add an evaluator wrapper that keep the best individual found so far

eo/test/t-eoEvalKeepBest.cpp

@@ -0,0 +1,78 @@
+#include <iostream>
+
+#include <es/make_real.h>
+#include <apply.h>
+#include <eoEvalKeepBest.h>
+#include "real_value.h"
+
+using namespace std;
+
+int main(int argc, char* argv[])
+{
+
+    typedef eoReal<eoMinimizingFitness> EOT;
+
+    eoParser parser(argc, argv);  // for user-parameter reading
+    eoState state;    // keeps all things allocated
+
+
+    /*********************************************
+     * problem or representation dependent stuff *
+     *********************************************/
+
+    // The evaluation fn - encapsulated into an eval counter for output
+    eoEvalFuncPtr<EOT, double, const std::vector<double>&>
+        main_eval( real_value ); // use a function defined in real_value.h
+
+    // wrap the evaluation function in a call counter
+    eoEvalFuncCounter<EOT> eval_counter(main_eval);
+
+    // the genotype - through a genotype initializer
+    eoRealInitBounded<EOT>& init = make_genotype(parser, state, EOT());
+
+    // Build the variation operator (any seq/prop construct)
+    eoGenOp<EOT>& op = make_op(parser, state, init);
+
+
+    /*********************************************
+     * Now the representation-independent things *
+     *********************************************/
+
+
+    // initialize the population - and evaluate
+    // yes, this is representation indepedent once you have an eoInit
+    eoPop<EOT>& pop   = make_pop(parser, state, init);
+
+    // stopping criteria
+    eoContinue<EOT> & term = make_continue(parser, state, eval_counter);
+
+    // things that are called at each generation
+    eoCheckPoint<EOT> & checkpoint = make_checkpoint(parser, state, eval_counter, term);
+
+    // wrap the evaluator in another one that will keep the best individual
+    // evaluated so far
+    eoEvalKeepBest<EOT> eval_keep( eval_counter );
+
+    // algorithm
+    eoAlgo<EOT>& ea = make_algo_scalar(parser, state, eval_keep, checkpoint, op);
+
+
+    /***************************************
+     * Now, call functors and DO something *
+     ***************************************/
+
+    // to be called AFTER all parameters have been read!
+    make_help(parser);
+
+    // evaluate intial population AFTER help and status in case it takes time
+    apply<EOT>(eval_keep, pop);
+
+    std::clog << "Best individual after initialization and " << eval_counter.value() << " evaluations" << std::endl;
+    std::cout << eval_keep.best_element() << std::endl;
+
+    ea(pop); // run the ea
+
+    std::cout << "Best individual after search and " << eval_counter.value() << " evaluations" << std::endl;
+    // you can also call value(), because it is an eoParam
+    std::cout << eval_keep.value() << std::endl;
+}