| 1 | package net.bmahe.genetics4j.core.spec.selection; | |
| 2 | ||
| 3 | import java.util.Comparator; | |
| 4 | ||
| 5 | import org.apache.commons.lang3.Validate; | |
| 6 | import org.immutables.value.Value; | |
| 7 | ||
| 8 | import net.bmahe.genetics4j.core.Individual; | |
| 9 | ||
| 10 | /** | |
| 11 | * Selective Refinement Tournament selection strategy that enhances traditional tournament selection by applying an | |
| 12 | * additional refinement step to a subset of candidates. | |
| 13 | * <p>This selection mechanism first performs standard tournament selection, then applies a secondary refinement process | |
| 14 | * using a custom comparator to a portion of the selected candidates. This allows for more sophisticated selection | |
| 15 | * criteria beyond simple fitness-based comparison.</p> | |
| 16 | * | |
| 17 | * <h3>Algorithm Overview:</h3> | |
| 18 | * <ol> | |
| 19 | * <li>Conduct standard tournament selection based on the configured tournament parameters</li> | |
| 20 | * <li>Apply refinement using the provided comparator to a fraction of candidates (determined by refinementRatio)</li> | |
| 21 | * <li>Return the refined selection results</li> | |
| 22 | * </ol> | |
| 23 | * | |
| 24 | * <h3>Use Cases:</h3> | |
| 25 | * <ul> | |
| 26 | * <li>Multi-objective optimization where secondary criteria matter</li> | |
| 27 | * <li>Diversity preservation by considering genetic distance in refinement</li> | |
| 28 | * <li>Age-based selection refinement in evolutionary strategies</li> | |
| 29 | * <li>Custom fitness landscape exploration with domain-specific comparators</li> | |
| 30 | * </ul> | |
| 31 | * | |
| 32 | * @param <T> the fitness type, must be Comparable | |
| 33 | * | |
| 34 | * @see Tournament | |
| 35 | * @see SelectionPolicy | |
| 36 | * @see net.bmahe.genetics4j.core.selection.SelectiveRefinementTournamentSelector | |
| 37 | */ | |
| 38 | @Value.Immutable | |
| 39 | public abstract class SelectiveRefinementTournament<T extends Comparable<T>> implements SelectionPolicy { | |
| 40 | ||
| 41 | /** | |
| 42 | * Gets the base tournament configuration used for initial selection. | |
| 43 | * <p>This tournament defines the primary selection mechanism including the number of candidates per tournament and | |
| 44 | * the comparison strategy for determining winners.</p> | |
| 45 | * | |
| 46 | * @return the tournament configuration for initial selection | |
| 47 | */ | |
| 48 | public abstract Tournament<T> tournament(); | |
| 49 | ||
| 50 | /** | |
| 51 | * Gets the comparator used for refining the selection results. | |
| 52 | * <p>This comparator is applied during the refinement phase to reorder or filter a subset of the initially selected | |
| 53 | * individuals. It allows for secondary selection criteria beyond basic fitness comparison, such as diversity | |
| 54 | * measures, age-based preferences, or multi-objective considerations.</p> | |
| 55 | * | |
| 56 | * @return the comparator for refinement selection | |
| 57 | */ | |
| 58 | public abstract Comparator<Individual<T>> refinementComparator(); | |
| 59 | ||
| 60 | /** | |
| 61 | * Gets the ratio of candidates that undergo refinement selection. | |
| 62 | * <p>This value determines what fraction of the initially selected candidates will be subject to the refinement | |
| 63 | * process using the refinement comparator. A value of 0.0 means no refinement (equivalent to standard tournament), | |
| 64 | * while 1.0 means all candidates undergo refinement.</p> | |
| 65 | * | |
| 66 | * @return the refinement ratio, must be between 0.0 and 1.0 inclusive | |
| 67 | */ | |
| 68 | public abstract float refinementRatio(); | |
| 69 | ||
| 70 | /** | |
| 71 | * Validates the configuration parameters for this selection policy. | |
| 72 | * <p>Ensures that the refinement ratio is within the valid range of [0.0, 1.0]. This method is automatically called | |
| 73 | * by the Immutables framework during object construction.</p> | |
| 74 | * | |
| 75 | * @throws IllegalArgumentException if refinement ratio is not between 0.0 and 1.0 inclusive | |
| 76 | */ | |
| 77 | @Value.Check | |
| 78 | public void check() { | |
| 79 | Validate.inclusiveBetween(0, 1, refinementRatio()); | |
| 80 | } | |
| 81 | ||
| 82 | /** | |
| 83 | * Builder class for constructing SelectiveRefinementTournament instances. | |
| 84 | * <p>Provides a fluent API for configuring all aspects of the selective refinement tournament selection strategy. | |
| 85 | * All parameters are required except where noted.</p> | |
| 86 | * | |
| 87 | * @param <T> the fitness type, must be Comparable | |
| 88 | * | |
| 89 | * @see SelectiveRefinementTournament | |
| 90 | */ | |
| 91 | public static class Builder<T extends Comparable<T>> extends ImmutableSelectiveRefinementTournament.Builder<T> { | |
| 92 | } | |
| 93 | ||
| 94 | public static <U extends Comparable<U>> Builder<U> builder() { | |
| 95 |
2
1. builder : removed call to net/bmahe/genetics4j/core/spec/selection/SelectiveRefinementTournament$Builder::<init> → NO_COVERAGE 2. builder : replaced return value with null for net/bmahe/genetics4j/core/spec/selection/SelectiveRefinementTournament::builder → NO_COVERAGE |
return new Builder<U>(); |
| 96 | } | |
| 97 | } | |
Mutations | ||
| 95 |
1.1 2.2 |