CbmKFUMeasurement.cxx

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#include "CbmKFUMeasurement.h"
 
#include <cmath>
 
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;
}