discretization.java

一个数据挖掘软件ALPHAMINERR的整个过程的JAVA版源代码

/*
 *    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.
 */

 /**
  * Title: XELOPES Data Mining Library
  * Description: The XELOPES library is an open platform-independent and data-source-independent library for Embedded Data Mining.
  * Copyright: Copyright (c) 2002 Prudential Systems Software GmbH
  * Company: ZSoft (www.zsoft.ru), Prudsys (www.prudsys.com)
  * @author Michael Thess
  * @version 1.0
  */
package com.prudsys.pdm.Transform.OneToOne;


import java.util.ArrayList;

import com.prudsys.pdm.Adapters.PmmlVersion20.DerivedField;
import com.prudsys.pdm.Adapters.PmmlVersion20.Discretize;
import com.prudsys.pdm.Adapters.PmmlVersion20.DiscretizeBin;
import com.prudsys.pdm.Core.Category;
import com.prudsys.pdm.Core.MiningAttribute;
import com.prudsys.pdm.Core.MiningException;
import com.prudsys.pdm.Core.NumericAttribute;
import com.prudsys.pdm.Core.OrdinalAttribute;
import com.prudsys.pdm.Transform.OneToOneMapping;

import eti.bi.util.NumberFormatter;

/**
 * Realization of discretization. Not invertable.
 *
 * Transforms numeric into categorical attribute.
 * Assignment to categories is defined through
 * discretization intervals. The intervals are given
 * by an array of bounds.
 */
public class Discretization extends OneToOneMapping
{
  // -----------------------------------------------------------------------
  //  Variables declarations
  // -----------------------------------------------------------------------
  /** Array of bounds formining the discretization intervalls. */
  private double[] bounds = null;

  // -----------------------------------------------------------------------
  //  Constructor
  // -----------------------------------------------------------------------
  /**
   * Empty constructor.
   */
  public Discretization()
  {
  }

  // -----------------------------------------------------------------------
  //  Getter and setter methods
  // -----------------------------------------------------------------------
  /**
   * Returns array of interval bounds.
   *
   * @return array of interval bounds
   */
  public double[] getBounds()
  {
    return bounds;
  }

  /**
   * Sets array of interval bounds.
   *
   * @param bounds new array of interval bounds
   */
  public void setBounds(double[] bounds)
  {
    this.bounds = bounds;
  }

  // -----------------------------------------------------------------------
  //  Transformation methods
  // -----------------------------------------------------------------------
  /**
   * Transforms the numeric source attribute. The result is the
   * ordinal target attribute.
   *
   * @return transformed (discretized) attribute
   * @exception MiningException could not transform attribute
   */
  public MiningAttribute transformAttribute() throws MiningException
  {
  		NumberFormatter numberFormatter = new NumberFormatter();
      if (getSourceAttribute() == null)
        throw new MiningException("Could not find source attribute: " + sourceName);

      if (! (getSourceAttribute() instanceof NumericAttribute))
        throw new MiningException("Source attribute '" + sourceName + "' must be numeric");

      NumericAttribute sourceAttribute      = (NumericAttribute) getSourceAttribute();
      OrdinalAttribute transformedAttribute = new OrdinalAttribute();

      transformedAttribute.setName( getTargetNameDynamic() );
      transformedAttribute.setCyclic( sourceAttribute.isCyclic() );

      if (bounds != null && bounds.length >= 0) {
        ArrayList categs = new ArrayList();

        int nInts = bounds.length + 1;
        // 1 Interval:
        if (nInts == 1) {
          String catName = "(" + String.valueOf( Double.NEGATIVE_INFINITY ) + "," + String.valueOf(Double.POSITIVE_INFINITY) + ")";
          Category cat = new Category(catName);
          categs.add(cat);
        }
        else {
          String catName = "(" + String.valueOf( Double.NEGATIVE_INFINITY ) + "," + NumberFormatter.format(bounds[0]) + "]";
          Category cat = new Category(catName);
          categs.add(cat);
          for (int i = 1; i <= nInts-2; i++) {
            catName = "(" + NumberFormatter.format(bounds[i-1]) + "," + NumberFormatter.format(bounds[i]) + "]";
            cat = new Category(catName);
            categs.add(cat);
          };
          catName = "(" + NumberFormatter.format(bounds[nInts-2]) + "," + String.valueOf(Double.POSITIVE_INFINITY) + ")";
          cat = new Category(catName);
          categs.add(cat);
        };
        try {
          transformedAttribute.setValues(categs);
        }
        catch (Exception ex) {};
      };

      return transformedAttribute;
  }

  /**
   * Transforms attribute value. The result is also a value.
   *
   * @param attributeValue value of attribute to be transformed
   * @return transformed (discterized) value
   * @exception MiningException could not transform attribute value
   */
  public double transformAttributeValue( double attributeValue ) throws MiningException
  {
    // Missing value:
    if (Category.isMissingValue(attributeValue))
      return attributeValue;

    // Special cases:
    if (bounds == null || bounds.length == 0)
      return 0;
    if (bounds.length == 1) {
      if (attributeValue <= bounds[0])
        return 0;
      else
        return 1;
    };

    // Search index:
    if (attributeValue <= bounds[0])
      return 0;
    for (int i = 1; i < bounds.length; i++) {
      if (attributeValue <= bounds[i] && attributeValue > bounds[i-1])
        return i;
    };

    return bounds.length;
  }

  // -----------------------------------------------------------------------
  //  Methods of PMML handling
  // -----------------------------------------------------------------------
  /**
   * Creates PMML object DerivedField of this object of Discretize type.
   *
   * @return DerivedField element
   * @exception MiningException cannot create PMML object
   */
  public Object createPmmlObject() throws MiningException
  {
    DerivedField field = (DerivedField) super.createPmmlObject();

    Discretize discretize = new Discretize();
    discretize.setField( sourceName );

    int nInts = bounds.length + 1;
    DiscretizeBin[] discBin = new DiscretizeBin[nInts];
    // 1 Interval:
    if (nInts == 1) {
      com.prudsys.pdm.Core.Interval interval = new com.prudsys.pdm.Core.Interval();
      interval.setClosure( com.prudsys.pdm.Core.Interval.OPEN_OPEN );
      interval.setLowerBound( Double.NEGATIVE_INFINITY );
      interval.setUpperBound( Double.POSITIVE_INFINITY );

      discBin[0] = new DiscretizeBin();
      discBin[0].setBinValue( interval.toString() );
      discBin[0].setInterval( (com.prudsys.pdm.Adapters.PmmlVersion20.Interval) interval.createPmmlObject());
    }
    else {
      com.prudsys.pdm.Core.Interval interval = new com.prudsys.pdm.Core.Interval();
      interval.setClosure( com.prudsys.pdm.Core.Interval.OPEN_CLOSED );
      interval.setLowerBound( Double.NEGATIVE_INFINITY );
      interval.setUpperBound( bounds[0] );
      discBin[0] = new DiscretizeBin();
      discBin[0].setBinValue( interval.toString() );
      discBin[0].setInterval( (com.prudsys.pdm.Adapters.PmmlVersion20.Interval) interval.createPmmlObject());
      for (int i = 1; i <= nInts-2; i++) {
        interval = new com.prudsys.pdm.Core.Interval();
        interval.setClosure( com.prudsys.pdm.Core.Interval.OPEN_CLOSED );
        interval.setLowerBound( bounds[i-1] );
        interval.setUpperBound( bounds[i] );
        discBin[i] = new DiscretizeBin();
        discBin[i].setBinValue( interval.toString() );
        discBin[i].setInterval( (com.prudsys.pdm.Adapters.PmmlVersion20.Interval) interval.createPmmlObject());
      };
      interval = new com.prudsys.pdm.Core.Interval();
      interval.setClosure( com.prudsys.pdm.Core.Interval.OPEN_OPEN );
      interval.setLowerBound( bounds[nInts-2] );
      interval.setUpperBound( Double.POSITIVE_INFINITY );
      discBin[nInts-1] = new DiscretizeBin();
      discBin[nInts-1].setBinValue( interval.toString() );
      discBin[nInts-1].setInterval( (com.prudsys.pdm.Adapters.PmmlVersion20.Interval) interval.createPmmlObject());
    };

    discretize.setDiscretizeBin(discBin);
    field.setDiscretize(discretize);

    return field;
  }

  /**
   * Creates this object from PMML object DerivedField, subobject Discretize.
   *
   * @param pmml pmml element
   * @exception MiningException always thrown
   */
  public void parsePmmlObject(Object pmml) throws MiningException
  {
    super.parsePmmlObject(pmml);

    DerivedField field = (DerivedField) pmml;

    Discretize disc = field.getDiscretize();
    sourceName = disc.getField();

    DiscretizeBin[] discBin = disc.getDiscretizeBin();
    int nInts = discBin.length;
    bounds = new double[nInts-1];
    for (int i = 1; i < nInts; i++) {
      com.prudsys.pdm.Adapters.PmmlVersion20.Interval interval = discBin[i].getInterval();
      String lm = interval.getLeftMargin();
      bounds[i-1] = Double.parseDouble(lm);
    }
  }
}