| 1 | /*
|
|---|
| 2 | Example of using vertex fitter class to fit primary vertex
|
|---|
| 3 | assumed to be generated with Pythia8/ee_zh_smr-shf.cmn
|
|---|
| 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 | TH1D* hTrDiff = new TH1D("hTrDiff", "Found - available tracks", 21, -10.5, 10.5);
|
|---|
| 47 | // Chi2 for cuts
|
|---|
| 48 | TH1D* hChi2SngP = new TH1D("hChi2SngP", "#chi^2 for single tracks", 200, 0., 50.);
|
|---|
| 49 | TH1D* hChi2MaxP = new TH1D("hChi2MaxP", "#chi^2 max contribution", 200, 0., 50.);
|
|---|
| 50 | TH1D* hChi2SngN = new TH1D("hChi2SngN", "#chi^2 for single tracks", 200, 0., 50.);
|
|---|
| 51 | TH1D* hChi2MaxN = new TH1D("hChi2MaxN", "#chi^2 max contribution", 200, 0., 50.);
|
|---|
| 52 |
|
|---|
| 53 |
|
|---|
| 54 | //
|
|---|
| 55 | // Loop over all events
|
|---|
| 56 | Int_t Nev = TMath::Min(Nevent, (Int_t)numberOfEntries);
|
|---|
| 57 | for (Int_t entry = 0; entry < Nev; ++entry)
|
|---|
| 58 | {
|
|---|
| 59 | // Load selected branches with data from specified event
|
|---|
| 60 | treeReader->ReadEntry(entry);
|
|---|
| 61 | Int_t NtrG = branchTrack->GetEntries();
|
|---|
| 62 | TVectorD** pr = new TVectorD * [NtrG]; // Track Parameters
|
|---|
| 63 | TMatrixDSym** cv = new TMatrixDSym * [NtrG]; // Track covariances
|
|---|
| 64 | Bool_t *fprvx = new Bool_t[NtrG]; // Primary vertex flag
|
|---|
| 65 | //
|
|---|
| 66 | // test Particle branch
|
|---|
| 67 | Int_t Ngen = branchGenPart->GetEntries();
|
|---|
| 68 | //std::cout << "Nr. of generated particles: " << Ngen << std::endl;
|
|---|
| 69 | // If event contains at least 1 track
|
|---|
| 70 | //
|
|---|
| 71 | Double_t Nprim = 0.0;
|
|---|
| 72 | Double_t xpv = 0.0; // Init true primary vertex position
|
|---|
| 73 | Double_t ypv = 0.0;
|
|---|
| 74 | Double_t zpv = 0.0;
|
|---|
| 75 | if (branchTrack->GetEntries() > 0)
|
|---|
| 76 | {
|
|---|
| 77 | // Loop on tracks
|
|---|
| 78 | for (Int_t it = 0; it < branchTrack->GetEntries(); it++)
|
|---|
| 79 | {
|
|---|
| 80 | Track* trk = (Track*)branchTrack->At(it);
|
|---|
| 81 | //
|
|---|
| 82 | // Start fitting all available tracks
|
|---|
| 83 | //
|
|---|
| 84 | // Reconstructed track parameters
|
|---|
| 85 | Double_t obsD0 = trk->D0;
|
|---|
| 86 | Double_t obsPhi = trk->Phi;
|
|---|
| 87 | Double_t obsC = trk->C;
|
|---|
| 88 | Double_t obsZ0 = trk->DZ;
|
|---|
| 89 | Double_t obsCtg = trk->CtgTheta;
|
|---|
| 90 | //std::cout << "Got track parameters for track " << it << std::endl;
|
|---|
| 91 | //
|
|---|
| 92 | // Load all tracks for vertex fit
|
|---|
| 93 | Double_t oPar[5] = { obsD0, obsPhi, obsC, obsZ0, obsCtg };
|
|---|
| 94 | TVectorD obsPar(5, oPar); // Fill observed parameters
|
|---|
| 95 | pr[it] = new TVectorD(obsPar);
|
|---|
| 96 | cv[it] = new TMatrixDSym(trk->CovarianceMatrix());
|
|---|
| 97 | //
|
|---|
| 98 | // Find true primary vertex
|
|---|
| 99 | GenParticle* gp = (GenParticle*)trk->Particle.GetObject();
|
|---|
| 100 | //std::cout << "GenParticle pointer "<<gp << std::endl;
|
|---|
| 101 | //
|
|---|
| 102 | // Position of origin in mm
|
|---|
| 103 | Double_t x = gp->X;
|
|---|
| 104 | Double_t y = gp->Y;
|
|---|
| 105 | Double_t z = gp->Z;
|
|---|
| 106 | Bool_t prim = kTRUE; // Is primary?
|
|---|
| 107 | fprvx[it] = kFALSE;
|
|---|
| 108 | Int_t mp = gp->M1; // Mother
|
|---|
| 109 | while (mp > 0) {
|
|---|
| 110 | GenParticle* gm =
|
|---|
| 111 | (GenParticle*)branchGenPart->At(mp);
|
|---|
| 112 | Double_t xm = gm->X;
|
|---|
| 113 | Double_t ym = gm->Y;
|
|---|
| 114 | Double_t zm = gm->Z;
|
|---|
| 115 | if (x != xm || y != ym || z != zm) {
|
|---|
| 116 | prim = kFALSE;
|
|---|
| 117 | break;
|
|---|
| 118 | }
|
|---|
| 119 | else mp = gm->M1;
|
|---|
| 120 | }
|
|---|
| 121 | if (prim) { // It's a primary track
|
|---|
| 122 | Nprim++;
|
|---|
| 123 | fprvx[it] = kTRUE;
|
|---|
| 124 | xpv = x; // Store true primary
|
|---|
| 125 | ypv = y;
|
|---|
| 126 | zpv = z;
|
|---|
| 127 | }
|
|---|
| 128 |
|
|---|
| 129 | } // End loop on tracks
|
|---|
| 130 | }
|
|---|
| 131 | if(entry%500 ==0){
|
|---|
| 132 | std::cout << "Event "<<entry<<" opened containing " << NtrG << " / "<< Nprim
|
|---|
| 133 | << " Total / primary tracks"<< std::endl;
|
|---|
| 134 | }
|
|---|
| 135 | //std::cout<<"PVtxFind true vertex: Nprim= "<<Nprim<<", x,y,z= "<<xpv<<", "<<ypv<<", "<<zpv<<std::endl;
|
|---|
| 136 | //
|
|---|
| 137 | // Find primary vertex
|
|---|
| 138 | //
|
|---|
| 139 | //Beam constraint
|
|---|
| 140 | TVectorD xpvc(3);
|
|---|
| 141 | xpvc(0) = 1.0;
|
|---|
| 142 | xpvc(1) = -2.0;
|
|---|
| 143 | xpvc(2) = 10.0;
|
|---|
| 144 | TMatrixDSym covpvc(3); covpvc.Zero();
|
|---|
| 145 | covpvc(0, 0) = 0.0097 * 0.0097;
|
|---|
| 146 | covpvc(1, 1) = 2.55e-05 * 2.55e-05;
|
|---|
| 147 | covpvc(2, 2) = 0.64 * 0.64;
|
|---|
| 148 | if(Nprim == 0){
|
|---|
| 149 | xpv = xpvc(0);
|
|---|
| 150 | ypv = xpvc(1);
|
|---|
| 151 | zpv = xpvc(2);
|
|---|
| 152 | }
|
|---|
| 153 | //
|
|---|
| 154 | //
|
|---|
| 155 | // Skim tracks
|
|---|
| 156 | Int_t nSkim = 0;
|
|---|
| 157 | Int_t* nSkimmed = new Int_t[NtrG];
|
|---|
| 158 | TVectorD** PrSk = new TVectorD * [1];
|
|---|
| 159 | TMatrixDSym** CvSk = new TMatrixDSym * [1];
|
|---|
| 160 | Double_t MaxChi2 = 9.;
|
|---|
| 161 | for (Int_t n = 0; n < NtrG; n++) {
|
|---|
| 162 | PrSk[0] = new TVectorD(*pr[n]);
|
|---|
| 163 | CvSk[0] = new TMatrixDSym(*cv[n]);
|
|---|
| 164 | VertexFit* Vskim = new VertexFit(1,PrSk, CvSk);
|
|---|
| 165 | Vskim->AddVtxConstraint(xpvc, covpvc);
|
|---|
| 166 | Double_t Chi2One = Vskim->GetVtxChi2();
|
|---|
| 167 | //std::cout<<"Track "<<n<<", Chi2 = "<<Chi2One<<std::endl;
|
|---|
| 168 | if(fprvx[n])hChi2SngP->Fill(Chi2One);
|
|---|
| 169 | else hChi2SngN->Fill(Chi2One);
|
|---|
| 170 | //
|
|---|
| 171 | if (Chi2One < MaxChi2) {
|
|---|
| 172 | nSkimmed[nSkim] = n;
|
|---|
| 173 | //std::cout << "nSkimmed[" << nSkim << "] = " << n << std::endl;
|
|---|
| 174 | nSkim++;
|
|---|
| 175 | }
|
|---|
| 176 | // Cleanup
|
|---|
| 177 | delete Vskim;
|
|---|
| 178 | }
|
|---|
| 179 | delete PrSk[0];
|
|---|
| 180 | delete CvSk[0];
|
|---|
| 181 | delete[] PrSk;
|
|---|
| 182 | delete[] CvSk;
|
|---|
| 183 | //
|
|---|
| 184 | // Load tracks for primary fit
|
|---|
| 185 | Int_t MinTrk = 1; // Minumum # tracks for vertex fit
|
|---|
| 186 | std::vector<Int_t> trnum;
|
|---|
| 187 | if (nSkim >= MinTrk) {
|
|---|
| 188 | TVectorD** PrFit = new TVectorD * [nSkim];
|
|---|
| 189 | TMatrixDSym** CvFit = new TMatrixDSym * [nSkim];
|
|---|
| 190 | for (Int_t n = 0; n < nSkim; n++) {
|
|---|
| 191 | PrFit[n] = new TVectorD(*pr[nSkimmed[n]]);
|
|---|
| 192 | CvFit[n] = new TMatrixDSym(*cv[nSkimmed[n]]);
|
|---|
| 193 | trnum.push_back(nSkimmed[n]);
|
|---|
| 194 | }
|
|---|
| 195 | delete[] nSkimmed;
|
|---|
| 196 | Int_t Nfound = nSkim;
|
|---|
| 197 | if(entry%500 ==0)std::cout << "Found tracks "<<Nfound << std::endl;
|
|---|
| 198 | const Int_t MaxFound = 100; Double_t Chi2LL[MaxFound]; Double_t *Chi2L = Chi2LL;
|
|---|
| 199 | VertexFit* Vtx = new VertexFit(nSkim, PrFit, CvFit);
|
|---|
| 200 | //std::cout << "Vertex fit created " << std::endl;
|
|---|
| 201 | Vtx->AddVtxConstraint(xpvc, covpvc);
|
|---|
| 202 | //
|
|---|
| 203 | // Remove tracks with large chi2
|
|---|
| 204 | Double_t MaxChi2Fit = 8.0;
|
|---|
| 205 | Bool_t Done = kFALSE;
|
|---|
| 206 | while (!Done) {
|
|---|
| 207 | //std::cout << "After while " << std::endl;
|
|---|
| 208 | // Find largest Chi2 contribution
|
|---|
| 209 | TVectorD Chi2List = Vtx->GetVtxChi2List(); // Get contributions to Chi2
|
|---|
| 210 | //std::cout << "After Chi2List. " << std::endl; Chi2List.Print();
|
|---|
| 211 | //Double_t* Chi2L = new Double_t[Nfound];
|
|---|
| 212 | Chi2L = Chi2List.GetMatrixArray();
|
|---|
| 213 | Int_t iMax = TMath::LocMax(Nfound, Chi2L);
|
|---|
| 214 | //std::cout << "iMax = "<<iMax << std::endl;
|
|---|
| 215 | Double_t Chi2Mx = Chi2L[iMax];
|
|---|
| 216 | //std::cout << "Chi2Mx "<<Chi2Mx << std::endl;
|
|---|
| 217 | if(fprvx[trnum[iMax]])hChi2MaxP->Fill(Chi2Mx);
|
|---|
| 218 | else hChi2MaxN->Fill(Chi2Mx);
|
|---|
| 219 | if (Chi2Mx > MaxChi2Fit && Nfound > 1) {
|
|---|
| 220 | //std::cout << "Before remove. Nfound = "<<Nfound << std::endl;
|
|---|
| 221 | Vtx->RemoveTrk(iMax);
|
|---|
| 222 | trnum.erase(trnum.begin() + iMax);
|
|---|
| 223 | //std::cout << "After remove." << std::endl;
|
|---|
| 224 | Nfound--;
|
|---|
| 225 | }
|
|---|
| 226 | else {
|
|---|
| 227 | Done = kTRUE;
|
|---|
| 228 | }
|
|---|
| 229 | }
|
|---|
| 230 | //
|
|---|
| 231 | //std::cout << "Before getting vertex " << std::endl;
|
|---|
| 232 | //
|
|---|
| 233 | // Require minimum number of tracks in vertex
|
|---|
| 234 | Int_t Nmin = 1;
|
|---|
| 235 | if (Nfound >= Nmin) {
|
|---|
| 236 | TVectorD xvtx = Vtx->GetVtx();
|
|---|
| 237 | //std::cout << "Found vertex " << xvtx(0)<<", "<<xvtx(1)<<", "<<xvtx(2) << std::endl;
|
|---|
| 238 | TMatrixDSym covX = Vtx->GetVtxCov();
|
|---|
| 239 | Double_t Chi2 = Vtx->GetVtxChi2();
|
|---|
| 240 | Double_t Ndof = 2 * (Double_t)Nfound;
|
|---|
| 241 | Double_t PullX = (xvtx(0) - xpv) / TMath::Sqrt(covX(0, 0));
|
|---|
| 242 | Double_t PullY = (xvtx(1) - ypv) / TMath::Sqrt(covX(1, 1));
|
|---|
| 243 | Double_t PullZ = (xvtx(2) - zpv) / TMath::Sqrt(covX(2, 2));
|
|---|
| 244 | //
|
|---|
| 245 | // Fill histograms
|
|---|
| 246 | hXpull->Fill(PullX);
|
|---|
| 247 | hYpull->Fill(PullY);
|
|---|
| 248 | hZpull->Fill(PullZ);
|
|---|
| 249 | hChi2->Fill(Chi2 / Ndof);
|
|---|
| 250 | //
|
|---|
| 251 | hTrPrim->Fill(Nprim);
|
|---|
| 252 | hTrFound->Fill((Double_t)Nfound);
|
|---|
| 253 | hTrDiff->Fill((Double_t)Nfound-Nprim);
|
|---|
| 254 | //std::cout << "Histograms filled " << std::endl;
|
|---|
| 255 | }
|
|---|
| 256 | //
|
|---|
| 257 | // Clean
|
|---|
| 258 | delete Vtx;
|
|---|
| 259 | for (Int_t i = 0; i < nSkim; i++) delete PrFit[i];
|
|---|
| 260 | for (Int_t i = 0; i < nSkim; i++) delete CvFit[i];
|
|---|
| 261 | delete[] PrFit;
|
|---|
| 262 | delete[] CvFit;
|
|---|
| 263 | delete[] fprvx;
|
|---|
| 264 | trnum.clear();
|
|---|
| 265 | }
|
|---|
| 266 |
|
|---|
| 267 | //std::cout << "Vertex chi2/Ndof = " << Chi2 / Ndof << std::endl;
|
|---|
| 268 | //
|
|---|
| 269 | // Cleanup
|
|---|
| 270 | for (Int_t i = 0; i < NtrG; i++) delete pr[i];
|
|---|
| 271 | for (Int_t i = 0; i < NtrG; i++) delete cv[i];
|
|---|
| 272 | delete[] pr;
|
|---|
| 273 | delete[] cv;
|
|---|
| 274 | }
|
|---|
| 275 | //
|
|---|
| 276 | // Show resulting histograms
|
|---|
| 277 | //
|
|---|
| 278 | TCanvas* Cnv = new TCanvas("Cnv", "Delphes primary vertex pulls", 50, 50, 900, 500);
|
|---|
| 279 | Cnv->Divide(2, 2);
|
|---|
| 280 | Cnv->cd(1); gPad->SetLogy(1); gStyle->SetOptFit(1111); gStyle->SetOptStat(111111);
|
|---|
| 281 | hXpull->Fit("gaus"); hXpull->Draw();
|
|---|
| 282 | Cnv->cd(2); gPad->SetLogy(1); gStyle->SetOptFit(1111); gStyle->SetOptStat(111111);
|
|---|
| 283 | hYpull->Fit("gaus"); hYpull->Draw();
|
|---|
| 284 | Cnv->cd(3); gPad->SetLogy(1); gStyle->SetOptFit(1111); gStyle->SetOptStat(111111);
|
|---|
| 285 | hZpull->Fit("gaus"); hZpull->Draw();
|
|---|
| 286 | Cnv->cd(4); hChi2->Draw();
|
|---|
| 287 | //
|
|---|
| 288 | TCanvas* CnvN = new TCanvas("CnvN", "Primary tracks found", 100, 100, 900, 500);
|
|---|
| 289 | CnvN->Divide(2, 2);
|
|---|
| 290 | CnvN->cd(1);
|
|---|
| 291 | hTrPrim->Draw();
|
|---|
| 292 | CnvN->cd(2);
|
|---|
| 293 | hTrFound->SetLineColor(kRed);
|
|---|
| 294 | hTrFound->Draw();
|
|---|
| 295 | CnvN->cd(3);
|
|---|
| 296 | hTrDiff->Draw();
|
|---|
| 297 | //
|
|---|
| 298 | TCanvas* CnvCh = new TCanvas("CnvCh", "#chi^2", 200, 200, 900, 500);
|
|---|
| 299 | CnvCh->Divide(2,1);
|
|---|
| 300 | CnvCh->cd(1);
|
|---|
| 301 | hChi2SngP->Draw();
|
|---|
| 302 | hChi2SngN->SetLineColor(kRed);
|
|---|
| 303 | hChi2SngN->Draw("SAME");
|
|---|
| 304 | CnvCh->cd(2);
|
|---|
| 305 | hChi2MaxP->Draw();
|
|---|
| 306 | hChi2MaxN->SetLineColor(kRed);
|
|---|
| 307 | hChi2MaxN->Draw("SAME");
|
|---|
| 308 | }
|
|---|
