OsiChooseVariable Class Reference

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

#include <OsiChooseVariable.hpp>

Inheritance diagram for OsiChooseVariable:

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Collaboration diagram for OsiChooseVariable:

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List of all members.

Public Member Functions
	OsiChooseVariable ()
	Default Constructor.
	OsiChooseVariable (const OsiSolverInterface *solver)
	Constructor from solver (so we can set up arrays etc).
	OsiChooseVariable (const OsiChooseVariable &)
	Copy constructor.
OsiChooseVariable &	operator= (const OsiChooseVariable &rhs)
	Assignment operator.
virtual OsiChooseVariable *	clone () const
	Clone.
virtual	~OsiChooseVariable ()
	Destructor.
virtual int	setupList (OsiBranchingInformation *info, bool initialize)
	Sets up strong list and clears all if initialize is true.
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.
bool	feasibleSolution (const OsiBranchingInformation info, const double solution, int numberObjects, const OsiObject **objects)
	Returns true if solution looks feasible against given objects.
void	saveSolution (const OsiSolverInterface *solver)
	Saves a good solution.
void	clearGoodSolution ()
	Clears out good solution after use.
virtual void	updateInformation (const OsiBranchingInformation info, int branch, OsiHotInfo hotInfo)
	Given a candidate fill in useful information e.g. estimates.
virtual void	updateInformation (int whichObject, int branch, double changeInObjective, double changeInValue, int status)
	Given a branch fill in useful information e.g. estimates.
double	goodObjectiveValue () const
	Objective value for feasible solution.
double	upChange () const
	Estimate of up change or change on chosen if n-way.
double	downChange () const
	Estimate of down change or max change on other possibilities if n-way.
const double *	goodSolution () const
	Good solution - deleted by finalize.
int	bestObjectIndex () const
	Index of chosen object.
void	setBestObjectIndex (int value)
	Set index of chosen object.
int	bestWhichWay () const
	Preferred way of chosen object.
void	setBestWhichWay (int value)
	Set preferred way of chosen object.
int	firstForcedObjectIndex () const
	Index of forced object.
void	setFirstForcedObjectIndex (int value)
	Set index of forced object.
int	firstForcedWhichWay () const
	Preferred way of forced object.
void	setFirstForcedWhichWay (int value)
	Set preferred way of forced object.
int	numberUnsatisfied () const
	Get the number of objects unsatisfied at this node - accurate on first pass.
int	numberStrong () const
	Number of objects to choose for strong branching.
void	setNumberStrong (int value)
	Set number of objects to choose for strong branching.
int	numberOnList () const
	Number left on strong list.
int	numberStrongDone () const
	Number of strong branches actually done.
int	numberStrongIterations () const
	Number of strong iterations actually done.
int	numberStrongFixed () const
	Number of strong branches which changed bounds.
const int *	candidates () const
	List of candidates.
bool	trustStrongForBound () const
	Trust results from strong branching for changing bounds.
void	setTrustStrongForBound (bool yesNo)
	Set trust results from strong branching for changing bounds.
bool	trustStrongForSolution () const
	Trust results from strong branching for valid solution.
void	setTrustStrongForSolution (bool yesNo)
	Set trust results from strong branching for valid solution.
void	setSolver (const OsiSolverInterface *solver)
	Set solver and redo arrays.
int	status () const
	Return status - -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().
void	setStatus (int value)
Protected Attributes
double	goodObjectiveValue_
	Objective value for feasible solution.
double	upChange_
	Estimate of up change or change on chosen if n-way.
double	downChange_
	Estimate of down change or max change on other possibilities if n-way.
double *	goodSolution_
	Good solution - deleted by finalize.
int *	list_
	List of candidates.
double *	useful_
	Useful array (for sorting etc).
const OsiSolverInterface *	solver_
	Pointer to solver.
int	status_
int	bestObjectIndex_
	Index of chosen object.
int	bestWhichWay_
	Preferred way of chosen object.
int	firstForcedObjectIndex_
	Index of forced object.
int	firstForcedWhichWay_
	Preferred way of forced object.
int	numberUnsatisfied_
	The number of objects unsatisfied at this node.
int	numberStrong_
	Number of objects to choose for strong branching.
int	numberOnList_
	Number left on strong list.
int	numberStrongDone_
	Number of strong branches actually done.
int	numberStrongIterations_
	Number of strong iterations actually done.
int	numberStrongFixed_
	Number of bound changes due to strong branching.
bool	trustStrongForBound_
	List of unsatisfied objects - first numberOnList_ for strong branching Trust results from strong branching for changing bounds.
bool	trustStrongForSolution_
	Trust results from strong branching for valid solution.

Detailed Description

This class chooses a variable to branch on.

The base class just chooses the variable and direction without strong branching but it has information which would normally be used by strong branching e.g. to re-enter having fixed a variable but using same candidates for strong branching.

The flow is : a) initialize the process. This decides on strong branching list and stores indices of all infeasible objects b) do strong branching on list. If list is empty then just choose one candidate and return without strong branching. If not empty then go through list and return best. However we may find that the node is infeasible or that we can fix a variable. If so we return and it is up to user to call again (after fixing a variable).

Definition at line 31 of file OsiChooseVariable.hpp.

Constructor & Destructor Documentation

OsiChooseVariable::OsiChooseVariable ( )

Default Constructor.

OsiChooseVariable::OsiChooseVariable ( const OsiSolverInterface * solver )

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

OsiChooseVariable::OsiChooseVariable ( const OsiChooseVariable & )

Copy constructor.

virtual OsiChooseVariable::~OsiChooseVariable ( ) [virtual]

Destructor.

Member Function Documentation

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

Assignment operator.

Reimplemented in OsiChooseStrongSubset, and OsiChooseStrong.

virtual OsiChooseVariable* OsiChooseVariable::clone ( ) const [virtual]

Clone.

Reimplemented in OsiChooseStrongSubset, and OsiChooseStrong.

virtual int OsiChooseVariable::setupList	(	OsiBranchingInformation *	info,
		bool	initialize
	)			`[virtual]`

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

Returns number of infeasibilities. If returns -1 then has worked out node is infeasible!

Reimplemented in OsiChooseStrongSubset, and OsiChooseStrong.

virtual int OsiChooseVariable::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.

Reimplemented in OsiChooseStrongSubset, and OsiChooseStrong.

bool OsiChooseVariable::feasibleSolution	(	const OsiBranchingInformation *	info,
		const double *	solution,
		int	numberObjects,
		const OsiObject **	objects
	)

Returns true if solution looks feasible against given objects.

void OsiChooseVariable::saveSolution ( const OsiSolverInterface * solver )

Saves a good solution.

void OsiChooseVariable::clearGoodSolution ( )

Clears out good solution after use.

virtual void OsiChooseVariable::updateInformation	(	const OsiBranchingInformation *	info,
		int	branch,
		OsiHotInfo *	hotInfo
	)			`[virtual]`

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

virtual void OsiChooseVariable::updateInformation	(	int	whichObject,
		int	branch,
		double	changeInObjective,
		double	changeInValue,
		int	status
	)			`[virtual]`

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

double OsiChooseVariable::goodObjectiveValue ( ) const [inline]

Objective value for feasible solution.

Definition at line 91 of file OsiChooseVariable.hpp.

double OsiChooseVariable::upChange ( ) const [inline]

Estimate of up change or change on chosen if n-way.

Definition at line 94 of file OsiChooseVariable.hpp.

double OsiChooseVariable::downChange ( ) const [inline]

Estimate of down change or max change on other possibilities if n-way.

Definition at line 97 of file OsiChooseVariable.hpp.

const double* OsiChooseVariable::goodSolution ( ) const [inline]

Good solution - deleted by finalize.

Definition at line 100 of file OsiChooseVariable.hpp.

int OsiChooseVariable::bestObjectIndex ( ) const [inline]

Index of chosen object.

Definition at line 103 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setBestObjectIndex ( int value ) [inline]

Set index of chosen object.

Definition at line 106 of file OsiChooseVariable.hpp.

int OsiChooseVariable::bestWhichWay ( ) const [inline]

Preferred way of chosen object.

Definition at line 109 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setBestWhichWay ( int value ) [inline]

Set preferred way of chosen object.

Definition at line 112 of file OsiChooseVariable.hpp.

int OsiChooseVariable::firstForcedObjectIndex ( ) const [inline]

Index of forced object.

Definition at line 115 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setFirstForcedObjectIndex ( int value ) [inline]

Set index of forced object.

Definition at line 118 of file OsiChooseVariable.hpp.

int OsiChooseVariable::firstForcedWhichWay ( ) const [inline]

Preferred way of forced object.

Definition at line 121 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setFirstForcedWhichWay ( int value ) [inline]

Set preferred way of forced object.

Definition at line 124 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberUnsatisfied ( ) const [inline]

Get the number of objects unsatisfied at this node - accurate on first pass.

Definition at line 127 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrong ( ) const [inline]

Number of objects to choose for strong branching.

Definition at line 130 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setNumberStrong ( int value ) [inline]

Set number of objects to choose for strong branching.

Definition at line 133 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberOnList ( ) const [inline]

Number left on strong list.

Definition at line 136 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrongDone ( ) const [inline]

Number of strong branches actually done.

Definition at line 139 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrongIterations ( ) const [inline]

Number of strong iterations actually done.

Definition at line 142 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrongFixed ( ) const [inline]

Number of strong branches which changed bounds.

Definition at line 145 of file OsiChooseVariable.hpp.

const int* OsiChooseVariable::candidates ( ) const [inline]

List of candidates.

Definition at line 148 of file OsiChooseVariable.hpp.

bool OsiChooseVariable::trustStrongForBound ( ) const [inline]

Trust results from strong branching for changing bounds.

Definition at line 151 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setTrustStrongForBound ( bool yesNo ) [inline]

Set trust results from strong branching for changing bounds.

Definition at line 154 of file OsiChooseVariable.hpp.

bool OsiChooseVariable::trustStrongForSolution ( ) const [inline]

Trust results from strong branching for valid solution.

Definition at line 157 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setTrustStrongForSolution ( bool yesNo ) [inline]

Set trust results from strong branching for valid solution.

Definition at line 160 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setSolver ( const OsiSolverInterface * solver )

Set solver and redo arrays.

int OsiChooseVariable::status ( ) const [inline]

Return status - -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().

Definition at line 175 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setStatus ( int value ) [inline]

Definition at line 177 of file OsiChooseVariable.hpp.