attribute.java

一个数据挖掘系统的源码

/**
 *
 *   AgentAcademy - an open source Data Mining framework for
 *   training intelligent agents
 *
 *   Copyright (C)   2001-2003 AA Consortium.
 *
 *   This library is open source software; you can redistribute it
 *   and/or modify it under the terms of the GNU Lesser General
 *   Public License as published by the Free Software Foundation;
 *   either version 2.0 of the License, or (at your option) any later
 *   version.
 *
 *   This library 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 Lesser General Public
 *   License along with this library; if not, write to the Free
 *   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *   MA  02111-1307 USA
 *
 */

package org.agentacademy.modules.dataminer.core;

/**
 * <p>Title: The Data Miner prototype</p>
 * <p>Description: A prototype for the DataMiner (DM), the Agent Academy (AA) module responsible for performing data mining on the contents of the Agent Use Repository (AUR). The extracted knowledge is to be sent back to the AUR in the form of a PMML document.</p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: CERTH</p>
 * @author asymeon
 * @version 0.3
 */


import java.io.Serializable;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Properties;
import java.io.StreamTokenizer;
import java.io.StringReader;
import java.io.IOException;
import org.apache.log4j.Logger;

/**
 * Class for handling an attribute. Once an attribute has been created,
 * it can't be changed. <p>
 *
 * Three attribute types are supported:
 * <ul>
 *    <li> numeric: <ul>
 *         This type of attribute represents a floating-point number.
 *    </ul>
 *    <li> nominal: <ul>
 *         This type of attribute represents a fixed set of nominal values.
 *    </ul>
 *    <li> string: <ul>
 *         This type of attribute represents a dynamically expanding set of
 *         nominal values. String attributes are not used by the learning
 *         schemes in Weka. They can be used, for example,  to store an
 *         identifier with each instance in a dataset.
 *    </ul>
 * </ul>
 * Typical usage (code from the main() method of this class): <p>
 *
 * <code>
 * ... <br>
 *
 * // Create numeric attributes "length" and "weight" <br>
 * Attribute length = new Attribute("length"); <br>
 * Attribute weight = new Attribute("weight"); <br><br>
 *
 * // Create vector to hold nominal values "first", "second", "third" <br>
 * FastVector my_nominal_values = new FastVector(3); <br>
 * my_nominal_values.addElement("first"); <br>
 * my_nominal_values.addElement("second"); <br>
 * my_nominal_values.addElement("third"); <br><br>
 *
 * // Create nominal attribute "position" <br>
 * Attribute position = new Attribute("position", my_nominal_values);<br>
 *
 * ... <br>
 * </code><p>
 *
 */
public class Attribute implements Copyable, Serializable {

 public static Logger                log = Logger.getLogger(Attribute.class);
  /** Constant set for numeric attributes. */
  public final static int NUMERIC = 0;

  /** Constant set for nominal attributes. */
  public final static int NOMINAL = 1;

  /** Constant set for attributes with string values. */
  public final static int STRING = 2;

  /** Constant set for attributes with date values. */
  public final static int DATE = 3;

  /** Constant set for symbolic attributes. */
  public final static int ORDERING_SYMBOLIC = 0;

  /** Constant set for ordered attributes. */
  public final static int ORDERING_ORDERED  = 1;

  /** Constant set for modulo-ordered attributes. */
  public final static int ORDERING_MODULO   = 2;

  /** Strings longer than this will be stored compressed. */
  private final static int STRING_COMPRESS_THRESHOLD = 200;

  /** The attribute's name. */
  private String m_Name;

  /** The attribute's type. */
  private int m_Type;

  /** The attribute's values (if nominal or string). */
  private FastVector m_Values;

  /** Mapping of values to indices (if nominal or string). */
  private Hashtable m_Hashtable;

  /** Date format specification for date attributes */
  private SimpleDateFormat m_DateFormat;

  /** The attribute's index. */
  private int m_Index;

  /** The attribute's metadata. */
  private ProtectedProperties m_Metadata;

  /** The attribute's ordering. */
  private int m_Ordering;

  /** Whether the attribute is regular. */
  private boolean m_IsRegular;

  /** Whether the attribute is averagable. */
  private boolean m_IsAveragable;

  /** Whether the attribute has a zeropoint. */
  private boolean m_HasZeropoint;

  /** The attribute's weight. */
  private double m_Weight;

  /** The attribute's lower numeric bound. */
  private double m_LowerBound;

  /** Whether the lower bound is open. */
  private boolean m_LowerBoundIsOpen;

  /** The attribute's upper numeric bound. */
  private double m_UpperBound;

  /** Whether the upper bound is open */
  private boolean m_UpperBoundIsOpen;

  /**
   * Constructor for a numeric attribute.
   *
   * @param attributeName the name for the attribute
   */
  public Attribute(String attributeName) {

    this(attributeName, new ProtectedProperties(new Properties()));
  }

  /**
   * Constructor for a numeric attribute, where metadata is supplied.
   *
   * @param attributeName the name for the attribute
   * @param metadata the attribute's properties
   */
  public Attribute(String attributeName, ProtectedProperties metadata) {

    m_Name = attributeName;
    m_Index = -1;
    m_Values = null;
    m_Hashtable = null;
    m_Type = NUMERIC;
    setMetadata(metadata);
  }

  /**
   * Constructor for a date attribute.
   *
   * @param attributeName the name for the attribute
   * @param dateFormat a string suitable for use with
   * SimpleDateFormatter for parsing dates.
   */
  public Attribute(String attributeName, String dateFormat) {

    this(attributeName, dateFormat,
	 new ProtectedProperties(new Properties()));
  }

  /**
   * Constructor for a date attribute, where metadata is supplied.
   *
   * @param attributeName the name for the attribute
   * @param dateFormat a string suitable for use with
   * SimpleDateFormatter for parsing dates.
   * @param metadata the attribute's properties
   */
  public Attribute(String attributeName, String dateFormat,
		   ProtectedProperties metadata) {

    m_Name = attributeName;
    m_Index = -1;
    m_Values = null;
    m_Hashtable = null;
    m_Type = DATE;
    if (dateFormat != null) {
      m_DateFormat = new SimpleDateFormat(dateFormat);
    } else {
      m_DateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
    }
    m_DateFormat.setLenient(false);
    setMetadata(metadata);
  }

  /**
   * Constructor for nominal attributes and string attributes.
   * If a null vector of attribute values is passed to the method,
   * the attribute is assumed to be a string.
   *
   * @param attributeName the name for the attribute
   * @param attributeValues a vector of strings denoting the
   * attribute values. Null if the attribute is a string attribute.
   */
  public Attribute(String attributeName,
		   FastVector attributeValues) {

    this(attributeName, attributeValues,
	 new ProtectedProperties(new Properties()));
  }

  /**
   * Constructor for nominal attributes and string attributes, where
   * metadata is supplied. If a null vector of attribute values is passed
   * to the method, the attribute is assumed to be a string.
   *
   * @param attributeName the name for the attribute
   * @param attributeValues a vector of strings denoting the
   * attribute values. Null if the attribute is a string attribute.
   * @param metadata the attribute's properties
   */
  public Attribute(String attributeName,
		   FastVector attributeValues,
		   ProtectedProperties metadata) {

    m_Name = attributeName;
    m_Index = -1;
    if (attributeValues == null) {
      m_Values = new FastVector();
      m_Hashtable = new Hashtable();
      m_Type = STRING;
    } else {
      m_Values = new FastVector(attributeValues.size());
      m_Hashtable = new Hashtable(attributeValues.size());
      for (int i = 0; i < attributeValues.size(); i++) {
	Object store = attributeValues.elementAt(i);
	if (((String)store).length() > STRING_COMPRESS_THRESHOLD) {
	  try {
	    store = new SerializedObject(attributeValues.elementAt(i), true);
	  } catch (Exception ex) {
	    System.err.println("Couldn't compress nominal attribute value -"
			       + " storing uncompressed.");
	  }
	}
	m_Values.addElement(store);
	m_Hashtable.put(store, new Integer(i));
      }
      m_Type = NOMINAL;
    }
    setMetadata(metadata);
  }

  /**
   * Produces a shallow copy of this attribute.
   *
   * @return a copy of this attribute with the same index
   */
  public Object copy() {

    Attribute copy = new Attribute(m_Name);

    copy.m_Index = m_Index;
    copy.m_Type = m_Type;
    copy.m_Values = m_Values;
    copy.m_Hashtable = m_Hashtable;
    copy.m_DateFormat = m_DateFormat;
    copy.setMetadata(m_Metadata);

    return copy;
  }

  /**
   * Returns an enumeration of all the attribute's values if
   * the attribute is nominal or a string, null otherwise.
   *
   * @return enumeration of all the attribute's values
   */
  public final Enumeration enumerateValues() {

    if (isNominal() || isString()) {
      final Enumeration ee = m_Values.elements();
      return new Enumeration () {
          public boolean hasMoreElements() {
            return ee.hasMoreElements();
          }
          public Object nextElement() {
            Object oo = ee.nextElement();
            if (oo instanceof SerializedObject) {
              return ((SerializedObject)oo).getObject();
            } else {
              return oo;
            }
          }
        };
    }
    return null;
  }

  /**
   * Tests if given attribute is equal to this attribute.
   *
   * @param other the Object to be compared to this attribute
   * @return true if the given attribute is equal to this attribute
   */
  public final boolean equals(Object other) {

    if ((other == null) || !(other.getClass().equals(this.getClass()))) {
      return false;
    }
    Attribute att = (Attribute) other;
    if (!m_Name.equals(att.m_Name)) {
      return false;
    }
    if (isNominal() && att.isNominal()) {
      if (m_Values.size() != att.m_Values.size()) {
        return false;
      }
      for (int i = 0; i < m_Values.size(); i++) {
        if (!m_Values.elementAt(i).equals(att.m_Values.elementAt(i))) {
          return false;
        }
      }
      return true;
    } else {
      return (type() == att.type());
    }
  }

  /**
   * Returns the index of this attribute.
   *
   * @return the index of this attribute
   */
  public final int index() {

    return m_Index;
  }

  /**
   * Returns the index of a given attribute value. (The index of
   * the first occurence of this value.)
   *
   * @param value the value for which the index is to be returned
   * @return the index of the given attribute value if attribute
   * is nominal or a string, -1 if it is numeric or the value
   * can't be found
   */
  public final int indexOfValue(String value) {

    if (!isNominal() && !isString())
      return -1;
    Object store = value;
    if (value.length() > STRING_COMPRESS_THRESHOLD) {
      try {
        store = new SerializedObject(value, true);
      } catch (Exception ex) {
        System.err.println("Couldn't compress string attribute value -"
                           + " searching uncompressed.");
      }
    }
    Integer val = (Integer)m_Hashtable.get(store);
    if (val == null) return -1;
    else return val.intValue();
  }

  /**
   * Test if the attribute is nominal.
   *
   * @return true if the attribute is nominal
   */
  public final boolean isNominal() {

    return (m_Type == NOMINAL);
  }

  /**
   * Tests if the attribute is numeric.
   *