Detailed Description

full strong LP branching rule

Author: Tobias Achterberg; Gerald Gamrath

#include <assert.h>
#include <string.h>
#include "scip/branch_fullstrong.h"

Macros
#define	BRANCHRULE_NAME "fullstrong"

#define	BRANCHRULE_DESC "full strong branching"

#define	BRANCHRULE_PRIORITY 0

#define	BRANCHRULE_MAXDEPTH -1

#define	BRANCHRULE_MAXBOUNDDIST 1.0

#define	DEFAULT_REEVALAGE 10LL

#define	DEFAULT_MAXPROPROUNDS -2

#define	DEFAULT_PROBINGBOUNDS TRUE

#define	DEFAULT_FORCESTRONGBRANCH FALSE

Functions
static	SCIP_DECL_BRANCHCOPY (branchCopyFullstrong)

static	SCIP_DECL_BRANCHFREE (branchFreeFullstrong)

static	SCIP_DECL_BRANCHINIT (branchInitFullstrong)

static	SCIP_DECL_BRANCHEXIT (branchExitFullstrong)

SCIP_RETCODE	SCIPselectVarStrongBranching (SCIP scip, SCIP_VAR lpcands, SCIP_Real lpcandssol, SCIP_Real lpcandsfrac, SCIP_Bool skipdown, SCIP_Bool skipup, int nlpcands, int npriolpcands, int ncomplete, int start, SCIP_Bool allowaddcons, int maxproprounds, SCIP_Bool probingbounds, SCIP_Bool forcestrongbranch, int bestcand, SCIP_Real bestdown, SCIP_Real bestup, SCIP_Real bestscore, SCIP_Bool bestdownvalid, SCIP_Bool bestupvalid, SCIP_Real provedbound, SCIP_RESULT result)

static	SCIP_DECL_BRANCHEXECLP (branchExeclpFullstrong)

SCIP_RETCODE	SCIPincludeBranchruleFullstrong (SCIP *scip)

Macro Definition Documentation

#define BRANCHRULE_NAME "fullstrong"

Definition at line 30 of file branch_fullstrong.c.

Referenced by SCIPincludeBranchruleFullstrong(), and SCIPselectVarStrongBranching().

#define BRANCHRULE_DESC "full strong branching"

Definition at line 31 of file branch_fullstrong.c.

Referenced by SCIPincludeBranchruleFullstrong().

#define BRANCHRULE_PRIORITY 0

Definition at line 32 of file branch_fullstrong.c.

Referenced by SCIPincludeBranchruleFullstrong().

#define BRANCHRULE_MAXDEPTH -1

Definition at line 33 of file branch_fullstrong.c.

Referenced by SCIPincludeBranchruleFullstrong().

#define BRANCHRULE_MAXBOUNDDIST 1.0

Definition at line 34 of file branch_fullstrong.c.

Referenced by SCIPincludeBranchruleFullstrong().

#define DEFAULT_REEVALAGE 10LL

number of intermediate LPs solved to trigger reevaluation of strong branching value for a variable that was already evaluated at the current node

Definition at line 36 of file branch_fullstrong.c.

Referenced by SCIPincludeBranchruleFullstrong().

#define DEFAULT_MAXPROPROUNDS -2

maximum number of propagation rounds to be performed during strong branching before solving the LP (-1: no limit, -2: parameter settings)

Definition at line 39 of file branch_fullstrong.c.

Referenced by SCIPincludeBranchruleFullstrong().

#define DEFAULT_PROBINGBOUNDS TRUE

should valid bounds be identified in a probing-like fashion during strong branching (only with propagation)?

Definition at line 42 of file branch_fullstrong.c.

Referenced by SCIPincludeBranchruleFullstrong().

#define DEFAULT_FORCESTRONGBRANCH FALSE

should strong branching be applied even if there is just a single candidate?

Definition at line 45 of file branch_fullstrong.c.

Referenced by SCIPincludeBranchruleFullstrong().

Function Documentation

static SCIP_DECL_BRANCHCOPY ( branchCopyFullstrong )

static

copy method for branchrule plugins (called when SCIP copies plugins)

Definition at line 70 of file branch_fullstrong.c.

static SCIP_DECL_BRANCHFREE ( branchFreeFullstrong )

static

destructor of branching rule to free user data (called when SCIP is exiting)

Definition at line 84 of file branch_fullstrong.c.

static SCIP_DECL_BRANCHINIT ( branchInitFullstrong )

static

initialization method of branching rule (called after problem was transformed)

Definition at line 104 of file branch_fullstrong.c.

static SCIP_DECL_BRANCHEXIT ( branchExitFullstrong )

static

deinitialization method of branching rule (called before transformed problem is freed)

Definition at line 119 of file branch_fullstrong.c.

SCIP_RETCODE SCIPselectVarStrongBranching	(	SCIP *	scip,
		SCIP_VAR **	lpcands,
		SCIP_Real *	lpcandssol,
		SCIP_Real *	lpcandsfrac,
		SCIP_Bool *	skipdown,
		SCIP_Bool *	skipup,
		int	nlpcands,
		int	npriolpcands,
		int	ncomplete,
		int *	start,
		SCIP_Bool	allowaddcons,
		int	maxproprounds,
		SCIP_Bool	probingbounds,
		SCIP_Bool	forcestrongbranch,
		int *	bestcand,
		SCIP_Real *	bestdown,
		SCIP_Real *	bestup,
		SCIP_Real *	bestscore,
		SCIP_Bool *	bestdownvalid,
		SCIP_Bool *	bestupvalid,
		SCIP_Real *	provedbound,
		SCIP_RESULT *	result
	)

Selects a variable from a set of candidates by strong branching

Returns: SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See SCIP_RETCODE for a complete list of error codes.

Note: The variables in the lpcands array must have a fractional value in the current LP solution

Parameters

scip	original SCIP data structure
lpcands	branching candidates
lpcandssol	solution values of the branching candidates
lpcandsfrac	fractional values of the branching candidates
skipdown	should down branchings be skipped?
skipup	should up branchings be skipped?
nlpcands	number of branching candidates
npriolpcands	number of priority branching candidates
ncomplete	number of branching candidates without skip
start	starting index in lpcands
allowaddcons	is the branching rule allowed to add constraints?
maxproprounds	maximum number of propagation rounds to be performed during strong branching before solving the LP (-1: no limit, -2: parameter settings)
probingbounds	should valid bounds be identified in a probing-like fashion during strong branching (only with propagation)?
forcestrongbranch	should strong branching be applied even if there is just a single candidate?
bestcand	best candidate for branching
bestdown	objective value of the down branch for bestcand
bestup	objective value of the up branch for bestcand
bestscore	score for bestcand
bestdownvalid	is bestdown a valid dual bound for the down branch?
bestupvalid	is bestup a valid dual bound for the up branch?
provedbound	proved dual bound for current subtree
result	result pointer