1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022013 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.Common;


25  using HeuristicLab.Core;


26  using HeuristicLab.Data;


27  using HeuristicLab.Optimization;


28  using HeuristicLab.Parameters;


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


30  using HeuristicLab.Problems.VehicleRouting.Interfaces;


31  using HeuristicLab.Problems.VehicleRouting.ProblemInstances;


32  using HeuristicLab.Problems.VehicleRouting.Variants;


33 


34  namespace 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  }

