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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 analyze (CbcModel *model, double *results)
void decrementCuts (int change=1)
 Decrement active cut counts.
void decrementParentCuts (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 ()
 Does next branch and updates state.
CbcNodeInfonodeInfo () const
double objectiveValue () const
void setObjectiveValue (double value)
int numberBranches () const
 Number of arms defined for the attached CbcBranchingObject.
int variable () const
 Branching `variable' associated with the attached CbcBranchingObject.
int way () const
int depth () const
 Depth in branch-and-cut search tree.
int numberUnsatisfied () const
 Get the number of objects unsatisfied at this node.
double guessedObjectiveValue () const
void setGuessedObjectiveValue (double value)
const CbcBranchingObjectbranchingObject () const
 Branching object for this node.
CbcBranchingObjectmodifiableBranchingObject () const
 Modifiable branching object for this node.

Private Attributes

CbcNodeInfonodeInfo_
 Information to make basis and bounds.
double objectiveValue_
double guessedObjectiveValue_
CbcBranchingObjectbranch_
 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.


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 385 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::analyze CbcModel model,
double *  results
 

void CbcNode::decrementCuts int  change = 1  ) 
 

Decrement active cut counts.

void CbcNode::decrementParentCuts 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 CbcBranchingObject.

See also:
CbcNodeInfo::initializeInfo(int).

int CbcNode::branch  ) 
 

Does next branch and updates state.

CbcNodeInfo* CbcNode::nodeInfo  )  const [inline]
 

Definition at line 501 of file CbcNode.hpp.

double CbcNode::objectiveValue  )  const [inline]
 

Definition at line 505 of file CbcNode.hpp.

void CbcNode::setObjectiveValue double  value  )  [inline]
 

Definition at line 507 of file CbcNode.hpp.

int CbcNode::numberBranches  )  const [inline]
 

Number of arms defined for the attached CbcBranchingObject.

Definition at line 510 of file CbcNode.hpp.

int CbcNode::variable  )  const [inline]
 

Branching `variable' associated with the attached CbcBranchingObject.

Check CbcBranchingObject::variable() for a longer explanation of `variable'.

Definition at line 521 of file CbcNode.hpp.

int CbcNode::way  )  const [inline]
 

Definition at line 530 of file CbcNode.hpp.

int CbcNode::depth  )  const [inline]
 

Depth in branch-and-cut search tree.

Definition at line 533 of file CbcNode.hpp.

int CbcNode::numberUnsatisfied  )  const [inline]
 

Get the number of objects unsatisfied at this node.

Definition at line 536 of file CbcNode.hpp.

double CbcNode::guessedObjectiveValue  )  const [inline]
 

Definition at line 540 of file CbcNode.hpp.

void CbcNode::setGuessedObjectiveValue double  value  )  [inline]
 

Definition at line 542 of file CbcNode.hpp.

const CbcBranchingObject* CbcNode::branchingObject  )  const [inline]
 

Branching object for this node.

Definition at line 545 of file CbcNode.hpp.

CbcBranchingObject* CbcNode::modifiableBranchingObject  )  const [inline]
 

Modifiable branching object for this node.

Definition at line 548 of file CbcNode.hpp.


Member Data Documentation

CbcNodeInfo* CbcNode::nodeInfo_ [private]
 

Information to make basis and bounds.

Definition at line 554 of file CbcNode.hpp.

double CbcNode::objectiveValue_ [private]
 

Definition at line 556 of file CbcNode.hpp.

double CbcNode::guessedObjectiveValue_ [private]
 

Definition at line 558 of file CbcNode.hpp.

CbcBranchingObject* CbcNode::branch_ [private]
 

Branching object for this node.

Definition at line 560 of file CbcNode.hpp.

int CbcNode::depth_ [private]
 

Depth of the node in the search tree.

Definition at line 562 of file CbcNode.hpp.

int CbcNode::numberUnsatisfied_ [private]
 

The number of objects unsatisfied at this node.

Definition at line 564 of file CbcNode.hpp.


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