Inheritance diagram for operations_research::CBCInterface:

Public Member Functions
	CBCInterface (MPSolver *solver)
	Constructor that takes a name for the underlying glpk solver.

	~CBCInterface () override

void	Reset () override
	--— Reset --—

void	SetOptimizationDirection (bool maximize) override
	Sets the optimization direction (min/max).

absl::Status	SetNumThreads (int num_threads) override
	--— Parameters --—

MPSolver::ResultStatus	Solve (const MPSolverParameters &param) override

virtual void	ExtractModel ()

bool	IsContinuous () const override
	Query problem type.

bool	IsLP () const override
	Returns true if the problem is continuous and linear.

bool	IsMIP () const override
	Returns true if the problem is discrete and linear.

void	SetVariableBounds (int var_index, double lb, double ub) override
	Modify bounds.

void	SetVariableInteger (int var_index, bool integer) override
	Modifies integrality of an extracted variable.

void	SetConstraintBounds (int row_index, double lb, double ub) override
	Modify bounds of an extracted variable.

void	AddRowConstraint (MPConstraint *ct) override
	Add constraint incrementally.

void	AddVariable (MPVariable *var) override
	Add variable incrementally.

void	SetCoefficient (MPConstraint const constraint, const MPVariable const variable, double new_value, double old_value) override
	Change a coefficient in a constraint.

void	ClearConstraint (MPConstraint *const constraint) override
	Clear a constraint from all its terms.

void	SetObjectiveCoefficient (const MPVariable *const variable, double coefficient) override
	Change a coefficient in the linear objective.

void	SetObjectiveOffset (double value) override
	Change the constant term in the linear objective.

void	ClearObjective () override
	Clear the objective from all its terms.

int64_t	iterations () const override
	Number of simplex iterations.

int64_t	nodes () const override
	Number of branch-and-bound nodes. Only available for discrete problems.

MPSolver::BasisStatus	row_status (int constraint_index) const override
	Returns the basis status of a row.

MPSolver::BasisStatus	column_status (int variable_index) const override
	Returns the basis status of a column.

void	ExtractNewVariables () override
	Extracts the variables that have not been extracted yet.

void	ExtractNewConstraints () override
	Extracts the constraints that have not been extracted yet.

void	ExtractObjective () override
	Extracts the objective.

std::string	SolverVersion () const override
	Returns a string describing the underlying solver and its version.

void *	underlying_solver () override

Public Member Functions inherited from operations_research::MPSolverInterface
	MPSolverInterface (MPSolver *solver)

virtual	~MPSolverInterface ()

virtual bool	SupportsDirectlySolveProto (std::atomic< bool > *) const

virtual MPSolutionResponse	DirectlySolveProto (LazyMutableCopy< MPModelRequest >, std::atomic< bool > *)

virtual void	Write (const std::string &filename)

virtual bool	AddIndicatorConstraint (MPConstraint *const)

virtual void	BranchingPriorityChangedForVariable (int)

double	best_objective_bound () const

double	objective_value () const
	Returns the objective value of the best solution found so far.

bool	CheckSolutionIsSynchronized () const

virtual bool	CheckSolutionExists () const

bool	CheckSolutionIsSynchronizedAndExists () const
	Handy shortcut to do both checks above (it is often used).

int	last_variable_index () const
	Returns the index of the last variable extracted.

bool	variable_is_extracted (int var_index) const

void	set_variable_as_extracted (int var_index, bool extracted)

bool	constraint_is_extracted (int ct_index) const

void	set_constraint_as_extracted (int ct_index, bool extracted)

bool	quiet () const
	Returns the boolean indicating the verbosity of the solver output.

void	set_quiet (bool quiet_value)
	Sets the boolean indicating the verbosity of the solver output.

MPSolver::ResultStatus	result_status () const
	Returns the result status of the last solve.

virtual double	ComputeExactConditionNumber () const

virtual void	SetStartingLpBasis (const std::vector< MPSolver::BasisStatus > &, const std::vector< MPSolver::BasisStatus > &)
	See MPSolver::SetStartingLpBasis().

virtual double	infinity ()

virtual bool	InterruptSolve ()

virtual bool	NextSolution ()
	See MPSolver::NextSolution() for contract.

virtual void	SetCallback (MPCallback *)
	See MPSolver::SetCallback() for details.

virtual bool	SupportsCallbacks () const

Additional Inherited Members
Public Types inherited from operations_research::MPSolverInterface
enum	SynchronizationStatus { MUST_RELOAD , MODEL_SYNCHRONIZED , SOLUTION_SYNCHRONIZED }

Static Public Attributes inherited from operations_research::MPSolverInterface
static constexpr int64_t	kUnknownNumberOfIterations = -1

static constexpr int64_t	kUnknownNumberOfNodes = -1

Protected Member Functions inherited from operations_research::MPSolverInterface
void	ExtractModel ()
	Extracts model stored in MPSolver.

void	ResetExtractionInformation ()
	Resets the extraction information.

void	InvalidateSolutionSynchronization ()

void	SetCommonParameters (const MPSolverParameters &param)
	Sets parameters common to LP and MIP in the underlying solver.

void	SetMIPParameters (const MPSolverParameters &param)
	Sets MIP specific parameters in the underlying solver.

void	SetUnsupportedDoubleParam (MPSolverParameters::DoubleParam param)
	Sets an unsupported double parameter.

virtual void	SetUnsupportedIntegerParam (MPSolverParameters::IntegerParam param)
	Sets an unsupported integer parameter.

void	SetDoubleParamToUnsupportedValue (MPSolverParameters::DoubleParam param, double value)
	Sets a supported double parameter to an unsupported value.

virtual void	SetIntegerParamToUnsupportedValue (MPSolverParameters::IntegerParam param, int value)
	Sets a supported integer parameter to an unsupported value.

virtual bool	SetSolverSpecificParametersAsString (const std::string &parameters)

Protected Attributes inherited from operations_research::MPSolverInterface
MPSolver *const	solver_

SynchronizationStatus	sync_status_
	Indicates whether the model and the solution are synchronized.

MPSolver::ResultStatus	result_status_

bool	maximize_
	Optimization direction.

int	last_constraint_index_
	Index in MPSolver::variables_ of last constraint extracted.

int	last_variable_index_
	Index in MPSolver::constraints_ of last variable extracted.

double	objective_value_
	The value of the objective function.

double	best_objective_bound_
	The value of the best objective bound. Used only for MIP solvers.

bool	quiet_
	Boolean indicator for the verbosity of the solver output.

Static Protected Attributes inherited from operations_research::MPSolverInterface
static const int	kDummyVariableIndex = 0
	-------— MPSolverInterface -------—

Detailed Description

Definition at line 45 of file cbc_interface.cc.

Constructor & Destructor Documentation

◆ CBCInterface()

operations_research::CBCInterface::CBCInterface ( MPSolver * solver )

explicit

Constructor that takes a name for the underlying glpk solver.

--— Solver --—

Creates a LP/MIP instance with the specified name and minimization objective.

Definition at line 161 of file cbc_interface.cc.

◆ ~CBCInterface()

operations_research::CBCInterface::~CBCInterface ( )

override

Definition at line 170 of file cbc_interface.cc.

Member Function Documentation

◆ AddRowConstraint()

void operations_research::CBCInterface::AddRowConstraint ( MPConstraint * ct )

overridevirtual

Add constraint incrementally.

Implements operations_research::MPSolverInterface.

Definition at line 234 of file cbc_interface.cc.

◆ AddVariable()

void operations_research::CBCInterface::AddVariable ( MPVariable * var )

overridevirtual

Add variable incrementally.

Implements operations_research::MPSolverInterface.

Definition at line 238 of file cbc_interface.cc.

◆ ClearConstraint()

void operations_research::CBCInterface::ClearConstraint ( MPConstraint *const constraint )

inlineoverridevirtual

Clear a constraint from all its terms.

Implements operations_research::MPSolverInterface.

Definition at line 93 of file cbc_interface.cc.

◆ ClearObjective()

void operations_research::CBCInterface::ClearObjective ( )

inlineoverridevirtual

Clear the objective from all its terms.

Implements operations_research::MPSolverInterface.

Definition at line 105 of file cbc_interface.cc.

◆ column_status()

MPSolver::BasisStatus operations_research::CBCInterface::column_status ( int variable_index ) const

inlineoverridevirtual

Returns the basis status of a column.

Implements operations_research::MPSolverInterface.

Definition at line 118 of file cbc_interface.cc.

◆ ExtractModel()

virtual void operations_research::CBCInterface::ExtractModel ( )

inlinevirtual

Todo: (user): separate the solve from the model extraction.

Definition at line 70 of file cbc_interface.cc.

◆ ExtractNewConstraints()

void operations_research::CBCInterface::ExtractNewConstraints ( )

inlineoverridevirtual

Extracts the constraints that have not been extracted yet.

Implements operations_research::MPSolverInterface.

Definition at line 124 of file cbc_interface.cc.

◆ ExtractNewVariables()

void operations_research::CBCInterface::ExtractNewVariables ( )

inlineoverridevirtual

Extracts the variables that have not been extracted yet.

Implements operations_research::MPSolverInterface.

Definition at line 123 of file cbc_interface.cc.

◆ ExtractObjective()

void operations_research::CBCInterface::ExtractObjective ( )

inlineoverridevirtual

Extracts the objective.

Implements operations_research::MPSolverInterface.

Definition at line 125 of file cbc_interface.cc.

◆ IsContinuous()

bool operations_research::CBCInterface::IsContinuous ( ) const

inlineoverridevirtual

Query problem type.

Implements operations_research::MPSolverInterface.

Definition at line 73 of file cbc_interface.cc.

◆ IsLP()

bool operations_research::CBCInterface::IsLP ( ) const

inlineoverridevirtual

Returns true if the problem is continuous and linear.

Implements operations_research::MPSolverInterface.

Definition at line 74 of file cbc_interface.cc.

◆ IsMIP()

bool operations_research::CBCInterface::IsMIP ( ) const

inlineoverridevirtual

Returns true if the problem is discrete and linear.

Implements operations_research::MPSolverInterface.

Definition at line 75 of file cbc_interface.cc.

◆ iterations()

int64_t operations_research::CBCInterface::iterations ( ) const

overridevirtual

Number of simplex iterations.

---— Query statistics on the solution and the solve ---—

Implements operations_research::MPSolverInterface.

Definition at line 470 of file cbc_interface.cc.

◆ nodes()

int64_t operations_research::CBCInterface::nodes ( ) const

overridevirtual

Number of branch-and-bound nodes. Only available for discrete problems.

Implements operations_research::MPSolverInterface.

Definition at line 475 of file cbc_interface.cc.

◆ Reset()

void operations_research::CBCInterface::Reset ( )

overridevirtual

--— Reset --—

Reset the solver.

Implements operations_research::MPSolverInterface.

Definition at line 173 of file cbc_interface.cc.

◆ row_status()

MPSolver::BasisStatus operations_research::CBCInterface::row_status ( int constraint_index ) const

inlineoverridevirtual

Returns the basis status of a row.

Implements operations_research::MPSolverInterface.

Definition at line 113 of file cbc_interface.cc.

◆ SetCoefficient()

void operations_research::CBCInterface::SetCoefficient	(	MPConstraint *const	constraint,
		const MPVariable *const	variable,
		double	new_value,
		double	old_value )

inlineoverridevirtual

Change a coefficient in a constraint.

Implements operations_research::MPSolverInterface.

Definition at line 87 of file cbc_interface.cc.

◆ SetConstraintBounds()

void operations_research::CBCInterface::SetConstraintBounds	(	int	index,
		double	lb,
		double	ub )

overridevirtual

Modify bounds of an extracted variable.

Implements operations_research::MPSolverInterface.

Definition at line 225 of file cbc_interface.cc.

◆ SetNumThreads()

absl::Status operations_research::CBCInterface::SetNumThreads ( int num_threads )

inlineoverridevirtual

--— Parameters --—

Reimplemented from operations_research::MPSolverInterface.

Definition at line 59 of file cbc_interface.cc.

◆ SetObjectiveCoefficient()

void operations_research::CBCInterface::SetObjectiveCoefficient	(	const MPVariable *const	variable,
		double	coefficient )

inlineoverridevirtual

Change a coefficient in the linear objective.

Implements operations_research::MPSolverInterface.

Definition at line 98 of file cbc_interface.cc.

◆ SetObjectiveOffset()

void operations_research::CBCInterface::SetObjectiveOffset ( double value )

inlineoverridevirtual

Change the constant term in the linear objective.

Implements operations_research::MPSolverInterface.

Definition at line 103 of file cbc_interface.cc.

◆ SetOptimizationDirection()

void operations_research::CBCInterface::SetOptimizationDirection ( bool maximize )

overridevirtual

Sets the optimization direction (min/max).

Implements operations_research::MPSolverInterface.

Definition at line 188 of file cbc_interface.cc.

◆ SetVariableBounds()

void operations_research::CBCInterface::SetVariableBounds	(	int	var_index,
		double	lb,
		double	ub )

overridevirtual

Modify bounds.

Implements operations_research::MPSolverInterface.

Definition at line 202 of file cbc_interface.cc.

◆ SetVariableInteger()

void operations_research::CBCInterface::SetVariableInteger	(	int	index,
		bool	integer )

overridevirtual

Modifies integrality of an extracted variable.

Todo: (user) : Check if this is actually a change.

Implements operations_research::MPSolverInterface.

Definition at line 211 of file cbc_interface.cc.

◆ Solve()

MPSolver::ResultStatus operations_research::CBCInterface::Solve ( const MPSolverParameters & param )

overridevirtual

--— Solve --— Solve the problem using the parameter values specified.

Solve the LP/MIP. Returns true only if the optimal solution was revealed. Returns the status of the search.

CBC requires unique variable and constraint names. By using Lookup*, we generate variable and constraint indices and ensure the duplicate name crash will happen here with a readable error message.

Note: CBC does not provide any incrementality.

Special case if the model is empty since CBC is not able to handle this special case by itself.

Finish preparing the problem. Define variables.

Create dummy variable for objective offset.

Define constraints.

Changing optimization direction through OSI so that the model file (written through OSI) has the correct optimization duration.

Solve

Set log level.

Time limit.

And solve.

Here we use the default function from the command-line CBC solver. This enables to activate all the features and get the same performance as the CBC stand-alone executable. The syntax is ugly, however.

Always turn presolve on (it's the CBC default and it consistently improves performance).

Special way to set the relative MIP gap parameter as it cannot be set through callCbc.

Note: Trailing space is required to avoid buffer overflow in cbc.

to the CBC source

Check the status: optimal, infeasible, etc.

Order of tests counts; if model.isContinuousUnbounded() returns true, then so does model.isProvenInfeasible()!

Get the results

if optimal or feasible solution is found.

Implements operations_research::MPSolverInterface.

Definition at line 244 of file cbc_interface.cc.

◆ SolverVersion()

std::string operations_research::CBCInterface::SolverVersion ( ) const

inlineoverridevirtual

Returns a string describing the underlying solver and its version.

Implements operations_research::MPSolverInterface.

Definition at line 127 of file cbc_interface.cc.

◆ underlying_solver()

void * operations_research::CBCInterface::underlying_solver ( )

inlineoverridevirtual

Todo: (user): Maybe we should expose the CbcModel build from osi_ instead, but a new CbcModel is built every time Solve is called, so it is not possible right now.

Implements operations_research::MPSolverInterface.

Definition at line 132 of file cbc_interface.cc.

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

ortools/linear_solver/cbc_interface.cc

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ CBCInterface()

◆ ~CBCInterface()

Member Function Documentation

◆ AddRowConstraint()

◆ AddVariable()

◆ ClearConstraint()

◆ ClearObjective()

◆ column_status()

◆ ExtractModel()

◆ ExtractNewConstraints()

◆ ExtractNewVariables()

◆ ExtractObjective()

◆ IsContinuous()

◆ IsLP()

◆ IsMIP()

◆ iterations()

◆ nodes()

◆ Reset()

◆ row_status()

◆ SetCoefficient()

◆ SetConstraintBounds()

◆ SetNumThreads()

◆ SetObjectiveCoefficient()

◆ SetObjectiveOffset()

◆ SetOptimizationDirection()

◆ SetVariableBounds()

◆ SetVariableInteger()

◆ Solve()

◆ SolverVersion()

◆ underlying_solver()