Java tutorial
/*********************************************************************** This file is part of KEEL-software, the Data Mining tool for regression, classification, clustering, pattern mining and so on. Copyright (C) 2004-2010 F. Herrera (herrera@decsai.ugr.es) L. Snchez (luciano@uniovi.es) J. Alcal-Fdez (jalcala@decsai.ugr.es) S. Garca (sglopez@ujaen.es) A. Fernndez (alberto.fernandez@ujaen.es) J. Luengo (julianlm@decsai.ugr.es) This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/ **********************************************************************/ /** * <p> * @author Written by Cristobal Romero (Universidad de Crdoba) 10/10/2007 * @version 0.1 * @since JDK 1.5 *</p> */ package keel.Algorithms.Decision_Trees.C45; import java.io.*; /** para commons.configuration import org.apache.commons.configuration.*; */ /** * Class to implement the C4.5 algorithm @author Cristbal Romero Morales (UCO) (30-03-06) @author modified by Alberto Fernandez (UGR) @version 1.2 (29-04-10) */ public class C45 extends Algorithm { /** Decision tree. */ private Tree root; /** Is the tree pruned or not. */ private boolean prune = true; /** Confidence level. */ private float confidence = 0.25f; /** Minimum number of itemsets per leaf. */ private int minItemsets = 2; /** The prior probabilities of the classes. */ private double[] priorsProbabilities; /** Resolution of the margin histogram. */ private static int marginResolution = 500; /** Cumulative margin classification. */ private double marginCounts[]; /** The sum of counts for priors. */ private double classPriorsSum; /** Constructor. * * @param paramFile The parameters file. * * @throws Exception If the algorithm cannot be executed. */ public C45(String paramFile) throws Exception { try { // starts the time long startTime = System.currentTimeMillis(); /* Sets the options of the execution from text file*/ StreamTokenizer tokenizer = new StreamTokenizer(new BufferedReader(new FileReader(paramFile))); initTokenizer(tokenizer); setOptions(tokenizer); /* Sets the options from XML file */ /** para commons.configuration XMLConfiguration config = new XMLConfiguration(paramFile); setOptions( config ); */ /* Initializes the dataset. */ modelDataset = new Dataset(modelFileName, true); trainDataset = new Dataset(trainFileName, false); testDataset = new Dataset(testFileName, false); priorsProbabilities = new double[modelDataset.numClasses()]; priorsProbabilities(); marginCounts = new double[marginResolution + 1]; // generate the tree generateTree(modelDataset); printTrain(); printTest(); printResult(); } catch (Exception e) { System.err.println(e.getMessage()); System.exit(-1); } } /** Function to read the options from the xml parameter file and assign the values to the corresponding member variables of C45 class: * modelFileName, trainFileName, testFileName, trainOutputFileName, testOutputFileName, resultFileName, prune, confidence, minItemsets. * * @param config The XMLObject with the parameters. * * @throws Exception If there is any problem with the xml file */ /** para commons.configuration protected void setOptions( XMLConfiguration config ) throws Exception { String algorithm = config.getString("algorithm"); if (!algorithm.equalsIgnoreCase( "C4.5" ) ) throw new Exception( "The name of the algorithm is not correct." ); modelFileName = config.getString("inputData.inputData1"); trainFileName = config.getString("inputData.inputData2"); testFileName = config.getString("inputData.inputData3"); trainOutputFileName = config.getString("outputData.outputData1"); testOutputFileName = config.getString("outputData.outputData2"); resultFileName = config.getString("outputData.outputData3"); prune = config.getBoolean("parameter.pruned"); confidence = config.getFloat("parameter.confidence"); minItemsets = config.getInt("parameter.instancesPerLeaf"); } */ /** Function to read the options from the execution file and assign the values to the parameters. * * @param options The StreamTokenizer that reads the parameters file. * * @throws Exception If the format of the file is not correct. */ protected void setOptions(StreamTokenizer options) throws Exception { options.nextToken(); /* Checks that the file starts with the token algorithm */ if (options.sval.equalsIgnoreCase("algorithm")) { options.nextToken(); options.nextToken(); //if (!options.sval.equalsIgnoreCase( "C4.5" ) ) // throw new Exception( "The name of the algorithm is not correct." ); options.nextToken(); options.nextToken(); options.nextToken(); options.nextToken(); /* Reads the names of the input files*/ if (options.sval.equalsIgnoreCase("inputData")) { options.nextToken(); options.nextToken(); modelFileName = options.sval; if (options.nextToken() != StreamTokenizer.TT_EOL) { trainFileName = options.sval; options.nextToken(); testFileName = options.sval; if (options.nextToken() != StreamTokenizer.TT_EOL) { trainFileName = modelFileName; options.nextToken(); } } } else { throw new Exception("No file test provided."); } /* Reads the names of the output files*/ while (true) { if (options.nextToken() == StreamTokenizer.TT_EOF) { throw new Exception("No output file provided."); } if (options.sval == null) { continue; } else if (options.sval.equalsIgnoreCase("outputData")) { break; } } options.nextToken(); options.nextToken(); trainOutputFileName = options.sval; options.nextToken(); testOutputFileName = options.sval; options.nextToken(); resultFileName = options.sval; if (!getNextToken(options)) { return; } while (options.ttype != StreamTokenizer.TT_EOF) { /* Reads the prune parameter */ if (options.sval.equalsIgnoreCase("pruned")) { options.nextToken(); options.nextToken(); if (options.sval.equalsIgnoreCase("TRUE")) { prune = true; } else { //prune = false; prune = true; } } /* Reads the confidence parameter */ if (options.sval.equalsIgnoreCase("confidence")) { if (!prune) { throw new Exception("Doesn't make sense to change confidence for prune " + "tree!"); } options.nextToken(); options.nextToken(); /* Checks that the confidence threshold is between 0 and 1. */ float cf = Float.parseFloat(options.sval); if (cf <= 1 || cf >= 0) { confidence = Float.parseFloat(options.sval); } } /* Reads the itemsets per leaf parameter */ if (options.sval.equalsIgnoreCase("itemsetsPerLeaf")) { options.nextToken(); options.nextToken(); if (Integer.parseInt(options.sval) > 0) { minItemsets = Integer.parseInt(options.sval); } } getNextToken(options); } } } /** Generates the tree. * * @param itemsets The dataset used to build the tree. * * @throws Exception If the tree cannot be built. */ public void generateTree(Dataset itemsets) throws Exception { SelectCut selectCut; selectCut = new SelectCut(minItemsets, itemsets); root = new Tree(selectCut, prune, confidence); root.buildTree(itemsets); } /** Function to evaluate the class which the itemset must have according to the classification of the tree. * * @param itemset The itemset to evaluate. * * @return The index of the class index predicted. */ public double evaluateItemset(Itemset itemset) throws Exception { Itemset classMissing = (Itemset) itemset.copy(); double prediction = 0; classMissing.setDataset(itemset.getDataset()); classMissing.setClassMissing(); double[] classification = classificationForItemset(classMissing); prediction = maxIndex(classification); updateStats(classification, itemset, itemset.numClasses()); //itemset.setPredictedValue( prediction ); return prediction; } /** Updates all the statistics for the current itemset. * * @param predictedClassification Distribution of class values predicted for the itemset. * @param itemset The itemset. * @param nClasses The number of classes. * */ private void updateStats(double[] predictedClassification, Itemset itemset, int nClasses) { int actualClass = (int) itemset.getClassValue(); if (!itemset.classIsMissing()) { updateMargins(predictedClassification, actualClass, nClasses); // Determine the predicted class (doesn't detect multiple classifications) int predictedClass = -1; double bestProb = 0.0; for (int i = 0; i < nClasses; i++) { if (predictedClassification[i] > bestProb) { predictedClass = i; bestProb = predictedClassification[i]; } } // Update counts when no class was predicted if (predictedClass < 0) { return; } double predictedProb = Math.max(Double.MIN_VALUE, predictedClassification[actualClass]); double priorProb = Math.max(Double.MIN_VALUE, priorsProbabilities[actualClass] / classPriorsSum); } } /** Returns class probabilities for an itemset. * * @param itemset The itemset. * * @throws Exception If cannot compute the classification. */ public final double[] classificationForItemset(Itemset itemset) throws Exception { return root.classificationForItemset(itemset); } /** Update the cumulative record of classification margins. * * @param predictedClassification Distribution of class values predicted for the itemset. * @param actualClass The class value. * @param nClasses Number of classes. */ private void updateMargins(double[] predictedClassification, int actualClass, int nClasses) { double probActual = predictedClassification[actualClass]; double probNext = 0; for (int i = 0; i < nClasses; i++) { if ((i != actualClass) && ( //Comparators.isGreater( predictedClassification[i], probNext ) ) ) predictedClassification[i] > probNext)) { probNext = predictedClassification[i]; } } double margin = probActual - probNext; int bin = (int) ((margin + 1.0) / 2.0 * marginResolution); marginCounts[bin]++; } /** Evaluates if a string is a boolean value. * * @param value The string to evaluate. * * @return True if value is a boolean value. False otherwise. */ private boolean isBoolean(String value) { if (value.equalsIgnoreCase("TRUE") || value.equalsIgnoreCase("FALSE")) { return true; } else { return false; } } /** Returns index of maximum element in a given array of doubles. First maximum is returned. * * @param doubles The array of elements. * */ public static int maxIndex(double[] doubles) { double maximum = 0; int maxIndex = 0; for (int i = 0; i < doubles.length; i++) { if ((i == 0) || // doubles[i] > maximum) { maxIndex = i; maximum = doubles[i]; } } return maxIndex; } /** Sets the class prior probabilities. * * @throws Exception If cannot compute the probabilities. */ public void priorsProbabilities() throws Exception { for (int i = 0; i < modelDataset.numClasses(); i++) { priorsProbabilities[i] = 1; } classPriorsSum = modelDataset.numClasses(); for (int i = 0; i < modelDataset.numItemsets(); i++) { if (!modelDataset.itemset(i).classIsMissing()) { try { priorsProbabilities[(int) modelDataset.itemset(i).getClassValue()] += modelDataset.itemset(i) .getWeight(); classPriorsSum += modelDataset.itemset(i).getWeight(); } catch (Exception e) { System.err.println(e.getMessage()); } } } } /** Writes the tree and the results of the training and the test in the file. * * @exception If the file cannot be written. */ public void printResult() throws IOException { long totalTime = (System.currentTimeMillis() - startTime) / 1000; long seconds = totalTime % 60; long minutes = ((totalTime - seconds) % 3600) / 60; String tree = ""; PrintWriter resultPrint; tree += toString(); tree += "\n@TotalNumberOfNodes " + root.NumberOfNodes; tree += "\n@NumberOfLeafs " + root.NumberOfLeafs; tree += "\n@TotalNumberOfNodes " + root.NumberOfNodes; int atts = root.getAttributesPerRule(); if (atts > 0) { tree += "\n@NumberOfAntecedentsByRule " + (1.0 * atts) / root.NumberOfLeafs; } else { tree += "\n@NumberOfAntecedentsByRule 0"; } tree += "\n\n@NumberOfItemsetsTraining " + trainDataset.numItemsets(); tree += "\n@NumberOfCorrectlyClassifiedTraining " + correct; tree += "\n@PercentageOfCorrectlyClassifiedTraining " + (float) (correct * 100.0) / (float) trainDataset.numItemsets() + "%"; tree += "\n@NumberOfInCorrectlyClassifiedTraining " + (trainDataset.numItemsets() - correct); tree += "\n@PercentageOfInCorrectlyClassifiedTraining " + (float) ((trainDataset.numItemsets() - correct) * 100.0) / (float) trainDataset.numItemsets() + "%"; tree += "\n\n@NumberOfItemsetsTest " + testDataset.numItemsets(); tree += "\n@NumberOfCorrectlyClassifiedTest " + testCorrect; tree += "\n@PercentageOfCorrectlyClassifiedTest " + (float) (testCorrect * 100.0) / (float) testDataset.numItemsets() + "%"; tree += "\n@NumberOfInCorrectlyClassifiedTest " + (testDataset.numItemsets() - testCorrect); tree += "\n@PercentageOfInCorrectlyClassifiedTest " + (float) ((testDataset.numItemsets() - testCorrect) * 100.0) / (float) testDataset.numItemsets() + "%"; tree += "\n\n@ElapsedTime " + (totalTime - minutes * 60 - seconds) / 3600 + ":" + minutes / 60 + ":" + seconds; resultPrint = new PrintWriter(new FileWriter(resultFileName)); resultPrint.print(getHeader() + "\n@decisiontree\n\n" + tree); resultPrint.close(); } /** Evaluates the training dataset and writes the results in the file. * * @exception If the file cannot be written. */ public void printTrain() { String text = getHeader(); for (int i = 0; i < trainDataset.numItemsets(); i++) { try { Itemset itemset = trainDataset.itemset(i); int cl = (int) evaluateItemset(itemset); if (cl == (int) itemset.getValue(trainDataset.getClassIndex())) { correct++; } text += trainDataset.getClassAttribute().value(((int) itemset.getClassValue())) + " " + trainDataset.getClassAttribute().value(cl) + "\n"; } catch (Exception e) { System.err.println(e.getMessage()); } } try { PrintWriter print = new PrintWriter(new FileWriter(trainOutputFileName)); print.print(text); print.close(); } catch (IOException e) { System.err.println("Can not open the training output file: " + e.getMessage()); } } /** Evaluates the test dataset and writes the results in the file. * * @exception If the file cannot be written. */ public void printTest() { String text = getHeader(); for (int i = 0; i < testDataset.numItemsets(); i++) { try { int cl = (int) evaluateItemset(testDataset.itemset(i)); Itemset itemset = testDataset.itemset(i); if (cl == (int) itemset.getValue(testDataset.getClassIndex())) { testCorrect++; } text += testDataset.getClassAttribute().value(((int) itemset.getClassValue())) + " " + testDataset.getClassAttribute().value(cl) + "\n"; } catch (Exception e) { System.err.println(e.getMessage()); } } try { PrintWriter print = new PrintWriter(new FileWriter(testOutputFileName)); print.print(text); print.close(); } catch (IOException e) { System.err.println("Can not open the training output file."); } } /** Function to print the tree. * */ public String toString() { return root.toString(); } /** Main function. * * @param args The parameters file. * * @throws Exception If the algorithm cannot been executed properly. */ public static void main(String[] args) { try { if (args.length != 1) { throw new Exception( "\nError: you have to specify the parameters file\n\tusage: java -jar C45.java parameterfile.txt"); } else { C45 classifier = new C45(args[0]); } } catch (Exception e) { System.err.println(e.getMessage()); System.exit(-1); } } }