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 **************************************************************************/
16 //_________________________________________________________________________
17 // This is a TTask that made the calculation of the Time zero using TOF.
18 // Description: The algorithm used to calculate the time zero of interaction
19 // using TOF detector is the following.
20 // We select in the MonteCarlo some primary particles - or tracks in the following -
21 // that strike the TOF detector (the larger part are pions, kaons or protons).
22 // We choose a set of 10 selected tracks, for each track You have the length
23 // of the track when the TOF is reached (a standard TOF hit does not contain this
24 // additional information, this is the reason why we implemented a new time zero
25 // dedicated TOF hit class AliTOFhitT0; in order to store this type of hit You
26 // have to use the AliTOFv4T0 as TOF class in Your Config.C. In AliTOFv4T0 the
27 // StepManager was modified in order to fill the TOF hit branch with this type
28 // of hits; in fact the AliTOF::AddT0Hit is called rather that the usual AliTOF::AddHit),
29 // the momentum at generation (from TreeK) and the time of flight
30 // given by the TOF detector.
31 // (Observe that the ctor of the AliTOF class, when the AliTOFv4T0 class is used, is called
32 // with the "tzero" option: it is in order create the fHits TClonesArray filled with
33 // AliTOFhitT0 objects, rather than with normal AliTOFhit)
34 // Then Momentum and time of flight for each track are smeared according to
35 // known experimental resolution (all sources of error have been token into account).
36 // Let consider now only one set of 10 tracks (the algorithm is the same for all sets).
37 // Assuming the (mass) hypothesis that each track can be AUT a pion, AUT a kaon, AUT a proton,
38 // we consider all the 3 at 10 possible cases.
39 // For each track in each (mass) configuration
40 // (a configuration can be e.g. pion/pion/kaon/proton/pion/proton/kaon/kaon/pion/pion)
41 // we calculate the time zero (we know in fact the velocity of the track after
42 // the assumption about its mass, the time of flight given by the TOF, and the
43 // corresponding path travelled till the TOF detector). Then for each mass configuration we have
44 // 10 time zero and we can calculate the ChiSquare for the current configuration using the
45 // weighted mean over all 10 time zero.
46 // We call the best assignment the mass configuration that gives the minimum value of the ChiSquare.
47 // We plot the weighted mean over all 10 time zero for the best assignment,
48 // the ChiSquare for the best assignment and the corresponding confidence level.
49 // The strong assumption is the MC selection of primary particles. It will be introduced
50 // in the future also some more realistic simulation about this point.
52 // root [0] AliTOFT0 * tzero = new AliTOFT0("galice.root")
53 // Warning in <TDatabasePDG::TDatabasePDG>: object already instantiated
54 // root [1] tzero->ExecuteTask()
55 // root [2] tzero->ExecuteTask("tim")
56 // // available parameters:
57 // tim - print benchmarking information
58 // all - print usefull informations about the number of misidentified tracks
59 // and a comparison about the true configuration (known from MC) and the best
61 //-- Author: F. Pierella
62 //////////////////////////////////////////////////////////////////////////////
65 #include "AliTOFhitT0.h"
67 #include "AliTOFv4T0.h"
69 #include "AliDetector.h"
81 #include "TBenchmark.h"
82 #include "TParticle.h"
83 #include "TClonesArray.h"
91 //____________________________________________________________________________
92 AliTOFT0::AliTOFT0():TTask("AliTOFT0","")
98 //____________________________________________________________________________
99 AliTOFT0::AliTOFT0(char* headerFile, Int_t nEvents):TTask("AliTOFT0","")
101 fNevents=nEvents ; // Number of events for which calculate the T0,
102 // default 0: it means all evens in current file
103 fLowerMomBound=1.5; // [GeV/c] default value
104 fUpperMomBound=2. ; // [GeV/c] default value
105 fTimeResolution = 1.2e-10; // 120 ps by default
106 fHeadersFile = headerFile ;
108 TFile * file = (TFile*) gROOT->GetFile(fHeadersFile.Data() ) ;
110 //File was not opened yet
112 if(fHeadersFile.Contains("rfio"))
113 file = TFile::Open(fHeadersFile,"update") ;
115 file = new TFile(fHeadersFile.Data(),"update") ;
116 gAlice = (AliRun *) file->Get("gAlice") ;
119 // add Task to //root/Tasks folder
120 TTask * roottasks = (TTask*)gROOT->GetRootFolder()->FindObject("Tasks") ;
121 roottasks->Add(this) ;
124 //____________________________________________________________________________
125 AliTOFT0::~AliTOFT0()
130 //____________________________________________________________________________
131 void AliTOFT0::Exec(Option_t *option)
134 // calculate T0 distribution for all events using chisquare
137 Int_t nmisidentified=0;
138 Int_t nmisidentified0=0;
139 Int_t nmisidentified1=0;
140 Int_t nmisidentified2=0;
141 Int_t nmisidentified3=0;
142 Int_t nmisidentified4=0;
143 Int_t nmisidentified5=0;
144 Int_t nmisidentified6=0;
145 Int_t nmisidentified7=0;
146 Int_t nmisidentified8=0;
147 Int_t nmisidentified9=0;
152 Float_t timeresolutioninns=fTimeResolution*(1.e+9); // convert in [ns]
153 const Int_t kUPDATE = 5; // for visual option
159 if(strstr(option,"visual")){
160 // Create a new canvas.
161 //c1 = new TCanvas("c1","Dynamic Visual Filling of time zero histo",10,10,500,500);
162 c1 = new TCanvas("c1","Dynamic Visual Filling of time zero histo",10,10,370,370);
163 c1->SetFillColor(35);
164 c1->GetFrame()->SetFillColor(21);
165 c1->GetFrame()->SetBorderSize(6);
166 c1->GetFrame()->SetBorderMode(-1);
168 //c2 = new TCanvas("c2","Dynamic Visual Filling of chisquare histo",550,10,500,500);
169 c2 = new TCanvas("c2","Dynamic Visual Filling of chisquare histo",380,10,370,370);
170 c2->SetFillColor(35);
171 c2->GetFrame()->SetFillColor(21);
172 c2->GetFrame()->SetBorderSize(6);
173 c2->GetFrame()->SetBorderMode(-1);
175 //c3 = new TCanvas("c3","Dynamic Visual Filling of confidence level histo",280,550,500,500);
176 c3 = new TCanvas("c3","Dynamic Visual Filling of confidence level histo",760,10,370,370);
177 c3->SetFillColor(35);
178 c3->GetFrame()->SetFillColor(21);
179 c3->GetFrame()->SetBorderSize(6);
180 c3->GetFrame()->SetBorderMode(-1);
183 if(strstr(option,"tim") || strstr(option,"all"))
184 gBenchmark->Start("TOFT0");
186 TH1F *htzerobest= new TH1F("htzerobest","T0 for best assignment",200,-1.,1.);
187 TH1F* hchibest = new TH1F("hchibest","ChiSquare Min Distribution",80,0.,40.);
188 TH1F* hchibestconflevel = new TH1F("hchibestconflevel","ChiSquare Min Confidence Level",10,0.,1.);
190 // setting histo colors
191 if(strstr(option,"visual")){
192 htzerobest->SetFillColor(48);
193 hchibest->SetFillColor(50);
194 hchibestconflevel->SetFillColor(52);
197 Int_t assparticle[10]={3,3,3,3,3,3,3,3,3,3};
198 Int_t truparticle[10]={3,3,3,3,3,3,3,3,3,3};
200 Float_t timeofflight[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
201 Float_t momentum[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
202 Float_t timezero[10];
203 Float_t weightedtimezero[10];
204 Float_t beta[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
205 Float_t sqMomError[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
206 Float_t sqTrackError[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
207 Float_t massarray[3]={0.13957,0.493677,0.9382723};
208 Float_t dummychisquare=0.;
209 Float_t chisquare=999.;
210 Float_t tracktoflen[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
212 AliTOF *TOF = (AliTOF *) gAlice->GetDetector ("TOF");
215 Error("AliTOFT0","TOF not found");
219 if(strstr(option,"all")){
220 cout << "Selecting primary tracks with momentum between " << fLowerMomBound << " GeV/c and " << fUpperMomBound << " GeV/c" << endl;
221 cout << "Memorandum: 0 means PION | 1 means KAON | 2 means PROTON" << endl;
224 if (fNevents == 0) fNevents = (Int_t) gAlice->TreeE()->GetEntries();
226 for (Int_t ievent = 0; ievent < fNevents; ievent++) {
227 gAlice->GetEvent(ievent);
228 TTree *TH = gAlice->TreeH ();
233 TClonesArray* TOFhits = TOF->Hits();
238 TH->SetBranchStatus("*",0); // switch off all branches
239 TH->SetBranchStatus("TOF*",1); // switch on only TOF
241 // Start loop on primary tracks in the hits containers
243 Int_t ntracks = static_cast<Int_t>(TH->GetEntries());
244 for (Int_t track = 0; track < ntracks; track++)
246 if(nset>=5) break; // check on the number of set analyzed
250 particle = gAlice->Particle(track);
251 Int_t nhits = TOFhits->GetEntriesFast();
253 for (Int_t hit = 0; hit < nhits; hit++)
255 tofHit = (AliTOFhitT0 *) TOFhits->UncheckedAt(hit);
256 ipart = tofHit->GetTrack();
257 // check to discard the case when the same particle is selected more than one
260 if (ipart != ipartold){
262 particle = (TParticle*)gAlice->Particle(ipart);
264 Float_t idealtime=tofHit->GetTof();
265 // Float_t time=idealtime;
266 Float_t time = gRandom->Gaus(idealtime, fTimeResolution);
267 Float_t toflen=tofHit->GetLen();
268 toflen=toflen/100.; // toflen given in m
269 Int_t pdg = particle->GetPdgCode();
270 Int_t abspdg =TMath::Abs(pdg);
271 Float_t idealmom = particle->P();
272 Float_t momres=idealmom*0.025; // 2.5% res token into account for all momenta
273 Float_t mom =gRandom->Gaus(idealmom,momres);
275 Bool_t isgoodpart=(abspdg==211 || abspdg==2212 || abspdg==321);
277 time*=1.E+9; // tof given in nanoseconds
278 if (particle->GetFirstMother() < 0 && isgoodpart && mom<=fUpperMomBound && mom>=fLowerMomBound){
282 Int_t index=selected-1;
283 timeofflight[index]=time;
284 tracktoflen[index]=toflen;
286 // cout << timeofflight[index] << " " << tracktoflen[index] << " " << momentum[index] << endl;
289 truparticle[index]=0;
292 truparticle[index]=1;
295 truparticle[index]=2;
302 if(istop==10){ // start analysis on current set
307 //cout << "starting t0 calculation for current set" << endl;
308 for (Int_t i1=0; i1<3;i1++) {
309 beta[0]=momentum[0]/sqrt(massarray[i1]*massarray[i1]+momentum[0]*momentum[0]);
310 for (Int_t i2=0; i2<3;i2++) {
311 beta[1]=momentum[1]/sqrt(massarray[i2]*massarray[i2]+momentum[1]*momentum[1]);
312 for (Int_t i3=0; i3<3;i3++) {
313 beta[2]=momentum[2]/sqrt(massarray[i3]*massarray[i3]+momentum[2]*momentum[2]);
314 for (Int_t i4=0; i4<3;i4++) {
315 beta[3]=momentum[3]/sqrt(massarray[i4]*massarray[i4]+momentum[3]*momentum[3]);
316 for (Int_t i5=0; i5<3;i5++) {
317 beta[4]=momentum[4]/sqrt(massarray[i5]*massarray[i5]+momentum[4]*momentum[4]);
318 for (Int_t i6=0; i6<3;i6++) {
319 beta[5]=momentum[5]/sqrt(massarray[i6]*massarray[i6]+momentum[5]*momentum[5]);
320 for (Int_t i7=0; i7<3;i7++) {
321 beta[6]=momentum[6]/sqrt(massarray[i7]*massarray[i7]+momentum[6]*momentum[6]);
322 for (Int_t i8=0; i8<3;i8++) {
323 beta[7]=momentum[7]/sqrt(massarray[i8]*massarray[i8]+momentum[7]*momentum[7]);
324 for (Int_t i9=0; i9<3;i9++) {
325 beta[8]=momentum[8]/sqrt(massarray[i9]*massarray[i9]+momentum[8]*momentum[8]);
326 for (Int_t i10=0; i10<3;i10++) {
327 beta[9]=momentum[9]/sqrt(massarray[i10]*massarray[i10]+momentum[9]*momentum[9]);
329 Float_t meantzero=0.;
330 Float_t sumAllweights=0.;
331 for (Int_t itz=0; itz<10;itz++) {
332 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
333 sqTrackError[itz]=(timeresolutioninns*timeresolutioninns+sqMomError[itz]); // total error for the current track
334 sumAllweights+=1./sqTrackError[itz];
336 timezero[itz]=(tracktoflen[itz]/(beta[itz]*0.299792))-timeofflight[itz];
337 weightedtimezero[itz]=((tracktoflen[itz]/(beta[itz]*0.299792))-timeofflight[itz])/sqTrackError[itz];// weighted time zero for current track
338 meantzero+=weightedtimezero[itz];
339 } // end loop for (Int_t itz=0; itz<10;itz++)
340 meantzero=meantzero/sumAllweights; // it is given in [ns]
343 // calculate the chisquare for the current assignment
344 for (Int_t icsq=0; icsq<10;icsq++) {
345 dummychisquare+=(timezero[icsq]-meantzero)*(timezero[icsq]-meantzero)/sqTrackError[icsq];
346 } // end loop for (Int_t icsq=0; icsq<10;icsq++)
348 if(dummychisquare<=chisquare){
359 chisquare=dummychisquare;
361 } // close if(dummychisquare<=chisquare)
374 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;
375 if(truparticle[0]!=assparticle[0]) nmisidentified0+=1;
376 if(truparticle[1]!=assparticle[1]) nmisidentified1+=1;
377 if(truparticle[2]!=assparticle[2]) nmisidentified2+=1;
378 if(truparticle[3]!=assparticle[3]) nmisidentified3+=1;
379 if(truparticle[4]!=assparticle[4]) nmisidentified4+=1;
380 if(truparticle[5]!=assparticle[5]) nmisidentified5+=1;
381 if(truparticle[6]!=assparticle[6]) nmisidentified6+=1;
382 if(truparticle[7]!=assparticle[7]) nmisidentified7+=1;
383 if(truparticle[8]!=assparticle[8]) nmisidentified8+=1;
384 if(truparticle[9]!=assparticle[9]) nmisidentified9+=1;
386 htzerobest->Fill(t0best);
387 hchibest->Fill(chisquare);
388 Double_t dblechisquare=(Double_t)chisquare;
389 Float_t confLevel=(Float_t)TMath::Prob(dblechisquare,9); // ndf 10-1=9
390 hchibestconflevel->Fill(confLevel);
392 if(strstr(option,"all")){
393 cout << "True Assignment " << truparticle[0] << truparticle[1] << truparticle[2] << truparticle[3] << truparticle[4] << truparticle[5] << truparticle[6] << truparticle[7] << truparticle[8] << truparticle[9] <<endl;
394 cout << "Best Assignment " << assparticle[0] << assparticle[1] << assparticle[2] << assparticle[3] << assparticle[4] << assparticle[5] << assparticle[6] << assparticle[7] << assparticle[8] << assparticle[9] << endl;
395 cout << "Minimum ChiSquare for current set " << chisquare << endl;
396 cout << "Confidence Level (Minimum ChiSquare) " << confLevel << endl;
398 if (strstr(option,"visual") && itimes && (itimes%kUPDATE) == 0) {
399 if (itimes == kUPDATE){
405 hchibestconflevel->Draw();
413 if (gSystem->ProcessEvents())
419 } // end for the current set. close if(istop==5)
420 } // end condition on ipartold
421 } // end loop on hits for the current track
423 } // end loop on ntracks
426 if(strstr(option,"all")){
427 nmisidentified=(nmisidentified0+nmisidentified1+nmisidentified2+nmisidentified3+nmisidentified4+nmisidentified5+nmisidentified6+nmisidentified7+nmisidentified8+nmisidentified9);
428 cout << "total number of tracks token into account " << 10*5*fNevents << endl;
429 Float_t badPercentage=100.*(Float_t)nmisidentified/(10*5*fNevents);
430 cout << "total misidentified " << nmisidentified << "("<< badPercentage << "%)" <<endl;
431 cout << "Total Number of set token into account " << 5*fNevents << endl;
432 Float_t goodSetPercentage=100.*(Float_t)ngood/(5*fNevents);
433 cout << "Number of set with no misidentified tracks " << ngood << "("<< goodSetPercentage << "%)" <<endl;
436 // free used memory for canvas
441 // generating output filename only if not previously specified using SetTZeroFile
442 char outFileName[70];
443 strcpy(outFileName,"ht010tr120ps"); // global time resolution has to be converted from Int_t to char
444 // in order to have in the output filename this parameter
445 strcat(outFileName,fHeadersFile);
447 if(fT0File.IsNull()) fT0File=outFileName;
449 TFile* houtfile = new TFile(fT0File,"recreate");
451 htzerobest->Write(0,TObject::kOverwrite);
452 hchibest->Write(0,TObject::kOverwrite);
453 hchibestconflevel->Write(0,TObject::kOverwrite);
457 if(strstr(option,"tim") || strstr(option,"all")){
458 gBenchmark->Stop("TOFT0");
459 cout << "AliTOFT0:" << endl ;
460 cout << " took " << gBenchmark->GetCpuTime("TOFT0") << " seconds in order to calculate T0 "
461 << gBenchmark->GetCpuTime("TOFT0")/fNevents << " seconds per event " << endl ;
466 //__________________________________________________________________
467 void AliTOFT0::SetTZeroFile(char * file ){
468 cout << "Destination file : " << file << endl ;
471 //__________________________________________________________________
472 void AliTOFT0::Print(Option_t* option)const
474 cout << "------------------- "<< GetName() << " -------------" << endl ;
475 if(!fT0File.IsNull())
476 cout << " Writing T0 Distribution to file " << (char*) fT0File.Data() << endl ;
479 //__________________________________________________________________
480 Bool_t AliTOFT0::operator==( AliTOFT0 const &tzero )const
485 if( (fTimeResolution==tzero.fTimeResolution)&&(fLowerMomBound==tzero.fLowerMomBound)&&(fUpperMomBound==tzero.fUpperMomBound))