converterutils.java

矩阵的QR分解算法

      
      return result;
    }
    
    /**
     * returns the next element and sets the specified dataset, null if 
     * none available.
     * 
     * @param dataset	the dataset to set for the instance
     * @return		the next Instance
     */
    public Instance nextElement(Instances dataset) {
      Instance	result;
      
      result = null;
      
      if (isIncremental()) {
	// is there still an instance in the buffer?
	if (m_IncrementalBuffer != null) {
	  result              = m_IncrementalBuffer;
	  m_IncrementalBuffer = null;
	}
	else {
	  try {
	    result = m_Loader.getNextInstance(dataset);
	  }
	  catch (Exception e) {
	    e.printStackTrace();
	    result = null;
	  }
	}
      }
      else {
	if (m_BatchCounter < m_BatchBuffer.numInstances()) {
	  result = m_BatchBuffer.instance(m_BatchCounter);
	  m_BatchCounter++;
	}
      }

      result.setDataset(dataset);
      
      return result;
    }
    
    /**
     * convencience method for loading a dataset in batch mode.
     * 
     * @param location		the dataset to load
     * @return			the dataset
     * @throws Exception	if loading fails
     * @see			#DataSource(String)
     */
    public static Instances read(String location) throws Exception {
      DataSource	source;
      Instances		result;
      
      source = new DataSource(location);
      result = source.getDataSet();
      
      return result;
    }
    
    /**
     * convencience method for loading a dataset in batch mode from a stream.
     * 
     * @param stream		the stream to load the dataset from
     * @return			the dataset
     * @throws Exception	if loading fails
     * @see			#DataSource(InputStream)
     */
    public static Instances read(InputStream stream) throws Exception {
      DataSource	source;
      Instances		result;
      
      source = new DataSource(stream);
      result = source.getDataSet();
      
      return result;
    }
    
    /**
     * convencience method for loading a dataset in batch mode.
     * 
     * @param loader		the loader to get the dataset from
     * @return			the dataset
     * @throws Exception	if loading fails
     * @see			#DataSource(Loader)
     */
    public static Instances read(Loader loader) throws Exception {
      DataSource	source;
      Instances		result;
      
      source = new DataSource(loader);
      result = source.getDataSet();
      
      return result;
    }
    
    /**
     * for testing only - takes a data file as input.
     * 
     * @param args		the commandline arguments
     * @throws Exception 	if something goes wrong
     */
    public static void main(String[] args) throws Exception {
      if (args.length != 1) {
	System.out.println("\nUsage: " + DataSource.class.getName() + " <file>\n");
	System.exit(1);
      }
      
      DataSource loader = new DataSource(args[0]);
      
      System.out.println("Incremental? " + loader.isIncremental());
      System.out.println("Loader: " + loader.getLoader().getClass().getName());
      System.out.println("Data:\n");
      Instances structure = loader.getStructure();
      System.out.println(structure);
      while (loader.hasMoreElements(structure))
	System.out.println(loader.nextElement(structure));
      
      Instances inst = loader.getDataSet();
      loader = new DataSource(inst);
      System.out.println("\n\nProxy-Data:\n");
      System.out.println(loader.getStructure());
      while (loader.hasMoreElements(structure))
	System.out.println(loader.nextElement(inst));
    }
  }

  /**
   * Helper class for saving data to files. Via the ConverterUtils
   * class it determines which converter to use for saving the data.
   * It is the logical counterpart to <code>DataSource</code>.
   * 
   * @author FracPete (fracpete at waikato dot ac dot nz)
   * @version $Revision: 1.14 $
   * @see DataSource
   */
  public static class DataSink
    implements Serializable {

    /** for serialization. */
    private static final long serialVersionUID = -1504966891136411204L;

    /** the saver to use for storing the data. */
    protected Saver m_Saver = null;
    
    /** the stream to store the data in (always in ARFF format). */
    protected OutputStream m_Stream = null;
    
    /**
     * initializes the sink to save the data to the given file.
     * 
     * @param filename		the file to save data to
     * @throws Exception	if set of saver fails
     */
    public DataSink(String filename) throws Exception {
      m_Stream = null;
      
      if (DataSource.isArff(filename))
	m_Saver = new ArffSaver();
      else
	m_Saver = getSaverForFile(filename);
      
      ((AbstractFileSaver) m_Saver).setFile(new File(filename));
    }
    
    /**
     * initializes the sink to save the data to the given Saver (expected to be 
     * fully configured).
     * 
     * @param saver	the saver to use for saving the data
     */
    public DataSink(Saver saver) {
      m_Saver  = saver;
      m_Stream = null;
    }
    
    /**
     * initializes the sink to save the data in the stream (always in ARFF 
     * format).
     * 
     * @param stream	the output stream to use for storing the data in ARFF
     * 			format
     */
    public DataSink(OutputStream stream) {
      m_Saver  = null;
      m_Stream = stream;
    }

    /**
     * writes the given data either via the saver or to the defined 
     * output stream (depending on the constructor). In case of the stream, 
     * the stream is only flushed, but not closed.
     * 
     * @param data		the data to save
     * @throws Exception	if saving fails
     */
    public void write(Instances data) throws Exception {
      if (m_Saver != null) {
	m_Saver.setInstances(data);
	m_Saver.writeBatch();
      }
      else {
	m_Stream.write(data.toString().getBytes());
	m_Stream.flush();
      }
    }
    
    /**
     * writes the data to the given file.
     * 
     * @param filename		the file to write the data to
     * @param data		the data to store
     * @throws Exception	if writing fails
     */
    public static void write(String filename, Instances data) throws Exception {
      DataSink	sink;
      
      sink = new DataSink(filename);
      sink.write(data);
    }
    
    /**
     * writes the data via the given saver.
     * 
     * @param saver		the saver to use for writing the data
     * @param data		the data to store
     * @throws Exception	if writing fails
     */
    public static void write(Saver saver, Instances data) throws Exception {
      DataSink	sink;
      
      sink = new DataSink(saver);
      sink.write(data);
    }
    
    /**
     * writes the data to the given stream (always in ARFF format).
     * 
     * @param stream		the stream to write the data to (ARFF format)
     * @param data		the data to store
     * @throws Exception	if writing fails
     */
    public static void write(OutputStream stream, Instances data) throws Exception {
      DataSink	sink;
      
      sink = new DataSink(stream);
      sink.write(data);
    }
    
    /**
     * for testing only - takes a data file as input and a data file for the
     * output.
     * 
     * @param args		the commandline arguments
     * @throws Exception 	if something goes wrong
     */
    public static void main(String[] args) throws Exception {
      if (args.length != 2) {
	System.out.println(
	    "\nUsage: " + DataSource.class.getName() + " <input-file> <output-file>\n");
	System.exit(1);
      }

      // load data
      Instances data = DataSource.read(args[0]);
      
      // save data
      DataSink.write(args[1], data);
    }
  }
  
  /** the core loaders - hardcoded list necessary for RMI/Remote Experiments 
   * (comma-separated list). */
  public final static String CORE_FILE_LOADERS = 
      weka.core.converters.ArffLoader.class.getName() + ","
    + weka.core.converters.C45Loader.class.getName() + ","
    + weka.core.converters.CSVLoader.class.getName() + ","
    + weka.core.converters.DatabaseConverter.class.getName() + ","
    + weka.core.converters.LibSVMLoader.class.getName() + ","
    + weka.core.converters.SerializedInstancesLoader.class.getName() + ","
    + weka.core.converters.TextDirectoryLoader.class.getName() + ","
    + weka.core.converters.XRFFLoader.class.getName();

  /** the core savers - hardcoded list necessary for RMI/Remote Experiments 
   * (comma-separated list). */
  public final static String CORE_FILE_SAVERS =
      weka.core.converters.ArffSaver.class.getName() + ","
    + weka.core.converters.C45Saver.class.getName() + ","
    + weka.core.converters.CSVSaver.class.getName() + ","
    + weka.core.converters.DatabaseConverter.class.getName() + ","
    + weka.core.converters.LibSVMSaver.class.getName() + ","
    + weka.core.converters.SerializedInstancesSaver.class.getName() + ","
    + weka.core.converters.XRFFSaver.class.getName();
  
  /** all available loaders (extension &lt;-&gt; classname). */
  protected static Hashtable<String,String> m_FileLoaders;
  
  /** all available URL loaders (extension &lt;-&gt; classname). */
  protected static Hashtable<String,String> m_URLFileLoaders;

  /** all available savers (extension &lt;-&gt; classname). */
  protected static Hashtable<String,String> m_FileSavers;
  
  // determine all loaders/savers
  static {
    Vector classnames;
    
    try {
      // generate properties 
      // Note: does NOT work with RMI, hence m_FileLoadersCore/m_FileSaversCore
      GenericPropertiesCreator creator = new GenericPropertiesCreator();
      creator.execute(false);
      Properties props = creator.getOutputProperties();

      // init
      m_FileLoaders    = new Hashtable<String,String>();
      m_URLFileLoaders = new Hashtable<String,String>();
      m_FileSavers     = new Hashtable<String,String>();
      
      // loaders
      m_FileLoaders = getFileConverters(
	  		props.getProperty(Loader.class.getName(), CORE_FILE_LOADERS),
	  		new String[]{FileSourcedConverter.class.getName()});
      
      // URL loaders
      m_URLFileLoaders = getFileConverters(
	  		   props.getProperty(Loader.class.getName(), CORE_FILE_LOADERS),
	  		   new String[]{
	  		     FileSourcedConverter.class.getName(), 
	  		     URLSourcedLoader.class.getName()});

      // savers
      m_FileSavers = getFileConverters(
	  		props.getProperty(Saver.class.getName(), CORE_FILE_SAVERS),
	  		new String[]{FileSourcedConverter.class.getName()});
    }
    catch (Exception e) {
      // ignore
    }
    finally {
      // loaders
      if (m_FileLoaders.size() == 0) {
	classnames = GenericObjectEditor.getClassnames(AbstractFileLoader.class.getName());
	if (classnames.size() > 0)
	  m_FileLoaders = getFileConverters(
	                    classnames,
	                    new String[]{FileSourcedConverter.class.getName()});
	else
	  m_FileLoaders = getFileConverters(
	                    CORE_FILE_LOADERS,
	                    new String[]{FileSourcedConverter.class.getName()});
      }

      // URL loaders
      if (m_URLFileLoaders.size() == 0) {
        classnames = GenericObjectEditor.getClassnames(AbstractFileLoader.class.getName());
        if (classnames.size() > 0)
	  m_URLFileLoaders = getFileConverters(
	  		       classnames,
	  		       new String[]{
	  			   FileSourcedConverter.class.getName(), 
	  			   URLSourcedLoader.class.getName()});
        else
          m_URLFileLoaders = getFileConverters(
	                       CORE_FILE_LOADERS,
	                       new String[]{
	                	   FileSourcedConverter.class.getName(), 
	                	   URLSourcedLoader.class.getName()});
      }

      // savers
      if (m_FileSavers.size() == 0) {
	classnames = GenericObjectEditor.getClassnames(AbstractFileSaver.class.getName());
	if (classnames.size() > 0)
	  m_FileSavers = getFileConverters(
	  		   classnames,
	  		   new String[]{FileSourcedConverter.class.getName()});
	else
	  m_FileSavers = getFileConverters(