source: branches/2521_ProblemRefactoring/HeuristicLab.Problems.Binary/3.3/HIFFProblem.cs @ 17545

Last change on this file since 17545 was 17545, checked in by abeham, 8 weeks ago

#2521: Reverse behavior, parameters are not readonly by default, can be readonly if computed automatically

File size: 3.2 KB
Line 
1#region License Information
2
3/* HeuristicLab
4 * Copyright (C) Heuristic and Evolutionary Algorithms Laboratory (HEAL)
5 *
6 * This file is part of HeuristicLab.
7 *
8 * HeuristicLab is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 3 of the License, or
11 * (at your option) any later version.
12 *
13 * HeuristicLab is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#endregion
23
24using System;
25using System.Threading;
26using HEAL.Attic;
27using HeuristicLab.Common;
28using HeuristicLab.Core;
29using HeuristicLab.Encodings.BinaryVectorEncoding;
30using HeuristicLab.Optimization;
31
32namespace HeuristicLab.Problems.Binary {
33  [Item("Hierararchical If and only If problem (HIFF)", "Genome evaluated in nested subsets to see if each subset contains either all 0s or all 1s.")]
34  [StorableType("8AC6D94E-E7B4-4216-B2CA-8E142E7A1391")]
35  [Creatable(CreatableAttribute.Categories.CombinatorialProblems, Priority = 220)]
36  public class HIFFProblem : BinaryVectorProblem {
37
38    public HIFFProblem() : base() {
39      Maximization = true;
40      Dimension = 64;
41    }
42
43    // In the GECCO paper, Section 4.1
44    public override ISingleObjectiveEvaluationResult Evaluate(BinaryVector individual, IRandom random, CancellationToken cancellationToken) {
45      int[] level = new int[individual.Length];
46      int levelLength = individual.Length;
47
48      // Initialize the level to the current solution
49      for (int i = 0; i < levelLength; i++) {
50        level[i] = Convert.ToInt32(individual[i]);
51      }
52      int power = 1;
53      int nextLength = levelLength / 2;
54      int total = 0;
55      int maximum = 0;
56
57      // Keep going while the next level actual has bits in it
58      while (nextLength > 0) {
59        int[] nextLevel = new int[nextLength];
60        // Construct the next level using the current level
61        for (int i = 0; i + 1 < levelLength; i += 2) {
62          if (level[i] == level[i + 1] && level[i] != -1) {
63            // Score points for a correct setting at this level
64            total += power;
65            nextLevel[i / 2] = level[i];
66          } else {
67            nextLevel[i / 2] = -1;
68          }
69          // Keep track of the maximum possible score
70          maximum += power;
71        }
72        level = nextLevel;
73        levelLength = nextLength;
74        nextLength = levelLength / 2;
75        power *= 2;
76      }
77
78      // Convert to percentage of total
79      var quality = (double)total / maximum;
80      return new SingleObjectiveEvaluationResult(quality);
81    }
82
83    [StorableConstructor]
84    protected HIFFProblem(StorableConstructorFlag _) : base(_) { }
85    protected HIFFProblem(HIFFProblem original, Cloner cloner)
86      : base(original, cloner) {
87    }
88    public override IDeepCloneable Clone(Cloner cloner) {
89      return new HIFFProblem(this, cloner);
90    }
91  }
92}
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