1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022010 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  using System;


23  using System.Collections.Generic;


24  using HeuristicLab.Core;


25  using HeuristicLab.Data;


26  using HeuristicLab.Encodings.PermutationEncoding;


27  using HeuristicLab.Optimization;


28  using HeuristicLab.Parameters;


29  using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;


30  using HeuristicLab.Common;


31  using HeuristicLab.Problems.VehicleRouting.Interfaces;


32  using HeuristicLab.Problems.VehicleRouting.ProblemInstances;


33  using HeuristicLab.Problems.VehicleRouting.Variants;


34 


35  namespace HeuristicLab.Problems.VehicleRouting.Encodings.Potvin {


36  [Item("IterativeInsertionCreator", "Creates a randomly initialized VRP solution.")]


37  [StorableClass]


38  public sealed class IterativeInsertionCreator : PotvinCreator, IStochasticOperator {


39  #region IStochasticOperator Members


40  public ILookupParameter<IRandom> RandomParameter {


41  get { return (LookupParameter<IRandom>)Parameters["Random"]; }


42  }


43  #endregion


44 


45  public IValueParameter<BoolValue> AdhereTimeWindowsParameter {


46  get { return (IValueParameter<BoolValue>)Parameters["AdhereTimeWindows"]; }


47  }


48 


49  [StorableConstructor]


50  private IterativeInsertionCreator(bool deserializing) : base(deserializing) { }


51 


52  public IterativeInsertionCreator()


53  : base() {


54  Parameters.Add(new LookupParameter<IRandom>("Random", "The pseudo random number generator."));


55  Parameters.Add(new ValueParameter<BoolValue>("AdhereTimeWindows", "Specifies if the time windows should be considered during construction.", new BoolValue(true)));


56  }


57 


58  public override IDeepCloneable Clone(Cloner cloner) {


59  return new IterativeInsertionCreator(this, cloner);


60  }


61 


62  private IterativeInsertionCreator(IterativeInsertionCreator original, Cloner cloner)


63  : base(original, cloner) {


64  }


65 


66  private static double CalculateAngleToDepot(IVRPProblemInstance instance, int city) {


67  double dx = instance.Coordinates[0, 0];


68  double dy = instance.Coordinates[0, 1];


69 


70  double cx = instance.Coordinates[city, 0];


71  double cy = instance.Coordinates[city, 1];


72 


73  double alpha = Math.Atan((cx  dx) / (dy  cy)) * (180.0 / Math.PI);


74  if (cx > dx && cy > dy)


75  alpha = (90.0 + alpha) + 90.0;


76  else if (cx < dx && cy > dy)


77  alpha = alpha + 180.0;


78  else if (cx < dx && cy < dy)


79  alpha = (90.0 + alpha) + 270.0;


80 


81  return alpha;


82  }


83 


84  private static PotvinEncoding CreateSolution(IVRPProblemInstance instance, IRandom random, bool adhereTimeWindows) {


85  PotvinEncoding result = new PotvinEncoding(instance);


86 


87  IPickupAndDeliveryProblemInstance pdp = instance as IPickupAndDeliveryProblemInstance;


88 


89  List<int> customers = new List<int>();


90  for (int i = 1; i <= instance.Cities.Value; i++)


91  if(pdp == null  pdp.Demand[i] >= 0)


92  customers.Add(i);


93 


94  customers.Sort(delegate(int city1, int city2)


95  {


96  double angle1 = CalculateAngleToDepot(instance, city1);


97  double angle2 = CalculateAngleToDepot(instance, city2);


98 


99  return angle1.CompareTo(angle2);


100  });


101 


102  Tour currentTour = new Tour();


103 


104  int j = random.Next(customers.Count);


105  for (int i = 0; i < customers.Count; i++) {


106  int index = (i + j) % customers.Count;


107 


108  int stopIdx = result.FindBestInsertionPlace(currentTour, customers[index]);


109  currentTour.Stops.Insert(stopIdx, customers[index]);


110 


111  if (pdp != null) {


112  stopIdx = result.FindBestInsertionPlace(currentTour, pdp.PickupDeliveryLocation[customers[index]]);


113  currentTour.Stops.Insert(stopIdx, pdp.PickupDeliveryLocation[customers[index]]);


114  }


115 


116  CVRPEvaluation evaluation = instance.Evaluate(currentTour) as CVRPEvaluation;


117  if (result.Tours.Count < instance.Vehicles.Value &&


118  ((adhereTimeWindows && !instance.Feasible(evaluation))  ((!adhereTimeWindows) && evaluation.Overload > double.Epsilon))) {


119  currentTour.Stops.Remove(customers[index]);


120  if (pdp != null)


121  currentTour.Stops.Remove(pdp.PickupDeliveryLocation[customers[index]]);


122 


123  if(currentTour.Stops.Count > 0)


124  result.Tours.Add(currentTour);


125  currentTour = new Tour();


126 


127  currentTour.Stops.Add(customers[index]);


128  }


129  }


130 


131  if (currentTour.Stops.Count > 0)


132  result.Tours.Add(currentTour);


133 


134  return result;


135  }


136 


137  public override IOperation Apply() {


138  VRPToursParameter.ActualValue = CreateSolution(ProblemInstance, RandomParameter.ActualValue, AdhereTimeWindowsParameter.Value.Value);


139 


140  return base.Apply();


141  }


142  }


143  }

