4 // General implementation of a single cut strategy, which can be:
5 // - a value contained in a given interval [--> IsBetween() ]
6 // - a value equal to a given reference [--> MatchesValue()]
8 // In all cases, the reference value(s) is (are) given as data members
9 // and each kind of cut requires a given value type (Int, UInt, Double),
10 // but the cut check procedure is then automatized and chosen thanks to
11 // an enumeration of the implemented cut types.
12 // At the end, the user (or any other point which uses this object) has
13 // to use the method IsSelected() to check if this cut has been passed.
15 // authors: Martin Vala (martin.vala@cern.ch)
16 // Alberto Pulvirenti (alberto.pulvirenti@ct.infn.it)
20 #include "AliExternalTrackParam.h"
22 #include "AliRsnDaughter.h"
23 #include "AliRsnCutPID.h"
25 ClassImp(AliRsnCutPID)
27 //_________________________________________________________________________________________________
28 AliRsnCutPID::AliRsnCutPID() :
34 // Default constructor.
35 // Sets the cut to realistic PID with default weights,
36 // and defines the 'fMinI' value of the base class as the PID
37 // to which we want to compare this object.
42 for (i = 0; i < kDetectors; i++)
44 fUseDetector[i] = kFALSE;
45 fPtThreshold[i] = 0.0;
46 fGoAboveThreshold[i] = kTRUE;
49 for (i = 0; i < AliPID::kSPECIES; i++)
55 SetTargetType(AliRsnTarget::kDaughter);
58 //_________________________________________________________________________________________________
59 AliRsnCutPID::AliRsnCutPID(const char *name, AliPID::EParticleType pid, Double_t probMin, Bool_t perfectPID) :
60 AliRsnCut(name, AliRsnCut::kDaughter, (Int_t)pid),
65 // Default constructor.
66 // Sets the cut to realistic PID with default weights,
67 // and defines the 'fMinI' value of the base class as the PID
68 // to which we want to compare this object.
73 for (i = 0; i < kDetectors; i++)
75 fUseDetector[i] = kFALSE;
76 fPtThreshold[i] = 0.0;
77 fGoAboveThreshold[i] = kTRUE;
80 for (i = 0; i < AliPID::kSPECIES; i++)
89 SetTargetType(AliRsnTarget::kDaughter);
92 //_____________________________________________________________________________
93 Bool_t AliRsnCutPID::CheckThreshold(EDetector det, Double_t value)
96 // Checks if the passed value (track pT) stays in the
97 // interval where the detector should be accepted
100 if (!CheckBounds(det)) return kFALSE;
102 if (fGoAboveThreshold[det]) return (value >= fPtThreshold[det]);
103 else return (value <= fPtThreshold[det]);
106 //_________________________________________________________________________________________________
107 Bool_t AliRsnCutPID::ComputeWeights(AliRsnDaughter *daughter)
110 // Compute the PID weights using the class settings.
111 // If the argument is an ESD track, customized weights can be computed
112 // It the argument is a track (ESD or AOD), at least default weights
113 // can be computed, otherwise, no weights can be defined.
114 // The return value tells if the operation was successful.
118 Bool_t useDefault = fUseDefault;
119 Bool_t perfectPID = fPerfect;
120 if (perfectPID && !daughter->GetRefMC()) return kFALSE;
121 if (!daughter->GetRefESDtrack()) useDefault = kTRUE;
122 if (!daughter->GetRefESDtrack() && !daughter->GetRefAODtrack()) return kFALSE;
124 // if perfect PID ise required,
125 // compare the PDG code of the type stored in 'fMinI' of the cut
126 // and that of the particle which is checked, looking at its MC
129 i = TMath::Abs(AliPID::ParticleCode(fMinI));
130 j = daughter->GetPDG();
134 // if default weights are (or need to be) used,
135 // they are taken directly and function exits
138 if (daughter->GetRefESDtrack())
139 daughter->GetRefESDtrack()->GetESDpid(fWeight);
142 for (i = 0; i < AliPID::kSPECIES; i++)
143 fWeight[i] = daughter->GetRefAODtrack()->PID()[i];
148 // if we arrive here, this means that we have an ESD track
149 // and we want to customize the PID
150 AliESDtrack *track = daughter->GetRefESDtrack();
151 Double_t w[kDetectors][AliPID::kSPECIES];
152 track->GetITSpid(w[kITS]);
153 track->GetTPCpid(w[kTPC]);
154 track->GetTRDpid(w[kTRD]);
155 track->GetTOFpid(w[kTOF]);
156 track->GetHMPIDpid(w[kHMPID]);
158 // if a detector is excluded or the track has not the right pT
159 // all related weights are set to 1 in order not to contribute
160 // to final multiplication
161 for (i = 0; i < kDetectors; i++)
163 if (!fUseDetector[i] || !CheckThreshold((EDetector)i, track->Pt()))
165 for (j = 0; j < AliPID::kSPECIES; j++) {
171 // multiplicate all weights to compute final one
172 for (i = 0; i < AliPID::kSPECIES; i++)
174 fWeight[i] = w[kITS][i] * w[kTPC][i] * w[kTRD][i] * w[kTOF][i] * w[kHMPID][i];
180 //_________________________________________________________________________________________________
181 Int_t AliRsnCutPID::RealisticPID(AliRsnDaughter * const daughter, Double_t &prob)
184 // Combines the weights collected from chosen detectors with the priors
185 // and gives the corresponding particle with the largest probability,
186 // in terms of the AliPID particle type enumeration.
187 // The argument, passed by reference, gives the corresponding probability,
188 // since the cut could require that it is larger than a threshold.
191 // try to compute the weights
192 if (!ComputeWeights(daughter))
195 return AliPID::kUnknown;
198 // combine with priors and normalize
200 Double_t sum = 0.0, w[AliPID::kSPECIES];
201 for (i = 0; i < AliPID::kSPECIES; i++)
203 w[i] = fWeight[i] * fPrior[i];
210 return AliPID::kUnknown;
212 for (i = 0; i < AliPID::kSPECIES; i++) w[i] /= sum;
214 // find the largest probability and related PID
217 for (i = 1; i < AliPID::kSPECIES; i++)
226 // return the value, while the probability
227 // will be consequentially set
231 //_________________________________________________________________________________________________
232 Int_t AliRsnCutPID::PerfectPID(AliRsnDaughter * const daughter)
235 // If MC is present, retrieve the particle corresponding to the used track
236 // (using the fRefMC data member) and then return the true particle type
237 // taken from the PDG code of the reference particle itself, converted
238 // into the enumeration from AliPID object.
241 // works only if the MC is present
242 if (!daughter->GetRefMC()) return AliPID::kUnknown;
244 // get the PDG code of the particle
245 Int_t pdg = daughter->GetPDG();
247 // loop over all species listed in AliPID to find the match
249 for (i = 0; i < AliPID::kSPECIES; i++)
251 if (AliPID::ParticleCode(i) == pdg) return i;
254 return AliPID::kUnknown;
257 //_________________________________________________________________________________________________
258 Bool_t AliRsnCutPID::IsSelected(TObject *object)
264 // convert the object into the unique correct type
266 if (!TargetOK(object))
268 AliError(Form("[%s]: this cut works only with AliRsnDaughter objects", GetName()));
272 // if target is OK, do a dynamic cast
273 AliRsnDaughter *daughter = dynamic_cast<AliRsnDaughter*>(object);
275 // depending on the PID type, recalls the appropriate method:
276 // in case of perfect PID, checks only if the PID type is
277 // corresponding to the request in the cut (fMinI)
278 // while in case of realistic PID checks also the probability
279 // to be within the required interval
282 fCutValueI = PerfectPID(daughter);
287 fCutValueI = RealisticPID(daughter, fCutValueD);
288 return OkValueI() && OkRangeD();
292 //__________________________________________________________________________________________________
293 void AliRsnCutPID::IncludeDetector(EDetector det, Double_t threshold, Bool_t goAbove)
296 // Include a detector for a customized weight computing
297 // and specify also its eventual threshold and if the detector
298 // must be used above or below the threshold.
299 // By default the threshold is zero and detector is always used.
302 if (!CheckBounds(det)) return;
304 fUseDetector[det] = kTRUE;
305 fPtThreshold[det] = threshold;
306 fGoAboveThreshold[det] = goAbove;