The Constraint class is used to manage a constraint. More...

#include <Constraint.h>

Public Member Functions
	Constraint ()
	Default constructor.

	Constraint (UInt id, UInt index, FunctionPtr f, double lb, double ub, std::string name)
	This is the only real constructor. All others should call this constructor.

virtual	~Constraint ()
	Destroy.

double	getActivity (const double x, int error) const
	Get the value or activity at a given point.

bool	getBFlag () const
	Get the value of the bool flag.

int	getITemp () const

void	setITemp (int i)

FunctionPtr	getFunction () const
	Return a pointer to the function.

FunctionType	getFunctionType () const
	Get the function type.

UInt	getId () const
	Return the unique id of the constraint.

UInt	getIndex () const
	Return the index of the constraint.

double	getLb () const
	Get the 'l' value. or the lower bound constraint on 'f'.

LinearFunctionPtr	getLinearFunction () const
	Get the linear part of the constraint function 'f'.

const std::string	getName () const

NonlinearFunctionPtr	getNonlinearFunction () const
	Get the nonlinear part of the constraint function 'f'.

QuadraticFunctionPtr	getQuadraticFunction () const
	Get the quadratic part of the constraint function 'f'.

ConsState	getState () const
	Get the current state of the constraint: freed, fixed etc.

ConsSrcType	getSrcType () const
	Get the src type of the constraint.

ConsType	getType () const

double	getUb () const
	Get the 'u' value. or the upper bound constraint on 'f'.

void	setpId (UInt n)

int	getpId ()

void	setUB (double newub)

Convexity	getConvexity ()

void	setConvexity (Convexity convex)

void	incrAct ()

void	setBFlag (bool b)
	Set the value of the bool flag.

void	setSrcType (ConsSrcType src)
	Set src type.

void	setType (ConsType type)

void	write (std::ostream &out) const
	display the constraint

Protected Member Functions
void	add_ (double cb)
	Add a constant to the constraint function. lb - c <= f <= ub - c.

void	changeLf_ (LinearFunctionPtr lf)
	Change the linear part of constraint.

void	changeNlf_ (NonlinearFunctionPtr nlf)
	Change the nonlinear part of constraint.

void	delFixedVar_ (VariablePtr v, double val)
	Delete variables fixed at value val.

void	reverseSense_ ()
	Negate the constraint.

void	setId_ (UInt n)
	Set the id.

void	setIndex_ (UInt n)
	Set the index.

void	setLb_ (double newlb)
	Set a new lower bound.

void	setName_ (std::string name)
	Set name of the constraint.

void	setState_ (ConsState state)
	Set state of the constraint.

void	setUb_ (double newub)
	Set a new upper bound.

void	subst_ (VariablePtr out, VariablePtr in, double rat, bool *instay)
	Substitute a variable by .

Friends
class	Problem

class	PerspCon

class	TransSep

class	QGHandler

Detailed Description

The Constraint class is used to manage a constraint.

The general form of a constraint is:

$l \leq f(x) \leq u,$

where $f(x)$ is a function of the variables and $l, u$ are constraints placed on $f$ . $l$ can be $-\infty$ and/or $u$ can be $\infty$ .

A constraint should only be constructed through a Problem object. Doing this ensures that constraints have ID's unique for that problem. A constraint can thus be part of only one problem. A function $f$ that is part of a constraint should also not be shared at several places in the same problem or amongst different problems. Similarly, constraints should be deleted only through a problem. Changes in a constraint (e.g. changing name, bounds etc) may be done directly.

The state of a constraint describes whether the constraint is free or deleted etc. It is Fixed if each variable in the constraints has been fixed.

A Constraint also stores a map of variables that occur in that constraint. The map tells whether the variable is in a non-linear, or quadratic etc part of the constraint. A variable that occurs once in linear and thrice in quadratic parts will have four entries in the map, once for each occurrence.

The name of a constraint can be set by the user. There are no checks for duplicate names. The ID of the constraint however is unique in the problem.

Constructor & Destructor Documentation

◆ Constraint()

Constraint::Constraint	(	UInt	id,
		UInt	index,
		FunctionPtr	f,
		double	lb,
		double	ub,
		std::string	name
	)

This is the only real constructor. All others should call this constructor.

Create a constraint with

Parameters

[in]	id	the unique id of the constraint (determined by Problem object),
[in]	index	the index of the constraint in the problem,
[in]	f	the function in the body of the constraint,
[in]	lb	the lower bound, can be -INFINITY,
[in]	ub	the upper bound, can be INFINITY,
[in]	name	The string name of the constraint.
[in]	src	The source type of the constraint.

Member Function Documentation

◆ reverseSense_()

void Constraint::reverseSense_ ( )

protected

Negate the constraint.

Convert the constraint to

$-u \leq -f(x) \leq -l$

◆ setLb_()

void Minotaur::Constraint::setLb_ ( double newlb )

inlineprotected

Set a new lower bound.

The new lower bound can be -INFINITY. It can change the state of the constraint.

◆ setUb_()

void Minotaur::Constraint::setUb_ ( double newub )

inlineprotected

Set a new upper bound.

The new bound can be INFINITY. It can affect the state of the constraint.

Friends And Related Symbol Documentation

◆ Problem

friend class Problem

friend

Only Problem class can modify a Constraint. All modification methods are private.

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

/home/amahajan/tmp/minotaur-test/src/base/Constraint.h
/home/amahajan/tmp/minotaur-test/src/base/Constraint.cpp

Public Member Functions

Protected Member Functions

Friends