MuonR4::SegmentFitHelpers Namespace Reference

Functions
double	chiSqTermMdt (double y0, double tanTheta, const MuonR4::HoughHitType &measurement)
double	chiSqTermStrip (double x0, double y0, double tanPhi, double tanTheta, const MuonR4::HoughHitType &measurement)
double	segmentChiSquare (const double *par, const std::vector< MuonR4::HoughHitType > &hits, std::vector< double > &chi2PerMeas)

Function Documentation

chiSqTermMdt()

double MuonR4::SegmentFitHelpers::chiSqTermMdt	(	double	y0,
		double	tanTheta,
		const MuonR4::HoughHitType &	measurement
	)

TODO FIXME Johannes (@jojungge / @the.minions): Fix the -1 sign flip in your algebra!!!!! !

Definition at line 8 of file SegmentFitHelperFunctions.cxx.

                                                                                                        {
    const double theta{std::atan(-tanTheta)};
    const Amg::Vector3D dir{0., -std::sin(theta), std::cos(theta)};
    const Amg::Vector3D x0{y0 * Amg::Vector3D::UnitY()};
    double dchi2 = std::abs((x0 - measurement->positionInChamber()).cross(dir).dot(Amg::Vector3D::UnitX())) - measurement->driftRadius();
    return dchi2*dchi2 / (measurement->uncertainty().y()*measurement->uncertainty().y()); 
}

chiSqTermStrip()

double MuonR4::SegmentFitHelpers::chiSqTermStrip	(	double	x0,
		double	y0,
		double	tanPhi,
		double	tanTheta,
		const MuonR4::HoughHitType &	measurement
	)

Definition at line 17 of file SegmentFitHelperFunctions.cxx.

                                                                                                                                    {
    Amg::Vector2D residual{x0 + measurement->positionInChamber().z() * tanPhi - measurement->positionInChamber().x(), 
                         y0 + measurement->positionInChamber().z() * tanTheta - measurement->positionInChamber().y()
                        }; 
    AmgSymMatrix(2) weightMatrix = measurement->covariance().inverse(); 
    return residual.dot(weightMatrix * residual); 
}

segmentChiSquare()

double MuonR4::SegmentFitHelpers::segmentChiSquare	(	const double *	par,
		const std::vector< MuonR4::HoughHitType > &	hits,
		std::vector< double > &	chi2PerMeas
	)

Definition at line 24 of file SegmentFitHelperFunctions.cxx.

                                                                                                                                        {
 
    double y0 = par[(int)MuonSegmentFitterEventData::parameterIndices::y0];
    double x0 = par[(int)MuonSegmentFitterEventData::parameterIndices::x0];
    double tanTheta = par[(int)MuonSegmentFitterEventData::parameterIndices::tanTheta];
    double tanPhi = par[(int)MuonSegmentFitterEventData::parameterIndices::tanPhi];
    double chi2 = 0.;
    double nDF = -2.;
    size_t iHit = 0; 
    for (auto & hit : hits){
        double localchi2 = 0; 
        switch (hit->primaryMeasurement()->type()){
            case xAOD::UncalibMeasType::MdtDriftCircleType: 
                localchi2 = SegmentFitHelpers::chiSqTermMdt(y0,tanTheta, hit);
                ++nDF; 
                break; 
            case xAOD::UncalibMeasType::TgcStripType:
            case xAOD::UncalibMeasType::RpcStripType: 
                localchi2 = SegmentFitHelpers::chiSqTermStrip(x0,y0,tanPhi,tanTheta, hit);
                nDF+=2; 
                break; 
            case xAOD::UncalibMeasType::MMClusterType: 
                // FIXME TODO
                break; 
            case xAOD::UncalibMeasType::sTgcStripType: 
                // FIXME TODO
                break; 
            default: 
                break;
        }
        chi2PerMeas.at(iHit) = localchi2;
        chi2 += localchi2;  
        ++iHit; 
    }
    return (nDF != 0 ?  chi2/nDF : chi2); 
}