Digitizer
[u/mrichter/AliRoot.git] / START / AliSTARTDigitizer.cxx
1
2 /**************************************************************************
3  * Copyright(c) 1998-2000, ALICE Experiment at CERN, All rights reserved. *
4  *                                                                        *
5  * Author: The ALICE Off-line Project.                                    *
6  * Contributors are mentioned in the code where appropriate.              *
7  *                                                                        *
8  * Permission to use, copy, modify and distribute this software and its   *
9  * documentation strictly for non-commercial purposes is hereby granted   *
10  * without fee, provided that the above copyright notice appears in all   *
11  * copies and that both the copyright notice and this permission notice   *
12  * appear in the supporting documentation. The authors make no claims     *
13  * about the suitability of this software for any purpose. It is          *
14  * provided "as is" without express or implied warranty.                  *
15  **************************************************************************/
16
17
18 #include <TTree.h> 
19 #include <TVector.h>
20 #include <TObjArray.h>
21 #include <TFile.h>
22 #include <TDirectory.h>
23 #include <TRandom.h>
24
25
26 #include "AliSTARTDigitizer.h"
27 #include "AliSTART.h"
28 #include "AliSTARThit.h"
29 #include "AliSTARTdigit.h"
30 #include "AliRunDigitizer.h"
31
32 #include "AliRun.h"
33 #include "AliPDG.h"
34
35 #include <stdlib.h>
36 #include <iostream.h>
37 #include <fstream.h>
38
39 ClassImp(AliSTARTDigitizer)
40
41 //___________________________________________
42   AliSTARTDigitizer::AliSTARTDigitizer()  :AliDigitizer()
43 {
44 // Default ctor - don't use it
45   ;
46 }
47
48 //___________________________________________
49 AliSTARTDigitizer::AliSTARTDigitizer(AliRunDigitizer* manager) 
50     :AliDigitizer(manager) 
51 {
52         cout<<"AliSTARTDigitizer::AliSTARTDigitizer"<<endl;
53 // ctor which should be used
54 //  fDebug =0;
55  // if (GetDebug()>2)
56   //  cerr<<"AliSTARTDigitizer::AliSTARTDigitizer"
57    //     <<"(AliRunDigitizer* manager) was processed"<<endl;
58
59 }
60
61 //------------------------------------------------------------------------
62 AliSTARTDigitizer::~AliSTARTDigitizer()
63 {
64 // Destructor
65
66
67 }
68
69  //------------------------------------------------------------------------
70 Bool_t AliSTARTDigitizer::Init()
71 {
72 // Initialization
73  cout<<"AliSTARTDigitizer::Init"<<endl;
74  return kTRUE;
75 }
76  
77
78 //---------------------------------------------------------------------
79
80 void AliSTARTDigitizer::Exec(Option_t* option)
81 {
82
83
84
85 #ifdef DEBUG
86   cout<<"AliSTARTDigitizer::>SDigits2Digits start...\n";
87 #endif
88   //
89   // From hits to digits
90   //
91   Int_t hit;
92   Int_t nhits;
93   Int_t volume,pmt;
94   char nameDigits[20];
95   Float_t timediff,timeright,timeleft,timeav;
96   Float_t besttimeright,besttimeleft,meanTime;
97   Int_t channelWidth=10;
98   fHits = new TClonesArray ("AliSTARThit", 1000);
99   AliSTART *START  = (AliSTART*) gAlice->GetDetector("START");
100
101   AliSTARThit  *startHit;
102   TBranch *brHits=0;
103   fdigits= new AliSTARTdigit();
104
105   Int_t nFiles=fManager->GetNinputs();
106   for (Int_t inputFile=0; inputFile<nFiles;  inputFile++) {
107     sprintf(nameDigits,"START_D_%d",fManager->GetOutputEventNr());
108  
109     besttimeright=9999.;
110     besttimeleft=9999.;
111     Int_t timeDiff=0;
112     Int_t timeAv=0;
113     TClonesArray *STARThits = START->Hits ();
114
115    TTree *th = fManager->GetInputTreeH(inputFile);
116     brHits = th->GetBranch("START");
117     if (brHits) {
118       START->SetHitsAddressBranch(brHits);
119     }else{
120       cerr<<"EXEC Branch START hit not found"<<exit;
121     } 
122     Int_t ntracks    = (Int_t) th->GetEntries();
123     if (ntracks<=0) return;
124     // Start loop on tracks in the hits containers
125     for (Int_t track=0; track<ntracks;track++) {
126       brHits->GetEntry(track);
127       nhits = STARThits->GetEntriesFast();
128       for (hit=0;hit<nhits;hit++) {
129         startHit   = (AliSTARThit*) STARThits->UncheckedAt(hit);
130         pmt=startHit->fPmt;
131         volume = startHit->fVolume;
132         if(volume==1){
133           timeright = startHit->fTime;
134           if(timeright<besttimeright) {
135             besttimeright=timeright;
136           } //timeright
137         }//time for right shoulder
138         if(volume==2){            
139           timeleft = startHit->fTime;
140           //                printf("timeleft %f\n",timeleft);
141           if(timeleft<besttimeleft) {
142             besttimeleft=timeleft;
143           } //timeleftbest
144         }//time for left shoulder
145       } //hit loop
146     } //track loop
147  
148     //folding with experimental time distribution
149     Float_t besttimerightGaus=gRandom->Gaus(besttimeright,0.05);
150     Float_t besttimeleftGaus=gRandom->Gaus(besttimeleft,0.05);
151     timediff=besttimerightGaus-besttimeleftGaus;
152     meanTime=(besttimerightGaus+besttimeleftGaus)/2.;
153     if ( TMath::Abs(timediff)<TMath::Abs(10.) && meanTime<TMath::Abs(7.1)) 
154      {
155        //we assume centre of bunch is 5ns after TTS signal
156        //TOF values are relative of the end of bunch
157        Float_t ppBunch=25;
158     
159        ppBunch=ppBunch-10/2;
160        Float_t t1=1000.*besttimeleftGaus;
161        Float_t t2=1000.*besttimerightGaus;
162        t1=t1/channelWidth+ppBunch; //time in ps to channelWidth
163        t2=t2/channelWidth+ppBunch; //time in ps to channelWidth
164      
165        timeav=(t1+t2)/2.;
166      
167        // Time to TDC signal
168        // 256 channels for timediff, range 1ns
169        
170        timediff=128+1000*timediff/channelWidth; // time in ps 
171
172        timeAv = (Int_t)(timeav);   // time (ps) channel numbres
173        timeDiff = (Int_t)(timediff); // time ( ps) channel numbres
174        fdigits->Set(timeAv,timeDiff);
175       fdigits->Print();
176      }
177     else
178       {timeAv=999999; timeDiff=99999;}
179
180 // trick to find out output dir:
181     TTree *outTree = fManager->GetTreeD();
182     if (!outTree) {
183       cerr<<"something wrong with output...."<<exit;
184       return;
185     }
186     TDirectory *wd = gDirectory;
187     outTree->GetDirectory()->cd();
188     fdigits->Write(nameDigits);
189     wd->cd();
190   }
191
192 }
193
194