nbtreeclassifiertree.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.operator.learner.decisiontree.y45.j48;

import weka.core.*;
import weka.classifiers.*;
import java.io.*;

/**
 * Class for handling a naive bayes tree structure used for
 * classification.
 *
 * @author Mark Hall ([e-mail])
 * @version $Revision: 1.1 $
 */ 

public class NBTreeClassifierTree extends ClassifierTree {

  public NBTreeClassifierTree(ModelSelection toSelectLocModel) {
    super(toSelectLocModel);
  }

  /**
   * Method for building a naive bayes classifier tree
   *
   * @exception Exception if something goes wrong
   */
  public void buildClassifier(Instances data) throws Exception {

   if (data.classAttribute().isNumeric())
     throw new UnsupportedClassTypeException("Class is numeric!");
   if (data.checkForStringAttributes()) {
     throw new UnsupportedAttributeTypeException("Cannot handle string attributes!");
   }
   data = new Instances(data);
   data.deleteWithMissingClass();
   buildTree(data, false);
   cleanup(new Instances(data, 0));
   assignIDs(-1);
  }

  /**
   * Assigns a uniqe id to every node in the tree.
   *
  public int assignIDs(int lastID) {

    int currLastID = lastID + 1;

    m_id = currLastID;
    if (m_sons != null) {
      for (int i = 0; i < m_sons.length; i++) {
	currLastID = m_sons[i].assignIDs(currLastID);
      }
    }
    return currLastID;
    } */

  /**
   * Returns a newly created tree.
   *
   * @param data the training data
   * @exception Exception if something goes wrong
   */
  protected ClassifierTree getNewTree(Instances data) throws Exception {
	 
    ClassifierTree newTree = new NBTreeClassifierTree(m_toSelectModel);
    newTree.buildTree(data, false);
    
    return newTree;
  }

  /**
   * Returns a newly created tree.
   *
   * @param data the training data
   * @param test the pruning data.
   * @exception Exception if something goes wrong
   */
  protected ClassifierTree getNewTree(Instances train, Instances test) 
       throws Exception {
	 
    ClassifierTree newTree = new NBTreeClassifierTree(m_toSelectModel);
    newTree.buildTree(train, test, false);
    
    return newTree;
  }

  /**
   * Print the models at the leaves
   *
   * @return textual description of the leaf models
   */
  public String printLeafModels() {
    StringBuffer text = new StringBuffer();

    if (m_isLeaf) {
      text.append("\nLeaf number: " + m_id+" ");
      text.append(m_localModel.toString());
      text.append("\n");
    } else {
       for (int i=0;i<m_sons.length;i++) {
	 text.append(((NBTreeClassifierTree)m_sons[i]).printLeafModels());
       }
    } 
    return text.toString();
  }

  /**
   * Prints tree structure.
   */
  public String toString() {

    try {
      StringBuffer text = new StringBuffer();
      
      if (m_isLeaf) {
	text.append(": NB");
	text.append(m_id);
      }else
	dumpTreeNB(0,text);

      text.append("\n"+printLeafModels());
      text.append("\n\nNumber of Leaves  : \t"+numLeaves()+"\n");
      text.append("\nSize of the tree : \t"+numNodes()+"\n");
 
      return text.toString();
    } catch (Exception e) {
      e.printStackTrace();
      return "Can't print nb tree.";
    }
  }

  /**
   * Help method for printing tree structure.
   *
   * @exception Exception if something goes wrong
   */
  private void dumpTreeNB(int depth,StringBuffer text) 
       throws Exception {
    
    int i,j;
    
    for (i=0;i<m_sons.length;i++) {
      text.append("\n");;
      for (j=0;j<depth;j++)
	text.append("|   ");
      text.append(m_localModel.leftSide(m_train));
      text.append(m_localModel.rightSide(i, m_train));
      if (m_sons[i].m_isLeaf) {
	text.append(": NB ");
	text.append(m_sons[i].m_id);
      }else
	((NBTreeClassifierTree)m_sons[i]).dumpTreeNB(depth+1,text);
    }
  }

  /**
   * Returns graph describing the tree.
   *
   * @exception Exception if something goes wrong
   */
  public String graph() throws Exception {

    StringBuffer text = new StringBuffer();

    text.append("digraph J48Tree {\n");
    if (m_isLeaf) {
      text.append("N" + m_id 
		  + " [label=\"" + 
		  "NB model" + "\" " + 
		  "shape=box style=filled ");
      if (m_train != null && m_train.numInstances() > 0) {
	text.append("data =\n" + m_train + "\n");
	text.append(",\n");

      }
      text.append("]\n");
    }else {
      text.append("N" + m_id 
		  + " [label=\"" + 
		  m_localModel.leftSide(m_train) + "\" ");
      if (m_train != null && m_train.numInstances() > 0) {
	text.append("data =\n" + m_train + "\n");
	text.append(",\n");
     }
      text.append("]\n");
      graphTree(text);
    }
    
    return text.toString() +"}\n";
  }

  /**
   * Help method for printing tree structure as a graph.
   *
   * @exception Exception if something goes wrong
   */
  private void graphTree(StringBuffer text) throws Exception {
    
    for (int i = 0; i < m_sons.length; i++) {
      text.append("N" + m_id  
		  + "->" + 
		  "N" + m_sons[i].m_id +
		  " [label=\"" + m_localModel.rightSide(i,m_train).trim() + 
		  "\"]\n");
      if (m_sons[i].m_isLeaf) {
	text.append("N" + m_sons[i].m_id +
		    " [label=\""+"NB Model"+"\" "+ 
		    "shape=box style=filled ");
	if (m_train != null && m_train.numInstances() > 0) {
	  text.append("data =\n" + m_sons[i].m_train + "\n");
	  text.append(",\n");
	}
	text.append("]\n");
      } else {
	text.append("N" + m_sons[i].m_id +
		    " [label=\""+m_sons[i].m_localModel.leftSide(m_train) + 
		    "\" ");
	if (m_train != null && m_train.numInstances() > 0) {
	  text.append("data =\n" + m_sons[i].m_train + "\n");
	  text.append(",\n");
	}
	text.append("]\n");
	((NBTreeClassifierTree)m_sons[i]).graphTree(text);
      }
    }
  }
}