# CglOddHole Class Reference

Odd Hole Cut Generator Class. More...

`#include <CglOddHole.hpp>`

Inheritance diagram for CglOddHole:
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Collaboration diagram for CglOddHole:
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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())
| Generate odd hole cuts for the model of the solver interface, si.
Create Row List
void | createRowList (const OsiSolverInterface &si, const int *possible=NULL)
| Create a list of rows which might yield cuts this is to speed up process The possible parameter is a list to cut down search.
void | createRowList (int numberRows, const int *whichRow)
| This version passes in a list - 1 marks possible.
Create Clique List
void | createCliqueList (int numberCliques, const int *cliqueStart, const int *cliqueMember)
| Create a list of extra row cliques which may not be in matrix At present these are classical cliques.
Number Possibilities
int | numberPossible ()
| Returns how many rows might give odd hole cuts.
Gets and Sets
double | getMinimumViolation () const
| Minimum violation.
void | setMinimumViolation (double value)
| Minimum violation.
double | getMinimumViolationPer () const
| Minimum violation per entry.
void | setMinimumViolationPer (double value)
| Minimum violation.
int | getMaximumEntries () const
| Maximum number of entries in a cut.
void | setMaximumEntries (int value)
| Minimum violation.
Constructors and destructors
| CglOddHole ()
| Default constructor.
| CglOddHole (const CglOddHole &)
| Copy constructor.
virtual CglCutGenerator * | clone () const
| Clone.
CglOddHole & | operator= (const CglOddHole &rhs)
| Assignment operator.
virtual | ~CglOddHole ()
| Destructor.
virtual void | refreshSolver (OsiSolverInterface *solver)
| This can be used to refresh any inforamtion.
## Private Member Functions
Private methods
void | generateCuts (const OsiRowCutDebugger *debugger, const CoinPackedMatrix &rowCopy, const double *solution, const double *dj, OsiCuts &cs, const int *suitableRow, const int *fixedColumn, const CglTreeInfo info, bool packed)
| Generate cuts from matrix copy and solution If packed true then <=1 rows, otherwise >=1 rows.
## Private Attributes
Private member data
int * | suitableRows_
| list of suitableRows
int * | startClique_
| start of each clique
int * | member_
| clique members
double | epsilon_
| epsilon
double | onetol_
| 1-epsilon
double | minimumViolation_
| Minimum violation.
double | minimumViolationPer_
| Minimum violation per entry.
int | maximumEntries_
| Maximum number of entries in a cut.
int | numberRows_
| number of rows when suitability tested
int | numberCliques_
| number of cliques
## Friends
void | CglOddHoleUnitTest (const OsiSolverInterface *siP, const std::string mpdDir)
| A function that tests the methods in the CglOddHole class.

## Detailed Description

Odd Hole Cut Generator Class.

Definition at line 14 of file CglOddHole.hpp.

## Constructor & Destructor Documentation

CglOddHole::CglOddHole | ( |  | ) |

Default constructor.

CglOddHole::CglOddHole | ( | const CglOddHole & |  | ) |

Copy constructor.

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

Destructor.

## Member Function Documentation

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

Generate odd hole cuts for the model of the solver interface, si.

This looks at all rows of type sum x(i) <= 1 (or == 1) (x 0-1) and sees if there is an odd cycle cut. See Grotschel, Lovasz and Schrijver (1988) for method. This is then lifted by using the corresponding Chvatal cut i.e. Take all rows in cycle and add them together. RHS will be odd so weaken all odd coefficients so 1.0 goes to 0.0 etc - then constraint is sum even(j)*x(j) <= odd which can be replaced by sum (even(j)/2)*x(j) <= (odd-1.0)/2. A similar cut can be generated for sum x(i) >= 1.

Insert the generated cuts into OsiCut, cs.

This is only done for rows with unsatisfied 0-1 variables. If there are many of these it will be slow. Improvements would do a randomized subset and also speed up shortest path algorithm used.

Implements CglCutGenerator.

void CglOddHole::createRowList | ( | const OsiSolverInterface & | si,
|  | const int * | possible = `NULL` |
| ) |  |  |

Create a list of rows which might yield cuts this is to speed up process The possible parameter is a list to cut down search.

void CglOddHole::createRowList | ( | int | numberRows,
|  | const int * | whichRow |
| ) |  |  |

This version passes in a list - 1 marks possible.

void CglOddHole::createCliqueList | ( | int | numberCliques,
|  | const int * | cliqueStart,
|  | const int * | cliqueMember |
| ) |  |  |

Create a list of extra row cliques which may not be in matrix At present these are classical cliques.

int CglOddHole::numberPossible | ( |  | ) |

Returns how many rows might give odd hole cuts.

double CglOddHole::getMinimumViolation | ( |  | ) | const

Minimum violation.

void CglOddHole::setMinimumViolation | ( | double | value | ) |

Minimum violation.

double CglOddHole::getMinimumViolationPer | ( |  | ) | const

Minimum violation per entry.

void CglOddHole::setMinimumViolationPer | ( | double | value | ) |

Minimum violation.

int CglOddHole::getMaximumEntries | ( |  | ) | const

Maximum number of entries in a cut.

void CglOddHole::setMaximumEntries | ( | int | value | ) |

Minimum violation.

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

Clone.

Implements CglCutGenerator.

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

Assignment operator.

Reimplemented from CglCutGenerator.

virtual void CglOddHole::refreshSolver | ( | OsiSolverInterface * | solver | ) | `[virtual]`

This can be used to refresh any inforamtion.

Reimplemented from CglCutGenerator.

void CglOddHole::generateCuts | ( | const OsiRowCutDebugger * | debugger,
|  | const CoinPackedMatrix & | rowCopy,
|  | const double * | solution,
|  | const double * | dj,
|  | OsiCuts & | cs,
|  | const int * | suitableRow,
|  | const int * | fixedColumn,
|  | const CglTreeInfo | info,
|  | bool | packed |
| ) |  |  | `[private]`

Generate cuts from matrix copy and solution If packed true then <=1 rows, otherwise >=1 rows.

## Friends And Related Function Documentation

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

A function that tests the methods in the CglOddHole 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

int* CglOddHole::suitableRows_`[private]`

list of suitableRows

Definition at line 129 of file CglOddHole.hpp.

int* CglOddHole::startClique_`[private]`

start of each clique

Definition at line 131 of file CglOddHole.hpp.

int* CglOddHole::member_`[private]`

clique members

Definition at line 133 of file CglOddHole.hpp.

double CglOddHole::epsilon_`[private]`

epsilon

Definition at line 135 of file CglOddHole.hpp.

double CglOddHole::onetol_`[private]`

1-epsilon

Definition at line 137 of file CglOddHole.hpp.

double CglOddHole::minimumViolation_`[private]`

Minimum violation.

Definition at line 139 of file CglOddHole.hpp.

double CglOddHole::minimumViolationPer_`[private]`

Minimum violation per entry.

Definition at line 141 of file CglOddHole.hpp.

int CglOddHole::maximumEntries_`[private]`

Maximum number of entries in a cut.

Definition at line 143 of file CglOddHole.hpp.

int CglOddHole::numberRows_`[private]`

number of rows when suitability tested

Definition at line 145 of file CglOddHole.hpp.

int CglOddHole::numberCliques_`[private]`

number of cliques

Definition at line 147 of file CglOddHole.hpp.

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

- /home/coin/svn-release/Alps-1.5.2/Cgl/src/CglOddHole/CglOddHole.hpp