PatExamples/bin/monitorJetEnergyScale.C

0001 #include <algorithm>
0002 #include <iostream>
0003 #include <string>
0004 #include <vector>
0005
0006 #include "TF1.h"
0007 #include "TH1F.h"
0008 #include "TFile.h"
0009 #include "TStyle.h"
0010 #include "TCanvas.h"
0011 #include "TLegend.h"
0012
0013 /// maximal number of bins used for the jet
0014 /// response plots
0015 static const unsigned int MAXBIN=8;
0016 /// binning used for the jet response plots
0017 /// (NOTE BINS must have a length of MAXBIN
0018 /// +1)
0019 static const float BINS[]={30., 40., 50., 60., 70., 80., 100., 125., 150.};
0020
0021 /// -------------------------------------------------------------------------------
0022 ///
0023 /// Determine and display the Jet Response for Uncorrected, L2Relative and
0024 /// L3Absolute corrected jets as a function of the pt of the matched genJet
0025 /// from a set of basic histograms filled in the PatJetAnalyzer. The mean
0026 /// jet energy response is determined from simple gaussien fits w/o any
0027 /// extras.
0028 /// The use case is:
0029 /// .x PhysicsTools/PatExamples/bin/monitorJetEnergyScale.C+
0030 ///
0031 /// -------------------------------------------------------------------------------
0032 void monitorJetEnergyScale()
0033 {
0034   gStyle->SetOptStat(   0);
0035   gStyle->SetOptFit (1111);
0036
0037   // list of valid histogram names
0038   std::vector<std::string> corrLevels_;
0039   corrLevels_.push_back("Uncorrected");
0040   corrLevels_.push_back("L2Relative" );
0041   corrLevels_.push_back("L3Absolute" );
0042
0043   //open file
0044   TFile* file = new TFile("analyzeJetEnergyScale.root");
0045
0046   // define jet energy scale histograms
0047   std::vector<TH1F*> jes;
0048   for(unsigned int idx=0; idx<corrLevels_.size(); ++idx){
0049     jes.push_back(new TH1F(std::string("jes").append(corrLevels_[idx]).c_str(), "Jet Response", MAXBIN, BINS));
0050   }
0051
0052   // load base histograms
0053   std::vector<std::vector<TH1F*> > hists;
0054   for(unsigned int idx=0; idx<corrLevels_.size(); ++idx){
0055     std::vector<TH1F*> buffer;
0056     for(unsigned int jdx=0; jdx<MAXBIN; ++jdx){
0057       char path[50]; sprintf (path, "%s/jes_%i", corrLevels_[idx].c_str(), jdx);
0058       buffer.push_back((TH1F*)file->Get(path));
0059     }
0060     hists.push_back(buffer);
0061   }
0062
0063   // fit gaussians to base histograms
0064   for(unsigned int idx=0; idx<corrLevels_.size(); ++idx){
0065     for(unsigned int jdx=0; jdx<MAXBIN; ++jdx){
0066       hists[idx][jdx]->Fit("gaus");
0067       jes[idx]->SetBinContent(jdx+1, hists[idx][jdx]->GetFunction("gaus")->GetParameter(1));
0068       jes[idx]->SetBinError  (jdx+1, hists[idx][jdx]->GetFunction("gaus")->GetParError (1));
0069     }
0070   }
0071
0072   // setup the canvas and draw the histograms
0073   TCanvas* canv0 = new TCanvas("canv0", "canv0", 600, 600);
0074   canv0->cd(0);
0075   canv0->SetGridx(1);
0076   canv0->SetGridy(1);
0077   jes[2]->SetMinimum(0.);
0078   jes[2]->SetMaximum(2.);
0079   jes[2]->SetLineColor(kRed);
0080   jes[2]->SetLineWidth(3.);
0081   jes[2]->SetMarkerStyle(20.);
0082   jes[2]->SetMarkerColor(kRed);
0083   jes[2]->GetXaxis()->SetTitle("p_{T}^{gen} [GeV]");
0084   jes[2]->Draw();
0085   jes[1]->SetLineColor(kBlue);
0086   jes[1]->SetLineWidth(3.);
0087   jes[1]->SetMarkerStyle(21.);
0088   jes[1]->SetMarkerColor(kBlue);
0089   jes[1]->Draw("same");
0090   jes[0]->SetLineColor(kBlack);
0091   jes[0]->SetLineWidth(3.);
0092   jes[0]->SetMarkerStyle(22.);
0093   jes[0]->SetMarkerColor(kBlack);
0094   jes[0]->Draw("same");
0095
0096   TLegend* leg = new TLegend(0.4,0.6,0.90,0.90);
0097   leg->SetFillStyle (0);
0098   leg->SetFillColor (0);
0099   leg->SetBorderSize(0);
0100   leg->AddEntry( jes[2], "L3Absolute" , "LP");
0101   leg->AddEntry( jes[1], "L2Relative" , "LP");
0102   leg->AddEntry( jes[0], "Uncorrected", "LP");
0103   leg->Draw("same");
0104 }
0105
0106