[u/mrichter/AliRoot.git] / MFT / AliMuonForwardTrack.cxx

/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * 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.                  *
 **************************************************************************/

//====================================================================================================================================================
//
//      Description of an ALICE muon forward track, combining the information of the Muon Spectrometer and the Muon Forward Tracker
//
//      Contact author: antonio.uras@cern.ch
//
//====================================================================================================================================================

#include "AliLog.h"
#include "AliMUONTrack.h"
#include "AliMFTCluster.h"
#include "AliMUONVCluster.h"
#include "AliMUONTrackParam.h"
#include "AliMUONTrackExtrap.h"
#include "TClonesArray.h"
#include "TMatrixD.h"
#include "TParticle.h"
#include "AliMuonForwardTrack.h"

ClassImp(AliMuonForwardTrack)

//====================================================================================================================================================

AliMuonForwardTrack::AliMuonForwardTrack():
  AliMUONTrack(),
  fMUONTrack(0),
  fMCTrackRef(0),
  fMFTClusters(0)
{

  // default constructor
  for (Int_t iPlane=0; iPlane<fMaxNPlanesMFT; iPlane++) fPlaneExists[iPlane] = kFALSE;
  fMFTClusters = new TClonesArray("AliMFTCluster");

}

//====================================================================================================================================================

AliMuonForwardTrack::AliMuonForwardTrack(AliMUONTrack *MUONTrack):
  AliMUONTrack(),
  fMUONTrack(0),
  fMCTrackRef(0),
  fMFTClusters(0)
{

  SetMUONTrack(MUONTrack);
  for (Int_t iPlane=0; iPlane<fMaxNPlanesMFT; iPlane++) fPlaneExists[iPlane] = kFALSE;
  fMFTClusters = new TClonesArray("AliMFTCluster");

}

//====================================================================================================================================================

AliMuonForwardTrack::AliMuonForwardTrack(const AliMuonForwardTrack& track): 
  AliMUONTrack(track),
  fMUONTrack(track.fMUONTrack),
  fMCTrackRef(track.fMCTrackRef),
  fMFTClusters(track.fMFTClusters)
{

  // copy constructor
  for (Int_t iPlane=0; iPlane<fMaxNPlanesMFT; iPlane++) fPlaneExists[iPlane] = (track.fPlaneExists)[iPlane];
  
}

//====================================================================================================================================================

AliMuonForwardTrack& AliMuonForwardTrack::operator=(const AliMuonForwardTrack& track) {

  // Asignment operator

  // check assignement to self
  if (this == &track) return *this;

  // base class assignement
  AliMUONTrack::operator=(track);
  
  // clear memory
  Clear();
  
  fMUONTrack    = track.fMUONTrack;
  fMCTrackRef   = track.fMCTrackRef;
  fMFTClusters  = track.fMFTClusters;

  for (Int_t iPlane=0; iPlane<fMaxNPlanesMFT; iPlane++) fPlaneExists[iPlane] = (track.fPlaneExists)[iPlane];
  
  return *this;

}

//====================================================================================================================================================

void AliMuonForwardTrack::SetMUONTrack(AliMUONTrack *MUONTrack) {

  if (fMUONTrack) {
    AliInfo("fMUONTrack already exists, nothing will be done");
    return;
  }

  fMUONTrack = MUONTrack;
  
}

//====================================================================================================================================================

void AliMuonForwardTrack::SetMCTrackRef(TParticle *MCTrackRef) {

  if (fMCTrackRef) {
    AliInfo("fMCTrackRef already exists, nothing will be done");
    return;
  }

  fMCTrackRef = MCTrackRef;
  
}

//====================================================================================================================================================

void AliMuonForwardTrack::AddTrackParamAtMFTCluster(AliMUONTrackParam &trackParam, AliMFTCluster &mftCluster) {

  AliDebug(1, Form("fMFTClusters=%p has %d entries", fMFTClusters, fMFTClusters->GetEntries()));
  Int_t iMFTCluster = fMFTClusters->GetEntries();
  AliDebug(1, Form("mftCluster->GetX() = %f  mftCluster->GetY() = %f  mftCluster->GetErrX() = %f  cmftCluster->GetErrY() = %f", 
	   mftCluster.GetX(), mftCluster.GetY(), mftCluster.GetErrX(), mftCluster.GetErrY()));
  AliMUONVCluster *muonCluster = (AliMUONVCluster*) mftCluster.CreateMUONCluster();
  AliDebug(1, Form("Created MUON cluster %p", muonCluster));
  trackParam.SetUniqueID(iMFTCluster);    // we profit of this slot to store the reference to the corresponding MFTCluster
  AliDebug(1, Form("Now adding muonCluster %p and trackParam %p",muonCluster, &trackParam));
  AddTrackParamAtCluster(trackParam, *muonCluster, kTRUE);
  AliDebug(1, Form("GetTrackParamAtCluster() = %p  has %d entries",GetTrackParamAtCluster(), GetTrackParamAtCluster()->GetEntries()));
  // we pass the parameters this->GetTrackParamAtCluster()->First() to the Kalman Filter algorithm: they will be updated!!
  Double_t chi2Kalman = RunKalmanFilter(*(AliMUONTrackParam*)(GetTrackParamAtCluster()->First()));
  Double_t newGlobalChi2 = GetGlobalChi2() + chi2Kalman;
  mftCluster.SetLocalChi2(chi2Kalman);
  mftCluster.SetTrackChi2(newGlobalChi2);
  new ((*fMFTClusters)[iMFTCluster]) AliMFTCluster(mftCluster);
  AliDebug(1, Form("muonCluster->GetZ() = %f, trackParam->GetZ() = %f",muonCluster->GetZ(), trackParam.GetZ()));
  SetGlobalChi2(newGlobalChi2);
  ((AliMUONTrackParam*) GetTrackParamAtCluster()->First())->SetTrackChi2(newGlobalChi2);
  for (Int_t iPar=0; iPar<GetTrackParamAtCluster()->GetEntries(); iPar++) {
    AliDebug(1, Form("GetTrackParamAtCluster()->At(%d)->GetClusterPtr() = %p",
		     iPar, ((AliMUONTrackParam*)(GetTrackParamAtCluster()->At(iPar)))->GetClusterPtr()));
  }

}

//====================================================================================================================================================

AliMUONTrackParam* AliMuonForwardTrack::GetTrackParamAtMUONCluster(Int_t iMUONCluster) {

  if (iMUONCluster<0 || iMUONCluster>=GetNMUONClusters()) {
    AliError("Invalid MUON cluster index. NULL pointer will be returned");
    return NULL;
  }

  AliMUONTrackParam *trackParam = (AliMUONTrackParam*) fMUONTrack->GetTrackParamAtCluster()->At(iMUONCluster); 

  return trackParam;

}

//====================================================================================================================================================

AliMUONTrackParam* AliMuonForwardTrack::GetTrackParamAtMFTCluster(Int_t iMFTCluster) {

  if (iMFTCluster<0 || iMFTCluster>=GetNMFTClusters()) {
    AliError("Invalid MFT cluster index. NULL pointer will be returned");
    return NULL;
  }

  AliMUONTrackParam *trackParam = (AliMUONTrackParam*) GetTrackParamAtCluster()->At(iMFTCluster); 

  return trackParam;

}

//====================================================================================================================================================

AliMUONVCluster* AliMuonForwardTrack::GetMUONCluster(Int_t iMUONCluster) {

  if (iMUONCluster<0 || iMUONCluster>=GetNMUONClusters()) {
    AliError("Invalid MUON cluster index. NULL pointer will be returned");
    return NULL;
  }

  AliMUONTrackParam *trackParam = GetTrackParamAtMUONCluster(iMUONCluster);
  AliMUONVCluster *muonCluster = trackParam->GetClusterPtr();

  return muonCluster;

}

//====================================================================================================================================================

AliMFTCluster* AliMuonForwardTrack::GetMFTCluster(Int_t iMFTCluster) {

  if (iMFTCluster<0 || iMFTCluster>=GetNMFTClusters()) {
    AliError("Invalid MFT cluster index. NULL pointer will be returned");
    return NULL;
  }

  AliMUONTrackParam *trackParam = GetTrackParamAtMFTCluster(iMFTCluster);
  AliMFTCluster *mftCluster = (AliMFTCluster*) fMFTClusters->At(trackParam->GetUniqueID());

  return mftCluster;

}

//====================================================================================================================================================

Double_t AliMuonForwardTrack::RunKalmanFilter(AliMUONTrackParam &trackParamAtCluster) {

  AliDebug(1, Form("Running Kalman filter for parameters %p (z = %f) and cluster %p (z = %f)", 
		   &trackParamAtCluster, trackParamAtCluster.GetZ(), trackParamAtCluster.GetClusterPtr(), trackParamAtCluster.GetClusterPtr()->GetZ()));
  
  // Compute new track parameters and their covariances including new cluster using kalman filter
  // return the *additional* track chi2
  
  // Get actual track parameters (p)
  TMatrixD param(trackParamAtCluster.GetParameters());
  
  // Get new cluster parameters (m)
  AliMUONVCluster *cluster = trackParamAtCluster.GetClusterPtr();
  AliDebug(1, Form("cluster->GetX() = %f  cluster->GetY() = %f  cluster->GetErrX() = %f  cluster->GetErrY() = %f", 
		   cluster->GetX(), cluster->GetY(), cluster->GetErrX(), cluster->GetErrY()));
  TMatrixD clusterParam(5,1);
  clusterParam.Zero();
  clusterParam(0,0) = cluster->GetX();
  clusterParam(2,0) = cluster->GetY();

  // Compute the current parameter weight (W)
  TMatrixD paramWeight(trackParamAtCluster.GetCovariances());
  if (paramWeight.Determinant() != 0) {
    paramWeight.Invert();
  } else {
    Warning("RunKalmanFilter"," Determinant = 0");
    return 1.e10;
  }
  
  // Compute the new cluster weight (U)
  TMatrixD clusterWeight(5,5);
  clusterWeight.Zero();
  clusterWeight(0,0) = 1. / cluster->GetErrX2();
  clusterWeight(2,2) = 1. / cluster->GetErrY2();

  // Compute the new parameters covariance matrix ( (W+U)^-1 )
  TMatrixD newParamCov(paramWeight,TMatrixD::kPlus,clusterWeight);
  if (newParamCov.Determinant() != 0) {
    newParamCov.Invert();
  } 
  else {
    Warning("RunKalmanFilter"," Determinant = 0");
    return 1.e10;
  }
  
  // Save the new parameters covariance matrix
  trackParamAtCluster.SetCovariances(newParamCov);
  
  // Compute the new parameters (p' = ((W+U)^-1)U(m-p) + p)
  TMatrixD tmp(clusterParam,TMatrixD::kMinus,param);
  TMatrixD tmp2(clusterWeight,TMatrixD::kMult,tmp);    // U(m-p)
  TMatrixD newParam(newParamCov,TMatrixD::kMult,tmp2); // ((W+U)^-1)U(m-p)
  newParam += param;                                   // ((W+U)^-1)U(m-p) + p

  // Save the new parameters
  trackParamAtCluster.SetParameters(newParam);
  
  // Compute the additional chi2 (= ((p'-p)^-1)W(p'-p) + ((p'-m)^-1)U(p'-m))
  tmp = newParam; // p'
  tmp -= param;   // (p'-p)
  TMatrixD tmp3(paramWeight,TMatrixD::kMult,tmp);           // W(p'-p)
  TMatrixD addChi2Track(tmp,TMatrixD::kTransposeMult,tmp3); // ((p'-p)^-1)W(p'-p)
  tmp = newParam;      // p'
  tmp -= clusterParam; // (p'-m)
  TMatrixD tmp4(clusterWeight,TMatrixD::kMult,tmp);            // U(p'-m)
  addChi2Track += TMatrixD(tmp,TMatrixD::kTransposeMult,tmp4); // ((p'-p)^-1)W(p'-p) + ((p'-m)^-1)U(p'-m)
  
  AliDebug(1,Form("Adding Kalman chi2 = %f",addChi2Track(0,0)));

  return addChi2Track(0,0);
  
}

//====================================================================================================================================================

Double_t AliMuonForwardTrack::GetWeightedOffset(Double_t x, Double_t y, Double_t z) {

  AliMUONTrackParam *param = GetTrackParamAtMFTCluster(0);
  AliMUONTrackExtrap::ExtrapToZCov(param, z);

  TMatrixD cov(5,5);
  cov = param->GetCovariances();

  TMatrixD covCoordinates(2,2);
  covCoordinates(0,0) = cov(0,0);
  covCoordinates(0,1) = cov(0,2);
  covCoordinates(1,0) = cov(2,0);
  covCoordinates(1,1) = cov(2,2);
  
  TMatrixD covCoordinatesInverse = covCoordinates.Invert();

  Double_t dX = param->GetNonBendingCoor() - x;
  Double_t dY = param->GetBendingCoor()    - y;
  
  Double_t weightedOffset = TMath::Sqrt(0.5*(dX*dX*covCoordinatesInverse(0,0) + 
					     dY*dY*covCoordinatesInverse(1,1) + 
					     2.*dX*dY*covCoordinatesInverse(0,1)));

  return weightedOffset;

}

//====================================================================================================================================================

Double_t AliMuonForwardTrack::GetOffsetX(Double_t x, Double_t z) {

  AliMUONTrackParam *param = GetTrackParamAtMFTCluster(0);
  AliMUONTrackExtrap::ExtrapToZCov(param, z);
  Double_t dX = param->GetNonBendingCoor() - x;
  return dX;

}

//====================================================================================================================================================

Double_t AliMuonForwardTrack::GetOffsetY(Double_t y, Double_t z) {

  AliMUONTrackParam *param = GetTrackParamAtMFTCluster(0);
  AliMUONTrackExtrap::ExtrapToZCov(param, z);
  Double_t dY = param->GetBendingCoor() - y;
  return dY;

}

//====================================================================================================================================================

Double_t AliMuonForwardTrack::GetOffset(Double_t x, Double_t y, Double_t z) {

  AliMUONTrackParam *param = GetTrackParamAtMFTCluster(0);
  AliMUONTrackExtrap::ExtrapToZCov(param, z);
  Double_t dX = param->GetNonBendingCoor() - x;
  Double_t dY = param->GetBendingCoor()    - y;
  return TMath::Sqrt(dX*dX + dY*dY);

}

//====================================================================================================================================================
Commit	Line	Data
	1	/**************************************************************************
	2	* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	8	* documentation strictly for non-commercial purposes is hereby granted *
	9	* without fee, provided that the above copyright notice appears in all *
	10	* copies and that both the copyright notice and this permission notice *
	11	* appear in the supporting documentation. The authors make no claims *
	12	* about the suitability of this software for any purpose. It is *
	13	* provided "as is" without express or implied warranty. *
	14	**************************************************************************/
	15
	16	//====================================================================================================================================================
	17	//
	18	// Description of an ALICE muon forward track, combining the information of the Muon Spectrometer and the Muon Forward Tracker
	19	//
	20	// Contact author: antonio.uras@cern.ch
	21	//
	22	//====================================================================================================================================================
	23
	24	#include "AliLog.h"
	25	#include "AliMUONTrack.h"
	26	#include "AliMFTCluster.h"
	27	#include "AliMUONVCluster.h"
	28	#include "AliMUONTrackParam.h"
	29	#include "AliMUONTrackExtrap.h"
	30	#include "TClonesArray.h"
	31	#include "TMatrixD.h"
	32	#include "TParticle.h"
	33	#include "AliMuonForwardTrack.h"
	34
	35	ClassImp(AliMuonForwardTrack)
	36
	37	//====================================================================================================================================================
	38
	39	AliMuonForwardTrack::AliMuonForwardTrack():
	40	AliMUONTrack(),
	41	fMUONTrack(0),
	42	fMCTrackRef(0),
	43	fMFTClusters(0)
	44	{
	45
	46	// default constructor
	47	for (Int_t iPlane=0; iPlane<fMaxNPlanesMFT; iPlane++) fPlaneExists[iPlane] = kFALSE;
	48	fMFTClusters = new TClonesArray("AliMFTCluster");
	49
	50	}
	51
	52	//====================================================================================================================================================
	53
	54	AliMuonForwardTrack::AliMuonForwardTrack(AliMUONTrack *MUONTrack):
	55	AliMUONTrack(),
	56	fMUONTrack(0),
	57	fMCTrackRef(0),
	58	fMFTClusters(0)
	59	{
	60
	61	SetMUONTrack(MUONTrack);
	62	for (Int_t iPlane=0; iPlane<fMaxNPlanesMFT; iPlane++) fPlaneExists[iPlane] = kFALSE;
	63	fMFTClusters = new TClonesArray("AliMFTCluster");
	64
	65	}
	66
	67	//====================================================================================================================================================
	68
	69	AliMuonForwardTrack::AliMuonForwardTrack(const AliMuonForwardTrack& track):
	70	AliMUONTrack(track),
	71	fMUONTrack(track.fMUONTrack),
	72	fMCTrackRef(track.fMCTrackRef),
	73	fMFTClusters(track.fMFTClusters)
	74	{
	75
	76	// copy constructor
	77	for (Int_t iPlane=0; iPlane<fMaxNPlanesMFT; iPlane++) fPlaneExists[iPlane] = (track.fPlaneExists)[iPlane];
	78
	79	}
	80
	81	//====================================================================================================================================================
	82
	83	AliMuonForwardTrack& AliMuonForwardTrack::operator=(const AliMuonForwardTrack& track) {
	84
	85	// Asignment operator
	86
	87	// check assignement to self
	88	if (this == &track) return *this;
	89
	90	// base class assignement
	91	AliMUONTrack::operator=(track);
	92
	93	// clear memory
	94	Clear();
	95
	96	fMUONTrack = track.fMUONTrack;
	97	fMCTrackRef = track.fMCTrackRef;
	98	fMFTClusters = track.fMFTClusters;
	99
	100	for (Int_t iPlane=0; iPlane<fMaxNPlanesMFT; iPlane++) fPlaneExists[iPlane] = (track.fPlaneExists)[iPlane];
	101
	102	return *this;
	103
	104	}
	105
	106	//====================================================================================================================================================
	107
	108	void AliMuonForwardTrack::SetMUONTrack(AliMUONTrack *MUONTrack) {
	109
	110	if (fMUONTrack) {
	111	AliInfo("fMUONTrack already exists, nothing will be done");
	112	return;
	113	}
	114
	115	fMUONTrack = MUONTrack;
	116
	117	}
	118
	119	//====================================================================================================================================================
	120
	121	void AliMuonForwardTrack::SetMCTrackRef(TParticle *MCTrackRef) {
	122
	123	if (fMCTrackRef) {
	124	AliInfo("fMCTrackRef already exists, nothing will be done");
	125	return;
	126	}
	127
	128	fMCTrackRef = MCTrackRef;
	129
	130	}
	131
	132	//====================================================================================================================================================
	133
	134	void AliMuonForwardTrack::AddTrackParamAtMFTCluster(AliMUONTrackParam &trackParam, AliMFTCluster &mftCluster) {
	135
	136	AliDebug(1, Form("fMFTClusters=%p has %d entries", fMFTClusters, fMFTClusters->GetEntries()));
	137	Int_t iMFTCluster = fMFTClusters->GetEntries();
	138	AliDebug(1, Form("mftCluster->GetX() = %f mftCluster->GetY() = %f mftCluster->GetErrX() = %f cmftCluster->GetErrY() = %f",
	139	mftCluster.GetX(), mftCluster.GetY(), mftCluster.GetErrX(), mftCluster.GetErrY()));
	140	AliMUONVCluster muonCluster = (AliMUONVCluster) mftCluster.CreateMUONCluster();
	141	AliDebug(1, Form("Created MUON cluster %p", muonCluster));
	142	trackParam.SetUniqueID(iMFTCluster); // we profit of this slot to store the reference to the corresponding MFTCluster
	143	AliDebug(1, Form("Now adding muonCluster %p and trackParam %p",muonCluster, &trackParam));
	144	AddTrackParamAtCluster(trackParam, *muonCluster, kTRUE);
	145	AliDebug(1, Form("GetTrackParamAtCluster() = %p has %d entries",GetTrackParamAtCluster(), GetTrackParamAtCluster()->GetEntries()));
	146	// we pass the parameters this->GetTrackParamAtCluster()->First() to the Kalman Filter algorithm: they will be updated!!
	147	Double_t chi2Kalman = RunKalmanFilter((AliMUONTrackParam)(GetTrackParamAtCluster()->First()));
	148	Double_t newGlobalChi2 = GetGlobalChi2() + chi2Kalman;
	149	mftCluster.SetLocalChi2(chi2Kalman);
	150	mftCluster.SetTrackChi2(newGlobalChi2);
	151	new ((*fMFTClusters)[iMFTCluster]) AliMFTCluster(mftCluster);
	152	AliDebug(1, Form("muonCluster->GetZ() = %f, trackParam->GetZ() = %f",muonCluster->GetZ(), trackParam.GetZ()));
	153	SetGlobalChi2(newGlobalChi2);
	154	((AliMUONTrackParam*) GetTrackParamAtCluster()->First())->SetTrackChi2(newGlobalChi2);
	155	for (Int_t iPar=0; iPar<GetTrackParamAtCluster()->GetEntries(); iPar++) {
	156	AliDebug(1, Form("GetTrackParamAtCluster()->At(%d)->GetClusterPtr() = %p",
	157	iPar, ((AliMUONTrackParam*)(GetTrackParamAtCluster()->At(iPar)))->GetClusterPtr()));
	158	}
	159
	160	}
	161
	162	//====================================================================================================================================================
	163
	164	AliMUONTrackParam* AliMuonForwardTrack::GetTrackParamAtMUONCluster(Int_t iMUONCluster) {
	165
	166	if (iMUONCluster<0 \|\| iMUONCluster>=GetNMUONClusters()) {
	167	AliError("Invalid MUON cluster index. NULL pointer will be returned");
	168	return NULL;
	169	}
	170
	171	AliMUONTrackParam trackParam = (AliMUONTrackParam) fMUONTrack->GetTrackParamAtCluster()->At(iMUONCluster);
	172
	173	return trackParam;
	174
	175	}
	176
	177	//====================================================================================================================================================
	178
	179	AliMUONTrackParam* AliMuonForwardTrack::GetTrackParamAtMFTCluster(Int_t iMFTCluster) {
	180
	181	if (iMFTCluster<0 \|\| iMFTCluster>=GetNMFTClusters()) {
	182	AliError("Invalid MFT cluster index. NULL pointer will be returned");
	183	return NULL;
	184	}
	185
	186	AliMUONTrackParam trackParam = (AliMUONTrackParam) GetTrackParamAtCluster()->At(iMFTCluster);
	187
	188	return trackParam;
	189
	190	}
	191
	192	//====================================================================================================================================================
	193
	194	AliMUONVCluster* AliMuonForwardTrack::GetMUONCluster(Int_t iMUONCluster) {
	195
	196	if (iMUONCluster<0 \|\| iMUONCluster>=GetNMUONClusters()) {
	197	AliError("Invalid MUON cluster index. NULL pointer will be returned");
	198	return NULL;
	199	}
	200
	201	AliMUONTrackParam *trackParam = GetTrackParamAtMUONCluster(iMUONCluster);
	202	AliMUONVCluster *muonCluster = trackParam->GetClusterPtr();
	203
	204	return muonCluster;
	205
	206	}
	207
	208	//====================================================================================================================================================
	209
	210	AliMFTCluster* AliMuonForwardTrack::GetMFTCluster(Int_t iMFTCluster) {
	211
	212	if (iMFTCluster<0 \|\| iMFTCluster>=GetNMFTClusters()) {
	213	AliError("Invalid MFT cluster index. NULL pointer will be returned");
	214	return NULL;
	215	}
	216
	217	AliMUONTrackParam *trackParam = GetTrackParamAtMFTCluster(iMFTCluster);
	218	AliMFTCluster mftCluster = (AliMFTCluster) fMFTClusters->At(trackParam->GetUniqueID());
	219
	220	return mftCluster;
	221
	222	}
	223
	224	//====================================================================================================================================================
	225
	226	Double_t AliMuonForwardTrack::RunKalmanFilter(AliMUONTrackParam &trackParamAtCluster) {
	227
	228	AliDebug(1, Form("Running Kalman filter for parameters %p (z = %f) and cluster %p (z = %f)",
	229	&trackParamAtCluster, trackParamAtCluster.GetZ(), trackParamAtCluster.GetClusterPtr(), trackParamAtCluster.GetClusterPtr()->GetZ()));
	230
	231	// Compute new track parameters and their covariances including new cluster using kalman filter
	232	// return the additional track chi2
	233
	234	// Get actual track parameters (p)
	235	TMatrixD param(trackParamAtCluster.GetParameters());
	236
	237	// Get new cluster parameters (m)
	238	AliMUONVCluster *cluster = trackParamAtCluster.GetClusterPtr();
	239	AliDebug(1, Form("cluster->GetX() = %f cluster->GetY() = %f cluster->GetErrX() = %f cluster->GetErrY() = %f",
	240	cluster->GetX(), cluster->GetY(), cluster->GetErrX(), cluster->GetErrY()));
	241	TMatrixD clusterParam(5,1);
	242	clusterParam.Zero();
	243	clusterParam(0,0) = cluster->GetX();
	244	clusterParam(2,0) = cluster->GetY();
	245
	246	// Compute the current parameter weight (W)
	247	TMatrixD paramWeight(trackParamAtCluster.GetCovariances());
	248	if (paramWeight.Determinant() != 0) {
	249	paramWeight.Invert();
	250	} else {
	251	Warning("RunKalmanFilter"," Determinant = 0");
	252	return 1.e10;
	253	}
	254
	255	// Compute the new cluster weight (U)
	256	TMatrixD clusterWeight(5,5);
	257	clusterWeight.Zero();
	258	clusterWeight(0,0) = 1. / cluster->GetErrX2();
	259	clusterWeight(2,2) = 1. / cluster->GetErrY2();
	260
	261	// Compute the new parameters covariance matrix ( (W+U)^-1 )
	262	TMatrixD newParamCov(paramWeight,TMatrixD::kPlus,clusterWeight);
	263	if (newParamCov.Determinant() != 0) {
	264	newParamCov.Invert();
	265	}
	266	else {
	267	Warning("RunKalmanFilter"," Determinant = 0");
	268	return 1.e10;
	269	}
	270
	271	// Save the new parameters covariance matrix
	272	trackParamAtCluster.SetCovariances(newParamCov);
	273
	274	// Compute the new parameters (p' = ((W+U)^-1)U(m-p) + p)
	275	TMatrixD tmp(clusterParam,TMatrixD::kMinus,param);
	276	TMatrixD tmp2(clusterWeight,TMatrixD::kMult,tmp); // U(m-p)
	277	TMatrixD newParam(newParamCov,TMatrixD::kMult,tmp2); // ((W+U)^-1)U(m-p)
	278	newParam += param; // ((W+U)^-1)U(m-p) + p
	279
	280	// Save the new parameters
	281	trackParamAtCluster.SetParameters(newParam);
	282
	283	// Compute the additional chi2 (= ((p'-p)^-1)W(p'-p) + ((p'-m)^-1)U(p'-m))
	284	tmp = newParam; // p'
	285	tmp -= param; // (p'-p)
	286	TMatrixD tmp3(paramWeight,TMatrixD::kMult,tmp); // W(p'-p)
	287	TMatrixD addChi2Track(tmp,TMatrixD::kTransposeMult,tmp3); // ((p'-p)^-1)W(p'-p)
	288	tmp = newParam; // p'
	289	tmp -= clusterParam; // (p'-m)
	290	TMatrixD tmp4(clusterWeight,TMatrixD::kMult,tmp); // U(p'-m)
	291	addChi2Track += TMatrixD(tmp,TMatrixD::kTransposeMult,tmp4); // ((p'-p)^-1)W(p'-p) + ((p'-m)^-1)U(p'-m)
	292
	293	AliDebug(1,Form("Adding Kalman chi2 = %f",addChi2Track(0,0)));
	294
	295	return addChi2Track(0,0);
	296
	297	}
	298
	299	//====================================================================================================================================================
	300
	301	Double_t AliMuonForwardTrack::GetWeightedOffset(Double_t x, Double_t y, Double_t z) {
	302
	303	AliMUONTrackParam *param = GetTrackParamAtMFTCluster(0);
	304	AliMUONTrackExtrap::ExtrapToZCov(param, z);
	305
	306	TMatrixD cov(5,5);
	307	cov = param->GetCovariances();
	308
	309	TMatrixD covCoordinates(2,2);
	310	covCoordinates(0,0) = cov(0,0);
	311	covCoordinates(0,1) = cov(0,2);
	312	covCoordinates(1,0) = cov(2,0);
	313	covCoordinates(1,1) = cov(2,2);
	314
	315	TMatrixD covCoordinatesInverse = covCoordinates.Invert();
	316
	317	Double_t dX = param->GetNonBendingCoor() - x;
	318	Double_t dY = param->GetBendingCoor() - y;
	319
	320	Double_t weightedOffset = TMath::Sqrt(0.5(dXdX*covCoordinatesInverse(0,0) +
	321	dYdYcovCoordinatesInverse(1,1) +
	322	2.dXdY*covCoordinatesInverse(0,1)));
	323
	324	return weightedOffset;
	325
	326	}
	327
	328	//====================================================================================================================================================
	329
	330	Double_t AliMuonForwardTrack::GetOffsetX(Double_t x, Double_t z) {
	331
	332	AliMUONTrackParam *param = GetTrackParamAtMFTCluster(0);
	333	AliMUONTrackExtrap::ExtrapToZCov(param, z);
	334	Double_t dX = param->GetNonBendingCoor() - x;
	335	return dX;
	336
	337	}
	338
	339	//====================================================================================================================================================
	340
	341	Double_t AliMuonForwardTrack::GetOffsetY(Double_t y, Double_t z) {
	342
	343	AliMUONTrackParam *param = GetTrackParamAtMFTCluster(0);
	344	AliMUONTrackExtrap::ExtrapToZCov(param, z);
	345	Double_t dY = param->GetBendingCoor() - y;
	346	return dY;
	347
	348	}
	349
	350	//====================================================================================================================================================
	351
	352	Double_t AliMuonForwardTrack::GetOffset(Double_t x, Double_t y, Double_t z) {
	353
	354	AliMUONTrackParam *param = GetTrackParamAtMFTCluster(0);
	355	AliMUONTrackExtrap::ExtrapToZCov(param, z);
	356	Double_t dX = param->GetNonBendingCoor() - x;
	357	Double_t dY = param->GetBendingCoor() - y;
	358	return TMath::Sqrt(dXdX + dYdY);
	359
	360	}
	361
	362	//====================================================================================================================================================
	363