示例#1
0
  /** Computes the difference between two given attribute values. */
  protected double difference(int index, double val1, double val2) {

    switch (m_instances.attribute(index).type()) {
      case Attribute.NOMINAL:

        // If attribute is nominal
        if (Instance.isMissingValue(val1)
            || Instance.isMissingValue(val2)
            || ((int) val1 != (int) val2)) {
          return 1;
        } else {
          return 0;
        }
      case Attribute.NUMERIC:

        // If attribute is numeric
        if (Instance.isMissingValue(val1) || Instance.isMissingValue(val2)) {
          if (Instance.isMissingValue(val1) && Instance.isMissingValue(val2)) {
            return 1;
          } else {
            double diff;
            if (Instance.isMissingValue(val2)) {
              diff = norm(val1, index);
            } else {
              diff = norm(val2, index);
            }
            if (diff < 0.5) {
              diff = 1.0 - diff;
            }
            return diff;
          }
        } else {
          return norm(val1, index) - norm(val2, index);
        }
      default:
        return 0;
    }
  }
  /** Main method for testing this class. */
  public static void main(String[] options) {

    try {

      // Create numeric attributes "length" and "weight"
      Attribute length = new Attribute("length");
      Attribute weight = new Attribute("weight");

      // Create vector to hold nominal values "first", "second", "third"
      FastVector my_nominal_values = new FastVector(3);
      my_nominal_values.addElement("first");
      my_nominal_values.addElement("second");

      // Create nominal attribute "position"
      Attribute position = new Attribute("position", my_nominal_values);

      // Create vector of the above attributes
      FastVector attributes = new FastVector(3);
      attributes.addElement(length);
      attributes.addElement(weight);
      attributes.addElement(position);

      // Create the empty dataset "race" with above attributes
      Instances race = new Instances("race", attributes, 0);

      // Make position the class attribute
      race.setClassIndex(position.index());

      // Create empty instance with three attribute values
      BinarySparseInstance inst = new BinarySparseInstance(3);

      // Set instance's values for the attributes "length", "weight", and "position"
      inst.setValue(length, (float) 5.3);
      inst.setValue(weight, 300);
      inst.setValue(position, "first");

      // Set instance's dataset to be the dataset "race"
      inst.setDataset(race);

      // Print the instance
      System.out.println("The instance: " + inst);

      // Print the first attribute
      System.out.println("First attribute: " + inst.attribute(0));

      // Print the class attribute
      System.out.println("Class attribute: " + inst.classAttribute());

      // Print the class index
      System.out.println("Class index: " + inst.classIndex());

      // Say if class is missing
      System.out.println("Class is missing: " + inst.classIsMissing());

      // Print the instance's class value in internal format
      System.out.println("Class value (internal format): " + inst.classValue());

      // Print a shallow copy of this instance
      SparseInstance copy = (SparseInstance) inst.copy();
      System.out.println("Shallow copy: " + copy);

      // Set dataset for shallow copy
      copy.setDataset(inst.dataset());
      System.out.println("Shallow copy with dataset set: " + copy);

      // Print out all values in internal format
      System.out.print("All stored values in internal format: ");
      for (int i = 0; i < inst.numValues(); i++) {
        if (i > 0) {
          System.out.print(",");
        }
        System.out.print(inst.valueSparse(i));
      }
      System.out.println();

      // Set all values to zero
      System.out.print("All values set to zero: ");
      while (inst.numValues() > 0) {
        inst.setValueSparse(0, 0);
      }
      for (int i = 0; i < inst.numValues(); i++) {
        if (i > 0) {
          System.out.print(",");
        }
        System.out.print(inst.valueSparse(i));
      }
      System.out.println();

      // Set all values to one
      System.out.print("All values set to one: ");
      for (int i = 0; i < inst.numAttributes(); i++) {
        inst.setValue(i, 1);
      }
      for (int i = 0; i < inst.numValues(); i++) {
        if (i > 0) {
          System.out.print(",");
        }
        System.out.print(inst.valueSparse(i));
      }
      System.out.println();

      // Unset dataset for copy, delete first attribute, and insert it again
      copy.setDataset(null);
      copy.deleteAttributeAt(0);
      copy.insertAttributeAt(0);
      copy.setDataset(inst.dataset());
      System.out.println("Copy with first attribute deleted and inserted: " + copy);

      // Same for second attribute
      copy.setDataset(null);
      copy.deleteAttributeAt(1);
      copy.insertAttributeAt(1);
      copy.setDataset(inst.dataset());
      System.out.println("Copy with second attribute deleted and inserted: " + copy);

      // Same for last attribute
      copy.setDataset(null);
      copy.deleteAttributeAt(2);
      copy.insertAttributeAt(2);
      copy.setDataset(inst.dataset());
      System.out.println("Copy with third attribute deleted and inserted: " + copy);

      // Enumerate attributes (leaving out the class attribute)
      System.out.println("Enumerating attributes (leaving out class):");
      Enumeration enu = inst.enumerateAttributes();
      while (enu.hasMoreElements()) {
        Attribute att = (Attribute) enu.nextElement();
        System.out.println(att);
      }

      // Headers are equivalent?
      System.out.println("Header of original and copy equivalent: " + inst.equalHeaders(copy));

      // Test for missing values
      System.out.println("Length of copy missing: " + copy.isMissing(length));
      System.out.println("Weight of copy missing: " + copy.isMissing(weight.index()));
      System.out.println("Length of copy missing: " + Instance.isMissingValue(copy.value(length)));
      System.out.println("Missing value coded as: " + Instance.missingValue());

      // Prints number of attributes and classes
      System.out.println("Number of attributes: " + copy.numAttributes());
      System.out.println("Number of classes: " + copy.numClasses());

      // Replace missing values
      float[] meansAndModes = {2, 3, 0};
      copy.replaceMissingValues(meansAndModes);
      System.out.println("Copy with missing value replaced: " + copy);

      // Setting and getting values and weights
      copy.setClassMissing();
      System.out.println("Copy with missing class: " + copy);
      copy.setClassValue(0);
      System.out.println("Copy with class value set to first value: " + copy);
      copy.setClassValue("second");
      System.out.println("Copy with class value set to \"second\": " + copy);
      copy.setMissing(1);
      System.out.println("Copy with second attribute set to be missing: " + copy);
      copy.setMissing(length);
      System.out.println("Copy with length set to be missing: " + copy);
      copy.setValue(0, 0);
      System.out.println("Copy with first attribute set to 0: " + copy);
      copy.setValue(weight, 1);
      System.out.println("Copy with weight attribute set to 1: " + copy);
      copy.setValue(position, "second");
      System.out.println("Copy with position set to \"second\": " + copy);
      copy.setValue(2, "first");
      System.out.println("Copy with last attribute set to \"first\": " + copy);
      System.out.println("Current weight of instance copy: " + copy.weight());
      copy.setWeight(2);
      System.out.println("Current weight of instance copy (set to 2): " + copy.weight());
      System.out.println("Last value of copy: " + copy.toString(2));
      System.out.println("Value of position for copy: " + copy.toString(position));
      System.out.println("Last value of copy (internal format): " + copy.value(2));
      System.out.println("Value of position for copy (internal format): " + copy.value(position));
    } catch (Exception e) {
      e.printStackTrace();
    }
  }