content: /*
   *    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.
   */
  
  /*
   * NominalToString.java
   * Copyright (C) 2007 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.Range;
  import weka.core.UnsupportedAttributeTypeException;
  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 a nominal attribute (i.e. set number of values) to string (i.e. unspecified number of values).
   * <p/>
   <!-- globalinfo-end -->
   *
   <!-- options-start -->
   * Valid options are: <p/>
   * 
   * <pre> -C &lt;col&gt;
   *  Sets the range of attributes to convert (default last).</pre>
   * 
   <!-- options-end -->
   *
   * @author FracPete (fracpete at waikato dot ac dot nz)
   * @version $Revision: 6246 $
   */
  public class NominalToString
    extends Filter 
    implements UnsupervisedFilter, OptionHandler {
  
    /** for serialization */
    static final long serialVersionUID = 8655492378380068939L;
    
    /** The attribute's index setting. */
    private Range m_AttIndex = 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 nominal attribute (that is, a set number of values) to string "
        + "(that is, an unspecified number of values).";
    }
  
    /** 
     * 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 UnsupportedAttributeTypeException 	if the selected attribute
     * 						a string attribute.
     * @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);
      
      /*    if (!instanceInfo.attribute(m_AttIndex.getIndex()).isNominal())
        throw new UnsupportedAttributeTypeException("Chosen attribute is not of "
        + "type nominal."); */
  
      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.
     */
    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.
     * @throws IllegalStateException 	if no input structure has been defined.
     */
    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());
      } 
  
      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 result = new Vector();
  
      result.addElement(new Option(
  	"\tSets the range of attributes to convert (default last).",
  	"C", 1, "-C <col>"));
  
      return result.elements();
    }
  
  
    /**
     * Parses a given list of options. <p/>
     * 
     <!-- options-start -->
     * Valid options are: <p/>
     * 
     * <pre> -C &lt;col&gt;
     *  Sets the range of attributes to convert (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	tmpStr;
      
      tmpStr = Utils.getOption('C', options);
      if (tmpStr.length() != 0)
        setAttributeIndexes(tmpStr);
      else
        setAttributeIndexes("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() {
      Vector    result;
  
      result = new Vector();
  
      result.add("-C");
      result.add("" + (getAttributeIndexes()));
  
      return (String[]) result.toArray(new String[result.size()]);	  
    }
  
    /**
     * Returns the tip text for this property
     * 
     * @return 		tip text for this property suitable for
     * 			displaying in the explorer/experimenter gui
     */
    public String attributeIndexesTipText() {
      return "Sets a range attributes to process. Any non-nominal "
        + "attributes in the range are left untouched (\"first\" and \"last\" are valid values)";
    }
  
    /**
     * Get the index of the attribute used.
     *
     * @return 		the index of the attribute
     */
    public String getAttributeIndexes() {
      //    return m_AttIndex.getSingleIndex();
      return m_AttIndex.getRanges();
    }
  
    /**
     * Sets index of the attribute used.
     *
     * @param attIndex 	the index of the attribute
     */
    public void setAttributeIndexes(String attIndex) {
      //    m_AttIndex.setSingleIndex(attIndex);
      m_AttIndex.setRanges(attIndex);
    }
  
    /**
     * 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;
        
      // Compute new attributes
      newAtts = new FastVector(getInputFormat().numAttributes());
      for (int j = 0; j < getInputFormat().numAttributes(); j++) {
        Attribute att = getInputFormat().attribute(j);
  
        if (!att.isNominal() || !m_AttIndex.isInRange(j))
  	newAtts.addElement(att); 
        else
  	newAtts.addElement(new Attribute(att.name(), (FastVector) null));
      }
        
      // 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: 6246 $");
    }
    
    /**
     * Main method for testing this class.
     *
     * @param args 	should contain arguments to the filter: use -h for help
     */
    public static void main(String [] args) {
      runFilter(new NominalToString(), args);
    }
  }
  
  