Resolve "pi0 resolution for ECal barrel"

Closes #19 (closed)

benchmarks/barrel_ecal/scripts/emcal_barrel_pions_analysis.cxx

@@ -95,14 +95,36 @@ void emcal_barrel_pions_analysis(const char* input_fname = "sim_output/sim_emcal
     return result;
   };
 
+  // Energy Resolution = Esampling - Ethrown
+  auto eResol = [](const std::vector<double>& sampled, const std::vector<double>& thrown) {
+    std::vector<double> result;
+    auto it_sam = sampled.cbegin();
+    auto it_thr = thrown.cbegin();
+    for (; it_sam != sampled.end() && it_thr != thrown.end(); ++it_sam, ++it_thr) {
+        result.push_back(*it_sam - *it_thr);
+    }
+    return result;
+  };
+
+  // Relative Energy Resolution = (Esampling - Ethrown)/Ethrown
+  auto eResol_rel = [](const std::vector<double>& sampled, const std::vector<double>& thrown) {
+    std::vector<double> result;
+    auto it_sam = sampled.cbegin();
+    auto it_thr = thrown.cbegin();
+    for (; it_sam != sampled.end() && it_thr != thrown.end(); ++it_sam, ++it_thr) {
+        result.push_back((*it_sam - *it_thr) / *it_sam);
+    }
+    return result;
+  };
+
   // Define variables
   auto d1 = d0.Define("Ethr",  Ethr,  {"mcparticles"})
-	      .Define("nhits", nhits, {"EcalBarrelHits"})
-	      .Define("Esim",  Esim,  {"EcalBarrelHits"})
+	      .Define("nhits",  nhits,      {"EcalBarrelHits"})
+	      .Define("Esim",   Esim,       {"EcalBarrelHits"})
 	      //.Define("fsam",  fsam,  {"Esim","Ethr"})
-        .Define("fsam",  fsam2,  {"Esim","Ethr"})
-        .Define("dE", "Ethr-Esim")
-        .Define("dE_rel", "(Ethr - Esim)/Esim")
+        .Define("fsam",   fsam2,      {"Esim","Ethr"})
+        .Define("dE",     eResol,     {"Esim", "Ethr"})
+        .Define("dE_rel", eResol_rel, {"Esim", "Ethr"})
 	      ;
 
   // Define Histograms
@@ -156,12 +178,10 @@ void emcal_barrel_pions_analysis(const char* input_fname = "sim_output/sim_emcal
   c4->SaveAs("results/emcal_barrel_pions_fsam.pdf");
 
   //Energy Resolution Work
-  auto hdE          = d1.Histo1D({"hdE",      "dE; dE[GeV]; Events",              100, -7.5, 7.5}, "dE");
-  auto hdE_rel      = d1.Histo1D({"hdE_rel",  "dE Relative; dE Relative; Events", 100, -7.5, 7.5}, "dE_rel");
-  TFitResultPtr f1  = hdE_rel->Fit("gaus", "S");
-  const double* res = f1->GetParams();
-  auto tf1          = new TF1("", "TMath::Gaus(x, [0], [1], [2])", -7.5, 7.5);
-  tf1               -> SetParameters(res[0], res[1], res[2]); 
+  auto hdE          = d1.Histo1D({"hdE",      "dE; dE[GeV]; Events",              20, -7.5, 7.5}, "dE");//changed from 100
+  auto hdE_rel      = d1.Histo1D({"hdE_rel",  "dE Relative; dE Relative; Events", 20, -7.5, 7.5}, "dE_rel");//changed from 100
+  hdE_rel->Fit("gaus", "", "", -7.5,  7.5);
+  //double* res       = hdE_rel->GetFunction("gaus")->GetParameters();
 
   //Pass/Fail
   /*
@@ -171,7 +191,7 @@ void emcal_barrel_pions_analysis(const char* input_fname = "sim_output/sim_emcal
     pion0_energy_resolution.fail(res[2]);
   }
   */
-  std::printf("Energy Resolution is %f\n", res[2]);
+  //std::printf("Energy Resolution is %f\n", res[2]);
 
   //Energy Resolution Histogram Plotting
   auto *cdE = new TCanvas("cdE", "cdE", 700, 500);
@@ -187,10 +207,9 @@ void emcal_barrel_pions_analysis(const char* input_fname = "sim_output/sim_emcal
   hdE_rel->GetYaxis()->SetTitleOffset(1.4);
   hdE_rel->SetLineWidth(2);
   hdE_rel->SetLineColor(kBlue);
-  tf1->SetLineWidth(2);
-  tf1->SetLineColor(kRed);
+  hdE_rel->GetFunction("gaus")->SetLineWidth(2);
+  hdE_rel->GetFunction("gaus")->SetLineColor(kRed);
   hdE_rel->DrawClone();
-  tf1->Draw("SAME");
   cdE_rel->SaveAs("results/emcal_barrel_pi0_dE_rel.png");
   cdE_rel->SaveAs("results/emcal_barrel_pi0_dE_rel.pdf");