Cbc  2.8.12
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CbcNode Class Reference

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

#include <CbcNode.hpp>

+ Inheritance diagram for CbcNode:
+ Collaboration diagram for CbcNode:

Public Member Functions

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

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 49 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 216 of file CbcNode.hpp.

double CbcNode::objectiveValue ( ) const
inline

Definition at line 221 of file CbcNode.hpp.

void CbcNode::setObjectiveValue ( double  value)
inline

Definition at line 224 of file CbcNode.hpp.

int CbcNode::numberBranches ( ) const
inline

Number of arms defined for the attached OsiBranchingObject.

Definition at line 228 of file CbcNode.hpp.

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

Depth in branch-and-cut search tree.

Definition at line 243 of file CbcNode.hpp.

void CbcNode::setDepth ( int  value)
inline

Set depth in branch-and-cut search tree.

Definition at line 247 of file CbcNode.hpp.

int CbcNode::numberUnsatisfied ( ) const
inline

Get the number of objects unsatisfied at this node.

Definition at line 251 of file CbcNode.hpp.

void CbcNode::setNumberUnsatisfied ( int  value)
inline

Set the number of objects unsatisfied at this node.

Definition at line 255 of file CbcNode.hpp.

double CbcNode::sumInfeasibilities ( ) const
inline

Get sum of "infeasibilities" reported by each object.

Definition at line 259 of file CbcNode.hpp.

void CbcNode::setSumInfeasibilities ( double  value)
inline

Set sum of "infeasibilities" reported by each object.

Definition at line 263 of file CbcNode.hpp.

double CbcNode::guessedObjectiveValue ( ) const
inline

Definition at line 267 of file CbcNode.hpp.

void CbcNode::setGuessedObjectiveValue ( double  value)
inline

Definition at line 270 of file CbcNode.hpp.

const OsiBranchingObject* CbcNode::branchingObject ( ) const
inline

Branching object for this node.

Definition at line 274 of file CbcNode.hpp.

OsiBranchingObject* CbcNode::modifiableBranchingObject ( ) const
inline

Modifiable branching object for this node.

Definition at line 278 of file CbcNode.hpp.

void CbcNode::setBranchingObject ( OsiBranchingObject *  branchingObject)
inline

Set branching object for this node (takes ownership)

Definition at line 282 of file CbcNode.hpp.

int CbcNode::nodeNumber ( ) const
inline

The node number.

Definition at line 286 of file CbcNode.hpp.

void CbcNode::setNodeNumber ( int  node)
inline

Definition at line 289 of file CbcNode.hpp.

bool CbcNode::onTree ( ) const
inline

Returns true if on tree.

Definition at line 293 of file CbcNode.hpp.

void CbcNode::setOnTree ( bool  yesNo)
inline

Sets true if on tree.

Definition at line 297 of file CbcNode.hpp.

bool CbcNode::active ( ) const
inline

Returns true if active.

Definition at line 302 of file CbcNode.hpp.

void CbcNode::setActive ( bool  yesNo)
inline

Sets true if active.

Definition at line 306 of file CbcNode.hpp.

void CbcNode::print ( ) const

Print.

void CbcNode::checkInfo ( ) const
inline

Debug.

Definition at line 313 of file CbcNode.hpp.


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