Classes | Public Types | Public Member Functions | Static Public Member Functions | Protected Types | Protected Member Functions | Protected Attributes | Static Protected Attributes | Private Member Functions | Private Attributes | List of all members
Bonmin::BonChooseVariable Class Reference

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

#include <BonChooseVariable.hpp>

Inheritance diagram for Bonmin::BonChooseVariable:
Inheritance graph
[legend]
Collaboration diagram for Bonmin::BonChooseVariable:
Collaboration graph
[legend]

Classes

class  Messages
 

Public Types

enum  DoStrongReturnStatuses {
  provenInfeasible = -1, doneNoFixing, doneCanFix, interuptedCanFix,
  maxTime
}
 
enum  chooseVariableReturnStatuses {
  infeasibleNode = -1, hasCandidate, feasibleNode, canFixAndStrongBranch,
  canFixAndBranch, canFixNoCandidate
}
 Return statuses for chooseVariable. More...
 

Public Member Functions

 BonChooseVariable (BabSetupBase &b, const OsiSolverInterface *solver)
 Constructor from solver (so we can set up arrays etc) More...
 
 BonChooseVariable (const BonChooseVariable &)
 Copy constructor. More...
 
BonChooseVariableoperator= (const BonChooseVariable &rhs)
 Assignment operator. More...
 
virtual OsiChooseVariable * clone () const
 Clone. More...
 
virtual ~BonChooseVariable ()
 Destructor. More...
 
double maxminCrit (const OsiBranchingInformation *info) const
 Helper functions for setupList and chooseVariable. More...
 
void computeMultipliers (double &upMult, double &downMult) const
 
double computeUsefulness (const double MAXMIN_CRITERION, const double upMult, const double dowMult, const double value, const OsiObject *object, int i, double &value2) const
 
virtual int setupList (OsiBranchingInformation *info, bool initialize)
 Sets up strong list and clears all if initialize is true. More...
 
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. More...
 
virtual void updateInformation (const OsiBranchingInformation *info, int branch, OsiHotInfo *hotInfo)
 This is a utility function which does strong branching on a list of objects and stores the results in OsiHotInfo.objects. More...
 
virtual void updateInformation (int whichObject, int branch, double changeInObjective, double changeInValue, int status)
 Given a branch fill in useful information e.g. estimates. More...
 
void setCbcModel (CbcModel *cbc_model)
 Method for setting CbcModel, which is used to get statusOfSearch. More...
 
void setOnlyPseudoWhenTrusted (bool only_pseudo_when_trusted)
 
const OsiPseudoCosts & pseudoCosts () const
 Access to pseudo costs storage. More...
 
OsiPseudoCosts & pseudoCosts ()
 Access to pseudo costs storage. More...
 

Static Public Member Functions

static void registerOptions (Ipopt::SmartPtr< Bonmin::RegisteredOptions > roptions)
 

Protected Types

enum  StrongStatus { NotDone =-1, Feasible, Infeasible, NotFinished }
 Statuses for strong branching candidates. More...
 

Protected Member Functions

virtual int doStrongBranching (OsiSolverInterface *solver, OsiBranchingInformation *info, int numberToDo, int returnCriterion)
 This is a utility function which does strong branching on a list of objects and stores the results in OsiHotInfo.objects. More...
 
int determineStatus (OsiSolverInterface *solver) const
 Determine status of strong branching solution. More...
 
bool isRootNode (const OsiBranchingInformation *info) const
 detecting if this is root node More...
 

Protected Attributes

Ipopt::SmartPtr
< Ipopt::Journalist > 
jnlst_
 Holding on the a pointer to the journalist. More...
 
int bb_log_level_
 verbosity level More...
 
vector< HotInforesults_
 Stores strong branching results. More...
 
CbcModel * cbc_model_
 CbcModel, used to get status of search. More...
 
bool only_pseudo_when_trusted_
 Flag indicating whether we don't want to mix strong branching and pseudo costs during the decision which variable to branch on. More...
 
int number_not_trusted_
 Number of variables put into the list because there were not trusted. More...
 
CoinMessageHandler * handler_
 Message handler. More...
 
Messages messages_
 Messages. More...
 
Algoirithmic options
double maxmin_crit_no_sol_
 maxmin weight in branching decision when no solution has been found yet More...
 
double maxmin_crit_have_sol_
 maxmin weight in branching decision when no solution has been found yet More...
 
double setup_pseudo_frac_
 fraction of branching candidates that are not trusted yet More...
 
int numberBeforeTrustedList_
 number of times a branch has to happen so that it is trusted in setupList More...
 
int numberStrongRoot_
 number of strong branching points at root node More...
 
int numberStrongBackup_
 backup of numberStrong_ before Root node solve More...
 
int numberLookAhead_
 number of look-ahead strong-branching steps More...
 
int minNumberStrongBranch_
 Always strong branch that many first candidate in the list regardless of numberTrusted. More...
 
OsiPseudoCosts pseudoCosts_
 Stores the pseudo costs. More...
 
int trustStrongForPseudoCosts_
 Wether or not to trust strong branching results for updating pseudo costs. More...
 

Static Protected Attributes

static const std::string CNAME = "BonChooseVariable"
 Stores the class name for throwing errors. More...
 

Private Member Functions

 BonChooseVariable ()
 Default Constructor, forbiden for some reason. More...
 

Private Attributes

double time_limit_
 Global time limit for algorithm. More...
 
double start_time_
 Starting time of algorithm. More...
 

Message handling.

enum  Messages_Types {
  PS_COST_HISTORY = 0, PS_COST_MULT, PS_COST_ESTIMATES, CANDIDATE_LIST,
  CANDIDATE_LIST2, CANDIDATE_LIST3, SB_START, SB_HEADER,
  SB_RES, BRANCH_VAR, CHOSEN_VAR, UPDATE_PS_COST,
  BON_CHOOSE_MESSAGES_DUMMY_END
}
 
void passInMessageHandler (CoinMessageHandler *handler)
 
CoinMessageHandler & message (Messages_Types type) const
 

Detailed Description

This class chooses a variable to branch on.

This is the base class for the branching rules in Bonmin (inherits from OsiChooseVariable). This class implements a simple strong branching algorithm where the changes in the objective value induced by branching on a specific object are estimated with the pure virtual function fill_changes.

Definition at line 81 of file BonChooseVariable.hpp.

Member Enumeration Documentation

Statuses for strong branching candidates.

Enumerator
NotDone 
Feasible 

Child is proven feasible.

Infeasible 

Child is proven infeasible.

NotFinished 

Child is not finished.

Definition at line 109 of file BonChooseVariable.hpp.

Enumerator
PS_COST_HISTORY 
PS_COST_MULT 
PS_COST_ESTIMATES 
CANDIDATE_LIST 
CANDIDATE_LIST2 
CANDIDATE_LIST3 
SB_START 
SB_HEADER 
SB_RES 
BRANCH_VAR 
CHOSEN_VAR 
UPDATE_PS_COST 
BON_CHOOSE_MESSAGES_DUMMY_END 

Definition at line 117 of file BonChooseVariable.hpp.

Enumerator
provenInfeasible 
doneNoFixing 

All done no variable can be fixed.

doneCanFix 

Several variable can be fixed.

interuptedCanFix 

Interupted and found a variable to fix.

maxTime 

Interupted because of time limit.

Definition at line 153 of file BonChooseVariable.hpp.

Return statuses for chooseVariable.

Enumerator
infeasibleNode 
hasCandidate 

Normal termination, found a variable to branch on.

feasibleNode 

All variable are feasible, the node is feasible.

canFixAndStrongBranch 

Found variable to fix and also has remaining candidate for strong branching.

canFixAndBranch 

Found variable to fix and also has a (non-strong) branching candidate.

canFixNoCandidate 

Can fix variables but does not have strong branching candidates.

Definition at line 161 of file BonChooseVariable.hpp.

Constructor & Destructor Documentation

Bonmin::BonChooseVariable::BonChooseVariable ( BabSetupBase b,
const OsiSolverInterface *  solver 
)

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

Set values of standard branching options.

Get values of options specific to BonChooseVariable.

Definition at line 42 of file BonChooseVariable.cpp.

Bonmin::BonChooseVariable::BonChooseVariable ( const BonChooseVariable rhs)

Copy constructor.

Definition at line 87 of file BonChooseVariable.cpp.

Bonmin::BonChooseVariable::~BonChooseVariable ( )
virtual

Destructor.

Definition at line 147 of file BonChooseVariable.cpp.

Bonmin::BonChooseVariable::BonChooseVariable ( )
private

Default Constructor, forbiden for some reason.

Member Function Documentation

int Bonmin::BonChooseVariable::doStrongBranching ( OsiSolverInterface *  solver,
OsiBranchingInformation *  info,
int  numberToDo,
int  returnCriterion 
)
protectedvirtual

This is a utility function which does strong branching on a list of objects and stores the results in OsiHotInfo.objects.

On entry the object sequence is stored in the OsiHotInfo object and maybe more. It returns - -1 - one branch was infeasible both ways 0 - all inspected - nothing can be fixed 1 - all inspected - some can be fixed (returnCriterion==0) 2 - may be returning early - one can be fixed (last one done) (returnCriterion==1) 3 - returning because max time

Reimplemented in Couenne::CouenneChooseStrong.

Definition at line 787 of file BonChooseVariable.cpp.

void Bonmin::BonChooseVariable::passInMessageHandler ( CoinMessageHandler *  handler)
inline

Definition at line 139 of file BonChooseVariable.hpp.

CoinMessageHandler& Bonmin::BonChooseVariable::message ( Messages_Types  type) const
inline

Definition at line 146 of file BonChooseVariable.hpp.

BonChooseVariable & Bonmin::BonChooseVariable::operator= ( const BonChooseVariable rhs)

Assignment operator.

Definition at line 114 of file BonChooseVariable.cpp.

OsiChooseVariable * Bonmin::BonChooseVariable::clone ( ) const
virtual

Clone.

Reimplemented in Couenne::CouenneChooseStrong.

Definition at line 142 of file BonChooseVariable.cpp.

void Bonmin::BonChooseVariable::registerOptions ( Ipopt::SmartPtr< Bonmin::RegisteredOptions roptions)
static

Definition at line 153 of file BonChooseVariable.cpp.

double Bonmin::BonChooseVariable::maxminCrit ( const OsiBranchingInformation *  info) const

Helper functions for setupList and chooseVariable.

Definition at line 965 of file BonChooseVariable.cpp.

void Bonmin::BonChooseVariable::computeMultipliers ( double &  upMult,
double &  downMult 
) const

Definition at line 204 of file BonChooseVariable.cpp.

double Bonmin::BonChooseVariable::computeUsefulness ( const double  MAXMIN_CRITERION,
const double  upMult,
const double  dowMult,
const double  value,
const OsiObject *  object,
int  i,
double &  value2 
) const

Definition at line 231 of file BonChooseVariable.cpp.

int Bonmin::BonChooseVariable::setupList ( OsiBranchingInformation *  info,
bool  initialize 
)
virtual

Sets up strong list and clears all if initialize is true.

Returns number of infeasibilities.

Reimplemented in Couenne::CouenneChooseStrong.

Definition at line 307 of file BonChooseVariable.cpp.

int Bonmin::BonChooseVariable::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 Couenne::CouenneChooseStrong.

Definition at line 599 of file BonChooseVariable.cpp.

void Bonmin::BonChooseVariable::updateInformation ( const OsiBranchingInformation *  info,
int  branch,
OsiHotInfo *  hotInfo 
)
virtual

This is a utility function which does strong branching on a list of objects and stores the results in OsiHotInfo.objects.

On entry the object sequence is stored in the OsiHotInfo object and maybe more. It returns - -1 - one branch was infeasible both ways 0 - all inspected - nothing can be fixed 1 - all inspected - some can be fixed (returnCriterion==0) 2 - may be returning early - one can be fixed (last one done) (returnCriterion==1) 3 - returning because max timeGiven a candidate fill in useful information e.g. estimates

Definition at line 981 of file BonChooseVariable.cpp.

void Bonmin::BonChooseVariable::updateInformation ( int  whichObject,
int  branch,
double  changeInObjective,
double  changeInValue,
int  status 
)
virtual

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

Definition at line 1031 of file BonChooseVariable.cpp.

void Bonmin::BonChooseVariable::setCbcModel ( CbcModel *  cbc_model)
inline

Method for setting CbcModel, which is used to get statusOfSearch.

Definition at line 237 of file BonChooseVariable.hpp.

void Bonmin::BonChooseVariable::setOnlyPseudoWhenTrusted ( bool  only_pseudo_when_trusted)
inline

Definition at line 242 of file BonChooseVariable.hpp.

const OsiPseudoCosts& Bonmin::BonChooseVariable::pseudoCosts ( ) const
inline

Access to pseudo costs storage.

Definition at line 249 of file BonChooseVariable.hpp.

OsiPseudoCosts& Bonmin::BonChooseVariable::pseudoCosts ( )
inline

Access to pseudo costs storage.

Definition at line 253 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::determineStatus ( OsiSolverInterface *  solver) const
inlineprotected

Determine status of strong branching solution.

Definition at line 267 of file BonChooseVariable.hpp.

bool Bonmin::BonChooseVariable::isRootNode ( const OsiBranchingInformation *  info) const
protected

detecting if this is root node

Definition at line 959 of file BonChooseVariable.cpp.

Member Data Documentation

Ipopt::SmartPtr<Ipopt::Journalist> Bonmin::BonChooseVariable::jnlst_
protected

Holding on the a pointer to the journalist.

Definition at line 258 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::bb_log_level_
protected

verbosity level

Definition at line 261 of file BonChooseVariable.hpp.

vector<HotInfo> Bonmin::BonChooseVariable::results_
protected

Stores strong branching results.

Definition at line 264 of file BonChooseVariable.hpp.

double Bonmin::BonChooseVariable::time_limit_
private

Global time limit for algorithm.

Definition at line 282 of file BonChooseVariable.hpp.

double Bonmin::BonChooseVariable::start_time_
private

Starting time of algorithm.

Definition at line 285 of file BonChooseVariable.hpp.

CbcModel* Bonmin::BonChooseVariable::cbc_model_
protected

CbcModel, used to get status of search.

Definition at line 288 of file BonChooseVariable.hpp.

bool Bonmin::BonChooseVariable::only_pseudo_when_trusted_
protected

Flag indicating whether we don't want to mix strong branching and pseudo costs during the decision which variable to branch on.

Definition at line 293 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::number_not_trusted_
protected

Number of variables put into the list because there were not trusted.

Definition at line 297 of file BonChooseVariable.hpp.

CoinMessageHandler* Bonmin::BonChooseVariable::handler_
protected

Message handler.

Definition at line 300 of file BonChooseVariable.hpp.

Messages Bonmin::BonChooseVariable::messages_
protected

Messages.

Definition at line 303 of file BonChooseVariable.hpp.

double Bonmin::BonChooseVariable::maxmin_crit_no_sol_
protected

maxmin weight in branching decision when no solution has been found yet

Definition at line 309 of file BonChooseVariable.hpp.

double Bonmin::BonChooseVariable::maxmin_crit_have_sol_
protected

maxmin weight in branching decision when no solution has been found yet

Definition at line 312 of file BonChooseVariable.hpp.

double Bonmin::BonChooseVariable::setup_pseudo_frac_
protected

fraction of branching candidates that are not trusted yet

Definition at line 314 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::numberBeforeTrustedList_
protected

number of times a branch has to happen so that it is trusted in setupList

Definition at line 317 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::numberStrongRoot_
protected

number of strong branching points at root node

Definition at line 319 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::numberStrongBackup_
protected

backup of numberStrong_ before Root node solve

Definition at line 321 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::numberLookAhead_
protected

number of look-ahead strong-branching steps

Definition at line 323 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::minNumberStrongBranch_
protected

Always strong branch that many first candidate in the list regardless of numberTrusted.

Definition at line 329 of file BonChooseVariable.hpp.

OsiPseudoCosts Bonmin::BonChooseVariable::pseudoCosts_
protected

Stores the pseudo costs.

Definition at line 331 of file BonChooseVariable.hpp.

int Bonmin::BonChooseVariable::trustStrongForPseudoCosts_
protected

Wether or not to trust strong branching results for updating pseudo costs.

Definition at line 333 of file BonChooseVariable.hpp.

const std::string Bonmin::BonChooseVariable::CNAME = "BonChooseVariable"
staticprotected

Stores the class name for throwing errors.

Definition at line 341 of file BonChooseVariable.hpp.


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