nlpsolver/ThirdParty/EvolutionarySolver/src/net/adaptivebox/goodness/ACRComparator.java

   1 /**
   2  * Description: For comparison of goodness in landscape with loosed constraints
   3  *  which varied adaptively according to the social information.
   4  *
   5  * @Applied domain: efficiently for ridge class feasible space (SF), such as
   6  *  the problem with eqaulity constraints
   7  *
   8  * @ Author        Create/Modi     Note
   9  * Xiaofeng Xie    Jun 24, 2003     Created
  10  * Xiaofeng Xie    May 11, 2004
  11  *
  12  * This library is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Lesser General Public
  14  * License as published by the Free Software Foundation; either
  15  * version 2.1 of the License, or (at your option) any later version.
  16  *
  17  * This library is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * Lesser General Public License for more details.
  21  *
  22  * Please acknowledge the author(s) if you use this code in any way.
  23  *
  24  * @version 1.0
  25  * @Since MAOS1.2
  26  *
  27  * [1] Xie X F, Zhang W J, Bi D C. Handling equality constraints by adaptive
  28  * relaxing rule for swarm algorithms. Congress on Evolutionary Computation,
  29  * Oregon, USA, 2004
  30  */
  31
  32 package net.adaptivebox.goodness;
  33
  34 import net.adaptivebox.knowledge.*;
  35 import net.adaptivebox.global.*;
  36
  37
  38 public class ACRComparator implements IGoodnessCompareEngine, IUpdateCycleEngine {
  39   private Library socialPool;
  40   private double epsilon_t = 0;
  41
  42   private double RU = 0.75;
  43   private double RL = 0.25;
  44   private double BETAF = 0.618;
  45   private double BETAL = 0.618;
  46   private double BETAU = 1.382;
  47
  48   private double T = -1;
  49
  50   private double TthR = 0.5;
  51
  52   public ACRComparator(Library lib, int T) {
  53     socialPool = lib;
  54     this.T = T;
  55     //set the (epsilon_t|t=0) as the maximum CONS value among the SearchPoints in the library
  56     epsilon_t = lib.getExtremalVcon(true);
  57   }
  58
  59   static public int compare(double data1, double data2) {
  60     if (data1 < data2)
  61       return LESS_THAN;
  62     else if (data1 > data2)
  63       return LARGER_THAN;
  64     else
  65       return EQUAL_TO;
  66   }
  67
  68   public int compare(double[] fit1, double[] fit2) {
  69     if(Math.max(fit1[0], fit2[0])<=Math.max(0, epsilon_t)) { //epsilon>0
  70       return compare(fit1[1], fit2[1]);
  71     } else {
  72       return compare(fit1[0], fit2[0]);
  73     }
  74   }
  75
  76   public void updateCycle(int t) {
  77     //calculates the ratio
  78     double rn = (double)socialPool.getVconThanNum(epsilon_t)/(double)socialPool.getPopSize();
  79     if(t>TthR*T &&T!=-1) { //Forcing sub-rule
  80       epsilon_t *= BETAF;
  81     } else {              //Ratio-keeping sub-rules
  82       if(rn>RU) {
  83         epsilon_t *= BETAL;  //Shrink
  84       }
  85       if(rn<RL) {
  86         epsilon_t *= BETAU;  //Relax
  87       }
  88     }
  89   }
  90 }