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 |