aco/strategy/acs/ACSPheromoneStrategy.java

   1 package aco.strategy.acs;
   2
   3 import aco.ant.*;
   4 import aco.strategy.*;
   5 import aco.mediator.*;
   6 import aco.mediator.acs.*;
   7
   8 public class ACSPheromoneStrategy
   9   extends PheromoneStrategy {
  10
  11   public ACSPheromoneStrategy(ACSMediator acom) {
  12     super((ACOMediator) acom);
  13   }
  14
  15   //global Pheromone Update
  16   public void pheromoneUpdate(Ant[] ants) {
  17     double deltaTau = 1.0 / (double)acom.getGlobalBestTourLength();
  18     int j;
  19     int l;
  20     for (int i = 0; i < acom.getNumOfCities(); i++) {
  21       j = acom.getGlobalBestTour(i);
  22       l = acom.getGlobalBestTour(i+1);
  23       acom.setPheromone(j, l,
  24           ( (1 - acom.getRoh()) * acom.getPheromone(j, l) ) +
  25           (acom.getRoh() * deltaTau) );
  26
  27       //g.pheromones[l][j] = g.pheromones[j][l];
  28       acom.setChoiceInformation(j, l,
  29           acom.getPheromone(j, l) *
  30           Math.pow((1.0/  acom.getDistance(j, l) ), acom.getBeta()));
  31
  32       //g.choice_info[j][l] =  g.pheromones[j][l] *
  33       //Math.pow((1.0/g.distance_matrix[j][l]), beta);
  34       //g.choice_info[l][j] = g.choice_info[l][j];
  35     }
  36   }
  37
  38   //local Pheromone Update
  39   public void localPheromoneUpdate(Ant k, int i) {
  40     int j = k.getTour(i-1);
  41     int l = k.getTour(i);
  42
  43     acom.setPheromone(j, l,
  44         ( (1 - acom.getRoh()) * acom.getPheromone(j, l) ) +
  45         ( acom.getRoh() * acom.getTauZero() ));
  46
  47     //g.pheromones[l][j] = g.pheromones[j][l];
  48     acom.setChoiceInformation(j, l,
  49         acom.getPheromone(j, l) *
  50         Math.pow( (1.0/acom.getDistance(j, l)), acom.getBeta() ) );
  51   }
  52
  53   protected void depositPheromone(Ant ant) {}
  54
  55   protected void evaporate() {}
  56
  57 }