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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 | |
3d1463c8 | 37 | //----------------------------------------------------------------------------- |
e036a7af | 38 | /// \class AliMUONClusterFinderSimpleFit |
39 | /// | |
40 | /// Basic cluster finder | |
41 | /// | |
42 | /// We simply use AliMUONPreClusterFinder to get basic cluster, | |
43 | /// and then we try to fit the charge repartition using a Mathieson | |
44 | /// distribution, varying the position. | |
45 | /// | |
46 | /// FIXME: this one is still at the developping stage... | |
47 | /// | |
48 | /// \author Laurent Aphecetche | |
3d1463c8 | 49 | //----------------------------------------------------------------------------- |
e036a7af | 50 | |
78649106 | 51 | /// \cond CLASSIMP |
e036a7af | 52 | ClassImp(AliMUONClusterFinderSimpleFit) |
53 | /// \endcond | |
54 | ||
55 | namespace | |
56 | { | |
57 | //___________________________________________________________________________ | |
58 | void | |
59 | FitFunction(Int_t& /*notused*/, Double_t* /*notused*/, | |
60 | Double_t& f, Double_t* par, | |
61 | Int_t /*notused*/) | |
62 | { | |
63 | /// Chi2 Function to minimize: Mathieson charge distribution in 2 dimensions | |
64 | ||
65 | TObjArray* userObjects = static_cast<TObjArray*>(TVirtualFitter::GetFitter()->GetObjectFit()); | |
66 | ||
67 | AliMUONCluster* cluster = static_cast<AliMUONCluster*>(userObjects->At(0)); | |
68 | AliMUONMathieson* mathieson = static_cast<AliMUONMathieson*>(userObjects->At(1)); | |
69 | ||
70 | f = 0.0; | |
71 | Float_t qTot = cluster->Charge(); | |
32074b02 | 72 | // Float_t chargeCorrel[] = { cluster->Charge(0)/qTot, cluster->Charge(1)/qTot }; |
73 | // Float_t qRatio[] = { 1.0/par[2], par[2] }; | |
e036a7af | 74 | |
75 | for ( Int_t i = 0 ; i < cluster->Multiplicity(); ++i ) | |
76 | { | |
77 | AliMUONPad* pad = cluster->Pad(i); | |
78 | // skip pads w/ saturation or other problem(s) | |
79 | if ( pad->Status() ) continue; | |
ff331318 | 80 | TVector2 lowerLeft = TVector2(par[0],par[1]) - pad->Position() - pad->Dimensions(); |
e036a7af | 81 | TVector2 upperRight(lowerLeft + pad->Dimensions()*2.0); |
32074b02 | 82 | Float_t estimatedCharge = mathieson->IntXY(lowerLeft.X(),lowerLeft.Y(), |
83 | upperRight.X(),upperRight.Y()); | |
84 | // estimatedCharge *= 2/(1+qRatio[pad->Cathode()]); | |
85 | Float_t actualCharge = pad->Charge()/qTot; | |
e036a7af | 86 | |
87 | Float_t delta = (estimatedCharge - actualCharge); | |
88 | ||
32074b02 | 89 | f += delta*delta; |
e036a7af | 90 | } |
91 | } | |
92 | } | |
93 | ||
94 | //_____________________________________________________________________________ | |
b1a19e07 | 95 | AliMUONClusterFinderSimpleFit::AliMUONClusterFinderSimpleFit(AliMUONVClusterFinder* clusterFinder) |
e036a7af | 96 | : AliMUONVClusterFinder(), |
b1a19e07 | 97 | fClusterFinder(clusterFinder), |
e036a7af | 98 | fMathieson(0x0) |
99 | { | |
100 | /// ctor | |
101 | } | |
102 | ||
103 | //_____________________________________________________________________________ | |
104 | AliMUONClusterFinderSimpleFit::~AliMUONClusterFinderSimpleFit() | |
105 | { | |
106 | /// dtor | |
107 | delete fClusterFinder; | |
108 | delete fMathieson; | |
109 | } | |
110 | ||
111 | //_____________________________________________________________________________ | |
112 | Bool_t | |
113 | AliMUONClusterFinderSimpleFit::Prepare(const AliMpVSegmentation* segmentations[2], | |
3887d11e | 114 | const AliMUONVDigitStore& digitStore) |
e036a7af | 115 | { |
116 | /// Prepare for clustering | |
117 | ||
118 | // FIXME: should we get the Mathieson from elsewhere ? | |
119 | ||
120 | // Find out the DetElemId | |
121 | Int_t detElemId(-1); | |
122 | ||
3887d11e | 123 | TIter next(digitStore.CreateIterator()); |
124 | AliMUONVDigit* d = static_cast<AliMUONVDigit*>(next()); | |
125 | ||
126 | if (d) | |
e036a7af | 127 | { |
3887d11e | 128 | detElemId = d->DetElemId(); |
e036a7af | 129 | } |
3887d11e | 130 | else |
e036a7af | 131 | { |
3887d11e | 132 | AliWarning("Could not find DE. Probably no digits at all : here's the digitStore :"); |
133 | StdoutToAliWarning(digitStore.Print();); | |
e036a7af | 134 | return kFALSE; |
135 | } | |
136 | ||
866c3232 | 137 | AliMp::StationType stationType = AliMpDEManager::GetStationType(detElemId); |
e036a7af | 138 | |
139 | Float_t kx3 = AliMUONConstants::SqrtKx3(); | |
140 | Float_t ky3 = AliMUONConstants::SqrtKy3(); | |
141 | Float_t pitch = AliMUONConstants::Pitch(); | |
142 | ||
866c3232 | 143 | if ( stationType == AliMp::kStation1 ) |
e036a7af | 144 | { |
145 | kx3 = AliMUONConstants::SqrtKx3St1(); | |
146 | ky3 = AliMUONConstants::SqrtKy3St1(); | |
147 | pitch = AliMUONConstants::PitchSt1(); | |
148 | } | |
149 | ||
150 | delete fMathieson; | |
151 | fMathieson = new AliMUONMathieson; | |
152 | ||
153 | fMathieson->SetPitch(pitch); | |
154 | fMathieson->SetSqrtKx3AndDeriveKx2Kx4(kx3); | |
155 | fMathieson->SetSqrtKy3AndDeriveKy2Ky4(ky3); | |
156 | ||
3887d11e | 157 | return fClusterFinder->Prepare(segmentations,digitStore); |
e036a7af | 158 | } |
159 | ||
160 | //_____________________________________________________________________________ | |
161 | AliMUONCluster* | |
162 | AliMUONClusterFinderSimpleFit::NextCluster() | |
163 | { | |
164 | /// Returns next cluster | |
165 | ||
166 | if ( !fClusterFinder ) return 0x0; | |
167 | AliMUONCluster* cluster = fClusterFinder->NextCluster(); | |
168 | if ( cluster ) | |
169 | { | |
170 | ComputePosition(*cluster); | |
171 | ||
172 | if ( cluster->Charge() < 7 ) | |
173 | { | |
174 | // skip that one | |
175 | return NextCluster(); | |
176 | } | |
177 | } | |
178 | return cluster; | |
179 | } | |
180 | ||
181 | //_____________________________________________________________________________ | |
182 | void | |
183 | AliMUONClusterFinderSimpleFit::ComputePosition(AliMUONCluster& cluster) | |
184 | { | |
185 | /// Compute the position of the given cluster, by fitting a Mathieson | |
186 | /// charge distribution to it | |
187 | ||
188 | TVirtualFitter* fitter = TVirtualFitter::Fitter(0,2); | |
189 | fitter->SetFCN(FitFunction); | |
190 | ||
191 | if ( cluster.Multiplicity() < 3 ) return; | |
192 | ||
193 | // We try a Mathieson fit, starting | |
194 | // with the center-of-gravity estimate as a first guess | |
195 | // for the cluster center. | |
196 | ||
197 | Double_t xCOG = cluster.Position().X(); | |
198 | Double_t yCOG = cluster.Position().Y(); | |
199 | ||
200 | Float_t stepX = 0.01; // cm | |
201 | Float_t stepY = 0.01; // cm | |
202 | ||
32074b02 | 203 | Double_t arg(-1); // disable printout |
e036a7af | 204 | |
32074b02 | 205 | fitter->ExecuteCommand("SET PRINT",&arg,1); |
e036a7af | 206 | |
207 | fitter->SetParameter(0,"cluster X position",xCOG,stepX,0,0); | |
208 | fitter->SetParameter(1,"cluster Y position",yCOG,stepY,0,0); | |
e036a7af | 209 | |
210 | TObjArray userObjects; | |
211 | ||
212 | userObjects.Add(&cluster); | |
213 | userObjects.Add(fMathieson); | |
214 | ||
e036a7af | 215 | fitter->SetObjectFit(&userObjects); |
216 | ||
32074b02 | 217 | Int_t val = fitter->ExecuteCommand("MIGRAD",0,0); |
218 | AliDebug(1,Form("ExecuteCommand returned value=%d",val)); | |
219 | if ( val ) | |
220 | { | |
221 | // fit failed. Using COG results, with big errors | |
222 | AliWarning("Fit failed. Using COG results for cluster="); | |
223 | StdoutToAliWarning(cluster.Print()); | |
224 | cluster.SetPosition(TVector2(xCOG,yCOG),TVector2(TMath::Abs(xCOG),TMath::Abs(yCOG))); | |
225 | cluster.SetChi2(1E3); | |
226 | } | |
e036a7af | 227 | |
228 | Double_t results[] = { fitter->GetParameter(0), | |
229 | fitter->GetParameter(1) }; | |
230 | ||
231 | Double_t errors[] = { fitter->GetParError(0), | |
232 | fitter->GetParError(1) }; | |
233 | ||
234 | cluster.SetPosition(TVector2(results[0],results[1]), | |
235 | TVector2(errors[0],errors[1])); | |
236 | ||
32074b02 | 237 | Double_t amin, edm, errdef; |
238 | Int_t nvpar, nparx; | |
239 | ||
240 | fitter->GetStats(amin, edm, errdef, nvpar, nparx); | |
241 | ||
242 | Double_t chi2 = amin; | |
e036a7af | 243 | |
32074b02 | 244 | AliDebug(1,Form("Cluster fitted to (x,y)=(%e,%e) (xerr,yerr)=(%e,%e) \n chi2=%e ndf=%d", |
e036a7af | 245 | results[0],results[1], |
32074b02 | 246 | errors[0],errors[1],chi2,fitter->GetNumberFreeParameters())); |
247 | cluster.SetChi2(chi2); | |
e036a7af | 248 | } |
249 | ||
250 | ||
251 |