functioncharacteristicagenerator.java

一个很好的LIBSVM的JAVA源码。对于要研究和改进SVM算法的学者。可以参考。来自数据挖掘工具YALE工具包。

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2001-2004
 *      Simon Fischer, Ralf Klinkenberg, Ingo Mierswa, 
 *          Katharina Morik, Oliver Ritthoff
 *      Artificial Intelligence Unit
 *      Computer Science Department
 *      University of Dortmund
 *      44221 Dortmund,  Germany
 *  email: [e-mail]
 *  web:   http://yale.cs.uni-dortmund.de/
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA.
 */
package edu.udo.cs.yale.generator;

import edu.udo.cs.yale.tools.LogService;
import edu.udo.cs.yale.tools.Ontology;
import edu.udo.cs.yale.example.Example;
import edu.udo.cs.yale.example.DataRow;
import edu.udo.cs.yale.example.ExampleTable;
import edu.udo.cs.yale.example.Attribute;
import edu.udo.cs.yale.example.ExampleSet;

import java.util.List;
import java.util.ArrayList;

/**  A <tt>FunctionCharacteristicaGenerator</tt> expects a function value series
 *   as input (attribute value type <tt>Ontology.NUMERICAL</tt> and attribute block
 *   type <tt>Ontology.VALUE_SERIES</tt>, where the first attribute is of the more
 *   specific attribute block type <tt>Ontology.VALUE_SERIES_START</tt>).
 *   <i>The proper attribute input types have to be ensured by the calling class /method,
 *   or by its source, e.g. the corresponding <tt>AttributeAndExampleSource</tt>-Operator.</i>
 *   The output consists of six generated attributes, each of attribute value type
 *   <tt>Ontology.NUMERICAL</tt> and of attribute block type <tt>Ontology.SINGLE_VALUE</tt>:
 *   <ol>
 *     <li><b>WP1.x : </b> x-value of the first turning point (of the value series). </li>
 *     <li><b>WP1.y : </b> y-value of the first turning point (of the value series). </li>
 *     <li><b>Max.x : </b> x-value of the global maximum (of the value series). </li>
 *     <li><b>Max.y : </b> y-value of the global maximum (of the value series). </li>
 *     <li><b>WP2.x : </b> x-value of the second turning point (of the value series). </li>
 *     <li><b>WP2.y : </b> y-value of the second turning point (of the value series). </li>
 *   </ol>
 *   <b>Important Note:</b> <i>This generator has been designed for a special form of
 *   functions (function value series), i.e. for functions which have one global maximum (Max),
 *   one turning point left of the maximum (WP1), and one turning point right of the
 *   maximum (WP2).  This generator will probably not work with other function types.</i>
 *
 *   @author simon, ingo
 *   @version $Id: FunctionCharacteristicaGenerator.java,v 2.10 2004/08/27 11:57:33 ingomierswa Exp $
 */
public class FunctionCharacteristicaGenerator extends FeatureGenerator {

    /** Input attribute value type and block type:  Block type <tt>Ontology.VALUE_SERIES</tt> here means that one
     *  or more attributes of the specified attribute value type <tt>Ontology.NUMERICAL</tt> may be used as input
     *  for this generator as long as they have the same block number and they will be interpreted as a function
     *  value series (e.g. a time series).
     */
    private static final Attribute[] INPUT_ATTR = { new Attribute(Ontology.NUMERICAL, Ontology.VALUE_SERIES_START) };

    // Generator input:  series of numerical function values.
    private static final int[] VALUE_TYPES = {Ontology.NUMERICAL};
    private static final int[] BLOCK_TYPES = {Ontology.VALUE_SERIES_START};

    // Generator output:  six numeric single values (WP1.x, WP1.y, Max.x, Max.y, WP2.x, WP2.y).
    private static final int[] RESULT_VALUE_TYPE = { Ontology.NUMERICAL, Ontology.NUMERICAL, Ontology.NUMERICAL,
						     Ontology.NUMERICAL, Ontology.NUMERICAL, Ontology.NUMERICAL };
    private static final int[] RESULT_BLOCK_TYPE = { Ontology.SINGLE_VALUE, Ontology.SINGLE_VALUE,
						     Ontology.SINGLE_VALUE, Ontology.SINGLE_VALUE,
						     Ontology.SINGLE_VALUE, Ontology.SINGLE_VALUE };

    // Positions (indices) of the new attributes within the array of new attribute values
    private static final int  WP1_X = 0;
    private static final int  WP1_Y = 1;
    private static final int  MAX_X = 2;
    private static final int  MAX_Y = 3;
    private static final int  WP2_X = 4;
    private static final int  WP2_Y = 5;
    public static final String[] FUNCTION_NAMES = { "WP1.X", "WP1.Y", "Max.X", "Max.Y", "WP2.X", "WP2.Y" };

    /* --------- Private Variables ---------- */

    private int          attributeIndexStart,  // attribute index of the first and last attribute (value)
		         attributeIndexEnd;    // of function value series (if valueSeriesStart >= 0)
    private double[]     y;		       // array with the y-values of the function value series
    private int          n;		       // number of y-values of the function value series


    /* --------- Public Methods ---------- */

    /** creates a <tt>FunctionCharacteristicaGenerator</tt> that has to be initialized with the methods
     *  <tt>setArguements(...)</tt> and <tt>setAttributeSet(...)</tt> before its <tt>generate(...)</tt>
     *  method may be called.
     *  The method <tt>setAttributeSet(...)</tt> is called automatically in <tt>generateAll(...)</tt> of
     *  the super class <tt>FeatureGenerator</tt> before this methods calls the <tt>generate(...)</tt>
     *  method of each <tt>Generator</tt> in its list.
     */
    public FunctionCharacteristicaGenerator() {
	super();
	attributeIndexStart = -1;
	attributeIndexEnd   = -2;
	y = null;
	n = -1;
    }

    public FeatureGenerator newInstance() {
  	return new FunctionCharacteristicaGenerator();
    }

//     public int getNumberOfApplicableGenerations(ExampleSet exampleSet) {
// 	int counter = 0;
// 	for (int i = 0; i < exampleSet.getNumberOfAttributes(); i++) {
// 	    if (exampleSet.getAttribute(i).compatible(INPUT_ATTR[0])) {
// 		counter++;
// 		i = exampleSet.getBlockEndIndex(i);
// 	    }
// 	}
// 	return counter;
//     }

    /** Ignores max depth and functions which should not be used. */
    public List getInputCandidates(ExampleSet exampleSet, int maxDepth, String[] functions) {
	List result = new ArrayList();
	for (int i = 0; i < exampleSet.getNumberOfAttributes(); i++) {
	    if (exampleSet.getAttribute(i).compatible(INPUT_ATTR[0])) {
		List series = new ArrayList();
		int blockNr = exampleSet.getAttribute(i).getBlockNr();
		boolean seriesEnd = false;
		while (exampleSet.getAttribute(i).getBlockNr() == blockNr)
		    series.add(exampleSet.getAttribute(i++));
		Attribute[] seriesArray = new Attribute[series.size()];
		series.toArray(seriesArray);
		result.add(seriesArray);
	    }
	}
	return result;
    }

    /** returns an array with the expected input <tt>Attribute</tt>s (i.e. value types and block types);
     *  here: an array with one element of value type <tt>Ontology.NUMERICAL</tt> and block type
     *  <tt>Ontology.VALUE_SERIES</tt>.
     */
    public Attribute[] getInputAttributes() {
	return INPUT_ATTR;
    }


    /** returns a list of the output attributes */
    public Attribute[] getOutputAttributes(ExampleTable input) {

	Attribute   inputAttribute   = getArgument(0);
	Attribute[] outputAttributes = new Attribute[6];
	for (int i=0; i<6; i++) {
	  outputAttributes[i] = new Attribute(Ontology.NUMERICAL, Ontology.SINGLE_VALUE,
					      FUNCTION_NAMES[i], new Attribute[] {inputAttribute}, 
					      false,
					      Attribute.UNDEFINED_BLOCK_NR,
					      null);
	}
	return outputAttributes;
    }


    public void setFunction(String name) {
	for (int i = 0; i < FUNCTION_NAMES.length; i++) {
	    if (FUNCTION_NAMES[i].equals(name)) return;
	}
	LogService.logMessage("Illegal function name '"+name+"' for "+getClass().getName()+".", 
			      LogService.ERROR);
    }
    public String getFunction() {
	return "FunctionCharacteristica";
    }


    /** This method generates the new attributes' values for the given example and returns them in an array.
     */
    public void generate(DataRow data) throws GenerationException {
	double[] functionCharacteristica = new double[6]; // array for WP1.x, WP1.y, Max.x, Max.y, WP2.x, WP2.y
							  // (output of the generator)

	for (int i = 0; i < functionCharacteristica.length; i++) 
	    functionCharacteristica[i] = Double.NaN;

	// ----- determine start and end index of the value series within the attribute set -----
	// ----- and allocate array for values of the value series (both done only once)    -----
        if (y == null) {
	    attributeIndexStart = getArgument(0).getIndex();
	    attributeIndexEnd   = getExampleTable().getBlockEndIndex(attributeIndexStart);
	    n = attributeIndexEnd - attributeIndexStart + 1;    // number of values in the value series
	    if (n < 5) {
		throw new GenerationException("FunctionCharacteristicaGenerator.generate(Example): "
					      +"this generator can only be applied to value series "
					      +"with at least five values.");
	    }
	    y = new double[n];     // array for the values of the value series (input of the generator)
 	}

	// ----- get the attribute values of the example to be used as input value series -----