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source: branches/MOCMAEvolutionStrategy/HeuristicLab.Algorithms.MOCMAEvolutionStrategy/3.3/Indicators/HypervolumeIndicator.cs @ 15176

Last change on this file since 15176 was 15176, checked in by bwerth, 7 years ago

#2592 formatting & removed unreferenced enum

File size: 3.3 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2015 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 */
20#endregion
21
22
23using System;
24using System.Collections.Generic;
25using System.Linq;
26using HeuristicLab.Common;
27using HeuristicLab.Core;
28using HeuristicLab.Encodings.RealVectorEncoding;
29using HeuristicLab.Optimization;
30using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
31using HeuristicLab.Problems.TestFunctions.MultiObjective;
32namespace HeuristicLab.Algorithms.MOCMAEvolutionStrategy {
33  [Item("HypervolumeIndicator", "Selection of Offspring based on contributing Hypervolume")]
34  [StorableClass]
35  internal class HypervolumeIndicator : Item, IIndicator {
36    #region Constructors and Cloning
37    [StorableConstructor]
38    protected HypervolumeIndicator(bool deserializing) : base(deserializing) { }
39    protected HypervolumeIndicator(HypervolumeIndicator original, Cloner cloner) : base(original, cloner) { }
40    public override IDeepCloneable Clone(Cloner cloner) { return new HypervolumeIndicator(this, cloner); }
41    public HypervolumeIndicator() { }
42    #endregion
43
44    public int LeastContributer(IReadOnlyList<Individual> front, MultiObjectiveBasicProblem<RealVectorEncoding> problem) {
45      var frontCopy = front.Select(x => x.PenalizedFitness).ToList();
46      if (frontCopy.Count <= 1) return 0;
47      var p = problem as MultiObjectiveTestFunctionProblem;
48      var refPoint = BuildReferencePoint(p != null ? frontCopy.Concat(new[] { p.ReferencePoint.CloneAsArray() }) : frontCopy, problem.Maximization);
49      var contributions = Enumerable.Range(0, frontCopy.Count).Select(i => Contribution(frontCopy, i, problem.Maximization, refPoint));
50      return contributions.Select((value, index) => new { value, index }).OrderBy(x => x.value).First().index;
51    }
52
53    #region Helpers
54    private static double Contribution(IList<double[]> front, int idx, bool[] maximization, double[] refPoint) {
55      var point = front[idx];
56      front.RemoveAt(idx);
57      var contribution = -Hypervolume.Calculate(front.ToArray(), refPoint, maximization);
58      front.Insert(idx, point);
59      return contribution;
60    }
61    private static double[] BuildReferencePoint(IEnumerable<double[]> front, IReadOnlyList<bool> maximization) {
62      var refPoint = new double[maximization.Count];
63      foreach (var point in front)
64        for (var i = 0; i < maximization.Count; i++)
65          refPoint[i] = maximization[i] ? Math.Min(refPoint[i], point[i]) : Math.Max(refPoint[i], point[i]);
66      return refPoint;
67    }
68    #endregion
69  }
70}
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