source: branches/HeuristicLab.BinPacking/HeuristicLab.Problems.BinPacking/3.3/Evaluators/PackingRatioEvaluator.cs @ 14128

Last change on this file since 14128 was 14128, checked in by gkronber, 5 years ago

#1966: refactoring of bin packing implementation

File size: 4.0 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2015 Joseph Helm and 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 HeuristicLab.Core;
24using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
25using HeuristicLab.Data;
26using HeuristicLab.Common;
27using HeuristicLab.Encodings.PackingEncoding;
28
29namespace HeuristicLab.Problems.BinPacking {
30  [StorableClass]
31  public abstract class PackingRatioEvaluator<D, B, I> : EvaluatorBase<D, B, I>
32    where D : class, IPackingPosition
33    where B : PackingShape<D>
34    where I : PackingShape<D>, IPackingItem {
35
36    [StorableConstructor]
37    protected PackingRatioEvaluator(bool deserializing) : base(deserializing) { }
38    protected PackingRatioEvaluator(PackingRatioEvaluator<D, B, I> original, Cloner cloner)
39      : base(original, cloner) {
40    }
41    public PackingRatioEvaluator() : base() { }
42
43    protected override double Evaluate() {
44      DoubleValue quality = new DoubleValue(0);
45
46      IPackingPlan plan = PackingPlanParameter.ActualValue;
47      B binMeasure = PackingBinMeasuresParameter.ActualValue;
48      ItemList<I> itemMeasures = PackingItemMeasuresParameter.ActualValue;
49
50
51      //Check if data is valid
52      //if (plan.PackingItemPositions.Count != itemMeasures.Count)
53      //  throw new Exception("ERROR: ItemMeasures.count does not match packingPosition.count");
54
55
56      ////Check if any items are overlapping or not contained in their bins
57      //bool itemPositionsAreValid = !HasOverlappingOrNotContainedItems(plan.PackingItemPositions, binMeasure, itemMeasures, nrOfBins);
58
59
60
61      //if (itemPositionsAreValid)
62      return CalculatePackingRatio(plan as PackingPlan<D, B, I>);
63
64      //return quality;
65    }
66
67    /*
68        Falkenauer:1996 - A Hybrid Grouping Genetic Algorithm for Bin Packing
69       
70        fBPP = (SUM[i=1..N](Fi / C)^k)/N
71        N.......the number of bins used in the solution,
72        Fi......the sum of sizes of the items in the bin i (the fill of the bin),
73        C.......the bin capacity and
74        k.......a constant, k>1.
75     */
76    public static double CalculatePackingRatio(PackingPlan<D, B, I> plan) {
77      int nrOfBins = plan.NrOfBins;
78      double result = 0;
79
80      //C
81      //double usableSpace = binMeasure.MultipliedMeasures;
82      //nrOfBins = N
83      for (int i = 0; i < nrOfBins; i++) {
84        //C
85        //double usableSpace = plan.GetPackingBinMeasuresForBinNr(0).MultipliedMeasures;//plan.GetPackingBinMeasuresForBinNr(i).MultipliedMeasures;
86        //var indexes = plan.PackingItemPositions.Select((Value, Index) => new { Value, Index }).Where(s => s.Value.Value.AssignedBin == i).Select(s => s.Index);
87        //var packedItemsInThisBin = plan.PackingItemMeasures.Select((Value, Index) => new { Value, Index }).Where(s => indexes.Contains(s.Index));
88        //Fi
89        //double usedSpaceInThisBin = packedItemsInThisBin.Select(s => s.Value.MultipliedMeasures).Sum();
90        //k = 2 --> (Fi/C)*(Fi/C)
91        //result += (((usedSpaceInThisBin) / (usableSpace)) * ((usedSpaceInThisBin) / (usableSpace))) / (i*i + 1);
92        var pd = plan.BinPackings[i].PackingDensity;
93        result += (pd * pd) / (i + 1);
94      }
95
96      result = result / nrOfBins;
97      return result;
98    }
99  }
100}
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