<exNumTrain[trainIt->first][i] <<endl;
                    //                    cout<<"a = " << a << " b = " << b << " val =" << val<<endl;
                    if( greaterThan(dist + val, numeric_limits<double>::max())){
                        //                        cerr<<"OOOOOOOOOOOOOOOPA!!!"<<endl;
                        //                        exit(0);
                        dist = numeric_limits<double>::max() - 1.0;
                        break;
                    }
                    dist += val;
                    //                    cout<<"dist =" << dist<<endl;
                }
                similarity[trainIt->first] += dist;
            }

            //categorical KNN
            for(map<string, vector<string> >::iterator trainIt  = exCatTrain.begin(); trainIt != exCatTrain.end(); trainIt++){
                double dist = 0.0;

                for(unsigned int i = 0; i < catTokens.size(); i++){
                    string trainTok = exCatTrain[trainIt->first][i];
                    string testTok = catTokens[i];

                    double catCred = getCategoricalCredibility(i, testTok, stats->getTrainClass(trainIt->first));
//                    cout<<"catCred = " <<catCred<<endl;
//                    cout<<" i = " << i << "teste = " << testTok<<" treino = " << trainTok<<endl;
                    if(trainTok != testTok){
//                        dist+= 1.0/(catCred+ 1.0) + 1.0;
                        dist+= 1.0/(catCred+ 1.0);
//                        cout<<"dist = " << dist<<endl;
                    }
                }
                similarity[trainIt->first] += dist;
            }
 //               cout<<"class = " << classId << " doc = " << trainIt->first<< " docClass = " << stats->getTrainClass(trainIt->first) << " dist="<<dist<< " 1/dist = " <<1.0/dist<< " sqrt = "<<sqrt(dist)<<endl;
        }

        if(!valuesSaved && usingKNNOptimize){
            saveValues[eId] = similarity;
        }

        //sim of each example in test set
        set<docWeighted, docWeightedCmp> sim;
        for(map<string, double>::iterator testIt = similarity.begin(); testIt != similarity.end(); testIt++){
            
            //calculating graph credibility....if so
            vector<double> graphsCreds(graphsCredibility.size());
            double similarityValue = testIt->second;

//            cout<< " eid = " << eId << " eclass = " << classId << " traindocclass = " << stats->getTrainClass(testIt->first) << " similarit = " << similarityValue<< endl;

            for(unsigned int g = 0 ; g < graphsCredibility.size(); g++){
                double gsim = getGraphCredibility(g, eId, stats->getTrainClass(testIt->first));
                similarityValue /= (0.5+gsim);
            } 
           
            //never change this, it is necessary
            docWeighted dw(testIt->first, similarityValue);
            sim.insert(dw);
        }
        
        string predictedLabel = getPredictedClass(sim);

        computeConfusionMatrix(classId, predictedLabel);

        //        if(io->usingPredictionsFile)
        savePrediction(eId, classId, predictedLabel);

        if(predictedLabel == classId){
            classHits[classId] ++;			
        }
        else{
            classMiss[classId]++;
        }

        mappedDocs[predictedLabel]++;
        docsPerClass[classId]++;
    }
    if(valuesSaved == false){
        valuesSaved = true;
    }
    calculateF1(classHits,classMiss,docsPerClass, mappedDocs);
//    showConfusionMatrix();
}