Implements Sequential_Forward_Floating_Search and Sequential_Backward_Floating_Search. More...

#include <search_seq_sffs.hpp>

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

Classes
struct	OneSubset
	Structure to hold [subset,criterion value] temporary solutions in the course of search. More...

Public Types
typedef Search_Sequential< RETURNTYPE, DIMTYPE, SUBSET, CRITERION, EVALUATOR >	parent
	base class alias
typedef parent::parent	grandparent
	the shared Search base (output detail, result tracker)
typedef std::shared_ptr< EVALUATOR >	PEvaluator
	shared pointer to the sequential-step evaluator
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
Public Types inherited from FST::Search_Sequential< RETURNTYPE, DIMTYPE, SUBSET, CRITERION, EVALUATOR >
typedef Search< RETURNTYPE, DIMTYPE, SUBSET, CRITERION >	parent
	base class alias
typedef std::shared_ptr< EVALUATOR >	PEvaluator
	shared pointer to the sequential-step evaluator that implements Step()'s candidate generation and selection
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
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_SFFS (const PEvaluator evaluator)
	`evaluator` must be non-null; direction defaults to FORWARD (SFFS); call set_search_direction(BACKWARD) for SBFS
virtual bool	search (const DIMTYPE target_d, RETURNTYPE &result, const PSubset sub, const PCriterion crit, std::ostream &os=std::cout) override
	returns found subset + criterion value
void	set_search_direction (const SearchDirection direction)
	FORWARD selects SFFS, BACKWARD selects SBFS (do not change concurrently to a running search()).
SearchDirection	get_search_direction () const
	the currently configured direction (see set_search_direction())
void	set_delta (const DIMTYPE delta)
	optional parameter to restrict search extent: bounds the floating frontier to at most target_d+delta features forward and at least target_d-delta backward (0 = unrestricted, the classic full floating frontier); has no effect when target_d==0 (best-dimensionality search)
DIMTYPE	get_delta () const
	the currently configured delta bound (see set_delta())
bool	get_result (const DIMTYPE d, RETURNTYPE &result, PSubset &sub)
	retrieves temporary solution of cardinality d that had been updated in the course of the last search (if it exists)
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_Sequential< RETURNTYPE, DIMTYPE, SUBSET, CRITERION, EVALUATOR >
	Search_Sequential (const PEvaluator evaluator)
	`evaluator` must be non-null
bool	Step (const bool forward, RETURNTYPE &result, const PSubset sub, const PCriterion crit, std::ostream &os=std::cout)
	Performs one sequential step: adds (`forward`) or removes (!`forward`) the best g-tuple of features, g being the generalization level.
void	set_generalization_level (const DIMTYPE g)
	optional parameter to enlarge the number of considered candidates (g is the number of features added/removed in one Step)
DIMTYPE	get_generalization_level () const
	the currently configured generalization level (see set_generalization_level())
void	enable_initial_subset ()
	makes search() start from the caller-supplied contents of its `sub` argument instead of the concrete method's default (empty set for FORWARD, full set for BACKWARD)
void	disable_initial_subset ()
	reverts to the default: incoming `sub` contents are ignored by search()
bool	initial_subset_enabled () const
	true if enable_initial_subset() was called (and not since disabled by disable_initial_subset())
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
SearchDirection	_direction
DIMTYPE	_delta
	frontier restriction around target_d (0 = unrestricted); see set_delta()
std::unique_ptr< OneSubset[]>	bsubs
	per-cardinality best-known result found in the course of the last search() (index d-1); read by get_result()
DIMTYPE	_n
	bsubs array size
std::unique_ptr< SUBSET >	pivotsub
	the subset the next forward step continues from: the deepest backtracking result that improved its cardinality's record. NOTE the name means something else in Search_DOS, where "pivot" denotes the best-so-far subset - that one is called maxcritsub here
std::unique_ptr< SUBSET >	maxcritsub
	stores the subset with maximum known crit value
Protected Attributes inherited from FST::Search_Sequential< RETURNTYPE, DIMTYPE, SUBSET, CRITERION, EVALUATOR >
PEvaluator	_evaluator
	the sequential-step evaluator injected at construction; drives Step()'s candidate generation and best/worst choice
DIMTYPE	_generalization_level
	number of features added/removed together in one Step() call (see set_generalization_level())
bool	_initial_subset_enabled
	by default all concrete search methods ignore the contents of supplied 'PSubset set' and initialize sub according to their definition; if enabled, then (if possible) the search() starts from supplied 'PSubset sub' contents
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 EVALUATOR>
class FST::Search_SFFS< RETURNTYPE, DIMTYPE, SUBSET, CRITERION, EVALUATOR >

Implements Sequential_Forward_Floating_Search and Sequential_Backward_Floating_Search.

Note: By default any initial subset contents are ignored; SFFS starts from empty set and SBFS starts from full set. Call enable_initial_subset() to let the search start from the initial sub contents.; This implementation follows the original SFFS definition closely. See Search_SFRS for a closely related, slower, but more thorough method.; Among subsets of EQUAL criterion value the search prefers the SMALLER one, both when updating the best-so-far used for the target_d==0 (optimize cardinality) answer and, implicitly, in that a per-cardinality record is only replaced by a strictly better value.

Examples: demo55.cpp.

Member Function Documentation

◆ print()

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

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

overridevirtual

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, class EVALUATOR>

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

overridevirtual

returns found subset + criterion value

Implements FST::Search_Sequential< RETURNTYPE, DIMTYPE, SUBSET, CRITERION, EVALUATOR >.

Examples: demo55.cpp.

Member Data Documentation

◆ _direction

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

SearchDirection FST::Search_SFFS< RETURNTYPE, DIMTYPE, SUBSET, CRITERION, EVALUATOR >::_direction

protected

accepted values FORWARD for SFFS or BACKWARD for SBFS

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

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

Classes

Public Types

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ print()

◆ search()

Member Data Documentation

◆ _direction