#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.Encodings.PermutationEncoding;
using HeuristicLab.Optimization.Operators;
namespace HeuristicLab.Problems.TravelingSalesman {
///
/// An operator that performs similarity calculation between two traveling salesman solutions.
///
[Item("TSPSimilarityCalculator", "An operator that performs similarity calculation between two traveling salesman solutions.")]
public sealed class TSPSimilarityCalculator : SimilarityCalculator {
private TSPSimilarityCalculator(bool deserializing) : base(deserializing) { }
private TSPSimilarityCalculator(TSPSimilarityCalculator original, Cloner cloner) : base(original, cloner) { }
public TSPSimilarityCalculator() : base() { }
public static double CalculateSimilarity(Permutation left, Permutation right) {
if (left == null || right == null)
throw new ArgumentException("Cannot calculate similarity because one of the provided solutions or both are null.");
int[,] edges = new int[right.Length, 2];
for (int i = 0; i < right.Length; i++) {
edges[right[i], 0] = right[(i + 1) % right.Length];
edges[right[i], 1] = right[(i - 1 + right.Length) % right.Length];
}
double similarity = 0.0;
for (int i = 0; i < left.Length; i++) {
int targetCity = left[(i + 1) % left.Length];
if (targetCity == edges[left[i], 0] || targetCity == edges[left[i], 1])
similarity++;
}
return similarity / left.Length;
}
protected override double CalculateSimilarity(IScope left, IScope right) {
Permutation sol1 = left.Variables[Target].Value as Permutation;
Permutation sol2 = right.Variables[Target].Value as Permutation;
return CalculateSimilarity(sol1, sol2);
}
}
}