alcor_recodata Class Reference

Container and analysis engine for a collection of reconstructed ALCOR hits. More...

#include <alcor_recodata.h>

Inheritance diagram for alcor_recodata:

Public Member Functions
	alcor_recodata ()=default
	Default constructor — creates an empty container.
	alcor_recodata (const std::vector< alcor_finedata_struct > &d)
	Construct a container pre-filled with an existing hit vector.
Core Access
Direct access to the underlying storage and the finedata factory.
std::vector< alcor_finedata_struct >	get_recodata () const
	Return a copy of the full hit vector.
std::vector< alcor_finedata_struct > *	get_recodata_ptr ()
	Return the raw pointer to the active hit vector (may be external).
alcor_finedata_struct	get_recodata (int i) const
	Return a copy of the hit struct at index i.
std::vector< alcor_finedata_struct > &	get_recodata_link ()
	Return a mutable reference to the full hit vector.
alcor_finedata_struct &	get_recodata_link (int i)
	Return a mutable reference to the hit struct at index i.
alcor_finedata	get_finedata (int i) const
	Construct and return a full alcor_finedata object for hit i.
std::vector< trigger_event >	get_triggers () const
	Return a copy of the full trigger vector.
std::vector< trigger_event > *	get_triggers_ptr ()
	Return the raw pointer to the active trigger vector (may be external).
std::vector< trigger_event > &	get_triggers_link ()
	Return a mutable reference to the full trigger vector.
Per-hit Field Getters
Convenience wrappers forwarding to the stored alcor_finedata_struct fields or constructing a temporary alcor_finedata for derived quantities.
uint32_t	get_global_index (int i) const
	Global channel index for hit i.
float	get_hit_x (int i) const
	Hit x-coordinate from channel mapping [mm].
float	get_hit_y (int i) const
	Hit y-coordinate from channel mapping [mm].
uint32_t	get_hit_mask (int i) const
	Hit quality / classification bitmask.
float	get_hit_t (int i) const
	Calibrated hit time [ns] for hit i.
float	get_hit_r (int i) const
	Radial distance from the detector origin [mm].
float	get_hit_r (int i, std::array< float, 2 > v) const
	Radial distance from a custom centre v [mm].
float	get_hit_phi (int i) const
	Azimuthal angle from the detector origin [rad].
float	get_hit_phi (int i, std::array< float, 2 > v) const
	Azimuthal angle from a custom centre v [rad].
float	get_hit_x_rnd (int i) const
	Pixel-randomised x-coordinate (uniform ±1.5 mm jitter within the pixel cell).
float	get_hit_y_rnd (int i) const
	Pixel-randomised y-coordinate (uniform ±1.5 mm jitter within the pixel cell).
float	get_hit_r_rnd (int i) const
	Radial distance from the origin using randomised coordinates.
float	get_hit_r_rnd (int i, std::array< float, 2 > v) const
	Radial distance from v using randomised coordinates.
float	get_hit_phi_rnd (int i) const
	Azimuthal angle from the origin using randomised coordinates [rad].
float	get_hit_phi_rnd (int i, std::array< float, 2 > v) const
	Azimuthal angle from v using randomised coordinates [rad].
Channel Decode Getters
All forward to the corresponding alcor_finedata methods via get_finedata.
int	get_hit_tdc (int i) const
	TDC sub-channel index for hit i.
int	get_device (int i) const
	Readout device ID for hit i.
int	get_fifo (int i) const
	FIFO number for hit i.
int	get_chip (int i) const
	Chip ID for hit i.
int	get_eo_channel (int i) const
	Even/odd channel index for hit i.
int	get_column (int i) const
	Column address for hit i.
int	get_pixel (int i) const
	Pixel address for hit i.
int	get_device_index (int i) const
	Per-device flat index for hit i.
int	get_global_channel_index (int i) const
	Global channel index stripped of TDC info for hit i.
Trigger Access
std::optional< trigger_event >	get_trigger_by_index (uint8_t index) const
	Look up the first trigger whose index field matches index.
std::optional< trigger_event >	get_timing_trigger () const
	Return the timing trigger for this event, if present.
Setters
void	set_recodata (std::vector< alcor_finedata_struct > v)
	Replace the entire hit collection.
void	set_recodata (int i, alcor_finedata_struct v)
	Replace the hit at index i.
void	set_triggers (const std::vector< trigger_event > v)
	Replace the entire trigger collection.
void	set_recodata_ptr (std::vector< alcor_finedata_struct > *v)
	Redirect the active hit pointer to an external vector.
void	set_triggers_ptr (std::vector< trigger_event > *v)
	Redirect the active trigger pointer to an external vector.
void	set_global_index (int i, uint32_t v)
	Overwrite the global channel index of hit i.
void	set_hit_x (int i, float v)
	Overwrite the x-coordinate of hit i [mm].
void	set_hit_y (int i, float v)
	Overwrite the y-coordinate of hit i [mm].
void	set_hit_mask (int i, uint32_t v)
	Overwrite the quality bitmask of hit i (full replacement).
void	set_recodata_link (std::vector< alcor_finedata_struct > &v)
	Rebind the active hit pointer to v (copies vector and rebinds pointer).
void	set_triggers_link (std::vector< trigger_event > &v)
	Rebind the active trigger pointer to v (copies vector and rebinds pointer).
Hit and Trigger Builders
void	add_hit_mask (int i, uint32_t v)
	OR v into the bitmask of hit i.
void	add_hit_mask_bit (int i, uint32_t v)
	Set the bit at position v in the bitmask of hit i.
void	add_trigger (uint8_t index, uint16_t coarse, float fine_time=0.)
	Append a trigger from its constituent fields.
void	add_trigger (trigger_event hit)
	Append a pre-built trigger_event.
int	add_hit (const alcor_finedata_struct &hit)
	Append a hit from an alcor_finedata_struct.
int	add_hit (const alcor_finedata &hit)
	Append a hit from an alcor_finedata object (stores its underlying struct).
int	add_hit (uint32_t rollover, uint16_t coarse, uint8_t fine, float hit_x, float hit_y, uint32_t global_index, uint32_t hit_mask)
	Append a hit from individual fields (constructed in-place).
Boolean Checks
bool	check_trigger (uint8_t v)
	True if a trigger with index v exists for this event.
bool	is_start_of_spill ()
	True if the start-of-spill trigger is present.
bool	is_first_frames ()
	True if the first-frames trigger is present.
bool	is_timing_available ()
	True if a timing trigger is present.
bool	is_embedded_tracking_available ()
	True if embedded tracking data are attached to this event.
bool	is_ring_found ()
	True if at least one ring has been reconstructed.
bool	check_hit_mask (int i, uint32_t v)
	True if any bit of v is set in the mask of hit i.
bool	is_afterpulse (int i)
	True if hit i is flagged as an afterpulse (delegates to alcor_finedata).
bool	is_cross_talk (int i)
	True if hit i is flagged as optical cross-talk (delegates to alcor_finedata).
bool	is_ring_tagged (int i)
	True if hit i has been associated with a reconstructed ring.
I/O Utilities
void	clear ()
	Clear all hits and triggers, resetting the container to an empty state. Does not reset the Hough LUT or accumulator configuration.
bool	link_to_tree (TTree *input_tree)
	Attach the container to branches of an existing input TTree.
void	write_to_tree (TTree *output_tree)
	Create branches in output_tree for hits and triggers.
Analysis Utilities
void	find_rings (float_t distance_length_cut, float_t distance_time_cut)
	Cluster hits into ring candidates using DBSCAN in the (R, t) plane.
void	build_hough_lut (const std::map< int, std::array< float, 2 > > &index_to_hit_xy, float r_min, float r_max, float r_step, float cell_size)
	Pre-compute the Hough-transform look-up table (LUT).
void	find_rings_hough (float threshold_fraction, int min_hits)
	Find ring candidates using the pre-computed Hough LUT.

Detailed Description

Container and analysis engine for a collection of reconstructed ALCOR hits.

Ownership and pointer semantics

By default the class owns its data through internal std::vector members. The set_*_ptr / set_*_link family of methods allows an external vector to be adopted, which is useful when the data are managed by a ROOT branch. After calling link_to_tree() the internal pointers are re-targeted to ROOT's branch buffers and must not be invalidated while the tree is in use.

Warning

Mixing owned and borrowed storage (i.e. calling set_recodata_ptr after link_to_tree) leads to undefined behaviour.

Constructor & Destructor Documentation

alcor_recodata()

alcor_recodata::alcor_recodata ( const std::vector< alcor_finedata_struct > &  d )

explicit

Construct a container pre-filled with an existing hit vector.

Parameters

d	Vector of alcor_finedata_struct hits to copy.

Member Function Documentation

build_hough_lut()

void alcor_recodata::build_hough_lut	(	const std::map< int, std::array< float, 2 > > &	index_to_hit_xy,
		float	r_min,
		float	r_max,
		float	r_step,
		float	cell_size
	)

Pre-compute the Hough-transform look-up table (LUT).

The Hough transform votes for ring centre candidates: for each hit position and candidate radius R, the set of accumulator cells consistent with that (hit, R) pair is pre-computed once here and reused per event. Call once per run (or whenever the geometry changes) before find_rings_hough.

Parameters

index_to_hit_xy	Map from global channel index to (x, y) position [mm].
r_min	Minimum candidate ring radius [mm].
r_max	Maximum candidate ring radius [mm].
r_step	Radius step size [mm].
cell_size	Linear size of each accumulator cell [mm].

find_rings()

void alcor_recodata::find_rings	(	float_t	distance_length_cut,
		float_t	distance_time_cut
	)

Cluster hits into ring candidates using DBSCAN in the (R, t) plane.

DBSCAN (Density-Based Spatial Clustering of Applications with Noise) groups hits that are close in both radial distance R and time t. Hits assigned to a cluster are tagged with the ring flag; if any cluster is found the event-level ring trigger is added.

Parameters

distance_length_cut	Maximum ΔR between neighbouring hits [mm].
distance_time_cut	Maximum Δt between neighbouring hits [ns].

find_rings_hough()

void alcor_recodata::find_rings_hough	(	float	threshold_fraction,
		int	min_hits
	)

Find ring candidates using the pre-computed Hough LUT.

Each hit votes for the accumulator cells stored in the LUT. Cells exceeding the threshold are declared ring candidates; contributing hits and the event-level ring trigger are updated accordingly.

Precondition

build_hough_lut must have been called with geometry consistent with the current event data.

Parameters

threshold_fraction	Minimum fraction of active hits required in a peak cell to be accepted as a ring centre (range 0–1).
min_hits	Minimum absolute vote count for acceptance.

get_finedata()

alcor_finedata alcor_recodata::get_finedata ( int  i ) const

inline

Construct and return a full alcor_finedata object for hit i.

Construction from alcor_finedata_struct is a plain struct copy — no heap allocation. Use this whenever calibrated timing or channel-decode methods are needed. Timing results depend on the static calibration table; without it the methods return 0 (see class-level note on re-calibration).

Parameters

i	Zero-based hit index.

get_hit_t()

float alcor_recodata::get_hit_t ( int  i ) const

inline

Calibrated hit time [ns] for hit i.

Delegates to alcor_finedata::get_time_ns. Returns 0 if no calibration is loaded — intentional, to allow re-calibration without re-processing.

get_trigger_by_index()

std::optional< trigger_event > alcor_recodata::get_trigger_by_index

(

uint8_t

index

)

const

Look up the first trigger whose index field matches index.

Returns

The matching trigger_event wrapped in std::optional, or std::nullopt if absent.

link_to_tree()

bool alcor_recodata::link_to_tree

(

TTree *

input_tree

)

Attach the container to branches of an existing input TTree.

Parameters

input_tree

Source tree; must remain valid for the lifetime of any GetEntry calls.

write_to_tree()

void alcor_recodata::write_to_tree

(

TTree *

output_tree

)

Create branches in output_tree for hits and triggers.

Parameters

output_tree

Destination tree.

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

• /home/runner/work/epic-drich-beam-test-analysis/epic-drich-beam-test-analysis/include/alcor_recodata.h
• /home/runner/work/epic-drich-beam-test-analysis/epic-drich-beam-test-analysis/src/alcor_recodata.cxx