source: branches/ScatterSearch/HeuristicLab.Algorithms.ScatterSearch/3.3/TestFunctions/TestFunctionsImprovementOperator.cs @ 7775

Last change on this file since 7775 was 7775, checked in by jkarder, 9 years ago

#1331:

  • added operators for TestFunctions problems
  • added more path relinking operators for the TravelingSalesman and the Knapsack problem
  • added 2-tier version of the SolutionPoolUpdateMethod
  • added parameters and adjusted types
  • added some exception handling
  • adjusted event handling
  • updated plugin dependencies
  • minor code improvements
File size: 10.5 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2012 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 HeuristicLab.Common;
24using HeuristicLab.Core;
25using HeuristicLab.Data;
26using HeuristicLab.Encodings.RealVectorEncoding;
27using HeuristicLab.Operators;
28using HeuristicLab.Optimization;
29using HeuristicLab.Parameters;
30using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
31using HeuristicLab.Problems.Knapsack;
32using HeuristicLab.Problems.TestFunctions;
33
34namespace HeuristicLab.Algorithms.ScatterSearch.TestFunctions {
35  /// <summary>
36  /// An operator that improves test functions solutions.
37  /// </summary>
38  [Item("TestFunctionsImprovementOperator", "An operator that improves test functions solutions.")]
39  [StorableClass]
40  public abstract class TestFunctionsImprovementOperator : SingleSuccessorOperator, ILocalImprovementOperator, IScatterSearchTargetProcessor {
41    #region Problem properties
42    public Type ProblemType {
43      get { return typeof(KnapsackProblem); }
44    }
45    [Storable]
46    private KnapsackProblem problem;
47    public IProblem Problem {
48      get { return problem; }
49      set { problem = (KnapsackProblem)value; }
50    }
51    #endregion
52
53    #region Parameter properties
54    public ScopeParameter CurrentScopeParameter {
55      get { return (ScopeParameter)Parameters["CurrentScope"]; }
56    }
57    public IValueLookupParameter<DoubleMatrix> CoordinatesParameter {
58      get { return (IValueLookupParameter<DoubleMatrix>)Parameters["Coordinates"]; }
59    }
60    public IValueLookupParameter<ISingleObjectiveTestFunctionProblemEvaluator> EvaluatorParameter {
61      get { return (IValueLookupParameter<ISingleObjectiveTestFunctionProblemEvaluator>)Parameters["Evaluator"]; }
62    }
63    public IValueLookupParameter<IntValue> ImprovementAttemptsParameter {
64      get { return (IValueLookupParameter<IntValue>)Parameters["ImprovementAttempts"]; }
65    }
66    public IValueLookupParameter<IRandom> RandomParameter {
67      get { return (IValueLookupParameter<IRandom>)Parameters["Random"]; }
68    }
69    public IValueLookupParameter<IItem> TargetParameter {
70      get { return (IValueLookupParameter<IItem>)Parameters["Target"]; }
71    }
72    public IValueParameter<DoubleValue> AlphaParameter {
73      get { return (IValueParameter<DoubleValue>)Parameters["Alpha"]; }
74    }
75    public IValueParameter<DoubleValue> BetaParameter {
76      get { return (IValueParameter<DoubleValue>)Parameters["Beta"]; }
77    }
78    public IValueParameter<DoubleValue> GammaParameter {
79      get { return (IValueParameter<DoubleValue>)Parameters["Gamma"]; }
80    }
81    public IValueParameter<DoubleValue> DeltaParameter {
82      get { return (IValueParameter<DoubleValue>)Parameters["Delta"]; }
83    }
84    #region ILocalImprovementOperator Parameters
85    public IValueLookupParameter<IntValue> MaximumIterationsParameter {
86      get { return (IValueLookupParameter<IntValue>)Parameters["MaximumIterations"]; }
87    }
88    public ILookupParameter<IntValue> EvaluatedSolutionsParameter {
89      get { return (ILookupParameter<IntValue>)Parameters["EvaluatedSolutions"]; }
90    }
91    public ILookupParameter<ResultCollection> ResultsParameter {
92      get { return (ILookupParameter<ResultCollection>)Parameters["Results"]; }
93    }
94    #endregion
95    #endregion
96
97    #region Properties
98    private IItem Target {
99      get { return TargetParameter.ActualValue; }
100    }
101    private DoubleValue Alpha {
102      get { return AlphaParameter.Value; }
103    }
104    private DoubleValue Beta {
105      get { return BetaParameter.Value; }
106    }
107    private DoubleValue Gamma {
108      get { return GammaParameter.Value; }
109    }
110    private DoubleValue Delta {
111      get { return DeltaParameter.Value; }
112    }
113    protected Func<RealVector, double> FunctionEvaluator { get; set; }
114    public IScope CurrentScope {
115      get { return CurrentScopeParameter.ActualValue; }
116    }
117    public DoubleMatrix Coordinates {
118      get { return CoordinatesParameter.ActualValue; }
119      set { CoordinatesParameter.ActualValue = value; }
120    }
121    public ISingleObjectiveTestFunctionProblemEvaluator Evaluator {
122      get { return EvaluatorParameter.ActualValue; }
123      set { EvaluatorParameter.ActualValue = value; }
124    }
125    public IntValue ImprovementAttempts {
126      get { return ImprovementAttemptsParameter.ActualValue; }
127      set { ImprovementAttemptsParameter.ActualValue = value; }
128    }
129    public IRandom Random {
130      get { return RandomParameter.ActualValue; }
131      set { RandomParameter.ActualValue = value; }
132    }
133    #endregion
134
135    [StorableConstructor]
136    protected TestFunctionsImprovementOperator(bool deserializing) : base(deserializing) { }
137    protected TestFunctionsImprovementOperator(TestFunctionsImprovementOperator original, Cloner cloner)
138      : base(original, cloner) {
139      this.problem = cloner.Clone(original.problem);
140    }
141    public TestFunctionsImprovementOperator()
142      : base() {
143      #region Create parameters
144      Parameters.Add(new ScopeParameter("CurrentScope"));
145      Parameters.Add(new ValueLookupParameter<DoubleMatrix>("Coordinates"));
146      Parameters.Add(new ValueLookupParameter<ISingleObjectiveTestFunctionProblemEvaluator>("Evaluator"));
147      Parameters.Add(new ValueLookupParameter<IntValue>("ImprovementAttempts", new IntValue(100)));
148      Parameters.Add(new ValueLookupParameter<IRandom>("Random"));
149      Parameters.Add(new ValueLookupParameter<IItem>("Target"));
150      Parameters.Add(new ValueParameter<DoubleValue>("Alpha", new DoubleValue(1.0)));
151      Parameters.Add(new ValueParameter<DoubleValue>("Beta", new DoubleValue(2.0)));
152      Parameters.Add(new ValueParameter<DoubleValue>("Gamma", new DoubleValue(0.5)));
153      Parameters.Add(new ValueParameter<DoubleValue>("Delta", new DoubleValue(0.5)));
154      #endregion
155      TargetParameter.ActualName = "Point"; // temporary solution for the test functions problem
156    }
157
158    public override IOperation Apply() {
159      var bestSol = CurrentScope.Variables[TargetParameter.ActualName].Value as RealVector;
160      var bestSolQuality = FunctionEvaluator(bestSol);
161
162      // create perturbed solutions
163      var simplex = new RealVector[bestSol.Length];
164      for (int i = 0; i < simplex.Length; i++) {
165        simplex[i] = bestSol.Clone() as RealVector;
166        simplex[i][i] += 0.1 * (Evaluator.Bounds[0, 1] - Evaluator.Bounds[0, 0]);
167        if (simplex[i][i] > Evaluator.Bounds[0, 1]) simplex[i][i] = Evaluator.Bounds[0, 1];
168        if (simplex[i][i] < Evaluator.Bounds[0, 0]) simplex[i][i] = Evaluator.Bounds[0, 0];
169      }
170
171      // improve solutions
172      for (int i = 0; i < ImprovementAttempts.Value; i++) {
173        // order according to their objective function value
174        Array.Sort(simplex, (x, y) => FunctionEvaluator(x).CompareTo(FunctionEvaluator(y)));
175
176        // calculate centroid
177        var centroid = new RealVector(bestSol.Length);
178        foreach (var vector in simplex)
179          for (int j = 0; j < centroid.Length; j++)
180            centroid[j] += vector[j];
181        for (int j = 0; j < centroid.Length; j++)
182          centroid[j] /= simplex.Length;
183
184        // reflection
185        var reflectionPoint = new RealVector(bestSol.Length);
186        for (int j = 0; j < reflectionPoint.Length; j++)
187          reflectionPoint[j] = centroid[j] + Alpha.Value * (centroid[j] - simplex[simplex.Length - 1][j]);
188        double reflectionPointQuality = FunctionEvaluator(reflectionPoint);
189        if (FunctionEvaluator(simplex[0]) <= reflectionPointQuality
190            && reflectionPointQuality < FunctionEvaluator(simplex[simplex.Length - 2]))
191          simplex[simplex.Length - 1] = reflectionPoint;
192
193        // expansion
194        if (reflectionPointQuality < FunctionEvaluator(simplex[0])) {
195          var expansionPoint = new RealVector(bestSol.Length);
196          for (int j = 0; j < expansionPoint.Length; j++)
197            expansionPoint[j] = centroid[j] + Beta.Value * (reflectionPoint[j] - centroid[j]);
198          simplex[simplex.Length - 1] = FunctionEvaluator(expansionPoint) < reflectionPointQuality ? expansionPoint : reflectionPoint;
199        }
200
201        // contraction
202        if (FunctionEvaluator(simplex[simplex.Length - 2]) <= reflectionPointQuality
203            && reflectionPointQuality < FunctionEvaluator(simplex[simplex.Length - 1])) {
204          var outsideContractionPoint = new RealVector(bestSol.Length);
205          for (int j = 0; j < outsideContractionPoint.Length; j++)
206            outsideContractionPoint[j] = centroid[j] + Gamma.Value * (reflectionPoint[j] - centroid[j]);
207          if (FunctionEvaluator(outsideContractionPoint) <= reflectionPointQuality) {
208            simplex[simplex.Length - 1] = outsideContractionPoint;
209            if (FunctionEvaluator(reflectionPoint) >= FunctionEvaluator(simplex[simplex.Length - 1])) {
210              var insideContractionPoint = new RealVector(bestSol.Length);
211              for (int j = 0; j < insideContractionPoint.Length; j++)
212                insideContractionPoint[j] = centroid[j] - Gamma.Value * (reflectionPoint[j] - centroid[j]);
213              if (FunctionEvaluator(insideContractionPoint) < FunctionEvaluator(simplex[simplex.Length - 1])) simplex[simplex.Length - 1] = insideContractionPoint;
214            }
215          }
216        }
217
218        // reduction
219        for (int j = 1; j < simplex.Length; j++)
220          for (int k = 0; k < simplex[j].Length; k++)
221            simplex[j][k] = simplex[0][k] + Delta.Value * (simplex[j][k] - simplex[0][k]);
222      }
223
224      for (int i = 0; i < simplex[0].Length; i++) {
225        if (simplex[0][i] > Evaluator.Bounds[0, 1]) simplex[0][i] = Evaluator.Bounds[0, 1];
226        if (simplex[0][i] < Evaluator.Bounds[0, 0]) simplex[0][i] = Evaluator.Bounds[0, 0];
227      }
228
229      CurrentScope.Variables[TargetParameter.ActualName].Value = simplex[0];
230
231      return base.Apply();
232    }
233  }
234}
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