CutPool Class Reference

A Cut management system. More...

#include <cuts.h>

Classes
class	CutInfo
	Class for communication between CutPool and LinearRelax. More...
Public Types
enum	CutType { SIMPLE, LINEARIZATION, INTERVALGRADIENT }
Public Member Functions
	CutPool (int inactivetime_limit_global_=10, int inactivetime_limit_local_=3)
	CutPool (const CutPool &cutpool, Pointer< MinlpNode > node=NULL)
	A copy of a given cutpool, containing only these cuts, which are defined for a specific node, or are global.
CutInfo	add_cut (Pointer< SimpleCut >, Pointer< MinlpNode > node, int blocknr=-1)
	Adds a cut to the pool.
CutInfo	add_cut (Pointer< IntervalGradientCut > intgradcut, Pointer< MinlpNode > node, int blocknr)
	Adds a IntervalGradientCut to the pool.
CutInfo	add_cut (Pointer< LinearizationCut > linearizationcut, Pointer< MinlpNode > node, int blocknr)
	Adds a LinearizationCut to the pool.
void	integrate (const CutPool &cutpool, Pointer< MinlpNode > node=NULL)
	Adds the untagged cuts of a cutpool to this one.
void	duplicate_nodeinfo (Pointer< MinlpNode > oldnode, Pointer< MinlpNode > newnode)
void	remove_node (Pointer< MinlpNode > node)
void	update_nodeinfo (list< CutInfo > &cutinfos, int block_nr, Pointer< MinlpNode > node)
	Updates the information, which cuts were inactive.
void	get_cuts (list< CutInfo > &cutinfos, int blocknr, Pointer< MinlpNode > node=NULL)
	Builds a list of CutInfo's to point to these cuts, which belong to a given node.
void	update_cuts (Pointer< MinlpNode > node, int blocknr, const dvector &low, const dvector &up, IntervalGradientCutGenerator &generator, LinearizedConCutGenerator &linconcutgen)
	Updates the IntervalGradientCuts of a specific node after the bounds changed.
bool	feasible (Pointer< MinlpNode > node, const dvector &x, double tol=1E-4) const
	Checks, whether a point is feasible for the cuts.
int	nr_local_cuts (Pointer< MinlpNode > node) const
	The number of local cuts for a specific node.
int	nr_global_cuts () const
	The number of global cuts.
int	nr_all_cuts () const
	The complete number of cuts, all local cuts plus the global ones.
Private Attributes
list< Cut< SimpleCut > >	simplecuts
	Cuts which are defined by a seperating hyperplane.
list< Cut< LinearizationCut > >	linearizationcuts
	Cuts also defined by a seperating hyperplane.
list< Cut< IntervalGradientCut > >	intgradcuts
	IntervalGradientCuts.
int	cuts_size
	The number of cuts in this CutPool.
int	inactivetime_limit_global
int	inactivetime_limit_local

Detailed Description

A Cut management system.

Parameters:

Cut

inactive time limit options integer defaults 10 level 2 Determines, after how many consecutive (R)-solves, in which a cut was inactive, will be removed. 0 means no removals. Affects only cuts which are not specific for a node (global). So called local cuts are removed (from their node) as soon as they become inactive.

Definition at line 235 of file cuts.h.

Member Enumeration Documentation

enum CutPool::CutType

Enumerator:

SIMPLE
LINEARIZATION
INTERVALGRADIENT

Definition at line 258 of file cuts.h.

Constructor & Destructor Documentation

CutPool::CutPool	(	int	inactivetime_limit_global_ = `10`,
		int	inactivetime_limit_local_ = `3`
	)			`[inline]`

Definition at line 315 of file cuts.h.

CutPool::CutPool	(	const CutPool &	cutpool,
		Pointer< MinlpNode >	node = `NULL`
	)

A copy of a given cutpool, containing only these cuts, which are defined for a specific node, or are global.

Member Function Documentation

CutInfo CutPool::add_cut	(	Pointer< SimpleCut >	,
		Pointer< MinlpNode >	node,
		int	blocknr = `-1`
	)

Adds a cut to the pool.

Parameters:

	cut	The cut to add.
	node	For local cuts, put the node, the cut belongs to, here. For global cuts, put NULL here.
	blocknr	The block number to put into the CutInfo. -1 for cuts that couple several blocks.

Returns:: cutinfo A CutInfo for the new cut.

CutInfo CutPool::add_cut	(	Pointer< IntervalGradientCut >	intgradcut,
		Pointer< MinlpNode >	node,
		int	blocknr
	)

Adds a IntervalGradientCut to the pool.

Parameters:

	cut	The cut to add.
	node	For local cuts, put the node, the cut belongs to, here. For global cuts, put NULL here.
	blocknr	The block number to put in the CutInfo.

Returns:: cutinfo A CutInfo for the new cut.

CutInfo CutPool::add_cut	(	Pointer< LinearizationCut >	linearizationcut,
		Pointer< MinlpNode >	node,
		int	blocknr
	)

Adds a LinearizationCut to the pool.

void CutPool::integrate	(	const CutPool &	cutpool,
		Pointer< MinlpNode >	node = `NULL`
	)

Adds the untagged cuts of a cutpool to this one.

Parameters:

	cutpool	The cuts to add.
	node	The node, which should use these cuts. Or NULL, if intended as global cuts.

void CutPool::duplicate_nodeinfo	(	Pointer< MinlpNode >	oldnode,
		Pointer< MinlpNode >	newnode
	)

void CutPool::remove_node ( Pointer< MinlpNode > node )

void CutPool::update_nodeinfo	(	list< CutInfo > &	cutinfos,
		int	block_nr,
		Pointer< MinlpNode >	node
	)

Updates the information, which cuts were inactive.

If a cut is not needed anymore, it's removed from the cutlist.

Parameters:

	cutinfos	On input, info about the inactivity of the cuts. On output, info about which cuts are invalid for the node now.
	block_nr	Only CutInfo's with this block number are checked.

void CutPool::get_cuts	(	list< CutInfo > &	cutinfos,
		int	blocknr,
		Pointer< MinlpNode >	node = `NULL`
	)

Builds a list of CutInfo's to point to these cuts, which belong to a given node.

This method is used for the communication between the CutPool and the LinearRelaxSolver about inactivity of cuts. A list, where we can push back the CutInfos. The number of the block to put into the CutInfos. Give -1 for coupling cuts.

void CutPool::update_cuts	(	Pointer< MinlpNode >	node,
		int	blocknr,
		const dvector &	low,
		const dvector &	up,
		IntervalGradientCutGenerator &	generator,
		LinearizedConCutGenerator &	linconcutgen
	)