Implements exhaustive (optimal) search yielding optimal feature subset with respect to chosen criterion. More...

#include <search_exhaustive.hpp>

Inheritance diagram for FST::Search_Exhaustive< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >:

Public Types
typedef Search< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >	parent
	base class: the generic search interface
typedef std::shared_ptr< CRITERION >	PCriterion
	shared pointer to the criterion being optimized
typedef std::shared_ptr< SUBSET >	PSubset
	shared pointer to a feature subset
typedef Candidate_Evaluator< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >	EVALUATORENGINE
	the candidate-evaluation engine type (sequential or threaded)
typedef std::shared_ptr< EVALUATORENGINE >	PEvaluatorEngine
	shared pointer to the evaluation engine
Public Types inherited from FST::Search< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >
typedef std::shared_ptr< CRITERION >	PCriterion
	shared pointer to the criterion the search optimizes
typedef std::shared_ptr< SUBSET >	PSubset
	shared pointer to a feature subset
typedef std::shared_ptr< Result_Tracker< RETURNTYPE, SUBSET > >	PResultTracker
	shared pointer to the result tracker enabled via enable_result_tracking()
typedef Search_Observer< RETURNTYPE, SUBSET >	OBSERVER
	the observer interface type this search reports through (see Search_Observer)
typedef std::shared_ptr< OBSERVER >	PObserver
	shared pointer to an OBSERVER, as set via set_observer()

Public Member Functions
	Search_Exhaustive (PEvaluatorEngine engine=PEvaluatorEngine())
	Constructs the search with the given candidate-evaluation engine; a default-constructed `engine` falls back to Candidate_Evaluator_Sequential (in-line, unthreaded evaluation).
virtual bool	search (const DIMTYPE target_d, RETURNTYPE &result, const PSubset sub, const PCriterion crit, std::ostream &os=std::cout) override
	evaluates every subset of the requested size (every subset of any size from 1 to n if target_d==0) and returns the best one + its criterion value; false if no candidate could be generated (n==0, or the subset object refused to enumerate) or a criterion evaluation failed
virtual std::ostream &	print (std::ostream &os) const override
	writes a human-readable identification of the search and its configuration; base default writes nothing
Public Member Functions inherited from FST::Search< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >
void	enable_result_tracking (PResultTracker tracker)
	assigns a result tracker to the search process, i.e., enables logging of all evaluated subsets for future reuse (re-evaluation, etc.)
void	disable_result_tracking ()
	detaches any result tracker (result_tracker_active() then returns false)
bool	result_tracker_active () const
	true if a result tracker was assigned via enable_result_tracking() and not since disabled
void	set_output_detail (OutputDetail detail)
	sets the amount of information that is logged to output stream throughout the course of search
OutputDetail	get_output_detail () const
	the currently configured output detail level
bool	output_normal () const
	true unless output detail is SILENT
bool	output_detailed () const
	true only at the DETAILED output level
void	set_observer (PObserver observer)
	redirects search progress reporting away from the default syncout text output to `observer`

Protected Attributes
PEvaluatorEngine	_engine
	the injected candidate-evaluation engine (defaults to sequential)
Protected Attributes inherited from FST::Search< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >
PResultTracker	_tracker
	the assigned result tracker, or null (see enable_result_tracking()/result_tracker_active())
OutputDetail	_detail
	the output detail level set via set_output_detail(); read by output_normal()/output_detailed()
PObserver	_observer
	the attached progress observer, or null (see set_observer(), report(), report_solution())

Additional Inherited Members
Protected Member Functions inherited from FST::Search< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >
void	report (std::ostream &os, const msgbuf &m) const
	delivers one pre-formatted progress message: to the observer if attached, otherwise as syncout text to os
void	report_solution (std::ostream &os, const RETURNTYPE value, const SUBSET &sub, const msgbuf &m) const
	like report(), for sites announcing a new (sub-)solution; fires on_solution instead

Detailed Description

template<class RETURNTYPE, typename DIMTYPE, class SUBSET, class CRITERION>
class FST::Search_Exhaustive< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >

Implements exhaustive (optimal) search yielding optimal feature subset with respect to chosen criterion.

This single class serves both the sequential and the threaded execution model: the evaluation strategy (a Candidate_Evaluator implementation) is injected through the constructor and defaults to sequential in-line evaluation; construct with a Candidate_Evaluator_Threaded to evaluate candidates in a thread pool. Results are the same either way - for a fixed seed the search yields the same subset at any thread count. Candidates are streamed to the evaluation engine - they are never materialized as a whole (their count grows combinatorially with n).

Note: Due to possibly high number of subsets to be tested expect excessive computational time. In case of result tracking the excessive number of possible combinations may consume unacceptable amount of memory - to prevent this it is highly recommended to set up result tracker storage limit.

Constructor & Destructor Documentation

◆ Search_Exhaustive()

template<class RETURNTYPE, typename DIMTYPE, class SUBSET, class CRITERION>

FST::Search_Exhaustive< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >::Search_Exhaustive ( PEvaluatorEngine engine = PEvaluatorEngine() )

inlineexplicit

Constructs the search with the given candidate-evaluation engine; a default-constructed engine falls back to Candidate_Evaluator_Sequential (in-line, unthreaded evaluation).

Parameters

engine the evaluation strategy to use; pass a Candidate_Evaluator_Threaded to evaluate candidates in a thread pool

Member Function Documentation

◆ print()

template<class RETURNTYPE, typename DIMTYPE, class SUBSET, class CRITERION>

virtual std::ostream & FST::Search_Exhaustive< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >::print ( std::ostream & os ) const

inlineoverridevirtual

writes a human-readable identification of the search and its configuration; base default writes nothing

Reimplemented from FST::Search< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >.

◆ search()

template<class RETURNTYPE, typename DIMTYPE, class SUBSET, class CRITERION>

bool FST::Search_Exhaustive< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >::search	(	const DIMTYPE	target_d,
		RETURNTYPE &	result,
		const PSubset	sub,
		const PCriterion	crit,
		std::ostream &	os = std::cout )

overridevirtual

evaluates every subset of the requested size (every subset of any size from 1 to n if target_d==0) and returns the best one + its criterion value; false if no candidate could be generated (n==0, or the subset object refused to enumerate) or a criterion evaluation failed

Implements FST::Search< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >.

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

/Users/psms/dev/devtest1/_src_search/search_exhaustive.hpp

Public Types

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Search_Exhaustive()

Member Function Documentation

◆ print()

◆ search()