Java tutorial
/* * 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/>. */ /* * PolyKernel.java * Copyright (C) 1999-2012 University of Waikato, Hamilton, New Zealand * */ package weka.classifiers.functions.supportVector; import java.util.Collections; import java.util.Enumeration; import java.util.Vector; import weka.core.Capabilities; import weka.core.Capabilities.Capability; import weka.core.Instance; import weka.core.Instances; import weka.core.Option; import weka.core.RevisionUtils; import weka.core.Utils; /** * <!-- globalinfo-start --> The polynomial kernel : K(x, y) = <x, y>^p or * K(x, y) = (<x, y>+1)^p * <p/> * <!-- globalinfo-end --> * * <!-- options-start --> Valid options are: * <p/> * * <pre> * -D * Enables debugging output (if available) to be printed. * (default: off) * </pre> * * <pre> * -C <num> * The size of the cache (a prime number), 0 for full cache and * -1 to turn it off. * (default: 250007) * </pre> * * <pre> * -E <num> * The Exponent to use. * (default: 1.0) * </pre> * * <pre> * -L * Use lower-order terms. * (default: no) * </pre> * * <!-- options-end --> * * @author Eibe Frank (eibe@cs.waikato.ac.nz) * @author Shane Legg (shane@intelligenesis.net) (sparse vector code) * @author Stuart Inglis (stuart@reeltwo.com) (sparse vector code) * @version $Revision$ */ public class PolyKernel extends CachedKernel { /** for serialization */ static final long serialVersionUID = -321831645846363201L; /** Use lower-order terms? */ protected boolean m_lowerOrder = false; /** The exponent for the polynomial kernel. */ protected double m_exponent = 1.0; /** * default constructor - does nothing. */ public PolyKernel() { super(); } /** * Creates a new <code>PolyKernel</code> instance. * * @param data the training dataset used. * @param cacheSize the size of the cache (a prime number) * @param exponent the exponent to use * @param lowerOrder whether to use lower-order terms * @throws Exception if something goes wrong */ public PolyKernel(Instances data, int cacheSize, double exponent, boolean lowerOrder) throws Exception { super(); setCacheSize(cacheSize); setExponent(exponent); setUseLowerOrder(lowerOrder); buildKernel(data); } /** * Returns a string describing the kernel * * @return a description suitable for displaying in the explorer/experimenter * gui */ @Override public String globalInfo() { return "The polynomial kernel : K(x, y) = <x, y>^p or K(x, y) = (<x, y>+1)^p"; } /** * Returns an enumeration describing the available options. * * @return an enumeration of all the available options. */ @Override public Enumeration<Option> listOptions() { Vector<Option> result = new Vector<Option>(); result.addElement(new Option("\tThe Exponent to use.\n" + "\t(default: 1.0)", "E", 1, "-E <num>")); result.addElement(new Option("\tUse lower-order terms.\n" + "\t(default: no)", "L", 0, "-L")); result.addAll(Collections.list(super.listOptions())); return result.elements(); } /** * Parses a given list of options. * <p/> * * <!-- options-start --> Valid options are: * <p/> * * <pre> * -D * Enables debugging output (if available) to be printed. * (default: off) * </pre> * * <pre> * -C <num> * The size of the cache (a prime number), 0 for full cache and * -1 to turn it off. * (default: 250007) * </pre> * * <pre> * -E <num> * The Exponent to use. * (default: 1.0) * </pre> * * <pre> * -L * Use lower-order terms. * (default: no) * </pre> * * <!-- options-end --> * * @param options the list of options as an array of strings * @throws Exception if an option is not supported */ @Override public void setOptions(String[] options) throws Exception { String tmpStr; tmpStr = Utils.getOption('E', options); if (tmpStr.length() != 0) { setExponent(Double.parseDouble(tmpStr)); } else { setExponent(1.0); } setUseLowerOrder(Utils.getFlag('L', options)); super.setOptions(options); } /** * Gets the current settings of the Kernel. * * @return an array of strings suitable for passing to setOptions */ @Override public String[] getOptions() { Vector<String> result = new Vector<String>(); result.add("-E"); result.add("" + getExponent()); if (getUseLowerOrder()) { result.add("-L"); } Collections.addAll(result, super.getOptions()); return result.toArray(new String[result.size()]); } /** * * @param id1 the index of instance 1 * @param id2 the index of instance 2 * @param inst1 the instance 1 object * @return the dot product * @throws Exception if something goes wrong */ @Override protected double evaluate(int id1, int id2, Instance inst1) throws Exception { double result; if (id1 == id2) { result = dotProd(inst1, inst1); } else { result = dotProd(inst1, m_data.instance(id2)); } // Use lower order terms? if (m_lowerOrder) { result += 1.0; } if (m_exponent != 1.0) { result = Math.pow(result, m_exponent); } return result; } /** * Returns the Capabilities of this kernel. * * @return the capabilities of this object * @see Capabilities */ @Override public Capabilities getCapabilities() { Capabilities result = super.getCapabilities(); result.disableAll(); result.enable(Capability.NUMERIC_ATTRIBUTES); result.enableAllClasses(); result.enable(Capability.MISSING_CLASS_VALUES); result.enable(Capability.NO_CLASS); return result; } /** * Sets the exponent value. * * @param value the exponent value */ public void setExponent(double value) { m_exponent = value; } /** * Gets the exponent value. * * @return the exponent value */ public double getExponent() { return m_exponent; } /** * Returns the tip text for this property * * @return tip text for this property suitable for displaying in the * explorer/experimenter gui */ public String exponentTipText() { return "The exponent value."; } /** * Sets whether to use lower-order terms. * * @param value true if lower-order terms will be used */ public void setUseLowerOrder(boolean value) { m_lowerOrder = value; } /** * Gets whether lower-order terms are used. * * @return true if lower-order terms are used */ public boolean getUseLowerOrder() { return m_lowerOrder; } /** * Returns the tip text for this property * * @return tip text for this property suitable for displaying in the * explorer/experimenter gui */ public String useLowerOrderTipText() { return "Whether to use lower-order terms."; } /** * returns a string representation for the Kernel * * @return a string representaiton of the kernel */ @Override public String toString() { String result; if (getExponent() == 1.0) { if (getUseLowerOrder()) { result = "Linear Kernel with lower order: K(x,y) = <x,y> + 1"; } else { result = "Linear Kernel: K(x,y) = <x,y>"; } } else { if (getUseLowerOrder()) { result = "Poly Kernel with lower order: K(x,y) = (<x,y> + 1)^" + getExponent(); } else { result = "Poly Kernel: K(x,y) = <x,y>^" + getExponent(); } } return result; } /** * Returns the revision string. * * @return the revision */ @Override public String getRevision() { return RevisionUtils.extract("$Revision$"); } }