In memory representation of the objective of an optimization model. More...

#include <objective_storage.h>

Classes
struct	Diff

Public Member Functions
	ObjectiveStorage (absl::string_view name={})

AuxiliaryObjectiveId	AddAuxiliaryObjective (int64_t priority, absl::string_view name)

bool	maximize (ObjectiveId id) const

int64_t	priority (ObjectiveId id) const

double	offset (ObjectiveId id) const

double	linear_term (ObjectiveId id, VariableId v) const

double	quadratic_term (ObjectiveId id, VariableId v1, VariableId v2) const

const std::string &	name (ObjectiveId id) const

const absl::flat_hash_map< VariableId, double > &	linear_terms (ObjectiveId id) const

const SparseSymmetricMatrix &	quadratic_terms (ObjectiveId id) const

template<typename DiffIter >
void	set_maximize (ObjectiveId id, bool maximize, const iterator_range< DiffIter > &diffs)

template<typename DiffIter >
void	set_priority (ObjectiveId id, int64_t priority, const iterator_range< DiffIter > &diffs)

template<typename DiffIter >
void	set_offset (ObjectiveId id, double offset, const iterator_range< DiffIter > &diffs)

template<typename DiffIter >
void	set_linear_term (ObjectiveId id, VariableId variable, double value, const iterator_range< DiffIter > &diffs)

template<typename DiffIter >
void	set_quadratic_term (ObjectiveId id, VariableId v1, VariableId v2, double val, const iterator_range< DiffIter > &diffs)

template<typename DiffIter >
void	Delete (AuxiliaryObjectiveId id, const iterator_range< DiffIter > &diffs)

int64_t	num_auxiliary_objectives () const

AuxiliaryObjectiveId	next_id () const

void	ensure_next_id_at_least (AuxiliaryObjectiveId minimum)

bool	contains (AuxiliaryObjectiveId id) const
	Returns true if this id has been created and not yet deleted.

std::vector< AuxiliaryObjectiveId >	AuxiliaryObjectives () const
	The AuxiliaryObjectivesIds in use (not deleted), order not defined.

std::vector< AuxiliaryObjectiveId >	SortedAuxiliaryObjectives () const

template<typename DiffIter >
void	Clear (ObjectiveId id, const iterator_range< DiffIter > &diffs)

template<typename DiffIter >
void	DeleteVariable (VariableId variable, const iterator_range< DiffIter > &diffs)

std::pair< ObjectiveProto, google::protobuf::Map< int64_t, ObjectiveProto > >	Proto () const

bool	diff_is_empty (const Diff &diff) const

std::pair< ObjectiveUpdatesProto, AuxiliaryObjectivesUpdatesProto >	Update (const Diff &diff, const absl::flat_hash_set< VariableId > &deleted_variables, absl::Span< const VariableId > new_variables) const

void	AdvanceCheckpointInDiff (VariableId variable_checkpoint, Diff &diff) const
	Updates the checkpoint and clears all stored changes in diff.

Detailed Description

In memory representation of the objective of an optimization model.

Definition at line 38 of file objective_storage.h.

Constructor & Destructor Documentation

◆ ObjectiveStorage()

operations_research::math_opt::ObjectiveStorage::ObjectiveStorage ( absl::string_view name = {} )

inlineexplicit

Definition at line 248 of file objective_storage.h.

Member Function Documentation

◆ AddAuxiliaryObjective()

AuxiliaryObjectiveId operations_research::math_opt::ObjectiveStorage::AddAuxiliaryObjective	(	int64_t	priority,
		absl::string_view	name )

Adds an auxiliary objective to the model and returns its id.

The returned ids begin at zero and strictly increase (in particular, if ensure_next_id_at_least() is not used, they will be consecutive). Deleted ids are NOT reused.

Definition at line 66 of file objective_storage.cc.

◆ AdvanceCheckpointInDiff()

void operations_research::math_opt::ObjectiveStorage::AdvanceCheckpointInDiff	(	VariableId	variable_checkpoint,
		Diff &	diff ) const

Updates the checkpoint and clears all stored changes in diff.

Definition at line 203 of file objective_storage.cc.

◆ AuxiliaryObjectives()

std::vector< AuxiliaryObjectiveId > operations_research::math_opt::ObjectiveStorage::AuxiliaryObjectives ( ) const

The AuxiliaryObjectivesIds in use (not deleted), order not defined.

Definition at line 78 of file objective_storage.cc.

◆ Clear()

template<typename DiffIter >

void operations_research::math_opt::ObjectiveStorage::Clear	(	ObjectiveId	id,
		const iterator_range< DiffIter > &	diffs )

Clears the objective function (coefficients and offset), but not the sense or priority.

Definition at line 392 of file objective_storage.h.

◆ contains()

bool operations_research::math_opt::ObjectiveStorage::contains ( AuxiliaryObjectiveId id ) const

inline

Returns true if this id has been created and not yet deleted.

Definition at line 387 of file objective_storage.h.

◆ Delete()

template<typename DiffIter >

void operations_research::math_opt::ObjectiveStorage::Delete	(	AuxiliaryObjectiveId	id,
		const iterator_range< DiffIter > &	diffs )

Removes an auxiliary objective from the model.

It is an error to use a deleted auxiliary objective id as input to any subsequent function calls on the model.

Definition at line 362 of file objective_storage.h.

◆ DeleteVariable()

template<typename DiffIter >

void operations_research::math_opt::ObjectiveStorage::DeleteVariable	(	VariableId	variable,
		const iterator_range< DiffIter > &	diffs )

Removes all occurrences of var from the objective. Runs in O(# objectives) time (though this can potentially be improved to O(1) if the need arises).

Definition at line 416 of file objective_storage.h.

◆ diff_is_empty()

bool operations_research::math_opt::ObjectiveStorage::diff_is_empty ( const Diff & diff ) const

inline

Functions for working with Diff Returns true if there are no changes (tracked changes before the checkpoint).

Note: when there are new variables with nonzero objective coefficient, the Diff object can be empty (and diff_is_empty will return true), but Update() can return a non-empty ObjectiveUpdatesProto. This behavior MAY CHANGE in the future (this new behavior would be more intuitive, though it is harder to implement efficiently).

There is a new auxiliary objective that needs extracting.

We must apply an objective modification.

If nonempty we need to delete some auxiliary objectives.

Definition at line 430 of file objective_storage.h.

◆ ensure_next_id_at_least()

void operations_research::math_opt::ObjectiveStorage::ensure_next_id_at_least ( AuxiliaryObjectiveId minimum )

inline

Sets the next auxiliary objective id to be the maximum of next_id() and minimum.

Definition at line 382 of file objective_storage.h.

◆ linear_term()

double operations_research::math_opt::ObjectiveStorage::linear_term	(	ObjectiveId	id,
		VariableId	v ) const

inline

Definition at line 264 of file objective_storage.h.

◆ linear_terms()

const absl::flat_hash_map< VariableId, double > & operations_research::math_opt::ObjectiveStorage::linear_terms ( ObjectiveId id ) const

inline

Definition at line 279 of file objective_storage.h.

◆ maximize()

bool operations_research::math_opt::ObjectiveStorage::maximize ( ObjectiveId id ) const

inline

Definition at line 252 of file objective_storage.h.

◆ name()

const std::string & operations_research::math_opt::ObjectiveStorage::name ( ObjectiveId id ) const

inline

Definition at line 275 of file objective_storage.h.

◆ next_id()

AuxiliaryObjectiveId operations_research::math_opt::ObjectiveStorage::next_id ( ) const

inline

The returned id of the next call to AddAuxiliaryObjective.

Equal to the number of auxiliary objectives created.

Definition at line 378 of file objective_storage.h.

◆ num_auxiliary_objectives()

int64_t operations_research::math_opt::ObjectiveStorage::num_auxiliary_objectives ( ) const

inline

The number of auxiliary objectives in the model.

Equal to the number of auxiliary objectives created minus the number of auxiliary objectives deleted.

Definition at line 374 of file objective_storage.h.

◆ offset()

double operations_research::math_opt::ObjectiveStorage::offset ( ObjectiveId id ) const

inline

Definition at line 260 of file objective_storage.h.

◆ priority()

int64_t operations_research::math_opt::ObjectiveStorage::priority ( ObjectiveId id ) const

inline

Definition at line 256 of file objective_storage.h.

◆ Proto()

std::pair< ObjectiveProto, google::protobuf::Map< int64_t, ObjectiveProto > > operations_research::math_opt::ObjectiveStorage::Proto ( ) const

Returns a proto description for the primary objective (.first) and all auxiliary objectives (.second).

Definition at line 96 of file objective_storage.cc.

◆ quadratic_term()

double operations_research::math_opt::ObjectiveStorage::quadratic_term	(	ObjectiveId	id,
		VariableId	v1,
		VariableId	v2 ) const

inline

Definition at line 269 of file objective_storage.h.

◆ quadratic_terms()

const SparseSymmetricMatrix & operations_research::math_opt::ObjectiveStorage::quadratic_terms ( ObjectiveId id ) const

inline

Definition at line 284 of file objective_storage.h.

◆ set_linear_term()

template<typename DiffIter >

void operations_research::math_opt::ObjectiveStorage::set_linear_term	(	ObjectiveId	id,
		VariableId	variable,
		double	value,
		const iterator_range< DiffIter > &	diffs )

Definition at line 333 of file objective_storage.h.

◆ set_maximize()

template<typename DiffIter >

void operations_research::math_opt::ObjectiveStorage::set_maximize	(	ObjectiveId	id,
		bool	maximize,
		const iterator_range< DiffIter > &	diffs )

Definition at line 290 of file objective_storage.h.

◆ set_offset()

template<typename DiffIter >

void operations_research::math_opt::ObjectiveStorage::set_offset	(	ObjectiveId	id,
		double	offset,
		const iterator_range< DiffIter > &	diffs )

Definition at line 319 of file objective_storage.h.

◆ set_priority()

template<typename DiffIter >

void operations_research::math_opt::ObjectiveStorage::set_priority	(	ObjectiveId	id,
		int64_t	priority,
		const iterator_range< DiffIter > &	diffs )

Definition at line 304 of file objective_storage.h.

◆ set_quadratic_term()

template<typename DiffIter >

void operations_research::math_opt::ObjectiveStorage::set_quadratic_term	(	ObjectiveId	id,
		VariableId	v1,
		VariableId	v2,
		double	val,
		const iterator_range< DiffIter > &	diffs )

Definition at line 347 of file objective_storage.h.

◆ SortedAuxiliaryObjectives()

std::vector< AuxiliaryObjectiveId > operations_research::math_opt::ObjectiveStorage::SortedAuxiliaryObjectives ( ) const

Returns a sorted vector of all existing (not deleted) auxiliary objectives in the model.

Runs in O(n log(n)), where n is the number of auxiliary objectives returned.

Definition at line 88 of file objective_storage.cc.

◆ Update()

std::pair< ObjectiveUpdatesProto, AuxiliaryObjectivesUpdatesProto > operations_research::math_opt::ObjectiveStorage::Update	(	const Diff &	diff,
		const absl::flat_hash_set< VariableId > &	deleted_variables,
		absl::Span< const VariableId >	new_variables ) const

Note: any Delete()d objective will not be in the objectives_ map. Hence, each entry is either new (if not extracted) or potentially an update on an existing objective.

An un-extracted objective goes in the new_objectives map. It is fresh and so there is no need to update, so we continue.

Diff provides no guarantees on which objectives will have entries in objective_diffs; a missing entry is equivalent to one with an empty key.

If the update message is empty we do not export it. This is particularly important for auxiliary objectives as we do not want to add empty map entries.

Definition at line 158 of file objective_storage.cc.

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

ortools/math_opt/storage/objective_storage.h
ortools/math_opt/storage/objective_storage.cc

Classes

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ ObjectiveStorage()

Member Function Documentation

◆ AddAuxiliaryObjective()

◆ AdvanceCheckpointInDiff()

◆ AuxiliaryObjectives()

◆ Clear()

◆ contains()

◆ Delete()

◆ DeleteVariable()

◆ diff_is_empty()

◆ ensure_next_id_at_least()

◆ linear_term()

◆ linear_terms()

◆ maximize()

◆ name()

◆ next_id()

◆ num_auxiliary_objectives()

◆ offset()

◆ priority()

◆ Proto()

◆ quadratic_term()

◆ quadratic_terms()

◆ set_linear_term()

◆ set_maximize()

◆ set_offset()

◆ set_priority()

◆ set_quadratic_term()

◆ SortedAuxiliaryObjectives()

◆ Update()