//____________________________________________________________________
-Double_t AliTRDseedV1::EstimatedCrossPoint(AliTRDpadPlane *pp)
+Double_t AliTRDseedV1::EstimatedCrossPoint(AliTRDpadPlane *pp, Float_t bz)
{
// Algorithm to estimate cross point in the x-z plane for pad row cross tracklets or the z coordinate of pad row without pad row cross in the local chamber coordinates.
-// Returns radial offset from anode wire in case of raw cross.
+// Returns variance of the radial offset from anode wire in case of raw cross or 0 otherwise.
Int_t row[] = {-1, -1};
Double_t zoff(0.5 * (pp->GetRow0() + pp->GetRowEnd())), sx(0.), mean(0.5*pp->GetNrows()-0.5);
}
AliTRDCommonParam *cp = AliTRDCommonParam::Instance();
Double_t freq(cp?cp->GetSamplingFrequency():10.);
- fS2Y = ((itb+0.5)/freq - fT0 - 0.189)*fVD; // xOff
- sx = dtb*fVD*0.288675134594812921/freq;
+ fS2Y = ((itb-0.5)/freq - fT0 - 0.189)*fVD; // xOff
+ sx = dtb*0.288675134594812921/freq; sx *= sx; sx += 1.56e-2; sx *= fVD*fVD;
}
}
- // correct for the bias in dzdx
+ // estimate dzdx
Float_t dx(fX0-fS2Y);
- fZfit[1] = (fZfit[0]+zoff)/dx;
- if(!IsRowCross()) fZfit[1] *= 1.09;
- // compute local z @ anode wire
- //fZfit[0]+= fZfit[1]*fS2Y;
-// printf("EstimatedCrossPoint : zoff[%f]\n", zoff);
-// fS2Z = 0.05+0.4*TMath::Abs(fZfit[1]);
- Float_t s2dzdx(0.0245-0.0014*fZfit[1]+0.0557*fZfit[1]*fZfit[1]); s2dzdx*=s2dzdx;
- fS2Z = fZfit[1]*fZfit[1]*sx*sx+fS2Y*fS2Y*s2dzdx;
- //
- // MI modification 02.05.2014 - add wire step + unisochronity contribution + diffusion contribution
- // Normalization factor for fS2Z+=(factor*wirepitch/sqrt(12))^2
- // MI question - fS2Y definetion looks strange. Is it used somewhere at all???
- //
- const Double_t kWirePitch=0.125;
- const Double_t kWirePitchFactor=12;
- fS2Z+=kWirePitch*kWirePitch/kWirePitchFactor;
+ fZfit[1] = (fZfit[0]+zoff)/dx;
+
+ // correct dzdx for the bias
+ UnbiasDZDX(IsRowCross(), bz);
+ if(IsRowCross()){
+ // correct x_cross/sigma(x_cross) for the bias in dzdx
+ const AliTRDrecoParam* const recoParam = fkReconstructor->GetRecoParam();
+ if(recoParam){
+ fS2Y += recoParam->GetCorrDZDXxcross()*TMath::Abs(fZfit[1]);
+ sx += recoParam->GetCorrDZDXxcross()*recoParam->GetCorrDZDXxcross()*GetS2DZDX(fZfit[1]);
+ }
+ // correct sigma(x_cross) for the width of the crossing area
+ sx += GetS2XcrossDZDX(TMath::Abs(fZfit[1]));
+
+ // estimate z and error @ anode wire
+ fZfit[0] += fZfit[1]*fS2Y;
+ fS2Z = fZfit[1]*fZfit[1]*sx+fS2Y*fS2Y*GetS2DZDX(fZfit[1]);
+ }
+ return sx;
+}
+
+//____________________________________________________________________
+void AliTRDseedV1::UnbiasDZDX(Bool_t rc, Float_t bz)
+{
+ // correct dzdx for the bias in z according to MC
+ const AliTRDrecoParam* const recoParam = fkReconstructor->GetRecoParam();
+ if(!recoParam) return;
+ fZfit[1] *= recoParam->GetCorrDZDX(rc)-(bz>0?0.01:0.);
+ if(rc) fZfit[1] += recoParam->GetCorrDZDXbiasRC(fZfit[1]<0);
+}
- return fS2Y;
+//____________________________________________________________________
+Double_t AliTRDseedV1::UnbiasY(Bool_t rc, Float_t bz)
+{
+// correct y coordinate for tail cancellation. This should be fixed by considering TC as a function of q/pt.
+// rc : TRUE if tracklet crosses rows
+// bz : magnetic field z component
+
+ const AliTRDrecoParam* const recoParam = fkReconstructor->GetRecoParam();
+ if(!recoParam) return 0.;
+ Double_t par[3]={0.};
+ Int_t idx(2*(rc?1:0)+Int_t(bz>0));
+ recoParam->GetYcorrTailCancel(idx, par);
+ return par[0]*TMath::Sin(par[1]*fYref[1])+par[2];
}
+
//____________________________________________________________________
Float_t AliTRDseedV1::GetQperTB(Int_t tb) const
{
}
//____________________________________________________________________
-void AliTRDseedV1::GetCovAt(Double_t x, Double_t *cov) const
+void AliTRDseedV1::GetCovAt(Double_t /*x*/, Double_t *cov) const
{
// Computes covariance in the y-z plane at radial point x (in tracking coordinates)
// and returns the results in the preallocated array cov[3] as :
//
- Double_t xr = fX0-x;
- Double_t sy2 = fCov[0] +2.*xr*fCov[1] + xr*xr*fCov[2];
+ //Double_t xr = fX0-x;
+ Double_t sy2 = fCov[0];// +2.*xr*fCov[1] + xr*xr*fCov[2];
Double_t sz2 = fS2Z;
//GetPadLength()*GetPadLength()/12.;
}
// rotate covariance matrix if no RC
- Double_t t2 = GetTilt()*GetTilt();
if(!IsRowCross()){
+ Double_t t2 = GetTilt()*GetTilt();
Double_t correction = 1./(1. + t2);
cov[0] = (sy2+t2*sz2)*correction;
cov[1] = GetTilt()*(sz2 - sy2)*correction;
cov[2] = (t2*sy2+sz2)*correction;
} else {
cov[0] = sy2; cov[1] = 0.; cov[2] = sz2;
- //
- // MI change (03.05.2014)
- // current implemenatation of the linear fit does not take into account step for padrow crossing
- // bug to be fixed - step should be taken properly into account in the fit, rather than increase of the error estimate
- cov[0]+=t2*GetPadLength()*GetPadLength()/24.; //this line will disappear after fix of linear FIT
}
-
AliDebug(4, Form("C(%6.1f %+6.3f %6.1f) RC[%c]", 1.e4*TMath::Sqrt(cov[0]), cov[1], 1.e4*TMath::Sqrt(cov[2]), IsRowCross()?'y':'n'));
}
//____________________________________________________________________
-Bool_t AliTRDseedV1::FitRobust(AliTRDpadPlane *pp, Int_t opt)
+Bool_t AliTRDseedV1::FitRobust(AliTRDpadPlane *pp, TGeoHMatrix *mDet, Float_t bz, Int_t chg, Int_t opt)
{
//
// Linear fit of the clusters attached to the tracklet
SetChmbGood(calibration->IsChamberGood(fDet));
if(!IsChmbGood()) kScalePulls*=10.;
}
-
+ AliTRDCommonParam *cp = AliTRDCommonParam::Instance();
+ Double_t freq(cp?cp->GetSamplingFrequency():10.);
+
// evaluate locally z and dzdx from TRD only information
- if(EstimatedCrossPoint(pp)<0.) return kFALSE;
+ if(EstimatedCrossPoint(pp, bz)<0.) return kFALSE;
//printf("D%03d RC[%c] dzdx[%f %f] opt[%d]\n", fDet, IsRowCross()?'y':'n', fZref[1], fZfit[1], opt);
Double_t //xchmb = 0.5 * AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick(),
//zchmb = 0.5 * (pp->GetRow0() + pp->GetRowEnd()),
- z0 = 0.5 * (pp->GetRow0() + pp->GetRowEnd()) + fZfit[0], z;
- Double_t xc[kNclusters], yc[kNclusters], dz(0.), dzdx(0.), s2dz(0.), s2dzdx(0.), sy[kNclusters],
- cs(0.);
+ z0(0.5 * (pp->GetRow0() + pp->GetRowEnd()) + fZfit[0]),
+ DZ(pp->GetRow0() - pp->GetRowEnd() - pp->GetAnodeWireOffset() + fZfit[0]),
+ z, d(-1.);
+ Double_t xc[kNclusters], yc[kNclusters], dz(0.), dzdx(0.),
+ s2dz(0.), s2dzdx(0.), sy[kNclusters],
+ s2x((8.33e-2/freq/freq+1.56e-2)*fVD*fVD), // error of 1tb + error of mean time (TRF)
+ t2(fPad[2]*fPad[2]), loc[3]={0.};
Int_t n(0), // clusters used in fit
- row[]={-1, -1},// pad row spanned by the tracklet
- col(-1); // pad column of current cluster
+ row[]={-1, -1};// pad row spanned by the tracklet
+ Double_t ycorr(UnbiasY(IsRowCross(), bz)),
+ kS2Ycorr(recoParam->GetS2Ycorr(IsRowCross(), chg>0));
+
AliTRDcluster *c(NULL), **jc = &fClusters[0];
for(Int_t ic=0; ic<kNtb; ic++, ++jc) {
if(!(c = (*jc))) continue;
switch(opt){
case 0: // no dz correction (only for RC tracklet) and dzdx from chamber position assuming primary
dzdx = IsRowCross()?fZfit[1]:0.;
- s2dzdx= IsRowCross()?(0.0245-0.0014*dzdx+0.0557*dzdx*dzdx):(0.0379-0.0006*dzdx+0.0771*dzdx*dzdx);
- s2dzdx*=s2dzdx;
- dz = IsRowCross()?(z - z0):0.;//5*dzdx*xchmb;
- s2dz = IsRowCross()?(2.5e-4+1.e-2*dzdx*dzdx+1.e-2*TMath::Abs(dzdx)):0.;
+ s2dzdx= IsRowCross()?GetS2DZDX(dzdx):0.;
+ dz = IsRowCross()?(z - z0):0.;
+ s2dz = IsRowCross()?fS2Z:0.;
break;
case 1: // dz correction only for RC tracklet and dzdx from reference
dzdx = fZref[1];
- dz = IsRowCross()?(z - z0):0.;//5*dzdx*xchmb;
+ dz = IsRowCross()?(z - z0):0.;
break;
case 2: // full z correction (z0 & dzdx from reference)
dzdx = fZref[1];
break;
}
}
- if(col != c->GetPadCol()){
- col = c->GetPadCol();
- cs = pp->GetColSize(col);
- }
- //Use local cluster coordinates - the code should be identical with AliTRDtransform::Transform() !!!
- //A.Bercuci 27.11.13
- xc[n] = c->GetXloc(fT0, fVD); // c->GetX();
- yc[n] = c->GetYloc(pp->GetColPos(col) + .5*cs, fS2PRF, cs) - xc[n]*fExB; //c->GetY();
+ //Use local cluster coordinates
+ //A.Bercuci 27.11.13/30.06.14
+ Double_t trk[] = {c->GetX(), c->GetY(), c->GetZ()};
+ mDet->MasterToLocal(trk, loc);
+ xc[n] = AliTRDgeometry::AnodePos()-loc[0]; //c->GetXloc(fT0, fVD); // c->GetX();
+ yc[n] = loc[1]; //c->GetYloc(pp->GetColPos(col) + .5*cs, fS2PRF, cs) - xc[n]*fExB; //c->GetY();
yc[n]-= fPad[2]*(dz+xc[n]*dzdx);
-// sy[n] = c->GetSigmaY2()>0?(TMath::Min(TMath::Sqrt(c->GetSigmaY2()), 0.08)):0.08;
+ yc[n]-= ycorr;
+ if(IsRowCross()){ // estimate closest distance to anode wire
+ d = DZ-xc[n]*dzdx;
+ d -= ((Int_t)(2 * d)) / 2.0;
+ if (d > 0.25) d = 0.5 - d;
+ }
+ // recalculate cluster error from knowledge of the track inclination in the bending plane
+ // and eventually distance to anode wire
+ c->SetSigmaY2(fS2PRF, fDiffT, fExB, xc[n], d, fYref[1]);
+ s2x = c->GetSX(c->GetLocalTimeBin(), d); s2x*=s2x;
sy[n] = c->GetSigmaY2()>0?(TMath::Min(Double_t(c->GetSigmaY2()), 6.4e-3)):6.4e-3;
- sy[n]+= fPad[2]*fPad[2]*(s2dz+xc[n]*xc[n]*s2dzdx);
+ sy[n]+= t2*(s2dz+xc[n]*xc[n]*s2dzdx+dzdx*dzdx*s2x);
sy[n] = TMath::Sqrt(sy[n]);
n++;
}
break;
}
}
- if(col != c->GetPadCol()){
- col = c->GetPadCol();
- cs = pp->GetColSize(col);
- }
+
//Use local cluster coordinates - the code should be identical with AliTRDtransform::Transform() !!!
//A.Bercuci 27.11.13
- xc[n] = c->GetXloc(fT0, fVD); // c->GetX();
- yc[n] = c->GetYloc(pp->GetColPos(col) + .5*cs, fS2PRF, cs) - xc[n]*fExB ;
- yc[n] -= fPad[2]*(dz+xc[n]*dzdx);
- //sy[n] = c->GetSigmaY2()>0?(TMath::Min(TMath::Sqrt(c->GetSigmaY2()), 0.08)):0.08;
+ Double_t trk[] = {c->GetX(), c->GetY(), c->GetZ()};
+ mDet->MasterToLocal(trk, loc);
+ xc[n] = AliTRDgeometry::AnodePos()-loc[0]; //c->GetXloc(fT0, fVD); // c->GetX();
+ yc[n] = loc[1]; //c->GetYloc(pp->GetColPos(col) + .5*cs, fS2PRF, cs) - xc[n]*fExB; //c->GetY();
+ yc[n]-= fPad[2]*(dz+xc[n]*dzdx);
+ yc[n]-= ycorr;
+
+ d = DZ-xc[n]*dzdx;
+ d -= ((Int_t)(2 * d)) / 2.0;
+ if (d > 0.25) d = 0.5 - d;
+ c->SetSigmaY2(fS2PRF, fDiffT, fExB, xc[n], d, fYref[1]);
+ s2x = c->GetSX(c->GetLocalTimeBin(), d); s2x*=s2x;
sy[n] = c->GetSigmaY2()>0?(TMath::Min(Double_t(c->GetSigmaY2()), 6.4e-3)):6.4e-3;
- sy[n]+= fPad[2]*fPad[2]*(s2dz+xc[n]*xc[n]*s2dzdx);
+ sy[n]+= t2*(s2dz+xc[n]*xc[n]*s2dzdx+dzdx*dzdx*s2x);
sy[n] = TMath::Sqrt(sy[n]);
n++;
}
fYfit[1] = -par[1];
//printf(" yfit: %f [%f] x[%e] dydx[%f]\n", fYfit[0], par[0], fX, par[1]);
// store covariance
-
- //
- // MI comment modification (03.05.2014)
- // In currently used code variance is used to estimate the tracklet error
- // see AliTRDtrackerV1::AliTRDLeastSquare::Eval()
- // 2 problems:
- // a.) Assumption about the intdpendent error not valid beacause of time response function
- // b.) Constuction of cluster errors used in cl->GetSigmaY2() and AliTRDtrackerV1::AliTRDLeastSquare::Eval
- // to be parameterized
- // c.) For crossing pad-rows the linear fit AliTRDtrackerV1::AliTRDLeastSquare::Eval do not take into account step
- // Therefore y possition is biased, bias is y dependent
- // Effective correction factor used to rescale error estimates
- // In future additional angular dependent error should be investigated ( as in TPC and in previous versions of the TRD tracking)
- //
- const Double_t kCorrelError=1.5;
-
- fCov[0] = kCorrelError*kScalePulls*cov[0]; // variance of y0
- fCov[1] = kCorrelError*kScalePulls*cov[2]; // covariance of y0, dydx
- fCov[2] = kCorrelError*kScalePulls*cov[1]; // variance of dydx
+ fCov[0] = kS2Ycorr*cov[0]; // variance of y0
+ fCov[1] = kScalePulls*cov[2]; // covariance of y0, dydx
+ fCov[2] = kScalePulls*cov[1]; // variance of dydx
// check radial position
Float_t xs=fX+.5*AliTRDgeometry::CamHght();
if(xs < 0. || xs > AliTRDgeometry::CamHght()+AliTRDgeometry::CdrHght()){
}
//___________________________________________________________________
-void AliTRDseedV1::SetXYZ(TGeoHMatrix *mDet/*, Float_t zpp*/)
+void AliTRDseedV1::SetXYZ(TGeoHMatrix *mDet)
{
// Apply alignment to the local position of tracklet
// A.Bercuci @ 27.11.2013
-// Int_t stk(AliTRDgeometry::GetStack(fDet));
-// Float_t zcorr[] = {-1.37, -0.59, 0., 0.62, 1.30};
Double_t loc[] = {AliTRDgeometry::AnodePos(), GetLocalY(), fZfit[0]}, trk[3]={0.};
mDet->LocalToMaster(loc, trk);
fX0 = trk[0];
fY = trk[1];
- fZ = trk[2];//-zcorr[stk];
- fZfit[1] = fZ/(fX0-fS2Y);
-
- if(!IsRowCross()){fZfit[1] *= 1.09; return;}
- // recalculate local z coordinate assuming primary track for row cross tracklets
- Double_t zoff(fZ-fZfit[0]); // no alignment aware !
- //printf("SetXYZ : zoff[%f] zpp[%f]\n", zoff, zpp);
- fZfit[0] = fX0*fZfit[1] - zoff;
- // recalculate tracking coordinates based on the new z coordinate
- loc[2] = fZfit[0];
- mDet->LocalToMaster(loc, trk);
- fX0 = trk[0];
- fY = trk[1];
- fZ = trk[2];//-zcorr[stk];
- fZfit[1] = /*(IsRowCross()?1.05:1.09)**/fZ/(fX0-fS2Y);
+ fZ = trk[2];
+ return;
+// if(!IsRowCross()){/*fZfit[1] *= 1.09;*/ return;}
+// // recalculate local z coordinate assuming primary track for row cross tracklets
+// Double_t zoff(fZ-fZfit[0]); // no alignment aware !
+// //printf("SetXYZ : zoff[%f] zpp[%f]\n", zoff, zpp);
+// fZfit[0] = fX0*fZfit[1] - zoff;
+// // recalculate tracking coordinates based on the new z coordinate
+// loc[2] = fZfit[0];
+// mDet->LocalToMaster(loc, trk);
+// fX0 = trk[0];
+// fY = trk[1];
+// fZ = trk[2];//-zcorr[stk];
+ //fZfit[1] = /*(IsRowCross()?1.05:1.09)**/fZ/(fX0-fS2Y);
}
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