logarithmic.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.Adapters.PmmlVersion20.DerivedField;
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.Transform.OneToOneMapping;

/**
 * Realization of Logarithmic transformation. Inverse of Exponential transformation.
 *
 * Missing values are transformed into missing values.
 */
public class Logarithmic extends OneToOneMapping
{
  // -----------------------------------------------------------------------
  //  Constructor
  // -----------------------------------------------------------------------
  /**
   * Empty constructor.
   */
  public Logarithmic()
  {
  }

  // -----------------------------------------------------------------------
  //  Transformation methods
  // -----------------------------------------------------------------------
  /**
   * Transforms the source attribute. The result is the target attribute.
   *
   * @return transformed (Logarithmic) 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 NumericAttribute))
        throw new MiningException("Source attribute '" + sourceName + "' must be numeric");

      NumericAttribute sourceAttribute      = (NumericAttribute) getSourceAttribute();
      NumericAttribute transformedAttribute = (NumericAttribute) sourceAttribute.clone();

      transformedAttribute.setName( getTargetNameDynamic() );

      // Set new bounds:
      double lb = sourceAttribute.getLowerBound();
      double ub = sourceAttribute.getUpperBound();
      double tt = lb;
      if (lb > 0.0) {
        lb = Math.log(lb);
        ub = Math.log(ub);
      }
      else {
        lb = Double.NEGATIVE_INFINITY;
        if (ub >= 0.0)
          ub = Math.log(ub);
        else
          ub = Double.NEGATIVE_INFINITY;
      };
      transformedAttribute.setLowerBound( lb );
      transformedAttribute.setUpperBound( ub );

      return transformedAttribute;
  }

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

      // Transformation:
      double transformedValue = Math.log( attributeValue );

      return transformedValue;
  }

  // -----------------------------------------------------------------------
  //  Methods of PMML handling
  // -----------------------------------------------------------------------
  /**
   * Creates PMML object DerivedField of this object of logarithmic type.
   *
   * @return DerivedField element
   * @see com.prudsys.pdm.Adapters.PmmlVersion20.Logarithmic
   * @exception MiningException could not create PMML object
   */
  public Object createPmmlObject() throws MiningException
  {
      DerivedField field = (DerivedField) super.createPmmlObject();

      com.prudsys.pdm.Adapters.PmmlVersion20.Logarithmic logarithmic = new com.prudsys.pdm.Adapters.PmmlVersion20.Logarithmic();
      logarithmic.setField( sourceName );

      field.setLogarithmic( logarithmic );
      return field;
  }

  /**
   * Creates this object from PMML object DerivedField, subobject Logarithmic.
   *
   * @param pmml DerivedField element
   * @see com.prudsys.pdm.Adapters.PmmlVersion20.Logarithmic
   * @exception MiningException could not parse PMML object
   */
  public void parsePmmlObject(Object pmml) throws MiningException
  {
      super.parsePmmlObject(pmml);

      DerivedField field = (DerivedField) pmml;

      com.prudsys.pdm.Adapters.PmmlVersion20.Logarithmic log = field.getLogarithmic();
      sourceName = log.getField();
  }
}