ClpPresolve Class Reference

This is the Clp interface to CoinPresolve. More...

#include <ClpPresolve.hpp>

Collaboration diagram for ClpPresolve:

Public Member Functions
Main Constructor, destructor

	ClpPresolve ()
	Default constructor.
virtual	~ClpPresolve ()
	Virtual destructor.
presolve - presolves a model, transforming the model
and saving information in the ClpPresolve object needed for postsolving. This underlying (protected) method is virtual; the idea is that in the future, one could override this method to customize how the various presolve techniques are applied. This version of presolve returns a pointer to a new presolved model. NULL if infeasible or unbounded. This should be paired with postsolve below. The advantage of going back to original model is that it will be exactly as it was i.e. 0.0 will not become 1.0e-19. If keepIntegers is true then bounds may be tightened in original. Bounds will be moved by up to feasibilityTolerance to try and stay feasible. Names will be dropped in presolved model if asked
ClpSimplex *	presolvedModel (ClpSimplex &si, double feasibilityTolerance=0.0, bool keepIntegers=true, int numberPasses=5, bool dropNames=false, bool doRowObjective=false)
	This version saves data in a file.
int	presolvedModelToFile (ClpSimplex &si, std::string fileName, double feasibilityTolerance=0.0, bool keepIntegers=true, int numberPasses=5, bool doRowObjective=false)
	This version saves data in a file.
ClpSimplex *	model () const
	Return pointer to presolved model, Up to user to destroy.
ClpSimplex *	originalModel () const
	Return pointer to original model.
void	setOriginalModel (ClpSimplex *model)
	Set pointer to original model.
const int *	originalColumns () const
	return pointer to original columns
const int *	originalRows () const
	return pointer to original rows
void	setNonLinearValue (double value)
	"Magic" number.
double	nonLinearValue () const
	This version saves data in a file.
bool	doDual () const
	Whether we want to do dual part of presolve.
void	setDoDual (bool doDual)
	This version saves data in a file.
bool	doSingleton () const
	Whether we want to do singleton part of presolve.
void	setDoSingleton (bool doSingleton)
	This version saves data in a file.
bool	doDoubleton () const
	Whether we want to do doubleton part of presolve.
void	setDoDoubleton (bool doDoubleton)
	This version saves data in a file.
bool	doTripleton () const
	Whether we want to do tripleton part of presolve.
void	setDoTripleton (bool doTripleton)
	This version saves data in a file.
bool	doTighten () const
	Whether we want to do tighten part of presolve.
void	setDoTighten (bool doTighten)
	This version saves data in a file.
bool	doForcing () const
	Whether we want to do forcing part of presolve.
void	setDoForcing (bool doForcing)
	This version saves data in a file.
bool	doImpliedFree () const
	Whether we want to do impliedfree part of presolve.
void	setDoImpliedFree (bool doImpliedfree)
	This version saves data in a file.
bool	doDupcol () const
	Whether we want to do dupcol part of presolve.
void	setDoDupcol (bool doDupcol)
	This version saves data in a file.
bool	doDuprow () const
	Whether we want to do duprow part of presolve.
void	setDoDuprow (bool doDuprow)
	This version saves data in a file.
bool	doSingletonColumn () const
	Whether we want to do singleton column part of presolve.
void	setDoSingletonColumn (bool doSingleton)
	This version saves data in a file.
int	presolveActions () const
	Set whole group.
void	setPresolveActions (int action)
	This version saves data in a file.
void	setSubstitution (int value)
	Substitution level.
void	statistics ()
	Asks for statistics.
postsolve - postsolve the problem. If the problem
has not been solved to optimality, there are no guarantees. If you are using an algorithm like simplex that has a concept of "basic" rows/cols, then set updateStatus Note that if you modified the original problem after presolving, then you must ``undo'' these modifications before calling postsolve. This version updates original
virtual void	postsolve (bool updateStatus=true)
	Gets rid of presolve actions (e.g.when infeasible).
void	destroyPresolve ()
	Gets rid of presolve actions (e.g.when infeasible).
private or protected data

ClpSimplex *	originalModel_
	Original model - must not be destroyed before postsolve.
ClpSimplex *	presolvedModel_
	ClpPresolved model - up to user to destroy by deleteClpPresolvedModel.
double	nonLinearValue_
	"Magic" number.
int *	originalColumn_
	Original column numbers.
int *	originalRow_
	Original row numbers.
double *	rowObjective_
	Row objective.
const CoinPresolveAction *	paction_
	The list of transformations applied.
int	ncols_
	The postsolved problem will expand back to its former size as postsolve transformations are applied.
int	nrows_
	Original model - must not be destroyed before postsolve.
CoinBigIndex	nelems_
	Original model - must not be destroyed before postsolve.
int	numberPasses_
	Number of major passes.
int	substitution_
	Substitution level.
std::string	saveFile_
	Name of saved model file.
int	presolveActions_
	Whether we want to skip dual part of presolve etc.
virtual const CoinPresolveAction *	presolve (CoinPresolveMatrix *prob)
	If you want to apply the individual presolve routines differently, or perhaps add your own to the mix, define a derived class and override this method.
virtual void	postsolve (CoinPostsolveMatrix &prob)
	Postsolving is pretty generic; just apply the transformations in reverse order.
virtual ClpSimplex *	gutsOfPresolvedModel (ClpSimplex *originalModel, double feasibilityTolerance, bool keepIntegers, int numberPasses, bool dropNames, bool doRowObjective)
	This is main part of Presolve.

Detailed Description

This is the Clp interface to CoinPresolve.

Definition at line 13 of file ClpPresolve.hpp.

Constructor & Destructor Documentation

ClpPresolve::ClpPresolve ( )

Default constructor.

virtual ClpPresolve::~ClpPresolve ( ) [virtual]

Virtual destructor.

Member Function Documentation

ClpSimplex* ClpPresolve::presolvedModel	(	ClpSimplex &	si,
		double	feasibilityTolerance = `0.0`,
		bool	keepIntegers = `true`,
		int	numberPasses = `5`,
		bool	dropNames = `false`,
		bool	doRowObjective = `false`
	)

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

int ClpPresolve::presolvedModelToFile	(	ClpSimplex &	si,
		std::string	fileName,
		double	feasibilityTolerance = `0.0`,
		bool	keepIntegers = `true`,
		int	numberPasses = `5`,
		bool	doRowObjective = `false`
	)

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

ClpSimplex* ClpPresolve::model ( ) const

Return pointer to presolved model, Up to user to destroy.

ClpSimplex* ClpPresolve::originalModel ( ) const

Return pointer to original model.

void ClpPresolve::setOriginalModel ( ClpSimplex * model )

Set pointer to original model.

const int* ClpPresolve::originalColumns ( ) const

return pointer to original columns

const int* ClpPresolve::originalRows ( ) const

return pointer to original rows

void ClpPresolve::setNonLinearValue ( double value ) [inline]

"Magic" number.

If this is non-zero then any elements with this value may change and so presolve is very limited in what can be done to the row and column. This is for non-linear problems.

Definition at line 71 of file ClpPresolve.hpp.

double ClpPresolve::nonLinearValue ( ) const [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 73 of file ClpPresolve.hpp.

bool ClpPresolve::doDual ( ) const [inline]

Whether we want to do dual part of presolve.

Definition at line 76 of file ClpPresolve.hpp.

void ClpPresolve::setDoDual ( bool doDual ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 78 of file ClpPresolve.hpp.

bool ClpPresolve::doSingleton ( ) const [inline]

Whether we want to do singleton part of presolve.

Definition at line 81 of file ClpPresolve.hpp.

void ClpPresolve::setDoSingleton ( bool doSingleton ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 83 of file ClpPresolve.hpp.

bool ClpPresolve::doDoubleton ( ) const [inline]

Whether we want to do doubleton part of presolve.

Definition at line 86 of file ClpPresolve.hpp.

void ClpPresolve::setDoDoubleton ( bool doDoubleton ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 88 of file ClpPresolve.hpp.

bool ClpPresolve::doTripleton ( ) const [inline]

Whether we want to do tripleton part of presolve.

Definition at line 91 of file ClpPresolve.hpp.

void ClpPresolve::setDoTripleton ( bool doTripleton ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 93 of file ClpPresolve.hpp.

bool ClpPresolve::doTighten ( ) const [inline]

Whether we want to do tighten part of presolve.

Definition at line 96 of file ClpPresolve.hpp.

void ClpPresolve::setDoTighten ( bool doTighten ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 98 of file ClpPresolve.hpp.

bool ClpPresolve::doForcing ( ) const [inline]

Whether we want to do forcing part of presolve.

Definition at line 101 of file ClpPresolve.hpp.

void ClpPresolve::setDoForcing ( bool doForcing ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 103 of file ClpPresolve.hpp.

bool ClpPresolve::doImpliedFree ( ) const [inline]

Whether we want to do impliedfree part of presolve.

Definition at line 106 of file ClpPresolve.hpp.

void ClpPresolve::setDoImpliedFree ( bool doImpliedfree ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 108 of file ClpPresolve.hpp.

bool ClpPresolve::doDupcol ( ) const [inline]

Whether we want to do dupcol part of presolve.

Definition at line 111 of file ClpPresolve.hpp.

void ClpPresolve::setDoDupcol ( bool doDupcol ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 113 of file ClpPresolve.hpp.

bool ClpPresolve::doDuprow ( ) const [inline]

Whether we want to do duprow part of presolve.

Definition at line 116 of file ClpPresolve.hpp.

void ClpPresolve::setDoDuprow ( bool doDuprow ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 118 of file ClpPresolve.hpp.

bool ClpPresolve::doSingletonColumn ( ) const [inline]

Whether we want to do singleton column part of presolve.

Definition at line 121 of file ClpPresolve.hpp.

void ClpPresolve::setDoSingletonColumn ( bool doSingleton ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 123 of file ClpPresolve.hpp.

int ClpPresolve::presolveActions ( ) const [inline]

Set whole group.

Definition at line 126 of file ClpPresolve.hpp.

void ClpPresolve::setPresolveActions ( int action ) [inline]

This version saves data in a file.

The passed in model is updated to be presolved model. names are always dropped. Returns non-zero if infeasible

Definition at line 128 of file ClpPresolve.hpp.

void ClpPresolve::setSubstitution ( int value ) [inline]

Substitution level.

Definition at line 131 of file ClpPresolve.hpp.

void ClpPresolve::statistics ( ) [inline]

Asks for statistics.

Definition at line 134 of file ClpPresolve.hpp.

virtual void ClpPresolve::postsolve ( bool updateStatus = true ) [virtual]

Gets rid of presolve actions (e.g.when infeasible).

void ClpPresolve::destroyPresolve ( )

Gets rid of presolve actions (e.g.when infeasible).

virtual const CoinPresolveAction* ClpPresolve::presolve ( CoinPresolveMatrix * prob ) [protected, virtual]

If you want to apply the individual presolve routines differently, or perhaps add your own to the mix, define a derived class and override this method.

virtual void ClpPresolve::postsolve ( CoinPostsolveMatrix & prob ) [protected, virtual]

Postsolving is pretty generic; just apply the transformations in reverse order.

You will probably only be interested in overriding this method if you want to add code to test for consistency while debugging new presolve techniques.

virtual ClpSimplex* ClpPresolve::gutsOfPresolvedModel	(	ClpSimplex *	originalModel,
		double	feasibilityTolerance,
		bool	keepIntegers,
		int	numberPasses,
		bool	dropNames,
		bool	doRowObjective
	)			`[protected, virtual]`

This is main part of Presolve.

Member Data Documentation

ClpSimplex* ClpPresolve::originalModel_ [private]

Original model - must not be destroyed before postsolve.

Definition at line 153 of file ClpPresolve.hpp.

ClpSimplex* ClpPresolve::presolvedModel_ [private]

ClpPresolved model - up to user to destroy by deleteClpPresolvedModel.

Definition at line 156 of file ClpPresolve.hpp.

double ClpPresolve::nonLinearValue_ [private]

"Magic" number.

If this is non-zero then any elements with this value may change and so presolve is very limited in what can be done to the row and column. This is for non-linear problems. One could also allow for cases where sign of coefficient is known.

Definition at line 162 of file ClpPresolve.hpp.

int* ClpPresolve::originalColumn_ [private]

Original column numbers.

Definition at line 164 of file ClpPresolve.hpp.

int* ClpPresolve::originalRow_ [private]

Original row numbers.

Definition at line 166 of file ClpPresolve.hpp.

double* ClpPresolve::rowObjective_ [private]

Row objective.

Definition at line 168 of file ClpPresolve.hpp.

const CoinPresolveAction* ClpPresolve::paction_ [private]

The list of transformations applied.

Definition at line 170 of file ClpPresolve.hpp.

int ClpPresolve::ncols_ [private]

The postsolved problem will expand back to its former size as postsolve transformations are applied.

It is efficient to allocate data structures for the final size of the problem rather than expand them as needed. These fields give the size of the original problem.

Definition at line 177 of file ClpPresolve.hpp.

int ClpPresolve::nrows_ [private]

Original model - must not be destroyed before postsolve.

Definition at line 178 of file ClpPresolve.hpp.

CoinBigIndex ClpPresolve::nelems_ [private]

Original model - must not be destroyed before postsolve.

Definition at line 179 of file ClpPresolve.hpp.

int ClpPresolve::numberPasses_ [private]

Number of major passes.

Definition at line 181 of file ClpPresolve.hpp.

int ClpPresolve::substitution_ [private]

Substitution level.