//---- standard headers ----
#include <Riostream.h>
//---- Root headers --------
-#include <TKey.h>
#include <TFile.h>
#include <TTree.h>
#include <TMatrixD.h>
//---- AliRoot headers -----
-#include "AliStrLine.h"
-#include "AliITStrackV2.h"
#include "AliESDVertex.h"
#include "AliITSVertexerTracks.h"
#include "AliESD.h"
#include "AliESDtrack.h"
+#include "AliVertexerTracks.h"
ClassImp(AliITSVertexerTracks)
//
// Check if the conv. const. has been set
//
- AliITStrackV2 t;
- Double_t cc = t.GetConvConst();
- Double_t field = 100./0.299792458/cc;
+ Double_t field = AliTracker::GetBz(); // in kG
- if(field<0.1 || field>0.6) {
+ if(field<1 || field>6) {
printf("AliITSVertexerTracks::CheckField():\n ERROR: AliKalmanTrack::fConvConst not set\n Use AliKalmanTrack::SetConvConst() or AliITSVertexerTracks::SetField()\n");
return kFALSE;
}
FindPrimaryVertexForCurrentEvent(ev);
if(!fCurrentVertex) {
- printf("AliITSVertexerTracks::FindVertixes(): no tracks tree for event %d\n",ev);
+ printf("AliITSVertexerTracks::FindVertices(): no tracks tree for event %d\n",ev);
continue;
}
// Propagate tracks to initial vertex position and store them in a TObjArray
//
Double_t maxd0rphi = 3.;
+ Double_t alpha,xlStart,d0rphi;
Int_t nTrks = 0;
Bool_t skipThis;
- Double_t d0rphi;
Int_t nEntries = (Int_t)trkTree.GetEntries();
+ Double_t field=AliTracker::GetBz();
+
if(!fTrkArray.IsEmpty()) fTrkArray.Clear();
fTrkArray.Expand(nEntries);
printf(" PrepareTracks()\n");
trkTree.Print();
}
- cout<<" entr tree its tracks = "<<nEntries<<endl;
+
for(Int_t i=0; i<nEntries; i++) {
// check tracks to skip
skipThis = kFALSE;
}
if(skipThis) continue;
- AliITStrackV2 *itstrack = new AliITStrackV2;
- trkTree.SetBranchAddress("tracks",&itstrack);
+ AliESDtrack *track = new AliESDtrack;
+ trkTree.SetBranchAddress("tracks",&track);
trkTree.GetEvent(i);
- d0rphi=Prepare(itstrack);
- if(d0rphi> maxd0rphi) { if(fDebug)cout<<" !!!! d0rphi "<<d0rphi<<endl;continue; }
- fTrkArray.AddLast(itstrack);
-
- nTrks++;
- if(fDebug)cout<<" :-) nTrks, d0rphi "<<nTrks<<" "<<d0rphi<<endl;
-
- }
- if(fTrksToSkip) delete [] fTrksToSkip;
- return nTrks;
-}
-//----------------------------------------------------------------------------
-Int_t AliITSVertexerTracks::PrepareTracks(AliESD* esdEvent,Int_t nofCand, Int_t *trkPos) {
- //
- // Propagate tracks to initial vertex position and store them in a TObjArray
- //
- Int_t nTrks = 0;
- Double_t maxd0rphi = 3.;
- Double_t d0rphi;
+ // propagate track to vtxSeed
+ alpha = track->GetAlpha();
+ xlStart = fNominalPos[0]*TMath::Cos(alpha)+fNominalPos[1]*TMath::Sin(alpha);
+ track->PropagateTo(xlStart,field); // to vtxSeed
- if(!fTrkArray.IsEmpty()) fTrkArray.Clear();
- fTrkArray.Expand(100);
+ // select tracks with d0rphi < maxd0rphi
+ d0rphi = TMath::Abs(track->GetD(fNominalPos[0],fNominalPos[1],field));
+ if(d0rphi > maxd0rphi) { delete track; continue; }
- if(fDebug) {
- printf(" PrepareTracks()\n");
- }
- AliITStrackV2* itstrack;
-
- for(Int_t i=0; i<nofCand;i++){
- AliESDtrack *esdTrack = (AliESDtrack*)esdEvent->GetTrack(trkPos[i]);
- UInt_t status=esdTrack->GetStatus();
- if ((status&AliESDtrack::kTPCin)==0)continue;
- if ((status&AliESDtrack::kITSin)==0)continue;
- if ((status&AliESDtrack::kITSrefit)==0) continue;
-
- itstrack = new AliITStrackV2(*esdTrack);
- d0rphi=Prepare(itstrack);
- if(d0rphi> maxd0rphi) { if(fDebug)cout<<" !!!! d0rphi "<<d0rphi<<endl;continue; }
- Int_t nclus=itstrack->GetNumberOfClusters();
-
- if(nclus<6){delete itstrack;continue;}
- fTrkArray.AddLast(itstrack);
+ fTrkArray.AddLast(track);
nTrks++;
if(fDebug)cout<<" :-) nTrks, d0rphi "<<nTrks<<" "<<d0rphi<<endl;
- //delete itstrack;
+
}
-
-
if(fTrksToSkip) delete [] fTrksToSkip;
+
return nTrks;
-}
-//----------------------------------------------------------------------------
-Double_t AliITSVertexerTracks::Prepare(AliITStrackV2* itstrack){
-
- //
- Double_t alpha,xlStart,d0rphi;
- // propagate track to vtxSeed
- alpha = itstrack->GetAlpha();
- xlStart = fNominalPos[0]*TMath::Cos(alpha)+fNominalPos[1]*TMath::Sin(alpha);
- if(itstrack->GetX()>3.)itstrack->PropagateTo(3.,0.0023,65.19); // to beam pipe (0.8 mm of Be)
- itstrack->PropagateTo(xlStart,0.,0.);
- // select tracks with d0rphi < maxd0rphi
- d0rphi = TMath::Abs(itstrack->GetD(fNominalPos[0],fNominalPos[1]));
- return d0rphi;
-
-}
+}
//----------------------------------------------------------------------------
void AliITSVertexerTracks::PrintStatus() const {
//
// Print status
-//
- printf(" Initial position (%f,%f)\n",fNominalPos[0],fNominalPos[1]);
- printf(" Vertex position after vertex finder:\n");
- fSimpVert.Print();
+// printf(" Initial position (%f,%f)\n",fNominalPos[0],fNominalPos[1]);
printf(" Number of tracks in array: %d\n",(Int_t)fTrkArray.GetEntriesFast());
printf(" Minimum # tracks required in fit: %d\n",fMinTracks);
return;
}
//----------------------------------------------------------------------------
+AliVertex* AliITSVertexerTracks::VertexForSelectedTracks(AliESD *esdEvent,Int_t nofCand, Int_t *trkPos, Int_t opt){
+
+ //
+ // Computes the vertex for selected tracks
+ // trkPos=vector with track positions in ESD
+ //
+ Double_t vtx[3];
+ esdEvent->GetVertex()->GetXYZ(vtx);
+ TTree *trkTree = new TTree("TreeT","tracks");
+ AliESDtrack *esdTrack = 0;
+ trkTree->Branch("tracks","AliESDtrack",&esdTrack);
+ for(Int_t i=0; i<nofCand;i++){
+ esdTrack = (AliESDtrack*)esdEvent->GetTrack(trkPos[i]);
+
+ if(!esdTrack->GetStatus()&AliESDtrack::kTPCin) continue;
+ if(!esdTrack->GetStatus()&AliESDtrack::kITSin) continue;
+ if(!esdTrack->GetStatus()&AliESDtrack::kITSrefit) continue;
+
+ Int_t nclus=esdTrack->GetNcls(0); // check number of clusters in ITS
+ if(nclus<6) continue;
+ trkTree->Fill();
+ }
+ delete esdTrack;
+ Int_t nTrks = PrepareTracks(*trkTree);
+ //delete trkTree;// :-))
+ if(fDebug) printf(" tracks prepared: %d\n",nTrks);
+ if(nTrks < fMinTracks) {
+ printf("TooFewTracks\n");
+ AliVertex *theVert=new AliVertex();
+ theVert->SetDispersion(999);
+ theVert->SetNContributors(-5);
+ return theVert;
+ }
+
+ AliVertexerTracks *vertexer=new AliVertexerTracks(vtx[0],vtx[1]);
+ vertexer->SetFinderAlgorithm(opt);
+ AliVertex *theVert=(AliVertex*)vertexer->VertexForSelectedTracks(&fTrkArray);
+// beware: newvt object should be deleted by the caller
+ AliVertex *newvt = new AliVertex(*theVert);
+ delete vertexer;
+ return newvt;
+}
+//----------------------------------------------------------------------------
AliESDVertex* AliITSVertexerTracks::FindPrimaryVertexForCurrentEvent(Int_t evnumb) {
//
// Vertex for current event
fCurrentVertex = 0;
// get tree with tracks from input file
- TString treeName = "TreeT_ITS_";
- treeName += evnumb;
- TTree *trkTree=(TTree*)fInFile->Get(treeName.Data());
- if(!trkTree) return fCurrentVertex;
-
-
- // get tracks and propagate them to initial vertex position
- Int_t nTrks = PrepareTracks(*trkTree);
- delete trkTree;
- if(fDebug) printf(" tracks prepared: %d\n",nTrks);
- if(nTrks < fMinTracks) { TooFewTracks(); return fCurrentVertex; }
-
- // VERTEX FINDER
- VertexFinder();
-
- // VERTEX FITTER
- ComputeMaxChi2PerTrack(nTrks);
- VertexFitter();
- if(fDebug) printf(" vertex fit completed\n");
+ fInFile->cd();
+ TTree *esdTree = (TTree*)fInFile->Get("esdTree");
- return fCurrentVertex;
+ if(!esdTree) {
+ printf("AliITSVertexerTracks::FindPrimaryVertexForCurrentEvent(): no tree in file!\n");
+ return fCurrentVertex;
+ }
+ AliESD *esdEvent = new AliESD;
+ esdTree->SetBranchAddress("ESD",&esdEvent);
+ esdTree->GetEvent(evnumb);
+ return FindPrimaryVertexForCurrentEvent(esdEvent);
}
//----------------------------------------------------------------------------
AliESDVertex* AliITSVertexerTracks::FindPrimaryVertexForCurrentEvent(AliESD *esdEvent)
fCurrentVertex = 0;
Double_t vtx[3],cvtx[6];
- // put tracks reco in ITS in a tree
Int_t entr = (Int_t)esdEvent->GetNumberOfTracks();
- TTree *trkTree = new TTree("TreeT_ITS","its tracks");
- AliITStrackV2 *itstrack = 0;
- trkTree->Branch("tracks","AliITStrackV2",&itstrack,entr,0);
+ TTree *trkTree = new TTree("TreeT","tracks");
+ AliESDtrack *esdTrack = 0;
+ trkTree->Branch("tracks","AliESDtrack",&esdTrack);
for(Int_t i=0; i<entr; i++) {
- AliESDtrack *esdTrack = (AliESDtrack*)esdEvent->GetTrack(i);
- if(!esdTrack->GetStatus()&AliESDtrack::kITSin)
- { delete esdTrack; continue; }
- try {
- itstrack = new AliITStrackV2(*esdTrack);
- }
- catch (const Char_t *msg) {
- Warning("FindPrimaryVertexForCurrentEvent",msg);
- delete esdTrack;
- continue;
- }
-
+ esdTrack = (AliESDtrack*)esdEvent->GetTrack(i);
+ if(!esdTrack->GetStatus()&AliESDtrack::kITSin) continue;
trkTree->Fill();
- itstrack = 0;
- delete esdTrack;
}
- delete itstrack;
+ delete esdTrack;
// preselect tracks and propagate them to initial vertex position
Int_t nTrks = PrepareTracks(*trkTree);
// Set initial vertex position from ESD
esdEvent->GetVertex()->GetXYZ(vtx);
SetVtxStart(vtx[0],vtx[1]);
- // VERTEX FINDER
- VertexFinder();
// VERTEX FITTER
ComputeMaxChi2PerTrack(nTrks);
cout<<"Vertex: "<<vtx[0]<<", "<<vtx[1]<<", "<<vtx[2]<<endl;
return fCurrentVertex;
}
-//----------------------------------------------------------------------------
-AliVertex* AliITSVertexerTracks::VertexForSelectedTracks(AliESD *esdEvent,Int_t nofCand, Int_t *trkPos, Int_t opt){
-
- //
- // Computes the vertex for selected tracks
- // trkPos=vector with track positions in ESD
- // values of opt -> see AliITSVertexerTracks.h
- //
- Double_t vtx[3]={0,0,0};
-
- Int_t nTrks = PrepareTracks(esdEvent,nofCand, trkPos);
- //delete trkTree;// :-))
- if(fDebug) printf(" tracks prepared: %d\n",nTrks);
- if(nTrks < fMinTracks) {
- fSimpVert.SetXYZ(vtx);
- fSimpVert.SetDispersion(999);
- fSimpVert.SetNContributors(-5);
- return &fSimpVert;
- }
-
- // Set initial vertex position from ESD
- esdEvent->GetVertex()->GetXYZ(vtx);
- SetVtxStart(vtx[0],vtx[1]);
- if(opt==1) StrLinVertexFinderMinDist(1);
- if(opt==2) StrLinVertexFinderMinDist(0);
- if(opt==3) HelixVertexFinder();
- if(opt==4) VertexFinder(1);
- if(opt==5) VertexFinder(0);
- return &fSimpVert;
-}
-
//---------------------------------------------------------------------------
void AliITSVertexerTracks::SetSkipTracks(Int_t n,Int_t *skipped) {
//
return;
}
//---------------------------------------------------------------------------
-void AliITSVertexerTracks::VertexFinder(Int_t OptUseWeights) {
-
- // Get estimate of vertex position in (x,y) from tracks DCA
- // Then this estimate is stored to the data member fSimpVert
- // (previous values are overwritten)
-
-
- Double_t initPos[3];
- initPos[2] = 0.;
- for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
- Int_t nacc = (Int_t)fTrkArray.GetEntriesFast();
- Double_t aver[3]={0.,0.,0.};
- Double_t aversq[3]={0.,0.,0.};
- Double_t sigmasq[3]={0.,0.,0.};
- Double_t sigma=0;
- Int_t ncombi = 0;
- AliITStrackV2 *track1;
- AliITStrackV2 *track2;
- Double_t alpha,mindist;
-
- for(Int_t i=0; i<nacc; i++){
- track1 = (AliITStrackV2*)fTrkArray.At(i);
- alpha=track1->GetAlpha();
- mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
- AliStrLine *line1 = new AliStrLine();
- track1->ApproximateHelixWithLine(mindist,line1);
-
- if(fDebug>5){
- Double_t xv,par[5];
- track1->GetExternalParameters(xv,par);
- cout<<"Track in position "<<i<<" xr= "<<xv<<endl;
- for(Int_t ii=0;ii<5;ii++)cout<<par[ii]<<" ";
- cout<<endl;
- }
-
- for(Int_t j=i+1; j<nacc; j++){
- track2 = (AliITStrackV2*)fTrkArray.At(j);
- alpha=track2->GetAlpha();
- mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
- AliStrLine *line2 = new AliStrLine();
- track2->ApproximateHelixWithLine(mindist,line2);
- Double_t distCA=line2->GetDCA(line1);
- if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){
- Double_t pnt1[3],pnt2[3],crosspoint[3];
-
- if(OptUseWeights<=0){
- Int_t retcode = line2->Cross(line1,crosspoint);
- if(retcode<0){
- if(fDebug>10)cout<<" i= "<<i<<", j= "<<j<<endl;
- if(fDebug>10)cout<<"bad intersection\n";
- line1->PrintStatus();
- line2->PrintStatus();
- }
- else {
- ncombi++;
- for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
- for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
- if(fDebug>10)cout<<" i= "<<i<<", j= "<<j<<endl;
- if(fDebug>10)cout<<"\n Cross point: ";
- if(fDebug>10)cout<<crosspoint[0]<<" "<<crosspoint[1]<<" "<<crosspoint[2]<<endl;
- }
- }
- if(OptUseWeights>0){
- Int_t retcode = line1->CrossPoints(line2,pnt1,pnt2);
- if(retcode>=0){
- Double_t alpha, cs, sn;
- alpha=track1->GetAlpha();
- cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
- Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
- alpha=track2->GetAlpha();
- cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
- Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
- Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
- Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
- Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
- Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
- crosspoint[0]=wx1*pnt1[0] + wx2*pnt2[0];
- crosspoint[1]=wy1*pnt1[1] + wy2*pnt2[1];
- crosspoint[2]=wz1*pnt1[2] + wz2*pnt2[2];
-
- ncombi++;
- for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
- for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
- }
- }
- }
- delete line2;
- }
- delete line1;
- }
- if(ncombi>0){
- for(Int_t jj=0;jj<3;jj++){
- initPos[jj] = aver[jj]/ncombi;
- aversq[jj]/=ncombi;
- sigmasq[jj]=aversq[jj]-initPos[jj]*initPos[jj];
- sigma+=sigmasq[jj];
- }
- sigma=TMath::Sqrt(TMath::Abs(sigma));
- }
- else {
- Warning("VertexFinder","Finder did not succed");
- sigma=999;
- }
- fSimpVert.SetXYZ(initPos);
- fSimpVert.SetDispersion(sigma);
- fSimpVert.SetNContributors(ncombi);
-}
-//---------------------------------------------------------------------------
-void AliITSVertexerTracks::HelixVertexFinder() {
-
- // Get estimate of vertex position in (x,y) from tracks DCA
- // Then this estimate is stored to the data member fSimpVert
- // (previous values are overwritten)
-
-
- Double_t initPos[3];
- initPos[2] = 0.;
- for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
-
- Int_t nacc = (Int_t)fTrkArray.GetEntriesFast();
-
- Double_t aver[3]={0.,0.,0.};
- Double_t averquad[3]={0.,0.,0.};
- Double_t sigmaquad[3]={0.,0.,0.};
- Double_t sigma=0;
- Int_t ncombi = 0;
- AliITStrackV2 *track1;
- AliITStrackV2 *track2;
- Double_t distCA;
- Double_t x, par[5];
- Double_t alpha, cs, sn;
- Double_t crosspoint[3];
- for(Int_t i=0; i<nacc; i++){
- track1 = (AliITStrackV2*)fTrkArray.At(i);
-
-
- for(Int_t j=i+1; j<nacc; j++){
- track2 = (AliITStrackV2*)fTrkArray.At(j);
-
-
- distCA=track2->PropagateToDCA(track1);
-
- if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){
- track1->GetExternalParameters(x,par);
- alpha=track1->GetAlpha();
- cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
- Double_t x1=x*cs - par[0]*sn;
- Double_t y1=x*sn + par[0]*cs;
- Double_t z1=par[1];
- Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
-
- track2->GetExternalParameters(x,par);
- alpha=track2->GetAlpha();
- cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
- Double_t x2=x*cs - par[0]*sn;
- Double_t y2=x*sn + par[0]*cs;
- Double_t z2=par[1];
- Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
- // printf("Track %d pos=(%f,%f,%f) - dca=%f\n",i,x1,y1,z1,distCA);
- //printf("Track %d pos=(%f,%f,%f)\n",j,x2,y2,z2);
-
- Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
- Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
- Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
- Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
- crosspoint[0]=wx1*x1 + wx2*x2;
- crosspoint[1]=wy1*y1 + wy2*y2;
- crosspoint[2]=wz1*z1 + wz2*z2;
-
- ncombi++;
- for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
- for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]);
- }
- }
-
- }
- if(ncombi>0){
- for(Int_t jj=0;jj<3;jj++){
- initPos[jj] = aver[jj]/ncombi;
- averquad[jj]/=ncombi;
- sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj];
- sigma+=sigmaquad[jj];
- }
- sigma=TMath::Sqrt(TMath::Abs(sigma));
- }
- else {
- Warning("VertexFinder","Finder did not succed");
- sigma=999;
- }
- fSimpVert.SetXYZ(initPos);
- fSimpVert.SetDispersion(sigma);
- fSimpVert.SetNContributors(ncombi);
-}
-//---------------------------------------------------------------------------
-void AliITSVertexerTracks::StrLinVertexFinderMinDist(Int_t OptUseWeights){
-
- // Calculate the point at minimum distance to prepared tracks
- // Then this estimate is stored to the data member fSimpVert
- // (previous values are overwritten)
-
- Double_t initPos[3];
- initPos[2] = 0.;
- Double_t sigma=0;
- for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
- const Int_t knacc = (Int_t)fTrkArray.GetEntriesFast();
-
- AliITStrackV2 *track1;
- Double_t (*vectP0)[3]=new Double_t [knacc][3];
- Double_t (*vectP1)[3]=new Double_t [knacc][3];
-
- Double_t sum[3][3];
- Double_t dsum[3]={0,0,0};
- for(Int_t i=0;i<3;i++)
- for(Int_t j=0;j<3;j++)sum[i][j]=0;
- for(Int_t i=0; i<knacc; i++){
- track1 = (AliITStrackV2*)fTrkArray.At(i);
- Double_t alpha=track1->GetAlpha();
- Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
- AliStrLine *line1 = new AliStrLine();
- track1->ApproximateHelixWithLine(mindist,line1);
-
- Double_t p0[3],cd[3];
- line1->GetP0(p0);
- line1->GetCd(cd);
- Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]};
- vectP0[i][0]=p0[0];
- vectP0[i][1]=p0[1];
- vectP0[i][2]=p0[2];
- vectP1[i][0]=p1[0];
- vectP1[i][1]=p1[1];
- vectP1[i][2]=p1[2];
-
- Double_t matr[3][3];
- Double_t dknow[3];
- if(OptUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow);
- if(OptUseWeights==1){
- Double_t sigmasq[3];
- sigmasq[0]=track1->GetSigmaY2();
- sigmasq[1]=track1->GetSigmaY2();
- sigmasq[2]=track1->GetSigmaZ2();
- GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow);
- }
-
- for(Int_t iii=0;iii<3;iii++){
- dsum[iii]+=dknow[iii];
- for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj];
- }
- delete line1;
- }
-
- Double_t vett[3][3];
- Double_t det=GetDeterminant3X3(sum);
-
- if(det!=0){
- for(Int_t zz=0;zz<3;zz++){
- for(Int_t ww=0;ww<3;ww++){
- for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk];
- }
- for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk];
- initPos[zz]=GetDeterminant3X3(vett)/det;
- }
-
-
- for(Int_t i=0; i<knacc; i++){
- Double_t p0[3]={0,0,0},p1[3]={0,0,0};
- for(Int_t ii=0;ii<3;ii++){
- p0[ii]=vectP0[i][ii];
- p1[ii]=vectP1[i][ii];
- }
- sigma+=GetStrLinMinDist(p0,p1,initPos);
- }
-
- sigma=TMath::Sqrt(sigma);
- }else{
- Warning("VertexFinder","Finder did not succed");
- sigma=999;
- }
- delete vectP0;
- delete vectP1;
- fSimpVert.SetXYZ(initPos);
- fSimpVert.SetDispersion(sigma);
- fSimpVert.SetNContributors(knacc);
-}
-//_______________________________________________________________________
-Double_t AliITSVertexerTracks::GetDeterminant3X3(Double_t matr[][3]){
- //
- 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];
- return det;
-}
-//____________________________________________________________________________
-void AliITSVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t m[][3],Double_t *d){
-
- //
- Double_t x12=p0[0]-p1[0];
- Double_t y12=p0[1]-p1[1];
- Double_t z12=p0[2]-p1[2];
- Double_t kk=x12*x12+y12*y12+z12*z12;
- m[0][0]=2-2/kk*x12*x12;
- m[0][1]=-2/kk*x12*y12;
- m[0][2]=-2/kk*x12*z12;
- m[1][0]=-2/kk*x12*y12;
- m[1][1]=2-2/kk*y12*y12;
- m[1][2]=-2/kk*y12*z12;
- m[2][0]=-2/kk*x12*z12;
- m[2][1]=-2*y12*z12;
- m[2][2]=2-2/kk*z12*z12;
- d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12;
- d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12;
- d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12;
-
-}
-//____________________________________________________________________________
-void AliITSVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t m[][3],Double_t *d){
- //
- Double_t x12=p1[0]-p0[0];
- Double_t y12=p1[1]-p0[1];
- Double_t z12=p1[2]-p0[2];
-
- Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1];
-
- Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]);
-
- Double_t cc[3];
- cc[0]=-x12/sigmasq[0];
- cc[1]=-y12/sigmasq[1];
- cc[2]=-z12/sigmasq[2];
-
- 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;
-
- Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2];
-
- Double_t aa[3];
- aa[0]=x12*sigmasq[1]*sigmasq[2]/den;
- aa[1]=y12*sigmasq[0]*sigmasq[2]/den;
- aa[2]=z12*sigmasq[0]*sigmasq[1]/den;
-
- m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0];
- m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0];
- m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0];
-
- m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1];
- m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1];
- m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1];
-
- m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2];
- m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2];
- m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2];
-
- d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0];
- d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1];
- d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2];
-
-}
-//_____________________________________________________________________________
-Double_t AliITSVertexerTracks::GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0){
- //
- Double_t x12=p0[0]-p1[0];
- Double_t y12=p0[1]-p1[1];
- Double_t z12=p0[2]-p1[2];
- Double_t x10=p0[0]-x0[0];
- Double_t y10=p0[1]-x0[1];
- Double_t z10=p0[2]-x0[2];
- 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);
-
-}
-//---------------------------------------------------------------------------
void AliITSVertexerTracks::VertexFitter() {
//
// The optimal estimate of the vertex position is given by a "weighted
printf(" VertexFitter(): start\n");
PrintStatus();
}
+ AliVertexerTracks *vertexer=new AliVertexerTracks(fNominalPos[0],fNominalPos[1]);
+ vertexer->SetFinderAlgorithm(5);
+ AliVertex *thevert=(AliVertex*)vertexer->VertexForSelectedTracks(&fTrkArray);
+ Double_t initPos[3];
+ thevert->GetXYZ(initPos);
+ delete vertexer;
Int_t i,j,k,step=0;
TMatrixD rv(3,1);
TMatrixD vV(3,3);
- Double_t initPos[3];
- fSimpVert.GetXYZ(initPos);
rv(0,0) = initPos[0];
rv(1,0) = initPos[1];
rv(2,0) = 0.;
Int_t nUsedTrks;
Double_t chi2,chi2i;
Int_t arrEntries = (Int_t)fTrkArray.GetEntries();
- AliITStrackV2 *t = 0;
+ AliESDtrack *t = 0;
Int_t failed = 0;
Int_t *skipTrack = new Int_t[arrEntries];
for(k=0; k<arrEntries; k++) {
if(skipTrack[k]) continue;
// get track from track array
- t = (AliITStrackV2*)fTrkArray.At(k);
+ t = (AliESDtrack*)fTrkArray.At(k);
alpha = t->GetAlpha();
xlStart = initPos[0]*TMath::Cos(alpha)+initPos[1]*TMath::Sin(alpha);
- t->PropagateTo(xlStart,0.,0.); // to vtxSeed
+ t->PropagateTo(xlStart,AliTracker::GetBz()); // to vtxSeed
rotAngle = alpha;
if(alpha<0.) rotAngle += 2.*TMath::Pi();
cosRot = TMath::Cos(rotAngle);
if(fDebug) printf(" tracks prepared: %d\n",nTrks);
if(nTrks < fMinTracks) { TooFewTracks(); return fCurrentVertex; }
- // VERTEX FINDER
- VertexFinder();
-
// VERTEX FITTER
ComputeMaxChi2PerTrack(nTrks);
VertexFitter();
--- /dev/null
+/**************************************************************************
+ * Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
+ * *
+ * Author: The ALICE Off-line Project. *
+ * Contributors are mentioned in the code where appropriate. *
+ * *
+ * Permission to use, copy, modify and distribute this software and its *
+ * documentation strictly for non-commercial purposes is hereby granted *
+ * without fee, provided that the above copyright notice appears in all *
+ * copies and that both the copyright notice and this permission notice *
+ * appear in the supporting documentation. The authors make no claims *
+ * about the suitability of this software for any purpose. It is *
+ * provided "as is" without express or implied warranty. *
+ **************************************************************************/
+
+//-----------------------------------------------------------------
+// Implementation of the vertexer from ESD tracks
+//
+// Origin: AliITSVertexerTracks
+// A.Dainese, Padova,
+// andrea.dainese@pd.infn.it
+// M.Masera, Torino,
+// massimo.masera@to.infn.it
+// Moved to STEER and adapted to ESD tracks:
+// F.Prino, Torino, prino@to.infn.it
+//-----------------------------------------------------------------
+
+//---- Root headers --------
+#include <TTree.h>
+//---- AliRoot headers -----
+#include "AliStrLine.h"
+#include "AliVertexerTracks.h"
+#include "AliESDtrack.h"
+
+ClassImp(AliVertexerTracks)
+
+
+//----------------------------------------------------------------------------
+AliVertexerTracks::AliVertexerTracks():
+ TObject(),fVert()
+{
+//
+// Default constructor
+//
+ SetVtxStart();
+ SetMinTracks();
+ fDCAcut=0;
+ fAlgo=1;
+}
+//-----------------------------------------------------------------------------
+AliVertexerTracks::AliVertexerTracks(Double_t xStart, Double_t yStart):
+ TObject(),fVert()
+{
+//
+// Standard constructor
+//
+ SetVtxStart(xStart,yStart);
+ SetMinTracks();
+ fDCAcut=0;
+ fAlgo=1;
+}
+//-----------------------------------------------------------------------------
+AliVertexerTracks::~AliVertexerTracks() {
+ // Default Destructor
+ // The objects poited by the following pointers are not owned
+ // by this class and are not deleted
+}
+//----------------------------------------------------------------------------
+Int_t AliVertexerTracks::PrepareTracks(TTree &trkTree) {
+//
+// Propagate tracks to initial vertex position and store them in a TObjArray
+//
+ Double_t alpha,xlStart;
+ Int_t nTrks = 0;
+
+ Int_t nEntries = (Int_t)trkTree.GetEntries();
+ if(!fTrkArray.IsEmpty()) fTrkArray.Clear();
+ fTrkArray.Expand(nEntries);
+
+ for(Int_t i=0; i<nEntries; i++) {
+ AliESDtrack *track = new AliESDtrack;
+ trkTree.SetBranchAddress("tracks",&track);
+ trkTree.GetEvent(i);
+
+ // propagate track to vtxSeed
+ alpha = track->GetAlpha();
+ xlStart = fNominalPos[0]*TMath::Cos(alpha)+fNominalPos[1]*TMath::Sin(alpha);
+ track->PropagateTo(xlStart,GetField()); // to vtxSeed
+ fTrkArray.AddLast(track);
+ nTrks++;
+ }
+ return nTrks;
+}
+//----------------------------------------------------------------------------
+AliVertex* AliVertexerTracks::VertexForSelectedTracks(TTree *trkTree) {
+//
+// Return vertex from tracks in trkTree
+//
+
+ // get tracks and propagate them to initial vertex position
+ Int_t nTrks = PrepareTracks(*trkTree);
+ if(nTrks < fMinTracks) {
+ printf("TooFewTracks\n");
+ Double_t vtx[3]={0,0,0};
+ fVert.SetXYZ(vtx);
+ fVert.SetDispersion(999);
+ fVert.SetNContributors(-5);
+ return &fVert;
+ }
+
+ // Set initial vertex position from ESD
+ if(fAlgo==1) StrLinVertexFinderMinDist(1);
+ if(fAlgo==2) StrLinVertexFinderMinDist(0);
+ if(fAlgo==3) HelixVertexFinder();
+ if(fAlgo==4) VertexFinder(1);
+ if(fAlgo==5) VertexFinder(0);
+ return &fVert;
+}
+//----------------------------------------------------------------------------
+AliVertex* AliVertexerTracks::VertexForSelectedTracks(TObjArray *trkArray) {
+//
+// Return vertex from array of tracks
+//
+
+ // get tracks and propagate them to initial vertex position
+ Int_t nTrks = trkArray->GetEntriesFast();
+ if(nTrks < fMinTracks) {
+ printf("TooFewTracks\n");
+ Double_t vtx[3]={0,0,0};
+ fVert.SetXYZ(vtx);
+ fVert.SetDispersion(999);
+ fVert.SetNContributors(-5);
+ return &fVert;
+ }
+ TTree *trkTree = new TTree("TreeT","tracks");
+ AliESDtrack *esdTrack = 0;
+ trkTree->Branch("tracks","AliESDtrack",&esdTrack);
+ for(Int_t i=0; i<nTrks; i++){
+ esdTrack = (AliESDtrack*)trkArray->At(i);
+ trkTree->Fill();
+ }
+
+ return VertexForSelectedTracks(trkTree);
+}
+
+//---------------------------------------------------------------------------
+void AliVertexerTracks::VertexFinder(Int_t optUseWeights) {
+
+ // Get estimate of vertex position in (x,y) from tracks DCA
+
+ Double_t initPos[3];
+ initPos[2] = 0.;
+ for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
+ Int_t nacc = (Int_t)fTrkArray.GetEntriesFast();
+ Double_t aver[3]={0.,0.,0.};
+ Double_t aversq[3]={0.,0.,0.};
+ Double_t sigmasq[3]={0.,0.,0.};
+ Double_t sigma=0;
+ Int_t ncombi = 0;
+ AliESDtrack *track1;
+ AliESDtrack *track2;
+ Double_t alpha,mindist;
+ Double_t field=GetField();
+
+ for(Int_t i=0; i<nacc; i++){
+ track1 = (AliESDtrack*)fTrkArray.At(i);
+ alpha=track1->GetAlpha();
+ mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
+ AliStrLine *line1 = new AliStrLine();
+ track1->ApproximateHelixWithLine(mindist,field,line1);
+
+ for(Int_t j=i+1; j<nacc; j++){
+ track2 = (AliESDtrack*)fTrkArray.At(j);
+ alpha=track2->GetAlpha();
+ mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
+ AliStrLine *line2 = new AliStrLine();
+ track2->ApproximateHelixWithLine(mindist,field,line2);
+ Double_t distCA=line2->GetDCA(line1);
+ if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){
+ Double_t pnt1[3],pnt2[3],crosspoint[3];
+
+ if(optUseWeights<=0){
+ Int_t retcode = line2->Cross(line1,crosspoint);
+ if(retcode>=0){
+ ncombi++;
+ for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
+ for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
+ }
+ }
+ if(optUseWeights>0){
+ Int_t retcode = line1->CrossPoints(line2,pnt1,pnt2);
+ if(retcode>=0){
+ Double_t alpha, cs, sn;
+ alpha=track1->GetAlpha();
+ cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
+ Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
+ alpha=track2->GetAlpha();
+ cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
+ Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
+ Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
+ Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
+ Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
+ Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
+ crosspoint[0]=wx1*pnt1[0] + wx2*pnt2[0];
+ crosspoint[1]=wy1*pnt1[1] + wy2*pnt2[1];
+ crosspoint[2]=wz1*pnt1[2] + wz2*pnt2[2];
+
+ ncombi++;
+ for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
+ for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
+ }
+ }
+ }
+ delete line2;
+ }
+ delete line1;
+ }
+ if(ncombi>0){
+ for(Int_t jj=0;jj<3;jj++){
+ initPos[jj] = aver[jj]/ncombi;
+ aversq[jj]/=ncombi;
+ sigmasq[jj]=aversq[jj]-initPos[jj]*initPos[jj];
+ sigma+=sigmasq[jj];
+ }
+ sigma=TMath::Sqrt(TMath::Abs(sigma));
+ }
+ else {
+ Warning("VertexFinder","Finder did not succed");
+ sigma=999;
+ }
+ fVert.SetXYZ(initPos);
+ fVert.SetDispersion(sigma);
+ fVert.SetNContributors(ncombi);
+}
+//---------------------------------------------------------------------------
+void AliVertexerTracks::HelixVertexFinder() {
+
+ // Get estimate of vertex position in (x,y) from tracks DCA
+
+
+ Double_t initPos[3];
+ initPos[2] = 0.;
+ for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
+ Double_t field=GetField();
+
+ Int_t nacc = (Int_t)fTrkArray.GetEntriesFast();
+
+ Double_t aver[3]={0.,0.,0.};
+ Double_t averquad[3]={0.,0.,0.};
+ Double_t sigmaquad[3]={0.,0.,0.};
+ Double_t sigma=0;
+ Int_t ncombi = 0;
+ AliESDtrack *track1;
+ AliESDtrack *track2;
+ Double_t distCA;
+ Double_t x, par[5];
+ Double_t alpha, cs, sn;
+ Double_t crosspoint[3];
+ for(Int_t i=0; i<nacc; i++){
+ track1 = (AliESDtrack*)fTrkArray.At(i);
+
+
+ for(Int_t j=i+1; j<nacc; j++){
+ track2 = (AliESDtrack*)fTrkArray.At(j);
+
+ distCA=track2->PropagateToDCA(track1,field);
+
+ if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){
+ track1->GetExternalParameters(x,par);
+ alpha=track1->GetAlpha();
+ cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
+ Double_t x1=x*cs - par[0]*sn;
+ Double_t y1=x*sn + par[0]*cs;
+ Double_t z1=par[1];
+ Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
+ track2->GetExternalParameters(x,par);
+ alpha=track2->GetAlpha();
+ cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
+ Double_t x2=x*cs - par[0]*sn;
+ Double_t y2=x*sn + par[0]*cs;
+ Double_t z2=par[1];
+ Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
+ Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
+ Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
+ Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
+ Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
+ crosspoint[0]=wx1*x1 + wx2*x2;
+ crosspoint[1]=wy1*y1 + wy2*y2;
+ crosspoint[2]=wz1*z1 + wz2*z2;
+
+ ncombi++;
+ for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
+ for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]);
+ }
+ }
+
+ }
+ if(ncombi>0){
+ for(Int_t jj=0;jj<3;jj++){
+ initPos[jj] = aver[jj]/ncombi;
+ averquad[jj]/=ncombi;
+ sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj];
+ sigma+=sigmaquad[jj];
+ }
+ sigma=TMath::Sqrt(TMath::Abs(sigma));
+ }
+ else {
+ Warning("HelixVertexFinder","Finder did not succed");
+ sigma=999;
+ }
+ fVert.SetXYZ(initPos);
+ fVert.SetDispersion(sigma);
+ fVert.SetNContributors(ncombi);
+}
+//---------------------------------------------------------------------------
+void AliVertexerTracks::StrLinVertexFinderMinDist(Int_t optUseWeights){
+
+ // Calculate the point at minimum distance to prepared tracks
+
+ Double_t initPos[3];
+ initPos[2] = 0.;
+ Double_t sigma=0;
+ for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
+ const Int_t knacc = (Int_t)fTrkArray.GetEntriesFast();
+ Double_t field=GetField();
+
+ AliESDtrack *track1;
+ Double_t (*vectP0)[3]=new Double_t [knacc][3];
+ Double_t (*vectP1)[3]=new Double_t [knacc][3];
+
+ Double_t sum[3][3];
+ Double_t dsum[3]={0,0,0};
+ for(Int_t i=0;i<3;i++)
+ for(Int_t j=0;j<3;j++)sum[i][j]=0;
+ for(Int_t i=0; i<knacc; i++){
+ track1 = (AliESDtrack*)fTrkArray.At(i);
+ Double_t alpha=track1->GetAlpha();
+ Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
+ AliStrLine *line1 = new AliStrLine();
+ track1->ApproximateHelixWithLine(mindist,field,line1);
+
+ Double_t p0[3],cd[3];
+ line1->GetP0(p0);
+ line1->GetCd(cd);
+ Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]};
+ vectP0[i][0]=p0[0];
+ vectP0[i][1]=p0[1];
+ vectP0[i][2]=p0[2];
+ vectP1[i][0]=p1[0];
+ vectP1[i][1]=p1[1];
+ vectP1[i][2]=p1[2];
+
+ Double_t matr[3][3];
+ Double_t dknow[3];
+ if(optUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow);
+ if(optUseWeights==1){
+ Double_t sigmasq[3];
+ sigmasq[0]=track1->GetSigmaY2();
+ sigmasq[1]=track1->GetSigmaY2();
+ sigmasq[2]=track1->GetSigmaZ2();
+ GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow);
+ }
+
+ for(Int_t iii=0;iii<3;iii++){
+ dsum[iii]+=dknow[iii];
+ for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj];
+ }
+ delete line1;
+ }
+
+ Double_t vett[3][3];
+ Double_t det=GetDeterminant3X3(sum);
+
+ if(det!=0){
+ for(Int_t zz=0;zz<3;zz++){
+ for(Int_t ww=0;ww<3;ww++){
+ for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk];
+ }
+ for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk];
+ initPos[zz]=GetDeterminant3X3(vett)/det;
+ }
+
+
+ for(Int_t i=0; i<knacc; i++){
+ Double_t p0[3]={0,0,0},p1[3]={0,0,0};
+ for(Int_t ii=0;ii<3;ii++){
+ p0[ii]=vectP0[i][ii];
+ p1[ii]=vectP1[i][ii];
+ }
+ sigma+=GetStrLinMinDist(p0,p1,initPos);
+ }
+
+ sigma=TMath::Sqrt(sigma);
+ }else{
+ Warning("StrLinVertexFinderMinDist","Finder did not succed");
+ sigma=999;
+ }
+ delete vectP0;
+ delete vectP1;
+ fVert.SetXYZ(initPos);
+ fVert.SetDispersion(sigma);
+ fVert.SetNContributors(knacc);
+}
+//_______________________________________________________________________
+Double_t AliVertexerTracks::GetDeterminant3X3(Double_t matr[][3]){
+ //
+ 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];
+ return det;
+}
+//____________________________________________________________________________
+void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t m[][3],Double_t *d){
+
+ //
+ Double_t x12=p0[0]-p1[0];
+ Double_t y12=p0[1]-p1[1];
+ Double_t z12=p0[2]-p1[2];
+ Double_t kk=x12*x12+y12*y12+z12*z12;
+ m[0][0]=2-2/kk*x12*x12;
+ m[0][1]=-2/kk*x12*y12;
+ m[0][2]=-2/kk*x12*z12;
+ m[1][0]=-2/kk*x12*y12;
+ m[1][1]=2-2/kk*y12*y12;
+ m[1][2]=-2/kk*y12*z12;
+ m[2][0]=-2/kk*x12*z12;
+ m[2][1]=-2*y12*z12;
+ m[2][2]=2-2/kk*z12*z12;
+ d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12;
+ d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12;
+ d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12;
+
+}
+//____________________________________________________________________________
+void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t m[][3],Double_t *d){
+ //
+ Double_t x12=p1[0]-p0[0];
+ Double_t y12=p1[1]-p0[1];
+ Double_t z12=p1[2]-p0[2];
+
+ Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1];
+
+ Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]);
+
+ Double_t cc[3];
+ cc[0]=-x12/sigmasq[0];
+ cc[1]=-y12/sigmasq[1];
+ cc[2]=-z12/sigmasq[2];
+
+ 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;
+
+ Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2];
+
+ Double_t aa[3];
+ aa[0]=x12*sigmasq[1]*sigmasq[2]/den;
+ aa[1]=y12*sigmasq[0]*sigmasq[2]/den;
+ aa[2]=z12*sigmasq[0]*sigmasq[1]/den;
+
+ m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0];
+ m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0];
+ m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0];
+
+ m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1];
+ m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1];
+ m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1];
+
+ m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2];
+ m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2];
+ m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2];
+
+ d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0];
+ d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1];
+ d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2];
+
+}
+//_____________________________________________________________________________
+Double_t AliVertexerTracks::GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0){
+ //
+ Double_t x12=p0[0]-p1[0];
+ Double_t y12=p0[1]-p1[1];
+ Double_t z12=p0[2]-p1[2];
+ Double_t x10=p0[0]-x0[0];
+ Double_t y10=p0[1]-x0[1];
+ Double_t z10=p0[2]-x0[2];
+ 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);
+}