Modifications needed by the HBT analysis (P.Skowronski)
[u/mrichter/AliRoot.git] / MUON / AliMUONHitForRec.cxx
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a9e2aefa 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
88cb7938 16/* $Id$ */
a9e2aefa 17
18//__________________________________________________________________________
19//
20// Hit for reconstruction in ALICE dimuon spectrometer
21//__________________________________________________________________________
22
23#include "AliMUONHitForRec.h"
24#include "AliMUONTrackParam.h"
25#include "AliMUONRawCluster.h"
26#include "AliMUONHit.h"
27
28ClassImp(AliMUONHitForRec) // Class implementation in ROOT context
29
30 //__________________________________________________________________________
31AliMUONHitForRec::AliMUONHitForRec(AliMUONHit* Ghit)
32{
33 // Constructor for AliMUONHitForRec from a GEANT hit.
34 // Fills the bending, non bending, and Z coordinates,
35 // which are taken from the coordinates of the GEANT hit,
36 // the track number (GEANT and not TH),
37 // and the chamber number (0...).
94de3818 38 fBendingCoor = Ghit->Y();
39 fNonBendingCoor = Ghit->X();
40 fZ = Ghit->Z();
a9e2aefa 41 // fTrack = Ghit->fTrack; ?????????
e819fbd3 42 fChamberNumber = Ghit->Chamber() - 1;
a9e2aefa 43 // other fields will be updated in
44 // AliMUONEventReconstructor::NewHitForRecFromGEANT,
45 // except the following ones
46 fIndexOfFirstSegment = -1;
47 fNSegments = 0;
48 fFirstTrackHitPtr = fLastTrackHitPtr = NULL;
49 fNTrackHits = 0;
50 return;
51}
52
53// //__________________________________________________________________________
54// AliMUONHitForRec::AliMUONHitForRec(AliMUONReconstHit* CathCorrel)
55// {
56// // Constructor for AliMUONHitForRec from a (cathode correlated) raw cluster.
57// // Fills the bending and non bending coordinates.
58// // Only the first correlation is taken into account.
59// // The bending coordinate is taken from the first cathode.
60// // The non bending coordinate is taken
61// // from the second cathode if it exists,
62// // from the first one otherwise.
63// fBendingCoor = CathCorrel->fY[3];
64// if (CathCorrel->fCorrelIndex[0] >= 0) fNonBendingCoor = CathCorrel->fX[0];
65// else fNonBendingCoor = CathCorrel->fX[3];
66// return;
67// }
68
69 //__________________________________________________________________________
70AliMUONHitForRec::AliMUONHitForRec(AliMUONRawCluster* RawCluster)
71{
72 // Constructor for AliMUONHitForRec from a raw cluster.
73 // Fills the bending and non bending coordinates.
74 fNonBendingCoor = RawCluster->fX[0];
75 fBendingCoor = RawCluster->fY[0];
76 // other fields will be updated in
77 // AliMUONEventReconstructor::AddHitsForRecFromRawClusters,
78 // except the following ones
79 fTHTrack = -1;
80 fGeantSignal = -1;
81 fIndexOfFirstSegment = -1;
82 fNSegments = 0;
83 fFirstTrackHitPtr = fLastTrackHitPtr = NULL;
84 fNTrackHits = 0;
85 return;
86}
87
d9a3473d 88AliMUONHitForRec::AliMUONHitForRec (const AliMUONHitForRec& MUONHitForRec):TObject(MUONHitForRec)
a9e2aefa 89{
90// Dummy copy constructor
91}
92
d9a3473d 93AliMUONHitForRec & AliMUONHitForRec::operator=(const AliMUONHitForRec& /*MUONHitForRec*/)
a9e2aefa 94{
95// Dummy assignment operator
96 return *this;
97}
a9e2aefa 98 //__________________________________________________________________________
83dbc640 99/*AZ
2a941f4e 100Int_t AliMUONHitForRec::Compare(const TObject* Hit) const
a9e2aefa 101{
102 // "Compare" function to sort with increasing chamber number.
103 // Returns -1 (0, +1) if ChamberNumber of current HitForRec
104 // is smaller than (equal to, larger than) ChamberNumber of Hit
105 if (fChamberNumber < ((AliMUONHitForRec*)Hit)->fChamberNumber) return(-1);
106 else if (fChamberNumber == ((AliMUONHitForRec*)Hit)->fChamberNumber) return( 0);
107 else return(+1);
108}
83dbc640 109*/
110 //__________________________________________________________________________
111Int_t AliMUONHitForRec::Compare(const TObject* Hit) const
112{
5b64e914 113 // "Compare" function to sort with decreasing Z-coordinate (spectro. MUON z<0).
114 // Returns 1 (0, -1) if Z-coordinate of current HitForRec
83dbc640 115 // is smaller than (equal to, larger than) Z-coordinate of Hit
5b64e914 116 if (fZ < ((AliMUONHitForRec*)Hit)->fZ) return(1);
83dbc640 117 else if (fZ == ((AliMUONHitForRec*)Hit)->fZ) return( 0);
5b64e914 118 else return(-1);
83dbc640 119}
a9e2aefa 120
121 //__________________________________________________________________________
122Double_t AliMUONHitForRec::NormalizedChi2WithHitForRec(AliMUONHitForRec* HitForRec, Double_t Sigma2Cut)
123{
124 // Calculate the normalized Chi2 between the current HitForRec (this)
125 // and the HitForRec pointed to by "HitForRec",
126 // i.e. the square deviations between the coordinates,
127 // in both the bending and the non bending plane,
128 // divided by the variance of the same quantities and by "Sigma2Cut".
129 // Returns 3 if none of the 2 quantities is OK,
130 // something smaller than or equal to 2 otherwise.
131 // Would it be more correct to use a real chi square
132 // including the non diagonal term ????
133 Double_t chi2, chi2Max, diff, normDiff;
134 chi2 = 0.0;
135 chi2Max = 3.0;
136 // coordinate in bending plane
137 diff = this->fBendingCoor - HitForRec->fBendingCoor;
138 normDiff = diff * diff /
139 (this->fBendingReso2 + HitForRec->fBendingReso2) / Sigma2Cut;
140 if (normDiff > 1.0) return chi2Max;
141 chi2 = chi2 + normDiff;
142 // coordinate in non bending plane
143 diff = this->fNonBendingCoor - HitForRec->fNonBendingCoor;
144 normDiff = diff * diff /
145 (this->fNonBendingReso2 + HitForRec->fNonBendingReso2) / Sigma2Cut;
146 if (normDiff > 1.0) return chi2Max;
147 chi2 = chi2 + normDiff;
148 return chi2;
149}