[2871] | 1 | #region License Information
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| 2 | /* HeuristicLab
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[15583] | 3 | * Copyright (C) 2002-2018 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
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[2871] | 4 | *
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| 5 | * This file is part of HeuristicLab.
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| 6 | *
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| 7 | * HeuristicLab is free software: you can redistribute it and/or modify
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| 8 | * it under the terms of the GNU General Public License as published by
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| 9 | * the Free Software Foundation, either version 3 of the License, or
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| 10 | * (at your option) any later version.
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| 11 | *
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| 12 | * HeuristicLab is distributed in the hope that it will be useful,
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| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 15 | * GNU General Public License for more details.
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| 16 | *
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| 17 | * You should have received a copy of the GNU General Public License
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| 18 | * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
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| 19 | */
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| 20 | #endregion
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| 21 |
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| 22 | using System;
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[4722] | 23 | using HeuristicLab.Common;
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[2871] | 24 | using HeuristicLab.Core;
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| 25 | using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
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| 26 |
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[3053] | 27 | namespace HeuristicLab.Encodings.PermutationEncoding {
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[2871] | 28 | /// <summary>
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| 29 | /// An operator which performs a slight variant of the order crossover on two permutations.
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| 30 | /// </summary>
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| 31 | /// <remarks>
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| 32 | /// It is implemented as described in Affenzeller, M. et al. 2009. Genetic Algorithms and Genetic Programming - Modern Concepts and Practical Applications. CRC Press. p. 135.<br />
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| 33 | /// Crosses two permutations by copying a randomly chosen interval from the first permutation, preserving
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| 34 | /// the positions. But then, instead of starting from the end of the copied interval, the missing values are copied from the start of the permutation in the order they occur.
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| 35 | /// </remarks>
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| 36 | [Item("OrderCrossover2", "An operator which performs an order crossover of two permutations. It is implemented as described in Affenzeller, M. et al. 2009. Genetic Algorithms and Genetic Programming - Modern Concepts and Practical Applications. CRC Press. p. 135.")]
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[3017] | 37 | [StorableClass]
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[2871] | 38 | public class OrderCrossover2 : PermutationCrossover {
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[4722] | 39 | [StorableConstructor]
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| 40 | protected OrderCrossover2(bool deserializing) : base(deserializing) { }
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| 41 | protected OrderCrossover2(OrderCrossover2 original, Cloner cloner) : base(original, cloner) { }
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| 42 | public OrderCrossover2() : base() { }
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| 43 |
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| 44 | public override IDeepCloneable Clone(Cloner cloner) {
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| 45 | return new OrderCrossover2(this, cloner);
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| 46 | }
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| 47 |
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[2871] | 48 | /// <summary>
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| 49 | /// Performs a slight variation of the order crossover of two permutations.
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| 50 | /// </summary>
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| 51 | /// <exception cref="ArgumentException">Thrown when <paramref name="parent1"/> and <paramref name="parent2"/> are not of equal length.</exception>
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| 52 | /// <remarks>
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| 53 | /// Crosses two permutations by copying a randomly chosen interval from the first permutation, preserving
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| 54 | /// the positions. Then, from the beginning of the permutation, copies the missing values from the second permutation
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| 55 | /// in the order they occur.
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| 56 | /// </remarks>
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| 57 | /// <param name="random">A random number generator.</param>
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| 58 | /// <param name="parent1">The first parent permutation to cross.</param>
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| 59 | /// <param name="parent2">The second parent permutation to cross.</param>
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| 60 | /// <returns>The new permutation resulting from the crossover.</returns>
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| 61 | public static Permutation Apply(IRandom random, Permutation parent1, Permutation parent2) {
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| 62 | if (parent1.Length != parent2.Length) throw new ArgumentException("OrderCrossover2: The parent permutations are of unequal length.");
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| 63 | int[] result = new int[parent1.Length];
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| 64 | bool[] copied = new bool[result.Length];
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| 65 |
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| 66 | int breakPoint1 = random.Next(result.Length - 1);
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| 67 | int breakPoint2 = random.Next(breakPoint1 + 1, result.Length);
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| 68 |
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| 69 | for (int i = breakPoint1; i <= breakPoint2; i++) { // copy part of first permutation
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| 70 | result[i] = parent1[i];
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| 71 | copied[parent1[i]] = true;
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| 72 | }
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| 73 |
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| 74 | int index = 0;
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| 75 | for (int i = 0; i < parent2.Length; i++) { // copy remaining part of second permutation
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| 76 | if (index == breakPoint1) { // skip already copied part
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| 77 | index = breakPoint2 + 1;
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| 78 | }
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| 79 | if (!copied[parent2[i]]) {
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| 80 | result[index] = parent2[i];
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| 81 | index++;
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| 82 | }
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| 83 | }
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[3231] | 84 | return new Permutation(parent1.PermutationType, result);
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[2871] | 85 | }
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| 86 |
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| 87 | /// <summary>
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| 88 | /// Checks number of parents and calls <see cref="Apply(IRandom, Permutation, Permutation)"/>.
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| 89 | /// </summary>
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| 90 | /// <exception cref="InvalidOperationException">Thrown if there are not exactly two parents.</exception>
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| 91 | /// <param name="random">A random number generator.</param>
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| 92 | /// <param name="parents">An array containing the two permutations that should be crossed.</param>
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| 93 | /// <returns>The new permutation resulting from the crossover.</returns>
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| 94 | protected override Permutation Cross(IRandom random, ItemArray<Permutation> parents) {
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| 95 | if (parents.Length != 2) throw new InvalidOperationException("OrderCrossover2: Number of parents is not equal to 2.");
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| 96 | return Apply(random, parents[0], parents[1]);
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| 97 | }
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| 98 | }
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| 99 | }
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