bugfix MeVPrtl to classify boone ntuple flux type as simple flux, and fix flux weight calculator to pick neutrino energy from MCTruth if MCFlux energy is -1

Author: VCLanNguyen

sbncode/EventGenerator/MeVPrtl/Tools/BNBKaonGen_tool.cc

@@ -311,7 +311,7 @@ simb::MCFlux BNBKaonGen::MakeMCFlux(const bsim::BooNe &boone) {
                                       << std::endl;
   }
 
-  flux.fFluxType = simb::kDk2Nu;
+  flux.fFluxType = simb::kSimple_Flux;
   flux.fnimpwt   = fBooneNtp.beamwgt;
   flux.fvx       = fBooneNtp.ini_pos[0][0]; //0
   flux.fvy       = fBooneNtp.ini_pos[0][1]; //0

sbncode/SBNEventWeight/Calculators/BNBFlux/FluxCalcPrep.cxx

@@ -224,7 +224,7 @@ namespace sbn {
       }
 
       //or do the above 3 lines in one line
-//      auto const& mclist = *e.getValidHandle<std::vector<simb::MCTruth>>(fGeneratorModuleLabel);
+      auto const& mclist = *e.getValidHandle<std::vector<simb::MCTruth>>(fGeneratorModuleLabel);
 
       // If no neutrinos in this event, gives 0 weight;
       int NUni = fParameterSet.fNuniverses;
@@ -264,8 +264,8 @@ namespace sbn {
         }
 
         // Collect neutrino energy; mclist is replaced with fluxlist.
-//        double enu= mclist[inu].GetNeutrino().Nu().E();
         double enu= fluxlist[inu].fnenergyn;
+        if ( enu == -1 ) enu= mclist[inu].GetNeutrino().Nu().E(); //For MeVPrtl generator, not all MCFlux result in a neutrino, so equivalent neutrino energy is computed and saved as MCTruth
 
         //Let's make a weights based on the calculator you have requested