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source: trunk/sources/HeuristicLab.Encodings.RealVectorEncoding/3.3/Manipulators/PolynomialAllPositionManipulator.cs @ 3376

Last change on this file since 3376 was 3376, checked in by swagner, 14 years ago

Moved interfaces and classes for deep cloning from HeuristicLab.Core to HeuristicLab.Common (#975).

File size: 6.0 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2010 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.Parameters;
27using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
28
29namespace HeuristicLab.Encodings.RealVectorEncoding {
30  /// <summary>
31  /// Performs the polynomial manipulation on all positions in the real vector.
32  /// </summary>
33  /// <remarks>
34  /// The polynomial manipulation is implemented as described in Deb, K. & Goyal, M. A. 1996. Combined Genetic Adaptive Search (GeneAS) for Engineering Design Computer Science and Informatics, 26, pp. 30-45.
35  /// It is performed on all positions of a real vector.
36  /// </remarks>
37  [Item("PolynomialAllPositionManipulator", "The polynomial manipulation is implemented as described in Deb, K. & Goyal, M. A. 1996. Combined Genetic Adaptive Search (GeneAS) for Engineering Design Computer Science and Informatics, 26, pp. 30-45. In this operator it is performed on all positions of the real vector.")]
38  [StorableClass]
39  public class PolynomialAllPositionManipulator : RealVectorManipulator {
40    /// <summary>
41    /// The contiguity parameter specifies the shape of the probability density function that controls the mutation. Setting it to 0 is similar to a uniform distribution over the entire manipulation range (specified by <see cref="MaximumManipulationParameter"/>.
42    /// A higher value will shape the density function such that values closer to 0 (little manipulation) are more likely than values closer to 1 or -1 (maximum manipulation).
43    /// </summary>
44    public ValueLookupParameter<DoubleValue> ContiguityParameter {
45      get { return (ValueLookupParameter<DoubleValue>)Parameters["Contiguity"]; }
46    }
47    /// <summary>
48    /// The maximum manipulation parameter specifies the range of the manipulation. The value specified here is the highest value the mutation will ever add to the current value.
49    /// </summary>
50    /// <remarks>
51    /// If there are bounds specified the manipulated value is restricted by the given lower and upper bounds.
52    /// </remarks>
53    public ValueLookupParameter<DoubleValue> MaximumManipulationParameter {
54      get { return (ValueLookupParameter<DoubleValue>)Parameters["MaximumManipulation"]; }
55    }
56
57    /// <summary>
58    /// Initializes a new instance of <see cref="PolynomialAllPositionManipulator"/> with two parameters
59    /// (<c>Contiguity</c> and <c>MaximumManipulation</c>).
60    /// </summary>
61    public PolynomialAllPositionManipulator()
62      : base() {
63      Parameters.Add(new ValueLookupParameter<DoubleValue>("Contiguity", "Specifies whether the manipulation should produce far stretching (small value) or close (large value) manipulations with higher probability. Valid values must be greater or equal to 0.", new DoubleValue(2)));
64      Parameters.Add(new ValueLookupParameter<DoubleValue>("MaximumManipulation", "Specifies the maximum value that should be added or subtracted by the manipulation. If this value is set to 0 no mutation will be performed.", new DoubleValue(1)));
65    }
66
67    /// <summary>
68    /// Performs the polynomial mutation on a single position in the real vector.
69    /// </summary>
70    /// <param name="random">The random number generator to use.</param>
71    /// <param name="vector">The vector that should be manipulated.</param>
72    /// <param name="contiguity">A parameter describing the shape of the probability density function which influences the strength of the manipulation.</param>
73    /// <param name="maxManipulation">The maximum strength of the manipulation.</param>
74    public static void Apply(IRandom random, RealVector vector, DoubleValue contiguity, DoubleValue maxManipulation) {
75      if (contiguity.Value < 0) throw new ArgumentException("PolynomialAllPositionManipulator: Contiguity value is smaller than 0", "contiguity");
76      double u, delta = 0;
77
78      for (int index = 0; index < vector.Length; index++) {
79        u = random.NextDouble();
80        if (u < 0.5) {
81          delta = Math.Pow(2 * u, 1.0 / (contiguity.Value + 1)) - 1.0;
82        } else if (u > 0.5) {
83          delta = 1.0 - Math.Pow(2.0 - 2.0 * u, 1.0 / contiguity.Value + 1);
84        } else if (u == 0.5) delta = 0;
85
86        vector[index] += delta * maxManipulation.Value;
87      }
88    }
89
90    /// <summary>
91    /// Checks the availability of the parameters and forwards the call to <see cref="Apply(IRandom, RealVector, DoubleValue, DoubleValue)"/>.
92    /// </summary>
93    /// <param name="random">The random number generator to use.</param>
94    /// <param name="realVector">The vector of real values to manipulate.</param>
95    protected override void Manipulate(IRandom random, RealVector realVector) {
96      if (ContiguityParameter.ActualValue == null) throw new InvalidOperationException("PolynomialAllPositionManipulator: Parameter " + ContiguityParameter.ActualName + " could not be found.");
97      if (MaximumManipulationParameter.ActualValue == null) throw new InvalidOperationException("PolynomialAllPositionManipulator: Parameter " + MaximumManipulationParameter.ActualName + " could not be found.");
98      Apply(random, realVector, ContiguityParameter.ActualValue, MaximumManipulationParameter.ActualValue);
99    }
100  }
101}
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