| 006b5f7f |
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 | //------------------------------------------------------------------------- |
| 17 | // Implementation of the ITS track class |
| 18 | // |
| 19 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch |
| a9a2d814 |
20 | // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch |
| 006b5f7f |
21 | //------------------------------------------------------------------------- |
| 22 | |
| 23 | #include <TMatrixD.h> |
| 24 | |
| 25 | #include <TMath.h> |
| 006b5f7f |
26 | |
| 27 | #include "AliCluster.h" |
| 517b130f |
28 | #include "AliTPCtrack.h" |
| 83d73500 |
29 | #include "AliESDtrack.h" |
| 006b5f7f |
30 | #include "AliITStrackV2.h" |
| 31 | |
| 32 | ClassImp(AliITStrackV2) |
| 33 | |
| 7f6ddf58 |
34 | const Int_t kWARN=5; |
| 8676d691 |
35 | |
| 22b13da0 |
36 | //____________________________________________________________________________ |
| e6ba4672 |
37 | AliITStrackV2::AliITStrackV2():AliKalmanTrack(), |
| 22b13da0 |
38 | fX(0), |
| 39 | fAlpha(0), |
| 40 | fdEdx(0), |
| 41 | fP0(0), |
| 42 | fP1(0), |
| 43 | fP2(0), |
| 44 | fP3(0), |
| 45 | fP4(0), |
| 46 | fC00(0), |
| 47 | fC10(0), |
| 48 | fC11(0), |
| 49 | fC20(0), |
| 50 | fC21(0), |
| 51 | fC22(0), |
| 52 | fC30(0), |
| 53 | fC31(0), |
| 54 | fC32(0), |
| 55 | fC33(0), |
| 56 | fC40(0), |
| 57 | fC41(0), |
| 58 | fC42(0), |
| 59 | fC43(0), |
| 83d73500 |
60 | fC44(0), |
| babd135a |
61 | fNUsed(0), |
| 62 | fNSkipped(0), |
| 63 | fReconstructed(kFALSE), |
| 83d73500 |
64 | fESDtrack(0) |
| e6ba4672 |
65 | { |
| 22b13da0 |
66 | for(Int_t i=0; i<kMaxLayer; i++) fIndex[i]=0; |
| 67 | for(Int_t i=0; i<4; i++) fdEdxSample[i]=0; |
| babd135a |
68 | for(Int_t i=0; i<6; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0; fChi2MIP[i]=0;} |
| 22b13da0 |
69 | } |
| 83d73500 |
70 | |
| 006b5f7f |
71 | //____________________________________________________________________________ |
| e1a65e92 |
72 | AliITStrackV2::AliITStrackV2(const AliTPCtrack& t) throw (const Char_t *) : |
| 73 | AliKalmanTrack(t) { |
| 006b5f7f |
74 | //------------------------------------------------------------------ |
| 9b280d80 |
75 | //Conversion TPC track -> ITS track |
| 006b5f7f |
76 | //------------------------------------------------------------------ |
| 006b5f7f |
77 | SetChi2(0.); |
| 78 | SetNumberOfClusters(0); |
| 14825d5a |
79 | |
| 7f6ddf58 |
80 | fdEdx = t.GetdEdx(); |
| 81 | SetMass(t.GetMass()); |
| 82 | |
| 006b5f7f |
83 | fAlpha = t.GetAlpha(); |
| 84 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); |
| 85 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); |
| 86 | |
| 83d73500 |
87 | //Conversion of the track parameters |
| 88 | Double_t x,p[5]; t.GetExternalParameters(x,p); |
| 89 | fX=x; x=GetConvConst(); |
| 90 | fP0=p[0]; |
| 91 | fP1=p[1]; |
| 92 | fP2=p[2]; |
| 93 | fP3=p[3]; |
| 94 | fP4=p[4]/x; |
| 95 | |
| 96 | //Conversion of the covariance matrix |
| 97 | Double_t c[15]; t.GetExternalCovariance(c); |
| 98 | |
| 99 | fC00=c[0 ]; |
| 100 | fC10=c[1 ]; fC11=c[2 ]; |
| 101 | fC20=c[3 ]; fC21=c[4 ]; fC22=c[5 ]; |
| 102 | fC30=c[6 ]; fC31=c[7 ]; fC32=c[8 ]; fC33=c[9 ]; |
| 103 | fC40=c[10]/x; fC41=c[11]/x; fC42=c[12]/x; fC43=c[13]/x; fC44=c[14]/x/x; |
| 104 | |
| babd135a |
105 | for(Int_t i=0; i<6; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0;} |
| 106 | // |
| 83d73500 |
107 | if (!Invariant()) throw "AliITStrackV2: conversion failed !\n"; |
| 108 | |
| 109 | } |
| 110 | |
| 111 | //____________________________________________________________________________ |
| 67c3dcbe |
112 | AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c) throw (const Char_t *) : |
| 83d73500 |
113 | AliKalmanTrack() { |
| 114 | //------------------------------------------------------------------ |
| 67c3dcbe |
115 | // Conversion ESD track -> ITS track. |
| 116 | // If c==kTRUE, create the ITS track out of the constrained params. |
| 83d73500 |
117 | //------------------------------------------------------------------ |
| 118 | SetNumberOfClusters(t.GetITSclusters(fIndex)); |
| 119 | SetLabel(t.GetLabel()); |
| 120 | SetMass(t.GetMass()); |
| 121 | |
| 122 | fdEdx=t.GetITSsignal(); |
| 123 | fAlpha = t.GetAlpha(); |
| 124 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); |
| 125 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); |
| 126 | |
| 9b280d80 |
127 | //Conversion of the track parameters |
| 67c3dcbe |
128 | Double_t x,p[5]; |
| 129 | if (c) t.GetConstrainedExternalParameters(x,p); |
| 130 | else t.GetExternalParameters(x,p); |
| 9b280d80 |
131 | fX=x; x=GetConvConst(); |
| 006b5f7f |
132 | fP0=p[0]; |
| 133 | fP1=p[1]; |
| 134 | fP2=p[2]; |
| 135 | fP3=p[3]; |
| 136 | fP4=p[4]/x; |
| 137 | |
| 9b280d80 |
138 | //Conversion of the covariance matrix |
| 67c3dcbe |
139 | Double_t cv[15]; |
| 140 | if (c) t.GetConstrainedExternalCovariance(cv); |
| 141 | else t.GetExternalCovariance(cv); |
| 142 | fC00=cv[0 ]; |
| 143 | fC10=cv[1 ]; fC11=cv[2 ]; |
| 144 | fC20=cv[3 ]; fC21=cv[4 ]; fC22=cv[5 ]; |
| 145 | fC30=cv[6 ]; fC31=cv[7 ]; fC32=cv[8 ]; fC33=cv[9 ]; |
| 146 | fC40=cv[10]/x; fC41=cv[11]/x; fC42=cv[12]/x; fC43=cv[13]/x; fC44=cv[14]/x/x; |
| 006b5f7f |
147 | |
| 83d73500 |
148 | if (t.GetStatus()&AliESDtrack::kTIME) { |
| 149 | StartTimeIntegral(); |
| 150 | Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times); |
| 151 | SetIntegratedLength(t.GetIntegratedLength()); |
| 152 | } |
| 153 | fESDtrack=&t; |
| babd135a |
154 | fNUsed = 0; |
| 155 | fReconstructed = kFALSE; |
| 156 | fNSkipped =0; |
| 157 | for(Int_t i=0; i<6; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0;; fChi2MIP[i]=0;} |
| 0aa211b1 |
158 | //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n"; |
| babd135a |
159 | SetFakeRatio(t.GetITSFakeRatio()); |
| 006b5f7f |
160 | } |
| 161 | |
| 83d73500 |
162 | void AliITStrackV2::UpdateESDtrack(ULong_t flags) { |
| 163 | fESDtrack->UpdateTrackParams(this,flags); |
| babd135a |
164 | if (flags == AliESDtrack::kITSin) fESDtrack->SetITSChi2MIP(fChi2MIP); |
| 83d73500 |
165 | } |
| 67c3dcbe |
166 | void AliITStrackV2::SetConstrainedESDtrack(Double_t chi2) { |
| 167 | fESDtrack->SetConstrainedTrackParams(this,chi2); |
| 168 | } |
| 83d73500 |
169 | |
| 006b5f7f |
170 | //____________________________________________________________________________ |
| 171 | AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : AliKalmanTrack(t) { |
| 172 | //------------------------------------------------------------------ |
| 173 | //Copy constructor |
| 174 | //------------------------------------------------------------------ |
| 175 | fX=t.fX; |
| 176 | fAlpha=t.fAlpha; |
| 177 | fdEdx=t.fdEdx; |
| 178 | |
| 179 | fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4; |
| 180 | |
| 181 | fC00=t.fC00; |
| 182 | fC10=t.fC10; fC11=t.fC11; |
| 183 | fC20=t.fC20; fC21=t.fC21; fC22=t.fC22; |
| 184 | fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33; |
| 185 | fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44; |
| 186 | |
| 187 | Int_t n=GetNumberOfClusters(); |
| 23efe5f1 |
188 | for (Int_t i=0; i<n; i++) { |
| a9a2d814 |
189 | fIndex[i]=t.fIndex[i]; |
| 190 | if (i<4) fdEdxSample[i]=t.fdEdxSample[i]; |
| 23efe5f1 |
191 | } |
| 83d73500 |
192 | fESDtrack=t.fESDtrack; |
| babd135a |
193 | fNUsed = t.fNUsed; |
| 194 | fReconstructed = t.fReconstructed; |
| 195 | fNSkipped = t.fNSkipped; |
| 196 | for(Int_t i=0; i<6; i++) {fDy[i]=t.fDy[i]; fDz[i]=t.fDz[i]; fSigmaY[i]=t.fSigmaY[i]; fSigmaZ[i]=t.fSigmaZ[i];; fChi2MIP[i]=t.fChi2MIP[i];} |
| 006b5f7f |
197 | } |
| a9a2d814 |
198 | |
| 006b5f7f |
199 | //_____________________________________________________________________________ |
| 200 | Int_t AliITStrackV2::Compare(const TObject *o) const { |
| 201 | //----------------------------------------------------------------- |
| 202 | // This function compares tracks according to the their curvature |
| 203 | //----------------------------------------------------------------- |
| 7f6ddf58 |
204 | AliITStrackV2 *t=(AliITStrackV2*)o; |
| a9a2d814 |
205 | //Double_t co=TMath::Abs(t->Get1Pt()); |
| 206 | //Double_t c =TMath::Abs(Get1Pt()); |
| babd135a |
207 | Double_t co=t->GetSigmaY2()*t->GetSigmaZ2()*TMath::Sqrt(TMath::Abs(fP4)); |
| 208 | Double_t c =GetSigmaY2()*GetSigmaZ2()*TMath::Sqrt(TMath::Abs(fP4)); |
| 006b5f7f |
209 | if (c>co) return 1; |
| 210 | else if (c<co) return -1; |
| 211 | return 0; |
| 212 | } |
| 213 | |
| 214 | //_____________________________________________________________________________ |
| 215 | void AliITStrackV2::GetExternalCovariance(Double_t cc[15]) const { |
| 216 | //------------------------------------------------------------------------- |
| 217 | // This function returns an external representation of the covriance matrix. |
| 218 | // (See comments in AliTPCtrack.h about external track representation) |
| 219 | //------------------------------------------------------------------------- |
| 9b280d80 |
220 | Double_t a=GetConvConst(); |
| 006b5f7f |
221 | |
| 222 | cc[0 ]=fC00; |
| 223 | cc[1 ]=fC10; cc[2 ]=fC11; |
| 224 | cc[3 ]=fC20; cc[4 ]=fC21; cc[5 ]=fC22; |
| 225 | cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=fC32; cc[9 ]=fC33; |
| 226 | cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=fC42*a; cc[13]=fC43*a; cc[14]=fC44*a*a; |
| 227 | } |
| 228 | |
| 229 | //____________________________________________________________________________ |
| a9a2d814 |
230 | Int_t AliITStrackV2::PropagateToVertex(Double_t d,Double_t x0) { |
| 006b5f7f |
231 | //------------------------------------------------------------------ |
| 232 | //This function propagates a track to the minimal distance from the origin |
| 233 | //------------------------------------------------------------------ |
| 5b316485 |
234 | //Double_t xv=fP2*(fX*fP2 - fP0*TMath::Sqrt(1.- fP2*fP2)); //linear approxim. |
| 235 | Double_t tgf=-(fP4*fX - fP2)/(fP4*fP0 + TMath::Sqrt(1 - fP2*fP2)); |
| 236 | Double_t snf=tgf/TMath::Sqrt(1.+ tgf*tgf); |
| 237 | Double_t xv=(snf - fP2)/fP4 + fX; |
| 238 | return PropagateTo(xv,d,x0); |
| 006b5f7f |
239 | } |
| 240 | |
| 241 | //____________________________________________________________________________ |
| 242 | Int_t AliITStrackV2:: |
| 243 | GetGlobalXYZat(Double_t xk, Double_t &x, Double_t &y, Double_t &z) const { |
| 244 | //------------------------------------------------------------------ |
| 245 | //This function returns a track position in the global system |
| 246 | //------------------------------------------------------------------ |
| 247 | Double_t dx=xk-fX; |
| 248 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| a9a2d814 |
249 | if (TMath::Abs(f2) >= 0.9999) { |
| 7f6ddf58 |
250 | Int_t n=GetNumberOfClusters(); |
| 251 | if (n>kWARN) |
| 8676d691 |
252 | Warning("GetGlobalXYZat","Propagation failed (%d) !\n",n); |
| 006b5f7f |
253 | return 0; |
| 254 | } |
| 255 | |
| 256 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 257 | |
| 258 | Double_t yk = fP0 + dx*(f1+f2)/(r1+r2); |
| 259 | Double_t zk = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 260 | |
| 261 | Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha); |
| 262 | x = xk*cs - yk*sn; |
| 263 | y = xk*sn + yk*cs; |
| 264 | z = zk; |
| 265 | |
| 266 | return 1; |
| 267 | } |
| 268 | |
| 269 | //_____________________________________________________________________________ |
| 270 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const |
| 271 | { |
| 272 | //----------------------------------------------------------------- |
| 273 | // This function calculates a predicted chi2 increment. |
| 274 | //----------------------------------------------------------------- |
| 275 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); |
| 276 | r00+=fC00; r01+=fC10; r11+=fC11; |
| babd135a |
277 | // |
| 006b5f7f |
278 | Double_t det=r00*r11 - r01*r01; |
| 7f6ddf58 |
279 | if (TMath::Abs(det) < 1.e-30) { |
| 006b5f7f |
280 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
281 | if (n>kWARN) |
| 8676d691 |
282 | Warning("GetPredictedChi2","Singular matrix (%d) !\n",n); |
| 006b5f7f |
283 | return 1e10; |
| 284 | } |
| 285 | Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01; |
| 33329428 |
286 | |
| 006b5f7f |
287 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
| 33329428 |
288 | |
| 006b5f7f |
289 | return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det; |
| 290 | } |
| 291 | |
| 006b5f7f |
292 | //____________________________________________________________________________ |
| a9a2d814 |
293 | Int_t AliITStrackV2::CorrectForMaterial(Double_t d, Double_t x0) { |
| 294 | //------------------------------------------------------------------ |
| 295 | //This function corrects the track parameters for crossed material |
| 296 | //------------------------------------------------------------------ |
| 297 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 298 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 299 | d*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2)); |
| 300 | |
| 301 | //Multiple scattering****************** |
| 302 | if (d!=0) { |
| 33329428 |
303 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(d); |
| 304 | //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*TMath::Abs(d)*9.36*2.33; |
| a9a2d814 |
305 | fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3); |
| 306 | fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3); |
| 307 | fC43 += theta2*fP3*fP4*(1. + fP3*fP3); |
| 308 | fC44 += theta2*fP3*fP4*fP3*fP4; |
| 309 | } |
| 310 | |
| 311 | //Energy losses************************ |
| 312 | if (x0!=0.) { |
| 313 | d*=x0; |
| 314 | Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d; |
| 83d73500 |
315 | if (beta2/(1-beta2)>3.5*3.5) |
| 316 | dE=0.153e-3/beta2*(log(3.5*5940)+0.5*log(beta2/(1-beta2)) - beta2)*d; |
| a9a2d814 |
317 | fP4*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE); |
| 318 | } |
| 319 | |
| 320 | if (!Invariant()) return 0; |
| 321 | |
| 322 | return 1; |
| 323 | } |
| 324 | |
| 325 | //____________________________________________________________________________ |
| 326 | Int_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) { |
| 006b5f7f |
327 | //------------------------------------------------------------------ |
| 328 | //This function propagates a track |
| 329 | //------------------------------------------------------------------ |
| 330 | Double_t x1=fX, x2=xk, dx=x2-x1; |
| 331 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| a9a2d814 |
332 | if (TMath::Abs(f2) >= 0.9999) { |
| 006b5f7f |
333 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
334 | if (n>kWARN) |
| 8676d691 |
335 | Warning("PropagateTo","Propagation failed !\n",n); |
| 006b5f7f |
336 | return 0; |
| 337 | } |
| 338 | |
| f29dbb4b |
339 | // old position [SR, GSI, 17.02.2003] |
| 340 | Double_t oldX = fX, oldY = fP0, oldZ = fP1; |
| 341 | |
| 006b5f7f |
342 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 343 | |
| 344 | fP0 += dx*(f1+f2)/(r1+r2); |
| 345 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 346 | fP2 += dx*fP4; |
| 347 | |
| 348 | //f = F - 1 |
| 349 | |
| 350 | Double_t f02= dx/(r1*r1*r1); |
| 351 | Double_t f04=0.5*dx*dx/(r1*r1*r1); |
| 352 | Double_t f12= dx*fP3*f1/(r1*r1*r1); |
| 353 | Double_t f14=0.5*dx*dx*fP3*f1/(r1*r1*r1); |
| 354 | Double_t f13= dx/r1; |
| 355 | Double_t f24= dx; |
| 356 | |
| 357 | //b = C*ft |
| 358 | Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30; |
| 359 | Double_t b02=f24*fC40; |
| 360 | Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31; |
| 361 | Double_t b12=f24*fC41; |
| 362 | Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32; |
| 363 | Double_t b22=f24*fC42; |
| 364 | Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43; |
| 365 | Double_t b42=f24*fC44; |
| 366 | Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33; |
| 367 | Double_t b32=f24*fC43; |
| 368 | |
| 369 | //a = f*b = f*C*ft |
| 370 | Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a02=f02*b22+f04*b42; |
| 371 | Double_t a11=f12*b21+f14*b41+f13*b31,a12=f12*b22+f14*b42+f13*b32; |
| 372 | Double_t a22=f24*b42; |
| 373 | |
| 374 | //F*C*Ft = C + (b + bt + a) |
| 375 | fC00 += b00 + b00 + a00; |
| 376 | fC10 += b10 + b01 + a01; |
| 377 | fC20 += b20 + b02 + a02; |
| 378 | fC30 += b30; |
| 379 | fC40 += b40; |
| 380 | fC11 += b11 + b11 + a11; |
| 381 | fC21 += b21 + b12 + a12; |
| 382 | fC31 += b31; |
| 383 | fC41 += b41; |
| 384 | fC22 += b22 + b22 + a22; |
| 385 | fC32 += b32; |
| 386 | fC42 += b42; |
| 387 | |
| 388 | fX=x2; |
| 389 | |
| a9a2d814 |
390 | if (!CorrectForMaterial(d,x0)) return 0; |
| 006b5f7f |
391 | |
| f29dbb4b |
392 | // Integrated Time [SR, GSI, 17.02.2003] |
| 880f41b9 |
393 | if (IsStartedTimeIntegral() && fX>oldX) { |
| 8676d691 |
394 | Double_t l2 = (fX-oldX)*(fX-oldX)+(fP0-oldY)*(fP0-oldY)+ |
| 395 | (fP1-oldZ)*(fP1-oldZ); |
| f29dbb4b |
396 | AddTimeStep(TMath::Sqrt(l2)); |
| 397 | } |
| 398 | // |
| 399 | |
| 006b5f7f |
400 | return 1; |
| 401 | } |
| 402 | |
| 403 | //____________________________________________________________________________ |
| 404 | Int_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, UInt_t index) { |
| 405 | //------------------------------------------------------------------ |
| 406 | //This function updates track parameters |
| 407 | //------------------------------------------------------------------ |
| 408 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
| 409 | Double_t c00=fC00; |
| 410 | Double_t c10=fC10, c11=fC11; |
| 411 | Double_t c20=fC20, c21=fC21, c22=fC22; |
| 412 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; |
| 413 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; |
| 414 | |
| 415 | |
| 416 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); |
| 417 | r00+=fC00; r01+=fC10; r11+=fC11; |
| 418 | Double_t det=r00*r11 - r01*r01; |
| 419 | Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det; |
| 420 | |
| babd135a |
421 | |
| 006b5f7f |
422 | Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11; |
| 423 | Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11; |
| 424 | Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11; |
| 425 | Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11; |
| 426 | Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11; |
| 427 | |
| 428 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
| babd135a |
429 | Int_t layer = (index & 0xf0000000) >> 28; |
| 430 | fDy[layer] = dy; |
| 431 | fDz[layer] = dz; |
| 432 | fSigmaY[layer] = TMath::Sqrt(c->GetSigmaY2()+fC00); |
| 433 | fSigmaZ[layer] = TMath::Sqrt(c->GetSigmaZ2()+fC11); |
| 434 | |
| 006b5f7f |
435 | Double_t sf=fP2 + k20*dy + k21*dz; |
| 7f6ddf58 |
436 | |
| 006b5f7f |
437 | fP0 += k00*dy + k01*dz; |
| 438 | fP1 += k10*dy + k11*dz; |
| 439 | fP2 = sf; |
| 440 | fP3 += k30*dy + k31*dz; |
| 441 | fP4 += k40*dy + k41*dz; |
| 442 | |
| 443 | Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40; |
| 444 | Double_t c12=fC21, c13=fC31, c14=fC41; |
| 445 | |
| 446 | fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11; |
| 447 | fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13; |
| 448 | fC40-=k00*c04+k01*c14; |
| 449 | |
| 450 | fC11-=k10*c01+k11*fC11; |
| 451 | fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13; |
| 452 | fC41-=k10*c04+k11*c14; |
| 453 | |
| 454 | fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13; |
| 455 | fC42-=k20*c04+k21*c14; |
| 456 | |
| 457 | fC33-=k30*c03+k31*c13; |
| 458 | fC43-=k30*c04+k31*c14; |
| 459 | |
| 460 | fC44-=k40*c04+k41*c14; |
| 461 | |
| 462 | if (!Invariant()) { |
| 463 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
| 464 | fC00=c00; |
| 465 | fC10=c10; fC11=c11; |
| 466 | fC20=c20; fC21=c21; fC22=c22; |
| 467 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; |
| 468 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; |
| 469 | return 0; |
| 470 | } |
| 471 | |
| 67c3dcbe |
472 | if (chi2<0) return 1; |
| 473 | |
| 006b5f7f |
474 | Int_t n=GetNumberOfClusters(); |
| 475 | fIndex[n]=index; |
| 476 | SetNumberOfClusters(n+1); |
| 477 | SetChi2(GetChi2()+chi2); |
| 478 | |
| 479 | return 1; |
| 480 | } |
| 481 | |
| 006b5f7f |
482 | Int_t AliITStrackV2::Invariant() const { |
| 483 | //------------------------------------------------------------------ |
| 484 | // This function is for debugging purpose only |
| 485 | //------------------------------------------------------------------ |
| 7f6ddf58 |
486 | Int_t n=GetNumberOfClusters(); |
| 487 | |
| a9a2d814 |
488 | if (TMath::Abs(fP2)>=0.9999){ |
| 8676d691 |
489 | if (n>kWARN) Warning("Invariant","fP2=%f\n",fP2); |
| a9a2d814 |
490 | return 0; |
| 491 | } |
| 492 | if (fC00<=0 || fC00>9.) { |
| 8676d691 |
493 | if (n>kWARN) Warning("Invariant","fC00=%f\n",fC00); |
| a9a2d814 |
494 | return 0; |
| 495 | } |
| 496 | if (fC11<=0 || fC11>9.) { |
| 8676d691 |
497 | if (n>kWARN) Warning("Invariant","fC11=%f\n",fC11); |
| a9a2d814 |
498 | return 0; |
| 499 | } |
| 500 | if (fC22<=0 || fC22>1.) { |
| 8676d691 |
501 | if (n>kWARN) Warning("Invariant","fC22=%f\n",fC22); |
| a9a2d814 |
502 | return 0; |
| 503 | } |
| 504 | if (fC33<=0 || fC33>1.) { |
| 8676d691 |
505 | if (n>kWARN) Warning("Invariant","fC33=%f\n",fC33); |
| a9a2d814 |
506 | return 0; |
| 507 | } |
| 508 | if (fC44<=0 || fC44>6e-5) { |
| 8676d691 |
509 | if (n>kWARN) Warning("Invariant","fC44=%f\n",fC44); |
| a9a2d814 |
510 | return 0; |
| 14825d5a |
511 | } |
| 14825d5a |
512 | return 1; |
| 006b5f7f |
513 | } |
| 514 | |
| 515 | //____________________________________________________________________________ |
| a9a2d814 |
516 | Int_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) { |
| 006b5f7f |
517 | //------------------------------------------------------------------ |
| 518 | //This function propagates a track |
| 519 | //------------------------------------------------------------------ |
| 33329428 |
520 | Double_t alpha=fAlpha, x=fX; |
| 006b5f7f |
521 | Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4; |
| 522 | Double_t c00=fC00; |
| 523 | Double_t c10=fC10, c11=fC11; |
| 524 | Double_t c20=fC20, c21=fC21, c22=fC22; |
| 525 | Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33; |
| 526 | Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44; |
| 527 | |
| 33329428 |
528 | if (alp < -TMath::Pi()) alp += 2*TMath::Pi(); |
| 529 | else if (alp >= TMath::Pi()) alp -= 2*TMath::Pi(); |
| 530 | Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha); |
| 531 | Double_t sf=fP2, cf=TMath::Sqrt(1.- fP2*fP2); |
| 006b5f7f |
532 | |
| 33329428 |
533 | TMatrixD *T=0; |
| 534 | // **** rotation ********************** |
| 535 | { |
| 006b5f7f |
536 | fAlpha = alp; |
| 33329428 |
537 | fX = x*ca + p0*sa; |
| 538 | fP0= -x*sa + p0*ca; |
| 539 | fP2= sf*ca - cf*sa; |
| 540 | |
| 541 | TMatrixD C(5,5); |
| 542 | C(0,0)=c00; |
| 543 | C(1,0)=c10; C(1,1)=c11; |
| 544 | C(2,0)=c20; C(2,1)=c21; C(2,2)=c22; |
| 545 | C(3,0)=c30; C(3,1)=c31; C(3,2)=c32; C(3,3)=c33; |
| 546 | C(4,0)=c40; C(4,1)=c41; C(4,2)=c42; C(4,3)=c43; C(4,4)=c44; |
| 547 | C(0,1)=C(1,0); |
| 548 | C(0,2)=C(2,0); C(1,2)=C(2,1); |
| 549 | C(0,3)=C(3,0); C(1,3)=C(3,1); C(2,3)=C(3,2); |
| 550 | C(0,4)=C(4,0); C(1,4)=C(4,1); C(2,4)=C(4,2); C(3,4)=C(4,3); |
| 006b5f7f |
551 | |
| 33329428 |
552 | TMatrixD F(6,5); |
| 553 | F(0,0)=sa; |
| 554 | F(1,0)=ca; |
| 555 | F(2,1)=F(4,3)=F(5,4)=1; |
| 556 | F(3,2)=ca + sf/cf*sa; |
| 006b5f7f |
557 | |
| 33329428 |
558 | TMatrixD tmp(C,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F)); |
| 559 | T=new TMatrixD(F,TMatrixD::kMult,tmp); |
| 560 | } |
| 006b5f7f |
561 | |
| 33329428 |
562 | // **** translation ****************** |
| 563 | { |
| 564 | Double_t dx=xk-fX; |
| 006b5f7f |
565 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| a9a2d814 |
566 | if (TMath::Abs(f2) >= 0.9999) { |
| 006b5f7f |
567 | Int_t n=GetNumberOfClusters(); |
| 7f6ddf58 |
568 | if (n>kWARN) |
| 8676d691 |
569 | Warning("Propagate","Propagation failed (%d) !\n",n); |
| 006b5f7f |
570 | return 0; |
| 571 | } |
| 33329428 |
572 | Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2); |
| 006b5f7f |
573 | |
| 33329428 |
574 | fX=xk; |
| 006b5f7f |
575 | fP0 += dx*(f1+f2)/(r1+r2); |
| 576 | fP1 += dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 577 | fP2 += dx*fP4; |
| 578 | |
| 33329428 |
579 | TMatrixD F(5,6); |
| 580 | F(0,1)=F(1,2)=F(2,3)=F(3,4)=F(4,5)=1; |
| 581 | F(0,3)=dx/(r1+r2)*(2+(f1+f2)*(f2/r2+f1/r1)/(r1+r2)); |
| 582 | F(0,5)=dx*dx/(r1+r2)*(1+(f1+f2)*f2/(r1+r2)); |
| 583 | F(1,3)=dx*fP3/(f1*r2 + f2*r1)*(2-(f1+f2)*(r2-f1*f2/r2+r1-f2*f1/r1)/(f1*r2 + f2*r1)); |
| 584 | F(1,4)=dx*(f1+f2)/(f1*r2 + f2*r1); |
| 585 | F(1,5)=dx*dx*fP3/(f1*r2 + f2*r1)*(1-(f1+f2)*(-f1*f2/r2+r1)/(f1*r2 + f2*r1)); |
| 586 | F(2,5)=dx; |
| 587 | F(0,0)=-1/(r1+r2)*((f1+f2)+dx*fP4*(1+(f1+f2)/(r1+r2)*f2/r2)); |
| 588 | F(1,0)=-fP3/(f1*r2 + f2*r1)*((f1+f2)+dx*fP4*(1+(f1+f2)/(f1*r2 + f2*r1)*(f1*f2/r2-r1))); |
| 589 | F(2,0)=-fP4; |
| 590 | |
| 591 | TMatrixD tmp(*T,TMatrixD::kMult,TMatrixD(TMatrixD::kTransposed, F)); |
| 592 | delete T; |
| 593 | TMatrixD C(F,TMatrixD::kMult,tmp); |
| 006b5f7f |
594 | |
| 595 | fC00=C(0,0); |
| 596 | fC10=C(1,0); fC11=C(1,1); |
| 597 | fC20=C(2,0); fC21=C(2,1); fC22=C(2,2); |
| 598 | fC30=C(3,0); fC31=C(3,1); fC32=C(3,2); fC33=C(3,3); |
| 599 | fC40=C(4,0); fC41=C(4,1); fC42=C(4,2); fC43=C(4,3); fC44=C(4,4); |
| 600 | |
| 006b5f7f |
601 | if (!Invariant()) { |
| 33329428 |
602 | fAlpha=alpha; |
| 603 | fX=x; |
| 006b5f7f |
604 | fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4; |
| 605 | fC00=c00; |
| 606 | fC10=c10; fC11=c11; |
| 607 | fC20=c20; fC21=c21; fC22=c22; |
| 608 | fC30=c30; fC31=c31; fC32=c32; fC33=c33; |
| 609 | fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44; |
| 610 | return 0; |
| 611 | } |
| 33329428 |
612 | } |
| 006b5f7f |
613 | |
| 614 | return 1; |
| 615 | } |
| 616 | |
| a6a6f799 |
617 | Double_t AliITStrackV2::GetD(Double_t x, Double_t y) const { |
| 006b5f7f |
618 | //------------------------------------------------------------------ |
| a6a6f799 |
619 | // This function calculates the transverse impact parameter |
| 620 | // with respect to a point with global coordinates (x,y) |
| 006b5f7f |
621 | //------------------------------------------------------------------ |
| a6a6f799 |
622 | Double_t xt=fX, yt=fP0; |
| 623 | |
| 624 | Double_t sn=TMath::Sin(fAlpha), cs=TMath::Cos(fAlpha); |
| 625 | Double_t a = x*cs + y*sn; |
| 626 | y = -x*sn + y*cs; x=a; |
| 627 | xt-=x; yt-=y; |
| 628 | |
| 629 | sn=fP4*xt - fP2; cs=fP4*yt + TMath::Sqrt(1.- fP2*fP2); |
| 630 | a=2*(xt*fP2 - yt*TMath::Sqrt(1.- fP2*fP2))-fP4*(xt*xt + yt*yt); |
| 006b5f7f |
631 | if (fP4<0) a=-a; |
| 632 | return a/(1 + TMath::Sqrt(sn*sn + cs*cs)); |
| a9a2d814 |
633 | } |
| 006b5f7f |
634 | |
| babd135a |
635 | Double_t AliITStrackV2::GetZat(Double_t x) const { |
| 636 | //------------------------------------------------------------------ |
| 637 | // This function calculates the z at given x point - in current coordinate system |
| 638 | //------------------------------------------------------------------ |
| 639 | Double_t x1=fX, x2=x, dx=x2-x1; |
| 640 | // |
| 641 | Double_t f1=fP2, f2=f1 + fP4*dx; |
| 642 | if (TMath::Abs(f2) >= 0.9999) { |
| 643 | return 10000000; |
| 644 | } |
| 645 | |
| 646 | Double_t r1=sqrt(1.- f1*f1), r2=sqrt(1.- f2*f2); |
| 647 | Double_t z = fP1 + dx*(f1+f2)/(f1*r2 + f2*r1)*fP3; |
| 648 | return z; |
| 649 | } |
| 650 | |
| 651 | |
| 652 | |
| 653 | |
| 8676d691 |
654 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) { |
| a9a2d814 |
655 | //------------------------------------------------------------------ |
| 656 | //This function improves angular track parameters |
| 657 | //------------------------------------------------------------------ |
| 8676d691 |
658 | Double_t cs=TMath::Cos(fAlpha), sn=TMath::Sin(fAlpha); |
| 659 | //Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex |
| 660 | Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the |
| 661 | Double_t zv = xyz[2]; // local frame |
| a9a2d814 |
662 | Double_t dy=fP0-yv, dz=fP1-zv; |
| 663 | Double_t r2=fX*fX+dy*dy; |
| 664 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 665 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 666 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| 8676d691 |
667 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
| 668 | //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; |
| a9a2d814 |
669 | { |
| 670 | Double_t parp=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); |
| 671 | Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 672 | sigma2p += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); |
| 8676d691 |
673 | sigma2p += ers[1]*ers[1]/r2; |
| a9a2d814 |
674 | sigma2p += 0.25*fC44*fX*fX; |
| 675 | Double_t eps2p=sigma2p/(fC22+sigma2p); |
| 676 | fP0 += fC20/(fC22+sigma2p)*(parp-fP2); |
| 677 | fP2 = eps2p*fP2 + (1-eps2p)*parp; |
| 678 | fC22 *= eps2p; |
| 679 | fC20 *= eps2p; |
| 680 | } |
| 681 | { |
| 682 | Double_t parl=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); |
| 683 | Double_t sigma2l=theta2; |
| 684 | sigma2l += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); |
| 8676d691 |
685 | sigma2l += ers[2]*ers[2]/r2; |
| a9a2d814 |
686 | Double_t eps2l=sigma2l/(fC33+sigma2l); |
| 687 | fP1 += fC31/(fC33+sigma2l)*(parl-fP3); |
| 688 | fP4 += fC43/(fC33+sigma2l)*(parl-fP3); |
| 689 | fP3 = eps2l*fP3 + (1-eps2l)*parl; |
| 690 | fC33 *= eps2l; fC43 *= eps2l; |
| 691 | fC31 *= eps2l; |
| 692 | } |
| 693 | if (!Invariant()) return 0; |
| 694 | return 1; |
| 695 | } |
| 006b5f7f |
696 | |
| a9a2d814 |
697 | /* |
| 006b5f7f |
698 | Int_t AliITStrackV2::Improve(Double_t x0,Double_t yv,Double_t zv) { |
| 699 | //------------------------------------------------------------------ |
| 700 | //This function improves angular track parameters |
| 701 | //------------------------------------------------------------------ |
| 702 | Double_t dy=fP0-yv, dz=fP1-zv; |
| 703 | Double_t r2=fX*fX+dy*dy; |
| 704 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
| 7f6ddf58 |
705 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
| 006b5f7f |
706 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); |
| a9a2d814 |
707 | //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; |
| 708 | Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; |
| 006b5f7f |
709 | |
| 710 | Double_t par=0.5*(fP4*fX + dy*TMath::Sqrt(4/r2-fP4*fP4)); |
| 711 | Double_t sigma2 = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl()); |
| 712 | sigma2 += fC00/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2); |
| 713 | sigma2 += kSigmaYV*kSigmaYV/r2; |
| 714 | sigma2 += 0.25*fC44*fX*fX; |
| 715 | Double_t eps2=sigma2/(fC22+sigma2), eps=TMath::Sqrt(eps2); |
| 716 | if (10*r2*fC44<fC22) { |
| 717 | fP2 = eps2*fP2 + (1-eps2)*par; |
| 718 | fC22*=eps2; fC21*=eps; fC20*=eps; fC32*=eps; fC42*=eps; |
| 719 | } |
| 720 | |
| 721 | par=0.5*fP4*dz/TMath::ASin(0.5*fP4*TMath::Sqrt(r2)); |
| 722 | sigma2=theta2; |
| 723 | sigma2 += fC11/r2+fC00*dy*dy*dz*dz/(r2*r2*r2); |
| 724 | sigma2 += kSigmaZV*kSigmaZV/r2; |
| 725 | eps2=sigma2/(fC33+sigma2); eps=TMath::Sqrt(eps2); |
| 726 | Double_t tgl=fP3; |
| 727 | fP3 = eps2*fP3 + (1-eps2)*par; |
| 728 | fC33*=eps2; fC32*=eps; fC31*=eps; fC30*=eps; fC43*=eps; |
| 729 | |
| 730 | eps=TMath::Sqrt((1+fP3*fP3)/(1+tgl*tgl)); |
| 731 | fP4*=eps; |
| 732 | fC44*=eps*eps; fC43*=eps;fC42*=eps; fC41*=eps; fC40*=eps; |
| 733 | |
| 734 | if (!Invariant()) return 0; |
| 735 | return 1; |
| 736 | } |
| 006b5f7f |
737 | */ |
| 14825d5a |
738 | void AliITStrackV2::ResetCovariance() { |
| 739 | //------------------------------------------------------------------ |
| 740 | //This function makes a track forget its history :) |
| 741 | //------------------------------------------------------------------ |
| 742 | |
| 743 | fC00*=10.; |
| 744 | fC10=0.; fC11*=10.; |
| 745 | fC20=0.; fC21=0.; fC22*=10.; |
| 746 | fC30=0.; fC31=0.; fC32=0.; fC33*=10.; |
| 747 | fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.; |
| 748 | |
| 749 | } |
| 23efe5f1 |
750 | |
| 751 | void AliITStrackV2::CookdEdx(Double_t low, Double_t up) { |
| 752 | //----------------------------------------------------------------- |
| a9a2d814 |
753 | // This function calculates dE/dX within the "low" and "up" cuts. |
| 754 | // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch |
| 23efe5f1 |
755 | //----------------------------------------------------------------- |
| 23efe5f1 |
756 | // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1 |
| c0dd5278 |
757 | |
| 758 | Int_t i; |
| 759 | Int_t nc=0; |
| 760 | for (i=0; i<GetNumberOfClusters(); i++) { |
| 761 | Int_t idx=GetClusterIndex(i); |
| 762 | idx=(idx&0xf0000000)>>28; |
| 763 | if (idx>1) nc++; // Take only SSD and SDD |
| 764 | } |
| 23efe5f1 |
765 | |
| a9a2d814 |
766 | Int_t swap;//stupid sorting |
| 23efe5f1 |
767 | do { |
| 768 | swap=0; |
| 769 | for (i=0; i<nc-1; i++) { |
| 770 | if (fdEdxSample[i]<=fdEdxSample[i+1]) continue; |
| 771 | Float_t tmp=fdEdxSample[i]; |
| 772 | fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp; |
| 773 | swap++; |
| 774 | } |
| 775 | } while (swap); |
| 776 | |
| a9a2d814 |
777 | Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX |
| 778 | // values from four ones choose |
| 779 | // nu=2 |
| 23efe5f1 |
780 | Float_t dedx=0; |
| a9a2d814 |
781 | for (i=nl; i<nu; i++) dedx += fdEdxSample[i]; |
| c0dd5278 |
782 | if (nu-nl>0) dedx /= (nu-nl); |
| 23efe5f1 |
783 | |
| 23efe5f1 |
784 | SetdEdx(dedx); |
| 785 | } |
git://git.uio.no / u / mrichter / AliRoot.git / blame