branch_multaggr.c File Reference

Detailed Description

fullstrong branching on fractional and multi-aggregated variables

Author

Anna Melchiori

Gerald Gamrath

This branching rule uses all fractional binary and integer variables as candidates, as well as fractional multiaggregated binary and integer variables. Although not directly contained in the presolved problem anymore, the multi-aggregation provides an affine linear sum of integer variables, on which branching can be performed.

For more details, see G.Gamrath, A.Melchiori, T.Berthold, A.M.Gleixner, D.Salvagnin: Branching on Multi-aggregated Variables (http://dx.doi.org/10.1007/978-3-319-18008-3_10)

Definition in file branch_multaggr.c.

#include <assert.h>
#include <string.h>
#include "scip/branch_multaggr.h"
#include "scip/branch_fullstrong.h"
#include "scip/cons_linear.h"
#include "scip/var.h"
#include "scip/set.h"
#include "scip/pub_tree.h"
#include "scip/struct_scip.h"
#include "scip/clock.h"

Go to the source code of this file.

Macros
#define	BRANCHRULE_NAME   "multaggr"
#define	BRANCHRULE_DESC   "fullstrong branching on fractional and multi-aggregated variables"
#define	BRANCHRULE_PRIORITY   0
#define	BRANCHRULE_MAXDEPTH   -1
#define	BRANCHRULE_MAXBOUNDDIST   1.0
#define	DEFAULT_REEVALAGE   0LL
#define	DEFAULT_MAXPROPROUNDS   0
#define	DEFAULT_PROBINGBOUNDS   TRUE

Functions
static SCIP_RETCODE	selectVarMultAggrBranching (SCIP *scip, SCIP_VAR **bestcand, SCIP_Real *bestscore, SCIP_Real *bestsol, SCIP_Real *bestdown, SCIP_Real *bestup, SCIP_Bool *bestdownvalid, SCIP_Bool *bestupvalid, SCIP_Real *provedbound, SCIP_Real *estimatedown, SCIP_Real *estimateup, SCIP_RESULT *result)
static	SCIP_DECL_BRANCHCOPY (branchCopyMultAggr)
static	SCIP_DECL_BRANCHFREE (branchFreeMultAggr)
static	SCIP_DECL_BRANCHINIT (branchInitMultAggr)
static	SCIP_DECL_BRANCHEXIT (branchExitMultAggr)
static	SCIP_DECL_BRANCHEXECLP (branchExeclpMultAggr)
SCIP_RETCODE	SCIPincludeBranchruleMultAggr (SCIP *scip)

Macro Definition Documentation

BRANCHRULE_NAME

#define BRANCHRULE_NAME   "multaggr"

Definition at line 43 of file branch_multaggr.c.

Referenced by SCIPincludeBranchruleMultAggr(), and selectVarMultAggrBranching().

BRANCHRULE_DESC

#define BRANCHRULE_DESC   "fullstrong branching on fractional and multi-aggregated variables"

Definition at line 44 of file branch_multaggr.c.

Referenced by SCIPincludeBranchruleMultAggr().

BRANCHRULE_PRIORITY

#define BRANCHRULE_PRIORITY   0

Definition at line 45 of file branch_multaggr.c.

Referenced by SCIPincludeBranchruleMultAggr().

BRANCHRULE_MAXDEPTH

#define BRANCHRULE_MAXDEPTH   -1

Definition at line 46 of file branch_multaggr.c.

Referenced by SCIPincludeBranchruleMultAggr().

BRANCHRULE_MAXBOUNDDIST

#define BRANCHRULE_MAXBOUNDDIST   1.0

Definition at line 47 of file branch_multaggr.c.

Referenced by SCIPincludeBranchruleMultAggr().

DEFAULT_REEVALAGE

#define DEFAULT_REEVALAGE   0LL

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 50 of file branch_multaggr.c.

Referenced by SCIPincludeBranchruleMultAggr().

DEFAULT_MAXPROPROUNDS

#define DEFAULT_MAXPROPROUNDS   0

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

Definition at line 53 of file branch_multaggr.c.

Referenced by SCIPincludeBranchruleMultAggr().

DEFAULT_PROBINGBOUNDS

#define DEFAULT_PROBINGBOUNDS   TRUE

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

Definition at line 56 of file branch_multaggr.c.

Referenced by SCIPincludeBranchruleMultAggr().

Function Documentation

selectVarMultAggrBranching()

static SCIP_RETCODE selectVarMultAggrBranching ( SCIP *  scip, SCIP_VAR **  bestcand, SCIP_Real *  bestscore, SCIP_Real *  bestsol, SCIP_Real *  bestdown, SCIP_Real *  bestup, SCIP_Bool *  bestdownvalid, SCIP_Bool *  bestupvalid, SCIP_Real *  provedbound, SCIP_Real *  estimatedown, SCIP_Real *  estimateup, SCIP_RESULT *  result  )

static

Parameters

scip	original SCIP data structure
bestcand	the best candidate variable selected by strong branching
bestscore	score of the best branching candidate
bestsol	solution value of the best branching candidate
bestdown	objective value of the down node when branching on bestcand
bestup	objective value of the up node when branching on 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 the current subtree
estimatedown	pointer to store the down child nodes estimate
estimateup	pointer to store the up child nodes estimate
result	pointer to store results of branching

Definition at line 144 of file branch_multaggr.c.

References BRANCHRULE_NAME, FALSE, MAX, SCIP_Bool, SCIP_CALL, SCIP_CONSADDED, SCIP_CUTOFF, SCIP_DECL_BRANCHCOPY(), SCIP_DIDNOTRUN, SCIP_LPSOLSTAT_INFEASIBLE, SCIP_LPSOLSTAT_ITERLIMIT, SCIP_LPSOLSTAT_NOTSOLVED, SCIP_LPSOLSTAT_OBJLIMIT, SCIP_LPSOLSTAT_TIMELIMIT, SCIP_LPSOLSTAT_UNBOUNDEDRAY, SCIP_MAXTREEDEPTH, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_MULTAGGR, SCIP_VARTYPE_BINARY, SCIP_VARTYPE_INTEGER, SCIPaddConsNode(), SCIPallColsInLP(), SCIPallocBufferArray, SCIPbacktrackProbing(), SCIPbranchruleGetData(), SCIPconsGetName(), SCIPcreateConsLinear(), SCIPdebugMsg, SCIPendProbing(), SCIPfeasCeil(), SCIPfeasFloor(), SCIPfindBranchrule(), SCIPfreeBufferArray, SCIPgetBranchScore(), SCIPgetCurrentNode(), SCIPgetCutoffbound(), SCIPgetDepth(), SCIPgetFixedVars(), SCIPgetLPBranchCands(), SCIPgetLPObjval(), SCIPgetLPSolstat(), SCIPgetNFixedVars(), SCIPinfinity(), SCIPinfoMessage(), SCIPisExactSolve(), SCIPisFeasIntegral(), SCIPisGE(), SCIPnewProbingNode(), SCIPnodeGetLowerbound(), SCIPprintCons(), SCIPreleaseCons(), SCIPsetFeasCeil(), SCIPsetFeasFloor(), SCIPsolveProbingLP(), SCIPstartProbing(), SCIPstatistic, SCIPvarGetLPSol(), SCIPvarGetMultaggrConstant(), SCIPvarGetMultaggrNVars(), SCIPvarGetMultaggrScalars(), SCIPvarGetMultaggrVars(), SCIPvarGetName(), SCIPvarGetPseudocost(), SCIPvarGetStatus(), SCIPvarGetType(), Scip::set, Scip::stat, and TRUE.

SCIP_DECL_BRANCHCOPY()

static SCIP_DECL_BRANCHCOPY ( branchCopyMultAggr  )

static

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

Definition at line 551 of file branch_multaggr.c.

Referenced by selectVarMultAggrBranching().

SCIP_DECL_BRANCHFREE()

static SCIP_DECL_BRANCHFREE ( branchFreeMultAggr  )

static

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

Definition at line 565 of file branch_multaggr.c.

SCIP_DECL_BRANCHINIT()

static SCIP_DECL_BRANCHINIT ( branchInitMultAggr  )

static

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

Definition at line 585 of file branch_multaggr.c.

SCIP_DECL_BRANCHEXIT()

static SCIP_DECL_BRANCHEXIT ( branchExitMultAggr  )

static

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

Definition at line 622 of file branch_multaggr.c.

SCIP_DECL_BRANCHEXECLP()

static SCIP_DECL_BRANCHEXECLP ( branchExeclpMultAggr  )

static

branching execution method for fractional LP solutions

Definition at line 723 of file branch_multaggr.c.