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ClpPresolve Class Reference

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

`#include <ClpPresolve.hpp>`

Collaboration diagram for ClpPresolve:
[legend]

## 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 | ( |  | ) |

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`,
|  | const char * | prohibitedRows = `NULL`,
|  | const char * | prohibitedColumns = `NULL`
| ) |  |

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

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 76 of file ClpPresolve.hpp.

double ClpPresolve::nonLinearValue | ( |  | ) | const
| inline

Definition at line 80 of file ClpPresolve.hpp.

bool ClpPresolve::doDual | ( |  | ) | const
| inline

Whether we want to do dual part of presolve.

Definition at line 85 of file ClpPresolve.hpp.

void ClpPresolve::setDoDual | ( | bool | doDual | ) |
| inline

Definition at line 89 of file ClpPresolve.hpp.

bool ClpPresolve::doSingleton | ( |  | ) | const
| inline

Whether we want to do singleton part of presolve.

Definition at line 97 of file ClpPresolve.hpp.

void ClpPresolve::setDoSingleton | ( | bool | doSingleton | ) |
| inline

Definition at line 101 of file ClpPresolve.hpp.

bool ClpPresolve::doDoubleton | ( |  | ) | const
| inline

Whether we want to do doubleton part of presolve.

Definition at line 109 of file ClpPresolve.hpp.

void ClpPresolve::setDoDoubleton | ( | bool | doDoubleton | ) |
| inline

Definition at line 113 of file ClpPresolve.hpp.

bool ClpPresolve::doTripleton | ( |  | ) | const
| inline

Whether we want to do tripleton part of presolve.

Definition at line 121 of file ClpPresolve.hpp.

void ClpPresolve::setDoTripleton | ( | bool | doTripleton | ) |
| inline

Definition at line 125 of file ClpPresolve.hpp.

bool ClpPresolve::doTighten | ( |  | ) | const
| inline

Whether we want to do tighten part of presolve.

Definition at line 133 of file ClpPresolve.hpp.

void ClpPresolve::setDoTighten | ( | bool | doTighten | ) |
| inline

Definition at line 137 of file ClpPresolve.hpp.

bool ClpPresolve::doForcing | ( |  | ) | const
| inline

Whether we want to do forcing part of presolve.

Definition at line 145 of file ClpPresolve.hpp.

void ClpPresolve::setDoForcing | ( | bool | doForcing | ) |
| inline

Definition at line 149 of file ClpPresolve.hpp.

bool ClpPresolve::doImpliedFree | ( |  | ) | const
| inline

Whether we want to do impliedfree part of presolve.

Definition at line 157 of file ClpPresolve.hpp.

void ClpPresolve::setDoImpliedFree | ( | bool | doImpliedfree | ) |
| inline

Definition at line 161 of file ClpPresolve.hpp.

bool ClpPresolve::doDupcol | ( |  | ) | const
| inline

Whether we want to do dupcol part of presolve.

Definition at line 169 of file ClpPresolve.hpp.

void ClpPresolve::setDoDupcol | ( | bool | doDupcol | ) |
| inline

Definition at line 173 of file ClpPresolve.hpp.

bool ClpPresolve::doDuprow | ( |  | ) | const
| inline

Whether we want to do duprow part of presolve.

Definition at line 181 of file ClpPresolve.hpp.

void ClpPresolve::setDoDuprow | ( | bool | doDuprow | ) |
| inline

Definition at line 185 of file ClpPresolve.hpp.

bool ClpPresolve::doDependency | ( |  | ) | const
| inline

Whether we want to do dependency part of presolve.

Definition at line 193 of file ClpPresolve.hpp.

void ClpPresolve::setDoDependency | ( | bool | doDependency | ) |
| inline

Definition at line 197 of file ClpPresolve.hpp.

bool ClpPresolve::doTransfer | ( |  | ) | const
| inline

Whether we want to do transfer part of presolve.

Definition at line 205 of file ClpPresolve.hpp.

void ClpPresolve::setDoTransfer | ( | bool | doTransfer | ) |
| inline

Definition at line 209 of file ClpPresolve.hpp.

bool ClpPresolve::doSingletonColumn | ( |  | ) | const
| inline

Whether we want to do singleton column part of presolve.

Definition at line 217 of file ClpPresolve.hpp.

void ClpPresolve::setDoSingletonColumn | ( | bool | doSingleton | ) |
| inline

Definition at line 221 of file ClpPresolve.hpp.

bool ClpPresolve::doGubrow | ( |  | ) | const
| inline

Whether we want to do gubrow part of presolve.

Definition at line 229 of file ClpPresolve.hpp.

void ClpPresolve::setDoGubrow | ( | bool | doGubrow | ) |
| inline

Definition at line 233 of file ClpPresolve.hpp.

bool ClpPresolve::doTwoxTwo | ( |  | ) | const
| inline

Whether we want to do twoxtwo part of presolve.

Definition at line 241 of file ClpPresolve.hpp.

void ClpPresolve::setDoTwoxtwo | ( | bool | doTwoxTwo | ) |
| inline

Definition at line 245 of file ClpPresolve.hpp.

bool ClpPresolve::doIntersection | ( |  | ) | const
| inline

Whether we want to allow duplicate intersections.

Definition at line 253 of file ClpPresolve.hpp.

void ClpPresolve::setDoIntersection | ( | bool | doIntersection | ) |
| inline

Definition at line 257 of file ClpPresolve.hpp.

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.

void ClpPresolve::setZeroSmall | ( | int | value | ) |
| inline

Definition at line 270 of file ClpPresolve.hpp.

int ClpPresolve::presolveActions | ( |  | ) | const
| inline

Set whole group.

Definition at line 276 of file ClpPresolve.hpp.

void ClpPresolve::setPresolveActions | ( | int | action | ) |
| inline

Definition at line 280 of file ClpPresolve.hpp.

void ClpPresolve::setSubstitution | ( | int | value | ) |
| inline

Substitution level.

Definition at line 285 of file ClpPresolve.hpp.

void ClpPresolve::statistics | ( |  | ) |
| inline

Asks for statistics.

Definition at line 290 of file ClpPresolve.hpp.

int ClpPresolve::presolveStatus | ( |  | ) | const

Return presolve status (0,1,2)

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,
|  | const char * | prohibitedRows = `NULL`,
|  | const char * | prohibitedColumns = `NULL`
| ) |  |
| 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 313 of file ClpPresolve.hpp.

ClpSimplex* ClpPresolve::presolvedModel_
| private

ClpPresolved model - up to user to destroy by deleteClpPresolvedModel.

Definition at line 316 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 322 of file ClpPresolve.hpp.

int* ClpPresolve::originalColumn_
| private

Original column numbers.

Definition at line 324 of file ClpPresolve.hpp.

int* ClpPresolve::originalRow_
| private

Original row numbers.

Definition at line 326 of file ClpPresolve.hpp.

double* ClpPresolve::rowObjective_
| private

Row objective.

Definition at line 328 of file ClpPresolve.hpp.

const CoinPresolveAction* ClpPresolve::paction_
| private

The list of transformations applied.

Definition at line 330 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 337 of file ClpPresolve.hpp.

int ClpPresolve::nrows_
| private

Definition at line 338 of file ClpPresolve.hpp.

CoinBigIndex ClpPresolve::nelems_
| private

Definition at line 339 of file ClpPresolve.hpp.

int ClpPresolve::numberPasses_
| private

Number of major passes.

Definition at line 341 of file ClpPresolve.hpp.

int ClpPresolve::substitution_
| private

Substitution level.

Definition at line 343 of file ClpPresolve.hpp.

std::string ClpPresolve::saveFile_
| private

Name of saved model file.

Definition at line 346 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 352 of file ClpPresolve.hpp.

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

- /tmp/Clp-1.17.6/Clp/src/ClpPresolve.hpp