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source: trunk/sources/HeuristicLab.Problems.TravelingSalesman/3.3/Evaluators/TSPCoordinatesPathEvaluator.cs @ 3816

Last change on this file since 3816 was 3430, checked in by swagner, 15 years ago

Added ReadOnly property to all items of HeuristicLab.Data (#969)

File size: 4.7 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 HeuristicLab.Common;
23using HeuristicLab.Core;
24using HeuristicLab.Data;
25using HeuristicLab.Encodings.PermutationEncoding;
26using HeuristicLab.Parameters;
27using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
28
29namespace HeuristicLab.Problems.TravelingSalesman {
30  /// <summary>
31  /// A base class for operators which evaluate TSP solutions given in path representation using city coordinates.
32  /// </summary>
33  [Item("TSPCoordinatesPathEvaluator", "A base class for operators which evaluate TSP solutions given in path representation using city coordinates.")]
34  [StorableClass]
35  public abstract class TSPCoordinatesPathEvaluator : TSPEvaluator, ITSPCoordinatesPathEvaluator {
36    public ILookupParameter<Permutation> PermutationParameter {
37      get { return (ILookupParameter<Permutation>)Parameters["Permutation"]; }
38    }
39    public ILookupParameter<DoubleMatrix> CoordinatesParameter {
40      get { return (ILookupParameter<DoubleMatrix>)Parameters["Coordinates"]; }
41    }
42    public ILookupParameter<DoubleMatrix> DistanceMatrixParameter {
43      get { return (ILookupParameter<DoubleMatrix>)Parameters["DistanceMatrix"]; }
44    }
45    public ILookupParameter<BoolValue> UseDistanceMatrixParameter {
46      get { return (ILookupParameter<BoolValue>)Parameters["UseDistanceMatrix"]; }
47    }
48
49    protected TSPCoordinatesPathEvaluator()
50      : base() {
51      Parameters.Add(new LookupParameter<Permutation>("Permutation", "The TSP solution given in path representation which should be evaluated."));
52      Parameters.Add(new LookupParameter<DoubleMatrix>("Coordinates", "The x- and y-Coordinates of the cities."));
53      Parameters.Add(new LookupParameter<DoubleMatrix>("DistanceMatrix", "The matrix which contains the distances between the cities."));
54      Parameters.Add(new LookupParameter<BoolValue>("UseDistanceMatrix", "True if a distance matrix should be calculated and used for evaluation, otherwise false."));
55    }
56
57    public sealed override IOperation Apply() {
58      if (UseDistanceMatrixParameter.ActualValue.Value) {
59        Permutation p = PermutationParameter.ActualValue;
60        DoubleMatrix dm = DistanceMatrixParameter.ActualValue;
61
62        if (dm == null) {  // calculate distance matrix
63          DoubleMatrix c = CoordinatesParameter.ActualValue;
64
65          dm = new DoubleMatrix(c.Rows, c.Rows);
66          for (int i = 0; i < dm.Rows; i++) {
67            for (int j = 0; j < dm.Columns; j++)
68              dm[i, j] = CalculateDistance(c[i, 0], c[i, 1], c[j, 0], c[j, 1]);
69          }
70          DistanceMatrixParameter.ActualValue = (DoubleMatrix)dm.AsReadOnly();
71        }
72
73        double length = 0;
74        for (int i = 0; i < p.Length - 1; i++)
75          length += dm[p[i], p[i + 1]];
76        length += dm[p[p.Length - 1], p[0]];
77        QualityParameter.ActualValue = new DoubleValue(length);
78      } else {
79        Permutation p = PermutationParameter.ActualValue;
80        DoubleMatrix c = CoordinatesParameter.ActualValue;
81
82        double length = 0;
83        for (int i = 0; i < p.Length - 1; i++)
84          length += CalculateDistance(c[p[i], 0], c[p[i], 1], c[p[i + 1], 0], c[p[i + 1], 1]);
85        length += CalculateDistance(c[p[p.Length - 1], 0], c[p[p.Length - 1], 1], c[p[0], 0], c[p[0], 1]);
86        QualityParameter.ActualValue = new DoubleValue(length);
87      }
88      return base.Apply();
89    }
90
91    /// <summary>
92    /// Calculates the distance between two points.
93    /// </summary>
94    /// <param name="x1">The x-coordinate of point 1.</param>
95    /// <param name="y1">The y-coordinate of point 1.</param>
96    /// <param name="x2">The x-coordinate of point 2.</param>
97    /// <param name="y2">The y-coordinate of point 2.</param>
98    /// <returns>The calculated distance.</returns>
99    protected abstract double CalculateDistance(double x1, double y1, double x2, double y2);
100  }
101}
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