--- /dev/null
+// @(#) $Id$
+
+// Author: Anders Vestbo <mailto:vestbo@fi.uib.no>
+//*-- Copyright © ALICE HLT Group
+
+#include "AliHLTTPCStandardIncludes.h"
+#include "AliHLTTPCRootTypes.h"
+#include "AliHLTTPCLogging.h"
+#include "AliHLTTPCVertex.h"
+#include "AliHLTTPCConfMapTrack.h"
+#include "AliHLTTPCConfMapPoint.h"
+#include "AliHLTTPCTransform.h"
+#include "AliHLTTPCConfMapFit.h"
+
+/** \class AliHLTTPCConfMapFit
+<pre>
+//_____________________________________________________________
+// AliHLTTPCConfMapFit
+//
+// Fit class for conformal mapping tracking
+</pre>
+*/
+
+#if __GNUC__ >= 3
+using namespace std;
+#endif
+
+ClassImp(AliHLTTPCConfMapFit)
+
+
+AliHLTTPCConfMapFit::AliHLTTPCConfMapFit(AliHLTTPCConfMapTrack *track,AliHLTTPCVertex *vertex)
+{
+ //constructor
+ fTrack = track;
+ fVertex = vertex;
+}
+
+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::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 num_of_hits = 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!=num_of_hits)
+ LOG(AliHLTTPCLog::kError,"AliHLTTPCConfMapFit::FitCircle","TrackFit")<<AliHLTTPCLog::kDec<<
+ "Mismatch of hits. Counter: "<<co<<" nHits: "<<num_of_hits<<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<num_of_hits; 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 ;
+
+ Int_t const 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);
+
+ //
+// 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 num_of_hits = 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 total_s ;
+
+ if ( fabs(localPsi) < 1. )
+ {
+ total_s = 2.0 * radius * asin ( localPsi ) ;
+ }
+ else
+ {
+ total_s = 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<num_of_hits; 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(cHit != fTrack->GetFirstHit())// hits->First())
+ {
+ 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(total_s);
+ // cHit->s = total_s ;
+
+ 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<num_of_hits; 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);
+
+ return 0 ;
+}
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff