CbcFathomDynamicProgramming Class Reference

FathomDynamicProgramming class. More...

#include <CbcFathomDynamicProgramming.hpp>

Inheritance diagram for CbcFathomDynamicProgramming:

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Collaboration diagram for CbcFathomDynamicProgramming:

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List of all members.

Public Member Functions
	CbcFathomDynamicProgramming ()
	CbcFathomDynamicProgramming (CbcModel &model)
	CbcFathomDynamicProgramming (const CbcFathomDynamicProgramming &rhs)
virtual	~CbcFathomDynamicProgramming ()
virtual void	setModel (CbcModel *model)
	update model (This is needed if cliques update matrix etc)
virtual CbcFathom *	clone () const
	Clone.
virtual void	resetModel (CbcModel *model)
	Resets stuff if model changes.
virtual int	fathom (double *&newSolution)
	returns 0 if no fathoming attempted, 1 fully fathomed , 2 incomplete search, 3 incomplete search but treat as complete.
int	maximumSize () const
	Maximum size allowed.
void	setMaximumSize (int value)
int	checkPossible (int allowableSize=0)
	Returns type of algorithm and sets up arrays.
void	setAlgorithm (int value)
bool	tryColumn (int numberElements, const int rows, const double coefficients, double cost, int upper=COIN_INT_MAX)
	Tries a column returns true if was used in making any changes.
const double *	cost () const
	Returns cost array.
const int *	back () const
	Returns back array.
int	target () const
	Gets bit pattern for target result.
void	setTarget (int value)
	Sets bit pattern for target result.
Protected Attributes
int	size_
	Size of states (power of 2 unless just one constraint).
int	type_
	Type - 0 coefficients and rhs all 1, 1 - coefficients > 1 or rhs > 1.
double *	cost_
	Space for states.
int *	back_
	Which state produced this cheapest one.
int *	lookup_
	Some rows may be satisified so we need a lookup.
int *	indices_
	Space for sorted indices.
int	numberActive_
	Number of active rows.
int	maximumSizeAllowed_
	Maximum size allowed.
int *	startBit_
	Start bit for each active row.
int *	numberBits_
	Number bits for each active row.
int *	rhs_
	Effective rhs.
int *	coefficients_
	Space for sorted coefficients.
int	target_
	Target pattern.
int	numberNonOne_
	Number of Non 1 rhs.
int	bitPattern_
	Current bit pattern.
int	algorithm_
	Current algorithm.
Private Member Functions
void	gutsOfDelete ()
	Does deleteions.
bool	addOneColumn0 (int numberElements, const int *rows, double cost)
	Adds one attempt of one column of type 0, returns true if was used in making any changes.
bool	addOneColumn1 (int numberElements, const int rows, const int coefficients, double cost)
	Adds one attempt of one column of type 1, returns true if was used in making any changes.
bool	addOneColumn1A (int numberElements, const int rows, const int coefficients, double cost)
	Adds one attempt of one column of type 1, returns true if was used in making any changes.
int	bitPattern (int numberElements, const int rows, const int coefficients)
	Gets bit pattern from original column.
int	bitPattern (int numberElements, const int rows, const double coefficients)
	Gets bit pattern from original column.
int	decodeBitPattern (int bitPattern, int *values, int numberRows)
	Fills in original column (dense) from bit pattern - returning number nonzero.
CbcFathomDynamicProgramming &	operator= (const CbcFathomDynamicProgramming &rhs)
	Illegal Assignment operator.

Detailed Description

FathomDynamicProgramming class.

The idea is that after some branching the problem will be effectively smaller than the original problem and maybe there will be a more specialized technique which can completely fathom this branch quickly.

This is a dynamic programming implementation which is very fast for some specialized problems. It expects small integral rhs, an all integer problem and positive integral coefficients. At present it can not do general set covering problems just set partitioning. It can find multiple optima for various rhs combinations.

The main limiting factor is size of state space. Each 1 rhs doubles the size of the problem. 2 or 3 rhs quadruples, 4,5,6,7 by 8 etc.

Definition at line 25 of file CbcFathomDynamicProgramming.hpp.

Constructor & Destructor Documentation

CbcFathomDynamicProgramming::CbcFathomDynamicProgramming ( )

CbcFathomDynamicProgramming::CbcFathomDynamicProgramming ( CbcModel & model )

CbcFathomDynamicProgramming::CbcFathomDynamicProgramming ( const CbcFathomDynamicProgramming & rhs )

virtual CbcFathomDynamicProgramming::~CbcFathomDynamicProgramming ( ) [virtual]

Member Function Documentation

virtual void CbcFathomDynamicProgramming::setModel ( CbcModel * model ) [virtual]

update model (This is needed if cliques update matrix etc)

Reimplemented from CbcFathom.

virtual CbcFathom* CbcFathomDynamicProgramming::clone ( ) const [virtual]

Clone.

Implements CbcFathom.

virtual void CbcFathomDynamicProgramming::resetModel ( CbcModel * model ) [virtual]

Resets stuff if model changes.

Implements CbcFathom.

virtual int CbcFathomDynamicProgramming::fathom ( double *& newSolution ) [virtual]

returns 0 if no fathoming attempted, 1 fully fathomed , 2 incomplete search, 3 incomplete search but treat as complete.

If solution then newSolution will not be NULL and will be freed by CbcModel. It is expected that the solution is better than best so far but CbcModel will double check.

If returns 3 then of course there is no guarantee of global optimum

Implements CbcFathom.

int CbcFathomDynamicProgramming::maximumSize ( ) const [inline]

Maximum size allowed.

Definition at line 57 of file CbcFathomDynamicProgramming.hpp.

void CbcFathomDynamicProgramming::setMaximumSize ( int value ) [inline]

Definition at line 59 of file CbcFathomDynamicProgramming.hpp.

int CbcFathomDynamicProgramming::checkPossible ( int allowableSize = 0 )

Returns type of algorithm and sets up arrays.

void CbcFathomDynamicProgramming::setAlgorithm ( int value ) [inline]

Definition at line 64 of file CbcFathomDynamicProgramming.hpp.

bool CbcFathomDynamicProgramming::tryColumn	(	int	numberElements,
		const int *	rows,
		const double *	coefficients,
		double	cost,
		int	upper = `COIN_INT_MAX`
	)