antroutingentry.java

JAVA版的蚂蚁算法(Ant Colony Optimization Algorithms)

package dk.itu.nulx30.networkModel;

/**
 * An <code>AntRoutingEntry</code> contains a wire and a pheromone value and is
 * the basic element saved in a <code>RoutingTable</code> (one for each
 * destination for each outgoing queue).
 *        
 * @author  Mikkel Bundgaard
 * @author  Troels C. Damgaard
 * @author  Federico Decara
 * @author  Jacob W. Winther
 *
 * @see RoutingTable
 */
public class AntRoutingEntry {
  /** the wire to route by*/
  private Wire outputWire;
  /** the pheromone value of this choice*/
  private double pheromoneValue;
  /**
   * the initial trail value in an entry (some small constant greater than 0)
   */
  private static final double INITIAL_PHEROMONE_VALUE = 10.0;

  /**
   * Class constructor for this class which takes an wire as argument. 
   *
   * @param wire the wire of this entry
   */
  public AntRoutingEntry( Wire wire ) {
    outputWire = wire;
    // Initialize pheromonevalue to the constant INITIAL_PHEROMONE_VALUE
    pheromoneValue = INITIAL_PHEROMONE_VALUE;
  }

  /**
   * Accessor method for the wire of this object.
   *
   * @return the wire of this entry
   */
  public Wire getWire() {
    return outputWire;
  }

  /**
   * Accessor method for pheromoneValue.
   *
   * @return the pheromone value of this entry
   */
  public double getPheromoneValue() {
    return pheromoneValue;
  }

  /**
   * Sets the value of the pheromone to the value given as argument.
   *
   * @param newVal the new pheromone value for this entry
   */
  public void setPheromoneValue( double newVal ) {
    pheromoneValue = newVal;
  }

  /**
   * Adds the value given as argument to the current value of the pheromone.
   *
   * @param toAdd the value to add to the pheromone value
   */
  public void incrementPheromoneValue( double toAdd ) {
    pheromoneValue += toAdd;
  }

  /**
   * Evaporates the pheromone value by multiplying it with a factor
   *
   * @param factor the factor to multiply the pheromone value with
   */
  public void evaporatePheromoneValue( double factor ) {
    pheromoneValue *= factor;
  }

  /**
   * Provides a string representation of this object.
   *
   * @return a string representation of this
   * <code>AntRoutingEntry</code>. The string representation contains a
   * string representation of the wire and of the pheromone value.
   */
  public String toString() {
    return new StringBuffer( "( " + outputWire + " ) : " +
                             pheromoneValue + "\t" ).toString();
  }
}