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source: branches/HeuristicLab.BinPacking/HeuristicLab.Problems.BinPacking/3.3/Evaluators/Abstract/PackingRatioRegularIdenticalBinEvaluator.cs @ 9473

Last change on this file since 9473 was 9473, checked in by jhelm, 11 years ago

#1966: Fixed some problems in MCV-move operators; Added parts of potvin-encoding implementation;

File size: 4.4 KB
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1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2012 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;
23using System.Collections.Generic;
24using System.Linq;
25using System.Text;
26using HeuristicLab.Core;
27using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
28using HeuristicLab.Problems.BinPacking.Interfaces;
29using HeuristicLab.Problems.BinPacking.Shapes;
30using HeuristicLab.Data;
31using HeuristicLab.Common;
32using HeuristicLab.Encodings.PackingEncoding.PackingPlan;
33
34namespace HeuristicLab.Problems.BinPacking.Evaluators {
35  [Item("Packing-Ratio Regular Identical-Bin Evaluator", "Represents an evaluation-algorithm for regular-shaped bin-packing problems with identical bins which calculates the ratio between packed and unpacked space. Found in Falkenauer:1996")]
36  [StorableClass]
37  public abstract class PackingRatioRegularIdenticalBinEvaluator<D, B, I> : RegularSimpleRotationIdenticalBinPackingPlanEvaluator<D, B, I>
38    where D : class, IPackingDimensions
39    where B : PackingShape<D>, IPackingBin, IRegularPackingShape
40    where I : PackingShape<D>, IPackingItem, IRegularPackingShape {
41
42    [StorableConstructor]
43    protected PackingRatioRegularIdenticalBinEvaluator(bool deserializing) : base(deserializing) { }
44    protected PackingRatioRegularIdenticalBinEvaluator(PackingRatioRegularIdenticalBinEvaluator<D, B, I> original, Cloner cloner)
45      : base(original, cloner) {
46    }
47    public PackingRatioRegularIdenticalBinEvaluator() : base() { }
48
49    protected override DoubleValue Evaluate() {
50      DoubleValue quality = new DoubleValue(0);
51
52      IPackingPlan plan = PackingPlanParameter.ActualValue;
53      B binMeasure = PackingBinMeasuresParameter.ActualValue;
54      ItemList<I> itemMeasures = PackingItemMeasuresParameter.ActualValue;
55
56
57      //Check if data is valid
58      //if (plan.PackingItemPositions.Count != itemMeasures.Count)
59      //  throw new Exception("ERROR: ItemMeasures.count does not match packingPosition.count");
60
61
62      ////Check if any items are overlapping or not contained in their bins
63      //bool itemPositionsAreValid = !HasOverlappingOrNotContainedItems(plan.PackingItemPositions, binMeasure, itemMeasures, nrOfBins);
64
65
66
67      //if (itemPositionsAreValid)
68      return CalculatePackingRatio(plan as PackingPlan<D, B, I>, binMeasure, itemMeasures);
69
70      //return quality;
71    }
72
73    /*
74        Falkenauer:1996 - A Hybrid Grouping Genetic Algorithm for Bin Packing
75       
76        fBPP = (SUM[i=1..N](Fi / C)^k)/N
77        N.......the number of bins used in the solution,
78        Fi......the sum of sizes of the items in the bin i (the fill of the bin),
79        C.......the bin capacity and
80        k.......a constant, k>1.
81     */
82    public static DoubleValue CalculatePackingRatio(PackingPlan<D, B, I> plan, B binMeasure, ItemList<I> itemMeasures) {
83      int nrOfBins = plan.NrOfBins;
84      double result = 0;
85
86      //C
87      double usableSpace = binMeasure.MultipliedMeasures;
88      //nrOfBins = N
89      for (int i = 0; i < nrOfBins; i++) {
90        var indexes = plan.PackingItemPositions.Select((Value, Index) => new { Value, Index }).Where(s => s.Value.Value.AssignedBin == i).Select(s => s.Index);
91        var packedItemsInThisBin = itemMeasures.Select((Value, Index) => new { Value, Index }).Where(s => indexes.Contains(s.Index));
92        //Fi
93        double usedSpaceInThisBin = packedItemsInThisBin.Select(s => s.Value.MultipliedMeasures).Sum();
94        //k = 2 --> (Fi/C)*(Fi/C)
95        result += (((usedSpaceInThisBin) / (usableSpace)) * ((usedSpaceInThisBin) / (usableSpace))) / (i*i + 1);
96      }
97
98      result = result / nrOfBins;
99      return new DoubleValue (result);
100    }
101  }
102}
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