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 ///////////////////////////////////////////////////////////////////////////////
20 // TRD cluster finder for the fast simulator. It takes the hits from the //
21 // fast simulator (one hit per plane) and transforms them //
22 // into cluster, by applying position smearing and merging //
23 // of nearby cluster. The searing is done uniformly in z-direction //
24 // over the length of a readout pad. In rphi-direction a Gaussian //
25 // smearing is applied with a sigma given by fRphiSigma. //
26 // Clusters are considered as overlapping when they are closer in //
27 // rphi-direction than the value defined in fRphiDist. //
28 // Use the macro fastClusterCreate.C to create the cluster. //
30 ///////////////////////////////////////////////////////////////////////////////
38 #include "AliTRDclusterizerV0.h"
39 #include "AliTRDhit.h"
40 #include "AliTRDgeometry.h"
41 #include "AliTRDrecPoint.h"
42 #include "AliTRDparameter.h"
44 ClassImp(AliTRDclusterizerV0)
46 //_____________________________________________________________________________
47 AliTRDclusterizerV0::AliTRDclusterizerV0():AliTRDclusterizer(), fTRD(NULL)
50 // AliTRDclusterizerV0 default constructor
55 //_____________________________________________________________________________
56 AliTRDclusterizerV0::AliTRDclusterizerV0(const Text_t* name, const Text_t* title)
57 :AliTRDclusterizer(name,title), fTRD(NULL)
60 // AliTRDclusterizerV0 default constructor
67 //_____________________________________________________________________________
68 AliTRDclusterizerV0::~AliTRDclusterizerV0()
71 // AliTRDclusterizerV0 destructor
76 //_____________________________________________________________________________
77 void AliTRDclusterizerV0::Init()
80 // Initializes the cluster finder
83 // Position resolution in rphi-direction
85 // Minimum distance of non-overlapping cluster
90 //_____________________________________________________________________________
91 Bool_t AliTRDclusterizerV0::MakeClusters()
94 // Generates the cluster
98 fTRD = (AliTRD*) gAlice->GetDetector("TRD");
100 printf("AliTRDclusterizerV0::makClusters -- ");
101 printf("No TRD detector object found\n");
105 if (fTRD->IsVersion() != 0) {
106 printf("AliTRDclusterizerV0::MakeCluster -- ");
107 printf("TRD must be version 0 (fast simulator).\n");
112 AliTRDgeometry *geo = fTRD->GetGeometry();
114 // Create a default parameter class if none is defined
116 fPar = new AliTRDparameter("TRDparameter","Standard TRD parameter");
118 printf("<AliTRDclusterizerV0::MakeCluster> ");
119 printf("Create the default parameter object.\n");
123 printf("AliTRDclusterizerV0::MakeCluster -- ");
124 printf("Start creating cluster.\n");
130 // Get the pointer to the hit tree
131 TTree *hitTree = fTRD->TreeH();
132 // Get the pointer to the reconstruction tree
133 TTree *clusterTree = gAlice->TreeR();
135 TObjArray *chamberArray = new TObjArray();
137 // Get the number of entries in the hit tree
138 // (Number of primary particles creating a hit somewhere)
139 Int_t nTrack = (Int_t) hitTree->GetEntries();
141 // Loop through all the chambers
142 for (Int_t icham = 0; icham < AliTRDgeometry::Ncham(); icham++) {
143 for (Int_t iplan = 0; iplan < AliTRDgeometry::Nplan(); iplan++) {
144 for (Int_t isect = 0; isect < AliTRDgeometry::Nsect(); isect++) {
146 Int_t nColMax = fPar->GetColMax(iplan);
147 Float_t row0 = fPar->GetRow0(iplan,icham,isect);
148 Float_t col0 = fPar->GetCol0(iplan);
149 Float_t time0 = fPar->GetTime0(iplan);
151 Float_t rowPadSize = fPar->GetRowPadSize(iplan,icham,isect);
152 Float_t colPadSize = fPar->GetColPadSize(iplan);
153 Float_t timeBinSize = fPar->GetDriftVelocity()
154 / fPar->GetSamplingFrequency();
156 // Loop through all entries in the tree
157 for (Int_t iTrack = 0; iTrack < nTrack; iTrack++) {
160 nBytes += hitTree->GetEvent(iTrack);
162 // Get the number of hits in the TRD created by this particle
163 Int_t nHit = fTRD->Hits()->GetEntriesFast();
165 // Loop through the TRD hits
166 for (Int_t iHit = 0; iHit < nHit; iHit++) {
168 if (!(hit = (AliTRDhit *) fTRD->Hits()->UncheckedAt(iHit)))
175 Int_t track = hit->Track();
176 Int_t detector = hit->GetDetector();
177 Int_t plane = geo->GetPlane(detector);
178 Int_t sector = geo->GetSector(detector);
179 Int_t chamber = geo->GetChamber(detector);
181 if ((sector != isect) ||
186 // Rotate the sectors on top of each other
188 geo->Rotate(detector,pos,rot);
190 // Add this recPoint to the temporary array for this chamber
191 AliTRDrecPoint *recPoint = new AliTRDrecPoint("");
192 recPoint->SetLocalRow(rot[2]);
193 recPoint->SetLocalCol(rot[1]);
194 recPoint->SetLocalTime(rot[0]);
195 recPoint->SetEnergy(0);
196 recPoint->SetDetector(detector);
197 recPoint->AddDigit(track);
198 chamberArray->Add(recPoint);
204 // Loop through the temporary cluster-array
205 for (Int_t iClus1 = 0; iClus1 < chamberArray->GetEntries(); iClus1++) {
207 AliTRDrecPoint *recPoint1 = (AliTRDrecPoint *)
208 chamberArray->UncheckedAt(iClus1);
209 Float_t row1 = recPoint1->GetLocalRow();
210 Float_t col1 = recPoint1->GetLocalCol();
211 Float_t time1 = recPoint1->GetLocalTime();
213 if (recPoint1->GetEnergy() < 0) continue; // Skip marked cluster
215 const Int_t kNsave = 5;
216 Int_t idxSave[kNsave];
219 const Int_t kNsaveTrack = 3;
220 Int_t tracks[kNsaveTrack];
221 tracks[0] = recPoint1->GetDigit(0);
223 // Check the other cluster to see, whether there are close ones
224 for (Int_t iClus2 = iClus1 + 1; iClus2 < chamberArray->GetEntries(); iClus2++) {
226 AliTRDrecPoint *recPoint2 = (AliTRDrecPoint *)
227 chamberArray->UncheckedAt(iClus2);
228 Float_t row2 = recPoint2->GetLocalRow();
229 Float_t col2 = recPoint2->GetLocalCol();
231 if ((TMath::Abs(row1 - row2) < rowPadSize) ||
232 (TMath::Abs(col1 - col2) < fRphiDist)) {
233 if (iSave == kNsave) {
234 printf("AliTRDclusterizerV0::MakeCluster -- ");
235 printf("Boundary error: iSave = %d, kNsave = %d.\n"
239 idxSave[iSave] = iClus2;
241 if (iSave < kNsaveTrack) tracks[iSave] = recPoint2->GetDigit(0);
246 // Merge close cluster
247 Float_t rowMerge = row1;
248 Float_t colMerge = col1;
250 for (Int_t iMerge = 0; iMerge < iSave; iMerge++) {
251 AliTRDrecPoint *recPoint2 =
252 (AliTRDrecPoint *) chamberArray->UncheckedAt(idxSave[iMerge]);
253 rowMerge += recPoint2->GetLocalRow();
254 colMerge += recPoint2->GetLocalCol();
255 recPoint2->SetEnergy(-1); // Mark merged cluster
257 rowMerge /= (iSave + 1);
258 colMerge /= (iSave + 1);
263 // The position smearing in row-direction (uniform over pad width)
264 Int_t row = (Int_t) ((rowMerge - row0) / rowPadSize);
265 smear[0] = (row + gRandom->Rndm()) * rowPadSize + row0;
267 // The position smearing in rphi-direction (Gaussian)
270 smear[1] = gRandom->Gaus(colMerge,fRphiSigma);
271 while ((smear[1] < col0 ) ||
272 (smear[1] > col0 + nColMax * colPadSize));
274 // Time direction stays unchanged
277 // Transform into local coordinates
278 smear[0] = (Int_t) ((smear[0] - row0) / rowPadSize);
279 smear[1] = (Int_t) ((smear[1] - col0) / colPadSize);
280 smear[2] = (Int_t) ((time0 - smear[2]) / timeBinSize);
282 // Add the smeared cluster to the output array
283 Int_t detector = recPoint1->GetDetector();
284 Int_t tr[9] = { -1 };
286 Float_t sigma[2] = { 0.0 };
289 pos[2] = (time0 - smear[2]) / timeBinSize;
290 AddCluster(pos,detector,0.0,tr,sigma,0);
294 // Clear the temporary cluster-array and delete the cluster
295 chamberArray->Delete();
301 printf("AliTRDclusterizerV0::MakeCluster -- ");
302 printf("Found %d points.\n",RecPoints()->GetEntries());
303 printf("AliTRDclusterizerV0::MakeCluster -- ");
304 printf("Fill the cluster tree.\n");