Implements a 1-dim density grid to be filled with track Gaussian distributions. Each single track is modelled as a 2(!)-dim Gaussian distribution grid in the d0-z0 plane, but only the overlap with the z-axis (i.e. a 1-dim density vector) needs to be calculated. The position of the highest track density (of either a single bin or the sum of a certain region) can be determined. Single tracks can be cached and removed from the overall density. More...

#include <acts/blob/sPHENIX/Core/include/Acts/Vertexing/GaussianGridTrackDensity.hpp>

Collaboration diagram for Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >:

Classes
struct	Config
	The configuration struct. More...

Public Types
using	MainGridVector = Eigen::Matrix< float, mainGridSize, 1 >

using	TrackGridVector = Eigen::Matrix< float, trkGridSize, 1 >

Public Member Functions
	GaussianGridTrackDensity (const Config &cfg)

Result< float >	getMaxZPosition (MainGridVector &mainGrid) const
	Returns the z position of maximum track density.

Result< std::pair< float, float > >	getMaxZPositionAndWidth (MainGridVector &mainGrid) const
	Returns the z position of maximum track density and the estimated width.

std::pair< int, TrackGridVector >	addTrack (const BoundTrackParameters &trk, MainGridVector &mainGrid) const
	Adds a single track to the overall grid density.

void	removeTrackGridFromMainGrid (int zBin, const TrackGridVector &trkGrid, MainGridVector &mainGrid) const
	Removes a track from the overall grid density.

Private Member Functions
void	addTrackGridToMainGrid (int zBin, const TrackGridVector &trkGrid, MainGridVector &mainGrid) const
	Helper function that actually adds the track to the main density grid.

void	modifyMainGridWithTrackGrid (int zBin, const TrackGridVector &trkGrid, MainGridVector &mainGrid, int modifyModeSign) const
	Helper function that modifies the main density grid (either adds or removes a track)

TrackGridVector	createTrackGrid (float d0, float distCtrZ, const Acts::SquareMatrix2 &cov) const
	Function that creates a 1-dim track grid (i.e. a vector) with the correct density contribution of a track along the z-axis.

Result< float >	estimateSeedWidth (MainGridVector &mainGrid, float maxZ) const
	Function that estimates the seed width based on the FWHM of the maximum density peak.

float	normal2D (float d, float z, const SquareMatrix2 &cov) const
	Helper to retrieve values according to a 2-dim normal distribution.

int	getHighestSumZPosition (MainGridVector &mainGrid) const
	Checks the (up to) first three density maxima (only those that have a maximum relative deviation of 'relativeDensityDev' from the main maximum) and take the z-bin of the maximum with the highest surrounding density.

double	getDensitySum (const MainGridVector &mainGrid, int pos) const
	Calculates the density sum of a z-bin and its two neighboring bins as needed for 'getHighestSumZPosition'.

Private Attributes
Config	m_cfg

Detailed Description

template<int mainGridSize = 2000, int trkGridSize = 15>
class Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >

Implements a 1-dim density grid to be filled with track Gaussian distributions. Each single track is modelled as a 2(!)-dim Gaussian distribution grid in the d0-z0 plane, but only the overlap with the z-axis (i.e. a 1-dim density vector) needs to be calculated. The position of the highest track density (of either a single bin or the sum of a certain region) can be determined. Single tracks can be cached and removed from the overall density.

Template Parameters

mainGridSize	The size of the z-axis 1-dim main density grid
trkGridSize	The 2(!)-dim grid size of a single track, i.e. a single track is modelled as a (trkGridSize x trkGridSize) grid in the d0-z0 plane. Note: trkGridSize has to be an odd value.

Definition at line 30 of file GaussianGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 30 of file GaussianGridTrackDensity.hpp

Member Typedef Documentation

template<int mainGridSize = 2000, int trkGridSize = 15>

using Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::MainGridVector = Eigen::Matrix<float, mainGridSize, 1>

Definition at line 37 of file GaussianGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 37 of file GaussianGridTrackDensity.hpp

template<int mainGridSize = 2000, int trkGridSize = 15>

using Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::TrackGridVector = Eigen::Matrix<float, trkGridSize, 1>

Definition at line 38 of file GaussianGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 38 of file GaussianGridTrackDensity.hpp

Constructor & Destructor Documentation

template<int mainGridSize = 2000, int trkGridSize = 15>

Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::GaussianGridTrackDensity ( const Config & cfg )

inline

Definition at line 70 of file GaussianGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 70 of file GaussianGridTrackDensity.hpp

Member Function Documentation

template<int mainGridSize, int trkGridSize>

std::pair< int, typename Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::TrackGridVector > Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::addTrack	(	const BoundTrackParameters &	trk,
		MainGridVector &	mainGrid
	)		const

Adds a single track to the overall grid density.

Parameters

trk	The track to be added
mainGrid	The main 1-dim density grid along the z-axis

Returns: A pair storing information about the z-bin position the track was added (int) and the 1-dim density contribution of the track itself

Definition at line 59 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 59 of file GaussianGridTrackDensity.ipp

References Acts::Test::cov, m_cfg(), Acts::GenericBoundTrackParameters< particle_hypothesis_t >::parameters(), and Acts::GenericBoundTrackParameters< particle_hypothesis_t >::spatialImpactParameterCovariance().

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template<int mainGridSize, int trkGridSize>

void Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::addTrackGridToMainGrid	(	int	zBin,
		const TrackGridVector &	trkGrid,
		MainGridVector &	mainGrid
	)		const

private

Helper function that actually adds the track to the main density grid.

Parameters

zBin	The center z-bin position the track
trkGrid	The 1-dim density contribution of the track
mainGrid	The main 1-dim density grid along the z-axis

Definition at line 98 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 98 of file GaussianGridTrackDensity.ipp

template<int mainGridSize, int trkGridSize>

Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::TrackGridVector Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::createTrackGrid	(	float	d0,
		float	distCtrZ,
		const Acts::SquareMatrix2 &	cov
	)		const

private

Function that creates a 1-dim track grid (i.e. a vector) with the correct density contribution of a track along the z-axis.

Parameters

d0	Transverse impact parameter
distCtrZ	The distance in z0 from the track position to its bin center in the 2-dim grid
cov	The track covariance matrix

Definition at line 139 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 139 of file GaussianGridTrackDensity.ipp

References f, j, m_cfg(), and physmon_track_finding_ttbar::z.

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template<int mainGridSize, int trkGridSize>

Acts::Result< float > Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::estimateSeedWidth	(	MainGridVector &	mainGrid,
		float	maxZ
	)		const

private

Function that estimates the seed width based on the FWHM of the maximum density peak.

Note: This only works if the maximum is sufficiently isolated since overlapping neighboring peaks might lead to an overestimation of the seed width.

Parameters

mainGrid	The main 1-dim density grid along the z-axis
maxZ	z-position of the maximum density value

Returns: The width

Definition at line 154 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 154 of file GaussianGridTrackDensity.ipp

References m_cfg(), and width.

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template<int mainGridSize, int trkGridSize>

double Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::getDensitySum	(	const MainGridVector &	mainGrid,
		int	pos
	)		const

private

Calculates the density sum of a z-bin and its two neighboring bins as needed for 'getHighestSumZPosition'.

Parameters

mainGrid	The main 1-dim density grid along the z-axis
pos	The center z-bin position

Returns: The sum

Definition at line 259 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 259 of file GaussianGridTrackDensity.ipp

References sum().

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template<int mainGridSize, int trkGridSize>

int Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::getHighestSumZPosition ( MainGridVector & mainGrid ) const

private

Checks the (up to) first three density maxima (only those that have a maximum relative deviation of 'relativeDensityDev' from the main maximum) and take the z-bin of the maximum with the highest surrounding density.

Parameters

mainGrid The main 1-dim density grid along the z-axis

Returns: The z-bin position

Definition at line 211 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 211 of file GaussianGridTrackDensity.ipp

References m_cfg().

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template<int mainGridSize, int trkGridSize>

Acts::Result< float > Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::getMaxZPosition ( MainGridVector & mainGrid ) const

Returns the z position of maximum track density.

Parameters

mainGrid The main 1-dim density grid along the z-axis

Returns: The z position of maximum track density

Definition at line 15 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 15 of file GaussianGridTrackDensity.ipp

References f, and m_cfg().

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template<int mainGridSize, int trkGridSize>

Acts::Result< std::pair< float, float > > Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::getMaxZPositionAndWidth ( MainGridVector & mainGrid ) const

Returns the z position of maximum track density and the estimated width.

Parameters

mainGrid The main 1-dim density grid along the z-axis

Returns: The z position of maximum track density and width

Definition at line 37 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 37 of file GaussianGridTrackDensity.ipp

References maxZ, and width.

template<int mainGridSize, int trkGridSize>

void Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::modifyMainGridWithTrackGrid	(	int	zBin,
		const TrackGridVector &	trkGrid,
		MainGridVector &	mainGrid,
		int	modifyModeSign
	)		const

private

Helper function that modifies the main density grid (either adds or removes a track)

Parameters

zBin	The center z-bin position the track
trkGrid	The 1-dim density contribution of the track
mainGrid	The main 1-dim density grid along the z-axis
modifyModeSign	Sign that determines the mode of modification, +1 for adding a track, -1 for removing a track

Definition at line 112 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 112 of file GaussianGridTrackDensity.ipp

References width.

template<int mainGridSize, int trkGridSize>

float Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::normal2D	(	float	d,
		float	z,
		const SquareMatrix2 &	cov
	)		const

private

Helper to retrieve values according to a 2-dim normal distribution.

Note: This function is defined in coordinate system centered around d0 and z0

Definition at line 199 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 199 of file GaussianGridTrackDensity.ipp

References Acts::Test::cov, Acts::safeExp(), and physmon_track_finding_ttbar::z.

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template<int mainGridSize, int trkGridSize>

void Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::removeTrackGridFromMainGrid	(	int	zBin,
		const TrackGridVector &	trkGrid,
		MainGridVector &	mainGrid
	)		const

Removes a track from the overall grid density.

Parameters

zBin	The center z-bin position the track needs to be removed from
trkGrid	The 1-dim density contribution of the track
mainGrid	The main 1-dim density grid along the z-axis

Definition at line 105 of file GaussianGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 105 of file GaussianGridTrackDensity.ipp

Member Data Documentation

template<int mainGridSize = 2000, int trkGridSize = 15>

Config Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >::m_cfg

private

Definition at line 175 of file GaussianGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 175 of file GaussianGridTrackDensity.hpp

The documentation for this class was generated from the following files:

acts/blob/sPHENIX/Core/include/Acts/Vertexing/GaussianGridTrackDensity.hpp
acts/blob/sPHENIX/Core/include/Acts/Vertexing/GaussianGridTrackDensity.ipp

Classes

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

template<int mainGridSize = 2000, int trkGridSize = 15> class Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<int mainGridSize = 2000, int trkGridSize = 15>
class Acts::GaussianGridTrackDensity< mainGridSize, trkGridSize >