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