@Override
public void performIteration(NichingAlgorithm alg) {
Preconditions.checkState(
alg.getOptimisationProblem() instanceof DeratingOptimisationProblem,
"DeratingNichePSO can only be used with DeratingOptimisationProblem.");
DeratingOptimisationProblem problem =
(DeratingOptimisationProblem) alg.getOptimisationProblem();
List<PopulationBasedAlgorithm> subswarms =
List.<PopulationBasedAlgorithm>iterableList(alg.getPopulations());
subswarms =
onMainSwarm(Algorithms.<PopulationBasedAlgorithm>initialise())
.andThen(phase1(alg))
.andThen(onSubswarms(clearDeratingSolutions(problem)))
.andThen(phase2(alg))
.andThen(joinAndMerge(alg, subswarms))
.f(
NichingSwarms.of(
alg.getMainSwarm(), Collections.<PopulationBasedAlgorithm>emptyList()))
._2();
problem.clearSolutions();
problem.addSolutions(
subswarms
.map(Solutions.getPosition().o(Algorithms.<PopulationBasedAlgorithm>getBestSolution()))
.toCollection());
alg.setPopulations(Lists.newLinkedList(subswarms.toCollection()));
alg.getMainSwarm().setOptimisationProblem(problem);
// dont need to set the main swarm because it gets reinitialised
}
@Test
public void testCreation() {
Particle p1 =
NichingFunctionsTest.createParticle(new MinimisationFitness(3.0), Vector.of(0.0, 1.0));
Particle p2 =
NichingFunctionsTest.createParticle(new MinimisationFitness(2.0), Vector.of(1.0, 1.0));
Particle p3 =
NichingFunctionsTest.createParticle(new MinimisationFitness(1.0), Vector.of(2.0, 2.0));
PSO pso = new PSO();
pso.getTopology().addAll(Arrays.asList(p1, p2, p3));
ClosestNeighbourNicheCreationStrategy creator = new ClosestNeighbourNicheCreationStrategy();
creator.setSwarmBehavior(new ParticleBehavior());
NichingSwarms swarms =
creator.f(NichingSwarms.of(pso, List.<PopulationBasedAlgorithm>nil()), p1);
Assert.assertEquals(1, swarms._1().getTopology().size());
Assert.assertEquals(
Vector.of(2.0, 2.0), swarms._1().getTopology().get(0).getCandidateSolution());
Assert.assertEquals(2, swarms._2().head().getTopology().size());
Assert.assertEquals(
Vector.of(0.0, 1.0), swarms._2().head().getTopology().get(0).getCandidateSolution());
Assert.assertEquals(
Vector.of(1.0, 1.0), swarms._2().head().getTopology().get(1).getCandidateSolution());
}