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Overlap fixed (M. Sitta)
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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 "AliTracker.h"
28#include "AliESDtrack.h"
29#include "AliITStrackV2.h"
30
31const Int_t AliITStrackV2::fgkWARN = 5;
32
33ClassImp(AliITStrackV2)
34
35
36//____________________________________________________________________________
37AliITStrackV2::AliITStrackV2() : AliKalmanTrack(),
38 fdEdx(0),
39 fESDtrack(0)
40{
41 for(Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) {fIndex[i]=-1; fModule[i]=-1;}
42 for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
43}
44
45
46//____________________________________________________________________________
47AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c) throw (const Char_t *) :
48 AliKalmanTrack(),
49 fdEdx(t.GetITSsignal()),
50 fESDtrack(&t)
51{
52 //------------------------------------------------------------------
53 // Conversion ESD track -> ITS track.
54 // If c==kTRUE, create the ITS track out of the constrained params.
55 //------------------------------------------------------------------
56 const AliExternalTrackParam *par=&t;
57 if (c) {
58 par=t.GetConstrainedParam();
59 if (!par) throw "AliITStrackV2: conversion failed !\n";
60 }
61 Set(par->GetX(),par->GetAlpha(),par->GetParameter(),par->GetCovariance());
62
63 //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
64
65 SetLabel(t.GetLabel());
66 SetMass(t.GetMass());
67 SetNumberOfClusters(t.GetITSclusters(fIndex));
68
69 if (t.GetStatus()&AliESDtrack::kTIME) {
70 StartTimeIntegral();
71 Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times);
72 SetIntegratedLength(t.GetIntegratedLength());
73 }
74
75 for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
76}
77
78void AliITStrackV2::UpdateESDtrack(ULong_t flags) const {
79 fESDtrack->UpdateTrackParams(this,flags);
80 // copy the module indices
81 for(Int_t i=0;i<12;i++) {
82 // printf(" %d\n",GetModuleIndex(i));
83 fESDtrack->SetITSModuleIndex(i,GetModuleIndex(i));
84 }
85}
86
87//____________________________________________________________________________
88AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) :
89 AliKalmanTrack(t),
90 fdEdx(t.fdEdx),
91 fESDtrack(t.fESDtrack)
92{
93 //------------------------------------------------------------------
94 //Copy constructor
95 //------------------------------------------------------------------
96 Int_t i;
97 for (i=0; i<4; i++) fdEdxSample[i]=t.fdEdxSample[i];
98 for (i=0; i<2*AliITSgeomTGeo::GetNLayers(); i++) {
99 fIndex[i]=t.fIndex[i];
100 fModule[i]=t.fModule[i];
101 }
102}
103
104//_____________________________________________________________________________
105Int_t AliITStrackV2::Compare(const TObject *o) const {
106 //-----------------------------------------------------------------
107 // This function compares tracks according to the their curvature
108 //-----------------------------------------------------------------
109 AliITStrackV2 *t=(AliITStrackV2*)o;
110 //Double_t co=OneOverPt();
111 //Double_t c =OneOverPt();
112 Double_t co=t->GetSigmaY2()*t->GetSigmaZ2();
113 Double_t c =GetSigmaY2()*GetSigmaZ2();
114 if (c>co) return 1;
115 else if (c<co) return -1;
116 return 0;
117}
118
119//____________________________________________________________________________
120Bool_t
121AliITStrackV2::PropagateToVertex(const AliESDVertex *v,Double_t d,Double_t x0)
122{
123 //------------------------------------------------------------------
124 //This function propagates a track to the minimal distance from the origin
125 //------------------------------------------------------------------
126 Double_t bz=GetBz();
127 if (PropagateToDCA(v,bz,kVeryBig)) {
128 Double_t xOverX0,xTimesRho;
129 xOverX0 = d; xTimesRho = d*x0;
130 if (CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kTRUE;
131 }
132 return kFALSE;
133}
134
135//____________________________________________________________________________
136Bool_t AliITStrackV2::
137GetGlobalXYZat(Double_t xloc, Double_t &x, Double_t &y, Double_t &z) const {
138 //------------------------------------------------------------------
139 //This function returns a track position in the global system
140 //------------------------------------------------------------------
141 Double_t r[3];
142 Bool_t rc=GetXYZAt(xloc, AliTracker::GetBz(), r);
143 x=r[0]; y=r[1]; z=r[2];
144 return rc;
145}
146
147//_____________________________________________________________________________
148Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const {
149 //-----------------------------------------------------------------
150 // This function calculates a predicted chi2 increment.
151 //-----------------------------------------------------------------
152 Double_t p[2]={c->GetY(), c->GetZ()};
153 Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()};
154 return AliExternalTrackParam::GetPredictedChi2(p,cov);
155}
156
157//____________________________________________________________________________
158Bool_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) {
159 //------------------------------------------------------------------
160 //This function propagates a track
161 //------------------------------------------------------------------
162
163 Double_t oldX=GetX(), oldY=GetY(), oldZ=GetZ();
164
165 Double_t bz=GetBz();
166 if (!AliExternalTrackParam::PropagateTo(xk,bz)) return kFALSE;
167 Double_t xOverX0,xTimesRho;
168 xOverX0 = d; xTimesRho = d*x0;
169 if (!CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kFALSE;
170
171 Double_t x=GetX(), y=GetY(), z=GetZ();
172 if (IsStartedTimeIntegral() && x>oldX) {
173 Double_t l2 = (x-oldX)*(x-oldX) + (y-oldY)*(y-oldY) + (z-oldZ)*(z-oldZ);
174 AddTimeStep(TMath::Sqrt(l2));
175 }
176
177 return kTRUE;
178}
179
180//____________________________________________________________________________
181Bool_t AliITStrackV2::PropagateToTGeo(Double_t xToGo, Int_t nstep, Double_t &xOverX0, Double_t &xTimesRho) {
182 //-------------------------------------------------------------------
183 // Propagates the track to a reference plane x=xToGo in n steps.
184 // These n steps are only used to take into account the curvature.
185 // The material is calculated with TGeo. (L.Gaudichet)
186 //-------------------------------------------------------------------
187
188 Double_t startx = GetX(), starty = GetY(), startz = GetZ();
189 Double_t sign = (startx<xToGo) ? -1.:1.;
190 Double_t step = (xToGo-startx)/TMath::Abs(nstep);
191
192 Double_t start[3], end[3], mparam[7], bz = GetBz();
193 Double_t x = startx;
194
195 for (Int_t i=0; i<nstep; i++) {
196
197 GetXYZ(start); //starting global position
198 x += step;
199 if (!GetXYZAt(x, bz, end)) return kFALSE;
200 if (!AliExternalTrackParam::PropagateTo(x, bz)) return kFALSE;
201 AliTracker::MeanMaterialBudget(start, end, mparam);
202 if (mparam[1]<900000) {
203 xTimesRho = sign*mparam[4]*mparam[0];
204 xOverX0 = mparam[1];
205 if (!AliExternalTrackParam::CorrectForMeanMaterial(xOverX0,
206 xTimesRho,GetMass())) return kFALSE;
207 }
208 }
209
210 if (IsStartedTimeIntegral() && GetX()>startx) {
211 Double_t l2 = ( (GetX()-startx)*(GetX()-startx) +
212 (GetY()-starty)*(GetY()-starty) +
213 (GetZ()-startz)*(GetZ()-startz) );
214 AddTimeStep(TMath::Sqrt(l2));
215 }
216
217 return kTRUE;
218}
219
220//____________________________________________________________________________
221Bool_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, Int_t index)
222{
223 //------------------------------------------------------------------
224 //This function updates track parameters
225 //------------------------------------------------------------------
226 Double_t p[2]={c->GetY(), c->GetZ()};
227 Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()};
228
229 if (!AliExternalTrackParam::Update(p,cov)) return kFALSE;
230
231 if (!Invariant()) {
232 AliWarning("Wrong invariant !");
233 return kFALSE;
234 }
235
236 if (chi2<0) return kTRUE;
237
238 AliTracker::FillResiduals(this,p,cov,c->GetVolumeId());
239
240 Int_t n=GetNumberOfClusters();
241 fIndex[n]=index;
242 SetNumberOfClusters(n+1);
243 SetChi2(GetChi2()+chi2);
244
245 return kTRUE;
246}
247
248Bool_t AliITStrackV2::Invariant() const {
249 //------------------------------------------------------------------
250 // This function is for debugging purpose only
251 //------------------------------------------------------------------
252 Int_t n=GetNumberOfClusters();
253
254 Double_t sP2=GetParameter()[2];
255 if (TMath::Abs(sP2) >= kAlmost1){
256 if (n>fgkWARN) Warning("Invariant","fP2=%f\n",sP2);
257 return kFALSE;
258 }
259 Double_t sC00=GetCovariance()[0];
260 if (sC00<=0 || sC00>9.) {
261 if (n>fgkWARN) Warning("Invariant","fC00=%f\n",sC00);
262 return kFALSE;
263 }
264 Double_t sC11=GetCovariance()[2];
265 if (sC11<=0 || sC11>9.) {
266 if (n>fgkWARN) Warning("Invariant","fC11=%f\n",sC11);
267 return kFALSE;
268 }
269 Double_t sC22=GetCovariance()[5];
270 if (sC22<=0 || sC22>1.) {
271 if (n>fgkWARN) Warning("Invariant","fC22=%f\n",sC22);
272 return kFALSE;
273 }
274 Double_t sC33=GetCovariance()[9];
275 if (sC33<=0 || sC33>1.) {
276 if (n>fgkWARN) Warning("Invariant","fC33=%f\n",sC33);
277 return kFALSE;
278 }
279 Double_t sC44=GetCovariance()[14];
280 if (sC44<=0 /*|| sC44>6e-5*/) {
281 if (n>fgkWARN) Warning("Invariant","fC44=%f\n",sC44);
282 return kFALSE;
283 }
284
285 return kTRUE;
286}
287
288//____________________________________________________________________________
289Bool_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) {
290 //------------------------------------------------------------------
291 //This function propagates a track
292 //------------------------------------------------------------------
293 Double_t bz=GetBz();
294 if (!AliExternalTrackParam::Propagate(alp,xk,bz)) return kFALSE;
295
296 if (!Invariant()) {
297 AliWarning("Wrong invariant !");
298 return kFALSE;
299 }
300
301 return kTRUE;
302}
303
304Bool_t AliITStrackV2::MeanBudgetToPrimVertex(Double_t xyz[3], Double_t step, Double_t &d) const {
305
306 //-------------------------------------------------------------------
307 // Get the mean material budget between the actual point and the
308 // primary vertex. (L.Gaudichet)
309 //-------------------------------------------------------------------
310
311 Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha());
312 Double_t vertexX = xyz[0]*cs + xyz[1]*sn;
313
314 Int_t nstep = Int_t((GetX()-vertexX)/step);
315 if (nstep<1) nstep = 1;
316 step = (GetX()-vertexX)/nstep;
317
318 // Double_t mparam[7], densMean=0, radLength=0, length=0;
319 Double_t mparam[7];
320 Double_t p1[3], p2[3], x = GetX(), bz = GetBz();
321 GetXYZ(p1);
322
323 d=0.;
324
325 for (Int_t i=0; i<nstep; i++) {
326 x += step;
327 if (!GetXYZAt(x, bz, p2)) return kFALSE;
328 AliTracker::MeanMaterialBudget(p1, p2, mparam);
329 if (mparam[1]>900000) return kFALSE;
330 d += mparam[1];
331
332 p1[0] = p2[0];
333 p1[1] = p2[1];
334 p1[2] = p2[2];
335 }
336
337 return kTRUE;
338}
339
340Bool_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) {
341 //------------------------------------------------------------------
342 //This function improves angular track parameters
343 //------------------------------------------------------------------
344 Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha());
345//Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex
346 Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the
347 Double_t zv = xyz[2]; // local frame
348
349 Double_t dy = Par(0) - yv, dz = Par(1) - zv;
350 Double_t r2=GetX()*GetX() + dy*dy;
351 Double_t p2=(1.+ GetTgl()*GetTgl())/(GetSigned1Pt()*GetSigned1Pt());
352 Double_t beta2=p2/(p2 + GetMass()*GetMass());
353 x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp()));
354 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0;
355 //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33;
356
357 Double_t cnv=GetBz()*kB2C;
358 {
359 Double_t dummy = 4/r2 - GetC()*GetC();
360 if (dummy < 0) return kFALSE;
361 Double_t parp = 0.5*(GetC()*GetX() + dy*TMath::Sqrt(dummy));
362 Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl());
363 sigma2p += Cov(0)/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2);
364 sigma2p += ers[1]*ers[1]/r2;
365 sigma2p += 0.25*Cov(14)*cnv*cnv*GetX()*GetX();
366 Double_t eps2p=sigma2p/(Cov(5) + sigma2p);
367 Par(0) += Cov(3)/(Cov(5) + sigma2p)*(parp - GetSnp());
368 Par(2) = eps2p*GetSnp() + (1 - eps2p)*parp;
369 Cov(5) *= eps2p;
370 Cov(3) *= eps2p;
371 }
372 {
373 Double_t parl=0.5*GetC()*dz/TMath::ASin(0.5*GetC()*TMath::Sqrt(r2));
374 Double_t sigma2l=theta2;
375 sigma2l += Cov(2)/r2 + Cov(0)*dy*dy*dz*dz/(r2*r2*r2);
376 sigma2l += ers[2]*ers[2]/r2;
377 Double_t eps2l = sigma2l/(Cov(9) + sigma2l);
378 Par(1) += Cov(7 )/(Cov(9) + sigma2l)*(parl - Par(3));
379 Par(4) += Cov(13)/(Cov(9) + sigma2l)*(parl - Par(3));
380 Par(3) = eps2l*Par(3) + (1-eps2l)*parl;
381 Cov(9) *= eps2l;
382 Cov(13)*= eps2l;
383 Cov(7) *= eps2l;
384 }
385 if (!Invariant()) return kFALSE;
386
387 return kTRUE;
388}
389
390void AliITStrackV2::CookdEdx(Double_t low, Double_t up) {
391 //-----------------------------------------------------------------
392 // This function calculates dE/dX within the "low" and "up" cuts.
393 // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
394 //-----------------------------------------------------------------
395 // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1
396
397 Int_t i;
398 Int_t nc=0;
399 for (i=0; i<GetNumberOfClusters(); i++) {
400 Int_t idx=GetClusterIndex(i);
401 idx=(idx&0xf0000000)>>28;
402 if (idx>1) nc++; // Take only SSD and SDD
403 }
404
405 Int_t swap;//stupid sorting
406 do {
407 swap=0;
408 for (i=0; i<nc-1; i++) {
409 if (fdEdxSample[i]<=fdEdxSample[i+1]) continue;
410 Float_t tmp=fdEdxSample[i];
411 fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp;
412 swap++;
413 }
414 } while (swap);
415
416 Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX
417 // values from four ones choose
418 // nu=2
419 Float_t dedx=0;
420 for (i=nl; i<nu; i++) dedx += fdEdxSample[i];
421 if (nu-nl>0) dedx /= (nu-nl);
422
423 SetdEdx(dedx);
424}
425
426Double_t AliITStrackV2::GetBz() const {
427 //
428 // returns Bz component of the magnetic field (kG)
429 //
430 if (AliTracker::UniformField()) return AliTracker::GetBz();
431 Double_t r[3]; GetXYZ(r);
432 return AliTracker::GetBz(r);
433}
434
435//____________________________________________________________________________
436Bool_t AliITStrackV2::
437GetPhiZat(Double_t r, Double_t &phi, Double_t &z) const {
438 //------------------------------------------------------------------
439 // This function returns the global cylindrical (phi,z) of the track
440 // position estimated at the radius r.
441 // The track curvature is neglected.
442 //------------------------------------------------------------------
443 Double_t d=GetD(0.,0.);
444 if (TMath::Abs(d) > r) return kFALSE;
445
446 Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
447 if (TMath::Abs(d) > rcurr) return kFALSE;
448 Double_t phicurr=GetAlpha()+TMath::ASin(GetSnp());
449
450 phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
451 z=GetZ()+GetTgl()*(TMath::Sqrt((r-d)*(r+d))-TMath::Sqrt((rcurr-d)*(rcurr+d)));
452 return kTRUE;
453}
454//____________________________________________________________________________
455Bool_t AliITStrackV2::
456GetLocalXat(Double_t r,Double_t &xloc) const {
457 //------------------------------------------------------------------
458 // This function returns the local x of the track
459 // position estimated at the radius r.
460 // The track curvature is neglected.
461 //------------------------------------------------------------------
462 Double_t d=GetD(0.,0.);
463 if (TMath::Abs(d) > r) return kFALSE;
464
465 Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
466 Double_t phicurr=GetAlpha()+TMath::ASin(GetSnp());
467 Double_t phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
468
469 xloc=r*(TMath::Cos(phi)*TMath::Cos(GetAlpha())
470 +TMath::Sin(phi)*TMath::Sin(GetAlpha()));
471
472 return kTRUE;
473}
474