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source: branches/ParameterBinding/HeuristicLab.Selection/3.3/LinearRankSelector.cs @ 11923

Last change on this file since 11923 was 4722, checked in by swagner, 14 years ago

Merged cloning refactoring branch back into trunk (#922)

File size: 3.4 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2010 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
22using System.Collections.Generic;
23using System.Linq;
24using HeuristicLab.Common;
25using HeuristicLab.Core;
26using HeuristicLab.Data;
27using HeuristicLab.Optimization;
28using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
29
30namespace HeuristicLab.Selection {
31  /// <summary>
32  /// A linear rank selection operator which considers the rank based on a single double quality value for selection.
33  /// </summary>
34  [Item("LinearRankSelector", "A linear rank selection operator which considers the rank based on a single double quality value for selection.")]
35  [StorableClass]
36  public sealed class LinearRankSelector : StochasticSingleObjectiveSelector, ISingleObjectiveSelector {
37    [StorableConstructor]
38    private LinearRankSelector(bool deserializing) : base(deserializing) { }
39    private LinearRankSelector(LinearRankSelector original, Cloner cloner)
40      : base(original, cloner) {
41    }
42    public override IDeepCloneable Clone(Cloner cloner) {
43      return new LinearRankSelector(this, cloner);
44    }
45    public LinearRankSelector() : base() { }
46
47    protected override IScope[] Select(List<IScope> scopes) {
48      int count = NumberOfSelectedSubScopesParameter.ActualValue.Value;
49      bool copy = CopySelectedParameter.Value.Value;
50      IRandom random = RandomParameter.ActualValue;
51      bool maximization = MaximizationParameter.ActualValue.Value;
52      ItemArray<DoubleValue> qualities = QualityParameter.ActualValue;
53      IScope[] selected = new IScope[count];
54
55      // create a list for each scope that contains the scope's index in the original scope list and its lots
56      var temp = qualities.Select((x, index) => new { index, x.Value });
57      if (maximization)
58        temp = temp.OrderBy(x => x.Value);
59      else
60        temp = temp.OrderByDescending(x => x.Value);
61      var list = temp.Select((x, index) => new { x.index, lots = index + 1 }).ToList();
62
63      int lotSum = list.Count * (list.Count + 1) / 2;
64      for (int i = 0; i < count; i++) {
65        int selectedLot = random.Next(lotSum) + 1;
66        int j = 0;
67        int currentLot = list[j].lots;
68        while (currentLot < selectedLot) {
69          j++;
70          currentLot += list[j].lots;
71        }
72        if (copy)
73          selected[i] = (IScope)scopes[list[j].index].Clone();
74        else {
75          selected[i] = scopes[list[j].index];
76          scopes[list[j].index] = null;
77          lotSum -= list[j].lots;
78          list.RemoveAt(j);
79        }
80      }
81      if (!copy) scopes.RemoveAll(x => x == null);
82      return selected;
83    }
84  }
85}
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