horizontalpartitionminingstream.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.Special;

import com.prudsys.pdm.Core.MiningDataSpecification;
import com.prudsys.pdm.Core.MiningException;
import com.prudsys.pdm.Input.MiningInputStream;

/**
 * Partitiones a given mining input stream horizontally
 * into some mining input stream with same meta data
 * and user-defined size.
 *
 * @see MiningInputStream
 */
public class HorizontalPartitionMiningStream extends com.prudsys.pdm.Cwm.Core.Class
{
    // -----------------------------------------------------------------------
    //  Variables declarations
    // -----------------------------------------------------------------------
    /** Number of vectors per partition. */
    private int[] partVectNumb = null;

    // -----------------------------------------------------------------------
    //  Constructor
    // -----------------------------------------------------------------------
    /**
     * Empty constructor.
     */
    public HorizontalPartitionMiningStream() {

    }

    // -----------------------------------------------------------------------
    //  Getter and setter methods
    // -----------------------------------------------------------------------
    /**
     * Returns number of vectors per partition (in same order like
     * new streams in transform method).
     *
     * @return number of vectors per partition, null if equal partitions
     */
    public int[] getPartVectNumb()
    {
      return partVectNumb;
    }

    /**
     * Sets number of vectors per partition (in same order like
     * new streams in transform method).
     *
     * @param partVectNumb array of vector numbers, null for equal partitions
     */
    public void setPartVectNumb(int[] partVectNumb)
    {
      this.partVectNumb = partVectNumb;
    }

    // -----------------------------------------------------------------------
    //  Transformation methods
    // -----------------------------------------------------------------------
  /**
   * Partitions mining input and copies partitions to target streams.
   * The targetStreams must be updatable mining streams.
   *
   * @param sourceStream mining stream used as source to partition
   * @param targetStreams mining streams used as targets of copy
   * @return number of partitions
   * @exception MiningException could not partition stream
   */
  public int transform( MiningInputStream sourceStream, MiningInputStream[] targetStreams )
    throws MiningException {

    int nStreams = targetStreams.length;
    int nVec     = sourceStream.getVectorsNumber();

    // If partition sizes are set, check whether they match with streams:
    if (partVectNumb != null) {
      if (partVectNumb.length != targetStreams.length)
        throw new MiningException("# " + partVectNumb.length +
                                  " partition sizes given, but " +
                                  "# " + targetStreams.length + " partition streams");
      int vectNumb = 0;
      for (int i = 0; i < partVectNumb.length; i++)
        vectNumb = vectNumb + partVectNumb[i];
      if (vectNumb != nVec)
        throw new MiningException("# " + vectNumb +
                                  " total vector number given, but " +
                                  "# " + nVec + " in source stream");
    };

    // Copy metadata:
    MiningDataSpecification metaDataSource = sourceStream.getMetaData();
    for (int i = 0; i < nStreams; i++)
      targetStreams[i].updateSetMetaData( metaDataSource );

    // Partition stream:
    int nPartVec = nVec / nStreams;
    sourceStream.reset();
    for (int i = 0; i < nStreams; i++) {
      targetStreams[i].updateRemoveAllVectors();

      // Vector numbers of next partition:
      int nPart = nPartVec;
      if (partVectNumb == null) {
        if (i == nStreams - 1) nPart = nVec - (nStreams-1)*nPartVec;
      }
      else
        nPart = partVectNumb[i];

      // Add vectors to new stream:
      for (int j = 0; j < nPart; j++) {
        sourceStream.next();
        targetStreams[i].updateAppendVector( sourceStream.read() );
      };
    };

    return nStreams;
  }
}