categnummapping.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 Rolf Rossius
  * @author Michael Thess
  * @version 1.0
  */
package com.prudsys.pdm.Transform.OneToOne;

import java.util.Enumeration;
import java.util.Hashtable;

import com.prudsys.pdm.Adapters.PmmlVersion20.DerivedField;
import com.prudsys.pdm.Adapters.PmmlVersion20.FieldColumnPair;
import com.prudsys.pdm.Adapters.PmmlVersion20.InlineTable;
import com.prudsys.pdm.Adapters.PmmlVersion20.MapValuesNum;
import com.prudsys.pdm.Adapters.PmmlVersion20.Member;
import com.prudsys.pdm.Adapters.PmmlVersion20.Pargroup;
import com.prudsys.pdm.Adapters.PmmlVersion20.Row;
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;
import com.prudsys.pdm.Transform.OneToOneMapping;

/**
 * Realization of categorical to numerical mapping. In general, not invertable.
 *
 * Transforms a categorical into a numeric attribute
 * by mapping categories onto numeric values. Mapping is given by a table.
 *
 * In the simple case of replacing categories by their keys, the Numerization
 * transformation can be used instead of this class.
 *
 * @see Numerization
 */
public class CategNumMapping extends OneToOneMapping
{
  // -----------------------------------------------------------------------
  //  Variables declarations
  // -----------------------------------------------------------------------
  /** Hashtable containing assignment of source to target values. */
  private Hashtable map = new Hashtable( 100 );

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

  // -----------------------------------------------------------------------
  //  Getter and setter methods
  // -----------------------------------------------------------------------
  /**
   * Returns map. Key is category of source attribute, value double value
   * of target attribute.
   *
   * @return map
   */
  public Hashtable getMap()
  {
    return map;
  }

  /**
   * Sets map. Key is category of source attribute, value double object of
   * target attribute.
   *
   * @param map new map
   */
  public void setMap(Hashtable map)
  {
    this.map = map;
  }

  /**
   * Adds new category-value pair to map.
   *
   * @param source category of source attribute
   * @param target assigned double object of target attribute that will replace source category
   * @exception MiningException thrown if source category already exists
   */
  public void addCategoryPair(Category source, Double target)
    throws MiningException {

    Double val = (Double) map.get(source);
    if (val != null)
      throw new MiningException("Source category already exists in map");

    map.put(source, target);
  }

  // -----------------------------------------------------------------------
  //  Transformation methods
  // -----------------------------------------------------------------------
  /**
   * Transforms the categorical source attribute. The result is the
   * new numeric target attribute where the double values are
   * obtained by the map.
   *
   * @return transformed (mapped) 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");

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

      transformedAttribute.setName( getTargetNameDynamic() );

      return transformedAttribute;
  }

  /**
   * Transforms key of a category of source attribute into the
   * assigned value of the target attribute.
   *
   * @param attributeValue key of category to be mapped
   * @return key of mapped category, missing value if no category for key found
   * @exception MiningException could not transform attribute value
   */
  public double transformAttributeValue( double attributeValue ) throws MiningException
  {
    CategoricalAttribute sourceAttribute  = (CategoricalAttribute) getSourceAttribute();
    Category cat = sourceAttribute.getCategory(attributeValue);
    // attributeValue does not exist in source attribute:
    if (cat == null)
      return Category.MISSING_VALUE;

    // value does not exist in map:
    Double value = (Double) map.get(cat);
    if (value == null)
      return Category.MISSING_VALUE;

    return value.doubleValue();
  }

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

    MapValuesNum mapVal = new MapValuesNum();
    mapVal.setOutputColumn("pargroup");
    FieldColumnPair[] fcp = new FieldColumnPair[1];
    fcp[0] = new FieldColumnPair();
    fcp[0].setField(sourceName);
    fcp[0].setColumn("member");
    mapVal.setFieldColumnPair(fcp);

    InlineTable table = new InlineTable();

    Enumeration keys = map.keys();
    while (keys.hasMoreElements()) {
      Category key = (Category) keys.nextElement();
      Double value = (Double) map.get( key );

      Row row     = new Row();
      Member memb = new Member();
      memb.setName( key.toString() );
      row.setMember( memb );
      Pargroup pgroup = new Pargroup();
      pgroup.setName( value.toString() );
      row.setPargroup( pgroup );
      table.addRow(row);
    };
    mapVal.setInlineTable(table);

    field.setMapValuesNum(mapVal);
    return field;
  }

  /**
   * Creates this object from PMML object DerivedField, subobject MapValuesNum.
   *
   * @param pmml pmml element
   * @exception MiningException cannot parse PMML object
   */
  public void parsePmmlObject(Object pmml) throws MiningException
  {
    super.parsePmmlObject(pmml);

    DerivedField field = (DerivedField) pmml;

    MapValuesNum mv = field.getMapValuesNum();
    FieldColumnPair[] fcp = mv.getFieldColumnPair();
    sourceName       = fcp[0].getField();
    InlineTable it   = mv.getInlineTable();
    Row[] rows       = it.getRow();

    if (rows == null) return;

    // Read inline table and build graph:
    map.clear();
    for (int i = 0; i < rows.length; i++) {
      Member memb     = rows[i].getMember();
      String childval = memb.getName();
      Pargroup pgroup = rows[i].getPargroup();
      String parval   = pgroup.getName();
      Double parent   = new Double(parval);
      Category child  = new Category(childval);
      addCategoryPair(child, parent);
    };
  }
}