third attempt to save pion root file

benchmarks/barrel_ecal/scripts/emcal_barrel_pions_analysis.cxx

@@ -21,6 +21,7 @@
 #include "TH1D.h"
 #include <TFitResult.h>
 #include "TSystem.h"
+#include <fstream>
 
 using ROOT::RDataFrame;
 using namespace ROOT::VecOps;
@@ -52,10 +53,17 @@ void emcal_barrel_pions_analysis(const char* input_fname = "sim_output/sim_emcal
        {"quantity", "resolution (in %)"},
        {"target", std::to_string(resolutionTarget)}}};
 */
-  gSystem->Exec("cp sim_output/sim_emcal_barrel_uniform_pions.root results/sim_emcal_barrel_uniform_pions.root");
+  //gSystem->Exec("cp sim_output/sim_emcal_barrel_uniform_pions.root results/sim_emcal_barrel_uniform_pions.root");
   ROOT::EnableImplicitMT();
   ROOT::RDataFrame d0("events", input_fname);
 
+  auto colNames = d0.GetColumnNames();
+
+  ofstream out;
+  out.open("results/column_list.txt");
+  for (auto &&col : colNames){out << col << endl;}
+  out.close();
+
   // Thrown Energy [GeV]
   auto Ethr = [](std::vector<dd4pod::Geant4ParticleData> const& input) {
     std::vector<double> result;