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# CglGomory Class Reference

Gomory Cut Generator Class. More...

`#include <CglGomory.hpp>`

Inheritance diagram for CglGomory:

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Collaboration diagram for CglGomory:

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List of all members.

## Public Member Functions
Generate Cuts
virtual void | generateCuts (const OsiSolverInterface &si, OsiCuts &cs, const CglTreeInfo info=CglTreeInfo()) const
| Generate Mixed Integer Gomory cuts for the model of the solver interface, si.
int | generateCuts (const OsiRowCutDebugger *debugger, OsiCuts &cs, const CoinPackedMatrix &columnCopy, const CoinPackedMatrix &rowCopy, const double *colsol, const double *colLower, const double *colUpper, const double *rowLower, const double *rowUpper, const char *intVar, const CoinWarmStartBasis *warm, const CglTreeInfo info=CglTreeInfo()) const
| Generates cuts given matrix and solution etc, returns number of cuts generated.
int | generateCuts (const OsiRowCutDebugger *debugger, OsiCuts &cs, const CoinPackedMatrix &columnCopy, const double *colsol, const double *colLower, const double *colUpper, const double *rowLower, const double *rowUpper, const char *intVar, const CoinWarmStartBasis *warm, const CglTreeInfo info=CglTreeInfo()) const
| Generates cuts given matrix and solution etc, returns number of cuts generated (no row copy passed in).
virtual bool | needsOptimalBasis () const
| Return true if needs optimal basis to do cuts (will return true).
Change limit on how many variables in cut (default 50)
void | setLimit (int limit)
| Set.
int | getLimit () const
| Get.
void | setLimitAtRoot (int limit)
| Set at root (if <normal then use normal).
int | getLimitAtRoot () const
| Get at root.
virtual int | maximumLengthOfCutInTree () const
| Return maximum length of cut in tree.
Change criterion on which variables to look at. All ones
more than "away" away from integrality will be investigated (default 0.05)
void | setAway (double value)
| Set away.
double | getAway () const
| Get away.
void | setAwayAtRoot (double value)
| Set away at root.
double | getAwayAtRoot () const
| Get away at root.
Change criterion on which the cut id relaxed if the code
thinks the factorization has inaccuracies. The relaxation to RHS is smallest of - 1) 1.0e-4 2) conditionNumberMultiplier * condition number of factorization 3) largestFactorMultiplier * largest (dual*element) forming tableau row
void | setConditionNumberMultiplier (double value)
| Set ConditionNumberMultiplier.
double | getConditionNumberMultiplier () const
| Get ConditionNumberMultiplier.
void | setLargestFactorMultiplier (double value)
| Set LargestFactorMultiplier.
double | getLargestFactorMultiplier () const
| Get LargestFactorMultiplier.
change factorization
void | useAlternativeFactorization (bool yes=true)
| Set/unset alternative factorization.
bool | alternativeFactorization () const
| Get whether alternative factorization being used.
Constructors and destructors
| CglGomory ()
| Default constructor.
| CglGomory (const CglGomory &)
| Copy constructor.
virtual CglCutGenerator * | clone () const
| Clone.
CglGomory & | operator= (const CglGomory &rhs)
| Assignment operator.
virtual | ~CglGomory ()
| Destructor.
virtual std::string | generateCpp (FILE *fp)
| Create C++ lines to get to current state.
## Private Attributes
Private member data
double | away_
| Only investigate if more than this away from integrality.
double | awayAtRoot_
| Only investigate if more than this away from integrality (at root).
double | conditionNumberMultiplier_
| Multiplier for conditionNumber cut relaxation.
double | largestFactorMultiplier_
| Multiplier for largest factor cut relaxation.
int | limit_
| Limit - only generate if fewer than this in cut.
int | limitAtRoot_
| Limit - only generate if fewer than this in cut (at root).
int | dynamicLimitInTree_
| Dynamic limit in tree.
int | numberTimesStalled_
| Number of times stalled.
int | alternateFactorization_
| nonzero to use alternative factorization
## Friends
void | CglGomoryUnitTest (const OsiSolverInterface *siP, const std::string mpdDir)
| A function that tests the methods in the CglGomory class.

## Detailed Description

Gomory Cut Generator Class.

Definition at line 12 of file CglGomory.hpp.

## Constructor & Destructor Documentation

CglGomory::CglGomory | ( |  | ) |

Default constructor.

CglGomory::CglGomory | ( | const CglGomory & |  | ) |

Copy constructor.

virtual CglGomory::~CglGomory | ( |  | ) | `[virtual]`

Destructor.

## Member Function Documentation

virtual void CglGomory::generateCuts | ( | const OsiSolverInterface & | si,
|  | OsiCuts & | cs,
|  | const CglTreeInfo | info = `CglTreeInfo()` |
| ) |  |  | const`[virtual]`

Generate Mixed Integer Gomory cuts for the model of the solver interface, si.

Insert the generated cuts into OsiCut, cs.

There is a limit option, which will only generate cuts with less than this number of entries.

We can also only look at 0-1 variables a certain distance from integer.

Implements CglCutGenerator.

int CglGomory::generateCuts | ( | const OsiRowCutDebugger * | debugger,
|  | OsiCuts & | cs,
|  | const CoinPackedMatrix & | columnCopy,
|  | const CoinPackedMatrix & | rowCopy,
|  | const double * | colsol,
|  | const double * | colLower,
|  | const double * | colUpper,
|  | const double * | rowLower,
|  | const double * | rowUpper,
|  | const char * | intVar,
|  | const CoinWarmStartBasis * | warm,
|  | const CglTreeInfo | info = `CglTreeInfo()` |
| ) |  |  | const

Generates cuts given matrix and solution etc, returns number of cuts generated.

int CglGomory::generateCuts | ( | const OsiRowCutDebugger * | debugger,
|  | OsiCuts & | cs,
|  | const CoinPackedMatrix & | columnCopy,
|  | const double * | colsol,
|  | const double * | colLower,
|  | const double * | colUpper,
|  | const double * | rowLower,
|  | const double * | rowUpper,
|  | const char * | intVar,
|  | const CoinWarmStartBasis * | warm,
|  | const CglTreeInfo | info = `CglTreeInfo()` |
| ) |  |  | const

Generates cuts given matrix and solution etc, returns number of cuts generated (no row copy passed in).

virtual bool CglGomory::needsOptimalBasis | ( |  | ) | const`[virtual]`

Return true if needs optimal basis to do cuts (will return true).

Reimplemented from CglCutGenerator.

void CglGomory::setLimit | ( | int | limit | ) |

Set.

int CglGomory::getLimit | ( |  | ) | const

Get.

void CglGomory::setLimitAtRoot | ( | int | limit | ) |

Set at root (if <normal then use normal).

int CglGomory::getLimitAtRoot | ( |  | ) | const

Get at root.

virtual int CglGomory::maximumLengthOfCutInTree | ( |  | ) | const`[virtual]`

Return maximum length of cut in tree.

Reimplemented from CglCutGenerator.

void CglGomory::setAway | ( | double | value | ) |

Set away.

double CglGomory::getAway | ( |  | ) | const

Get away.

void CglGomory::setAwayAtRoot | ( | double | value | ) |

Set away at root.

double CglGomory::getAwayAtRoot | ( |  | ) | const

Get away at root.

void CglGomory::setConditionNumberMultiplier | ( | double | value | ) |

Set ConditionNumberMultiplier.

double CglGomory::getConditionNumberMultiplier | ( |  | ) | const

Get ConditionNumberMultiplier.

void CglGomory::setLargestFactorMultiplier | ( | double | value | ) |

Set LargestFactorMultiplier.

double CglGomory::getLargestFactorMultiplier | ( |  | ) | const

Get LargestFactorMultiplier.

void CglGomory::useAlternativeFactorization | ( | bool | yes = `true` | ) | `[inline]`

Set/unset alternative factorization.

Definition at line 112 of file CglGomory.hpp.

References alternateFactorization_.

bool CglGomory::alternativeFactorization | ( |  | ) | const`[inline]`

Get whether alternative factorization being used.

Definition at line 115 of file CglGomory.hpp.

References alternateFactorization_.

virtual CglCutGenerator* CglGomory::clone | ( |  | ) | const`[virtual]`

Clone.

Implements CglCutGenerator.

CglGomory& CglGomory::operator= | ( | const CglGomory & | rhs | ) |

Assignment operator.

virtual std::string CglGomory::generateCpp | ( | FILE * | fp | ) | `[virtual]`

Create C++ lines to get to current state.

Reimplemented from CglCutGenerator.

## Friends And Related Function Documentation

void CglGomoryUnitTest | ( | const OsiSolverInterface * | siP,
|  | const std::string | mpdDir |
| ) |  |  | `[friend]`

A function that tests the methods in the CglGomory class.

The only reason for it not to be a member method is that this way it doesn't have to be compiled into the library. And that's a gain, because the library should be compiled with optimization on, but this method should be compiled with debugging.

## Member Data Documentation

double CglGomory::away_`[private]`

Only investigate if more than this away from integrality.

Definition at line 152 of file CglGomory.hpp.

double CglGomory::awayAtRoot_`[private]`

Only investigate if more than this away from integrality (at root).

Definition at line 154 of file CglGomory.hpp.

double CglGomory::conditionNumberMultiplier_`[private]`

Multiplier for conditionNumber cut relaxation.

Definition at line 156 of file CglGomory.hpp.

double CglGomory::largestFactorMultiplier_`[private]`

Multiplier for largest factor cut relaxation.

Definition at line 158 of file CglGomory.hpp.

int CglGomory::limit_`[private]`

Limit - only generate if fewer than this in cut.

Definition at line 160 of file CglGomory.hpp.

int CglGomory::limitAtRoot_`[private]`

Limit - only generate if fewer than this in cut (at root).

Definition at line 162 of file CglGomory.hpp.

int CglGomory::dynamicLimitInTree_`[mutable, private]`

Dynamic limit in tree.

Definition at line 164 of file CglGomory.hpp.

int CglGomory::numberTimesStalled_`[mutable, private]`

Number of times stalled.

Definition at line 166 of file CglGomory.hpp.

int CglGomory::alternateFactorization_`[private]`

nonzero to use alternative factorization

Definition at line 168 of file CglGomory.hpp.

Referenced by alternativeFactorization(), and useAlternativeFactorization().

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

- /home/coin/SVN-release/Cgl-0.55.0/Cgl/src/CglGomory/CglGomory.hpp