diff options
Diffstat (limited to 'src/jcgp/backend/modules/es')
| -rw-r--r-- | src/jcgp/backend/modules/es/EvolutionaryStrategy.java | 13 | ||||
| -rw-r--r-- | src/jcgp/backend/modules/es/MuPlusLambda.java | 43 | ||||
| -rw-r--r-- | src/jcgp/backend/modules/es/TournamentSelection.java | 33 |
3 files changed, 52 insertions, 37 deletions
diff --git a/src/jcgp/backend/modules/es/EvolutionaryStrategy.java b/src/jcgp/backend/modules/es/EvolutionaryStrategy.java index 1a14552..30a3c4a 100644 --- a/src/jcgp/backend/modules/es/EvolutionaryStrategy.java +++ b/src/jcgp/backend/modules/es/EvolutionaryStrategy.java @@ -33,12 +33,21 @@ import jcgp.backend.resources.Resources; public abstract class EvolutionaryStrategy extends Module { /** + * For internal use only, initialises the resources field. + * + * @param resources the experiment's resources. + */ + protected EvolutionaryStrategy(Resources resources) { + super(resources); + } + + /** * Performs the selection algorithm and uses the mutator to create * the next generation of solutions. * * @param population the population to evolve. * @param mutator the mutator with which to mutate the promoted individuals. - * @param resources parameters and utilities for optional reference. */ - public abstract void evolve(Population population, Mutator mutator, Resources resources); + public abstract void evolve(Population population, Mutator mutator); + } diff --git a/src/jcgp/backend/modules/es/MuPlusLambda.java b/src/jcgp/backend/modules/es/MuPlusLambda.java index 8186b11..3743ee6 100644 --- a/src/jcgp/backend/modules/es/MuPlusLambda.java +++ b/src/jcgp/backend/modules/es/MuPlusLambda.java @@ -28,21 +28,21 @@ import jcgp.backend.resources.Resources; * */ public class MuPlusLambda extends EvolutionaryStrategy { - + private IntegerParameter mu, lambda; private BooleanParameter report; - + /** * Creates a new instance of MuPlusLambda. * * @param resources a reference to the experiment's resources. */ public MuPlusLambda(final Resources resources) { - super(); + super(resources); mu = new IntegerParameter(1, "Parents (μ)") { @Override public void validate(Number newValue) { - if (newValue.intValue() + lambda.get() != resources.populationSize()) { + if (newValue.intValue() + lambda.get() != getResources().populationSize()) { status = ParameterStatus.INVALID; status.setDetails("Parents + offspring must equal population size."); } else if (newValue.intValue() <= 0) { @@ -53,11 +53,11 @@ public class MuPlusLambda extends EvolutionaryStrategy { } } }; - + lambda = new IntegerParameter(4, "Offspring (λ)") { @Override public void validate(Number newValue) { - if (newValue.intValue() + mu.get() != resources.populationSize()) { + if (newValue.intValue() + mu.get() != getResources().populationSize()) { status = ParameterStatus.INVALID; status.setDetails("Parents + offspring must equal population size."); } else if (newValue.intValue() <= 0) { @@ -68,29 +68,30 @@ public class MuPlusLambda extends EvolutionaryStrategy { } } }; - + report = new BooleanParameter(false, "Report"); - + setName("(μ + λ)"); registerParameters(mu, lambda, report); } - + @Override - public void evolve(Population population, Mutator mutator, Resources resources) { - /* Population is sorted in ascending order of fitness, so leave the last - * mu chromosomes intact - */ - for (int i = 0; i < resources.populationSize() - mu.get(); i++) { + public void evolve(Population population, Mutator mutator) { + // sort the population in order of best fitness + population.sort(); + + // population is now sorted in ascending order of fitness, the last chromosomes are the fittest + for (int i = 0; i < getResources().populationSize() - mu.get(); i++) { // select a random parent out of the lambda offspring individuals - int randomParent = resources.populationSize() - 1 - resources.getRandomInt(mu.get()); - if (report.get()) resources.reportln("[ES] Copying Chr " + randomParent + " to population position " + i); + int randomParent = getResources().populationSize() - 1 - getResources().getRandomInt(mu.get()); + if (report.get()) getResources().reportln("[ES] Copying Chr " + randomParent + " to population position " + i); population.copyChromosome(randomParent, i); - + // mutate selected chromosome - if (report.get()) resources.reportln("[ES] Mutating copied chromosome"); - mutator.mutate(population.getChromosome(i), resources); + if (report.get()) getResources().reportln("[ES] Mutating copied chromosome"); + mutator.mutate(population.get(i)); } - - if (report.get()) resources.reportln("[ES] Generation is complete"); + + if (report.get()) getResources().reportln("[ES] Generation is complete"); } } diff --git a/src/jcgp/backend/modules/es/TournamentSelection.java b/src/jcgp/backend/modules/es/TournamentSelection.java index 209caca..6d467f5 100644 --- a/src/jcgp/backend/modules/es/TournamentSelection.java +++ b/src/jcgp/backend/modules/es/TournamentSelection.java @@ -44,7 +44,7 @@ public class TournamentSelection extends EvolutionaryStrategy { * @param resources a reference to the experiment's resources. */ public TournamentSelection(final Resources resources) { - super(); + super(resources); tournamentSize = new IntegerParameter(1, "Tournament size") { @Override public void validate(Number newValue) { @@ -73,17 +73,22 @@ public class TournamentSelection extends EvolutionaryStrategy { } @Override - public void evolve(Population population, Mutator mutator, Resources resources) { + public void evolve(Population population, Mutator mutator) { /* Create an entirely new population by isolating random subsets of * the original population and choosing the fittest individual within * that subset. Each chosen individual is mutated and copied back into the * population. */ - Chromosome[] newPopulation = new Chromosome[resources.populationSize()]; + + // sort the population by fitness to make things easier + population.sort(); + + // this array holds the new population temporarily, until it is copied over + Chromosome[] newPopulation = new Chromosome[getResources().populationSize()]; // start by selecting all of the chromosomes that will be promoted - for (int i = 0; i < resources.populationSize(); i++) { - if (report.get()) resources.reportln("[ES] Starting tournament " + i); + for (int i = 0; i < getResources().populationSize(); i++) { + if (report.get()) getResources().reportln("[ES] Starting tournament " + i); /* the population is sorted in ascending order of fitness, * meaning the higher the index of the contender, the fitter @@ -91,21 +96,21 @@ public class TournamentSelection extends EvolutionaryStrategy { */ int[] contenders = new int[tournamentSize.get()]; for (int t = 0; t < tournamentSize.get() - 1; t++) { - contenders[t] = resources.getRandomInt(resources.populationSize()); + contenders[t] = getResources().getRandomInt(getResources().populationSize()); } - if (report.get()) resources.reportln("[ES] Selected contenders: " + Arrays.toString(contenders)); + if (report.get()) getResources().reportln("[ES] Selected contenders: " + Arrays.toString(contenders)); Arrays.sort(contenders); - if (report.get()) resources.reportln("[ES] Chr " + contenders[contenders.length - 1] + " wins the tournament, copying and mutating..."); + if (report.get()) getResources().reportln("[ES] Chr " + contenders[contenders.length - 1] + " wins the tournament, copying and mutating..."); // create a copy of the selected chromosome and mutate it - newPopulation[i] = new Chromosome(population.getChromosome(contenders[contenders.length - 1])); - mutator.mutate(newPopulation[i], resources); + newPopulation[i] = new Chromosome(population.get(contenders[contenders.length - 1])); + mutator.mutate(newPopulation[i]); } - if (report.get()) resources.reportln("[ES] Tournaments are finished, copying new chromosomes into population"); + if (report.get()) getResources().reportln("[ES] Tournaments are finished, copying new chromosomes into population"); // newPopulation has been generated, copy into the population - for (int c = 0; c < resources.populationSize(); c++) { - population.getChromosome(c).copyGenes(newPopulation[c]); + for (int c = 0; c < getResources().populationSize(); c++) { + population.get(c).copyGenes(newPopulation[c]); } - if (report.get()) resources.reportln("[ES] Generation is complete"); + if (report.get()) getResources().reportln("[ES] Generation is complete"); } } |