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source: branches/ALPS(old)/HeuristicLab.Problems.Binary/3.3/HIFFProblem.cs @ 12081

Last change on this file since 12081 was 11996, checked in by mkommend, 10 years ago

#2282: Fixed maximization flag and solution creators for binary problems.

File size: 3.1 KB
Line 
1#region License Information
2
3/* HeuristicLab
4 * Copyright (C) 2002-2015 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 HeuristicLab.Common;
26using HeuristicLab.Core;
27using HeuristicLab.Encodings.BinaryVectorEncoding;
28using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
29
30namespace HeuristicLab.Problems.Binary {
31  [Item("Hierararchical If and only If problem", "Genome evaluated in nested subsets to see if each subset contains either all 0s or all 1s.")]
32  [StorableClass]
33  [Creatable("Problems")]
34  public class HIFFProblem : BinaryProblem {
35    [StorableConstructor]
36    protected HIFFProblem(bool deserializing) : base(deserializing) { }
37    protected HIFFProblem(HIFFProblem original, Cloner cloner)
38      : base(original, cloner) {
39    }
40    public override IDeepCloneable Clone(Cloner cloner) {
41      return new HIFFProblem(this, cloner);
42    }
43
44    public override bool Maximization {
45      get { return true; }
46    }
47
48    public HIFFProblem()
49      : base() {
50        Encoding.Length = 64;
51    }
52    // In the GECCO paper, Section 4.1
53    public override double Evaluate(BinaryVector individual, IRandom random) {
54      int[] level = new int[individual.Length];
55      int levelLength = individual.Length;
56
57      // Initialize the level to the current solution
58      for (int i = 0; i < levelLength; i++) {
59        level[i] = Convert.ToInt32(individual[i]);
60      }
61      int power = 1;
62      int nextLength = levelLength / 2;
63      int total = 0;
64      int maximum = 0;
65
66      // Keep going while the next level actual has bits in it
67      while (nextLength > 0) {
68        int[] nextLevel = new int[nextLength];
69        // Construct the next level using the current level
70        for (int i = 0; i + 1 < levelLength; i += 2) {
71          if (level[i] == level[i + 1] && level[i] != -1) {
72            // Score points for a correct setting at this level
73            total += power;
74            nextLevel[i / 2] = level[i];
75          } else {
76            nextLevel[i / 2] = -1;
77          }
78          // Keep track of the maximum possible score
79          maximum += power;
80        }
81        level = nextLevel;
82        levelLength = nextLength;
83        nextLength = levelLength / 2;
84        power *= 2;
85      }
86
87      // Convert to percentage of total
88      return (double)total / maximum;
89    }
90  }
91}
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