Aleph::CA::Activity_Observer< Lattice > Class Template Reference

Records the number of cells that changed across each step. More...

#include <ca-observer.H>

Collaboration diagram for Aleph::CA::Activity_Observer< Lattice >:

Public Member Functions
	Activity_Observer ()=default
	Construct an empty activity observer.
const Array< ca_size_t > &	activity () const noexcept
	Return the activity time series.
std::size_t	size () const noexcept
	Return the number of recorded steps.
void	reset () noexcept
	Clear the previous frame and activity samples.
void	on_step_begin (std::size_t step, const Lattice &frame)
	Capture the frame before a step.
void	on_step_end (const std::size_t step, const Lattice &frame)
	Record changed cells after a step.

Private Attributes
std::optional< Lattice >	prev_
Array< ca_size_t >	activity_

Detailed Description

template<typename Lattice>
class Aleph::CA::Activity_Observer< Lattice >

Records the number of cells that changed across each step.

Implementation note: the observer maintains a copy of the previous frame between on_step_begin and on_step_end. This costs O(N) memory but avoids depending on the engine to expose the previous frame, and keeps the observer self-contained.

Template Parameters

Lattice

lattice type the observer is wired to. Stored as a member so the previous frame can be retained.

Complexity

on_step_begin copies one frame in O(N); on_step_end compares frames in O(N).

Thread-safety

Thread-safe for concurrent readers after simulation stops; not thread-safe for concurrent callbacks.

Exception-safety

Strong guarantee unless copying the frame or appending the sample throws.

Definition at line 458 of file ca-observer.H.

Constructor & Destructor Documentation

Activity_Observer()

template<typename Lattice >

Aleph::CA::Activity_Observer< Lattice >::Activity_Observer ( )

default

Construct an empty activity observer.

Exceptions

This	function does not throw.

Member Function Documentation

activity()

template<typename Lattice >

const Array< ca_size_t > & Aleph::CA::Activity_Observer< Lattice >::activity ( ) const

inlinenoexcept

Return the activity time series.

Returns

changed-cell counts, one per completed step.

Exceptions

This	function does not throw.

Definition at line 473 of file ca-observer.H.

References Aleph::CA::Activity_Observer< Lattice >::activity_.

on_step_begin()

template<typename Lattice >

void Aleph::CA::Activity_Observer< Lattice >::on_step_begin ( std::size_t  step, const Lattice &  frame  )

inline

Capture the frame before a step.

Parameters

[in]	step	step index about to run, ignored.
[in]	frame	frame before the step.

Exceptions

Any	exception thrown while copying frame.

Definition at line 504 of file ca-observer.H.

References Aleph::blossom_maximum_cardinality_matching(), and Aleph::CA::Activity_Observer< Lattice >::prev_.

on_step_end()

template<typename Lattice >

void Aleph::CA::Activity_Observer< Lattice >::on_step_end ( const std::size_t  step, const Lattice &  frame  )

inline

Record changed cells after a step.

Parameters

[in]	step	completed step index, ignored.
[in]	frame	frame after the step.

Exceptions

std::bad_alloc

if appending the sample allocates.

Definition at line 515 of file ca-observer.H.

References Aleph::CA::Activity_Observer< Lattice >::activity_, Aleph::Array< T >::append(), Aleph::blossom_maximum_cardinality_matching(), Aleph::CA::cell_diff_count(), and Aleph::CA::Activity_Observer< Lattice >::prev_.

reset()

template<typename Lattice >

void Aleph::CA::Activity_Observer< Lattice >::reset ( )

inlinenoexcept

Clear the previous frame and activity samples.

Exceptions

This	function does not throw.

Complexity

O(size()) plus destruction cost of the stored frame.

Definition at line 493 of file ca-observer.H.

References Aleph::CA::Activity_Observer< Lattice >::activity_, Aleph::Array< T >::clear(), and Aleph::CA::Activity_Observer< Lattice >::prev_.

size()

template<typename Lattice >

std::size_t Aleph::CA::Activity_Observer< Lattice >::size ( ) const

inlinenoexcept

Return the number of recorded steps.

Returns

sample count.

Exceptions

This	function does not throw.

Definition at line 482 of file ca-observer.H.

References Aleph::CA::Activity_Observer< Lattice >::activity_, and Aleph::Array< T >::size().

Member Data Documentation

activity_

template<typename Lattice >

Array<ca_size_t> Aleph::CA::Activity_Observer< Lattice >::activity_

private

Definition at line 461 of file ca-observer.H.

Referenced by Aleph::CA::Activity_Observer< Lattice >::activity(), Aleph::CA::Activity_Observer< Lattice >::on_step_end(), Aleph::CA::Activity_Observer< Lattice >::reset(), and Aleph::CA::Activity_Observer< Lattice >::size().

prev_

template<typename Lattice >

std::optional<Lattice> Aleph::CA::Activity_Observer< Lattice >::prev_

private

Definition at line 460 of file ca-observer.H.

Referenced by Aleph::CA::Activity_Observer< Lattice >::on_step_begin(), Aleph::CA::Activity_Observer< Lattice >::on_step_end(), and Aleph::CA::Activity_Observer< Lattice >::reset().

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

• ca-observer.H