Home Original page

Google OR-Tools: operations_research::MPObjective Class Reference

A class to express a linear objective. More...

A class to express a linear objective.

Definition at line 1023 of file linear_solver.h.

#include <linear_solver.h>

Public Member Functions

 MPObjective (const MPObjective &)=delete
MPObjective & operator= (const MPObjective &)=delete
void Clear ()
void SetCoefficient (const MPVariable *var, double coeff)
double GetCoefficient (const MPVariable *var) const
const absl::flat_hash_map< const MPVariable *, double > & terms () const
void SetOffset (double value)
 Sets the constant term in the objective.
double offset () const
 Gets the constant term in the objective.
void OptimizeLinearExpr (const LinearExpr &linear_expr, bool is_maximization)
void MaximizeLinearExpr (const LinearExpr &linear_expr)
 Resets the current objective to maximize linear_expr.
void MinimizeLinearExpr (const LinearExpr &linear_expr)
 Resets the current objective to minimize linear_expr.
void AddLinearExpr (const LinearExpr &linear_expr)
 Adds linear_expr to the current objective, does not change the direction.
void SetOptimizationDirection (bool maximize)
 Sets the optimization direction (maximize: true or minimize: false).
void SetMinimization ()
 Sets the optimization direction to minimize.
void SetMaximization ()
 Sets the optimization direction to maximize.
bool maximization () const
 Is the optimization direction set to maximize?
bool minimization () const
 Is the optimization direction set to minimize?
double Value () const
double BestBound () const

Friends

class MPSolver
class MPSolverInterface
class CBCInterface
class CLPInterface
class GLPKInterface
class SCIPInterface
class SLMInterface
class GurobiInterface
class CplexInterface
class XpressInterface
class GLOPInterface
class BopInterface
class SatInterface
class PdlpInterface
class HighsInterface
class KnapsackInterface
operations_research::MPObjective::MPObjective ( const MPObjective & )
delete

◆ AddLinearExpr()

void operations_research::MPObjective::AddLinearExpr ( const LinearExpr & linear_expr)

Adds linear_expr to the current objective, does not change the direction.

Definition at line 242 of file linear_solver.cc.

◆ BestBound()

double operations_research::MPObjective::BestBound ( ) const

Returns the best objective bound.

In case of minimization, it is a lower bound on the objective value of the optimal integer solution. Only available for discrete problems.

Definition at line 279 of file linear_solver.cc.

◆ Clear()

void operations_research::MPObjective::Clear ( )

Clears the offset, all variables and coefficients, and the optimization direction.

Definition at line 250 of file linear_solver.cc.

◆ GetCoefficient()

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

Gets the coefficient of a given variable in the objective

It returns 0 if the variable does not appear in the objective).

Definition at line 194 of file linear_solver.cc.

◆ maximization()

bool operations_research::MPObjective::maximization ( ) const

Is the optimization direction set to maximize?

Definition at line 268 of file linear_solver.cc.

◆ MaximizeLinearExpr()

void operations_research::MPObjective::MaximizeLinearExpr ( const LinearExpr & linear_expr)
inline

Resets the current objective to maximize linear_expr.

Definition at line 1074 of file linear_solver.h.

◆ minimization()

bool operations_research::MPObjective::minimization ( ) const

Is the optimization direction set to minimize?

Definition at line 270 of file linear_solver.cc.

◆ MinimizeLinearExpr()

void operations_research::MPObjective::MinimizeLinearExpr ( const LinearExpr & linear_expr)
inline

Resets the current objective to minimize linear_expr.

Definition at line 1078 of file linear_solver.h.

◆ offset()

double operations_research::MPObjective::offset ( ) const
inline

◆ operator=()

MPObjective & operations_research::MPObjective::operator= ( const MPObjective & )
delete

◆ OptimizeLinearExpr()

void operations_research::MPObjective::OptimizeLinearExpr ( const LinearExpr & linear_expr,
bool is_maximization )

Resets the current objective to take the value of linear_expr, and sets the objective direction to maximize if "is_maximize", otherwise minimizes.

Definition at line 230 of file linear_solver.cc.

◆ SetCoefficient()

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

Sets the coefficient of the variable in the objective.

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

Definition at line 200 of file linear_solver.cc.

◆ SetMaximization()

void operations_research::MPObjective::SetMaximization ( )
inline

◆ SetMinimization()

void operations_research::MPObjective::SetMinimization ( )
inline

◆ SetOffset()

void operations_research::MPObjective::SetOffset ( double value)

◆ SetOptimizationDirection()

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

Sets the optimization direction (maximize: true or minimize: false).

Definition at line 257 of file linear_solver.cc.

◆ terms()

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

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

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

Definition at line 1057 of file linear_solver.h.

◆ Value()

double operations_research::MPObjective::Value ( ) const

Returns the objective value of the best solution found so far.

It is the optimal objective value if the problem has been solved to optimality.

Note: the objective value may be slightly different than what you could compute yourself using MPVariable::solution_value(); please use the –verify_solution flag to gain confidence about the numerical stability of your solution.

Definition at line 272 of file linear_solver.cc.

◆ BopInterface

friend class BopInterface

 friend

◆ CBCInterface

friend class CBCInterface

 friend

◆ CLPInterface

friend class CLPInterface

 friend

◆ CplexInterface

friend class CplexInterface

 friend

◆ GLOPInterface

friend class GLOPInterface

 friend

◆ GLPKInterface

friend class GLPKInterface

 friend

◆ GurobiInterface

friend class GurobiInterface

 friend

◆ HighsInterface

friend class HighsInterface

 friend

◆ KnapsackInterface

friend class KnapsackInterface

 friend

◆ MPSolver

◆ MPSolverInterface

friend class MPSolverInterface

 friend

◆ PdlpInterface

friend class PdlpInterface

 friend

◆ SatInterface

friend class SatInterface

 friend

◆ SCIPInterface

friend class SCIPInterface

 friend

◆ SLMInterface

friend class SLMInterface

 friend

◆ XpressInterface

friend class XpressInterface

 friend

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