OsiObject Class Reference

Abstract base class for `objects'. More...

#include <OsiBranchingObject.hpp>

Inheritance diagram for OsiObject:
Inheritance graph
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List of all members.

Public Member Functions

 OsiObject ()
 Default Constructor.
 OsiObject (const OsiObject &)
 Copy constructor.
OsiObjectoperator= (const OsiObject &rhs)
 Assignment operator.
virtual OsiObjectclone () const =0
 Clone.
virtual ~OsiObject ()
 Destructor.
double infeasibility (const OsiSolverInterface *solver, int &whichWay) const
 Infeasibility of the object.
virtual double infeasibility (const OsiBranchingInformation *info, int &whichWay) const =0
virtual double checkInfeasibility (const OsiBranchingInformation *info) const
virtual double feasibleRegion (OsiSolverInterface *solver) const
 For the variable(s) referenced by the object, look at the current solution and set bounds to match the solution.
virtual double feasibleRegion (OsiSolverInterface *solver, const OsiBranchingInformation *info) const =0
 For the variable(s) referenced by the object, look at the current solution and set bounds to match the solution.
virtual OsiBranchingObjectcreateBranch (OsiSolverInterface *, const OsiBranchingInformation *, int) const
 Create a branching object and indicate which way to branch first.
virtual bool canDoHeuristics () const
 Return true if object can take part in normal heuristics.
virtual bool canMoveToNearest () const
 Return true if object can take part in move to nearest heuristic.
virtual int columnNumber () const
 Column number if single column object -1 otherwise, Used by heuristics.
int priority () const
 Return Priority - note 1 is highest priority.
void setPriority (int priority)
 Set priority.
virtual bool boundBranch () const
 Return true if branch should only bound variables.
virtual bool canHandleShadowPrices () const
 Return true if knows how to deal with Pseudo Shadow Prices.
int numberWays () const
 Return maximum number of ways branch may have.
void setNumberWays (int numberWays)
 Set maximum number of ways branch may have.
void setWhichWay (int way)
 Return preferred way to branch.
int whichWay () const
 Return current preferred way to branch.
virtual int preferredWay () const
 Get pre-emptive preferred way of branching - -1 off, 0 down, 1 up (for 2-way).
double infeasibility () const
 Return infeasibility.
virtual double upEstimate () const
 Return "up" estimate (default 1.0e-5).
virtual double downEstimate () const
 Return "down" estimate (default 1.0e-5).
virtual void resetBounds (const OsiSolverInterface *)
 Reset variable bounds to their original values.
virtual void resetSequenceEtc (int, const int *)
 Change column numbers after preprocessing.
virtual void updateBefore (const OsiObject *)
 Updates stuff like pseudocosts before threads.
virtual void updateAfter (const OsiObject *, const OsiObject *)
 Updates stuff like pseudocosts after threads finished.

Protected Attributes

double infeasibility_
 data
short whichWay_
 Computed preferred way to branch.
short numberWays_
 Maximum number of ways on branch.
int priority_
 Priority.

Detailed Description

Abstract base class for `objects'.

The branching model used in Osi is based on the idea of an object. In the abstract, an object is something that has a feasible region, can be evaluated for infeasibility, can be branched on (i.e., there's some constructive action to be taken to move toward feasibility), and allows comparison of the effect of branching.

This class (OsiObject) is the base class for an object. To round out the branching model, the class OsiBranchingObject describes how to perform a branch, and the class OsiBranchDecision describes how to compare two OsiBranchingObjects.

To create a new type of object you need to provide three methods: infeasibility(), feasibleRegion(), and createBranch(), described below.

This base class is primarily virtual to allow for any form of structure. Any form of discontinuity is allowed.

As there is an overhead in getting information from solvers and because other useful information is available there is also an OsiBranchingInformation class which can contain pointers to information. If used it must at minimum contain pointers to current value of objective, maximum allowed objective and pointers to arrays for bounds and solution and direction of optimization. Also integer and primal tolerance.

Classes which inherit might have other information such as depth, number of solutions, pseudo-shadow prices etc etc. May be easier just to throw in here - as I keep doing

Definition at line 53 of file OsiBranchingObject.hpp.


Constructor & Destructor Documentation

OsiObject::OsiObject (  ) 

Default Constructor.

OsiObject::OsiObject ( const OsiObject  ) 

Copy constructor.

virtual OsiObject::~OsiObject (  )  [virtual]

Destructor.


Member Function Documentation

OsiObject& OsiObject::operator= ( const OsiObject rhs  ) 

Assignment operator.

virtual OsiObject* OsiObject::clone (  )  const [pure virtual]

Clone.

Implemented in OsiSimpleInteger, OsiSOS, and OsiLotsize.

double OsiObject::infeasibility ( const OsiSolverInterface solver,
int &  whichWay 
) const

Infeasibility of the object.

This is some measure of the infeasibility of the object. 0.0 indicates that the object is satisfied.

The preferred branching direction is returned in whichWay, where for normal two-way branching 0 is down, 1 is up

This is used to prepare for strong branching but should also think of case when no strong branching

The object may also compute an estimate of cost of going "up" or "down". This will probably be based on pseudo-cost ideas

This should also set mutable infeasibility_ and whichWay_ This is for instant re-use for speed

Default for this just calls infeasibility with OsiBranchingInformation NOTE - Convention says that an infeasibility of COIN_DBL_MAX means object has worked out it can't be satisfied!

virtual double OsiObject::infeasibility ( const OsiBranchingInformation info,
int &  whichWay 
) const [pure virtual]

Implemented in OsiSimpleInteger, OsiSOS, and OsiLotsize.

virtual double OsiObject::checkInfeasibility ( const OsiBranchingInformation info  )  const [virtual]
virtual double OsiObject::feasibleRegion ( OsiSolverInterface solver  )  const [virtual]

For the variable(s) referenced by the object, look at the current solution and set bounds to match the solution.

Returns measure of how much it had to move solution to make feasible

virtual double OsiObject::feasibleRegion ( OsiSolverInterface solver,
const OsiBranchingInformation info 
) const [pure virtual]

For the variable(s) referenced by the object, look at the current solution and set bounds to match the solution.

Returns measure of how much it had to move solution to make feasible Faster version

Implemented in OsiSimpleInteger, OsiSOS, and OsiLotsize.

virtual OsiBranchingObject* OsiObject::createBranch ( OsiSolverInterface ,
const OsiBranchingInformation ,
int   
) const [inline, virtual]

Create a branching object and indicate which way to branch first.

The branching object has to know how to create branches (fix variables, etc.)

Reimplemented in OsiSimpleInteger, OsiSOS, and OsiLotsize.

Definition at line 116 of file OsiBranchingObject.hpp.

virtual bool OsiObject::canDoHeuristics (  )  const [inline, virtual]

Return true if object can take part in normal heuristics.

Reimplemented in OsiSOS, and OsiLotsize.

Definition at line 122 of file OsiBranchingObject.hpp.

virtual bool OsiObject::canMoveToNearest (  )  const [inline, virtual]

Return true if object can take part in move to nearest heuristic.

Definition at line 126 of file OsiBranchingObject.hpp.

virtual int OsiObject::columnNumber (  )  const [virtual]

Column number if single column object -1 otherwise, Used by heuristics.

Reimplemented in OsiSimpleInteger, and OsiLotsize.

int OsiObject::priority (  )  const [inline]

Return Priority - note 1 is highest priority.

Definition at line 133 of file OsiBranchingObject.hpp.

void OsiObject::setPriority ( int  priority  )  [inline]

Set priority.

Definition at line 136 of file OsiBranchingObject.hpp.

virtual bool OsiObject::boundBranch (  )  const [inline, virtual]

Return true if branch should only bound variables.

Definition at line 140 of file OsiBranchingObject.hpp.

virtual bool OsiObject::canHandleShadowPrices (  )  const [inline, virtual]

Return true if knows how to deal with Pseudo Shadow Prices.

Reimplemented in OsiSimpleInteger, OsiSOS, and OsiLotsize.

Definition at line 143 of file OsiBranchingObject.hpp.

int OsiObject::numberWays (  )  const [inline]

Return maximum number of ways branch may have.

Definition at line 146 of file OsiBranchingObject.hpp.

void OsiObject::setNumberWays ( int  numberWays  )  [inline]

Set maximum number of ways branch may have.

Definition at line 149 of file OsiBranchingObject.hpp.

void OsiObject::setWhichWay ( int  way  )  [inline]

Return preferred way to branch.

If two then way=0 means down and 1 means up, otherwise way points to preferred branch

Definition at line 155 of file OsiBranchingObject.hpp.

int OsiObject::whichWay (  )  const [inline]

Return current preferred way to branch.

If two then way=0 means down and 1 means up, otherwise way points to preferred branch

Definition at line 161 of file OsiBranchingObject.hpp.

virtual int OsiObject::preferredWay (  )  const [inline, virtual]

Get pre-emptive preferred way of branching - -1 off, 0 down, 1 up (for 2-way).

Reimplemented in OsiObject2.

Definition at line 164 of file OsiBranchingObject.hpp.

double OsiObject::infeasibility (  )  const [inline]

Return infeasibility.

Definition at line 167 of file OsiBranchingObject.hpp.

virtual double OsiObject::upEstimate (  )  const [virtual]

Return "up" estimate (default 1.0e-5).

Reimplemented in OsiSimpleInteger, OsiSOS, and OsiLotsize.

virtual double OsiObject::downEstimate (  )  const [virtual]

Return "down" estimate (default 1.0e-5).

Reimplemented in OsiSimpleInteger, OsiSOS, and OsiLotsize.

virtual void OsiObject::resetBounds ( const OsiSolverInterface  )  [inline, virtual]

Reset variable bounds to their original values.

Bounds may be tightened, so it may be good to be able to reset them to their original values.

Reimplemented in OsiSimpleInteger, and OsiLotsize.

Definition at line 177 of file OsiBranchingObject.hpp.

virtual void OsiObject::resetSequenceEtc ( int  ,
const int *   
) [inline, virtual]

Change column numbers after preprocessing.

Reimplemented in OsiSimpleInteger, OsiSOS, and OsiLotsize.

Definition at line 180 of file OsiBranchingObject.hpp.

virtual void OsiObject::updateBefore ( const OsiObject  )  [inline, virtual]

Updates stuff like pseudocosts before threads.

Definition at line 182 of file OsiBranchingObject.hpp.

virtual void OsiObject::updateAfter ( const OsiObject ,
const OsiObject  
) [inline, virtual]

Updates stuff like pseudocosts after threads finished.

Definition at line 184 of file OsiBranchingObject.hpp.


Member Data Documentation

double OsiObject::infeasibility_ [mutable, protected]

data

Computed infeasibility

Definition at line 190 of file OsiBranchingObject.hpp.

short OsiObject::whichWay_ [mutable, protected]

Computed preferred way to branch.

Definition at line 192 of file OsiBranchingObject.hpp.

short OsiObject::numberWays_ [protected]

Maximum number of ways on branch.

Definition at line 194 of file OsiBranchingObject.hpp.

int OsiObject::priority_ [protected]

Priority.

Definition at line 196 of file OsiBranchingObject.hpp.


The documentation for this class was generated from the following file:
Generated on Sat Jul 10 18:05:44 2010 by  doxygen 1.6.3