Detailed Description

presolver for storing symmetry information about current problem

Author: Marc Pfetsch; Thomas Rehn

This presolver computes symmetries of the problem and stores this information in adequate form. It does not perform additional actions. The symmetry information can be accessed through external functions. However, the user has to declare the type of symmetry that is needed before execution, see SYMsetSpecRequirement().

Note: We treat implict integer variables as if they were continuous/real variables. The reason is that there is currently no distinction between implicit integer and implicit binary. Moreover, currently implicit integer variables hurt our code more than continuous/real variables (we basically do not handle integral variables at all).; We do not copy symmetry information, since it is not clear how this information transfers. Moreover, copying symmetry might inhibit heuristics. But note that solving the a sub-SCIP might then happen without symmetry information!

Definition in file presol_symmetry.c.

#include <scip/cons_linear.h>
#include <scip/cons_knapsack.h>
#include <scip/cons_varbound.h>
#include <scip/cons_setppc.h>
#include <scip/cons_and.h>
#include <scip/cons_logicor.h>
#include <scip/cons_or.h>
#include <scip/cons_xor.h>
#include <scip/cons_linking.h>
#include <scip/presol_symmetry.h>
#include <symmetry/compute_symmetry.h>
#include <string.h>

Go to the source code of this file.

Data Structures
struct	SYM_Sortrhstype

Macros
#define	PRESOL_NAME "symmetry"

#define	PRESOL_DESC "presolver for computing and storing symmetry information about current problem"

#define	PRESOL_PRIORITY 0

#define	PRESOL_MAXROUNDS -1

#define	PRESOL_TIMING SCIP_PRESOLTIMING_EXHAUSTIVE /* timing of the presolver (fast, medium, or exhaustive) */

#define	DEFAULT_MAXGENERATORS 1500

#define	DEFAULT_CHECKSYMMETRIES FALSE

#define	DEFAULT_DISPLAYNORBITVARS FALSE

#define	MAXGENNUMERATOR 64000000

Typedefs
typedef struct SYM_Sortrhstype	SYM_SORTRHSTYPE

Functions
static	SCIP_DECL_HASHGETKEY (SYMhashGetKeyVartype)

static	SCIP_DECL_HASHKEYEQ (SYMhashKeyEQVartype)

static	SCIP_DECL_HASHKEYVAL (SYMhashKeyValVartype)

static	SCIP_DECL_SORTINDCOMP (SYMsortRhsTypes)

static	SCIP_DECL_SORTINDCOMP (SYMsortMatCoef)

static SCIP_Bool	SymmetryFixVar (SYM_SPEC fixedtype, SCIP_VAR *var)

static SCIP_RETCODE	getActiveVariables (SCIP scip, SCIP_VAR vars, SCIP_Real scalars, int nvars, SCIP_Real constant, SCIP_Bool transformed)

static SCIP_RETCODE	collectCoefficients (SCIP scip, SCIP_VAR linvars, SCIP_Real linvals, int nlinvars, SCIP_Real lhs, SCIP_Real rhs, SCIP_Bool istransformed, SYM_RHSSENSE rhssense, SYM_MATRIXDATA *matrixdata)

static SCIP_RETCODE	checkSymmetriesAreSymmetries (SCIP scip, SYM_SPEC fixedtype, SYM_MATRIXDATA matrixdata, int nperms, int **perms)

static int	getNSymhandableConss (SCIP *scip)

static SCIP_RETCODE	computeSymmetryGroup (SCIP scip, int maxgenerators, SYM_SPEC fixedtype, SCIP_Bool local, SCIP_Bool checksymmetries, int npermvars, SCIP_VAR *permvars, SCIP_Real permvarsobj, int nperms, int nmaxperms, int **perms, SCIP_Real log10groupsize, SCIP_Bool *success)

static SCIP_RETCODE	computeNOrbitVars (SCIP scip, SCIP_PRESOLDATA presoldata, SCIP_Bool completestatistic)

static SCIP_RETCODE	determineSymmetry (SCIP scip, SCIP_PRESOLDATA presoldata, SYM_SPEC symspecrequire, SYM_SPEC symspecrequirefixed)

static	SCIP_DECL_PRESOLINIT (presolInitSymmetry)

static	SCIP_DECL_PRESOLEXIT (presolExitSymmetry)

static	SCIP_DECL_PRESOLFREE (presolFreeSymmetry)

static	SCIP_DECL_PRESOLEXEC (presolExecSymmetry)

SCIP_RETCODE	SCIPincludePresolSymmetry (SCIP *scip)

SCIP_RETCODE	SCIPgetGeneratorsSymmetry (SCIP scip, SYM_SPEC symspecrequire, SYM_SPEC symspecrequirefixed, SCIP_Bool recompute, int npermvars, SCIP_VAR **permvars, int nperms, int **perms, SCIP_Real log10groupsize, SCIP_Bool *binvaraffected)

SCIP_RETCODE	SCIPgetPermvarsObjSymmetry (SCIP scip, SCIP_Real *permvarsobj)

Macro Definition Documentation

◆ PRESOL_NAME

#define PRESOL_NAME "symmetry"

Definition at line 52 of file presol_symmetry.c.

Referenced by SCIP_DECL_PRESOLEXEC(), SCIP_DECL_PRESOLEXIT(), SCIP_DECL_PRESOLFREE(), SCIP_DECL_PRESOLINIT(), SCIPgetGeneratorsSymmetry(), SCIPgetPermvarsObjSymmetry(), and SCIPincludePresolSymmetry().

◆ PRESOL_DESC

#define PRESOL_DESC "presolver for computing and storing symmetry information about current problem"

Definition at line 53 of file presol_symmetry.c.

Referenced by SCIPincludePresolSymmetry().

◆ PRESOL_PRIORITY

#define PRESOL_PRIORITY 0

priority of the presolver (>= 0: before, < 0: after constraint handlers)

Definition at line 54 of file presol_symmetry.c.

Referenced by SCIPincludePresolSymmetry().

◆ PRESOL_MAXROUNDS

#define PRESOL_MAXROUNDS -1

maximal number of presolving rounds the presolver participates in (-1: no limit)

Definition at line 55 of file presol_symmetry.c.

Referenced by SCIPincludePresolSymmetry().

◆ PRESOL_TIMING

#define PRESOL_TIMING SCIP_PRESOLTIMING_EXHAUSTIVE /* timing of the presolver (fast, medium, or exhaustive) */

Definition at line 56 of file presol_symmetry.c.

Referenced by SCIPincludePresolSymmetry().

◆ DEFAULT_MAXGENERATORS

#define DEFAULT_MAXGENERATORS 1500

limit on the number of generators that should be produced within symmetry detection (0 = no limit)

Definition at line 59 of file presol_symmetry.c.

Referenced by SCIPincludePresolSymmetry().

◆ DEFAULT_CHECKSYMMETRIES

#define DEFAULT_CHECKSYMMETRIES FALSE

Should all symmetries be checked after computation?

Definition at line 60 of file presol_symmetry.c.

Referenced by SCIPincludePresolSymmetry().

◆ DEFAULT_DISPLAYNORBITVARS

#define DEFAULT_DISPLAYNORBITVARS FALSE

Should the number of variables affected by some symmetry be displayed?

Definition at line 61 of file presol_symmetry.c.

Referenced by SCIPincludePresolSymmetry().

◆ MAXGENNUMERATOR

#define MAXGENNUMERATOR 64000000

determine maximal number of generators by dividing this number by the number of variables

Definition at line 64 of file presol_symmetry.c.

Referenced by determineSymmetry().

Typedef Documentation

◆ SYM_SORTRHSTYPE

typedef struct SYM_Sortrhstype SYM_SORTRHSTYPE

Definition at line 157 of file presol_symmetry.c.

Function Documentation

◆ SCIP_DECL_HASHGETKEY()

static SCIP_DECL_HASHGETKEY ( SYMhashGetKeyVartype )

static

gets the key of the given element

Definition at line 97 of file presol_symmetry.c.

◆ SCIP_DECL_HASHKEYEQ()

static SCIP_DECL_HASHKEYEQ ( SYMhashKeyEQVartype )

static

returns TRUE iff both keys are equal

Compare the types of two variables according to objective, lower and upper bound, and variable type.

Definition at line 107 of file presol_symmetry.c.

References FALSE, SYM_Vartype::lb, SYM_Vartype::obj, SCIPisEQ(), TRUE, SYM_Vartype::type, and SYM_Vartype::ub.

◆ SCIP_DECL_HASHKEYVAL()

static SCIP_DECL_HASHKEYVAL ( SYMhashKeyValVartype )

static

returns the hash value of the key

Definition at line 138 of file presol_symmetry.c.

References SYM_Vartype::lb, SYM_Vartype::obj, SCIPcombineTwoInt, SCIPhashTwo, SCIPrealHashCode(), and SYM_Vartype::ub.

◆ SCIP_DECL_SORTINDCOMP() [1/2]

static SCIP_DECL_SORTINDCOMP ( SYMsortRhsTypes )

static

sort rhs types - first by sense, then by value

Due to numerical issues, we first sort by sense, then by value.

result: < 0: ind1 comes before (is better than) ind2 = 0: both indices have the same value

0: ind2 comes after (is worse than) ind2

Definition at line 169 of file presol_symmetry.c.

References SYM_Sortrhstype::nrhscoef, SCIP_Real, SYM_Sortrhstype::senses, and SYM_Sortrhstype::vals.

◆ SCIP_DECL_SORTINDCOMP() [2/2]

static SCIP_DECL_SORTINDCOMP ( SYMsortMatCoef )

static

sort matrix coefficients

result: < 0: ind1 comes before (is better than) ind2 = 0: both indices have the same value

0: ind2 comes after (is worse than) ind2

Definition at line 203 of file presol_symmetry.c.

References SCIP_Real, and SYM_Sortrhstype::vals.

◆ SymmetryFixVar()

static SCIP_Bool SymmetryFixVar	(	SYM_SPEC	fixedtype,
		SCIP_VAR *	var
	)

static

determines whether variable should be fixed by permutations

Parameters

fixedtype	bitset of variable types that should be fixed
var	variable to be considered

Definition at line 226 of file presol_symmetry.c.

References FALSE, SCIP_VARTYPE_BINARY, SCIP_VARTYPE_CONTINUOUS, SCIP_VARTYPE_IMPLINT, SCIP_VARTYPE_INTEGER, SCIPvarGetType(), SYM_SPEC_BINARY, SYM_SPEC_INTEGER, SYM_SPEC_REAL, and TRUE.

Referenced by checkSymmetriesAreSymmetries(), and computeSymmetryGroup().

◆ getActiveVariables()

static SCIP_RETCODE getActiveVariables	(	SCIP *	scip,
		SCIP_VAR ***	vars,
		SCIP_Real **	scalars,
		int *	nvars,
		SCIP_Real *	constant,
		SCIP_Bool	transformed
	)

static

Transforms given variables, scalars, and constant to the corresponding active variables, scalars, and constant.

Note: constant needs to be initialized!

Parameters

scip	SCIP data structure
vars	pointer to vars array to get active variables for
scalars	pointer to scalars a_1, ..., a_n in linear sum a_1x_1 + ... + a_nx_n + c
nvars	pointer to number of variables and values in vars and vals array
constant	pointer to constant c in linear sum a_1x_1 + ... + a_nx_n + c
transformed	transformed constraint?

Definition at line 247 of file presol_symmetry.c.

References NULL, SCIP_CALL, SCIP_OKAY, SCIPgetProbvarLinearSum(), SCIPreallocBufferArray, SCIPvarGetOrigvarSum(), and TRUE.

Referenced by collectCoefficients().

◆ collectCoefficients()

static SCIP_RETCODE collectCoefficients	(	SCIP *	scip,
		SCIP_VAR **	linvars,
		SCIP_Real *	linvals,
		int	nlinvars,
		SCIP_Real	lhs,
		SCIP_Real	rhs,
		SCIP_Bool	istransformed,
		SYM_RHSSENSE	rhssense,
		SYM_MATRIXDATA *	matrixdata
	)

static

fill in matrix elements into coefficient arrays

Parameters

scip	SCIP data structure
linvars	array of linear variables
linvals	array of linear coefficients values (or NULL if all linear coefficient values are 1)
nlinvars	number of linear variables
lhs	left hand side
rhs	right hand side
istransformed	whether the constraint is transformed
rhssense	identifier of constraint type
matrixdata	matrix data to be filled in

Definition at line 293 of file presol_symmetry.c.

References getActiveVariables(), SYM_Matrixdata::matcoef, SYM_Matrixdata::matidx, SYM_Matrixdata::matrhsidx, SYM_Matrixdata::matvaridx, SYM_Matrixdata::nmatcoef, SYM_Matrixdata::nmaxmatcoef, SYM_Matrixdata::nrhscoef, SYM_Sortrhstype::nrhscoef, NULL, SYM_Matrixdata::rhscoef, SYM_Matrixdata::rhsidx, SYM_Matrixdata::rhssense, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPcalcMemGrowSize(), SCIPdebugMsg, SCIPduplicateBufferArray, SCIPfreeBufferArray, SCIPgetNVars(), SCIPisEQ(), SCIPisInfinity(), SCIPreallocBlockMemoryArray, SCIPvarGetProbindex(), SYM_SENSE_EQUATION, SYM_SENSE_INEQUALITY, and SYM_Sortrhstype::vals.

Referenced by computeSymmetryGroup().

◆ checkSymmetriesAreSymmetries()

static SCIP_RETCODE checkSymmetriesAreSymmetries	(	SCIP *	scip,
		SYM_SPEC	fixedtype,
		SYM_MATRIXDATA *	matrixdata,
		int	nperms,
		int **	perms
	)

static

checks whether given permutations form a symmetry of a MIP

We need the matrix and rhs in the original order in order to speed up the comparison process. The matrix is needed in the right order to easily check rows. The rhs is used because of cache effects.

Parameters

scip	SCIP data structure
fixedtype	variable types that must be fixed by symmetries
matrixdata	matrix data
nperms	number of permutations
perms	permutations

Definition at line 462 of file presol_symmetry.c.

References FALSE, SYM_Matrixdata::matcoef, SYM_Matrixdata::matrhsidx, SYM_Matrixdata::matvaridx, SYM_Matrixdata::nmatcoef, SYM_Matrixdata::npermvars, SYM_Matrixdata::nrhscoef, SYM_Sortrhstype::nrhscoef, NULL, SYM_Matrixdata::permvars, SYM_Matrixdata::rhscoef, SYM_Matrixdata::rhssense, SCIP_Bool, SCIP_CALL, SCIP_ERROR, SCIP_OKAY, SCIP_Real, SCIPallocBlockMemoryArray, SCIPdebugMsg, SCIPerrorMessage, SCIPfreeBlockMemoryArray, SCIPisEQ(), SCIPisZero(), SymmetryFixVar(), and TRUE.

Referenced by computeSymmetryGroup().

◆ getNSymhandableConss()

static int getNSymhandableConss ( SCIP * scip )

static

returns the number of active constraints that can be handled by symmetry

Parameters

scip	SCIP instance

Definition at line 608 of file presol_symmetry.c.

References NULL, SCIPconshdlrGetNActiveConss(), and SCIPfindConshdlr().

Referenced by computeSymmetryGroup(), and determineSymmetry().

◆ computeSymmetryGroup()

static SCIP_RETCODE computeSymmetryGroup	(	SCIP *	scip,
		int	maxgenerators,
		SYM_SPEC	fixedtype,
		SCIP_Bool	local,
		SCIP_Bool	checksymmetries,
		int *	npermvars,
		SCIP_VAR ***	permvars,
		SCIP_Real **	permvarsobj,
		int *	nperms,
		int *	nmaxperms,
		int ***	perms,
		SCIP_Real *	log10groupsize,
		SCIP_Bool *	success
	)

static

compute symmetry group of MIP

Parameters

scip	SCIP pointer
maxgenerators	maximal number of generators constructed (= 0 if unlimited)
fixedtype	variable types that must be fixed by symmetries
local	Use local variable bounds?
checksymmetries	Should all symmetries be checked after computation?
npermvars	pointer to store number of variables for permutations
permvars	pointer to store variables on which permutations act
permvarsobj	objective values of permuted variables
nperms	pointer to store number of permutations
nmaxperms	pointer to store maximal number of permutations (needed for freeing storage)
perms	pointer to store permutation generators as (nperms x npermvars) matrix
log10groupsize	pointer to store log10 of size of group
success	pointer to store whether symmetry computation was successful

Definition at line 643 of file presol_symmetry.c.

References checkSymmetriesAreSymmetries(), collectCoefficients(), SYM_Vartype::color, FALSE, getNSymhandableConss(), SYM_Vartype::lb, SYM_Matrixdata::matcoef, SYM_Matrixdata::matcoefcolors, SYM_Matrixdata::matidx, SYM_Matrixdata::matrhsidx, SYM_Matrixdata::matvaridx, SYM_Matrixdata::nmatcoef, SYM_Matrixdata::nmaxmatcoef, SYM_Matrixdata::npermvars, SYM_Matrixdata::nrhscoef, SYM_Sortrhstype::nrhscoef, NULL, SYM_Matrixdata::nuniquemat, SYM_Matrixdata::nuniquerhs, SYM_Matrixdata::nuniquevars, SYM_Vartype::obj, SYM_Matrixdata::permvarcolors, SYM_Matrixdata::permvars, SYM_Matrixdata::rhscoef, SYM_Matrixdata::rhscoefcolors, SYM_Matrixdata::rhsidx, SYM_Matrixdata::rhssense, SCIP_CALL, SCIP_ERROR, SCIP_INVALID, SCIP_Longint, SCIP_OKAY, SCIP_Real, SCIP_SETPPCTYPE_COVERING, SCIP_SETPPCTYPE_PACKING, SCIP_SETPPCTYPE_PARTITIONING, SCIP_STAGE_INITPRESOLVE, SCIP_STAGE_SOLVING, SCIPallocBlockMemoryArray, SCIPblkmem(), SCIPconsGetHdlr(), SCIPconsGetName(), SCIPconshdlrGetName(), SCIPconsIsActive(), SCIPconsIsConflict(), SCIPconsIsTransformed(), SCIPdebugMsg, SCIPduplicateBlockMemoryArray, SCIPerrorMessage, SCIPfreeBlockMemoryArray, SCIPfreeBlockMemoryArrayNull, SCIPgetBinvarsLinking(), SCIPgetCapacityKnapsack(), SCIPgetConss(), SCIPgetIntvarLinking(), SCIPgetIntVarXor(), SCIPgetLhsLinear(), SCIPgetLhsVarbound(), SCIPgetNActiveConss(), SCIPgetNConss(), SCIPgetNFixedVars(), SCIPgetNVars(), SCIPgetNVarsAnd(), SCIPgetNVarsKnapsack(), SCIPgetNVarsLinear(), SCIPgetNVarsLogicor(), SCIPgetNVarsOr(), SCIPgetNVarsSetppc(), SCIPgetNVarsXor(), SCIPgetResultantAnd(), SCIPgetResultantOr(), SCIPgetRhsLinear(), SCIPgetRhsVarbound(), SCIPgetRhsXor(), SCIPgetStage(), SCIPgetTypeSetppc(), SCIPgetValsLinear(), SCIPgetValsLinking(), SCIPgetVars(), SCIPgetVarsAnd(), SCIPgetVarsKnapsack(), SCIPgetVarsLinear(), SCIPgetVarsLogicor(), SCIPgetVarsOr(), SCIPgetVarsSetppc(), SCIPgetVarsXor(), SCIPgetVarVarbound(), SCIPgetVbdcoefVarbound(), SCIPgetVbdvarVarbound(), SCIPgetWeightsKnapsack(), SCIPhashtableCreate(), SCIPhashtableExists(), SCIPhashtableFree(), SCIPhashtableInsert(), SCIPhashtableRetrieve(), SCIPinfinity(), SCIPisEQ(), SCIPisStopped(), SCIPmarkDoNotMultaggrVar(), SCIPsort(), SCIPvarGetLbGlobal(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetObj(), SCIPvarGetProbindex(), SCIPvarGetType(), SCIPvarGetUbGlobal(), SCIPvarGetUbLocal(), SYM_Sortrhstype::senses, SYM_SENSE_AND, SYM_SENSE_EQUATION, SYM_SENSE_INEQUALITY, SYM_SENSE_OR, SYM_SENSE_UNKOWN, SYM_SENSE_XOR, SYMcanComputeSymmetry(), SYMcomputeSymmetryGenerators(), SymmetryFixVar(), TRUE, SYM_Vartype::type, SYM_Vartype::ub, and SYM_Sortrhstype::vals.

Referenced by determineSymmetry().

◆ computeNOrbitVars()

static SCIP_RETCODE computeNOrbitVars	(	SCIP *	scip,
		SCIP_PRESOLDATA *	presoldata,
		SCIP_Bool	completestatistic
	)

static

Parameters

scip	SCIP instance
presoldata	presolver data
completestatistic	whether a complete statistic on affected vars should be computed

Definition at line 1185 of file presol_symmetry.c.

References NULL, SCIP_CALL, SCIP_OKAY, SCIP_Shortbool, SCIPallocClearBufferArray, SCIPfreeBufferArray, SCIPvarIsBinary(), and TRUE.

Referenced by determineSymmetry().

◆ determineSymmetry()

static SCIP_RETCODE determineSymmetry	(	SCIP *	scip,
		SCIP_PRESOLDATA *	presoldata,
		SYM_SPEC	symspecrequire,
		SYM_SPEC	symspecrequirefixed
	)

static

determine symmetry

Parameters

scip	SCIP instance
presoldata	presolver data
symspecrequire	symmetry specification for which we need to compute symmetries
symspecrequirefixed	symmetry specification of variables which must be fixed by symmetries

Definition at line 1246 of file presol_symmetry.c.

References computeNOrbitVars(), computeSymmetryGroup(), FALSE, getNSymhandableConss(), MAXGENNUMERATOR, MIN, NULL, SCIP_CALL, SCIP_OKAY, SCIP_VERBLEVEL_HIGH, SCIPgetIntParam(), SCIPgetNActiveConss(), SCIPgetNActivePricers(), SCIPgetNBinVars(), SCIPgetNContVars(), SCIPgetNImplVars(), SCIPgetNIntVars(), SCIPgetNVars(), SCIPgetSolvingTime(), SCIPsetIntParam(), SCIPverbMessage(), SCIPwarningMessage(), SYM_SPEC_BINARY, SYM_SPEC_INTEGER, SYM_SPEC_REAL, SYMcanComputeSymmetry(), and TRUE.

Referenced by SCIPgetGeneratorsSymmetry().

◆ SCIP_DECL_PRESOLINIT()

static SCIP_DECL_PRESOLINIT ( presolInitSymmetry )

static

initialization method of presolver (called after problem was transformed)

Definition at line 1427 of file presol_symmetry.c.

References NULL, PRESOL_NAME, SCIP_CALL, SCIP_OKAY, SCIPgetIntParam(), SCIPpresolGetData(), and SCIPpresolGetName().

◆ SCIP_DECL_PRESOLEXIT()

static SCIP_DECL_PRESOLEXIT ( presolExitSymmetry )

static

deinitialization method of presolver (called before transformed problem is freed)

Definition at line 1446 of file presol_symmetry.c.

References FALSE, NULL, PRESOL_NAME, SCIP_CALL, SCIP_OKAY, SCIPdebugMsg, SCIPfreeBlockMemoryArray, SCIPfreeBlockMemoryArrayNull, SCIPpresolGetData(), SCIPpresolGetName(), and SCIPsetIntParam().

◆ SCIP_DECL_PRESOLFREE()

static SCIP_DECL_PRESOLFREE ( presolFreeSymmetry )

static

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

Definition at line 1491 of file presol_symmetry.c.

References NULL, PRESOL_NAME, SCIP_OKAY, SCIPdebugMsg, SCIPfreeBlockMemory, SCIPpresolGetData(), and SCIPpresolGetName().

◆ SCIP_DECL_PRESOLEXEC()

static SCIP_DECL_PRESOLEXEC ( presolExecSymmetry )

static

execution method of presolver

Definition at line 1512 of file presol_symmetry.c.

References NULL, PRESOL_NAME, SCIP_DIDNOTRUN, SCIP_OKAY, and SCIPpresolGetName().

◆ SCIPincludePresolSymmetry()

SCIP_RETCODE SCIPincludePresolSymmetry ( SCIP * scip )

include symmetry constraint handler

Parameters

scip	SCIP data structure

Definition at line 1531 of file presol_symmetry.c.

References DEFAULT_CHECKSYMMETRIES, DEFAULT_DISPLAYNORBITVARS, DEFAULT_MAXGENERATORS, FALSE, NULL, PRESOL_DESC, PRESOL_MAXROUNDS, PRESOL_NAME, PRESOL_PRIORITY, PRESOL_TIMING, SCIP_CALL, SCIP_OKAY, SCIPaddBoolParam(), SCIPaddIntParam(), SCIPallocBlockMemory, SCIPincludeExternalCodeInformation(), SCIPincludePresolBasic(), SCIPsetPresolExit(), SCIPsetPresolFree(), SCIPsetPresolInit(), SYMcanComputeSymmetry(), SYMsymmetryGetDesc(), SYMsymmetryGetName(), and TRUE.

Referenced by SCIPincludeDefaultPlugins().

◆ SCIPgetGeneratorsSymmetry()

SCIP_RETCODE SCIPgetGeneratorsSymmetry	(	SCIP *	scip,
		SYM_SPEC	symspecrequire,
		SYM_SPEC	symspecrequirefixed,
		SCIP_Bool	recompute,
		int *	npermvars,
		SCIP_VAR ***	permvars,
		int *	nperms,
		int ***	perms,
		SCIP_Real *	log10groupsize,
		SCIP_Bool *	binvaraffected
	)

return symmetry group generators

Parameters

scip	SCIP data structure
symspecrequire	symmetry specification for which we need to compute symmetries
symspecrequirefixed	symmetry specification of variables which must be fixed by symmetries
recompute	Have symmetries already been computed?
npermvars	pointer to store number of variables for permutations
permvars	pointer to store variables on which permutations act
nperms	pointer to store number of permutations
perms	pointer to store permutation generators as (nperms x npermvars) matrix
log10groupsize	pointer to store log10 of group size (or NULL)
binvaraffected	pointer to store whether binary variables are affected

Definition at line 1589 of file presol_symmetry.c.

References determineSymmetry(), FALSE, NULL, PRESOL_NAME, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_STAGE_EXITPRESOLVE, SCIP_STAGE_INITPRESOLVE, SCIP_STAGE_INITSOLVE, SCIP_STAGE_PRESOLVED, SCIP_STAGE_PRESOLVING, SCIP_STAGE_SOLVING, SCIPerrorMessage, SCIPfindPresol(), SCIPfreeBlockMemoryArray, SCIPfreeBlockMemoryArrayNull, SCIPgetStage(), SCIPpresolGetData(), and SCIPpresolGetName().

Referenced by getSymmetries(), and tryAddSymmetryHandlingConss().

◆ SCIPgetPermvarsObjSymmetry()

SCIP_RETCODE SCIPgetPermvarsObjSymmetry	(	SCIP *	scip,
		SCIP_Real **	permvarsobj
	)

return objective coefficients of permuted variables at time of symmetry computation

Parameters

scip	SCIP data structure
permvarsobj	pointer to store objective coefficients of permuted variables (NULL if not available)

Definition at line 1676 of file presol_symmetry.c.

References NULL, PRESOL_NAME, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIPerrorMessage, SCIPfindPresol(), SCIPpresolGetData(), and SCIPpresolGetName().

Referenced by propagateOrbitalFixing().

SCIP

Detailed Description

Data Structures

Macros

Typedefs

Functions

Macro Definition Documentation

◆ PRESOL_NAME

◆ PRESOL_DESC

◆ PRESOL_PRIORITY

◆ PRESOL_MAXROUNDS

◆ PRESOL_TIMING

◆ DEFAULT_MAXGENERATORS

◆ DEFAULT_CHECKSYMMETRIES

◆ DEFAULT_DISPLAYNORBITVARS

◆ MAXGENNUMERATOR

Typedef Documentation

◆ SYM_SORTRHSTYPE

Function Documentation

◆ SCIP_DECL_HASHGETKEY()

◆ SCIP_DECL_HASHKEYEQ()

◆ SCIP_DECL_HASHKEYVAL()

◆ SCIP_DECL_SORTINDCOMP() [1/2]

◆ SCIP_DECL_SORTINDCOMP() [2/2]

◆ SymmetryFixVar()

◆ getActiveVariables()

◆ collectCoefficients()

◆ checkSymmetriesAreSymmetries()

◆ getNSymhandableConss()

◆ computeSymmetryGroup()

◆ computeNOrbitVars()

◆ determineSymmetry()

◆ SCIP_DECL_PRESOLINIT()

◆ SCIP_DECL_PRESOLEXIT()

◆ SCIP_DECL_PRESOLFREE()

◆ SCIP_DECL_PRESOLEXEC()

◆ SCIPincludePresolSymmetry()

◆ SCIPgetGeneratorsSymmetry()

◆ SCIPgetPermvarsObjSymmetry()