AbcBranchDefaultDecision Class Reference

Branching decision default class. More...

#include <AbcBranchActual.h>

Inheritance diagram for AbcBranchDefaultDecision:

[legend]

Collaboration diagram for AbcBranchDefaultDecision:

[legend]

List of all members.

Public Member Functions
	AbcBranchDefaultDecision ()
	AbcBranchDefaultDecision (const AbcBranchDefaultDecision &)
virtual	~AbcBranchDefaultDecision ()
virtual AbcBranchDecision *	clone () const
	Clone.
virtual void	initialize (AbcModel *model)
	Initialize, e.g. before the start of branch selection at a node.
virtual int	betterBranch (int thisOne, int bestSoFar, double changeUp, int numInfUp, double changeDn, int numInfDn)
	Compare two branching objects.
Private Member Functions
AbcBranchDefaultDecision &	operator= (const AbcBranchDefaultDecision &rhs)
	Illegal Assignment operator.
Private Attributes
AbcModel *	model_
	data Point to the model
double	bestCriterion_
	"best" so far
double	bestChangeUp_
	Change up for best.
int	bestNumberUp_
	Number of infeasibilities for up.
double	bestChangeDown_
	Change down for best.
int	bestNumberDown_
	Number of infeasibilities for down.
int	bestObject_
	Index of the best branching integer variable.

Detailed Description

Branching decision default class.

This class implements a simple default algorithm (betterBranch()) for choosing a branching variable.

Definition at line 38 of file AbcBranchActual.h.

Constructor & Destructor Documentation

AbcBranchDefaultDecision::AbcBranchDefaultDecision ( )

AbcBranchDefaultDecision::AbcBranchDefaultDecision ( const AbcBranchDefaultDecision & )

virtual AbcBranchDefaultDecision::~AbcBranchDefaultDecision ( ) [virtual]

Member Function Documentation

virtual AbcBranchDecision* AbcBranchDefaultDecision::clone ( ) const [virtual]

Clone.

Implements AbcBranchDecision.

virtual void AbcBranchDefaultDecision::initialize ( AbcModel * model ) [virtual]

Initialize, e.g. before the start of branch selection at a node.

Implements AbcBranchDecision.

virtual int AbcBranchDefaultDecision::betterBranch	(	int	thisOne,
		int	bestSoFar,
		double	changeUp,
		int	numInfUp,
		double	changeDn,
		int	numInfDn
	)			`[virtual]`

Compare two branching objects.

Return nonzero if thisOne is better than bestSoFar.

The routine compares branches using the values supplied in numInfUp and numInfDn until a solution is found by search, after which it uses the values supplied in changeUp and changeDn. The best branching object seen so far and the associated parameter values are remembered in the AbcBranchDefaultDecision object. The nonzero return value is +1 if the up branch is preferred, -1 if the down branch is preferred.

As the names imply, the assumption is that the values supplied for numInfUp and numInfDn will be the number of infeasibilities reported by the branching object, and changeUp and changeDn will be the estimated change in objective. Other measures can be used if desired.

Because an AbcBranchDefaultDecision object remembers the current best branching candidate (bestObject_) as well as the values used in the comparison, the parameter bestSoFar is redundant, hence unused.

Implements AbcBranchDecision.

AbcBranchDefaultDecision& AbcBranchDefaultDecision::operator= ( const AbcBranchDefaultDecision & rhs ) [private]