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• BallTreeConstructor.java

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weka.core.neighboursearch.balltrees.BallTreeConstructor Maven / Gradle / Ivy

/*
 *   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 .
 */

/*
 * BallTreeConstructor.java
 * Copyright (C) 2007-2012 University of Waikato, Hamilton, New Zealand
 */

package weka.core.neighboursearch.balltrees;

import java.io.Serializable;
import java.util.Enumeration;
import java.util.Vector;

import weka.core.DistanceFunction;
import weka.core.EuclideanDistance;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.Option;
import weka.core.OptionHandler;
import weka.core.RevisionHandler;
import weka.core.RevisionUtils;
import weka.core.Utils;

/**
 * Abstract class for constructing a BallTree .
 * 
 * @author Ashraf M. Kibriya (amk14[at-the-rate]cs[dot]waikato[dot]ac[dot]nz)
 * @version $Revision: 10203 $
 */
public abstract class BallTreeConstructor implements OptionHandler,
  Serializable, RevisionHandler {

  /** ID to avoid warning */
  private static final long serialVersionUID = 982315539809240771L;

  /** The maximum number of instances allowed in a leaf. */
  protected int m_MaxInstancesInLeaf = 40;

  /**
   * The maximum relative radius of a leaf node (relative to the smallest ball
   * enclosing all the data (training) points).
   */
  protected double m_MaxRelLeafRadius = 0.001;

  /**
   * Should a parent ball completely enclose the balls of its two children, or
   * only the points inside its children.
   */
  protected boolean m_FullyContainChildBalls = false;

  /** The instances on which to build the tree. */
  protected Instances m_Instances;

  /** The distance function to use to build the tree. */
  protected DistanceFunction m_DistanceFunction;

  /**
   * The number of internal and leaf nodes in the built tree.
   */
  protected int m_NumNodes;

  /** The number of leaf nodes in the built tree. */
  protected int m_NumLeaves;

  /** The depth of the built tree. */
  protected int m_MaxDepth;

  /** The master index array. */
  protected int[] m_InstList;

  /**
   * Creates a new instance of BallTreeConstructor.
   */
  public BallTreeConstructor() {
  }

  /**
   * Builds the ball tree.
   * 
   * @return The root node of the tree.
   * @throws Exception If there is problem building the tree.
   */
  public abstract BallNode buildTree() throws Exception;

  /**
   * Adds an instance to the ball tree.
   * 
   * @param node The root node of the tree.
   * @param inst The instance to add to the tree.
   * @return The new master index array after adding the instance.
   * @throws Exception If there is some problem adding the given instance to the
   *           tree.
   */
  public abstract int[] addInstance(BallNode node, Instance inst)
    throws Exception;

  /**
   * Returns the tip text for this property.
   * 
   * @return tip text for this property suitable for displaying in the
   *         explorer/experimenter gui.
   */
  public String maxInstancesInLeafTipText() {
    return "The maximum number of instances allowed in a leaf.";
  }

  /**
   * Returns the maximum number of instances allowed in a leaf.
   * 
   * @return The maximum number of instances allowed in a leaf.
   */
  public int getMaxInstancesInLeaf() {
    return m_MaxInstancesInLeaf;
  }

  /**
   * Sets the maximum number of instances allowed in a leaf.
   * 
   * @param num The maximum number of instances allowed in a leaf.
   * @throws Exception If the num is < 1.
   */
  public void setMaxInstancesInLeaf(int num) throws Exception {
    if (num < 1) {
      throw new Exception("The maximum number of instances in a leaf must "
        + "be >=1.");
    }
    m_MaxInstancesInLeaf = num;
  }

  /**
   * Returns the tip text for this property.
   * 
   * @return tip text for this property suitable for displaying in the
   *         explorer/experimenter gui.
   */
  public String maxRelativeLeafRadiusTipText() {
    return "The maximum relative radius allowed for a leaf node. "
      + "Itis relative to the radius of the smallest ball "
      + "enclosing all the data points (that were used to "
      + "build the tree). This smallest ball would be the "
      + "same as the root node's ball, if ContainChildBalls "
      + "property is set to false (default).";
  }

  /**
   * Returns the maximum relative radius of a leaf node. It is relative to the
   * radius of the smallest ball enclosing all the data points (that were used
   * to build the tree). This smallest ball would be the same as the root node's
   * ball, if ContainChildBalls property is set to false (default).
   * 
   * @return The maximum relative radius allowed for a leaf.
   */
  public double getMaxRelativeLeafRadius() {
    return m_MaxRelLeafRadius;
  }

  /**
   * Sets the maximum relative radius, allowed for a leaf node. The radius is
   * relative to the radius of the smallest ball enclosing all the data points
   * (that were used to build the tree). This smallest ball would be the same as
   * the root node's ball, if ContainChildBalls property is set to false
   * (default).
   * 
   * @param radius The maximum relative radius allowed for a leaf.
   * @throws Exception If radius is < 0.0.
   */
  public void setMaxRelativeLeafRadius(double radius) throws Exception {
    if (radius < 0.0) {
      throw new Exception("The radius for the leaves should be >= 0.0");
    }
    m_MaxRelLeafRadius = radius;
  }

  /**
   * Returns the tip text for this property.
   * 
   * @return tip text for this property suitable for displaying in the
   *         explorer/experimenter gui.
   */
  public String containChildBallsTipText() {
    return "Whether to contain fully the child balls.";
  }

  /**
   * Gets whether if a parent ball should completely enclose its two child
   * balls.
   * 
   * @return true if parent ball is to enclose its child balls.
   */
  public boolean getContainChildBalls() {
    return m_FullyContainChildBalls;
  }

  /**
   * Sets whether if a parent ball should completely enclose its two child
   * balls.
   * 
   * @param containChildBalls Should be tree if parent ball is to enclose its
   *          child balls.
   */
  public void setContainChildBalls(boolean containChildBalls) {
    m_FullyContainChildBalls = containChildBalls;
  }

  /**
   * Sets the instances on which the tree is to be built.
   * 
   * @param inst The instances on which to build the ball tree.
   */
  public void setInstances(Instances inst) {
    m_Instances = inst;
  }

  /**
   * Sets the master index array that points to instances in m_Instances, so
   * that only this array is manipulated, and m_Instances is left untouched.
   * 
   * @param instList The master index array.
   */
  public void setInstanceList(int[] instList) {
    m_InstList = instList;
  }

  /**
   * Sets the distance function to use to build the tree.
   * 
   * @param func The distance function.
   */
  public void setEuclideanDistanceFunction(EuclideanDistance func) {
    m_DistanceFunction = func;
  }

  /**
   * Returns the number of nodes (internal + leaf) in the built tree.
   * 
   * @return The number of nodes in the tree.
   */
  public int getNumNodes() {
    return m_NumNodes;
  }

  /**
   * Returns the number of leaves in the built tree.
   * 
   * @return The number of leaves in the tree.
   */
  public int getNumLeaves() {
    return m_NumLeaves;
  }

  /**
   * Returns the depth of the built tree.
   * 
   * @return The depth of the tree.
   */
  public int getMaxDepth() {
    return m_MaxDepth;
  }

  /**
   * Returns an enumeration describing the available options.
   * 
   * @return an enumeration of all the available options.
   */
  @Override
  public Enumeration listOptions() {
    Vector newVector = new Vector();

    newVector.addElement(new Option(
      "\tSet maximum number of instances in a leaf node\n" + "\t(default: 40)",
      "N", 0, "-N "));

    newVector.addElement(new Option(
      "\tSet internal nodes' radius to the sum \n"
        + "\tof the child balls radii. So that it \n"
        + "contains the child balls.", "R", 0, "-R"));

    return newVector.elements();
  }

  /**
   * Parses a given list of options.
   * 
   * @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 optionString = Utils.getOption('N', options);
    if (optionString.length() != 0) {
      setMaxInstancesInLeaf(Integer.parseInt(optionString));
    } else {
      setMaxInstancesInLeaf(40);
    }

    setContainChildBalls(Utils.getFlag('R', options));
  }

  /**
   * Gets the current settings.
   * 
   * @return an array of strings suitable for passing to setOptions
   */
  @Override
  public String[] getOptions() {
    Vector result = new Vector();

    result.add("-N");
    result.add("" + getMaxInstancesInLeaf());

    if (getContainChildBalls()) {
      result.add("-R");
    }

    return result.toArray(new String[result.size()]);
  }

  /**
   * Returns the revision string.
   * 
   * @return the revision
   */
  @Override
  public String getRevision() {
    return RevisionUtils.extract("$Revision: 10203 $");
  }
}