Question
Asked 15th Mar, 2014
J. Karthikeyan
J. Karthikeyan

Does anyone have code for ant colony optimization algorithm in java?

I need to use my project
Ant Colony Optimization
Optimization Algorithms

Most recent answer

package de.jungblut.antcolony;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import cern.jet.random.Uniform;
public final class AntColonyOptimization {
// greedy
public static final double ALPHA = -0.2d;
// rapid selection
public static final double BETA = 9.6d;
// heuristic parameters
public static final double Q = 0.0001d; // somewhere between 0 and 1
public static final double PHEROMONE_PERSISTENCE = 0.3d; // between 0 and 1
public static final double INITIAL_PHEROMONES = 0.8d; // can be anything
// use power of 2
public static final int numOfAgents = 2048 * 20;
private static final int poolSize = Runtime.getRuntime().availableProcessors();
private Uniform uniform;
private final ExecutorService threadPool = Executors.newFixedThreadPool(poolSize);
private final ExecutorCompletionService agentCompletionService = new ExecutorCompletionService(
threadPool);
final double[][] matrix;
final double[][] invertedMatrix;
private final double[][] pheromones;
private final Object[][] mutexes;
public AntColonyOptimization() throws IOException {
// read the matrix
matrix = readMatrixFromFile();
invertedMatrix = invertMatrix();
pheromones = initializePheromones();
mutexes = initializeMutexObjects();
// (double min, double max, int seed)
uniform = new Uniform(0, matrix.length – 1, (int) System.currentTimeMillis());
}
private final Object[][] initializeMutexObjects() {
final Object[][] localMatrix = new Object[matrix.length][matrix.length];
int rows = matrix.length;
for (int columns = 0; columns < matrix.length; columns++) {
for (int i = 0; i = 0.0d) {
pheromones[x][y] = result;
} else {
pheromones[x][y] = 0;
}
}
}
private final double calculatePheromones(double current, double newPheromone) {
final double result = (1 – AntColonyOptimization.PHEROMONE_PERSISTENCE) * current
+ newPheromone;
return result;
}
final void adjustPheromone(int[] way, double newPheromone) {
synchronized (pheromones) {
for (int i = 0; i < way.length – 1; i++) {
pheromones[way[i]][way[i + 1]] = calculatePheromones(
pheromones[way[i]][way[i + 1]], newPheromone);
}
pheromones[way[way.length – 1]][way[0]] = calculatePheromones(
pheromones[way.length – 1][way[0]], newPheromone);
}
}
private final double[][] initializePheromones() {
final double[][] localMatrix = new double[matrix.length][matrix.length];
int rows = matrix.length;
for (int columns = 0; columns < matrix.length; columns++) {
for (int i = 0; i < rows; i++) {
localMatrix[columns][i] = INITIAL_PHEROMONES;
}
}
return localMatrix;
}
private final double[][] readMatrixFromFile() throws IOException {
final BufferedReader br = new BufferedReader(new FileReader(new File("files/berlin52.tsp")));
final LinkedList records = new LinkedList();
boolean readAhead = false;
String line;
while ((line = br.readLine()) != null) {
if (line.equals(“EOF”)) {
break;
}
if (readAhead) {
String[] split = line.trim().split(” “);
records.add(new Record(Double.parseDouble(split[1].trim()), Double
.parseDouble(split[2].trim())));
}
if (line.equals(“NODE_COORD_SECTION”)) {
readAhead = true;
}
}
br.close();
final double[][] localMatrix = new double[records.size()][records.size()];
int rIndex = 0;
for (Record r : records) {
int hIndex = 0;
for (Record h : records) {
localMatrix[rIndex][hIndex] = calculateEuclidianDistance(r.x, r.y, h.x, h.y);
hIndex++;
}
rIndex++;
}
return localMatrix;
}
private final double[][] invertMatrix() {
double[][] local = new double[matrix.length][matrix.length];
for (int i = 0; i < matrix.length; i++) {
for (int j = 0; j < matrix.length; j++) {
local[i][j] = invertDouble(matrix[i][j]);
}
}
return local;
}
private final double invertDouble(double distance) {
if (distance == 0)
return 0;
else
return 1.0d / distance;
}
private final double calculateEuclidianDistance(double x1, double y1, double x2, double y2) {
return Math.abs((Math.sqrt(Math.pow(x2 – x1, 2) + Math.pow(y2 – y1, 2))));
}
final double start() throws InterruptedException, ExecutionException {
WalkedWay bestDistance = null;
int agentsSend = 0;
int agentsDone = 0;
int agentsWorking = 0;
for (int agentNumber = 0; agentNumber = poolSize) {
WalkedWay way = agentCompletionService.take().get();
if (bestDistance == null || way.distance < bestDistance.distance) {
bestDistance = way;
System.out.println("Agent returned with new best distance of: " + way.distance);
}
agentsDone++;
agentsWorking–;
}
}
final int left = agentsSend – agentsDone;
System.out.println("Waiting for " + left + " agents to finish their random walk!");
for (int i = 0; i < left; i++) {
WalkedWay way = agentCompletionService.take().get();
if (bestDistance == null || way.distance < bestDistance.distance) {
bestDistance = way;
System.out.println("Agent returned with new best distance of: " + way.distance);
}
}
threadPool.shutdownNow();
System.out.println("Found best so far: " + bestDistance.distance);
System.out.println(Arrays.toString(bestDistance.way));
return bestDistance.distance;
}
private final int getGaussianDistributionRowIndex() {
return uniform.nextInt();
}
static class Record {
double x;
double y;
public Record(double x, double y) {
super();
this.x = x;
this.y = y;
}
}
static class WalkedWay {
int[] way;
double distance;
public WalkedWay(int[] way, double distance) {
super();
this.way = way;
this.distance = distance;
}
}
public static void main(String[] args) throws IOException, InterruptedException,
ExecutionException {
long start = System.currentTimeMillis();
AntColonyOptimization antColonyOptimization = new AntColonyOptimization();
antColonyOptimization.start();
System.out.println("Took: " + (System.currentTimeMillis() – start) + " ms!");
}
}
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1 Recommendation

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All Answers (5)

Amir Sedaghatdoost
Texas A&M University
Thanks Mr. Karthikeyan for this question.
I will also glad if anyone have the FORTRAN code too.
Cite
Tousif Zaman
Worcester Polytechnic Institute
For Java, check this http://sourceforge.net/projects/myra/
Cite
Harshpreet Singh
Lovely Professional University
http://www.aco-metaheuristic.org/tutorials-courses.html
Cite
Carlos Gavidia-Calderon
Alan Turing Institute
I know is kind of late, but this Java Framework might be useful: http://cptanalatriste.github.io/isula/
https://github.com/cptanalatriste/isula
Cite
1 Recommendation
package de.jungblut.antcolony;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import cern.jet.random.Uniform;
public final class AntColonyOptimization {
// greedy
public static final double ALPHA = -0.2d;
// rapid selection
public static final double BETA = 9.6d;
// heuristic parameters
public static final double Q = 0.0001d; // somewhere between 0 and 1
public static final double PHEROMONE_PERSISTENCE = 0.3d; // between 0 and 1
public static final double INITIAL_PHEROMONES = 0.8d; // can be anything
// use power of 2
public static final int numOfAgents = 2048 * 20;
private static final int poolSize = Runtime.getRuntime().availableProcessors();
private Uniform uniform;
private final ExecutorService threadPool = Executors.newFixedThreadPool(poolSize);
private final ExecutorCompletionService agentCompletionService = new ExecutorCompletionService(
threadPool);
final double[][] matrix;
final double[][] invertedMatrix;
private final double[][] pheromones;
private final Object[][] mutexes;
public AntColonyOptimization() throws IOException {
// read the matrix
matrix = readMatrixFromFile();
invertedMatrix = invertMatrix();
pheromones = initializePheromones();
mutexes = initializeMutexObjects();
// (double min, double max, int seed)
uniform = new Uniform(0, matrix.length – 1, (int) System.currentTimeMillis());
}
private final Object[][] initializeMutexObjects() {
final Object[][] localMatrix = new Object[matrix.length][matrix.length];
int rows = matrix.length;
for (int columns = 0; columns < matrix.length; columns++) {
for (int i = 0; i = 0.0d) {
pheromones[x][y] = result;
} else {
pheromones[x][y] = 0;
}
}
}
private final double calculatePheromones(double current, double newPheromone) {
final double result = (1 – AntColonyOptimization.PHEROMONE_PERSISTENCE) * current
+ newPheromone;
return result;
}
final void adjustPheromone(int[] way, double newPheromone) {
synchronized (pheromones) {
for (int i = 0; i < way.length – 1; i++) {
pheromones[way[i]][way[i + 1]] = calculatePheromones(
pheromones[way[i]][way[i + 1]], newPheromone);
}
pheromones[way[way.length – 1]][way[0]] = calculatePheromones(
pheromones[way.length – 1][way[0]], newPheromone);
}
}
private final double[][] initializePheromones() {
final double[][] localMatrix = new double[matrix.length][matrix.length];
int rows = matrix.length;
for (int columns = 0; columns < matrix.length; columns++) {
for (int i = 0; i < rows; i++) {
localMatrix[columns][i] = INITIAL_PHEROMONES;
}
}
return localMatrix;
}
private final double[][] readMatrixFromFile() throws IOException {
final BufferedReader br = new BufferedReader(new FileReader(new File("files/berlin52.tsp")));
final LinkedList records = new LinkedList();
boolean readAhead = false;
String line;
while ((line = br.readLine()) != null) {
if (line.equals(“EOF”)) {
break;
}
if (readAhead) {
String[] split = line.trim().split(” “);
records.add(new Record(Double.parseDouble(split[1].trim()), Double
.parseDouble(split[2].trim())));
}
if (line.equals(“NODE_COORD_SECTION”)) {
readAhead = true;
}
}
br.close();
final double[][] localMatrix = new double[records.size()][records.size()];
int rIndex = 0;
for (Record r : records) {
int hIndex = 0;
for (Record h : records) {
localMatrix[rIndex][hIndex] = calculateEuclidianDistance(r.x, r.y, h.x, h.y);
hIndex++;
}
rIndex++;
}
return localMatrix;
}
private final double[][] invertMatrix() {
double[][] local = new double[matrix.length][matrix.length];
for (int i = 0; i < matrix.length; i++) {
for (int j = 0; j < matrix.length; j++) {
local[i][j] = invertDouble(matrix[i][j]);
}
}
return local;
}
private final double invertDouble(double distance) {
if (distance == 0)
return 0;
else
return 1.0d / distance;
}
private final double calculateEuclidianDistance(double x1, double y1, double x2, double y2) {
return Math.abs((Math.sqrt(Math.pow(x2 – x1, 2) + Math.pow(y2 – y1, 2))));
}
final double start() throws InterruptedException, ExecutionException {
WalkedWay bestDistance = null;
int agentsSend = 0;
int agentsDone = 0;
int agentsWorking = 0;
for (int agentNumber = 0; agentNumber = poolSize) {
WalkedWay way = agentCompletionService.take().get();
if (bestDistance == null || way.distance < bestDistance.distance) {
bestDistance = way;
System.out.println("Agent returned with new best distance of: " + way.distance);
}
agentsDone++;
agentsWorking–;
}
}
final int left = agentsSend – agentsDone;
System.out.println("Waiting for " + left + " agents to finish their random walk!");
for (int i = 0; i < left; i++) {
WalkedWay way = agentCompletionService.take().get();
if (bestDistance == null || way.distance < bestDistance.distance) {
bestDistance = way;
System.out.println("Agent returned with new best distance of: " + way.distance);
}
}
threadPool.shutdownNow();
System.out.println("Found best so far: " + bestDistance.distance);
System.out.println(Arrays.toString(bestDistance.way));
return bestDistance.distance;
}
private final int getGaussianDistributionRowIndex() {
return uniform.nextInt();
}
static class Record {
double x;
double y;
public Record(double x, double y) {
super();
this.x = x;
this.y = y;
}
}
static class WalkedWay {
int[] way;
double distance;
public WalkedWay(int[] way, double distance) {
super();
this.way = way;
this.distance = distance;
}
}
public static void main(String[] args) throws IOException, InterruptedException,
ExecutionException {
long start = System.currentTimeMillis();
AntColonyOptimization antColonyOptimization = new AntColonyOptimization();
antColonyOptimization.start();
System.out.println("Took: " + (System.currentTimeMillis() – start) + " ms!");
}
}
Cite
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