#include <TMath.h>
#include "AliCluster.h"
-#include "AliESDtrack.h"
#include "AliESDVertex.h"
#include "AliITSReconstructor.h"
#include "AliITStrackV2.h"
#include "AliTracker.h"
+#include "AliLog.h"
const Int_t AliITStrackV2::fgkWARN = 5;
//____________________________________________________________________________
AliITStrackV2::AliITStrackV2() : AliKalmanTrack(),
+ fCheckInvariant(kTRUE),
fdEdx(0),
fESDtrack(0)
{
for(Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) {fIndex[i]=-1; fModule[i]=-1;}
+ for(Int_t i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=0;}
for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
}
//____________________________________________________________________________
-AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c) throw (const Char_t *) :
+AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c):
AliKalmanTrack(),
+ fCheckInvariant(kTRUE),
fdEdx(t.GetITSsignal()),
fESDtrack(&t)
{
const AliExternalTrackParam *par=&t;
if (c) {
par=t.GetConstrainedParam();
- if (!par) throw "AliITStrackV2: conversion failed !\n";
+ if (!par) AliError("AliITStrackV2: conversion failed !\n");
}
Set(par->GetX(),par->GetAlpha(),par->GetParameter(),par->GetCovariance());
- //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
-
SetLabel(t.GetLabel());
SetMass(t.GetMass());
SetNumberOfClusters(t.GetITSclusters(fIndex));
SetIntegratedLength(t.GetIntegratedLength());
}
+ for(Int_t i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=0;}
for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
}
// Reset the array of attached clusters.
//------------------------------------------------------------------
for (Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) fIndex[i]=-1;
+ for (Int_t i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=0;}
SetChi2(0.);
SetNumberOfClusters(0);
}
+//____________________________________________________________________________
void AliITStrackV2::UpdateESDtrack(ULong_t flags) const {
+ // Update track params
fESDtrack->UpdateTrackParams(this,flags);
// copy the module indices
- for(Int_t i=0;i<12;i++) {
+ Int_t i;
+ for(i=0;i<2*AliITSgeomTGeo::kNLayers;i++) {
// printf(" %d\n",GetModuleIndex(i));
fESDtrack->SetITSModuleIndex(i,GetModuleIndex(i));
}
+ // copy the map of shared clusters
+ if(flags==AliESDtrack::kITSin) {
+ UChar_t itsSharedMap=0;
+ for(i=0;i<AliITSgeomTGeo::kNLayers;i++) {
+ if(fSharedWeight[i]>0) SETBIT(itsSharedMap,i);
+
+ }
+ fESDtrack->SetITSSharedMap(itsSharedMap);
+ }
+
+ // copy the 4 dedx samples
+ Double_t sdedx[4]={0.,0.,0.,0.};
+ for(i=0; i<4; i++) sdedx[i]=fdEdxSample[i];
+ fESDtrack->SetITSdEdxSamples(sdedx);
}
//____________________________________________________________________________
AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) :
AliKalmanTrack(t),
+ fCheckInvariant(t.fCheckInvariant),
fdEdx(t.fdEdx),
fESDtrack(t.fESDtrack)
{
fIndex[i]=t.fIndex[i];
fModule[i]=t.fModule[i];
}
+ for (i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=t.fSharedWeight[i];}
}
//_____________________________________________________________________________
Double_t oldX=GetX(), oldY=GetY(), oldZ=GetZ();
- Double_t bz=GetBz();
- if (!AliExternalTrackParam::PropagateTo(xk,bz)) return kFALSE;
+ //Double_t bz=GetBz();
+ //if (!AliExternalTrackParam::PropagateTo(xk,bz)) return kFALSE;
+ Double_t b[3]; GetBxByBz(b);
+ if (!AliExternalTrackParam::PropagateToBxByBz(xk,b)) return kFALSE;
Double_t xOverX0,xTimesRho;
xOverX0 = d; xTimesRho = d*x0;
if (!CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kFALSE;
Double_t sign = (startx<xToGo) ? -1.:1.;
Double_t step = (xToGo-startx)/TMath::Abs(nstep);
- Double_t start[3], end[3], mparam[7], bz = GetBz();
+ Double_t start[3], end[3], mparam[7];
+ //Double_t bz = GetBz();
+ Double_t b[3]; GetBxByBz(b);
+ Double_t bz = b[2];
+
Double_t x = startx;
for (Int_t i=0; i<nstep; i++) {
GetXYZ(start); //starting global position
x += step;
if (!GetXYZAt(x, bz, end)) return kFALSE;
- if (!AliExternalTrackParam::PropagateTo(x, bz)) return kFALSE;
+ //if (!AliExternalTrackParam::PropagateTo(x, bz)) return kFALSE;
+ if (!AliExternalTrackParam::PropagateToBxByBz(x, b)) return kFALSE;
AliTracker::MeanMaterialBudget(start, end, mparam);
xTimesRho = sign*mparam[4]*mparam[0];
xOverX0 = mparam[1];
//This function updates track parameters
//------------------------------------------------------------------
Double_t p[2]={c->GetY(), c->GetZ()};
- Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()};
+ Double_t cov[3]={c->GetSigmaY2(), c->GetSigmaYZ(), c->GetSigmaZ2()};
if (!AliExternalTrackParam::Update(p,cov)) return kFALSE;
Int_t n=GetNumberOfClusters();
if (!Invariant()) {
- if (n>fgkWARN) AliWarning("Wrong invariant !");
+ if (n>fgkWARN) AliDebug(1,"Wrong invariant !");
return kFALSE;
}
//------------------------------------------------------------------
// This function is for debugging purpose only
//------------------------------------------------------------------
- Int_t n=GetNumberOfClusters();
+ if(!fCheckInvariant) return kTRUE;
+ Int_t n=GetNumberOfClusters();
+ static Float_t bz = GetBz();
// take into account the misalignment error
Float_t maxMisalErrY2=0,maxMisalErrZ2=0;
+ //RS
+ const AliITSRecoParam* recopar = AliITSReconstructor::GetRecoParam();
+ if (!recopar) recopar = AliITSRecoParam::GetHighFluxParam();
+
for (Int_t lay=0; lay<AliITSgeomTGeo::kNLayers; lay++) {
- maxMisalErrY2 = TMath::Max(maxMisalErrY2,AliITSReconstructor::GetRecoParam()->GetClusterMisalErrorY(lay));
- maxMisalErrZ2 = TMath::Max(maxMisalErrZ2,AliITSReconstructor::GetRecoParam()->GetClusterMisalErrorZ(lay));
+ maxMisalErrY2 = TMath::Max(maxMisalErrY2,recopar->GetClusterMisalErrorY(lay,bz));
+ maxMisalErrZ2 = TMath::Max(maxMisalErrZ2,recopar->GetClusterMisalErrorZ(lay,bz));
}
maxMisalErrY2 *= maxMisalErrY2;
maxMisalErrZ2 *= maxMisalErrZ2;
Double_t sP2=GetParameter()[2];
if (TMath::Abs(sP2) >= kAlmost1){
- if (n>fgkWARN) Warning("Invariant","fP2=%f\n",sP2);
+ if (n>fgkWARN) AliDebug(1,Form("fP2=%f\n",sP2));
return kFALSE;
}
Double_t sC00=GetCovariance()[0];
if (sC00<=0 || sC00>(9.+maxMisalErrY2)) {
- if (n>fgkWARN) Warning("Invariant","fC00=%f\n",sC00);
+ if (n>fgkWARN) AliDebug(1,Form("fC00=%f\n",sC00));
return kFALSE;
}
Double_t sC11=GetCovariance()[2];
if (sC11<=0 || sC11>(9.+maxMisalErrZ2)) {
- if (n>fgkWARN) Warning("Invariant","fC11=%f\n",sC11);
+ if (n>fgkWARN) AliDebug(1,Form("fC11=%f\n",sC11));
return kFALSE;
}
Double_t sC22=GetCovariance()[5];
if (sC22<=0 || sC22>1.) {
- if (n>fgkWARN) Warning("Invariant","fC22=%f\n",sC22);
+ if (n>fgkWARN) AliDebug(1,Form("fC22=%f\n",sC22));
return kFALSE;
}
Double_t sC33=GetCovariance()[9];
if (sC33<=0 || sC33>1.) {
- if (n>fgkWARN) Warning("Invariant","fC33=%f\n",sC33);
+ if (n>fgkWARN) AliDebug(1,Form("fC33=%f\n",sC33));
return kFALSE;
}
Double_t sC44=GetCovariance()[14];
if (sC44<=0 /*|| sC44>6e-5*/) {
- if (n>fgkWARN) Warning("Invariant","fC44=%f\n",sC44);
+ if (n>fgkWARN) AliDebug(1,Form("fC44=%f\n",sC44));
return kFALSE;
}
//------------------------------------------------------------------
//This function propagates a track
//------------------------------------------------------------------
- Double_t bz=GetBz();
- if (!AliExternalTrackParam::Propagate(alp,xk,bz)) return kFALSE;
+ //Double_t bz=GetBz();
+ //if (!AliExternalTrackParam::Propagate(alp,xk,bz)) return kFALSE;
+ Double_t b[3]; GetBxByBz(b);
+ if (!AliExternalTrackParam::PropagateBxByBz(alp,xk,b)) return kFALSE;
if (!Invariant()) {
Int_t n=GetNumberOfClusters();
- if (n>fgkWARN) AliWarning("Wrong invariant !");
+ if (n>fgkWARN) AliDebug(1,"Wrong invariant !");
return kFALSE;
}
//------------------------------------------------------------------
//This function improves angular track parameters
//------------------------------------------------------------------
+ //Store the initail track parameters
+
+ Double_t x = GetX();
+ Double_t alpha = GetAlpha();
+ Double_t par[] = {GetY(),GetZ(),GetSnp(),GetTgl(),GetSigned1Pt()};
+ Double_t cov[] = {
+ GetSigmaY2(),
+ GetSigmaZY(),
+ GetSigmaZ2(),
+ GetSigmaSnpY(),
+ GetSigmaSnpZ(),
+ GetSigmaSnp2(),
+ GetSigmaTglY(),
+ GetSigmaTglZ(),
+ GetSigmaTglSnp(),
+ GetSigmaTgl2(),
+ GetSigma1PtY(),
+ GetSigma1PtZ(),
+ GetSigma1PtSnp(),
+ GetSigma1PtTgl(),
+ GetSigma1Pt2()
+ };
+
+
Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha());
-//Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex
+ Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex
Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the
Double_t zv = xyz[2]; // local frame
- Double_t dy = Par(0) - yv, dz = Par(1) - zv;
- Double_t r2=GetX()*GetX() + dy*dy;
+ Double_t dx = x - xv, dy = par[0] - yv, dz = par[1] - zv;
+ Double_t r2=dx*dx + dy*dy;
Double_t p2=(1.+ GetTgl()*GetTgl())/(GetSigned1Pt()*GetSigned1Pt());
Double_t beta2=p2/(p2 + GetMass()*GetMass());
x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp()));
Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0;
//Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33;
- Double_t cnv=GetBz()*kB2C;
+ Double_t bz=GetBz();
+ Double_t cnv=bz*kB2C;
+ Double_t curv=GetC(bz);
{
- Double_t dummy = 4/r2 - GetC()*GetC();
+ Double_t dummy = 4/r2 - curv*curv;
if (dummy < 0) return kFALSE;
- Double_t parp = 0.5*(GetC()*GetX() + dy*TMath::Sqrt(dummy));
- Double_t sigma2p = theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl());
- sigma2p += Cov(0)/r2*(1.- dy*dy/r2)*(1.- dy*dy/r2);
+ Double_t parp = 0.5*(curv*dx + dy*TMath::Sqrt(dummy));
+ Double_t sigma2p = theta2*(1.-GetSnp())*(1.+GetSnp())*(1. + GetTgl()*GetTgl());
+ Double_t ovSqr2 = 1./TMath::Sqrt(r2);
+ Double_t tfact = ovSqr2*(1.-dy*ovSqr2)*(1.+dy*ovSqr2);
+ sigma2p += cov[0]*tfact*tfact;
sigma2p += ers[1]*ers[1]/r2;
- sigma2p += 0.25*Cov(14)*cnv*cnv*GetX()*GetX();
- Double_t eps2p=sigma2p/(Cov(5) + sigma2p);
- Par(0) += Cov(3)/(Cov(5) + sigma2p)*(parp - GetSnp());
- Par(2) = eps2p*GetSnp() + (1 - eps2p)*parp;
- Cov(5) *= eps2p;
- Cov(3) *= eps2p;
+ sigma2p += 0.25*cov[14]*cnv*cnv*dx*dx;
+ Double_t eps2p=sigma2p/(cov[5] + sigma2p);
+ par[0] += cov[3]/(cov[5] + sigma2p)*(parp - GetSnp());
+ par[2] = eps2p*GetSnp() + (1 - eps2p)*parp;
+ cov[5] *= eps2p;
+ cov[3] *= eps2p;
}
{
- Double_t parl=0.5*GetC()*dz/TMath::ASin(0.5*GetC()*TMath::Sqrt(r2));
+ Double_t parl=0.5*curv*dz/TMath::ASin(0.5*curv*TMath::Sqrt(r2));
Double_t sigma2l=theta2;
- sigma2l += Cov(2)/r2 + Cov(0)*dy*dy*dz*dz/(r2*r2*r2);
+ sigma2l += cov[2]/r2 + cov[0]*dy*dy*dz*dz/(r2*r2*r2);
sigma2l += ers[2]*ers[2]/r2;
- Double_t eps2l = sigma2l/(Cov(9) + sigma2l);
- Par(1) += Cov(7 )/(Cov(9) + sigma2l)*(parl - Par(3));
- Par(4) += Cov(13)/(Cov(9) + sigma2l)*(parl - Par(3));
- Par(3) = eps2l*Par(3) + (1-eps2l)*parl;
- Cov(9) *= eps2l;
- Cov(13)*= eps2l;
- Cov(7) *= eps2l;
+ Double_t eps2l = sigma2l/(cov[9] + sigma2l);
+ par[1] += cov[7 ]/(cov[9] + sigma2l)*(parl - par[3]);
+ par[4] += cov[13]/(cov[9] + sigma2l)*(parl - par[3]);
+ par[3] = eps2l*par[3] + (1-eps2l)*parl;
+ cov[9] *= eps2l;
+ cov[13]*= eps2l;
+ cov[7] *= eps2l;
}
+
+ Set(x,alpha,par,cov);
+
if (!Invariant()) return kFALSE;
return kTRUE;
}
-void AliITStrackV2::CookdEdx(Double_t low, Double_t up) {
+void AliITStrackV2::CookdEdx(Double_t /*low*/, Double_t /*up*/) {
//-----------------------------------------------------------------
// This function calculates dE/dX within the "low" and "up" cuts.
// Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
+ // Updated: F. Prino 8-June-2009
//-----------------------------------------------------------------
- // The clusters order is: SSD-2, SSD-1, SDD-2, SDD-1, SPD-2, SPD-1
+ // The cluster order is: SDD-1, SDD-2, SSD-1, SSD-2
- Int_t i;
Int_t nc=0;
- for (i=0; i<GetNumberOfClusters(); i++) {
- Int_t idx=GetClusterIndex(i);
- idx=(idx&0xf0000000)>>28;
- if (idx>1) nc++; // Take only SSD and SDD
+ Float_t dedx[4];
+ for (Int_t il=0; il<4; il++) { // count good (>0) dE/dx values
+ if(fdEdxSample[il]>0.){
+ dedx[nc]= fdEdxSample[il];
+ nc++;
+ }
+ }
+ if(nc<1){
+ SetdEdx(0.);
+ return;
}
- Int_t swap;//stupid sorting
+ Int_t swap; // sort in ascending order
do {
swap=0;
- for (i=0; i<nc-1; i++) {
- if (fdEdxSample[i]<=fdEdxSample[i+1]) continue;
- Float_t tmp=fdEdxSample[i];
- fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp;
+ for (Int_t i=0; i<nc-1; i++) {
+ if (dedx[i]<=dedx[i+1]) continue;
+ Float_t tmp=dedx[i];
+ dedx[i]=dedx[i+1];
+ dedx[i+1]=tmp;
swap++;
}
} while (swap);
- Int_t nl=Int_t(low*nc), nu=Int_t(up*nc); //b.b. to take two lowest dEdX
- // values from four ones choose
- // nu=2
- Float_t dedx=0;
- for (i=nl; i<nu; i++) dedx += fdEdxSample[i];
- if (nu-nl>0) dedx /= (nu-nl);
- SetdEdx(dedx);
+ Double_t sumamp=0,sumweight=0;
+ Double_t weight[4]={1.,1.,0.,0.};
+ if(nc==3) weight[1]=0.5;
+ else if(nc<3) weight[1]=0.;
+ for (Int_t i=0; i<nc; i++) {
+ sumamp+= dedx[i]*weight[i];
+ sumweight+=weight[i];
+ }
+ SetdEdx(sumamp/sumweight);
}
//____________________________________________________________________________
// The track curvature is neglected.
//------------------------------------------------------------------
Double_t d=GetD(0.,0.);
- if (TMath::Abs(d) > r) return kFALSE;
+ if (TMath::Abs(d) > r) {
+ if (r>1e-1) return kFALSE;
+ r = TMath::Abs(d);
+ }
Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
- if (TMath::Abs(d) > rcurr) return kFALSE;
- Double_t phicurr=GetAlpha()+TMath::ASin(GetSnp());
+ if (TMath::Abs(d) > rcurr) return kFALSE;
+ Double_t globXYZcurr[3]; GetXYZ(globXYZcurr);
+ Double_t phicurr=TMath::ATan2(globXYZcurr[1],globXYZcurr[0]);
+
+ if (GetX()>=0.) {
+ phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
+ } else {
+ phi=phicurr+TMath::ASin(d/r)+TMath::ASin(d/rcurr)-TMath::Pi();
+ }
- phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
+ // return a phi in [0,2pi[
+ if (phi<0.) phi+=2.*TMath::Pi();
+ else if (phi>=2.*TMath::Pi()) phi-=2.*TMath::Pi();
z=GetZ()+GetTgl()*(TMath::Sqrt((r-d)*(r+d))-TMath::Sqrt((rcurr-d)*(rcurr+d)));
return kTRUE;
}
// The track curvature is neglected.
//------------------------------------------------------------------
Double_t d=GetD(0.,0.);
- if (TMath::Abs(d) > r) return kFALSE;
+ if (TMath::Abs(d) > r) {
+ if (r>1e-1) return kFALSE;
+ r = TMath::Abs(d);
+ }
Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
- Double_t phicurr=GetAlpha()+TMath::ASin(GetSnp());
- Double_t phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
+ Double_t globXYZcurr[3]; GetXYZ(globXYZcurr);
+ Double_t phicurr=TMath::ATan2(globXYZcurr[1],globXYZcurr[0]);
+ Double_t phi;
+ if (GetX()>=0.) {
+ phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
+ } else {
+ phi=phicurr+TMath::ASin(d/r)+TMath::ASin(d/rcurr)-TMath::Pi();
+ }
xloc=r*(TMath::Cos(phi)*TMath::Cos(GetAlpha())
+TMath::Sin(phi)*TMath::Sin(GetAlpha()));
return kTRUE;
}
+
+//____________________________________________________________________________
+Bool_t AliITStrackV2::ImproveKalman(Double_t xyz[3],Double_t ers[3], const Double_t* xlMS, const Double_t* x2X0MS, Int_t nMS)
+{
+ // Substitute the state of the track (p_{k|k},C_{k|k}) at the k-th measumerent by its
+ // smoothed value from the k-th measurement + measurement at the vertex.
+ // Account for the MS on nMS layers at x-postions xlMS with x/x0 = x2X0MS
+ // p_{k|kv} = p_{k|k} + C_{k|k}*D^Tr_{k+1} B^{-1}_{k+1} ( vtx - D_{k+1}*p_{k|k})
+ // C_{k|kv} = C_{k|k}*( I - D^Tr_{k+1} B^{-1}_{k+1} D_{k+1} C^Tr_{k|k})
+ //
+ // where D_{k} = H_{k} F_{k} with H being the matrix converting the tracks parameters
+ // to measurements m_{k} = H_{k} p_{k} and F_{k} the matrix propagating the track between the
+ // the point k-1 and k: p_{k|k-1} = F_{k} p_{k-1|k-1}
+ //
+ // B_{k+1} = V_{k+1} + H_{k+1} C_{k+1|k} H^Tr_{k+1} with V_{k+1} being the error of the measurment
+ // at point k+1 (i.e. vertex), and C_{k+1|k} - error matrix extrapolated from k-th measurement to
+ // k+1 (vtx) and accounting for the MS inbetween
+ //
+ // H = {{1,0,0,0,0},{0,1,0,0,0}}
+ //
+ double covc[15], *cori = (double*) GetCovariance(),par[5] = {GetY(),GetZ(),GetSnp(),GetTgl(),GetSigned1Pt()},
+ &c00=cori[0],
+ &c01=cori[1],&c11=cori[2],
+ &c02=cori[3],&c12=cori[4],&c22=cori[5],
+ &c03=cori[6],&c13=cori[7],&c23=cori[8],&c33=cori[9],
+ &c04=cori[10],&c14=cori[11],&c24=cori[12],&c34=cori[13],&c44=cori[14],
+ // for smoothed cov matrix
+ &cov00=covc[0],
+ &cov01=covc[1],&cov11=covc[2],
+ &cov02=covc[3],&cov12=covc[4],&cov22=covc[5],
+ &cov03=covc[6],&cov13=covc[7],&cov23=covc[8],&cov33=covc[9],
+ &cov04=covc[10],&cov14=covc[11],&cov24=covc[12],&cov34=covc[13],&cov44=covc[14];
+ //
+ double x = GetX(), alpha = GetAlpha();
+ // vertex in the track frame
+ double cs=TMath::Cos(alpha), sn=TMath::Sin(alpha);
+ double xv = xyz[0]*cs + xyz[1]*sn, yv =-xyz[0]*sn + xyz[1]*cs, zv = xyz[2];
+ double dx = xv - GetX();
+ if (TMath::Abs(dx)<=kAlmost0) return kTRUE;
+ //
+ double cnv=GetBz()*kB2C, x2r=cnv*par[4]*dx, f1=par[2], f2=f1+x2r;
+ if (TMath::Abs(f1) >= kAlmost1 || TMath::Abs(f2) >= kAlmost1) {
+ AliInfo(Form("Fail: %+e %+e",f1,f2));
+ return kFALSE;
+ }
+ double r1=TMath::Sqrt((1.-f1)*(1.+f1)), r2=TMath::Sqrt((1.-f2)*(1.+f2)), dx2r=dx/(r1+r2);
+ // elements of matrix F_{k+1} (1s on diagonal)
+ double f02 = 2*dx2r, f04 = cnv*dx*dx2r, f13/*, f24 = cnv*dx*/;
+ if (TMath::Abs(x2r)<0.05) f13 = dx*r2+f2*(f1+f2)*dx2r; // see AliExternalTrackParam::PropagateTo
+ else {
+ double dy2dx = (f1+f2)/(r1+r2);
+ f13 = 2*TMath::ASin(0.5*TMath::Sqrt(1+dy2dx*dy2dx)*x2r)/(cnv*par[4]);
+ }
+ // elements of matrix D_{k+1} = H_{k+1} * F_{k+1}
+ // double d00 = 1., d11 = 1.;
+ double &d02 = f02, &d04 = f04, &d13 = f13;
+ //
+ // elements of matrix DC = D_{k+1}*C_{kk}^T
+ double dc00 = c00+c02*d02+c04*d04, dc10 = c01+c03*d13;
+ double dc01 = c01+c12*d02+c14*d04, dc11 = c11+c13*d13;
+ double dc02 = c02+c22*d02+c24*d04, dc12 = c12+c23*d13;
+ double dc03 = c03+c23*d02+c34*d04, dc13 = c13+c33*d13;
+ double dc04 = c04+c24*d02+c44*d04, dc14 = c14+c34*d13;
+ //
+ // difference between the vertex and the the track extrapolated to vertex
+ yv -= par[0] + par[2]*d02 + par[4]*d04;
+ zv -= par[1] + par[3]*d13;
+ //
+ // y,z part of the cov.matrix extrapolated to vtx (w/o MS contribution)
+ // C_{k+1,k} = H F_{k+1} C_{k,k} F^Tr_{k+1} H^Tr = D C D^Tr
+ double cv00 = dc00+dc02*d02+dc04*d04, cv01 = dc01+dc03*d13, cv11 = dc11+dc13*d13;
+ //
+ // add MS contribution layer by layer
+ double xCurr = x;
+ double p2Curr = par[2];
+ //
+ // precalculated factors of MS contribution matrix:
+ double ms22t = (1. + par[3]*par[3]);
+ double ms33t = ms22t*ms22t;
+ double p34 = par[3]*par[4];
+ double ms34t = p34*ms22t;
+ double ms44t = p34*p34;
+ //
+ double p2=(1.+ par[3]*par[3])/(par[4]*par[4]);
+ double beta2 = p2/(p2+GetMass()*GetMass());
+ double theta2t = 14.1*14.1/(beta2*p2*1e6) * (1. + par[3]*par[3]);
+ //
+ // account for the MS in the layers between the last measurement and the vertex
+ for (int il=0;il<nMS;il++) {
+ double dfx = xlMS[il] - xCurr;
+ xCurr = xlMS[il];
+ p2Curr += dfx*cnv*par[4]; // p2 at the scattering layer
+ double dxL=xv - xCurr; // distance from scatering layer to vtx
+ double x2rL=cnv*par[4]*dxL, f1L=p2Curr, f2L=f1L+x2rL;
+ if (TMath::Abs(f1L) >= kAlmost1 || TMath::Abs(f2L) >= kAlmost1) {
+ AliInfo(Form("FailMS at step %d of %d: dfx:%e dxL:%e %e %e",il,nMS,dfx,dxL,f1L,f2L));
+ return kFALSE;
+ }
+ double r1L=TMath::Sqrt((1.-f1L)*(1.+f1L)), r2L=TMath::Sqrt((1.-f2L)*(1.+f2L)), dx2rL=dxL/(r1L+r2L);
+ // elements of matrix for propagation from scatering layer to vertex
+ double f02L = 2*dx2rL, f04L = cnv*dxL*dx2rL, f13L/*, f24L = cnv*dxL*/;
+ if (TMath::Abs(x2rL)<0.05) f13L = dxL*r2L+f2L*(f1L+f2L)*dx2rL; // see AliExternalTrackParam::PropagateTo
+ else {
+ double dy2dxL = (f1L+f2L)/(r1L+r2L);
+ f13L = 2*TMath::ASin(0.5*TMath::Sqrt(1+dy2dxL*dy2dxL)*x2rL)/(cnv*par[4]);
+ }
+ // MS contribution matrix:
+ double theta2 = theta2t*TMath::Abs(x2X0MS[il]);
+ double ms22 = theta2*(1.-p2Curr)*(1.+p2Curr)*ms22t;
+ double ms33 = theta2*ms33t;
+ double ms34 = theta2*ms34t;
+ double ms44 = theta2*ms44t;
+ //
+ // add H F MS F^Tr H^Tr to cv
+ cv00 += f02L*f02L*ms22 + f04L*f04L*ms44;
+ cv01 += f04L*f13L*ms34;
+ cv11 += f13L*f13L*ms33;
+ }
+ //
+ // inverse of matrix B
+ double b11 = ers[1]*ers[1] + cv00;
+ double b00 = ers[2]*ers[2] + cv11;
+ double det = b11*b00 - cv01*cv01;
+ if (TMath::Abs(det)<kAlmost0) {
+ AliInfo(Form("Fail on det %e: %e %e %e",det,cv00,cv11,cv01));
+ return kFALSE;
+ }
+ det = 1./det;
+ b00 *= det; b11 *= det;
+ double b01 = -cv01*det;
+ //
+ // elements of matrix DC^Tr * B^-1
+ double dcb00 = b00*dc00+b01*dc10, dcb01 = b01*dc00+b11*dc10;
+ double dcb10 = b00*dc01+b01*dc11, dcb11 = b01*dc01+b11*dc11;
+ double dcb20 = b00*dc02+b01*dc12, dcb21 = b01*dc02+b11*dc12;
+ double dcb30 = b00*dc03+b01*dc13, dcb31 = b01*dc03+b11*dc13;
+ double dcb40 = b00*dc04+b01*dc14, dcb41 = b01*dc04+b11*dc14;
+ //
+ // p_{k|k+1} = p_{k|k} + C_{k|k}*D^Tr_{k+1} B^{-1}_{k+1} ( vtx - D_{k+1}*p_{k|k})
+ par[0] += dcb00*yv + dcb01*zv;
+ par[1] += dcb10*yv + dcb11*zv;
+ par[2] += dcb20*yv + dcb21*zv;
+ par[3] += dcb30*yv + dcb31*zv;
+ par[4] += dcb40*yv + dcb41*zv;
+ //
+ // C_{k|kv} = C_{k|k} - C_{k|k} D^Tr_{k+1} B^{-1}_{k+1} D_{k+1} C^Tr_{k|k})
+ //
+ cov00 = c00 - (dc00*dcb00 + dc10*dcb01);
+ cov01 = c01 - (dc01*dcb00 + dc11*dcb01);
+ cov02 = c02 - (dc02*dcb00 + dc12*dcb01);
+ cov03 = c03 - (dc03*dcb00 + dc13*dcb01);
+ cov04 = c04 - (dc04*dcb00 + dc14*dcb01);
+ //
+ cov11 = c11 - (dc01*dcb10 + dc11*dcb11);
+ cov12 = c12 - (dc02*dcb10 + dc12*dcb11);
+ cov13 = c13 - (dc03*dcb10 + dc13*dcb11);
+ cov14 = c14 - (dc04*dcb10 + dc14*dcb11);
+ //
+ cov22 = c22 - (dc02*dcb20 + dc12*dcb21);
+ cov23 = c23 - (dc03*dcb20 + dc13*dcb21);
+ cov24 = c24 - (dc04*dcb20 + dc14*dcb21);
+ //
+ cov33 = c33 - (dc03*dcb30 + dc13*dcb31);
+ cov34 = c34 - (dc04*dcb30 + dc14*dcb31);
+ //
+ cov44 = c44 - (dc04*dcb40 + dc14*dcb41);
+ //
+ Set(x,alpha,par,covc);
+ if (!Invariant()) {
+ AliInfo(Form("Fail on Invariant, X=%e",GetX()));
+ return kFALSE;
+ }
+ return kTRUE;
+ //
+}