MuonR4::HoughHelpers::Eta Namespace Reference

Functions
double	houghParamMdtLeft (double tanBeta, const MuonR4::HoughHitType &dc)
	left-side straight line parametrisation for drift circles
double	houghParamMdtRight (double tanBeta, const MuonR4::HoughHitType &dc)
	right-side straight line parametrisation for drift circles
double	houghParamStrip (double tanBeta, const MuonR4::HoughHitType &strip)
	straight line parametrisation for strip detector measurements
double	houghWidthMdt (double tanBeta, const MuonR4::HoughHitType &dc, double targetReso)
	uncertainty parametrisation for drift circles
double	houghWidthStrip (double tanBeta, const MuonR4::HoughHitType &strip, double targetReso)
	Uncertainty parametrisation for strip measurements.

Function Documentation

houghParamMdtLeft()

double MuonR4::HoughHelpers::Eta::houghParamMdtLeft	(	double	tanBeta,
		const MuonR4::HoughHitType &	dc )

left-side straight line parametrisation for drift circles

Parameters

tanBeta	the input inclination angle
dc	the drift circle (expressed as a space point)

Returns

the y offset needed to touch the drift radius on the left for an inclination angle tanBeta

Definition at line 11 of file HoughHelperFunctions.cxx.

                                                                               {
            return DC->localPosition().y() - tanBeta * DC->localPosition().z() -
                    DC->driftRadius() * Acts::fastHypot(1., tanBeta);    // using cos(theta) = sqrt(1/[1+tan²(theta)])
        }

houghParamMdtRight()

double MuonR4::HoughHelpers::Eta::houghParamMdtRight	(	double	tanBeta,
		const MuonR4::HoughHitType &	dc )

right-side straight line parametrisation for drift circles

Parameters

tanBeta	the input inclination angle
dc	the drift circle (expressed as a space point)

Returns

the y offset needed to touch the drift radius on the right for an inclination angle tanBeta

Definition at line 15 of file HoughHelperFunctions.cxx.

                                                                                {
            return DC->localPosition().y() - tanBeta * DC->localPosition().z() +
                   DC->driftRadius() * Acts::fastHypot(1., tanBeta);    // using cos(theta) = sqrt(1/[1+tan²(theta)])
        }

houghParamStrip()

double MuonR4::HoughHelpers::Eta::houghParamStrip	(	double	tanBeta,
		const MuonR4::HoughHitType &	strip )

straight line parametrisation for strip detector measurements

Parameters

tanBeta	the input inclination angle
strip	the strip measurement (expressed as a space point)

Returns

the y offset needed to pass through the center of the strip space point for an inclination angle tanBeta

Definition at line 19 of file HoughHelperFunctions.cxx.

                                                                                {
            return strip->localPosition().y() - tanBeta * strip->localPosition().z();
        }

houghWidthMdt()

double MuonR4::HoughHelpers::Eta::houghWidthMdt	(	double	tanBeta,
		const MuonR4::HoughHitType &	dc,
		double	targetReso )

uncertainty parametrisation for drift circles

Parameters

tanBeta	the input inclination angle
dc	the drift circle (expressed as a space point)

Returns

the uncertainty on the y offset - calculated from an inflated drift circle error and a baseline uncertainty to account for the not fully known t0

Scale reported errors up to at least 1 mm or 3 times the reported error as drift circle calibration is not fully reliable at this stage

Definition at line 22 of file HoughHelperFunctions.cxx.

                                                                                        {
            return std::max(3.* std::sqrt(DC->covariance()[Acts::toUnderlying(AxisDefs::etaCov)]),
                            targetReso);  // scale reported errors up to at least 1mm or 3
        }

houghWidthStrip()

double MuonR4::HoughHelpers::Eta::houghWidthStrip	(	double	tanBeta,
		const MuonR4::HoughHitType &	strip,
		double	targetReso )

Uncertainty parametrisation for strip measurements.

Parameters

tanBeta	the input inclination angle (not used)
strip	the strip measurement (expressed as a space point)

Returns

the uncertainty on the y offset - based on the strip pitch

Definition at line 28 of file HoughHelperFunctions.cxx.

                                                                                             {
            const double nomCov = 3.*std::sqrt(strip->covariance()[Acts::toUnderlying(AxisDefs::etaCov)]);
            return std::max(targetReso, nomCov* ((strip->type() == xAOD::UncalibMeasType::TgcStripType && !strip->measuresPhi()) ? 1.5 : 1.0));  
            // return positional uncertainty defined during SP creation
        }