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 <TClonesArray.h>
31 #include <TDirectory.h>
33 //---- AliRoot headers -----
34 #include "AliStrLine.h"
35 #include "AliExternalTrackParam.h"
36 #include "AliNeutralTrackParam.h"
37 #include "AliVEvent.h"
38 #include "AliVTrack.h"
39 #include "AliESDtrack.h"
40 #include "AliVertexerTracks.h"
42 ClassImp(AliVertexerTracks)
45 //----------------------------------------------------------------------------
46 AliVertexerTracks::AliVertexerTracks():
73 fSelectOnTOFBunchCrossing(kFALSE),
74 fKeepAlsoUnflaggedTOFBunchCrossing(kTRUE)
77 // Default constructor
82 //----------------------------------------------------------------------------
83 AliVertexerTracks::AliVertexerTracks(Double_t fieldkG):
110 fSelectOnTOFBunchCrossing(kFALSE),
111 fKeepAlsoUnflaggedTOFBunchCrossing(kTRUE)
114 // Standard constructor
119 //-----------------------------------------------------------------------------
120 AliVertexerTracks::~AliVertexerTracks()
122 // Default Destructor
123 // The objects pointed by the following pointer are not owned
124 // by this class and are not deleted
126 if(fTrksToSkip) { delete [] fTrksToSkip; fTrksToSkip=NULL; }
127 if(fIdSel) { delete [] fIdSel; fIdSel=NULL; }
129 //----------------------------------------------------------------------------
130 AliESDVertex* AliVertexerTracks::FindPrimaryVertex(const AliVEvent *vEvent)
133 // Primary vertex for current ESD or AOD event
135 // 1st with 5*fNSigma*sigma cut w.r.t. to initial vertex
136 // + cut on sqrt(d0d0+z0z0) if fConstraint=kFALSE
137 // 2nd with fNSigma*sigma cut w.r.t. to vertex found in 1st iteration)
141 TString evtype = vEvent->IsA()->GetName();
142 Bool_t inputAOD = ((evtype=="AliAODEvent") ? kTRUE : kFALSE);
144 if(inputAOD && fMode==1) {
145 printf("Error : AliVertexerTracks: no TPC-only vertex from AOD\n");
147 return fCurrentVertex;
150 // accept 1-track case only if constraint is available
151 if(!fConstraint && fMinTracks==1) fMinTracks=2;
153 // read tracks from AlivEvent
154 Int_t nTrks = (Int_t)vEvent->GetNumberOfTracks();
155 if(nTrks<fMinTracks) {
157 return fCurrentVertex;
161 TDirectory * olddir = gDirectory;
163 if(nTrks>500) f = new TFile("VertexerTracks.root","recreate");
164 TObjArray trkArrayOrig(nTrks);
165 UShort_t *idOrig = new UShort_t[nTrks];
168 AliExternalTrackParam *t=0;
170 for(Int_t i=0; i<nTrks; i++) {
171 AliVTrack *track = (AliVTrack*)vEvent->GetTrack(i);
172 // check tracks to skip
173 Bool_t skipThis = kFALSE;
174 for(Int_t j=0; j<fNTrksToSkip; j++) {
175 if(track->GetID()==fTrksToSkip[j]) {
176 AliDebug(1,Form("skipping track: %d",i));
180 if(skipThis) continue;
182 // skip pure ITS SA tracks (default)
183 if(!fITSpureSA && (track->GetStatus()&AliESDtrack::kITSpureSA)) continue;
184 // or use only pure ITS SA tracks
185 if(fITSpureSA && !(track->GetStatus()&AliESDtrack::kITSpureSA)) continue;
188 if(fMode==0 && fITSrefit && !(track->GetStatus()&AliESDtrack::kITSrefit)) continue;
190 // reject tracks according to bunch crossing id from TOF
191 if(fSelectOnTOFBunchCrossing) {
192 Int_t bcTOF = track->GetTOFBunchCrossing();
193 if(bcTOF>0) continue;
194 if(bcTOF==-1 && !fKeepAlsoUnflaggedTOFBunchCrossing) continue;
198 if(!inputAOD) { // ESD
199 AliESDtrack* esdt = (AliESDtrack*)track;
200 if(esdt->GetNcls(fMode) < fMinClusters) continue;
201 if(fMode==0) { // ITS mode
202 Double_t x,p[5],cov[15];
203 esdt->GetExternalParameters(x,p);
204 esdt->GetExternalCovariance(cov);
205 t = new AliExternalTrackParam(x,esdt->GetAlpha(),p,cov);
206 } else if(fMode==1) { // TPC mode
207 t = (AliExternalTrackParam*)esdt->GetTPCInnerParam();
209 Double_t radius = 2.8; //something less than the beam pipe radius
210 if(!PropagateTrackTo(t,radius)) continue;
212 } else { // AOD (only ITS mode)
214 for(Int_t l=0;l<6;l++) if(TESTBIT(track->GetITSClusterMap(),l)) ncls0++;
215 if(ncls0 < fMinClusters) continue;
216 t = new AliExternalTrackParam(track);
218 trkArrayOrig.AddLast(t);
219 idOrig[nTrksOrig]=(UShort_t)track->GetID();
221 } // end loop on tracks
223 // call method that will reconstruct the vertex
224 FindPrimaryVertex(&trkArrayOrig,idOrig);
226 if(fMode==0) trkArrayOrig.Delete();
227 delete [] idOrig; idOrig=NULL;
230 f->Close(); delete f; f = NULL;
231 gSystem->Unlink("VertexerTracks.root");
235 // set vertex ID for tracks used in the fit
238 Int_t nIndices = fCurrentVertex->GetNIndices();
239 UShort_t *indices = fCurrentVertex->GetIndices();
240 for(Int_t ind=0; ind<nIndices; ind++) {
241 AliESDtrack *esdt = (AliESDtrack*)vEvent->GetTrack(indices[ind]);
242 esdt->SetVertexID(-1);
246 return fCurrentVertex;
248 //----------------------------------------------------------------------------
249 AliESDVertex* AliVertexerTracks::FindPrimaryVertex(const TObjArray *trkArrayOrig,
253 // Primary vertex using the AliExternalTrackParam's in the TObjArray.
254 // idOrig must contain the track IDs from AliESDtrack::GetID()
256 // 1st with 5*fNSigma*sigma cut w.r.t. to initial vertex
257 // + cut on sqrt(d0d0+z0z0) if fConstraint=kFALSE
258 // 2nd with fNSigma*sigma cut w.r.t. to vertex found in 1st iteration)
262 // accept 1-track case only if constraint is available
263 if(!fConstraint && fMinTracks==1) fMinTracks=2;
265 // read tracks from array
266 Int_t nTrksOrig = (Int_t)trkArrayOrig->GetEntriesFast();
267 AliDebug(1,Form("Initial number of tracks: %d",nTrksOrig));
268 if(nTrksOrig<fMinTracks) {
269 AliDebug(1,"TooFewTracks");
271 return fCurrentVertex;
274 // If fConstraint=kFALSE
275 // run VertexFinder(1) to get rough estimate of initVertex (x,y)
277 // fill fTrkArraySel, for VertexFinder()
278 fIdSel = new UShort_t[nTrksOrig];
279 PrepareTracks(*trkArrayOrig,idOrig,0);
280 if(fIdSel) { delete [] fIdSel; fIdSel=NULL; }
281 Double_t cutsave = fDCAcut;
282 fDCAcut = fDCAcutIter0;
284 switch (fAlgoIter0) {
285 case 1: StrLinVertexFinderMinDist(1); break;
286 case 2: StrLinVertexFinderMinDist(0); break;
287 case 3: HelixVertexFinder(); break;
288 case 4: VertexFinder(1); break;
289 case 5: VertexFinder(0); break;
290 default: printf("Wrong algorithm\n"); break;
293 if(fVert.GetNContributors()>0) {
294 fVert.GetXYZ(fNominalPos);
295 fNominalPos[0] = fVert.GetXv();
296 fNominalPos[1] = fVert.GetYv();
297 fNominalPos[2] = fVert.GetZv();
298 AliDebug(1,Form("No mean vertex: VertexFinder gives (%f, %f, %f)",fNominalPos[0],fNominalPos[1],fNominalPos[2]));
303 AliDebug(1,"No mean vertex and VertexFinder failed");
310 // propagate tracks to fNominalPos vertex
312 // if(constraint) reject for |d0|>5*fNSigma*sigma w.r.t. fNominal... vertex
313 // else reject for |d0|\oplus|z0| > 5 mm w.r.t. fNominal... vertex
315 // propagate tracks to best between initVertex and fCurrentVertex
316 // preselect tracks (reject for |d0|>fNSigma*sigma w.r.t. best
317 // between initVertex and fCurrentVertex)
318 for(Int_t iter=1; iter<=2; iter++) {
319 if(fOnlyFitter && iter==1) continue;
320 if(fIdSel) { delete [] fIdSel; fIdSel=NULL; }
321 fIdSel = new UShort_t[nTrksOrig];
322 Int_t nTrksSel = PrepareTracks(*trkArrayOrig,idOrig,iter);
323 AliDebug(1,Form("N tracks selected in iteration %d: %d",iter,nTrksSel));
324 if(nTrksSel < fMinTracks) {
326 return fCurrentVertex;
332 AliDebug(1,"Just one track");
333 OneTrackVertFinder();
336 case 1: StrLinVertexFinderMinDist(1); break;
337 case 2: StrLinVertexFinderMinDist(0); break;
338 case 3: HelixVertexFinder(); break;
339 case 4: VertexFinder(1); break;
340 case 5: VertexFinder(0); break;
341 default: printf("Wrong algorithm"); break;
344 AliDebug(1," Vertex finding completed");
349 } // end loop on the two iterations
352 // set indices of used tracks
353 UShort_t *indices = 0;
354 if(fCurrentVertex->GetNContributors()>0) {
355 Int_t nIndices = (Int_t)fTrkArraySel.GetEntriesFast();
356 indices = new UShort_t[nIndices];
357 for(Int_t jj=0; jj<nIndices; jj++)
358 indices[jj] = fIdSel[jj];
359 fCurrentVertex->SetIndices(nIndices,indices);
361 if (indices) {delete [] indices; indices=NULL;}
365 TString title="VertexerTracksNoConstraint";
367 title="VertexerTracksWithConstraint";
368 if(fOnlyFitter) title.Append("OnlyFitter");
370 fCurrentVertex->SetTitle(title.Data());
373 AliDebug(1,Form("xyz: %f %f %f; nc %d",fCurrentVertex->GetXv(),fCurrentVertex->GetYv(),fCurrentVertex->GetZv(),fCurrentVertex->GetNContributors()));
376 delete [] fIdSel; fIdSel=NULL;
377 fTrkArraySel.Delete();
378 if(fTrksToSkip) { delete [] fTrksToSkip; fTrksToSkip=NULL; }
381 return fCurrentVertex;
383 //------------------------------------------------------------------------
384 Double_t AliVertexerTracks::GetDeterminant3X3(Double_t matr[][3])
387 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];
390 //-------------------------------------------------------------------------
391 void AliVertexerTracks::GetStrLinDerivMatrix(const Double_t *p0,const Double_t *p1,Double_t (*m)[3],Double_t *d)
394 Double_t x12=p0[0]-p1[0];
395 Double_t y12=p0[1]-p1[1];
396 Double_t z12=p0[2]-p1[2];
397 Double_t kk=x12*x12+y12*y12+z12*z12;
398 m[0][0]=2-2/kk*x12*x12;
399 m[0][1]=-2/kk*x12*y12;
400 m[0][2]=-2/kk*x12*z12;
401 m[1][0]=-2/kk*x12*y12;
402 m[1][1]=2-2/kk*y12*y12;
403 m[1][2]=-2/kk*y12*z12;
404 m[2][0]=-2/kk*x12*z12;
406 m[2][2]=2-2/kk*z12*z12;
407 d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12;
408 d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12;
409 d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12;
412 //--------------------------------------------------------------------------
413 void AliVertexerTracks::GetStrLinDerivMatrix(const Double_t *p0,const Double_t *p1,const Double_t *sigmasq,Double_t (*m)[3],Double_t *d)
416 Double_t x12=p1[0]-p0[0];
417 Double_t y12=p1[1]-p0[1];
418 Double_t z12=p1[2]-p0[2];
420 Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1];
422 Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]);
425 cc[0]=-x12/sigmasq[0];
426 cc[1]=-y12/sigmasq[1];
427 cc[2]=-z12/sigmasq[2];
429 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;
431 Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2];
434 aa[0]=x12*sigmasq[1]*sigmasq[2]/den;
435 aa[1]=y12*sigmasq[0]*sigmasq[2]/den;
436 aa[2]=z12*sigmasq[0]*sigmasq[1]/den;
438 m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0];
439 m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0];
440 m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0];
442 m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1];
443 m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1];
444 m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1];
446 m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2];
447 m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2];
448 m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2];
450 d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0];
451 d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1];
452 d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2];
455 //--------------------------------------------------------------------------
456 Double_t AliVertexerTracks::GetStrLinMinDist(const Double_t *p0,const Double_t *p1,const Double_t *x0)
459 Double_t x12=p0[0]-p1[0];
460 Double_t y12=p0[1]-p1[1];
461 Double_t z12=p0[2]-p1[2];
462 Double_t x10=p0[0]-x0[0];
463 Double_t y10=p0[1]-x0[1];
464 Double_t z10=p0[2]-x0[2];
465 // 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);
466 return ((y10*z12-z10*y12)*(y10*z12-z10*y12)+
467 (z10*x12-x10*z12)*(z10*x12-x10*z12)+
468 (x10*y12-y10*x12)*(x10*y12-y10*x12))
469 /(x12*x12+y12*y12+z12*z12);
471 //---------------------------------------------------------------------------
472 void AliVertexerTracks::OneTrackVertFinder()
474 // find vertex for events with 1 track, using DCA to nominal beam axis
475 AliDebug(1,Form("Number of prepared tracks =%d - Call OneTrackVertFinder",fTrkArraySel.GetEntries()));
476 AliExternalTrackParam *track1;
477 track1 = (AliExternalTrackParam*)fTrkArraySel.At(0);
478 Double_t alpha=track1->GetAlpha();
479 Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
480 Double_t pos[3],dir[3];
481 track1->GetXYZAt(mindist,GetFieldkG(),pos);
482 track1->GetPxPyPzAt(mindist,GetFieldkG(),dir);
483 AliStrLine *line1 = new AliStrLine(pos,dir);
484 Double_t p1[3]={fNominalPos[0],fNominalPos[1],0.};
485 Double_t p2[3]={fNominalPos[0],fNominalPos[1],10.};
486 AliStrLine *zeta=new AliStrLine(p1,p2,kTRUE);
487 Double_t crosspoint[3]={0.,0.,0.};
490 Int_t retcode = zeta->Cross(line1,crosspoint);
492 sigma=line1->GetDistFromPoint(crosspoint);
497 fVert.SetXYZ(crosspoint);
498 fVert.SetDispersion(sigma);
499 fVert.SetNContributors(nContrib);
501 //---------------------------------------------------------------------------
502 void AliVertexerTracks::HelixVertexFinder()
504 // Get estimate of vertex position in (x,y) from tracks DCA
509 for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
511 Int_t nacc = (Int_t)fTrkArraySel.GetEntriesFast();
513 Double_t aver[3]={0.,0.,0.};
514 Double_t averquad[3]={0.,0.,0.};
515 Double_t sigmaquad[3]={0.,0.,0.};
518 AliExternalTrackParam *track1;
519 AliExternalTrackParam *track2;
522 Double_t alpha, cs, sn;
523 Double_t crosspoint[3];
524 for(Int_t i=0; i<nacc; i++){
525 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
528 for(Int_t j=i+1; j<nacc; j++){
529 track2 = (AliExternalTrackParam*)fTrkArraySel.At(j);
531 distCA=track2->PropagateToDCA(track1,GetFieldkG());
532 if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){
534 alpha=track1->GetAlpha();
535 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
536 Double_t x1=x*cs - track1->GetY()*sn;
537 Double_t y1=x*sn + track1->GetY()*cs;
538 Double_t z1=track1->GetZ();
540 Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
542 alpha=track2->GetAlpha();
543 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
544 Double_t x2=x*cs - track2->GetY()*sn;
545 Double_t y2=x*sn + track2->GetY()*cs;
546 Double_t z2=track2->GetZ();
547 Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
548 Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
549 Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
550 Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
551 Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
552 crosspoint[0]=wx1*x1 + wx2*x2;
553 crosspoint[1]=wy1*y1 + wy2*y2;
554 crosspoint[2]=wz1*z1 + wz2*z2;
557 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
558 for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]);
564 for(Int_t jj=0;jj<3;jj++){
565 initPos[jj] = aver[jj]/ncombi;
566 averquad[jj]/=ncombi;
567 sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj];
568 sigma+=sigmaquad[jj];
570 sigma=TMath::Sqrt(TMath::Abs(sigma));
573 Warning("HelixVertexFinder","Finder did not succed");
576 fVert.SetXYZ(initPos);
577 fVert.SetDispersion(sigma);
578 fVert.SetNContributors(ncombi);
580 //----------------------------------------------------------------------------
581 Int_t AliVertexerTracks::PrepareTracks(const TObjArray &trkArrayOrig,
582 const UShort_t *idOrig,
586 // Propagate tracks to initial vertex position and store them in a TObjArray
588 AliDebug(1," PrepareTracks()");
590 Int_t nTrksOrig = (Int_t)trkArrayOrig.GetEntriesFast();
593 Double_t sigmaCurr[3];
594 Double_t normdistx,normdisty;
595 Double_t d0z0[2],covd0z0[3];
598 AliESDVertex *initVertex = new AliESDVertex(fNominalPos,fNominalCov,1,1);
600 if(!fTrkArraySel.IsEmpty()) fTrkArraySel.Delete();
602 AliExternalTrackParam *track=0;
605 for(Int_t i=0; i<nTrksOrig; i++) {
606 AliExternalTrackParam *trackOrig=(AliExternalTrackParam*)trkArrayOrig.At(i);
607 if(trackOrig->Charge()!=0) { // normal tracks
608 track = new AliExternalTrackParam(*(AliExternalTrackParam*)trkArrayOrig.At(i));
609 } else { // neutral tracks (from a V0)
610 track = new AliNeutralTrackParam(*(AliNeutralTrackParam*)trkArrayOrig.At(i));
614 if(TMath::Abs(track->GetTgl())>fMaxTgl) {
615 AliDebug(1,Form(" rejecting track with tgl = %f",track->GetTgl()));
616 delete track; continue;
619 Bool_t propagateOK = kFALSE, cutond0z0 = kTRUE;
620 // propagate track to vertex
621 if(optImpParCut<2 || fOnlyFitter) { // optImpParCut==1 or 0
622 propagateOK = track->PropagateToDCA(initVertex,GetFieldkG(),100.,d0z0,covd0z0);
623 } else { // optImpParCut==2
624 fCurrentVertex->GetSigmaXYZ(sigmaCurr);
625 normdistx = TMath::Abs(fCurrentVertex->GetXv()-fNominalPos[0])/TMath::Sqrt(sigmaCurr[0]*sigmaCurr[0]+fNominalCov[0]);
626 normdisty = TMath::Abs(fCurrentVertex->GetYv()-fNominalPos[1])/TMath::Sqrt(sigmaCurr[1]*sigmaCurr[1]+fNominalCov[2]);
627 AliDebug(1,Form("normdistx %f %f %f",fCurrentVertex->GetXv(),fNominalPos[0],TMath::Sqrt(sigmaCurr[0]*sigmaCurr[0]+fNominalCov[0])));
628 AliDebug(1,Form("normdisty %f %f %f",fCurrentVertex->GetYv(),fNominalPos[1],TMath::Sqrt(sigmaCurr[1]*sigmaCurr[1]+fNominalCov[2])));
629 AliDebug(1,Form("sigmaCurr %f %f %f",sigmaCurr[0],sigmaCurr[1],TMath::Sqrt(fNominalCov[0])+TMath::Sqrt(fNominalCov[2])));
630 if(normdistx < 3. && normdisty < 3. &&
631 (sigmaCurr[0]+sigmaCurr[1])<(TMath::Sqrt(fNominalCov[0])+TMath::Sqrt(fNominalCov[2]))) {
632 propagateOK = track->PropagateToDCA(fCurrentVertex,GetFieldkG(),100.,d0z0,covd0z0);
634 propagateOK = track->PropagateToDCA(initVertex,GetFieldkG(),100.,d0z0,covd0z0);
635 if(fConstraint) cutond0z0=kFALSE;
640 AliDebug(1," rejected");
641 delete track; continue;
644 sigmad0 = TMath::Sqrt(covd0z0[0]);
645 maxd0rphi = fNSigma*sigmad0;
646 if(optImpParCut==1) maxd0rphi *= 5.;
647 maxd0rphi = TMath::Min(maxd0rphi,fFiducialR);
648 //sigmad0z0 = TMath::Sqrt(covd0z0[0]+covd0z0[2]);
650 AliDebug(1,Form("trk %d; id %d; |d0| = %f; d0 cut = %f; |z0| = %f; |d0|oplus|z0| = %f; d0z0 cut = %f",i,(Int_t)idOrig[i],TMath::Abs(d0z0[0]),maxd0rphi,TMath::Abs(d0z0[1]),TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1]),fMaxd0z0));
653 //---- track selection based on impact parameters ----//
655 // always reject tracks outside fiducial volume
656 if(TMath::Abs(d0z0[0])>fFiducialR || TMath::Abs(d0z0[1])>fFiducialZ) {
657 AliDebug(1," rejected");
658 delete track; continue;
661 // during iterations 1 and 2 , reject tracks with d0rphi > maxd0rphi
662 if(optImpParCut>0 && TMath::Abs(d0z0[0])>maxd0rphi) {
663 AliDebug(1," rejected");
664 delete track; continue;
667 // if fConstraint=kFALSE, during iterations 1 and 2 ||
668 // if fConstraint=kTRUE, during iteration 2,
669 // select tracks with d0oplusz0 < fMaxd0z0
670 if((!fConstraint && optImpParCut>0 && fVert.GetNContributors()>0) ||
671 ( fConstraint && optImpParCut==2 && cutond0z0)) {
673 TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1])>fMaxd0z0) {
674 AliDebug(1," rejected");
675 delete track; continue;
679 // track passed all selections
680 fTrkArraySel.AddLast(track);
681 fIdSel[nTrksSel] = idOrig[i];
683 } // end loop on tracks
689 //----------------------------------------------------------------------------
690 Bool_t AliVertexerTracks::PropagateTrackTo(AliExternalTrackParam *track,
692 //----------------------------------------------------------------
693 // COPIED from AliTracker
695 // Propagates the track to the plane X=xk (cm).
697 // Origin: Marian Ivanov, Marian.Ivanov@cern.ch
698 //----------------------------------------------------------------
700 const Double_t kEpsilon = 0.00001;
701 Double_t xpos = track->GetX();
702 Double_t dir = (xpos<xToGo) ? 1. : -1.;
703 Double_t maxStep = 5;
704 Double_t maxSnp = 0.8;
706 while ( (xToGo-xpos)*dir > kEpsilon){
707 Double_t step = dir*TMath::Min(TMath::Abs(xToGo-xpos), maxStep);
708 Double_t x = xpos+step;
709 Double_t xyz0[3],xyz1[3];
710 track->GetXYZ(xyz0); //starting global position
712 if(!track->GetXYZAt(x,GetFieldkG(),xyz1)) return kFALSE; // no prolongation
713 xyz1[2]+=kEpsilon; // waiting for bug correction in geo
715 if(TMath::Abs(track->GetSnpAt(x,GetFieldkG())) >= maxSnp) return kFALSE;
716 if(!track->PropagateTo(x,GetFieldkG())) return kFALSE;
718 if(TMath::Abs(track->GetSnp()) >= maxSnp) return kFALSE;
719 track->GetXYZ(xyz0); // global position
720 Double_t alphan = TMath::ATan2(xyz0[1], xyz0[0]);
722 Double_t ca=TMath::Cos(alphan-track->GetAlpha()),
723 sa=TMath::Sin(alphan-track->GetAlpha());
724 Double_t sf=track->GetSnp(), cf=TMath::Sqrt((1.-sf)*(1.+sf));
725 Double_t sinNew = sf*ca - cf*sa;
726 if(TMath::Abs(sinNew) >= maxSnp) return kFALSE;
727 if(!track->Rotate(alphan)) return kFALSE;
729 xpos = track->GetX();
733 //---------------------------------------------------------------------------
734 AliESDVertex* AliVertexerTracks::RemoveTracksFromVertex(AliESDVertex *inVtx,
735 const TObjArray *trkArray,
737 const Float_t *diamondxy) const
740 // Removes tracks in trksTree from fit of inVtx
743 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraint")) {
744 printf("ERROR: primary vertex has no constraint: cannot remove tracks");
747 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraintOnlyFitter"))
748 printf("WARNING: result of tracks' removal will be only approximately correct");
751 rv(0,0) = inVtx->GetXv();
752 rv(1,0) = inVtx->GetYv();
753 rv(2,0) = inVtx->GetZv();
756 inVtx->GetCovMatrix(cov);
758 vV(0,1) = cov[1]; vV(1,0) = cov[1];
760 vV(0,2) = cov[3]; vV(2,0) = cov[3];
761 vV(1,2) = cov[4]; vV(2,1) = cov[4];
764 TMatrixD sumWi(TMatrixD::kInverted,vV);
765 TMatrixD sumWiri(sumWi,TMatrixD::kMult,rv);
767 Int_t nUsedTrks = inVtx->GetNIndices();
768 Double_t chi2 = inVtx->GetChi2();
770 AliExternalTrackParam *track = 0;
771 Int_t ntrks = (Int_t)trkArray->GetEntriesFast();
772 for(Int_t i=0;i<ntrks;i++) {
773 track = (AliExternalTrackParam*)trkArray->At(i);
774 if(!inVtx->UsesTrack(id[i])) {
775 printf("track %d was not used in vertex fit",id[i]);
778 Double_t alpha = track->GetAlpha();
779 Double_t xl = diamondxy[0]*TMath::Cos(alpha)+diamondxy[1]*TMath::Sin(alpha);
780 track->PropagateTo(xl,GetFieldkG());
781 // vector of track global coordinates
783 // covariance matrix of ri
786 // get space point from track
787 if(!TrackToPoint(track,ri,wWi)) continue;
789 TMatrixD wWiri(wWi,TMatrixD::kMult,ri);
794 // track contribution to chi2
795 TMatrixD deltar = rv; deltar -= ri;
796 TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar);
797 Double_t chi2i = deltar(0,0)*wWideltar(0,0)+
798 deltar(1,0)*wWideltar(1,0)+
799 deltar(2,0)*wWideltar(2,0);
800 // remove from total chi2
805 printf("Trying to remove too many tracks!");
813 // new inverted of weights matrix
814 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
816 // new position of primary vertex
817 rvnew.Mult(vVnew,sumWiri);
819 Double_t position[3];
820 position[0] = rvnew(0,0);
821 position[1] = rvnew(1,0);
822 position[2] = rvnew(2,0);
830 // store data in the vertex object
831 AliESDVertex *outVtx = new AliESDVertex(position,cov,chi2,nUsedTrks+1); // the +1 is for the constraint
832 outVtx->SetTitle(inVtx->GetTitle());
833 UShort_t *inindices = inVtx->GetIndices();
834 Int_t nIndices = nUsedTrks;
835 UShort_t *outindices = new UShort_t[nIndices];
837 for(Int_t k=0; k<inVtx->GetNIndices(); k++) {
838 Bool_t copyindex=kTRUE;
839 for(Int_t l=0; l<ntrks; l++) {
840 if(inindices[k]==id[l]) copyindex=kFALSE;
843 outindices[j] = inindices[k]; j++;
846 outVtx->SetIndices(nIndices,outindices);
847 if (outindices) delete [] outindices;
850 printf("Vertex before removing tracks:");
851 inVtx->PrintStatus();
852 inVtx->PrintIndices();
853 printf("Vertex after removing tracks:");
854 outVtx->PrintStatus();
855 outVtx->PrintIndices();
860 //---------------------------------------------------------------------------
861 AliESDVertex* AliVertexerTracks::RemoveConstraintFromVertex(AliESDVertex *inVtx,
863 Float_t *diamondcov) const
866 // Removes diamond constraint from fit of inVtx
869 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraint")) {
870 printf("ERROR: primary vertex has no constraint: cannot remove it\n");
873 if(inVtx->GetNContributors()<3) {
874 printf("ERROR: primary vertex has less than 2 tracks: cannot remove contraint\n");
878 // diamond constraint
880 vVb(0,0) = diamondcov[0];
881 vVb(0,1) = diamondcov[1];
883 vVb(1,0) = diamondcov[1];
884 vVb(1,1) = diamondcov[2];
888 vVb(2,2) = diamondcov[5];
889 TMatrixD vVbInv(TMatrixD::kInverted,vVb);
891 rb(0,0) = diamondxyz[0];
892 rb(1,0) = diamondxyz[1];
893 rb(2,0) = diamondxyz[2];
894 TMatrixD vVbInvrb(vVbInv,TMatrixD::kMult,rb);
898 rv(0,0) = inVtx->GetXv();
899 rv(1,0) = inVtx->GetYv();
900 rv(2,0) = inVtx->GetZv();
903 inVtx->GetCovMatrix(cov);
905 vV(0,1) = cov[1]; vV(1,0) = cov[1];
907 vV(0,2) = cov[3]; vV(2,0) = cov[3];
908 vV(1,2) = cov[4]; vV(2,1) = cov[4];
910 TMatrixD vVInv(TMatrixD::kInverted,vV);
911 TMatrixD vVInvrv(vVInv,TMatrixD::kMult,rv);
914 TMatrixD sumWi = vVInv - vVbInv;
917 TMatrixD sumWiri = vVInvrv - vVbInvrb;
922 // new inverted of weights matrix
923 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
925 // new position of primary vertex
926 rvnew.Mult(vVnew,sumWiri);
928 Double_t position[3];
929 position[0] = rvnew(0,0);
930 position[1] = rvnew(1,0);
931 position[2] = rvnew(2,0);
940 Double_t chi2 = inVtx->GetChi2();
942 // diamond constribution to chi2
943 TMatrixD deltar = rv; deltar -= rb;
944 TMatrixD vVbInvdeltar(vVbInv,TMatrixD::kMult,deltar);
945 Double_t chi2b = deltar(0,0)*vVbInvdeltar(0,0)+
946 deltar(1,0)*vVbInvdeltar(1,0)+
947 deltar(2,0)*vVbInvdeltar(2,0);
948 // remove from total chi2
951 // store data in the vertex object
952 AliESDVertex *outVtx = new AliESDVertex(position,cov,chi2,inVtx->GetNContributors()-1);
953 outVtx->SetTitle("VertexerTracksNoConstraint");
954 UShort_t *inindices = inVtx->GetIndices();
955 Int_t nIndices = inVtx->GetNIndices();
956 outVtx->SetIndices(nIndices,inindices);
960 //---------------------------------------------------------------------------
961 void AliVertexerTracks::SetCuts(Double_t *cuts)
967 SetDCAcutIter0(cuts[1]);
969 if(fMode==0 && cuts[3]<0) SetITSrefitNotRequired();
970 SetMinClusters((Int_t)(TMath::Abs(cuts[3])));
971 SetMinTracks((Int_t)(cuts[4]));
972 SetNSigmad0(cuts[5]);
973 SetMinDetFitter(cuts[6]);
975 SetFiducialRZ(cuts[8],cuts[9]);
976 fAlgo=(Int_t)(cuts[10]);
977 fAlgoIter0=(Int_t)(cuts[11]);
981 //---------------------------------------------------------------------------
982 void AliVertexerTracks::SetITSMode(Double_t dcacut,
983 Double_t dcacutIter0,
988 Double_t mindetfitter,
993 Int_t finderAlgoIter0)
996 // Cut values for ITS mode
1000 SetITSrefitRequired();
1002 SetITSrefitNotRequired();
1005 SetDCAcutIter0(dcacutIter0);
1006 SetMaxd0z0(maxd0z0);
1007 SetMinClusters(TMath::Abs(minCls));
1008 SetMinTracks(mintrks);
1009 SetNSigmad0(nsigma);
1010 SetMinDetFitter(mindetfitter);
1012 SetFiducialRZ(fidR,fidZ);
1014 fAlgoIter0=finderAlgoIter0;
1018 //---------------------------------------------------------------------------
1019 void AliVertexerTracks::SetTPCMode(Double_t dcacut,
1020 Double_t dcacutIter0,
1025 Double_t mindetfitter,
1030 Int_t finderAlgoIter0)
1033 // Cut values for TPC mode
1036 SetITSrefitNotRequired();
1038 SetDCAcutIter0(dcacutIter0);
1039 SetMaxd0z0(maxd0z0);
1040 SetMinClusters(minCls);
1041 SetMinTracks(mintrks);
1042 SetNSigmad0(nsigma);
1043 SetMinDetFitter(mindetfitter);
1045 SetFiducialRZ(fidR,fidZ);
1047 fAlgoIter0=finderAlgoIter0;
1051 //---------------------------------------------------------------------------
1052 void AliVertexerTracks::SetSkipTracks(Int_t n,const Int_t *skipped)
1055 // Mark the tracks not to be used in the vertex reconstruction.
1056 // Tracks are identified by AliESDtrack::GetID()
1058 fNTrksToSkip = n; fTrksToSkip = new Int_t[n];
1059 for(Int_t i=0;i<n;i++) fTrksToSkip[i] = skipped[i];
1062 //---------------------------------------------------------------------------
1063 void AliVertexerTracks::SetVtxStart(AliESDVertex *vtx)
1066 // Set initial vertex knowledge
1068 vtx->GetXYZ(fNominalPos);
1069 vtx->GetCovMatrix(fNominalCov);
1073 //---------------------------------------------------------------------------
1074 void AliVertexerTracks::StrLinVertexFinderMinDist(Int_t optUseWeights)
1076 AliExternalTrackParam *track1;
1077 const Int_t knacc = (Int_t)fTrkArraySel.GetEntriesFast();
1078 AliStrLine **linarray = new AliStrLine* [knacc];
1079 for(Int_t i=0; i<knacc; i++){
1080 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
1081 Double_t alpha=track1->GetAlpha();
1082 Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1083 Double_t pos[3],dir[3],sigmasq[3];
1084 track1->GetXYZAt(mindist,GetFieldkG(),pos);
1085 track1->GetPxPyPzAt(mindist,GetFieldkG(),dir);
1086 sigmasq[0]=TMath::Sin(alpha)*TMath::Sin(alpha)*track1->GetSigmaY2();
1087 sigmasq[1]=TMath::Cos(alpha)*TMath::Cos(alpha)*track1->GetSigmaY2();
1088 sigmasq[2]=track1->GetSigmaZ2();
1091 if(!TrackToPoint(track1,ri,wWi)) {optUseWeights=kFALSE;printf("WARNING\n");}
1094 for(Int_t ia=0;ia<3;ia++){
1095 for(Int_t ib=0;ib<3;ib++){
1096 wmat[iel]=wWi(ia,ib);
1100 linarray[i] = new AliStrLine(pos,sigmasq,wmat,dir);
1102 fVert=TrackletVertexFinder(linarray,knacc,optUseWeights);
1103 for(Int_t i=0; i<knacc; i++) delete linarray[i];
1106 //---------------------------------------------------------------------------
1107 AliESDVertex AliVertexerTracks::TrackletVertexFinder(const TClonesArray *lines, Int_t optUseWeights)
1109 // Calculate the point at minimum distance to prepared tracks (TClonesArray)
1110 const Int_t knacc = (Int_t)lines->GetEntriesFast();
1111 AliStrLine** lines2 = new AliStrLine* [knacc];
1112 for(Int_t i=0; i<knacc; i++){
1113 lines2[i]= (AliStrLine*)lines->At(i);
1115 AliESDVertex vert = TrackletVertexFinder(lines2,knacc,optUseWeights);
1120 //---------------------------------------------------------------------------
1121 AliESDVertex AliVertexerTracks::TrackletVertexFinder(AliStrLine **lines, const Int_t knacc, Int_t optUseWeights)
1123 // Calculate the point at minimum distance to prepared tracks (array of AliStrLine)
1125 Double_t initPos[3]={0.,0.,0.};
1127 Double_t (*vectP0)[3]=new Double_t [knacc][3]();
1128 Double_t (*vectP1)[3]=new Double_t [knacc][3]();
1131 Double_t dsum[3]={0,0,0};
1132 TMatrixD sumWi(3,3);
1133 for(Int_t i=0;i<3;i++){
1134 for(Int_t j=0;j<3;j++){
1140 for(Int_t i=0; i<knacc; i++){
1141 AliStrLine *line1 = lines[i];
1142 Double_t p0[3],cd[3],sigmasq[3];
1144 if(!line1) { printf("ERROR %d %d\n",i,knacc); continue; }
1147 line1->GetSigma2P0(sigmasq);
1148 line1->GetWMatrix(wmat);
1151 for(Int_t ia=0;ia<3;ia++){
1152 for(Int_t ib=0;ib<3;ib++){
1153 wWi(ia,ib)=wmat[iel];
1160 Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]};
1168 Double_t matr[3][3];
1170 if(optUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow);
1171 else GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow);
1174 for(Int_t iii=0;iii<3;iii++){
1175 dsum[iii]+=dknow[iii];
1176 for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj];
1180 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
1181 Double_t covmatrix[6];
1182 covmatrix[0] = invsumWi(0,0);
1183 covmatrix[1] = invsumWi(0,1);
1184 covmatrix[2] = invsumWi(1,1);
1185 covmatrix[3] = invsumWi(0,2);
1186 covmatrix[4] = invsumWi(1,2);
1187 covmatrix[5] = invsumWi(2,2);
1189 Double_t vett[3][3];
1190 Double_t det=GetDeterminant3X3(sum);
1193 if(TMath::Abs(det) > kAlmost0){
1194 for(Int_t zz=0;zz<3;zz++){
1195 for(Int_t ww=0;ww<3;ww++){
1196 for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk];
1198 for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk];
1199 initPos[zz]=GetDeterminant3X3(vett)/det;
1203 for(Int_t i=0; i<knacc; i++){
1204 Double_t p0[3]={0,0,0},p1[3]={0,0,0};
1205 for(Int_t ii=0;ii<3;ii++){
1206 p0[ii]=vectP0[i][ii];
1207 p1[ii]=vectP1[i][ii];
1209 sigma+=GetStrLinMinDist(p0,p1,initPos);
1212 if(sigma>0.) {sigma=TMath::Sqrt(sigma);}else{sigma=999;}
1216 AliESDVertex theVert(initPos,covmatrix,99999.,knacc);
1217 theVert.SetDispersion(sigma);
1223 //---------------------------------------------------------------------------
1224 Bool_t AliVertexerTracks::TrackToPoint(AliExternalTrackParam *t,
1225 TMatrixD &ri,TMatrixD &wWi,
1226 Bool_t uUi3by3) const
1229 // Extract from the AliExternalTrackParam the global coordinates ri and covariance matrix
1230 // wWi of the space point that it represents (to be used in VertexFitter())
1234 Double_t rotAngle = t->GetAlpha();
1235 if(rotAngle<0.) rotAngle += 2.*TMath::Pi();
1236 Double_t cosRot = TMath::Cos(rotAngle);
1237 Double_t sinRot = TMath::Sin(rotAngle);
1239 ri(0,0) = t->GetX()*cosRot-t->GetY()*sinRot;
1240 ri(1,0) = t->GetX()*sinRot+t->GetY()*cosRot;
1241 ri(2,0) = t->GetZ();
1246 // matrix to go from global (x,y,z) to local (y,z);
1255 // covariance matrix of local (y,z) - inverted
1257 uUi(0,0) = t->GetSigmaY2();
1258 uUi(0,1) = t->GetSigmaZY();
1259 uUi(1,0) = t->GetSigmaZY();
1260 uUi(1,1) = t->GetSigmaZ2();
1262 //printf(" %f %f",uUi(0,0),uUi(0,1));
1263 //printf(" %f %f",uUi(1,0),uUi(1,1));
1265 if(uUi.Determinant() <= 0.) return kFALSE;
1266 TMatrixD uUiInv(TMatrixD::kInverted,uUi);
1268 // weights matrix: wWi = qQiT * uUiInv * qQi
1269 TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi);
1270 TMatrixD m(qQi,TMatrixD::kTransposeMult,uUiInvQi);
1273 if(fVert.GetNContributors()<1) AliFatal("Vertex from finder is empty");
1274 // matrix to go from global (x,y,z) to local (x,y,z);
1286 // covariance of fVert along the track
1287 Double_t p[3],pt,ptot;
1289 pt = TMath::Sqrt(p[0]*p[0]+p[1]*p[1]);
1290 ptot = TMath::Sqrt(pt*pt+p[2]*p[2]);
1291 Double_t cphi = p[0]/pt; //cos(phi)=px/pt
1292 Double_t sphi = p[1]/pt; //sin(phi)=py/pt
1293 Double_t clambda = pt/ptot; //cos(lambda)=pt/ptot
1294 Double_t slambda = p[2]/ptot; //sin(lambda)=pz/ptot
1295 Double_t covfVert[6];
1296 fVert.GetCovMatrix(covfVert);
1297 Double_t covfVertalongt =
1298 covfVert[0]*cphi*cphi*clambda*clambda
1299 +covfVert[1]*2.*cphi*sphi*clambda*clambda
1300 +covfVert[3]*2.*cphi*clambda*slambda
1301 +covfVert[2]*sphi*sphi*clambda*clambda
1302 +covfVert[4]*2.*sphi*clambda*slambda
1303 +covfVert[5]*slambda*slambda;
1304 // covariance matrix of local (x,y,z) - inverted
1306 uUi(0,0) = covfVertalongt * fnSigmaForUi00 * fnSigmaForUi00;
1307 AliDebug(1,Form("=====> sqrtUi00 cm %f",TMath::Sqrt(uUi(0,0))));
1311 uUi(1,1) = t->GetSigmaY2();
1312 uUi(1,2) = t->GetSigmaZY();
1314 uUi(2,1) = t->GetSigmaZY();
1315 uUi(2,2) = t->GetSigmaZ2();
1316 //printf(" Ui :\n");
1317 //printf(" %f %f\n",uUi(0,0),uUi(0,1));
1318 //printf(" %f %f\n",uUi(1,0),uUi(1,1));
1320 if(uUi.Determinant() <= 0.) return kFALSE;
1321 TMatrixD uUiInv(TMatrixD::kInverted,uUi);
1323 // weights matrix: wWi = qQiT * uUiInv * qQi
1324 TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi);
1325 TMatrixD m(qQi,TMatrixD::kTransposeMult,uUiInvQi);
1332 //---------------------------------------------------------------------------
1333 void AliVertexerTracks::TooFewTracks()
1336 // When the number of tracks is < fMinTracks,
1337 // deal with vertices not found and prepare to exit
1339 AliDebug(1,"TooFewTracks");
1341 Double_t pos[3],err[3];
1342 pos[0] = fNominalPos[0];
1343 err[0] = TMath::Sqrt(fNominalCov[0]);
1344 pos[1] = fNominalPos[1];
1345 err[1] = TMath::Sqrt(fNominalCov[2]);
1346 pos[2] = fNominalPos[2];
1347 err[2] = TMath::Sqrt(fNominalCov[5]);
1348 Int_t ncontr = (err[0]>1. ? -1 : -3);
1349 if(fCurrentVertex) { delete fCurrentVertex; fCurrentVertex=0; }
1350 fCurrentVertex = new AliESDVertex(pos,err);
1351 fCurrentVertex->SetNContributors(ncontr);
1354 fCurrentVertex->SetTitle("VertexerTracksWithConstraint");
1356 fCurrentVertex->SetTitle("VertexerTracksNoConstraint");
1359 if(!fTrkArraySel.IsEmpty()) fTrkArraySel.Delete();
1360 if(fIdSel) {delete [] fIdSel; fIdSel=NULL;}
1361 if(fTrksToSkip) {delete [] fTrksToSkip; fTrksToSkip=NULL;}
1365 //---------------------------------------------------------------------------
1366 void AliVertexerTracks::VertexFinder(Int_t optUseWeights)
1369 // Get estimate of vertex position in (x,y) from tracks DCA
1371 Double_t initPos[3];
1373 for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
1374 Int_t nacc = (Int_t)fTrkArraySel.GetEntriesFast();
1375 Double_t aver[3]={0.,0.,0.};
1376 Double_t aversq[3]={0.,0.,0.};
1377 Double_t sigmasq[3]={0.,0.,0.};
1380 AliExternalTrackParam *track1;
1381 AliExternalTrackParam *track2;
1382 Double_t pos[3],dir[3];
1383 Double_t alpha,mindist;
1385 for(Int_t i=0; i<nacc; i++){
1386 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
1387 alpha=track1->GetAlpha();
1388 mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1389 track1->GetXYZAt(mindist,GetFieldkG(),pos);
1390 track1->GetPxPyPzAt(mindist,GetFieldkG(),dir);
1391 AliStrLine *line1 = new AliStrLine(pos,dir);
1393 // AliStrLine *line1 = new AliStrLine();
1394 // track1->ApproximateHelixWithLine(mindist,GetFieldkG(),line1);
1396 for(Int_t j=i+1; j<nacc; j++){
1397 track2 = (AliExternalTrackParam*)fTrkArraySel.At(j);
1398 alpha=track2->GetAlpha();
1399 mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1400 track2->GetXYZAt(mindist,GetFieldkG(),pos);
1401 track2->GetPxPyPzAt(mindist,GetFieldkG(),dir);
1402 AliStrLine *line2 = new AliStrLine(pos,dir);
1403 // AliStrLine *line2 = new AliStrLine();
1404 // track2->ApproximateHelixWithLine(mindist,GetFieldkG(),line2);
1405 Double_t distCA=line2->GetDCA(line1);
1406 //printf("%d %d %f\n",i,j,distCA);
1407 if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){
1408 Double_t pnt1[3],pnt2[3],crosspoint[3];
1410 if(optUseWeights<=0){
1411 Int_t retcode = line2->Cross(line1,crosspoint);
1414 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
1415 for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
1418 if(optUseWeights>0){
1419 Int_t retcode = line1->CrossPoints(line2,pnt1,pnt2);
1422 alpha=track1->GetAlpha();
1423 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
1424 Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
1425 alpha=track2->GetAlpha();
1426 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
1427 Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
1428 Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
1429 Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
1430 Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
1431 Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
1432 crosspoint[0]=wx1*pnt1[0] + wx2*pnt2[0];
1433 crosspoint[1]=wy1*pnt1[1] + wy2*pnt2[1];
1434 crosspoint[2]=wz1*pnt1[2] + wz2*pnt2[2];
1437 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
1438 for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
1447 for(Int_t jj=0;jj<3;jj++){
1448 initPos[jj] = aver[jj]/ncombi;
1449 //printf("%f\n",initPos[jj]);
1451 sigmasq[jj]=aversq[jj]-initPos[jj]*initPos[jj];
1454 sigma=TMath::Sqrt(TMath::Abs(sigma));
1457 Warning("VertexFinder","Finder did not succed");
1460 fVert.SetXYZ(initPos);
1461 fVert.SetDispersion(sigma);
1462 fVert.SetNContributors(ncombi);
1464 //---------------------------------------------------------------------------
1465 void AliVertexerTracks::VertexFitter()
1468 // The optimal estimate of the vertex position is given by a "weighted
1469 // average of tracks positions".
1470 // Original method: V. Karimaki, CMS Note 97/0051
1472 Bool_t useConstraint = fConstraint;
1473 Double_t initPos[3];
1475 fVert.GetXYZ(initPos);
1477 initPos[0]=fNominalPos[0];
1478 initPos[1]=fNominalPos[1];
1479 initPos[2]=fNominalPos[2];
1482 Int_t nTrksSel = (Int_t)fTrkArraySel.GetEntries();
1483 if(nTrksSel==1) useConstraint=kTRUE;
1484 AliDebug(1,"--- VertexFitter(): start");
1485 AliDebug(1,Form(" Number of tracks in array: %d\n",nTrksSel));
1486 AliDebug(1,Form(" Minimum # tracks required in fit: %d\n",fMinTracks));
1487 AliDebug(1,Form(" Vertex position after finder: %f,%f,%f\n",initPos[0],initPos[1],initPos[2]));
1488 if(useConstraint) AliDebug(1,Form(" This vertex will be used in fit: (%f+-%f,%f+-%f)\n",fNominalPos[0],TMath::Sqrt(fNominalCov[0]),fNominalPos[1],TMath::Sqrt(fNominalCov[2])));
1490 // special treatment for few-tracks fits (e.g. secondary vertices)
1491 Bool_t uUi3by3 = kFALSE; if(nTrksSel<5 && !useConstraint) uUi3by3 = kTRUE;
1496 rv(0,0) = initPos[0];
1497 rv(1,0) = initPos[1];
1499 Double_t xlStart,alpha;
1501 Double_t chi2,chi2i,chi2b;
1502 AliExternalTrackParam *t = 0;
1505 // initial vertex covariance matrix
1507 vVb(0,0) = fNominalCov[0];
1508 vVb(0,1) = fNominalCov[1];
1510 vVb(1,0) = fNominalCov[1];
1511 vVb(1,1) = fNominalCov[2];
1515 vVb(2,2) = fNominalCov[5];
1516 TMatrixD vVbInv(TMatrixD::kInverted,vVb);
1518 rb(0,0) = fNominalPos[0];
1519 rb(1,0) = fNominalPos[1];
1520 rb(2,0) = fNominalPos[2];
1521 TMatrixD vVbInvrb(vVbInv,TMatrixD::kMult,rb);
1525 // 1st - estimate of vtx using all tracks
1526 // 2nd - estimate of global chi2
1527 for(step=0; step<2; step++) {
1528 AliDebug(1,Form(" step = %d\n",step));
1532 if(step==1) { initPos[0]=rv(0,0); initPos[0]=rv(1,0); }
1534 TMatrixD sumWiri(3,1);
1535 TMatrixD sumWi(3,3);
1536 for(i=0; i<3; i++) {
1538 for(j=0; j<3; j++) sumWi(j,i) = 0.;
1541 // mean vertex constraint
1544 sumWiri(i,0) += vVbInvrb(i,0);
1545 for(k=0;k<3;k++) sumWi(i,k) += vVbInv(i,k);
1548 TMatrixD deltar = rv; deltar -= rb;
1549 TMatrixD vVbInvdeltar(vVbInv,TMatrixD::kMult,deltar);
1550 chi2b = deltar(0,0)*vVbInvdeltar(0,0)+
1551 deltar(1,0)*vVbInvdeltar(1,0)+
1552 deltar(2,0)*vVbInvdeltar(2,0);
1557 for(k=0; k<nTrksSel; k++) {
1558 // get track from track array
1559 t = (AliExternalTrackParam*)fTrkArraySel.At(k);
1560 alpha = t->GetAlpha();
1561 xlStart = initPos[0]*TMath::Cos(alpha)+initPos[1]*TMath::Sin(alpha);
1562 // to vtxSeed (from finder)
1563 t->PropagateTo(xlStart,GetFieldkG());
1565 // vector of track global coordinates
1567 // covariance matrix of ri
1570 // get space point from track
1571 if(!TrackToPoint(t,ri,wWi,uUi3by3)) continue;
1572 TMatrixD wWiri(wWi,TMatrixD::kMult,ri);
1575 TMatrixD deltar = rv; deltar -= ri;
1576 TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar);
1577 chi2i = deltar(0,0)*wWideltar(0,0)+
1578 deltar(1,0)*wWideltar(1,0)+
1579 deltar(2,0)*wWideltar(2,0);
1581 // add to total chi2
1588 } // end loop on tracks
1590 if(nTrksUsed < fMinTracks) {
1595 Double_t determinant = sumWi.Determinant();
1596 if(determinant < fMinDetFitter) {
1597 AliDebug(1,Form("det(V) = %f (<%f)\n",determinant,fMinDetFitter));
1603 // inverted of weights matrix
1604 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
1606 // position of primary vertex
1607 rv.Mult(vV,sumWiri);
1609 } // end loop on the 2 steps
1616 Double_t position[3];
1617 position[0] = rv(0,0);
1618 position[1] = rv(1,0);
1619 position[2] = rv(2,0);
1620 Double_t covmatrix[6];
1621 covmatrix[0] = vV(0,0);
1622 covmatrix[1] = vV(0,1);
1623 covmatrix[2] = vV(1,1);
1624 covmatrix[3] = vV(0,2);
1625 covmatrix[4] = vV(1,2);
1626 covmatrix[5] = vV(2,2);
1628 // for correct chi2/ndf, count constraint as additional "track"
1629 if(fConstraint) nTrksUsed++;
1630 // store data in the vertex object
1631 if(fCurrentVertex) { delete fCurrentVertex; fCurrentVertex=0; }
1632 fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nTrksUsed);
1634 AliDebug(1," Vertex after fit:");
1635 AliDebug(1,Form("xyz: %f %f %f; nc %d",fCurrentVertex->GetXv(),fCurrentVertex->GetYv(),fCurrentVertex->GetZv(),fCurrentVertex->GetNContributors()));
1636 AliDebug(1,"--- VertexFitter(): finish\n");
1641 //----------------------------------------------------------------------------
1642 AliESDVertex* AliVertexerTracks::VertexForSelectedTracks(const TObjArray *trkArray,
1644 Bool_t optUseFitter,
1645 Bool_t optPropagate,
1646 Bool_t optUseDiamondConstraint)
1649 // Return vertex from tracks (AliExternalTrackParam) in array
1652 // set optUseDiamondConstraint=TRUE only if you are reconstructing the
1654 if(optUseDiamondConstraint) {
1660 // get tracks and propagate them to initial vertex position
1661 fIdSel = new UShort_t[(Int_t)trkArray->GetEntriesFast()];
1662 Int_t nTrksSel = PrepareTracks(*trkArray,id,0);
1663 if((!optUseDiamondConstraint && nTrksSel<TMath::Max(2,fMinTracks)) ||
1664 (optUseDiamondConstraint && nTrksSel<1)) {
1666 return fCurrentVertex;
1671 AliDebug(1,"Just one track");
1672 OneTrackVertFinder();
1675 case 1: StrLinVertexFinderMinDist(1); break;
1676 case 2: StrLinVertexFinderMinDist(0); break;
1677 case 3: HelixVertexFinder(); break;
1678 case 4: VertexFinder(1); break;
1679 case 5: VertexFinder(0); break;
1680 default: printf("Wrong algorithm\n"); break;
1683 AliDebug(1," Vertex finding completed\n");
1689 Double_t position[3]={fVert.GetXv(),fVert.GetYv(),fVert.GetZv()};
1690 Double_t covmatrix[6];
1691 fVert.GetCovMatrix(covmatrix);
1692 Double_t chi2=99999.;
1693 Int_t nTrksUsed=fVert.GetNContributors();
1694 fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nTrksUsed);
1696 fCurrentVertex->SetDispersion(fVert.GetDispersion());
1699 // set indices of used tracks and propagate track to found vertex
1700 UShort_t *indices = 0;
1701 Double_t d0z0[2],covd0z0[3];
1702 AliExternalTrackParam *t = 0;
1703 if(fCurrentVertex->GetNContributors()>0) {
1704 indices = new UShort_t[fTrkArraySel.GetEntriesFast()];
1705 for(Int_t jj=0; jj<(Int_t)fTrkArraySel.GetEntriesFast(); jj++) {
1706 indices[jj] = fIdSel[jj];
1707 t = (AliExternalTrackParam*)fTrkArraySel.At(jj);
1708 if(optPropagate && optUseFitter) {
1709 if(TMath::Sqrt(fCurrentVertex->GetXv()*fCurrentVertex->GetXv()+fCurrentVertex->GetYv()*fCurrentVertex->GetYv())<3.) {
1710 t->PropagateToDCA(fCurrentVertex,GetFieldkG(),100.,d0z0,covd0z0);
1711 AliDebug(1,Form("Track %d propagated to found vertex",jj));
1713 AliWarning("Found vertex outside beam pipe!");
1717 fCurrentVertex->SetIndices(fCurrentVertex->GetNContributors(),indices);
1721 if (indices) {delete [] indices; indices=NULL;}
1722 delete [] fIdSel; fIdSel=NULL;
1723 fTrkArraySel.Delete();
1725 return fCurrentVertex;
1727 //----------------------------------------------------------------------------
1728 AliESDVertex* AliVertexerTracks::VertexForSelectedESDTracks(TObjArray *trkArray,
1729 Bool_t optUseFitter,
1730 Bool_t optPropagate,
1731 Bool_t optUseDiamondConstraint)
1735 // Return vertex from array of ESD tracks
1738 Int_t nTrks = (Int_t)trkArray->GetEntriesFast();
1739 UShort_t *id = new UShort_t[nTrks];
1741 AliESDtrack *esdt = 0;
1742 for(Int_t i=0; i<nTrks; i++){
1743 esdt = (AliESDtrack*)trkArray->At(i);
1744 id[i] = (UShort_t)esdt->GetID();
1747 VertexForSelectedTracks(trkArray,id,optUseFitter,optPropagate,optUseDiamondConstraint);
1749 delete [] id; id=NULL;
1751 return fCurrentVertex;
1753 //--------------------------------------------------------------------------