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Macro to calibrate L1 time delay in the TPC(C.Cheshkov)
[u/mrichter/AliRoot.git] / TPC / AliTPCtrack.cxx
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73042f01 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
803d1ab0 16/* $Id$ */
0938c7d3 17
73042f01 18//-----------------------------------------------------------------
19// Implementation of the TPC track class
7c27857f 20// This class is used by the AliTPCtracker class
21// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
73042f01 22//-----------------------------------------------------------------
23
19364939 24#include <Riostream.h>
b19a0509 25
73042f01 26#include "AliTPCtrack.h"
7c27857f 27#include "AliCluster.h"
83d73500 28#include "AliESDtrack.h"
73042f01 29
30ClassImp(AliTPCtrack)
b9de75e1 31
e3f7105e 32//_________________________________________________________________________
33AliTPCtrack::AliTPCtrack(): AliKalmanTrack()
34{
2fc0c115 35 //-------------------------------------------------
36 // default constructor
37 //-------------------------------------------------
e3f7105e 38 fX = fP0 = fP1 = fP2 = fP3 = fP3 = fP4 = 0.0;
39 fAlpha = fdEdx = 0.0;
24de2d6d 40 fNumber = 0; // [SR, 01.04.2003]
c84a5e9e 41 for (Int_t i=0; i<3;i++) fKinkIndexes[i]=0;
e3f7105e 42}
43
73042f01 44//_________________________________________________________________________
51ad6848 45
46
47
73042f01 48AliTPCtrack::AliTPCtrack(UInt_t index, const Double_t xx[5],
b19a0509 49const Double_t cc[15], Double_t xref, Double_t alpha) : AliKalmanTrack() {
73042f01 50 //-----------------------------------------------------------------
51 // This is the main track constructor.
52 //-----------------------------------------------------------------
73042f01 53 fX=xref;
be9c5115 54 fAlpha=alpha;
55 if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
56 if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
57 fdEdx=0.;
73042f01 58
b19a0509 59 fP0=xx[0]; fP1=xx[1]; fP2=xx[2]; fP3=xx[3]; fP4=xx[4];
73042f01 60
c84a5e9e 61 SaveLocalConvConst();
62
b19a0509 63 fC00=cc[0];
64 fC10=cc[1]; fC11=cc[2];
65 fC20=cc[3]; fC21=cc[4]; fC22=cc[5];
66 fC30=cc[6]; fC31=cc[7]; fC32=cc[8]; fC33=cc[9];
67 fC40=cc[10]; fC41=cc[11]; fC42=cc[12]; fC43=cc[13]; fC44=cc[14];
73042f01 68
be9c5115 69 fIndex[0]=index;
70 SetNumberOfClusters(1);
51584047 71 //
72 //MI
73 fSdEdx = 0;
74 fNFoundable = 0;
75 fBConstrain = 0;
76 fLastPoint = 0;
77 fFirstPoint = 0;
78 fRemoval = 0;
79 fTrackType = 0;
80 fLab2 = 0;
51ad6848 81 for (Int_t i=0; i<3;i++) fKinkIndexes[i]=0;
81e97e0d 82 for (Int_t i=0; i<3;i++) fV0Indexes[i]=0;
b9de75e1 83}
84
83d73500 85//_____________________________________________________________________________
86AliTPCtrack::AliTPCtrack(const AliESDtrack& t) : AliKalmanTrack() {
87 //-----------------------------------------------------------------
88 // Conversion AliESDtrack -> AliTPCtrack.
89 //-----------------------------------------------------------------
90 SetNumberOfClusters(t.GetTPCclusters(fIndex));
91 SetLabel(t.GetLabel());
92 SetMass(t.GetMass());
51ad6848 93 for (Int_t i=0; i<3;i++) fKinkIndexes[i]=t.GetKinkIndex(i);
81e97e0d 94 for (Int_t i=0; i<3;i++) fV0Indexes[i]=t.GetV0Index(i);
83d73500 95
96 fdEdx = t.GetTPCsignal();
97 fAlpha = t.GetAlpha();
98 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
99 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
100
101 //Conversion of the track parameters
102 Double_t x,p[5]; t.GetExternalParameters(x,p);
51ad6848 103 Double_t c[15]; t.GetExternalCovariance(c);
104
c84a5e9e 105 fX=x;
83d73500 106 fP0=p[0];
c84a5e9e 107 fP1=p[1]; SaveLocalConvConst();
108 fP3=p[3]; x=GetLocalConvConst();
83d73500 109 fP4=p[4]/x;
110 fP2=fP4*fX - p[2];
111
112 //Conversion of the covariance matrix
83d73500 113 c[10]/=x; c[11]/=x; c[12]/=x; c[13]/=x; c[14]/=x*x;
114
115 Double_t c22=fX*fX*c[14] - 2*fX*c[12] + c[5];
116 Double_t c32=fX*c[13] - c[8];
117 Double_t c20=fX*c[10] - c[3], c21=fX*c[11] - c[4], c42=fX*c[14] - c[12];
118
119 fC00=c[0 ];
120 fC10=c[1 ]; fC11=c[2 ];
121 fC20=c20; fC21=c21; fC22=c22;
122 fC30=c[6 ]; fC31=c[7 ]; fC32=c32; fC33=c[9 ];
123 fC40=c[10]; fC41=c[11]; fC42=c42; fC43=c[13]; fC44=c[14];
124
0798b21e 125 if ((t.GetStatus()&AliESDtrack::kTIME) == 0) return;
83d73500 126 StartTimeIntegral();
127 Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times);
128 SetIntegratedLength(t.GetIntegratedLength());
51584047 129 //
130 //MI
131 fSdEdx = 0;
132 fNFoundable = 0;
133 fBConstrain = 0;
134 fLastPoint = 0;
135 fFirstPoint = 0;
136 fRemoval = 0;
137 fTrackType = 0;
138 fLab2 = 0;
babd135a 139 // SetFakeRatio(t.GetTPCFakeRatio());
83d73500 140}
141
73042f01 142//_____________________________________________________________________________
b19a0509 143AliTPCtrack::AliTPCtrack(const AliTPCtrack& t) : AliKalmanTrack(t) {
73042f01 144 //-----------------------------------------------------------------
145 // This is a track copy constructor.
146 //-----------------------------------------------------------------
be9c5115 147 fX=t.fX;
148 fAlpha=t.fAlpha;
73042f01 149 fdEdx=t.fdEdx;
150
be9c5115 151 fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4;
152
153 fC00=t.fC00;
154 fC10=t.fC10; fC11=t.fC11;
155 fC20=t.fC20; fC21=t.fC21; fC22=t.fC22;
156 fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33;
157 fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44;
158
176aff27 159 //Int_t n=GetNumberOfClusters();
51584047 160 for (Int_t i=0; i<kMaxRow; i++) fIndex[i]=t.fIndex[i];
161 //
162 //MI
163 fSdEdx = t.fSdEdx;
164 fNFoundable = t.fNFoundable;
165 fBConstrain = t.fBConstrain;
166 fLastPoint = t.fLastPoint;
167 fFirstPoint = t.fFirstPoint;
168 fRemoval = t.fRemoval ;
169 fTrackType = t.fTrackType;
170 fLab2 = t.fLab2;
51ad6848 171 for (Int_t i=0; i<3;i++) fKinkIndexes[i]=t.fKinkIndexes[i];
81e97e0d 172 for (Int_t i=0; i<3;i++) fV0Indexes[i]=t.fV0Indexes[i];
be9c5115 173}
174
175//_____________________________________________________________________________
176Int_t AliTPCtrack::Compare(const TObject *o) const {
177 //-----------------------------------------------------------------
178 // This function compares tracks according to the their curvature
179 //-----------------------------------------------------------------
180 AliTPCtrack *t=(AliTPCtrack*)o;
024a7fe9 181 //Double_t co=TMath::Abs(t->Get1Pt());
182 //Double_t c =TMath::Abs(Get1Pt());
183 Double_t co=t->GetSigmaY2()*t->GetSigmaZ2();
184 Double_t c =GetSigmaY2()*GetSigmaZ2();
be9c5115 185 if (c>co) return 1;
186 else if (c<co) return -1;
187 return 0;
188}
189
190//_____________________________________________________________________________
191void AliTPCtrack::GetExternalCovariance(Double_t cc[15]) const {
c84a5e9e 192 //-------------------------------------------------------------------------
be9c5115 193 // This function returns an external representation of the covriance matrix.
194 // (See comments in AliTPCtrack.h about external track representation)
195 //-------------------------------------------------------------------------
c84a5e9e 196 Double_t a=GetLocalConvConst();
be9c5115 197
b9de75e1 198 Double_t c22=fX*fX*fC44-2*fX*fC42+fC22;
199 Double_t c32=fX*fC43-fC32;
200 Double_t c20=fX*fC40-fC20, c21=fX*fC41-fC21, c42=fX*fC44-fC42;
be9c5115 201
202 cc[0 ]=fC00;
203 cc[1 ]=fC10; cc[2 ]=fC11;
204 cc[3 ]=c20; cc[4 ]=c21; cc[5 ]=c22;
b9de75e1 205 cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=c32; cc[9 ]=fC33;
206 cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=c42*a; cc[13]=fC43*a; cc[14]=fC44*a*a;
be9c5115 207
208}
209
210//_____________________________________________________________________________
211Double_t AliTPCtrack::GetPredictedChi2(const AliCluster *c) const
212{
213 //-----------------------------------------------------------------
214 // This function calculates a predicted chi2 increment.
215 //-----------------------------------------------------------------
216 Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
217 r00+=fC00; r01+=fC10; r11+=fC11;
218
219 Double_t det=r00*r11 - r01*r01;
220 if (TMath::Abs(det) < 1.e-10) {
221 Int_t n=GetNumberOfClusters();
222 if (n>4) cerr<<n<<" AliKalmanTrack warning: Singular matrix !\n";
223 return 1e10;
224 }
225 Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
226
227 Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
228
229 return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
73042f01 230}
231
c630aafd 232Double_t AliTPCtrack::GetYat(Double_t xk) const {
233//-----------------------------------------------------------------
234// This function calculates the Y-coordinate of a track at the plane x=xk.
235//-----------------------------------------------------------------
236 Double_t c1=fP4*fX - fP2, r1=TMath::Sqrt(1.- c1*c1);
df02fd67 237 Double_t c2=fP4*xk - fP2;
238 if (c2*c2>0.99999) {
239 Int_t n=GetNumberOfClusters();
240 if (n>4) cerr<<n<<"AliTPCtrack::GetYat: can't evaluate the y-coord !\n";
241 return 1e10;
242 }
243 Double_t r2=TMath::Sqrt(1.- c2*c2);
c630aafd 244 return fP0 + (xk-fX)*(c1+c2)/(r1+r2);
245}
246
73042f01 247//_____________________________________________________________________________
176aff27 248Int_t AliTPCtrack::PropagateTo(Double_t xk,Double_t /*x0*/,Double_t rho) {
73042f01 249 //-----------------------------------------------------------------
250 // This function propagates a track to a reference plane x=xk.
251 //-----------------------------------------------------------------
1627d1c4 252 if (TMath::Abs(fP4*xk - fP2) >= 0.9) {
253 // Int_t n=GetNumberOfClusters();
254 //if (n>4) cerr<<n<<" AliTPCtrack warning: Propagation failed !\n";
73042f01 255 return 0;
256 }
c84a5e9e 257 Double_t lcc=GetLocalConvConst();
258
e3f7105e 259 // old position for time [SR, GSI 17.02.2003]
260 Double_t oldX = fX;
261 Double_t oldY = fP0;
262 Double_t oldZ = fP1;
263 //
73042f01 264
b19a0509 265 Double_t x1=fX, x2=x1+(xk-x1), dx=x2-x1, y1=fP0, z1=fP1;
b9de75e1 266 Double_t c1=fP4*x1 - fP2, r1=sqrt(1.- c1*c1);
267 Double_t c2=fP4*x2 - fP2, r2=sqrt(1.- c2*c2);
73042f01 268
b19a0509 269 fP0 += dx*(c1+c2)/(r1+r2);
b9de75e1 270 fP1 += dx*(c1+c2)/(c1*r2 + c2*r1)*fP3;
73042f01 271
272 //f = F - 1
273 Double_t rr=r1+r2, cc=c1+c2, xx=x1+x2;
b19a0509 274 Double_t f02=-dx*(2*rr + cc*(c1/r1 + c2/r2))/(rr*rr);
b9de75e1 275 Double_t f04= dx*(rr*xx + cc*(c1*x1/r1+c2*x2/r2))/(rr*rr);
73042f01 276 Double_t cr=c1*r2+c2*r1;
b9de75e1 277 Double_t f12=-dx*fP3*(2*cr + cc*(c2*c1/r1-r1 + c1*c2/r2-r2))/(cr*cr);
278 Double_t f13= dx*cc/cr;
279 Double_t f14=dx*fP3*(cr*xx-cc*(r1*x2-c2*c1*x1/r1+r2*x1-c1*c2*x2/r2))/(cr*cr);
73042f01 280
281 //b = C*ft
b9de75e1 282 Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30;
283 Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31;
284 Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32;
285 Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33;
286 Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43;
73042f01 287
288 //a = f*b = f*C*ft
b9de75e1 289 Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a11=f12*b21+f14*b41+f13*b31;
73042f01 290
291 //F*C*Ft = C + (a + b + bt)
b19a0509 292 fC00 += a00 + 2*b00;
293 fC10 += a01 + b01 + b10;
294 fC20 += b20;
295 fC30 += b30;
296 fC40 += b40;
297 fC11 += a11 + 2*b11;
298 fC21 += b21;
299 fC31 += b31;
300 fC41 += b41;
73042f01 301
302 fX=x2;
303
c84a5e9e 304 //Change of the magnetic field *************
305 SaveLocalConvConst();
306 cc=fP4;
307 fP4*=lcc/GetLocalConvConst();
308 fP2+=fX*(fP4-cc);
309
310 //Multiple scattering ******************
b19a0509 311 Double_t d=sqrt((x1-fX)*(x1-fX)+(y1-fP0)*(y1-fP0)+(z1-fP1)*(z1-fP1));
be9c5115 312 Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
7f6ddf58 313 Double_t beta2=p2/(p2 + GetMass()*GetMass());
babd135a 314 beta2 = TMath::Min(beta2,0.99999999999);
024a7fe9 315 //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*d/x0*rho;
316 Double_t theta2=1.0259e-6*10*10/20/(beta2*p2)*d*rho;
73042f01 317
b9de75e1 318 Double_t ey=fP4*fX - fP2, ez=fP3;
319 Double_t xz=fP4*ez, zz1=ez*ez+1, xy=fP2+ey;
982aff31 320
b19a0509 321 fC22 += (2*ey*ez*ez*fP2+1-ey*ey+ez*ez+fP2*fP2*ez*ez)*theta2;
b9de75e1 322 fC32 += ez*zz1*xy*theta2;
323 fC33 += zz1*zz1*theta2;
324 fC42 += xz*ez*xy*theta2;
325 fC43 += xz*zz1*theta2;
326 fC44 += xz*xz*theta2;
982aff31 327 /*
328 //
329 //MI coeficints
330 Double_t dc22 = (1-ey*ey+xz*xz*fX*fX)*theta2;
331 Double_t dc32 = (xz*fX*zz1)*theta2;
332 Double_t dc33 = (zz1*zz1)*theta2;
333 Double_t dc42 = (xz*fX*xz)*theta2;
334 Double_t dc43 = (zz1*xz)*theta2;
335 Double_t dc44 = (xz*xz)*theta2;
336 fC22 += dc22;
337 fC32 += dc32;
338 fC33 += dc33;
339 fC42 += dc42;
340 fC43 += dc43;
341 fC44 += dc44;
342 */
c84a5e9e 343 //Energy losses ************************
73042f01 344 Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d*rho;
345 if (x1 < x2) dE=-dE;
b9de75e1 346 cc=fP4;
982aff31 347
348 //Double_t E = sqrt(p2+GetMass()*GetMass());
349 //Double_t mifac = TMath::Sqrt(1.+dE*dE/p2+2*E*dE/p2)-1;
350 //Double_t belfac = E*dE/p2;
351 //
7f6ddf58 352 fP4*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE);
b9de75e1 353 fP2+=fX*(fP4-cc);
73042f01 354
e3f7105e 355 // Integrated Time [SR, GSI, 17.02.2003]
0fa7dfa7 356 if (x1 < x2)
357 if (IsStartedTimeIntegral()) {
e3f7105e 358 Double_t l2 = (fX-oldX)*(fX-oldX)+(fP0-oldY)*(fP0-oldY)+(fP1-oldZ)*(fP1-oldZ);
359 AddTimeStep(TMath::Sqrt(l2));
360 }
361 //
362
73042f01 363 return 1;
364}
365
366//_____________________________________________________________________________
7f6ddf58 367Int_t AliTPCtrack::PropagateToVertex(Double_t x0,Double_t rho)
73042f01 368{
369 //-----------------------------------------------------------------
370 // This function propagates tracks to the "vertex".
371 //-----------------------------------------------------------------
b9de75e1 372 Double_t c=fP4*fX - fP2;
373 Double_t tgf=-fP2/(fP4*fP0 + sqrt(1-c*c));
73042f01 374 Double_t snf=tgf/sqrt(1.+ tgf*tgf);
b9de75e1 375 Double_t xv=(fP2+snf)/fP4;
7f6ddf58 376 return PropagateTo(xv,x0,rho);
73042f01 377}
378
379//_____________________________________________________________________________
be9c5115 380Int_t AliTPCtrack::Update(const AliCluster *c, Double_t chisq, UInt_t index) {
73042f01 381 //-----------------------------------------------------------------
382 // This function associates a cluster with this track.
383 //-----------------------------------------------------------------
384 Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
b19a0509 385 r00+=fC00; r01+=fC10; r11+=fC11;
73042f01 386 Double_t det=r00*r11 - r01*r01;
387 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
388
b19a0509 389 Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11;
390 Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11;
391 Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11;
392 Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11;
393 Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11;
73042f01 394
b19a0509 395 Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
b9de75e1 396 Double_t cur=fP4 + k40*dy + k41*dz, eta=fP2 + k20*dy + k21*dz;
1627d1c4 397 if (TMath::Abs(cur*fX-eta) >= 0.9) {
398 // Int_t n=GetNumberOfClusters();
399 //if (n>4) cerr<<n<<" AliTPCtrack warning: Filtering failed !\n";
be9c5115 400 return 0;
73042f01 401 }
402
b19a0509 403 fP0 += k00*dy + k01*dz;
404 fP1 += k10*dy + k11*dz;
405 fP2 = eta;
b9de75e1 406 fP3 += k30*dy + k31*dz;
407 fP4 = cur;
73042f01 408
b19a0509 409 Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40;
410 Double_t c12=fC21, c13=fC31, c14=fC41;
73042f01 411
b19a0509 412 fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11;
413 fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13;
414 fC40-=k00*c04+k01*c14;
73042f01 415
b19a0509 416 fC11-=k10*c01+k11*fC11;
417 fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13;
418 fC41-=k10*c04+k11*c14;
73042f01 419
b19a0509 420 fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13;
421 fC42-=k20*c04+k21*c14;
73042f01 422
b19a0509 423 fC33-=k30*c03+k31*c13;
b9de75e1 424 fC43-=k40*c03+k41*c13;
73042f01 425
b19a0509 426 fC44-=k40*c04+k41*c14;
73042f01 427
be9c5115 428 Int_t n=GetNumberOfClusters();
429 fIndex[n]=index;
430 SetNumberOfClusters(n+1);
431 SetChi2(GetChi2()+chisq);
432
433 return 1;
73042f01 434}
435
436//_____________________________________________________________________________
437Int_t AliTPCtrack::Rotate(Double_t alpha)
438{
439 //-----------------------------------------------------------------
440 // This function rotates this track.
441 //-----------------------------------------------------------------
442 fAlpha += alpha;
be9c5115 443 if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
444 if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
73042f01 445
b19a0509 446 Double_t x1=fX, y1=fP0;
73042f01 447 Double_t ca=cos(alpha), sa=sin(alpha);
b9de75e1 448 Double_t r1=fP4*fX - fP2;
73042f01 449
450 fX = x1*ca + y1*sa;
b19a0509 451 fP0=-x1*sa + y1*ca;
b9de75e1 452 fP2=fP2*ca + (fP4*y1 + sqrt(1.- r1*r1))*sa;
73042f01 453
b9de75e1 454 Double_t r2=fP4*fX - fP2;
73042f01 455 if (TMath::Abs(r2) >= 0.99999) {
be9c5115 456 Int_t n=GetNumberOfClusters();
457 if (n>4) cerr<<n<<" AliTPCtrack warning: Rotation failed !\n";
73042f01 458 return 0;
459 }
460
b9de75e1 461 Double_t y0=fP0 + sqrt(1.- r2*r2)/fP4;
462 if ((fP0-y0)*fP4 >= 0.) {
be9c5115 463 Int_t n=GetNumberOfClusters();
464 if (n>4) cerr<<n<<" AliTPCtrack warning: Rotation failed !!!\n";
73042f01 465 return 0;
466 }
467
468 //f = F - 1
b9de75e1 469 Double_t f00=ca-1, f24=(y1 - r1*x1/sqrt(1.- r1*r1))*sa,
470 f20=fP4*sa, f22=(ca + sa*r1/sqrt(1.- r1*r1))-1;
73042f01 471
472 //b = C*ft
b9de75e1 473 Double_t b00=fC00*f00, b02=fC00*f20+fC40*f24+fC20*f22;
474 Double_t b10=fC10*f00, b12=fC10*f20+fC41*f24+fC21*f22;
475 Double_t b20=fC20*f00, b22=fC20*f20+fC42*f24+fC22*f22;
476 Double_t b30=fC30*f00, b32=fC30*f20+fC43*f24+fC32*f22;
477 Double_t b40=fC40*f00, b42=fC40*f20+fC44*f24+fC42*f22;
73042f01 478
479 //a = f*b = f*C*ft
b9de75e1 480 Double_t a00=f00*b00, a02=f00*b02, a22=f20*b02+f24*b42+f22*b22;
73042f01 481
482 // *** Double_t dy2=fCyy;
483
484 //F*C*Ft = C + (a + b + bt)
b19a0509 485 fC00 += a00 + 2*b00;
486 fC10 += b10;
487 fC20 += a02+b20+b02;
488 fC30 += b30;
489 fC40 += b40;
490 fC21 += b12;
491 fC32 += b32;
492 fC22 += a22 + 2*b22;
493 fC42 += b42;
73042f01 494
495 // *** fCyy+=dy2*sa*sa*r1*r1/(1.- r1*r1);
496 // *** fCzz+=d2y*sa*sa*fT*fT/(1.- r1*r1);
497
498 return 1;
499}
500
b9de75e1 501void AliTPCtrack::ResetCovariance() {
502 //------------------------------------------------------------------
503 //This function makes a track forget its history :)
504 //------------------------------------------------------------------
505
506 fC00*=10.;
507 fC10=0.; fC11*=10.;
508 fC20=0.; fC21=0.; fC22*=10.;
509 fC30=0.; fC31=0.; fC32=0.; fC33*=10.;
510 fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.;
511
73042f01 512}
77e58468 513
514////////////////////////////////////////////////////////////////////////
515Double_t AliTPCtrack::Phi() const {
7c27857f 516//
517//
518//
77e58468 519 Double_t phi = TMath::ASin(GetSnp()) + fAlpha;
520 if (phi<0) phi+=2*TMath::Pi();
521 if (phi>=2*TMath::Pi()) phi-=2*TMath::Pi();
522 return phi;
523}
524////////////////////////////////////////////////////////////////////////
525
51584047 526
527
528////////////////////////////////////////////////////////////////////////
529// MI ADDITION
530
531Float_t AliTPCtrack::Density(Int_t row0, Int_t row1)
532{
533 //
534 // calculate cluster density
535 Int_t good = 0;
536 Int_t found = 0;
537 //if (row0<fFirstPoint) row0 = fFirstPoint;
538 if (row1>fLastPoint) row1 = fLastPoint;
539
540
541 for (Int_t i=row0;i<=row1;i++){
542 // Int_t index = fClusterIndex[i];
543 Int_t index = fIndex[i];
544 if (index!=-1) good++;
545 if (index>0) found++;
546 }
547 Float_t density=0;
548 if (good>0) density = Float_t(found)/Float_t(good);
549 return density;
550}
551
552
553Float_t AliTPCtrack::Density2(Int_t row0, Int_t row1)
554{
555 //
556 // calculate cluster density
557 Int_t good = 0;
558 Int_t found = 0;
559 //
560 for (Int_t i=row0;i<=row1;i++){
561 Int_t index = fIndex[i];
562 if (index!=-1) good++;
563 if (index>0) found++;
564 }
565 Float_t density=0;
566 if (good>0) density = Float_t(found)/Float_t(good);
567 return density;
568}
569
570
571Double_t AliTPCtrack::GetZat0() const
572{
573 //
574 // return virtual z - supposing that x = 0
575 if (TMath::Abs(fP2)>1) return 0;
576 if (TMath::Abs(fX*fP4-fP2)>1) return 0;
577 Double_t vz = fP1+fP3/fP4*(asin(-fP2)-asin(fX*fP4-fP2));
578 return vz;
579}
580
581
582Double_t AliTPCtrack::GetD(Double_t x, Double_t y) const {
583 //------------------------------------------------------------------
584 // This function calculates the transverse impact parameter
585 // with respect to a point with global coordinates (x,y)
586 //------------------------------------------------------------------
587 //Double_t xt=fX, yt=fP0;
588
589 Double_t sn=TMath::Sin(fAlpha), cs=TMath::Cos(fAlpha);
590 Double_t a = x*cs + y*sn;
591 y = -x*sn + y*cs; x=a;
592 //
593 Double_t r = TMath::Abs(1/fP4);
594 Double_t x0 = TMath::Abs(fP2*r);
595 Double_t y0 = fP0;
596 y0= fP0+TMath::Sqrt(1-(fP4*fX-fP2)*(fP4*fX-fP2))/fP4;
597
598 Double_t delta = TMath::Sqrt((x-x0)*(x-x0)+(y-y0)*(y-y0));
599 // Double_t delta = TMath::Sqrt(TMath::Abs(x*x-2*x0*x+x0*x0+ y*y-2*y*y0+y0*y0));
600 delta -= TMath::Abs(r);
601 return delta;
602}
51ad6848 603
604//
605//
606
607void AliTPCtrack::UpdatePoints()
608{
609 //--------------------------------------------------
610 //calculates first ,amx dens and last points
611 //--------------------------------------------------
612 Float_t density[160];
613 for (Int_t i=0;i<160;i++) density[i]=-1.;
614 fPoints[0]= 160;
615 fPoints[1] = -1;
616 //
617 Int_t ngood=0;
618 Int_t undeff=0;
619 Int_t nall =0;
620 Int_t range=20;
621 for (Int_t i=0;i<160;i++){
622 Int_t last = i-range;
623 if (nall<range) nall++;
624 if (last>=0){
625 if (fIndex[last]>0&& (fIndex[last]&0x8000)==0) ngood--;
626 if (fIndex[last]==-1) undeff--;
627 }
628 if (fIndex[i]>0&& (fIndex[i]&0x8000)==0) ngood++;
629 if (fIndex[i]==-1) undeff++;
630 if (nall==range &&undeff<range/2) density[i-range/2] = Float_t(ngood)/Float_t(nall-undeff);
631 }
632 Float_t maxdens=0;
633 Int_t indexmax =0;
634 for (Int_t i=0;i<160;i++){
635 if (density[i]<0) continue;
636 if (density[i]>maxdens){
637 maxdens=density[i];
638 indexmax=i;
639 }
640 }
641 //
642 //max dens point
643 fPoints[3] = maxdens;
644 fPoints[1] = indexmax;
645 //
646 // last point
647 for (Int_t i=indexmax;i<160;i++){
648 if (density[i]<0) continue;
649 if (density[i]<maxdens/2.) {
650 break;
651 }
652 fPoints[2]=i;
653 }
654 //
655 // first point
656 for (Int_t i=indexmax;i>0;i--){
657 if (density[i]<0) continue;
658 if (density[i]<maxdens/2.) {
659 break;
660 }
661 fPoints[0]=i;
662 }
663 //
664}