CbmKFUMeasurement.cxx

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#include "CbmKFUMeasurement.h"
 
#include <cmath>
 
ClassImp(CbmKFUMeasurement)
 
  void CbmKFUMeasurement::Set(Double_t z_,
                              Double_t u_,
                              Double_t phi_,
                              Double_t sigma2_) {
  this->z      = z_;
  this->u      = u_;
  this->phi    = phi_;
  this->sigma2 = sigma2_;
  phi_s        = sin(phi_);
  phi_c        = cos(phi_);
  phi_ss       = phi_s * phi_s;
  phi_cc       = phi_c * phi_c;
  phi_2sc      = 2. * phi_s * phi_c;
}
 
Int_t CbmKFUMeasurement::Filter(CbmKFTrackInterface& track) {
 
  Double_t* T = track.GetTrack();
  Double_t* C = track.GetCovMatrix();
 
  Double_t W = sigma2 + phi_cc * C[0] + phi_2sc * C[1] + phi_ss * C[2];
  if (!finite(W) || W < 1.e-10) return 1;
  W = 1. / W;
  if (!finite(W)) return 1;
 
  Double_t zeta = phi_c * T[0] + phi_s * T[1] - u;
 
  track.GetRefChi2() += zeta * zeta * W;
  track.GetRefNDF() += 1;
  Double_t K[5] = {phi_c * C[0] + phi_s * C[1],
                   phi_c * C[1] + phi_s * C[2],
                   phi_c * C[3] + phi_s * C[4],
                   phi_c * C[6] + phi_s * C[7],
                   phi_c * C[10] + phi_s * C[11]};
 
  Double_t KW[5] = {K[0] * W, K[1] * W, K[2] * W, K[3] * W, K[4] * W};
 
  T[0] -= KW[0] * zeta;
  T[1] -= KW[1] * zeta;
  T[2] -= KW[2] * zeta;
  T[3] -= KW[3] * zeta;
  T[4] -= KW[4] * zeta;
 
  C[0] -= K[0] * KW[0];
  C[1] -= K[1] * KW[0];
  C[2] -= K[1] * KW[1];
  C[3] -= K[2] * KW[0];
  C[4] -= K[2] * KW[1];
  C[5] -= K[2] * KW[2];
  C[6] -= K[3] * KW[0];
  C[7] -= K[3] * KW[1];
  C[8] -= K[3] * KW[2];
  C[9] -= K[3] * KW[3];
  C[10] -= K[4] * KW[0];
  C[11] -= K[4] * KW[1];
  C[12] -= K[4] * KW[2];
  C[13] -= K[4] * KW[3];
  C[14] -= K[4] * KW[4];
  return 0;
}