STEER/AliKalmanTrack.cxx

   1 /**************************************************************************
   2  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   3  *                                                                        *
   4  * Author: The ALICE Off-line Project.                                    *
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  15
  16 //-------------------------------------------------------------------------
  17 //                Implementation of the AliKalmanTrack class
  18 //
  19 //        Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
  20 //-------------------------------------------------------------------------
  21
  22 #include "AliKalmanTrack.h"
  23 #include "AliCluster.h"
  24 #include <TMath.h>
  25 #include <iostream.h>
  26
  27 ClassImp(AliKalmanTrack)
  28
  29 //_____________________________________________________________________________
  30 AliKalmanTrack::AliKalmanTrack(const AliKalmanTrack& t) {
  31   //-----------------------------------------------------------------
  32   // This is a copy constructor.
  33   //-----------------------------------------------------------------
  34   fLab=t.fLab;
  35
  36   fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4;
  37
  38   fC00=t.fC00;
  39   fC10=t.fC10;  fC11=t.fC11;
  40   fC20=t.fC20;  fC21=t.fC21;  fC22=t.fC22;
  41   fC30=t.fC30;  fC31=t.fC31;  fC32=t.fC32;  fC33=t.fC33;
  42   fC40=t.fC40;  fC41=t.fC41;  fC42=t.fC42;  fC43=t.fC43;  fC44=t.fC44;
  43
  44   fChi2=t.fChi2;
  45   fN=t.fN;
  46 }
  47
  48 //_____________________________________________________________________________
  49 Int_t AliKalmanTrack::Compare(TObject *o) {
  50   //-----------------------------------------------------------------
  51   // This function compares tracks according to the their curvature
  52   //-----------------------------------------------------------------
  53   AliKalmanTrack *t=(AliKalmanTrack*)o;
  54   Double_t co=TMath::Abs(t->GetPt());
  55   Double_t c =TMath::Abs(GetPt());
  56   if (c<co) return 1;
  57   else if (c>co) return -1;
  58   return 0;
  59 }
  60
  61 //_____________________________________________________________________________
  62 Double_t AliKalmanTrack::GetPredictedChi2(const AliCluster *c) const
  63 {
  64   //-----------------------------------------------------------------
  65   // This function calculates a predicted chi2 increment.
  66   //-----------------------------------------------------------------
  67   Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
  68   r00+=fC00; r01+=fC10; r11+=fC11;
  69
  70   Double_t det=r00*r11 - r01*r01;
  71   if (TMath::Abs(det) < 1.e-10) {
  72     if (fN>4) cerr<<fN<<" AliKalmanTrack warning: Singular matrix !\n";
  73     return 1e10;
  74   }
  75   Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
  76
  77   Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1;
  78
  79   return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
  80 }
  81
  82 //_____________________________________________________________________________
  83 void AliKalmanTrack::GetCovariance(Double_t cc[15]) const {
  84   // return covariance maxtrix
  85   cc[0 ]=fC00;
  86   cc[1 ]=fC10;  cc[2 ]=fC11;
  87   cc[3 ]=fC20;  cc[4 ]=fC21;  cc[5 ]=fC22;
  88   cc[6 ]=fC30;  cc[7 ]=fC31;  cc[8 ]=fC32;  cc[9 ]=fC33;
  89   cc[10]=fC40;  cc[11]=fC41;  cc[12]=fC42;  cc[13]=fC43;  cc[14]=fC44;
  90 }
  91
  92 //____________________________________________________________________________
  93 void AliKalmanTrack::Streamer(TBuffer &R__b)
  94 {
  95   //-----------------------------------------------------
  96   // This is AliKalmanTrack streamer.
  97   //-----------------------------------------------------
  98    if (R__b.IsReading()) {
  99       Version_t R__v = R__b.ReadVersion(); if (R__v) { }
 100       TObject::Streamer(R__b);
 101       R__b >> fLab;
 102       R__b >> fP0;
 103       R__b >> fP1;
 104       R__b >> fP2;
 105       R__b >> fP3;
 106       R__b >> fP4;
 107       R__b >> fC00;
 108       R__b >> fC10;
 109       R__b >> fC11;
 110       R__b >> fC20;
 111       R__b >> fC21;
 112       R__b >> fC22;
 113       R__b >> fC30;
 114       R__b >> fC31;
 115       R__b >> fC32;
 116       R__b >> fC33;
 117       R__b >> fC40;
 118       R__b >> fC41;
 119       R__b >> fC42;
 120       R__b >> fC43;
 121       R__b >> fC44;
 122       R__b >> fChi2;
 123       R__b >> fN;
 124    } else {
 125       R__b.WriteVersion(AliKalmanTrack::IsA());
 126       TObject::Streamer(R__b);
 127       R__b << fLab;
 128       R__b << fP0;
 129       R__b << fP1;
 130       R__b << fP2;
 131       R__b << fP3;
 132       R__b << fP4;
 133       R__b << fC00;
 134       R__b << fC10;
 135       R__b << fC11;
 136       R__b << fC20;
 137       R__b << fC21;
 138       R__b << fC22;
 139       R__b << fC30;
 140       R__b << fC31;
 141       R__b << fC32;
 142       R__b << fC33;
 143       R__b << fC40;
 144       R__b << fC41;
 145       R__b << fC42;
 146       R__b << fC43;
 147       R__b << fC44;
 148       R__b << fChi2;
 149       R__b << fN;
 150    }
 151 }
 152
 153