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 #include <TClonesArray.h>
19 #include <TParticle.h>
22 #include "AliMUONSDigitizerV2.h"
25 #include "AliMUONChamber.h"
26 #include "AliMUONVDigit.h"
27 #include "AliMUONHit.h"
28 #include "AliMUONVDigitStore.h"
29 #include "AliMUONVHitStore.h"
30 #include "AliMUONResponseTrigger.h"
31 #include "AliMUONConstants.h"
34 #include "AliMpDEManager.h"
37 #include "AliCDBManager.h"
38 #include "AliLoader.h"
40 #include "AliRunLoader.h"
42 #include "AliHeader.h"
43 #include "AliGenCocktailEventHeader.h"
45 //-----------------------------------------------------------------------------
46 /// The sdigitizer performs the transformation from hits (energy deposits by
47 /// the transport code) to sdigits (equivalent of charges on pad).
49 /// It does so by converting the energy deposit into a charge and then spreading
50 /// this charge over several pads, according to the response function (a
51 /// Mathieson distribution, basically).
53 /// See also AliMUONResponseV0, which is doing the real job (in DisIntegrate
54 /// method), while this sdigitizer is just "steering" the process.
56 /// Please note that we do *not* merge sdigits after creation, which means
57 /// that after sdigitization, a given pad can have several sdigits. This
58 /// merging is taken care of later on by the digitizer(V3).
59 //-----------------------------------------------------------------------------
61 ClassImp(AliMUONSDigitizerV2)
63 Float_t AliMUONSDigitizerV2::fgkMaxIntTime = 10.0;
64 Float_t AliMUONSDigitizerV2::fgkMaxPosTimeDif = 1.22E-6;
65 Float_t AliMUONSDigitizerV2::fgkMaxNegTimeDif = -3.5E-6;
66 Float_t AliMUONSDigitizerV2::fgkMinTimeDif = 25E-9;
68 //_____________________________________________________________________________
69 AliMUONSDigitizerV2::AliMUONSDigitizerV2()
70 : TNamed("AliMUONSDigitizerV2","From Hits to SDigits for MUON")
77 if ( ! AliMpCDB::LoadMpSegmentation() ) {
78 AliFatal("Could not access mapping from OCDB !");
82 //_____________________________________________________________________________
83 AliMUONSDigitizerV2::~AliMUONSDigitizerV2()
90 //_____________________________________________________________________________
92 AliMUONSDigitizerV2::Digitize(Option_t*)
95 /// Go from hits to sdigits.
97 /// In the code below, apart from the loop itself (which look complicated
98 /// but is really only a loop on each hit in the input file) the main
99 /// work is done in AliMUONResponse::DisIntegrate method, which converts
100 /// a single hit in (possibly) several sdigits.
105 AliRunLoader* runLoader = AliRunLoader::Instance();
106 AliLoader* loader = runLoader->GetDetectorLoader("MUON");
108 loader->LoadHits("READ");
110 AliMUON* muon = static_cast<AliMUON*>(gAlice->GetModule("MUON"));
112 Int_t nofEvents(runLoader->GetNumberOfEvents());
114 TString classname = muon->DigitStoreClassName();
116 AliMUONVDigitStore* sDigitStore = AliMUONVDigitStore::Create(classname.Data());
120 AliFatal(Form("Could not create digitstore of class %s",classname.Data()));
123 AliDebug(1,Form("Will use digitStore of type %s",sDigitStore->ClassName()));
125 // average arrival time to chambers, for pileup studies
127 for ( Int_t iEvent = 0; iEvent < nofEvents; ++iEvent )
131 tdlist.SetOwner(kTRUE);
133 AliDebug(1,Form("iEvent=%d",iEvent));
134 runLoader->GetEvent(iEvent);
136 // for pile up studies
137 float t0=fgkMaxIntTime; int aa=0;
138 AliHeader* header = runLoader->GetHeader();
139 AliGenCocktailEventHeader* cocktailHeader =
140 dynamic_cast<AliGenCocktailEventHeader*>(header->GenEventHeader());
141 if (cocktailHeader) {
142 AliGenCocktailEventHeader* genEventHeader = (AliGenCocktailEventHeader*) (header->GenEventHeader());
143 TList* headers = genEventHeader->GetHeaders();
144 TIter nextH(headers);
145 AliGenEventHeader *entry;
146 while((entry = (AliGenEventHeader*)nextH())) {
147 float t = entry->InteractionTime();
148 if (TMath::Abs(t)<TMath::Abs(t0)) t0 = t;
152 AliGenEventHeader* evtHeader =
153 (AliGenEventHeader*)(header->GenEventHeader());
156 float t = evtHeader->InteractionTime();
157 if (TMath::Abs(t)<TMath::Abs(t0)) t0 = t;
162 // some generators may not offer a header, if which
163 // case we cannot get the interaction time, so we assume zero
168 loader->MakeSDigitsContainer();
170 TTree* treeS = loader->TreeS();
177 sDigitStore->Connect(*treeS);
179 TTree* treeH = loader->TreeH();
181 AliMUONVHitStore* hitStore = AliMUONVHitStore::Create(*treeH);
182 hitStore->Connect(*treeH);
184 Long64_t nofTracks = treeH->GetEntries();
186 for ( Long64_t iTrack = 0; iTrack < nofTracks; ++iTrack )
188 // Loop over the tracks of this event.
189 treeH->GetEvent(iTrack);
192 TIter next(hitStore->CreateIterator());
195 while ( ( hit = static_cast<AliMUONHit*>(next()) ) )
197 Int_t chamberId = hit->Chamber()-1;
198 Float_t age = hit->Age()-t0;
200 AliMUONChamber& chamber = muon->Chamber(chamberId);
201 AliMUONResponse* response = chamber.ResponseModel();
203 // This is the heart of this method : the dis-integration
205 if (aa>1){ // if there are pileup events
206 Float_t chamberTime = AliMUONConstants::AverageChamberT(chamberId);
207 Float_t timeDif=age-chamberTime;
208 if (timeDif>fgkMaxPosTimeDif || timeDif<fgkMaxNegTimeDif) {
211 if(TMath::Abs(timeDif)>fgkMinTimeDif){
212 response->DisIntegrate(*hit,digits,timeDif);
215 response->DisIntegrate(*hit,digits,0.);
219 response->DisIntegrate(*hit,digits,0.);
222 TIter nextd(&digits);
224 while ( ( d = (AliMUONVDigit*)nextd() ) )
226 // Update some sdigit information that could not be known
227 // by the DisIntegrate method
230 d->AddTrack(hit->GetTrack(),d->Charge());
236 } // end of loop on tracks within an event
241 while ( ( d = static_cast<AliMUONVDigit*>(next()) ) )
243 d->ChargeInFC(kTRUE);
245 AliMUONVDigit* added = sDigitStore->Add(*d,AliMUONVDigitStore::kMerge);
248 AliError("Could not add digit to digitStore");
254 loader->WriteSDigits("OVERWRITE");
256 sDigitStore->Clear();
258 loader->UnloadSDigits();
264 loader->UnloadHits();