/*
* 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.
*/
/*
* NominalToBinary.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.Instances;
import weka.core.Option;
import weka.core.OptionHandler;
import weka.core.Range;
import weka.core.RevisionUtils;
import weka.core.SparseInstance;
import weka.core.Utils;
import weka.core.Capabilities.Capability;
import weka.filters.Filter;
import weka.filters.UnsupervisedFilter;
import java.util.Enumeration;
import java.util.Vector;
/**
<!-- globalinfo-start -->
* Converts all nominal attributes into binary numeric attributes. An attribute with k values is transformed into k binary attributes if the class is nominal (using the one-attribute-per-value approach). Binary attributes are left binary, if option '-A' is not given.If the class is numeric, you might want to use the supervised version of this filter.
* <p/>
<!-- globalinfo-end -->
*
<!-- options-start -->
* Valid options are: <p/>
*
* <pre> -N
* Sets if binary attributes are to be coded as nominal ones.</pre>
*
* <pre> -A
* For each nominal value a new attribute is created,
* not only if there are more than 2 values.</pre>
*
* <pre> -R <col1,col2-col4,...>
* Specifies list of columns to act on. First and last are
* valid indexes.
* (default: first-last)</pre>
*
* <pre> -V
* Invert matching sense of column indexes.</pre>
*
<!-- options-end -->
*
* @author Eibe Frank (eibe@cs.waikato.ac.nz)
* @version $Revision: 1.12 $
*/
public class NominalToBinary
extends Filter
implements UnsupervisedFilter, OptionHandler {
/** for serialization */
static final long serialVersionUID = -1130642825710549138L;
/** Stores which columns to act on */
protected Range m_Columns = new Range();
/** Are the new attributes going to be nominal or numeric ones? */
private boolean m_Numeric = true;
/** Are all values transformed into new attributes? */
private boolean m_TransformAll = false;
/** Constructor - initialises the filter */
public NominalToBinary() {
setAttributeIndices("first-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 "Converts all nominal attributes into binary numeric attributes. An "
+ "attribute with k values is transformed into k binary attributes if "
+ "the class is nominal (using the one-attribute-per-value approach). "
+ "Binary attributes are left binary, if option '-A' is not given."
+ "If the class is numeric, you might want to use the supervised version of "
+ "this filter.";
}
/**
* Returns the Capabilities of this filter.
*
* @return the capabilities of this object
* @see Capabilities
*/
public Capabilities getCapabilities() {
Capabilities result = super.getCapabilities();
// 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_Columns.setUpper(instanceInfo.numAttributes() - 1);
setOutputFormat();
return true;
}
/**
* Input an instance for filtering. Filter requires all
* training instances be read before producing output.
*
* @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;
}
convertInstance(instance);
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 if binary attributes are to be coded as nominal ones.",
"N", 0, "-N"));
newVector.addElement(new Option(
"\tFor each nominal value a new attribute is created, \n"
+ "\tnot only if there are more than 2 values.",
"A", 0, "-A"));
newVector.addElement(new Option(
"\tSpecifies list of columns to act on. First and last are \n"
+ "\tvalid indexes.\n"
+ "\t(default: first-last)",
"R", 1, "-R <col1,col2-col4,...>"));
newVector.addElement(new Option(
"\tInvert matching sense of column indexes.",
"V", 0, "-V"));
return newVector.elements();
}
/**
* Parses a given list of options. <p/>
*
<!-- options-start -->
* Valid options are: <p/>
*
* <pre> -N
* Sets if binary attributes are to be coded as nominal ones.</pre>
*
* <pre> -A
* For each nominal value a new attribute is created,
* not only if there are more than 2 values.</pre>
*
* <pre> -R <col1,col2-col4,...>
* Specifies list of columns to act on. First and last are
* valid indexes.
* (default: first-last)</pre>
*
* <pre> -V
* Invert matching sense of column indexes.</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 {
setBinaryAttributesNominal(Utils.getFlag('N', options));
setTransformAllValues(Utils.getFlag('A', options));
String convertList = Utils.getOption('R', options);
if (convertList.length() != 0) {
setAttributeIndices(convertList);
} else {
setAttributeIndices("first-last");
}
setInvertSelection(Utils.getFlag('V', options));
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 [4];
int current = 0;
if (getBinaryAttributesNominal()) {
options[current++] = "-N";
}
if (getTransformAllValues()) {
options[current++] = "-A";
}
if (!getAttributeIndices().equals("")) {
options[current++] = "-R"; options[current++] = getAttributeIndices();
}
if (getInvertSelection()) {
options[current++] = "-V";
}
while (current < options.length) {
options[current++] = "";
}
return options;
}
/**
* Returns the tip text for this property
*
* @return tip text for this property suitable for
* displaying in the explorer/experimenter gui
*/
public String binaryAttributesNominalTipText() {
return "Whether resulting binary attributes will be nominal.";
}
/**
* Gets if binary attributes are to be treated as nominal ones.
*
* @return true if binary attributes are to be treated as nominal ones
*/
public boolean getBinaryAttributesNominal() {
return !m_Numeric;
}
/**
* Sets if binary attributes are to be treates as nominal ones.
*
* @param bool true if binary attributes are to be treated as nominal ones
*/
public void setBinaryAttributesNominal(boolean bool) {
m_Numeric = !bool;
}
/**
* Returns the tip text for this property
*
* @return tip text for this property suitable for
* displaying in the explorer/experimenter gui
*/
public String transformAllValuesTipText() {
return "Whether all nominal values are turned into new attributes, not only if there are more than 2.";
}
/**
* Gets if all nominal values are turned into new attributes, not only if
* there are more than 2.
*
* @return true all nominal values are transformed into new attributes
*/
public boolean getTransformAllValues() {
return m_TransformAll;
}
/**
* Sets whether all nominal values are transformed into new attributes, not
* just if there are more than 2.
*
* @param bool true if all nominal value are transformed into new attributes
*/
public void setTransformAllValues(boolean bool) {
m_TransformAll = bool;
}
/**
* Returns the tip text for this property
*
* @return tip text for this property suitable for
* displaying in the explorer/experimenter gui
*/
public String invertSelectionTipText() {
return "Set attribute selection mode. If false, only selected"
+ " (numeric) attributes in the range will be discretized; if"
+ " true, only non-selected attributes will be discretized.";
}
/**
* Gets whether the supplied columns are to be removed or kept
*
* @return true if the supplied columns will be kept
*/
public boolean getInvertSelection() {
return m_Columns.getInvert();
}
/**
* Sets whether selected columns should be removed or kept. If true the
* selected columns are kept and unselected columns are deleted. If false
* selected columns are deleted and unselected columns are kept.
*
* @param invert the new invert setting
*/
public void setInvertSelection(boolean invert) {
m_Columns.setInvert(invert);
}
/**
* Returns the tip text for this property
*
* @return tip text for this property suitable for
* displaying in the explorer/experimenter gui
*/
public String attributeIndicesTipText() {
return "Specify range of attributes to act on."
+ " This is a comma separated list of attribute indices, with"
+ " \"first\" and \"last\" valid values. Specify an inclusive"
+ " range with \"-\". E.g: \"first-3,5,6-10,last\".";
}
/**
* Gets the current range selection
*
* @return a string containing a comma separated list of ranges
*/
public String getAttributeIndices() {
return m_Columns.getRanges();
}
/**
* Sets which attributes are to be acted on.
*
* @param rangeList a string representing the list of attributes. Since
* the string will typically come from a user, attributes are indexed from
* 1. <br>
* eg: first-3,5,6-last
* @throws IllegalArgumentException if an invalid range list is supplied
*/
public void setAttributeIndices(String rangeList) {
m_Columns.setRanges(rangeList);
}
/**
* Set the output format if the class is nominal.
*/
private void setOutputFormat() {
FastVector newAtts;
int newClassIndex;
StringBuffer attributeName;
Instances outputFormat;
FastVector vals;
// Compute new attributes
newClassIndex = getInputFormat().classIndex();
newAtts = new FastVector();
for (int j = 0; j < getInputFormat().numAttributes(); j++) {
Attribute att = getInputFormat().attribute(j);
if (!att.isNominal() || (j == getInputFormat().classIndex()) ||
!m_Columns.isInRange(j)) {
newAtts.addElement(att.copy());
} else {
if ( (att.numValues() <= 2) && (!m_TransformAll) ) {
if (m_Numeric) {
newAtts.addElement(new Attribute(att.name()));
} else {
newAtts.addElement(att.copy());
}
} else {
if (newClassIndex >= 0 && j < getInputFormat().classIndex()) {
newClassIndex += att.numValues() - 1;
}
// Compute values for new attributes
for (int k = 0; k < att.numValues(); k++) {
attributeName =
new StringBuffer(att.name() + "=");
attributeName.append(att.value(k));
if (m_Numeric) {
newAtts.
addElement(new Attribute(attributeName.toString()));
} else {
vals = new FastVector(2);
vals.addElement("f"); vals.addElement("t");
newAtts.
addElement(new Attribute(attributeName.toString(), vals));
}
}
}
}
}
outputFormat = new Instances(getInputFormat().relationName(),
newAtts, 0);
outputFormat.setClassIndex(newClassIndex);
setOutputFormat(outputFormat);
}
/**
* Convert a single instance over if the class is nominal. The converted
* instance is added to the end of the output queue.
*
* @param instance the instance to convert
*/
private void convertInstance(Instance instance) {
double [] vals = new double [outputFormatPeek().numAttributes()];
int attSoFar = 0;
for(int j = 0; j < getInputFormat().numAttributes(); j++) {
Attribute att = getInputFormat().attribute(j);
if (!att.isNominal() || (j == getInputFormat().classIndex()) ||
!m_Columns.isInRange(j)) {
vals[attSoFar] = instance.value(j);
attSoFar++;
} else {
if ( (att.numValues() <= 2) && (!m_TransformAll) ) {
vals[attSoFar] = instance.value(j);
attSoFar++;
} else {
if (instance.isMissing(j)) {
for (int k = 0; k < att.numValues(); k++) {
vals[attSoFar + k] = instance.value(j);
}
} else {
for (int k = 0; k < att.numValues(); k++) {
if (k == (int)instance.value(j)) {
vals[attSoFar + k] = 1;
} else {
vals[attSoFar + k] = 0;
}
}
}
attSoFar += att.numValues();
}
}
}
Instance inst = null;
if (instance instanceof SparseInstance) {
inst = new SparseInstance(instance.weight(), vals);
} else {
inst = new Instance(instance.weight(), vals);
}
inst.setDataset(getOutputFormat());
copyValues(inst, false, instance.dataset(), getOutputFormat());
inst.setDataset(getOutputFormat());
push(inst);
}
/**
* Returns the revision string.
*
* @return the revision
*/
public String getRevision() {
return RevisionUtils.extract("$Revision: 1.12 $");
}
/**
* 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 NominalToBinary(), argv);
}
}