Auxiliary variable. More...

#include <CouenneExprAux.hpp>

Inheritance diagram for Couenne::exprAux:

Public Types
enum	intType { Unset =-1, Continuous, Integer }
	integrality type of an auxiliary variable: unset, continuous, integer More...

Public Types inherited from Couenne::expression
enum	auxSign { AUX_UNDEF =-2, AUX_LEQ =-1, AUX_EQ, AUX_GEQ }
	"sign" of the constraint defining an auxiliary. More...

Public Member Functions
enum nodeType	Type () const
	Node type. More...

	exprAux (expression , int, int, intType=Unset, Domain =NULL, enum auxSign=expression::AUX_EQ)
	Constructor. More...

	exprAux (expression , Domain =NULL, enum auxSign=expression::AUX_EQ)
	Constructor to be used with standardize ([...], false) More...

virtual	~exprAux ()
	Destructor. More...

	exprAux (const exprAux &, Domain *d=NULL)
	Copy constructor. More...

virtual exprVar *	clone (Domain *d=NULL) const
	Cloning method. More...

expression *	Lb ()
	get lower bound expression More...

expression *	Ub ()
	get upper bound expression More...

virtual void	print (std::ostream &=std::cout, bool=false) const
	Print expression. More...

expression *	Image () const
	The expression associated with this auxiliary variable. More...

void	Image (expression *image)
	Sets expression associated with this auxiliary variable. More...

CouNumber	operator() ()
	Null function for evaluating the expression. More...

int	DepList (std::set< int > &deplist, enum dig_type type=ORIG_ONLY)
	fill in the set with all indices of variables appearing in the expression More...

expression *	simplify ()
	simplify More...

int	Linearity ()
	Get a measure of "how linear" the expression is (see CouenneTypes.h) More...

void	crossBounds ()
	Get lower and upper bound of an expression (if any) More...

void	generateCuts (OsiCuts &, const CouenneCutGenerator , t_chg_bounds =NULL, int=-1, CouNumber=-COUENNE_INFINITY, CouNumber=COUENNE_INFINITY)
	generate cuts for expression associated with this auxiliary More...

virtual int	rank ()
	used in rank-based branching variable choice More...

virtual bool	isDefinedInteger ()
	is this expression defined as integer? More...

virtual bool	isInteger ()
	is this expression integer? More...

virtual void	setInteger (bool value)
	Set this variable as integer. More...

void	increaseMult ()
	Tell this variable appears once more. More...

void	decreaseMult ()
	Tell this variable appears once less (standardized within exprSum, for instance) More...

void	zeroMult ()
	Disable this auxiliary variable. More...

int	Multiplicity ()
	How many times this variable appears. More...

void	linkDomain (Domain *d)
	link this variable to a domain More...

bool &	top_level ()
	return top_level_ More...

CouenneObject *	properObject (CouenneCutGenerator c, CouenneProblem p, Bonmin::BabSetupBase *base, JnlstPtr jnlst)
	return proper object to handle expression associated with this variable (NULL if this is not an auxiliary) More...

virtual enum auxSign	sign () const
	return its sign in the definition constraint More...

Public Member Functions inherited from Couenne::exprVar
	exprVar (int varIndex, Domain *d=NULL)
	Constructor. More...

virtual	~exprVar ()
	destructor More...

	exprVar (const exprVar &e, Domain *d=NULL)
	Copy constructor. More...

int	Index () const
	Get variable index in problem. More...

virtual CouNumber &	lb ()
	Get/set lower bound value. More...

virtual CouNumber &	ub ()
	Get/set upper bound value. More...

virtual CouNumber	gradientNorm (const double *x)
	return l-2 norm of gradient at given point More...

virtual expression *	differentiate (int index)
	differentiation More...

virtual void	getBounds (expression &, expression &)
	Get expressions of lower and upper bound of an expression (if any) More...

virtual void	getBounds (CouNumber &lb, CouNumber &ub)
	Get value of lower and upper bound of an expression (if any) More...

virtual void	generateCuts (expression w, OsiCuts &cs, const CouenneCutGenerator cg, t_chg_bounds *=NULL, int=-1, CouNumber=-COUENNE_INFINITY, CouNumber=COUENNE_INFINITY)
	generate convexification cut for constraint w = this More...

virtual enum expr_type	code ()
	code for comparison More...

virtual bool	impliedBound (int, CouNumber , CouNumber , t_chg_bounds *, enum auxSign=expression::AUX_EQ)
	implied bound processing More...

virtual void	fillDepSet (std::set< DepNode , compNode > , DepGraph *)
	update dependence set with index of this variable More...

virtual bool	isFixed ()
	is this variable fixed? More...

virtual Domain *	domain ()
	return pointer to variable domain More...

virtual enum convexity	convexity () const
	either CONVEX, CONCAVE, AFFINE, or NONCONVEX More...

Public Member Functions inherited from Couenne::expression
	expression ()
	Constructor. More...

	expression (const expression &e, Domain *d=NULL)
	Copy constructor. More...

virtual	~expression ()
	Destructor. More...

virtual int	nArgs () const
	return number of arguments (when applicable, that is, with N-ary functions) More...

virtual expression **	ArgList () const
	return arglist (when applicable, that is, with N-ary functions) More...

virtual void	ArgList (expression **al)
	set arglist (used in deleting nodes without deleting children) More...

virtual expression *	Argument () const
	return argument (when applicable, i.e., with univariate functions) More...

virtual expression **	ArgPtr ()
	return pointer to argument (when applicable, i.e., with univariate functions) More...

virtual CouNumber	Value () const
	value (empty) More...

virtual const expression *	Original () const
	If this is an exprClone of a exprClone of an expr???, point to the original expr??? instead of an exprClone – improve computing efficiency. More...

virtual int	dependsOn (int *ind, int n, enum dig_type type=STOP_AT_AUX)
	dependence on variable set: return cardinality of subset of the set of indices in first argument which occur in expression. More...

int	dependsOn (int singleton, enum dig_type type=STOP_AT_AUX)
	version with one index only More...

virtual exprAux *	standardize (CouenneProblem *p, bool addAux=true)
	Create standard form of this expression, by: More...

virtual int	compare (expression &)
	compare expressions More...

virtual int	compare (exprCopy &)
	compare copies of expressions More...

virtual CouNumber	selectBranch (const CouenneObject obj, const OsiBranchingInformation info, expression &var, double &brpts, double *&brDist, int &way)
	set up branching object by evaluating many branching points for each expression's arguments. More...

virtual void	replace (exprVar , exprVar )
	replace expression with another More...

virtual void	realign (const CouenneProblem *p)
	empty function to redirect variables to proper variable vector More...

virtual bool	isBijective () const
	indicating if function is monotonically increasing More...

virtual CouNumber	inverse (expression *vardep) const
	compute the inverse function More...

virtual void	closestFeasible (expression varind, expression vardep, CouNumber &left, CouNumber &right) const
	closest feasible points in function in both directions More...

virtual bool	isCuttable (CouenneProblem *problem, int index) const
	can this expression be further linearized or are we on its concave ("bad") side More...

virtual bool	isaCopy () const
	return true if this is a copy of something (i.e. an exprCopy) More...

virtual expression *	Copy () const
	return copy of this expression (only makes sense in exprCopy) More...

Protected Attributes
expression *	image_
	The expression associated with this auxiliary variable. More...

expression *	lb_
	lower bound, a function of the associated expression and the bounds on the variables in the expression More...

expression *	ub_
	upper bound, a function of the associated expression and the bounds on the variables in the expression More...

int	rank_
	used in rank-based branching variable choice: original variables have rank 1; auxiliary w=f(x) has rank r(w) = r(x)+1; finally, auxiliary w=f(x1,x2...,xk) has rank r(w) = 1+max{r(xi):i=1..k}. More...

int	multiplicity_
	number of appearances of this aux in the formulation. More...

enum intType	integer_
	is this variable integer? More...

bool	top_level_
	True if this variable replaces the lhs of a constraint, i.e., if it is a top level variable in the DAG of the problem. More...

enum auxSign	sign_
	"sign" of the defining constraint More...

Protected Attributes inherited from Couenne::exprVar
int	varIndex_
	The index of the variable. More...

Domain *	domain_
	Pointer to a descriptor of the current point/bounds. More...

Detailed Description

Auxiliary variable.

It is associated with an expression which depends, in general, on original and/or other auxiliary variables. It is used for AMPL's defined variables (aka common expressions) and to reformulate nonlinear constraints/objectives.

Definition at line 32 of file CouenneExprAux.hpp.

Member Enumeration Documentation

enum Couenne::exprAux::intType

integrality type of an auxiliary variable: unset, continuous, integer

Enumerator
Unset
Continuous
Integer

Definition at line 37 of file CouenneExprAux.hpp.

Constructor & Destructor Documentation

Couenne::exprAux::exprAux	(	expression *	,
		int	,
		int	,
		intType	= `Unset`,
		Domain *	= `NULL`,
		enum	auxSign = `expression::AUX_EQ`
	)

Constructor.

Referenced by clone().

Couenne::exprAux::exprAux	(	expression *	,
		Domain *	= `NULL`,
		enum	auxSign = `expression::AUX_EQ`
	)

Constructor to be used with standardize ([...], false)

virtual Couenne::exprAux::~exprAux ( )

virtual

Destructor.

Couenne::exprAux::exprAux	(	const exprAux &	,
		Domain *	d = `NULL`
	)

Copy constructor.

Member Function Documentation

enum nodeType Couenne::exprAux::Type ( ) const

inlinevirtual

Node type.

Reimplemented from Couenne::exprVar.

Definition at line 75 of file CouenneExprAux.hpp.

References Couenne::AUX.

virtual exprVar* Couenne::exprAux::clone ( Domain * d = NULL ) const

inlinevirtual

Cloning method.

Reimplemented from Couenne::exprVar.

Definition at line 91 of file CouenneExprAux.hpp.

References exprAux().

expression* Couenne::exprAux::Lb ( )

inlinevirtual

get lower bound expression

Reimplemented from Couenne::exprVar.

Definition at line 94 of file CouenneExprAux.hpp.

References lb_.

expression* Couenne::exprAux::Ub ( )

inlinevirtual

get upper bound expression

Reimplemented from Couenne::exprVar.

Definition at line 95 of file CouenneExprAux.hpp.

References ub_.

virtual void Couenne::exprAux::print	(	std::ostream &	= `std::cout`,
		bool	= `false`
	)		const

virtual

Print expression.

Reimplemented from Couenne::exprVar.

expression* Couenne::exprAux::Image ( ) const

inlinevirtual

The expression associated with this auxiliary variable.

Reimplemented from Couenne::expression.

Definition at line 102 of file CouenneExprAux.hpp.

References image_.

void Couenne::exprAux::Image ( expression * image )

inlinevirtual

Sets expression associated with this auxiliary variable.

Reimplemented from Couenne::expression.

Definition at line 106 of file CouenneExprAux.hpp.

References image_.

CouNumber Couenne::exprAux::operator() ( )

inlinevirtual

Null function for evaluating the expression.

Reimplemented from Couenne::exprVar.

Definition at line 110 of file CouenneExprAux.hpp.

References Couenne::exprVar::domain_, and Couenne::exprVar::varIndex_.

int Couenne::exprAux::DepList	(	std::set< int > &	deplist,
		enum dig_type	type = `ORIG_ONLY`
	)

virtual

fill in the set with all indices of variables appearing in the expression

Reimplemented from Couenne::exprVar.

expression* Couenne::exprAux::simplify ( )

virtual

simplify

Reimplemented from Couenne::exprVar.

int Couenne::exprAux::Linearity ( )

inlinevirtual

Get a measure of "how linear" the expression is (see CouenneTypes.h)

Reimplemented from Couenne::exprVar.

Definition at line 122 of file CouenneExprAux.hpp.

References Couenne::LINEAR.

void Couenne::exprAux::crossBounds ( )

virtual

Get lower and upper bound of an expression (if any)

set bounds depending on both branching rules and propagated bounds. To be used after standardization

Reimplemented from Couenne::exprVar.

void Couenne::exprAux::generateCuts	(	OsiCuts &	,
		const CouenneCutGenerator *	,
		t_chg_bounds *	= `NULL`,
		int	= `-1`,
		CouNumber	= `-COUENNE_INFINITY`,
		CouNumber	= `COUENNE_INFINITY`
	)

virtual

generate cuts for expression associated with this auxiliary

Reimplemented from Couenne::exprVar.

virtual int Couenne::exprAux::rank ( )

inlinevirtual

used in rank-based branching variable choice

Reimplemented from Couenne::exprVar.

Definition at line 141 of file CouenneExprAux.hpp.

References rank_.

virtual bool Couenne::exprAux::isDefinedInteger ( )

inlinevirtual

is this expression defined as integer?

Reimplemented from Couenne::exprVar.

Definition at line 145 of file CouenneExprAux.hpp.

References Continuous, image_, Integer, integer_, isInteger(), and Unset.

Referenced by isInteger().

virtual bool Couenne::exprAux::isInteger ( )

inlinevirtual

is this expression integer?

Reimplemented from Couenne::exprVar.

Definition at line 154 of file CouenneExprAux.hpp.

References COUENNE_round, isDefinedInteger(), Couenne::exprVar::lb(), and Couenne::exprVar::ub().

Referenced by isDefinedInteger().

virtual void Couenne::exprAux::setInteger ( bool value )

inlinevirtual

Set this variable as integer.

Reimplemented from Couenne::exprVar.

Definition at line 166 of file CouenneExprAux.hpp.

References Continuous, Integer, and integer_.

void Couenne::exprAux::increaseMult ( )

inline

Tell this variable appears once more.

Definition at line 170 of file CouenneExprAux.hpp.

References multiplicity_.

void Couenne::exprAux::decreaseMult ( )

inlinevirtual

Tell this variable appears once less (standardized within exprSum, for instance)

Reimplemented from Couenne::exprVar.

Definition at line 174 of file CouenneExprAux.hpp.

References multiplicity_.

void Couenne::exprAux::zeroMult ( )

inlinevirtual

Disable this auxiliary variable.

Reimplemented from Couenne::exprVar.

Definition at line 177 of file CouenneExprAux.hpp.

References multiplicity_.

int Couenne::exprAux::Multiplicity ( )

inlinevirtual

How many times this variable appears.

Reimplemented from Couenne::expression.

Definition at line 180 of file CouenneExprAux.hpp.

References multiplicity_.

void Couenne::exprAux::linkDomain ( Domain * d )

inlinevirtual

link this variable to a domain

Reimplemented from Couenne::exprVar.

Definition at line 183 of file CouenneExprAux.hpp.

References Couenne::exprVar::domain_, lb_, and ub_.

bool& Couenne::exprAux::top_level ( )

inline

return top_level_

Definition at line 190 of file CouenneExprAux.hpp.

References top_level_.

CouenneObject* Couenne::exprAux::properObject	(	CouenneCutGenerator *	c,
		CouenneProblem *	p,
		Bonmin::BabSetupBase *	base,
		JnlstPtr	jnlst
	)

virtual

return proper object to handle expression associated with this variable (NULL if this is not an auxiliary)

Reimplemented from Couenne::exprVar.

virtual enum auxSign Couenne::exprAux::sign ( ) const

inlinevirtual

return its sign in the definition constraint

Reimplemented from Couenne::exprVar.

Definition at line 201 of file CouenneExprAux.hpp.

References sign_.

Member Data Documentation

expression* Couenne::exprAux::image_

protected

The expression associated with this auxiliary variable.

Definition at line 42 of file CouenneExprAux.hpp.

Referenced by Image(), and isDefinedInteger().

expression* Couenne::exprAux::lb_

protected

lower bound, a function of the associated expression and the bounds on the variables in the expression

Definition at line 46 of file CouenneExprAux.hpp.

Referenced by Lb(), and linkDomain().

expression* Couenne::exprAux::ub_

protected

upper bound, a function of the associated expression and the bounds on the variables in the expression

Definition at line 50 of file CouenneExprAux.hpp.

Referenced by linkDomain(), and Ub().

int Couenne::exprAux::rank_

protected

used in rank-based branching variable choice: original variables have rank 1; auxiliary w=f(x) has rank r(w) = r(x)+1; finally, auxiliary w=f(x1,x2...,xk) has rank r(w) = 1+max{r(xi):i=1..k}.

Definition at line 55 of file CouenneExprAux.hpp.

Referenced by rank().

int Couenne::exprAux::multiplicity_

protected

number of appearances of this aux in the formulation.

The more times it occurs in the formulation, the more implication its branching has on other variables

Definition at line 60 of file CouenneExprAux.hpp.

Referenced by decreaseMult(), increaseMult(), Multiplicity(), and zeroMult().

enum intType Couenne::exprAux::integer_

protected

is this variable integer?

Definition at line 63 of file CouenneExprAux.hpp.

Referenced by isDefinedInteger(), and setInteger().

bool Couenne::exprAux::top_level_

protected

True if this variable replaces the lhs of a constraint, i.e., if it is a top level variable in the DAG of the problem.

Definition at line 67 of file CouenneExprAux.hpp.

Referenced by top_level().

enum auxSign Couenne::exprAux::sign_

protected

"sign" of the defining constraint

Definition at line 70 of file CouenneExprAux.hpp.

Referenced by sign().

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

CouenneExprAux.hpp

Public Types

Public Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation