operations_research::sat::FeasibilityPump Class Reference

#include <feasibility_pump.h>

Public Types
typedef glop::RowIndex	ConstraintIndex

Public Member Functions
	FeasibilityPump (Model *model)
	~FeasibilityPump ()
void	SetMaxFPIterations (int max_iter)
void	AddLinearConstraint (const LinearConstraint &ct)
	Add a new linear constraint to this LP.
void	SetObjectiveCoefficient (IntegerVariable ivar, IntegerValue coeff)
bool	HasLPSolution () const
double	LPSolutionObjectiveValue () const
double	GetLPSolutionValue (IntegerVariable variable) const
bool	LPSolutionIsInteger () const
double	LPSolutionFractionality () const
bool	HasIntegerSolution () const
int64_t	IntegerSolutionObjectiveValue () const
bool	IntegerSolutionIsFeasible () const
int64_t	GetIntegerSolutionValue (IntegerVariable variable) const
bool	Solve ()
	Returns false if the model is proven to be infeasible.

Detailed Description

Definition at line 42 of file feasibility_pump.h.

Member Typedef Documentation

ConstraintIndex

typedef glop::RowIndex operations_research::sat::FeasibilityPump::ConstraintIndex

Definition at line 47 of file feasibility_pump.h.

Constructor & Destructor Documentation

FeasibilityPump()

operations_research::sat::FeasibilityPump::FeasibilityPump ( Model * model )

explicit

Tweak the default parameters to make the solve incremental.

Note(user): Primal simplex does better here since we have a limit on simplex iterations. So dual simplex sometimes fails to find a LP feasible solution.

Definition at line 58 of file feasibility_pump.cc.

~FeasibilityPump()

operations_research::sat::FeasibilityPump::~FeasibilityPump

(

)

Definition at line 80 of file feasibility_pump.cc.

Member Function Documentation

AddLinearConstraint()

void operations_research::sat::FeasibilityPump::AddLinearConstraint

(

const LinearConstraint &

ct

)

Add a new linear constraint to this LP.

We still create the mirror variable right away though.

We only use positive variable inside this class.

Important to keep lp_data_ "clean".

Definition at line 85 of file feasibility_pump.cc.

GetIntegerSolutionValue()

int64_t operations_research::sat::FeasibilityPump::GetIntegerSolutionValue

(

IntegerVariable

variable

)

const

----------------—Rounding----------------------------------—

Definition at line 452 of file feasibility_pump.cc.

GetLPSolutionValue()

double operations_research::sat::FeasibilityPump::GetLPSolutionValue

(

IntegerVariable

variable

)

const

Definition at line 438 of file feasibility_pump.cc.

HasIntegerSolution()

bool operations_research::sat::FeasibilityPump::HasIntegerSolution ( ) const

inline

Returns the Integer solution value of a variable in the current rounded solution. These functions should only be called when HasIntegerSolution() is true.

Definition at line 73 of file feasibility_pump.h.

HasLPSolution()

bool operations_research::sat::FeasibilityPump::HasLPSolution ( ) const

inline

Returns the LP value of a variable in the current solution. These functions should only be called when HasSolution() is true.

Definition at line 64 of file feasibility_pump.h.

IntegerSolutionIsFeasible()

bool operations_research::sat::FeasibilityPump::IntegerSolutionIsFeasible ( ) const

inline

Definition at line 77 of file feasibility_pump.h.

IntegerSolutionObjectiveValue()

int64_t operations_research::sat::FeasibilityPump::IntegerSolutionObjectiveValue ( ) const

inline

Definition at line 74 of file feasibility_pump.h.

LPSolutionFractionality()

double operations_research::sat::FeasibilityPump::LPSolutionFractionality ( ) const

inline

Definition at line 68 of file feasibility_pump.h.

LPSolutionIsInteger()

bool operations_research::sat::FeasibilityPump::LPSolutionIsInteger ( ) const

inline

Definition at line 67 of file feasibility_pump.h.

LPSolutionObjectiveValue()

double operations_research::sat::FeasibilityPump::LPSolutionObjectiveValue ( ) const

inline

Definition at line 65 of file feasibility_pump.h.

SetMaxFPIterations()

void operations_research::sat::FeasibilityPump::SetMaxFPIterations ( int max_iter )

inline

Definition at line 49 of file feasibility_pump.h.

SetObjectiveCoefficient()

void operations_research::sat::FeasibilityPump::SetObjectiveCoefficient	(	IntegerVariable	ivar,
		IntegerValue	coeff )

Set the coefficient of the variable in the objective. Calling it twice will overwrite the previous value. Note that this doesn't set the objective coefficient if the variable doesn't appear in any constraints. So this has to be called after all the constraints are added.

Definition at line 110 of file feasibility_pump.cc.

Solve()

bool operations_research::sat::FeasibilityPump::Solve

(

)

Returns false if the model is proven to be infeasible.

Restore the original objective

We don't end this loop if the integer solutions is feasible in hope to get better solution.

Definition at line 163 of file feasibility_pump.cc.

---

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

• ortools/sat/feasibility_pump.h
• ortools/sat/feasibility_pump.cc