# OsiChooseVariable Class Reference

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

`#include <OsiChooseVariable.hpp>`

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

## Public Member Functions
| OsiChooseVariable ()
| Default Constructor.
| OsiChooseVariable (const OsiSolverInterface *solver)
| Constructor from solver (so we can set up arrays etc).
| OsiChooseVariable (const OsiChooseVariable &)
| Copy constructor.
OsiChooseVariable & | operator= (const OsiChooseVariable &rhs)
| Assignment operator.
virtual OsiChooseVariable * | clone () const
| Clone.
virtual | ~OsiChooseVariable ()
| 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.
virtual bool | feasibleSolution (const OsiBranchingInformation *info, const double *solution, int numberObjects, const OsiObject **objects)
| Returns true if solution looks feasible against given objects.
void | saveSolution (const OsiSolverInterface *solver)
| Saves a good solution.
void | clearGoodSolution ()
| Clears out good solution after use.
virtual void | updateInformation (const OsiBranchingInformation *info, int branch, OsiHotInfo *hotInfo)
| Given a candidate fill in useful information e.g. estimates.
virtual void | updateInformation (int whichObject, int branch, double changeInObjective, double changeInValue, int status)
| Given a branch fill in useful information e.g. estimates.
double | goodObjectiveValue () const
| Objective value for feasible solution.
double | upChange () const
| Estimate of up change or change on chosen if n-way.
double | downChange () const
| Estimate of down change or max change on other possibilities if n-way.
const double * | goodSolution () const
| Good solution - deleted by finalize.
int | bestObjectIndex () const
| Index of chosen object.
void | setBestObjectIndex (int value)
| Set index of chosen object.
int | bestWhichWay () const
| Preferred way of chosen object.
void | setBestWhichWay (int value)
| Set preferred way of chosen object.
int | firstForcedObjectIndex () const
| Index of forced object.
void | setFirstForcedObjectIndex (int value)
| Set index of forced object.
int | firstForcedWhichWay () const
| Preferred way of forced object.
void | setFirstForcedWhichWay (int value)
| Set preferred way of forced object.
int | numberUnsatisfied () const
| Get the number of objects unsatisfied at this node - accurate on first pass.
int | numberStrong () const
| Number of objects to choose for strong branching.
void | setNumberStrong (int value)
| Set number of objects to choose for strong branching.
int | numberOnList () const
| Number left on strong list.
int | numberStrongDone () const
| Number of strong branches actually done.
int | numberStrongIterations () const
| Number of strong iterations actually done.
int | numberStrongFixed () const
| Number of strong branches which changed bounds.
const int * | candidates () const
| List of candidates.
bool | trustStrongForBound () const
| Trust results from strong branching for changing bounds.
void | setTrustStrongForBound (bool yesNo)
| Set trust results from strong branching for changing bounds.
bool | trustStrongForSolution () const
| Trust results from strong branching for valid solution.
void | setTrustStrongForSolution (bool yesNo)
| Set trust results from strong branching for valid solution.
void | setSolver (const OsiSolverInterface *solver)
| Set solver and redo arrays.
int | status () const
| Return status - -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().
void | setStatus (int value)
## Protected Attributes
double | goodObjectiveValue_
| Objective value for feasible solution.
double | upChange_
| Estimate of up change or change on chosen if n-way.
double | downChange_
| Estimate of down change or max change on other possibilities if n-way.
double * | goodSolution_
| Good solution - deleted by finalize.
int * | list_
| List of candidates.
double * | useful_
| Useful array (for sorting etc).
const OsiSolverInterface * | solver_
| Pointer to solver.
int | status_
int | bestObjectIndex_
| Index of chosen object.
int | bestWhichWay_
| Preferred way of chosen object.
int | firstForcedObjectIndex_
| Index of forced object.
int | firstForcedWhichWay_
| Preferred way of forced object.
int | numberUnsatisfied_
| The number of objects unsatisfied at this node.
int | numberStrong_
| Number of objects to choose for strong branching.
int | numberOnList_
| Number left on strong list.
int | numberStrongDone_
| Number of strong branches actually done.
int | numberStrongIterations_
| Number of strong iterations actually done.
int | numberStrongFixed_
| Number of bound changes due to strong branching.
bool | trustStrongForBound_
| List of unsatisfied objects - first numberOnList_ for strong branching Trust results from strong branching for changing bounds.
bool | trustStrongForSolution_
| Trust results from strong branching for valid solution.

## Detailed Description

This class chooses a variable to branch on.

The base class just chooses the variable and direction without strong branching but it has information which would normally be used by strong branching e.g. to re-enter having fixed a variable but using same candidates for 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 33 of file OsiChooseVariable.hpp.

## Constructor & Destructor Documentation

OsiChooseVariable::OsiChooseVariable | ( |  | ) |

Default Constructor.

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

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

OsiChooseVariable::OsiChooseVariable | ( | const OsiChooseVariable & |  | ) |

Copy constructor.

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

Destructor.

## Member Function Documentation

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

Assignment operator.

Reimplemented in OsiChooseStrong.

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

Clone.

Reimplemented in OsiChooseStrong.

virtual int OsiChooseVariable::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 in OsiChooseStrong.

virtual int OsiChooseVariable::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 in OsiChooseStrong.

virtual bool OsiChooseVariable::feasibleSolution | ( | const OsiBranchingInformation * | info,
|  | const double * | solution,
|  | int | numberObjects,
|  | const OsiObject ** | objects |
| ) |  |  | `[virtual]`

Returns true if solution looks feasible against given objects.

void OsiChooseVariable::saveSolution | ( | const OsiSolverInterface * | solver | ) |

Saves a good solution.

void OsiChooseVariable::clearGoodSolution | ( |  | ) |

Clears out good solution after use.

virtual void OsiChooseVariable::updateInformation | ( | const OsiBranchingInformation * | info,
|  | int | branch,
|  | OsiHotInfo * | hotInfo |
| ) |  |  | `[virtual]`

Given a candidate fill in useful information e.g. estimates.

virtual void OsiChooseVariable::updateInformation | ( | int | whichObject,
|  | int | branch,
|  | double | changeInObjective,
|  | double | changeInValue,
|  | int | status |
| ) |  |  | `[virtual]`

Given a branch fill in useful information e.g. estimates.

double OsiChooseVariable::goodObjectiveValue | ( |  | ) | const`[inline]`

Objective value for feasible solution.

Definition at line 93 of file OsiChooseVariable.hpp.

double OsiChooseVariable::upChange | ( |  | ) | const`[inline]`

Estimate of up change or change on chosen if n-way.

Definition at line 96 of file OsiChooseVariable.hpp.

double OsiChooseVariable::downChange | ( |  | ) | const`[inline]`

Estimate of down change or max change on other possibilities if n-way.

Definition at line 99 of file OsiChooseVariable.hpp.

const double* OsiChooseVariable::goodSolution | ( |  | ) | const`[inline]`

Good solution - deleted by finalize.

Definition at line 102 of file OsiChooseVariable.hpp.

int OsiChooseVariable::bestObjectIndex | ( |  | ) | const`[inline]`

Index of chosen object.

Definition at line 105 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setBestObjectIndex | ( | int | value | ) | `[inline]`

Set index of chosen object.

Definition at line 108 of file OsiChooseVariable.hpp.

int OsiChooseVariable::bestWhichWay | ( |  | ) | const`[inline]`

Preferred way of chosen object.

Definition at line 111 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setBestWhichWay | ( | int | value | ) | `[inline]`

Set preferred way of chosen object.

Definition at line 114 of file OsiChooseVariable.hpp.

int OsiChooseVariable::firstForcedObjectIndex | ( |  | ) | const`[inline]`

Index of forced object.

Definition at line 117 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setFirstForcedObjectIndex | ( | int | value | ) | `[inline]`

Set index of forced object.

Definition at line 120 of file OsiChooseVariable.hpp.

int OsiChooseVariable::firstForcedWhichWay | ( |  | ) | const`[inline]`

Preferred way of forced object.

Definition at line 123 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setFirstForcedWhichWay | ( | int | value | ) | `[inline]`

Set preferred way of forced object.

Definition at line 126 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberUnsatisfied | ( |  | ) | const`[inline]`

Get the number of objects unsatisfied at this node - accurate on first pass.

Definition at line 129 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrong | ( |  | ) | const`[inline]`

Number of objects to choose for strong branching.

Definition at line 132 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setNumberStrong | ( | int | value | ) | `[inline]`

Set number of objects to choose for strong branching.

Definition at line 135 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberOnList | ( |  | ) | const`[inline]`

Number left on strong list.

Definition at line 138 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrongDone | ( |  | ) | const`[inline]`

Number of strong branches actually done.

Definition at line 141 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrongIterations | ( |  | ) | const`[inline]`

Number of strong iterations actually done.

Definition at line 144 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrongFixed | ( |  | ) | const`[inline]`

Number of strong branches which changed bounds.

Definition at line 147 of file OsiChooseVariable.hpp.

const int* OsiChooseVariable::candidates | ( |  | ) | const`[inline]`

List of candidates.

Definition at line 150 of file OsiChooseVariable.hpp.

bool OsiChooseVariable::trustStrongForBound | ( |  | ) | const`[inline]`

Trust results from strong branching for changing bounds.

Definition at line 153 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setTrustStrongForBound | ( | bool | yesNo | ) | `[inline]`

Set trust results from strong branching for changing bounds.

Definition at line 156 of file OsiChooseVariable.hpp.

bool OsiChooseVariable::trustStrongForSolution | ( |  | ) | const`[inline]`

Trust results from strong branching for valid solution.

Definition at line 159 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setTrustStrongForSolution | ( | bool | yesNo | ) | `[inline]`

Set trust results from strong branching for valid solution.

Definition at line 162 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setSolver | ( | const OsiSolverInterface * | solver | ) |

Set solver and redo arrays.

int OsiChooseVariable::status | ( |  | ) | const`[inline]`

Return status - -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().

Definition at line 177 of file OsiChooseVariable.hpp.

void OsiChooseVariable::setStatus | ( | int | value | ) | `[inline]`

Definition at line 179 of file OsiChooseVariable.hpp.

## Member Data Documentation

double OsiChooseVariable::goodObjectiveValue_`[protected]`

Objective value for feasible solution.

Definition at line 186 of file OsiChooseVariable.hpp.

double OsiChooseVariable::upChange_`[protected]`

Estimate of up change or change on chosen if n-way.

Definition at line 188 of file OsiChooseVariable.hpp.

double OsiChooseVariable::downChange_`[protected]`

Estimate of down change or max change on other possibilities if n-way.

Definition at line 190 of file OsiChooseVariable.hpp.

double* OsiChooseVariable::goodSolution_`[protected]`

Good solution - deleted by finalize.

Definition at line 192 of file OsiChooseVariable.hpp.

int* OsiChooseVariable::list_`[protected]`

List of candidates.

Definition at line 194 of file OsiChooseVariable.hpp.

double* OsiChooseVariable::useful_`[protected]`

Useful array (for sorting etc).

Definition at line 196 of file OsiChooseVariable.hpp.

const OsiSolverInterface* OsiChooseVariable::solver_`[protected]`

Pointer to solver.

Definition at line 198 of file OsiChooseVariable.hpp.

int OsiChooseVariable::status_`[protected]`

Definition at line 207 of file OsiChooseVariable.hpp.

int OsiChooseVariable::bestObjectIndex_`[protected]`

Index of chosen object.

Definition at line 209 of file OsiChooseVariable.hpp.

int OsiChooseVariable::bestWhichWay_`[protected]`

Preferred way of chosen object.

Definition at line 211 of file OsiChooseVariable.hpp.

int OsiChooseVariable::firstForcedObjectIndex_`[protected]`

Index of forced object.

Definition at line 213 of file OsiChooseVariable.hpp.

int OsiChooseVariable::firstForcedWhichWay_`[protected]`

Preferred way of forced object.

Definition at line 215 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberUnsatisfied_`[protected]`

The number of objects unsatisfied at this node.

Definition at line 217 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrong_`[protected]`

Number of objects to choose for strong branching.

Definition at line 219 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberOnList_`[protected]`

Number left on strong list.

Definition at line 221 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrongDone_`[protected]`

Number of strong branches actually done.

Definition at line 223 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrongIterations_`[protected]`

Number of strong iterations actually done.

Definition at line 225 of file OsiChooseVariable.hpp.

int OsiChooseVariable::numberStrongFixed_`[protected]`

Number of bound changes due to strong branching.

Definition at line 227 of file OsiChooseVariable.hpp.

bool OsiChooseVariable::trustStrongForBound_`[protected]`

List of unsatisfied objects - first numberOnList_ for strong branching Trust results from strong branching for changing bounds.

Definition at line 230 of file OsiChooseVariable.hpp.

bool OsiChooseVariable::trustStrongForSolution_`[protected]`

Trust results from strong branching for valid solution.

Definition at line 232 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