operations_research::sat::AffineExpression Struct Reference

Detailed Description

Represents [coeff * variable + constant] or just a [constant].

In some places it is useful to manipulate such expression instead of having to create an extra integer variable. This is mainly used for scheduling related constraints.

Definition at line 268 of file integer_base.h.

#include <integer_base.h>

Public Member Functions
	AffineExpression ()=default
	Helper to construct an AffineExpression.
	AffineExpression (IntegerValue cst)
	AffineExpression (IntegerVariable v)
	AffineExpression (IntegerVariable v, IntegerValue c)
	AffineExpression (IntegerVariable v, IntegerValue c, IntegerValue cst)
IntegerLiteral	GreaterOrEqual (IntegerValue bound) const
	var * coeff + constant >= bound.
IntegerLiteral	LowerOrEqual (IntegerValue bound) const
	var * coeff + constant <= bound.
AffineExpression	Negated () const
AffineExpression	MultipliedBy (IntegerValue multiplier) const
bool	operator== (AffineExpression o) const
IntegerValue	ValueAt (IntegerValue var_value) const
	Returns the value of this affine expression given its variable value.
double	LpValue (const util_intops::StrongVector< IntegerVariable, double > &lp_values) const
	Returns the affine expression value under a given LP solution.
bool	IsConstant () const
std::string	DebugString () const

Public Attributes
IntegerVariable	var = kNoIntegerVariable
IntegerValue	coeff = IntegerValue(0)
IntegerValue	constant = IntegerValue(0)

Constructor & Destructor Documentation

AffineExpression() [1/5]

operations_research::sat::AffineExpression::AffineExpression ( )

default

Helper to construct an AffineExpression.

AffineExpression() [2/5]

operations_research::sat::AffineExpression::AffineExpression ( IntegerValue cst )

inline

Definition at line 271 of file integer_base.h.

AffineExpression() [3/5]

operations_research::sat::AffineExpression::AffineExpression ( IntegerVariable v )

inline

Definition at line 273 of file integer_base.h.

AffineExpression() [4/5]

operations_research::sat::AffineExpression::AffineExpression ( IntegerVariable v, IntegerValue c )

inline

Definition at line 275 of file integer_base.h.

AffineExpression() [5/5]

operations_research::sat::AffineExpression::AffineExpression ( IntegerVariable v, IntegerValue c, IntegerValue cst )

inline

Definition at line 277 of file integer_base.h.

Member Function Documentation

DebugString()

std::string operations_research::sat::AffineExpression::DebugString ( ) const

inline

Definition at line 316 of file integer_base.h.

GreaterOrEqual()

IntegerLiteral operations_research::sat::AffineExpression::GreaterOrEqual ( IntegerValue bound ) const

inline

var * coeff + constant >= bound.

Returns the integer literal corresponding to expression >= value or expression <= value.

On constant expressions, they will return IntegerLiteral::TrueLiteral() or IntegerLiteral::FalseLiteral().

Definition at line 550 of file integer_base.h.

IsConstant()

bool operations_research::sat::AffineExpression::IsConstant ( ) const

inline

Definition at line 314 of file integer_base.h.

LowerOrEqual()

IntegerLiteral operations_research::sat::AffineExpression::LowerOrEqual ( IntegerValue bound ) const

inline

var * coeff + constant <= bound.

Definition at line 562 of file integer_base.h.

LpValue()

double operations_research::sat::AffineExpression::LpValue ( const util_intops::StrongVector< IntegerVariable, double > & lp_values ) const

inline

Returns the affine expression value under a given LP solution.

Definition at line 308 of file integer_base.h.

MultipliedBy()

AffineExpression operations_research::sat::AffineExpression::MultipliedBy ( IntegerValue multiplier ) const

inline

Note

this also works if multiplier is negative.

Definition at line 293 of file integer_base.h.

Negated()

AffineExpression operations_research::sat::AffineExpression::Negated ( ) const

inline

Definition at line 288 of file integer_base.h.

operator==()

bool operations_research::sat::AffineExpression::operator== ( AffineExpression o ) const

inline

Definition at line 298 of file integer_base.h.

ValueAt()

IntegerValue operations_research::sat::AffineExpression::ValueAt ( IntegerValue var_value ) const

inline

Returns the value of this affine expression given its variable value.

Definition at line 303 of file integer_base.h.

Member Data Documentation

coeff

IntegerValue operations_research::sat::AffineExpression::coeff = IntegerValue(0)

Definition at line 331 of file integer_base.h.

constant

IntegerValue operations_research::sat::AffineExpression::constant = IntegerValue(0)

Definition at line 332 of file integer_base.h.

var

IntegerVariable operations_research::sat::AffineExpression::var = kNoIntegerVariable

The coefficient MUST be positive. Use NegationOf(var) if needed.

Todo

(user): Make this private to enforce the invariant that coeff cannot be negative.

Definition at line 330 of file integer_base.h.

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

• ortools/sat/integer_base.h