Representation of the hough plane - the histogram used for the hough transform with methods to fill and evaluate the histogram. More...

#include <Acts/Seeding/HoughTransformUtils.hpp>

Public Types
using	Axis
	hough histogram representation as a 2D-indexable vector of hough cells
using	HoughHist = Grid<HoughCell<identifier_t>, Axis, Axis>
	Type alias for Hough histogram grid.
using	Index = typename HoughHist::index_t
	Type alias for histogram index type.

Public Member Functions
	HoughPlane (const HoughPlaneConfig &cfg)
	instantiate the (empty) hough plane
Index	axisBins (std::size_t globalBin) const
	get the coordinates of the bin given the global bin index
template<class PointType>
void	fill (const PointType &measurement, const HoughAxisRanges &axisRanges, LineParametrisation< PointType > linePar, LineParametrisation< PointType > widthPar, const identifier_t &identifier, unsigned layer=0, YieldType weight=1.0f)
	fill and reset methods to modify the grid content
void	fillBin (std::size_t binX, std::size_t binY, const identifier_t &identifier, unsigned layer, double w=1.0f)
	Helper method to fill a bin of the hough histogram.
const std::unordered_set< std::size_t > &	getNonEmptyBins () const
	get the list of cells with non-zero content.
std::size_t	globalBin (Index indexBin) const
	get the globalBin index given the coordinates of the bin
std::span< const identifier_t, std::dynamic_extent >	hitIds (std::size_t xBin, std::size_t yBin) const
	get the identifiers of all hits in one cell of the histogram
std::span< const unsigned, std::dynamic_extent >	layers (std::size_t xBin, std::size_t yBin) const
	get the layers with hits in one cell of the histogram
std::pair< std::size_t, std::size_t >	locMaxHits () const
	get the bin indices of the cell containing the largest number of (weighted) hits across the entire histogram
std::pair< std::size_t, std::size_t >	locMaxLayers () const
	get the bin indices of the cell containing the largest number of (weighted) layers with hits across the entire histogram
YieldType	maxHits () const
	get the maximum number of (weighted) hits seen in a single cell across the entire histrogram.
YieldType	maxLayers () const
	get the maximum number of (weighted) layers with hits seen in a single cell across the entire histrogram.
std::size_t	nBinsX () const
	get the number of bins on the first coordinate
std::size_t	nBinsY () const
	get the number of bins on the second coordinate
YieldType	nHits (std::size_t globalBin) const
	access the (weighted) number of hits in one cell of the histogram from globalBin index
YieldType	nHits (std::size_t xBin, std::size_t yBin) const
	access the (weighted) number of hits in one cell of the histogram from bin's coordinates
YieldType	nLayers (std::size_t xBin, std::size_t yBin) const
	get the (weighted) number of layers with hits in one cell of the histogram
void	reset ()
	resets the contents of the grid.
std::unordered_set< const identifier_t >	uniqueHitIds (std::size_t xBin, std::size_t yBin) const
	get the identifiers of all hits in one cell of the histogram

Detailed Description

template<class identifier_t>
class Acts::HoughTransformUtils::HoughPlane< identifier_t >

Representation of the hough plane - the histogram used for the hough transform with methods to fill and evaluate the histogram.

Templated to a class used as identifier for the hits

Member Typedef Documentation

◆ Axis

template<class identifier_t>

using Acts::HoughTransformUtils::HoughPlane< identifier_t >::Axis

Initial value:

Acts::Axis<Acts::AxisType::Equidistant, Acts::AxisBoundaryType::Bound>

Acts::Axis

calculate bin indices from a given binning structure

Definition AxisDefinitions.hpp:147

hough histogram representation as a 2D-indexable vector of hough cells

◆ HoughHist

template<class identifier_t>

using Acts::HoughTransformUtils::HoughPlane< identifier_t >::HoughHist = Grid<HoughCell<identifier_t>, Axis, Axis>

Type alias for Hough histogram grid.

◆ Index

template<class identifier_t>

using Acts::HoughTransformUtils::HoughPlane< identifier_t >::Index = typename HoughHist::index_t

Type alias for histogram index type.

Constructor & Destructor Documentation

◆ HoughPlane()

template<class identifier_t>

Acts::HoughTransformUtils::HoughPlane< identifier_t >::HoughPlane ( const HoughPlaneConfig & cfg )

explicit

instantiate the (empty) hough plane

Parameters

cfg	configuration

Member Function Documentation

◆ axisBins()

template<class identifier_t>

Index Acts::HoughTransformUtils::HoughPlane< identifier_t >::axisBins ( std::size_t globalBin ) const

get the coordinates of the bin given the global bin index

Parameters

globalBin Global bin index to convert to coordinates

Returns: Local bin coordinates (x,y) corresponding to global bin index

◆ fill()

template<class identifier_t>

template<class PointType>

void Acts::HoughTransformUtils::HoughPlane< identifier_t >::fill	(	const PointType &	measurement,
		const HoughAxisRanges &	axisRanges,
		LineParametrisation< PointType >	linePar,
		LineParametrisation< PointType >	widthPar,
		const identifier_t &	identifier,
		unsigned	layer = 0,
		YieldType	weight = 1.0f )

fill and reset methods to modify the grid content

add one measurement to the hough plane

Template Parameters

PointType Type of the objects to use when adding measurements (e.g. experiment EDM object)

Parameters

measurement	The measurement to add
axisRanges	Ranges of the hough axes, used to map the bin numbers to parameter values
linePar	The function y(x) parametrising the hough space line for a given measurement
widthPar	The function dy(x) parametrising the width of the y(x) curve for a given measurement
identifier	The unique identifier for the given hit
layer	A layer index for this hit
weight	An optional weight to assign to this hit

◆ fillBin()

template<class identifier_t>

void Acts::HoughTransformUtils::HoughPlane< identifier_t >::fillBin	(	std::size_t	binX,
		std::size_t	binY,
		const identifier_t &	identifier,
		unsigned	layer,
		double	w = 1.0f )

Helper method to fill a bin of the hough histogram.

Updates the internal helper data structures (maximum tracker etc).

Parameters

binX	bin number along x
binY	bin number along y
identifier	hit identifier
layer	layer index
w	optional hit weight

◆ getNonEmptyBins()

template<class identifier_t>

const std::unordered_set< std::size_t > & Acts::HoughTransformUtils::HoughPlane< identifier_t >::getNonEmptyBins ( ) const

get the list of cells with non-zero content.

Useful for peak-finders in sparse data to avoid looping over all cells

Returns: Reference to set of global bin indices with non-zero content

◆ globalBin()

template<class identifier_t>

std::size_t Acts::HoughTransformUtils::HoughPlane< identifier_t >::globalBin ( Index indexBin ) const

get the globalBin index given the coordinates of the bin

Parameters

indexBin Bin coordinates to convert to global index

Returns: Global bin index corresponding to local bin coordinates

◆ hitIds()

template<class identifier_t>

std::span< const identifier_t, std::dynamic_extent > Acts::HoughTransformUtils::HoughPlane< identifier_t >::hitIds	(	std::size_t	xBin,
		std::size_t	yBin ) const

get the identifiers of all hits in one cell of the histogram

Parameters

xBin	bin index in the first coordinate
yBin	bin index in the second coordinate

Returns: the list of identifiers of the hits for this cell Can include duplicates if a hit was filled more than once

Exceptions

out	of range if indices are not within plane limits

◆ layers()

template<class identifier_t>

std::span< const unsigned, std::dynamic_extent > Acts::HoughTransformUtils::HoughPlane< identifier_t >::layers	(	std::size_t	xBin,
		std::size_t	yBin ) const

get the layers with hits in one cell of the histogram

Parameters

xBin	bin index in the first coordinate
yBin	bin index in the second coordinate

Returns: the layer indices that have hits for this cell

Exceptions

out	of range if indices are not within plane limits

◆ locMaxHits()

template<class identifier_t>

std::pair< std::size_t, std::size_t > Acts::HoughTransformUtils::HoughPlane< identifier_t >::locMaxHits ( ) const

get the bin indices of the cell containing the largest number of (weighted) hits across the entire histogram

Returns: Pair of (x,y) bin indices where maximum hits are found

◆ locMaxLayers()

template<class identifier_t>

std::pair< std::size_t, std::size_t > Acts::HoughTransformUtils::HoughPlane< identifier_t >::locMaxLayers ( ) const

get the bin indices of the cell containing the largest number of (weighted) layers with hits across the entire histogram

Returns: Pair of (x,y) bin indices where maximum layers are found

◆ maxHits()

template<class identifier_t>

YieldType Acts::HoughTransformUtils::HoughPlane< identifier_t >::maxHits ( ) const

get the maximum number of (weighted) hits seen in a single cell across the entire histrogram.

Returns: Maximum number of hits found in any single cell

◆ maxLayers()

template<class identifier_t>

YieldType Acts::HoughTransformUtils::HoughPlane< identifier_t >::maxLayers ( ) const

get the maximum number of (weighted) layers with hits seen in a single cell across the entire histrogram.

Returns: Maximum number of layers found in any single cell

◆ nBinsX()

template<class identifier_t>

std::size_t Acts::HoughTransformUtils::HoughPlane< identifier_t >::nBinsX ( ) const

get the number of bins on the first coordinate

Returns: Number of bins in the X direction

◆ nBinsY()

template<class identifier_t>

std::size_t Acts::HoughTransformUtils::HoughPlane< identifier_t >::nBinsY ( ) const

get the number of bins on the second coordinate

Returns: Number of bins in the Y direction

◆ nHits() [1/2]

template<class identifier_t>

YieldType Acts::HoughTransformUtils::HoughPlane< identifier_t >::nHits ( std::size_t globalBin ) const

access the (weighted) number of hits in one cell of the histogram from globalBin index

Parameters

globalBin global bin index

Returns: the (weighted) number of hits for this cell

◆ nHits() [2/2]

template<class identifier_t>

YieldType Acts::HoughTransformUtils::HoughPlane< identifier_t >::nHits	(	std::size_t	xBin,
		std::size_t	yBin ) const

access the (weighted) number of hits in one cell of the histogram from bin's coordinates

Parameters

xBin	bin index in the first coordinate
yBin	bin index in the second coordinate

Returns: the (weighted) number of hits for this cell

Exceptions

out	of range if indices are not within plane limits

◆ nLayers()

template<class identifier_t>

YieldType Acts::HoughTransformUtils::HoughPlane< identifier_t >::nLayers	(	std::size_t	xBin,
		std::size_t	yBin ) const

get the (weighted) number of layers with hits in one cell of the histogram

Parameters

xBin	bin index in the first coordinate
yBin	bin index in the second coordinate

Returns: the (weighed) number of layers that have hits for this cell

Exceptions

out	of range if indices are not within plane limits

◆ reset()

template<class identifier_t>

void Acts::HoughTransformUtils::HoughPlane< identifier_t >::reset ( )

resets the contents of the grid.

Can be used to avoid reallocating the histogram when switching regions / (sub)detectors

◆ uniqueHitIds()

template<class identifier_t>

std::unordered_set< const identifier_t > Acts::HoughTransformUtils::HoughPlane< identifier_t >::uniqueHitIds	(	std::size_t	xBin,
		std::size_t	yBin ) const

get the identifiers of all hits in one cell of the histogram

Parameters

xBin	bin index in the first coordinate
yBin	bin index in the second coordinate

Returns: the list of identifiers of the hits for this cell Guaranteed to not duplicate identifiers

Exceptions

out	of range if indices are not within plane limits

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ Axis

◆ HoughHist

◆ Index

Constructor & Destructor Documentation

◆ HoughPlane()

Member Function Documentation

◆ axisBins()

◆ fill()

◆ fillBin()

◆ getNonEmptyBins()

◆ globalBin()

◆ hitIds()

◆ layers()

◆ locMaxHits()

◆ locMaxLayers()

◆ maxHits()

◆ maxLayers()

◆ nBinsX()

◆ nBinsY()

◆ nHits() [1/2]

◆ nHits() [2/2]

◆ nLayers()

◆ reset()

◆ uniqueHitIds()