numerizationnumber.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 com.prudsys.pdm.Core.CategoricalAttribute;
import com.prudsys.pdm.Core.Category;
import com.prudsys.pdm.Core.MiningAttribute;
import com.prudsys.pdm.Core.MiningException;
import com.prudsys.pdm.Core.NumericAttribute;

/**
 * Realization of numerization.
 *
 * Transforms a categorical into a numeric attribute
 * in the following way: The category values are parsed
 * as numeric values. If this is impossible, missing
 * values are used.
 *
 * For advanced transformation from categorical into numeric
 * attributes use CategNumMapping.
 *
 * @see Numerization
 */
public class NumerizationNumber extends Numerization
{
  // -----------------------------------------------------------------------
  //  Variables declarations
  // -----------------------------------------------------------------------
  private CategoricalAttribute sourceAtt = null;

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

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

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

      sourceAtt  = (CategoricalAttribute) getSourceAttribute();
      NumericAttribute transformedAttribute = new NumericAttribute();

      transformedAttribute.setName( getTargetNameDynamic() );
      transformedAttribute.setLowerBound( Double.NEGATIVE_INFINITY );
      transformedAttribute.setUpperBound( Double.POSITIVE_INFINITY );

      return transformedAttribute;
  }

  /**
   * Transforms attribute value. The result is also a value.
   *
   * @param attributeValue value of attribute to be transformed
   * @return transformed (numerized) value
   * @exception MiningException could not transform attribute value
   */
  public double transformAttributeValue( double attributeValue ) throws MiningException
  {
    Category cat = sourceAtt.getCategory(attributeValue);
    if (cat == null)
      return Category.MISSING_VALUE;

    if (cat.getValue() instanceof Double)
      return ((Double) cat.getValue()).doubleValue();
    try {
      attributeValue = Double.parseDouble( cat.getDisplayValue() );
    }
    catch (Exception ex) {
      attributeValue = Category.MISSING_VALUE;
    }

    return attributeValue;
  }

}