TrackMomentumCalculator.cxx File Reference

#include "larreco/RecoAlg/TrackMomentumCalculator.h"

Go to the source code of this file.

Namespaces
	trkf

Functions
double	my_mcs_chi2 (const double *x)

Function Documentation

double my_mcs_chi2

(

const double *

x

)

Definition at line 7 of file TrackMomentumCalculator.cxx.

References eymeas, LOG_DEBUG, nmeas, xmeas, xx, and ymeas.

Referenced by trkf::TrackMomentumCalculator::GetMomentumMultiScatterChi2().

{
  Double_t result = 0.0;
  
  Double_t p = x[0]; 
  
  Double_t theta0 = x[1]; 
  
  for ( Int_t i=0; i<nmeas; i++ )
    {
      Double_t xx = xmeas[i]; 
      
      Double_t yy = ymeas[i]; 
      
      Double_t ey = eymeas[i]; 
      
      Double_t rad_length = 14.0;
      
      Double_t l0 = xx/rad_length;
      
      Double_t res1 = 0.0;
      
      if ( xx>0 && p>0 ) res1 = ( 13.6/p )*sqrt( l0 )*( 1.0+0.038*TMath::Log( l0 ) );
      
      res1 = sqrt( res1*res1+theta0*theta0 );
      
      Double_t diff = yy-res1;
      
      if ( ey==0 ) { cout << " Zero denominator in my_mcs_chi2 ! " << endl; return -1; }
      
      Double_t incre = pow( diff/ey, 2.0 );
      
      result += incre;
      
    }
  
  result += 2.0/( 4.6 )*theta0; // *TMath::Log( 1.0/14.0 );
  
  if ( isnan( float(result) ) || isinf( float(result) ) ) { 
    LOG_DEBUG("TrackMomentumCalculator")<<" Is nan in my_mcs_chi2 ! ";
    return -1; }
    
  return result;
  
}