/**
* Returns the best individual (the elite) currently present in the population, based of the
* values returned by the <code>getFitness</code> method.
*
* @return The elite individual
*/
public AbstractIndividual getBestIndividual() {
AbstractIndividual best = this.individuals[0];
for (AbstractIndividual individual : this.individuals) {
if (Double.isNaN(best.getFitness()) || individual.getFitness() > best.getFitness()) {
best = individual;
}
}
return best;
}
/**
* Computes an average fitness of all the individuals in the population, using their <code>
* getFitness</code> method.
*
* @return average fitness in the population
*/
public double getAvgFitness() {
avgFitness = 0;
for (AbstractIndividual individual : individuals) {
individual.getFitness();
avgFitness += individual.getFitness();
bestFitness = Math.max(bestFitness, individual.getFitness());
}
avgFitness = avgFitness / individuals.length;
return avgFitness;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("=== POPULATION ===\n");
for (AbstractIndividual individual : individuals) {
sb.append(individual.toString());
sb.append("\n");
}
sb.append("=== avgFIT: ").append(avgFitness).append(" ===\n");
return sb.toString();
}
/**
* Returns a <code>pair</code> of two integers. The first one is a number of nodes that are
* activated and the second one is a number of how many edges are not covered.
*
* @param individual Usually the best individual in a population
* @return <code>pair</code> of two integers
*/
public Pair getVertexCover(AbstractIndividual individual) {
Pair<Integer, Integer> pair = new Pair<>();
int activeNodeCounter = 0;
int notCoveredEdgesCount = 0;
for (int i = 0; i < StateSpace.nodesCount(); i++) {
if (individual.isNodeSelected(i)) {
activeNodeCounter++;
} else {
for (Edge edge : StateSpace.getNode(i).getEdges()) {
if (!individual.isNodeSelected(edge.getToId())) {
notCoveredEdgesCount++;
}
}
}
}
pair.a = activeNodeCounter;
pair.b = notCoveredEdgesCount;
return pair;
}
