1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
18 //_________________________________________________________________________
19 // This is a TTask that made the calculation of the Time zero using TOF.
20 // Description: The algorithm used to calculate the time zero of interaction
21 // using TOF detector is the following.
22 // We select in the MonteCarlo some primary particles - or tracks in the following -
23 // that strike the TOF detector (the larger part are pions, kaons or protons).
24 // We choose a set of 10 selected tracks, for each track You have the length
25 // of the track when the TOF is reached (a standard TOF hit does not contain this
26 // additional information, this is the reason why we implemented a new time zero
27 // dedicated TOF hit class AliTOFhitT0; in order to store this type of hit You
28 // have to use the AliTOFv4T0 as TOF class in Your Config.C. In AliTOFv4T0 the
29 // StepManager was modified in order to fill the TOF hit branch with this type
30 // of hits; in fact the AliTOF::AddT0Hit is called rather that the usual AliTOF::AddHit),
31 // the momentum at generation (from TreeK) and the time of flight
32 // given by the TOF detector.
33 // (Observe that the ctor of the AliTOF class, when the AliTOFv4T0 class is used, is called
34 // with the "tzero" option: it is in order create the fHits TClonesArray filled with
35 // AliTOFhitT0 objects, rather than with normal AliTOFhit)
36 // Then Momentum and time of flight for each track are smeared according to
37 // known experimental resolution (all sources of error have been token into account).
38 // Let consider now only one set of 10 tracks (the algorithm is the same for all sets).
39 // Assuming the (mass) hypothesis that each track can be AUT a pion, AUT a kaon, AUT a proton,
40 // we consider all the 3 at 10 possible cases.
41 // For each track in each (mass) configuration
42 // (a configuration can be e.g. pion/pion/kaon/proton/pion/proton/kaon/kaon/pion/pion)
43 // we calculate the time zero (we know in fact the velocity of the track after
44 // the assumption about its mass, the time of flight given by the TOF, and the
45 // corresponding path travelled till the TOF detector). Then for each mass configuration we have
46 // 10 time zero and we can calculate the ChiSquare for the current configuration using the
47 // weighted mean over all 10 time zero.
48 // We call the best assignment the mass configuration that gives the minimum value of the ChiSquare.
49 // We plot the weighted mean over all 10 time zero for the best assignment,
50 // the ChiSquare for the best assignment and the corresponding confidence level.
51 // The strong assumption is the MC selection of primary particles. It will be introduced
52 // in the future also some more realistic simulation about this point.
54 // root [0] AliTOFT0 * tzero = new AliTOFT0("galice.root")
55 // Warning in <TDatabasePDG::TDatabasePDG>: object already instantiated
56 // root [1] tzero->ExecuteTask()
57 // root [2] tzero->ExecuteTask("tim")
58 // // available parameters:
59 // tim - print benchmarking information
60 // all - print usefull informations about the number of misidentified tracks
61 // and a comparison about the true configuration (known from MC) and the best
63 //-- Author: F. Pierella
64 //////////////////////////////////////////////////////////////////////////////
66 #include <Riostream.h>
69 #include <TBenchmark.h>
71 #include <TClonesArray.h>
76 #include <TParticle.h>
81 #include <TVirtualMC.h>
83 #include "AliDetector.h"
87 #include "AliTOFhitT0.h"
88 #include "AliTOFv4T0.h"
93 //____________________________________________________________________________
94 AliTOFT0::AliTOFT0():TTask("AliTOFT0","")
100 //____________________________________________________________________________
101 AliTOFT0::AliTOFT0(char* headerFile, Int_t nEvents):TTask("AliTOFT0","")
103 fNevents=nEvents ; // Number of events for which calculate the T0,
104 // default 0: it means all evens in current file
105 fLowerMomBound=1.5; // [GeV/c] default value
106 fUpperMomBound=2. ; // [GeV/c] default value
107 fTimeResolution = 1.2e-10; // 120 ps by default
108 fHeadersFile = headerFile ;
110 TFile * file = (TFile*) gROOT->GetFile(fHeadersFile.Data() ) ;
112 //File was not opened yet
114 if(fHeadersFile.Contains("rfio"))
115 file = TFile::Open(fHeadersFile,"update") ;
117 file = new TFile(fHeadersFile.Data(),"update") ;
118 gAlice = (AliRun *) file->Get("gAlice") ;
121 // add Task to //root/Tasks folder
122 TTask * roottasks = (TTask*)gROOT->GetRootFolder()->FindObject("Tasks") ;
123 roottasks->Add(this) ;
126 //____________________________________________________________________________
127 AliTOFT0::AliTOFT0(const AliTOFT0 & tzero):TTask("AliTOFT0","")
129 ( (AliTOFT0 &)tzero ).Copy(*this);
132 //____________________________________________________________________________
133 AliTOFT0::~AliTOFT0()
138 //____________________________________________________________________________
139 void AliTOFT0::Exec(Option_t *option)
142 // calculate T0 distribution for all events using chisquare
145 Int_t nmisidentified=0;
146 Int_t nmisidentified0=0;
147 Int_t nmisidentified1=0;
148 Int_t nmisidentified2=0;
149 Int_t nmisidentified3=0;
150 Int_t nmisidentified4=0;
151 Int_t nmisidentified5=0;
152 Int_t nmisidentified6=0;
153 Int_t nmisidentified7=0;
154 Int_t nmisidentified8=0;
155 Int_t nmisidentified9=0;
160 Float_t timeresolutioninns=fTimeResolution*(1.e+9); // convert in [ns]
161 const Int_t kUPDATE = 5; // for visual option
167 if(strstr(option,"visual")){
168 // Create a new canvas.
169 //c1 = new TCanvas("c1","Dynamic Visual Filling of time zero histo",10,10,500,500);
170 c1 = new TCanvas("c1","Dynamic Visual Filling of time zero histo",10,10,370,370);
171 c1->SetFillColor(35);
172 c1->GetFrame()->SetFillColor(21);
173 c1->GetFrame()->SetBorderSize(6);
174 c1->GetFrame()->SetBorderMode(-1);
176 //c2 = new TCanvas("c2","Dynamic Visual Filling of chisquare histo",550,10,500,500);
177 c2 = new TCanvas("c2","Dynamic Visual Filling of chisquare histo",380,10,370,370);
178 c2->SetFillColor(35);
179 c2->GetFrame()->SetFillColor(21);
180 c2->GetFrame()->SetBorderSize(6);
181 c2->GetFrame()->SetBorderMode(-1);
183 //c3 = new TCanvas("c3","Dynamic Visual Filling of confidence level histo",280,550,500,500);
184 c3 = new TCanvas("c3","Dynamic Visual Filling of confidence level histo",760,10,370,370);
185 c3->SetFillColor(35);
186 c3->GetFrame()->SetFillColor(21);
187 c3->GetFrame()->SetBorderSize(6);
188 c3->GetFrame()->SetBorderMode(-1);
191 if(strstr(option,"tim") || strstr(option,"all"))
192 gBenchmark->Start("TOFT0");
194 TH1F *htzerobest= new TH1F("htzerobest","T0 for best assignment",200,-1.,1.);
195 TH1F* hchibest = new TH1F("hchibest","ChiSquare Min Distribution",80,0.,40.);
196 TH1F* hchibestconflevel = new TH1F("hchibestconflevel","ChiSquare Min Confidence Level",10,0.,1.);
198 // setting histo colors
199 if(strstr(option,"visual")){
200 htzerobest->SetFillColor(48);
201 hchibest->SetFillColor(50);
202 hchibestconflevel->SetFillColor(52);
205 Int_t assparticle[10]={3,3,3,3,3,3,3,3,3,3};
206 Int_t truparticle[10]={3,3,3,3,3,3,3,3,3,3};
208 Float_t timeofflight[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
209 Float_t momentum[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
210 Float_t timezero[10];
211 Float_t weightedtimezero[10];
212 Float_t beta[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
213 Float_t sqMomError[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
214 Float_t sqTrackError[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
215 Float_t massarray[3]={0.13957,0.493677,0.9382723};
216 Float_t dummychisquare=0.;
217 Float_t chisquare=999.;
218 Float_t tracktoflen[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
220 AliTOF *TOF = (AliTOF *) gAlice->GetDetector ("TOF");
223 Error("AliTOFT0","TOF not found");
227 if(strstr(option,"all")){
228 cout << "Selecting primary tracks with momentum between " << fLowerMomBound << " GeV/c and " << fUpperMomBound << " GeV/c" << endl;
229 cout << "Memorandum: 0 means PION | 1 means KAON | 2 means PROTON" << endl;
232 if (fNevents == 0) fNevents = (Int_t) gAlice->TreeE()->GetEntries();
234 for (Int_t ievent = 0; ievent < fNevents; ievent++) {
235 gAlice->GetEvent(ievent);
236 TTree *TH = TOF->TreeH ();
241 TClonesArray* TOFhits = TOF->Hits();
246 TH->SetBranchStatus("*",0); // switch off all branches
247 TH->SetBranchStatus("TOF*",1); // switch on only TOF
249 // Start loop on primary tracks in the hits containers
251 Int_t ntracks = static_cast<Int_t>(TH->GetEntries());
252 for (Int_t track = 0; track < ntracks; track++)
254 if(nset>=5) break; // check on the number of set analyzed
258 particle = gAlice->GetMCApp()->Particle(track);
259 Int_t nhits = TOFhits->GetEntriesFast();
261 for (Int_t hit = 0; hit < nhits; hit++)
263 tofHit = (AliTOFhitT0 *) TOFhits->UncheckedAt(hit);
264 ipart = tofHit->GetTrack();
265 // check to discard the case when the same particle is selected more than one
268 if (ipart != ipartold){
270 particle = (TParticle*)gAlice->GetMCApp()->Particle(ipart);
272 Float_t idealtime=tofHit->GetTof();
273 // Float_t time=idealtime;
274 Float_t time = gRandom->Gaus(idealtime, fTimeResolution);
275 Float_t toflen=tofHit->GetLen();
276 toflen=toflen/100.; // toflen given in m
277 Int_t pdg = particle->GetPdgCode();
278 Int_t abspdg =TMath::Abs(pdg);
279 Float_t idealmom = particle->P();
280 Float_t momres=idealmom*0.025; // 2.5% res token into account for all momenta
281 Float_t mom =gRandom->Gaus(idealmom,momres);
283 Bool_t isgoodpart=(abspdg==211 || abspdg==2212 || abspdg==321);
285 time*=1.E+9; // tof given in nanoseconds
286 if (particle->GetFirstMother() < 0 && isgoodpart && mom<=fUpperMomBound && mom>=fLowerMomBound){
290 Int_t index=selected-1;
291 timeofflight[index]=time;
292 tracktoflen[index]=toflen;
294 // cout << timeofflight[index] << " " << tracktoflen[index] << " " << momentum[index] << endl;
297 truparticle[index]=0;
300 truparticle[index]=1;
303 truparticle[index]=2;
310 if(istop==10){ // start analysis on current set
315 //cout << "starting t0 calculation for current set" << endl;
316 for (Int_t i1=0; i1<3;i1++) {
317 beta[0]=momentum[0]/sqrt(massarray[i1]*massarray[i1]+momentum[0]*momentum[0]);
318 for (Int_t i2=0; i2<3;i2++) {
319 beta[1]=momentum[1]/sqrt(massarray[i2]*massarray[i2]+momentum[1]*momentum[1]);
320 for (Int_t i3=0; i3<3;i3++) {
321 beta[2]=momentum[2]/sqrt(massarray[i3]*massarray[i3]+momentum[2]*momentum[2]);
322 for (Int_t i4=0; i4<3;i4++) {
323 beta[3]=momentum[3]/sqrt(massarray[i4]*massarray[i4]+momentum[3]*momentum[3]);
324 for (Int_t i5=0; i5<3;i5++) {
325 beta[4]=momentum[4]/sqrt(massarray[i5]*massarray[i5]+momentum[4]*momentum[4]);
326 for (Int_t i6=0; i6<3;i6++) {
327 beta[5]=momentum[5]/sqrt(massarray[i6]*massarray[i6]+momentum[5]*momentum[5]);
328 for (Int_t i7=0; i7<3;i7++) {
329 beta[6]=momentum[6]/sqrt(massarray[i7]*massarray[i7]+momentum[6]*momentum[6]);
330 for (Int_t i8=0; i8<3;i8++) {
331 beta[7]=momentum[7]/sqrt(massarray[i8]*massarray[i8]+momentum[7]*momentum[7]);
332 for (Int_t i9=0; i9<3;i9++) {
333 beta[8]=momentum[8]/sqrt(massarray[i9]*massarray[i9]+momentum[8]*momentum[8]);
334 for (Int_t i10=0; i10<3;i10++) {
335 beta[9]=momentum[9]/sqrt(massarray[i10]*massarray[i10]+momentum[9]*momentum[9]);
337 Float_t meantzero=0.;
338 Float_t sumAllweights=0.;
339 for (Int_t itz=0; itz<10;itz++) {
340 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
341 sqTrackError[itz]=(timeresolutioninns*timeresolutioninns+sqMomError[itz]); // total error for the current track
342 sumAllweights+=1./sqTrackError[itz];
344 timezero[itz]=(tracktoflen[itz]/(beta[itz]*0.299792))-timeofflight[itz];
345 weightedtimezero[itz]=((tracktoflen[itz]/(beta[itz]*0.299792))-timeofflight[itz])/sqTrackError[itz];// weighted time zero for current track
346 meantzero+=weightedtimezero[itz];
347 } // end loop for (Int_t itz=0; itz<10;itz++)
348 meantzero=meantzero/sumAllweights; // it is given in [ns]
351 // calculate the chisquare for the current assignment
352 for (Int_t icsq=0; icsq<10;icsq++) {
353 dummychisquare+=(timezero[icsq]-meantzero)*(timezero[icsq]-meantzero)/sqTrackError[icsq];
354 } // end loop for (Int_t icsq=0; icsq<10;icsq++)
356 if(dummychisquare<=chisquare){
367 chisquare=dummychisquare;
369 } // close if(dummychisquare<=chisquare)
382 if(truparticle[0]==assparticle[0] && truparticle[1]==assparticle[1] && truparticle[2]==assparticle[2] && truparticle[3]==assparticle[3] && truparticle[4]==assparticle[4]&& truparticle[5]==assparticle[5] && truparticle[6]==assparticle[6] && truparticle[7]==assparticle[7] && truparticle[8]==assparticle[8] && truparticle[9]==assparticle[9]) ngood+=1;
383 if(truparticle[0]!=assparticle[0]) nmisidentified0+=1;
384 if(truparticle[1]!=assparticle[1]) nmisidentified1+=1;
385 if(truparticle[2]!=assparticle[2]) nmisidentified2+=1;
386 if(truparticle[3]!=assparticle[3]) nmisidentified3+=1;
387 if(truparticle[4]!=assparticle[4]) nmisidentified4+=1;
388 if(truparticle[5]!=assparticle[5]) nmisidentified5+=1;
389 if(truparticle[6]!=assparticle[6]) nmisidentified6+=1;
390 if(truparticle[7]!=assparticle[7]) nmisidentified7+=1;
391 if(truparticle[8]!=assparticle[8]) nmisidentified8+=1;
392 if(truparticle[9]!=assparticle[9]) nmisidentified9+=1;
394 htzerobest->Fill(t0best);
395 hchibest->Fill(chisquare);
396 Double_t dblechisquare=(Double_t)chisquare;
397 Float_t confLevel=(Float_t)TMath::Prob(dblechisquare,9); // ndf 10-1=9
398 hchibestconflevel->Fill(confLevel);
400 if(strstr(option,"all")){
401 cout << "True Assignment " << truparticle[0] << truparticle[1] << truparticle[2] << truparticle[3] << truparticle[4] << truparticle[5] << truparticle[6] << truparticle[7] << truparticle[8] << truparticle[9] <<endl;
402 cout << "Best Assignment " << assparticle[0] << assparticle[1] << assparticle[2] << assparticle[3] << assparticle[4] << assparticle[5] << assparticle[6] << assparticle[7] << assparticle[8] << assparticle[9] << endl;
403 cout << "Minimum ChiSquare for current set " << chisquare << endl;
404 cout << "Confidence Level (Minimum ChiSquare) " << confLevel << endl;
406 if (strstr(option,"visual") && itimes && (itimes%kUPDATE) == 0) {
407 if (itimes == kUPDATE){
413 hchibestconflevel->Draw();
421 if (gSystem->ProcessEvents())
427 } // end for the current set. close if(istop==5)
428 } // end condition on ipartold
429 } // end loop on hits for the current track
431 } // end loop on ntracks
434 if(strstr(option,"all")){
435 nmisidentified=(nmisidentified0+nmisidentified1+nmisidentified2+nmisidentified3+nmisidentified4+nmisidentified5+nmisidentified6+nmisidentified7+nmisidentified8+nmisidentified9);
436 cout << "total number of tracks token into account " << 10*5*fNevents << endl;
437 Float_t badPercentage=100.*(Float_t)nmisidentified/(10*5*fNevents);
438 cout << "total misidentified " << nmisidentified << "("<< badPercentage << "%)" <<endl;
439 cout << "Total Number of set token into account " << 5*fNevents << endl;
440 Float_t goodSetPercentage=100.*(Float_t)ngood/(5*fNevents);
441 cout << "Number of set with no misidentified tracks " << ngood << "("<< goodSetPercentage << "%)" <<endl;
444 // free used memory for canvas
449 // generating output filename only if not previously specified using SetTZeroFile
450 char outFileName[70];
451 strcpy(outFileName,"ht010tr120ps"); // global time resolution has to be converted from Int_t to char
452 // in order to have in the output filename this parameter
453 strcat(outFileName,fHeadersFile);
455 if(fT0File.IsNull()) fT0File=outFileName;
457 TFile* houtfile = new TFile(fT0File,"recreate");
459 htzerobest->Write(0,TObject::kOverwrite);
460 hchibest->Write(0,TObject::kOverwrite);
461 hchibestconflevel->Write(0,TObject::kOverwrite);
465 if(strstr(option,"tim") || strstr(option,"all")){
466 gBenchmark->Stop("TOFT0");
467 cout << "AliTOFT0:" << endl ;
468 cout << " took " << gBenchmark->GetCpuTime("TOFT0") << " seconds in order to calculate T0 "
469 << gBenchmark->GetCpuTime("TOFT0")/fNevents << " seconds per event " << endl ;
474 //__________________________________________________________________
475 void AliTOFT0::SetTZeroFile(char * file ){
476 cout << "Destination file : " << file << endl ;
479 //__________________________________________________________________
480 void AliTOFT0::Print(Option_t* /*option*/)const
482 cout << "------------------- "<< GetName() << " -------------" << endl ;
483 if(!fT0File.IsNull())
484 cout << " Writing T0 Distribution to file " << (char*) fT0File.Data() << endl ;
487 //__________________________________________________________________
488 Bool_t AliTOFT0::operator==( AliTOFT0 const &tzero )const
493 if( (fTimeResolution==tzero.fTimeResolution)&&(fLowerMomBound==tzero.fLowerMomBound)&&(fUpperMomBound==tzero.fUpperMomBound))