void tzero15tracks(const char* datafile, Float_t globalTimeRes=1.2e-10) { // // Calculate the t0 distribution // selecting 15 tracks // (primary particles reaching TOF) // NB: see the description of the analogous AliTOFT0 class // NB II: apply this macro to a realistic Pb-Pb event (e.g. Hijing event) // Use case // - start root // root [0] .L tzero15tracksopt.C // // exec the macro with the default time resolution 120 ps // root [1] tzero15tracksopt("hij25evCentralTOFv4T0Set10.04T.root") // // exec the macro with 150 ps global time resolution // // NB: time resolution has to be given in [s] // root [1] tzero15tracksopt("hij25evCentralTOFv4T0Set10.04T.root", 1.5e-10)) // Dynamically link some shared libs if (gClassTable->GetID("AliRun") < 0) { gROOT->LoadMacro("loadlibs.C"); loadlibs(); } // Connect the Root Galice file containing Geometry, Kine and Hits Int_t ngood; Int_t nmisidentified=0; Int_t nmisidentified0=0; Int_t nmisidentified1=0; Int_t nmisidentified2=0; Int_t nmisidentified3=0; Int_t nmisidentified4=0; Int_t nmisidentified5=0; Int_t nmisidentified6=0; Int_t nmisidentified7=0; Int_t nmisidentified8=0; Int_t nmisidentified9=0; Int_t nmisidentified10=0; Int_t nmisidentified11=0; Int_t nmisidentified12=0; Int_t nmisidentified13=0; Int_t nmisidentified14=0; Int_t nbytes = 0; Int_t ipartold = -1; Int_t dblehit = 0; Int_t j,hit,ipart; Int_t nhits; Int_t selected=0; Int_t istop=0; const Float_t timeresolution=globalTimeRes; // in [s] Float_t timeresolutioninns=timeresolution*(1.e+9); // convert in [ns] cout << "Global Time Resolution " << timeresolutioninns << " ns" << endl; // // output (histos!) filename char outFileName[100]; strcpy(outFileName,"ht015tr"); strcat(outFileName,datafile); gBenchmark->Start("TOFT0"); TH1F* htzerobest= new TH1F("htzerobest","T0 for best assignment",200,-1.,1.); TH1F* hchibest = new TH1F("hchibest","ChiSquare Min Distribution",80,0.,40.); TH1F* hchibestconflevel = new TH1F("hchibestconflevel","ChiSquare Min Confidence Level",10,0.,1.); Float_t t0best=999.; Int_t assparticle[15]={3,3,3,3,3,3,3,3,3,3,3,3,3,3,3}; Int_t truparticle[15]={3,3,3,3,3,3,3,3,3,3,3,3,3,3,3}; Float_t timeofflight[15]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.}; Float_t momentum[15]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.}; Float_t timezero[15]; Float_t weightedtimezero[15]; Float_t beta[15]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.}; Float_t sqMomError[15]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.}; Float_t sqTrackError[15]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.}; Float_t massarray[3]={0.13957,0.493677,0.9382723}; Float_t chisquare=999.; Float_t tracktoflen[15]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.}; TRandom* rnd = new TRandom(); TParticle *particle; AliTOFhitT0 *tofHit; TFile *file = TFile::Open(datafile,"old"); // Get AliRun object from file or create it if not on file gAlice = (AliRun*)file->Get("gAlice"); // Import the Kine and Hits Trees for the event evNumber in the file Int_t nallevents = (Int_t) gAlice->TreeE()->GetEntries(); for (Int_t nev=0; nevGetEvent(nev); if (nparticles <= 0) return; // ngood=0; // Get pointers to Alice detectors and Hits containers AliDetector *TOF = gAlice->GetDetector("TOF"); TObjArray *Particles = gAlice->Particles(); if (TOF) TClonesArray *TOFhits = TOF->Hits(); TTree *TH = gAlice->TreeH(); Int_t ntracks = TH->GetEntries(); // Start loop on primary tracks in the hits containers Int_t lasttrack=-1; Int_t nset=0; for (Int_t track=lasttrack+1; track=3) break; // check on the number of set analyzed gAlice->ResetHits(); nbytes += TH->GetEvent(track); // =======>Histogram TOF if (TOF) { nhits = TOFhits->GetEntriesFast(); for (hit=0;hitUncheckedAt(hit); ipart = tofHit->GetTrack(); // check to discard the case when the same particle is selected more than one // time if (ipart != ipartold){ particle = (TParticle*)gAlice->Particle(ipart); Float_t idealtime=tofHit->GetTof(); // Float_t time=idealtime; Float_t time = rnd->Gaus(idealtime, timeresolution); Float_t toflen=tofHit->GetLen(); toflen=toflen/100.; // toflen given in m because GEANT gives cm! Int_t pdg = particle->GetPdgCode(); Int_t abspdg =TMath::Abs(pdg); Float_t idealmom = particle->P(); Float_t momres=idealmom*0.025; // 2.5% res token into account for all momenta //Float_t mom =idealmom+2.*(rnd->Rndm()-0.5)*momres; Float_t mom =rnd->Gaus(idealmom,momres); Bool_t isgoodpart=(abspdg==211 || abspdg==2212 || abspdg==321); time*=1.e+9; // tof given in nanoseconds if (particle->GetFirstMother() < 0 && isgoodpart && mom<=1.75 && mom>=1.25){ selected+=1; istop=selected; if(istop>15) break; Int_t index=selected-1; timeofflight[index]=time; tracktoflen[index]=toflen; momentum[index]=mom; switch (abspdg) { case 211: truparticle[index]=0; break ; case 321: truparticle[index]=1; break ; case 2212: truparticle[index]=2; break ; } } ipartold = ipart; if(istop==15){ // start analysis on current set nset+=1; lasttrack=track; istop=0; selected=0; cout << "starting t0 calculation for current set" << endl; for (Int_t i1=0; i1<3;i1++) { beta[0]=momentum[0]/TMath::Sqrt(massarray[i1]*massarray[i1]+momentum[0]*momentum[0]); for (Int_t i2=0; i2<3;i2++) { beta[1]=momentum[1]/TMath::Sqrt(massarray[i2]*massarray[i2]+momentum[1]*momentum[1]); for (Int_t i3=0; i3<3;i3++) { beta[2]=momentum[2]/TMath::Sqrt(massarray[i3]*massarray[i3]+momentum[2]*momentum[2]); for (Int_t i4=0; i4<3;i4++) { beta[3]=momentum[3]/TMath::Sqrt(massarray[i4]*massarray[i4]+momentum[3]*momentum[3]); for (Int_t i5=0; i5<3;i5++) { beta[4]=momentum[4]/TMath::Sqrt(massarray[i5]*massarray[i5]+momentum[4]*momentum[4]); for (Int_t i6=0; i6<3;i6++) { beta[5]=momentum[5]/TMath::Sqrt(massarray[i6]*massarray[i6]+momentum[5]*momentum[5]); for (Int_t i7=0; i7<3;i7++) { beta[6]=momentum[6]/TMath::Sqrt(massarray[i7]*massarray[i7]+momentum[6]*momentum[6]); for (Int_t i8=0; i8<3;i8++) { beta[7]=momentum[7]/TMath::Sqrt(massarray[i8]*massarray[i8]+momentum[7]*momentum[7]); for (Int_t i9=0; i9<3;i9++) { beta[8]=momentum[8]/TMath::Sqrt(massarray[i9]*massarray[i9]+momentum[8]*momentum[8]); for (Int_t i10=0; i10<3;i10++) { beta[9]=momentum[9]/TMath::Sqrt(massarray[i10]*massarray[i10]+momentum[9]*momentum[9]); for (Int_t i11=0; i11<3;i11++) { beta[10]=momentum[10]/TMath::Sqrt(massarray[i11]*massarray[i11]+momentum[10]*momentum[10]); for (Int_t i12=0; i12<3;i12++) { beta[11]=momentum[11]/TMath::Sqrt(massarray[i12]*massarray[i12]+momentum[11]*momentum[11]); for (Int_t i13=0; i13<3;i13++) { beta[12]=momentum[12]/TMath::Sqrt(massarray[i13]*massarray[i13]+momentum[12]*momentum[12]); for (Int_t i14=0; i14<3;i14++) { beta[13]=momentum[13]/TMath::Sqrt(massarray[i14]*massarray[i14]+momentum[13]*momentum[13]); for (Int_t i15=0; i15<3;i15++) { beta[14]=momentum[14]/TMath::Sqrt(massarray[i15]*massarray[i15]+momentum[14]*momentum[14]); Float_t meantzero=0.; Float_t sumAllweights=0.; for (Int_t itz=0; itz<15;itz++) { sqMomError[itz]=((1.-beta[itz]*beta[itz])*0.025)*((1.-beta[itz]*beta[itz])*0.025)*(tracktoflen[itz]/(0.299792*beta[itz]))*(tracktoflen[itz]/(0.299792*beta[itz])); // this gives the square of the momentum error in nanoseconds sqTrackError[itz]=(timeresolutioninns*timeresolutioninns+sqMomError[itz]); // total error for the current track sumAllweights+=1./sqTrackError[itz]; timezero[itz]=(tracktoflen[itz]/(beta[itz]*0.299792))-timeofflight[itz]; weightedtimezero[itz]=((tracktoflen[itz]/(beta[itz]*0.299792))-timeofflight[itz])/sqTrackError[itz];// weighted time zero for current track meantzero+=weightedtimezero[itz]; } meantzero=meantzero/sumAllweights; // it is given in [ns] Float_t dummychisquare=0.; // calculate the chisquare for the current assignment for (Int_t itz=0; itz<15;itz++) { dummychisquare+=(timezero[itz]-meantzero)*(timezero[itz]-meantzero)/sqTrackError[itz]; } if(dummychisquare<=chisquare){ assparticle[0]=i1; assparticle[1]=i2; assparticle[2]=i3; assparticle[3]=i4; assparticle[4]=i5; assparticle[5]=i6; assparticle[6]=i7; assparticle[7]=i8; assparticle[8]=i9; assparticle[9]=i10; assparticle[10]=i11; assparticle[11]=i12; assparticle[12]=i13; assparticle[13]=i14; assparticle[14]=i15; chisquare=dummychisquare; t0best=meantzero; } } } } } } } } } } } } } } } } cout << "true" << truparticle[0] << truparticle[1] << truparticle[2] << truparticle[3] << truparticle[4] << truparticle[5] << truparticle[6] << truparticle[7] << truparticle[8] << truparticle[9] <Fill(t0best); hchibest->Fill(chisquare); Double_t dblechisquare=(Double_t)chisquare; Float_t confLevel=(Float_t)TMath::Prob(dblechisquare,14); cout << "conf level " << confLevel << endl; hchibestconflevel->Fill(confLevel); chisquare=999.; t0best=999.; } // end for the current set. close if(istop==15) } // end condition on ipartold }// end loop on hits for the current track }// end TOF if(istop>=15) break; }// end loop on Tracks cout << "ngood for current event " << ngood << endl; }//end loop on events nmisidentified=(nmisidentified0+nmisidentified1+nmisidentified2+nmisidentified3+nmisidentified4+nmisidentified5+nmisidentified6+nmisidentified7+nmisidentified8+nmisidentified9+nmisidentified10+nmisidentified11+nmisidentified12+nmisidentified13+nmisident ified14); cout << "total misidentified " << nmisidentified << endl; TFile *houtfile = new TFile(outFileName,"recreate"); houtfile->cd(); htzerobest->Write(); hchibest->Write(); hchibestconflevel->Write(); houtfile->Close(); gBenchmark->Stop("TOFT0"); cout << "15 tracks:" << endl ; cout << " took " << gBenchmark->GetCpuTime("TOFT0") << " seconds in order to calculate T0 " << gBenchmark->GetCpuTime("TOFT0")/nallevents << " seconds per event " << endl ; cout << endl ; }