/*
* 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.
*/
/*
* PotentialClassIgnorer.java
* Copyright (C) 2003 University of Waikato, Hamilton, New Zealand
*
*/
package weka.filters.unsupervised.attribute;
import weka.core.Instances;
import weka.core.Option;
import weka.core.OptionHandler;
import weka.core.Utils;
import weka.filters.Filter;
import java.util.Enumeration;
import java.util.Vector;
/**
* This filter should be extended by other unsupervised attribute
* filters to allow processing of the class attribute if that's
* required. It the class is to be ignored it is essential that the
* extending filter does not change the position (i.e. index) of the
* attribute that is originally the class attribute !
*
* @author Eibe Frank (eibe@cs.waikato.ac.nz), Mark Hall (mhall@cs.waikato.ac.nz)
* @version $Revision: 1.7 $
*/
public abstract class PotentialClassIgnorer
extends Filter
implements OptionHandler {
/** for serialization */
private static final long serialVersionUID = 8625371119276845454L;
/** True if the class is to be unset */
protected boolean m_IgnoreClass = false;
/** Storing the class index */
protected int m_ClassIndex = -1;
/**
* Returns an enumeration describing the available options.
*
* @return an enumeration of all the available options.
*/
public Enumeration listOptions() {
Vector result = new Vector();
result.addElement(new Option(
"\tUnsets the class index temporarily before the filter is\n"
+ "\tapplied to the data.\n"
+ "\t(default: no)",
"unset-class-temporarily", 1, "-unset-class-temporarily"));
return result.elements();
}
/**
* Parses a list of options for this object.
*
* @param options the list of options as an array of strings
* @throws Exception if an option is not supported
*/
public void setOptions(String[] options) throws Exception {
setIgnoreClass(Utils.getFlag("unset-class-temporarily", options));
}
/**
* Gets the current settings of the filter.
*
* @return an array of strings suitable for passing to setOptions
*/
public String[] getOptions() {
Vector result;
result = new Vector();
if (getIgnoreClass())
result.add("-unset-class-temporarily");
return (String[]) result.toArray(new String[result.size()]);
}
/**
* Sets the format of the input instances. If the filter is able to
* determine the output format before seeing any input instances, it
* does so here. This default implementation clears the output format
* and output queue, and the new batch flag is set. Overriders should
* call <code>super.setInputFormat(Instances)</code>
*
* @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
* @throws Exception if the inputFormat can't be set successfully
*/
public boolean setInputFormat(Instances instanceInfo) throws Exception {
boolean result = super.setInputFormat(instanceInfo);
if (m_IgnoreClass) {
m_ClassIndex = inputFormatPeek().classIndex();
inputFormatPeek().setClassIndex(-1);
}
return result;
}
/**
* Gets the format of the output instances. This should only be called
* after input() or batchFinished() has returned true. The relation
* name of the output instances should be changed to reflect the
* action of the filter (eg: add the filter name and options).
*
* @return an Instances object containing the output instance
* structure only.
* @throws NullPointerException if no input structure has been
* defined (or the output format hasn't been determined yet)
*/
public Instances getOutputFormat() {
if (m_IgnoreClass) {
outputFormatPeek().setClassIndex(m_ClassIndex);
}
return super.getOutputFormat();
}
/**
* Returns the tip text for this property
*
* @return tip text for this property suitable for
* displaying in the explorer/experimenter gui
*/
public String ignoreClassTipText() {
return "The class index will be unset temporarily before the filter is applied.";
}
/**
* Set the IgnoreClass value. Set this to true if the
* class index is to be unset before the filter is applied.
*
* @param newIgnoreClass The new IgnoreClass value.
*/
public void setIgnoreClass(boolean newIgnoreClass) {
m_IgnoreClass = newIgnoreClass;
}
/**
* Gets the IgnoreClass value. If this to true then the
* class index is to unset before the filter is applied.
*
* @return the current IgnoreClass value.
*/
public boolean getIgnoreClass() {
return m_IgnoreClass;
}
}