1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
18 ////////////////////////////////////////////////////////////////////////////
20 // The TRD offline tracklet
22 // The running horse of the TRD reconstruction. The following tasks are preformed:
23 // 1. Clusters attachment to tracks based on prior information stored at tracklet level (see AttachClusters)
24 // 2. Clusters position recalculation based on track information (see GetClusterXY and Fit)
25 // 3. Cluster error parametrization recalculation (see Fit)
26 // 4. Linear track approximation (Fit)
27 // 5. Optimal position (including z estimate for pad row cross tracklets) and covariance matrix of the track fit inside one TRD chamber (Fit)
28 // 6. Tilt pad correction and systematic effects (GetCovAt)
29 // 7. dEdx calculation (CookdEdx)
30 // 8. PID probabilities estimation (CookPID)
33 // Alex Bercuci <A.Bercuci@gsi.de> //
34 // Markus Fasel <M.Fasel@gsi.de> //
36 ////////////////////////////////////////////////////////////////////////////
39 #include "TLinearFitter.h"
40 #include "TClonesArray.h" // tmp
41 #include <TTreeStream.h>
44 #include "AliMathBase.h"
45 #include "AliCDBManager.h"
46 #include "AliTracker.h"
48 #include "AliTRDpadPlane.h"
49 #include "AliTRDcluster.h"
50 #include "AliTRDseedV1.h"
51 #include "AliTRDtrackV1.h"
52 #include "AliTRDcalibDB.h"
53 #include "AliTRDchamberTimeBin.h"
54 #include "AliTRDtrackingChamber.h"
55 #include "AliTRDtrackerV1.h"
56 #include "AliTRDReconstructor.h"
57 #include "AliTRDrecoParam.h"
58 #include "AliTRDCommonParam.h"
60 #include "Cal/AliTRDCalPID.h"
61 #include "Cal/AliTRDCalROC.h"
62 #include "Cal/AliTRDCalDet.h"
64 ClassImp(AliTRDseedV1)
66 //____________________________________________________________________
67 AliTRDseedV1::AliTRDseedV1(Int_t det)
94 for(Int_t ic=kNclusters; ic--;) fIndexes[ic] = -1;
95 memset(fClusters, 0, kNclusters*sizeof(AliTRDcluster*));
96 memset(fPad, 0, 3*sizeof(Float_t));
97 fYref[0] = 0.; fYref[1] = 0.;
98 fZref[0] = 0.; fZref[1] = 0.;
99 fYfit[0] = 0.; fYfit[1] = 0.;
100 fZfit[0] = 0.; fZfit[1] = 0.;
101 memset(fdEdx, 0, kNslices*sizeof(Float_t));
102 for(int ispec=0; ispec<AliPID::kSPECIES; ispec++) fProb[ispec] = -1.;
103 fLabels[0]=-1; fLabels[1]=-1; // most freq MC labels
104 fLabels[2]=0; // number of different labels for tracklet
105 memset(fRefCov, 0, 7*sizeof(Double_t));
106 // covariance matrix [diagonal]
107 // default sy = 200um and sz = 2.3 cm
108 fCov[0] = 4.e-4; fCov[1] = 0.; fCov[2] = 5.3;
109 SetStandAlone(kFALSE);
112 //____________________________________________________________________
113 AliTRDseedV1::AliTRDseedV1(const AliTRDseedV1 &ref)
114 :AliTRDtrackletBase((AliTRDtrackletBase&)ref)
138 // Copy Constructor performing a deep copy
143 SetBit(kOwner, kFALSE);
144 SetStandAlone(ref.IsStandAlone());
148 //____________________________________________________________________
149 AliTRDseedV1& AliTRDseedV1::operator=(const AliTRDseedV1 &ref)
152 // Assignment Operator using the copy function
158 SetBit(kOwner, kFALSE);
163 //____________________________________________________________________
164 AliTRDseedV1::~AliTRDseedV1()
167 // Destructor. The RecoParam object belongs to the underlying tracker.
170 //printf("I-AliTRDseedV1::~AliTRDseedV1() : Owner[%s]\n", IsOwner()?"YES":"NO");
173 for(int itb=0; itb<kNclusters; itb++){
174 if(!fClusters[itb]) continue;
175 //AliInfo(Form("deleting c %p @ %d", fClusters[itb], itb));
176 delete fClusters[itb];
177 fClusters[itb] = 0x0;
182 //____________________________________________________________________
183 void AliTRDseedV1::Copy(TObject &ref) const
190 AliTRDseedV1 &target = (AliTRDseedV1 &)ref;
192 target.fReconstructor = fReconstructor;
193 target.fClusterIter = 0x0;
197 target.fS2PRF = fS2PRF;
198 target.fDiffL = fDiffL;
199 target.fDiffT = fDiffT;
200 target.fClusterIdx = 0;
212 target.fChi2 = fChi2;
214 memcpy(target.fIndexes, fIndexes, kNclusters*sizeof(Int_t));
215 memcpy(target.fClusters, fClusters, kNclusters*sizeof(AliTRDcluster*));
216 memcpy(target.fPad, fPad, 3*sizeof(Float_t));
217 target.fYref[0] = fYref[0]; target.fYref[1] = fYref[1];
218 target.fZref[0] = fZref[0]; target.fZref[1] = fZref[1];
219 target.fYfit[0] = fYfit[0]; target.fYfit[1] = fYfit[1];
220 target.fZfit[0] = fZfit[0]; target.fZfit[1] = fZfit[1];
221 memcpy(target.fdEdx, fdEdx, kNslices*sizeof(Float_t));
222 memcpy(target.fProb, fProb, AliPID::kSPECIES*sizeof(Float_t));
223 memcpy(target.fLabels, fLabels, 3*sizeof(Int_t));
224 memcpy(target.fRefCov, fRefCov, 7*sizeof(Double_t));
225 memcpy(target.fCov, fCov, 3*sizeof(Double_t));
231 //____________________________________________________________
232 Bool_t AliTRDseedV1::Init(AliTRDtrackV1 *track)
234 // Initialize this tracklet using the track information
237 // track - the TRD track used to initialize the tracklet
239 // Detailed description
240 // The function sets the starting point and direction of the
241 // tracklet according to the information from the TRD track.
244 // The TRD track has to be propagated to the beginning of the
245 // chamber where the tracklet will be constructed
249 if(!track->GetProlongation(fX0, y, z)) return kFALSE;
255 //_____________________________________________________________________________
256 void AliTRDseedV1::Reset()
261 fExB=0.;fVD=0.;fT0=0.;fS2PRF=0.;
267 fdX=0.;fX0=0.; fX=0.; fY=0.; fZ=0.;
271 for(Int_t ic=kNclusters; ic--;) fIndexes[ic] = -1;
272 memset(fClusters, 0, kNclusters*sizeof(AliTRDcluster*));
273 memset(fPad, 0, 3*sizeof(Float_t));
274 fYref[0] = 0.; fYref[1] = 0.;
275 fZref[0] = 0.; fZref[1] = 0.;
276 fYfit[0] = 0.; fYfit[1] = 0.;
277 fZfit[0] = 0.; fZfit[1] = 0.;
278 memset(fdEdx, 0, kNslices*sizeof(Float_t));
279 for(int ispec=0; ispec<AliPID::kSPECIES; ispec++) fProb[ispec] = -1.;
280 fLabels[0]=-1; fLabels[1]=-1; // most freq MC labels
281 fLabels[2]=0; // number of different labels for tracklet
282 memset(fRefCov, 0, 7*sizeof(Double_t));
283 // covariance matrix [diagonal]
284 // default sy = 200um and sz = 2.3 cm
285 fCov[0] = 4.e-4; fCov[1] = 0.; fCov[2] = 5.3;
288 //____________________________________________________________________
289 void AliTRDseedV1::Update(const AliTRDtrackV1 *trk)
291 // update tracklet reference position from the TRD track
293 Double_t fSnp = trk->GetSnp();
294 Double_t fTgl = trk->GetTgl();
296 Double_t norm =1./TMath::Sqrt(1. - fSnp*fSnp);
297 fYref[1] = fSnp*norm;
298 fZref[1] = fTgl*norm;
299 SetCovRef(trk->GetCovariance());
301 Double_t dx = trk->GetX() - fX0;
302 fYref[0] = trk->GetY() - dx*fYref[1];
303 fZref[0] = trk->GetZ() - dx*fZref[1];
306 //_____________________________________________________________________________
307 void AliTRDseedV1::UpdateUsed()
310 // Calculate number of used clusers in the tracklet
313 Int_t nused = 0, nshared = 0;
314 for (Int_t i = kNclusters; i--; ) {
315 if (!fClusters[i]) continue;
316 if(fClusters[i]->IsUsed()){
318 } else if(fClusters[i]->IsShared()){
319 if(IsStandAlone()) nused++;
327 //_____________________________________________________________________________
328 void AliTRDseedV1::UseClusters()
333 // In stand alone mode:
334 // Clusters which are marked as used or shared from another track are
335 // removed from the tracklet
338 // - Clusters which are used by another track become shared
339 // - Clusters which are attached to a kink track become shared
341 AliTRDcluster **c = &fClusters[0];
342 for (Int_t ic=kNclusters; ic--; c++) {
345 if((*c)->IsShared() || (*c)->IsUsed()){
346 if((*c)->IsShared()) SetNShared(GetNShared()-1);
347 else SetNUsed(GetNUsed()-1);
354 if((*c)->IsUsed() || IsKink()){
365 //____________________________________________________________________
366 void AliTRDseedV1::CookdEdx(Int_t nslices)
368 // Calculates average dE/dx for all slices and store them in the internal array fdEdx.
371 // nslices : number of slices for which dE/dx should be calculated
373 // store results in the internal array fdEdx. This can be accessed with the method
374 // AliTRDseedV1::GetdEdx()
376 // Detailed description
377 // Calculates average dE/dx for all slices. Depending on the PID methode
378 // the number of slices can be 3 (LQ) or 8(NN).
379 // The calculation of dQ/dl are done using the tracklet fit results (see AliTRDseedV1::GetdQdl(Int_t))
381 // The following effects are included in the calculation:
382 // 1. calibration values for t0 and vdrift (using x coordinate to calculate slice)
383 // 2. cluster sharing (optional see AliTRDrecoParam::SetClusterSharing())
387 Int_t nclusters[kNslices];
388 memset(nclusters, 0, kNslices*sizeof(Int_t));
389 memset(fdEdx, 0, kNslices*sizeof(Float_t));
391 const Double_t kDriftLength = (.5 * AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());
393 AliTRDcluster *c = 0x0;
394 for(int ic=0; ic<AliTRDtrackerV1::GetNTimeBins(); ic++){
395 if(!(c = fClusters[ic]) && !(c = fClusters[ic+kNtb])) continue;
396 Float_t dx = TMath::Abs(fX0 - c->GetX());
398 // Filter clusters for dE/dx calculation
400 // 1.consider calibration effects for slice determination
402 if(dx<kDriftLength){ // TODO should be replaced by c->IsInChamber()
403 slice = Int_t(dx * nslices / kDriftLength);
404 } else slice = c->GetX() < fX0 ? nslices-1 : 0;
407 // 2. take sharing into account
408 Float_t w = /*c->IsShared() ? .5 :*/ 1.;
410 // 3. take into account large clusters TODO
411 //w *= c->GetNPads() > 3 ? .8 : 1.;
414 fdEdx[slice] += w * GetdQdl(ic); //fdQdl[ic];
416 } // End of loop over clusters
418 //if(fReconstructor->GetPIDMethod() == AliTRDReconstructor::kLQPID){
419 if(nslices == AliTRDpidUtil::kLQslices){
420 // calculate mean charge per slice (only LQ PID)
421 for(int is=0; is<nslices; is++){
422 if(nclusters[is]) fdEdx[is] /= nclusters[is];
427 //_____________________________________________________________________________
428 void AliTRDseedV1::CookLabels()
431 // Cook 2 labels for seed
437 for (Int_t i = 0; i < kNclusters; i++) {
438 if (!fClusters[i]) continue;
439 for (Int_t ilab = 0; ilab < 3; ilab++) {
440 if (fClusters[i]->GetLabel(ilab) >= 0) {
441 labels[nlab] = fClusters[i]->GetLabel(ilab);
447 fLabels[2] = AliMathBase::Freq(nlab,labels,out,kTRUE);
449 if ((fLabels[2] > 1) && (out[3] > 1)) fLabels[1] = out[2];
453 //____________________________________________________________________
454 Float_t AliTRDseedV1::GetdQdl(Int_t ic, Float_t *dl) const
456 // Using the linear approximation of the track inside one TRD chamber (TRD tracklet)
457 // the charge per unit length can be written as:
459 // #frac{dq}{dl} = #frac{q_{c}}{dx * #sqrt{1 + #(){#frac{dy}{dx}}^{2}_{fit} + #(){#frac{dz}{dx}}^{2}_{ref}}}
461 // where qc is the total charge collected in the current time bin and dx is the length
463 // The following correction are applied :
464 // - charge : pad row cross corrections
465 // [diffusion and TRF assymetry] TODO
466 // - dx : anisochronity, track inclination - see Fit and AliTRDcluster::GetXloc()
467 // and AliTRDcluster::GetYloc() for the effects taken into account
470 //<img src="TRD/trackletDQDT.gif">
472 // In the picture the energy loss measured on the tracklet as a function of drift time [left] and respectively
473 // drift length [right] for different particle species is displayed.
474 // Author : Alex Bercuci <A.Bercuci@gsi.de>
477 // check whether both clusters are inside the chamber
478 Bool_t hasClusterInChamber = kFALSE;
479 if(fClusters[ic] && fClusters[ic]->IsInChamber()){
480 hasClusterInChamber = kTRUE;
481 dq += TMath::Abs(fClusters[ic]->GetQ());
482 }else if(fClusters[ic+kNtb] && fClusters[ic+kNtb]->IsInChamber()){
483 hasClusterInChamber = kTRUE;
484 dq += TMath::Abs(fClusters[ic+kNtb]->GetQ());
486 if(!hasClusterInChamber) return 0.;
487 if(dq<1.e-3) return 0.;
490 if(ic-1>=0 && ic+1<kNtb){
491 Float_t x2(0.), x1(0.);
492 // try to estimate upper radial position (find the cluster which is inside the chamber)
493 if(fClusters[ic-1] && fClusters[ic-1]->IsInChamber()) x2 = fClusters[ic-1]->GetX();
494 else if(fClusters[ic-1+kNtb] && fClusters[ic-1+kNtb]->IsInChamber()) x2 = fClusters[ic-1+kNtb]->GetX();
495 else if(fClusters[ic] && fClusters[ic]->IsInChamber()) x2 = fClusters[ic]->GetX()+fdX;
496 else x2 = fClusters[ic+kNtb]->GetX()+fdX;
497 // try to estimate lower radial position (find the cluster which is inside the chamber)
498 if(fClusters[ic+1] && fClusters[ic+1]->IsInChamber()) x1 = fClusters[ic+1]->GetX();
499 else if(fClusters[ic+1+kNtb] && fClusters[ic+1+kNtb]->IsInChamber()) x1 = fClusters[ic+1+kNtb]->GetX();
500 else if(fClusters[ic] && fClusters[ic]->IsInChamber()) x1 = fClusters[ic]->GetX()-fdX;
501 else x1 = fClusters[ic+kNtb]->GetX()-fdX;
505 dx *= TMath::Sqrt(1. + fYfit[1]*fYfit[1] + fZref[1]*fZref[1]);
510 //____________________________________________________________
511 Float_t AliTRDseedV1::GetMomentum(Float_t *err) const
513 // Returns momentum of the track after update with the current tracklet as:
515 // p=#frac{1}{1/p_{t}} #sqrt{1+tgl^{2}}
517 // and optionally the momentum error (if err is not null).
518 // The estimated variance of the momentum is given by:
520 // #sigma_{p}^{2} = (#frac{dp}{dp_{t}})^{2} #sigma_{p_{t}}^{2}+(#frac{dp}{dtgl})^{2} #sigma_{tgl}^{2}+2#frac{dp}{dp_{t}}#frac{dp}{dtgl} cov(tgl,1/p_{t})
522 // which can be simplified to
524 // #sigma_{p}^{2} = p^{2}p_{t}^{4}tgl^{2}#sigma_{tgl}^{2}-2p^{2}p_{t}^{3}tgl cov(tgl,1/p_{t})+p^{2}p_{t}^{2}#sigma_{1/p_{t}}^{2}
528 Double_t p = fPt*TMath::Sqrt(1.+fZref[1]*fZref[1]);
530 Double_t tgl2 = fZref[1]*fZref[1];
531 Double_t pt2 = fPt*fPt;
534 p2*tgl2*pt2*pt2*fRefCov[4]
535 -2.*p2*fZref[1]*fPt*pt2*fRefCov[5]
537 (*err) = TMath::Sqrt(s2);
543 //____________________________________________________________________
544 Float_t* AliTRDseedV1::GetProbability(Bool_t force)
546 if(!force) return &fProb[0];
547 if(!CookPID()) return 0x0;
551 //____________________________________________________________
552 Bool_t AliTRDseedV1::CookPID()
554 // Fill probability array for tracklet from the DB.
559 // returns pointer to the probability array and 0x0 if missing DB access
561 // Retrieve PID probabilities for e+-, mu+-, K+-, pi+- and p+- from the DB according to tracklet information:
562 // - estimated momentum at tracklet reference point
563 // - dE/dx measurements
566 // According to the steering settings specified in the reconstruction one of the following methods are used
567 // - Neural Network [default] - option "nn"
568 // - 2D Likelihood - option "!nn"
570 AliTRDcalibDB *calibration = AliTRDcalibDB::Instance();
572 AliError("No access to calibration data");
576 if (!fReconstructor) {
577 AliError("Reconstructor not set.");
581 // Retrieve the CDB container class with the parametric detector response
582 const AliTRDCalPID *pd = calibration->GetPIDObject(fReconstructor->GetPIDMethod());
584 AliError("No access to AliTRDCalPID object");
587 //AliInfo(Form("Method[%d] : %s", fReconstructor->GetRecoParam() ->GetPIDMethod(), pd->IsA()->GetName()));
589 // calculate tracklet length TO DO
590 Float_t length = (AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());
591 /// TMath::Sqrt((1.0 - fSnp[iPlane]*fSnp[iPlane]) / (1.0 + fTgl[iPlane]*fTgl[iPlane]));
594 CookdEdx(fReconstructor->GetNdEdxSlices());
596 // Sets the a priori probabilities
597 for(int ispec=0; ispec<AliPID::kSPECIES; ispec++) {
598 fProb[ispec] = pd->GetProbability(ispec, GetMomentum(), &fdEdx[0], length, GetPlane());
604 //____________________________________________________________________
605 Float_t AliTRDseedV1::GetQuality(Bool_t kZcorr) const
608 // Returns a quality measurement of the current seed
611 Float_t zcorr = kZcorr ? GetTilt() * (fZfit[0] - fZref[0]) : 0.;
613 .5 * TMath::Abs(18.0 - GetN())
614 + 10.* TMath::Abs(fYfit[1] - fYref[1])
615 + 5. * TMath::Abs(fYfit[0] - fYref[0] + zcorr)
616 + 2. * TMath::Abs(fZfit[0] - fZref[0]) / GetPadLength();
619 //____________________________________________________________________
620 void AliTRDseedV1::GetCovAt(Double_t x, Double_t *cov) const
622 // Computes covariance in the y-z plane at radial point x (in tracking coordinates)
623 // and returns the results in the preallocated array cov[3] as :
630 // For the linear transformation
634 // The error propagation has the general form
636 // C_{Y} = T_{x} C_{X} T_{x}^{T}
638 // We apply this formula 2 times. First to calculate the covariance of the tracklet
639 // at point x we consider:
641 // T_{x} = (1 x); X=(y0 dy/dx); C_{X}=#(){#splitline{Var(y0) Cov(y0, dy/dx)}{Cov(y0, dy/dx) Var(dy/dx)}}
643 // and secondly to take into account the tilt angle
645 // T_{#alpha} = #(){#splitline{cos(#alpha) __ sin(#alpha)}{-sin(#alpha) __ cos(#alpha)}}; X=(y z); C_{X}=#(){#splitline{Var(y) 0}{0 Var(z)}}
648 // using simple trigonometrics one can write for this last case
650 // C_{Y}=#frac{1}{1+tg^{2}#alpha} #(){#splitline{(#sigma_{y}^{2}+tg^{2}#alpha#sigma_{z}^{2}) __ tg#alpha(#sigma_{z}^{2}-#sigma_{y}^{2})}{tg#alpha(#sigma_{z}^{2}-#sigma_{y}^{2}) __ (#sigma_{z}^{2}+tg^{2}#alpha#sigma_{y}^{2})}}
652 // which can be aproximated for small alphas (2 deg) with
654 // C_{Y}=#(){#splitline{#sigma_{y}^{2} __ (#sigma_{z}^{2}-#sigma_{y}^{2})tg#alpha}{((#sigma_{z}^{2}-#sigma_{y}^{2})tg#alpha __ #sigma_{z}^{2}}}
657 // before applying the tilt rotation we also apply systematic uncertainties to the tracklet
658 // position which can be tunned from outside via the AliTRDrecoParam::SetSysCovMatrix(). They might
659 // account for extra misalignment/miscalibration uncertainties.
662 // Alex Bercuci <A.Bercuci@gsi.de>
663 // Date : Jan 8th 2009
668 Double_t sy2 = fCov[0] +2.*xr*fCov[1] + xr*xr*fCov[2];
670 //GetPadLength()*GetPadLength()/12.;
672 // insert systematic uncertainties
674 Double_t sys[15]; memset(sys, 0, 15*sizeof(Double_t));
675 fReconstructor->GetRecoParam()->GetSysCovMatrix(sys);
679 // rotate covariance matrix
680 Double_t t2 = GetTilt()*GetTilt();
681 Double_t correction = 1./(1. + t2);
682 cov[0] = (sy2+t2*sz2)*correction;
683 cov[1] = GetTilt()*(sz2 - sy2)*correction;
684 cov[2] = (t2*sy2+sz2)*correction;
686 //printf("C(%6.1f %+6.3f %6.1f) [%s]\n", 1.e4*TMath::Sqrt(cov[0]), cov[1], 1.e4*TMath::Sqrt(cov[2]), IsRowCross()?" RC ":"-");
689 //____________________________________________________________
690 Double_t AliTRDseedV1::GetCovSqrt(Double_t *c, Double_t *d)
692 // Helper function to calculate the square root of the covariance matrix.
693 // The input matrix is stored in the vector c and the result in the vector d.
694 // Both arrays have to be initialized by the user with at least 3 elements. Return negative in case of failure.
696 // For calculating the square root of the symmetric matrix c
697 // the following relation is used:
699 // C^{1/2} = VD^{1/2}V^{-1}
701 // with V being the matrix with the n eigenvectors as columns.
702 // In case C is symmetric the followings are true:
703 // - matrix D is diagonal with the diagonal given by the eigenvalues of C
706 // Author A.Bercuci <A.Bercuci@gsi.de>
709 Double_t L[2], // eigenvalues
710 V[3]; // eigenvectors
711 // the secular equation and its solution :
712 // (c[0]-L)(c[2]-L)-c[1]^2 = 0
713 // L^2 - L*Tr(c)+DET(c) = 0
714 // L12 = [Tr(c) +- sqrt(Tr(c)^2-4*DET(c))]/2
715 Double_t Tr = c[0]+c[2], // trace
716 DET = c[0]*c[2]-c[1]*c[1]; // determinant
717 if(TMath::Abs(DET)<1.e-20) return -1.;
718 Double_t DD = TMath::Sqrt(Tr*Tr - 4*DET);
721 if(L[0]<0. || L[1]<0.) return -1.;
726 Double_t tmp = (L[0]-c[0])/c[1];
727 V[0] = TMath::Sqrt(1./(tmp*tmp+1));
729 V[2] = V[1]*c[1]/(L[1]-c[2]);
731 L[0] = TMath::Sqrt(L[0]); L[1] = TMath::Sqrt(L[1]);
732 d[0] = V[0]*V[0]*L[0]+V[1]*V[1]*L[1];
733 d[1] = V[0]*V[1]*L[0]+V[1]*V[2]*L[1];
734 d[2] = V[1]*V[1]*L[0]+V[2]*V[2]*L[1];
739 //____________________________________________________________
740 Double_t AliTRDseedV1::GetCovInv(Double_t *c, Double_t *d)
742 // Helper function to calculate the inverse of the covariance matrix.
743 // The input matrix is stored in the vector c and the result in the vector d.
744 // Both arrays have to be initialized by the user with at least 3 elements
745 // The return value is the determinant or 0 in case of singularity.
747 // Author A.Bercuci <A.Bercuci@gsi.de>
750 Double_t Det = c[0]*c[2] - c[1]*c[1];
751 if(TMath::Abs(Det)<1.e-20) return 0.;
752 Double_t InvDet = 1./Det;
759 //____________________________________________________________________
760 UShort_t AliTRDseedV1::GetVolumeId() const
763 while(ic<kNclusters && !fClusters[ic]) ic++;
764 return fClusters[ic] ? fClusters[ic]->GetVolumeId() : 0;
768 //____________________________________________________________________
769 void AliTRDseedV1::Calibrate()
771 // Retrieve calibration and position parameters from OCDB.
772 // The following information are used
774 // - column and row position of first attached cluster. If no clusters are attached
775 // to the tracklet a random central chamber position (c=70, r=7) will be used.
777 // The following information is cached in the tracklet
778 // t0 (trigger delay)
781 // omega*tau = tg(a_L)
782 // diffusion coefficients (longitudinal and transversal)
785 // Alex Bercuci <A.Bercuci@gsi.de>
786 // Date : Jan 8th 2009
789 AliCDBManager *cdb = AliCDBManager::Instance();
790 if(cdb->GetRun() < 0){
791 AliError("OCDB manager not properly initialized");
795 AliTRDcalibDB *calib = AliTRDcalibDB::Instance();
796 AliTRDCalROC *vdROC = calib->GetVdriftROC(fDet),
797 *t0ROC = calib->GetT0ROC(fDet);;
798 const AliTRDCalDet *vdDet = calib->GetVdriftDet();
799 const AliTRDCalDet *t0Det = calib->GetT0Det();
801 Int_t col = 70, row = 7;
802 AliTRDcluster **c = &fClusters[0];
805 while (ic<kNclusters && !(*c)){ic++; c++;}
807 col = (*c)->GetPadCol();
808 row = (*c)->GetPadRow();
812 fT0 = t0Det->GetValue(fDet) + t0ROC->GetValue(col,row);
813 fVD = vdDet->GetValue(fDet) * vdROC->GetValue(col, row);
814 fS2PRF = calib->GetPRFWidth(fDet, col, row); fS2PRF *= fS2PRF;
815 fExB = AliTRDCommonParam::Instance()->GetOmegaTau(fVD);
816 AliTRDCommonParam::Instance()->GetDiffCoeff(fDiffL,
818 SetBit(kCalib, kTRUE);
821 //____________________________________________________________________
822 void AliTRDseedV1::SetOwner()
824 //AliInfo(Form("own [%s] fOwner[%s]", own?"YES":"NO", fOwner?"YES":"NO"));
826 if(TestBit(kOwner)) return;
827 for(int ic=0; ic<kNclusters; ic++){
828 if(!fClusters[ic]) continue;
829 fClusters[ic] = new AliTRDcluster(*fClusters[ic]);
834 //____________________________________________________________
835 void AliTRDseedV1::SetPadPlane(AliTRDpadPlane *p)
837 // Shortcut method to initialize pad geometry.
839 SetTilt(TMath::Tan(TMath::DegToRad()*p->GetTiltingAngle()));
840 SetPadLength(p->GetLengthIPad());
841 SetPadWidth(p->GetWidthIPad());
845 //____________________________________________________________________
846 Bool_t AliTRDseedV1::AttachClusters(AliTRDtrackingChamber *chamber, Bool_t tilt)
849 // Projective algorithm to attach clusters to seeding tracklets. The following steps are performed :
850 // 1. Collapse x coordinate for the full detector plane
851 // 2. truncated mean on y (r-phi) direction
853 // 4. truncated mean on z direction
857 // - chamber : pointer to tracking chamber container used to search the tracklet
858 // - tilt : switch for tilt correction during road building [default true]
860 // - true : if tracklet found successfully. Failure can happend because of the following:
862 // Detailed description
864 // We start up by defining the track direction in the xy plane and roads. The roads are calculated based
865 // on tracking information (variance in the r-phi direction) and estimated variance of the standard
866 // clusters (see AliTRDcluster::SetSigmaY2()) corrected for tilt (see GetCovAt()). From this the road is
868 // r_{y} = 3*#sqrt{12*(#sigma^{2}_{Trk}(y) + #frac{#sigma^{2}_{cl}(y) + tg^{2}(#alpha_{L})#sigma^{2}_{cl}(z)}{1+tg^{2}(#alpha_{L})})}
869 // r_{z} = 1.5*L_{pad}
872 // Author : Alexandru Bercuci <A.Bercuci@gsi.de>
875 Bool_t kPRINT = kFALSE;
876 if(!fReconstructor->GetRecoParam() ){
877 AliError("Seed can not be used without a valid RecoParam.");
880 // Initialize reco params for this tracklet
881 // 1. first time bin in the drift region
883 Int_t kClmin = Int_t(fReconstructor->GetRecoParam() ->GetFindableClusters()*AliTRDtrackerV1::GetNTimeBins());
885 Double_t s2yTrk= fRefCov[0],
887 s2zCl = GetPadLength()*GetPadLength()/12.,
888 syRef = TMath::Sqrt(s2yTrk),
889 t2 = GetTilt()*GetTilt();
891 Double_t kroady = 1., //fReconstructor->GetRecoParam() ->GetRoad1y();
892 kroadz = GetPadLength() * 1.5 + 1.;
893 // define probing cluster (the perfect cluster) and default calibration
894 Short_t sig[] = {0, 0, 10, 30, 10, 0,0};
895 AliTRDcluster cp(fDet, 6, 75, 0, sig, 0);
898 if(kPRINT) printf("AttachClusters() sy[%f] road[%f]\n", syRef, kroady);
901 const Int_t kNrows = 16;
902 const Int_t kNcls = 3*kNclusters; // buffer size
903 AliTRDcluster *clst[kNrows][kNcls];
904 Double_t cond[4], dx, dy, yt, zt, yres[kNrows][kNcls];
905 Int_t idxs[kNrows][kNcls], ncl[kNrows], ncls = 0;
906 memset(ncl, 0, kNrows*sizeof(Int_t));
907 memset(yres, 0, kNrows*kNcls*sizeof(Double_t));
908 memset(clst, 0, kNrows*kNcls*sizeof(AliTRDcluster*));
910 // Do cluster projection
911 AliTRDcluster *c = 0x0;
912 AliTRDchamberTimeBin *layer = 0x0;
913 Bool_t kBUFFER = kFALSE;
914 for (Int_t it = 0; it < kNtb; it++) {
915 if(!(layer = chamber->GetTB(it))) continue;
916 if(!Int_t(*layer)) continue;
917 // get track projection at layers position
918 dx = fX0 - layer->GetX();
919 yt = fYref[0] - fYref[1] * dx;
920 zt = fZref[0] - fZref[1] * dx;
921 // get standard cluster error corrected for tilt
922 cp.SetLocalTimeBin(it);
923 cp.SetSigmaY2(0.02, fDiffT, fExB, dx, -1./*zt*/, fYref[1]);
924 s2yCl = (cp.GetSigmaY2() + t2*s2zCl)/(1.+t2);
925 // get estimated road
926 kroady = 3.*TMath::Sqrt(12.*(s2yTrk + s2yCl));
928 if(kPRINT) printf(" %2d dx[%f] yt[%f] zt[%f] sT[um]=%6.2f sy[um]=%6.2f syTilt[um]=%6.2f yRoad[mm]=%f\n", it, dx, yt, zt, 1.e4*TMath::Sqrt(s2yTrk), 1.e4*TMath::Sqrt(cp.GetSigmaY2()), 1.e4*TMath::Sqrt(s2yCl), 1.e1*kroady);
931 cond[0] = yt; cond[2] = kroady;
932 cond[1] = zt; cond[3] = kroadz;
934 layer->GetClusters(cond, idx, n, 6);
935 for(Int_t ic = n; ic--;){
936 c = (*layer)[idx[ic]];
938 dy += tilt ? GetTilt() * (c->GetZ() - zt) : 0.;
939 // select clusters on a 3 sigmaKalman level
940 /* if(tilt && TMath::Abs(dy) > 3.*syRef){
941 printf("too large !!!\n");
944 Int_t r = c->GetPadRow();
945 if(kPRINT) printf("\t\t%d dy[%f] yc[%f] r[%d]\n", ic, TMath::Abs(dy), c->GetY(), r);
947 idxs[r][ncl[r]] = idx[ic];
948 yres[r][ncl[r]] = dy;
951 if(ncl[r] >= kNcls) {
952 AliWarning(Form("Cluster candidates reached buffer limit %d. Some may be lost.", kNcls));
959 if(kPRINT) printf("Found %d clusters\n", ncls);
960 if(ncls<kClmin) return kFALSE;
962 // analyze each row individualy
963 Double_t mean, syDis;
964 Int_t nrow[] = {0, 0, 0}, nr = 0, lr=-1;
965 for(Int_t ir=kNrows; ir--;){
966 if(!(ncl[ir])) continue;
967 if(lr>0 && lr-ir != 1){
968 if(kPRINT) printf("W - gap in rows attached !!\n");
970 if(kPRINT) printf("\tir[%d] lr[%d] n[%d]\n", ir, lr, ncl[ir]);
971 // Evaluate truncated mean on the y direction
972 if(ncl[ir] > 3) AliMathBase::EvaluateUni(ncl[ir], yres[ir], mean, syDis, Int_t(ncl[ir]*.8));
974 mean = 0.; syDis = 0.;
978 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 3){
979 TTreeSRedirector &cstreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
980 TVectorD dy(ncl[ir], yres[ir]);
982 if(IsKink()) SETBIT(stat, 0);
983 if(IsStandAlone()) SETBIT(stat, 1);
984 cstreamer << "AttachClusters"
995 // TODO check mean and sigma agains cluster resolution !!
996 if(kPRINT) printf("\tr[%2d] m[%f %5.3fsigma] s[%f]\n", ir, mean, TMath::Abs(mean/syDis), syDis);
997 // select clusters on a 3 sigmaDistr level
998 Bool_t kFOUND = kFALSE;
999 for(Int_t ic = ncl[ir]; ic--;){
1000 if(yres[ir][ic] - mean > 3. * syDis){
1001 clst[ir][ic] = 0x0; continue;
1003 nrow[nr]++; kFOUND = kTRUE;
1007 lr = ir; if(nr>=3) break;
1009 if(kPRINT) printf("lr[%d] nr[%d] nrow[0]=%d nrow[1]=%d nrow[2]=%d\n", lr, nr, nrow[0], nrow[1], nrow[2]);
1011 // classify cluster rows
1018 SetBit(kRowCross, kTRUE); // mark pad row crossing
1019 if(nrow[0] > nrow[1]){ row = lr+1; lr = -1;}
1028 SetBit(kRowCross, kTRUE); // mark pad row crossing
1031 if(kPRINT) printf("\trow[%d] n[%d]\n\n", row, nrow[0]);
1032 if(row<0) return kFALSE;
1034 // Select and store clusters
1035 // We should consider here :
1036 // 1. How far is the chamber boundary
1037 // 2. How big is the mean
1039 for (Int_t ir = 0; ir < nr; ir++) {
1040 Int_t jr = row + ir*lr;
1041 if(kPRINT) printf("\tattach %d clusters for row %d\n", ncl[jr], jr);
1042 for (Int_t ic = 0; ic < ncl[jr]; ic++) {
1043 if(!(c = clst[jr][ic])) continue;
1044 Int_t it = c->GetPadTime();
1045 // TODO proper indexing of clusters !!
1046 fIndexes[it+kNtb*ir] = chamber->GetTB(it)->GetGlobalIndex(idxs[jr][ic]);
1047 fClusters[it+kNtb*ir] = c;
1049 //printf("\tid[%2d] it[%d] idx[%d]\n", ic, it, fIndexes[it]);
1055 // number of minimum numbers of clusters expected for the tracklet
1057 //AliWarning(Form("Not enough clusters to fit the tracklet %d [%d].", n, kClmin));
1062 // Load calibration parameters for this tracklet
1065 // calculate dx for time bins in the drift region (calibration aware)
1066 Float_t x[2] = {0.,0.}; Int_t tb[2]={0,0};
1067 for (Int_t it = t0, irp=0; irp<2 && it < AliTRDtrackerV1::GetNTimeBins(); it++) {
1068 if(!fClusters[it]) continue;
1069 x[irp] = fClusters[it]->GetX();
1070 tb[irp] = fClusters[it]->GetLocalTimeBin();
1073 Int_t dtb = tb[1] - tb[0];
1074 fdX = dtb ? (x[0] - x[1]) / dtb : 0.15;
1078 //____________________________________________________________
1079 void AliTRDseedV1::Bootstrap(const AliTRDReconstructor *rec)
1081 // Fill in all derived information. It has to be called after recovery from file or HLT.
1082 // The primitive data are
1083 // - list of clusters
1084 // - detector (as the detector will be removed from clusters)
1085 // - position of anode wire (fX0) - temporary
1086 // - track reference position and direction
1087 // - momentum of the track
1088 // - time bin length [cm]
1090 // A.Bercuci <A.Bercuci@gsi.de> Oct 30th 2008
1092 fReconstructor = rec;
1094 AliTRDpadPlane *pp = g.GetPadPlane(fDet);
1095 fPad[0] = pp->GetLengthIPad();
1096 fPad[1] = pp->GetWidthIPad();
1097 fPad[3] = TMath::Tan(TMath::DegToRad()*pp->GetTiltingAngle());
1098 //fSnp = fYref[1]/TMath::Sqrt(1+fYref[1]*fYref[1]);
1100 Int_t n = 0, nshare = 0, nused = 0;
1101 AliTRDcluster **cit = &fClusters[0];
1102 for(Int_t ic = kNclusters; ic--; cit++){
1105 if((*cit)->IsShared()) nshare++;
1106 if((*cit)->IsUsed()) nused++;
1108 SetN(n); SetNUsed(nused); SetNShared(nshare);
1115 //____________________________________________________________________
1116 Bool_t AliTRDseedV1::Fit(Bool_t tilt, Bool_t zcorr)
1119 // Linear fit of the clusters attached to the tracklet
1122 // - tilt : switch for tilt pad correction of cluster y position based on
1123 // the z, dzdx info from outside [default false].
1124 // - zcorr : switch for using z information to correct for anisochronity
1125 // and a finner error parameterization estimation [default false]
1127 // True if successful
1129 // Detailed description
1131 // Fit in the xy plane
1133 // The fit is performed to estimate the y position of the tracklet and the track
1134 // angle in the bending plane. The clusters are represented in the chamber coordinate
1135 // system (with respect to the anode wire - see AliTRDtrackerV1::FollowBackProlongation()
1136 // on how this is set). The x and y position of the cluster and also their variances
1137 // are known from clusterizer level (see AliTRDcluster::GetXloc(), AliTRDcluster::GetYloc(),
1138 // AliTRDcluster::GetSX() and AliTRDcluster::GetSY()).
1139 // If gaussian approximation is used to calculate y coordinate of the cluster the position
1140 // is recalculated taking into account the track angle. The general formula to calculate the
1141 // error of cluster position in the gaussian approximation taking into account diffusion and track
1142 // inclination is given for TRD by:
1144 // #sigma^{2}_{y} = #sigma^{2}_{PRF} + #frac{x#delta_{t}^{2}}{(1+tg(#alpha_{L}))^{2}} + #frac{x^{2}tg^{2}(#phi-#alpha_{L})tg^{2}(#alpha_{L})}{12}
1147 // Since errors are calculated only in the y directions, radial errors (x direction) are mapped to y
1148 // by projection i.e.
1150 // #sigma_{x|y} = tg(#phi) #sigma_{x}
1152 // and also by the lorentz angle correction
1154 // Fit in the xz plane
1156 // The "fit" is performed to estimate the radial position (x direction) where pad row cross happens.
1157 // If no pad row crossing the z position is taken from geometry and radial position is taken from the xy
1160 // There are two methods to estimate the radial position of the pad row cross:
1161 // 1. leading cluster radial position : Here the lower part of the tracklet is considered and the last
1162 // cluster registered (at radial x0) on this segment is chosen to mark the pad row crossing. The error
1163 // of the z estimate is given by :
1165 // #sigma_{z} = tg(#theta) #Delta x_{x_{0}}/12
1167 // The systematic errors for this estimation are generated by the following sources:
1168 // - no charge sharing between pad rows is considered (sharp cross)
1169 // - missing cluster at row cross (noise peak-up, under-threshold signal etc.).
1171 // 2. charge fit over the crossing point : Here the full energy deposit along the tracklet is considered
1172 // to estimate the position of the crossing by a fit in the qx plane. The errors in the q directions are
1173 // parameterized as s_q = q^2. The systematic errors for this estimation are generated by the following sources:
1174 // - no general model for the qx dependence
1175 // - physical fluctuations of the charge deposit
1176 // - gain calibration dependence
1178 // Estimation of the radial position of the tracklet
1180 // For pad row cross the radial position is taken from the xz fit (see above). Otherwise it is taken as the
1181 // interpolation point of the tracklet i.e. the point where the error in y of the fit is minimum. The error
1182 // in the y direction of the tracklet is (see AliTRDseedV1::GetCovAt()):
1184 // #sigma_{y} = #sigma^{2}_{y_{0}} + 2xcov(y_{0}, dy/dx) + #sigma^{2}_{dy/dx}
1186 // and thus the radial position is:
1188 // x = - cov(y_{0}, dy/dx)/#sigma^{2}_{dy/dx}
1191 // Estimation of tracklet position error
1193 // The error in y direction is the error of the linear fit at the radial position of the tracklet while in the z
1194 // direction is given by the cluster error or pad row cross error. In case of no pad row cross this is given by:
1196 // #sigma_{y} = #sigma^{2}_{y_{0}} - 2cov^{2}(y_{0}, dy/dx)/#sigma^{2}_{dy/dx} + #sigma^{2}_{dy/dx}
1197 // #sigma_{z} = Pad_{length}/12
1199 // For pad row cross the full error is calculated at the radial position of the crossing (see above) and the error
1200 // in z by the width of the crossing region - being a matter of parameterization.
1202 // #sigma_{z} = tg(#theta) #Delta x_{x_{0}}/12
1204 // In case of no tilt correction (default in the barrel tracking) the tilt is taken into account by the rotation of
1205 // the covariance matrix. See AliTRDseedV1::GetCovAt() for details.
1208 // A.Bercuci <A.Bercuci@gsi.de>
1210 if(!IsCalibrated()) Calibrate();
1212 const Int_t kClmin = 8;
1214 // get track direction
1215 Double_t y0 = fYref[0];
1216 Double_t dydx = fYref[1];
1217 Double_t z0 = fZref[0];
1218 Double_t dzdx = fZref[1];
1221 //AliTRDtrackerV1::AliTRDLeastSquare fitterZ;
1222 TLinearFitter fitterY(1, "pol1");
1223 TLinearFitter fitterZ(1, "pol1");
1225 // book cluster information
1226 Double_t qc[kNclusters], xc[kNclusters], yc[kNclusters], zc[kNclusters], sy[kNclusters];
1229 AliTRDcluster *c=0x0, **jc = &fClusters[0];
1230 for (Int_t ic=0; ic<kNtb; ic++, ++jc) {
1235 if(!(c = (*jc))) continue;
1236 if(!c->IsInChamber()) continue;
1239 if(c->GetNPads()>4) w = .5;
1240 if(c->GetNPads()>5) w = .2;
1243 qc[n] = TMath::Abs(c->GetQ());
1244 // pad row of leading
1246 // Radial cluster position
1247 //Int_t jc = TMath::Max(fN-3, 0);
1248 //xc[fN] = c->GetXloc(fT0, fVD, &qc[jc], &xc[jc]/*, z0 - c->GetX()*dzdx*/);
1249 xc[n] = fX0 - c->GetX();
1251 // extrapolated track to cluster position
1252 yt = y0 - xc[n]*dydx;
1253 zt = z0 - xc[n]*dzdx;
1255 // Recalculate cluster error based on tracking information
1256 c->SetSigmaY2(fS2PRF, fDiffT, fExB, xc[n], zcorr?zt:-1., dydx);
1257 sy[n] = TMath::Sqrt(c->GetSigmaY2());
1259 yc[n] = fReconstructor->UseGAUS() ?
1260 c->GetYloc(y0, sy[n], GetPadWidth()): c->GetY();
1262 //optional tilt correction
1263 if(tilt) yc[n] -= (GetTilt()*(zc[n] - zt));
1265 fitterY.AddPoint(&xc[n], yc[n], TMath::Sqrt(sy[n]));
1266 fitterZ.AddPoint(&xc[n], qc[n], 1.);
1270 if (n < kClmin) return kFALSE;
1274 fYfit[0] = fitterY.GetParameter(0);
1275 fYfit[1] = -fitterY.GetParameter(1);
1277 Double_t *p = fitterY.GetCovarianceMatrix();
1278 fCov[0] = p[0]; // variance of y0
1279 fCov[1] = p[1]; // covariance of y0, dydx
1280 fCov[2] = p[3]; // variance of dydx
1281 // the ref radial position is set at the minimum of
1282 // the y variance of the tracklet
1283 fX = -fCov[1]/fCov[2];
1287 /* // THE LEADING CLUSTER METHOD
1289 Int_t ic=n=kNclusters-1; jc = &fClusters[ic];
1290 AliTRDcluster *c0 =0x0, **kc = &fClusters[kNtb-1];
1291 for(; ic>kNtb; ic--, --jc, --kc){
1292 if((c0 = (*kc)) && c0->IsInChamber() && (xMin>c0->GetX())) xMin = c0->GetX();
1293 if(!(c = (*jc))) continue;
1294 if(!c->IsInChamber()) continue;
1295 zc[kNclusters-1] = c->GetZ();
1296 fX = fX0 - c->GetX();
1298 fZfit[0] = .5*(zc[0]+zc[kNclusters-1]); fZfit[1] = 0.;
1299 // Error parameterization
1300 fS2Z = fdX*fZref[1];
1301 fS2Z *= fS2Z; fS2Z *= 0.2887; // 1/sqrt(12)*/
1303 // THE FIT X-Q PLANE METHOD
1304 Int_t ic=n=kNclusters-1; jc = &fClusters[ic];
1305 for(; ic>kNtb; ic--, --jc){
1306 if(!(c = (*jc))) continue;
1307 if(!c->IsInChamber()) continue;
1308 qc[n] = TMath::Abs(c->GetQ());
1309 xc[n] = fX0 - c->GetX();
1311 fitterZ.AddPoint(&xc[n], -qc[n], 1.);
1316 if(fitterZ.GetParameter(1)!=0.){
1317 fX = -fitterZ.GetParameter(0)/fitterZ.GetParameter(1);
1319 Float_t dl = .5*AliTRDgeometry::CamHght()+AliTRDgeometry::CdrHght();
1321 fX-=.055; // TODO to be understood
1324 fZfit[0] = .5*(zc[0]+zc[kNclusters-1]); fZfit[1] = 0.;
1325 // temporary external error parameterization
1326 fS2Z = 0.05+0.4*TMath::Abs(fZref[1]); fS2Z *= fS2Z;
1327 // TODO correct formula
1328 //fS2Z = sigma_x*TMath::Abs(fZref[1]);
1330 fZfit[0] = zc[0]; fZfit[1] = 0.;
1331 fS2Z = GetPadLength()*GetPadLength()/12.;
1333 fS2Y = fCov[0] +2.*fX*fCov[1] + fX*fX*fCov[2];
1339 //_____________________________________________________________________________
1340 void AliTRDseedV1::FitMI()
1344 // Marian Ivanov's version
1346 // linear fit on the y direction with respect to the reference direction.
1347 // The residuals for each x (x = xc - x0) are deduced from:
1349 // the tilting correction is written :
1350 // y = yc + h*(zc-zt) (2)
1351 // yt = y0+dy/dx*x (3)
1352 // zt = z0+dz/dx*x (4)
1353 // from (1),(2),(3) and (4)
1354 // dy = yc - y0 - (dy/dx + h*dz/dx)*x + h*(zc-z0)
1355 // the last term introduces the correction on y direction due to tilting pads. There are 2 ways to account for this:
1356 // 1. use tilting correction for calculating the y
1357 // 2. neglect tilting correction here and account for it in the error parametrization of the tracklet.
1358 const Float_t kRatio = 0.8;
1359 const Int_t kClmin = 5;
1360 const Float_t kmaxtan = 2;
1362 if (TMath::Abs(fYref[1]) > kmaxtan){
1363 //printf("Exit: Abs(fYref[1]) = %3.3f, kmaxtan = %3.3f\n", TMath::Abs(fYref[1]), kmaxtan);
1364 return; // Track inclined too much
1367 Float_t sigmaexp = 0.05 + TMath::Abs(fYref[1] * 0.25); // Expected r.m.s in y direction
1368 Float_t ycrosscor = GetPadLength() * GetTilt() * 0.5; // Y correction for crossing
1379 // Buffering: Leave it constant fot Performance issues
1380 Int_t zints[kNtb]; // Histograming of the z coordinate
1381 // Get 1 and second max probable coodinates in z
1382 Int_t zouts[2*kNtb];
1383 Float_t allowedz[kNtb]; // Allowed z for given time bin
1384 Float_t yres[kNtb]; // Residuals from reference
1385 //Float_t anglecor = GetTilt() * fZref[1]; // Correction to the angle
1387 Float_t pos[3*kNtb]; memset(pos, 0, 3*kNtb*sizeof(Float_t));
1388 Float_t *fX = &pos[0], *fY = &pos[kNtb], *fZ = &pos[2*kNtb];
1390 Int_t fN = 0; AliTRDcluster *c = 0x0;
1392 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins(); i++) {
1394 if (!(c = fClusters[i])) continue;
1395 if(!c->IsInChamber()) continue;
1397 //yres[i] = fY[i] - fYref[0] - (fYref[1] + anglecor) * fX[i] + GetTilt()*(fZ[i] - fZref[0]);
1398 fX[i] = fX0 - c->GetX();
1401 yres[i] = fY[i] - GetTilt()*(fZ[i] - (fZref[0] - fX[i]*fZref[1]));
1402 zints[fN] = Int_t(fZ[i]);
1407 //printf("Exit fN < kClmin: fN = %d\n", fN);
1410 Int_t nz = AliTRDtrackerV1::Freq(fN, zints, zouts, kFALSE);
1411 Float_t fZProb = zouts[0];
1412 if (nz <= 1) zouts[3] = 0;
1413 if (zouts[1] + zouts[3] < kClmin) {
1414 //printf("Exit zouts[1] = %d, zouts[3] = %d\n",zouts[1],zouts[3]);
1418 // Z distance bigger than pad - length
1419 if (TMath::Abs(zouts[0]-zouts[2]) > 12.0) zouts[3] = 0;
1421 Int_t breaktime = -1;
1422 Bool_t mbefore = kFALSE;
1423 Int_t cumul[kNtb][2];
1424 Int_t counts[2] = { 0, 0 };
1426 if (zouts[3] >= 3) {
1429 // Find the break time allowing one chage on pad-rows
1430 // with maximal number of accepted clusters
1433 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins(); i++) {
1434 cumul[i][0] = counts[0];
1435 cumul[i][1] = counts[1];
1436 if (TMath::Abs(fZ[i]-zouts[0]) < 2) counts[0]++;
1437 if (TMath::Abs(fZ[i]-zouts[2]) < 2) counts[1]++;
1440 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins(); i++) {
1441 Int_t after = cumul[AliTRDtrackerV1::GetNTimeBins()][0] - cumul[i][0];
1442 Int_t before = cumul[i][1];
1443 if (after + before > maxcount) {
1444 maxcount = after + before;
1448 after = cumul[AliTRDtrackerV1::GetNTimeBins()-1][1] - cumul[i][1];
1449 before = cumul[i][0];
1450 if (after + before > maxcount) {
1451 maxcount = after + before;
1459 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1460 if (i > breaktime) allowedz[i] = mbefore ? zouts[2] : zouts[0];
1461 if (i <= breaktime) allowedz[i] = (!mbefore) ? zouts[2] : zouts[0];
1464 if (((allowedz[0] > allowedz[AliTRDtrackerV1::GetNTimeBins()]) && (fZref[1] < 0)) ||
1465 ((allowedz[0] < allowedz[AliTRDtrackerV1::GetNTimeBins()]) && (fZref[1] > 0))) {
1467 // Tracklet z-direction not in correspondance with track z direction
1470 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1471 allowedz[i] = zouts[0]; // Only longest taken
1477 // Cross pad -row tracklet - take the step change into account
1479 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1480 if (!fClusters[i]) continue;
1481 if(!fClusters[i]->IsInChamber()) continue;
1482 if (TMath::Abs(fZ[i] - allowedz[i]) > 2) continue;
1484 //yres[i] = fY[i] - fYref[0] - (fYref[1] + anglecor) * fX[i] + GetTilt()*(fZ[i] - fZref[0]);
1485 yres[i] = fY[i] - GetTilt()*(fZ[i] - (fZref[0] - fX[i]*fZref[1]));
1486 // if (TMath::Abs(fZ[i] - fZProb) > 2) {
1487 // if (fZ[i] > fZProb) yres[i] += GetTilt() * GetPadLength();
1488 // if (fZ[i] < fZProb) yres[i] -= GetTilt() * GetPadLength();
1493 Double_t yres2[kNtb];
1496 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1497 if (!fClusters[i]) continue;
1498 if(!fClusters[i]->IsInChamber()) continue;
1499 if (TMath::Abs(fZ[i] - allowedz[i]) > 2) continue;
1500 yres2[fN2] = yres[i];
1504 //printf("Exit fN2 < kClmin: fN2 = %d\n", fN2);
1508 AliMathBase::EvaluateUni(fN2,yres2,mean,sigma, Int_t(fN2*kRatio-2.));
1509 if (sigma < sigmaexp * 0.8) {
1512 //Float_t fSigmaY = sigma;
1527 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1528 if (!fClusters[i]) continue;
1529 if (!fClusters[i]->IsInChamber()) continue;
1530 if (TMath::Abs(fZ[i] - allowedz[i]) > 2){fClusters[i] = 0x0; continue;}
1531 if (TMath::Abs(yres[i] - mean) > 4.0 * sigma){fClusters[i] = 0x0; continue;}
1534 fMPads += fClusters[i]->GetNPads();
1535 Float_t weight = 1.0;
1536 if (fClusters[i]->GetNPads() > 4) weight = 0.5;
1537 if (fClusters[i]->GetNPads() > 5) weight = 0.2;
1541 //printf("x = %7.3f dy = %7.3f fit %7.3f\n", x, yres[i], fY[i]-yres[i]);
1544 sumwx += x * weight;
1545 sumwx2 += x*x * weight;
1546 sumwy += weight * yres[i];
1547 sumwxy += weight * (yres[i]) * x;
1548 sumwz += weight * fZ[i];
1549 sumwxz += weight * fZ[i] * x;
1554 //printf("Exit fN2 < kClmin(2): fN2 = %d\n",fN2);
1558 fMeanz = sumwz / sumw;
1559 Float_t correction = 0;
1561 // Tracklet on boundary
1562 if (fMeanz < fZProb) correction = ycrosscor;
1563 if (fMeanz > fZProb) correction = -ycrosscor;
1566 Double_t det = sumw * sumwx2 - sumwx * sumwx;
1567 fYfit[0] = (sumwx2 * sumwy - sumwx * sumwxy) / det;
1568 fYfit[1] = (sumw * sumwxy - sumwx * sumwy) / det;
1571 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1572 if (!TESTBIT(fUsable,i)) continue;
1573 Float_t delta = yres[i] - fYfit[0] - fYfit[1] * fX[i];
1574 fS2Y += delta*delta;
1576 fS2Y = TMath::Sqrt(fS2Y / Float_t(fN2-2));
1577 // TEMPORARY UNTIL covariance properly calculated
1578 fS2Y = TMath::Max(fS2Y, Float_t(.1));
1580 fZfit[0] = (sumwx2 * sumwz - sumwx * sumwxz) / det;
1581 fZfit[1] = (sumw * sumwxz - sumwx * sumwz) / det;
1582 // fYfitR[0] += fYref[0] + correction;
1583 // fYfitR[1] += fYref[1];
1584 // fYfit[0] = fYfitR[0];
1585 fYfit[1] = -fYfit[1];
1590 //___________________________________________________________________
1591 void AliTRDseedV1::Print(Option_t *o) const
1594 // Printing the seedstatus
1597 AliInfo(Form("Det[%3d] X0[%7.2f] Pad{L[%5.2f] W[%5.2f] Tilt[%+6.2f]}", fDet, fX0, GetPadLength(), GetPadWidth(), GetTilt()));
1598 AliInfo(Form("N[%2d] Nused[%2d] Nshared[%2d] [%d]", GetN(), GetNUsed(), GetNShared(), fN));
1599 AliInfo(Form("FLAGS : RC[%c] Kink[%c] SA[%c]", IsRowCross()?'y':'n', IsKink()?'y':'n', IsStandAlone()?'y':'n'));
1601 Double_t cov[3], x=GetX();
1603 AliInfo(" | x[cm] | y[cm] | z[cm] | dydx | dzdx |");
1604 AliInfo(Form("Fit | %7.2f | %7.2f+-%7.2f | %7.2f+-%7.2f| %5.2f | ----- |", x, GetY(), TMath::Sqrt(cov[0]), GetZ(), TMath::Sqrt(cov[2]), fYfit[1]));
1605 AliInfo(Form("Ref | %7.2f | %7.2f+-%7.2f | %7.2f+-%7.2f| %5.2f | %5.2f |", x, fYref[0]-fX*fYref[1], TMath::Sqrt(fRefCov[0]), fZref[0]-fX*fYref[1], TMath::Sqrt(fRefCov[2]), fYref[1], fZref[1]))
1608 if(strcmp(o, "a")!=0) return;
1610 AliTRDcluster* const* jc = &fClusters[0];
1611 for(int ic=0; ic<kNclusters; ic++, jc++) {
1612 if(!(*jc)) continue;
1618 //___________________________________________________________________
1619 Bool_t AliTRDseedV1::IsEqual(const TObject *o) const
1621 // Checks if current instance of the class has the same essential members
1624 if(!o) return kFALSE;
1625 const AliTRDseedV1 *inTracklet = dynamic_cast<const AliTRDseedV1*>(o);
1626 if(!inTracklet) return kFALSE;
1628 for (Int_t i = 0; i < 2; i++){
1629 if ( fYref[i] != inTracklet->fYref[i] ) return kFALSE;
1630 if ( fZref[i] != inTracklet->fZref[i] ) return kFALSE;
1633 if ( fS2Y != inTracklet->fS2Y ) return kFALSE;
1634 if ( GetTilt() != inTracklet->GetTilt() ) return kFALSE;
1635 if ( GetPadLength() != inTracklet->GetPadLength() ) return kFALSE;
1637 for (Int_t i = 0; i < kNclusters; i++){
1638 // if ( fX[i] != inTracklet->GetX(i) ) return kFALSE;
1639 // if ( fY[i] != inTracklet->GetY(i) ) return kFALSE;
1640 // if ( fZ[i] != inTracklet->GetZ(i) ) return kFALSE;
1641 if ( fIndexes[i] != inTracklet->fIndexes[i] ) return kFALSE;
1643 // if ( fUsable != inTracklet->fUsable ) return kFALSE;
1645 for (Int_t i=0; i < 2; i++){
1646 if ( fYfit[i] != inTracklet->fYfit[i] ) return kFALSE;
1647 if ( fZfit[i] != inTracklet->fZfit[i] ) return kFALSE;
1648 if ( fLabels[i] != inTracklet->fLabels[i] ) return kFALSE;
1651 /* if ( fMeanz != inTracklet->GetMeanz() ) return kFALSE;
1652 if ( fZProb != inTracklet->GetZProb() ) return kFALSE;*/
1653 if ( fN != inTracklet->fN ) return kFALSE;
1654 //if ( fNUsed != inTracklet->fNUsed ) return kFALSE;
1655 //if ( fFreq != inTracklet->GetFreq() ) return kFALSE;
1656 //if ( fNChange != inTracklet->GetNChange() ) return kFALSE;
1658 if ( fC != inTracklet->fC ) return kFALSE;
1659 //if ( fCC != inTracklet->GetCC() ) return kFALSE;
1660 if ( fChi2 != inTracklet->fChi2 ) return kFALSE;
1661 // if ( fChi2Z != inTracklet->GetChi2Z() ) return kFALSE;
1663 if ( fDet != inTracklet->fDet ) return kFALSE;
1664 if ( fPt != inTracklet->fPt ) return kFALSE;
1665 if ( fdX != inTracklet->fdX ) return kFALSE;
1667 for (Int_t iCluster = 0; iCluster < kNclusters; iCluster++){
1668 AliTRDcluster *curCluster = fClusters[iCluster];
1669 AliTRDcluster *inCluster = inTracklet->fClusters[iCluster];
1670 if (curCluster && inCluster){
1671 if (! curCluster->IsEqual(inCluster) ) {
1672 curCluster->Print();
1677 // if one cluster exists, and corresponding
1678 // in other tracklet doesn't - return kFALSE
1679 if(curCluster || inCluster) return kFALSE;