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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 | /////////////////////////////////////////////////////////////////////////// | |
19 | // Implementation of the ITS track class | |
20 | // | |
21 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch | |
22 | // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch | |
23 | /////////////////////////////////////////////////////////////////////////// | |
24 | #include <TMath.h> | |
25 | ||
26 | #include "AliCluster.h" | |
27 | #include "AliESDVertex.h" | |
28 | #include "AliITSReconstructor.h" | |
29 | #include "AliITStrackV2.h" | |
30 | #include "AliTracker.h" | |
31 | #include "AliLog.h" | |
32 | ||
33 | const Int_t AliITStrackV2::fgkWARN = 5; | |
34 | ||
35 | ClassImp(AliITStrackV2) | |
36 | ||
37 | ||
38 | //____________________________________________________________________________ | |
39 | AliITStrackV2::AliITStrackV2() : AliKalmanTrack(), | |
40 | fCheckInvariant(kTRUE), | |
41 | fdEdx(0), | |
42 | fESDtrack(0) | |
43 | { | |
44 | for(Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) {fIndex[i]=-1; fModule[i]=-1;} | |
45 | for(Int_t i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=0;} | |
46 | for(Int_t i=0; i<4; i++) fdEdxSample[i]=0; | |
47 | } | |
48 | ||
49 | ||
50 | //____________________________________________________________________________ | |
51 | AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c): | |
52 | AliKalmanTrack(), | |
53 | fCheckInvariant(kTRUE), | |
54 | fdEdx(t.GetITSsignal()), | |
55 | fESDtrack(&t) | |
56 | { | |
57 | //------------------------------------------------------------------ | |
58 | // Conversion ESD track -> ITS track. | |
59 | // If c==kTRUE, create the ITS track out of the constrained params. | |
60 | //------------------------------------------------------------------ | |
61 | const AliExternalTrackParam *par=&t; | |
62 | if (c) { | |
63 | par=t.GetConstrainedParam(); | |
64 | if (!par) AliError("AliITStrackV2: conversion failed !\n"); | |
65 | } | |
66 | Set(par->GetX(),par->GetAlpha(),par->GetParameter(),par->GetCovariance()); | |
67 | ||
68 | SetLabel(t.GetITSLabel()); | |
69 | SetMass(t.GetMass()); | |
70 | SetNumberOfClusters(t.GetITSclusters(fIndex)); | |
71 | ||
72 | if (t.GetStatus()&AliESDtrack::kTIME) { | |
73 | StartTimeIntegral(); | |
74 | Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times); | |
75 | SetIntegratedLength(t.GetIntegratedLength()); | |
76 | } | |
77 | ||
78 | for(Int_t i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=0;} | |
79 | for(Int_t i=0; i<4; i++) fdEdxSample[i]=0; | |
80 | } | |
81 | ||
82 | //____________________________________________________________________________ | |
83 | void AliITStrackV2::ResetClusters() { | |
84 | //------------------------------------------------------------------ | |
85 | // Reset the array of attached clusters. | |
86 | //------------------------------------------------------------------ | |
87 | for (Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) fIndex[i]=-1; | |
88 | for (Int_t i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=0;} | |
89 | SetChi2(0.); | |
90 | SetNumberOfClusters(0); | |
91 | } | |
92 | ||
93 | //____________________________________________________________________________ | |
94 | void AliITStrackV2::UpdateESDtrack(ULong_t flags) const { | |
95 | // Update track params | |
96 | fESDtrack->UpdateTrackParams(this,flags); | |
97 | // | |
98 | // set correctly the global label | |
99 | if (fESDtrack->IsOn(AliESDtrack::kTPCin)) { | |
100 | // for global track the GetLabel should be negative if | |
101 | // 1) GetTPCLabel<0 | |
102 | // 2) this->GetLabel()<0 | |
103 | // 3) GetTPCLabel() != this->GetLabel() | |
104 | int label = fESDtrack->GetTPCLabel(); | |
105 | int itsLabel = GetLabel(); | |
106 | if (label<0 || itsLabel<0 || itsLabel!=label) label = -TMath::Abs(label); | |
107 | fESDtrack->SetLabel(label); | |
108 | } | |
109 | // | |
110 | // copy the module indices | |
111 | Int_t i; | |
112 | for(i=0;i<2*AliITSgeomTGeo::kNLayers;i++) { | |
113 | // printf(" %d\n",GetModuleIndex(i)); | |
114 | fESDtrack->SetITSModuleIndex(i,GetModuleIndex(i)); | |
115 | } | |
116 | // copy the map of shared clusters | |
117 | if(flags==AliESDtrack::kITSin) { | |
118 | UChar_t itsSharedMap=0; | |
119 | for(i=0;i<AliITSgeomTGeo::kNLayers;i++) { | |
120 | if(fSharedWeight[i]>0) SETBIT(itsSharedMap,i); | |
121 | ||
122 | } | |
123 | fESDtrack->SetITSSharedMap(itsSharedMap); | |
124 | } | |
125 | ||
126 | // copy the 4 dedx samples | |
127 | Double_t sdedx[4]={0.,0.,0.,0.}; | |
128 | for(i=0; i<4; i++) sdedx[i]=fdEdxSample[i]; | |
129 | fESDtrack->SetITSdEdxSamples(sdedx); | |
130 | } | |
131 | ||
132 | //____________________________________________________________________________ | |
133 | AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) : | |
134 | AliKalmanTrack(t), | |
135 | fCheckInvariant(t.fCheckInvariant), | |
136 | fdEdx(t.fdEdx), | |
137 | fESDtrack(t.fESDtrack) | |
138 | { | |
139 | //------------------------------------------------------------------ | |
140 | //Copy constructor | |
141 | //------------------------------------------------------------------ | |
142 | Int_t i; | |
143 | for (i=0; i<4; i++) fdEdxSample[i]=t.fdEdxSample[i]; | |
144 | for (i=0; i<2*AliITSgeomTGeo::GetNLayers(); i++) { | |
145 | fIndex[i]=t.fIndex[i]; | |
146 | fModule[i]=t.fModule[i]; | |
147 | } | |
148 | for (i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=t.fSharedWeight[i];} | |
149 | } | |
150 | ||
151 | //_____________________________________________________________________________ | |
152 | Int_t AliITStrackV2::Compare(const TObject *o) const { | |
153 | //----------------------------------------------------------------- | |
154 | // This function compares tracks according to the their curvature | |
155 | //----------------------------------------------------------------- | |
156 | AliITStrackV2 *t=(AliITStrackV2*)o; | |
157 | //Double_t co=OneOverPt(); | |
158 | //Double_t c =OneOverPt(); | |
159 | Double_t co=t->GetSigmaY2()*t->GetSigmaZ2(); | |
160 | Double_t c =GetSigmaY2()*GetSigmaZ2(); | |
161 | if (c>co) return 1; | |
162 | else if (c<co) return -1; | |
163 | return 0; | |
164 | } | |
165 | ||
166 | //____________________________________________________________________________ | |
167 | Bool_t | |
168 | AliITStrackV2::PropagateToVertex(const AliESDVertex *v,Double_t d,Double_t x0) | |
169 | { | |
170 | //------------------------------------------------------------------ | |
171 | //This function propagates a track to the minimal distance from the origin | |
172 | //------------------------------------------------------------------ | |
173 | Double_t bz=GetBz(); | |
174 | if (PropagateToDCA(v,bz,kVeryBig)) { | |
175 | Double_t xOverX0,xTimesRho; | |
176 | xOverX0 = d; xTimesRho = d*x0; | |
177 | if (CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kTRUE; | |
178 | } | |
179 | return kFALSE; | |
180 | } | |
181 | ||
182 | //____________________________________________________________________________ | |
183 | Bool_t AliITStrackV2:: | |
184 | GetGlobalXYZat(Double_t xloc, Double_t &x, Double_t &y, Double_t &z) const { | |
185 | //------------------------------------------------------------------ | |
186 | //This function returns a track position in the global system | |
187 | //------------------------------------------------------------------ | |
188 | Double_t r[3]; | |
189 | Bool_t rc=GetXYZAt(xloc, GetBz(), r); | |
190 | x=r[0]; y=r[1]; z=r[2]; | |
191 | return rc; | |
192 | } | |
193 | ||
194 | //_____________________________________________________________________________ | |
195 | Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const { | |
196 | //----------------------------------------------------------------- | |
197 | // This function calculates a predicted chi2 increment. | |
198 | //----------------------------------------------------------------- | |
199 | Double_t p[2]={c->GetY(), c->GetZ()}; | |
200 | Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()}; | |
201 | return AliExternalTrackParam::GetPredictedChi2(p,cov); | |
202 | } | |
203 | ||
204 | //____________________________________________________________________________ | |
205 | Bool_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) { | |
206 | //------------------------------------------------------------------ | |
207 | //This function propagates a track | |
208 | //------------------------------------------------------------------ | |
209 | ||
210 | Double_t oldX=GetX(), oldY=GetY(), oldZ=GetZ(); | |
211 | ||
212 | //Double_t bz=GetBz(); | |
213 | //if (!AliExternalTrackParam::PropagateTo(xk,bz)) return kFALSE; | |
214 | Double_t b[3]; GetBxByBz(b); | |
215 | if (!AliExternalTrackParam::PropagateToBxByBz(xk,b)) return kFALSE; | |
216 | Double_t xOverX0,xTimesRho; | |
217 | xOverX0 = d; xTimesRho = d*x0; | |
218 | if (!CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kFALSE; | |
219 | ||
220 | Double_t x=GetX(), y=GetY(), z=GetZ(); | |
221 | if (IsStartedTimeIntegral() && x>oldX) { | |
222 | Double_t l2 = (x-oldX)*(x-oldX) + (y-oldY)*(y-oldY) + (z-oldZ)*(z-oldZ); | |
223 | AddTimeStep(TMath::Sqrt(l2)); | |
224 | } | |
225 | ||
226 | return kTRUE; | |
227 | } | |
228 | ||
229 | //____________________________________________________________________________ | |
230 | Bool_t AliITStrackV2::PropagateToTGeo(Double_t xToGo, Int_t nstep, Double_t &xOverX0, Double_t &xTimesRho, Bool_t addTime) { | |
231 | //------------------------------------------------------------------- | |
232 | // Propagates the track to a reference plane x=xToGo in n steps. | |
233 | // These n steps are only used to take into account the curvature. | |
234 | // The material is calculated with TGeo. (L.Gaudichet) | |
235 | //------------------------------------------------------------------- | |
236 | ||
237 | Double_t startx = GetX(), starty = GetY(), startz = GetZ(); | |
238 | Double_t sign = (startx<xToGo) ? -1.:1.; | |
239 | Double_t step = (xToGo-startx)/TMath::Abs(nstep); | |
240 | ||
241 | Double_t start[3], end[3], mparam[7]; | |
242 | //Double_t bz = GetBz(); | |
243 | Double_t b[3]; GetBxByBz(b); | |
244 | Double_t bz = b[2]; | |
245 | ||
246 | Double_t x = startx; | |
247 | ||
248 | for (Int_t i=0; i<nstep; i++) { | |
249 | ||
250 | GetXYZ(start); //starting global position | |
251 | x += step; | |
252 | if (!GetXYZAt(x, bz, end)) return kFALSE; | |
253 | //if (!AliExternalTrackParam::PropagateTo(x, bz)) return kFALSE; | |
254 | if (!AliExternalTrackParam::PropagateToBxByBz(x, b)) return kFALSE; | |
255 | AliTracker::MeanMaterialBudget(start, end, mparam); | |
256 | xTimesRho = sign*mparam[4]*mparam[0]; | |
257 | xOverX0 = mparam[1]; | |
258 | if (mparam[1]<900000) { | |
259 | if (!AliExternalTrackParam::CorrectForMeanMaterial(xOverX0, | |
260 | xTimesRho,GetMass())) return kFALSE; | |
261 | } else { // this happens when MeanMaterialBudget cannot cross a boundary | |
262 | return kFALSE; | |
263 | } | |
264 | } | |
265 | ||
266 | if (addTime && IsStartedTimeIntegral() && GetX()>startx) { | |
267 | Double_t l2 = ( (GetX()-startx)*(GetX()-startx) + | |
268 | (GetY()-starty)*(GetY()-starty) + | |
269 | (GetZ()-startz)*(GetZ()-startz) ); | |
270 | AddTimeStep(TMath::Sqrt(l2)); | |
271 | } | |
272 | ||
273 | return kTRUE; | |
274 | } | |
275 | ||
276 | //____________________________________________________________________________ | |
277 | Bool_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, Int_t index) | |
278 | { | |
279 | //------------------------------------------------------------------ | |
280 | //This function updates track parameters | |
281 | //------------------------------------------------------------------ | |
282 | Double_t p[2]={c->GetY(), c->GetZ()}; | |
283 | Double_t cov[3]={c->GetSigmaY2(), c->GetSigmaYZ(), c->GetSigmaZ2()}; | |
284 | ||
285 | if (!AliExternalTrackParam::Update(p,cov)) return kFALSE; | |
286 | ||
287 | Int_t n=GetNumberOfClusters(); | |
288 | if (!Invariant()) { | |
289 | if (n>fgkWARN) AliDebug(1,"Wrong invariant !"); | |
290 | return kFALSE; | |
291 | } | |
292 | ||
293 | if (chi2<0) return kTRUE; | |
294 | ||
295 | // fill residuals for ITS+TPC tracks | |
296 | if (fESDtrack) { | |
297 | if (fESDtrack->GetStatus()&AliESDtrack::kTPCin) { | |
298 | AliTracker::FillResiduals(this,p,cov,c->GetVolumeId()); | |
299 | } | |
300 | } | |
301 | ||
302 | fIndex[n]=index; | |
303 | SetNumberOfClusters(n+1); | |
304 | SetChi2(GetChi2()+chi2); | |
305 | ||
306 | return kTRUE; | |
307 | } | |
308 | ||
309 | Bool_t AliITStrackV2::Invariant() const { | |
310 | //------------------------------------------------------------------ | |
311 | // This function is for debugging purpose only | |
312 | //------------------------------------------------------------------ | |
313 | if(!fCheckInvariant) return kTRUE; | |
314 | ||
315 | Int_t n=GetNumberOfClusters(); | |
316 | static Float_t bz = GetBz(); | |
317 | // take into account the misalignment error | |
318 | Float_t maxMisalErrY2=0,maxMisalErrZ2=0; | |
319 | //RS | |
320 | const AliITSRecoParam* recopar = AliITSReconstructor::GetRecoParam(); | |
321 | if (!recopar) recopar = AliITSRecoParam::GetHighFluxParam(); | |
322 | ||
323 | for (Int_t lay=0; lay<AliITSgeomTGeo::kNLayers; lay++) { | |
324 | maxMisalErrY2 = TMath::Max(maxMisalErrY2,recopar->GetClusterMisalErrorY(lay,bz)); | |
325 | maxMisalErrZ2 = TMath::Max(maxMisalErrZ2,recopar->GetClusterMisalErrorZ(lay,bz)); | |
326 | } | |
327 | maxMisalErrY2 *= maxMisalErrY2; | |
328 | maxMisalErrZ2 *= maxMisalErrZ2; | |
329 | // this is because when we reset before refitting, we multiply the | |
330 | // matrix by 10 | |
331 | maxMisalErrY2 *= 10.; | |
332 | maxMisalErrZ2 *= 10.; | |
333 | ||
334 | Double_t sP2=GetParameter()[2]; | |
335 | if (TMath::Abs(sP2) >= kAlmost1){ | |
336 | if (n>fgkWARN) AliDebug(1,Form("fP2=%f\n",sP2)); | |
337 | return kFALSE; | |
338 | } | |
339 | Double_t sC00=GetCovariance()[0]; | |
340 | if (sC00<=0 || sC00>(9.+maxMisalErrY2)) { | |
341 | if (n>fgkWARN) AliDebug(1,Form("fC00=%f\n",sC00)); | |
342 | return kFALSE; | |
343 | } | |
344 | Double_t sC11=GetCovariance()[2]; | |
345 | if (sC11<=0 || sC11>(9.+maxMisalErrZ2)) { | |
346 | if (n>fgkWARN) AliDebug(1,Form("fC11=%f\n",sC11)); | |
347 | return kFALSE; | |
348 | } | |
349 | Double_t sC22=GetCovariance()[5]; | |
350 | if (sC22<=0 || sC22>1.) { | |
351 | if (n>fgkWARN) AliDebug(1,Form("fC22=%f\n",sC22)); | |
352 | return kFALSE; | |
353 | } | |
354 | Double_t sC33=GetCovariance()[9]; | |
355 | if (sC33<=0 || sC33>1.) { | |
356 | if (n>fgkWARN) AliDebug(1,Form("fC33=%f\n",sC33)); | |
357 | return kFALSE; | |
358 | } | |
359 | Double_t sC44=GetCovariance()[14]; | |
360 | if (sC44<=0 /*|| sC44>6e-5*/) { | |
361 | if (n>fgkWARN) AliDebug(1,Form("fC44=%f\n",sC44)); | |
362 | return kFALSE; | |
363 | } | |
364 | ||
365 | return kTRUE; | |
366 | } | |
367 | ||
368 | //____________________________________________________________________________ | |
369 | Bool_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) { | |
370 | //------------------------------------------------------------------ | |
371 | //This function propagates a track | |
372 | //------------------------------------------------------------------ | |
373 | //Double_t bz=GetBz(); | |
374 | //if (!AliExternalTrackParam::Propagate(alp,xk,bz)) return kFALSE; | |
375 | Double_t b[3]; GetBxByBz(b); | |
376 | if (!AliExternalTrackParam::PropagateBxByBz(alp,xk,b)) return kFALSE; | |
377 | ||
378 | if (!Invariant()) { | |
379 | Int_t n=GetNumberOfClusters(); | |
380 | if (n>fgkWARN) AliDebug(1,"Wrong invariant !"); | |
381 | return kFALSE; | |
382 | } | |
383 | ||
384 | return kTRUE; | |
385 | } | |
386 | ||
387 | Bool_t AliITStrackV2::MeanBudgetToPrimVertex(Double_t xyz[3], Double_t step, Double_t &d) const { | |
388 | ||
389 | //------------------------------------------------------------------- | |
390 | // Get the mean material budget between the actual point and the | |
391 | // primary vertex. (L.Gaudichet) | |
392 | //------------------------------------------------------------------- | |
393 | ||
394 | Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha()); | |
395 | Double_t vertexX = xyz[0]*cs + xyz[1]*sn; | |
396 | ||
397 | Int_t nstep = Int_t((GetX()-vertexX)/step); | |
398 | if (nstep<1) nstep = 1; | |
399 | step = (GetX()-vertexX)/nstep; | |
400 | ||
401 | // Double_t mparam[7], densMean=0, radLength=0, length=0; | |
402 | Double_t mparam[7]; | |
403 | Double_t p1[3], p2[3], x = GetX(), bz = GetBz(); | |
404 | GetXYZ(p1); | |
405 | ||
406 | d=0.; | |
407 | ||
408 | for (Int_t i=0; i<nstep; i++) { | |
409 | x += step; | |
410 | if (!GetXYZAt(x, bz, p2)) return kFALSE; | |
411 | AliTracker::MeanMaterialBudget(p1, p2, mparam); | |
412 | if (mparam[1]>900000) return kFALSE; | |
413 | d += mparam[1]; | |
414 | ||
415 | p1[0] = p2[0]; | |
416 | p1[1] = p2[1]; | |
417 | p1[2] = p2[2]; | |
418 | } | |
419 | ||
420 | return kTRUE; | |
421 | } | |
422 | ||
423 | Bool_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) { | |
424 | //------------------------------------------------------------------ | |
425 | //This function improves angular track parameters | |
426 | //------------------------------------------------------------------ | |
427 | //Store the initail track parameters | |
428 | ||
429 | Double_t x = GetX(); | |
430 | Double_t alpha = GetAlpha(); | |
431 | Double_t par[] = {GetY(),GetZ(),GetSnp(),GetTgl(),GetSigned1Pt()}; | |
432 | Double_t cov[] = { | |
433 | GetSigmaY2(), | |
434 | GetSigmaZY(), | |
435 | GetSigmaZ2(), | |
436 | GetSigmaSnpY(), | |
437 | GetSigmaSnpZ(), | |
438 | GetSigmaSnp2(), | |
439 | GetSigmaTglY(), | |
440 | GetSigmaTglZ(), | |
441 | GetSigmaTglSnp(), | |
442 | GetSigmaTgl2(), | |
443 | GetSigma1PtY(), | |
444 | GetSigma1PtZ(), | |
445 | GetSigma1PtSnp(), | |
446 | GetSigma1PtTgl(), | |
447 | GetSigma1Pt2() | |
448 | }; | |
449 | ||
450 | ||
451 | Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha()); | |
452 | Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex | |
453 | Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the | |
454 | Double_t zv = xyz[2]; // local frame | |
455 | ||
456 | Double_t dx = x - xv, dy = par[0] - yv, dz = par[1] - zv; | |
457 | Double_t r2=dx*dx + dy*dy; | |
458 | Double_t p2=(1.+ GetTgl()*GetTgl())/(GetSigned1Pt()*GetSigned1Pt()); | |
459 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); | |
460 | x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp())); | |
461 | Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0; | |
462 | //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33; | |
463 | ||
464 | Double_t bz=GetBz(); | |
465 | Double_t cnv=bz*kB2C; | |
466 | Double_t curv=GetC(bz); | |
467 | { | |
468 | Double_t dummy = 4/r2 - curv*curv; | |
469 | if (dummy < 0) return kFALSE; | |
470 | Double_t parp = 0.5*(curv*dx + dy*TMath::Sqrt(dummy)); | |
471 | Double_t sigma2p = theta2*(1.-GetSnp())*(1.+GetSnp())*(1. + GetTgl()*GetTgl()); | |
472 | Double_t ovSqr2 = 1./TMath::Sqrt(r2); | |
473 | Double_t tfact = ovSqr2*(1.-dy*ovSqr2)*(1.+dy*ovSqr2); | |
474 | sigma2p += cov[0]*tfact*tfact; | |
475 | sigma2p += ers[1]*ers[1]/r2; | |
476 | sigma2p += 0.25*cov[14]*cnv*cnv*dx*dx; | |
477 | Double_t eps2p=sigma2p/(cov[5] + sigma2p); | |
478 | par[0] += cov[3]/(cov[5] + sigma2p)*(parp - GetSnp()); | |
479 | par[2] = eps2p*GetSnp() + (1 - eps2p)*parp; | |
480 | cov[5] *= eps2p; | |
481 | cov[3] *= eps2p; | |
482 | } | |
483 | { | |
484 | Double_t parl=0.5*curv*dz/TMath::ASin(0.5*curv*TMath::Sqrt(r2)); | |
485 | Double_t sigma2l=theta2; | |
486 | sigma2l += cov[2]/r2 + cov[0]*dy*dy*dz*dz/(r2*r2*r2); | |
487 | sigma2l += ers[2]*ers[2]/r2; | |
488 | Double_t eps2l = sigma2l/(cov[9] + sigma2l); | |
489 | par[1] += cov[7 ]/(cov[9] + sigma2l)*(parl - par[3]); | |
490 | par[4] += cov[13]/(cov[9] + sigma2l)*(parl - par[3]); | |
491 | par[3] = eps2l*par[3] + (1-eps2l)*parl; | |
492 | cov[9] *= eps2l; | |
493 | cov[13]*= eps2l; | |
494 | cov[7] *= eps2l; | |
495 | } | |
496 | ||
497 | Set(x,alpha,par,cov); | |
498 | ||
499 | if (!Invariant()) return kFALSE; | |
500 | ||
501 | return kTRUE; | |
502 | } | |
503 | ||
504 | void AliITStrackV2::CookdEdx(Double_t /*low*/, Double_t /*up*/) { | |
505 | //----------------------------------------------------------------- | |
506 | // This function calculates dE/dX within the "low" and "up" cuts. | |
507 | // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch | |
508 | // Updated: F. Prino 8-June-2009 | |
509 | //----------------------------------------------------------------- | |
510 | // The cluster order is: SDD-1, SDD-2, SSD-1, SSD-2 | |
511 | ||
512 | Int_t nc=0; | |
513 | Float_t dedx[4]; | |
514 | for (Int_t il=0; il<4; il++) { // count good (>0) dE/dx values | |
515 | if(fdEdxSample[il]>0.){ | |
516 | dedx[nc]= fdEdxSample[il]; | |
517 | nc++; | |
518 | } | |
519 | } | |
520 | if(nc<1){ | |
521 | SetdEdx(0.); | |
522 | return; | |
523 | } | |
524 | ||
525 | Int_t swap; // sort in ascending order | |
526 | do { | |
527 | swap=0; | |
528 | for (Int_t i=0; i<nc-1; i++) { | |
529 | if (dedx[i]<=dedx[i+1]) continue; | |
530 | Float_t tmp=dedx[i]; | |
531 | dedx[i]=dedx[i+1]; | |
532 | dedx[i+1]=tmp; | |
533 | swap++; | |
534 | } | |
535 | } while (swap); | |
536 | ||
537 | ||
538 | Double_t sumamp=0,sumweight=0; | |
539 | Double_t weight[4]={1.,1.,0.,0.}; | |
540 | if(nc==3) weight[1]=0.5; | |
541 | else if(nc<3) weight[1]=0.; | |
542 | for (Int_t i=0; i<nc; i++) { | |
543 | sumamp+= dedx[i]*weight[i]; | |
544 | sumweight+=weight[i]; | |
545 | } | |
546 | SetdEdx(sumamp/sumweight); | |
547 | } | |
548 | ||
549 | //____________________________________________________________________________ | |
550 | Bool_t AliITStrackV2:: | |
551 | GetPhiZat(Double_t r, Double_t &phi, Double_t &z) const { | |
552 | //------------------------------------------------------------------ | |
553 | // This function returns the global cylindrical (phi,z) of the track | |
554 | // position estimated at the radius r. | |
555 | // The track curvature is neglected. | |
556 | //------------------------------------------------------------------ | |
557 | Double_t d=GetD(0.,0.); | |
558 | if (TMath::Abs(d) > r) { | |
559 | if (r>1e-1) return kFALSE; | |
560 | r = TMath::Abs(d); | |
561 | } | |
562 | ||
563 | Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY()); | |
564 | if (TMath::Abs(d) > rcurr) return kFALSE; | |
565 | Double_t globXYZcurr[3]; GetXYZ(globXYZcurr); | |
566 | Double_t phicurr=TMath::ATan2(globXYZcurr[1],globXYZcurr[0]); | |
567 | ||
568 | if (GetX()>=0.) { | |
569 | phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr); | |
570 | } else { | |
571 | phi=phicurr+TMath::ASin(d/r)+TMath::ASin(d/rcurr)-TMath::Pi(); | |
572 | } | |
573 | ||
574 | // return a phi in [0,2pi[ | |
575 | if (phi<0.) phi+=2.*TMath::Pi(); | |
576 | else if (phi>=2.*TMath::Pi()) phi-=2.*TMath::Pi(); | |
577 | z=GetZ()+GetTgl()*(TMath::Sqrt((r-d)*(r+d))-TMath::Sqrt((rcurr-d)*(rcurr+d))); | |
578 | return kTRUE; | |
579 | } | |
580 | //____________________________________________________________________________ | |
581 | Bool_t AliITStrackV2:: | |
582 | GetLocalXat(Double_t r,Double_t &xloc) const { | |
583 | //------------------------------------------------------------------ | |
584 | // This function returns the local x of the track | |
585 | // position estimated at the radius r. | |
586 | // The track curvature is neglected. | |
587 | //------------------------------------------------------------------ | |
588 | Double_t d=GetD(0.,0.); | |
589 | if (TMath::Abs(d) > r) { | |
590 | if (r>1e-1) return kFALSE; | |
591 | r = TMath::Abs(d); | |
592 | } | |
593 | ||
594 | Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY()); | |
595 | Double_t globXYZcurr[3]; GetXYZ(globXYZcurr); | |
596 | Double_t phicurr=TMath::ATan2(globXYZcurr[1],globXYZcurr[0]); | |
597 | Double_t phi; | |
598 | if (GetX()>=0.) { | |
599 | phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr); | |
600 | } else { | |
601 | phi=phicurr+TMath::ASin(d/r)+TMath::ASin(d/rcurr)-TMath::Pi(); | |
602 | } | |
603 | ||
604 | xloc=r*(TMath::Cos(phi)*TMath::Cos(GetAlpha()) | |
605 | +TMath::Sin(phi)*TMath::Sin(GetAlpha())); | |
606 | ||
607 | return kTRUE; | |
608 | } | |
609 | ||
610 | //____________________________________________________________________________ | |
611 | Bool_t AliITStrackV2::ImproveKalman(Double_t xyz[3],Double_t ers[3], const Double_t* xlMS, const Double_t* x2X0MS, Int_t nMS) | |
612 | { | |
613 | // Substitute the state of the track (p_{k|k},C_{k|k}) at the k-th measumerent by its | |
614 | // smoothed value from the k-th measurement + measurement at the vertex. | |
615 | // Account for the MS on nMS layers at x-postions xlMS with x/x0 = x2X0MS | |
616 | // p_{k|kv} = p_{k|k} + C_{k|k}*D^Tr_{k+1} B^{-1}_{k+1} ( vtx - D_{k+1}*p_{k|k}) | |
617 | // C_{k|kv} = C_{k|k}*( I - D^Tr_{k+1} B^{-1}_{k+1} D_{k+1} C^Tr_{k|k}) | |
618 | // | |
619 | // where D_{k} = H_{k} F_{k} with H being the matrix converting the tracks parameters | |
620 | // to measurements m_{k} = H_{k} p_{k} and F_{k} the matrix propagating the track between the | |
621 | // the point k-1 and k: p_{k|k-1} = F_{k} p_{k-1|k-1} | |
622 | // | |
623 | // B_{k+1} = V_{k+1} + H_{k+1} C_{k+1|k} H^Tr_{k+1} with V_{k+1} being the error of the measurment | |
624 | // at point k+1 (i.e. vertex), and C_{k+1|k} - error matrix extrapolated from k-th measurement to | |
625 | // k+1 (vtx) and accounting for the MS inbetween | |
626 | // | |
627 | // H = {{1,0,0,0,0},{0,1,0,0,0}} | |
628 | // | |
629 | double covc[15], *cori = (double*) GetCovariance(),par[5] = {GetY(),GetZ(),GetSnp(),GetTgl(),GetSigned1Pt()}, | |
630 | &c00=cori[0], | |
631 | &c01=cori[1],&c11=cori[2], | |
632 | &c02=cori[3],&c12=cori[4],&c22=cori[5], | |
633 | &c03=cori[6],&c13=cori[7],&c23=cori[8],&c33=cori[9], | |
634 | &c04=cori[10],&c14=cori[11],&c24=cori[12],&c34=cori[13],&c44=cori[14], | |
635 | // for smoothed cov matrix | |
636 | &cov00=covc[0], | |
637 | &cov01=covc[1],&cov11=covc[2], | |
638 | &cov02=covc[3],&cov12=covc[4],&cov22=covc[5], | |
639 | &cov03=covc[6],&cov13=covc[7],&cov23=covc[8],&cov33=covc[9], | |
640 | &cov04=covc[10],&cov14=covc[11],&cov24=covc[12],&cov34=covc[13],&cov44=covc[14]; | |
641 | // | |
642 | double x = GetX(), alpha = GetAlpha(); | |
643 | // vertex in the track frame | |
644 | double cs=TMath::Cos(alpha), sn=TMath::Sin(alpha); | |
645 | double xv = xyz[0]*cs + xyz[1]*sn, yv =-xyz[0]*sn + xyz[1]*cs, zv = xyz[2]; | |
646 | double dx = xv - GetX(); | |
647 | if (TMath::Abs(dx)<=kAlmost0) return kTRUE; | |
648 | // | |
649 | double cnv=GetBz()*kB2C, x2r=cnv*par[4]*dx, f1=par[2], f2=f1+x2r; | |
650 | if (TMath::Abs(f1) >= kAlmost1 || TMath::Abs(f2) >= kAlmost1) { | |
651 | AliInfo(Form("Fail: %+e %+e",f1,f2)); | |
652 | return kFALSE; | |
653 | } | |
654 | double r1=TMath::Sqrt((1.-f1)*(1.+f1)), r2=TMath::Sqrt((1.-f2)*(1.+f2)), dx2r=dx/(r1+r2); | |
655 | // elements of matrix F_{k+1} (1s on diagonal) | |
656 | double f02 = 2*dx2r, f04 = cnv*dx*dx2r, f13/*, f24 = cnv*dx*/; | |
657 | if (TMath::Abs(x2r)<0.05) f13 = dx*r2+f2*(f1+f2)*dx2r; // see AliExternalTrackParam::PropagateTo | |
658 | else { | |
659 | double dy2dx = (f1+f2)/(r1+r2); | |
660 | f13 = 2*TMath::ASin(0.5*TMath::Sqrt(1+dy2dx*dy2dx)*x2r)/(cnv*par[4]); | |
661 | } | |
662 | // elements of matrix D_{k+1} = H_{k+1} * F_{k+1} | |
663 | // double d00 = 1., d11 = 1.; | |
664 | double &d02 = f02, &d04 = f04, &d13 = f13; | |
665 | // | |
666 | // elements of matrix DC = D_{k+1}*C_{kk}^T | |
667 | double dc00 = c00+c02*d02+c04*d04, dc10 = c01+c03*d13; | |
668 | double dc01 = c01+c12*d02+c14*d04, dc11 = c11+c13*d13; | |
669 | double dc02 = c02+c22*d02+c24*d04, dc12 = c12+c23*d13; | |
670 | double dc03 = c03+c23*d02+c34*d04, dc13 = c13+c33*d13; | |
671 | double dc04 = c04+c24*d02+c44*d04, dc14 = c14+c34*d13; | |
672 | // | |
673 | // difference between the vertex and the the track extrapolated to vertex | |
674 | yv -= par[0] + par[2]*d02 + par[4]*d04; | |
675 | zv -= par[1] + par[3]*d13; | |
676 | // | |
677 | // y,z part of the cov.matrix extrapolated to vtx (w/o MS contribution) | |
678 | // C_{k+1,k} = H F_{k+1} C_{k,k} F^Tr_{k+1} H^Tr = D C D^Tr | |
679 | double cv00 = dc00+dc02*d02+dc04*d04, cv01 = dc01+dc03*d13, cv11 = dc11+dc13*d13; | |
680 | // | |
681 | // add MS contribution layer by layer | |
682 | double xCurr = x; | |
683 | double p2Curr = par[2]; | |
684 | // | |
685 | // precalculated factors of MS contribution matrix: | |
686 | double ms22t = (1. + par[3]*par[3]); | |
687 | double ms33t = ms22t*ms22t; | |
688 | double p34 = par[3]*par[4]; | |
689 | double ms34t = p34*ms22t; | |
690 | double ms44t = p34*p34; | |
691 | // | |
692 | double p2=(1.+ par[3]*par[3])/(par[4]*par[4]); | |
693 | double beta2 = p2/(p2+GetMass()*GetMass()); | |
694 | double theta2t = 14.1*14.1/(beta2*p2*1e6) * (1. + par[3]*par[3]); | |
695 | // | |
696 | // account for the MS in the layers between the last measurement and the vertex | |
697 | for (int il=0;il<nMS;il++) { | |
698 | double dfx = xlMS[il] - xCurr; | |
699 | xCurr = xlMS[il]; | |
700 | p2Curr += dfx*cnv*par[4]; // p2 at the scattering layer | |
701 | double dxL=xv - xCurr; // distance from scatering layer to vtx | |
702 | double x2rL=cnv*par[4]*dxL, f1L=p2Curr, f2L=f1L+x2rL; | |
703 | if (TMath::Abs(f1L) >= kAlmost1 || TMath::Abs(f2L) >= kAlmost1) { | |
704 | AliInfo(Form("FailMS at step %d of %d: dfx:%e dxL:%e %e %e",il,nMS,dfx,dxL,f1L,f2L)); | |
705 | return kFALSE; | |
706 | } | |
707 | double r1L=TMath::Sqrt((1.-f1L)*(1.+f1L)), r2L=TMath::Sqrt((1.-f2L)*(1.+f2L)), dx2rL=dxL/(r1L+r2L); | |
708 | // elements of matrix for propagation from scatering layer to vertex | |
709 | double f02L = 2*dx2rL, f04L = cnv*dxL*dx2rL, f13L/*, f24L = cnv*dxL*/; | |
710 | if (TMath::Abs(x2rL)<0.05) f13L = dxL*r2L+f2L*(f1L+f2L)*dx2rL; // see AliExternalTrackParam::PropagateTo | |
711 | else { | |
712 | double dy2dxL = (f1L+f2L)/(r1L+r2L); | |
713 | f13L = 2*TMath::ASin(0.5*TMath::Sqrt(1+dy2dxL*dy2dxL)*x2rL)/(cnv*par[4]); | |
714 | } | |
715 | // MS contribution matrix: | |
716 | double theta2 = theta2t*TMath::Abs(x2X0MS[il]); | |
717 | double ms22 = theta2*(1.-p2Curr)*(1.+p2Curr)*ms22t; | |
718 | double ms33 = theta2*ms33t; | |
719 | double ms34 = theta2*ms34t; | |
720 | double ms44 = theta2*ms44t; | |
721 | // | |
722 | // add H F MS F^Tr H^Tr to cv | |
723 | cv00 += f02L*f02L*ms22 + f04L*f04L*ms44; | |
724 | cv01 += f04L*f13L*ms34; | |
725 | cv11 += f13L*f13L*ms33; | |
726 | } | |
727 | // | |
728 | // inverse of matrix B | |
729 | double b11 = ers[1]*ers[1] + cv00; | |
730 | double b00 = ers[2]*ers[2] + cv11; | |
731 | double det = b11*b00 - cv01*cv01; | |
732 | if (TMath::Abs(det)<kAlmost0) { | |
733 | AliInfo(Form("Fail on det %e: %e %e %e",det,cv00,cv11,cv01)); | |
734 | return kFALSE; | |
735 | } | |
736 | det = 1./det; | |
737 | b00 *= det; b11 *= det; | |
738 | double b01 = -cv01*det; | |
739 | // | |
740 | // elements of matrix DC^Tr * B^-1 | |
741 | double dcb00 = b00*dc00+b01*dc10, dcb01 = b01*dc00+b11*dc10; | |
742 | double dcb10 = b00*dc01+b01*dc11, dcb11 = b01*dc01+b11*dc11; | |
743 | double dcb20 = b00*dc02+b01*dc12, dcb21 = b01*dc02+b11*dc12; | |
744 | double dcb30 = b00*dc03+b01*dc13, dcb31 = b01*dc03+b11*dc13; | |
745 | double dcb40 = b00*dc04+b01*dc14, dcb41 = b01*dc04+b11*dc14; | |
746 | // | |
747 | // p_{k|k+1} = p_{k|k} + C_{k|k}*D^Tr_{k+1} B^{-1}_{k+1} ( vtx - D_{k+1}*p_{k|k}) | |
748 | par[0] += dcb00*yv + dcb01*zv; | |
749 | par[1] += dcb10*yv + dcb11*zv; | |
750 | par[2] += dcb20*yv + dcb21*zv; | |
751 | par[3] += dcb30*yv + dcb31*zv; | |
752 | par[4] += dcb40*yv + dcb41*zv; | |
753 | // | |
754 | // C_{k|kv} = C_{k|k} - C_{k|k} D^Tr_{k+1} B^{-1}_{k+1} D_{k+1} C^Tr_{k|k}) | |
755 | // | |
756 | cov00 = c00 - (dc00*dcb00 + dc10*dcb01); | |
757 | cov01 = c01 - (dc01*dcb00 + dc11*dcb01); | |
758 | cov02 = c02 - (dc02*dcb00 + dc12*dcb01); | |
759 | cov03 = c03 - (dc03*dcb00 + dc13*dcb01); | |
760 | cov04 = c04 - (dc04*dcb00 + dc14*dcb01); | |
761 | // | |
762 | cov11 = c11 - (dc01*dcb10 + dc11*dcb11); | |
763 | cov12 = c12 - (dc02*dcb10 + dc12*dcb11); | |
764 | cov13 = c13 - (dc03*dcb10 + dc13*dcb11); | |
765 | cov14 = c14 - (dc04*dcb10 + dc14*dcb11); | |
766 | // | |
767 | cov22 = c22 - (dc02*dcb20 + dc12*dcb21); | |
768 | cov23 = c23 - (dc03*dcb20 + dc13*dcb21); | |
769 | cov24 = c24 - (dc04*dcb20 + dc14*dcb21); | |
770 | // | |
771 | cov33 = c33 - (dc03*dcb30 + dc13*dcb31); | |
772 | cov34 = c34 - (dc04*dcb30 + dc14*dcb31); | |
773 | // | |
774 | cov44 = c44 - (dc04*dcb40 + dc14*dcb41); | |
775 | // | |
776 | Set(x,alpha,par,covc); | |
777 | if (!Invariant()) { | |
778 | AliInfo(Form("Fail on Invariant, X=%e",GetX())); | |
779 | return kFALSE; | |
780 | } | |
781 | return kTRUE; | |
782 | // | |
783 | } |