1 /**************************************************************************
2 * Copyright(c) 1998-2003, 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 **************************************************************************/
16 //-----------------------------------------------------------------
17 // Implementation of the vertexer from tracks
19 // Origin: AliITSVertexerTracks
21 // andrea.dainese@pd.infn.it
23 // massimo.masera@to.infn.it
24 // Moved to STEER and adapted to ESD tracks:
25 // F.Prino, Torino, prino@to.infn.it
26 //-----------------------------------------------------------------
28 //---- Root headers --------
30 #include <TDirectory.h>
34 //---- AliRoot headers -----
35 #include "AliStrLine.h"
36 #include "AliExternalTrackParam.h"
37 #include "AliESDEvent.h"
38 #include "AliESDtrack.h"
39 #include "AliVertexerTracks.h"
41 ClassImp(AliVertexerTracks)
44 //----------------------------------------------------------------------------
45 AliVertexerTracks::AliVertexerTracks():
67 // Default constructor
76 //----------------------------------------------------------------------------
77 AliVertexerTracks::AliVertexerTracks(Double_t fieldkG):
99 // Standard constructor
109 //-----------------------------------------------------------------------------
110 AliVertexerTracks::~AliVertexerTracks()
112 // Default Destructor
113 // The objects pointed by the following pointer are not owned
114 // by this class and are not deleted
116 if(fTrksToSkip) { delete [] fTrksToSkip; fTrksToSkip=NULL; }
117 if(fIdSel) { delete [] fIdSel; fIdSel=NULL; }
119 //----------------------------------------------------------------------------
120 AliESDVertex* AliVertexerTracks::FindPrimaryVertex(const AliESDEvent *esdEvent)
123 // Primary vertex for current ESD event
125 // 1st with 5*fNSigma*sigma cut w.r.t. to initial vertex
126 // + cut on sqrt(d0d0+z0z0) if fConstraint=kFALSE
127 // 2nd with fNSigma*sigma cut w.r.t. to vertex found in 1st iteration)
131 // accept 1-track case only if constraint is available
132 if(!fConstraint && fMinTracks==1) fMinTracks=2;
134 // read tracks from ESD
135 Int_t nTrks = (Int_t)esdEvent->GetNumberOfTracks();
138 return fCurrentVertex;
142 TDirectory * olddir = gDirectory;
143 TFile f("VertexerTracks.root","recreate");
144 TObjArray trkArrayOrig(nTrks);
145 UShort_t *idOrig = new UShort_t[nTrks];
148 for(Int_t i=0; i<nTrks; i++) {
149 AliESDtrack *esdt = esdEvent->GetTrack(i);
150 // check tracks to skip
151 Bool_t skipThis = kFALSE;
152 for(Int_t j=0; j<fNTrksToSkip; j++) {
153 if(esdt->GetID()==fTrksToSkip[j]) {
154 if(fDebug) printf("skipping track: %d\n",i);
158 if(skipThis) continue;
160 if(!(esdt->GetStatus()&AliESDtrack::kITSrefit)) continue;
161 // check number of clusters in ITS
162 if(esdt->GetNcls(0)<fMinITSClusters) continue;
164 Double_t x,p[5],cov[15];
165 esdt->GetExternalParameters(x,p);
166 esdt->GetExternalCovariance(cov);
167 AliExternalTrackParam *t = new AliExternalTrackParam(x,esdt->GetAlpha(),p,cov);
168 trkArrayOrig.AddLast(t);
169 idOrig[nTrksOrig]=(UShort_t)esdt->GetID();
173 FindPrimaryVertex(&trkArrayOrig,idOrig);
175 trkArrayOrig.Delete();
176 delete [] idOrig; idOrig=NULL;
178 gSystem->Unlink("VertexerTracks.root");
181 return fCurrentVertex;
183 //----------------------------------------------------------------------------
184 AliESDVertex* AliVertexerTracks::FindPrimaryVertex(TObjArray *trkArrayOrig,
188 // Primary vertex using the AliExternalTrackParam's in the TObjArray.
189 // idOrig must contain the track IDs from AliESDtrack::GetID()
191 // 1st with 5*fNSigma*sigma cut w.r.t. to initial vertex
192 // + cut on sqrt(d0d0+z0z0) if fConstraint=kFALSE
193 // 2nd with fNSigma*sigma cut w.r.t. to vertex found in 1st iteration)
197 // accept 1-track case only if constraint is available
198 if(!fConstraint && fMinTracks==1) fMinTracks=2;
200 // read tracks from ESD
201 Int_t nTrksOrig = (Int_t)trkArrayOrig->GetEntriesFast();
202 if(fDebug) printf("Initial number of tracks: %d\n",nTrksOrig);
204 if(fDebug) printf("TooFewTracks\n");
206 return fCurrentVertex;
209 // If fConstraint=kFALSE
210 // run VertexFinder(1) to get rough estimate of initVertex (x,y)
212 // fill fTrkArraySel, for VertexFinder()
213 fIdSel = new UShort_t[nTrksOrig];
214 PrepareTracks(*trkArrayOrig,idOrig,0);
215 if(fIdSel) { delete [] fIdSel; fIdSel=NULL; }
216 Double_t cutsave = fDCAcut;
217 fDCAcut = (fITSrefit ? 0.1 : 0.5);
218 VertexFinder(1); // using weights, cutting dca < fDCAcut
220 if(fVert.GetNContributors()>0) {
221 fVert.GetXYZ(fNominalPos);
222 fNominalPos[0] = fVert.GetXv();
223 fNominalPos[1] = fVert.GetYv();
224 fNominalPos[2] = fVert.GetZv();
225 if(fDebug) printf("No mean vertex: VertexFinder gives (%f, %f, %f)\n",fNominalPos[0],fNominalPos[1],fNominalPos[2]);
230 if(fDebug) printf("No mean vertex and VertexFinder failed\n");
237 // propagate tracks to fNominalPos vertex
239 // if(constraint) reject for |d0|>5*fNSigma*sigma w.r.t. fNominal... vertex
240 // else reject for |d0|\oplus|z0| > 5 mm w.r.t. fNominal... vertex
242 // propagate tracks to best between initVertex and fCurrentVertex
243 // preselect tracks (reject for |d0|>fNSigma*sigma w.r.t. best
244 // between initVertex and fCurrentVertex)
245 for(Int_t iter=1; iter<=2; iter++) {
246 if(fOnlyFitter && iter==1) continue;
247 if(fIdSel) { delete [] fIdSel; fIdSel=NULL; }
248 fIdSel = new UShort_t[nTrksOrig];
249 Int_t nTrksSel = PrepareTracks(*trkArrayOrig,idOrig,iter);
250 if(fDebug) printf("N tracks selected in iteration %d: %d\n",iter,nTrksSel);
251 if(nTrksSel < fMinTracks) {
253 return fCurrentVertex;
259 if(fDebug) printf("Just one track\n");
260 OneTrackVertFinder();
263 case 1: StrLinVertexFinderMinDist(1); break;
264 case 2: StrLinVertexFinderMinDist(0); break;
265 case 3: HelixVertexFinder(); break;
266 case 4: VertexFinder(1); break;
267 case 5: VertexFinder(0); break;
268 default: printf("Wrong algorithm\n"); break;
271 if(fDebug) printf(" Vertex finding completed\n");
276 } // end loop on the two iterations
279 // set indices of used tracks
280 UShort_t *indices = 0;
281 if(fCurrentVertex->GetNContributors()>0) {
282 Int_t nIndices = (Int_t)fTrkArraySel.GetEntriesFast();
283 indices = new UShort_t[nIndices];
284 for(Int_t jj=0; jj<nIndices; jj++)
285 indices[jj] = fIdSel[jj];
286 fCurrentVertex->SetIndices(nIndices,indices);
288 delete [] indices; indices=NULL;
292 TString title="VertexerTracksNoConstraint";
294 title="VertexerTracksWithConstraint";
295 if(fOnlyFitter) title.Append("OnlyFitter");
297 fCurrentVertex->SetTitle(title.Data());
301 fCurrentVertex->PrintStatus();
302 fCurrentVertex->PrintIndices();
306 delete [] fIdSel; fIdSel=NULL;
307 fTrkArraySel.Delete();
308 if(fTrksToSkip) { delete [] fTrksToSkip; fTrksToSkip=NULL; }
311 return fCurrentVertex;
313 //------------------------------------------------------------------------
314 Double_t AliVertexerTracks::GetDeterminant3X3(Double_t matr[][3])
317 Double_t det=matr[0][0]*matr[1][1]*matr[2][2]-matr[0][0]*matr[1][2]*matr[2][1]-matr[0][1]*matr[1][0]*matr[2][2]+matr[0][1]*matr[1][2]*matr[2][0]+matr[0][2]*matr[1][0]*matr[2][1]-matr[0][2]*matr[1][1]*matr[2][0];
320 //-------------------------------------------------------------------------
321 void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d)
324 Double_t x12=p0[0]-p1[0];
325 Double_t y12=p0[1]-p1[1];
326 Double_t z12=p0[2]-p1[2];
327 Double_t kk=x12*x12+y12*y12+z12*z12;
328 m[0][0]=2-2/kk*x12*x12;
329 m[0][1]=-2/kk*x12*y12;
330 m[0][2]=-2/kk*x12*z12;
331 m[1][0]=-2/kk*x12*y12;
332 m[1][1]=2-2/kk*y12*y12;
333 m[1][2]=-2/kk*y12*z12;
334 m[2][0]=-2/kk*x12*z12;
336 m[2][2]=2-2/kk*z12*z12;
337 d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12;
338 d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12;
339 d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12;
342 //--------------------------------------------------------------------------
343 void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d)
346 Double_t x12=p1[0]-p0[0];
347 Double_t y12=p1[1]-p0[1];
348 Double_t z12=p1[2]-p0[2];
350 Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1];
352 Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]);
355 cc[0]=-x12/sigmasq[0];
356 cc[1]=-y12/sigmasq[1];
357 cc[2]=-z12/sigmasq[2];
359 Double_t ww=(-p0[0]*x12*sigmasq[1]*sigmasq[2]-p0[1]*y12*sigmasq[0]*sigmasq[2]-p0[2]*z12*sigmasq[0]*sigmasq[1])/den;
361 Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2];
364 aa[0]=x12*sigmasq[1]*sigmasq[2]/den;
365 aa[1]=y12*sigmasq[0]*sigmasq[2]/den;
366 aa[2]=z12*sigmasq[0]*sigmasq[1]/den;
368 m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0];
369 m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0];
370 m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0];
372 m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1];
373 m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1];
374 m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1];
376 m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2];
377 m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2];
378 m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2];
380 d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0];
381 d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1];
382 d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2];
385 //--------------------------------------------------------------------------
386 Double_t AliVertexerTracks::GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0)
389 Double_t x12=p0[0]-p1[0];
390 Double_t y12=p0[1]-p1[1];
391 Double_t z12=p0[2]-p1[2];
392 Double_t x10=p0[0]-x0[0];
393 Double_t y10=p0[1]-x0[1];
394 Double_t z10=p0[2]-x0[2];
395 // return ((x10*x10+y10*y10+z10*z10)*(x12*x12+y12*y12+z12*z12)-(x10*x12+y10*y12+z10*z12)*(x10*x12+y10*y12+z10*z12))/(x12*x12+y12*y12+z12*z12);
397 return ((y10*z12-z10*y12)*(y10*z12-z10*y12)+
398 (z10*x12-x10*z12)*(z10*x12-x10*z12)+
399 (x10*y12-y10*x12)*(x10*y12-y10*x12))
400 /(x12*x12+y12*y12+z12*z12);
403 //---------------------------------------------------------------------------
404 void AliVertexerTracks::OneTrackVertFinder()
406 // find vertex for events with 1 track, using DCA to nominal beam axis
407 if(fDebug) printf("Number of prepared tracks =%d - Call OneTrackVertFinder",fTrkArraySel.GetEntries());
408 AliExternalTrackParam *track1;
409 track1 = (AliExternalTrackParam*)fTrkArraySel.At(0);
410 Double_t field=GetFieldkG();
411 Double_t alpha=track1->GetAlpha();
412 Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
413 Double_t pos[3],dir[3];
414 track1->GetXYZAt(mindist,field,pos);
415 track1->GetPxPyPzAt(mindist,field,dir);
416 AliStrLine *line1 = new AliStrLine(pos,dir);
417 Double_t p1[3]={fNominalPos[0],fNominalPos[1],0.};
418 Double_t p2[3]={fNominalPos[0],fNominalPos[1],10.};
419 AliStrLine *zeta=new AliStrLine(p1,p2,kTRUE);
420 Double_t crosspoint[3]={0.,0.,0.};
423 Int_t retcode = zeta->Cross(line1,crosspoint);
425 sigma=line1->GetDistFromPoint(crosspoint);
430 fVert.SetXYZ(crosspoint);
431 fVert.SetDispersion(sigma);
432 fVert.SetNContributors(nContrib);
434 //---------------------------------------------------------------------------
435 void AliVertexerTracks::HelixVertexFinder()
437 // Get estimate of vertex position in (x,y) from tracks DCA
442 for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
443 Double_t field=GetFieldkG();
445 Int_t nacc = (Int_t)fTrkArraySel.GetEntriesFast();
447 Double_t aver[3]={0.,0.,0.};
448 Double_t averquad[3]={0.,0.,0.};
449 Double_t sigmaquad[3]={0.,0.,0.};
452 AliExternalTrackParam *track1;
453 AliExternalTrackParam *track2;
456 Double_t alpha, cs, sn;
457 Double_t crosspoint[3];
458 for(Int_t i=0; i<nacc; i++){
459 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
462 for(Int_t j=i+1; j<nacc; j++){
463 track2 = (AliExternalTrackParam*)fTrkArraySel.At(j);
465 distCA=track2->PropagateToDCA(track1,field);
466 if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){
468 alpha=track1->GetAlpha();
469 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
470 Double_t x1=x*cs - track1->GetY()*sn;
471 Double_t y1=x*sn + track1->GetY()*cs;
472 Double_t z1=track1->GetZ();
474 Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
476 alpha=track2->GetAlpha();
477 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
478 Double_t x2=x*cs - track2->GetY()*sn;
479 Double_t y2=x*sn + track2->GetY()*cs;
480 Double_t z2=track2->GetZ();
481 Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
482 Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
483 Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
484 Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
485 Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
486 crosspoint[0]=wx1*x1 + wx2*x2;
487 crosspoint[1]=wy1*y1 + wy2*y2;
488 crosspoint[2]=wz1*z1 + wz2*z2;
491 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
492 for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]);
498 for(Int_t jj=0;jj<3;jj++){
499 initPos[jj] = aver[jj]/ncombi;
500 averquad[jj]/=ncombi;
501 sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj];
502 sigma+=sigmaquad[jj];
504 sigma=TMath::Sqrt(TMath::Abs(sigma));
507 Warning("HelixVertexFinder","Finder did not succed");
510 fVert.SetXYZ(initPos);
511 fVert.SetDispersion(sigma);
512 fVert.SetNContributors(ncombi);
514 //----------------------------------------------------------------------------
515 Int_t AliVertexerTracks::PrepareTracks(TObjArray &trkArrayOrig,
520 // Propagate tracks to initial vertex position and store them in a TObjArray
522 if(fDebug) printf(" PrepareTracks()\n");
524 Int_t nTrksOrig = (Int_t)trkArrayOrig.GetEntriesFast();
527 Double_t maxd0z0 = (fITSrefit ? fMaxd0z0 : 10.*fMaxd0z0);
528 Double_t sigmaCurr[3];
529 Double_t normdistx,normdisty;
530 Double_t d0z0[2],covd0z0[3];
532 Double_t field = GetFieldkG();
534 AliESDVertex *initVertex = new AliESDVertex(fNominalPos,fNominalCov,1,1);
536 if(!fTrkArraySel.IsEmpty()) fTrkArraySel.Delete();
538 AliExternalTrackParam *track=0;
540 for(Int_t i=0; i<nTrksOrig; i++) {
541 track = new AliExternalTrackParam(*(AliExternalTrackParam*)trkArrayOrig.At(i));
542 // only TPC tracks in |eta|<0.9
543 if(!fITSrefit && TMath::Abs(track->GetTgl())>1.) {
544 if(fDebug) printf(" rejecting track with tgl = %f\n",track->GetTgl());
549 // propagate track to vertex
550 if(optImpParCut<2 || fOnlyFitter) { // optImpParCut==1 or 0
551 track->PropagateToDCA(initVertex,field,100.,d0z0,covd0z0);
552 } else { // optImpParCut==2
553 fCurrentVertex->GetSigmaXYZ(sigmaCurr);
554 normdistx = TMath::Abs(fCurrentVertex->GetXv()-fNominalPos[0])/TMath::Sqrt(sigmaCurr[0]*sigmaCurr[0]+fNominalCov[0]);
555 normdisty = TMath::Abs(fCurrentVertex->GetYv()-fNominalPos[1])/TMath::Sqrt(sigmaCurr[1]*sigmaCurr[1]+fNominalCov[2]);
556 if(normdistx < 3. && normdisty < 3. &&
557 (sigmaCurr[0]+sigmaCurr[1])<(TMath::Sqrt(fNominalCov[0])+TMath::Sqrt(fNominalCov[2]))) {
558 track->PropagateToDCA(fCurrentVertex,field,100.,d0z0,covd0z0);
560 track->PropagateToDCA(initVertex,field,100.,d0z0,covd0z0);
564 sigmad0 = TMath::Sqrt(covd0z0[0]);
565 maxd0rphi = fNSigma*sigmad0;
566 if(optImpParCut==1) maxd0rphi *= 5.;
567 //sigmad0z0 = TMath::Sqrt(covd0z0[0]+covd0z0[2]); // for future improvement
568 //maxd0z0 = 10.*fNSigma*sigmad0z0;
570 if(fDebug) printf("trk %d; id %d; |d0| = %f; d0 cut = %f; |z0| = %f; |d0|oplus|z0| = %f; d0z0 cut = %f\n",i,(Int_t)idOrig[i],TMath::Abs(d0z0[0]),maxd0rphi,TMath::Abs(d0z0[1]),TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1]),maxd0z0);
572 // if fConstraint=kFALSE, during iterations 1 and 2 ||
573 // if fConstraint=kTRUE, during iteration 2,
574 // select tracks with d0oplusz0 < maxd0z0
575 if((!fConstraint && optImpParCut>0 && fVert.GetNContributors()>0) ||
576 ( fConstraint && optImpParCut==2)) {
578 TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1])>maxd0z0) {
579 if(fDebug) printf(" rejected\n");
580 delete track; continue;
585 // select tracks with d0rphi < maxd0rphi
586 if(optImpParCut>0 && TMath::Abs(d0z0[0])>maxd0rphi) {
587 if(fDebug) printf(" rejected\n");
588 delete track; continue;
591 fTrkArraySel.AddLast(track);
592 fIdSel[nTrksSel] = idOrig[i];
600 //---------------------------------------------------------------------------
601 AliESDVertex* AliVertexerTracks::RemoveTracksFromVertex(AliESDVertex *inVtx,
607 // Removes tracks in trksTree from fit of inVtx
610 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraint")) {
611 printf("ERROR: primary vertex has no constraint: cannot remove tracks\n");
614 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraintOnlyFitter"))
615 printf("WARNING: result of tracks' removal will be only approximately correct\n");
618 rv(0,0) = inVtx->GetXv();
619 rv(1,0) = inVtx->GetYv();
620 rv(2,0) = inVtx->GetZv();
623 inVtx->GetCovMatrix(cov);
625 vV(0,1) = cov[1]; vV(1,0) = cov[1];
627 vV(0,2) = cov[3]; vV(2,0) = cov[3];
628 vV(1,2) = cov[4]; vV(2,1) = cov[4];
631 TMatrixD sumWi(TMatrixD::kInverted,vV);
632 TMatrixD sumWiri(sumWi,TMatrixD::kMult,rv);
634 Int_t nUsedTrks = inVtx->GetNIndices();
635 Double_t chi2 = inVtx->GetChi2();
637 AliExternalTrackParam *track = 0;
638 Int_t ntrks = (Int_t)trkArray->GetEntriesFast();
639 for(Int_t i=0;i<ntrks;i++) {
640 track = (AliExternalTrackParam*)trkArray->At(i);
641 if(!inVtx->UsesTrack(id[i])) {
642 printf("track %d was not used in vertex fit\n",id[i]);
645 Double_t alpha = track->GetAlpha();
646 Double_t xl = diamondxy[0]*TMath::Cos(alpha)+diamondxy[1]*TMath::Sin(alpha);
647 track->PropagateTo(xl,GetFieldkG());
648 // vector of track global coordinates
650 // covariance matrix of ri
653 // get space point from track
654 if(!TrackToPoint(track,ri,wWi)) continue;
656 TMatrixD wWiri(wWi,TMatrixD::kMult,ri);
662 TMatrixD deltar = rv; deltar -= ri;
663 TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar);
664 Double_t chi2i = deltar(0,0)*wWideltar(0,0)+
665 deltar(1,0)*wWideltar(1,0)+
666 deltar(2,0)*wWideltar(2,0);
667 // remove from total chi2
672 printf("Trying to remove too many tracks!\n");
680 // new inverted of weights matrix
681 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
683 // new position of primary vertex
684 rvnew.Mult(vVnew,sumWiri);
686 Double_t position[3];
687 position[0] = rvnew(0,0);
688 position[1] = rvnew(1,0);
689 position[2] = rvnew(2,0);
697 // store data in the vertex object
698 AliESDVertex *outVtx = new AliESDVertex(position,cov,chi2,nUsedTrks);
699 outVtx->SetTitle(inVtx->GetTitle());
700 UShort_t *inindices = inVtx->GetIndices();
701 Int_t nIndices = nUsedTrks;
702 UShort_t *outindices = new UShort_t[nIndices];
704 for(Int_t k=0; k<inVtx->GetNIndices(); k++) {
705 Bool_t copyindex=kTRUE;
706 for(Int_t l=0; l<ntrks; l++) {
707 if(inindices[k]==id[l]) copyindex=kFALSE;
710 outindices[j] = inindices[k]; j++;
713 outVtx->SetIndices(nIndices,outindices);
714 delete [] outindices;
717 printf("Vertex before removing tracks:\n");
718 inVtx->PrintStatus();
719 inVtx->PrintIndices();
720 printf("Vertex after removing tracks:\n");
721 outVtx->PrintStatus();
722 outVtx->PrintIndices();
727 //---------------------------------------------------------------------------
728 void AliVertexerTracks::SetSkipTracks(Int_t n,Int_t *skipped)
731 // Mark the tracks not to be used in the vertex reconstruction.
732 // Tracks are identified by AliESDtrack::GetID()
734 fNTrksToSkip = n; fTrksToSkip = new Int_t[n];
735 for(Int_t i=0;i<n;i++) fTrksToSkip[i] = skipped[i];
738 //---------------------------------------------------------------------------
739 void AliVertexerTracks::SetVtxStart(AliESDVertex *vtx)
742 // Set initial vertex knowledge
744 vtx->GetXYZ(fNominalPos);
745 vtx->GetCovMatrix(fNominalCov);
749 //---------------------------------------------------------------------------
750 void AliVertexerTracks::StrLinVertexFinderMinDist(Int_t optUseWeights)
752 AliExternalTrackParam *track1;
753 Double_t field=GetFieldkG();
754 const Int_t knacc = (Int_t)fTrkArraySel.GetEntriesFast();
755 static TClonesArray linarray("AliStrLine",knacc);
756 for(Int_t i=0; i<knacc; i++){
757 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
758 Double_t alpha=track1->GetAlpha();
759 Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
760 Double_t pos[3],dir[3],sigmasq[3];
761 track1->GetXYZAt(mindist,field,pos);
762 track1->GetPxPyPzAt(mindist,field,dir);
763 sigmasq[0]=TMath::Sin(alpha)*TMath::Sin(alpha)*track1->GetSigmaY2();
764 sigmasq[1]=TMath::Cos(alpha)*TMath::Cos(alpha)*track1->GetSigmaY2();
765 sigmasq[2]=track1->GetSigmaZ2();
768 if(!TrackToPoint(track1,ri,wWi)) continue;
771 for(Int_t ia=0;ia<3;ia++){
772 for(Int_t ib=0;ib<3;ib++){
773 wmat[iel]=wWi(ia,ib);
777 new(linarray[i]) AliStrLine(pos,sigmasq,wmat,dir);
779 fVert=TrackletVertexFinder(&linarray,optUseWeights);
782 //---------------------------------------------------------------------------
783 AliESDVertex AliVertexerTracks::TrackletVertexFinder(TClonesArray *lines, Int_t optUseWeights)
785 // Calculate the point at minimum distance to prepared tracks
787 const Int_t knacc = (Int_t)lines->GetEntriesFast();
788 Double_t initPos[3]={0.,0.,0.};
790 Double_t (*vectP0)[3]=new Double_t [knacc][3];
791 Double_t (*vectP1)[3]=new Double_t [knacc][3];
794 Double_t dsum[3]={0,0,0};
796 for(Int_t i=0;i<3;i++){
797 for(Int_t j=0;j<3;j++){
803 for(Int_t i=0; i<knacc; i++){
804 AliStrLine* line1 = (AliStrLine*)lines->At(i);
805 Double_t p0[3],cd[3],sigmasq[3];
809 line1->GetSigma2P0(sigmasq);
810 line1->GetWMatrix(wmat);
813 for(Int_t ia=0;ia<3;ia++){
814 for(Int_t ib=0;ib<3;ib++){
815 wWi(ia,ib)=wmat[iel];
822 Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]};
832 if(optUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow);
833 else GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow);
836 for(Int_t iii=0;iii<3;iii++){
837 dsum[iii]+=dknow[iii];
838 for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj];
842 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
843 Double_t covmatrix[6];
844 covmatrix[0] = invsumWi(0,0);
845 covmatrix[1] = invsumWi(0,1);
846 covmatrix[2] = invsumWi(1,1);
847 covmatrix[3] = invsumWi(0,2);
848 covmatrix[4] = invsumWi(1,2);
849 covmatrix[5] = invsumWi(2,2);
852 Double_t det=GetDeterminant3X3(sum);
856 for(Int_t zz=0;zz<3;zz++){
857 for(Int_t ww=0;ww<3;ww++){
858 for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk];
860 for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk];
861 initPos[zz]=GetDeterminant3X3(vett)/det;
865 for(Int_t i=0; i<knacc; i++){
866 Double_t p0[3]={0,0,0},p1[3]={0,0,0};
867 for(Int_t ii=0;ii<3;ii++){
868 p0[ii]=vectP0[i][ii];
869 p1[ii]=vectP1[i][ii];
871 sigma+=GetStrLinMinDist(p0,p1,initPos);
874 sigma=TMath::Sqrt(sigma);
878 AliESDVertex theVert(initPos,covmatrix,99999.,knacc);
879 theVert.SetDispersion(sigma);
884 //---------------------------------------------------------------------------
885 Bool_t AliVertexerTracks::TrackToPoint(AliExternalTrackParam *t,
886 TMatrixD &ri,TMatrixD &wWi,
887 Bool_t uUi3by3) const
890 // Extract from the AliExternalTrackParam the global coordinates ri and covariance matrix
891 // wWi of the space point that it represents (to be used in VertexFitter())
895 Double_t rotAngle = t->GetAlpha();
896 if(rotAngle<0.) rotAngle += 2.*TMath::Pi();
897 Double_t cosRot = TMath::Cos(rotAngle);
898 Double_t sinRot = TMath::Sin(rotAngle);
900 ri(0,0) = t->GetX()*cosRot-t->GetY()*sinRot;
901 ri(1,0) = t->GetX()*sinRot+t->GetY()*cosRot;
907 // matrix to go from global (x,y,z) to local (y,z);
916 // covariance matrix of local (y,z) - inverted
918 uUi(0,0) = t->GetSigmaY2();
919 uUi(0,1) = t->GetSigmaZY();
920 uUi(1,0) = t->GetSigmaZY();
921 uUi(1,1) = t->GetSigmaZ2();
923 //printf(" %f %f\n",uUi(0,0),uUi(0,1));
924 //printf(" %f %f\n",uUi(1,0),uUi(1,1));
926 if(uUi.Determinant() <= 0.) return kFALSE;
927 TMatrixD uUiInv(TMatrixD::kInverted,uUi);
929 // weights matrix: wWi = qQiT * uUiInv * qQi
930 TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi);
931 TMatrixD m(qQi,TMatrixD::kTransposeMult,uUiInvQi);
934 if(fVert.GetNContributors()<1) AliFatal("Vertex from finder is empty");
935 // matrix to go from global (x,y,z) to local (x,y,z);
947 // covariance of fVert along the track
948 Double_t p[3],pt,ptot;
950 pt = TMath::Sqrt(p[0]*p[0]+p[1]*p[1]);
951 ptot = TMath::Sqrt(pt*pt+p[2]*p[2]);
952 Double_t cphi = p[0]/pt; //cos(phi)=px/pt
953 Double_t sphi = p[1]/pt; //sin(phi)=py/pt
954 Double_t clambda = pt/ptot; //cos(lambda)=pt/ptot
955 Double_t slambda = p[2]/ptot; //sin(lambda)=pz/ptot
956 Double_t covfVert[6];
957 fVert.GetCovMatrix(covfVert);
958 Double_t covfVertalongt =
959 covfVert[0]*cphi*cphi*clambda*clambda
960 +covfVert[1]*2.*cphi*sphi*clambda*clambda
961 +covfVert[3]*2.*cphi*clambda*slambda
962 +covfVert[2]*sphi*sphi*clambda*clambda
963 +covfVert[4]*2.*sphi*clambda*slambda
964 +covfVert[5]*slambda*slambda;
965 // covariance matrix of local (x,y,z) - inverted
967 uUi(0,0) = covfVertalongt * fnSigmaForUi00 * fnSigmaForUi00;
968 if(fDebug) printf("=====> sqrtUi00 cm %f\n",TMath::Sqrt(uUi(0,0)));
972 uUi(1,1) = t->GetSigmaY2();
973 uUi(1,2) = t->GetSigmaZY();
975 uUi(2,1) = t->GetSigmaZY();
976 uUi(2,2) = t->GetSigmaZ2();
978 //printf(" %f %f\n",uUi(0,0),uUi(0,1));
979 //printf(" %f %f\n",uUi(1,0),uUi(1,1));
981 if(uUi.Determinant() <= 0.) return kFALSE;
982 TMatrixD uUiInv(TMatrixD::kInverted,uUi);
984 // weights matrix: wWi = qQiT * uUiInv * qQi
985 TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi);
986 TMatrixD m(qQi,TMatrixD::kTransposeMult,uUiInvQi);
993 //---------------------------------------------------------------------------
994 void AliVertexerTracks::TooFewTracks()
997 // When the number of tracks is < fMinTracks,
998 // deal with vertices not found and prepare to exit
1000 if(fDebug) printf("TooFewTracks\n");
1002 Double_t pos[3],err[3];
1003 pos[0] = fNominalPos[0];
1004 err[0] = TMath::Sqrt(fNominalCov[0]);
1005 pos[1] = fNominalPos[1];
1006 err[1] = TMath::Sqrt(fNominalCov[2]);
1007 pos[2] = fNominalPos[2];
1008 err[2] = TMath::Sqrt(fNominalCov[5]);
1009 Int_t ncontr = (err[0]>1. ? -1 : -3);
1011 fCurrentVertex = new AliESDVertex(pos,err);
1012 fCurrentVertex->SetNContributors(ncontr);
1015 fCurrentVertex->SetTitle("VertexerTracksWithConstraint");
1017 fCurrentVertex->SetTitle("VertexerTracksNoConstraint");
1020 if(!fTrkArraySel.IsEmpty()) fTrkArraySel.Delete();
1021 if(fIdSel) {delete [] fIdSel; fIdSel=NULL;}
1022 if(fTrksToSkip) {delete [] fTrksToSkip; fTrksToSkip=NULL;}
1026 //---------------------------------------------------------------------------
1027 void AliVertexerTracks::VertexFinder(Int_t optUseWeights)
1030 // Get estimate of vertex position in (x,y) from tracks DCA
1032 Double_t initPos[3];
1034 for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
1035 Int_t nacc = (Int_t)fTrkArraySel.GetEntriesFast();
1036 Double_t aver[3]={0.,0.,0.};
1037 Double_t aversq[3]={0.,0.,0.};
1038 Double_t sigmasq[3]={0.,0.,0.};
1041 AliExternalTrackParam *track1;
1042 AliExternalTrackParam *track2;
1043 Double_t pos[3],dir[3];
1044 Double_t alpha,mindist;
1045 Double_t field=GetFieldkG();
1047 for(Int_t i=0; i<nacc; i++){
1048 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
1049 alpha=track1->GetAlpha();
1050 mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1051 track1->GetXYZAt(mindist,field,pos);
1052 track1->GetPxPyPzAt(mindist,field,dir);
1053 AliStrLine *line1 = new AliStrLine(pos,dir);
1055 // AliStrLine *line1 = new AliStrLine();
1056 // track1->ApproximateHelixWithLine(mindist,field,line1);
1058 for(Int_t j=i+1; j<nacc; j++){
1059 track2 = (AliExternalTrackParam*)fTrkArraySel.At(j);
1060 alpha=track2->GetAlpha();
1061 mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1062 track2->GetXYZAt(mindist,field,pos);
1063 track2->GetPxPyPzAt(mindist,field,dir);
1064 AliStrLine *line2 = new AliStrLine(pos,dir);
1065 // AliStrLine *line2 = new AliStrLine();
1066 // track2->ApproximateHelixWithLine(mindist,field,line2);
1067 Double_t distCA=line2->GetDCA(line1);
1068 //printf("%d %d %f\n",i,j,distCA);
1069 if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){
1070 Double_t pnt1[3],pnt2[3],crosspoint[3];
1072 if(optUseWeights<=0){
1073 Int_t retcode = line2->Cross(line1,crosspoint);
1076 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
1077 for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
1080 if(optUseWeights>0){
1081 Int_t retcode = line1->CrossPoints(line2,pnt1,pnt2);
1084 alpha=track1->GetAlpha();
1085 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
1086 Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
1087 alpha=track2->GetAlpha();
1088 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
1089 Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
1090 Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
1091 Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
1092 Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
1093 Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
1094 crosspoint[0]=wx1*pnt1[0] + wx2*pnt2[0];
1095 crosspoint[1]=wy1*pnt1[1] + wy2*pnt2[1];
1096 crosspoint[2]=wz1*pnt1[2] + wz2*pnt2[2];
1099 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
1100 for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
1109 for(Int_t jj=0;jj<3;jj++){
1110 initPos[jj] = aver[jj]/ncombi;
1111 //printf("%f\n",initPos[jj]);
1113 sigmasq[jj]=aversq[jj]-initPos[jj]*initPos[jj];
1116 sigma=TMath::Sqrt(TMath::Abs(sigma));
1119 Warning("VertexFinder","Finder did not succed");
1122 fVert.SetXYZ(initPos);
1123 fVert.SetDispersion(sigma);
1124 fVert.SetNContributors(ncombi);
1126 //---------------------------------------------------------------------------
1127 void AliVertexerTracks::VertexFitter()
1130 // The optimal estimate of the vertex position is given by a "weighted
1131 // average of tracks positions".
1132 // Original method: V. Karimaki, CMS Note 97/0051
1134 Bool_t useConstraint = fConstraint;
1135 Double_t initPos[3];
1137 fVert.GetXYZ(initPos);
1139 initPos[0]=fNominalPos[0];
1140 initPos[1]=fNominalPos[1];
1141 initPos[2]=fNominalPos[2];
1144 Int_t nTrksSel = (Int_t)fTrkArraySel.GetEntries();
1145 if(nTrksSel==1) useConstraint=kTRUE;
1147 printf("--- VertexFitter(): start\n");
1148 printf(" Number of tracks in array: %d\n",nTrksSel);
1149 printf(" Minimum # tracks required in fit: %d\n",fMinTracks);
1150 printf(" Vertex position after finder: %f,%f,%f\n",initPos[0],initPos[1],initPos[2]);
1151 if(useConstraint) printf(" This vertex will be used in fit: (%f+-%f,%f+-%f)\n",fNominalPos[0],TMath::Sqrt(fNominalCov[0]),fNominalPos[1],TMath::Sqrt(fNominalCov[2]));
1154 // special treatment for few-tracks fits (e.g. secondary vertices)
1155 Bool_t uUi3by3 = kFALSE; if(nTrksSel<5 && !useConstraint) uUi3by3 = kTRUE;
1160 rv(0,0) = initPos[0];
1161 rv(1,0) = initPos[1];
1163 Double_t xlStart,alpha;
1165 Double_t chi2,chi2i,chi2b;
1166 AliExternalTrackParam *t = 0;
1169 // initial vertex covariance matrix
1171 vVb(0,0) = fNominalCov[0];
1172 vVb(0,1) = fNominalCov[1];
1174 vVb(1,0) = fNominalCov[1];
1175 vVb(1,1) = fNominalCov[2];
1179 vVb(2,2) = fNominalCov[5];
1180 TMatrixD vVbInv(TMatrixD::kInverted,vVb);
1182 rb(0,0) = fNominalPos[0];
1183 rb(1,0) = fNominalPos[1];
1184 rb(2,0) = fNominalPos[2];
1185 TMatrixD vVbInvrb(vVbInv,TMatrixD::kMult,rb);
1189 // 1st - estimate of vtx using all tracks
1190 // 2nd - estimate of global chi2
1191 for(step=0; step<2; step++) {
1192 if(fDebug) printf(" step = %d\n",step);
1196 if(step==1) { initPos[0]=rv(0,0); initPos[0]=rv(1,0); }
1198 TMatrixD sumWiri(3,1);
1199 TMatrixD sumWi(3,3);
1200 for(i=0; i<3; i++) {
1202 for(j=0; j<3; j++) sumWi(j,i) = 0.;
1205 // mean vertex constraint
1208 sumWiri(i,0) += vVbInvrb(i,0);
1209 for(k=0;k<3;k++) sumWi(i,k) += vVbInv(i,k);
1212 TMatrixD deltar = rv; deltar -= rb;
1213 TMatrixD vVbInvdeltar(vVbInv,TMatrixD::kMult,deltar);
1214 chi2b = deltar(0,0)*vVbInvdeltar(0,0)+
1215 deltar(1,0)*vVbInvdeltar(1,0)+
1216 deltar(2,0)*vVbInvdeltar(2,0);
1221 for(k=0; k<nTrksSel; k++) {
1222 // get track from track array
1223 t = (AliExternalTrackParam*)fTrkArraySel.At(k);
1224 alpha = t->GetAlpha();
1225 xlStart = initPos[0]*TMath::Cos(alpha)+initPos[1]*TMath::Sin(alpha);
1226 // to vtxSeed (from finder)
1227 t->PropagateTo(xlStart,GetFieldkG());
1229 // vector of track global coordinates
1231 // covariance matrix of ri
1234 // get space point from track
1235 if(!TrackToPoint(t,ri,wWi,uUi3by3)) continue;
1236 TMatrixD wWiri(wWi,TMatrixD::kMult,ri);
1239 TMatrixD deltar = rv; deltar -= ri;
1240 TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar);
1241 chi2i = deltar(0,0)*wWideltar(0,0)+
1242 deltar(1,0)*wWideltar(1,0)+
1243 deltar(2,0)*wWideltar(2,0);
1245 // add to total chi2
1252 } // end loop on tracks
1254 if(nTrksUsed < fMinTracks) {
1259 Double_t determinant = sumWi.Determinant();
1260 //cerr<<" determinant: "<<determinant<<endl;
1261 if(determinant < 100.) {
1262 printf("det(V) = 0\n");
1268 // inverted of weights matrix
1269 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
1271 // position of primary vertex
1272 rv.Mult(vV,sumWiri);
1274 } // end loop on the 2 steps
1281 Double_t position[3];
1282 position[0] = rv(0,0);
1283 position[1] = rv(1,0);
1284 position[2] = rv(2,0);
1285 Double_t covmatrix[6];
1286 covmatrix[0] = vV(0,0);
1287 covmatrix[1] = vV(0,1);
1288 covmatrix[2] = vV(1,1);
1289 covmatrix[3] = vV(0,2);
1290 covmatrix[4] = vV(1,2);
1291 covmatrix[5] = vV(2,2);
1293 // for correct chi2/ndf, count constraint as additional "track"
1294 if(fConstraint) nTrksUsed++;
1295 // store data in the vertex object
1296 fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nTrksUsed);
1299 printf(" Vertex after fit:\n");
1300 fCurrentVertex->PrintStatus();
1301 printf("--- VertexFitter(): finish\n");
1306 //----------------------------------------------------------------------------
1307 AliESDVertex* AliVertexerTracks::VertexForSelectedTracks(TObjArray *trkArray,
1309 Bool_t optUseFitter,
1310 Bool_t optPropagate)
1313 // Return vertex from tracks (AliExternalTrackParam) in array
1318 // get tracks and propagate them to initial vertex position
1319 fIdSel = new UShort_t[(Int_t)trkArray->GetEntriesFast()];
1320 Int_t nTrksSel = PrepareTracks(*trkArray,id,0);
1321 if(nTrksSel < TMath::Max(2,fMinTracks)) {
1323 return fCurrentVertex;
1328 case 1: StrLinVertexFinderMinDist(1); break;
1329 case 2: StrLinVertexFinderMinDist(0); break;
1330 case 3: HelixVertexFinder(); break;
1331 case 4: VertexFinder(1); break;
1332 case 5: VertexFinder(0); break;
1333 default: printf("Wrong algorithm\n"); break;
1335 if(fDebug) printf(" Vertex finding completed\n");
1341 Double_t position[3]={fVert.GetXv(),fVert.GetYv(),fVert.GetZv()};
1342 Double_t covmatrix[6];
1343 fVert.GetCovMatrix(covmatrix);
1344 Double_t chi2=99999.;
1345 Int_t nTrksUsed=fVert.GetNContributors();
1346 fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nTrksUsed);
1348 fCurrentVertex->SetDispersion(fVert.GetDispersion());
1351 // set indices of used tracks and propagate track to found vertex
1352 UShort_t *indices = 0;
1353 Double_t d0z0[2],covd0z0[3];
1354 AliExternalTrackParam *t = 0;
1355 if(fCurrentVertex->GetNContributors()>0) {
1356 indices = new UShort_t[fCurrentVertex->GetNContributors()];
1357 for(Int_t jj=0; jj<(Int_t)fTrkArraySel.GetEntriesFast(); jj++) {
1358 indices[jj] = fIdSel[jj];
1359 t = (AliExternalTrackParam*)fTrkArraySel.At(jj);
1360 if(optPropagate && optUseFitter) {
1361 if(TMath::Sqrt(fCurrentVertex->GetXv()*fCurrentVertex->GetXv()+fCurrentVertex->GetYv()*fCurrentVertex->GetYv())<3.) {
1362 t->PropagateToDCA(fCurrentVertex,GetFieldkG(),100.,d0z0,covd0z0);
1363 if(fDebug) printf("Track %d propagated to found vertex\n",jj);
1365 AliWarning("Found vertex outside beam pipe!");
1369 fCurrentVertex->SetIndices(fCurrentVertex->GetNContributors(),indices);
1373 delete [] indices; indices=NULL;
1374 delete [] fIdSel; fIdSel=NULL;
1375 fTrkArraySel.Delete();
1377 return fCurrentVertex;
1379 //----------------------------------------------------------------------------
1380 AliESDVertex* AliVertexerTracks::VertexForSelectedESDTracks(TObjArray *trkArray,
1381 Bool_t optUseFitter,
1382 Bool_t optPropagate)
1385 // Return vertex from array of ESD tracks
1388 Int_t nTrks = (Int_t)trkArray->GetEntriesFast();
1389 UShort_t *id = new UShort_t[nTrks];
1391 AliESDtrack *esdt = 0;
1392 for(Int_t i=0; i<nTrks; i++){
1393 esdt = (AliESDtrack*)trkArray->At(i);
1394 id[i] = (UShort_t)esdt->GetID();
1397 VertexForSelectedTracks(trkArray,id,optUseFitter,optPropagate);
1399 delete [] id; id=NULL;
1401 return fCurrentVertex;
1403 //--------------------------------------------------------------------------