#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.Data;
using HeuristicLab.Encodings.PermutationEncoding;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
namespace HeuristicLab.Problems.TravelingSalesman {
///
/// A base class for operators which evaluate TSP solutions given in path representation using city coordinates.
///
[Item("TSPCoordinatesPathEvaluator", "A base class for operators which evaluate TSP solutions given in path representation using city coordinates.")]
[StorableClass]
public abstract class TSPCoordinatesPathEvaluator : TSPEvaluator, ITSPCoordinatesPathEvaluator {
private object locker = new object();
public ILookupParameter PermutationParameter {
get { return (ILookupParameter)Parameters["Permutation"]; }
}
public ILookupParameter CoordinatesParameter {
get { return (ILookupParameter)Parameters["Coordinates"]; }
}
public ILookupParameter DistanceMatrixParameter {
get { return (ILookupParameter)Parameters["DistanceMatrix"]; }
}
public ILookupParameter UseDistanceMatrixParameter {
get { return (ILookupParameter)Parameters["UseDistanceMatrix"]; }
}
[StorableConstructor]
protected TSPCoordinatesPathEvaluator(bool deserializing) : base(deserializing) { }
protected TSPCoordinatesPathEvaluator(TSPCoordinatesPathEvaluator original, Cloner cloner) : base(original, cloner) { }
protected TSPCoordinatesPathEvaluator()
: base() {
Parameters.Add(new LookupParameter("Permutation", "The TSP solution given in path representation which should be evaluated."));
Parameters.Add(new LookupParameter("Coordinates", "The x- and y-Coordinates of the cities."));
Parameters.Add(new LookupParameter("DistanceMatrix", "The matrix which contains the distances between the cities."));
Parameters.Add(new LookupParameter("UseDistanceMatrix", "True if a distance matrix should be calculated and used for evaluation, otherwise false."));
}
[StorableHook(HookType.AfterDeserialization)]
private void AfterDeserialization() {
// BackwardsCompatibility3.3
#region Backwards compatible code (remove with 3.4)
LookupParameter oldDistanceMatrixParameter = Parameters["DistanceMatrix"] as LookupParameter;
if (oldDistanceMatrixParameter != null) {
Parameters.Remove(oldDistanceMatrixParameter);
Parameters.Add(new LookupParameter("DistanceMatrix", "The matrix which contains the distances between the cities."));
DistanceMatrixParameter.ActualName = oldDistanceMatrixParameter.ActualName;
}
#endregion
}
public static double Apply(TSPCoordinatesPathEvaluator evaluator, DoubleMatrix coordinates, Permutation tour) {
DoubleMatrix c = coordinates;
Permutation p = tour;
double length = 0;
for (int i = 0; i < p.Length - 1; i++)
length += evaluator.CalculateDistance(c[p[i], 0], c[p[i], 1], c[p[i + 1], 0], c[p[i + 1], 1]);
length += evaluator.CalculateDistance(c[p[p.Length - 1], 0], c[p[p.Length - 1], 1], c[p[0], 0], c[p[0], 1]);
return length;
}
public sealed override IOperation InstrumentedApply() {
if (UseDistanceMatrixParameter.ActualValue.Value) {
Permutation p = PermutationParameter.ActualValue;
DistanceMatrix dm = DistanceMatrixParameter.ActualValue;
if (dm == null) { // calculate distance matrix
lock (locker) {
dm = DistanceMatrixParameter.ActualValue;
if (dm == null) { // check again to avoid race condition
DoubleMatrix c = CoordinatesParameter.ActualValue;
if (c == null) throw new InvalidOperationException("Neither a distance matrix nor coordinates were given.");
dm = new DistanceMatrix(c.Rows, c.Rows);
for (int i = 0; i < dm.Rows; i++) {
for (int j = 0; j < dm.Columns; j++)
dm[i, j] = CalculateDistance(c[i, 0], c[i, 1], c[j, 0], c[j, 1]);
}
DistanceMatrixParameter.ActualValue = (DistanceMatrix)dm.AsReadOnly();
}
}
}
double length = 0;
for (int i = 0; i < p.Length - 1; i++)
length += dm[p[i], p[i + 1]];
length += dm[p[p.Length - 1], p[0]];
QualityParameter.ActualValue = new DoubleValue(length);
} else {
Permutation p = PermutationParameter.ActualValue;
DoubleMatrix c = CoordinatesParameter.ActualValue;
if (c == null) throw new InvalidOperationException("No coordinates were given.");
double length = 0;
for (int i = 0; i < p.Length - 1; i++)
length += CalculateDistance(c[p[i], 0], c[p[i], 1], c[p[i + 1], 0], c[p[i + 1], 1]);
length += CalculateDistance(c[p[p.Length - 1], 0], c[p[p.Length - 1], 1], c[p[0], 0], c[p[0], 1]);
QualityParameter.ActualValue = new DoubleValue(length);
}
return base.InstrumentedApply();
}
///
/// Calculates the distance between two points.
///
/// The x-coordinate of point 1.
/// The y-coordinate of point 1.
/// The x-coordinate of point 2.
/// The y-coordinate of point 2.
/// The calculated distance.
protected abstract double CalculateDistance(double x1, double y1, double x2, double y2);
}
}