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.

private or protected data

virtual const CoinPresolveActionpresolve (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.
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 CoinPresolveActionpaction_
 The list of transformations applied.
int ncols_
 The postsolved problem will expand back to its former size as postsolve transformations are applied.
int nrows_
 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.
CoinBigIndex nelems_
 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.
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.

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)
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
bool doDual () const
 Whether we want to do dual part of presolve.
void setDoDual (bool doDual)
bool doSingleton () const
 Whether we want to do singleton part of presolve.
void setDoSingleton (bool doSingleton)
bool doDoubleton () const
 Whether we want to do doubleton part of presolve.
void setDoDoubleton (bool doDoubleton)
bool doTripleton () const
 Whether we want to do tripleton part of presolve.
void setDoTripleton (bool doTripleton)
bool doTighten () const
 Whether we want to do tighten part of presolve.
void setDoTighten (bool doTighten)
bool doForcing () const
 Whether we want to do forcing part of presolve.
void setDoForcing (bool doForcing)
bool doImpliedFree () const
 Whether we want to do impliedfree part of presolve.
void setDoImpliedFree (bool doImpliedfree)
bool doDupcol () const
 Whether we want to do dupcol part of presolve.
void setDoDupcol (bool doDupcol)
bool doDuprow () const
 Whether we want to do duprow part of presolve.
void setDoDuprow (bool doDuprow)
bool doSingletonColumn () const
 Whether we want to do singleton column part of presolve.
void setDoSingletonColumn (bool doSingleton)
int presolveActions () const
 Set whole group.
void setPresolveActions (int action)
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)
void destroyPresolve ()
 Gets rid of presolve actions (e.g.when infeasible).

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 
)

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.

References nonLinearValue_.

double ClpPresolve::nonLinearValue (  )  const [inline]

Definition at line 73 of file ClpPresolve.hpp.

References nonLinearValue_.

bool ClpPresolve::doDual (  )  const [inline]

Whether we want to do dual part of presolve.

Definition at line 76 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 78 of file ClpPresolve.hpp.

References presolveActions_.

bool ClpPresolve::doSingleton (  )  const [inline]

Whether we want to do singleton part of presolve.

Definition at line 81 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 83 of file ClpPresolve.hpp.

References presolveActions_.

bool ClpPresolve::doDoubleton (  )  const [inline]

Whether we want to do doubleton part of presolve.

Definition at line 86 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 88 of file ClpPresolve.hpp.

References presolveActions_.

bool ClpPresolve::doTripleton (  )  const [inline]

Whether we want to do tripleton part of presolve.

Definition at line 91 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 93 of file ClpPresolve.hpp.

References presolveActions_.

bool ClpPresolve::doTighten (  )  const [inline]

Whether we want to do tighten part of presolve.

Definition at line 96 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 98 of file ClpPresolve.hpp.

References presolveActions_.

bool ClpPresolve::doForcing (  )  const [inline]

Whether we want to do forcing part of presolve.

Definition at line 101 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 103 of file ClpPresolve.hpp.

References presolveActions_.

bool ClpPresolve::doImpliedFree (  )  const [inline]

Whether we want to do impliedfree part of presolve.

Definition at line 106 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 108 of file ClpPresolve.hpp.

References presolveActions_.

bool ClpPresolve::doDupcol (  )  const [inline]

Whether we want to do dupcol part of presolve.

Definition at line 111 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 113 of file ClpPresolve.hpp.

References presolveActions_.

bool ClpPresolve::doDuprow (  )  const [inline]

Whether we want to do duprow part of presolve.

Definition at line 116 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 118 of file ClpPresolve.hpp.

References presolveActions_.

bool ClpPresolve::doSingletonColumn (  )  const [inline]

Whether we want to do singleton column part of presolve.

Definition at line 121 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 123 of file ClpPresolve.hpp.

References presolveActions_.

int ClpPresolve::presolveActions (  )  const [inline]

Set whole group.

Definition at line 126 of file ClpPresolve.hpp.

References presolveActions_.

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

Definition at line 128 of file ClpPresolve.hpp.

References presolveActions_.

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

Substitution level.

Definition at line 131 of file ClpPresolve.hpp.

References substitution_.

void ClpPresolve::statistics (  )  [inline]

Asks for statistics.

Definition at line 134 of file ClpPresolve.hpp.

References presolveActions_.

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

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.

Referenced by nonLinearValue(), and setNonLinearValue().

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]

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.

Definition at line 178 of file ClpPresolve.hpp.

CoinBigIndex ClpPresolve::nelems_ [private]

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.

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.

Definition at line 183 of file ClpPresolve.hpp.

Referenced by setSubstitution().

std::string ClpPresolve::saveFile_ [private]

Name of saved model file.

Definition at line 186 of file ClpPresolve.hpp.

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 192 of file ClpPresolve.hpp.

Referenced by doDoubleton(), doDual(), doDupcol(), doDuprow(), doForcing(), doImpliedFree(), doSingleton(), doSingletonColumn(), doTighten(), doTripleton(), presolveActions(), setDoDoubleton(), setDoDual(), setDoDupcol(), setDoDuprow(), setDoForcing(), setDoImpliedFree(), setDoSingleton(), setDoSingletonColumn(), setDoTighten(), setDoTripleton(), setPresolveActions(), and statistics().


The documentation for this class was generated from the following file:
Generated on Sun Nov 14 14:13:27 2010 for Coin-All by  doxygen 1.4.7