#region License Information
/* HeuristicLab
* Copyright (C) 2002-2016 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
*
* This file is part of HeuristicLab.
*
* HeuristicLab is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* HeuristicLab is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with HeuristicLab. If not, see .
*/
#endregion
using System;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
namespace HeuristicLab.Encodings.PermutationEncoding {
///
/// Manipulates a permutation array by swaping three randomly chosen elements.
///
///
/// It is implemented such that first 3 positions are randomly chosen in the interval [0;N) with N = length of the permutation with all positions being distinct from each other.
/// Then position 1 is put in place of position 3, position 2 is put in place of position 1 and position 3 is put in place of position 2.
///
[Item("Swap3Manipulator", "An operator which manipulates a permutation array by swaping three randomly chosen elements. It is implemented such that first 3 positions are randomly chosen in the interval [0;N) with N = length of the permutation with all positions being distinct from each other. Then position 1 is put in place of position 3, position 2 is put in place of position 1 and position 3 is put in place of position 2.")]
[StorableClass]
public class Swap3Manipulator : PermutationManipulator {
[StorableConstructor]
protected Swap3Manipulator(bool deserializing) : base(deserializing) { }
protected Swap3Manipulator(Swap3Manipulator original, Cloner cloner) : base(original, cloner) { }
public Swap3Manipulator() : base() { }
public override IDeepCloneable Clone(Cloner cloner) {
return new Swap3Manipulator(this, cloner);
}
///
/// Swaps three randomly chosen elements of the given array.
///
/// Thrown when the contains less than 3 elements.
///
/// It is implemented such that first 3 positions are randomly chosen in the interval [0;N) with N = length of the permutation with all positions being distinct from each other.
/// Then position 1 is put in place of position 3, position 2 is put in place of position 1 and position 3 is put in place of position 2.
///
/// The random number generator.
/// The permutation to manipulate.
public static void Apply(IRandom random, Permutation permutation) {
if (permutation.Length < 3) throw new ArgumentException("Swap3Manipulator: The permutation must be at least of size 3.", "permutation");
int index1, index2, index3;
do {
index1 = random.Next(permutation.Length);
index2 = random.Next(permutation.Length);
index3 = random.Next(permutation.Length);
} while (index1 == index2 || index2 == index3 || index1 == index3);
permutation.Swap(index1, index2);
permutation.Swap(index2, index3);
}
///
/// Swaps three randomly chosen elements of the given array.
///
/// Calls .
/// A random number generator.
/// The permutation to manipulate.
protected override void Manipulate(IRandom random, Permutation permutation) {
Apply(random, permutation);
}
}
}