#region License Information
/* HeuristicLab
* Copyright (C) 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.Collections.Generic;
using HEAL.Attic;
namespace HeuristicLab.Problems.TestFunctions.MultiObjective {
public static class NonDominatedSelect {
[StorableType("5EDA6CC0-30C6-4B71-8713-F84BB61B1180")]
public enum DominationResult { Dominates, IsDominated, IsNonDominated };
public static IEnumerable SelectNonDominatedVectors(IEnumerable qualities, bool[] maximization, bool dominateOnEqualQualities) {
List front = new List();
foreach (double[] row in qualities) {
bool insert = true;
for (int i = 0; i < front.Count; i++) {
DominationResult res = Dominates(front[i], row, maximization, dominateOnEqualQualities);
if (res == DominationResult.Dominates) { insert = false; break; } //Vector domiates Row
else if (res == DominationResult.IsDominated) { //Row dominates Vector
front.RemoveAt(i);
}
}
if (insert) {
front.Add(row);
}
}
return front;
}
public static IEnumerable GetDominatingVectors(IEnumerable qualities, double[] reference, bool[] maximization, bool dominateOnEqualQualities) {
List front = new List();
foreach (double[] vec in qualities) {
if (Dominates(vec, reference, maximization, dominateOnEqualQualities) == DominationResult.Dominates) {
front.Add(vec);
}
}
return front;
}
public static DominationResult Dominates(double[] left, double[] right, bool[] maximizations, bool dominateOnEqualQualities) {
//mkommend Caution: do not use LINQ.SequenceEqual for comparing the two quality arrays (left and right) due to performance reasons
if (dominateOnEqualQualities) {
var equal = true;
for (int i = 0; i < left.Length; i++) {
if (left[i] != right[i]) {
equal = false;
break;
}
}
if (equal) return DominationResult.Dominates;
}
bool leftIsBetter = false, rightIsBetter = false;
for (int i = 0; i < left.Length; i++) {
if (IsDominated(left[i], right[i], maximizations[i])) rightIsBetter = true;
else if (IsDominated(right[i], left[i], maximizations[i])) leftIsBetter = true;
if (leftIsBetter && rightIsBetter) break;
}
if (leftIsBetter && !rightIsBetter) return DominationResult.Dominates;
if (!leftIsBetter && rightIsBetter) return DominationResult.IsDominated;
return DominationResult.IsNonDominated;
}
private static bool IsDominated(double left, double right, bool maximization) {
return maximization && left < right
|| !maximization && left > right;
}
}
}