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FastVertexFit Class Reference

#include <FastVertexFit.h>

List of all members.

Public Member Functions

void addTrack (const int number, const HepVector helix, const HepSymMatrix err)
void addTrack (const int number, const HepVector helix, const HepSymMatrix err)
double chisq () const
double chisq () const
HepSymMatrix Evx () const
HepSymMatrix Evx () const
bool Fit ()
bool Fit ()
void init ()
void init ()
HepVector Pull () const
HepVector Pull () const
VertexParameter vtx () const
VertexParameter vtx () const
HepVector Vx () const
HepVector Vx () const
 ~FastVertexFit ()
 ~FastVertexFit ()

Static Public Member Functions

FastVertexFit * instance ()
FastVertexFit * instance ()

Private Member Functions

 FastVertexFit ()
 FastVertexFit ()
void updateMatrices (const HepVector helix, const HepSymMatrix err)
void updateMatrices (const HepVector helix, const HepSymMatrix err)

Private Attributes

double m_chisq
std::vector< HepMatrix > m_D
std::vector< HepMatrix > m_D
std::vector< HepSymMatrix > m_DTWD
std::vector< HepSymMatrix > m_DTWD
HepSymMatrix m_Evx
VertexParameter m_vtx_infit
HepVector m_Vx
std::vector< HepSymMatrix > m_W
std::vector< HepSymMatrix > m_W
std::vector< HepVector > m_xp
std::vector< HepVector > m_xp

Static Private Attributes

FastVertexFit * m_pointer
FastVertexFit * m_pointer = 0

Constructor & Destructor Documentation

FastVertexFit::~FastVertexFit (   ) 
  

00015 {;}

FastVertexFit::FastVertexFit (   )  [private]
  

00017 {;}

FastVertexFit::~FastVertexFit (   ) 
 

FastVertexFit::FastVertexFit (   )  [private]
 

Member Function Documentation

void FastVertexFit::addTrack (  const int  number,
const HepVector  helix,
const HepSymMatrix  err
) 
 

void FastVertexFit::addTrack (  const int  number,
const HepVector  helix,
const HepSymMatrix  err
) 
  

00029                                                                                             {
00030   int ifail;
00031   int ierr;
00032   //HepSymMatrix err0(5, 0); //inverse of err;
00033   //err0 = err.inverse(ifail);
00034   HepSymMatrix Wc(2, 0);
00035   Wc[0][0] = err[0][0];
00036   Wc[0][1] = Wc[1][0] = err[0][3];
00037   Wc[1][1] = err[3][3];
00038   Wc = Wc.inverse(ifail);
00039 
00040   HepVector p0(3, 0), v0(3, 0);
00041   double pxy = 1./fabs(helix[2]);
00042   p0[0] = 0 - pxy*sin(helix[1]); //px
00043   p0[1] = pxy*cos(helix[1]);     //py
00044   p0[2] = pxy * helix[4];        //pz
00045   v0[0] = helix[0]*cos(helix[1]);//x
00046   v0[1] = helix[0]*sin(helix[1]);//y
00047   v0[2] = helix[3];              //z  
00048 
00049   HepPoint3D vv0(v0[0], v0[1], v0[2]);
00050   double bField = VertexFitBField::instance()->getBFieldZRef();
00051 
00052   int charge = (helix[2]>0 ? +1 :-1);
00053   double a = alpha * bField * charge;
00054   double T0 = sqrt((p0[0]+a*p0[1])*(p0[0]+a*p0[1])+(p0[1]-a*p0[0])*(p0[1]-a*p0[0]));
00055 
00056   HepMatrix Dc(2, 3, 0);
00057   Dc[0][0] = (p0[1] - a*v0[0])/T0;
00058   Dc[0][1] = 0 - (p0[0] + a*v0[1])/T0;
00059   Dc[1][0] = 0 - (p0[2]/T0) * (p0[0] + a*v0[1])/T0;
00060   Dc[1][1] = 0 - (p0[2]/T0) * (p0[1] - a*v0[0])/T0;
00061   Dc[1][2] = 1;
00062 
00063   m_D.push_back(Dc);
00064   m_W.push_back(Wc);
00065 
00066   HepSymMatrix DTWD(3, 0);
00067   DTWD = Wc.similarity(Dc.T());
00068   HepVector qTrk(2, 0);
00069   qTrk[0] = helix[0];
00070   qTrk[1] = helix[3];
00071   //HepVector xp(3, 0);
00072   //xp = Dc.inverse(ierr) * qTrk;
00073   m_DTWD.push_back(DTWD);
00074   m_xp.push_back(v0);
00075 }

double FastVertexFit::chisq (   )  const [inline]
  

00038 {return m_chisq;}

double FastVertexFit::chisq (   )  const [inline]
  

00038 {return m_chisq;}

HepSymMatrix FastVertexFit::Evx (   )  const [inline]
  

00041 {return m_Evx;}

HepSymMatrix FastVertexFit::Evx (   )  const [inline]
  

00041 {return m_Evx;}

bool FastVertexFit::Fit (   ) 
 

bool FastVertexFit::Fit (   ) 
  

00077                         {
00078   bool fitResult = false;
00079 
00080   int ifail;
00081   HepSymMatrix total_DTWD(3, 0);
00082   HepVector total_xp(3, 0);
00083 
00084   for(int i = 0; i < m_DTWD.size(); i++) {
00085     total_DTWD += m_DTWD[i];  
00086     total_xp += m_DTWD[i]*m_xp[i]; 
00087   }
00088   m_Vx = total_DTWD.inverse(ifail) * total_xp;
00089   m_Evx = total_DTWD.inverse(ifail);
00090 
00091   double chisq = 0;
00092   for(int i = 0; i < m_xp.size(); i++) {
00093     double chi2 = (m_DTWD[i].similarity((m_xp[i] - m_Vx).T()))[0][0];  
00094     chisq += chi2;
00095   }
00096   m_chisq = chisq;
00097 
00098   fitResult = true;
00099   return fitResult;
00100 }

void FastVertexFit::init (   ) 
 

void FastVertexFit::init (   ) 
  

00019                          {
00020   m_D.clear();
00021   m_W.clear();
00022   m_DTWD.clear();
00023   m_xp.clear();
00024   m_chisq = 999;
00025   m_Vx = HepVector(3, 0);
00026   m_Evx = HepSymMatrix(3,0);
00027 }

FastVertexFit* FastVertexFit::instance (   )  [static]
 

FastVertexFit * FastVertexFit::instance (   )  [static]
  

00009                                         {
00010   if(m_pointer) return m_pointer;
00011   m_pointer = new FastVertexFit();
00012   return m_pointer;
00013 }

HepVector FastVertexFit::Pull (   )  const
 

HepVector FastVertexFit::Pull (   )  const
  

00102                                     {
00103   HepVector pull(3, 0);
00104   pull[0] = m_Vx[0]/sqrt(m_Evx[0][0]);
00105   pull[1] = m_Vx[1]/sqrt(m_Evx[1][1]);
00106   pull[2] = m_Vx[2]/sqrt(m_Evx[2][2]);
00107   return pull;
00108 }

void FastVertexFit::updateMatrices (  const HepVector  helix,
const HepSymMatrix  err
)  [private]
 

void FastVertexFit::updateMatrices (  const HepVector  helix,
const HepSymMatrix  err
)  [private]
 

VertexParameter FastVertexFit::vtx (   )  const [inline]
  

00039 {return m_vtx_infit;}

VertexParameter FastVertexFit::vtx (   )  const [inline]
  

00039 {return m_vtx_infit;}

HepVector FastVertexFit::Vx (   )  const [inline]
  

00040 {return m_Vx;}

HepVector FastVertexFit::Vx (   )  const [inline]
  

00040 {return m_Vx;}

Member Data Documentation

double FastVertexFit::m_chisq [private]
 

std::vector<HepMatrix> FastVertexFit::m_D [private]
 

std::vector<HepMatrix> FastVertexFit::m_D [private]
 

std::vector<HepSymMatrix> FastVertexFit::m_DTWD [private]
 

std::vector<HepSymMatrix> FastVertexFit::m_DTWD [private]
 

HepSymMatrix FastVertexFit::m_Evx [private]
 

FastVertexFit* FastVertexFit::m_pointer [static, private]
 

FastVertexFit * FastVertexFit::m_pointer = 0 [static, private]
 

VertexParameter FastVertexFit::m_vtx_infit [private]
 

HepVector FastVertexFit::m_Vx [private]
 

std::vector<HepSymMatrix> FastVertexFit::m_W [private]
 

std::vector<HepSymMatrix> FastVertexFit::m_W [private]
 

std::vector<HepVector> FastVertexFit::m_xp [private]
 

std::vector<HepVector> FastVertexFit::m_xp [private]
 

The documentation for this class was generated from the following files:
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