Implements a 1D (no time seeding) / 2D (time seeding) grid that is filled with track densities. Each track is modelled by a 2D / 3D Gaussian distribution in the d0-z0 / d0-z0-t0 plane, which is evaluated at d0=0. Therefore, each track effectively lives in 1D / 2D. 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. Unlike in the GaussianGridTrackDensity, the overall density map grows adaptively when tracks densities are added to the grid. More...

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

Collaboration diagram for Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >:

Classes
struct	Config
	The configuration struct. More...

Public Types
using	Bin = std::pair< int, int >

using	DensityMap = std::unordered_map< Bin, float, boost::hash< Bin >>

using	ZTPosition = std::pair< float, float >

using	ZTPositionAndWidth = std::pair< ZTPosition, float >

Public Member Functions
	AdaptiveGridTrackDensity (const Config &cfg)

DensityMap::const_iterator	highestDensityEntry (const DensityMap &densityMap) const
	Finds the maximum density of a DensityMap.

Result< ZTPosition >	getMaxZTPosition (DensityMap &densityMap) const
	Returns the z and t coordinate of maximum (surrounding) track density.

Result< ZTPositionAndWidth >	getMaxZTPositionAndWidth (DensityMap &densityMap) const
	Returns the z-t position of maximum track density and the estimated z-width of the maximum.

DensityMap	addTrack (const BoundTrackParameters &trk, DensityMap &mainDensityMap) const
	Adds a single track to the overall grid density.

void	subtractTrack (const DensityMap &trackDensityMap, DensityMap &mainDensityMap) const
	Removes a track from the overall grid density.

Static Public Member Functions
static float	getBinCenter (int bin, float binExtent)
	Calculates the bin center from the bin number.

static int	getBin (float value, float binExtent)
	Calculates the bin number corresponding to a d, z, or time value.

Private Member Functions
DensityMap	createTrackGrid (const Acts::Vector3 &impactParams, const Bin &centralBin, const Acts::SquareMatrix3 &cov) const
	Function that creates a track density map, i.e., a map from bins to the corresponding density values for a single track.

Result< float >	estimateSeedWidth (const DensityMap &densityMap, const ZTPosition &maxZT) const
	Function that estimates the seed width in z direction based on the full width at half maximum (FWHM) of the maximum density peak.

Bin	highestDensitySumBin (DensityMap &densityMap) const
	Checks (up to) first three density maxima that have a maximum relative deviation of 'relativeDensityDev' from the global maximum. Returns the bin of the maximum that has the highest surrounding density in z direction.

float	getDensitySum (const DensityMap &densityMap, const Bin &bin) const
	Calculates the density sum of a bin and its two neighboring bins in z direction.

Static Private Member Functions
template<unsigned int nDim>
static float	multivariateGaussian (const Acts::ActsVector< nDim > &args, const Acts::ActsSquareMatrix< nDim > &cov)
	Helper to retrieve values of an nDim-dimensional normal distribution.

Private Attributes
Config	m_cfg

Detailed Description

template<int spatialTrkGridSize = 15, int temporalTrkGridSize = 1>
class Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >

Implements a 1D (no time seeding) / 2D (time seeding) grid that is filled with track densities. Each track is modelled by a 2D / 3D Gaussian distribution in the d0-z0 / d0-z0-t0 plane, which is evaluated at d0=0. Therefore, each track effectively lives in 1D / 2D. 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. Unlike in the GaussianGridTrackDensity, the overall density map grows adaptively when tracks densities are added to the grid.

Template Parameters

spatialTrkGridSize	Number of bins per track in z direction
temporalTrkGridSize	Number of bins per track in t direction

Note: In total, a track is represented by a grid of size spatialTrkGridSize * temporalTrkGridSize

Definition at line 37 of file AdaptiveGridTrackDensity.hpp.

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

Member Typedef Documentation

template<int spatialTrkGridSize = 15, int temporalTrkGridSize = 1>

using Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::Bin = std::pair<int, int>

Definition at line 44 of file AdaptiveGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 44 of file AdaptiveGridTrackDensity.hpp

template<int spatialTrkGridSize = 15, int temporalTrkGridSize = 1>

using Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::DensityMap = std::unordered_map<Bin, float, boost::hash<Bin>>

Definition at line 46 of file AdaptiveGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 46 of file AdaptiveGridTrackDensity.hpp

template<int spatialTrkGridSize = 15, int temporalTrkGridSize = 1>

using Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::ZTPosition = std::pair<float, float>

Definition at line 49 of file AdaptiveGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 49 of file AdaptiveGridTrackDensity.hpp

template<int spatialTrkGridSize = 15, int temporalTrkGridSize = 1>

using Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::ZTPositionAndWidth = std::pair<ZTPosition, float>

Definition at line 51 of file AdaptiveGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 51 of file AdaptiveGridTrackDensity.hpp

Constructor & Destructor Documentation

template<int spatialTrkGridSize = 15, int temporalTrkGridSize = 1>

Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::AdaptiveGridTrackDensity ( const Config & cfg )

inline

Definition at line 99 of file AdaptiveGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 99 of file AdaptiveGridTrackDensity.hpp

Member Function Documentation

template<int spatialTrkGridSize, int temporalTrkGridSize>

Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::DensityMap Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::addTrack	(	const BoundTrackParameters &	trk,
		DensityMap &	mainDensityMap
	)		const

Adds a single track to the overall grid density.

Parameters

trk	The track to be added
mainDensityMap	Map between bins and corresponding density

Returns: The density map of the track that was added

Definition at line 98 of file AdaptiveGridTrackDensity.ipp.

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

References Acts::Test::cov, Acts::GenericBoundTrackParameters< particle_hypothesis_t >::impactParameterCovariance(), Acts::GenericBoundTrackParameters< particle_hypothesis_t >::impactParameters(), and m_cfg().

Referenced by Acts::Test::BOOST_AUTO_TEST_CASE().

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template<int spatialTrkGridSize, int temporalTrkGridSize>

Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::DensityMap Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::createTrackGrid	(	const Acts::Vector3 &	impactParams,
		const Bin &	centralBin,
		const Acts::SquareMatrix3 &	cov
	)		const

private

Function that creates a track density map, i.e., a map from bins to the corresponding density values for a single track.

Parameters

impactParams	vector containing d0, z0, and t0 of the track
centralBin	Central z and t bin of the track (where its density is the highest)
cov	3x3 impact parameter covariance matrix

Definition at line 151 of file AdaptiveGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 151 of file AdaptiveGridTrackDensity.ipp

References Acts::Test::cov, i, j, m_cfg(), t, and physmon_track_finding_ttbar::z.

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template<int spatialTrkGridSize, int temporalTrkGridSize>

Acts::Result< float > Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::estimateSeedWidth	(	const DensityMap &	densityMap,
		const ZTPosition &	maxZT
	)		const

private

Function that estimates the seed width in z direction based on the full width at half maximum (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

densityMap	Map from bins to corresponding track density
maxZT	z-t position of the maximum density value

Returns: The width

Definition at line 193 of file AdaptiveGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 193 of file AdaptiveGridTrackDensity.ipp

References m_cfg(), and width.

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template<int spatialTrkGridSize, int temporalTrkGridSize>

int Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::getBin	(	float	value,
		float	binExtent
	)

static

Calculates the bin number corresponding to a d, z, or time value.

Parameters

value	d, z, or time value
binExtent	Bin extent

Returns: Bin number

Definition at line 22 of file AdaptiveGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 22 of file AdaptiveGridTrackDensity.ipp

template<int spatialTrkGridSize, int temporalTrkGridSize>

float Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::getBinCenter	(	int	bin,
		float	binExtent
	)

static

Calculates the bin center from the bin number.

Parameters

bin	Bin number
binExtent	Bin extent

Returns: Bin center

Definition at line 15 of file AdaptiveGridTrackDensity.ipp.

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

Referenced by Acts::Test::BOOST_AUTO_TEST_CASE().

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template<int spatialTrkGridSize, int temporalTrkGridSize>

float Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::getDensitySum	(	const DensityMap &	densityMap,
		const Bin &	bin
	)		const

private

Calculates the density sum of a bin and its two neighboring bins in z direction.

Parameters

densityMap	Map between bins and corresponding density values
bin	Bin whose neighbors in z we want to sum up

Returns: The density sum

Definition at line 328 of file AdaptiveGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 328 of file AdaptiveGridTrackDensity.ipp

References sum().

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template<int spatialTrkGridSize, int temporalTrkGridSize>

Acts::Result< typename Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::ZTPosition > Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::getMaxZTPosition ( DensityMap & densityMap ) const

Returns the z and t coordinate of maximum (surrounding) track density.

Note: if time vertex seeding is not enabled, the t coordinate will be set to 0.

Parameters

densityMap Map between bins and corresponding density values

Returns: The z and t coordinates of maximum track density

Definition at line 44 of file AdaptiveGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 44 of file AdaptiveGridTrackDensity.ipp

References m_cfg(), and maxZ.

Referenced by Acts::Test::BOOST_AUTO_TEST_CASE().

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template<int spatialTrkGridSize, int temporalTrkGridSize>

Acts::Result< typename Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::ZTPositionAndWidth > Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::getMaxZTPositionAndWidth ( DensityMap & densityMap ) const

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

Parameters

densityMap Map between bins and corresponding density values

Returns: The z-t position of the maximum track density and its width

Definition at line 76 of file AdaptiveGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 76 of file AdaptiveGridTrackDensity.ipp

References width.

Referenced by Acts::Test::BOOST_AUTO_TEST_CASE().

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template<int spatialTrkGridSize, int temporalTrkGridSize>

Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::DensityMap::const_iterator Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::highestDensityEntry ( const DensityMap & densityMap ) const

Finds the maximum density of a DensityMap.

Parameters

densityMap Map between bins and corresponding density values

Returns: Iterator of the map entry with the highest density

Definition at line 31 of file AdaptiveGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 31 of file AdaptiveGridTrackDensity.ipp

References parse_cmake_options::begin, and end.

template<int spatialTrkGridSize, int temporalTrkGridSize>

Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::Bin Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::highestDensitySumBin ( DensityMap & densityMap ) const

private

Checks (up to) first three density maxima that have a maximum relative deviation of 'relativeDensityDev' from the global maximum. Returns the bin of the maximum that has the highest surrounding density in z direction.

Parameters

densityMap Map between bins and corresponding density values

Returns: The bin corresponding to the highest surrounding density

Definition at line 277 of file AdaptiveGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 277 of file AdaptiveGridTrackDensity.ipp

References m_cfg().

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template<int spatialTrkGridSize, int temporalTrkGridSize>

template<unsigned int nDim>

float Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::multivariateGaussian	(	const Acts::ActsVector< nDim > &	args,
		const Acts::ActsSquareMatrix< nDim > &	cov
	)

staticprivate

Helper to retrieve values of an nDim-dimensional normal distribution.

Note: The constant prefactor (2 * pi)^(- nDim / 2) is discarded

Parameters

args	Coordinates where the Gaussian should be evaluated

Note: args must be in a coordinate system with origin at the mean values of the Gaussian

Parameters

cov	Covariance matrix

Returns: Multivariate Gaussian evaluated at args

Definition at line 266 of file AdaptiveGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 266 of file AdaptiveGridTrackDensity.ipp

References check_smearing_config::args, and Acts::safeExp().

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template<int spatialTrkGridSize, int temporalTrkGridSize>

void Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::subtractTrack	(	const DensityMap &	trackDensityMap,
		DensityMap &	mainDensityMap
	)		const

Removes a track from the overall grid density.

Parameters

trackDensityMap Map between bins and corresponding density

Note: The track density comes from a single track

Parameters

mainDensityMap Map between bins and corresponding density

Note: The track density comes from an arbitrary number of tracks

Definition at line 140 of file AdaptiveGridTrackDensity.ipp.

View newest version in sPHENIX GitHub at line 140 of file AdaptiveGridTrackDensity.ipp

References it.

Referenced by Acts::Test::BOOST_AUTO_TEST_CASE().

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Member Data Documentation

template<int spatialTrkGridSize = 15, int temporalTrkGridSize = 1>

Config Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >::m_cfg

private

Definition at line 218 of file AdaptiveGridTrackDensity.hpp.

View newest version in sPHENIX GitHub at line 218 of file AdaptiveGridTrackDensity.hpp

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

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

Classes

Public Types

Public Member Functions

Static Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Detailed Description

template<int spatialTrkGridSize = 15, int temporalTrkGridSize = 1> class Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<int spatialTrkGridSize = 15, int temporalTrkGridSize = 1>
class Acts::AdaptiveGridTrackDensity< spatialTrkGridSize, temporalTrkGridSize >