This class chooses a variable to branch on. More...

#include <BonChooseVariable.hpp>

Inheritance diagram for Bonmin::BonChooseVariable:

Classes
class	Messages

Public Types
enum	DoStrongReturnStatuses { provenInfeasible = -1, doneNoFixing, doneCanFix, interuptedCanFix, maxTime }

enum	chooseVariableReturnStatuses { infeasibleNode = -1, hasCandidate, feasibleNode, canFixAndStrongBranch, canFixAndBranch, canFixNoCandidate }
	Return statuses for chooseVariable. More...

Public Member Functions
	BonChooseVariable (BabSetupBase &b, const OsiSolverInterface *solver)
	Constructor from solver (so we can set up arrays etc) More...

	BonChooseVariable (const BonChooseVariable &)
	Copy constructor. More...

BonChooseVariable &	operator= (const BonChooseVariable &rhs)
	Assignment operator. More...

virtual OsiChooseVariable *	clone () const
	Clone. More...

virtual	~BonChooseVariable ()
	Destructor. More...

double	maxminCrit (const OsiBranchingInformation *info) const
	Helper functions for setupList and chooseVariable. More...

void	computeMultipliers (double &upMult, double &downMult) const

double	computeUsefulness (const double MAXMIN_CRITERION, const double upMult, const double dowMult, const double value, const OsiObject *object, int i, double &value2) const

virtual int	setupList (OsiBranchingInformation *info, bool initialize)
	Sets up strong list and clears all if initialize is true. More...

virtual int	chooseVariable (OsiSolverInterface solver, OsiBranchingInformation info, bool fixVariables)
	Choose a variable Returns - -1 Node is infeasible 0 Normal termination - we have a candidate 1 All looks satisfied - no candidate 2 We can change the bound on a variable - but we also have a strong branching candidate 3 We can change the bound on a variable - but we have a non-strong branching candidate 4 We can change the bound on a variable - no other candidates We can pick up branch from bestObjectIndex() and bestWhichWay() We can pick up a forced branch (can change bound) from firstForcedObjectIndex() and firstForcedWhichWay() If we have a solution then we can pick up from goodObjectiveValue() and goodSolution() If fixVariables is true then 2,3,4 are all really same as problem changed. More...

virtual void	updateInformation (const OsiBranchingInformation info, int branch, OsiHotInfo hotInfo)
	This is a utility function which does strong branching on a list of objects and stores the results in OsiHotInfo.objects. More...

virtual void	updateInformation (int whichObject, int branch, double changeInObjective, double changeInValue, int status)
	Given a branch fill in useful information e.g. estimates. More...

void	setCbcModel (CbcModel *cbc_model)
	Method for setting CbcModel, which is used to get statusOfSearch. More...

void	setOnlyPseudoWhenTrusted (bool only_pseudo_when_trusted)

const OsiPseudoCosts &	pseudoCosts () const
	Access to pseudo costs storage. More...

OsiPseudoCosts &	pseudoCosts ()
	Access to pseudo costs storage. More...

Static Public Member Functions
static void	registerOptions (Ipopt::SmartPtr< Bonmin::RegisteredOptions > roptions)

Protected Types
enum	StrongStatus { NotDone =-1, Feasible, Infeasible, NotFinished }
	Statuses for strong branching candidates. More...

Protected Member Functions
virtual int	doStrongBranching (OsiSolverInterface solver, OsiBranchingInformation info, int numberToDo, int returnCriterion)
	This is a utility function which does strong branching on a list of objects and stores the results in OsiHotInfo.objects. More...

int	determineStatus (OsiSolverInterface *solver) const
	Determine status of strong branching solution. More...

bool	isRootNode (const OsiBranchingInformation *info) const
	detecting if this is root node More...

Protected Attributes
Ipopt::SmartPtr < Ipopt::Journalist >	jnlst_
	Holding on the a pointer to the journalist. More...

int	bb_log_level_
	verbosity level More...

vector< HotInfo >	results_
	Stores strong branching results. More...

CbcModel *	cbc_model_
	CbcModel, used to get status of search. More...

bool	only_pseudo_when_trusted_
	Flag indicating whether we don't want to mix strong branching and pseudo costs during the decision which variable to branch on. More...

int	number_not_trusted_
	Number of variables put into the list because there were not trusted. More...

CoinMessageHandler *	handler_
	Message handler. More...

Messages	messages_
	Messages. More...

Algoirithmic options
double	maxmin_crit_no_sol_
	maxmin weight in branching decision when no solution has been found yet More...

double	maxmin_crit_have_sol_
	maxmin weight in branching decision when no solution has been found yet More...

double	setup_pseudo_frac_
	fraction of branching candidates that are not trusted yet More...

int	numberBeforeTrustedList_
	number of times a branch has to happen so that it is trusted in setupList More...

int	numberStrongRoot_
	number of strong branching points at root node More...

int	numberStrongBackup_
	backup of numberStrong_ before Root node solve More...

int	numberLookAhead_
	number of look-ahead strong-branching steps More...

int	minNumberStrongBranch_
	Always strong branch that many first candidate in the list regardless of numberTrusted. More...

OsiPseudoCosts	pseudoCosts_
	Stores the pseudo costs. More...

int	trustStrongForPseudoCosts_
	Wether or not to trust strong branching results for updating pseudo costs. More...

Static Protected Attributes
static const std::string	CNAME
	Stores the class name for throwing errors. More...

Private Member Functions
	BonChooseVariable ()
	Default Constructor, forbiden for some reason. More...

Private Attributes
double	time_limit_
	Global time limit for algorithm. More...

double	start_time_
	Starting time of algorithm. More...

Message handling.
enum	Messages_Types { PS_COST_HISTORY = 0, PS_COST_MULT, PS_COST_ESTIMATES, CANDIDATE_LIST, CANDIDATE_LIST2, CANDIDATE_LIST3, SB_START, SB_HEADER, SB_RES, BRANCH_VAR, CHOSEN_VAR, UPDATE_PS_COST, BON_CHOOSE_MESSAGES_DUMMY_END }

void	passInMessageHandler (CoinMessageHandler *handler)

CoinMessageHandler &	message (Messages_Types type) const

Detailed Description

This class chooses a variable to branch on.

This is the base class for the branching rules in Bonmin (inherits from OsiChooseVariable). This class implements a simple strong branching algorithm where the changes in the objective value induced by branching on a specific object are estimated with the pure virtual function fill_changes.

Definition at line 81 of file BonChooseVariable.hpp.

Member Enumeration Documentation

enum Bonmin::BonChooseVariable::StrongStatus

protected

Statuses for strong branching candidates.

Enumerator
NotDone
Feasible	Child is proven feasible.
Infeasible	Child is proven infeasible.
NotFinished	Child is not finished.

Definition at line 109 of file BonChooseVariable.hpp.

enum Bonmin::BonChooseVariable::Messages_Types

Enumerator
PS_COST_HISTORY
PS_COST_MULT
PS_COST_ESTIMATES
CANDIDATE_LIST
CANDIDATE_LIST2
CANDIDATE_LIST3
SB_START
SB_HEADER
SB_RES
BRANCH_VAR
CHOSEN_VAR
UPDATE_PS_COST
BON_CHOOSE_MESSAGES_DUMMY_END

Definition at line 117 of file BonChooseVariable.hpp.

enum Bonmin::BonChooseVariable::DoStrongReturnStatuses

Enumerator
provenInfeasible
doneNoFixing	All done no variable can be fixed.
doneCanFix	Several variable can be fixed.
interuptedCanFix	Interupted and found a variable to fix.
maxTime	Interupted because of time limit.

Definition at line 153 of file BonChooseVariable.hpp.

enum Bonmin::BonChooseVariable::chooseVariableReturnStatuses

Return statuses for chooseVariable.

Enumerator
infeasibleNode
hasCandidate	Normal termination, found a variable to branch on.
feasibleNode	All variable are feasible, the node is feasible.
canFixAndStrongBranch	Found variable to fix and also has remaining candidate for strong branching.
canFixAndBranch	Found variable to fix and also has a (non-strong) branching candidate.
canFixNoCandidate	Can fix variables but does not have strong branching candidates.

Definition at line 161 of file BonChooseVariable.hpp.

Constructor & Destructor Documentation

Bonmin::BonChooseVariable::BonChooseVariable	(	BabSetupBase &	b,
		const OsiSolverInterface *	solver
	)

Constructor from solver (so we can set up arrays etc)

Bonmin::BonChooseVariable::BonChooseVariable ( const BonChooseVariable & )

Copy constructor.

virtual Bonmin::BonChooseVariable::~BonChooseVariable ( )

virtual

Destructor.

Bonmin::BonChooseVariable::BonChooseVariable ( )

private

Default Constructor, forbiden for some reason.

Member Function Documentation

virtual int Bonmin::BonChooseVariable::doStrongBranching	(	OsiSolverInterface *	solver,
		OsiBranchingInformation *	info,
		int	numberToDo,
		int	returnCriterion
	)

protectedvirtual

This is a utility function which does strong branching on a list of objects and stores the results in OsiHotInfo.objects.

On entry the object sequence is stored in the OsiHotInfo object and maybe more. It returns - -1 - one branch was infeasible both ways 0 - all inspected - nothing can be fixed 1 - all inspected - some can be fixed (returnCriterion==0) 2 - may be returning early - one can be fixed (last one done) (returnCriterion==1) 3 - returning because max time

void Bonmin::BonChooseVariable::passInMessageHandler ( CoinMessageHandler * handler )

inline

Definition at line 139 of file BonChooseVariable.hpp.

References handler_.

CoinMessageHandler& Bonmin::BonChooseVariable::message ( Messages_Types type ) const

inline

Definition at line 146 of file BonChooseVariable.hpp.

References handler_, and messages_.

BonChooseVariable& Bonmin::BonChooseVariable::operator= ( const BonChooseVariable & rhs )

Assignment operator.

virtual OsiChooseVariable* Bonmin::BonChooseVariable::clone ( ) const

virtual

Clone.

static void Bonmin::BonChooseVariable::registerOptions ( Ipopt::SmartPtr< Bonmin::RegisteredOptions > roptions )

static

double Bonmin::BonChooseVariable::maxminCrit ( const OsiBranchingInformation * info ) const

Helper functions for setupList and chooseVariable.

void Bonmin::BonChooseVariable::computeMultipliers	(	double &	upMult,
		double &	downMult
	)		const

double Bonmin::BonChooseVariable::computeUsefulness	(	const double	MAXMIN_CRITERION,
		const double	upMult,
		const double	dowMult,
		const double	value,
		const OsiObject *	object,
		int	i,
		double &	value2
	)		const

virtual int Bonmin::BonChooseVariable::setupList	(	OsiBranchingInformation *	info,
		bool	initialize
	)

virtual

Sets up strong list and clears all if initialize is true.

Returns number of infeasibilities.

virtual int Bonmin::BonChooseVariable::chooseVariable	(	OsiSolverInterface *	solver,
		OsiBranchingInformation *	info,
		bool	fixVariables
	)

virtual

Choose a variable Returns - -1 Node is infeasible 0 Normal termination - we have a candidate 1 All looks satisfied - no candidate 2 We can change the bound on a variable - but we also have a strong branching candidate 3 We can change the bound on a variable - but we have a non-strong branching candidate 4 We can change the bound on a variable - no other candidates We can pick up branch from bestObjectIndex() and bestWhichWay() We can pick up a forced branch (can change bound) from firstForcedObjectIndex() and firstForcedWhichWay() If we have a solution then we can pick up from goodObjectiveValue() and goodSolution() If fixVariables is true then 2,3,4 are all really same as problem changed.

virtual void Bonmin::BonChooseVariable::updateInformation	(	const OsiBranchingInformation *	info,
		int	branch,
		OsiHotInfo *	hotInfo
	)

virtual

This is a utility function which does strong branching on a list of objects and stores the results in OsiHotInfo.objects.

On entry the object sequence is stored in the OsiHotInfo object and maybe more. It returns - -1 - one branch was infeasible both ways 0 - all inspected - nothing can be fixed 1 - all inspected - some can be fixed (returnCriterion==0) 2 - may be returning early - one can be fixed (last one done) (returnCriterion==1) 3 - returning because max timeGiven a candidate fill in useful information e.g. estimates

virtual void Bonmin::BonChooseVariable::updateInformation	(	int	whichObject,
		int	branch,
		double	changeInObjective,
		double	changeInValue,
		int	status
	)

virtual

Given a branch fill in useful information e.g. estimates.

void Bonmin::BonChooseVariable::setCbcModel ( CbcModel * cbc_model )

inline

Method for setting CbcModel, which is used to get statusOfSearch.

Definition at line 237 of file BonChooseVariable.hpp.

References cbc_model_.

void Bonmin::BonChooseVariable::setOnlyPseudoWhenTrusted ( bool only_pseudo_when_trusted )

inline

Definition at line 242 of file BonChooseVariable.hpp.

References only_pseudo_when_trusted_.

const OsiPseudoCosts& Bonmin::BonChooseVariable::pseudoCosts ( ) const

inline

Access to pseudo costs storage.

Definition at line 249 of file BonChooseVariable.hpp.

References pseudoCosts_.

OsiPseudoCosts& Bonmin::BonChooseVariable::pseudoCosts ( )

inline

Access to pseudo costs storage.

Definition at line 253 of file BonChooseVariable.hpp.

References pseudoCosts_.

int Bonmin::BonChooseVariable::determineStatus ( OsiSolverInterface * solver ) const

inlineprotected

Determine status of strong branching solution.

Definition at line 267 of file BonChooseVariable.hpp.

bool Bonmin::BonChooseVariable::isRootNode ( const OsiBranchingInformation * info ) const

protected

detecting if this is root node

Member Data Documentation

Ipopt::SmartPtr<Ipopt::Journalist> Bonmin::BonChooseVariable::jnlst_

protected

Holding on the a pointer to the journalist.

Definition at line 258 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::bb_log_level_

protected

verbosity level

Definition at line 261 of file BonChooseVariable.hpp.

vector<HotInfo> Bonmin::BonChooseVariable::results_

protected

Stores strong branching results.

Definition at line 264 of file BonChooseVariable.hpp.

double Bonmin::BonChooseVariable::time_limit_

private

Global time limit for algorithm.

Definition at line 282 of file BonChooseVariable.hpp.

double Bonmin::BonChooseVariable::start_time_

private

Starting time of algorithm.

Definition at line 285 of file BonChooseVariable.hpp.

CbcModel* Bonmin::BonChooseVariable::cbc_model_

protected

CbcModel, used to get status of search.

Definition at line 288 of file BonChooseVariable.hpp.

Referenced by setCbcModel().

bool Bonmin::BonChooseVariable::only_pseudo_when_trusted_

protected

Flag indicating whether we don't want to mix strong branching and pseudo costs during the decision which variable to branch on.

Definition at line 293 of file BonChooseVariable.hpp.

Referenced by setOnlyPseudoWhenTrusted().

int Bonmin::BonChooseVariable::number_not_trusted_

protected

Number of variables put into the list because there were not trusted.

Definition at line 297 of file BonChooseVariable.hpp.

CoinMessageHandler* Bonmin::BonChooseVariable::handler_

protected

Message handler.

Definition at line 300 of file BonChooseVariable.hpp.

Referenced by message(), and passInMessageHandler().

Messages Bonmin::BonChooseVariable::messages_

protected

Messages.

Definition at line 303 of file BonChooseVariable.hpp.

Referenced by message().

double Bonmin::BonChooseVariable::maxmin_crit_no_sol_

protected

maxmin weight in branching decision when no solution has been found yet

Definition at line 309 of file BonChooseVariable.hpp.

double Bonmin::BonChooseVariable::maxmin_crit_have_sol_

protected

maxmin weight in branching decision when no solution has been found yet

Definition at line 312 of file BonChooseVariable.hpp.

double Bonmin::BonChooseVariable::setup_pseudo_frac_

protected

fraction of branching candidates that are not trusted yet

Definition at line 314 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::numberBeforeTrustedList_

protected

number of times a branch has to happen so that it is trusted in setupList

Definition at line 317 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::numberStrongRoot_

protected

number of strong branching points at root node

Definition at line 319 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::numberStrongBackup_

protected

backup of numberStrong_ before Root node solve

Definition at line 321 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::numberLookAhead_

protected

number of look-ahead strong-branching steps

Definition at line 323 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::minNumberStrongBranch_

protected

Always strong branch that many first candidate in the list regardless of numberTrusted.

Definition at line 329 of file BonChooseVariable.hpp.

OsiPseudoCosts Bonmin::BonChooseVariable::pseudoCosts_

protected

Stores the pseudo costs.

Definition at line 331 of file BonChooseVariable.hpp.

Referenced by pseudoCosts().

int Bonmin::BonChooseVariable::trustStrongForPseudoCosts_

protected

Wether or not to trust strong branching results for updating pseudo costs.

Definition at line 333 of file BonChooseVariable.hpp.

const std::string Bonmin::BonChooseVariable::CNAME

staticprotected

Stores the class name for throwing errors.

Definition at line 341 of file BonChooseVariable.hpp.

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

BonChooseVariable.hpp

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Static Protected Attributes

Private Member Functions

Private Attributes

Message handling.

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation