/* *    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. *//* * Element.java * Copyright (C) 2007 Sebastian Beer * */package weka.associations.gsp;import weka.core.FastVector;import weka.core.Instance;import weka.core.Instances;import java.io.Serializable;/** * Class representing an Element, i.e., a set of events/items. *  * @author  Sebastian Beer * @version $Revision: 1.1 $ */public class Element  implements Cloneable, Serializable {  /** for serialization */  private static final long serialVersionUID = -7900701276019516371L;    /** events/items stored as an array of ints */  protected int[] m_Events;  /**   * Constructor   */  public Element() {  }  /**   * Constructor accepting an initial size of the events Array as parameter.   *    * @param size 	the size   */  public Element(int size) {    m_Events = new int[size];  }  /**   * Returns all events of the given data set as Elements containing a single    * event. The order of events is determined by the header information of    * the corresponding ARFF file.   *    * @param instances 	the data set   * @return 		the set of 1-Elements   */  public static FastVector getOneElements (Instances instances) {    FastVector setOfOneElements = new FastVector();    Element curElement;    for (int i = 0; i < instances.numAttributes(); i++) {      for (int j = 0; j < instances.attribute(i).numValues(); j++) {	curElement = new Element();	curElement.setEvents(new int [instances.numAttributes()]);	for (int k = 0; k < instances.numAttributes(); k++) {	  curElement.getEvents()[k] = -1;	}	curElement.getEvents()[i] = j;	setOfOneElements.addElement(curElement);      }    }    return setOfOneElements;  }  /**   * Merges two Elements into one.   *    * @param element1 	first Element   * @param element2 	second Element   * @return 		the merged Element   */  public static Element merge(Element element1, Element element2) {    int[] element1Events = element1.getEvents();    int[] element2Events = element2.getEvents();    Element resultElement = new Element(element1Events.length);    int[] resultEvents = resultElement.getEvents();    for (int i = 0; i < element1Events.length; i++) {      if (element2Events[i] > -1) {	resultEvents[i] = element2Events[i];      } else {	resultEvents[i] = element1Events[i];      }    }    resultElement.setEvents(resultEvents);    return resultElement;  }  /**   * Returns a deep clone of an Element.   *    * @return 		the cloned Element   */  public Element clone() {    try {      Element clone = (Element) super.clone();      int[] cloneEvents = new int[m_Events.length];      for (int i = 0; i < m_Events.length; i++) {	cloneEvents[i] = m_Events[i];      }      clone.setEvents(cloneEvents);      return clone;    } catch (CloneNotSupportedException exc) {      exc.printStackTrace();    }    return null;  }  /**   * Checks if an Element contains over one event.   *    * @return 		true, if the Element contains over one event, else false   */  public boolean containsOverOneEvent() {    int numEvents = 0;    for (int i = 0; i < m_Events.length; i++) {      if (m_Events[i] > -1) {	numEvents++;      }      if (numEvents == 2) {	return true;      }    }    return false;  }  /**   * Deletes the first or last event of an Element.   *    * @param position 	the position of the event to be deleted (first or last)   */  public void deleteEvent(String position) {    if (position.equals("first")) {      //delete first event      for (int i = 0; i < m_Events.length; i++) {	if (m_Events[i] > -1) {	  m_Events[i] = -1;	  break;	}      }    }    if (position.equals("last")) {      //delete last event      for (int i = m_Events.length-1; i >= 0; i--) {	if (m_Events[i] > -1) {	  m_Events[i] = -1;	  break;	}      }    }  }  /**   * Checks if two Elements are equal.   *    * @return 		true, if the two Elements are equal, else false   */  public boolean equals(Object obj) {    Element element2 = (Element) obj;    for (int i=0; i < m_Events.length; i++) {      if (!(m_Events[i] == element2.getEvents()[i])) {	return false;      }    }    return true;  }  /**   * Returns the events Array of an Element.   *    * @return 		the events Array   */  public int[] getEvents() {    return m_Events;  }  /**   * Checks if an Element is contained by a given Instance.   *    * @param instance 	the given Instance   * @return 		true, if the Instance contains the Element, else false   */  public boolean isContainedBy(Instance instance) {    for (int i=0; i < instance.numAttributes(); i++) {      if (m_Events[i] > -1) {	if (instance.isMissing(i)) {	  return false;	}	if (m_Events[i] != (int) instance.value(i)) {	  return false;	}      }    }    return true;  }  /**   * Checks if the Element contains any events.   *    * @return 		true, if the Element contains no event, else false    */  public boolean isEmpty() {    for (int i=0; i < m_Events.length; i++) {      if (m_Events[i] > -1) {	return false;      }    }    return true;  }  /**   * Sets the events Array of an Element.   *    * @param events 	the events Array to set   */  protected void setEvents(int[] events) {    m_Events = events;  }  /**   * Returns a String representation of an Element where the numeric value    * of each event/item is represented by its respective nominal value.   *    * @param dataSet 	the corresponding data set containing the header information   * @return 		the String representation   */  public String toNominalString(Instances dataSet) {    StringBuffer result = new StringBuffer();    int addedValues = 0;    result.append("{");    for (int i=0; i < m_Events.length; i++) {      if (m_Events[i] > -1) {				result.append(dataSet.attribute(i).value(m_Events[i]) + ",");	addedValues++;      }    }    result.deleteCharAt(result.length()-1);    result.append("}");    return result.toString();  }  /**   * Returns a String representation of an Element.   *    * @return 		the String representation   */  public String toString() {    String result = "";    result += "{";    for (int i=0; i < m_Events.length; i++) {      result += m_Events[i];      if (i+1 < m_Events.length) {	result += ",";      }    }    result += "}";    return result;  }}