cutsel_hybrid.c File Reference

Detailed Description

hybrid cut selector

Author

Leona Gottwald

Felipe Serrano

Mark Turner

Definition in file cutsel_hybrid.c.

#include <assert.h>
#include "scip/scip_cutsel.h"
#include "scip/scip_cut.h"
#include "scip/scip_lp.h"
#include "scip/scip_randnumgen.h"
#include "scip/cutsel_hybrid.h"

Go to the source code of this file.

Macros
#define	CUTSEL_NAME   "hybrid"
#define	CUTSEL_DESC   "weighted sum of efficacy, dircutoffdist, objparal, and intsupport"
#define	CUTSEL_PRIORITY   8000
#define	RANDSEED   0x5EED
#define	GOODSCORE   0.9
#define	BADSCORE   0.0
#define	DEFAULT_EFFICACYWEIGHT   1.0
#define	DEFAULT_DIRCUTOFFDISTWEIGHT   0.0
#define	DEFAULT_OBJPARALWEIGHT   0.1
#define	DEFAULT_INTSUPPORTWEIGHT   0.1
#define	DEFAULT_MINORTHO   0.90
#define	DEFAULT_MINORTHOROOT   0.90

Functions
static SCIP_Real	scoring (SCIP *scip, SCIP_ROW **cuts, SCIP_RANDNUMGEN *randnumgen, SCIP_Real dircutoffdistweight, SCIP_Real efficacyweight, SCIP_Real objparalweight, SCIP_Real intsupportweight, int ncuts, SCIP_Real *scores)
static void	selectBestCut (SCIP_ROW **cuts, SCIP_Real *scores, int ncuts)
static int	filterWithParallelism (SCIP_ROW *cut, SCIP_ROW **cuts, SCIP_Real *scores, int ncuts, SCIP_Real goodscore, SCIP_Real goodmaxparall, SCIP_Real maxparall)
static	SCIP_DECL_CUTSELCOPY (cutselCopyHybrid)
static	SCIP_DECL_CUTSELFREE (cutselFreeHybrid)
static	SCIP_DECL_CUTSELINIT (cutselInitHybrid)
static	SCIP_DECL_CUTSELEXIT (cutselExitHybrid)
static	SCIP_DECL_CUTSELSELECT (cutselSelectHybrid)
SCIP_RETCODE	SCIPincludeCutselHybrid (SCIP *scip)
SCIP_RETCODE	SCIPselectCutsHybrid (SCIP *scip, SCIP_ROW **cuts, SCIP_ROW **forcedcuts, SCIP_RANDNUMGEN *randnumgen, SCIP_Real goodscorefac, SCIP_Real badscorefac, SCIP_Real goodmaxparall, SCIP_Real maxparall, SCIP_Real dircutoffdistweight, SCIP_Real efficacyweight, SCIP_Real objparalweight, SCIP_Real intsupportweight, int ncuts, int nforcedcuts, int maxselectedcuts, int *nselectedcuts)

Macro Definition Documentation

CUTSEL_NAME

#define CUTSEL_NAME   "hybrid"

Definition at line 44 of file cutsel_hybrid.c.

CUTSEL_DESC

#define CUTSEL_DESC   "weighted sum of efficacy, dircutoffdist, objparal, and intsupport"

Definition at line 45 of file cutsel_hybrid.c.

CUTSEL_PRIORITY

#define CUTSEL_PRIORITY   8000

Definition at line 46 of file cutsel_hybrid.c.

RANDSEED

#define RANDSEED   0x5EED

Definition at line 48 of file cutsel_hybrid.c.

GOODSCORE

#define GOODSCORE   0.9

Definition at line 49 of file cutsel_hybrid.c.

BADSCORE

#define BADSCORE   0.0

Definition at line 50 of file cutsel_hybrid.c.

DEFAULT_EFFICACYWEIGHT

#define DEFAULT_EFFICACYWEIGHT   1.0

weight of efficacy in score calculation

Definition at line 52 of file cutsel_hybrid.c.

DEFAULT_DIRCUTOFFDISTWEIGHT

#define DEFAULT_DIRCUTOFFDISTWEIGHT   0.0

weight of directed cutoff distance in score calculation

Definition at line 53 of file cutsel_hybrid.c.

DEFAULT_OBJPARALWEIGHT

#define DEFAULT_OBJPARALWEIGHT   0.1

weight of objective parallelism in score calculation

Definition at line 54 of file cutsel_hybrid.c.

DEFAULT_INTSUPPORTWEIGHT

#define DEFAULT_INTSUPPORTWEIGHT   0.1

weight of integral support in cut score calculation

Definition at line 55 of file cutsel_hybrid.c.

DEFAULT_MINORTHO

#define DEFAULT_MINORTHO   0.90

minimal orthogonality for a cut to enter the LP

Definition at line 56 of file cutsel_hybrid.c.

DEFAULT_MINORTHOROOT

#define DEFAULT_MINORTHOROOT   0.90

minimal orthogonality for a cut to enter the LP in the root node

Definition at line 57 of file cutsel_hybrid.c.

Function Documentation

scoring()

static SCIP_Real scoring ( SCIP *  scip, SCIP_ROW **  cuts, SCIP_RANDNUMGEN *  randnumgen, SCIP_Real  dircutoffdistweight, SCIP_Real  efficacyweight, SCIP_Real  objparalweight, SCIP_Real  intsupportweight, int  ncuts, SCIP_Real *  scores  )

static

returns the maximum score of cuts; if scores is not NULL, then stores the individual score of each cut in scores

Parameters

scip	SCIP data structure
cuts	array with cuts to score
randnumgen	random number generator for tie-breaking, or NULL
dircutoffdistweight	weight of directed cutoff distance in cut score calculation
efficacyweight	weight of efficacy in cut score calculation
objparalweight	weight of objective parallelism in cut score calculation
intsupportweight	weight of integral support in cut score calculation
ncuts	number of cuts in cuts array
scores	array to store the score of cuts or NULL

Definition at line 85 of file cutsel_hybrid.c.

References MAX, NULL, SCIP_Real, SCIPgetBestSol(), SCIPgetCutEfficacy(), SCIPgetCutLPSolCutoffDistance(), SCIPgetRowNumIntCols(), SCIPgetRowObjParallelism(), SCIPrandomGetReal(), SCIProwGetNNonz(), SCIProwIsInGlobalCutpool(), and SCIProwIsLocal().

Referenced by SCIPselectCutsHybrid().

selectBestCut()

static void selectBestCut ( SCIP_ROW **  cuts, SCIP_Real *  scores, int  ncuts  )

static

move the cut with the highest score to the first position in the array; there must be at least one cut

Parameters

cuts	array with cuts to perform selection algorithm
scores	array with scores of cuts to perform selection algorithm
ncuts	number of cuts in given array

Definition at line 201 of file cutsel_hybrid.c.

References NULL, SCIP_Real, SCIPswapPointers(), and SCIPswapReals().

Referenced by SCIPselectCutsHybrid().

filterWithParallelism()

static int filterWithParallelism ( SCIP_ROW *  cut, SCIP_ROW **  cuts, SCIP_Real *  scores, int  ncuts, SCIP_Real  goodscore, SCIP_Real  goodmaxparall, SCIP_Real  maxparall  )

static

filters the given array of cuts to enforce a maximum parallelism constraint w.r.t the given cut; moves filtered cuts to the end of the array and returns number of selected cuts

Parameters

cut	cut to filter orthogonality with
cuts	array with cuts to perform selection algorithm
scores	array with scores of cuts to perform selection algorithm
ncuts	number of cuts in given array
goodscore	threshold for the score to be considered a good cut
goodmaxparall	maximal parallelism for good cuts
maxparall	maximal parallelism for all cuts that are not good

Definition at line 234 of file cutsel_hybrid.c.

References NULL, SCIP_Real, SCIProwGetParallelism(), SCIPswapPointers(), and SCIPswapReals().

Referenced by SCIPselectCutsHybrid().

SCIP_DECL_CUTSELCOPY()

static SCIP_DECL_CUTSELCOPY ( cutselCopyHybrid  )

static

copy method for cut selector plugin (called when SCIP copies plugins)

Definition at line 277 of file cutsel_hybrid.c.

References CUTSEL_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPcutselGetName(), and SCIPincludeCutselHybrid().

SCIP_DECL_CUTSELFREE()

static SCIP_DECL_CUTSELFREE ( cutselFreeHybrid  )

static

destructor of cut selector to free user data (called when SCIP is exiting) ! [SnippetCutselFreeHybrid]

Definition at line 292 of file cutsel_hybrid.c.

References NULL, SCIP_OKAY, SCIPcutselGetData(), SCIPcutselSetData(), and SCIPfreeBlockMemory.

SCIP_DECL_CUTSELINIT()

static SCIP_DECL_CUTSELINIT ( cutselInitHybrid  )

static

! [SnippetCutselFreeHybrid] initialization method of cut selector (called after problem was transformed)

Definition at line 308 of file cutsel_hybrid.c.

References NULL, RANDSEED, SCIP_CALL, SCIP_OKAY, SCIPcreateRandom(), SCIPcutselGetData(), and TRUE.

SCIP_DECL_CUTSELEXIT()

static SCIP_DECL_CUTSELEXIT ( cutselExitHybrid  )

static

deinitialization method of cut selector (called before transformed problem is freed)

Definition at line 322 of file cutsel_hybrid.c.

References NULL, SCIP_OKAY, SCIPcutselGetData(), and SCIPfreeRandom().

SCIP_DECL_CUTSELSELECT()

static SCIP_DECL_CUTSELSELECT ( cutselSelectHybrid  )

static

cut selection method of cut selector

Definition at line 337 of file cutsel_hybrid.c.

References MAX, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_SUCCESS, SCIPcutselGetData(), and SCIPselectCutsHybrid().