File TrackProxy.hpp

namespace Acts

Note

This file is foreseen for the Geometry module to replace Extent

template<typename track_container_t, typename trajectory_t, template<typename> class holder_t, bool read_only = true> class TrackProxy

#include <Acts/EventData/TrackProxy.hpp>

Proxy class representing a single track.

Template Parameters

track_container_t – the container backend
trajectory_t – the track state container backend
holder_t – ownership management class for the backend
read_only – true if this track container is not mutable

Public Types

using ConstCovariance = typename detail_lt::Types<eBoundSize, true>::CovarianceMap

using ConstParameters = typename detail_lt::Types<eBoundSize, true>::CoefficientsMap

using ConstTrackProxy = TrackProxy<track_container_t, trajectory_t, holder_t, true>

using ConstTrackStateProxy = typename Trajectory::ConstTrackStateProxy

using Container = track_container_t

using Covariance = typename detail_lt::Types<eBoundSize, false>::CovarianceMap

using IndexType = typename Container::IndexType

using MutableTrackProxy = TrackProxy<track_container_t, trajectory_t, holder_t, false>

using Parameters = typename detail_lt::Types<eBoundSize, false>::CoefficientsMap

using TrackStateProxy = typename Trajectory::TrackStateProxy

using Trajectory = trajectory_t

Public Functions

inline TrackProxy(const MutableTrackProxy &other)

Copy constructor from a mutable track proxy.

This is always valid, either mutable to mutable or mutable to const

Parameters: other – the other track state proxy

inline ActsScalar absoluteMomentum() const

Get the absolute momentum of the tack.

Returns: The absolute track momentum

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline auto appendTrackState(TrackStatePropMask mask = TrackStatePropMask::All)

Append a track state to this track.

This will modify the tip index to point at the newly created track state, which will be directly after the previous track state at tip index.

Parameters: mask – The allocation prop mask for the new track state
Returns: The newly added track state

inline ActsScalar charge() const

Get the charge of the tack.

Note

this depends on the charge hypothesis

Returns: The absolute track momentum

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline float &chi2()

Return a mutable reference to the chi squared Mutable version.

Returns: The chi squared

inline float chi2() const

Return the chi squared for the track.

Const version

Returns: The chi squared

template<typename T, HashedString key, bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline constexpr T &component()

Retrieve a mutable reference to a component.

Template Parameters

T – The type of the component to access
key – String key for the component to access

Returns

Mutable reference to the component given by key

template<typename T, HashedString key> inline constexpr const T &component() const

Retrieve a const reference to a component.

Template Parameters

T – The type of the component to access
key – String key for the component to access

Returns

Const reference to the component given by key

template<typename T, bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline constexpr T &component(HashedString key)

Retrieve a mutable reference to a component.

Template Parameters: T – The type of the component to access
Parameters: key – String key for the component to access
Returns: Mutable reference to the component given by key

template<typename T> inline constexpr const T &component(HashedString key) const

Retrieve a const reference to a component.

Template Parameters: T – The type of the component to access
Parameters: key – String key for the component to access
Returns: Const reference to the component given by key

template<typename T, bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline constexpr T &component(std::string_view key)

Retrieve a mutable reference to a component.

Note

This might hash the key at runtime instead of compile-time

Template Parameters: T – The type of the component to access
Parameters: key – String key for the component to access
Returns: Mutable reference to the component given by key

template<typename T> inline constexpr const T &component(std::string_view key) const

Retrieve a const reference to a component.

Note

This might hash the key at runtime instead of compile-time

Template Parameters: T – The type of the component to access
Parameters: key – String key for the component to access
Returns: Const reference to the component given by key

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline auto &container()

Return a reference to the track container backend, mutable version.

Returns: reference to the track container backend

inline const auto &container() const

Return a reference to the track container backend, const version.

Returns: reference to the track container backend

template<typename track_proxy_t, bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline void copyFrom(const track_proxy_t &other, bool copyTrackStates = true)

Copy the content of another track proxy into this one.

Template Parameters

track_proxy_t – the other track proxy’s type

Parameters

other – The the track proxy
copyTrackStates – Copy the track state sequence from other

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline Covariance covariance()

Get the covariance of the track at the reference surface (e.g.

perigee). Mutable version

Returns: Proxy matrix for the covariance

inline ConstCovariance covariance() const

Get the covariance of the track at the reference surface (e.g.

perigee). Const version

Returns: Proxy matrix for the covariance

inline Vector3 direction() const

Get a unit vector along the track direction at the reference surface.

Returns: The direction unit vector

inline bool hasReferenceSurface() const

Return whether a reference surface is associated to this track.

Returns: whether a surface exists or not

inline IndexType index() const

Return the index of this track in the track container.

Note

This is separate from the tip index

Returns: the track index

inline ActsScalar loc0() const

Access the loc0 parameter of the track at the reference surface.

Returns: The loc0 parameter

inline ActsScalar loc1() const

Access the loc1 parameter of the track at the reference surface.

Returns: The loc1 parameter

inline Vector3 momentum() const

Get the global momentum vector.

Returns: the global momentum vector

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline unsigned int &nDoF()

Return a mutable reference to the number of degrees of freedom for the track.

Mutable version

Returns: The the number of degrees of freedom

inline unsigned int nDoF() const

Return the number of degrees of freedom for the track.

Const version

Returns: The number of degrees of freedom

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline unsigned int &nHoles()

Return a mutable reference to the number of holes for the track.

Mutable version

Returns: The number of holes

inline unsigned int nHoles() const

Return the number of measurements for the track.

Const version

Returns: The number of measurements

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline unsigned int &nMeasurements()

Return the number of measurements for the track.

Const version

Returns: The number of measurements

inline unsigned int nMeasurements() const

Return a mutable reference to the number of measurements for the track.

Mutable version

Returns: The number of measurements

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline unsigned int &nOutliers()

Return a mutable reference to the number of outliers for the track.

Mutable version

Returns: The number of outliers

inline unsigned int nOutliers() const

Return the number of outliers for the track.

Const version

Returns: The number of outliers

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline unsigned int &nSharedHits()

Return a mutable reference to the number of shared hits for the track.

Mutable version

Returns: The number of shared hits

inline unsigned int nSharedHits() const

Return the number of shared hits for the track.

Const version

Returns: The number of shared hits

inline unsigned int nTrackStates() const

Return the number of track states associated to this track.

Note

This is calculated by iterating over the track states which is somewhat expensive. Consider caching this value if you need It more than once.

Returns: The number of track states

inline TrackProxy &operator=(const MutableTrackProxy &other)

Copy assignment operator from mutable track proxy.

This is always valid, either mutable to mutable or mutable to const

Parameters: other – the other track state proxy

inline bool operator==(const TrackProxy &other) const

Equality operator with another track proxy Checks the container identity and the track index.

Returns: True if the track proxies refer to the same track

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline Parameters parameters()

Get the parameters of the track at the reference surface (e.g.

perigee). Mutable version

Returns: Proxy vector for the parameters

inline ConstParameters parameters() const

Get the parameters of the track at the reference surface (e.g.

perigee). Const version

Returns: Proxy vector for the parameters

inline ParticleHypothesis particleHypothesis() const

Get the particle hypothesis.

Returns: the particle hypothesis

inline ActsScalar phi() const

Access the phi parameter of the track at the reference surface.

Returns: The phi parameter

inline ActsScalar qOverP() const

Access the q/p (curvature) parameter of the track at the reference surface.

Returns: The q/p parameter

inline const Surface &referenceSurface() const

Get the reference surface of the track (e.g.

the perigee)

Returns: the reference surface

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline void reverseTrackStates(): Reverse the ordering of track states for this track Afterwards, the previous endpoint of the track state sequence will be the “innermost” track state.

Note

This is dangerous with branching track state sequences, as it will break them

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline void setParticleHypothesis(const ParticleHypothesis &particleHypothesis)

Set a new particle hypothesis for this track.

Parameters: particleHypothesis – The particle hypothesis to set

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline void setReferenceSurface(std::shared_ptr<const Surface> srf)

Set a new reference surface for this track.

Parameters: srf – The surface to set

inline ActsScalar theta() const

Access the theta parameter of the track at the reference surface.

Returns: The theta parameter

inline ActsScalar time() const

Access the time parameter of the track at the reference surface.

Returns: The time parameter

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline IndexType &tipIndex()

Get a mutable reference to the tip index, i.e.

the entry point into the track container

Returns: mutable reference to the tip index

inline IndexType tipIndex() const

Get the tip index, i.e.

the entry point into the track state container

Returns: the tip index by value

template<bool RO = ReadOnly, typename = std::enable_if_t<!RO>> inline auto trackStatesReversed()

Get a range over the track states of this track.

Return value is compatible with range based for loop. Mutable version

Returns: Track state range to iterate over

inline auto trackStatesReversed() const

Get a range over the track states of this track.

Return value is compatible with range based for loop. Const version

Returns: Track state range to iterate over

inline ActsScalar transverseMomentum() const

Get the transverse momentum of the track.

Returns: The track transverse momentum value

Public Static Attributes

static constexpr IndexType kInvalid = Container::kInvalid

static constexpr bool ReadOnly = read_only

Private Functions

inline TrackProxy(detail_tc::ConstIf<TrackContainer<Container, Trajectory, holder_t>, ReadOnly> &container, IndexType itrack)

Private Members

detail_lt::TransitiveConstPointer<detail_tc::ConstIf<TrackContainer<Container, Trajectory, holder_t>, ReadOnly>> m_container

IndexType m_index

Friends

friend class TrackProxy