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ffb1ee30 | 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 | // PID Response class for the TRD detector | |
17 | // Based on 1D Likelihood approach | |
18 | // Calculation of probabilities using Bayesian approach | |
19 | // Attention: This method is only used to separate electrons from pions | |
20 | // | |
21 | // Authors: | |
22 | // Markus Fasel <M.Fasel@gsi.de> | |
23 | // Anton Andronic <A.Andronic@gsi.de> | |
24 | // | |
25 | #include <TClass.h> | |
26 | #include <TAxis.h> | |
27 | #include <TFile.h> | |
28 | #include <TH1.h> | |
ce5d6908 | 29 | #include <TKey.h> |
ffb1ee30 | 30 | #include <TObjArray.h> |
31 | #include <TString.h> | |
ce5d6908 | 32 | #include <TROOT.h> |
ffb1ee30 | 33 | #include <TSystem.h> |
2ad33025 | 34 | #include <TDirectory.h> |
ffb1ee30 | 35 | |
36 | #include "AliLog.h" | |
37 | ||
38 | #include "AliTRDPIDResponse.h" | |
39 | ||
40 | ClassImp(AliTRDPIDResponse) | |
41 | ||
42 | const Double_t AliTRDPIDResponse::fgkPBins[kNPBins] = {1, 2, 3, 4, 5, 6}; | |
43 | ||
44 | //____________________________________________________________ | |
45 | AliTRDPIDResponse::AliTRDPIDResponse(const Char_t * filename): | |
46 | TObject() | |
47 | ,fReferences(NULL) | |
ce5d6908 | 48 | ,fGainNormalisationFactor(1.) |
ffb1ee30 | 49 | ,fPIDmethod(2) |
50 | { | |
51 | // | |
52 | // Default constructor | |
53 | // | |
ce5d6908 | 54 | for(Int_t ispec = 0; ispec < AliPID::kSPECIES; ispec++) |
55 | for(Int_t ipbin = 0; ipbin < kNPBins; ipbin++) | |
56 | fMapRefHists[ispec][ipbin] = -1; | |
57 | Load(filename); | |
ffb1ee30 | 58 | } |
59 | ||
60 | //____________________________________________________________ | |
61 | AliTRDPIDResponse::AliTRDPIDResponse(const AliTRDPIDResponse &ref): | |
62 | TObject(ref) | |
63 | ,fReferences(ref.fReferences) | |
ce5d6908 | 64 | ,fGainNormalisationFactor(ref.fGainNormalisationFactor) |
ffb1ee30 | 65 | ,fPIDmethod(ref.fPIDmethod) |
66 | { | |
67 | // | |
68 | // Copy constructor | |
69 | // Flat copy of the reference histos | |
70 | // For creating a deep copy call SetOwner | |
71 | // | |
ce5d6908 | 72 | Int_t size = (AliPID::kSPECIES)*(kNPBins); |
338c9979 | 73 | memcpy(fMapRefHists, ref.fMapRefHists, sizeof(Double_t) * size); |
ffb1ee30 | 74 | } |
75 | ||
76 | //____________________________________________________________ | |
77 | AliTRDPIDResponse &AliTRDPIDResponse::operator=(const AliTRDPIDResponse &ref){ | |
78 | // | |
79 | // Assignment operator | |
80 | // Performs a flat copy of the reference histos | |
81 | // | |
82 | if(this == &ref) return *this; | |
83 | ||
84 | // Make copy | |
85 | TObject::operator=(ref); | |
86 | if(IsOwner()){ | |
87 | if(fReferences){ | |
88 | fReferences->Delete(); | |
89 | delete fReferences; | |
90 | } | |
91 | SetBit(kIsOwner, kFALSE); | |
f59c1465 | 92 | } else if(fReferences) delete fReferences; |
ffb1ee30 | 93 | fReferences = ref.fReferences; |
ce5d6908 | 94 | Int_t size = (AliPID::kSPECIES)*(kNPBins); |
338c9979 | 95 | memcpy(fMapRefHists, ref.fMapRefHists, sizeof(Double_t) * size); |
ffb1ee30 | 96 | fPIDmethod = ref.fPIDmethod; |
97 | ||
98 | return *this; | |
99 | } | |
100 | ||
101 | //____________________________________________________________ | |
102 | AliTRDPIDResponse::~AliTRDPIDResponse(){ | |
103 | // | |
104 | // Destructor | |
105 | // | |
f59c1465 | 106 | if(IsOwner()){ |
107 | // Destroy histos | |
108 | if(fReferences) fReferences->Delete(); | |
ffb1ee30 | 109 | } |
f59c1465 | 110 | if(fReferences) delete fReferences; |
ffb1ee30 | 111 | } |
112 | ||
113 | //____________________________________________________________ | |
114 | Bool_t AliTRDPIDResponse::Load(const Char_t * filename){ | |
115 | // | |
116 | // Load References into the toolkit | |
117 | // | |
2ad33025 | 118 | |
119 | TDirectory *owd = gDirectory;// store old working directory | |
120 | ||
ffb1ee30 | 121 | if(!filename) |
122 | filename = Form("%s/STEER/LQ1dRef_v1.root",gSystem->ExpandPathName("$ALICE_ROOT")); | |
123 | TFile *in = TFile::Open(filename); | |
124 | if(!in){ | |
125 | AliError("Ref file not available."); | |
126 | return kFALSE; | |
127 | } | |
128 | ||
ce5d6908 | 129 | gROOT->cd(); |
ffb1ee30 | 130 | fReferences = new TObjArray(); |
131 | fReferences->SetOwner(); | |
132 | TIter iter(in->GetListOfKeys()); | |
ce5d6908 | 133 | TKey *histkey = NULL; |
ffb1ee30 | 134 | TObject *tmp = NULL; |
135 | Int_t arrayPos = 0, pbin = 0; | |
136 | AliPID::EParticleType species; | |
137 | TString histname; | |
ce5d6908 | 138 | while((histkey = dynamic_cast<TKey *>(iter()))){ |
139 | tmp = histkey->ReadObj(); | |
ffb1ee30 | 140 | histname = tmp->GetName(); |
141 | if(histname.BeginsWith("fHQel")){ // Electron histogram | |
142 | histname.ReplaceAll("fHQel_p",""); | |
143 | species = AliPID::kElectron; | |
144 | } else { // Pion histogram | |
145 | histname.ReplaceAll("fHQpi_p",""); | |
146 | species = AliPID::kPion; | |
147 | } | |
ce5d6908 | 148 | pbin = histname.Atoi() - 1; |
1bbef4ba | 149 | AliDebug(1, Form("Species %d, Histname %s, Pbin %d, Position in container %d", species, histname.Data(), pbin, arrayPos)); |
ffb1ee30 | 150 | fMapRefHists[species][pbin] = arrayPos; |
ce5d6908 | 151 | fReferences->AddAt(new TH1F(*dynamic_cast<TH1F *>(tmp)), arrayPos); |
ffb1ee30 | 152 | arrayPos++; |
153 | } | |
154 | in->Close(); | |
2ad33025 | 155 | owd->cd(); |
ffb1ee30 | 156 | AliDebug(2, Form("Successfully loaded %d Reference Histograms", arrayPos)); |
f59c1465 | 157 | SetBit(kIsOwner, kTRUE); |
ffb1ee30 | 158 | delete in; |
159 | return kTRUE; | |
160 | } | |
161 | ||
162 | //____________________________________________________________ | |
b439f460 | 163 | Bool_t AliTRDPIDResponse::GetResponse(Int_t n, Double_t *dedx, Float_t *p, Double_t prob[AliPID::kSPECIES], Bool_t kNorm) const |
ffb1ee30 | 164 | { |
165 | // | |
166 | // Calculate TRD likelihood values for the track based on dedx and | |
167 | // momentum values. The likelihoods are calculated by query the | |
168 | // reference data depending on the PID method selected | |
169 | // | |
170 | // Input parameter : | |
171 | // n - number of dedx slices/chamber | |
172 | // dedx - array of dedx slices organized layer wise | |
173 | // p - array of momentum measurements organized layer wise | |
174 | // | |
175 | // Return parameters | |
176 | // prob - probabilities allocated by TRD for particle specis | |
177 | // kNorm - switch to normalize probabilities to 1. By default true. If false return not normalized prob. | |
178 | // | |
179 | // Return value | |
180 | // true if calculation success | |
181 | // | |
182 | ||
183 | if(!fReferences){ | |
184 | AliWarning("Missing reference data. PID calculation not possible."); | |
185 | return kFALSE; | |
186 | } | |
187 | ||
188 | for(Int_t is(AliPID::kSPECIES); is--;) prob[is]=.2; | |
189 | Double_t prLayer[AliPID::kSPECIES]; | |
ffb1ee30 | 190 | Double_t DE[10], s(0.); |
191 | for(Int_t il(kNlayer); il--;){ | |
1bbef4ba | 192 | memset(prLayer, 0, AliPID::kSPECIES*sizeof(Double_t)); |
ffb1ee30 | 193 | if(!CookdEdx(&dedx[il*n], &DE[0])) continue; |
194 | ||
195 | s=0.; | |
196 | for(Int_t is(AliPID::kSPECIES); is--;){ | |
1bbef4ba | 197 | if((DE[0] > 0.) && (p[il] > 0.)) prLayer[is] = GetProbabilitySingleLayer(is, p[il], DE[0]); |
ce5d6908 | 198 | AliDebug(3, Form("Probability for Species %d in Layer %d: %f", is, il, prLayer[is])); |
ffb1ee30 | 199 | s+=prLayer[is]; |
200 | } | |
201 | if(s<1.e-30){ | |
202 | AliDebug(2, Form("Null all species prob layer[%d].", il)); | |
203 | continue; | |
204 | } | |
205 | for(Int_t is(AliPID::kSPECIES); is--;){ | |
206 | if(kNorm) prLayer[is] /= s; | |
207 | prob[is] *= prLayer[is]; | |
208 | } | |
209 | } | |
210 | if(!kNorm) return kTRUE; | |
211 | ||
212 | s=0.; | |
213 | for(Int_t is(AliPID::kSPECIES); is--;) s+=prob[is]; | |
214 | if(s<1.e-30){ | |
215 | AliDebug(2, "Null total prob."); | |
216 | return kFALSE; | |
217 | } | |
218 | for(Int_t is(AliPID::kSPECIES); is--;) prob[is]/=s; | |
219 | return kTRUE; | |
220 | } | |
221 | ||
222 | ||
223 | //____________________________________________________________ | |
b439f460 | 224 | Double_t AliTRDPIDResponse::GetProbabilitySingleLayer(Int_t species, Double_t plocal, Double_t dEdx) const { |
ffb1ee30 | 225 | // |
226 | // Get the non-normalized probability for a certain particle species as coming | |
227 | // from the reference histogram | |
228 | // Interpolation between momentum bins | |
229 | // | |
ce5d6908 | 230 | AliDebug(1, Form("Make Probability for Species %d with Momentum %f", species, plocal)); |
1bbef4ba | 231 | Int_t pbin = GetLowerMomentumBin(plocal); |
232 | AliDebug(1, Form("Bin %d", pbin)); | |
ffb1ee30 | 233 | Double_t pLayer = 0.; |
234 | // Do Interpolation exept for underflow and overflow | |
235 | if(pbin >= 0 && pbin < kNPBins-1){ | |
236 | TH1 *refHistUpper = NULL, *refHistLower = NULL; | |
1bbef4ba | 237 | if(fMapRefHists[species][pbin] >= 0) |
ce5d6908 | 238 | refHistLower = dynamic_cast<TH1 *>(fReferences->UncheckedAt(fMapRefHists[species][pbin])); |
1bbef4ba | 239 | if(fMapRefHists[species][pbin+1] >= 0) |
ce5d6908 | 240 | refHistUpper = dynamic_cast<TH1 *>(fReferences->UncheckedAt(fMapRefHists[species][pbin+1])); |
1bbef4ba | 241 | AliDebug(1, Form("Reference Histos (Upper/Lower): [%p|%p]", refHistUpper, refHistLower)); |
ffb1ee30 | 242 | |
338c9979 | 243 | if (refHistLower && refHistUpper ) { |
244 | Double_t pLower = refHistLower->GetBinContent(refHistLower->GetXaxis()->FindBin(dEdx)); | |
245 | Double_t pUpper = refHistUpper->GetBinContent(refHistUpper->GetXaxis()->FindBin(dEdx)); | |
ffb1ee30 | 246 | |
9590970b | 247 | pLayer = pLower + (pUpper - pLower)/(fgkPBins[pbin+1]-fgkPBins[pbin]) * (plocal - fgkPBins[pbin]); |
338c9979 | 248 | } |
ffb1ee30 | 249 | } |
250 | else{ | |
251 | TH1 *refHist = NULL; | |
252 | if(pbin < 0){ | |
253 | // underflow | |
ce5d6908 | 254 | if(fMapRefHists[species][0] >= 0){ |
255 | refHist = dynamic_cast<TH1 *>(fReferences->UncheckedAt(fMapRefHists[species][0])); | |
256 | } | |
ffb1ee30 | 257 | } else { |
258 | // overflow | |
ce5d6908 | 259 | if(fMapRefHists[species][kNPBins-1] > 0) |
260 | refHist = dynamic_cast<TH1 *>(fReferences->UncheckedAt(fMapRefHists[species][kNPBins-1])); | |
ffb1ee30 | 261 | } |
338c9979 | 262 | if (refHist) |
263 | pLayer = refHist->GetBinContent(refHist->GetXaxis()->FindBin(dEdx)); | |
ffb1ee30 | 264 | } |
ce5d6908 | 265 | AliDebug(1, Form("Probability %f", pLayer)); |
ffb1ee30 | 266 | return pLayer; |
267 | } | |
268 | ||
269 | //____________________________________________________________ | |
b439f460 | 270 | Int_t AliTRDPIDResponse::GetLowerMomentumBin(Double_t p) const { |
ffb1ee30 | 271 | // |
272 | // Get the momentum bin for a given momentum value | |
273 | // | |
274 | Int_t bin = -1; | |
275 | if(p > fgkPBins[kNPBins-1]) return kNPBins-1; | |
276 | for(Int_t ibin = 0; ibin < kNPBins - 1; ibin++){ | |
277 | if(p >= fgkPBins[ibin] && p < fgkPBins[ibin+1]){ | |
278 | bin = ibin; | |
279 | break; | |
280 | } | |
281 | } | |
282 | return bin; | |
283 | } | |
284 | ||
285 | //____________________________________________________________ | |
286 | void AliTRDPIDResponse::SetOwner(){ | |
287 | // | |
288 | // Make Deep Copy of the Reference Histograms | |
289 | // | |
290 | if(!fReferences || IsOwner()) return; | |
291 | TObjArray *ctmp = new TObjArray(); | |
292 | for(Int_t ien = 0; ien < fReferences->GetEntriesFast(); ien++) | |
293 | ctmp->AddAt(fReferences->UncheckedAt(ien)->Clone(), ien); | |
f59c1465 | 294 | delete fReferences; |
ffb1ee30 | 295 | fReferences = ctmp; |
296 | SetBit(kIsOwner, kTRUE); | |
297 | } | |
298 | ||
299 | //____________________________________________________________ | |
b439f460 | 300 | Bool_t AliTRDPIDResponse::CookdEdx(Double_t *in, Double_t *out) const |
ffb1ee30 | 301 | { |
302 | switch(fPIDmethod){ | |
303 | case 0: // NN | |
304 | break; | |
305 | case 1: // 2D LQ | |
306 | break; | |
307 | case 2: // 1D LQ | |
308 | out[0]= 0.; | |
ce5d6908 | 309 | for(Int_t islice = 0; islice < 8; islice++) out[0] += in[islice] * fGainNormalisationFactor; |
ffb1ee30 | 310 | if(out[0] < 1e-6) return kFALSE; |
311 | break; | |
312 | default: | |
313 | return kFALSE; | |
314 | } | |
315 | return kTRUE; | |
316 | } | |
317 |