localsolver.LSExpression Class Reference

Detailed Description

Mathematical modeling expression.

Expressions are used to build the mathematical optimization model associated to LocalSolver. An expression is composed of an operator (which corresponds to its type) and its operands (which are other expressions of the model).

See Also

LSModel, LSOperator

Public Member Functions
LSModel	GetModel ()
	Returns the model object associated to this expression.
LocalSolver	GetLocalSolver ()
	Returns the LocalSolver object associated to this expression.
LSOperator	GetOperator ()
	Gets the operator of this expression.
int	GetIndex ()
	Gets the index of this expression in the model.
bool	IsConstant ()
	Returns true if this expression is typed as constant in the model, false otherwise.
bool	IsDecision ()
	Returns true if this expression is typed as decision in the model, false otherwise.
bool	IsConstraint ()
	Returns true if this expression is tagged as constraint in the model, false otherwise.
bool	IsObjective ()
	Returns true if this expression is tagged as objective in the model, false otherwise.
bool	IsDouble ()
	Returns true if this expression is a double, false otherwise.
bool	IsInt ()
	Returns true if this expression is an integer, false otherwise.
bool	IsBool ()
	Returns true if this expression is a boolean (ie 0 or 1), false otherwise.
bool	IsArray ()
	Returns true if this expression is an array, false otherwise.
bool	IsCollection ()
	Returns true if this expression is a collection, false otherwise.
bool	IsFunction ()
	Returns true if this expression is a function, false otherwise.
void	AddOperand (LSExpression expr)
	Adds the given operand to this expression.
void	AddOperand (long constant)
	Add the given constant operand to this expression.
void	AddOperand (double constant)
	Add the given constant operand to this expression.
void	AddOperands (IEnumerable< LSExpression > operands)
	Add the given operands to the expression.
void	AddOperands (IEnumerable< long > operands)
	Add the given constant integer operands to the expression.
void	AddOperands (IEnumerable< double > operands)
	Add the given constant double operands to the expression.
void	AddOperands (params LSExpression[] operands)
	Add the given operands to the expression.
void	AddOperands (params double[] operands)
	Add the given constant double operands to the expression.
void	AddOperands (params long[] operands)
	Add the given constant integer operands to the expression.
LSExpression	GetOperand (int operandIndex)
	Gets the operand with the given index.
void	SetOperand (int operandIndex, LSExpression operand)
	Replaces the operand of the given index.
void	SetOperand (int operandIndex, long constant)
	Replaces the operand of the given index.
void	SetOperand (int operandIndex, double constant)
	Replaces the operand of the given index.
int	GetNbOperands ()
	Gets the number of operands of this expression.
void	SetValue (long value)
	Sets the value of this expression in the current solution found by the solver.
void	SetValue (double value)
	Sets the value of this expression in the current solution found by the solver.
void	SetIntValue (long value)
	Sets the value of this expression in the current solution found by the solver.
void	SetDoubleValue (double value)
	Sets the value of this expression in the current solution found by the solver.
long	GetValue ()
	Gets the value of this expression in the best solution found by the solver.
long	GetIntValue ()
	Gets the value of this expression in the best solution found by the solver.
double	GetDoubleValue ()
	Gets the value of this expression in the best solution found by the solver.
LSCollection	GetCollectionValue ()
	Gets the value of this expression in the best solution found by the solver.
bool	IsViolated ()
	Returns true if the given expression is violated in the best solution found by the solver.
void	SetName (string name)
	Sets the name of this expression.
bool	IsNamed ()
	Returns true if this expression has a name, and false otherwise.
string	GetName ()
	Gets the name of this expression or the empty string if no name has been set.
override string	ToString ()
	Returns a string representation of this expression.
string	GetInfo ()
	Returns useful info about this expression (according to the state of LocalSolver).

Member Function Documentation

LSModel localsolver.LSExpression.GetModel

(

)

Returns the model object associated to this expression.

Returns

LSModel object

LocalSolver localsolver.LSExpression.GetLocalSolver

(

)

Returns the LocalSolver object associated to this expression.

Returns

LocalSolver object

LSOperator localsolver.LSExpression.GetOperator

(

)

Gets the operator of this expression.

Returns

Operator.

int localsolver.LSExpression.GetIndex

(

)

Gets the index of this expression in the model.

Returns

Index in the model.

bool localsolver.LSExpression.IsConstant

(

)

Returns true if this expression is typed as constant in the model, false otherwise.

Returns

True if typed as constant.

bool localsolver.LSExpression.IsDecision

(

)

Returns true if this expression is typed as decision in the model, false otherwise.

Returns

True if typed as decision.

bool localsolver.LSExpression.IsConstraint

(

)

Returns true if this expression is tagged as constraint in the model, false otherwise.

Returns

True if tagged as constraint.

bool localsolver.LSExpression.IsObjective

(

)

Returns true if this expression is tagged as objective in the model, false otherwise.

Returns

True if tagged as objective.

bool localsolver.LSExpression.IsDouble

(

)

Returns true if this expression is a double, false otherwise.

Only allowed in states LSState::Paused or LSState::Stopped.

Returns

True if the expression is a double.

Since version 3.0

bool localsolver.LSExpression.IsInt

(

)

Returns true if this expression is an integer, false otherwise.

Only allowed in states LSState::Paused or LSState::Stopped. Note that a boolean is also an integer.

Returns

True if the expression is an integer.

Since version 3.0

bool localsolver.LSExpression.IsBool

(

)

Returns true if this expression is a boolean (ie 0 or 1), false otherwise.

Only allowed in states LSState::Paused or LSState::Stopped.

Returns

True if the expression is a boolean.

Since version 3.0

bool localsolver.LSExpression.IsArray

(

)

Returns true if this expression is an array, false otherwise.

Only allowed in states LSState::Paused or LSState::Stopped.

Returns

True if the expression is an array.

Since version 3.1

bool localsolver.LSExpression.IsCollection

(

)

Returns true if this expression is a collection, false otherwise.

Only allowed in states LSState::Paused or LSState::Stopped.

Returns

True if the expression is a collection.

Since version 5.5

bool localsolver.LSExpression.IsFunction

(

)

Returns true if this expression is a function, false otherwise.

Only allowed in states LSState::Paused or LSState::Stopped.

Returns

True if the expression is a function.

Since version 6.0

void localsolver.LSExpression.AddOperand

(

LSExpression

expr

)

Adds the given operand to this expression.

Only allowed in state LSState::Modeling.

Parameters

expr	Operand to add.

void localsolver.LSExpression.AddOperand

(

long

constant

)

Add the given constant operand to this expression.

Only allowed in state LSState::Modeling.

Parameters

constant

Constant operand to add.

void localsolver.LSExpression.AddOperand

(

double

constant

)

Add the given constant operand to this expression.

Only allowed in state LSState::Modeling.

Parameters

constant

Constant operand to add.

void localsolver.LSExpression.AddOperands

(

IEnumerable< LSExpression >

operands

)

Add the given operands to the expression.

Parameters

operands

The operands to be added.

void localsolver.LSExpression.AddOperands

(

IEnumerable< long >

operands

)

Add the given constant integer operands to the expression.

Parameters

operands

The operands to be added.

void localsolver.LSExpression.AddOperands

(

IEnumerable< double >

operands

)

Add the given constant double operands to the expression.

Parameters

operands

The operands to be added.

void localsolver.LSExpression.AddOperands

(

params LSExpression[]

operands

)

Add the given operands to the expression.

Parameters

operands

The operands to be added.

void localsolver.LSExpression.AddOperands

(

params double[]

operands

)

Add the given constant double operands to the expression.

Parameters

operands

The operands to be added.

void localsolver.LSExpression.AddOperands

(

params long[]

operands

)

Add the given constant integer operands to the expression.

Parameters

operands

The operands to be added.

LSExpression localsolver.LSExpression.GetOperand

(

int

operandIndex

)

Gets the operand with the given index.

Parameters

operandIndex

Index of the operand.

Returns

Operand.

void localsolver.LSExpression.SetOperand	(	int	operandIndex,
		LSExpression	operand
	)

Replaces the operand of the given index.

Parameters

operandIndex	Index of the operand to change
operand	New operand

void localsolver.LSExpression.SetOperand	(	int	operandIndex,
		long	constant
	)

Replaces the operand of the given index.

Parameters

operandIndex	Index of the operand to change.
constant	New constant operand.

void localsolver.LSExpression.SetOperand	(	int	operandIndex,
		double	constant
	)

Replaces the operand of the given index.

Parameters

operandIndex	Index of the operand to change.
constant	New constant operand.

Since version 3.0

int localsolver.LSExpression.GetNbOperands

(

)

Gets the number of operands of this expression.

Returns

Number of operands.

void localsolver.LSExpression.SetValue

(

long

value

)

Sets the value of this expression in the current solution found by the solver.

Only allowed for decisions. Only allowed in state LSState::Stopped. Only allowed if this expression is an integer or a boolean. If the solver was not launched, this value will be used as an initial value for the decision. This method is a shortcut for LSSolution::SetValue(LSExpression, long) and has the same behavior as LSExpression::SetIntValue(long).

Parameters

value

Value assigned to this expression.

See Also

LSSolution.SetValue(LSExpression, long), LSExpression.IsInt, LSExpression.IsBool

void localsolver.LSExpression.SetValue

(

double

value

)

Sets the value of this expression in the current solution found by the solver.

Only allowed for decisions. Only allowed in state LSState.Stopped. Only allowed if this expression is an integer or a boolean. If the solver was not launched, this value will be used as an initial value for the decision. This method is a shortcut for LSSolution::SetValue(LSExpression, double) and has the same behavior as LSExpression::SetDoubleValue(double).

Parameters

value

Value assigned to this expression.

See Also

LSSolution.SetValue(LSExpression, double), LSExpression.IsDouble

void localsolver.LSExpression.SetIntValue

(

long

value

)

Sets the value of this expression in the current solution found by the solver.

Only allowed for decisions. Only allowed in state LSState::Stopped. Only allowed if this expression is an integer or a boolean. If the solver was not launched, this value will be used as an initial value for the decision. This method is a shortcut for LSSolution::SetValue(LSExpression, long).

Parameters

value

Value assigned to this expression.

See Also

LSSolution.SetIntValue, LSExpression.IsInt, LSExpression.IsBool

Since version 3.0

void localsolver.LSExpression.SetDoubleValue

(

double

value

)

Sets the value of this expression in the current solution found by the solver.

Only allowed for decisions. Only allowed in state LSState::Stopped. Only allowed if this expression is a double. If the solver was not launched, this value will be used as an initial value for the decision. This method is a shortcut for LSSolution::SetValue(LSExpression, double).

Parameters

value

Value assigned to this expression.

See Also

LSSolution.SetDoubleValue, LSExpression.IsDouble

Since version 3.0

long localsolver.LSExpression.GetValue

(

)

Gets the value of this expression in the best solution found by the solver.

Only allowed in states LSState::Paused or LSState::Stopped. Only allowed if this expression is an integer or a boolean. This method is a shortcut for LSSolution::GetValue(LSExpression).

Returns

Value in the best solution.

See Also

LSSolution.GetValue, LSExpression.IsInt, LSExpression.IsBool

long localsolver.LSExpression.GetIntValue

(

)

Gets the value of this expression in the best solution found by the solver.

Only allowed in states LSState::Paused or LSState::Stopped. Only allowed if this expression is an integer or a boolean. This method is a shortcut for LSSolution::GetIntValue(LSExpression).

Returns

Value in the best solution.

See Also

LSSolution.GetIntValue, LSExpression.IsInt, LSExpression.IsBool

Since version 3.0

double localsolver.LSExpression.GetDoubleValue

(

)

Gets the value of this expression in the best solution found by the solver.

Only allowed in states LSState::Paused or LSState::Stopped. Only allowed if this expression is a double. This method is a shortcut for LSSolution::GetDoubleValue(LSExpression).

Returns

Value in the best solution.

See Also

LSSolution.GetDoubleValue, LSExpression.IsDouble

Since version 3.0

LSCollection localsolver.LSExpression.GetCollectionValue

(

)

Gets the value of this expression in the best solution found by the solver.

Only allowed in states LSState::Paused or LSState::Stopped. Only allowed if this expression is a collection (list). This method is a shortcut for LSSolution::GetCollectionValue(LSExpression).

Returns

Value in the best solution.

See Also

LSSolution.GetCollectionValue

Since version 5.5

bool localsolver.LSExpression.IsViolated

(

)

Returns true if the given expression is violated in the best solution found by the solver.

An expression can be violated in 3 cases:

1. It is a constraint and its value is 0.
2. It is a a double and its value is NaN (Not A Number).
3. It is an integer or boolean with no valid value (arithmetic or out of bounds exception).

Only allowed in states LSState::Paused or LSState::Stopped. This method is a shortcut for LSSolution::IsViolated(LSExpression).

Returns

True if this expression is violated in the best solution.

Since version 5.5

void localsolver.LSExpression.SetName

(

string

name

)

Sets the name of this expression.

Only allowed in state LSState::Modeling. The name cannot be empty. Two operators of the model cannot share the same name. Useful for debugging or logging purposes.

Parameters

name

Name.

bool localsolver.LSExpression.IsNamed

(

)

Returns true if this expression has a name, and false otherwise.

Returns

True if named.

string localsolver.LSExpression.GetName

(

)

Gets the name of this expression or the empty string if no name has been set.

Returns

Name.

override string localsolver.LSExpression.ToString

(

)

Returns a string representation of this expression.

This representation provides the index of the expression, its type, and its name (if any). Useful for debugging or logging purposes.

Returns

String representation.

string localsolver.LSExpression.GetInfo

(

)

Returns useful info about this expression (according to the state of LocalSolver).

Useful for debugging or logging purposes.

Returns

Info about this search during the solving process.