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

#include <ClpPresolve.hpp>

Collaboration diagram for ClpPresolve:

Public Member Functions
Main Constructor, destructor
	ClpPresolve ()
	Default constructor. More...

virtual	~ClpPresolve ()
	Virtual destructor. More...

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, const char prohibitedRows=NULL, const char prohibitedColumns=NULL)

int	presolvedModelToFile (ClpSimplex &si, std::string fileName, double feasibilityTolerance=0.0, bool keepIntegers=true, int numberPasses=5, bool dropNames=false, bool doRowObjective=false)
	This version saves data in a file. More...

ClpSimplex *	model () const
	Return pointer to presolved model, Up to user to destroy. More...

ClpSimplex *	originalModel () const
	Return pointer to original model. More...

void	setOriginalModel (ClpSimplex *model)
	Set pointer to original model. More...

const int *	originalColumns () const
	return pointer to original columns More...

const int *	originalRows () const
	return pointer to original rows More...

void	setNonLinearValue (double value)
	"Magic" number. More...

double	nonLinearValue () const

bool	doDual () const
	Whether we want to do dual part of presolve. More...

void	setDoDual (bool doDual)

bool	doSingleton () const
	Whether we want to do singleton part of presolve. More...

void	setDoSingleton (bool doSingleton)

bool	doDoubleton () const
	Whether we want to do doubleton part of presolve. More...

void	setDoDoubleton (bool doDoubleton)

bool	doTripleton () const
	Whether we want to do tripleton part of presolve. More...

void	setDoTripleton (bool doTripleton)

bool	doTighten () const
	Whether we want to do tighten part of presolve. More...

void	setDoTighten (bool doTighten)

bool	doForcing () const
	Whether we want to do forcing part of presolve. More...

void	setDoForcing (bool doForcing)

bool	doImpliedFree () const
	Whether we want to do impliedfree part of presolve. More...

void	setDoImpliedFree (bool doImpliedfree)

bool	doDupcol () const
	Whether we want to do dupcol part of presolve. More...

void	setDoDupcol (bool doDupcol)

bool	doDuprow () const
	Whether we want to do duprow part of presolve. More...

void	setDoDuprow (bool doDuprow)

bool	doDependency () const
	Whether we want to do dependency part of presolve. More...

void	setDoDependency (bool doDependency)

bool	doTransfer () const
	Whether we want to do transfer part of presolve. More...

void	setDoTransfer (bool doTransfer)

bool	doSingletonColumn () const
	Whether we want to do singleton column part of presolve. More...

void	setDoSingletonColumn (bool doSingleton)

bool	doGubrow () const
	Whether we want to do gubrow part of presolve. More...

void	setDoGubrow (bool doGubrow)

bool	doTwoxTwo () const
	Whether we want to do twoxtwo part of presolve. More...

void	setDoTwoxtwo (bool doTwoxTwo)

bool	doIntersection () const
	Whether we want to allow duplicate intersections. More...

void	setDoIntersection (bool doIntersection)

int	zeroSmall () const
	How much we want to zero small values from aggregation - ratio 0 - 1.0e-12, 1 1.0e-11, 2 1.0e-10, 3 1.0e-9. More...

void	setZeroSmall (int value)

int	presolveActions () const
	Set whole group. More...

void	setPresolveActions (int action)

void	setSubstitution (int value)
	Substitution level. More...

void	statistics ()
	Asks for statistics. More...

int	presolveStatus () const
	Return presolve status (0,1,2) More...

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)

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

private or protected data
ClpSimplex *	originalModel_
	Original model - must not be destroyed before postsolve. More...

ClpSimplex *	presolvedModel_
	ClpPresolved model - up to user to destroy by deleteClpPresolvedModel. More...

double	nonLinearValue_
	"Magic" number. More...

int *	originalColumn_
	Original column numbers. More...

int *	originalRow_
	Original row numbers. More...

double *	rowObjective_
	Row objective. More...

const CoinPresolveAction *	paction_
	The list of transformations applied. More...

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

int	nrows_

CoinBigIndex	nelems_

int	numberPasses_
	Number of major passes. More...

int	substitution_
	Substitution level. More...

std::string	saveFile_
	Name of saved model file. More...

int	presolveActions_
	Whether we want to skip dual part of presolve etc. More...

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. More...

virtual void	postsolve (CoinPostsolveMatrix &prob)
	Postsolving is pretty generic; just apply the transformations in reverse order. More...

virtual ClpSimplex *	gutsOfPresolvedModel (ClpSimplex originalModel, double feasibilityTolerance, bool keepIntegers, int numberPasses, bool dropNames, bool doRowObjective, const char prohibitedRows=NULL, const char *prohibitedColumns=NULL)
	This is main part of Presolve. More...

Detailed Description

This is the Clp interface to CoinPresolve.

Definition at line 15 of file ClpPresolve.hpp.

Constructor & Destructor Documentation

◆ ClpPresolve()

ClpPresolve::ClpPresolve ( )

Default constructor.

◆ ~ClpPresolve()

virtual ClpPresolve::~ClpPresolve ( )

virtual

Virtual destructor.

Member Function Documentation

◆ presolvedModel()

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

◆ presolvedModelToFile()

int ClpPresolve::presolvedModelToFile	(	ClpSimplex &	si,
		std::string	fileName,
		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.
Returns non-zero if infeasible

◆ model()

ClpSimplex* ClpPresolve::model ( ) const

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

◆ originalModel()

ClpSimplex* ClpPresolve::originalModel ( ) const

Return pointer to original model.

◆ setOriginalModel()

void ClpPresolve::setOriginalModel ( ClpSimplex * model )

Set pointer to original model.

◆ originalColumns()

const int* ClpPresolve::originalColumns ( ) const

return pointer to original columns

◆ originalRows()

const int* ClpPresolve::originalRows ( ) const

return pointer to original rows

◆ setNonLinearValue()

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 76 of file ClpPresolve.hpp.

◆ nonLinearValue()

double ClpPresolve::nonLinearValue ( ) const

inline

Definition at line 80 of file ClpPresolve.hpp.

◆ doDual()

bool ClpPresolve::doDual ( ) const

inline

Whether we want to do dual part of presolve.

Definition at line 85 of file ClpPresolve.hpp.

◆ setDoDual()

void ClpPresolve::setDoDual ( bool doDual )

inline

Definition at line 89 of file ClpPresolve.hpp.

◆ doSingleton()

bool ClpPresolve::doSingleton ( ) const

inline

Whether we want to do singleton part of presolve.

Definition at line 97 of file ClpPresolve.hpp.

◆ setDoSingleton()

void ClpPresolve::setDoSingleton ( bool doSingleton )

inline

Definition at line 101 of file ClpPresolve.hpp.

◆ doDoubleton()

bool ClpPresolve::doDoubleton ( ) const

inline

Whether we want to do doubleton part of presolve.

Definition at line 109 of file ClpPresolve.hpp.

◆ setDoDoubleton()

void ClpPresolve::setDoDoubleton ( bool doDoubleton )

inline

Definition at line 113 of file ClpPresolve.hpp.

◆ doTripleton()

bool ClpPresolve::doTripleton ( ) const

inline

Whether we want to do tripleton part of presolve.

Definition at line 121 of file ClpPresolve.hpp.

◆ setDoTripleton()

void ClpPresolve::setDoTripleton ( bool doTripleton )

inline

Definition at line 125 of file ClpPresolve.hpp.

◆ doTighten()

bool ClpPresolve::doTighten ( ) const

inline

Whether we want to do tighten part of presolve.

Definition at line 133 of file ClpPresolve.hpp.

◆ setDoTighten()

void ClpPresolve::setDoTighten ( bool doTighten )

inline

Definition at line 137 of file ClpPresolve.hpp.

◆ doForcing()

bool ClpPresolve::doForcing ( ) const

inline

Whether we want to do forcing part of presolve.

Definition at line 145 of file ClpPresolve.hpp.

◆ setDoForcing()

void ClpPresolve::setDoForcing ( bool doForcing )

inline

Definition at line 149 of file ClpPresolve.hpp.

◆ doImpliedFree()

bool ClpPresolve::doImpliedFree ( ) const

inline

Whether we want to do impliedfree part of presolve.

Definition at line 157 of file ClpPresolve.hpp.

◆ setDoImpliedFree()

void ClpPresolve::setDoImpliedFree ( bool doImpliedfree )

inline

Definition at line 161 of file ClpPresolve.hpp.

◆ doDupcol()

bool ClpPresolve::doDupcol ( ) const

inline

Whether we want to do dupcol part of presolve.

Definition at line 169 of file ClpPresolve.hpp.

◆ setDoDupcol()

void ClpPresolve::setDoDupcol ( bool doDupcol )

inline

Definition at line 173 of file ClpPresolve.hpp.

◆ doDuprow()

bool ClpPresolve::doDuprow ( ) const

inline

Whether we want to do duprow part of presolve.

Definition at line 181 of file ClpPresolve.hpp.

◆ setDoDuprow()

void ClpPresolve::setDoDuprow ( bool doDuprow )

inline

Definition at line 185 of file ClpPresolve.hpp.

◆ doDependency()

bool ClpPresolve::doDependency ( ) const

inline

Whether we want to do dependency part of presolve.

Definition at line 193 of file ClpPresolve.hpp.

◆ setDoDependency()

void ClpPresolve::setDoDependency ( bool doDependency )

inline

Definition at line 197 of file ClpPresolve.hpp.

◆ doTransfer()

bool ClpPresolve::doTransfer ( ) const

inline

Whether we want to do transfer part of presolve.

Definition at line 205 of file ClpPresolve.hpp.

◆ setDoTransfer()

void ClpPresolve::setDoTransfer ( bool doTransfer )

inline

Definition at line 209 of file ClpPresolve.hpp.

◆ doSingletonColumn()

bool ClpPresolve::doSingletonColumn ( ) const

inline

Whether we want to do singleton column part of presolve.

Definition at line 217 of file ClpPresolve.hpp.

◆ setDoSingletonColumn()

void ClpPresolve::setDoSingletonColumn ( bool doSingleton )

inline

Definition at line 221 of file ClpPresolve.hpp.

◆ doGubrow()

bool ClpPresolve::doGubrow ( ) const

inline

Whether we want to do gubrow part of presolve.

Definition at line 229 of file ClpPresolve.hpp.

◆ setDoGubrow()

void ClpPresolve::setDoGubrow ( bool doGubrow )

inline

Definition at line 233 of file ClpPresolve.hpp.

◆ doTwoxTwo()

bool ClpPresolve::doTwoxTwo ( ) const

inline

Whether we want to do twoxtwo part of presolve.

Definition at line 241 of file ClpPresolve.hpp.

◆ setDoTwoxtwo()

void ClpPresolve::setDoTwoxtwo ( bool doTwoxTwo )

inline

Definition at line 245 of file ClpPresolve.hpp.

◆ doIntersection()

bool ClpPresolve::doIntersection ( ) const

inline

Whether we want to allow duplicate intersections.

Definition at line 253 of file ClpPresolve.hpp.

◆ setDoIntersection()

void ClpPresolve::setDoIntersection ( bool doIntersection )

inline

Definition at line 257 of file ClpPresolve.hpp.

◆ zeroSmall()

int ClpPresolve::zeroSmall ( ) const

inline

How much we want to zero small values from aggregation - ratio 0 - 1.0e-12, 1 1.0e-11, 2 1.0e-10, 3 1.0e-9.

Definition at line 266 of file ClpPresolve.hpp.

◆ setZeroSmall()

void ClpPresolve::setZeroSmall ( int value )

inline

Definition at line 270 of file ClpPresolve.hpp.

◆ presolveActions()

int ClpPresolve::presolveActions ( ) const

inline

Set whole group.

Definition at line 276 of file ClpPresolve.hpp.

◆ setPresolveActions()

void ClpPresolve::setPresolveActions ( int action )

inline

Definition at line 280 of file ClpPresolve.hpp.

◆ setSubstitution()

void ClpPresolve::setSubstitution ( int value )

inline

Substitution level.

Definition at line 285 of file ClpPresolve.hpp.

◆ statistics()

void ClpPresolve::statistics ( )

inline

Asks for statistics.

Definition at line 290 of file ClpPresolve.hpp.

◆ presolveStatus()

int ClpPresolve::presolveStatus ( ) const

Return presolve status (0,1,2)

◆ postsolve() [1/2]

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

virtual

◆ destroyPresolve()

void ClpPresolve::destroyPresolve ( )

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

◆ presolve()

virtual const CoinPresolveAction* ClpPresolve::presolve ( CoinPresolveMatrix * prob )

protectedvirtual

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.

◆ postsolve() [2/2]

virtual void ClpPresolve::postsolve ( CoinPostsolveMatrix & prob )

protectedvirtual

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.

◆ gutsOfPresolvedModel()

virtual ClpSimplex* ClpPresolve::gutsOfPresolvedModel	(	ClpSimplex *	originalModel,
		double	feasibilityTolerance,
		bool	keepIntegers,
		int	numberPasses,
		bool	dropNames,
		bool	doRowObjective,
		const char *	prohibitedRows = `NULL`,
		const char *	prohibitedColumns = `NULL`
	)

protectedvirtual

This is main part of Presolve.

Member Data Documentation

◆ originalModel_

ClpSimplex* ClpPresolve::originalModel_

private

Original model - must not be destroyed before postsolve.

Definition at line 313 of file ClpPresolve.hpp.

◆ presolvedModel_

ClpSimplex* ClpPresolve::presolvedModel_

private

ClpPresolved model - up to user to destroy by deleteClpPresolvedModel.

Definition at line 316 of file ClpPresolve.hpp.

◆ nonLinearValue_

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 322 of file ClpPresolve.hpp.

◆ originalColumn_

int* ClpPresolve::originalColumn_

private

Original column numbers.

Definition at line 324 of file ClpPresolve.hpp.

◆ originalRow_

int* ClpPresolve::originalRow_

private

Original row numbers.

Definition at line 326 of file ClpPresolve.hpp.

◆ rowObjective_

double* ClpPresolve::rowObjective_

private

Row objective.

Definition at line 328 of file ClpPresolve.hpp.

◆ paction_

const CoinPresolveAction* ClpPresolve::paction_

private

The list of transformations applied.

Definition at line 330 of file ClpPresolve.hpp.

◆ ncols_

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 337 of file ClpPresolve.hpp.

◆ nrows_

int ClpPresolve::nrows_

private

Definition at line 338 of file ClpPresolve.hpp.

◆ nelems_

CoinBigIndex ClpPresolve::nelems_

private

Definition at line 339 of file ClpPresolve.hpp.

◆ numberPasses_

int ClpPresolve::numberPasses_

private

Number of major passes.

Definition at line 341 of file ClpPresolve.hpp.

◆ substitution_

int ClpPresolve::substitution_

private

Substitution level.

Definition at line 343 of file ClpPresolve.hpp.

◆ saveFile_

std::string ClpPresolve::saveFile_

private

Name of saved model file.

Definition at line 346 of file ClpPresolve.hpp.

◆ presolveActions_

int ClpPresolve::presolveActions_

private

Whether we want to skip dual part of presolve etc.

512 bit allows duplicate column processing on integer columns and dual stuff on integers

Definition at line 352 of file ClpPresolve.hpp.

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

/home/ted/tmp/tmp/Clp/Clp/src/ClpPresolve.hpp

Public Member Functions

private or protected data

Detailed Description

Constructor & Destructor Documentation

◆ ClpPresolve()

◆ ~ClpPresolve()

Member Function Documentation

◆ presolvedModel()

◆ presolvedModelToFile()

◆ model()

◆ originalModel()

◆ setOriginalModel()

◆ originalColumns()

◆ originalRows()

◆ setNonLinearValue()

◆ nonLinearValue()

◆ doDual()

◆ setDoDual()

◆ doSingleton()

◆ setDoSingleton()

◆ doDoubleton()

◆ setDoDoubleton()

◆ doTripleton()

◆ setDoTripleton()

◆ doTighten()

◆ setDoTighten()

◆ doForcing()

◆ setDoForcing()

◆ doImpliedFree()

◆ setDoImpliedFree()

◆ doDupcol()

◆ setDoDupcol()

◆ doDuprow()

◆ setDoDuprow()

◆ doDependency()

◆ setDoDependency()

◆ doTransfer()

◆ setDoTransfer()

◆ doSingletonColumn()

◆ setDoSingletonColumn()

◆ doGubrow()

◆ setDoGubrow()

◆ doTwoxTwo()

◆ setDoTwoxtwo()

◆ doIntersection()

◆ setDoIntersection()

◆ zeroSmall()

◆ setZeroSmall()

◆ presolveActions()

◆ setPresolveActions()

◆ setSubstitution()

◆ statistics()

◆ presolveStatus()

◆ postsolve() [1/2]

◆ destroyPresolve()

◆ presolve()

◆ postsolve() [2/2]

◆ gutsOfPresolvedModel()

Member Data Documentation

◆ originalModel_

◆ presolvedModel_

◆ nonLinearValue_

◆ originalColumn_

◆ originalRow_

◆ rowObjective_

◆ paction_

◆ ncols_

◆ nrows_

◆ nelems_

◆ numberPasses_

◆ substitution_

◆ saveFile_

◆ presolveActions_