attribute.java

矩阵的QR分解算法

   * @return a copy of this attribute with the same index
   */
  //@ also ensures \result instanceof Attribute;
  public /*@ pure non_null @*/ Object copy() {

    Attribute copy = new Attribute(m_Name);

    copy.m_Index = m_Index;
    copy.m_Type = m_Type;
    copy.m_Values = m_Values;
    copy.m_Hashtable = m_Hashtable;
    copy.m_DateFormat = m_DateFormat;
    copy.m_Header = m_Header;
    copy.setMetadata(m_Metadata);
 
    return copy;
  }

  /**
   * Returns an enumeration of all the attribute's values if the
   * attribute is nominal, string, or relation-valued, null otherwise.
   *
   * @return enumeration of all the attribute's values
   */
  public final /*@ pure @*/ Enumeration enumerateValues() {

    if (isNominal() || isString()) {
      final Enumeration ee = m_Values.elements();
      return new Enumeration () {
          public boolean hasMoreElements() {
            return ee.hasMoreElements();
          }
          public Object nextElement() {
            Object oo = ee.nextElement();
            if (oo instanceof SerializedObject) {
              return ((SerializedObject)oo).getObject();
            } else {
              return oo;
            }
          }
        };
    }
    return null;
  }

  /**
   * Tests if given attribute is equal to this attribute.
   *
   * @param other the Object to be compared to this attribute
   * @return true if the given attribute is equal to this attribute
   */
  public final /*@ pure @*/ boolean equals(Object other) {

    if ((other == null) || !(other.getClass().equals(this.getClass()))) {
      return false;
    }
    Attribute att = (Attribute) other;
    if (!m_Name.equals(att.m_Name)) {
      return false;
    }
    if (isNominal() && att.isNominal()) {
      if (m_Values.size() != att.m_Values.size()) {
        return false;
      }
      for (int i = 0; i < m_Values.size(); i++) {
        if (!m_Values.elementAt(i).equals(att.m_Values.elementAt(i))) {
          return false;
        }
      }
      return true;
    } 
    if (isRelationValued() && att.isRelationValued()) {
      if (!m_Header.equalHeaders(att.m_Header)) {
        return false;
      }
      return true;
    } 
    return (type() == att.type());
  }

  /**
   * Returns the index of this attribute.
   *
   * @return the index of this attribute
   */
  //@ ensures \result == m_Index;
  public final /*@ pure @*/ int index() {

    return m_Index;
  }

  /**
   * Returns the index of a given attribute value. (The index of
   * the first occurence of this value.)
   *
   * @param value the value for which the index is to be returned
   * @return the index of the given attribute value if attribute
   * is nominal or a string, -1 if it is not or the value 
   * can't be found
   */
  public final int indexOfValue(String value) {

    if (!isNominal() && !isString())
      return -1;
    Object store = value;
    if (value.length() > STRING_COMPRESS_THRESHOLD) {
      try {
        store = new SerializedObject(value, true);
      } catch (Exception ex) {
        System.err.println("Couldn't compress string attribute value -"
                           + " searching uncompressed.");
      }
    }
    Integer val = (Integer)m_Hashtable.get(store);
    if (val == null) return -1;
    else return val.intValue();
  }

  /**
   * Test if the attribute is nominal.
   *
   * @return true if the attribute is nominal
   */
  //@ ensures \result <==> (m_Type == NOMINAL);
  public final /*@ pure @*/ boolean isNominal() {

    return (m_Type == NOMINAL);
  }

  /**
   * Tests if the attribute is numeric.
   *
   * @return true if the attribute is numeric
   */
  //@ ensures \result <==> ((m_Type == NUMERIC) || (m_Type == DATE));
  public final /*@ pure @*/ boolean isNumeric() {

    return ((m_Type == NUMERIC) || (m_Type == DATE));
  }

  /**
   * Tests if the attribute is relation valued.
   *
   * @return true if the attribute is relation valued
   */
  //@ ensures \result <==> (m_Type == RELATIONAL);
  public final /*@ pure @*/ boolean isRelationValued() {

    return (m_Type == RELATIONAL);
  }

  /**
   * Tests if the attribute is a string.
   *
   * @return true if the attribute is a string
   */
  //@ ensures \result <==> (m_Type == STRING);
  public final /*@ pure @*/ boolean isString() {

    return (m_Type == STRING);
  }

  /**
   * Tests if the attribute is a date type.
   *
   * @return true if the attribute is a date type
   */
  //@ ensures \result <==> (m_Type == DATE);
  public final /*@ pure @*/ boolean isDate() {

    return (m_Type == DATE);
  }

  /**
   * Returns the attribute's name.
   *
   * @return the attribute's name as a string
   */
  //@ ensures \result == m_Name;
  public final /*@ pure @*/ String name() {

    return m_Name;
  }
  
  /**
   * Returns the number of attribute values. Returns 0 for 
   * attributes that are not either nominal, string, or
   * relation-valued.
   *
   * @return the number of attribute values
   */
  public final /*@ pure @*/ int numValues() {

    if (!isNominal() && !isString() && !isRelationValued()) {
      return 0;
    } else {
      return m_Values.size();
    }
  }

  /**
   * Returns a description of this attribute in ARFF format. Quotes
   * strings if they contain whitespace characters, or if they
   * are a question mark.
   *
   * @return a description of this attribute as a string
   */
  public final String toString() {
    
    StringBuffer text = new StringBuffer();
    
    text.append(ARFF_ATTRIBUTE).append(" ").append(Utils.quote(m_Name)).append(" ");
    switch (m_Type) {
    case NOMINAL:
      text.append('{');
      Enumeration enu = enumerateValues();
      while (enu.hasMoreElements()) {
	text.append(Utils.quote((String) enu.nextElement()));
	if (enu.hasMoreElements())
	  text.append(',');
      }
      text.append('}');
      break;
    case NUMERIC:
      text.append(ARFF_ATTRIBUTE_NUMERIC);
      break;
    case STRING:
      text.append(ARFF_ATTRIBUTE_STRING);
      break;
    case DATE:
      text.append(ARFF_ATTRIBUTE_DATE).append(" ").append(Utils.quote(m_DateFormat.toPattern()));
      break;
    case RELATIONAL:
      text.append(ARFF_ATTRIBUTE_RELATIONAL).append("\n");
      Enumeration enm = m_Header.enumerateAttributes();
      while (enm.hasMoreElements()) {
        text.append(enm.nextElement()).append("\n");
      }
      text.append(ARFF_END_SUBRELATION).append(" ").append(Utils.quote(m_Name));
      break;
    default:
      text.append("UNKNOWN");
      break;
    }
    return text.toString();
  }

  /**
   * Returns the attribute's type as an integer.
   *
   * @return the attribute's type.
   */
  //@ ensures \result == m_Type;
  public final /*@ pure @*/ int type() {

    return m_Type;
  }
  
  /**
   * Returns the Date format pattern in case this attribute is of type DATE,
   * otherwise an empty string.
   * 
   * @return the date format pattern
   * @see SimpleDateFormat
   */
  public final String getDateFormat() {
    if (isDate())
      return m_DateFormat.toPattern();
    else
      return "";
  }

  /**
   * Returns a value of a nominal or string attribute.  Returns an
   * empty string if the attribute is neither a string nor a nominal
   * attribute.
   *
   * @param valIndex the value's index
   * @return the attribute's value as a string
   */
  public final /*@ non_null pure @*/ String value(int valIndex) {
    
    if (!isNominal() && !isString()) {
      return "";
    } else {
      Object val = m_Values.elementAt(valIndex);
      
      // If we're storing strings compressed, uncompress it.
      if (val instanceof SerializedObject) {
        val = ((SerializedObject)val).getObject();
      }
      return (String) val;
    }
  }

  /**
   * Returns the header info for a relation-valued attribute,
   * null if the attribute is not relation-valued.
   *
   * @return the attribute's value as an Instances object
   */
  public final /*@ non_null pure @*/ Instances relation() {
    
    if (!isRelationValued()) {
      return null;
    } else {
      return m_Header;
    }
  }

  /**
   * Returns a value of a relation-valued attribute. Returns
   * null if the attribute is not relation-valued.
   *
   * @param valIndex the value's index
   * @return the attribute's value as an Instances object
   */
  public final /*@ non_null pure @*/ Instances relation(int valIndex) {
    
    if (!isRelationValued()) {
      return null;
    } else {
      return (Instances) m_Values.elementAt(valIndex);
    }
  }

  /**
   * Constructor for a numeric attribute with a particular index.
   *
   * @param attributeName the name for the attribute
   * @param index the attribute's index
   */
  //@ requires attributeName != null;
  //@ requires index >= 0;
  //@ ensures  m_Name == attributeName;
  //@ ensures  m_Index == index;
  public Attribute(String attributeName, int index) {

    this(attributeName);
    m_Index = index;
  }

  /**
   * Constructor for date attributes with a particular index.
   *
   * @param attributeName the name for the attribute
   * @param dateFormat a string suitable for use with
   * SimpleDateFormatter for parsing dates.  Null for a default format
   * string.
   * @param index the attribute's index
   */
  //@ requires attributeName != null;
  //@ requires index >= 0;
  //@ ensures  m_Name == attributeName;
  //@ ensures  m_Index == index;
  public Attribute(String attributeName, String dateFormat, 
	    int index) {

    this(attributeName, dateFormat);
    m_Index = index;
  }

  /**
   * Constructor for nominal attributes and string attributes with
   * a particular index.
   * If a null vector of attribute values is passed to the method,
   * the attribute is assumed to be a string.
   *
   * @param attributeName the name for the attribute
   * @param attributeValues a vector of strings denoting the attribute values.
   * Null if the attribute is a string attribute.
   * @param index the attribute's index
   */
  //@ requires attributeName != null;
  //@ requires index >= 0;
  //@ ensures  m_Name == attributeName;
  //@ ensures  m_Index == index;
  public Attribute(String attributeName, FastVector attributeValues, 
	    int index) {

    this(attributeName, attributeValues);
    m_Index = index;
  }

  /**
   * Constructor for a relation-valued attribute with a particular index.
   *
   * @param attributeName the name for the attribute
   * @param header the header information for this attribute
   * @param index the attribute's index
   */
  //@ requires attributeName != null;
  //@ requires index >= 0;
  //@ ensures  m_Name == attributeName;
  //@ ensures  m_Index == index;
  public Attribute(String attributeName, Instances header,
	    int index) {

    this(attributeName, header);