Pheromone.java

   1 class Pheromone {
   2
   3   protected Graph graph;
   4   protected double[][] Pheromone;
   5
   6   Pheromone(Graph graph) {
   7     this.graph = graph;
   8     this.Pheromone = new double[graph.getNumOfCities()][graph.getNumOfCities()];
   9
  10     for (int i = 0; i < graph.getNumOfCities(); i++) {
  11       for (int j = 0; j < graph.getNumOfCities(); j++) {
  12         setPheromone(i,j, 0.1);
  13       }
  14     }
  15
  16   }
  17
  18   public void pheromoneUpdate(Ant[] ants) {
  19     evaporate();
  20
  21     for (Ant ant : ants) {
  22       depositPheromone(ant);
  23     }
  24
  25     graph.computeChoiceInformation();
  26   }
  27
  28   public void evaporate() {
  29     for (int i = 1; i < graph.getNumOfCities(); i++) {
  30       for (int j = 1; j < graph.getNumOfCities(); j++) {
  31         Pheromone[i][j] = (1.0 - graph.getROH()) * Pheromone[i][j];
  32         Pheromone[j][i] = Pheromone[i][j];
  33       }
  34     }
  35   }
  36
  37   public void depositPheromone(Ant ant) {
  38     double dt = 1.0/ant.getTourLength();
  39     for (int i = 0; i < graph.getNumOfCities() - 1; i++) {
  40       int j = ant.getTour(i);
  41       int l = ant.getTour(i+1);
  42       Pheromone[j][l] = Pheromone[j][l] + dt;
  43       Pheromone[l][j] = Pheromone[j][l];
  44     }
  45   }
  46
  47   public double[][] getPheromone() {
  48     return this.Pheromone;
  49   }
  50
  51   public double getPheromone(int x, int y) {
  52     return this.Pheromone[x][y];
  53   }
  54
  55   public void setPheromone(double[][] Pheromone) {
  56     this.Pheromone = Pheromone;
  57   }
  58
  59   public void setPheromone(int x, int y, double Pheromone) {
  60     this.Pheromone[x][y] = Pheromone;
  61   }
  62
  63 }