more secure string operations
[u/mrichter/AliRoot.git] / TPC / AliTPCTracklet.cxx
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69209e2c 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// This class stores a tracklet (a track that lives only in a single TPC
18// sector). Its objects can be constructed out of TPCseeds, that are
19// holding the necessary cluster information.
20////
21////
22////
23
69209e2c 24#include "AliTPCTracklet.h"
25#include "TObjArray.h"
9318a5b4 26#include "TLinearFitter.h"
69209e2c 27#include "AliTPCseed.h"
28#include "AliESDVertex.h"
9318a5b4 29#include "AliTracker.h"
30#include "TTreeStream.h"
31#include "TRandom3.h"
32#include "TDecompChol.h"
33
34#include <iostream>
35using namespace std;
69209e2c 36
37ClassImp(AliTPCTracklet)
38
9318a5b4 39const Double_t AliTPCTracklet::kB2C=0.299792458e-3;
967eae0d 40Float_t AliTPCTracklet::fgEdgeCutY=3;
41Float_t AliTPCTracklet::fgEdgeCutX=0;
9318a5b4 42
69209e2c 43AliTPCTracklet::AliTPCTracklet()
9318a5b4 44 : fNClusters(0),fNStoredClusters(0),fClusters(0),fSector(-1),fOuter(0),
45 fInner(0),fPrimary(0) {
69209e2c 46 ////
47 // The default constructor. It is intended to be used for I/O only.
48 ////
49}
50
9318a5b4 51AliTPCTracklet::AliTPCTracklet(const AliTPCseed *track,Int_t sector,
52 TrackType type,Bool_t storeClusters)
53 : fNClusters(0),fNStoredClusters(0),fClusters(0),fSector(sector),fOuter(0),
54 fInner(0),fPrimary(0) {
69209e2c 55 ////
56 // Contructor for a tracklet out of a track. Only clusters within a given
57 // sector are used.
58 ///
69209e2c 59
9318a5b4 60 //TODO: only kalman works
61
69209e2c 62 for (Int_t i=0;i<160;++i) {
9318a5b4 63 AliTPCclusterMI *c=track->GetClusterPointer(i);
967eae0d 64 if (c && RejectCluster(c)) continue;
9318a5b4 65 if (c&&c->GetDetector()==sector)
66 ++fNClusters;
69209e2c 67 }
9318a5b4 68
69 if (storeClusters) {
70 fClusters=new AliTPCclusterMI[fNClusters];
71 for (Int_t i=0;i<160;++i) {
72 AliTPCclusterMI *c=track->GetClusterPointer(i);
967eae0d 73 if (c && RejectCluster(c)) continue;
9318a5b4 74 if (c&&c->GetDetector()==sector)
d47d1dfd 75 fClusters[fNStoredClusters]=*c;
9318a5b4 76 ++fNStoredClusters;
69209e2c 77 }
78 }
9318a5b4 79
80 switch (type) {
81 case kKalman:
82 FitKalman(track,sector);
83 break;
84 case kLinear:
85 case kQuadratic:
86 FitLinear(track,sector,type);
87 break;
88 case kRiemann:
89 FitRiemann(track,sector);
90 break;
69209e2c 91 }
69209e2c 92
9318a5b4 93}
69209e2c 94
c94a79e1 95AliTPCTracklet::AliTPCTracklet(const TObjArray &/*clusters*/,Int_t sector,
96 TrackType /*type*/,Bool_t /*storeClusters*/)
97 : fNClusters(0),fNStoredClusters(0),fClusters(0),fSector(sector),fOuter(0),
98 fInner(0),fPrimary(0) {
9318a5b4 99 //TODO: write it!
69209e2c 100}
101
102AliTPCTracklet::AliTPCTracklet(const AliTPCTracklet &t)
c94a79e1 103 : TObject(t),fNClusters(t.fNClusters),fNStoredClusters(t.fNStoredClusters),fClusters(0),
9318a5b4 104 fSector(t.fSector),fOuter(0),fInner(0),
69209e2c 105 fPrimary(0) {
106 ////
107 // The copy constructor. You can copy tracklets!
108 ////
109
9318a5b4 110 if (t.fClusters) {
111 fClusters=new AliTPCclusterMI[t.fNStoredClusters];
112 for (int i=0;i<t.fNStoredClusters;++i)
113 fClusters[i]=t.fClusters[i];
114 }
69209e2c 115 if (t.fOuter)
116 fOuter=new AliExternalTrackParam(*t.fOuter);
117 if (t.fInner)
118 fInner=new AliExternalTrackParam(*t.fInner);
119 if (t.fPrimary)
120 fPrimary=new AliExternalTrackParam(*t.fPrimary);
121}
122
123AliTPCTracklet& AliTPCTracklet::operator=(const AliTPCTracklet &t) {
124 ////
125 // The assignment constructor. You can assign tracklets!
126 ////
69209e2c 127 if (this!=&t) {
9318a5b4 128 fNClusters=t.fNClusters;
129 fNStoredClusters=fNStoredClusters;
130 delete fClusters;
131 if (t.fClusters) {
132 fClusters=new AliTPCclusterMI[t.fNStoredClusters];
133 for (int i=0;i<t.fNStoredClusters;++i)
134 fClusters[i]=t.fClusters[i];
135 }
136 else
137 fClusters=0;
138 fSector=t.fSector;
69209e2c 139 if (t.fOuter) {
140 if (fOuter)
141 *fOuter=*t.fOuter;
142 else
143 fOuter=new AliExternalTrackParam(*t.fOuter);
144 }
145 else {
146 delete fOuter;
147 fOuter=0;
148 }
149
150 if (t.fInner) {
151 if (fInner)
152 *fInner=*t.fInner;
153 else
154 fInner=new AliExternalTrackParam(*t.fInner);
155 }
156 else {
157 delete fInner;
158 fInner=0;
159 }
160
161 if (t.fPrimary) {
162 if (fPrimary)
163 *fPrimary=*t.fPrimary;
164 else
165 fPrimary=new AliExternalTrackParam(*t.fPrimary);
166 }
167 else {
168 delete fPrimary;
169 fPrimary=0;
170 }
171 }
172 return *this;
173}
174
175AliTPCTracklet::~AliTPCTracklet() {
176 //
177 // The destructor. Yes, you can even destruct tracklets.
178 //
9318a5b4 179 delete fClusters;
69209e2c 180 delete fOuter;
181 delete fInner;
182 delete fPrimary;
183}
184
ef0a7e89 185
186
ef0a7e89 187
188
189void AliTPCTracklet::FitKalman(const AliTPCseed *seed,Int_t sector) {
190 //
191 // Fit using Kalman filter
192 //
193 AliTPCseed *track=new AliTPCseed(*seed);
194 if (!track->Rotate(TMath::DegToRad()*(sector%18*20.+10.)-track->GetAlpha())) {
195 delete track;
196 return;
197 }
198 // fit from inner to outer row
199 Double_t covar[15];
200 for (Int_t i=0;i<15;i++) covar[i]=0;
b322e06a 201 covar[0]=1.*1.;
202 covar[2]=1.*1.;
203 covar[5]=1.*1./(64.*64.);
204 covar[9]=1.*1./(64.*64.);
205 covar[14]=0; // keep pt
ef0a7e89 206 Float_t xmin=1000, xmax=-10000;
207 Int_t imin=158, imax=0;
208 for (Int_t i=0;i<160;i++) {
209 AliTPCclusterMI *c=track->GetClusterPointer(i);
210 if (!c) continue;
211 if (c->GetDetector()!=sector) continue;
212 if (c->GetX()<xmin) xmin=c->GetX();
213 if (c->GetX()>xmax) xmax=c->GetX();
214 if (i<imin) imin=i;
215 if (i>imax) imax=i;
216 }
217 if(imax-imin<10) {
218 delete track;
219 return;
220 }
221
222 for (Float_t x=track->GetX(); x<xmin; x++) track->PropagateTo(x);
223 track->AddCovariance(covar);
224 //
225 AliExternalTrackParam paramIn;
226 AliExternalTrackParam paramOut;
227 Bool_t isOK=kTRUE;
228 //
229 //
230 //
231 for (Int_t i=imin; i<=imax; i++){
232 AliTPCclusterMI *c=track->GetClusterPointer(i);
233 if (!c) continue;
ef0a7e89 234 Double_t r[3]={c->GetX(),c->GetY(),c->GetZ()};
235 Double_t cov[3]={0.01,0.,0.01}; //TODO: correct error parametrisation
91350f5b 236 AliTPCseed::GetError(c, track,cov[0],cov[2]);
237 cov[0]*=cov[0];
238 cov[2]*=cov[2];
ef0a7e89 239 if (!track->PropagateTo(r[0])) {
240 isOK=kFALSE;
241 break;
242 }
42b40d07 243 if (RejectCluster(c,track)) continue;
ef0a7e89 244 if ( !((static_cast<AliExternalTrackParam*>(track)->Update(&r[1],cov)))) isOK=kFALSE;
245 }
246 if (!isOK) { delete track; return;}
247 track->AddCovariance(covar);
248 //
249 //
250 //
251 for (Int_t i=imax; i>=imin; i--){
252 AliTPCclusterMI *c=track->GetClusterPointer(i);
253 if (!c) continue;
ef0a7e89 254 Double_t r[3]={c->GetX(),c->GetY(),c->GetZ()};
91350f5b 255 Double_t cov[3]={0.01,0.,0.01};
256 AliTPCseed::GetError(c, track,cov[0],cov[2]);
257 cov[0]*=cov[0];
258 cov[2]*=cov[2];
ef0a7e89 259 if (!track->PropagateTo(r[0])) {
260 isOK=kFALSE;
261 break;
262 }
42b40d07 263 if (RejectCluster(c,track)) continue;
ef0a7e89 264 if ( !((static_cast<AliExternalTrackParam*>(track)->Update(&r[1],cov)))) isOK=kFALSE;
265 }
266 if (!isOK) { delete track; return;}
267 paramIn = *track;
268 track->AddCovariance(covar);
269 //
270 //
271 for (Int_t i=imin; i<=imax; i++){
272 AliTPCclusterMI *c=track->GetClusterPointer(i);
273 if (!c) continue;
ef0a7e89 274 Double_t r[3]={c->GetX(),c->GetY(),c->GetZ()};
91350f5b 275 Double_t cov[3]={0.01,0.,0.01};
276 AliTPCseed::GetError(c, track,cov[0],cov[2]);
277 cov[0]*=cov[0];
278 cov[2]*=cov[2];
ef0a7e89 279 if (!track->PropagateTo(r[0])) {
280 isOK=kFALSE;
281 break;
282 }
42b40d07 283 if (RejectCluster(c,track)) continue;
ef0a7e89 284 if ( !((static_cast<AliExternalTrackParam*>(track)->Update(&r[1],cov)))) isOK=kFALSE;
285 }
286 if (!isOK) { delete track; return;}
287 paramOut=*track;
288 //
289 //
290 //
291 fOuter=new AliExternalTrackParam(paramOut);
292 fInner=new AliExternalTrackParam(paramIn);
293 //
ef0a7e89 294 delete track;
295}
296
297
298
9318a5b4 299
300void AliTPCTracklet::FitLinear(const AliTPCseed *track,Int_t sector,
301 TrackType type) {
302 TLinearFitter fy(1);
303 TLinearFitter fz(1);
304 fy.StoreData(kFALSE);
305 fz.StoreData(kFALSE);
306 switch (type) {
307 case kLinear:
308 fy.SetFormula("1 ++ x");
309 fz.SetFormula("1 ++ x");
310 break;
311 case kQuadratic:
312 fy.SetFormula("1 ++ x ++ x*x");
313 fz.SetFormula("1 ++ x");
314 break;
c94a79e1 315 case kKalman:
316 case kRiemann:
317 break;
9318a5b4 318 }
319 Double_t xmax=-1.;
320 Double_t xmin=1000.;
321 for (Int_t i=0;i<160;++i) {
322 AliTPCclusterMI *c=track->GetClusterPointer(i);
967eae0d 323 if (c && RejectCluster(c)) continue;
9318a5b4 324 if (c&&c->GetDetector()==sector) {
325 Double_t x=c->GetX();
326 fy.AddPoint(&x,c->GetY());
327 fz.AddPoint(&x,c->GetZ());
328 xmax=TMath::Max(xmax,x);
329 xmin=TMath::Min(xmin,x);
330 }
331 }
332 fy.Eval();
333 fz.Eval();
334 Double_t a[3]={fy.GetParameter(0),
335 fy.GetParameter(1),
336 type==kQuadratic?fy.GetParameter(2):0.};
337 Double_t ca[6]={fy.GetCovarianceMatrixElement(0,0),
338 fy.GetCovarianceMatrixElement(1,0),
339 fy.GetCovarianceMatrixElement(1,1),
340 type==kQuadratic?fy.GetCovarianceMatrixElement(2,0):0.,
341 type==kQuadratic?fy.GetCovarianceMatrixElement(2,1):0.,
342 type==kQuadratic?fy.GetCovarianceMatrixElement(2,2):0.};
343 for (int i=0;i<6;++i) ca[i]*=fy.GetChisquare()/fNClusters;
344 Double_t b[2]={fz.GetParameter(0),
345 fz.GetParameter(1)};
346 Double_t cb[3]={fz.GetCovarianceMatrixElement(0,0),
347 fz.GetCovarianceMatrixElement(1,0),
348 fz.GetCovarianceMatrixElement(1,1)};
349 for (int i=0;i<3;++i) cb[i]*=fz.GetChisquare()/fNClusters;
350 Double_t p[5];
351 Double_t c[15];
352 Double_t alpha=track->GetAlpha();
353 Quadratic2Helix(a,ca,b,cb,0.,p,c);
354 fPrimary=new AliExternalTrackParam(0.,alpha,p,c);
355 Quadratic2Helix(a,ca,b,cb,xmin,p,c);
356 fInner=new AliExternalTrackParam(xmin,alpha,p,c);
357 Quadratic2Helix(a,ca,b,cb,xmax,p,c);
358 fOuter=new AliExternalTrackParam(xmax,alpha,p,c);
359}
360
361void AliTPCTracklet::Quadratic2Helix(Double_t *a,Double_t *ca,
362 Double_t *b,Double_t *cb,
363 Double_t x0,
364 Double_t *p,Double_t *c) {
365 // y(x)=a[0]+a[1]*x+a[2]*x^2
366 // z(x)=b[0]+b[1]*x
367 // parametrises the corosponding helix at x0
368
369 // get the polynoms at x0
370 Double_t a0=x0*x0*a[2] + x0*a[1] + a[0];
371 Double_t a1=2.*x0*a[2] + a[1];
372 Double_t a2= a[2];
373 Double_t ca00=ca[0]+x0*(2.*ca[1]+x0*(ca[2]+2.*ca[3]+x0*(2.*ca[4]+x0*ca[5])));
374 Double_t ca10=ca[1]+x0*(ca[2]+2.*ca[3]+x0*(3.*ca[4]+x0*2.*ca[5]));
375 Double_t ca11=ca[2]+x0*4.*(ca[4]+x0*ca[5]);
376 Double_t ca20=ca[3]+x0*(ca[4]+x0*ca[5]);
377 Double_t ca21=ca[3]+x0*2.*ca[5];
378 Double_t ca22=ca[5];
379
380 Double_t b0=x0*b[1] + b[0];
381 Double_t b1= b[1];
382 Double_t cb00=cb[0]+x0*(2.*cb[1]+x0*cb[2]);
383 Double_t cb10=cb[1]+x0*cb[2];
384 Double_t cb11=cb[2];
385
386 // transform to helix parameters
387 Double_t f =1.+a1*a1;
388 Double_t f2 =f*f;
389 Double_t fi =1./f;
390 Double_t fi12=TMath::Sqrt(fi);
391 Double_t fi32=fi*fi12;
392 Double_t fi2 =fi*fi;
393 Double_t fi52=fi2*fi12;
394 Double_t fi3 =fi2*fi;
395 Double_t fi5 =fi2*fi3;
396
397 Double_t xyz[3]={0.}; // TODO...
398 Double_t fc=1./(GetBz(xyz)*kB2C);
399
400 p[0]=a0; // y0
401 p[1]=b0; // z0
402 p[2]=a1*fi12; // snp
403 p[3]=b1; // tgl
404 p[4]=2.*a2*fi32*fc; // 1/pt
405
406 c[0] =ca00; // y0-y0
407 c[1] =0.; // z0-y0
408 c[2] =cb00; // z0-z0
409 c[3] =ca10*fi32; // snp-y0
410 c[4] =0.; // snp-z0
411 c[5] =ca11*fi3; // snp-snp
412 c[6] =0.; // tgl-y0
413 c[7] =cb10; // tgl-z0
414 c[8] =0.; // tgl-snp
415 c[9] =cb11; // tgl-tgl
416 c[10]=2.*(-3.*a1*a2*ca10+f*ca20)*fi3*fc; // 1/pt-y0
417 c[11]=0.; // 1/pt-z0
418 c[12]=2.*(-3.*a1*a2*ca11+f*ca21)*fi52*fc; // 1/pt-snp
419 c[13]=0.; // 1/pt-tgl
420 c[14]=(-12.*a1*a2*(-3.*a1*a2*ca11+2.*f*ca21)+4.*f2*ca22)*fi5
421 *fc*fc; // 1/pt-1/pt
422}
423
424
425void AliTPCTracklet::FitRiemann(const AliTPCseed *track,Int_t sector) {
426 TLinearFitter fy(2);
427 fy.StoreData(kFALSE);
428 fy.SetFormula("hyp2");
429 Double_t xmax=-1.;
430 Double_t xmin=1000.;
431 for (Int_t i=0;i<160;++i) {
432 AliTPCclusterMI *c=track->GetClusterPointer(i);
967eae0d 433 if (c && RejectCluster(c)) continue;
9318a5b4 434 if (c&&c->GetDetector()==sector) {
435 Double_t x=c->GetX();
436 Double_t y=c->GetY();
437 Double_t xy[2]={x,y};
438 Double_t r=x*x+y*y;
439 Double_t errx=1.,erry=1.;//TODO!
440 Double_t err=TMath::Sqrt(4.*x*x*errx+4.*y*y*erry);
441 err=1.;
442 fy.AddPoint(xy,r,err);
443 xmax=TMath::Max(xmax,x);
444 xmin=TMath::Min(xmin,x);
445 }
446 }
447 fy.Eval();
448 Double_t a[3]={fy.GetParameter(0),
449 fy.GetParameter(1),
450 fy.GetParameter(2)};
451 Double_t ca[6]={fy.GetCovarianceMatrixElement(0,0),
452 fy.GetCovarianceMatrixElement(1,0),
453 fy.GetCovarianceMatrixElement(1,1),
454 fy.GetCovarianceMatrixElement(2,0),
455 fy.GetCovarianceMatrixElement(2,1),
456 fy.GetCovarianceMatrixElement(2,2)};
457
458 TLinearFitter fz(1);
459 fz.StoreData(kFALSE);
460 fz.SetFormula("hyp1");
461 Double_t R=.5*TMath::Sqrt(4.*a[0]+a[1]*a[1]+a[2]*a[2]);
462 Double_t oldx=0.;
463 Double_t oldy=R;
464 Double_t phi=0.;
465 for (Int_t i=0;i<160;++i) {
466 AliTPCclusterMI *c=track->GetClusterPointer(i);
967eae0d 467 if (c && RejectCluster(c)) continue;
9318a5b4 468 if (c&&c->GetDetector()==sector) {
469 Double_t x=c->GetX();
470 Double_t y=c->GetY();
471 Double_t dx=x-oldx;
472 Double_t dy=y-oldy;
473 phi+=2.*TMath::Abs(TMath::ATan2(.5*TMath::Sqrt(dx*dx+dy*dy),R));
474 Double_t err=1.;
475 fz.AddPoint(&phi,c->GetZ(),err);
476 oldx=x;
477 oldy=y;
478 }
479 }
480 fz.Eval();
481 Double_t b[2]={fz.GetParameter(0),
482 fz.GetParameter(1)};
483 Double_t cb[3]={fz.GetCovarianceMatrixElement(0,0),
484 fz.GetCovarianceMatrixElement(1,0),
485 fz.GetCovarianceMatrixElement(1,1)};
486
487 Double_t p[5];
488 Double_t c[15];
489 Double_t alpha=track->GetAlpha();
490 if (Riemann2Helix(a,ca,b,cb,0.,p,c))
491 fPrimary=new AliExternalTrackParam(0.,alpha,p,c);
492 if (Riemann2Helix(a,ca,b,cb,xmin,p,c))
493 fInner=new AliExternalTrackParam(xmin,alpha,p,c);
494 if (Riemann2Helix(a,ca,b,cb,xmax,p,c))
495 fOuter=new AliExternalTrackParam(xmax,alpha,p,c);
496}
497
c94a79e1 498Bool_t AliTPCTracklet::Riemann2Helix(Double_t *a,Double_t */*ca*/,
499 Double_t *b,Double_t */*cb*/,
9318a5b4 500 Double_t x0,
501 Double_t *p,Double_t *c) {
502 //TODO: signs!
503
504 Double_t xr0=.5*a[1];
505 Double_t yr0=.5*a[2];
506 Double_t R=.5*TMath::Sqrt(4.*a[0]+a[1]*a[1]+a[2]*a[2]);
507 Double_t dx=x0-xr0;
508 if (dx*dx>=R*R) return kFALSE;
60e55aee 509 Double_t dy=TMath::Sqrt((R-dx)*(R+dx)); //sign!!
9318a5b4 510 if (TMath::Abs(yr0+dy)>TMath::Abs(yr0-dy))
511 dy=-dy;
512 Double_t y0=yr0+dy;
513 Double_t tgp=-dx/dy; //TODO: dy!=0
514 Double_t z0=b[0]+TMath::ATan(tgp)*b[1];
515 Double_t xyz[3]={x0,y0,z0};
516 Double_t fc=1./(GetBz(xyz)*kB2C);
517 fc=1;
518 p[0]=y0; // y0
519 p[1]=z0; // z0
520 p[2]=tgp/TMath::Sqrt(1.+tgp*tgp); // snp
521 p[3]=b[1]; // tgl
522 p[4]=1./R*fc; // 1/pt
523
524 c[0] =0.; // y0-y0
525 c[1] =0.; // z0-y0
526 c[2] =0.; // z0-z0
527 c[3] =0.; // snp-y0
528 c[4] =0.; // snp-z0
529 c[5] =0.; // snp-snp
530 c[6] =0.; // tgl-y0
531 c[7] =0.; // tgl-z0
532 c[8] =0.; // tgl-snp
533 c[9] =0.; // tgl-tgl
534 c[10]=0.; // 1/pt-y0
535 c[11]=0.; // 1/pt-z0
536 c[12]=0.; // 1/pt-snp
537 c[13]=0.; // 1/pt-tgl
538 c[14]=0.; // 1/pt-1/pt
539
540 return kTRUE;
541}
542
543TObjArray AliTPCTracklet::CreateTracklets(const AliTPCseed *track,
544 TrackType type,
545 Bool_t storeClusters,
69209e2c 546 Int_t minClusters,
547 Int_t maxTracklets) {
548// The tracklet factory: It creates several tracklets out of a track. They
549// are created for sectors that fullfill the constraint of having enough
550// clusters inside. Futhermore you can specify the maximum amount of
551// tracklets that are to be created.
552// The tracklets appear in a sorted fashion, beginning with those having the
553// most clusters.
554
555 Int_t sectors[72]={0};
556 for (Int_t i=0;i<160;++i) {
9318a5b4 557 AliTPCclusterMI *c=track->GetClusterPointer(i);
967eae0d 558 if (c && RejectCluster(c)) continue;
69209e2c 559 if (c)
560 ++sectors[c->GetDetector()];
561 }
562 Int_t indices[72];
563 TMath::Sort(72,sectors,indices);
564 TObjArray tracklets;
565 if (maxTracklets>72) maxTracklets=72; // just to protect against "users".
566 for (Int_t i=0;i<maxTracklets&&sectors[indices[i]]>=minClusters;++i) {
9318a5b4 567 tracklets.Add(new AliTPCTracklet(track,indices[i],type,storeClusters));
69209e2c 568 }
569 return tracklets;
570}
9318a5b4 571
c94a79e1 572TObjArray AliTPCTracklet::CreateTracklets(const TObjArray &/*clusters*/,
573 TrackType /*type*/,
574 Bool_t /*storeClusters*/,
575 Int_t /*minClusters*/,
576 Int_t /*maxTracklets*/) {
577 // TODO!
578
71d2416b 579 TObjArray tracklets;
580 return tracklets;
9318a5b4 581}
582
583Bool_t AliTPCTracklet::PropagateToMeanX(const AliTPCTracklet &t1,
584 const AliTPCTracklet &t2,
585 AliExternalTrackParam *&t1m,
586 AliExternalTrackParam *&t2m) {
587 // This function propagates two Tracklets to a common x-coordinate. This
588 // x is dermined as the one that is in the middle of the two tracklets (they
589 // are assumed to live on two distinct x-intervalls).
590 // The inner parametrisation of the outer Tracklet and the outer
591 // parametrisation of the inner Tracklet are used and propagated to this
592 // common x. This result is saved not inside the Tracklets but two new
593 // ExternalTrackParams are created (that means you might want to delete
594 // them).
595 // In the case that the alpha angles of the Tracklets differ both angles
596 // are tried out for this propagation.
597 // In case of any failure kFALSE is returned, no AliExternalTrackParam
598 // is created und the pointers are set to 0.
599
600 if (t1.GetInner() && t1.GetOuter() &&
601 t2.GetInner() && t2.GetOuter()) {
602 if (t1.GetOuter()->GetX()<t2.GetInner()->GetX()) {
603 t1m=new AliExternalTrackParam(*t1.GetOuter());
604 t2m=new AliExternalTrackParam(*t2.GetInner());
605 }
606 else {
607 t1m=new AliExternalTrackParam(*t1.GetInner());
608 t2m=new AliExternalTrackParam(*t2.GetOuter());
609 }
610 Double_t mx=.5*(t1m->GetX()+t2m->GetX());
273ccc8a 611 //Double_t b1,b2;
9318a5b4 612 Double_t xyz[3];
613 t1m->GetXYZ(xyz);
273ccc8a 614 //b1=GetBz(xyz);
615 Double_t b1[3]; AliTracker::GetBxByBz(xyz,b1);
9318a5b4 616 t2m->GetXYZ(xyz);
273ccc8a 617 //b2=GetBz(xyz);
618 Double_t b2[3]; AliTracker::GetBxByBz(xyz,b2);
9318a5b4 619 if (t1m->Rotate(t2m->GetAlpha())
273ccc8a 620 //&& t1m->PropagateTo(mx,b1)
621 //&& t2m->PropagateTo(mx,b2));
622 && t1m->PropagateToBxByBz(mx,b1)
623 && t2m->PropagateToBxByBz(mx,b2));
9318a5b4 624 else
625 if (t2m->Rotate(t1m->GetAlpha())
273ccc8a 626 //&& t1m->PropagateTo(mx,b1)
627 //&& t2m->PropagateTo(mx,b2));
628 && t1m->PropagateToBxByBz(mx,b1)
629 && t2m->PropagateToBxByBz(mx,b2));
9318a5b4 630 else {
631 delete t1m;
632 delete t2m;
633 t1m=t2m=0;
634 }
635 }
636 else {
637 t1m=t2m=0;
638 }
639 return t1m&&t2m;
640}
641
f7a1cc68 642double AliTPCTracklet::GetBz(Double_t *xyz)
643{
644 return AliTracker::GetBz(xyz);
9318a5b4 645}
646
647void AliTPCTracklet::RandomND(Int_t ndim,const Double_t *p,const Double_t *c,
648 Double_t *x) {
649 // This function generates a n-dimensional random variable x with mean
650 // p and covariance c.
651 // That is done using the cholesky decomposition of the covariance matrix,
652 // Begin_Latex C=U^{t} U End_Latex, with Begin_Latex U End_Latex being an
653 // upper triangular matrix. Given a vector v of iid gausian random variables
654 // with variance 1 one obtains the asked result as: Begin_Latex x=U^t v
655 // End_Latex.
656 // c is expected to be in a lower triangular format:
657 // c[0]
658 // c[1] c[2]
659 // c[3] c[4] c[5]
660 // etc.
661 static TRandom3 random;
662 Double_t *c2= new Double_t[ndim*ndim];
663 Int_t k=0;
664 for (Int_t i=0;i<ndim;++i)
665 for (Int_t j=0;j<=i;++j)
666 c2[i*ndim+j]=c2[j*ndim+i]=c[k++];
667 TMatrixDSym cm(ndim,c2);
668 delete[] c2;
669 TDecompChol chol(cm);
670 chol.Decompose();
671 const TVectorD pv(ndim);
672 const_cast<TVectorD*>(&pv)->Use(ndim,const_cast<Double_t*>(p));
673 TVectorD xv(ndim);
674 xv.Use(ndim,x);
675 for (Int_t i=0;i<ndim;++i)
676 xv[i]=random.Gaus();
677 TMatrixD L=chol.GetU();
678 L.T();
679 xv=L*xv+pv;
680}
681
682TEllipse AliTPCTracklet::ErrorEllipse(Double_t x,Double_t y,
683 Double_t sx,Double_t sy,Double_t sxy) {
684 /* Begin_Latex
685 r_{1,2}=1/2 (a+c#pm#sqrt{(a-c)^{2}+(2b)^{2}})
686 End_Latex */
687 Double_t det1=1./(sx*sy-sxy*sxy);
688 Double_t a=sy*det1;
689 Double_t b=-sxy*det1;
690 Double_t c=sx*det1;
691 Double_t d=c-a;
692 Double_t s=TMath::Sqrt(d*d+4.*b*b);
693 Double_t r1=TMath::Sqrt(.5*(a+c-s));
694 Double_t r2=TMath::Sqrt(.5*(a+c+s));
695 Double_t alpha=.5*TMath::ATan2(2.*b,d);
696 return TEllipse(x,y,r1,r2,0.,360.,alpha*TMath::RadToDeg());
697}
698
699void AliTPCTracklet::Test(const char* filename) {
700 /*
701 aliroot
702 AliTPCTracklet::Test("");
703 TFile f("AliTPCTrackletDebug.root");
704 TTree *t=f.Get("AliTPCTrackletDebug");
705 t->Draw("p0:p4");
706 TEllipse e=AliTPCTracklet::ErrorEllipse(0.,0.,4.,1.,1.8);
707 e.Draw();
708 */
c94a79e1 709 TTreeSRedirector ds(filename);
9318a5b4 710 Double_t p[5]={0.};
711 Double_t c[15]={4.,
712 0.,4.,
713 0.,0.,9.,
714 0.,0.,0.,16.,
715 1.8,0.,0.,0.,1.};
716 for (Int_t i=0;i<10000;++i) {
717 Double_t x[5];
718 RandomND(5,p,c,x);
719 ds<<"AliTPCTrackletDebug"
720 <<"p0="<<x[0]
721 <<"p1="<<x[1]
722 <<"p2="<<x[2]
723 <<"p3="<<x[3]
724 <<"p4="<<x[4]
725 <<"\n";
726 }
727
728 /*
729 Double_t b;
730 Double_t x=0.;
731 Double_t alpha=0.;
732 Double_t param[5]={0.};
733 Double_t covar[15]={1.,
734 0.,1.,
735 0.,0.,1.,
736 0.,0.,0.,1.,
737 0.,0.,0.,0.,1.};
738 AliExternalTrackParam track(x,alpha,param,covar);
739
740
741
742 for (Int_t i=0;i<points.GetNPoints();++i) {
743 Double_t x=0.;
744 Double_t alpha=0.;
745 Double_t param[5]={0.};
746 Double_t covar[15]={1.,
747 0.,1.,
748 0.,0.,1.,
749 0.,0.,0.,1.,
750 0.,0.,0.,0.,1.};
751 AliExternalTrackParam track(x,alpha,param,covar);
752 for (x=90.;x<250.;x+=1.) {
753 track.PropagateTo(x,b);
754 AliTPCclusterMI c();
755 }
756 }
757 */
758}
967eae0d 759
760
761Bool_t AliTPCTracklet::RejectCluster(AliTPCclusterMI* cl, AliExternalTrackParam * param){
762 //
763 // check the acceptance of cluster
764 // Cut on edge effects
765 //
766 Bool_t isReject = kFALSE;
767 Float_t edgeY = cl->GetX()*TMath::Tan(TMath::Pi()/18);
768 Float_t dist = edgeY - TMath::Abs(cl->GetY());
769 if (param) dist = edgeY - TMath::Abs(param->GetY());
770 if (dist<fgEdgeCutY) isReject=kTRUE;
771 if (cl->GetType()<0) isReject=kTRUE;
772 return isReject;
773}