| [82db145] | 1 | /*
|
|---|
| 2 | Example of using vertex fitter class to fit primary vertex
|
|---|
| 3 | assumed to be generated in (0,0,0)
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | #ifdef __CLING__
|
|---|
| 7 | R__LOAD_LIBRARY(libDelphes)
|
|---|
| 8 |
|
|---|
| 9 | #include "classes/DelphesClasses.h"
|
|---|
| 10 | #include "external/ExRootAnalysis/ExRootTreeReader.h"
|
|---|
| 11 | #include "modules/TrackCovariance.h"
|
|---|
| 12 | #include "external/TrackCovariance/TrkUtil.h"
|
|---|
| 13 | #include "external/TrackCovariance/VertexFit.h"
|
|---|
| 14 |
|
|---|
| 15 | #endif
|
|---|
| 16 |
|
|---|
| 17 |
|
|---|
| 18 | //------------------------------------------------------------------------------
|
|---|
| 19 |
|
|---|
| 20 | void ExamplePVtxFind(const char* inputFile, Int_t Nevent = 5)
|
|---|
| 21 | {
|
|---|
| 22 | // Create chain of root trees
|
|---|
| 23 | TChain chain("Delphes");
|
|---|
| 24 | chain.Add(inputFile);
|
|---|
| 25 |
|
|---|
| 26 | // Create object of class ExRootTreeReader
|
|---|
| 27 | ExRootTreeReader* treeReader = new ExRootTreeReader(&chain);
|
|---|
| 28 | Long64_t numberOfEntries = treeReader->GetEntries();
|
|---|
| 29 |
|
|---|
| 30 | // Get pointers to branches used in this analysis
|
|---|
| 31 | TClonesArray* branchGenPart = treeReader->UseBranch("Particle");
|
|---|
| 32 | TClonesArray* branchTrack = treeReader->UseBranch("Track");
|
|---|
| 33 |
|
|---|
| 34 | // Book histograms
|
|---|
| 35 | // Vertex fit pulls
|
|---|
| 36 | Int_t Nbin = 100;
|
|---|
| 37 | TH1D* hXpull = new TH1D("hXpull", "Pull X vertex component", Nbin, -10., 10.);
|
|---|
| 38 | TH1D* hYpull = new TH1D("hYpull", "Pull Y vertex component", Nbin, -10., 10.);
|
|---|
| 39 | TH1D* hZpull = new TH1D("hZpull", "Pull Z vertex component", Nbin, -10., 10.);
|
|---|
| 40 | TH1D* hChi2 = new TH1D("hChi2", "Vertex #chi^{2}/N_{dof}", Nbin, 0., 10.);
|
|---|
| 41 | // Track vertex associations
|
|---|
| 42 | TH1D* hTrPrim = new TH1D("hTrPrim", "Available primary tracks", 41, -0.5, 40.5);
|
|---|
| 43 | TH1D* hTrFound = new TH1D("hTrFound", "Found primary tracks", 41, -0.5, 40.5);
|
|---|
| 44 | TH1D* hTrFoundG = new TH1D("hTrFoundG", "Found GOOD primary tracks", 41, -0.5, 40.5);
|
|---|
| 45 | TH1D* hTrFoundB = new TH1D("hTrFoundB", "Found BAD primary tracks", 41, -0.5, 40.5);
|
|---|
| 46 | //
|
|---|
| 47 | // Loop over all events
|
|---|
| 48 | Int_t Nev = TMath::Min(Nevent, (Int_t)numberOfEntries);
|
|---|
| 49 | for (Int_t entry = 0; entry < Nev; ++entry)
|
|---|
| 50 | {
|
|---|
| 51 | // Load selected branches with data from specified event
|
|---|
| 52 | treeReader->ReadEntry(entry);
|
|---|
| 53 | Int_t Ntr = 0; // # of starting tracks used in primary vertex
|
|---|
| 54 | Int_t NtrG = branchTrack->GetEntries();
|
|---|
| 55 | //std::cout << "Event opened containing " << NtrG << " tracks" << std::endl;
|
|---|
| 56 | TVectorD** pr = new TVectorD * [NtrG];
|
|---|
| 57 | TMatrixDSym** cv = new TMatrixDSym * [NtrG];
|
|---|
| 58 | //
|
|---|
| 59 | // test Particle branch
|
|---|
| 60 | Int_t Ngen = branchGenPart->GetEntries();
|
|---|
| 61 | //std::cout << "Nr. of generated particles: " << Ngen << std::endl;
|
|---|
| 62 | // If event contains at least 1 track
|
|---|
| 63 | //
|
|---|
| 64 | Double_t Nprim = 0.0;
|
|---|
| 65 | if (branchTrack->GetEntries() > 0)
|
|---|
| 66 | {
|
|---|
| 67 | // Loop on tracks
|
|---|
| 68 | for (Int_t it = 0; it < branchTrack->GetEntries(); it++)
|
|---|
| 69 | {
|
|---|
| 70 | Track* trk = (Track*)branchTrack->At(it);
|
|---|
| 71 | //
|
|---|
| 72 | // Start fitting all available tracks
|
|---|
| 73 | //
|
|---|
| 74 | // Reconstructed track parameters
|
|---|
| 75 | Double_t obsD0 = trk->D0;
|
|---|
| 76 | Double_t obsPhi = trk->Phi;
|
|---|
| 77 | Double_t obsC = trk->C;
|
|---|
| 78 | Double_t obsZ0 = trk->DZ;
|
|---|
| 79 | Double_t obsCtg = trk->CtgTheta;
|
|---|
| 80 | //std::cout << "Got track parameters for track " << it << std::endl;
|
|---|
| 81 | //
|
|---|
| 82 | // Load tracks for vertex fit if impact parameters is not ridiculous
|
|---|
| 83 | Double_t Dmax = 1.0; // max is 1 mm
|
|---|
| 84 | if (TMath::Abs(obsD0) < Dmax) {
|
|---|
| 85 | Double_t oPar[5] = { obsD0, obsPhi, obsC, obsZ0, obsCtg };
|
|---|
| 86 | TVectorD obsPar(5, oPar); // Fill observed parameters
|
|---|
| 87 | pr[Ntr] = new TVectorD(obsPar);
|
|---|
| 88 | cv[Ntr] = new TMatrixDSym(trk->CovarianceMatrix());
|
|---|
| 89 | Ntr++;
|
|---|
| 90 | //std::cout << "Track loaded Ntr= " << Ntr << std::endl;
|
|---|
| 91 | }
|
|---|
| 92 | //
|
|---|
| 93 | // Get associated generated particle
|
|---|
| 94 | GenParticle* gp = (GenParticle*)trk->Particle.GetObject();
|
|---|
| 95 | //std::cout << "GenParticle pointer "<<gp << std::endl;
|
|---|
| 96 | //
|
|---|
| 97 | // Position of origin in mm
|
|---|
| 98 | Double_t x = gp->X;
|
|---|
| 99 | Double_t y = gp->Y;
|
|---|
| 100 | Double_t z = gp->Z;
|
|---|
| 101 | //std::cout << "Got position of origin " << std::endl;
|
|---|
| 102 | //
|
|---|
| 103 | // Count tracks originating from the primary vertex
|
|---|
| 104 | if (x == 0.0 && y == 0.0) Nprim++;
|
|---|
| 105 |
|
|---|
| 106 | } // End loop on tracks
|
|---|
| 107 | }
|
|---|
| 108 | //
|
|---|
| 109 | // Fit primary vertex
|
|---|
| 110 | //
|
|---|
| 111 | Int_t Nfound = Ntr;
|
|---|
| 112 | //std::cout << "Found tracks "<<Nfound << std::endl;
|
|---|
| 113 | Int_t MinTrk = 2; // Minumum # tracks for vertex fit
|
|---|
| 114 | Double_t MaxChi2 = 6.;
|
|---|
| 115 | if (Ntr >= MinTrk) {
|
|---|
| 116 | VertexFit* Vtx = new VertexFit(Ntr, pr, cv);
|
|---|
| 117 | //std::cout << "Vertex fit created " << std::endl;
|
|---|
| 118 | //
|
|---|
| 119 | // Remove tracks with large chi2
|
|---|
| 120 | Bool_t Done = kFALSE;
|
|---|
| 121 | while (!Done){
|
|---|
| 122 | //std::cout << "After while " << std::endl;
|
|---|
| 123 | // Find largest Chi2 contribution
|
|---|
| 124 | TVectorD Chi2List = Vtx->GetVtxChi2List(); // Get contributions to Chi2
|
|---|
| 125 | //std::cout << "After Chi2List. " << std::endl; Chi2List.Print();
|
|---|
| 126 | Double_t* Chi2L = new Double_t[Nfound];
|
|---|
| 127 | Chi2L = Chi2List.GetMatrixArray();
|
|---|
| 128 | Int_t iMax = TMath::LocMax(Nfound, Chi2L);
|
|---|
| 129 | //std::cout << "iMax = "<<iMax << std::endl;
|
|---|
| 130 | Double_t Chi2Mx = Chi2L[iMax];
|
|---|
| 131 | //std::cout << "Chi2Mx "<<Chi2Mx << std::endl;
|
|---|
| 132 | if (Chi2Mx > MaxChi2 && Nfound > 2) {
|
|---|
| 133 | Vtx->RemoveTrk(iMax);
|
|---|
| 134 | Nfound--;
|
|---|
| 135 | }
|
|---|
| 136 | else {
|
|---|
| 137 | Done = kTRUE;
|
|---|
| 138 | }
|
|---|
| 139 | //std::cout << "Done = " << Done << std::endl;
|
|---|
| 140 | //delete[] Chi2L;
|
|---|
| 141 | //std::cout << "Array Chi2L removed " << std::endl;
|
|---|
| 142 | }
|
|---|
| 143 | //
|
|---|
| 144 | //std::cout << "Before getting vertex " << std::endl;
|
|---|
| 145 | //
|
|---|
| 146 | // Require minimum number of tracks in vertex
|
|---|
| 147 | Int_t Nmin = 4;
|
|---|
| 148 | if (Nfound >= Nmin) {
|
|---|
| 149 | TVectorD xvtx = Vtx->GetVtx();
|
|---|
| 150 | //std::cout << "Found vertex " << xvtx(0)<<", "<<xvtx(1)<<", "<<xvtx(2) << std::endl;
|
|---|
| 151 | TMatrixDSym covX = Vtx->GetVtxCov();
|
|---|
| 152 | Double_t Chi2 = Vtx->GetVtxChi2();
|
|---|
| 153 | Double_t Ndof = 2 * (Double_t)Nfound - 3;
|
|---|
| 154 | Double_t PullX = xvtx(0) / TMath::Sqrt(covX(0, 0));
|
|---|
| 155 | Double_t PullY = xvtx(1) / TMath::Sqrt(covX(1, 1));
|
|---|
| 156 | Double_t PullZ = xvtx(2) / TMath::Sqrt(covX(2, 2));
|
|---|
| 157 | //
|
|---|
| 158 | // Fill histograms
|
|---|
| 159 | hXpull->Fill(PullX);
|
|---|
| 160 | hYpull->Fill(PullY);
|
|---|
| 161 | hZpull->Fill(PullZ);
|
|---|
| 162 | hChi2->Fill(Chi2 / Ndof);
|
|---|
| 163 | //
|
|---|
| 164 | hTrPrim->Fill(Nprim);
|
|---|
| 165 | hTrFound->Fill((Double_t)Nfound);
|
|---|
| 166 | //std::cout << "Histograms filled " << std::endl;
|
|---|
| 167 | }
|
|---|
| 168 | //
|
|---|
| 169 | delete Vtx;
|
|---|
| 170 | }
|
|---|
| 171 |
|
|---|
| 172 | //std::cout << "Vertex chi2/Ndof = " << Chi2 / Ndof << std::endl;
|
|---|
| 173 | //
|
|---|
| 174 | // Cleanup
|
|---|
| 175 | for (Int_t i = 0; i < Ntr; i++) delete pr[i];
|
|---|
| 176 | for (Int_t i = 0; i < Ntr; i++) delete cv[i];
|
|---|
| 177 | delete[] pr;
|
|---|
| 178 | delete[] cv;
|
|---|
| 179 | }
|
|---|
| 180 | //
|
|---|
| 181 | // Show resulting histograms
|
|---|
| 182 | //
|
|---|
| 183 | TCanvas* Cnv = new TCanvas("Cnv", "Delphes primary vertex pulls", 50, 50, 900, 500);
|
|---|
| 184 | Cnv->Divide(2, 2);
|
|---|
| 185 | Cnv->cd(1); gPad->SetLogy(1); gStyle->SetOptFit(1111);
|
|---|
| 186 | hXpull->Fit("gaus"); hXpull->Draw();
|
|---|
| 187 | Cnv->cd(2); gPad->SetLogy(1); gStyle->SetOptFit(1111);
|
|---|
| 188 | hYpull->Fit("gaus"); hYpull->Draw();
|
|---|
| 189 | Cnv->cd(3); gPad->SetLogy(1); gStyle->SetOptFit(1111);
|
|---|
| 190 | hZpull->Fit("gaus"); hZpull->Draw();
|
|---|
| 191 | Cnv->cd(4); hChi2->Draw();
|
|---|
| 192 | //
|
|---|
| 193 | TCanvas* CnvN = new TCanvas("CnvN", "Primary tracks found", 100, 100, 900, 500);
|
|---|
| 194 | CnvN->Divide(2, 1);
|
|---|
| 195 | CnvN->cd(1);
|
|---|
| 196 | hTrPrim->Draw();
|
|---|
| 197 | CnvN-> cd(2);
|
|---|
| 198 | hTrFound->SetLineColor(kRed);
|
|---|
| 199 | hTrFound->Draw();
|
|---|
| 200 | }
|
|---|
