Branching object for cliques. More...

#include <CbcClique.hpp>

Inheritance diagram for CbcClique:

Collaboration diagram for CbcClique:

Public Member Functions
	CbcClique ()
	Default Constructor.
	CbcClique (CbcModel model, int cliqueType, int numberMembers, const int which, const char *type, int identifier, int slack=-1)
	Useful constructor (which are integer indices) slack can denote a slack in set.
	CbcClique (const CbcClique &)
	Copy constructor.
virtual CbcObject *	clone () const
	Clone.
CbcClique &	operator= (const CbcClique &rhs)
	Assignment operator.
virtual	~CbcClique ()
	Destructor.
virtual double	infeasibility (const OsiBranchingInformation *info, int &preferredWay) const
	Infeasibility - large is 0.5.
virtual void	feasibleRegion ()
	This looks at solution and sets bounds to contain solution.
virtual CbcBranchingObject *	createCbcBranch (OsiSolverInterface solver, const OsiBranchingInformation info, int way)
	Creates a branching object.
int	numberMembers () const
	Number of members.
int	numberNonSOSMembers () const
	Number of variables with -1 coefficient.
const int *	members () const
	Members (indices in range 0 ... numberIntegers_-1).
char	type (int index) const
	Type of each member, i.e., which way is strong.
int	cliqueType () const
	Clique type: 0 is <=, 1 is ==.
virtual void	redoSequenceEtc (CbcModel model, int numberColumns, const int originalColumns)
	Redoes data when sequence numbers change.

Protected Attributes
int	numberMembers_
	data Number of members
int	numberNonSOSMembers_
	Number of Non SOS members i.e. fixing to zero is strong.
int *	members_
	Members (indices in range 0 ... numberIntegers_-1).
char *	type_
	Strong value for each member.
int	cliqueType_
	Clique type.
int	slack_
	Slack variable for the clique.

Detailed Description

Branching object for cliques.

A clique is defined to be a set of binary variables where fixing any one variable to its `strong' value fixes all other variables. An example is the most common SOS1 construction: a set of binary variables x_j s.t. SUM{j} x_j = 1. Setting any one variable to 1 forces all other variables to 0. (See comments for CbcSOS below.)

Other configurations are possible, however: Consider x1-x2+x3 <= 0. Setting x1 (x3) to 1 forces x2 to 1 and x3 (x1) to 0. Setting x2 to 0 forces x1 and x3 to 0.

The proper point of view to take when interpreting CbcClique is `generalisation of SOS1 on binary variables.' To get into the proper frame of mind, here's an example.

Consider the following sequence, where x_j = (1-y_j):

   x1 + x2 + x3 <=  1           all strong at 1
   x1 - y2 + x3 <=  0           y2 strong at 0; x1, x3 strong at 1
  -y1 - y2 + x3 <= -1           y1, y2 strong at 0, x3 strong at 1
  -y1 - y2 - y3 <= -2           all strong at 0

The first line is a standard SOS1 on binary variables.

Variables with +1 coefficients are SOS-style' and variables with -1 coefficients are non-SOS-style'. So numberNonSOSMembers_ simply tells you how many variables have -1 coefficients. The implicit rhs for a clique is 1-numberNonSOSMembers_.

Definition at line 41 of file CbcClique.hpp.

Constructor & Destructor Documentation

◆ CbcClique() [1/3]

CbcClique::CbcClique ( )

Default Constructor.

◆ CbcClique() [2/3]

CbcClique::CbcClique	(	CbcModel *	model,
		int	cliqueType,
		int	numberMembers,
		const int *	which,
		const char *	type,
		int	identifier,
		int	slack = -1 )

Useful constructor (which are integer indices) slack can denote a slack in set.

If type == NULL then as if 1

◆ CbcClique() [3/3]

CbcClique::CbcClique ( const CbcClique & )

Copy constructor.

◆ ~CbcClique()

virtual CbcClique::~CbcClique ( )

virtual

Destructor.

Member Function Documentation

◆ clone()

virtual CbcObject * CbcClique::clone ( ) const

virtual

Clone.

◆ operator=()

CbcClique & CbcClique::operator= ( const CbcClique & rhs )

Assignment operator.

◆ infeasibility()

virtual double CbcClique::infeasibility	(	const OsiBranchingInformation *	info,
		int &	preferredWay ) const

virtual

Infeasibility - large is 0.5.

◆ feasibleRegion()

virtual void CbcClique::feasibleRegion ( )

virtual

This looks at solution and sets bounds to contain solution.

◆ createCbcBranch()

virtual CbcBranchingObject * CbcClique::createCbcBranch	(	OsiSolverInterface *	solver,
		const OsiBranchingInformation *	info,
		int	way )

virtual

Creates a branching object.

◆ numberMembers()

int CbcClique::numberMembers ( ) const

inline

Number of members.

Definition at line 77 of file CbcClique.hpp.

◆ numberNonSOSMembers()

int CbcClique::numberNonSOSMembers ( ) const

inline

Number of variables with -1 coefficient.

Number of non-SOS members, i.e., fixing to zero is strong. See comments at head of class, and comments for type_.

Definition at line 86 of file CbcClique.hpp.

◆ members()

const int * CbcClique::members ( ) const

inline

Members (indices in range 0 ... numberIntegers_-1).

Definition at line 92 of file CbcClique.hpp.

◆ type()

char CbcClique::type ( int index ) const

inline

Type of each member, i.e., which way is strong.

This also specifies whether a variable has a +1 or -1 coefficient.

0 => -1 coefficient, 0 is strong value
1 => +1 coefficient, 1 is strong value If unspecified, all coefficients are assumed to be positive.

Indexed as 0 .. numberMembers_-1

Definition at line 106 of file CbcClique.hpp.

◆ cliqueType()

int CbcClique::cliqueType ( ) const

inline

Clique type: 0 is <=, 1 is ==.

Definition at line 115 of file CbcClique.hpp.

◆ redoSequenceEtc()

virtual void CbcClique::redoSequenceEtc	(	CbcModel *	model,
		int	numberColumns,
		const int *	originalColumns )

virtual

Redoes data when sequence numbers change.

Member Data Documentation

◆ numberMembers_

int CbcClique::numberMembers_

protected

data Number of members

Definition at line 125 of file CbcClique.hpp.

◆ numberNonSOSMembers_

int CbcClique::numberNonSOSMembers_

protected

Number of Non SOS members i.e. fixing to zero is strong.

Definition at line 128 of file CbcClique.hpp.

◆ members_

int* CbcClique::members_

protected

Members (indices in range 0 ... numberIntegers_-1).

Definition at line 131 of file CbcClique.hpp.

◆ type_

char* CbcClique::type_

protected

Strong value for each member.

This also specifies whether a variable has a +1 or -1 coefficient.

0 => -1 coefficient, 0 is strong value
1 => +1 coefficient, 1 is strong value If unspecified, all coefficients are assumed to be positive.

Indexed as 0 .. numberMembers_-1

Definition at line 142 of file CbcClique.hpp.

◆ cliqueType_

int CbcClique::cliqueType_

protected

Clique type.

0 defines a <= relation, 1 an equality. The assumed value of the rhs is numberNonSOSMembers_+1. (See comments for the class.)

Definition at line 149 of file CbcClique.hpp.

◆ slack_

int CbcClique::slack_

protected

Slack variable for the clique.

Identifies the slack variable for the clique (typically added to convert a <= relation to an equality). Value is sequence number within clique menbers.

Definition at line 157 of file CbcClique.hpp.

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

/builddir/build/BUILD/coin-or-Cbc-2.10.12-build/Cbc-releases-2.10.12/Cbc/src/CbcClique.hpp

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ CbcClique() [1/3]

◆ CbcClique() [2/3]

◆ CbcClique() [3/3]

◆ ~CbcClique()

Member Function Documentation

◆ clone()

◆ operator=()

◆ infeasibility()

◆ feasibleRegion()

◆ createCbcBranch()

◆ numberMembers()

◆ numberNonSOSMembers()

◆ members()

◆ type()

◆ cliqueType()

◆ redoSequenceEtc()

Member Data Documentation

◆ numberMembers_

◆ numberNonSOSMembers_

◆ members_

◆ type_

◆ cliqueType_

◆ slack_