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source: stable/HeuristicLab.Problems.VehicleRouting/3.4/Encodings/Alba/LocalImprovement/AlbaLambdaInterchangeLocalImprovementOperator.cs @ 15584

Last change on this file since 15584 was 15584, checked in by swagner, 6 years ago

#2640: Updated year of copyrights in license headers on stable

File size: 6.4 KB
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1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2018 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.Optimization;
27using HeuristicLab.Core;
28using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
29using HeuristicLab.Data;
30using HeuristicLab.Common;
31using HeuristicLab.Parameters;
32using HeuristicLab.Operators;
33using HeuristicLab.Problems.VehicleRouting.Interfaces;
34
35namespace HeuristicLab.Problems.VehicleRouting.Encodings.Alba {
36  [Item("AlbaLambdaInterchangeLocalImprovementOperator", "Takes a solution and finds the local optimum with respect to the lambda interchange neighborhood by decending along the steepest gradient.")]
37  [StorableClass]
38  public class AlbaLambdaInterchangeLocalImprovementOperator : VRPOperator, IStochasticOperator, ILocalImprovementOperator, ISingleObjectiveOperator {
39
40    public IValueLookupParameter<IntValue> MaximumIterationsParameter {
41      get { return (IValueLookupParameter<IntValue>)Parameters["MaximumIterations"]; }
42    }
43
44    public ILookupParameter<IntValue> EvaluatedSolutionsParameter {
45      get { return (ILookupParameter<IntValue>)Parameters["EvaluatedSolutions"]; }
46    }
47
48    public ILookupParameter<ResultCollection> ResultsParameter {
49      get { return (ILookupParameter<ResultCollection>)Parameters["Results"]; }
50    }
51
52    public ILookupParameter<IVRPEncoding> VRPToursParameter {
53      get { return (ILookupParameter<IVRPEncoding>)Parameters["VRPTours"]; }
54    }
55
56    public ILookupParameter<DoubleValue> QualityParameter {
57      get { return (ILookupParameter<DoubleValue>)Parameters["Quality"]; }
58    }
59
60    public IValueParameter<IntValue> LambdaParameter {
61      get { return (IValueParameter<IntValue>)Parameters["Lambda"]; }
62    }
63
64    public IValueParameter<IntValue> SampleSizeParameter {
65      get { return (IValueParameter<IntValue>)Parameters["SampleSize"]; }
66    }
67
68    public ILookupParameter<IRandom> RandomParameter {
69      get { return (ILookupParameter<IRandom>)Parameters["Random"]; }
70    }
71
72    [StorableConstructor]
73    protected AlbaLambdaInterchangeLocalImprovementOperator(bool deserializing) : base(deserializing) { }
74    protected AlbaLambdaInterchangeLocalImprovementOperator(AlbaLambdaInterchangeLocalImprovementOperator original, Cloner cloner)
75      : base(original, cloner) {
76    }
77    public AlbaLambdaInterchangeLocalImprovementOperator()
78      : base() {
79      Parameters.Add(new ValueLookupParameter<IntValue>("MaximumIterations", "The maximum amount of iterations that should be performed (note that this operator will abort earlier when a local optimum is reached.", new IntValue(10000)));
80      Parameters.Add(new LookupParameter<IntValue>("EvaluatedSolutions", "The amount of evaluated solutions (here a move is counted only as 4/n evaluated solutions with n being the length of the permutation)."));
81      Parameters.Add(new LookupParameter<ResultCollection>("Results", "The collection where to store results."));
82      Parameters.Add(new LookupParameter<IVRPEncoding>("VRPTours", "The VRP tours to be manipulated."));
83      Parameters.Add(new LookupParameter<DoubleValue>("Quality", "The quality value of the assignment."));
84      Parameters.Add(new ValueParameter<IntValue>("Lambda", "The lambda value.", new IntValue(1)));
85      Parameters.Add(new ValueParameter<IntValue>("SampleSize", "The number of moves to generate.", new IntValue(2000)));
86      Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator."));
87    }
88
89    public override IDeepCloneable Clone(Cloner cloner) {
90      return new AlbaLambdaInterchangeLocalImprovementOperator(this, cloner);
91    }
92
93    public static void Apply(AlbaEncoding solution, int maxIterations,
94      int lambda, int samples, IRandom random, IVRPProblemInstance problemInstance, ref double quality, out int evaluatedSolutions) {
95      evaluatedSolutions = 0;
96
97      for (int i = 0; i < maxIterations; i++) {
98        AlbaLambdaInterchangeMove bestMove = null;
99        foreach (AlbaLambdaInterchangeMove move in AlbaStochasticLambdaInterchangeMultiMoveGenerator.GenerateAllMoves(solution, problemInstance, lambda, samples, random)) {
100          AlbaEncoding newSolution = solution.Clone() as AlbaEncoding;
101          AlbaLambdaInterchangeMoveMaker.Apply(newSolution, move);
102          double moveQuality =
103            problemInstance.Evaluate(newSolution).Quality;
104
105          evaluatedSolutions++;
106          if (moveQuality < quality || quality == -1) {
107            quality = moveQuality;
108            bestMove = move;
109          }
110        }
111        if (bestMove != null)
112          AlbaLambdaInterchangeMoveMaker.Apply(solution, bestMove);
113      }
114    }
115
116    public override IOperation InstrumentedApply() {
117      int maxIterations = MaximumIterationsParameter.ActualValue.Value;
118      AlbaEncoding solution = null;
119
120      if (VRPToursParameter.ActualValue is AlbaEncoding)
121        solution = VRPToursParameter.ActualValue as AlbaEncoding;
122      else
123        VRPToursParameter.ActualValue = solution = AlbaEncoding.ConvertFrom(VRPToursParameter.ActualValue, ProblemInstance);
124
125      int lambda = LambdaParameter.Value.Value;
126      int samples = SampleSizeParameter.Value.Value;
127      IRandom random = RandomParameter.ActualValue;
128
129      double quality = QualityParameter.ActualValue.Value;
130      int evaluatedSolutions;
131
132      Apply(solution, maxIterations, lambda, samples, random, ProblemInstance, ref quality, out evaluatedSolutions);
133
134      EvaluatedSolutionsParameter.ActualValue.Value += evaluatedSolutions;
135      QualityParameter.ActualValue.Value = quality;
136
137      return base.InstrumentedApply();
138    }
139  }
140}
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