+++ /dev/null
-// @(#) $Id$
-// Original: AliHLTConfMapFit.cxx,v 1.14 2005/06/14 10:55:21 cvetan
-
-/**************************************************************************
- * This file is property of and copyright by the ALICE HLT Project *
- * ALICE Experiment at CERN, All rights reserved. *
- * *
- * Primary Authors: Anders Vestbo, maintained by *
- * Matthias Richter <Matthias.Richter@ift.uib.no> *
- * for The ALICE HLT Project. *
- * *
- * 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. *
- **************************************************************************/
-
-/** @file AliHLTTPCConfMapFit.cxx
- @author Anders Vestbo, maintained by Matthias Richter
- @date
- @brief Fit class for conformal mapping tracking.
-*/
-
-// see header file for class documentation //
-// or //
-// refer to README to build package //
-// or //
-// visit http://web.ift.uib.no/~kjeks/doc/alice-hlt //
-
-#include "AliHLTTPCRootTypes.h"
-#include "AliHLTTPCLogging.h"
-#include "AliHLTTPCVertex.h"
-#include "AliHLTTPCConfMapTrack.h"
-#include "AliHLTTPCConfMapPoint.h"
-#include "AliHLTTPCTransform.h"
-#include "AliHLTTPCConfMapFit.h"
-
-#if __GNUC__ >= 3
-using namespace std;
-#endif
-
-ClassImp(AliHLTTPCConfMapFit);
-
-AliHLTTPCConfMapFit::AliHLTTPCConfMapFit()
- :
- fTrack(NULL),
- fVertex(NULL)
-{
- //constructor
-}
-
-AliHLTTPCConfMapFit::AliHLTTPCConfMapFit(AliHLTTPCConfMapTrack *track,AliHLTTPCVertex *vertex)
- :
- fTrack(track),
- fVertex(vertex)
-
-{
- //constructor
-}
-
-AliHLTTPCConfMapFit::~AliHLTTPCConfMapFit()
-{
- // destructor
-}
-
-Int_t AliHLTTPCConfMapFit::FitHelix()
-{
- //fit the helix
- if(FitCircle())
- {
- LOG(AliHLTTPCLog::kError,"AliHLTTPCConfMapFit::FitHelix","TrackFit")<<AliHLTTPCLog::kDec<<
- "Problems during circle fit"<<ENDLOG;
- return 1;
- }
- if(FitLine())
- {
- LOG(AliHLTTPCLog::kError,"AliHLTTPCConfMapFit::FitHelix","TrackFit")<<AliHLTTPCLog::kDec<<
- "Problems during line fit"<<ENDLOG;
- return 1;
- }
- return 0;
-}
-
-Int_t AliHLTTPCConfMapFit::FitStraightLine() {
- //fit the straight line
- if(FitLineXY()) {
- LOG(AliHLTTPCLog::kError,"AliHLTTPCConfMapFit::FitStraightLine","TrackFit")<<AliHLTTPCLog::kDec<<
- "Problems during stright line fit in XY plane"<<ENDLOG;
- return 1;
- }
- if(FitLineSZ()){
- LOG(AliHLTTPCLog::kError,"AliHLTTPCConfMapFit::FitStraightLine","TrackFit")<<AliHLTTPCLog::kDec<<
- "Problems during stright line fit in SZ plane"<<ENDLOG;
- return 1;
- }
- return 0;
-}
-
-Int_t AliHLTTPCConfMapFit::FitCircle()
-{
- //-----------------------------------------------------------------
- //Fits circle parameters using algorithm
- //described by ChErnov and Oskov in Computer Physics
- //Communications.
- //
- //Written in FORTRAN by Jawluen Tang, Physics department , UT-Austin
- //Moved to C by Pablo Yepes
- //Moved to AliROOT by ASV.
- //------------------------------------------------------------------
-
- Double_t wsum = 0.0 ;
- Double_t xav = 0.0 ;
- Double_t yav = 0.0 ;
-
- Int_t numOfHits = fTrack->GetNumberOfPoints();
- //
- // Loop over hits calculating average
- Int_t co=0;
-
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit())
- {
- co++;
- AliHLTTPCConfMapPoint *cHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
- cHit->SetXYWeight( 1./ (Double_t)(cHit->GetXerr()*cHit->GetXerr() + cHit->GetYerr()*cHit->GetYerr()) );
- wsum += cHit->GetXYWeight() ;
- xav += cHit->GetXYWeight() * cHit->GetX() ;
- yav += cHit->GetXYWeight() * cHit->GetY() ;
- }
- if(co!=numOfHits)
- LOG(AliHLTTPCLog::kError,"AliHLTTPCConfMapFit::FitCircle","TrackFit")<<AliHLTTPCLog::kDec<<
- "Mismatch of hits. Counter: "<<co<<" nHits: "<<numOfHits<<ENDLOG;
- if (fTrack->ComesFromMainVertex() == true)
- {
- wsum += fVertex->GetXYWeight() ;
- xav += fVertex->GetX() ;
- yav += fVertex->GetY() ;
- }
-
- xav = xav / wsum ;
- yav = yav / wsum ;
-//
-// CALCULATE <X**2>, <XY>, AND <Y**2> WITH <X> = 0, & <Y> = 0
-//
- Double_t xxav = 0.0 ;
- Double_t xyav = 0.0 ;
- Double_t yyav = 0.0 ;
- Double_t xi, yi ;
-
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit())
- {
- //AliHLTTPCConfMapPoint *cHit = (AliHLTTPCConfMapPoint *)hits->At(hit_counter);
- AliHLTTPCConfMapPoint *cHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
- xi = cHit->GetX() - xav ;
- yi = cHit->GetY() - yav ;
- xxav += xi * xi * cHit->GetXYWeight() ;
- xyav += xi * yi * cHit->GetXYWeight() ;
- yyav += yi * yi * cHit->GetXYWeight() ;
- }
-
- if (fTrack->ComesFromMainVertex() == true)
- {
- xi = fVertex->GetX() - xav ;
- yi = fVertex->GetY() - yav ;
- xxav += xi * xi * fVertex->GetXYWeight() ;
- xyav += xi * yi * fVertex->GetXYWeight() ;
- yyav += yi * yi * fVertex->GetXYWeight() ;
- }
- xxav = xxav / wsum ;
- xyav = xyav / wsum ;
- yyav = yyav / wsum ;
-//
-//--> ROTATE COORDINATES SO THAT <XY> = 0
-//
-//--> SIGN(C**2 - S**2) = SIGN(XXAV - YYAV) >
-//--> & > ==> NEW : (XXAV-YYAV) > 0
-//--> SIGN(S) = SIGN(XYAV) >
-
- Double_t a = fabs( xxav - yyav ) ;
- Double_t b = 4.0 * xyav * xyav ;
-
- Double_t asqpb = a * a + b ;
- Double_t rasqpb = sqrt ( asqpb) ;
-
- Double_t splus = 1.0 + a / rasqpb ;
- Double_t sminus = b / (asqpb * splus) ;
-
- splus = sqrt (0.5 * splus ) ;
- sminus = sqrt (0.5 * sminus) ;
-//
-//-> FIRST REQUIRE : SIGN(C**2 - S**2) = SIGN(XXAV - YYAV)
-//
- Double_t sinrot, cosrot ;
- if ( xxav <= yyav ) {
- cosrot = sminus ;
- sinrot = splus ;
- }
- else {
- cosrot = splus ;
- sinrot = sminus ;
- }
-//
-//-> REQUIRE : SIGN(S) = SIGN(XYAV) * SIGN(C) (ASSUMING SIGN(C) > 0)
-//
- if ( xyav < 0.0 ) sinrot = - sinrot ;
-//
-//--> WE NOW HAVE THE SMALLEST ANGLE THAT GUARANTEES <X**2> > <Y**2>
-//--> TO GET THE SIGN OF THE CHARGE RIGHT, THE NEW X-AXIS MUST POINT
-//--> OUTWARD FROM THE ORGIN. WE ARE FREE TO CHANGE SIGNS OF BOTH
-//--> COSROT AND SINROT SIMULTANEOUSLY TO ACCOMPLISH THIS.
-//
-//--> CHOOSE SIGN OF C WISELY TO BE ABLE TO GET THE SIGN OF THE CHARGE
-//
- if ( cosrot*xav+sinrot*yav < 0.0 ) {
- cosrot = -cosrot ;
- sinrot = -sinrot ;
- }
-//
-//-> NOW GET <R**2> AND RSCALE= SQRT(<R**2>)
-//
- Double_t rrav = xxav + yyav ;
- Double_t rscale = sqrt(rrav) ;
-
- xxav = 0.0 ;
- yyav = 0.0 ;
- xyav = 0.0 ;
- Double_t xrrav = 0.0 ;
- Double_t yrrav = 0.0 ;
- Double_t rrrrav = 0.0 ;
-
- Double_t xixi, yiyi, riri, wiriri, xold, yold ;
-
- //for (hit_counter=0; hit_counter<numOfHits; hit_counter++)
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit())
- {
- //AliHLTTPCConfMapPoint *cHit = (AliHLTTPCConfMapPoint*)hits->At(hit_counter);
- AliHLTTPCConfMapPoint* cHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
-
- xold = cHit->GetX() - xav ;
- yold = cHit->GetY() - yav ;
- //
- //--> ROTATE SO THAT <XY> = 0 & DIVIDE BY RSCALE SO THAT <R**2> = 1
- //
- xi = ( cosrot * xold + sinrot * yold ) / rscale ;
- yi = ( -sinrot * xold + cosrot * yold ) / rscale ;
-
- xixi = xi * xi ;
- yiyi = yi * yi ;
- riri = xixi + yiyi ;
- wiriri = cHit->GetXYWeight() * riri ;
-
- xyav += cHit->GetXYWeight() * xi * yi ;
- xxav += cHit->GetXYWeight() * xixi ;
- yyav += cHit->GetXYWeight() * yiyi ;
-
- xrrav += wiriri * xi ;
- yrrav += wiriri * yi ;
- rrrrav += wiriri * riri ;
- }
- //
-// Include vertex if required
-//
- if (fTrack->ComesFromMainVertex() == true)
- {
- xold = fVertex->GetX() - xav ;
- yold = fVertex->GetY() - yav ;
- //
- //--> ROTATE SO THAT <XY> = 0 & DIVIDE BY RSCALE SO THAT <R**2> = 1
- //
- xi = ( cosrot * xold + sinrot * yold ) / rscale ;
- yi = ( -sinrot * xold + cosrot * yold ) / rscale ;
-
- xixi = xi * xi ;
- yiyi = yi * yi ;
- riri = xixi + yiyi ;
- wiriri = fVertex->GetXYWeight() * riri ;
-
- xyav += fVertex->GetXYWeight() * xi * yi ;
- xxav += fVertex->GetXYWeight() * xixi ;
- yyav += fVertex->GetXYWeight() * yiyi ;
-
- xrrav += wiriri * xi ;
- yrrav += wiriri * yi ;
- rrrrav += wiriri * riri ;
- }
- //
- //
- //
- //--> DIVIDE BY WSUM TO MAKE AVERAGES
- //
- xxav = xxav / wsum ;
- yyav = yyav / wsum ;
- xrrav = xrrav / wsum ;
- yrrav = yrrav / wsum ;
- rrrrav = rrrrav / wsum ;
- xyav = xyav / wsum ;
-
- const Int_t ntry = 5 ;
-//
-//--> USE THESE TO GET THE COEFFICIENTS OF THE 4-TH ORDER POLYNIMIAL
-//--> DON'T PANIC - THE THIRD ORDER TERM IS ZERO !
-//
- Double_t xrrxrr = xrrav * xrrav ;
- Double_t yrryrr = yrrav * yrrav ;
- Double_t rrrrm1 = rrrrav - 1.0 ;
- Double_t xxyy = xxav * yyav ;
-
- Double_t c0 = rrrrm1*xxyy - xrrxrr*yyav - yrryrr*xxav ;
- Double_t c1 = - rrrrm1 + xrrxrr + yrryrr - 4.0*xxyy ;
- Double_t c2 = 4.0 + rrrrm1 - 4.0*xxyy ;
- Double_t c4 = - 4.0 ;
-//
-//--> COEFFICIENTS OF THE DERIVATIVE - USED IN NEWTON-RAPHSON ITERATIONS
-//
- Double_t c2d = 2.0 * c2 ;
- Double_t c4d = 4.0 * c4 ;
-//
-//--> 0'TH VALUE OF LAMDA - LINEAR INTERPOLATION BETWEEN P(0) & P(YYAV)
-//
-// LAMDA = YYAV * C0 / (C0 + YRRSQ * (XXAV-YYAV))
- Double_t lamda = 0.0 ;
- Double_t dlamda = 0.0 ;
-//
- Double_t chiscl = wsum * rscale * rscale ;
- Double_t dlamax = 0.001 / chiscl ;
-
- Double_t p, pd ;
- for ( int itry = 1 ; itry <= ntry ; itry++ ) {
- p = c0 + lamda * (c1 + lamda * (c2 + lamda * lamda * c4 )) ;
- pd = (c1 + lamda * (c2d + lamda * lamda * c4d)) ;
- dlamda = -p / pd ;
- lamda = lamda + dlamda ;
- if (fabs(dlamda)< dlamax) break ;
- }
-
- Double_t chi2 = (Double_t)(chiscl * lamda) ;
-
- fTrack->SetChiSq1(chi2);
- // Double_t dchisq = chiscl * dlamda ;
-//
-//--> NOW CALCULATE THE MATRIX ELEMENTS FOR ALPHA, BETA & KAPPA
-//
- Double_t h11 = xxav - lamda ;
- Double_t h14 = xrrav ;
- Double_t h22 = yyav - lamda ;
- Double_t h24 = yrrav ;
- Double_t h34 = 1.0 + 2.0*lamda ;
- if ( h11 == 0.0 || h22 == 0.0 ){
- LOG(AliHLTTPCLog::kError,"AliHLTTPCConfMapFit::FitCircle","TrackFit")<<AliHLTTPCLog::kDec<<
- "Problems fitting circle"<<ENDLOG;
- return 1 ;
- }
- Double_t rootsq = (h14*h14)/(h11*h11) + 4.0*h34 ;
-
- Double_t ratio, kappa, beta ;
- if ( fabs(h22) > fabs(h24) ) {
- ratio = h24 / h22 ;
- rootsq = ratio * ratio + rootsq ;
- kappa = 1.0 / sqrt(rootsq) ;
- beta = - ratio * kappa ;
- }
- else {
- ratio = h22 / h24 ;
- rootsq = 1.0 + ratio * ratio * rootsq ;
- beta = 1.0 / sqrt(rootsq) ;
- if ( h24 > 0 ) beta = - beta ;
- kappa = -ratio * beta ;
- }
- Double_t alpha = - (h14/h11) * kappa ;
-//
-//--> transform these into the lab coordinate system
-//--> first get kappa and back to real dimensions
-//
- Double_t kappa1 = kappa / rscale ;
- Double_t dbro = 0.5 / kappa1 ;
-//
-//--> next rotate alpha and beta and scale
-//
- Double_t alphar = (cosrot * alpha - sinrot * beta)* dbro ;
- Double_t betar = (sinrot * alpha + cosrot * beta)* dbro ;
-//
-//--> then translate by (xav,yav)
-//
- Double_t acent = (double)(xav - alphar) ;
- Double_t bcent = (double)(yav - betar ) ;
- Double_t radius = (double)dbro ;
-//
-// Get charge
-//
- Int_t q = ( ( yrrav < 0 ) ? 1 : -1 ) ;
-
- fTrack->SetCharge(q);
-
-
- //Set the first point on the track to the space point coordinates of the innermost track
- //This will be updated to lie on the fit later on (AliHLTTPCTrack::UpdateToFirstPoint).
- Double_t x0,y0,psi,pt ;
- AliHLTTPCConfMapPoint *lHit = (AliHLTTPCConfMapPoint*)fTrack->GetLastHit();
- x0 = lHit->GetX();
- y0 = lHit->GetY();
- fTrack->SetFirstPoint(x0,y0,0); //Z-value is set in FitLine
-
- psi = (Double_t)atan2(bcent-y0,acent-x0) ;
- psi = psi + q * AliHLTTPCTransform::PiHalf();
- if ( psi < 0 ) psi = psi + AliHLTTPCTransform::TwoPi();
- pt = (Double_t)(AliHLTTPCTransform::GetBFieldValue() * radius ) ;
-
- //Update the track parameters with the parameters from this fit:
- fTrack->SetPsi(psi);
- fTrack->SetPt(pt);
- fTrack->SetRadius(radius);
- fTrack->SetCenterX(acent);
- fTrack->SetCenterY(bcent);
-
- fTrack->SetY0err(0.03);
- //set error for pT and Y. psi, Z and Tgl are set.
-
- //
-// Get errors from fast fit
-//
- //if ( getPara()->getErrors ) getErrorsCircleFit ( acent, bcent, radius ) ;
-//
- return 0 ;
-
-}
-
-//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-// Fit Line in s-z plane
-//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Int_t AliHLTTPCConfMapFit::FitLine ( )
-{
- //
- //Initialization
- //
- Double_t sum = 0.F ;
- Double_t ss = 0.F ;
- Double_t sz = 0.F ;
- Double_t sss = 0.F ;
- Double_t ssz = 0.F ;
- //
- //find sum , sums ,sumz, sumss
- //
- Double_t dx, dy ;
- Double_t radius = (Double_t)(fTrack->GetPt() / AliHLTTPCTransform::GetBFieldValue() ) ;
-
- //TObjArray *hits = fTrack->GetHits();
- //Int_t numOfHits = fTrack->GetNumberOfPoints();
-
- if (0)// fTrack->ComesFromMainVertex() == true )
- {
- dx = ((AliHLTTPCConfMapPoint*)fTrack->GetFirstHit())->GetX() - fVertex->GetX();
- dy = ((AliHLTTPCConfMapPoint*)fTrack->GetFirstHit())->GetY() - fVertex->GetY() ;
- }
- else
- {
- dx = ((AliHLTTPCConfMapPoint *)fTrack->GetFirstHit())->GetX() - ((AliHLTTPCConfMapPoint *)fTrack->GetLastHit())->GetX() ;
- dy = ((AliHLTTPCConfMapPoint *)fTrack->GetFirstHit())->GetY() - ((AliHLTTPCConfMapPoint *)fTrack->GetLastHit())->GetY() ;
- //dx = ((AliHLTTPCConfMapPoint *)hits->First())->GetX() - ((AliHLTTPCConfMapPoint *)hits->Last())->GetX() ;
- //dy = ((AliHLTTPCConfMapPoint *)hits->First())->GetY() - ((AliHLTTPCConfMapPoint *)hits->Last())->GetY() ;
- }
-
- Double_t localPsi = 0.5F * sqrt ( dx*dx + dy*dy ) / radius ;
- Double_t totalS ;
-
- if ( fabs(localPsi) < 1. )
- {
- totalS = 2.0 * radius * asin ( localPsi ) ;
- }
- else
- {
- totalS = 2.0 * radius * AliHLTTPCTransform::Pi() ;
- }
-
- AliHLTTPCConfMapPoint *previousHit = NULL;
-
- // FtfBaseHit *previousHit = 0 ;
-
- //for ( startLoop() ; done() ; nextHit() ) {
- Double_t dpsi,s;
-
- // for(hit_counter=0; hit_counter<numOfHits; hit_counter++)
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit())
- {
- // AliHLTTPCConfMapPoint *cHit = (AliHLTTPCConfMapPoint*)hits->At(hit_counter);
- AliHLTTPCConfMapPoint *cHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
- // if ( GetCurrentHit() != GetFirstHit() )
- if(previousHit)// hits->First())
- {
- // this means cHit != fTrack->GetFirstHit()
- dx = cHit->GetX() - previousHit->GetX() ;
- dy = cHit->GetY() - previousHit->GetY() ;
- dpsi = 0.5 * (Double_t)sqrt ( dx*dx + dy*dy ) / radius ;
- fTrack->SetPsierr(dpsi);
- s = previousHit->GetS() - 2.0 * radius * (Double_t)asin ( dpsi ) ;
- cHit->SetS(s);
- }
- else
- cHit->SetS(totalS);
- // cHit->s = totalS ;
-
- sum += cHit->GetZWeight() ;
- ss += cHit->GetZWeight() * cHit->GetS() ;
- sz += cHit->GetZWeight() * cHit->GetZ() ;
- sss += cHit->GetZWeight() * cHit->GetS() * cHit->GetS() ;
- ssz += cHit->GetZWeight() * cHit->GetS() * cHit->GetZ() ;
- previousHit = cHit ;
- }
-
- Double_t chi2,det = sum * sss - ss * ss;
- if ( fabs(det) < 1e-20)
- {
- chi2 = 99999.F ;
- fTrack->SetChiSq2(chi2);
- return 0 ;
- }
-
- //Compute the best fitted parameters A,B
- Double_t tanl,z0,dtanl,dz0;
-
- tanl = (Double_t)((sum * ssz - ss * sz ) / det );
- z0 = (Double_t)((sz * sss - ssz * ss ) / det );
-
- fTrack->SetTgl(tanl);
- fTrack->SetZ0(z0);
-
- // calculate chi-square
-
- chi2 = 0.;
- Double_t r1 ;
-
- //for(hit_counter=0; hit_counter<numOfHits; hit_counter++)
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit())
- {
- //AliHLTTPCConfMapPoint *cHit = (AliHLTTPCConfMapPoint*)hits->At(hit_counter);
- AliHLTTPCConfMapPoint *cHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
- r1 = cHit->GetZ() - tanl * cHit->GetS() - z0 ;
- chi2 += (Double_t) ( (Double_t)cHit->GetZWeight() * (r1 * r1) );
- }
- fTrack->SetChiSq2(chi2);
- //
- // calculate estimated variance
- // varsq=chi/(double(n)-2.)
- // calculate covariance matrix
- // siga=sqrt(varsq*sxx/det)
- // sigb=sqrt(varsq*sum/det)
- //
- dtanl = (Double_t) ( sum / det );
- dz0 = (Double_t) ( sss / det );
-
- fTrack->SetTglerr(dtanl);
- fTrack->SetZ0err(dz0);
-
- //The calculation of pT comes from "Perticle Physics Booklet":
- //24.11 Measurement of particle momenta in a uniform magnetic field.
- //(dk)^2=(dk_res)^2 + (dk_ms)^2
- //for now k_ms is 0. Need to find length of track in 3D.
-
- Double_t lengthXY = fTrack->GetLengthXY();
- //Double_t lengthTot = fTrack->GetLengthTot();
- //Double_t beta = fTrack->GetP()/TMath::Sqrt((fTrack->GetP()*fTrack->GetP())+(0.13957*0.13957));
- //Double_t lambda = TMath::ATan(fTrack->GetTgl());
- Double_t lengthXY2 = lengthXY*lengthXY;
- Int_t nCluster4 = fTrack->GetNHits()+4;
-
- Double_t Kres = 0.03/lengthXY2;
- Kres = Kres * TMath::Sqrt(720/nCluster4);
-
- //Double_t Kres = (0.03/(lengthXY*lengthXY))*TMath::Sqrt(720/(fTrack->GetNHits()+4));
-
- //Double_t d = lengthTot*fTrack->GetP()*beta*TMath::Cos(lambda)*TMath::Cos(lambda);
- //Double_t Kms = (0.016/d)*TMath::Sqrt(lengthTot/24.0);
- Double_t Kms = 0.0;
-
- Double_t KTot = TMath::Sqrt((Kres * Kres) + (Kms * Kms));
-
- Double_t Pterr = (1/(0.3*AliHLTTPCTransform::GetBField()))*KTot;
-
- fTrack->SetPterr(Pterr);
-
- return 0 ;
-}
-
-
-//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-// Straight Line Fit in x-y plane
-//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Int_t AliHLTTPCConfMapFit::FitLineXY ( ){
- // -----------------------------------------------------------------------------
- // Implementation after Numerical Recipes in C, 2nd Edtion, chapter 15.2, p. 661
- // with y = b*x + a
- // and Data Analysis for Physical Science Students, Luis Lyons, chapter 2.4 p.51
- // with y = a' + bx' , x' = x - <x>
- // -----------------------------------------------------------------------------
-
- Double_t s = 0.;
- Double_t sx = 0.;
-
- Double_t sPrime = 0.;
- Double_t sxPrime = 0.;
- Double_t sxxPrime = 0.;
- Double_t syPrime = 0.;
- Double_t sxyPrime = 0.;
-
- Double_t chi2 = 0.;
-
- Int_t numOfHits = fTrack->GetNumberOfPoints();
-
- Int_t co=0;
-
- // - Loop over hits calculating average : xav
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit()) {
- co++;
- AliHLTTPCConfMapPoint *currentHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
- // ** maybe not necessary, already done in ConfMapPoint
- currentHit->SetXYWeight( 1./ (Double_t)(currentHit->GetXerr()*currentHit->GetXerr() + currentHit->GetYerr()*currentHit->GetYerr()) );
- // **
- s += currentHit->GetXYWeight();
- sx += currentHit->GetXYWeight() * currentHit->GetX();
- }
-
- if(co!=numOfHits)
- LOG(AliHLTTPCLog::kError,"AliHLTTPCConfMapFit::FitLineXY","TrackFit") << "Mismatch of hits. Counter: "<<co<<" nHits: "<<numOfHits<<ENDLOG;
-
- Double_t xav = (Double_t)sx / s;
-
- // Calculate weighted means
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit()) {
- AliHLTTPCConfMapPoint *currentHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
-
- Double_t xPrime = currentHit->GetX() - xav;
- sPrime += currentHit->GetXYWeight();
- sxPrime += currentHit->GetXYWeight() * xPrime;
- sxxPrime += currentHit->GetXYWeight() * xPrime * xPrime;
- syPrime += currentHit->GetXYWeight() * currentHit->GetY();
- sxyPrime += currentHit->GetXYWeight() * xPrime * currentHit->GetY();
- }
-
- Double_t det = sPrime*sxxPrime + sxPrime*sxPrime;
-
- if (fabs(det) < 1e-20) {
- LOG(AliHLTTPCLog::kDebug,"AliHLTTPCConfMapFit::FitLineXY","TrackFit") << "Determinant == 0" << ENDLOG;
- chi2 = 99999.F ;
- fTrack->SetChiSq1(chi2);
- return -1 ;
- }
-
- Double_t b = (Double_t)(sPrime*sxyPrime - sxPrime*syPrime) / det; // line parameter b
- Double_t aPrime = (Double_t)(sxxPrime*syPrime - sxPrime*sxyPrime) / det; // line parameter a
-
- Double_t sigma2b = (Double_t)1. / sxxPrime;
- //-- Double_t sigma2aprime = (Double_t)1. /sPrime;
-
- // Get gradient angle psi of line in xy plane
- Double_t psi = (Double_t) atan(b) ;
-
- // Calculate chi2
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit()) {
- AliHLTTPCConfMapPoint *currentHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
- Double_t tempchi = currentHit->GetY() - aPrime - b*(currentHit->GetX() - xav);
- chi2 += tempchi*tempchi*currentHit->GetXYWeight() ;
- }
-
- Double_t a = aPrime - b*xav;
-
-
- // Set TrackParameter
- fTrack->SetChiSq1(chi2);
- fTrack->SetPsi(psi);
- fTrack->SetPsierr(sigma2b);
- fTrack->SetCenterX(0.); // Set to point on the track (for UpdateToFirstPoint)
- fTrack->SetCenterY(a); // Set to point on the track (for UpdateToFirstPoint)
-
- //Set the first point on the track to the space point coordinates of the innermost track
- //This will be updated to lie on the fit later on (AliHLTTPCTrack::UpdateToFirstPoint).
- AliHLTTPCConfMapPoint *lastHit = (AliHLTTPCConfMapPoint*)fTrack->GetLastHit();
- Double_t x0 = lastHit->GetX();
- Double_t y0 = lastHit->GetY();
- fTrack->SetFirstPoint(x0,y0,0); //Z-value is set in FitLineSZ
-
-
- //Set Defaults
- fTrack->SetRadius(-1.);
- fTrack->SetCharge(1);
- fTrack->SetPt(-1.);
-
-
- return 0;
-}
-
-
-//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-// Straight Line Fit in s-z plane
-//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Int_t AliHLTTPCConfMapFit::FitLineSZ ( ){
- // -----------------------------------------------------------------------------
- // Implementation after Numerical Recipes in C, 2nd Edtion, chapter 15.2, p. 661
- // with z = b*s + a
- // and Data Analysis for Physical Science Students, Luis Lyons, chapter 2.4 p.51
- // with z = a' + bs' , s' = s - <s>
- // -----------------------------------------------------------------------------
-
- Double_t S = 0.;
- Double_t Ss = 0.;
-
- Double_t sPrime = 0.;
- Double_t ssPrime = 0.;
- Double_t sssPrime = 0.;
- Double_t szPrime = 0.;
- Double_t sszPrime = 0.;
-
- Double_t chi2 = 0.;
-
- // Matthias 16.10.2007
- // what's that!!! local variables 's' and 'S'
- // change Double_t s = 0.; -> slength
- Double_t slength = 0.;
-
- // Matthias 23.02.2011
- // this looks like a bug: previousHit is initialized, not changed
- // in the loop, but dereferenced for all but the first hit
- // changing the condition and adding an assignment at the end
- // of the loop
- AliHLTTPCConfMapPoint *previousHit = NULL;
-
- // - Loop over hits calculating length in xy-plane: s
- // - Loop over hits calculating average : sav
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit()) {
- AliHLTTPCConfMapPoint *currentHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
- if(previousHit) {
- // this means currentHit != fTrack->GetFirstHit()
- Double_t dx = currentHit->GetX() - previousHit->GetX() ;
- Double_t dy = currentHit->GetY() - previousHit->GetY() ;
- slength = previousHit->GetS() - (Double_t)sqrt ( dx*dx + dy*dy );
- }
- else{
- Double_t dx = ((AliHLTTPCConfMapPoint *)fTrack->GetFirstHit())->GetX() - ((AliHLTTPCConfMapPoint *)fTrack->GetLastHit())->GetX();
- Double_t dy = ((AliHLTTPCConfMapPoint *)fTrack->GetFirstHit())->GetY() - ((AliHLTTPCConfMapPoint *)fTrack->GetLastHit())->GetY();
- slength = (Double_t)sqrt ( dx*dx + dy*dy );
- }
-
- currentHit->SetS(slength);
-
- S += currentHit->GetZWeight();
- Ss += currentHit->GetZWeight() * currentHit->GetS();
-
- // Matthias 23.02.2011
- // adding missing assignment, otherwise previousHit stays NULL
- previousHit=currentHit;
- }
-
- Double_t sav = (Double_t)Ss / S;
-
- // Calculate weighted means
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit()) {
- AliHLTTPCConfMapPoint *currentHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
-
- // Matthias 20.05.2008
- // here was a shadowed variable, sPrime is formerly defined
- // renamed it to lsPrime ('local')
- Double_t lsPrime = currentHit->GetS() - sav;
- lsPrime += currentHit->GetZWeight();
- ssPrime += currentHit->GetZWeight() * lsPrime;
- sssPrime += currentHit->GetZWeight() * lsPrime * lsPrime;
- szPrime += currentHit->GetZWeight() * currentHit->GetZ();
- sszPrime += currentHit->GetZWeight() * lsPrime * currentHit->GetZ();
- }
-
- Double_t det = sPrime*sssPrime + ssPrime*ssPrime;
-
- if (fabs(det) < 1e-20) {
- LOG(AliHLTTPCLog::kDebug,"AliHLTTPCConfMapFit::FitLineSZ","TrackFit") << "Determinant == 0" << ENDLOG;
- chi2 = 99999.F ;
- fTrack->SetChiSq2(chi2);
- return -1 ;
- }
-
- Double_t b = (Double_t)(sPrime*sszPrime - ssPrime*szPrime) / det; // line parameter b
- Double_t aPrime = (Double_t)(sssPrime*szPrime - ssPrime*sszPrime) / det; // line parameter a
-
- Double_t a = aPrime - b*sav;
-
- Double_t sigma2b = (Double_t) 1. / sssPrime;
- Double_t sigma2aprime = (Double_t) 1. /sPrime;
-
- Double_t sigma2a = sigma2aprime + sav*sav * sigma2b*sigma2b;
-
- // Calculate chi2
- for(fTrack->StartLoop(); fTrack->LoopDone(); fTrack->GetNextHit()) {
- AliHLTTPCConfMapPoint *currentHit = (AliHLTTPCConfMapPoint*)fTrack->GetCurrentHit();
- Double_t tempchi = currentHit->GetZ() - aPrime - b*(currentHit->GetS() - sav);
- chi2 += tempchi*tempchi*currentHit->GetZWeight() ;
- }
-
- // Set TrackParameter
- fTrack->SetChiSq2(chi2);
- fTrack->SetTgl(b);
- fTrack->SetZ0(a);
- fTrack->SetTglerr(sigma2b);
-// fTrack->SetZ0err(sigma2aprime); // maybe subject to check
- fTrack->SetZ0err(sigma2a); // maybe subject to check
- return 0;
-}
-
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff