Refactoring

eo/src/moo/eoNSGA_I_Eval.h

@@ -0,0 +1,73 @@
+#ifndef __eoNSGA_I_Eval_h_
+#define __eoNSGA_I_Eval_h_
+
+#include <moo/eoFrontSorter.h>
+#include <moo/eoMOEval.h>
+
+/**
+  The original Non Dominated Sorting algorithm from Srinivas and Deb
+*/
+template <class EOT>
+class eoNSGA_I_Eval : public eoMOEval<EOT>
+{
+public :
+  eoNSGA_I_Eval(double nicheWidth, eoEvalFunc<EOT>& eval)    : eoMOEval<EOT>(eval), nicheSize(nicheWidth) {}
+  eoNSGA_I_Eval(double nicheWidth, eoPopEvalFunc<EOT>& eval) : eoMOEval<EOT>(eval), nicheSize(nicheWidth) {}
+
+  void operator()(eoPop<EOT>& parents, eoPop<EOT>& offspring) {
+        eval(parents, offspring);
+
+        std::vector<EOT*> pop;
+        pop.reserve(parents.size() + offspring.size());
+        for (unsigned i = 0; i < parents.size(); ++i) pop.push_back(&parents[i]);
+        for (unsigned i = 0; i < offspring.size(); ++i) pop.push_back(&offspring[i]);
+
+        typename eoFrontSorter<EOT>::front_t front = sorter(pop);
+
+        for (unsigned i = 0; i < front.size(); ++i) {
+            assign_worths(front[i], front.size() - i, pop); 
+        }
+  }
+
+  private:
+  void assign_worths(const std::vector<detail::FitnessInfo>& front, unsigned rank, std::vector<EOT*>& parents) {
+
+        for (unsigned i = 0; i < front.size(); ++i)
+        { // calculate whether the other points lie within the nice
+          double niche_count = 0;
+
+          for (unsigned j = 0; j < front.size(); ++j)
+          {
+            if (i == j)
+              continue;
+
+            double dist = 0.0;
+
+            for (unsigned k = 0; k < front[j].fitness.size(); ++k)
+            {
+              double d = front[i].fitness[k] - front[j].fitness[k];
+              dist += d*d;
+            }
+
+            if (dist < nicheSize)
+            {
+              niche_count += 1.0 - pow(dist / nicheSize,2.);
+            }
+          }
+        
+          unsigned idx = front[i].index;
+          typename EOT::Fitness f = parents[idx]->fitness();
+          f.setWorth(rank + niche_count);
+          parents[ idx ]->fitness(f);
+        }
+  }
+
+  private :
+
+  double nicheSize;
+  eoFrontSorter<EOT> sorter;
+};
+
+#endif
+
+