#region License Information
/* HeuristicLab
* Copyright (C) 2002-2012 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.Data;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
namespace HeuristicLab.Encodings.IntegerVectorEncoding {
///
/// The rounded local crossover for integer vectors is similar to the , but where the factor alpha is chosen randomly in the interval [0;1) for each position.
/// cribed in Dumitrescu, D. et al. (2000), Evolutionary computation, CRC Press, Boca Raton, FL, p. 194.
///
[Item("RoundedLocalCrossover", @"The runded local crossover is similar to the arithmetic crossover, but uses a random alpha for each position x = alpha * p1 + (1-alpha) * p2.")]
[StorableClass]
public class RoundedLocalCrossover : BoundedIntegerVectorCrossover {
[StorableConstructor]
protected RoundedLocalCrossover(bool deserializing) : base(deserializing) { }
protected RoundedLocalCrossover(RoundedLocalCrossover original, Cloner cloner) : base(original, cloner) { }
public RoundedLocalCrossover() : base() { }
public override IDeepCloneable Clone(Cloner cloner) {
return new RoundedLocalCrossover(this, cloner);
}
///
/// Performs a local crossover on the two given parent vectors.
///
/// Thrown when two parents are not of the same length.
/// The random number generator.
/// The first parent for the crossover operation.
/// The second parent for the crossover operation.
/// The newly created integer vector, resulting from the local crossover.
public static IntegerVector Apply(IRandom random, IntegerVector parent1, IntegerVector parent2, IntMatrix bounds) {
if (parent1.Length != parent2.Length)
throw new ArgumentException("RoundedLocalCrossover: the two parents are not of the same length");
double factor;
int length = parent1.Length;
var result = new IntegerVector(length);
int min, max, step = 1;
for (int i = 0; i < length; i++) {
min = bounds[i % bounds.Rows, 0];
max = bounds[i % bounds.Rows, 1];
if (bounds.Columns > 2) step = bounds[i % bounds.Rows, 2];
max = FloorFeasible(min, max, step, max - 1);
factor = random.NextDouble();
result[i] = RoundFeasible(min, max, step, (factor * parent1[i]) + ((1 - factor) * parent2[i]));
}
return result;
}
///
/// Performs a local crossover operation for two given parent integer vectors.
///
/// Thrown if there are not exactly two parents.
/// A random number generator.
/// An array containing the two real vectors that should be crossed.
/// The bounds and step size for each dimension (will be cycled in case there are less rows than elements in the parent vectors).
/// The newly created integer vector, resulting from the crossover operation.
protected override IntegerVector CrossBounded(IRandom random, ItemArray parents, IntMatrix bounds) {
if (parents.Length != 2) throw new ArgumentException("RoundedLocalCrossover: The number of parents is not equal to 2");
return Apply(random, parents[0], parents[1], bounds);
}
}
}