From b83372b57b00b84206734659b92a314bffebcb1d Mon Sep 17 00:00:00 2001
From: Johann Dreo <johann.dreo@thalesgroup.com>
Date: Thu, 6 Sep 2012 16:05:00 +0200
Subject: [PATCH] Add a stat to keep the best individual found so far, even for
 non-monotonic algorithms

---
 eo/src/utils/eoStat.h | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/eo/src/utils/eoStat.h b/eo/src/utils/eoStat.h
index 32c3bf9f6..e7c5adca2 100644
--- a/eo/src/utils/eoStat.h
+++ b/eo/src/utils/eoStat.h
@@ -356,6 +356,38 @@ private :
 /** @example t-eoSSGA.cpp
  */
 
+/** Keep the best individual found so far
+ */
+template <class EOT>
+class eoBestIndividualStat : public eoStat<EOT, EOT>
+{
+public:
+    using eoStat<EOT, EOT>::value;
+
+    eoBestIndividualStat(std::string _description = "BestIndiv ")
+        : eoStat<EOT, EOT>( EOT(), _description )
+        {}
+
+    void operator()(const eoPop<EOT>& pop) 
+    {
+        EOT best = pop.best_element();
+        // on the first call, value() is invalid
+        if( value().invalid() ) {
+            // thus we cannot compare it to something else
+            value() = best;
+        } else {
+            // keep the best individual found so far
+            if( best.fitness() > value().fitness() ) {
+                value() = best;
+            }
+        }
+    }
+
+    virtual std::string className(void) const { return "eoBestIndividualStat"; }
+};
+
+
+
 template <class EOT>
 class eoDistanceStat : public eoStat<EOT, double>
 {