Java tutorial
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package algoritmogeneticocluster; import java.io.BufferedReader; import java.io.FileNotFoundException; import java.io.FileReader; import weka.classifiers.Classifier; import weka.classifiers.Evaluation; import weka.classifiers.evaluation.NominalPrediction; import weka.classifiers.functions.SMO; import weka.classifiers.rules.DecisionTable; import weka.classifiers.rules.PART; import weka.classifiers.trees.DecisionStump; import weka.classifiers.trees.J48; import weka.core.FastVector; import weka.core.Instances; /** * * @author charleshenriqueportoferreira */ public class NewClass { public static BufferedReader readDataFile(String filename) { BufferedReader inputReader = null; try { inputReader = new BufferedReader(new FileReader(filename)); } catch (FileNotFoundException ex) { System.err.println("File not found: " + filename); } return inputReader; } public static Evaluation classify(Classifier model, Instances trainingSet, Instances testingSet) throws Exception { Evaluation evaluation = new Evaluation(trainingSet); model.buildClassifier(trainingSet); evaluation.evaluateModel(model, testingSet); return evaluation; } public static double calculateAccuracy(FastVector predictions) { double correct = 0; for (int i = 0; i < predictions.size(); i++) { NominalPrediction np = (NominalPrediction) predictions.elementAt(i); if (np.predicted() == np.actual()) { correct++; } } return 100 * correct / predictions.size(); } public static Instances[][] crossValidationSplit(Instances data, int numberOfFolds) { Instances[][] split = new Instances[2][numberOfFolds]; for (int i = 0; i < numberOfFolds; i++) { split[0][i] = data.trainCV(numberOfFolds, i); split[1][i] = data.testCV(numberOfFolds, i); } return split; } public static void main(String[] args) throws Exception { BufferedReader datafile = readDataFile("tabela10.arff"); Instances data = new Instances(datafile); data.setClassIndex(data.numAttributes() - 1); // Do 10-split cross validation Instances[][] split = crossValidationSplit(data, 10); // Separate split into training and testing arrays Instances[] trainingSplits = split[0]; Instances[] testingSplits = split[1]; // Use a set of classifiers Classifier[] models = { new SMO(), new J48(), // a decision tree new PART(), new DecisionTable(), //decision table majority classifier new DecisionStump() //one-level decision tree }; // Run for each model for (int j = 0; j < models.length; j++) { // Collect every group of predictions for current model in a FastVector FastVector predictions = new FastVector(); // For each training-testing split pair, train and test the classifier for (int i = 0; i < trainingSplits.length; i++) { Evaluation validation = classify(models[j], trainingSplits[i], testingSplits[i]); predictions.appendElements(validation.predictions()); // Uncomment to see the summary for each training-testing pair. //System.out.println(models[j].toString()); } // Calculate overall accuracy of current classifier on all splits double accuracy = calculateAccuracy(predictions); // Print current classifier's name and accuracy in a complicated, // but nice-looking way. System.out.println("Accuracy of " + models[j].getClass().getSimpleName() + ": " + String.format("%.2f%%", accuracy) + "\n---------------------------------"); } } }