CbcNode Class Reference

Information required while the node is live. More...

#include <CbcNode.hpp>

List of all members.

Public Member Functions

 CbcNode ()
 Default Constructor.
 CbcNode (CbcModel *model, CbcNode *lastNode)
 Construct and increment parent reference count.
 CbcNode (const CbcNode &)
 Copy constructor.
CbcNodeoperator= (const CbcNode &rhs)
 Assignment operator.
 ~CbcNode ()
 Destructor.
void createInfo (CbcModel *model, CbcNode *lastNode, const CoinWarmStartBasis *lastws, const double *lastLower, const double *lastUpper, int numberOldActiveCuts, int numberNewCuts)
 Create a description of the subproblem at this node.
int chooseBranch (CbcModel *model, CbcNode *lastNode, int numberPassesLeft)
 Create a branching object for the node.
int chooseDynamicBranch (CbcModel *model, CbcNode *lastNode, OsiSolverBranch *&branches, int numberPassesLeft)
 Create a branching object for the node - when dynamic pseudo costs.
int chooseOsiBranch (CbcModel *model, CbcNode *lastNode, OsiBranchingInformation *usefulInfo, int branchState)
 Create a branching object for the node.
int chooseClpBranch (CbcModel *model, CbcNode *lastNode)
 Create a branching object for the node.
int analyze (CbcModel *model, double *results)
void decrementCuts (int change=1)
 Decrement active cut counts.
void decrementParentCuts (CbcModel *model, int change=1)
 Decrement all active cut counts in chain starting at parent.
void nullNodeInfo ()
 Nulls out node info.
void initializeInfo ()
 Initialize reference counts in attached CbcNodeInfo.
int branch (OsiSolverInterface *solver)
 Does next branch and updates state.
double checkIsCutoff (double cutoff)
 Double checks in case node can change its mind! Returns objective value Can change objective etc.
CbcNodeInfonodeInfo () const
double objectiveValue () const
void setObjectiveValue (double value)
int numberBranches () const
 Number of arms defined for the attached OsiBranchingObject.
int way () const
int depth () const
 Depth in branch-and-cut search tree.
void setDepth (int value)
 Set depth in branch-and-cut search tree.
int numberUnsatisfied () const
 Get the number of objects unsatisfied at this node.
void setNumberUnsatisfied (int value)
 Set the number of objects unsatisfied at this node.
double sumInfeasibilities () const
 Get sum of "infeasibilities" reported by each object.
void setSumInfeasibilities (double value)
 Set sum of "infeasibilities" reported by each object.
double guessedObjectiveValue () const
void setGuessedObjectiveValue (double value)
const OsiBranchingObject * branchingObject () const
 Branching object for this node.
OsiBranchingObject * modifiableBranchingObject () const
 Modifiable branching object for this node.
void setBranchingObject (OsiBranchingObject *branchingObject)
 Set branching object for this node (takes ownership).
int nodeNumber () const
 The node number.
void setNodeNumber (int node)
bool onTree () const
 Returns true if on tree.
void setOnTree (bool yesNo)
 Sets true if on tree.
bool active () const
 Returns true if active.
void setActive (bool yesNo)
 Sets true if active.
void print () const
 Print.
void checkInfo () const
 Debug.

Private Attributes

CbcNodeInfonodeInfo_
 Information to make basis and bounds.
double objectiveValue_
 Objective value.
double guessedObjectiveValue_
 Guessed satisfied Objective value.
double sumInfeasibilities_
 Sum of "infeasibilities" reported by each object.
OsiBranchingObject * branch_
 Branching object for this node.
int depth_
 Depth of the node in the search tree.
int numberUnsatisfied_
 The number of objects unsatisfied at this node.
int nodeNumber_
 The node number.
int state_
 State 1 - on tree 2 - active.

Detailed Description

Information required while the node is live.

When a subproblem is initially created, it is represented by an CbcNode object and an attached CbcNodeInfo object.

The CbcNode contains information (depth, branching instructions), that's needed while the subproblem remains `live', i.e., while the subproblem is not fathomed and there are branch arms still be be evaluated. The CbcNode is deleted when the last branch arm has been evaluated.

The CbcNodeInfo object contains the information needed to maintain the search tree and recreate the subproblem for the node. It remains in existence until there are no nodes remaining in the subtree rooted at this node.

Definition at line 474 of file CbcNode.hpp.


Constructor & Destructor Documentation

CbcNode::CbcNode (  ) 

Default Constructor.

CbcNode::CbcNode ( CbcModel model,
CbcNode lastNode 
)

Construct and increment parent reference count.

CbcNode::CbcNode ( const CbcNode  ) 

Copy constructor.

CbcNode::~CbcNode (  ) 

Destructor.


Member Function Documentation

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

Assignment operator.

void CbcNode::createInfo ( CbcModel model,
CbcNode lastNode,
const CoinWarmStartBasis *  lastws,
const double *  lastLower,
const double *  lastUpper,
int  numberOldActiveCuts,
int  numberNewCuts 
)

Create a description of the subproblem at this node.

The CbcNodeInfo structure holds the information (basis & variable bounds) required to recreate the subproblem for this node. It also links the node to its parent (via the parent's CbcNodeInfo object).

If lastNode == NULL, a CbcFullNodeInfo object will be created. All parameters except model are unused.

If lastNode != NULL, a CbcPartialNodeInfo object will be created. Basis and bounds information will be stored in the form of differences between the parent subproblem and this subproblem. (More precisely, lastws, lastUpper, lastLower, numberOldActiveCuts, and numberNewCuts are used.)

int CbcNode::chooseBranch ( CbcModel model,
CbcNode lastNode,
int  numberPassesLeft 
)

Create a branching object for the node.

The routine scans the object list of the model and selects a set of unsatisfied objects as candidates for branching. The candidates are evaluated, and an appropriate branch object is installed.

The numberPassesLeft is decremented to stop fixing one variable each time and going on and on (e.g. for stock cutting, air crew scheduling)

If evaluation determines that an object is monotone or infeasible, the routine returns immediately. In the case of a monotone object, the branch object has already been called to modify the model.

Return value:

  • 0: A branching object has been installed
  • -1: A monotone object was discovered
  • -2: An infeasible object was discovered
int CbcNode::chooseDynamicBranch ( CbcModel model,
CbcNode lastNode,
OsiSolverBranch *&  branches,
int  numberPassesLeft 
)

Create a branching object for the node - when dynamic pseudo costs.

The routine scans the object list of the model and selects a set of unsatisfied objects as candidates for branching. The candidates are evaluated, and an appropriate branch object is installed. This version gives preference in evaluation to variables which have not been evaluated many times. It also uses numberStrong to say give up if last few tries have not changed incumbent. See Achterberg, Koch and Martin.

The numberPassesLeft is decremented to stop fixing one variable each time and going on and on (e.g. for stock cutting, air crew scheduling)

If evaluation determines that an object is monotone or infeasible, the routine returns immediately. In the case of a monotone object, the branch object has already been called to modify the model.

Return value:

  • 0: A branching object has been installed
  • -1: A monotone object was discovered
  • -2: An infeasible object was discovered
  • >0: Number of quich branching objects (and branches will be non NULL)
int CbcNode::chooseOsiBranch ( CbcModel model,
CbcNode lastNode,
OsiBranchingInformation *  usefulInfo,
int  branchState 
)

Create a branching object for the node.

The routine scans the object list of the model and selects a set of unsatisfied objects as candidates for branching. The candidates are evaluated, and an appropriate branch object is installed.

The numberPassesLeft is decremented to stop fixing one variable each time and going on and on (e.g. for stock cutting, air crew scheduling)

If evaluation determines that an object is monotone or infeasible, the routine returns immediately. In the case of a monotone object, the branch object has already been called to modify the model.

Return value:

  • 0: A branching object has been installed
  • -1: A monotone object was discovered
  • -2: An infeasible object was discovered

Branch state:

  • -1: start
  • -1: A monotone object was discovered
  • -2: An infeasible object was discovered
int CbcNode::chooseClpBranch ( CbcModel model,
CbcNode lastNode 
)

Create a branching object for the node.

The routine scans the object list of the model and selects a set of unsatisfied objects as candidates for branching. It then solves a series of problems and a CbcGeneral branch object is installed.

If evaluation determines that an object is infeasible, the routine returns immediately.

Return value:

  • 0: A branching object has been installed
  • -2: An infeasible object was discovered
int CbcNode::analyze ( CbcModel model,
double *  results 
)
void CbcNode::decrementCuts ( int  change = 1  ) 

Decrement active cut counts.

void CbcNode::decrementParentCuts ( CbcModel model,
int  change = 1 
)

Decrement all active cut counts in chain starting at parent.

void CbcNode::nullNodeInfo (  ) 

Nulls out node info.

void CbcNode::initializeInfo (  ) 

Initialize reference counts in attached CbcNodeInfo.

This is a convenience routine, which will initialize the reference counts in the attached CbcNodeInfo object based on the attached OsiBranchingObject.

See also:
CbcNodeInfo::initializeInfo(int).
int CbcNode::branch ( OsiSolverInterface *  solver  ) 

Does next branch and updates state.

double CbcNode::checkIsCutoff ( double  cutoff  ) 

Double checks in case node can change its mind! Returns objective value Can change objective etc.

CbcNodeInfo* CbcNode::nodeInfo (  )  const [inline]

Definition at line 641 of file CbcNode.hpp.

double CbcNode::objectiveValue (  )  const [inline]

Definition at line 645 of file CbcNode.hpp.

void CbcNode::setObjectiveValue ( double  value  )  [inline]

Definition at line 647 of file CbcNode.hpp.

int CbcNode::numberBranches (  )  const [inline]

Number of arms defined for the attached OsiBranchingObject.

Definition at line 650 of file CbcNode.hpp.

int CbcNode::way (  )  const
int CbcNode::depth (  )  const [inline]

Depth in branch-and-cut search tree.

Definition at line 664 of file CbcNode.hpp.

void CbcNode::setDepth ( int  value  )  [inline]

Set depth in branch-and-cut search tree.

Definition at line 667 of file CbcNode.hpp.

int CbcNode::numberUnsatisfied (  )  const [inline]

Get the number of objects unsatisfied at this node.

Definition at line 670 of file CbcNode.hpp.

void CbcNode::setNumberUnsatisfied ( int  value  )  [inline]

Set the number of objects unsatisfied at this node.

Definition at line 673 of file CbcNode.hpp.

double CbcNode::sumInfeasibilities (  )  const [inline]

Get sum of "infeasibilities" reported by each object.

Definition at line 676 of file CbcNode.hpp.

void CbcNode::setSumInfeasibilities ( double  value  )  [inline]

Set sum of "infeasibilities" reported by each object.

Definition at line 679 of file CbcNode.hpp.

double CbcNode::guessedObjectiveValue (  )  const [inline]

Definition at line 682 of file CbcNode.hpp.

void CbcNode::setGuessedObjectiveValue ( double  value  )  [inline]

Definition at line 684 of file CbcNode.hpp.

const OsiBranchingObject* CbcNode::branchingObject (  )  const [inline]

Branching object for this node.

Definition at line 687 of file CbcNode.hpp.

OsiBranchingObject* CbcNode::modifiableBranchingObject (  )  const [inline]

Modifiable branching object for this node.

Definition at line 690 of file CbcNode.hpp.

void CbcNode::setBranchingObject ( OsiBranchingObject *  branchingObject  )  [inline]

Set branching object for this node (takes ownership).

Definition at line 693 of file CbcNode.hpp.

int CbcNode::nodeNumber (  )  const [inline]

The node number.

Definition at line 696 of file CbcNode.hpp.

void CbcNode::setNodeNumber ( int  node  )  [inline]

Definition at line 698 of file CbcNode.hpp.

bool CbcNode::onTree (  )  const [inline]

Returns true if on tree.

Definition at line 701 of file CbcNode.hpp.

void CbcNode::setOnTree ( bool  yesNo  )  [inline]

Sets true if on tree.

Definition at line 704 of file CbcNode.hpp.

bool CbcNode::active (  )  const [inline]

Returns true if active.

Definition at line 707 of file CbcNode.hpp.

void CbcNode::setActive ( bool  yesNo  )  [inline]

Sets true if active.

Definition at line 710 of file CbcNode.hpp.

void CbcNode::print (  )  const

Print.

void CbcNode::checkInfo (  )  const [inline]

Debug.

Definition at line 715 of file CbcNode.hpp.


Member Data Documentation

Information to make basis and bounds.

Definition at line 722 of file CbcNode.hpp.

double CbcNode::objectiveValue_ [private]

Objective value.

Definition at line 724 of file CbcNode.hpp.

Guessed satisfied Objective value.

Definition at line 726 of file CbcNode.hpp.

double CbcNode::sumInfeasibilities_ [private]

Sum of "infeasibilities" reported by each object.

Definition at line 728 of file CbcNode.hpp.

OsiBranchingObject* CbcNode::branch_ [private]

Branching object for this node.

Definition at line 730 of file CbcNode.hpp.

int CbcNode::depth_ [private]

Depth of the node in the search tree.

Definition at line 732 of file CbcNode.hpp.

The number of objects unsatisfied at this node.

Definition at line 734 of file CbcNode.hpp.

int CbcNode::nodeNumber_ [private]

The node number.

Definition at line 736 of file CbcNode.hpp.

int CbcNode::state_ [private]

State 1 - on tree 2 - active.

Definition at line 741 of file CbcNode.hpp.


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

Generated on Tue Nov 24 00:15:27 2009 by  doxygen 1.6.1