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source: trunk/sources/HeuristicLab.Problems.VehicleRouting/3.4/Encodings/Potvin/Creators/IterativeInsertionCreator.cs @ 10959

Last change on this file since 10959 was 10959, checked in by pfleck, 9 years ago

#2191: correctly set the stopIdx, as suggested in the mailing list

File size: 5.7 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2013 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 HeuristicLab.Common;
25using HeuristicLab.Core;
26using HeuristicLab.Data;
27using HeuristicLab.Optimization;
28using HeuristicLab.Parameters;
29using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
30using HeuristicLab.Problems.VehicleRouting.Interfaces;
31using HeuristicLab.Problems.VehicleRouting.ProblemInstances;
32using HeuristicLab.Problems.VehicleRouting.Variants;
33
34namespace HeuristicLab.Problems.VehicleRouting.Encodings.Potvin {
35  [Item("IterativeInsertionCreator", "Creates a randomly initialized VRP solution.")]
36  [StorableClass]
37  public sealed class IterativeInsertionCreator : PotvinCreator, IStochasticOperator {
38    #region IStochasticOperator Members
39    public ILookupParameter<IRandom> RandomParameter {
40      get { return (LookupParameter<IRandom>)Parameters["Random"]; }
41    }
42    #endregion
43
44    public IValueParameter<BoolValue> AdhereTimeWindowsParameter {
45      get { return (IValueParameter<BoolValue>)Parameters["AdhereTimeWindows"]; }
46    }
47
48    [StorableConstructor]
49    private IterativeInsertionCreator(bool deserializing) : base(deserializing) { }
50
51    public IterativeInsertionCreator()
52      : base() {
53      Parameters.Add(new LookupParameter<IRandom>("Random", "The pseudo random number generator."));
54      Parameters.Add(new ValueParameter<BoolValue>("AdhereTimeWindows", "Specifies if the time windows should be considered during construction.", new BoolValue(true)));
55    }
56
57    public override IDeepCloneable Clone(Cloner cloner) {
58      return new IterativeInsertionCreator(this, cloner);
59    }
60
61    private IterativeInsertionCreator(IterativeInsertionCreator original, Cloner cloner)
62      : base(original, cloner) {
63    }
64
65    private static double CalculateAngleToDepot(IVRPProblemInstance instance, int city) {
66      double dx = instance.GetCoordinates(0)[0];
67      double dy = instance.GetCoordinates(0)[1];
68
69      double cx = instance.GetCoordinates(city)[0];
70      double cy = instance.GetCoordinates(city)[1];
71
72      double alpha = Math.Atan((cx - dx) / (dy - cy)) * (180.0 / Math.PI);
73      if (cx > dx && cy > dy)
74        alpha = (90.0 + alpha) + 90.0;
75      else if (cx < dx && cy > dy)
76        alpha = alpha + 180.0;
77      else if (cx < dx && cy < dy)
78        alpha = (90.0 + alpha) + 270.0;
79
80      return alpha;
81    }
82
83    public static PotvinEncoding CreateSolution(IVRPProblemInstance instance, IRandom random, bool adhereTimeWindows) {
84      PotvinEncoding result = new PotvinEncoding(instance);
85
86      IPickupAndDeliveryProblemInstance pdp = instance as IPickupAndDeliveryProblemInstance;
87
88      List<int> customers = new List<int>();
89      for (int i = 1; i <= instance.Cities.Value; i++)
90        if (pdp == null || pdp.GetDemand(i) >= 0)
91          customers.Add(i);
92
93      customers.Sort((city1, city2) => {
94        double angle1 = CalculateAngleToDepot(instance, city1);
95        double angle2 = CalculateAngleToDepot(instance, city2);
96
97        return angle1.CompareTo(angle2);
98      });
99
100      Tour currentTour = new Tour();
101      result.Tours.Add(currentTour);
102
103      int j = random.Next(customers.Count);
104      for (int i = 0; i < customers.Count; i++) {
105        int index = (i + j) % customers.Count;
106
107        int stopIdx = 0;
108        if (currentTour.Stops.Count > 0)
109          stopIdx = result.FindBestInsertionPlace(currentTour, customers[index]);
110        currentTour.Stops.Insert(stopIdx, customers[index]);
111
112        if (pdp != null) {
113          stopIdx = result.FindBestInsertionPlace(currentTour, pdp.GetPickupDeliveryLocation(customers[index]));
114          currentTour.Stops.Insert(stopIdx, pdp.GetPickupDeliveryLocation(customers[index]));
115        }
116
117        CVRPEvaluation evaluation = instance.EvaluateTour(currentTour, result) as CVRPEvaluation;
118        if (result.Tours.Count < instance.Vehicles.Value &&
119          ((adhereTimeWindows && !instance.Feasible(evaluation)) || ((!adhereTimeWindows) && evaluation.Overload > double.Epsilon))) {
120          currentTour.Stops.Remove(customers[index]);
121          if (pdp != null)
122            currentTour.Stops.Remove(pdp.GetPickupDeliveryLocation(customers[index]));
123
124          if (currentTour.Stops.Count == 0)
125            result.Tours.Remove(currentTour);
126          currentTour = new Tour();
127          result.Tours.Add(currentTour);
128
129          currentTour.Stops.Add(customers[index]);
130          if (pdp != null) {
131            currentTour.Stops.Add(pdp.GetPickupDeliveryLocation(customers[index]));
132          }
133        }
134      }
135
136      if (currentTour.Stops.Count == 0)
137        result.Tours.Remove(currentTour);
138
139      return result;
140    }
141
142    public override IOperation InstrumentedApply() {
143      VRPToursParameter.ActualValue = CreateSolution(ProblemInstance, RandomParameter.ActualValue, AdhereTimeWindowsParameter.Value.Value);
144
145      return base.InstrumentedApply();
146    }
147  }
148}
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