Alternative implementations of preclusterfinder (currently under test)
[u/mrichter/AliRoot.git] / MUON / AliMUONPreClusterFinderV2.cxx
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c13ab450 1/**************************************************************************
2* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
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4* Author: The ALICE Off-line Project. *
5* Contributors are mentioned in the code where appropriate. *
6* *
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**************************************************************************/
15
16// $Id$
17
18#include "AliMUONPreClusterFinderV2.h"
19
20#include "AliLog.h"
21#include "AliMUONCluster.h"
22#include "AliMpVSegmentation.h"
23#include "TClonesArray.h"
24#include "TVector2.h"
25#include "AliMUONPad.h"
26#include "AliMUONVDigit.h"
27#include "AliMUONVDigitStore.h"
28
29/// \class AliMUONPreClusterFinderV2
30///
31/// Implementation of AliMUONVClusterFinder
32///
33/// This one ressembles the preclustering stage in the original ClusterFinderAZ
34///
35/// \author Laurent Aphecetche
36
37ClassImp(AliMUONPreClusterFinderV2)
38
39//_____________________________________________________________________________
40AliMUONPreClusterFinderV2::AliMUONPreClusterFinderV2()
41: AliMUONVClusterFinder(),
42 fClusters(0x0),
43 fSegmentations(0x0),
44 fDetElemId(0)
45{
46 /// ctor
47 for ( Int_t i = 0; i < 2; ++i )
48 {
49 fPads[i] = 0x0;
50 }
51}
52
53//_____________________________________________________________________________
54AliMUONPreClusterFinderV2::~AliMUONPreClusterFinderV2()
55{
56 /// dtor : note we're owner of the pads and the clusters, but not of
57 /// the remaining objects (digits, segmentations)
58 delete fClusters;
59 for ( Int_t i = 0; i < 2; ++i )
60 {
61 delete fPads[i];
62 }
63}
64
65//_____________________________________________________________________________
66Bool_t
67AliMUONPreClusterFinderV2::UsePad(const AliMUONPad& pad)
68{
69 /// Add a pad to the list of pads to be considered
70 if ( pad.DetElemId() != fDetElemId )
71 {
72 AliError(Form("Cannot add pad from DE %d to this cluster finder which is "
73 "currently dealing with DE %d",pad.DetElemId(),fDetElemId));
74 return kFALSE;
75 }
76
77 new ((*fPads[pad.Cathode()])[fPads[pad.Cathode()]->GetLast()+1]) AliMUONPad(pad);
78 // FIXME: should set the ClusterId of that new pad to be -1
79 return kTRUE;
80}
81
82//_____________________________________________________________________________
83Bool_t
84AliMUONPreClusterFinderV2::Prepare(const AliMpVSegmentation* segmentations[2],
85 const AliMUONVDigitStore& digitStore)
86// FIXME : add area on which to look for clusters here.
87{
88 /// Prepare for clustering, by giving access to segmentations and digit lists
89
90 fSegmentations = segmentations;
91
92 delete fClusters;
93 fClusters = new TClonesArray("AliMUONCluster");
94 for ( Int_t i = 0; i < 2; ++i )
95 {
96 delete fPads[i];
97 fPads[i] = new TClonesArray("AliMUONPad");
98 }
99
100 fDetElemId = -1;
101
102 TIter next(digitStore.CreateIterator());
103 AliMUONVDigit* d;
104
105 while ( ( d = static_cast<AliMUONVDigit*>(next()) ) )
106 {
107 Int_t ix = d->PadX();
108 Int_t iy = d->PadY();
109 Int_t cathode = d->Cathode();
110 AliMpPad pad = fSegmentations[cathode]->PadByIndices(AliMpIntPair(ix,iy));
111 TClonesArray& padArray = *(fPads[cathode]);
112 if ( fDetElemId == -1 )
113 {
114 fDetElemId = d->DetElemId();
115 }
116 else
117 {
118 if ( d->DetElemId() != fDetElemId )
119 {
120 AliError("Something is seriously wrong with DE. Aborting clustering");
121 return kFALSE;
122 }
123 }
124
125 AliMUONPad mpad(fDetElemId,cathode,
126 ix,iy,pad.Position().X(),pad.Position().Y(),
127 pad.Dimensions().X(),pad.Dimensions().Y(),
128 d->Charge());
129 if ( d->IsSaturated() ) mpad.SetSaturated(kTRUE);
130 new (padArray[padArray.GetLast()+1]) AliMUONPad(mpad);
131 }
132 if ( fPads[0]->GetLast() < 0 && fPads[1]->GetLast() < 0 )
133 {
134 // no pad at all, nothing to do...
135 return kFALSE;
136 }
137
138 return kTRUE;
139}
140
141//_____________________________________________________________________________
142void
143AliMUONPreClusterFinderV2::AddPad(AliMUONCluster& cluster, AliMUONPad* pad)
144{
145 /// Add a pad to a cluster
146
147 cluster.AddPad(*pad);
148 pad->SetClusterId(cluster.GetUniqueID());
149
150 Int_t cathode = pad->Cathode();
151 TClonesArray& padArray = *fPads[cathode];
152 padArray.Remove(pad);
153 TIter next(&padArray);
154
155 // Check neighbours
156 TObjArray neighbours;
157 AliMpPad p = fSegmentations[pad->Cathode()]->PadByIndices(AliMpIntPair(pad->Ix(),pad->Iy()),kTRUE);
158 Int_t nn = fSegmentations[pad->Cathode()]->GetNeighbours(p,neighbours);
159 for (Int_t in = 0; in < nn; ++in)
160 {
161 AliMpPad* p = static_cast<AliMpPad*>(neighbours.At(in));
162
163 TIter next(&padArray);
164 AliMUONPad* p2;
165
166 while ( ( p2 = static_cast<AliMUONPad*>(next()) ) )
167 {
168 if ( !p2->IsUsed() && p2->Ix()==p->GetIndices().GetFirst()
169 && p2->Iy() == p->GetIndices().GetSecond() &&
170 p2->Cathode() == pad->Cathode() )
171 {
172 AddPad(cluster,p2);
173 }
174 }
175 } // for (Int_t in = 0;
176}
177
178namespace
179{
180//_____________________________________________________________________________
181Bool_t
182AreOverlapping(const AliMUONPad& pad, const AliMUONCluster& cluster)
183{
184 /// Whether the pad overlaps with the cluster
185
186 static Double_t precision = 1E-4; // cm
187 static TVector2 precisionAdjustment(precision,precision);//-precision,-precision);
188 for ( Int_t i = 0; i < cluster.Multiplicity(); ++i )
189 {
190 AliMUONPad* testPad = cluster.Pad(i);
191 // Note: we use negative precision numbers, meaning
192 // the area of the pads will be *increased* by these small numbers
193 // prior to check the overlap by the AreOverlapping method,
194 // so pads touching only by the corners will be considered as
195 // overlapping.
196 if ( AliMUONPad::AreOverlapping(*testPad,pad,precisionAdjustment) )
197 {
198 return kTRUE;
199 }
200 }
201 return kFALSE;
202}
203}
204
205//_____________________________________________________________________________
206AliMUONCluster*
207AliMUONPreClusterFinderV2::NextCluster()
208{
209 /// Builds the next cluster, and returns it.
210
211 // Start a new cluster
212 Int_t id = fClusters->GetLast()+1;
213 AliMUONCluster* cluster = new ((*fClusters)[id]) AliMUONCluster;
214 cluster->SetUniqueID(id);
215
216 AliMUONPad* pad;
217 TIter next(fPads[0]);
218 while ( ( pad = static_cast<AliMUONPad*>(next())) && pad->IsUsed() );
219
220 if (!pad) // protection against no pad in first cathode, which might happen
221 {
222 // try other cathode
223 TIter next(fPads[1]);
224 while ( ( pad = static_cast<AliMUONPad*>(next())) && pad->IsUsed() );
225 if (!pad)
226 {
227 // we are done.
228 return 0x0;
229 }
230 // Builds (recursively) a cluster on second cathode only
231 AddPad(*cluster,pad);
232 }
233 else
234 {
235 // Builds (recursively) a cluster on first cathode only
236
237 AddPad(*cluster,pad);
238
239 // On the 2nd cathode, only add pads overlapping with the current cluster
240 TIter next1(fPads[1]);
241 AliMUONPad* testPad;
242
243 while ( ( testPad = static_cast<AliMUONPad*>(next1())))
244 {
245 if ( !testPad->IsUsed() && AreOverlapping(*testPad,*cluster) )
246 {
247 AddPad(*cluster,testPad);
248 }
249 }
250 }
251
252 if ( cluster->Multiplicity() <= 1 )
253 {
254 if ( cluster->Multiplicity() == 0 )
255 {
256 // no pad is suspicious
257 AliWarning("Got an empty cluster...");
258 }
259 // else only 1 pad (not suspicious, but kind of useless, probably noise)
260 // so we remove it from our list
261 fClusters->Remove(cluster);
262 fClusters->Compress();
263 // then proceed further
264 return NextCluster();
265 }
266
267 return cluster;
268}