/*
$Log$
+Revision 1.8 2001/01/08 11:01:02 gosset
+Modifications used for addendum to Dimuon TDR (JP Cussonneau):
+*. MaxBendingMomentum to make both a segment and a track (default 500)
+*. MaxChi2 per degree of freedom to make a track (default 100)
+*. MinBendingMomentum used also to make a track
+ and not only a segment (default 3)
+*. wider roads for track search in stations 1 to 3
+*. extrapolation to actual Z instead of Z(chamber) in FollowTracks
+*. in track fit:
+ - limits on parameters X and Y (+/-500)
+ - covariance matrices in double precision
+ - normalization of covariance matrices before inversion
+ - suppression of Minuit printouts
+*. correction against memory leak (delete extrapHit) in FollowTracks
+*. RMax to 10 degrees with Z(chamber) instead of fixed values;
+ RMin and Rmax cuts suppressed in NewHitForRecFromGEANT,
+ because useless with realistic geometry
+
+Revision 1.7 2000/09/19 15:50:46 gosset
+TrackChi2MCS function: covariance matrix better calculated,
+taking into account missing planes...
+
+Revision 1.6 2000/07/20 12:45:27 gosset
+New "EventReconstructor..." structure,
+ hopefully more adapted to tree/streamer.
+"AliMUONEventReconstructor::RemoveDoubleTracks"
+ to keep only one track among similar ones.
+
+Revision 1.5 2000/07/18 16:04:06 gosset
+AliMUONEventReconstructor package:
+* a few minor modifications and more comments
+* a few corrections
+ * right sign for Z of raw clusters
+ * right loop over chambers inside station
+ * symmetrized covariance matrix for measurements (TrackChi2MCS)
+ * right sign of charge in extrapolation (ExtrapToZ)
+ * right zEndAbsorber for Branson correction below 3 degrees
+* use of TVirtualFitter instead of TMinuit for AliMUONTrack::Fit
+* no parameter for AliMUONTrack::Fit() but more fit parameters in Track object
+
+Revision 1.4 2000/06/30 10:15:48 gosset
+Changes to EventReconstructor...:
+precision fit with multiple Coulomb scattering;
+extrapolation to vertex with Branson correction in absorber (JPC)
+
Revision 1.3 2000/06/25 13:23:28 hristov
stdlib.h needed for non-Linux compilation
#include <iostream.h>
#include <TClonesArray.h>
-#include <TMinuit.h>
#include <TMath.h>
-#include <TMatrix.h>
+#include <TMatrixD.h>
+#include <TObjArray.h>
+#include <TVirtualFitter.h>
#include "AliMUONEventReconstructor.h"
#include "AliMUONHitForRec.h"
#include <stdlib.h>
-// variables to be known from minimization functions
-static AliMUONTrack *trackBeingFitted;
-static AliMUONTrackParam *trackParamBeingFitted;
-
// Functions to be minimized with Minuit
void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
void TrackChi2MCS(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
ClassImp(AliMUONTrack) // Class implementation in ROOT context
+TVirtualFitter* AliMUONTrack::fgFitter = NULL;
+
//__________________________________________________________________________
AliMUONTrack::AliMUONTrack(AliMUONSegment* BegSegment, AliMUONSegment* EndSegment, AliMUONEventReconstructor* EventReconstructor)
{
// Constructor from two Segment's
fEventReconstructor = EventReconstructor; // link back to EventReconstructor
- // memory allocation for the TClonesArray of reconstructed TrackHit's
- fTrackHitsPtr = new TClonesArray("AliMUONTrackHit", 10);
+ // memory allocation for the TObjArray of pointers to reconstructed TrackHit's
+ fTrackHitsPtr = new TObjArray(10);
fNTrackHits = 0;
AddSegment(BegSegment); // add hits from BegSegment
AddSegment(EndSegment); // add hits from EndSegment
fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z
SetTrackParamAtVertex(); // set track parameters at vertex
+ // set fit conditions...
fFitMCS = 0;
+ fFitNParam = 3;
+ fFitStart = 1;
+ fFitFMin = -1.0;
return;
}
{
// Constructor from one Segment and one HitForRec
fEventReconstructor = EventReconstructor; // link back to EventReconstructor
- // memory allocation for the TClonesArray of reconstructed TrackHit's
- fTrackHitsPtr = new TClonesArray("AliMUONTrackHit", 10);
+ // memory allocation for the TObjArray of pointers to reconstructed TrackHit's
+ fTrackHitsPtr = new TObjArray(10);
fNTrackHits = 0;
AddSegment(Segment); // add hits from Segment
AddHitForRec(HitForRec); // add HitForRec
fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z
SetTrackParamAtVertex(); // set track parameters at vertex
+ // set fit conditions...
fFitMCS = 0;
+ fFitNParam = 3;
+ fFitStart = 1;
+ fFitFMin = -1.0;
return;
}
+ //__________________________________________________________________________
+AliMUONTrack::~AliMUONTrack()
+{
+ // Destructor
+ if (fTrackHitsPtr) {
+ delete fTrackHitsPtr; // delete the TObjArray of pointers to TrackHit's
+ fTrackHitsPtr = NULL;
+ }
+}
+
+ //__________________________________________________________________________
AliMUONTrack::AliMUONTrack (const AliMUONTrack& MUONTrack)
{
// Dummy copy constructor
}
+ //__________________________________________________________________________
AliMUONTrack & AliMUONTrack::operator=(const AliMUONTrack& MUONTrack)
{
// Dummy assignment operator
return *this;
}
+ //__________________________________________________________________________
+void AliMUONTrack::Remove()
+{
+ // Remove current track from array of tracks,
+ // and corresponding track hits from array of track hits.
+ // Compress the TClonesArray it belongs to.
+ AliMUONTrackHit *nextTrackHit;
+ AliMUONEventReconstructor *eventRec = this->fEventReconstructor;
+ TClonesArray *trackHitsPtr = eventRec->GetRecTrackHitsPtr();
+ // Loop over all track hits of track
+ AliMUONTrackHit *trackHit = (AliMUONTrackHit*) fTrackHitsPtr->First();
+ while (trackHit) {
+ nextTrackHit = (AliMUONTrackHit*) fTrackHitsPtr->After(trackHit);
+ // Remove TrackHit from event TClonesArray.
+ // Destructor is called,
+ // hence links between HitForRec's and TrackHit's are updated
+ trackHitsPtr->Remove(trackHit);
+ trackHit = nextTrackHit;
+ }
+ // Remove the track from event TClonesArray
+ // Destructor is called,
+ // hence space for TObjArray of pointers to TrackHit's is freed
+ eventRec->GetRecTracksPtr()->Remove(this);
+ // Number of tracks decreased by 1
+ eventRec->SetNRecTracks(eventRec->GetNRecTracks() - 1);
+ // Compress event TClonesArray of Track's:
+ // this is essential to retrieve the TClonesArray afterwards
+ eventRec->GetRecTracksPtr()->Compress();
+ // Compress event TClonesArray of TrackHit's:
+ // this is probably also essential to retrieve the TClonesArray afterwards
+ trackHitsPtr->Compress();
+}
+
//__________________________________________________________________________
void AliMUONTrack::SetFitMCS(Int_t FitMCS)
{
- // Set track fit option with or without multiple Coulomb scattering
+ // Set multiple Coulomb scattering option for track fit "fFitMCS"
// from "FitMCS" argument: 0 without, 1 with
- fFitMCS = FitMCS;
+ if ((FitMCS == 0) || (FitMCS == 1)) fFitMCS = FitMCS;
// better implementation with enum(with, without) ????
+ else {
+ cout << "ERROR in AliMUONTrack::SetFitMCS(FitMCS)" << endl;
+ cout << "FitMCS = " << FitMCS << " is neither 0 nor 1" << endl;
+ exit(0);
+ }
+ return;
+}
+
+ //__________________________________________________________________________
+void AliMUONTrack::SetFitNParam(Int_t FitNParam)
+{
+ // Set number of parameters for track fit "fFitNParam" from "FitNParam":
+ // 3 for momentum, 5 for momentum and position
+ if ((FitNParam == 3) || (FitNParam == 5)) fFitNParam = FitNParam;
+ else {
+ cout << "ERROR in AliMUONTrack::SetFitNParam(FitNParam)" << endl;
+ cout << "FitNParam = " << FitNParam << " is neither 3 nor 5" << endl;
+ exit(0);
+ }
+ return;
+}
+
+ //__________________________________________________________________________
+void AliMUONTrack::SetFitStart(Int_t FitStart)
+{
+ // Set multiple Coulomb scattering option for track fit "fFitStart"
+ // from "FitStart" argument: 0 without, 1 with
+ if ((FitStart == 0) || (FitStart == 1)) fFitStart = FitStart;
+ // better implementation with enum(vertex, firstHit) ????
+ else {
+ cout << "ERROR in AliMUONTrack::SetFitStart(FitStart)" << endl;
+ cout << "FitStart = " << FitStart << " is neither 0 nor 1" << endl;
+ exit(0);
+ }
return;
}
-// Inline functions for Get and Set: inline removed because it does not work !!!!
-AliMUONTrackParam* AliMUONTrack::GetTrackParamAtVertex(void) {
- // Get pointer to fTrackParamAtVertex
- return &fTrackParamAtVertex;}
+ //__________________________________________________________________________
AliMUONTrackParam* AliMUONTrack::GetTrackParamAtFirstHit(void) {
// Get pointer to TrackParamAtFirstHit
return ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetTrackParam();}
-TClonesArray* AliMUONTrack::GetTrackHitsPtr(void) {
- // Get fTrackHitsPtr
- return fTrackHitsPtr;}
-Int_t AliMUONTrack::GetNTrackHits(void) {
- // Get fNTrackHits
- return fNTrackHits;}
//__________________________________________________________________________
void AliMUONTrack::RecursiveDump(void)
}
//__________________________________________________________________________
-void AliMUONTrack::Fit(AliMUONTrackParam *TrackParam, Int_t NParam)
+Int_t AliMUONTrack::HitsInCommon(AliMUONTrack* Track)
+{
+ // Returns the number of hits in common
+ // between the current track ("this")
+ // and the track pointed to by "Track".
+ Int_t hitsInCommon = 0;
+ AliMUONTrackHit *trackHit1, *trackHit2;
+ // Loop over hits of first track
+ trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->First();
+ while (trackHit1) {
+ // Loop over hits of second track
+ trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->First();
+ while (trackHit2) {
+ // Increment "hitsInCommon" if both TrackHits point to the same HitForRec
+ if ( (trackHit1->GetHitForRecPtr()) ==
+ (trackHit2->GetHitForRecPtr()) ) hitsInCommon++;
+ trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->After(trackHit2);
+ } // trackHit2
+ trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->After(trackHit1);
+ } // trackHit1
+ return hitsInCommon;
+}
+
+ //__________________________________________________________________________
+void AliMUONTrack::Fit()
{
// Fit the current track ("this"),
- // starting with track parameters pointed to by "TrackParam",
- // and with 3 or 5 parameters ("NParam"):
- // 3 if one keeps X and Y fixed in "TrackParam",
- // 5 if one lets them vary.
- if ((NParam != 3) && (NParam != 5)) {
- cout << "ERROR in AliMUONTrack::Fit, NParam = " << NParam;
- cout << " , i.e. neither 3 nor 5 ====> EXIT" << endl;
- exit(0); // right instruction for exit ????
- }
- Int_t error = 0;
+ // with or without multiple Coulomb scattering according to "fFitMCS",
+ // with the number of parameters given by "fFitNParam"
+ // (3 if one keeps X and Y fixed in "TrackParam", 5 if one lets them vary),
+ // starting, according to "fFitStart",
+ // with track parameters at vertex or at the first TrackHit.
+ // "fFitMCS", "fFitNParam" and "fFitStart" have to be set before
+ // by calling the corresponding Set methods.
Double_t arg[1], benC, errorParam, invBenP, lower, nonBenC, upper, x, y;
- TString parName;
- TMinuit *minuit = new TMinuit(5);
- trackBeingFitted = this; // for the track to be known from the function to minimize
- trackParamBeingFitted = TrackParam; // for the track parameters to be known from the function to minimize; possible to use only Minuit parameters ????
- // try to use TVirtualFitter to get this feature automatically !!!!
- minuit->mninit(5, 10, 7); // sysrd, syswr, syssa: useful ????
+ char parName[50];
+ AliMUONTrackParam *trackParam;
+ // Check if Minuit is initialized...
+ fgFitter = TVirtualFitter::Fitter(this); // add 3 or 5 for the maximum number of parameters ???
+ fgFitter->Clear(); // necessary ???? probably yes
+ // how to reset the printout number at every fit ????
+ // is there any risk to leave it like that ????
// how to go faster ???? choice of Minuit parameters like EDM ????
// choice of function to be minimized according to fFitMCS
- if (fFitMCS == 0) minuit->SetFCN(TrackChi2);
- else minuit->SetFCN(TrackChi2MCS);
- minuit->SetPrintLevel(1); // More printing !!!!
- // set first 3 parameters
+ if (fFitMCS == 0) fgFitter->SetFCN(TrackChi2);
+ else fgFitter->SetFCN(TrackChi2MCS);
+ arg[0] = -1;
+ fgFitter->ExecuteCommand("SET PRINT", arg, 1); // More printing !!!!
+ // Parameters according to "fFitStart"
+ // (should be a function to be used at every place where needed ????)
+ if (fFitStart == 0) trackParam = &fTrackParamAtVertex;
+ else trackParam = this->GetTrackParamAtFirstHit();
+ // set first 3 Minuit parameters
// could be tried with no limits for the search (min=max=0) ????
- minuit->mnparm(0, "InvBenP",
- TrackParam->GetInverseBendingMomentum(),
- 0.003, -0.4, 0.4, error);
- minuit->mnparm(1, "BenS",
- TrackParam->GetBendingSlope(),
- 0.001, -0.5, 0.5, error);
- minuit->mnparm(2, "NonBenS",
- TrackParam->GetNonBendingSlope(),
- 0.001, -0.5, 0.5, error);
- if (NParam == 5) {
- // set last 2 parameters (no limits for the search: min=max=0)
- minuit->mnparm(3, "X",
- TrackParam->GetNonBendingCoor(),
- 0.03, 0.0, 0.0, error);
- minuit->mnparm(4, "Y",
- TrackParam->GetBendingCoor(),
- 0.10, 0.0, 0.0, error);
+ fgFitter->SetParameter(0, "InvBenP",
+ trackParam->GetInverseBendingMomentum(),
+ 0.003, -0.4, 0.4);
+ fgFitter->SetParameter(1, "BenS",
+ trackParam->GetBendingSlope(),
+ 0.001, -0.5, 0.5);
+ fgFitter->SetParameter(2, "NonBenS",
+ trackParam->GetNonBendingSlope(),
+ 0.001, -0.5, 0.5);
+ if (fFitNParam == 5) {
+ // set last 2 Minuit parameters
+ // mandatory limits in Bending to avoid NaN values of parameters
+ fgFitter->SetParameter(3, "X",
+ trackParam->GetNonBendingCoor(),
+ 0.03, -500.0, 500.0);
+ // mandatory limits in non Bending to avoid NaN values of parameters
+ fgFitter->SetParameter(4, "Y",
+ trackParam->GetBendingCoor(),
+ 0.10, -500.0, 500.0);
}
// search without gradient calculation in the function
- minuit->mnexcm("SET NOGRADIENT", arg, 0, error);
+ fgFitter->ExecuteCommand("SET NOGRADIENT", arg, 0);
// minimization
- minuit->mnexcm("MINIMIZE", arg, 0, error);
+ fgFitter->ExecuteCommand("MINIMIZE", arg, 0);
// exit from Minuit
- minuit->mnexcm("EXIT", arg, 0, error); // necessary ????
- // print results
- minuit->mnpout(0, parName, invBenP, errorParam, lower, upper, error);
- minuit->mnpout(1, parName, benC, errorParam, lower, upper, error);
- minuit->mnpout(2, parName, nonBenC, errorParam, lower, upper, error);
- if (NParam == 5) {
- minuit->mnpout(3, parName, x, errorParam, lower, upper, error);
- minuit->mnpout(4, parName, y, errorParam, lower, upper, error);
+ fgFitter->ExecuteCommand("EXIT", arg, 0); // necessary ????
+ // get results into "invBenP", "benC", "nonBenC" ("x", "y")
+ fgFitter->GetParameter(0, parName, invBenP, errorParam, lower, upper);
+ fgFitter->GetParameter(1, parName, benC, errorParam, lower, upper);
+ fgFitter->GetParameter(2, parName, nonBenC, errorParam, lower, upper);
+ if (fFitNParam == 5) {
+ fgFitter->GetParameter(3, parName, x, errorParam, lower, upper);
+ fgFitter->GetParameter(4, parName, y, errorParam, lower, upper);
}
// result of the fit into track parameters
- TrackParam->SetInverseBendingMomentum(invBenP);
- TrackParam->SetBendingSlope(benC);
- TrackParam->SetNonBendingSlope(nonBenC);
- if (NParam == 5) {
- TrackParam->SetNonBendingCoor(x);
- TrackParam->SetBendingCoor(y);
+ trackParam->SetInverseBendingMomentum(invBenP);
+ trackParam->SetBendingSlope(benC);
+ trackParam->SetNonBendingSlope(nonBenC);
+ if (fFitNParam == 5) {
+ trackParam->SetNonBendingCoor(x);
+ trackParam->SetBendingCoor(y);
}
- trackBeingFitted = NULL;
- delete minuit;
+ // global result of the fit
+ Double_t fedm, errdef;
+ Int_t npari, nparx;
+ fgFitter->GetStats(fFitFMin, fedm, errdef, npari, nparx);
}
//__________________________________________________________________________
void AliMUONTrack::AddSegment(AliMUONSegment* Segment)
{
- // Add Segment
+ // Add Segment to the track
AddHitForRec(Segment->GetHitForRec1()); // 1st hit
AddHitForRec(Segment->GetHitForRec2()); // 2nd hit
}
//__________________________________________________________________________
void AliMUONTrack::AddHitForRec(AliMUONHitForRec* HitForRec)
{
- // Add HitForRec
- new ((*fTrackHitsPtr)[fNTrackHits]) AliMUONTrackHit(HitForRec);
+ // Add HitForRec to the track:
+ // actual TrackHit into TClonesArray of TrackHit's for the event;
+ // pointer to actual TrackHit in TObjArray of pointers to TrackHit's for the track
+ TClonesArray *recTrackHitsPtr = this->fEventReconstructor->GetRecTrackHitsPtr();
+ Int_t eventTrackHits = this->fEventReconstructor->GetNRecTrackHits();
+ // event
+ AliMUONTrackHit* trackHit =
+ new ((*recTrackHitsPtr)[eventTrackHits]) AliMUONTrackHit(HitForRec);
+ this->fEventReconstructor->SetNRecTrackHits(eventTrackHits + 1);
+ // track
+ fTrackHitsPtr->Add(trackHit);
fNTrackHits++;
}
// Assumes that the track hits are sorted according to increasing Z.
// Track parameters at each TrackHit are updated accordingly.
// Multiple Coulomb scattering is not taken into account
+ AliMUONTrack *trackBeingFitted;
AliMUONTrackHit* hit;
AliMUONTrackParam param1;
Int_t hitNumber;
Double_t zHit;
Chi2 = 0.0; // initialize Chi2
// copy of track parameters to be fitted
- param1 = *trackParamBeingFitted;
+ trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
+ if (trackBeingFitted->GetFitStart() == 0)
+ param1 = *(trackBeingFitted->GetTrackParamAtVertex());
+ else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit());
// Minuit parameters to be fitted into this copy
param1.SetInverseBendingMomentum(Param[0]);
param1.SetBendingSlope(Param[1]);
// Assumes that the track hits are sorted according to increasing Z.
// Track parameters at each TrackHit are updated accordingly.
// Multiple Coulomb scattering is taken into account with covariance matrix.
+ AliMUONTrack *trackBeingFitted;
AliMUONTrackParam param1;
Chi2 = 0.0; // initialize Chi2
// copy of track parameters to be fitted
- param1 = *trackParamBeingFitted;
+ trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
+ if (trackBeingFitted->GetFitStart() == 0)
+ param1 = *(trackBeingFitted->GetTrackParamAtVertex());
+ else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit());
// Minuit parameters to be fitted into this copy
param1.SetInverseBendingMomentum(Param[0]);
param1.SetBendingSlope(Param[1]);
param1.SetBendingCoor(Param[4]);
}
- AliMUONTrackHit* hit, hit1, hit2, hit3;
- Bool_t GoodDeterminant;
- Int_t hitNumber, hitNumber1, hitNumber2, hitNumber3;
- Double_t zHit[10], paramBendingCoor[10], paramNonBendingCoor[10], ap[10];
- Double_t hitBendingCoor[10], hitNonBendingCoor[10];
- Double_t hitBendingReso2[10], hitNonBendingReso2[10];
- Int_t numberOfHit = TMath::Min(trackBeingFitted->GetNTrackHits(), 10);
- TMatrix *covBending = new TMatrix(numberOfHit, numberOfHit);
- TMatrix *covNonBending = new TMatrix(numberOfHit, numberOfHit);
+ AliMUONTrackHit *hit;
+ Bool_t goodDeterminant;
+ Int_t chCurrent, chPrev = 0, hitNumber, hitNumber1, hitNumber2, hitNumber3;
+ Double_t z, z1, z2, z3;
+ AliMUONTrackHit *hit1, *hit2, *hit3;
+ Double_t hbc1, hbc2, pbc1, pbc2;
+ Double_t hnbc1, hnbc2, pnbc1, pnbc2;
+ Int_t numberOfHit = trackBeingFitted->GetNTrackHits();
+ TMatrixD *covBending = new TMatrixD(numberOfHit, numberOfHit);
+ TMatrixD *covNonBending = new TMatrixD(numberOfHit, numberOfHit);
+ Double_t *msa2 = new Double_t[numberOfHit];
// Predicted coordinates and multiple scattering angles are first calculated
for (hitNumber = 0; hitNumber < numberOfHit; hitNumber++) {
hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber];
- zHit[hitNumber] = hit->GetHitForRecPtr()->GetZ();
+ z = hit->GetHitForRecPtr()->GetZ();
// do something special if 2 hits with same Z ????
// security against infinite loop ????
- (¶m1)->ExtrapToZ(zHit[hitNumber]); // extrapolation
+ (¶m1)->ExtrapToZ(z); // extrapolation
hit->SetTrackParam(¶m1);
- paramBendingCoor[hitNumber]= (¶m1)->GetBendingCoor();
- paramNonBendingCoor[hitNumber]= (¶m1)->GetNonBendingCoor();
- hitBendingCoor[hitNumber]= hit->GetHitForRecPtr()->GetBendingCoor();
- hitNonBendingCoor[hitNumber]= hit->GetHitForRecPtr()->GetNonBendingCoor();
- hitBendingReso2[hitNumber]= hit->GetHitForRecPtr()->GetBendingReso2();
- hitNonBendingReso2[hitNumber]= hit->GetHitForRecPtr()->GetNonBendingReso2();
- ap[hitNumber] = MultipleScatteringAngle2(hit); // multiple scatt. angle ^2
+ // square of multiple scattering angle at current hit, with one chamber
+ msa2[hitNumber] = MultipleScatteringAngle2(hit);
+ // correction for eventual missing hits or multiple hits in a chamber,
+ // according to the number of chambers
+ // between the current hit and the previous one
+ chCurrent = hit->GetHitForRecPtr()->GetChamberNumber();
+ if (hitNumber > 0) msa2[hitNumber] = msa2[hitNumber] * (chCurrent - chPrev);
+ chPrev = chCurrent;
}
// Calculates the covariance matrix
- for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) {
+ for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) {
+ hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
+ z1 = hit1->GetHitForRecPtr()->GetZ();
for (hitNumber2 = hitNumber1; hitNumber2 < numberOfHit; hitNumber2++) {
- (*covBending)(hitNumber1, hitNumber2) = 0;
- (*covBending)(hitNumber2, hitNumber1) = 0;
- if (hitNumber1 == hitNumber2){ // diagonal elements
- (*covBending)(hitNumber2, hitNumber1) =
- (*covBending)(hitNumber2, hitNumber1) + hitBendingReso2[hitNumber1];
- }
- // Multiple Scattering... loop on upstream chambers ??
- for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++){
+ hit2 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2];
+ z2 = hit2->GetHitForRecPtr()->GetZ();
+ // initialization to 0 (diagonal plus upper triangular part)
+ (*covBending)(hitNumber2, hitNumber1) = 0.0;
+ // contribution from multiple scattering in bending plane:
+ // loop over upstream hits
+ for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++) {
+ hit3 = (AliMUONTrackHit*)
+ (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber3];
+ z3 = hit3->GetHitForRecPtr()->GetZ();
(*covBending)(hitNumber2, hitNumber1) =
(*covBending)(hitNumber2, hitNumber1) +
- ((zHit[hitNumber1] - zHit[hitNumber3]) *
- (zHit[hitNumber2] - zHit[hitNumber3]) * ap[hitNumber3]);
- }
- (*covNonBending)(hitNumber1, hitNumber2) = 0;
+ ((z1 - z3) * (z2 - z3) * msa2[hitNumber3]);
+ }
+ // equal contribution from multiple scattering in non bending plane
(*covNonBending)(hitNumber2, hitNumber1) =
(*covBending)(hitNumber2, hitNumber1);
- if (hitNumber1 == hitNumber2) { // diagonal elements
+ if (hitNumber1 == hitNumber2) {
+ // Diagonal elements: add contribution from position measurements
+ // in bending plane
+ (*covBending)(hitNumber2, hitNumber1) =
+ (*covBending)(hitNumber2, hitNumber1) +
+ hit1->GetHitForRecPtr()->GetBendingReso2();
+ // and in non bending plane
(*covNonBending)(hitNumber2, hitNumber1) =
- (*covNonBending)(hitNumber2, hitNumber1) -
- hitBendingReso2[hitNumber1] + hitNonBendingReso2[hitNumber1] ;
- }
- }
- }
-
+ (*covNonBending)(hitNumber2, hitNumber1) +
+ hit1->GetHitForRecPtr()->GetNonBendingReso2();
+ }
+ else {
+ // Non diagonal elements: symmetrization
+ // for bending plane
+ (*covBending)(hitNumber1, hitNumber2) =
+ (*covBending)(hitNumber2, hitNumber1);
+ // and non bending plane
+ (*covNonBending)(hitNumber1, hitNumber2) =
+ (*covNonBending)(hitNumber2, hitNumber1);
+ }
+ } // for (hitNumber2 = hitNumber1;...
+ } // for (hitNumber1 = 0;...
+ // Normalization of covariance matrices
+ Double_t normCovBending2 = covBending->E2Norm();
+ Double_t normCovNonBending2 = covNonBending->E2Norm();
+ (*covBending) *= 1/normCovBending2;
+ (*covNonBending) *= 1/normCovNonBending2;
+// if (covBending->Determinant() < 1.e-33) {
+// printf(" *** covBending *** \n");
+// covBending->Print();
+// printf(" *** covNonBending *** \n");
+// covNonBending->Print();
+// cout << " number of hits " << numberOfHit << endl;
+// cout << "Momentum = " << 1/Param[0] <<endl;
+// cout << "normCovBending = " << normCovBending2 << endl;
+// cout << "normCovNonBending = " << normCovNonBending2 << endl;
+// exit(0);
+
+// }
// Inverts covariance matrix
- GoodDeterminant = kTRUE;
+ goodDeterminant = kTRUE;
+ // check whether the Invert method returns flag if matrix cannot be inverted,
+ // and do not calculate the Determinant in that case !!!!
if (covBending->Determinant() != 0) {
covBending->Invert();
} else {
- GoodDeterminant = kFALSE;
+ goodDeterminant = kFALSE;
cout << "Warning in ChiMCS Determinant Bending=0: " << endl;
}
- if (covNonBending->Determinant() != 0){
+ if (covNonBending->Determinant() != 0) {
covNonBending->Invert();
} else {
- GoodDeterminant = kFALSE;
+ goodDeterminant = kFALSE;
cout << "Warning in ChiMCS Determinant non Bending=0: " << endl;
}
+
+ // It would be worth trying to calculate the inverse of the covariance matrix
+ // only once per fit, since it cannot change much in principle,
+ // and it would save a lot of computing time !!!!
// Calculates Chi2
- if (GoodDeterminant) { // with Multiple Scattering if inversion correct
- for (hitNumber1=0; hitNumber1 < numberOfHit ; hitNumber1++){
- for (hitNumber2=0; hitNumber2 < numberOfHit; hitNumber2++){
- Chi2 = Chi2 +
- ((*covBending)(hitNumber2, hitNumber1) *
- (hitBendingCoor[hitNumber1] - paramBendingCoor[hitNumber1]) *
- (hitBendingCoor[hitNumber2] - paramBendingCoor[hitNumber2]));
+ if (goodDeterminant) {
+ // with Multiple Scattering if inversion correct
+ // Inverse matrices without normalization
+ (*covBending) *= 1/normCovBending2;
+ (*covNonBending) *= 1/normCovNonBending2;
+ for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
+ hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
+ hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor();
+ pbc1 = hit1->GetTrackParam()->GetBendingCoor();
+ hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor();
+ pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor();
+ for (hitNumber2 = 0; hitNumber2 < numberOfHit; hitNumber2++) {
+ hit2 = (AliMUONTrackHit*)
+ (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2];
+ hbc2 = hit2->GetHitForRecPtr()->GetBendingCoor();
+ pbc2 = hit2->GetTrackParam()->GetBendingCoor();
+ hnbc2 = hit2->GetHitForRecPtr()->GetNonBendingCoor();
+ pnbc2 = hit2->GetTrackParam()->GetNonBendingCoor();
Chi2 = Chi2 +
+ ((*covBending)(hitNumber2, hitNumber1) *
+ (hbc1 - pbc1) * (hbc2 - pbc2)) +
((*covNonBending)(hitNumber2, hitNumber1) *
- (hitNonBendingCoor[hitNumber1] - paramNonBendingCoor[hitNumber1]) *
- (hitNonBendingCoor[hitNumber2] - paramNonBendingCoor[hitNumber2]));
+ (hnbc1 - pnbc1) * (hnbc2 - pnbc2));
}
}
- } else { // without Multiple Scattering if inversion impossible
- for (hitNumber1=0; hitNumber1 < numberOfHit ; hitNumber1++) {
- Chi2 = Chi2 +
- ((hitBendingCoor[hitNumber1] - paramBendingCoor[hitNumber1]) *
- (hitBendingCoor[hitNumber1] - paramBendingCoor[hitNumber1]) /
- hitBendingReso2[hitNumber1]);
- Chi2 = Chi2 +
- ((hitNonBendingCoor[hitNumber1] - paramNonBendingCoor[hitNumber1]) *
- (hitNonBendingCoor[hitNumber1] - paramNonBendingCoor[hitNumber1]) /
- hitNonBendingReso2[hitNumber1]);
+ } else {
+ // without Multiple Scattering if inversion impossible
+ for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
+ hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
+ hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor();
+ pbc1 = hit1->GetTrackParam()->GetBendingCoor();
+ hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor();
+ pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor();
+ Chi2 = Chi2 +
+ ((hbc1 - pbc1) * (hbc1 - pbc1) /
+ hit1->GetHitForRecPtr()->GetBendingReso2()) +
+ ((hnbc1 - pnbc1) * (hnbc1 - pnbc1) /
+ hit1->GetHitForRecPtr()->GetNonBendingReso2());
}
}
delete covBending;
delete covNonBending;
+ delete [] msa2;
}
Double_t MultipleScatteringAngle2(AliMUONTrackHit *TrackHit)
// at TrackHit pointed to by "TrackHit"
Double_t slopeBending, slopeNonBending, radiationLength, inverseBendingMomentum2, inverseTotalMomentum2;
Double_t varMultipleScatteringAngle;
+ AliMUONTrack *trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
AliMUONTrackParam *param = TrackHit->GetTrackParam();
+ // Better implementation in AliMUONTrack class ????
slopeBending = param->GetBendingSlope();
slopeNonBending = param->GetNonBendingSlope();
// thickness in radiation length for the current track,
inverseBendingMomentum2 =
param->GetInverseBendingMomentum() * param->GetInverseBendingMomentum();
inverseTotalMomentum2 =
- inverseBendingMomentum2 * (1.0 + slopeBending*slopeBending) /
+ inverseBendingMomentum2 * (1.0 + slopeBending * slopeBending) /
(1.0 + slopeBending *slopeBending + slopeNonBending * slopeNonBending);
varMultipleScatteringAngle = 0.0136 * (1.0 + 0.038 * TMath::Log(radiationLength));
+ // The velocity is assumed to be 1 !!!!
varMultipleScatteringAngle = inverseTotalMomentum2 * radiationLength *
varMultipleScatteringAngle * varMultipleScatteringAngle;
return varMultipleScatteringAngle;
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff