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e036a7af | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
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 "AliMUONClusterFinderSimpleFit.h" | |
19 | ||
20 | #include "AliLog.h" | |
21 | #include "AliMpDEManager.h" | |
22 | #include "AliMpStationType.h" | |
23 | #include "AliMUONCluster.h" | |
24 | #include "AliMUONConstants.h" | |
3887d11e | 25 | #include "AliMUONVDigit.h" |
e036a7af | 26 | #include "AliMUONMathieson.h" |
27 | #include "AliMUONPad.h" | |
e036a7af | 28 | #include "AliMpArea.h" |
29 | #include "TClonesArray.h" | |
30 | #include "TObjArray.h" | |
31 | #include "TVector2.h" | |
32 | #include "TVirtualFitter.h" | |
33 | #include "TF1.h" | |
3887d11e | 34 | #include "AliMUONVDigitStore.h" |
35 | #include <Riostream.h> | |
e036a7af | 36 | |
37 | /// \class AliMUONClusterFinderSimpleFit | |
38 | /// | |
39 | /// Basic cluster finder | |
40 | /// | |
41 | /// We simply use AliMUONPreClusterFinder to get basic cluster, | |
42 | /// and then we try to fit the charge repartition using a Mathieson | |
43 | /// distribution, varying the position. | |
44 | /// | |
45 | /// FIXME: this one is still at the developping stage... | |
46 | /// | |
47 | /// \author Laurent Aphecetche | |
48 | ||
78649106 | 49 | /// \cond CLASSIMP |
e036a7af | 50 | ClassImp(AliMUONClusterFinderSimpleFit) |
51 | /// \endcond | |
52 | ||
53 | namespace | |
54 | { | |
55 | //___________________________________________________________________________ | |
56 | void | |
57 | FitFunction(Int_t& /*notused*/, Double_t* /*notused*/, | |
58 | Double_t& f, Double_t* par, | |
59 | Int_t /*notused*/) | |
60 | { | |
61 | /// Chi2 Function to minimize: Mathieson charge distribution in 2 dimensions | |
62 | ||
63 | TObjArray* userObjects = static_cast<TObjArray*>(TVirtualFitter::GetFitter()->GetObjectFit()); | |
64 | ||
65 | AliMUONCluster* cluster = static_cast<AliMUONCluster*>(userObjects->At(0)); | |
66 | AliMUONMathieson* mathieson = static_cast<AliMUONMathieson*>(userObjects->At(1)); | |
67 | ||
68 | f = 0.0; | |
69 | Float_t qTot = cluster->Charge(); | |
32074b02 | 70 | // Float_t chargeCorrel[] = { cluster->Charge(0)/qTot, cluster->Charge(1)/qTot }; |
71 | // Float_t qRatio[] = { 1.0/par[2], par[2] }; | |
e036a7af | 72 | |
73 | for ( Int_t i = 0 ; i < cluster->Multiplicity(); ++i ) | |
74 | { | |
75 | AliMUONPad* pad = cluster->Pad(i); | |
76 | // skip pads w/ saturation or other problem(s) | |
77 | if ( pad->Status() ) continue; | |
ff331318 | 78 | TVector2 lowerLeft = TVector2(par[0],par[1]) - pad->Position() - pad->Dimensions(); |
e036a7af | 79 | TVector2 upperRight(lowerLeft + pad->Dimensions()*2.0); |
32074b02 | 80 | Float_t estimatedCharge = mathieson->IntXY(lowerLeft.X(),lowerLeft.Y(), |
81 | upperRight.X(),upperRight.Y()); | |
82 | // estimatedCharge *= 2/(1+qRatio[pad->Cathode()]); | |
83 | Float_t actualCharge = pad->Charge()/qTot; | |
e036a7af | 84 | |
85 | Float_t delta = (estimatedCharge - actualCharge); | |
86 | ||
32074b02 | 87 | f += delta*delta; |
e036a7af | 88 | } |
89 | } | |
90 | } | |
91 | ||
92 | //_____________________________________________________________________________ | |
b1a19e07 | 93 | AliMUONClusterFinderSimpleFit::AliMUONClusterFinderSimpleFit(AliMUONVClusterFinder* clusterFinder) |
e036a7af | 94 | : AliMUONVClusterFinder(), |
b1a19e07 | 95 | fClusterFinder(clusterFinder), |
e036a7af | 96 | fMathieson(0x0) |
97 | { | |
98 | /// ctor | |
99 | } | |
100 | ||
101 | //_____________________________________________________________________________ | |
102 | AliMUONClusterFinderSimpleFit::~AliMUONClusterFinderSimpleFit() | |
103 | { | |
104 | /// dtor | |
105 | delete fClusterFinder; | |
106 | delete fMathieson; | |
107 | } | |
108 | ||
109 | //_____________________________________________________________________________ | |
110 | Bool_t | |
111 | AliMUONClusterFinderSimpleFit::Prepare(const AliMpVSegmentation* segmentations[2], | |
3887d11e | 112 | const AliMUONVDigitStore& digitStore) |
e036a7af | 113 | { |
114 | /// Prepare for clustering | |
115 | ||
116 | // FIXME: should we get the Mathieson from elsewhere ? | |
117 | ||
118 | // Find out the DetElemId | |
119 | Int_t detElemId(-1); | |
120 | ||
3887d11e | 121 | TIter next(digitStore.CreateIterator()); |
122 | AliMUONVDigit* d = static_cast<AliMUONVDigit*>(next()); | |
123 | ||
124 | if (d) | |
e036a7af | 125 | { |
3887d11e | 126 | detElemId = d->DetElemId(); |
e036a7af | 127 | } |
3887d11e | 128 | else |
e036a7af | 129 | { |
3887d11e | 130 | AliWarning("Could not find DE. Probably no digits at all : here's the digitStore :"); |
131 | StdoutToAliWarning(digitStore.Print();); | |
e036a7af | 132 | return kFALSE; |
133 | } | |
134 | ||
866c3232 | 135 | AliMp::StationType stationType = AliMpDEManager::GetStationType(detElemId); |
e036a7af | 136 | |
137 | Float_t kx3 = AliMUONConstants::SqrtKx3(); | |
138 | Float_t ky3 = AliMUONConstants::SqrtKy3(); | |
139 | Float_t pitch = AliMUONConstants::Pitch(); | |
140 | ||
866c3232 | 141 | if ( stationType == AliMp::kStation1 ) |
e036a7af | 142 | { |
143 | kx3 = AliMUONConstants::SqrtKx3St1(); | |
144 | ky3 = AliMUONConstants::SqrtKy3St1(); | |
145 | pitch = AliMUONConstants::PitchSt1(); | |
146 | } | |
147 | ||
148 | delete fMathieson; | |
149 | fMathieson = new AliMUONMathieson; | |
150 | ||
151 | fMathieson->SetPitch(pitch); | |
152 | fMathieson->SetSqrtKx3AndDeriveKx2Kx4(kx3); | |
153 | fMathieson->SetSqrtKy3AndDeriveKy2Ky4(ky3); | |
154 | ||
3887d11e | 155 | return fClusterFinder->Prepare(segmentations,digitStore); |
e036a7af | 156 | } |
157 | ||
158 | //_____________________________________________________________________________ | |
159 | AliMUONCluster* | |
160 | AliMUONClusterFinderSimpleFit::NextCluster() | |
161 | { | |
162 | /// Returns next cluster | |
163 | ||
164 | if ( !fClusterFinder ) return 0x0; | |
165 | AliMUONCluster* cluster = fClusterFinder->NextCluster(); | |
166 | if ( cluster ) | |
167 | { | |
168 | ComputePosition(*cluster); | |
169 | ||
170 | if ( cluster->Charge() < 7 ) | |
171 | { | |
172 | // skip that one | |
173 | return NextCluster(); | |
174 | } | |
175 | } | |
176 | return cluster; | |
177 | } | |
178 | ||
179 | //_____________________________________________________________________________ | |
180 | void | |
181 | AliMUONClusterFinderSimpleFit::ComputePosition(AliMUONCluster& cluster) | |
182 | { | |
183 | /// Compute the position of the given cluster, by fitting a Mathieson | |
184 | /// charge distribution to it | |
185 | ||
186 | TVirtualFitter* fitter = TVirtualFitter::Fitter(0,2); | |
187 | fitter->SetFCN(FitFunction); | |
188 | ||
189 | if ( cluster.Multiplicity() < 3 ) return; | |
190 | ||
191 | // We try a Mathieson fit, starting | |
192 | // with the center-of-gravity estimate as a first guess | |
193 | // for the cluster center. | |
194 | ||
195 | Double_t xCOG = cluster.Position().X(); | |
196 | Double_t yCOG = cluster.Position().Y(); | |
197 | ||
198 | Float_t stepX = 0.01; // cm | |
199 | Float_t stepY = 0.01; // cm | |
200 | ||
32074b02 | 201 | Double_t arg(-1); // disable printout |
e036a7af | 202 | |
32074b02 | 203 | fitter->ExecuteCommand("SET PRINT",&arg,1); |
e036a7af | 204 | |
205 | fitter->SetParameter(0,"cluster X position",xCOG,stepX,0,0); | |
206 | fitter->SetParameter(1,"cluster Y position",yCOG,stepY,0,0); | |
e036a7af | 207 | |
208 | TObjArray userObjects; | |
209 | ||
210 | userObjects.Add(&cluster); | |
211 | userObjects.Add(fMathieson); | |
212 | ||
e036a7af | 213 | fitter->SetObjectFit(&userObjects); |
214 | ||
32074b02 | 215 | Int_t val = fitter->ExecuteCommand("MIGRAD",0,0); |
216 | AliDebug(1,Form("ExecuteCommand returned value=%d",val)); | |
217 | if ( val ) | |
218 | { | |
219 | // fit failed. Using COG results, with big errors | |
220 | AliWarning("Fit failed. Using COG results for cluster="); | |
221 | StdoutToAliWarning(cluster.Print()); | |
222 | cluster.SetPosition(TVector2(xCOG,yCOG),TVector2(TMath::Abs(xCOG),TMath::Abs(yCOG))); | |
223 | cluster.SetChi2(1E3); | |
224 | } | |
e036a7af | 225 | |
226 | Double_t results[] = { fitter->GetParameter(0), | |
227 | fitter->GetParameter(1) }; | |
228 | ||
229 | Double_t errors[] = { fitter->GetParError(0), | |
230 | fitter->GetParError(1) }; | |
231 | ||
232 | cluster.SetPosition(TVector2(results[0],results[1]), | |
233 | TVector2(errors[0],errors[1])); | |
234 | ||
32074b02 | 235 | Double_t amin, edm, errdef; |
236 | Int_t nvpar, nparx; | |
237 | ||
238 | fitter->GetStats(amin, edm, errdef, nvpar, nparx); | |
239 | ||
240 | Double_t chi2 = amin; | |
e036a7af | 241 | |
32074b02 | 242 | AliDebug(1,Form("Cluster fitted to (x,y)=(%e,%e) (xerr,yerr)=(%e,%e) \n chi2=%e ndf=%d", |
e036a7af | 243 | results[0],results[1], |
32074b02 | 244 | errors[0],errors[1],chi2,fitter->GetNumberFreeParameters())); |
245 | cluster.SetChi2(chi2); | |
e036a7af | 246 | } |
247 | ||
248 | ||
249 |