HeuristicLab.Optimization.Operators/3.3/SquareRootDiscreteDoubleValueModifier.cs

   1 #region License Information
   2 /* HeuristicLab
   3  * Copyright (C) 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
  22 using System;
  23 using HeuristicLab.Common;
  24 using HeuristicLab.Core;
  25 using HEAL.Attic;
  26
  27 namespace HeuristicLab.Optimization.Operators {
  28   /// <summary>
  29   /// Modifies the value by square rooted fall (fast fall initially, slow fall to the end) or rise (fast rise initially, slow rise to the end).
  30   /// </summary>
  31   [Item("SquareRootDiscreteDoubleValueModifier", "Modifies the value by square rooted fall (fast fall initially, slow fall to the end) or rise (fast rise initially, slow rise to the end).")]
  32   [StorableType("0D62E89E-87D9-4F4F-889E-D64CB4CCBF6E")]
  33   public class SquareRootDiscreteDoubleValueModifier : DiscreteDoubleValueModifier {
  34     [StorableConstructor]
  35     protected SquareRootDiscreteDoubleValueModifier(StorableConstructorFlag _) : base(_) { }
  36     protected SquareRootDiscreteDoubleValueModifier(SquareRootDiscreteDoubleValueModifier original, Cloner cloner) : base(original, cloner) { }
  37     public SquareRootDiscreteDoubleValueModifier() : base() { }
  38
  39     public override IDeepCloneable Clone(Cloner cloner) {
  40       return new SquareRootDiscreteDoubleValueModifier(this, cloner);
  41     }
  42
  43     protected override double Modify(double value, double startValue, double endValue, int index, int startIndex, int endIndex) {
  44       return Apply(value, startValue, endValue, index, startIndex, endIndex);
  45     }
  46
  47     /// <summary>
  48     /// Calculates a new value based on sqrt decay or growth.
  49     /// </summary>
  50     /// <param name="value">The previous value.</param>
  51     /// <param name="startValue">The initial value.</param>
  52     /// <param name="endValue">The final value.</param>
  53     /// <param name="index">The current index.</param>
  54     /// <param name="startIndex">The initial index.</param>
  55     /// <param name="endIndex">The final index.</param>
  56     /// <returns>The new value.</returns>
  57     public static double Apply(double value, double startValue, double endValue, int index, int startIndex, int endIndex) {
  58       double a = (endValue - startValue) / Math.Sqrt(endIndex - startIndex);
  59       return a * Math.Sqrt(index - startIndex) + startValue;
  60     }
  61   }
  62 }