stringtonominalfilter.java

一个数据挖掘系统的源码

/**
 *
 *   AgentAcademy - an open source Data Mining framework for
 *   training intelligent agents
 *
 *   Copyright (C)   2001-2003 AA Consortium.
 *
 *   This library is open source software; you can redistribute it
 *   and/or modify it under the terms of the GNU Lesser General
 *   Public License as published by the Free Software Foundation;
 *   either version 2.0 of the License, or (at your option) any later
 *   version.
 *
 *   This library 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 Lesser General Public
 *   License along with this library; if not, write to the Free
 *   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *   MA  02111-1307 USA
 *
 */

package org.agentacademy.modules.dataminer.filters;

/**
 * <p>Title: The Data Miner prototype</p>
 * <p>Description: A prototype for the DataMiner (DM), the Agent Academy (AA) module responsible for performing data mining on the contents of the Agent Use Repository (AUR). The extracted knowledge is to be sent back to the AUR in the form of a PMML document.</p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: CERTH</p>
 * @author asymeon
 * @version 0.3
 */

import java.util.Enumeration;
import java.util.Vector;
import org.agentacademy.modules.dataminer.core.*;
import org.apache.log4j.Logger;
/**
 * Converts a string attribute (i.e. unspecified number of values) to nominal
 * (i.e. set number of values). You should ensure that all string values that
 * will appear are represented in the dataset.<p>
 *
 * Valid filter-specific options are: <p>
 *
 * -C col <br>
 * Index of the attribute to be changed. (default last)<p>
 *
 */
public class StringToNominalFilter extends Filter
  implements OptionHandler {

 public static Logger                log = Logger.getLogger(StringToNominalFilter.class);
  /** The attribute index setting (allows -1 = last). */
  private int m_AttIndexSet = -1;

  /** The attribute index. */
  private int m_AttIndex;

  /**
   * Sets the format of the input instances.
   *
   * @param instanceInfo an Instances object containing the input
   * instance structure (any instances contained in the object are
   * ignored - only the structure is required).
   * @return true if the outputFormat may be collected immediately.
   * @exception UnsupportedAttributeTypeException if the selected attribute
   * a string attribute.
   * @exception Exception if the input format can't be set
   * successfully.
   */
  public boolean setInputFormat(Instances instanceInfo)
       throws Exception {

    super.setInputFormat(instanceInfo);
    m_AttIndex = m_AttIndexSet;
    if (m_AttIndex < 0) {
      m_AttIndex = instanceInfo.numAttributes() - 1;
    }
    if (!instanceInfo.attribute(m_AttIndex).isString()) {
      throw new UnsupportedAttributeTypeException("Chosen attribute is not of type string.");
    }
    return false;
  }

  /**
   * Input an instance for filtering. The instance is processed
   * and made available for output immediately.
   *
   * @param instance the input instance.
   * @return true if the filtered instance may now be
   * collected with output().
   * @exception IllegalStateException if no input structure has been defined.
   */
  public boolean input(Instance instance) {

    if (getInputFormat() == null) {
      throw new IllegalStateException("No input instance format defined");
    }
    if (m_NewBatch) {
      resetQueue();
      m_NewBatch = false;
    }

    if (isOutputFormatDefined()) {
      Instance newInstance = (Instance)instance.copy();
      push(newInstance);
      return true;
    }

    bufferInput(instance);
    return false;
  }


  /**
   * Signifies that this batch of input to the filter is finished. If the
   * filter requires all instances prior to filtering, output() may now
   * be called to retrieve the filtered instances.
   *
   * @return true if there are instances pending output.
   * @exception IllegalStateException if no input structure has been defined.
   */
  public boolean batchFinished() throws Exception{

    if (getInputFormat() == null) {
      throw new IllegalStateException("No input instance format defined");
    }
    if (!isOutputFormatDefined()) {

      setOutputFormat();

      // Convert pending input instances
      for(int i = 0; i < getInputFormat().numInstances(); i++) {
	push((Instance) getInputFormat().instance(i).copy());
      }
    }

    flushInput();
    m_NewBatch = true;
    return (numPendingOutput() != 0);
  }


  /**
   * Returns an enumeration describing the available options.
   *
   * @return an enumeration of all the available options.
   */
  public Enumeration listOptions() {

    Vector newVector = new Vector(1);

    newVector.addElement(new Option(
              "\tSets the attribute index (default last).",
              "C", 1, "-C <col>"));

    return newVector.elements();
  }


  /**
   * Parses the options for this object. Valid options are: <p>
   *
   * -C col <br>
   * The column containing the values to be merged. (default last)<p>
   *
   * @param options the list of options as an array of strings
   * @exception Exception if an option is not supported
   */
  public void setOptions(String[] options) throws Exception {

    String attributeIndex = Utils.getOption('C', options);
    if (attributeIndex.length() != 0) {
      if (attributeIndex.toLowerCase().equals("last")) {
	setAttributeIndex(-1);
      } else if (attributeIndex.toLowerCase().equals("first")) {
	setAttributeIndex(0);
      } else {
	setAttributeIndex(Integer.parseInt(attributeIndex) - 1);
      }
    } else {
      setAttributeIndex(-1);
    }

    if (getInputFormat() != null) {
      setInputFormat(getInputFormat());
    }
  }

  /**
   * Gets the current settings of the filter.
   *
   * @return an array of strings suitable for passing to setOptions
   */
  public String [] getOptions() {

    String [] options = new String [6];
    int current = 0;

    options[current++] = "-C";
    options[current++] = "" + (getAttributeIndex() + 1);

    while (current < options.length) {
      options[current++] = "";
    }
    return options;
  }

  /**
   * Get the index of the attribute used.
   *
   * @return the index of the attribute
   */
  public int getAttributeIndex() {

    return m_AttIndexSet;
  }

  /**
   * Sets index of the attribute used.
   *
   * @param index the index of the attribute
   */
  public void setAttributeIndex(int attIndex) {

    m_AttIndexSet = attIndex;
  }

  /**
   * Set the output format. Takes the current average class values
   * and m_InputFormat and calls setOutputFormat(Instances)
   * appropriately.
   */
  private void setOutputFormat() throws Exception{

    Instances newData;
    FastVector newAtts, newVals;

    // Compute new attributes

    newAtts = new FastVector(getInputFormat().numAttributes());
    for (int j = 0; j < getInputFormat().numAttributes(); j++) {
      Attribute att = getInputFormat().attribute(j);
      if (j != m_AttIndex) {

	// We don't have to copy the attribute because the
	// attribute index remains unchanged.
	newAtts.addElement(att);
      } else {

	// Compute list of attribute values
	newVals = new FastVector(att.numValues());
	for (int i = 0; i < att.numValues(); i++) {
          newVals.addElement(att.value(i));
	}
	newAtts.addElement(new Attribute(att.name(), newVals));
      }
    }

    // Construct new header
    newData = new Instances(getInputFormat().relationName(), newAtts, 0);
    newData.setClassIndex(getInputFormat().classIndex());
    setOutputFormat(newData);
  }

  /**
   * Main method for testing this class.
   *
   * @param argv should contain arguments to the filter:
   * use -h for help
   */
  public static void main(String [] argv) {

    try {
      if (Utils.getFlag('b', argv)) {
 	Filter.batchFilterFile(new StringToNominalFilter(), argv);
      } else {
	Filter.filterFile(new StringToNominalFilter(), argv);
      }
    } catch (Exception ex) {
      log.error(ex.getMessage());
    }
  }
}