# OsiChooseStrong Class Reference

This class chooses a variable to branch on. More...

`#include <OsiChooseVariable.hpp>`

Inheritance diagram for OsiChooseStrong:
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Collaboration diagram for OsiChooseStrong:
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List of all members.

## Public Member Functions
| OsiChooseStrong ()
| Default Constructor.
| OsiChooseStrong (const OsiSolverInterface *solver)
| Constructor from solver (so we can set up arrays etc).
| OsiChooseStrong (const OsiChooseStrong &)
| Copy constructor.
OsiChooseStrong & | operator= (const OsiChooseStrong &rhs)
| Assignment operator.
virtual OsiChooseVariable * | clone () const
| Clone.
virtual | ~OsiChooseStrong ()
| Destructor.
virtual int | setupList (OsiBranchingInformation *info, bool initialize)
| Sets up strong list and clears all if initialize is true.
virtual int | chooseVariable (OsiSolverInterface *solver, OsiBranchingInformation *info, bool fixVariables)
| Choose a variable Returns - -1 Node is infeasible 0 Normal termination - we have a candidate 1 All looks satisfied - no candidate 2 We can change the bound on a variable - but we also have a strong branching candidate 3 We can change the bound on a variable - but we have a non-strong branching candidate 4 We can change the bound on a variable - no other candidates We can pick up branch from bestObjectIndex() and bestWhichWay() We can pick up a forced branch (can change bound) from firstForcedObjectIndex() and firstForcedWhichWay() If we have a solution then we can pick up from goodObjectiveValue() and goodSolution() If fixVariables is true then 2,3,4 are all really same as problem changed.
int | shadowPriceMode () const
| Pseudo Shadow Price mode 0 - off 1 - use if no strong info 2 - use if strong not trusted 3 - use even if trusted.
void | setShadowPriceMode (int value)
| Set Shadow price mode.
const OsiPseudoCosts & | pseudoCosts () const
| Accessor method to pseudo cost object.
OsiPseudoCosts & | pseudoCosts ()
| Accessor method to pseudo cost object.
int | numberBeforeTrusted () const
| A feww pass-through methods to access members of pseudoCosts_ as if they were members of OsiChooseStrong object.
void | setNumberBeforeTrusted (int value)
int | numberObjects () const
## Protected Member Functions
int | doStrongBranching (OsiSolverInterface *solver, OsiBranchingInformation *info, int numberToDo, int returnCriterion)
| This is a utility function which does strong branching on a list of objects and stores the results in OsiHotInfo.objects.
void | resetResults (int num)
| Clear out the results array.
## Protected Attributes
int | shadowPriceMode_
| Pseudo Shadow Price mode 0 - off 1 - use and multiply by strong info 2 - use.
OsiPseudoCosts | pseudoCosts_
| The pseudo costs for the chooser.
OsiHotInfo * | results_
| The results of the strong branching done on the candidates where the pseudocosts were not sufficient.
int | numResults_
| The number of OsiHotInfo objetcs that contain information.

## Detailed Description

This class chooses a variable to branch on.

This chooses the variable and direction with reliability strong branching.

The flow is : a) initialize the process. This decides on strong branching list and stores indices of all infeasible objects b) do strong branching on list. If list is empty then just choose one candidate and return without strong branching. If not empty then go through list and return best. However we may find that the node is infeasible or that we can fix a variable. If so we return and it is up to user to call again (after fixing a variable).

Definition at line 318 of file OsiChooseVariable.hpp.

## Constructor & Destructor Documentation

OsiChooseStrong::OsiChooseStrong | ( |  | ) |

Default Constructor.

OsiChooseStrong::OsiChooseStrong | ( | const OsiSolverInterface * | solver | ) |

Constructor from solver (so we can set up arrays etc).

OsiChooseStrong::OsiChooseStrong | ( | const OsiChooseStrong & |  | ) |

Copy constructor.

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

Destructor.

## Member Function Documentation

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

Assignment operator.

Reimplemented from OsiChooseVariable.

virtual OsiChooseVariable* OsiChooseStrong::clone | ( |  | ) | const`[virtual]`

Clone.

Reimplemented from OsiChooseVariable.

virtual int OsiChooseStrong::setupList | ( | OsiBranchingInformation * | info,
|  | bool | initialize |
| ) |  |  | `[virtual]`

Sets up strong list and clears all if initialize is true.

Returns number of infeasibilities. If returns -1 then has worked out node is infeasible!

Reimplemented from OsiChooseVariable.

virtual int OsiChooseStrong::chooseVariable | ( | OsiSolverInterface * | solver,
|  | OsiBranchingInformation * | info,
|  | bool | fixVariables |
| ) |  |  | `[virtual]`

Choose a variable Returns - -1 Node is infeasible 0 Normal termination - we have a candidate 1 All looks satisfied - no candidate 2 We can change the bound on a variable - but we also have a strong branching candidate 3 We can change the bound on a variable - but we have a non-strong branching candidate 4 We can change the bound on a variable - no other candidates We can pick up branch from bestObjectIndex() and bestWhichWay() We can pick up a forced branch (can change bound) from firstForcedObjectIndex() and firstForcedWhichWay() If we have a solution then we can pick up from goodObjectiveValue() and goodSolution() If fixVariables is true then 2,3,4 are all really same as problem changed.

Reimplemented from OsiChooseVariable.

int OsiChooseStrong::shadowPriceMode | ( |  | ) | const`[inline]`

Pseudo Shadow Price mode 0 - off 1 - use if no strong info 2 - use if strong not trusted 3 - use even if trusted.

Definition at line 366 of file OsiChooseVariable.hpp.

void OsiChooseStrong::setShadowPriceMode | ( | int | value | ) | `[inline]`

Set Shadow price mode.

Definition at line 369 of file OsiChooseVariable.hpp.

const OsiPseudoCosts& OsiChooseStrong::pseudoCosts | ( |  | ) | const`[inline]`

Accessor method to pseudo cost object.

Definition at line 373 of file OsiChooseVariable.hpp.

OsiPseudoCosts& OsiChooseStrong::pseudoCosts | ( |  | ) | `[inline]`

Accessor method to pseudo cost object.

Definition at line 377 of file OsiChooseVariable.hpp.

int OsiChooseStrong::numberBeforeTrusted | ( |  | ) | const`[inline]`

A feww pass-through methods to access members of pseudoCosts_ as if they were members of OsiChooseStrong object.

Definition at line 382 of file OsiChooseVariable.hpp.

void OsiChooseStrong::setNumberBeforeTrusted | ( | int | value | ) | `[inline]`

Definition at line 384 of file OsiChooseVariable.hpp.

int OsiChooseStrong::numberObjects | ( |  | ) | const`[inline]`

Definition at line 386 of file OsiChooseVariable.hpp.

int OsiChooseStrong::doStrongBranching | ( | OsiSolverInterface * | solver,
|  | OsiBranchingInformation * | info,
|  | int | numberToDo,
|  | int | returnCriterion |
| ) |  |  | `[protected]`

This is a utility function which does strong branching on a list of objects and stores the results in OsiHotInfo.objects.

On entry the object sequence is stored in the OsiHotInfo object and maybe more. It returns - -1 - one branch was infeasible both ways 0 - all inspected - nothing can be fixed 1 - all inspected - some can be fixed (returnCriterion==0) 2 - may be returning early - one can be fixed (last one done) (returnCriterion==1) 3 - returning because max time

void OsiChooseStrong::resetResults | ( | int | num | ) | `[protected]`

Clear out the results array.

## Member Data Documentation

int OsiChooseStrong::shadowPriceMode_`[protected]`

Pseudo Shadow Price mode 0 - off 1 - use and multiply by strong info 2 - use.

Definition at line 416 of file OsiChooseVariable.hpp.

OsiPseudoCosts OsiChooseStrong::pseudoCosts_`[protected]`

The pseudo costs for the chooser.

Definition at line 419 of file OsiChooseVariable.hpp.

OsiHotInfo* OsiChooseStrong::results_`[protected]`

The results of the strong branching done on the candidates where the pseudocosts were not sufficient.

Definition at line 423 of file OsiChooseVariable.hpp.

int OsiChooseStrong::numResults_`[protected]`

The number of OsiHotInfo objetcs that contain information.

Definition at line 425 of file OsiChooseVariable.hpp.

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

- /home/coin/svn-release/Alps-1.4.8/Osi/src/Osi/OsiChooseVariable.hpp