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 "AliTRDrecoParam.h"
57 #include "AliTRDCommonParam.h"
59 #include "Cal/AliTRDCalPID.h"
60 #include "Cal/AliTRDCalROC.h"
61 #include "Cal/AliTRDCalDet.h"
63 ClassImp(AliTRDseedV1)
65 TLinearFitter *AliTRDseedV1::fgFitterY = NULL;
66 TLinearFitter *AliTRDseedV1::fgFitterZ = NULL;
68 //____________________________________________________________________
69 AliTRDseedV1::AliTRDseedV1(Int_t det)
71 ,fkReconstructor(NULL)
97 memset(fIndexes,0xFF,kNclusters*sizeof(fIndexes[0]));
98 memset(fClusters, 0, kNclusters*sizeof(AliTRDcluster*));
99 memset(fPad, 0, 3*sizeof(Float_t));
100 fYref[0] = 0.; fYref[1] = 0.;
101 fZref[0] = 0.; fZref[1] = 0.;
102 fYfit[0] = 0.; fYfit[1] = 0.;
103 fZfit[0] = 0.; fZfit[1] = 0.;
104 memset(fdEdx, 0, kNslices*sizeof(Float_t));
105 for(int ispec=0; ispec<AliPID::kSPECIES; ispec++) fProb[ispec] = -1.;
106 fLabels[0]=-1; fLabels[1]=-1; // most freq MC labels
107 fLabels[2]=0; // number of different labels for tracklet
108 memset(fRefCov, 0, 7*sizeof(Double_t));
109 // covariance matrix [diagonal]
110 // default sy = 200um and sz = 2.3 cm
111 fCov[0] = 4.e-4; fCov[1] = 0.; fCov[2] = 5.3;
112 SetStandAlone(kFALSE);
115 //____________________________________________________________________
116 AliTRDseedV1::AliTRDseedV1(const AliTRDseedV1 &ref)
117 :AliTRDtrackletBase((AliTRDtrackletBase&)ref)
118 ,fkReconstructor(NULL)
142 // Copy Constructor performing a deep copy
147 SetBit(kOwner, kFALSE);
148 SetStandAlone(ref.IsStandAlone());
152 //____________________________________________________________________
153 AliTRDseedV1& AliTRDseedV1::operator=(const AliTRDseedV1 &ref)
156 // Assignment Operator using the copy function
162 SetBit(kOwner, kFALSE);
167 //____________________________________________________________________
168 AliTRDseedV1::~AliTRDseedV1()
171 // Destructor. The RecoParam object belongs to the underlying tracker.
174 //printf("I-AliTRDseedV1::~AliTRDseedV1() : Owner[%s]\n", IsOwner()?"YES":"NO");
177 for(int itb=0; itb<kNclusters; itb++){
178 if(!fClusters[itb]) continue;
179 //AliInfo(Form("deleting c %p @ %d", fClusters[itb], itb));
180 delete fClusters[itb];
181 fClusters[itb] = NULL;
186 //____________________________________________________________________
187 void AliTRDseedV1::Copy(TObject &ref) const
194 AliTRDseedV1 &target = (AliTRDseedV1 &)ref;
196 target.fkReconstructor = fkReconstructor;
197 target.fClusterIter = NULL;
201 target.fS2PRF = fS2PRF;
202 target.fDiffL = fDiffL;
203 target.fDiffT = fDiffT;
204 target.fClusterIdx = 0;
205 target.fErrorMsg = fErrorMsg;
217 target.fChi2 = fChi2;
219 memcpy(target.fIndexes, fIndexes, kNclusters*sizeof(Int_t));
220 memcpy(target.fClusters, fClusters, kNclusters*sizeof(AliTRDcluster*));
221 memcpy(target.fPad, fPad, 3*sizeof(Float_t));
222 target.fYref[0] = fYref[0]; target.fYref[1] = fYref[1];
223 target.fZref[0] = fZref[0]; target.fZref[1] = fZref[1];
224 target.fYfit[0] = fYfit[0]; target.fYfit[1] = fYfit[1];
225 target.fZfit[0] = fZfit[0]; target.fZfit[1] = fZfit[1];
226 memcpy(target.fdEdx, fdEdx, kNslices*sizeof(Float_t));
227 memcpy(target.fProb, fProb, AliPID::kSPECIES*sizeof(Float_t));
228 memcpy(target.fLabels, fLabels, 3*sizeof(Int_t));
229 memcpy(target.fRefCov, fRefCov, 7*sizeof(Double_t));
230 memcpy(target.fCov, fCov, 3*sizeof(Double_t));
236 //____________________________________________________________
237 Bool_t AliTRDseedV1::Init(AliTRDtrackV1 *track)
239 // Initialize this tracklet using the track information
242 // track - the TRD track used to initialize the tracklet
244 // Detailed description
245 // The function sets the starting point and direction of the
246 // tracklet according to the information from the TRD track.
249 // The TRD track has to be propagated to the beginning of the
250 // chamber where the tracklet will be constructed
254 if(!track->GetProlongation(fX0, y, z)) return kFALSE;
260 //_____________________________________________________________________________
261 void AliTRDseedV1::Reset(Option_t *opt)
264 // Reset seed. If option opt="c" is given only cluster arrays are cleared.
266 for(Int_t ic=kNclusters; ic--;) fIndexes[ic] = -1;
267 memset(fClusters, 0, kNclusters*sizeof(AliTRDcluster*));
268 fN=0; SetBit(kRowCross, kFALSE);
269 if(strcmp(opt, "c")==0) return;
271 fExB=0.;fVD=0.;fT0=0.;fS2PRF=0.;
277 fdX=0.;fX0=0.; fX=0.; fY=0.; fZ=0.;
281 memset(fPad, 0, 3*sizeof(Float_t));
282 fYref[0] = 0.; fYref[1] = 0.;
283 fZref[0] = 0.; fZref[1] = 0.;
284 fYfit[0] = 0.; fYfit[1] = 0.;
285 fZfit[0] = 0.; fZfit[1] = 0.;
286 memset(fdEdx, 0, kNslices*sizeof(Float_t));
287 for(int ispec=0; ispec<AliPID::kSPECIES; ispec++) fProb[ispec] = -1.;
288 fLabels[0]=-1; fLabels[1]=-1; // most freq MC labels
289 fLabels[2]=0; // number of different labels for tracklet
290 memset(fRefCov, 0, 7*sizeof(Double_t));
291 // covariance matrix [diagonal]
292 // default sy = 200um and sz = 2.3 cm
293 fCov[0] = 4.e-4; fCov[1] = 0.; fCov[2] = 5.3;
296 //____________________________________________________________________
297 void AliTRDseedV1::Update(const AliTRDtrackV1 *trk)
299 // update tracklet reference position from the TRD track
301 Double_t fSnp = trk->GetSnp();
302 Double_t fTgl = trk->GetTgl();
304 Double_t norm =1./TMath::Sqrt((1.-fSnp)*(1.+fSnp));
305 fYref[1] = fSnp*norm;
306 fZref[1] = fTgl*norm;
307 SetCovRef(trk->GetCovariance());
309 Double_t dx = trk->GetX() - fX0;
310 fYref[0] = trk->GetY() - dx*fYref[1];
311 fZref[0] = trk->GetZ() - dx*fZref[1];
314 //_____________________________________________________________________________
315 void AliTRDseedV1::UpdateUsed()
318 // Calculate number of used clusers in the tracklet
321 Int_t nused = 0, nshared = 0;
322 for (Int_t i = kNclusters; i--; ) {
323 if (!fClusters[i]) continue;
324 if(fClusters[i]->IsUsed()){
326 } else if(fClusters[i]->IsShared()){
327 if(IsStandAlone()) nused++;
335 //_____________________________________________________________________________
336 void AliTRDseedV1::UseClusters()
341 // In stand alone mode:
342 // Clusters which are marked as used or shared from another track are
343 // removed from the tracklet
346 // - Clusters which are used by another track become shared
347 // - Clusters which are attached to a kink track become shared
349 AliTRDcluster **c = &fClusters[0];
350 for (Int_t ic=kNclusters; ic--; c++) {
353 if((*c)->IsShared() || (*c)->IsUsed()){
354 if((*c)->IsShared()) SetNShared(GetNShared()-1);
355 else SetNUsed(GetNUsed()-1);
362 if((*c)->IsUsed() || IsKink()){
373 //____________________________________________________________________
374 void AliTRDseedV1::CookdEdx(Int_t nslices)
376 // Calculates average dE/dx for all slices and store them in the internal array fdEdx.
379 // nslices : number of slices for which dE/dx should be calculated
381 // store results in the internal array fdEdx. This can be accessed with the method
382 // AliTRDseedV1::GetdEdx()
384 // Detailed description
385 // Calculates average dE/dx for all slices. Depending on the PID methode
386 // the number of slices can be 3 (LQ) or 8(NN).
387 // The calculation of dQ/dl are done using the tracklet fit results (see AliTRDseedV1::GetdQdl(Int_t))
389 // The following effects are included in the calculation:
390 // 1. calibration values for t0 and vdrift (using x coordinate to calculate slice)
391 // 2. cluster sharing (optional see AliTRDrecoParam::SetClusterSharing())
395 Int_t nclusters[kNslices];
396 memset(nclusters, 0, kNslices*sizeof(Int_t));
397 memset(fdEdx, 0, kNslices*sizeof(Float_t));
399 const Double_t kDriftLength = (.5 * AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());
401 AliTRDcluster *c = NULL;
402 for(int ic=0; ic<AliTRDtrackerV1::GetNTimeBins(); ic++){
403 if(!(c = fClusters[ic]) && !(c = fClusters[ic+kNtb])) continue;
404 Float_t dx = TMath::Abs(fX0 - c->GetX());
406 // Filter clusters for dE/dx calculation
408 // 1.consider calibration effects for slice determination
410 if(dx<kDriftLength){ // TODO should be replaced by c->IsInChamber()
411 slice = Int_t(dx * nslices / kDriftLength);
412 } else slice = c->GetX() < fX0 ? nslices-1 : 0;
415 // 2. take sharing into account
416 Float_t w = /*c->IsShared() ? .5 :*/ 1.;
418 // 3. take into account large clusters TODO
419 //w *= c->GetNPads() > 3 ? .8 : 1.;
422 fdEdx[slice] += w * GetdQdl(ic); //fdQdl[ic];
424 } // End of loop over clusters
426 //if(fkReconstructor->GetPIDMethod() == AliTRDReconstructor::kLQPID){
427 if(nslices == AliTRDpidUtil::kLQslices){
428 // calculate mean charge per slice (only LQ PID)
429 for(int is=0; is<nslices; is++){
430 if(nclusters[is]) fdEdx[is] /= nclusters[is];
435 //_____________________________________________________________________________
436 void AliTRDseedV1::CookLabels()
439 // Cook 2 labels for seed
445 for (Int_t i = 0; i < kNclusters; i++) {
446 if (!fClusters[i]) continue;
447 for (Int_t ilab = 0; ilab < 3; ilab++) {
448 if (fClusters[i]->GetLabel(ilab) >= 0) {
449 labels[nlab] = fClusters[i]->GetLabel(ilab);
455 fLabels[2] = AliMathBase::Freq(nlab,labels,out,kTRUE);
457 if ((fLabels[2] > 1) && (out[3] > 1)) fLabels[1] = out[2];
461 //____________________________________________________________________
462 Float_t AliTRDseedV1::GetdQdl(Int_t ic, Float_t *dl) const
464 // Using the linear approximation of the track inside one TRD chamber (TRD tracklet)
465 // the charge per unit length can be written as:
467 // #frac{dq}{dl} = #frac{q_{c}}{dx * #sqrt{1 + #(){#frac{dy}{dx}}^{2}_{fit} + #(){#frac{dz}{dx}}^{2}_{ref}}}
469 // where qc is the total charge collected in the current time bin and dx is the length
471 // The following correction are applied :
472 // - charge : pad row cross corrections
473 // [diffusion and TRF assymetry] TODO
474 // - dx : anisochronity, track inclination - see Fit and AliTRDcluster::GetXloc()
475 // and AliTRDcluster::GetYloc() for the effects taken into account
478 //<img src="TRD/trackletDQDT.gif">
480 // In the picture the energy loss measured on the tracklet as a function of drift time [left] and respectively
481 // drift length [right] for different particle species is displayed.
482 // Author : Alex Bercuci <A.Bercuci@gsi.de>
485 // check whether both clusters are inside the chamber
486 Bool_t hasClusterInChamber = kFALSE;
487 if(fClusters[ic] && fClusters[ic]->IsInChamber()){
488 hasClusterInChamber = kTRUE;
489 dq += TMath::Abs(fClusters[ic]->GetQ());
490 }else if(fClusters[ic+kNtb] && fClusters[ic+kNtb]->IsInChamber()){
491 hasClusterInChamber = kTRUE;
492 dq += TMath::Abs(fClusters[ic+kNtb]->GetQ());
494 if(!hasClusterInChamber) return 0.;
495 if(dq<1.e-3) return 0.;
498 if(ic-1>=0 && ic+1<kNtb){
499 Float_t x2(0.), x1(0.);
500 // try to estimate upper radial position (find the cluster which is inside the chamber)
501 if(fClusters[ic-1] && fClusters[ic-1]->IsInChamber()) x2 = fClusters[ic-1]->GetX();
502 else if(fClusters[ic-1+kNtb] && fClusters[ic-1+kNtb]->IsInChamber()) x2 = fClusters[ic-1+kNtb]->GetX();
503 else if(fClusters[ic] && fClusters[ic]->IsInChamber()) x2 = fClusters[ic]->GetX()+fdX;
504 else x2 = fClusters[ic+kNtb]->GetX()+fdX;
505 // try to estimate lower radial position (find the cluster which is inside the chamber)
506 if(fClusters[ic+1] && fClusters[ic+1]->IsInChamber()) x1 = fClusters[ic+1]->GetX();
507 else if(fClusters[ic+1+kNtb] && fClusters[ic+1+kNtb]->IsInChamber()) x1 = fClusters[ic+1+kNtb]->GetX();
508 else if(fClusters[ic] && fClusters[ic]->IsInChamber()) x1 = fClusters[ic]->GetX()-fdX;
509 else x1 = fClusters[ic+kNtb]->GetX()-fdX;
513 dx *= TMath::Sqrt(1. + fYfit[1]*fYfit[1] + fZref[1]*fZref[1]);
515 if(dx>1.e-9) return dq/dx;
519 //____________________________________________________________
520 Float_t AliTRDseedV1::GetMomentum(Float_t *err) const
522 // Returns momentum of the track after update with the current tracklet as:
524 // p=#frac{1}{1/p_{t}} #sqrt{1+tgl^{2}}
526 // and optionally the momentum error (if err is not null).
527 // The estimated variance of the momentum is given by:
529 // #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})
531 // which can be simplified to
533 // #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}
537 Double_t p = fPt*TMath::Sqrt(1.+fZref[1]*fZref[1]);
539 Double_t tgl2 = fZref[1]*fZref[1];
540 Double_t pt2 = fPt*fPt;
543 p2*tgl2*pt2*pt2*fRefCov[4]
544 -2.*p2*fZref[1]*fPt*pt2*fRefCov[5]
546 (*err) = TMath::Sqrt(s2);
552 //____________________________________________________________________
553 Float_t* AliTRDseedV1::GetProbability(Bool_t force)
555 if(!force) return &fProb[0];
556 if(!CookPID()) return NULL;
560 //____________________________________________________________
561 Bool_t AliTRDseedV1::CookPID()
563 // Fill probability array for tracklet from the DB.
568 // returns pointer to the probability array and NULL if missing DB access
570 // Retrieve PID probabilities for e+-, mu+-, K+-, pi+- and p+- from the DB according to tracklet information:
571 // - estimated momentum at tracklet reference point
572 // - dE/dx measurements
575 // According to the steering settings specified in the reconstruction one of the following methods are used
576 // - Neural Network [default] - option "nn"
577 // - 2D Likelihood - option "!nn"
579 AliTRDcalibDB *calibration = AliTRDcalibDB::Instance();
581 AliError("No access to calibration data");
585 if (!fkReconstructor) {
586 AliError("Reconstructor not set.");
590 // Retrieve the CDB container class with the parametric detector response
591 const AliTRDCalPID *pd = calibration->GetPIDObject(fkReconstructor->GetPIDMethod());
593 AliError("No access to AliTRDCalPID object");
597 // calculate tracklet length TO DO
598 Float_t length = (AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick())/ TMath::Sqrt((1.0 - GetSnp()*GetSnp()) / (1.0 + GetTgl()*GetTgl()));
601 CookdEdx(fkReconstructor->GetNdEdxSlices());
602 AliDebug(4, Form("PID p[%f] dEdx[%7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f] l[%f]", GetMomentum(), fdEdx[0], fdEdx[1], fdEdx[2], fdEdx[3], fdEdx[4], fdEdx[5], fdEdx[6], fdEdx[7], length));
604 // Sets the a priori probabilities
605 for(int ispec=0; ispec<AliPID::kSPECIES; ispec++)
606 fProb[ispec] = pd->GetProbability(ispec, GetMomentum(), &fdEdx[0], length, GetPlane());
611 //____________________________________________________________________
612 Float_t AliTRDseedV1::GetQuality(Bool_t kZcorr) const
615 // Returns a quality measurement of the current seed
618 Float_t zcorr = kZcorr ? GetTilt() * (fZfit[0] - fZref[0]) : 0.;
620 .5 * TMath::Abs(18.0 - GetN())
621 + 10.* TMath::Abs(fYfit[1] - fYref[1])
622 + 5. * TMath::Abs(fYfit[0] - fYref[0] + zcorr)
623 + 2. * TMath::Abs(fZfit[0] - fZref[0]) / GetPadLength();
626 //____________________________________________________________________
627 void AliTRDseedV1::GetCovAt(Double_t x, Double_t *cov) const
629 // Computes covariance in the y-z plane at radial point x (in tracking coordinates)
630 // and returns the results in the preallocated array cov[3] as :
637 // For the linear transformation
641 // The error propagation has the general form
643 // C_{Y} = T_{x} C_{X} T_{x}^{T}
645 // We apply this formula 2 times. First to calculate the covariance of the tracklet
646 // at point x we consider:
648 // T_{x} = (1 x); X=(y0 dy/dx); C_{X}=#(){#splitline{Var(y0) Cov(y0, dy/dx)}{Cov(y0, dy/dx) Var(dy/dx)}}
650 // and secondly to take into account the tilt angle
652 // T_{#alpha} = #(){#splitline{cos(#alpha) __ sin(#alpha)}{-sin(#alpha) __ cos(#alpha)}}; X=(y z); C_{X}=#(){#splitline{Var(y) 0}{0 Var(z)}}
655 // using simple trigonometrics one can write for this last case
657 // 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})}}
659 // which can be aproximated for small alphas (2 deg) with
661 // 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}}}
664 // before applying the tilt rotation we also apply systematic uncertainties to the tracklet
665 // position which can be tunned from outside via the AliTRDrecoParam::SetSysCovMatrix(). They might
666 // account for extra misalignment/miscalibration uncertainties.
669 // Alex Bercuci <A.Bercuci@gsi.de>
670 // Date : Jan 8th 2009
675 Double_t sy2 = fCov[0] +2.*xr*fCov[1] + xr*xr*fCov[2];
677 //GetPadLength()*GetPadLength()/12.;
679 // insert systematic uncertainties
681 Double_t sys[15]; memset(sys, 0, 15*sizeof(Double_t));
682 fkReconstructor->GetRecoParam()->GetSysCovMatrix(sys);
686 // rotate covariance matrix
687 Double_t t2 = GetTilt()*GetTilt();
688 Double_t correction = 1./(1. + t2);
689 cov[0] = (sy2+t2*sz2)*correction;
690 cov[1] = GetTilt()*(sz2 - sy2)*correction;
691 cov[2] = (t2*sy2+sz2)*correction;
693 //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 ":"-");
696 //____________________________________________________________
697 Double_t AliTRDseedV1::GetCovSqrt(const Double_t * const c, Double_t *d)
699 // Helper function to calculate the square root of the covariance matrix.
700 // The input matrix is stored in the vector c and the result in the vector d.
701 // Both arrays have to be initialized by the user with at least 3 elements. Return negative in case of failure.
703 // For calculating the square root of the symmetric matrix c
704 // the following relation is used:
706 // C^{1/2} = VD^{1/2}V^{-1}
708 // with V being the matrix with the n eigenvectors as columns.
709 // In case C is symmetric the followings are true:
710 // - matrix D is diagonal with the diagonal given by the eigenvalues of C
713 // Author A.Bercuci <A.Bercuci@gsi.de>
716 Double_t l[2], // eigenvalues
717 v[3]; // eigenvectors
718 // the secular equation and its solution :
719 // (c[0]-L)(c[2]-L)-c[1]^2 = 0
720 // L^2 - L*Tr(c)+DET(c) = 0
721 // L12 = [Tr(c) +- sqrt(Tr(c)^2-4*DET(c))]/2
722 Double_t tr = c[0]+c[2], // trace
723 det = c[0]*c[2]-c[1]*c[1]; // determinant
724 if(TMath::Abs(det)<1.e-20) return -1.;
725 Double_t dd = TMath::Sqrt(tr*tr - 4*det);
728 if(l[0]<0. || l[1]<0.) return -1.;
733 Double_t tmp = (l[0]-c[0])/c[1];
734 v[0] = TMath::Sqrt(1./(tmp*tmp+1));
736 v[2] = v[1]*c[1]/(l[1]-c[2]);
738 l[0] = TMath::Sqrt(l[0]); l[1] = TMath::Sqrt(l[1]);
739 d[0] = v[0]*v[0]*l[0]+v[1]*v[1]*l[1];
740 d[1] = v[0]*v[1]*l[0]+v[1]*v[2]*l[1];
741 d[2] = v[1]*v[1]*l[0]+v[2]*v[2]*l[1];
746 //____________________________________________________________
747 Double_t AliTRDseedV1::GetCovInv(const Double_t * const c, Double_t *d)
749 // Helper function to calculate the inverse of the covariance matrix.
750 // The input matrix is stored in the vector c and the result in the vector d.
751 // Both arrays have to be initialized by the user with at least 3 elements
752 // The return value is the determinant or 0 in case of singularity.
754 // Author A.Bercuci <A.Bercuci@gsi.de>
757 Double_t det = c[0]*c[2] - c[1]*c[1];
758 if(TMath::Abs(det)<1.e-20) return 0.;
759 Double_t invDet = 1./det;
766 //____________________________________________________________________
767 UShort_t AliTRDseedV1::GetVolumeId() const
770 while(ic<kNclusters && !fClusters[ic]) ic++;
771 return fClusters[ic] ? fClusters[ic]->GetVolumeId() : 0;
774 //____________________________________________________________________
775 TLinearFitter* AliTRDseedV1::GetFitterY()
777 if(!fgFitterY) fgFitterY = new TLinearFitter(1, "pol1");
778 fgFitterY->ClearPoints();
782 //____________________________________________________________________
783 TLinearFitter* AliTRDseedV1::GetFitterZ()
785 if(!fgFitterZ) fgFitterZ = new TLinearFitter(1, "pol1");
786 fgFitterZ->ClearPoints();
790 //____________________________________________________________________
791 void AliTRDseedV1::Calibrate()
793 // Retrieve calibration and position parameters from OCDB.
794 // The following information are used
796 // - column and row position of first attached cluster. If no clusters are attached
797 // to the tracklet a random central chamber position (c=70, r=7) will be used.
799 // The following information is cached in the tracklet
800 // t0 (trigger delay)
803 // omega*tau = tg(a_L)
804 // diffusion coefficients (longitudinal and transversal)
807 // Alex Bercuci <A.Bercuci@gsi.de>
808 // Date : Jan 8th 2009
811 AliCDBManager *cdb = AliCDBManager::Instance();
812 if(cdb->GetRun() < 0){
813 AliError("OCDB manager not properly initialized");
817 AliTRDcalibDB *calib = AliTRDcalibDB::Instance();
818 AliTRDCalROC *vdROC = calib->GetVdriftROC(fDet),
819 *t0ROC = calib->GetT0ROC(fDet);;
820 const AliTRDCalDet *vdDet = calib->GetVdriftDet();
821 const AliTRDCalDet *t0Det = calib->GetT0Det();
823 Int_t col = 70, row = 7;
824 AliTRDcluster **c = &fClusters[0];
827 while (ic<kNclusters && !(*c)){ic++; c++;}
829 col = (*c)->GetPadCol();
830 row = (*c)->GetPadRow();
834 fT0 = (t0Det->GetValue(fDet) + t0ROC->GetValue(col,row)) / AliTRDCommonParam::Instance()->GetSamplingFrequency();
835 fVD = vdDet->GetValue(fDet) * vdROC->GetValue(col, row);
836 fS2PRF = calib->GetPRFWidth(fDet, col, row); fS2PRF *= fS2PRF;
837 fExB = AliTRDCommonParam::Instance()->GetOmegaTau(fVD);
838 AliTRDCommonParam::Instance()->GetDiffCoeff(fDiffL,
840 SetBit(kCalib, kTRUE);
843 //____________________________________________________________________
844 void AliTRDseedV1::SetOwner()
846 //AliInfo(Form("own [%s] fOwner[%s]", own?"YES":"NO", fOwner?"YES":"NO"));
848 if(TestBit(kOwner)) return;
849 for(int ic=0; ic<kNclusters; ic++){
850 if(!fClusters[ic]) continue;
851 fClusters[ic] = new AliTRDcluster(*fClusters[ic]);
856 //____________________________________________________________
857 void AliTRDseedV1::SetPadPlane(AliTRDpadPlane *p)
859 // Shortcut method to initialize pad geometry.
861 SetTilt(TMath::Tan(TMath::DegToRad()*p->GetTiltingAngle()));
862 SetPadLength(p->GetLengthIPad());
863 SetPadWidth(p->GetWidthIPad());
867 //____________________________________________________________________
868 Bool_t AliTRDseedV1::AttachClusters(AliTRDtrackingChamber *const chamber, Bool_t tilt)
871 // Projective algorithm to attach clusters to seeding tracklets. The following steps are performed :
872 // 1. Collapse x coordinate for the full detector plane
873 // 2. truncated mean on y (r-phi) direction
875 // 4. truncated mean on z direction
879 // - chamber : pointer to tracking chamber container used to search the tracklet
880 // - tilt : switch for tilt correction during road building [default true]
882 // - true : if tracklet found successfully. Failure can happend because of the following:
884 // Detailed description
886 // We start up by defining the track direction in the xy plane and roads. The roads are calculated based
887 // on tracking information (variance in the r-phi direction) and estimated variance of the standard
888 // clusters (see AliTRDcluster::SetSigmaY2()) corrected for tilt (see GetCovAt()). From this the road is
890 // 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})})}
891 // r_{z} = 1.5*L_{pad}
894 // Author : Alexandru Bercuci <A.Bercuci@gsi.de>
897 if(!fkReconstructor->GetRecoParam() ){
898 AliError("Tracklets can not be used without a valid RecoParam.");
901 // Initialize reco params for this tracklet
902 // 1. first time bin in the drift region
904 Int_t kClmin = Int_t(fkReconstructor->GetRecoParam() ->GetFindableClusters()*AliTRDtrackerV1::GetNTimeBins());
906 Double_t sysCov[5]; fkReconstructor->GetRecoParam()->GetSysCovMatrix(sysCov);
907 Double_t s2yTrk= fRefCov[0],
909 s2zCl = GetPadLength()*GetPadLength()/12.,
910 syRef = TMath::Sqrt(s2yTrk),
911 t2 = GetTilt()*GetTilt();
913 Double_t kroady = 1., //fkReconstructor->GetRecoParam() ->GetRoad1y();
914 kroadz = GetPadLength() * fkReconstructor->GetRecoParam()->GetRoadzMultiplicator() + 1.;
915 // define probing cluster (the perfect cluster) and default calibration
916 Short_t sig[] = {0, 0, 10, 30, 10, 0,0};
917 AliTRDcluster cp(fDet, 6, 75, 0, sig, 0);
918 if(fkReconstructor->IsHLT()) cp.SetRPhiMethod(AliTRDcluster::kCOG);
919 if(!IsCalibrated()) Calibrate();
922 AliDebug(4, Form("syKalman[%f] rY[%f] rZ[%f]", syRef, kroady, kroadz));
925 const Int_t kNrows = 16;
926 const Int_t kNcls = 3*kNclusters; // buffer size
927 AliTRDcluster *clst[kNrows][kNcls];
928 Bool_t blst[kNrows][kNcls];
929 Double_t cond[4], dx, dy, yt, zt, yres[kNrows][kNcls];
930 Int_t idxs[kNrows][kNcls], ncl[kNrows], ncls = 0;
931 memset(ncl, 0, kNrows*sizeof(Int_t));
932 memset(yres, 0, kNrows*kNcls*sizeof(Double_t));
933 memset(blst, 0, kNrows*kNcls*sizeof(Bool_t)); //this is 8 times faster to memset than "memset(clst, 0, kNrows*kNcls*sizeof(AliTRDcluster*))"
935 // Do cluster projection
936 AliTRDcluster *c = NULL;
937 AliTRDchamberTimeBin *layer = NULL;
938 Bool_t kBUFFER = kFALSE;
939 for (Int_t it = 0; it < kNtb; it++) {
940 if(!(layer = chamber->GetTB(it))) continue;
941 if(!Int_t(*layer)) continue;
942 // get track projection at layers position
943 dx = fX0 - layer->GetX();
944 yt = fYref[0] - fYref[1] * dx;
945 zt = fZref[0] - fZref[1] * dx;
946 // get standard cluster error corrected for tilt
947 cp.SetLocalTimeBin(it);
948 cp.SetSigmaY2(0.02, fDiffT, fExB, dx, -1./*zt*/, fYref[1]);
949 s2yCl = (cp.GetSigmaY2() + sysCov[0] + t2*s2zCl)/(1.+t2);
950 // get estimated road
951 kroady = 3.*TMath::Sqrt(12.*(s2yTrk + s2yCl));
953 AliDebug(5, Form(" %2d x[%f] yt[%f] zt[%f]", it, dx, yt, zt));
955 AliDebug(5, Form(" syTrk[um]=%6.2f syCl[um]=%6.2f syClTlt[um]=%6.2f Ry[mm]=%f", 1.e4*TMath::Sqrt(s2yTrk), 1.e4*TMath::Sqrt(cp.GetSigmaY2()), 1.e4*TMath::Sqrt(s2yCl), 1.e1*kroady));
958 cond[0] = yt; cond[2] = kroady;
959 cond[1] = zt; cond[3] = kroadz;
961 layer->GetClusters(cond, idx, n, 6);
962 for(Int_t ic = n; ic--;){
963 c = (*layer)[idx[ic]];
965 dy += tilt ? GetTilt() * (c->GetZ() - zt) : 0.;
966 // select clusters on a 3 sigmaKalman level
967 /* if(tilt && TMath::Abs(dy) > 3.*syRef){
968 printf("too large !!!\n");
971 Int_t r = c->GetPadRow();
972 AliDebug(5, Form(" -> dy[%f] yc[%f] r[%d]", TMath::Abs(dy), c->GetY(), r));
974 blst[r][ncl[r]] = kTRUE;
975 idxs[r][ncl[r]] = idx[ic];
976 yres[r][ncl[r]] = dy;
979 if(ncl[r] >= kNcls) {
980 AliWarning(Form("Cluster candidates row[%d] reached buffer limit[%d]. Some may be lost.", r, kNcls));
987 AliDebug(4, Form("Found %d clusters. Processing ...", ncls));
989 AliDebug(1, Form("CLUSTERS FOUND %d LESS THAN THRESHOLD %d.", ncls, kClmin));
990 SetErrorMsg(kAttachClFound);
994 // analyze each row individualy
995 Bool_t kRowSelection(kFALSE);
996 Double_t mean[]={1.e3, 1.e3, 1.3}, syDis[]={1.e3, 1.e3, 1.3};
997 Int_t nrow[] = {0, 0, 0}, rowId[] = {-1, -1, -1}, nr = 0, lr=-1;
999 for(Int_t ir=0; ir<kNrows; ir++){
1000 if(!(ncl[ir])) continue;
1001 if(lr>0 && ir-lr != 1){
1002 AliDebug(2, "Rows attached not continuous. Turn on selection.");
1003 kRowSelection=kTRUE;
1006 AliDebug(5, Form(" r[%d] n[%d]", ir, ncl[ir]));
1007 // Evaluate truncated mean on the y direction
1008 if(ncl[ir] < 4) continue;
1009 AliMathBase::EvaluateUni(ncl[ir], yres[ir], mean[nr], syDis[nr], Int_t(ncl[ir]*.8));
1011 // TODO check mean and sigma agains cluster resolution !!
1012 AliDebug(4, Form(" m_%d[%+5.3f (%5.3fs)] s[%f]", nr, mean[nr], TMath::Abs(mean[nr]/syDis[nr]), syDis[nr]));
1013 // remove outliers based on a 3 sigmaDistr level
1014 Bool_t kFOUND = kFALSE;
1015 for(Int_t ic = ncl[ir]; ic--;){
1016 if(yres[ir][ic] - mean[nr] > 3. * syDis[nr]){
1017 blst[ir][ic] = kFALSE; continue;
1019 nrow[nr]++; rowId[nr]=ir; kFOUND = kTRUE;
1022 vdy[nr].Use(nrow[nr], yres[ir]);
1025 lr = ir; if(nr>=3) break;
1027 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 3 && fkReconstructor->IsDebugStreaming()){
1028 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
1030 if(IsKink()) SETBIT(stat, 1);
1031 if(IsStandAlone()) SETBIT(stat, 2);
1032 cstreamer << "AttachClusters"
1037 << "r0=" << rowId[0]
1038 << "dy0=" << &vdy[0]
1040 << "s0=" << syDis[0]
1041 << "r1=" << rowId[1]
1042 << "dy1=" << &vdy[1]
1044 << "s1=" << syDis[1]
1045 << "r2=" << rowId[2]
1046 << "dy2=" << &vdy[2]
1048 << "s2=" << syDis[2]
1053 // analyze gap in rows attached
1055 SetErrorMsg(kAttachRowGap);
1056 Int_t rowRemove(-1);
1057 if(nr==2){ // select based on minimum distance to track projection
1058 if(TMath::Abs(mean[0])<TMath::Abs(mean[1])){
1059 if(nrow[1]>nrow[0]) AliDebug(2, Form("Conflicting mean[%f < %f] but ncl[%d < %d].", TMath::Abs(mean[0]), TMath::Abs(mean[1]), nrow[0], nrow[1]));
1061 if(nrow[1]<nrow[0]) AliDebug(2, Form("Conflicting mean[%f > %f] but ncl[%d > %d].", TMath::Abs(mean[0]), TMath::Abs(mean[1]), nrow[0], nrow[1]));
1062 Swap(nrow[0],nrow[1]); Swap(rowId[0],rowId[1]);
1063 Swap(mean[0],mean[1]); Swap(syDis[0],syDis[1]);
1066 } else if(nr==3){ // select based on 2 consecutive rows
1067 if(rowId[1]==rowId[0]+1 && rowId[1]!=rowId[2]-1){
1069 } else if(rowId[1]!=rowId[0]+1 && rowId[1]==rowId[2]-1){
1070 Swap(nrow[0],nrow[2]); Swap(rowId[0],rowId[2]);
1071 Swap(mean[0],mean[2]); Swap(syDis[0],syDis[2]);
1075 if(rowRemove>0){nrow[rowRemove]=0; rowId[rowRemove]=-1;}
1077 AliDebug(4, Form(" Ncl[%d[%d] + %d[%d] + %d[%d]]", nrow[0], rowId[0], nrow[1], rowId[1], nrow[2], rowId[2]));
1080 SetBit(kRowCross, kTRUE); // mark pad row crossing
1081 SetErrorMsg(kAttachRow);
1082 const Float_t am[]={TMath::Abs(mean[0]), TMath::Abs(mean[1]), TMath::Abs(mean[2])};
1083 AliDebug(4, Form("complex row configuration\n"
1084 " r[%d] n[%d] m[%6.3f] s[%6.3f]\n"
1085 " r[%d] n[%d] m[%6.3f] s[%6.3f]\n"
1086 " r[%d] n[%d] m[%6.3f] s[%6.3f]\n"
1087 , rowId[0], nrow[0], am[0], syDis[0]
1088 , rowId[1], nrow[1], am[1], syDis[1]
1089 , rowId[2], nrow[2], am[2], syDis[2]));
1090 Int_t id[]={0,1,2}; TMath::Sort(3, am, id, kFALSE);
1092 Int_t rnn[3]; memcpy(rnn, nrow, 3*sizeof(Int_t));
1093 Int_t rid[3]; memcpy(rid, rowId, 3*sizeof(Int_t));
1094 Double_t rm[3]; memcpy(rm, mean, 3*sizeof(Double_t));
1095 Double_t rs[3]; memcpy(rs, syDis, 3*sizeof(Double_t));
1096 nrow[0]=rnn[id[0]]; rowId[0]=rid[id[0]]; mean[0]=rm[id[0]]; syDis[0]=rs[id[0]];
1097 nrow[1]=rnn[id[1]]; rowId[1]=rid[id[1]]; mean[1]=rm[id[1]]; syDis[1]=rs[id[1]];
1098 nrow[2]=0; rowId[2]=-1; mean[2] = 1.e3; syDis[2] = 1.e3;
1099 AliDebug(4, Form("solved configuration\n"
1100 " r[%d] n[%d] m[%+6.3f] s[%6.3f]\n"
1101 " r[%d] n[%d] m[%+6.3f] s[%6.3f]\n"
1102 " r[%d] n[%d] m[%+6.3f] s[%6.3f]\n"
1103 , rowId[0], nrow[0], mean[0], syDis[0]
1104 , rowId[1], nrow[1], mean[1], syDis[1]
1105 , rowId[2], nrow[2], mean[2], syDis[2]));
1108 SetBit(kRowCross, kTRUE); // mark pad row crossing
1109 if(nrow[1] > nrow[0]){ // swap row order
1110 Swap(nrow[0],nrow[1]); Swap(rowId[0],rowId[1]);
1111 Swap(mean[0],mean[1]); Swap(syDis[0],syDis[1]);
1115 // Select and store clusters
1116 // We should consider here :
1117 // 1. How far is the chamber boundary
1118 // 2. How big is the mean
1119 Int_t n(0); Float_t dyc[kNclusters]; memset(dyc,0,kNclusters*sizeof(Float_t));
1120 for (Int_t ir = 0; ir < nr; ir++) {
1121 Int_t jr(rowId[ir]);
1122 AliDebug(4, Form(" Attaching Ncl[%d]=%d ...", jr, ncl[jr]));
1123 for (Int_t ic = 0; ic < ncl[jr]; ic++) {
1124 if(!blst[jr][ic])continue;
1126 Int_t it(c->GetPadTime());
1127 Int_t idx(it+kNtb*ir);
1129 AliDebug(4, Form("Many cluster candidates on row[%2d] tb[%2d].", jr, it));
1130 // TODO should save also the information on where the multiplicity happened and its size
1131 SetErrorMsg(kAttachMultipleCl);
1132 // TODO should also compare with mean and sigma for this row
1133 if(yres[jr][ic] > dyc[idx]) continue;
1136 // TODO proper indexing of clusters !!
1137 fIndexes[idx] = chamber->GetTB(it)->GetGlobalIndex(idxs[jr][ic]);
1139 dyc[idx] = yres[jr][ic];
1145 // number of minimum numbers of clusters expected for the tracklet
1146 if (GetN() < kClmin){
1147 AliDebug(1, Form("NOT ENOUGH CLUSTERS %d ATTACHED TO THE TRACKLET [min %d] FROM FOUND %d.", GetN(), kClmin, n));
1148 SetErrorMsg(kAttachClAttach);
1152 // Load calibration parameters for this tracklet
1155 // calculate dx for time bins in the drift region (calibration aware)
1156 Float_t x[2] = {0.,0.}; Int_t tb[2]={0,0};
1157 for (Int_t it = t0, irp=0; irp<2 && it < AliTRDtrackerV1::GetNTimeBins(); it++) {
1158 if(!fClusters[it]) continue;
1159 x[irp] = fClusters[it]->GetX();
1160 tb[irp] = fClusters[it]->GetLocalTimeBin();
1163 Int_t dtb = tb[1] - tb[0];
1164 fdX = dtb ? (x[0] - x[1]) / dtb : 0.15;
1168 //____________________________________________________________
1169 void AliTRDseedV1::Bootstrap(const AliTRDReconstructor *rec)
1171 // Fill in all derived information. It has to be called after recovery from file or HLT.
1172 // The primitive data are
1173 // - list of clusters
1174 // - detector (as the detector will be removed from clusters)
1175 // - position of anode wire (fX0) - temporary
1176 // - track reference position and direction
1177 // - momentum of the track
1178 // - time bin length [cm]
1180 // A.Bercuci <A.Bercuci@gsi.de> Oct 30th 2008
1182 fkReconstructor = rec;
1184 AliTRDpadPlane *pp = g.GetPadPlane(fDet);
1185 fPad[0] = pp->GetLengthIPad();
1186 fPad[1] = pp->GetWidthIPad();
1187 fPad[3] = TMath::Tan(TMath::DegToRad()*pp->GetTiltingAngle());
1188 //fSnp = fYref[1]/TMath::Sqrt(1+fYref[1]*fYref[1]);
1190 Int_t n = 0, nshare = 0, nused = 0;
1191 AliTRDcluster **cit = &fClusters[0];
1192 for(Int_t ic = kNclusters; ic--; cit++){
1195 if((*cit)->IsShared()) nshare++;
1196 if((*cit)->IsUsed()) nused++;
1198 SetN(n); SetNUsed(nused); SetNShared(nshare);
1205 //____________________________________________________________________
1206 Bool_t AliTRDseedV1::Fit(Bool_t tilt, Bool_t zcorr)
1209 // Linear fit of the clusters attached to the tracklet
1212 // - tilt : switch for tilt pad correction of cluster y position based on
1213 // the z, dzdx info from outside [default false].
1214 // - zcorr : switch for using z information to correct for anisochronity
1215 // and a finner error parameterization estimation [default false]
1217 // True if successful
1219 // Detailed description
1221 // Fit in the xy plane
1223 // The fit is performed to estimate the y position of the tracklet and the track
1224 // angle in the bending plane. The clusters are represented in the chamber coordinate
1225 // system (with respect to the anode wire - see AliTRDtrackerV1::FollowBackProlongation()
1226 // on how this is set). The x and y position of the cluster and also their variances
1227 // are known from clusterizer level (see AliTRDcluster::GetXloc(), AliTRDcluster::GetYloc(),
1228 // AliTRDcluster::GetSX() and AliTRDcluster::GetSY()).
1229 // If gaussian approximation is used to calculate y coordinate of the cluster the position
1230 // is recalculated taking into account the track angle. The general formula to calculate the
1231 // error of cluster position in the gaussian approximation taking into account diffusion and track
1232 // inclination is given for TRD by:
1234 // #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}
1237 // Since errors are calculated only in the y directions, radial errors (x direction) are mapped to y
1238 // by projection i.e.
1240 // #sigma_{x|y} = tg(#phi) #sigma_{x}
1242 // and also by the lorentz angle correction
1244 // Fit in the xz plane
1246 // The "fit" is performed to estimate the radial position (x direction) where pad row cross happens.
1247 // If no pad row crossing the z position is taken from geometry and radial position is taken from the xy
1250 // There are two methods to estimate the radial position of the pad row cross:
1251 // 1. leading cluster radial position : Here the lower part of the tracklet is considered and the last
1252 // cluster registered (at radial x0) on this segment is chosen to mark the pad row crossing. The error
1253 // of the z estimate is given by :
1255 // #sigma_{z} = tg(#theta) #Delta x_{x_{0}}/12
1257 // The systematic errors for this estimation are generated by the following sources:
1258 // - no charge sharing between pad rows is considered (sharp cross)
1259 // - missing cluster at row cross (noise peak-up, under-threshold signal etc.).
1261 // 2. charge fit over the crossing point : Here the full energy deposit along the tracklet is considered
1262 // to estimate the position of the crossing by a fit in the qx plane. The errors in the q directions are
1263 // parameterized as s_q = q^2. The systematic errors for this estimation are generated by the following sources:
1264 // - no general model for the qx dependence
1265 // - physical fluctuations of the charge deposit
1266 // - gain calibration dependence
1268 // Estimation of the radial position of the tracklet
1270 // For pad row cross the radial position is taken from the xz fit (see above). Otherwise it is taken as the
1271 // interpolation point of the tracklet i.e. the point where the error in y of the fit is minimum. The error
1272 // in the y direction of the tracklet is (see AliTRDseedV1::GetCovAt()):
1274 // #sigma_{y} = #sigma^{2}_{y_{0}} + 2xcov(y_{0}, dy/dx) + #sigma^{2}_{dy/dx}
1276 // and thus the radial position is:
1278 // x = - cov(y_{0}, dy/dx)/#sigma^{2}_{dy/dx}
1281 // Estimation of tracklet position error
1283 // The error in y direction is the error of the linear fit at the radial position of the tracklet while in the z
1284 // direction is given by the cluster error or pad row cross error. In case of no pad row cross this is given by:
1286 // #sigma_{y} = #sigma^{2}_{y_{0}} - 2cov^{2}(y_{0}, dy/dx)/#sigma^{2}_{dy/dx} + #sigma^{2}_{dy/dx}
1287 // #sigma_{z} = Pad_{length}/12
1289 // For pad row cross the full error is calculated at the radial position of the crossing (see above) and the error
1290 // in z by the width of the crossing region - being a matter of parameterization.
1292 // #sigma_{z} = tg(#theta) #Delta x_{x_{0}}/12
1294 // In case of no tilt correction (default in the barrel tracking) the tilt is taken into account by the rotation of
1295 // the covariance matrix. See AliTRDseedV1::GetCovAt() for details.
1298 // A.Bercuci <A.Bercuci@gsi.de>
1300 if(!IsCalibrated()) Calibrate();
1302 const Int_t kClmin = 8;
1304 // get track direction
1305 Double_t y0 = fYref[0];
1306 Double_t dydx = fYref[1];
1307 Double_t z0 = fZref[0];
1308 Double_t dzdx = fZref[1];
1311 AliTRDtrackerV1::AliTRDLeastSquare fitterY;
1312 AliTRDtrackerV1::AliTRDLeastSquare fitterZ;
1314 // book cluster information
1315 Double_t qc[kNclusters], xc[kNclusters], yc[kNclusters], zc[kNclusters], sy[kNclusters];
1318 AliTRDcluster *c=NULL, **jc = &fClusters[0];
1319 for (Int_t ic=0; ic<kNtb; ic++, ++jc) {
1324 if(!(c = (*jc))) continue;
1325 if(!c->IsInChamber()) continue;
1328 if(c->GetNPads()>4) w = .5;
1329 if(c->GetNPads()>5) w = .2;
1332 qc[n] = TMath::Abs(c->GetQ());
1333 // pad row of leading
1335 // Radial cluster position
1336 //Int_t jc = TMath::Max(fN-3, 0);
1337 //xc[fN] = c->GetXloc(fT0, fVD, &qc[jc], &xc[jc]/*, z0 - c->GetX()*dzdx*/);
1338 xc[n] = fX0 - c->GetX();
1340 // extrapolated track to cluster position
1341 yt = y0 - xc[n]*dydx;
1342 zt = z0 - xc[n]*dzdx;
1344 // Recalculate cluster error based on tracking information
1345 c->SetSigmaY2(fS2PRF, fDiffT, fExB, xc[n], zcorr?zt:-1., dydx);
1346 sy[n] = TMath::Sqrt(c->GetSigmaY2());
1348 yc[n] = fkReconstructor->GetRecoParam()->UseGAUS() ?
1349 c->GetYloc(y0, sy[n], GetPadWidth()): c->GetY();
1351 //optional tilt correction
1352 if(tilt) yc[n] -= (GetTilt()*(zc[n] - zt));
1354 fitterY.AddPoint(&xc[n], yc[n], TMath::Sqrt(sy[n]));
1355 if(IsRowCross()) fitterZ.AddPoint(&xc[n], qc[n], 1.);
1360 if (n < kClmin) return kFALSE;
1364 fYfit[0] = fitterY.GetFunctionParameter(0);
1365 fYfit[1] = -fitterY.GetFunctionParameter(1);
1368 fitterY.GetCovarianceMatrix(p);
1369 fCov[0] = p[0]; // variance of y0
1370 fCov[1] = p[2]; // covariance of y0, dydx
1371 fCov[2] = p[1]; // variance of dydx
1372 // the ref radial position is set at the minimum of
1373 // the y variance of the tracklet
1374 fX = -fCov[1]/fCov[2];
1376 // collect second row clusters
1379 /* // THE LEADING CLUSTER METHOD
1381 Int_t ic=n=kNclusters-1; jc = &fClusters[ic];
1382 AliTRDcluster *c0 =0x0, **kc = &fClusters[kNtb-1];
1383 for(; ic>kNtb; ic--, --jc, --kc){
1384 if((c0 = (*kc)) && c0->IsInChamber() && (xMin>c0->GetX())) xMin = c0->GetX();
1385 if(!(c = (*jc))) continue;
1386 if(!c->IsInChamber()) continue;
1387 zc[kNclusters-1] = c->GetZ();
1388 fX = fX0 - c->GetX();
1390 fZfit[0] = .5*(zc[0]+zc[kNclusters-1]); fZfit[1] = 0.;
1391 // Error parameterization
1392 fS2Z = fdX*fZref[1];
1393 fS2Z *= fS2Z; fS2Z *= 0.2887; // 1/sqrt(12)*/
1395 // THE FIT X-Q PLANE METHOD
1396 Int_t ic=n=kNclusters-1; jc = &fClusters[ic];
1397 for(; ic>kNtb; ic--, --jc){
1398 if(!(c = (*jc))) continue;
1399 if(!c->IsInChamber()) continue;
1400 qc[n] = TMath::Abs(c->GetQ());
1401 xc[n] = fX0 - c->GetX();
1403 fitterZ.AddPoint(&xc[n], -qc[n], 1.);
1408 if(m && IsRowCross()){
1410 if(fitterZ.GetFunctionParameter(1)!=0.){
1411 fX = -fitterZ.GetFunctionParameter(0)/fitterZ.GetFunctionParameter(1);
1413 Float_t dl = .5*AliTRDgeometry::CamHght()+AliTRDgeometry::CdrHght();
1415 fX-=.055; // TODO to be understood
1418 fZfit[0] = .5*(zc[0]+zc[kNclusters-1]); fZfit[1] = 0.;
1419 // temporary external error parameterization
1420 fS2Z = 0.05+0.4*TMath::Abs(fZref[1]); fS2Z *= fS2Z;
1421 // TODO correct formula
1422 //fS2Z = sigma_x*TMath::Abs(fZref[1]);
1424 if(IsRowCross() && !m){
1425 AliDebug(1, "Tracklet crossed row but no clusters found in neighbor row.");
1427 fZfit[0] = zc[0]; fZfit[1] = 0.;
1428 fS2Z = GetPadLength()*GetPadLength()/12.;
1430 fS2Y = fCov[0] +2.*fX*fCov[1] + fX*fX*fCov[2];
1436 //_____________________________________________________________________________
1437 void AliTRDseedV1::FitMI()
1441 // Marian Ivanov's version
1443 // linear fit on the y direction with respect to the reference direction.
1444 // The residuals for each x (x = xc - x0) are deduced from:
1446 // the tilting correction is written :
1447 // y = yc + h*(zc-zt) (2)
1448 // yt = y0+dy/dx*x (3)
1449 // zt = z0+dz/dx*x (4)
1450 // from (1),(2),(3) and (4)
1451 // dy = yc - y0 - (dy/dx + h*dz/dx)*x + h*(zc-z0)
1452 // the last term introduces the correction on y direction due to tilting pads. There are 2 ways to account for this:
1453 // 1. use tilting correction for calculating the y
1454 // 2. neglect tilting correction here and account for it in the error parametrization of the tracklet.
1455 const Float_t kRatio = 0.8;
1456 const Int_t kClmin = 5;
1457 const Float_t kmaxtan = 2;
1459 if (TMath::Abs(fYref[1]) > kmaxtan){
1460 //printf("Exit: Abs(fYref[1]) = %3.3f, kmaxtan = %3.3f\n", TMath::Abs(fYref[1]), kmaxtan);
1461 return; // Track inclined too much
1464 Float_t sigmaexp = 0.05 + TMath::Abs(fYref[1] * 0.25); // Expected r.m.s in y direction
1465 Float_t ycrosscor = GetPadLength() * GetTilt() * 0.5; // Y correction for crossing
1476 // Buffering: Leave it constant fot Performance issues
1477 Int_t zints[kNtb]; // Histograming of the z coordinate
1478 // Get 1 and second max probable coodinates in z
1479 Int_t zouts[2*kNtb];
1480 Float_t allowedz[kNtb]; // Allowed z for given time bin
1481 Float_t yres[kNtb]; // Residuals from reference
1482 //Float_t anglecor = GetTilt() * fZref[1]; // Correction to the angle
1484 Float_t pos[3*kNtb]; memset(pos, 0, 3*kNtb*sizeof(Float_t));
1485 Float_t *fX = &pos[0], *fY = &pos[kNtb], *fZ = &pos[2*kNtb];
1487 Int_t fN = 0; AliTRDcluster *c = 0x0;
1489 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins(); i++) {
1491 if (!(c = fClusters[i])) continue;
1492 if(!c->IsInChamber()) continue;
1494 //yres[i] = fY[i] - fYref[0] - (fYref[1] + anglecor) * fX[i] + GetTilt()*(fZ[i] - fZref[0]);
1495 fX[i] = fX0 - c->GetX();
1498 yres[i] = fY[i] - GetTilt()*(fZ[i] - (fZref[0] - fX[i]*fZref[1]));
1499 zints[fN] = Int_t(fZ[i]);
1504 //printf("Exit fN < kClmin: fN = %d\n", fN);
1507 Int_t nz = AliTRDtrackerV1::Freq(fN, zints, zouts, kFALSE);
1508 Float_t fZProb = zouts[0];
1509 if (nz <= 1) zouts[3] = 0;
1510 if (zouts[1] + zouts[3] < kClmin) {
1511 //printf("Exit zouts[1] = %d, zouts[3] = %d\n",zouts[1],zouts[3]);
1515 // Z distance bigger than pad - length
1516 if (TMath::Abs(zouts[0]-zouts[2]) > 12.0) zouts[3] = 0;
1518 Int_t breaktime = -1;
1519 Bool_t mbefore = kFALSE;
1520 Int_t cumul[kNtb][2];
1521 Int_t counts[2] = { 0, 0 };
1523 if (zouts[3] >= 3) {
1526 // Find the break time allowing one chage on pad-rows
1527 // with maximal number of accepted clusters
1530 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins(); i++) {
1531 cumul[i][0] = counts[0];
1532 cumul[i][1] = counts[1];
1533 if (TMath::Abs(fZ[i]-zouts[0]) < 2) counts[0]++;
1534 if (TMath::Abs(fZ[i]-zouts[2]) < 2) counts[1]++;
1537 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins(); i++) {
1538 Int_t after = cumul[AliTRDtrackerV1::GetNTimeBins()][0] - cumul[i][0];
1539 Int_t before = cumul[i][1];
1540 if (after + before > maxcount) {
1541 maxcount = after + before;
1545 after = cumul[AliTRDtrackerV1::GetNTimeBins()-1][1] - cumul[i][1];
1546 before = cumul[i][0];
1547 if (after + before > maxcount) {
1548 maxcount = after + before;
1556 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1557 if (i > breaktime) allowedz[i] = mbefore ? zouts[2] : zouts[0];
1558 if (i <= breaktime) allowedz[i] = (!mbefore) ? zouts[2] : zouts[0];
1561 if (((allowedz[0] > allowedz[AliTRDtrackerV1::GetNTimeBins()]) && (fZref[1] < 0)) ||
1562 ((allowedz[0] < allowedz[AliTRDtrackerV1::GetNTimeBins()]) && (fZref[1] > 0))) {
1564 // Tracklet z-direction not in correspondance with track z direction
1567 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1568 allowedz[i] = zouts[0]; // Only longest taken
1574 // Cross pad -row tracklet - take the step change into account
1576 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1577 if (!fClusters[i]) continue;
1578 if(!fClusters[i]->IsInChamber()) continue;
1579 if (TMath::Abs(fZ[i] - allowedz[i]) > 2) continue;
1581 //yres[i] = fY[i] - fYref[0] - (fYref[1] + anglecor) * fX[i] + GetTilt()*(fZ[i] - fZref[0]);
1582 yres[i] = fY[i] - GetTilt()*(fZ[i] - (fZref[0] - fX[i]*fZref[1]));
1583 // if (TMath::Abs(fZ[i] - fZProb) > 2) {
1584 // if (fZ[i] > fZProb) yres[i] += GetTilt() * GetPadLength();
1585 // if (fZ[i] < fZProb) yres[i] -= GetTilt() * GetPadLength();
1590 Double_t yres2[kNtb];
1593 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1594 if (!fClusters[i]) continue;
1595 if(!fClusters[i]->IsInChamber()) continue;
1596 if (TMath::Abs(fZ[i] - allowedz[i]) > 2) continue;
1597 yres2[fN2] = yres[i];
1601 //printf("Exit fN2 < kClmin: fN2 = %d\n", fN2);
1605 AliMathBase::EvaluateUni(fN2,yres2,mean,sigma, Int_t(fN2*kRatio-2.));
1606 if (sigma < sigmaexp * 0.8) {
1609 //Float_t fSigmaY = sigma;
1624 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1625 if (!fClusters[i]) continue;
1626 if (!fClusters[i]->IsInChamber()) continue;
1627 if (TMath::Abs(fZ[i] - allowedz[i]) > 2){fClusters[i] = 0x0; continue;}
1628 if (TMath::Abs(yres[i] - mean) > 4.0 * sigma){fClusters[i] = 0x0; continue;}
1631 fMPads += fClusters[i]->GetNPads();
1632 Float_t weight = 1.0;
1633 if (fClusters[i]->GetNPads() > 4) weight = 0.5;
1634 if (fClusters[i]->GetNPads() > 5) weight = 0.2;
1638 //printf("x = %7.3f dy = %7.3f fit %7.3f\n", x, yres[i], fY[i]-yres[i]);
1641 sumwx += x * weight;
1642 sumwx2 += x*x * weight;
1643 sumwy += weight * yres[i];
1644 sumwxy += weight * (yres[i]) * x;
1645 sumwz += weight * fZ[i];
1646 sumwxz += weight * fZ[i] * x;
1651 //printf("Exit fN2 < kClmin(2): fN2 = %d\n",fN2);
1655 fMeanz = sumwz / sumw;
1656 Float_t correction = 0;
1658 // Tracklet on boundary
1659 if (fMeanz < fZProb) correction = ycrosscor;
1660 if (fMeanz > fZProb) correction = -ycrosscor;
1663 Double_t det = sumw * sumwx2 - sumwx * sumwx;
1664 fYfit[0] = (sumwx2 * sumwy - sumwx * sumwxy) / det;
1665 fYfit[1] = (sumw * sumwxy - sumwx * sumwy) / det;
1668 for (Int_t i = 0; i < AliTRDtrackerV1::GetNTimeBins()+1; i++) {
1669 if (!TESTBIT(fUsable,i)) continue;
1670 Float_t delta = yres[i] - fYfit[0] - fYfit[1] * fX[i];
1671 fS2Y += delta*delta;
1673 fS2Y = TMath::Sqrt(fS2Y / Float_t(fN2-2));
1674 // TEMPORARY UNTIL covariance properly calculated
1675 fS2Y = TMath::Max(fS2Y, Float_t(.1));
1677 fZfit[0] = (sumwx2 * sumwz - sumwx * sumwxz) / det;
1678 fZfit[1] = (sumw * sumwxz - sumwx * sumwz) / det;
1679 // fYfitR[0] += fYref[0] + correction;
1680 // fYfitR[1] += fYref[1];
1681 // fYfit[0] = fYfitR[0];
1682 fYfit[1] = -fYfit[1];
1687 //___________________________________________________________________
1688 void AliTRDseedV1::Print(Option_t *o) const
1691 // Printing the seedstatus
1694 AliInfo(Form("Det[%3d] X0[%7.2f] Pad{L[%5.2f] W[%5.2f] Tilt[%+6.2f]}", fDet, fX0, GetPadLength(), GetPadWidth(), GetTilt()));
1695 AliInfo(Form("N[%2d] Nused[%2d] Nshared[%2d] [%d]", GetN(), GetNUsed(), GetNShared(), fN));
1696 AliInfo(Form("FLAGS : RC[%c] Kink[%c] SA[%c]", IsRowCross()?'y':'n', IsKink()?'y':'n', IsStandAlone()?'y':'n'));
1698 Double_t cov[3], x=GetX();
1700 AliInfo(" | x[cm] | y[cm] | z[cm] | dydx | dzdx |");
1701 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]));
1702 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]))
1703 AliInfo(Form("P / Pt [GeV/c] = %f / %f", GetMomentum(), fPt));
1704 AliInfo(Form("dEdx [a.u.] = %f / %f / %f / %f / %f/ %f / %f / %f", fdEdx[0], fdEdx[1], fdEdx[2], fdEdx[3], fdEdx[4], fdEdx[5], fdEdx[6], fdEdx[7]));
1705 AliInfo(Form("PID = %5.3f / %5.3f / %5.3f / %5.3f / %5.3f", fProb[0], fProb[1], fProb[2], fProb[3], fProb[4]));
1707 if(strcmp(o, "a")!=0) return;
1709 AliTRDcluster* const* jc = &fClusters[0];
1710 for(int ic=0; ic<kNclusters; ic++, jc++) {
1711 if(!(*jc)) continue;
1717 //___________________________________________________________________
1718 Bool_t AliTRDseedV1::IsEqual(const TObject *o) const
1720 // Checks if current instance of the class has the same essential members
1723 if(!o) return kFALSE;
1724 const AliTRDseedV1 *inTracklet = dynamic_cast<const AliTRDseedV1*>(o);
1725 if(!inTracklet) return kFALSE;
1727 for (Int_t i = 0; i < 2; i++){
1728 if ( fYref[i] != inTracklet->fYref[i] ) return kFALSE;
1729 if ( fZref[i] != inTracklet->fZref[i] ) return kFALSE;
1732 if ( fS2Y != inTracklet->fS2Y ) return kFALSE;
1733 if ( GetTilt() != inTracklet->GetTilt() ) return kFALSE;
1734 if ( GetPadLength() != inTracklet->GetPadLength() ) return kFALSE;
1736 for (Int_t i = 0; i < kNclusters; i++){
1737 // if ( fX[i] != inTracklet->GetX(i) ) return kFALSE;
1738 // if ( fY[i] != inTracklet->GetY(i) ) return kFALSE;
1739 // if ( fZ[i] != inTracklet->GetZ(i) ) return kFALSE;
1740 if ( fIndexes[i] != inTracklet->fIndexes[i] ) return kFALSE;
1742 // if ( fUsable != inTracklet->fUsable ) return kFALSE;
1744 for (Int_t i=0; i < 2; i++){
1745 if ( fYfit[i] != inTracklet->fYfit[i] ) return kFALSE;
1746 if ( fZfit[i] != inTracklet->fZfit[i] ) return kFALSE;
1747 if ( fLabels[i] != inTracklet->fLabels[i] ) return kFALSE;
1750 /* if ( fMeanz != inTracklet->GetMeanz() ) return kFALSE;
1751 if ( fZProb != inTracklet->GetZProb() ) return kFALSE;*/
1752 if ( fN != inTracklet->fN ) return kFALSE;
1753 //if ( fNUsed != inTracklet->fNUsed ) return kFALSE;
1754 //if ( fFreq != inTracklet->GetFreq() ) return kFALSE;
1755 //if ( fNChange != inTracklet->GetNChange() ) return kFALSE;
1757 if ( fC != inTracklet->fC ) return kFALSE;
1758 //if ( fCC != inTracklet->GetCC() ) return kFALSE;
1759 if ( fChi2 != inTracklet->fChi2 ) return kFALSE;
1760 // if ( fChi2Z != inTracklet->GetChi2Z() ) return kFALSE;
1762 if ( fDet != inTracklet->fDet ) return kFALSE;
1763 if ( fPt != inTracklet->fPt ) return kFALSE;
1764 if ( fdX != inTracklet->fdX ) return kFALSE;
1766 for (Int_t iCluster = 0; iCluster < kNclusters; iCluster++){
1767 AliTRDcluster *curCluster = fClusters[iCluster];
1768 AliTRDcluster *inCluster = inTracklet->fClusters[iCluster];
1769 if (curCluster && inCluster){
1770 if (! curCluster->IsEqual(inCluster) ) {
1771 curCluster->Print();
1776 // if one cluster exists, and corresponding
1777 // in other tracklet doesn't - return kFALSE
1778 if(curCluster || inCluster) return kFALSE;