/*
* 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.
*/
/*
* MergeTwoValues.java
* Copyright (C) 1999 University of Waikato, Hamilton, New Zealand
*
*/
package weka.filters.unsupervised.attribute;
import weka.core.Attribute;
import weka.core.Capabilities;
import weka.core.FastVector;
import weka.core.Instance;
import weka.core.DenseInstance;
import weka.core.Instances;
import weka.core.Option;
import weka.core.OptionHandler;
import weka.core.RevisionUtils;
import weka.core.SingleIndex;
import weka.core.UnsupportedAttributeTypeException;
import weka.core.Utils;
import weka.core.WekaException;
import weka.core.Capabilities.Capability;
import weka.filters.Filter;
import weka.filters.StreamableFilter;
import weka.filters.UnsupervisedFilter;
import java.util.Enumeration;
import java.util.Vector;
/**
<!-- globalinfo-start -->
* Merges two values of a nominal attribute into one value.
* <p/>
<!-- globalinfo-end -->
*
<!-- options-start -->
* Valid options are: <p/>
*
* <pre> -C <col>
* Sets the attribute index (default last).</pre>
*
* <pre> -F <value index>
* Sets the first value's index (default first).</pre>
*
* <pre> -S <value index>
* Sets the second value's index (default last).</pre>
*
<!-- options-end -->
*
* @author Eibe Frank (eibe@cs.waikato.ac.nz)
* @version $Revision: 5987 $
*/
public class MergeTwoValues
extends Filter
implements UnsupervisedFilter, StreamableFilter, OptionHandler {
/** for serialization */
static final long serialVersionUID = 2925048980504034018L;
/** The attribute's index setting. */
private SingleIndex m_AttIndex = new SingleIndex("last");
/** The first value's index setting. */
private SingleIndex m_FirstIndex = new SingleIndex("first");
/** The second value's index setting. */
private SingleIndex m_SecondIndex = new SingleIndex("last");
/**
* Returns a string describing this filter
*
* @return a description of the filter suitable for
* displaying in the explorer/experimenter gui
*/
public String globalInfo() {
return "Merges two values of a nominal attribute into one value.";
}
/**
* Returns the Capabilities of this filter.
*
* @return the capabilities of this object
* @see Capabilities
*/
public Capabilities getCapabilities() {
Capabilities result = super.getCapabilities();
result.disableAll();
// attributes
result.enableAllAttributes();
result.enable(Capability.MISSING_VALUES);
// class
result.enableAllClasses();
result.enable(Capability.MISSING_CLASS_VALUES);
result.enable(Capability.NO_CLASS);
return result;
}
/**
* 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
* @throws Exception if the input format can't be set
* successfully
*/
public boolean setInputFormat(Instances instanceInfo)
throws Exception {
super.setInputFormat(instanceInfo);
m_AttIndex.setUpper(instanceInfo.numAttributes() - 1);
m_FirstIndex.setUpper(instanceInfo.
attribute(m_AttIndex.getIndex()).numValues() - 1);
m_SecondIndex.setUpper(instanceInfo.
attribute(m_AttIndex.getIndex()).numValues() - 1);
if ((instanceInfo.classIndex() > -1) && (instanceInfo.classIndex() == m_AttIndex.getIndex())) {
throw new Exception("Cannot process class attribute.");
}
if (!instanceInfo.attribute(m_AttIndex.getIndex()).isNominal()) {
throw new UnsupportedAttributeTypeException("Chosen attribute not nominal.");
}
if (instanceInfo.attribute(m_AttIndex.getIndex()).numValues() < 2) {
throw new UnsupportedAttributeTypeException("Chosen attribute has less than " +
"two values.");
}
if (m_SecondIndex.getIndex() <= m_FirstIndex.getIndex()) {
// XXX Maybe we should just swap the values??
throw new Exception("The second index has to be greater "+
"than the first.");
}
setOutputFormat();
return true;
}
/**
* 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().
* @throws IllegalStateException if no input format has been set.
*/
public boolean input(Instance instance) {
if (getInputFormat() == null) {
throw new IllegalStateException("No input instance format defined");
}
if (m_NewBatch) {
resetQueue();
m_NewBatch = false;
}
Instance newInstance = (Instance)instance.copy();
if ((int)newInstance.value(m_AttIndex.getIndex()) == m_SecondIndex.getIndex()) {
newInstance.setValue(m_AttIndex.getIndex(), (double)m_FirstIndex.getIndex());
}
else if ((int)newInstance.value(m_AttIndex.getIndex()) > m_SecondIndex.getIndex()) {
newInstance.setValue(m_AttIndex.getIndex(),
newInstance.value(m_AttIndex.getIndex()) - 1);
}
push(newInstance);
return true;
}
/**
* Returns an enumeration describing the available options.
*
* @return an enumeration of all the available options.
*/
public Enumeration listOptions() {
Vector newVector = new Vector(3);
newVector.addElement(new Option(
"\tSets the attribute index (default last).",
"C", 1, "-C <col>"));
newVector.addElement(new Option(
"\tSets the first value's index (default first).",
"F", 1, "-F <value index>"));
newVector.addElement(new Option(
"\tSets the second value's index (default last).",
"S", 1, "-S <value index>"));
return newVector.elements();
}
/**
* Parses a given list of options. <p/>
*
<!-- options-start -->
* Valid options are: <p/>
*
* <pre> -C <col>
* Sets the attribute index (default last).</pre>
*
* <pre> -F <value index>
* Sets the first value's index (default first).</pre>
*
* <pre> -S <value index>
* Sets the second value's index (default last).</pre>
*
<!-- options-end -->
*
* @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 {
String attIndex = Utils.getOption('C', options);
if (attIndex.length() != 0) {
setAttributeIndex(attIndex);
} else {
setAttributeIndex("last");
}
String firstValIndex = Utils.getOption('F', options);
if (firstValIndex.length() != 0) {
setFirstValueIndex(firstValIndex);
} else {
setFirstValueIndex("first");
}
String secondValIndex = Utils.getOption('S', options);
if (secondValIndex.length() != 0) {
setSecondValueIndex(secondValIndex);
} else {
setSecondValueIndex("last");
}
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();
options[current++] = "-F";
options[current++] = "" + getFirstValueIndex();
options[current++] = "-S";
options[current++] = "" + getSecondValueIndex();
while (current < options.length) {
options[current++] = "";
}
return options;
}
/**
* @return tip text for this property suitable for
* displaying in the explorer/experimenter gui
*/
public String attributeIndexTipText() {
return "Sets which attribute to process. This "
+ "attribute must be nominal (\"first\" and \"last\" are valid values)";
}
/**
* Get the index of the attribute used.
*
* @return the index of the attribute
*/
public String getAttributeIndex() {
return m_AttIndex.getSingleIndex();
}
/**
* Sets index of the attribute used.
*
* @param attIndex the index of the attribute
*/
public void setAttributeIndex(String attIndex) {
m_AttIndex.setSingleIndex(attIndex);
}
/**
* @return tip text for this property suitable for
* displaying in the explorer/experimenter gui
*/
public String firstValueIndexTipText() {
return "Sets the first value to be merged. "
+ "(\"first\" and \"last\" are valid values)";
}
/**
* Get the index of the first value used.
*
* @return the index of the first value
*/
public String getFirstValueIndex() {
return m_FirstIndex.getSingleIndex();
}
/**
* Sets index of the first value used.
*
* @param firstIndex the index of the first value
*/
public void setFirstValueIndex(String firstIndex) {
m_FirstIndex.setSingleIndex(firstIndex);
}
/**
* @return tip text for this property suitable for
* displaying in the explorer/experimenter gui
*/
public String secondValueIndexTipText() {
return "Sets the second value to be merged. "
+ "(\"first\" and \"last\" are valid values)";
}
/**
* Get the index of the second value used.
*
* @return the index of the second value
*/
public String getSecondValueIndex() {
return m_SecondIndex.getSingleIndex();
}
/**
* Sets index of the second value used.
*
* @param secondIndex the index of the second value
*/
public void setSecondValueIndex(String secondIndex) {
m_SecondIndex.setSingleIndex(secondIndex);
}
/**
* Set the output format. Takes the current average class values
* and m_InputFormat and calls setOutputFormat(Instances)
* appropriately.
*/
private void setOutputFormat() {
Instances newData;
FastVector newAtts, newVals;
boolean firstEndsWithPrime = false,
secondEndsWithPrime = false;
StringBuffer text = new StringBuffer();
// 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.getIndex()) {
newAtts.addElement(att.copy());
} else {
// Compute new value
if (att.value(m_FirstIndex.getIndex()).endsWith("'")) {
firstEndsWithPrime = true;
}
if (att.value(m_SecondIndex.getIndex()).endsWith("'")) {
secondEndsWithPrime = true;
}
if (firstEndsWithPrime || secondEndsWithPrime) {
text.append("'");
}
if (firstEndsWithPrime) {
text.append(((String)att.value(m_FirstIndex.getIndex())).
substring(1, ((String)att.value(m_FirstIndex.getIndex())).
length() - 1));
} else {
text.append((String)att.value(m_FirstIndex.getIndex()));
}
text.append('_');
if (secondEndsWithPrime) {
text.append(((String)att.value(m_SecondIndex.getIndex())).
substring(1, ((String)att.value(m_SecondIndex.getIndex())).
length() - 1));
} else {
text.append((String)att.value(m_SecondIndex.getIndex()));
}
if (firstEndsWithPrime || secondEndsWithPrime) {
text.append("'");
}
// Compute list of attribute values
newVals = new FastVector(att.numValues() - 1);
for (int i = 0; i < att.numValues(); i++) {
if (i == m_FirstIndex.getIndex()) {
newVals.addElement(text.toString());
} else if (i != m_SecondIndex.getIndex()) {
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);
}
/**
* Returns the revision string.
*
* @return the revision
*/
public String getRevision() {
return RevisionUtils.extract("$Revision: 5987 $");
}
/**
* Main method for testing this class.
*
* @param argv should contain arguments to the filter:
* use -h for help
*/
public static void main(String [] argv) {
runFilter(new MergeTwoValues(), argv);
}
}