operations_research::SetCoverMip Class Reference

Detailed Description

Definition at line 33 of file set_cover_mip.h.

#include <set_cover_mip.h>

Inheritance diagram for operations_research::SetCoverMip:

Public Member Functions
	SetCoverMip (SetCoverInvariant *inv)
	Simpler constructors that uses SCIP by default.
	SetCoverMip (SetCoverInvariant *inv, absl::string_view name)
SetCoverMip &	UseMipSolver (SetCoverMipSolver mip_solver)
SetCoverMip &	UseIntegers (bool use_integers)
MPSolver::ResultStatus	solve_status () const
bool	NextSolution (absl::Span< const SubsetIndex > focus) final
bool	NextSolution () final
	Virtual methods that must be implemented by derived classes.
bool	NextSolution (const SubsetBoolVector &in_focus) final
	Same as above, but with a vector of Booleans as focus.
Public Member Functions inherited from operations_research::SubsetListBasedSolutionGenerator
	SubsetListBasedSolutionGenerator (SetCoverInvariant *inv, SetCoverInvariant::ConsistencyLevel consistency_level, absl::string_view class_name, absl::string_view name)
bool	NextSolution (absl::Span< const SubsetIndex > _) override
bool	NextSolution () final
	Virtual methods that must be implemented by derived classes.
bool	NextSolution (const SubsetBoolVector &in_focus) final
	Same as above, but with a vector of Booleans as focus.
Public Member Functions inherited from operations_research::SetCoverSolutionGenerator
	SetCoverSolutionGenerator (SetCoverInvariant *inv, SetCoverInvariant::ConsistencyLevel consistency_level, absl::string_view class_name, absl::string_view name)
virtual	~SetCoverSolutionGenerator ()=default
void	SetName (const absl::string_view name)
SetCoverInvariant *	inv () const
virtual SetCoverSolutionGenerator &	ResetLimits ()
	Resets the limits to their default values.
SetCoverSolutionGenerator &	SetMaxIterations (int64_t max_iterations)
	Sets the maximum number of iterations.
int64_t	max_iterations () const
	Returns the maximum number of iterations.
SetCoverSolutionGenerator &	SetTimeLimitInSeconds (double seconds)
	Sets the time limit in seconds.
absl::Duration	run_time () const
double	run_time_in_seconds () const
	Returns the total elapsed runtime in seconds.
double	run_time_in_microseconds () const
	Returns the total elapsed runtime in microseconds.
std::string	name () const
	Returns the name of the heuristic.
std::string	class_name () const
	Returns the name of the class.
Cost	cost () const
	Returns the current cost of the solution in the invariant.
bool	CheckInvariantConsistency () const

Additional Inherited Members
Protected Member Functions inherited from operations_research::SetCoverSolutionGenerator
SetCoverModel *	model () const
	Accessors.
BaseInt	num_subsets () const
double	time_limit_in_seconds () const
	The time limit in seconds.
Protected Attributes inherited from operations_research::SetCoverSolutionGenerator
absl::Duration	run_time_
	run_time_ is an abstract duration for the time spent in NextSolution().
SetCoverInvariant::ConsistencyLevel	consistency_level_
	The consistency needed by the solution generator.

Constructor & Destructor Documentation

SetCoverMip() [1/2]

operations_research::SetCoverMip::SetCoverMip ( SetCoverInvariant * inv )

inlineexplicit

Simpler constructors that uses SCIP by default.

Definition at line 36 of file set_cover_mip.h.

SetCoverMip() [2/2]

operations_research::SetCoverMip::SetCoverMip ( SetCoverInvariant * inv, absl::string_view name )

inline

Definition at line 39 of file set_cover_mip.h.

Member Function Documentation

NextSolution() [1/3]

bool operations_research::SubsetListBasedSolutionGenerator::NextSolution ( )

inlinefinalvirtual

Virtual methods that must be implemented by derived classes.

Computes the next full solution taking into account all the subsets.

Implements operations_research::SetCoverSolutionGenerator.

Definition at line 181 of file set_cover_heuristics.h.

NextSolution() [2/3]

bool operations_research::SetCoverMip::NextSolution ( absl::Span< const SubsetIndex > focus )

finalvirtual

Computes the next partial solution considering only the subsets whose indices are in focus.

We are using MPSolver, which is deprecated, because MathOpt does not provide an interface without using protobufs. We construct a restricted MIP, omitting all the parts of the problem that are already fixed in the invariant. The goal is to not spend time sending data, and having the MIP solver re-discover fixed variables.

The model should only contain elements that are not forcibly covered by subsets outside the focus.

set_time_limit takes milliseconds as a unit.

Call the solver.

Report the objective value as a lower bound, and mention that the cost is not consistent with the solution.

Implements operations_research::SetCoverSolutionGenerator.

Definition at line 46 of file set_cover_mip.cc.

NextSolution() [3/3]

bool operations_research::SubsetListBasedSolutionGenerator::NextSolution ( const SubsetBoolVector & in_focus )

inlinefinalvirtual

Same as above, but with a vector of Booleans as focus.

Implements operations_research::SetCoverSolutionGenerator.

Definition at line 183 of file set_cover_heuristics.h.

solve_status()

MPSolver::ResultStatus operations_research::SetCoverMip::solve_status ( ) const

inline

Definition at line 59 of file set_cover_mip.h.

UseIntegers()

SetCoverMip & operations_research::SetCoverMip::UseIntegers ( bool use_integers )

inline

Definition at line 51 of file set_cover_mip.h.

UseMipSolver()

SetCoverMip & operations_research::SetCoverMip::UseMipSolver ( SetCoverMipSolver mip_solver )

inline

Definition at line 46 of file set_cover_mip.h.

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

• ortools/set_cover/set_cover_mip.h
• ortools/set_cover/set_cover_mip.cc