/**
* Constructor. Creates a new instance of Spea2Fitness for a given <code>SolutionSet</code>.
*
* @param solutionSet The <code>SolutionSet</code>
*/
public Spea2Fitness(SolutionSet solutionSet) {
distance = distance_.distanceMatrix(solutionSet);
solutionSet_ = solutionSet;
for (int i = 0; i < solutionSet_.size(); i++) {
solutionSet_.get(i).setLocation(i);
} // for
} // Spea2Fitness
/**
* Gets 'size' elements from a population of more than 'size' elements using for this de
* enviromentalSelection truncation
*
* @param size The number of elements to get.
*/
public SolutionSet environmentalSelection(int size) {
if (solutionSet_.size() < size) {
size = solutionSet_.size();
}
// Create a new auxiliar population for no alter the original population
SolutionSet aux = new SolutionSet(solutionSet_.size());
int i = 0;
while (i < solutionSet_.size()) {
if (solutionSet_.get(i).getFitness() < 1.0) {
aux.add(solutionSet_.get(i));
solutionSet_.remove(i);
} else {
i++;
} // if
} // while
if (aux.size() < size) {
Comparator comparator = new FitnessComparator();
solutionSet_.sort(comparator);
int remain = size - aux.size();
for (i = 0; i < remain; i++) {
aux.add(solutionSet_.get(i));
}
return aux;
} else if (aux.size() == size) {
return aux;
}
double[][] distance = distance_.distanceMatrix(aux);
List<List<DistanceNode>> distanceList = new LinkedList<List<DistanceNode>>();
for (int pos = 0; pos < aux.size(); pos++) {
aux.get(pos).setLocation(pos);
List<DistanceNode> distanceNodeList = new ArrayList<DistanceNode>();
for (int ref = 0; ref < aux.size(); ref++) {
if (pos != ref) {
distanceNodeList.add(new DistanceNode(distance[pos][ref], ref));
} // if
} // for
distanceList.add(distanceNodeList);
} // for
for (int q = 0; q < distanceList.size(); q++) {
Collections.sort(distanceList.get(q), distanceNodeComparator);
} // for
while (aux.size() > size) {
double minDistance = Double.MAX_VALUE;
int toRemove = 0;
i = 0;
Iterator<List<DistanceNode>> iterator = distanceList.iterator();
while (iterator.hasNext()) {
List<DistanceNode> dn = iterator.next();
if (dn.get(0).getDistance() < minDistance) {
toRemove = i;
minDistance = dn.get(0).getDistance();
// i y toRemove have the same distance to the first solution
} else if (dn.get(0).getDistance() == minDistance) {
int k = 0;
while ((dn.get(k).getDistance() == distanceList.get(toRemove).get(k).getDistance())
&& k < (distanceList.get(i).size() - 1)) {
k++;
}
if (dn.get(k).getDistance() < distanceList.get(toRemove).get(k).getDistance()) {
toRemove = i;
} // if
} // if
i++;
} // while
int tmp = aux.get(toRemove).getLocation();
aux.remove(toRemove);
distanceList.remove(toRemove);
Iterator<List<DistanceNode>> externIterator = distanceList.iterator();
while (externIterator.hasNext()) {
Iterator<DistanceNode> interIterator = externIterator.next().iterator();
while (interIterator.hasNext()) {
if (interIterator.next().getReference() == tmp) {
interIterator.remove();
continue;
} // if
} // while
} // while
} // while
return aux;
} // environmentalSelection