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

   1 /**
   2  * Description: For comparison of goodness in landscape with stoch. ranking.
   3  *
   4  * @ Author        Create/Modi     Note
   5  * Xiaofeng Xie    May 29, 2004
   6  *
   7  * [1] Runarsson T P, Yao X. Stochastic ranking for constrained evolutionary
   8  * optimization. IEEE Trans. on Evolutionary Computation. 2000, 4 (3): 284-294
   9  *
  10  */
  11
  12 package net.adaptivebox.goodness;
  13
  14 import net.adaptivebox.global.*;
  15
  16 public class SRComparator implements IGoodnessCompareEngine, IUpdateCycleEngine {
  17   public double Pf = 0.5;
  18
  19   public SRComparator() {}
  20
  21   public SRComparator(double pf) {
  22     this.Pf = pf;
  23   }
  24
  25   public void updateCycle(int t) {
  26     Pf *=0.995;
  27   }
  28
  29   /**
  30    *  check the magnitude of two array, the frontial is more important
  31    * Stoch ranking: array size = 2
  32    **/
  33   public int compare(double[] fit1, double[] fit2) {
  34     if((fit1[0]==fit2[0])||Pf>Math.random()) {
  35       return GlobalCompare.compare(fit1[1], fit2[1]);
  36     } else {
  37       return GlobalCompare.compare(fit1[0], fit2[0]);
  38     }
  39   }
  40
  41 }