1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022019 Heuristic and Evolutionary Algorithms Laboratory (HEAL)


4  *


5  * This file is part of HeuristicLab.


6  *


7  * HeuristicLab is free software: you can redistribute it and/or modify


8  * it under the terms of the GNU General Public License as published by


9  * the Free Software Foundation, either version 3 of the License, or


10  * (at your option) any later version.


11  *


12  * HeuristicLab is distributed in the hope that it will be useful,


13  * but WITHOUT ANY WARRANTY; without even the implied warranty of


14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the


15  * GNU General Public License for more details.


16  *


17  * You should have received a copy of the GNU General Public License


18  * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.


19  */


20  #endregion


21  using System;


22  using System.Collections.Generic;


23  using System.Linq;


24  using HeuristicLab.Common;


25 


26  namespace HeuristicLab.Problems.TestFunctions.MultiObjective {


27 


28  /// <summary>


29  /// Spacing is defined as the standarddeviation of all d[i]


30  /// where d[i] is the minimum eukildean distance any point has


31  /// to all OTHER points in the same front


32  /// </summary>


33  public static class Spacing {


34 


35  public static double Calculate(IEnumerable<double[]> front) {


36  if (front == null) throw new ArgumentException("Front must not be null.");


37  if (!front.Any()) throw new ArgumentException("Front must not be empty.");


38 


39  var points = front.ToList();


40  var d = new List<double>();


41 


42  foreach (double[] r in points) {


43  var point = r;


44  var otherPoints = points.Where(p => p != point).DefaultIfEmpty(point);


45  double dist = Utilities.MinimumDistance(point, otherPoints);


46  d.Add(dist);


47  }


48 


49  return d.StandardDeviationPop();


50  }


51 


52  }


53  }

