possibility to define initial population

optimizer/Optimizer/EA/Variator.h

@@ -13,6 +13,9 @@
 #include "Optimizer/EA/Population.h"
 #include "Optimizer/Optimizer.h"
 
+#include "boost/property_tree/ptree.hpp"
+#include "boost/property_tree/json_parser.hpp"
+
 template<
       class ind_t
     , template <class> class CrossoverOperator
@@ -69,9 +72,68 @@ public:
 
     /// create an initial population
     void initial_population(size_t sizeInitial) {
-      for(size_t i = 0; i < sizeInitial; i++)
-            new_individual();
-
+        
+        std::string fname = args_->getArg<std::string>("start-population", "", false);
+        
+        if ( fname.empty() ) {
+            for(size_t i = 0; i < sizeInitial; i++)
+                new_individual();
+        } else {
+            typedef boost::property_tree::ptree ptree_t;
+            ptree_t tree;
+            
+            boost::property_tree::read_json(fname, tree);
+            
+            if ( tree.get<std::string>("name").compare("opt-pilot") ) {
+                throw OptPilotException("Variator::initial_population",
+                                        "Json file not generated by opt-pilot.");
+            }
+            
+            std::size_t nDVars = 0;
+            for(auto& elem : tree.get_child("dvar-bounds")) {
+                // check if it is a design variable
+                if (std::find(dNames_m.begin(), dNames_m.end(), elem.first) == dNames_m.end()) {
+                    throw OptPilotException("Variator::initial_population",
+                                            "The design variable '" + elem.first + "' is not in the list."); 
+                }
+                ++nDVars;
+            }
+            
+            if ( nDVars != dVarBounds_m.size() ) {
+                throw OptPilotException("Variator::initial_population",
+                                        "The number of design variables do not agree.");
+            }
+            
+            
+            boost::property_tree::ptree& population = tree.get_child("population");
+            
+            std::size_t size = 0;
+            Individual::genes_t dvars(nDVars);
+            for (auto& ind : population ) {
+                
+                if ( size > sizeInitial - 1 )
+                    break;
+                
+                /* just to be sure: It might be that the order of the design variables in the
+                 * Json file is not the same as it reads in, therefore, we check and take the order
+                 * of the container dNames_m.
+                 */
+                for (auto& dvar : population.get_child(ind.first).get_child("dvar")) {
+                    auto it = std::find(dNames_m.begin(), dNames_m.end(), dvar.first);
+                    std::size_t idx = std::distance(dNames_m.begin(), it);
+                    //FIXME requires random access of Individual::genes_t
+                    dvars[idx] = dvar.second.get_value<double>();
+                }
+                
+                new_individual(dvars);
+                ++size;
+            }
+            
+            // fill with random individuals
+            for (std::size_t i = size; i < sizeInitial; ++i) {
+                new_individual();
+            }
+        }
     }
 
     /// set an individual as individual: replace with a new individual
@@ -171,6 +233,13 @@ public:
 
 
 protected:
+    
+    /// create a new individual
+    void new_individual(Individual::genes_t& dvars) {
+        boost::shared_ptr<ind_t> ind(new ind_t(dVarBounds_m, dNames_m, constraints_m));
+        std::swap(ind->genes_m, dvars);
+        individualsToEvaluate_m.push( population_m->add_individual(ind) );
+    }
 
     /// create a new individual
     void new_individual() {