Protection for connected event in destructor.
[u/mrichter/AliRoot.git] / TRD / AliTRDpidESD.cxx
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b0f03c34 1/**************************************************************************
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4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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14 **************************************************************************/
15
dab811d0 16/* $Id$ */
17
b52cb1b6 18////////////////////////////////////////////////////////////////////////////
19// //
20// Implementation of the TRD PID class //
21// //
22// Assigns the electron and pion likelihoods to each ESD track. //
c8ab4518 23// The function MakePID(AliESDEvent *event) calculates the probability //
b52cb1b6 24// of having dedx and a maximum timbin at a given //
25// momentum (mom) and particle type k //
26// from the precalculated distributions. //
27// //
dab811d0 28// Authors : //
c8ab4518 29// Prashant Shukla <shukla@pi0.physi.uni-heidelberg.de> (orig. version) //
30// Alex Bercuci (a.bercuci@gsi.de) //
b52cb1b6 31// //
32////////////////////////////////////////////////////////////////////////////
b0f03c34 33
b52cb1b6 34#include "AliLog.h"
af885e0f 35#include "AliESDEvent.h"
b0f03c34 36#include "AliESDtrack.h"
c6011b06 37#include "AliTracker.h"
c8ab4518 38#include "AliRun.h"
b52cb1b6 39
40#include "AliTRDpidESD.h"
41#include "AliTRDgeometry.h"
cc7cef99 42#include "AliTRDcalibDB.h"
dab811d0 43#include "AliTRDtrack.h"
720a0a16 44#include "Cal/AliTRDCalPID.h"
b0f03c34 45
46ClassImp(AliTRDpidESD)
47
c8ab4518 48Bool_t AliTRDpidESD::fgCheckTrackStatus = kTRUE;
49Bool_t AliTRDpidESD::fgCheckKinkStatus = kFALSE;
50Int_t AliTRDpidESD::fgMinPlane = 0;
df34b21e 51
b52cb1b6 52//_____________________________________________________________________________
dab811d0 53AliTRDpidESD::AliTRDpidESD()
c8ab4518 54 :TObject()
55 ,fTrack(0x0)
b0f03c34 56{
57 //
b52cb1b6 58 // Default constructor
b0f03c34 59 //
b52cb1b6 60
b0f03c34 61}
62
b52cb1b6 63//_____________________________________________________________________________
dab811d0 64AliTRDpidESD::AliTRDpidESD(const AliTRDpidESD &p)
c8ab4518 65 :TObject(p)
66 ,fTrack(0x0)
eab5961e 67{
b0f03c34 68 //
b52cb1b6 69 // AliTRDpidESD copy constructor
b0f03c34 70 //
eab5961e 71
b52cb1b6 72 ((AliTRDpidESD &) p).Copy(*this);
73
74}
75
76//_____________________________________________________________________________
c6011b06 77AliTRDpidESD::~AliTRDpidESD()
78{
79 //
80 // Destructor
81 //
c8ab4518 82
83 if(fTrack) delete fTrack;
84
c6011b06 85}
86
87//_____________________________________________________________________________
b52cb1b6 88AliTRDpidESD &AliTRDpidESD::operator=(const AliTRDpidESD &p)
89{
90 //
91 // Assignment operator
92 //
93
94 if (this != &p) ((AliTRDpidESD &) p).Copy(*this);
95 return *this;
96
97}
98
99//_____________________________________________________________________________
100void AliTRDpidESD::Copy(TObject &p) const
101{
102 //
103 // Copy function
104 //
105
c8ab4518 106 ((AliTRDpidESD &) p).fgCheckTrackStatus = fgCheckTrackStatus;
107 ((AliTRDpidESD &) p).fgCheckKinkStatus = fgCheckKinkStatus;
108 ((AliTRDpidESD &) p).fgMinPlane = fgMinPlane;
c6011b06 109 ((AliTRDpidESD &) p).fTrack = 0x0;
110
b0f03c34 111}
112
b52cb1b6 113//_____________________________________________________________________________
af885e0f 114Int_t AliTRDpidESD::MakePID(AliESDEvent *event)
b0f03c34 115{
116 //
b52cb1b6 117 // This function calculates the PID probabilities based on TRD signals
b0f03c34 118 //
dab811d0 119 // The method produces probabilities based on the charge
120 // and the position of the maximum time bin in each layer.
121 // The dE/dx information can be used as global charge or 2 to 3
720a0a16 122 // slices. Check AliTRDCalPID and AliTRDCalPIDRefMaker for the actual
dab811d0 123 // implementation.
124 //
125 // Author
126 // Alex Bercuci (A.Bercuci@gsi.de) 2nd May 2007
c8ab4518 127 //
dab811d0 128
129 AliTRDcalibDB *calibration = AliTRDcalibDB::Instance();
130 if (!calibration) {
131 AliErrorGeneral("AliTRDpidESD::MakePID()"
132 ,"No access to calibration data");
133 return -1;
134 }
135
136 // Retrieve the CDB container class with the probability distributions
44dbae42 137 const AliTRDCalPID *pd = calibration->GetPIDObject(1);
dab811d0 138 if (!pd) {
139 AliErrorGeneral("AliTRDpidESD::MakePID()"
720a0a16 140 ,"No access to AliTRDCalPID");
dab811d0 141 return -1;
b52cb1b6 142 }
143
dab811d0 144 // Loop through all ESD tracks
145 Double_t p[10];
146 AliESDtrack *t = 0x0;
c6011b06 147 Float_t dedx[AliTRDtrack::kNslice], dEdx;
148 Int_t timebin;
149 Float_t mom, length;
150 Int_t nPlanePID;
dab811d0 151 for (Int_t i=0; i<event->GetNumberOfTracks(); i++) {
152 t = event->GetTrack(i);
c6011b06 153
dab811d0 154 // Check track
155 if(!CheckTrack(t)) continue;
c6011b06 156
dab811d0 157
158 // Skip tracks which have no TRD signal at all
159 if (t->GetTRDsignal() == 0.) continue;
160
161 // Loop over detector layers
c6011b06 162 mom = 0.;
163 length = 0.;
dab811d0 164 nPlanePID = 0;
c8ab4518 165 for (Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++)
166 p[iSpecies] = 1./AliPID::kSPECIES;
167
053767a4 168 for (Int_t iLayer = 0; iLayer < AliTRDgeometry::kNlayer; iLayer++) {
dab811d0 169 // read data for track segment
170 for(int iSlice=0; iSlice<AliTRDtrack::kNslice; iSlice++)
053767a4 171 dedx[iSlice] = t->GetTRDslice(iLayer, iSlice);
172 dEdx = t->GetTRDslice(iLayer, -1);
173 timebin = t->GetTRDTimBin(iLayer);
dab811d0 174
175 // check data
176 if ((dEdx <= 0.) || (timebin <= -1.)) continue;
177
178 // retrive kinematic info for this track segment
053767a4 179 if(!RecalculateTrackSegmentKine(t, iLayer, mom, length)){
c8b2a461 180 // information is not fully reliable especialy for length
181 // estimation. To be used in the future.
182 }
dab811d0 183
184 // this track segment has fulfilled all requierments
185 nPlanePID++;
c8b2a461 186
dab811d0 187 // Get the probabilities for the different particle species
188 for (Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++) {
053767a4 189 p[iSpecies] *= pd->GetProbability(iSpecies, mom, dedx, length, iLayer);
c6011b06 190 //p[iSpecies] *= pd->GetProbabilityT(iSpecies, mom, timebin);
dab811d0 191 }
192 }
c6011b06 193 if(nPlanePID == 0) continue;
194
dab811d0 195 // normalize probabilities
c6011b06 196 Double_t probTotal = 0.;
197 for (Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++) probTotal += p[iSpecies];
198 if(probTotal <= 0.){
c8ab4518 199 AliWarning(Form("The total probability (%e) over all species <= 0 in ESD track %d."
200 , probTotal, i));
201 AliWarning("This may be caused by some error in reference data.");
202 AliWarning("Calculation continues but results might be corrupted.");
c6011b06 203 continue;
204 }
205 for(Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++) p[iSpecies] /= probTotal;
dab811d0 206
207 // book PID to the track
208 t->SetTRDpid(p);
c6011b06 209 t->SetTRDpidQuality(nPlanePID);
dab811d0 210 }
211
212 return 0;
c8ab4518 213
dab811d0 214}
b52cb1b6 215
dab811d0 216//_____________________________________________________________________________
217Bool_t AliTRDpidESD::CheckTrack(AliESDtrack *t)
218{
219 //
220 // Check if track is eligible for PID calculations
221 //
222
223 // Check the ESD track status
c8ab4518 224 if (fgCheckTrackStatus) {
dab811d0 225 if (((t->GetStatus() & AliESDtrack::kTRDout ) == 0) &&
226 ((t->GetStatus() & AliESDtrack::kTRDrefit) == 0)) return kFALSE;
227 }
b52cb1b6 228
dab811d0 229 // Check for ESD kink tracks
c8ab4518 230 if (fgCheckKinkStatus && (t->GetKinkIndex(0) != 0)) return kFALSE;
b52cb1b6 231
dab811d0 232 return kTRUE;
c8ab4518 233
dab811d0 234}
b52cb1b6 235
dab811d0 236//_____________________________________________________________________________
c8ab4518 237Bool_t AliTRDpidESD::RecalculateTrackSegmentKine(AliESDtrack *esd
053767a4 238 , Int_t layer
c8ab4518 239 , Float_t &mom
240 , Float_t &length)
dab811d0 241{
242 //
243 // Retrive momentum "mom" and track "length" in TRD chamber from plane
244 // "plan" according to information stored in AliESDtrack "t".
c6011b06 245 //
246 // Origin
247 // Alex Bercuci (A.Bercuci@gsi.de)
c8ab4518 248 //
dab811d0 249
dab811d0 250 const Float_t kAmHalfWidth = AliTRDgeometry::AmThick() / 2.;
f162af62 251 const Float_t kDrWidth = AliTRDgeometry::DrThick();
053767a4 252 const Float_t kTime0 = AliTRDgeometry::GetTime0(layer);
dab811d0 253
c6011b06 254 // set initial length value to chamber height
255 length = 2 * kAmHalfWidth + kDrWidth;
dab811d0 256
c6011b06 257 // retrive track's outer param
258 const AliExternalTrackParam *op = esd->GetOuterParam();
259 if(!op){
260 mom = esd->GetP();
dab811d0 261 return kFALSE;
262 }
dab811d0 263
c6011b06 264 AliExternalTrackParam *param = 0x0;
265 if(!fTrack){
266 fTrack = new AliExternalTrackParam(*op);
267 param = fTrack;
c8b2a461 268 } else param = new(fTrack) AliExternalTrackParam(*op);
269
c6011b06 270 // retrive the magnetic field
271 Double_t xyz0[3];
272 op->GetXYZ(xyz0);
273 Float_t field = AliTracker::GetBz(xyz0); // Bz in kG at point xyz0
c8b2a461 274 Double_t s, t;
275
c6011b06 276 // propagate to chamber entrance
277 if(!param->PropagateTo(kTime0-kAmHalfWidth-kDrWidth, field)){
c8b2a461 278 mom = op->GetP();
279 s = op->GetSnp();
280 t = op->GetTgl();
01d8ed58 281 if (s < 1.) length /= TMath::Sqrt((1. - s*s) / (1. + t*t));
c6011b06 282 return kFALSE;
283 }
284 mom = param->GetP();
c8b2a461 285 s = param->GetSnp();
286 t = param->GetTgl();
01d8ed58 287 if (s < 1.) length /= TMath::Sqrt((1. - s*s) / (1. + t*t));
c6011b06 288
289 // check if track is crossing tracking sector by propagating to chamber exit- maybe is too much :)
290 Double_t alpha = param->GetAlpha();
291 if(!param->PropagateTo(kTime0+kAmHalfWidth, field)) return kFALSE;
292
293 // mark track segments which are crossing SM boundaries along chamber
294 if(TMath::Abs(alpha-param->GetAlpha())>.01) return kFALSE;
295
dab811d0 296 return kTRUE;
dab811d0 297
c8ab4518 298}