#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 HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Encodings.PermutationEncoding;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
namespace HeuristicLab.Problems.TravelingSalesman {
///
/// An operator to evaluate inversion moves (2-opt).
///
[Item("TSPInversionMovePathEvaluator", "Evaluates an inversion move (2-opt) by summing up the length of all added edges and subtracting the length of all deleted edges.")]
[StorableClass]
public abstract class TSPInversionMovePathEvaluator : TSPPathMoveEvaluator, IPermutationInversionMoveOperator {
public ILookupParameter InversionMoveParameter {
get { return (ILookupParameter)Parameters["InversionMove"]; }
}
[StorableConstructor]
protected TSPInversionMovePathEvaluator(bool deserializing) : base(deserializing) { }
protected TSPInversionMovePathEvaluator(TSPInversionMovePathEvaluator original, Cloner cloner) : base(original, cloner) { }
public TSPInversionMovePathEvaluator()
: base() {
Parameters.Add(new LookupParameter("InversionMove", "The move to evaluate."));
}
public static double EvaluateByCoordinates(Permutation permutation, InversionMove move, DoubleMatrix coordinates, TSPInversionMovePathEvaluator evaluator) {
int edge1source = permutation.GetCircular(move.Index1 - 1);
int edge1target = permutation[move.Index1];
int edge2source = permutation[move.Index2];
int edge2target = permutation.GetCircular(move.Index2 + 1);
if (move.Index2 - move.Index1 >= permutation.Length - 2) return 0;
double moveQuality = 0;
// remove two edges
moveQuality -= evaluator.CalculateDistance(coordinates[edge1source, 0], coordinates[edge1source, 1],
coordinates[edge1target, 0], coordinates[edge1target, 1]);
moveQuality -= evaluator.CalculateDistance(coordinates[edge2source, 0], coordinates[edge2source, 1],
coordinates[edge2target, 0], coordinates[edge2target, 1]);
// add two edges
moveQuality += evaluator.CalculateDistance(coordinates[edge1source, 0], coordinates[edge1source, 1],
coordinates[edge2source, 0], coordinates[edge2source, 1]);
moveQuality += evaluator.CalculateDistance(coordinates[edge1target, 0], coordinates[edge1target, 1],
coordinates[edge2target, 0], coordinates[edge2target, 1]);
return moveQuality;
}
public static double EvaluateByDistanceMatrix(Permutation permutation, InversionMove move, DistanceMatrix distanceMatrix) {
int edge1source = permutation.GetCircular(move.Index1 - 1);
int edge1target = permutation[move.Index1];
int edge2source = permutation[move.Index2];
int edge2target = permutation.GetCircular(move.Index2 + 1);
if (move.Index2 - move.Index1 >= permutation.Length - 2) return 0;
double moveQuality = 0;
// remove two edges
moveQuality -= distanceMatrix[edge1source, edge1target];
moveQuality -= distanceMatrix[edge2source, edge2target];
// add two edges
moveQuality += distanceMatrix[edge1source, edge2source];
moveQuality += distanceMatrix[edge1target, edge2target];
return moveQuality;
}
protected override double EvaluateByCoordinates(Permutation permutation, DoubleMatrix coordinates) {
return EvaluateByCoordinates(permutation, InversionMoveParameter.ActualValue, coordinates, this);
}
protected override double EvaluateByDistanceMatrix(Permutation permutation, DistanceMatrix distanceMatrix) {
return EvaluateByDistanceMatrix(permutation, InversionMoveParameter.ActualValue, distanceMatrix);
}
}
}