ClpPresolve Class Reference

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

#include <ClpPresolve.hpp>

Collaboration diagram for ClpPresolve:
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List of all members.

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

ClpSimplexpresolvedModel (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.
ClpSimplexmodel () const
 Return pointer to presolved model, Up to user to destroy.
ClpSimplexoriginalModel () 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.
bool doGubrow () const
 Whether we want to do gubrow part of presolve.
void setDoGubrow (bool doGubrow)
 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

ClpSimplexoriginalModel_
 Original model - must not be destroyed before postsolve.
ClpSimplexpresolvedModel_
 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 ClpSimplexgutsOfPresolvedModel (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 14 of file ClpPresolve.hpp.


Constructor & Destructor Documentation

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

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

Return pointer to original 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 72 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 75 of file ClpPresolve.hpp.

bool ClpPresolve::doDual ( ) const [inline]

Whether we want to do dual part of presolve.

Definition at line 79 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 82 of file ClpPresolve.hpp.

bool ClpPresolve::doSingleton ( ) const [inline]

Whether we want to do singleton part of presolve.

Definition at line 87 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 90 of file ClpPresolve.hpp.

bool ClpPresolve::doDoubleton ( ) const [inline]

Whether we want to do doubleton part of presolve.

Definition at line 95 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 98 of file ClpPresolve.hpp.

bool ClpPresolve::doTripleton ( ) const [inline]

Whether we want to do tripleton part of presolve.

Definition at line 103 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 106 of file ClpPresolve.hpp.

bool ClpPresolve::doTighten ( ) const [inline]

Whether we want to do tighten part of presolve.

Definition at line 111 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 114 of file ClpPresolve.hpp.

bool ClpPresolve::doForcing ( ) const [inline]

Whether we want to do forcing part of presolve.

Definition at line 119 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 122 of file ClpPresolve.hpp.

bool ClpPresolve::doImpliedFree ( ) const [inline]

Whether we want to do impliedfree part of presolve.

Definition at line 127 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 130 of file ClpPresolve.hpp.

bool ClpPresolve::doDupcol ( ) const [inline]

Whether we want to do dupcol part of presolve.

Definition at line 135 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 138 of file ClpPresolve.hpp.

bool ClpPresolve::doDuprow ( ) const [inline]

Whether we want to do duprow part of presolve.

Definition at line 143 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 146 of file ClpPresolve.hpp.

bool ClpPresolve::doSingletonColumn ( ) const [inline]

Whether we want to do singleton column part of presolve.

Definition at line 151 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 154 of file ClpPresolve.hpp.

bool ClpPresolve::doGubrow ( ) const [inline]

Whether we want to do gubrow part of presolve.

Definition at line 159 of file ClpPresolve.hpp.

void ClpPresolve::setDoGubrow ( bool  doGubrow) [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 162 of file ClpPresolve.hpp.

int ClpPresolve::presolveActions ( ) const [inline]

Set whole group.

Definition at line 167 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 170 of file ClpPresolve.hpp.

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

Substitution level.

Definition at line 174 of file ClpPresolve.hpp.

void ClpPresolve::statistics ( ) [inline]

Asks for statistics.

Definition at line 178 of file ClpPresolve.hpp.

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

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

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

Original model - must not be destroyed before postsolve.

Definition at line 198 of file ClpPresolve.hpp.

ClpPresolved model - up to user to destroy by deleteClpPresolvedModel.

Definition at line 201 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 207 of file ClpPresolve.hpp.

Original column numbers.

Definition at line 209 of file ClpPresolve.hpp.

int* ClpPresolve::originalRow_ [private]

Original row numbers.

Definition at line 211 of file ClpPresolve.hpp.

double* ClpPresolve::rowObjective_ [private]

Row objective.

Definition at line 213 of file ClpPresolve.hpp.

const CoinPresolveAction* ClpPresolve::paction_ [private]

The list of transformations applied.

Definition at line 215 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 222 of file ClpPresolve.hpp.

int ClpPresolve::nrows_ [private]

Original model - must not be destroyed before postsolve.

Definition at line 223 of file ClpPresolve.hpp.

CoinBigIndex ClpPresolve::nelems_ [private]

Original model - must not be destroyed before postsolve.

Definition at line 224 of file ClpPresolve.hpp.

Number of major passes.

Definition at line 226 of file ClpPresolve.hpp.

Substitution level.

Definition at line 228 of file ClpPresolve.hpp.

std::string ClpPresolve::saveFile_ [private]

Name of saved model file.

Definition at line 231 of file ClpPresolve.hpp.

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 237 of file ClpPresolve.hpp.


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