Java tutorial
/* * 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 3 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, see <http://www.gnu.org/licenses/>. */ /* * StringToNominal.java * Copyright (C) 2002-2012 University of Waikato, Hamilton, New Zealand * */ package weka.filters.unsupervised.attribute; import java.util.ArrayList; import java.util.Enumeration; import java.util.Vector; import weka.core.*; import weka.core.Capabilities.Capability; import weka.filters.Filter; import weka.filters.UnsupervisedFilter; /** * <!-- globalinfo-start --> Converts a range of string attributes (unspecified * number of values) to nominal (set number of values). You should ensure that * all string values that will appear are represented in the first batch of the * data. * <p/> * <!-- globalinfo-end --> * * <!-- options-start --> Valid options are: * <p/> * * <pre> * -R <col> * Sets the range of attribute indices ("first" and "last" are valid values * and ranges and lists can also be used) (default "last"). * </pre> * * <pre> * -V <col> * Invert the range specified by -R. * </pre> * * <!-- options-end --> * * @author Len Trigg (len@reeltwo.com) * @version $Revision$ */ public class StringToNominal extends Filter implements UnsupervisedFilter, OptionHandler, WeightedAttributesHandler, WeightedInstancesHandler { /** for serialization */ private static final long serialVersionUID = 4864084427902797605L; /** The attribute's range indices setting. */ private final Range m_AttIndices = new Range("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 a range of string attributes (unspecified number of values) to nominal " + "(set number of values). You should ensure that all string values that " + "will appear are represented in the first batch of the data."; } /** * Returns the Capabilities of this filter. * * @return the capabilities of this object * @see Capabilities */ @Override 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 UnsupportedAttributeTypeException if the selected attribute a * string attribute. * @throws Exception if the input format can't be set successfully. */ @Override public boolean setInputFormat(Instances instanceInfo) throws Exception { super.setInputFormat(instanceInfo); m_AttIndices.setUpper(instanceInfo.numAttributes() - 1); 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(). * @throws IllegalStateException if no input structure has been defined. */ @Override 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(); // make sure that we get the right indexes set for the converted // string attributes when operating on a second batch of instances for (int i = 0; i < newInstance.numAttributes(); i++) { if (newInstance.attribute(i).isString() && !newInstance.isMissing(i) && m_AttIndices.isInRange(i)) { Attribute outAtt = outputFormatPeek().attribute(i); String inVal = newInstance.stringValue(i); int outIndex = outAtt.indexOfValue(inVal); if (outIndex < 0) { newInstance.setMissing(i); } else { newInstance.setValue(i, outIndex); } } } push(newInstance, false); // No need to copy 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. * @throws IllegalStateException if no input structure has been defined. */ @Override public boolean batchFinished() { 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(), false); // No need to copy } } flushInput(); m_NewBatch = true; return (numPendingOutput() != 0); } /** * Returns an enumeration describing the available options. * * @return an enumeration of all the available options. */ @Override public Enumeration<Option> listOptions() { Vector<Option> newVector = new Vector<Option>(1); newVector .addElement(new Option( "\tSets which attributes to process (\"first\" and \"last\" are valid values " + "and ranges and lists can also be used) (default \"last\").", "R", 1, "-R <col>")); newVector.addElement(new Option("\tInvert the range specified by -R.", "V", 1, "-V <col>")); return newVector.elements(); } /** * Parses a given list of options. * <p/> * * <!-- options-start --> Valid options are: * <p/> * * <pre> * -R <col> * Sets the range of attribute indices ("first" and "last" are valid values * and ranges and lists can also be used) (default "last"). * </pre> * * <pre> * -V <col> * Invert the range specified by -R. * </pre> * * <!-- options-end --> * * @param options the list of options as an array of strings * @throws Exception if an option is not supported */ @Override public void setOptions(String[] options) throws Exception { String attIndices = Utils.getOption('R', options); if (attIndices.length() != 0) { setAttributeRange(attIndices); } else { setAttributeRange("last"); } String invertSelection = Utils.getOption('V', options); if (invertSelection.length() != 0) { m_AttIndices.setInvert(true); } else { m_AttIndices.setInvert(false); } if (getInputFormat() != null) { setInputFormat(getInputFormat()); } Utils.checkForRemainingOptions(options); } /** * Gets the current settings of the filter. * * @return an array of strings suitable for passing to setOptions */ @Override public String[] getOptions() { Vector<String> options = new Vector<String>(); options.add("-R"); options.add("" + (getAttributeRange())); if (this.m_AttIndices.getInvert()) { options.add("-V"); } return options.toArray(new String[0]); } /** * @return tip text for this property suitable for displaying in the * explorer/experimenter gui */ public String attributeRangeTipText() { return "Sets which attributes to process (\"first\" and \"last\" are valid values " + "and ranges and lists can also be used)."; } /** * Get the range of indices of the attributes used. * * @return the index of the attribute */ public String getAttributeRange() { return m_AttIndices.getRanges(); } /** * Sets range of indices of the attributes used. * * @param rangeList the list of attribute indices */ public void setAttributeRange(String rangeList) { m_AttIndices.setRanges(rangeList); } /** * Set the output format. Takes the current average class values and * m_InputFormat and calls setOutputFormat(Instances) appropriately. */ private void setOutputFormat() { Instances newData; ArrayList<Attribute> newAtts; ArrayList<String> newVals; // Compute new attributes newAtts = new ArrayList<Attribute>(getInputFormat().numAttributes()); for (int j = 0; j < getInputFormat().numAttributes(); j++) { Attribute att = getInputFormat().attribute(j); if (!m_AttIndices.isInRange(j) || !att.isString()) { // We don't have to copy the attribute because the // attribute index remains unchanged. newAtts.add(att); } else { // Compute list of attribute values newVals = new ArrayList<String>(att.numValues()); for (int i = 0; i < att.numValues(); i++) { newVals.add(att.value(i)); } Attribute newAtt = new Attribute(att.name(), newVals); newAtt.setWeight(att.weight()); newAtts.add(newAtt); } } // Construct new header newData = new Instances(getInputFormat().relationName(), newAtts, 0); newData.setClassIndex(getInputFormat().classIndex()); setOutputFormat(newData); } /** * Returns the revision string. * * @return the revision */ @Override public String getRevision() { return RevisionUtils.extract("$Revision$"); } /** * 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 StringToNominal(), argv); } }