Java tutorial
/* * ConceptDriftRealStream.java * Copyright (C) 2008 University of Waikato, Hamilton, New Zealand * @author Albert Bifet * 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 2 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, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ package tr.gov.ulakbim.jDenetX.streams; import tr.gov.ulakbim.jDenetX.core.InstancesHeader; import tr.gov.ulakbim.jDenetX.core.ObjectRepository; import tr.gov.ulakbim.jDenetX.options.AbstractOptionHandler; import tr.gov.ulakbim.jDenetX.options.ClassOption; import tr.gov.ulakbim.jDenetX.options.FloatOption; import tr.gov.ulakbim.jDenetX.options.IntOption; import tr.gov.ulakbim.jDenetX.tasks.TaskMonitor; import weka.core.*; import java.util.Random; // Generator that adds concept drift to examples in a stream with // different classes and attributes. Example: real datasets // // Example: // // ConceptDriftRealStream -s (ArffFileStream -f covtype.arff) \ // -d (ConceptDriftRealStream -s (ArffFileStream -f PokerOrig.arff) \ // -d (ArffFileStream -f elec.arff) -w 5000 -p 1000000 ) -w 5000 -p 581012 // // s : Stream // d : Concept drift Stream // p : Central position of concept drift change // w : Width of concept drift change public class ConceptDriftRealStream extends AbstractOptionHandler implements InstanceStream { @Override public String getPurposeString() { return "Adds Concept Drift to examples in a stream."; } private static final long serialVersionUID = 1L; public ClassOption streamOption = new ClassOption("stream", 's', "Stream to add concept drift.", InstanceStream.class, "generators.RandomTreeGenerator"); public ClassOption driftstreamOption = new ClassOption("driftstream", 'd', "Concept drift Stream.", InstanceStream.class, "generators.RandomTreeGenerator"); public FloatOption alphaOption = new FloatOption("alpha", 'a', "Angle alpha of change grade.", 0.0, 0.0, 90.0); public IntOption positionOption = new IntOption("position", 'p', "Central position of concept drift change.", 0); public IntOption widthOption = new IntOption("width", 'w', "Width of concept drift change.", 1000); public IntOption randomSeedOption = new IntOption("randomSeed", 'r', "Seed for random noise.", 1); protected InstanceStream inputStream; protected InstanceStream driftStream; protected Random random; protected int numberInstanceStream; protected InstancesHeader streamHeader; protected Instance inputInstance; protected Instance driftInstance; @Override public void prepareForUseImpl(TaskMonitor monitor, ObjectRepository repository) { this.inputStream = (InstanceStream) getPreparedClassOption(this.streamOption); this.driftStream = (InstanceStream) getPreparedClassOption(this.driftstreamOption); this.random = new Random(this.randomSeedOption.getValue()); numberInstanceStream = 0; if (this.alphaOption.getValue() != 0.0) { this.widthOption.setValue((int) (1 / Math.tan(this.alphaOption.getValue() * Math.PI / 180))); } // generate header Instances first = this.inputStream.getHeader(); Instances second = this.driftStream.getHeader(); FastVector newAttributes = new FastVector(); for (int i = 0; i < first.numAttributes() - 1; i++) { newAttributes.addElement(first.attribute(i)); } for (int i = 0; i < second.numAttributes() - 1; i++) { newAttributes.addElement(second.attribute(i)); } Attribute classLabels; if (first.numClasses() < second.numClasses()) { classLabels = second.classAttribute(); } else { classLabels = first.classAttribute(); } newAttributes.addElement(classLabels); this.streamHeader = new InstancesHeader( new Instances(getCLICreationString(InstanceStream.class), newAttributes, 0)); this.streamHeader.setClassIndex(this.streamHeader.numAttributes() - 1); restart(); } public long estimatedRemainingInstances() { return -1; } public boolean hasMoreInstances() { return true; } public InstancesHeader getHeader() { return this.streamHeader; } public boolean isRestartable() { return (this.inputStream.isRestartable() && this.driftStream.isRestartable()); } public Instance nextInstance() { numberInstanceStream++; double numclass = 0.0; double x = -4.0 * (double) (numberInstanceStream - this.positionOption.getValue()) / (double) this.widthOption.getValue(); double probabilityDrift = 1.0 / (1.0 + Math.exp(x)); if (this.random.nextDouble() > probabilityDrift) { if (!this.inputStream.hasMoreInstances()) { this.inputStream.restart(); } this.inputInstance = this.inputStream.nextInstance(); numclass = this.inputInstance.classValue(); } else { if (!this.driftStream.hasMoreInstances()) { this.driftStream.restart(); } this.driftInstance = this.driftStream.nextInstance(); numclass = this.driftInstance.classValue(); } int m = 0; double[] newVals = new double[this.inputInstance.numAttributes() + this.driftInstance.numAttributes() - 1]; for (int j = 0; j < this.inputInstance.numAttributes() - 1; j++, m++) { newVals[m] = this.inputInstance.value(j); } for (int j = 0; j < this.driftInstance.numAttributes() - 1; j++, m++) { newVals[m] = this.driftInstance.value(j); } newVals[m] = numclass; //return new Instance(1.0, newVals); Instance inst = new DenseInstance(1.0, newVals); inst.setDataset(this.getHeader()); inst.setClassValue(numclass); return inst; } public void restart() { this.inputStream.restart(); this.driftStream.restart(); numberInstanceStream = 0; this.inputInstance = this.inputStream.nextInstance(); this.driftInstance = this.driftStream.nextInstance(); } public void getDescription(StringBuilder sb, int indent) { // TODO Auto-generated method stub } }