Detailed Description

The class for constraints of a Mathematical Programming (MP) model.

A constraint is represented as a linear equation or inequality.

Definition at line 1122 of file linear_solver.h.

Public Member Functions
const std::string &	name () const
	Returns the name of the constraint. More...

void	Clear ()
	Clears all variables and coefficients. Does not clear the bounds. More...

void	SetCoefficient (const MPVariable *const var, double coeff)
	Sets the coefficient of the variable on the constraint. More...

double	GetCoefficient (const MPVariable *const var) const
	Gets the coefficient of a given variable on the constraint (which is 0 if the variable does not appear in the constraint). More...

const absl::flat_hash_map< const MPVariable *, double > &	terms () const
	Returns a map from variables to their coefficients in the constraint. More...

double	lb () const
	Returns the lower bound. More...

double	ub () const
	Returns the upper bound. More...

void	SetLB (double lb)
	Sets the lower bound. More...

void	SetUB (double ub)
	Sets the upper bound. More...

void	SetBounds (double lb, double ub)
	Sets both the lower and upper bounds. More...

bool	is_lazy () const
	Advanced usage: returns true if the constraint is "lazy" (see below). More...

void	set_is_lazy (bool laziness)
	Advanced usage: sets the constraint "laziness". More...

const MPVariable *	indicator_variable () const

bool	indicator_value () const

int	index () const
	Returns the index of the constraint in the MPSolver::constraints_. More...

double	dual_value () const
	Advanced usage: returns the dual value of the constraint in the current solution (only available for continuous problems). More...

MPSolver::BasisStatus	basis_status () const
	Advanced usage: returns the basis status of the constraint. More...

Protected Member Functions
	MPConstraint (int index, double lb, double ub, const std::string &name, MPSolverInterface *const interface_in)

void	set_dual_value (double dual_value)

Friends
class	MPSolver

class	MPSolverInterface

class	CBCInterface

class	CLPInterface

class	GLPKInterface

class	SCIPInterface

class	SLMInterface

class	GurobiInterface

class	CplexInterface

class	GLOPInterface

class	BopInterface

class	SatInterface

class	KnapsackInterface

Constructor & Destructor Documentation

◆ MPConstraint()

operations_research::MPConstraint::MPConstraint	(	int	index,
		double	lb,
		double	ub,
		const std::string &	name,
		MPSolverInterface *const	interface_in
	)

inlineprotected

Definition at line 1230 of file linear_solver.h.

Member Function Documentation

◆ basis_status()

MPSolver::BasisStatus operations_research::MPConstraint::basis_status ( ) const

Advanced usage: returns the basis status of the constraint.

It is only available for continuous problems).

Note that if a constraint "linear_expression in [lb, ub]" is transformed into "linear_expression + slack = 0" with slack in [-ub, -lb], then this status is the same as the status of the slack variable with AT_UPPER_BOUND and AT_LOWER_BOUND swapped.

See also: MPSolver::BasisStatus.

◆ Clear()

void operations_research::MPConstraint::Clear ( )

Clears all variables and coefficients. Does not clear the bounds.

◆ dual_value()

double operations_research::MPConstraint::dual_value ( ) const

Advanced usage: returns the dual value of the constraint in the current solution (only available for continuous problems).

◆ GetCoefficient()

double operations_research::MPConstraint::GetCoefficient ( const MPVariable *const var ) const

Gets the coefficient of a given variable on the constraint (which is 0 if the variable does not appear in the constraint).

◆ index()

int operations_research::MPConstraint::index ( ) const

inline

Returns the index of the constraint in the MPSolver::constraints_.

Definition at line 1190 of file linear_solver.h.

◆ indicator_value()

bool operations_research::MPConstraint::indicator_value ( ) const

inline

Definition at line 1187 of file linear_solver.h.

◆ indicator_variable()

const MPVariable* operations_research::MPConstraint::indicator_variable ( ) const

inline

Definition at line 1186 of file linear_solver.h.

◆ is_lazy()

bool operations_research::MPConstraint::is_lazy ( ) const

inline

Advanced usage: returns true if the constraint is "lazy" (see below).

Definition at line 1169 of file linear_solver.h.

◆ lb()

double operations_research::MPConstraint::lb ( ) const

inline

Returns the lower bound.

Definition at line 1154 of file linear_solver.h.

◆ name()

const std::string& operations_research::MPConstraint::name ( ) const

inline

Returns the name of the constraint.

Definition at line 1125 of file linear_solver.h.

◆ set_dual_value()

void operations_research::MPConstraint::set_dual_value ( double dual_value )

inlineprotected

Definition at line 1242 of file linear_solver.h.

◆ set_is_lazy()

void operations_research::MPConstraint::set_is_lazy ( bool laziness )

inline

Advanced usage: sets the constraint "laziness".

This is only supported for SCIP and has no effect on other solvers.

When laziness is true, the constraint is only considered by the Linear Programming solver if its current solution violates the constraint. In this case, the constraint is definitively added to the problem. This may be useful in some MIP problems, and may have a dramatic impact on performance.

For more info see: http://tinyurl.com/lazy-constraints.

Definition at line 1184 of file linear_solver.h.

◆ SetBounds()

void operations_research::MPConstraint::SetBounds	(	double	lb,
		double	ub
	)

Sets both the lower and upper bounds.

◆ SetCoefficient()

void operations_research::MPConstraint::SetCoefficient	(	const MPVariable *const	var,
		double	coeff
	)

Sets the coefficient of the variable on the constraint.

If the variable does not belong to the solver, the function just returns, or crashes in non-opt mode.

◆ SetLB()

void operations_research::MPConstraint::SetLB ( double lb )

inline

Sets the lower bound.

Definition at line 1160 of file linear_solver.h.

◆ SetUB()

void operations_research::MPConstraint::SetUB ( double ub )

inline

Sets the upper bound.

Definition at line 1163 of file linear_solver.h.

◆ terms()

const absl::flat_hash_map<const MPVariable*, double>& operations_research::MPConstraint::terms ( ) const

inline

Returns a map from variables to their coefficients in the constraint.

If a variable is not present in the map, then its coefficient is zero.

Definition at line 1149 of file linear_solver.h.

◆ ub()

double operations_research::MPConstraint::ub ( ) const

inline

Returns the upper bound.

Definition at line 1157 of file linear_solver.h.

Friends And Related Function Documentation

◆ BopInterface

friend class BopInterface

friend

Definition at line 1223 of file linear_solver.h.

◆ CBCInterface

friend class CBCInterface

friend

Definition at line 1215 of file linear_solver.h.

◆ CLPInterface

friend class CLPInterface

friend

Definition at line 1216 of file linear_solver.h.

◆ CplexInterface

friend class CplexInterface

friend

Definition at line 1221 of file linear_solver.h.

◆ GLOPInterface

friend class GLOPInterface

friend

Definition at line 1222 of file linear_solver.h.

◆ GLPKInterface

friend class GLPKInterface

friend

Definition at line 1217 of file linear_solver.h.

◆ GurobiInterface

friend class GurobiInterface

friend

Definition at line 1220 of file linear_solver.h.

◆ KnapsackInterface

friend class KnapsackInterface

friend

Definition at line 1225 of file linear_solver.h.

◆ MPSolver

friend class MPSolver

friend

Definition at line 1213 of file linear_solver.h.

◆ MPSolverInterface

friend class MPSolverInterface

friend

Definition at line 1214 of file linear_solver.h.

◆ SatInterface

friend class SatInterface

friend

Definition at line 1224 of file linear_solver.h.

◆ SCIPInterface

friend class SCIPInterface

friend

Definition at line 1218 of file linear_solver.h.

◆ SLMInterface

friend class SLMInterface

friend

Definition at line 1219 of file linear_solver.h.

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

linear_solver.h

Detailed Description

Public Member Functions

Protected Member Functions

Friends

Constructor & Destructor Documentation

◆ MPConstraint()

Member Function Documentation

◆ basis_status()

◆ Clear()

◆ dual_value()

◆ GetCoefficient()

◆ index()

◆ indicator_value()

◆ indicator_variable()

◆ is_lazy()

◆ lb()

◆ name()

◆ set_dual_value()

◆ set_is_lazy()

◆ SetBounds()

◆ SetCoefficient()

◆ SetLB()

◆ SetUB()

◆ terms()

◆ ub()

Friends And Related Function Documentation

◆ BopInterface

◆ CBCInterface

◆ CLPInterface

◆ CplexInterface

◆ GLOPInterface

◆ GLPKInterface

◆ GurobiInterface

◆ KnapsackInterface

◆ MPSolver

◆ MPSolverInterface

◆ SatInterface

◆ SCIPInterface

◆ SLMInterface